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1

Rapid and transient stimulation of intracellular reactive oxygen species by melatonin in normal and tumor leukocytes  

Science Conference Proceedings (OSTI)

Melatonin is a modified tryptophan with potent biological activity, exerted by stimulation of specific plasma membrane (MT1/MT2) receptors, by lower affinity intracellular enzymatic targets (quinone reductase, calmodulin), or through its strong anti-oxidant ability. Scattered studies also report a perplexing pro-oxidant activity, showing that melatonin is able to stimulate production of intracellular reactive oxygen species (ROS). Here we show that on U937 human monocytes melatonin promotes intracellular ROS in a fast (< 1 min) and transient (up to 5-6 h) way. Melatonin equally elicits its pro-radical effect on a set of normal or tumor leukocytes; intriguingly, ROS production does not lead to oxidative stress, as shown by absence of protein carbonylation, maintenance of free thiols, preservation of viability and regular proliferation rate. ROS production is independent from MT1/MT2 receptor interaction, since a) requires micromolar (as opposed to nanomolar) doses of melatonin; b) is not contrasted by the specific MT1/MT2 antagonist luzindole; c) is not mimicked by a set of MT1/MT2 high affinity melatonin analogues. Instead, chlorpromazine, the calmodulin inhibitor shown to prevent melatonin-calmodulin interaction, also prevents melatonin pro-radical effect, suggesting that the low affinity binding to calmodulin (in the micromolar range) may promote ROS production.

Radogna, Flavia [Dipartimento di Biologia, Universita di Roma Tor Vergata, via Ricerca Scientifica, 1, 00133 Roma (Italy); Paternoster, Laura [Dipartimento di Biologia, Universita di Roma Tor Vergata, via Ricerca Scientifica, 1, 00133 Roma (Italy); Istitututo di Chimica Biologica, Universita di Urbino Carlo Bo (Italy); De Nicola, Milena; Cerella, Claudia [Dipartimento di Biologia, Universita di Roma Tor Vergata, via Ricerca Scientifica, 1, 00133 Roma (Italy); Ammendola, Sergio [Ambiotec (Italy); Bedini, Annalida; Tarzia, Giorgio [Istituto di Chimica Farmaceutica, Universita di Urbino Carlo Bo (Italy); Aquilano, Katia; Ciriolo, Maria [Dipartimento di Biologia, Universita di Roma Tor Vergata, via Ricerca Scientifica, 1, 00133 Roma (Italy); Ghibelli, Lina [Dipartimento di Biologia, Universita di Roma Tor Vergata, via Ricerca Scientifica, 1, 00133 Roma (Italy)], E-mail: ghibelli@uniroma2.it

2009-08-15T23:59:59.000Z

2

Benzene's metabolites alter c-MYB activity via reactive oxygen species in HD3 cells  

Science Conference Proceedings (OSTI)

Benzene is a known leukemogen that is metabolized to form reactive intermediates and reactive oxygen species (ROS). The c-Myb oncoprotein is a transcription factor that has a critical role in hematopoiesis. c-Myb transcript and protein have been overexpressed in a number of leukemias and cancers. Given c-Myb's role in hematopoiesis and leukemias, it is hypothesized that benzene interferes with the c-Myb signaling pathway and that this involves ROS. To investigate our hypothesis, we evaluated whether benzene, 1,4-benzoquinone, hydroquinone, phenol, and catechol generated ROS in chicken erythroblast HD3 cells, as measured by 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate (DCFDA) and dihydrorhodamine-123 (DHR-123), and whether the addition of 100 U/ml of the antioxidating enzyme superoxide dismutase (SOD) could prevent ROS generation. Reduced to oxidized glutathione ratios (GSH:GSSG) were also assessed as well as hydroquinone and benzoquinone's effects on c-Myb protein levels and activation of a transiently transfected reporter construct. Finally we attempted to abrogate benzene metabolite mediated increases in c-Myb activity with the use of SOD. We found that benzoquinone, hydroquinone, and catechol increased DCFDA fluorescence, increased DHR-123 fluorescence, decreased GSH:GSSG ratios, and increased reporter construct expression after 24 h of exposure. SOD was able to prevent DCFDA fluorescence and c-Myb activity caused by benzoquinone and hydroquinone only. These results are consistent with other studies, which suggest metabolite differences in benzene-mediated toxicity. More importantly, this study supports the hypothesis that benzene may mediate its toxicity through ROS-mediated alterations in the c-Myb signaling pathway.

Wan, Joanne [Department of Pharmacology and Toxicology, Queen's University, Kingston, Ontario (Canada); Winn, Louise M. [Department of Pharmacology and Toxicology, Queen's University, Kingston, Ontario (Canada) and School of Environmental Studies, Queen's University, Kingston, Ontario (Canada)]. E-mail: winnl@queensu.ca

2007-07-15T23:59:59.000Z

3

Direct Observation of the Oxygenated Species during Oxygen Reduction on a  

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

Direct Observation of the Oxygenated Species during Oxygen Reduction on a Direct Observation of the Oxygenated Species during Oxygen Reduction on a Platinum Fuel Cell Cathode Friday, December 20, 2013 Fuel Cell Figure 1 Figure 1. In situ x-ray spectroscopy identification and DFT simulations of oxygenated intermediates on a platinum fuel-cell cathode. The study shows that two types of hydroxyl intermediates (non-hydrated OH and hydrated OH) with distinct activities coexist on a fuel-cell cathode. The performance of polymer-electrolyte-membrane (PEM) fuel cells is limited by the reduction at the cathode of various oxygenated intermediates in the four-electron pathway of the oxygen reduction reaction. A research team led by SLAC scientists performed x-ray spectroscopy identification and DFT simulations of oxygenated intermediates on a platinum fuel-cell cathode

4

Reactive oxygen species mediate arsenic induced cell transformation and tumorigenesis through Wnt/{beta}-catenin pathway in human colorectal adenocarcinoma DLD1 cells  

SciTech Connect

Long term exposure to arsenic can increase incidence of human cancers, such as skin, lung, and colon rectum. The mechanism of arsenic induced carcinogenesis is still unclear. It is generally believed that reactive oxygen species (ROS) may play an important role in this process. In the present study, we investigate the possible linkage between ROS, {beta}-catenin and arsenic induced transformation and tumorigenesis in human colorectal adenocarcinoma cell line, DLD1 cells. Our results show that arsenic was able to activate p47{sup phox} and p67{sup phox}, two key proteins for activation of NADPH oxidase. Arsenic was also able to generate ROS in DLD1 cells. Arsenic increased {beta}-catenin expression level and its promoter activity. ROS played a major role in arsenic-induced {beta}-catenin activation. Treatment of DLD1 cells by arsenic enhanced both transformation and tumorigenesis of these cells. The tumor volumes of arsenic treated group were much larger than those without arsenic treatment. Addition of either superoxide dismutase (SOD) or catalase reduced arsenic induced cell transformation and tumor formation. The results indicate that ROS are involved in arsenic induced cell transformation and tumor formation possible through Wnt/{beta}-catenin pathway in human colorectal adenocarcinoma cell line DLD1 cells. - Highlights: > Arsenic activates NADPH oxidase and increases reactive oxygen species generation in DLD1 cells. > Arsenic increases {beta}-catenin expression. > Inhibition of ROS induced by arsenic reduce {beta}-catenin expression. > Arsenic increases cell transformation in DLD1 cells and tumorigenesis in nude mice. > Blockage of ROS decrease cell transformation and tumorigenesis induced by arsenic.

Zhang Zhuo [Department of Preventive Medicine and Environmental Health, University of Kentucky, 121 Washington Avenue, Lexington, KY 40536 (United States); Wang Xin; Cheng Senping; Sun Lijuan; Son, Young-Ok [Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Yao Hua [Department of Stomatology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003 (China); Li Wenqi [Department of Preventive Medicine and Environmental Health, University of Kentucky, 121 Washington Avenue, Lexington, KY 40536 (United States); Budhraja, Amit [Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Li Li [Department of Family Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Shelton, Brent J.; Tucker, Thomas [Markey Cancer Control Program, University of Kentucky, 2365 Harrodsburg Rd, Lexington, KY 40504 (United States); Arnold, Susanne M. [Markey Cancer Center, University of Kentucky, 800 Rose street, Lexington, KY 40536 (United States); Shi Xianglin, E-mail: Xianglin.sh@uky.edu [Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States)

2011-10-15T23:59:59.000Z

5

He+O{sub 2}+H{sub 2}O plasmas as a source of reactive oxygen species  

Science Conference Proceedings (OSTI)

The effect of water in the chemistry of atmospheric-pressure He+O{sub 2} plasmas is studied by means of a comprehensive global model. Water enables the generation of reactive oxygen species (ROS) cocktails that are rich not only in O, O{sub 2}*, and O{sub 3} but also in OH and H{sub 2}O{sub 2}. Due to its polar nature, water also leads to cluster formation, possibly affecting the plasma dynamics. Since the lifetime of many of the ROS is short, the plasma chemistry plays two roles: (i) direct interaction with superficial cells and (ii) triggering of a secondary chemistry that propagates the plasma treatment to regions away from the plasma-surface interface.

Liu, D. X.; Wang, X. H.; Rong, M. Z. [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an City, Shaanxi Province, 710049 (China); Iza, F. [Department of Electronic and Electrical Engineering, Loughborough University, LE11 3TU (United Kingdom); Kong, M. G. [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an City, Shaanxi Province, 710049 (China); Department of Electronic and Electrical Engineering, Loughborough University, LE11 3TU (United Kingdom)

2011-05-30T23:59:59.000Z

6

Plumbagin-induced apoptosis in lymphocytes is mediated through increased reactive oxygen species production, upregulation of Fas, and activation of the caspase cascade  

Science Conference Proceedings (OSTI)

Extracts from plants containing plumbagin (PLB) continue to be used as a treatment of a number of chronic immunologically-based diseases. However, most of these claims are supported only by anecdotal evidence with few scientific reports describing the mechanism of action or the efficacy of plumbagin in the suppression of the immune response. In the current study, we tested the hypothesis that plumbagin-induced suppression of the immune response was mediated through the induction of apoptosis. Splenocytes from C57BL/6 mice cultured in the presence of 0.5 {mu}M or greater concentrations of PLB significantly reduced proliferative responses to mitogens, including anti-CD3 mAbs, concanavalin A (Con A), lipopolysaccharide (LPS) and staphylococcal enterotoxin B (SEB) in vitro. Exposure of naive and activated splenocytes to PLB led to a significant increase in the levels of apoptosis. In addition, PLB treatment led to a significant increase in the levels of reactive oxygen species (ROS) in naive and activated splenocytes. Furthermore, treatment with the ROS scavenger, N-acetylcysteine (NAC), prevented PLB-induced apoptosis, suggesting a role of ROS in PLB-induced apoptosis. PLB-induced apoptosis led to ROS-mediated activation of both the extrinsic and intrinsic apoptotic pathways. In addition, plumbagin led to increased expression of Fas. Finally, treatment of mice with PLB (5 mg/kg) led to thymic and splenic atrophy as well as a significant suppression of the response to SEB and dinitroflourobenzene (DNFB) in vivo. Together, these results suggest that plumbagin has significant immunosuppressive properties which are mediated by generation of ROS, upregulation of Fas, and the induction of apoptosis.

McKallip, Robert J., E-mail: mckallip_r@mercer.ed [Division of Basic Medical Sciences, School of Medicine, Mercer University (United States); Lombard, Catherine [Universite Catholique de Louvain and Cliniques Universitaires Saint-Luc, Brussels (Belgium); Sun Jingping [Division of Basic Medical Sciences, School of Medicine, Mercer University (United States); Ramakrishnan, Rupal [H. Lee Moffitt Cancer Center and Research Institute, MRC 2067, 12902 Magnolia Dr., Tampa, FL 33612 (United States)

2010-08-15T23:59:59.000Z

7

Phototriggered production of reactive oxygen species by TIO2 nanospheres and rods  

Science Conference Proceedings (OSTI)

We present the study of reactive oxygen species production under the light irradiation of two different types of TiO2 nanocrystals. Both TiO2 spheric NPs and anisotropic nanorods were investigated using activation of the horseradish ...

Bianca Geiseler, Marko Miljevic, Philipp Müller, Ljiljana Fruk

2012-01-01T23:59:59.000Z

8

ROS signaling, oxidative stress and Nrf2 in pancreatic beta-cell function  

Science Conference Proceedings (OSTI)

This review focuses on the emerging evidence that reactive oxygen species (ROS) derived from glucose metabolism, such as H{sub 2}O{sub 2}, act as metabolic signaling molecules for glucose-stimulated insulin secretion (GSIS) in pancreatic beta-cells. Particular emphasis is placed on the potential inhibitory role of endogenous antioxidants, which rise in response to oxidative stress, in glucose-triggered ROS and GSIS. We propose that cellular adaptive response to oxidative stress challenge, such as nuclear factor E2-related factor 2 (Nrf2)-mediated antioxidant induction, plays paradoxical roles in pancreatic beta-cell function. On the one hand, induction of antioxidant enzymes protects beta-cells from oxidative damage and possible cell death, thus minimizing oxidative damage-related impairment of insulin secretion. On the other hand, the induction of antioxidant enzymes by Nrf2 activation blunts glucose-triggered ROS signaling, thus resulting in reduced GSIS. These two premises are potentially relevant to impairment of beta-cells occurring in the late and early stage of Type 2 diabetes, respectively. In addition, we summarized our recent findings that persistent oxidative stress due to absence of uncoupling protein 2 activates cellular adaptive response which is associated with impaired pancreatic beta-cell function.

Pi Jingbo, E-mail: jpi@thehamner.or [Division of Translational Biology, Hamner Institutes for Health Sciences, 6 Davis Drive, Research Triangle Park, NC 27709 (United States); Zhang Qiang [Division of Computational Biology, Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); Fu Jingqi [Division of Translational Biology, Hamner Institutes for Health Sciences, 6 Davis Drive, Research Triangle Park, NC 27709 (United States); School of Public Health, China Medical University, Shenyang, 110001 (China); Woods, Courtney G. [Division of Computational Biology, Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); ExxonMobil Biomedical Sciences Incorporated, Annandale, NJ 08801 (United States); Hou Yongyong [Division of Translational Biology, Hamner Institutes for Health Sciences, 6 Davis Drive, Research Triangle Park, NC 27709 (United States); School of Public Health, China Medical University, Shenyang, 110001 (China); Corkey, Barbara E. [Obesity Research Center, Boston University School of Medicine, Boston, MA 02118 (United States); Collins, Sheila [Division of Translational Biology, Hamner Institutes for Health Sciences, 6 Davis Drive, Research Triangle Park, NC 27709 (United States); Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710 (United States); Andersen, Melvin E. [Division of Computational Biology, Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States)

2010-04-01T23:59:59.000Z

9

Lipid Oxidation Pathways, Volume 2Chapter 2 Chemistry and Reactions of Reactive Oxygen Species in Lipid Oxidation  

Science Conference Proceedings (OSTI)

Lipid Oxidation Pathways, Volume 2 Chapter 2 Chemistry and Reactions of Reactive Oxygen Species in Lipid Oxidation Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistry AC26ACB856C86AFB9EC8D10FE0DBB342 Press

10

Ab initio Calculation of Thermodynamic Data for Oxygenated Hydrocarbon Fuels and Radial Breakdown Species: R(OMe)n  

DOE Green Energy (OSTI)

There has long been interest in the use of oxygenated hydrocarbon additives to conventional fuels. These oxygenates have been shown to reduce soot emissions in diesel engines and CO emissions in spark-ignition engines; and often allow diesel operation with decreased NO{sub x}. The current widely used additive, MTBE is targeted for elimination as a gasoline additive due to its damaging effects on the environment. This creates a need for alternative oxygenated additives; and more importantly, amplifies the importance to fully understand the thermochemical and kinetic properties on these oxyhydrocarbons fuels and for their intermediate and radical breakdown products. We use CBS-Q and density-functional methods with isodesmic reactions (with group balance when possible) to compute thermodynamic quantities for these species. We have studied hydrocarbons with multiple substituted methoxy groups. In several cases, multioxygenated species are evaluated that may have potential use as new oxygenated fuel additives. Thermodynamic quantities (H{sub 298}{sup 0}, S{sub 298}{sup 0}, C{sub p}(T)) as well as group additivity contributions for the new oxygenated groups are reported. We also report trends in bond-energies with increasing methoxy substitution.

Kubota, A; Pitz, W J; Westbrook, C K; Bozzelli, J; Glaude, P-A

2001-03-23T23:59:59.000Z

11

Cadmium induces autophagy through ROS-dependent activation of the LKB1-AMPK signaling in skin epidermal cells  

Science Conference Proceedings (OSTI)

Cadmium is a toxic heavy metal which is environmentally and occupationally relevant. The mechanisms underlying cadmium-induced autophagy are not yet completely understood. The present study shows that cadmium induces autophagy, as demonstrated by the increase of LC3-II formation and the GFP-LC3 puncta cells. The induction of autophagosomes was directly visualized by electron microscopy in cadmium-exposed skin epidermal cells. Blockage of LKB1 or AMPK by siRNA transfection suppressed cadmium-induced autophagy. Cadmium-induced autophagy was inhibited in dominant-negative AMPK-transfected cells, whereas it was accelerated in cells transfected with the constitutively active form of AMPK. mTOR signaling, a negative regulator of autophagy, was downregulated in cadmium-exposed cells. In addition, cadmium generated reactive oxygen species (ROS) at relatively low levels, and caused poly(ADP-ribose) polymerase-1 (PARP) activation and ATP depletion. Inhibition of PARP by pharmacological inhibitors or its siRNA transfection suppressed ATP reduction and autophagy in cadmium-exposed cells. Furthermore, cadmium-induced autophagy signaling was attenuated by either exogenous addition of catalase and superoxide dismutase, or by overexpression of these enzymes. Consequently, these results suggest that cadmium-mediated ROS generation causes PARP activation and energy depletion, and eventually induces autophagy through the activation of LKB1-AMPK signaling and the down-regulation of mTOR in skin epidermal cells. - Highlights: > Cadmium, a toxic heavy metal, induces autophagic cell death through ROS-dependent activation of the LKB1-AMPK signaling. > Cadmium generates intracellular ROS at low levels and this leads to severe DNA damage and PARP activation, resulting in ATP depletion, which are the upstream events of LKB1-AMPK-mediated autophagy. > This novel finding may contribute to further understanding of cadmium-mediated diseases.

Son, Young-Ok; Wang Xin; Hitron, John Andrew [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Zhang Zhuo [Department of Preventive Medicine and Environmental Health, College of Public Health, University of Kentucky, Lexington, KY 40536-0305 (United States); Cheng Senping; Budhraja, Amit; Ding Songze [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lee, Jeong-Chae [Institute of Oral Biosciences and BK21 Program, Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States)

2011-09-15T23:59:59.000Z

12

Evidence of the production of hot hydrogen atoms in RF plasmas by catalytic reactions between hydrogen and oxygen species  

E-Print Network (OSTI)

Selective H-atom line broadening was found to be present throughout the volume (13.5 cm ID x 38 cm length) of RF generated H2O plasmas in a GEC cell. Notably, at low pressures (ca. hot' with energies greater than 40 eV with a pressure dependence, but only a weak power dependence. The degree of broadening was virtually independent of the position studied within the GEC cell, similar to the recent finding for He/H2 and Ar/H2 plasmas in the same GEC cell. In contrast to the atomic hydrogen lines, no broadening was observed in oxygen species lines at low pressures. Also, in control Xe/H2 plasmas run in the same cell at similar pressures and adsorbed power, no significant broadening of atomic hydrogen, Xe, or any other lines was observed. Stark broadening or acceleration of charged species due to high electric fields can not explain the results since (i) the electron density was insufficient by orders of magnitude, (ii) the RF field was essentially confined to the cathode fall region in contrast to the broadening that was independent of position, and (iii) only the atomic hydrogen lines were broadened. Rather, all of the data is consistent with a model that claims specific, predicted, species can act catalytically through a resonant energy transfer mechanism to create hot hydrogen atoms in plasmas.

Jonathan Phillips; Chun Ku Chen; Randell Mills

2004-02-06T23:59:59.000Z

13

Reactive oxygen species and oxidative DNA damage mediate the cytotoxicity of tungsten-nickel-cobalt alloys in vitro  

Science Conference Proceedings (OSTI)

Tungsten alloys (WA) have been introduced in an attempt to find safer alternatives to depleted uranium and lead munitions. However, it is known that at least one alloy, 91% tungsten-6% nickel-3% cobalt (WNC-91-6-3), causes rhabdomyosarcomas when fragments are implanted in rat muscle. This raises concerns that shrapnel, if not surgically removable, may result in similar tumours in humans. There is therefore a clear need to develop rapid and robust in vitro methods to characterise the toxicity of different WAs in order to identify those that are most likely to be harmful to human health and to guide development of new materials in the future. In the current study we have developed a rapid visual in vitro assay to detect toxicity mediated by individual WA particles in cultured L6-C11 rat muscle cells. Using a variety of techniques (histology, comet assay, caspase-3 activity, oxidation of 2'7'-dichlorofluorescin to measure the production of reactive oxygen species and whole-genome microarrays) we show that, in agreement with the in vivo rat carcinogenicity studies, WNC-91-6-3 was the most toxic of the alloys tested. On dissolution, it produces large amounts of reactive oxygen species, causes significant amounts of DNA damage, inhibits caspase-3, triggers a severe hypoxic response and kills the cells in the immediate vicinity of the alloy particles within 24 h. By combining these in vitro data we offer a mechanistic explanation of the effect of this alloy in vivo and show that in vitro tests are a viable alternative for assessing new alloys in the future.

Harris, R.M.; Williams, T.D.; Hodges, N.J.; Waring, R.H., E-mail: R.H.Waring@bham.ac.uk

2011-01-01T23:59:59.000Z

14

Evidence of the production of hot hydrogen atoms in RF plasmas by catalytic reactions between hydrogen and oxygen species  

E-Print Network (OSTI)

Selective H atom broadening was found to be present throughout the volume (13.5 cm diameter x 38 cm length) of RF generated H2O plasmas in a GEC cell. Notably, at low pressures (hot' witha energies greater than 40 eV, with a pressure dependence, but only a weak power dependence. The degree of broadening was virtually independent of the position within the GEC cell. In contrast to the atomic hydrogen lines, no broadening was observed in oxygen species lines at low pressure. Also, in 'control' Xe/H2 plasmas run in the saem cell at similar pressures and absorbed power, no significant broadening of atomic hydrogen, Xe or any other lines was observed. Stark broadeing or acceleration of charged species due to high electric fields can not explain the results since (i) the electron density was insufficient by orders or magnitude, (ii) the RF field was essentially confined to the cathode fall region in contrast to the broadening which was fou...

Phillips, J; Mills, R; Phillips, Jonathan; Chen, Chun Ku; Mills, Randell

2004-01-01T23:59:59.000Z

15

Low Dose Radiation Research Program: Comparisons of IR and ROS for  

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

Comparisons of IR and ROS for Induction of Damage to Cells Comparisons of IR and ROS for Induction of Damage to Cells Kathryn D. Held1, Yvonne L. McCarey1, Laurence Tartier1, Elena V. Rusyn1, Giuseppe Schettino2, Melvyn Folkard2, Kevin M. Prise2, and Barry D. Michael2 1Department of Radiation Oncology, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114; 2Gray Laboratory Cancer Research Trust, Mount Vernon Hospital, Northwood, HA6 2JR, UK Accurate evaluation of the risks associated with exposure to low doses of ionizing radiation (IR) is a major challenge for environmental sciences. Studies on the mechanisms of the actions of low doses of IR are needed to help understand possible risks. IR exerts its effects on cells through production of reactive oxidizing species (ROS) such as ·OH, H2O2 and

16

Perlick: ENERGY STAR Referral (HP48RO-S) | Department of Energy  

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

HP48RO-S) Perlick: ENERGY STAR Referral (HP48RO-S) February 8, 2011 DOE referred Perlick refrigerator HP48RO-S to EPA, brand manager of the ENERGY STAR program, for appropriate...

17

Chemically reactive species in liquids generated by atmospheric-pressure plasmas and their roles in plasma medicine  

SciTech Connect

Plasmas whose gas temperatures are close to room temperature may be generated in ambient air or a gas at atmospheric pressure with the use of low-frequency high voltage or low-power radio-frequency (RF) or microwave power applied to electrodes. Such plasmas can serve as a powerful source of free radicals and/or chemically reactive species that arise from atoms and molecules of the ambient gas. Recently use of such plasmas for medical purposes has attracted much attention as they can be implemented in possible medical devices that can cause blood coagulation, heal wounds, facilitate angiogenesis, sterilize surgical devices as well as living tissues without harming healthy cells, and selectively inactivate cancer cells. Especially of interest among reactive species generated by atmospheric-pressure plasmas (APP) are reactive oxygen species (ROS) and reactive nitrogen species (RNS) that are generated in liquid phase. Since most living tissues and cells are immersed in liquids (such as blood or culture media), reactive species generated by APPs in the gas phase are transported to the liquid phase and possibly converted to different types of reactive species therein before causing some influence on the tissues or cells. In this study, the rate equations are solved to evaluate concentrations of various reactive species in pure water that are originated by plasma reactions in atmosphere and possible effects of such species (including ROS/RNS) on living tissues and cells are discussed.

Hamaguchi, Satoshi [Center for Atomic and Molecular Technologies, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2013-07-11T23:59:59.000Z

18

Species identification in a laminar premixed low-pressure flame of morpholine as a model substance for oxygenated nitrogen-containing fuels.  

SciTech Connect

The combustion chemistry of morpholine (1-oxa-4-aza-cyclohexane) was investigated under laminar, premixed low-pressure conditions. Morpholine, as a heterocyclic secondary amine with numerous industrial applications, was studied as a model fuel which simultaneously contains oxygen and nitrogen heteroatoms. Stable and radical intermediates and products of the combustion process in a slightly fuel-rich {phi} = 1.3 (C/O = 0.41) flat premixed morpholine-oxygen-argon flame at 40 mbar (4 kPa) were identified. A detailed fuel destruction scheme is proposed based on combined measurements using two different in situ molecular beam mass spectrometry (MBMS) techniques. The results are discussed with special attention to hydrocarbon, oxygenated and N-containing compounds important in pollutant emission.

Hansen, Nils; Struckmeier, Ulf (Bielefeld University, Bielefeld, Germany); OBwald, Patrick (Bielefeld University, Bielefeld, Germany); Lucassen, Arnas (Bielefeld University, Bielefeld, Germany); Cool, Terrill A. (Cornell University, Ithaca, NY); Kohse-Hoinghaus, Katharina (Bielefeld University, Bielefeld, Germany); Kasper, Tina Silvia

2007-12-01T23:59:59.000Z

19

Oxygen analyzer  

DOE Patents (OSTI)

An oxygen analyzer which identifies and classifies microgram quantities of oxygen in ambient particulate matter and for quantitating organic oxygen in solvent extracts of ambient particulate matter. A sample is pyrolyzed in oxygen-free nitrogen gas (N.sub.2), and the resulting oxygen quantitatively converted to carbon monoxide (CO) by contact with hot granular carbon (C). Two analysis modes are made possible: (1) rapid determination of total pyrolyzable oxygen obtained by decomposing the sample at 1135.degree. C., or (2) temperature-programmed oxygen thermal analysis obtained by heating the sample from room temperature to 1135.degree. C. as a function of time. The analyzer basically comprises a pyrolysis tube containing a bed of granular carbon under N.sub.2, ovens used to heat the carbon and/or decompose the sample, and a non-dispersive infrared CO detector coupled to a mini-computer to quantitate oxygen in the decomposition products and control oven heating.

Benner, William H. (Danville, CA)

1986-01-01T23:59:59.000Z

20

Oxygen analyzer  

DOE Patents (OSTI)

An oxygen analyzer which identifies and classifies microgram quantities of oxygen in ambient particulate matter and for quantitating organic oxygen in solvent extracts of ambient particulate matter. A sample is pyrolyzed in oxygen-free nitrogen gas (N/sub 2/), and the resulting oxygen quantitatively converted to carbon monoxide (CO) by contact with hot granular carbon (C). Two analysis modes are made possible: (1) rapid determination of total pyrolyzable obtained by decomposing the sample at 1135/sup 0/C, or (2) temperature-programmed oxygen thermal analysis obtained by heating the sample from room temperature to 1135/sup 0/C as a function of time. The analyzer basically comprises a pyrolysis tube containing a bed of granular carbon under N/sub 2/, ovens used to heat the carbon and/or decompose the sample, and a non-dispersive infrared CO detector coupled to a mini-computer to quantitate oxygen in the decomposition products and control oven heating.

Benner, W.H.

1984-05-08T23:59:59.000Z

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21

Impact of the renewable oxygenate standard for reformulated gasoline on ethanol demand, energy use, and greenhouse gas emissions  

DOE Green Energy (OSTI)

To assure a place for renewable oxygenates in the national reformulated gasoline (RFG) program, the US Environmental Protection Agency has promulgated the renewable oxygenate standard (ROS) for RFG. It is assumed that ethanol derived from corn will be the only broadly available renewable oxygenate during Phase I of the RFG program. This report analyzes the impact that the ROS could have on the supply of ethanol, its transported volume, and its displacement from existing markets. It also considers the energy and crude oil consumption and greenhouse gas (GHG) emissions that could result from the production and use of various RFGs that could meet the ROS requirements. The report concludes that on the basis of current and projected near-term ethanol capacity, if ethanol is the only available renewable oxygenate used to meet the requirements of the ROS, diversion of ethanol from existing use as a fuel is likely to be necessary. Year-round use of ethanol and ETBE would eliminate the need for diversion by reducing winter demand for ethanol. On an RFG-program-wide basis, using ethanol and ETBE to satisfy the ROS can be expected to slightly reduce fossil energy use, increase crude oil use, and have essentially no effect on GHG emissions or total energy use relative to using RFG oxygenated only with MTBE.

Stork, K.C.; Singh, M.K.

1995-04-01T23:59:59.000Z

22

Oxygen Isotopes  

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

Pages to Isotopes Data Modern Records of Carbon and Oxygen Isotopes in Atmospheric Carbon Dioxide and Carbon-13 in Methane 800,000 Deuterium Record and Shorter Records of...

23

Sensitive Species  

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

Sensitive Species Sensitive Species Sensitive Species By avoiding or minimizing the impact of Laboratory activities on sensitive species, LANL can potentially reduce the possibility of these species being upgraded to federal protection. April 12, 2012 sensitive species The bald eagle is one of our sensitive species. Contact Environmental Communication & Public Involvement P.O. Box 1663 MS M996 Los Alamos, NM 87545 (505) 667-0216 Email Sensitive species are plants and animals that are protected at the state or local level. Keeping sensitive species safe We strive to minimize the impact of Laboratory operations on sensitive species, which are plants and animals not protected by the federal Endangered Species Act or the Migratory Bird Treaty Act, but are protected on state or local levels.

24

Transcriptome Profiling of a Toxic Dinoflagellate Reveals a Gene-Rich Protist and a Potential Impact on Gene  

E-Print Network (OSTI)

stress, reactive oxygen species (ROS; e.g., hydrogen peroxide) and ROS-scavenging molecules (e.g., APX that together make these organisms of central ecological and economic importance. On the one hand, as oxygenic photosynthesizers, about 50% of the known species play a vital role in oxygen evolution and ocean primary production

Bhattacharya, Debashish

25

MARINE ECOLOGY PROGRESS SERIES Mar Ecol Prog Ser  

E-Print Network (OSTI)

stress, reactive oxygen species (ROS; e.g., hydrogen peroxide) and ROS-scavenging molecules (e.g., APX that together make these organisms of central ecological and economic importance. On the one hand, as oxygenic photosynthesizers, about 50% of the known species play a vital role in oxygen evolution and ocean primary production

Bermingham, Eldredge

26

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

27

Algae for Oxygen  

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

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.

28

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.

29

High Selectivity Oxygen Delignification  

DOE Green Energy (OSTI)

Project Objective: The objectives of this project are as follows: (1) Examine the physical and chemical characteristics of a partner mill pre- and post-oxygen delignified pulp and compare them to lab generated oxygen delignified pulps; (2) Apply the chemical selectivity enhancement system to the partner pre-oxygen delignified pulps under mill conditions (with and without any predetermined amounts of carryover) to determine how efficiently viscosity is preserved, how well selectivity is enhanced, if strength is improved, measure any yield differences and/or bleachability differences; and (3) Initiate a mill scale oxygen delignification run using the selectivity enhancement agent, collect the mill data, analyze it, and propose any future plans for implementation.

Lucian A. Lucia

2005-11-15T23:59:59.000Z

30

Oxygen detection in biological systems  

Science Conference Proceedings (OSTI)

kinetics of flash induced oxygen evolution of algae through measuring ...... (1999) Fast response oxygen micro-optodes based on novel soluble ormosil glasses.

31

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

32

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

33

Oxygen Transport Membranes  

Science Conference Proceedings (OSTI)

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 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 (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

34

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

35

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

36

Molecular oxygen in the rho Ophiuchi cloud  

E-Print Network (OSTI)

Molecular oxygen, O2 has been expected historically to be an abundant component of the chemical species in molecular clouds and, as such, an important coolant of the dense interstellar medium. However, a number of attempts from both ground and from space have failed to detect O2 emission. The work described here uses heterodyne spectroscopy from space to search for molecular oxygen in the interstellar medium. The Odin satellite carries a 1.1 m sub-millimeter dish and a dedicated 119 GHz receiver for the ground state line of O2. Starting in 2002, the star forming molecular cloud core rho Oph A was observed with Odin for 34 days during several observing runs. We detect a spectral line at v(LSR) = 3.5 km/s with dv(FWHM) = 1.5 km/s, parameters which are also common to other species associated with rho Ohp A. This feature is identified as the O2 (N_J = 1_1 - 1_0) transition at 118 750.343 MHz. The abundance of molecular oxygen, relative to H2,, is 5E-8 averaged over the Odin beam. This abundance is consistently lower than previously reported upper limits.

B. Larsson; R. Liseau; L. Pagani; P. Bergman; P. Bernath; N. Biver; J. H. Black; R. S. Booth; V. Buat; J. Crovisier; C. L. Curry; M. Dahlgren; P. J. Encrenaz; E. Falgarone; P. A. Feldman; M. Fich; H. G. Flore'n; M. Fredrixon; U. Frisk; G. F. Gahm; M. Gerin; M. Hagstroem; J. Harju; T. Hasegawa; Aa. Hjalmarson; C. Horellou; L. E. B. Johansson; K. Justtanont; A. Klotz; E. Kyroelae; S. Kwok; A. Lecacheux; T. Liljestroem; E. J. Llewellyn; S. Lundin; G. Me'gie; G. F. Mitchell; D. Murtagh; L. H. Nordh; L. -Aa. Nyman; M. Olberg; A. O. H. Olofsson; G. Olofsson; H. Olofsson; G. Persson; R. Plume; H. Rickman; I. Ristorcelli; G. Rydbeck; Aa. Sandqvist; F. v. Sche'ele; G. Serra; S. Torchinsky; N. F. Tothill; K. Volk; T. Wiklind; C. D. Wilson; A. Winnberg; G. Witt

2007-02-19T23:59:59.000Z

37

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

38

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

39

Oxygen Transport Ceramic Membranes  

Science Conference Proceedings (OSTI)

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

40

Oxygen Transport Ceramic Membranes  

Science Conference Proceedings (OSTI)

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

Note: This page contains sample records for the topic "oxygen species ros" 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

Fuel cell oxygen electrode  

DOE Patents (OSTI)

An oxygen electrode for a fuel cell utilizing an acid electrolyte has a substrate of an alkali metal tungsten bronze of the formula: A.sub.x WO.sub.3 where A is an alkali metal and x is at least 0.2, which is covered with a thin layer of platinum tungsten bronze of the formula: Pt.sub.y WO.sub.3 where y is at least 0.8.

Shanks, Howard R. (Ames, IA); Bevolo, Albert J. (Ames, IA); Danielson, Gordon C. (Ames, IA); Weber, Michael F. (Wichita, KS)

1980-11-04T23:59:59.000Z

42

Dissolution of oxygen reduction electrocatalysts in acidic environment  

E-Print Network (OSTI)

Platinum (Pt) alloy nanoparticles are used as catalysts in electrochemical cells to reduce oxygen to water and to oxidize hydrogen; the overall reaction converts chemical energy into electrical energy. These nanocatalysts are deposited on a carbon substrate and their catalytic function takes place in acid medium. This harsh environment causes an undesired reaction, which is the dissolution of the metal atoms into the acid medium; thus affecting the catalyst life. This dissertation aims to investigate the dissolution mechanism of fuel cell cathode catalysts at the atomic level starting from the oxygen reaction intermediates on the cathode catalyst surface and propose guidelines to improve cathode catalysts durability based on our proposed mechanism. Density functional theory is employed to study various possible scenarios with the goals of understanding the mechanism of the metal atom dissolution process and establishing some guidelines that permit a rational design of catalysts with better stability against dissolution. A thermodynamic analysis of potential metal dissolution reactions in acid medium is presented first, using density functional theory calculations to explore the relative stabilities of transition metals in relation to that of Pt. The study is performed by comparing the change in reaction Gibbs free energies for different metals in a given dissolution reaction. Then, a series of density functional theory studies, tending to investigate the adsorbed atomic oxygen absorption process from cathode catalyst surface into its subsurface, includes: 1) the oxygen adsorption on various catalyst surfaces and oxygen absorption in subsurface sites to figure out the minimum energy pathway and energy barrier of on-surface oxygen migration and absorption into subsurface; 2) the oxygen coverage, the other oxygen reduction reaction intermediates, and water effects on the oxygen absorption process according to reaction pathways, energy barriers, and thermodynamic analysis; 3) the oxygen absorption process on several Pt-based alloys with various compositions and components to find out the best alloy to inhibit atomic oxygen absorption including both kinetic and thermodynamic analyses, and the effects of such alloyed species on the inhibition process.

Gu, Zhihui

2007-12-01T23:59:59.000Z

43

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

44

Oxygen Transport Ceramic Membranes  

Science Conference Proceedings (OSTI)

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

45

Culturing Aerobic and Anaerobic Bacteria and Mammalian Cells with a Microfluidic Differential Oxygenator  

E-Print Network (OSTI)

In this manuscript, we report on the culture of anaerobic and aerobic species within a disposable multilayer polydimethylsiloxane (PDMS) microfluidic device with an integrated differential oxygenator. A gas-filled microchannel ...

Lam, Raymond H. W.

46

High Selectivity Oxygen Delignification  

DOE Green Energy (OSTI)

The overall objective of this program was to develop improved extended oxygen delignification (EOD) technologies for current U.S. pulp mill operations. This was accomplished by: (1) Identifying pulping conditions that optimize O and OO performance; (2) Identifying structural features of lignin that enhance reactivity towards EOD of high kappa pulps; (3) Identifying factors minimizing carbohydrate degradation and improve pulp strength of EOD high kappa pulps; (4) Developing a simple, reproducible method of quantifying yield gains from EOD; and (5) Developing process conditions that significantly reduce the capital requirements of EOD while optimizing the yield benefits. Key research outcomes included, demonstrating the use of a mini-O sequence such as (E+O)Dkf:0.05(E+O) or Dkf:0.05(E+O)(E+O) without interstage washing could capture approximately 60% of the delignification efficiency of a conventional O-stage without the major capital requirements associated with an O-stage for conventional SW kraft pulps. The rate of formation and loss of fiber charge during an O-stage stage can be employed to maximize net fiber charge. Optimal fiber charge development and delignification are two independent parameters and do not parallel each other. It is possible to utilize an O-stage to enhance overall cellulosic fiber charge of low and high kappa SW kraft pulps which is beneficial for physical strength properties. The application of NIR and multi-variant analysis was developed into a rapid and simple method of determining the yield of pulp from an oxygen delignification stage that has real-world mill applications. A focus point of this program was the demonstration that Kraft pulping conditions and oxygen delignification of high and low-kappa SW and HW pulps are intimately related. Improved physical pulp properties and yield can be delivered by controlling the H-factor and active alkali charge. Low AA softwood kraft pulp with a kappa number 30 has an average improvement of 2% in yield and 4 cP in viscosity in comparison to high AA pulp for the oxygen delignification. This difference is also seen for high-kappa SW kraft pulps with an average improvement of {approx}3% in yield and 3 cP in viscosity for low AA high kappa number 50 pulp. Low AA hardwood kappa number 20 pulp had an average improvement of {approx}4% in yield and 6-12 cP in viscosity as compared to high AA pulp. Lower kraft cooking temperature (160 vs. 170 C) in combination with the medium AA provides a practical approach for integrating high kappa pulping of hardwoods (i.e., low rejects) with an advanced extended oxygen delignification stage. ECF pulp bleaching of low and high kappa kraft SW and HW pulps exhibit comparable optical and physical strength properties when bleached D(EPO)D.

Arthur J. Ragauskas

2005-09-30T23:59:59.000Z

47

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

48

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

49

Oxygen-reducing catalyst layer  

DOE Patents (OSTI)

An oxygen-reducing catalyst layer, and a method of making the oxygen-reducing catalyst layer, where the oxygen-reducing catalyst layer includes a catalytic material film disposed on a substrate with the use of physical vapor deposition and thermal treatment. The catalytic material film includes a transition metal that is substantially free of platinum. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

O' Brien, Dennis P. (Maplewood, MN); Schmoeckel, Alison K. (Stillwater, MN); Vernstrom, George D. (Cottage Grove, MN); Atanasoski, Radoslav (Edina, MN); Wood, Thomas E. (Stillwater, MN); Yang, Ruizhi (Halifax, CA); Easton, E. Bradley (Halifax, CA); Dahn, Jeffrey R. (Hubley, CA); O' Neill, David G. (Lake Elmo, MN)

2011-03-22T23:59:59.000Z

50

Plants and Night Oxygen Production  

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

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.

51

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

52

OXYGEN TRANSPORT CERAMIC MEMBRANES  

DOE Green Energy (OSTI)

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

53

Oxygenates vs. synthesis gas  

DOE Green Energy (OSTI)

Methanol synthesis from H{sub 2}/CO has been carried out at 7.6 MPa over zirconia-supported copper catalysts. Catalysts with nominal compositions of 10/90 mol% and 30/70 mol% Cu/ZrO{sub 2} were used in this study. Additionally, a 3 mol% cesium-doped 10/90 catalyst was prepared to study the effect of doping with heavy alkali, and this promoter greatly increased the methanol productivity. The effects of CO{sub 2} addition, water injection, reaction temperature, and H{sub 2}/C0 ratio have been investigated. Both CO{sub 2} addition to the synthesis gas and cesium doping of the catalyst promoted methanol synthesis, while inhibiting the synthesis of dimethyl ether. Injection of water, however, was found to slightly suppress methanol and dimethyl ether formation while being converted to CO{sub 2} via the water gas shift reaction over these catalysts. There was no clear correlation between copper surface area and catalyst activity. Surface analysis of the tested samples revealed that copper tended to migrate and enrich the catalyst surface. The concept of employing a double-bed reactor with a pronounced temperature gradient to enhance higher alcohol synthesis was explored, and it was found that utilization of a Cs-promoted Cu/ZnO/Cr{sub 2}O{sub 3} catalyst as a first lower temperature bed and a Cs-promoted ZnO/Cr{sub 2}O{sub 3} catalyst as a second high-temperature bed significantly promoted the productivity of 2-methyl-1-propanol (isobutanol) from H{sub 2}/CO synthesis gas mixtures. While the conversion of CO to C{sub 2+} oxygenates over the double-bed configuration was comparable to that observed over the single Cu-based catalyst, major changes in the product distribution occurred by the coupling to the zinc chromite catalyst; that is, the productivity of the C{sub 1}-C{sub 3} alcohols decreased dramatically, and 2-methyl branched alcohols were selectively formed. The desirable methanol/2-methyl oxygenate molar ratios close to 1 were obtained in the present double-bed system that provides the feedstock for the synthesis of high octane and high cetane ethers, where the isobutanol productivity was as high as 139 g/kg cat/hr. Higher alcohol synthesis has been investigated over a Cs/Cu/ZnO/Cr{sub 2}O{sub 3} catalyst at temperatures higher (up to 703K) than those previously utilized, and no sintering of the catalyst was observed during the short-term testing. However, the higher reaction temperatures led to lower CO conversion levels and lower yield of alcohols, especially of methanol, because of equilibrium limitations. With the double catalyst bed configuration, the effect of pressure in the range of 7.6--12.4 MPa on catalyst activity and selectivity was studied. The upper bed was composed of the copper-based catalyst at 598K, and the lower bed consisted of a copper-free Cs-ZnO/Cr{sub 2}O{sub 3} catalyst at a high temperature of 678K. High pressure was found to increase CO conversion to oxygenated products, although the increase in isobutanol productivity did not keep pace with that of methanol. It was also shown that the Cs/Cu/ZnO/Cr{sub 2}O{sub 3} catalyst could be utilized to advantage as the second-bed catalyst at 613--643K instead of the previously used copper-free Cs-ZnO/ Cr{sub 2}O{sub 3} catalyst at higher temperature, With double Cs/Cu/ZnO/Cr{sub 2}O{sub 3} catalysts, high space time yields of up to 202 g/kg cat/hr, with high selectivity to isobutanol, were achieved.

Kamil Klier; Richard G. Herman; Alessandra Beretta; Maria A. Burcham; Qun Sun; Yeping Cai; Biswanath Roy

1999-04-01T23:59:59.000Z

54

Frostbite Theater - Liquid Oxygen vs. Liquid Nitrogen - Liquid Oxygen and  

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

Cells vs. Liquid Nitrogen! Cells vs. Liquid Nitrogen! Previous Video (Cells vs. Liquid Nitrogen!) Frostbite Theater Main Index Next Video (Paramagnetism) Paramagnetism Liquid Oxygen and Fire! What happens when nitrogen and oxygen are exposed to fire? [ Show Transcript ] Announcer: Frostbite Theater presents... Cold Cuts! No baloney! Joanna and Steve: Just science! Joanna: Hi! I'm Joanna! Steve: And I'm Steve! Joanna: And this is a test tube of liquid nitrogen! Steve: And this is a test tube of liquid oxygen! Joanna: Let's see what happens when nitrogen and oxygen are exposed to fire. Steve: Fire?! Joanna: Yeah! Steve: Really?! Joanna: Why not! Steve: Okay! Joanna: As nitrogen boils, it changes into nitrogen gas. Because it's so cold, it's denser than the air in the room. The test tube fills up with

55

Oxygenate Supply/Demand Balances  

Gasoline and Diesel Fuel Update (EIA)

Oxygenate Supply/Demand Oxygenate Supply/Demand Balances in the Short-Term Integrated Forecasting Model By Tancred C.M. Lidderdale This article first appeared in the Short-Term Energy Outlook Annual Supplement 1995, Energy Information Administration, DOE/EIA-0202(95) (Washington, DC, July 1995), pp. 33-42, 83-85. The regression results and historical data for production, inventories, and imports have been updated in this presentation. Contents * Introduction o Table 1. Oxygenate production capacity and demand * Oxygenate demand o Table 2. Estimated RFG demand share - mandated RFG areas, January 1998 * Fuel ethanol supply and demand balance o Table 3. Fuel ethanol annual statistics * MTBE supply and demand balance o Table 4. EIA MTBE annual statistics * Refinery balances

56

It's Elemental - The Element Oxygen  

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

Nitrogen Nitrogen Previous Element (Nitrogen) The Periodic Table of Elements Next Element (Fluorine) Fluorine The Element Oxygen [Click for Isotope Data] 8 O Oxygen 15.9994 Atomic Number: 8 Atomic Weight: 15.9994 Melting Point: 54.36 K (-218.79°C or -361.82°F) Boiling Point: 90.20 K (-182.95°C or -297.31°F) Density: 0.001429 grams per cubic centimeter Phase at Room Temperature: Gas Element Classification: Non-metal Period Number: 2 Group Number: 16 Group Name: Chalcogen What's in a name? From the greek words oxys and genes, which together mean "acid forming." Say what? Oxygen is pronounced as OK-si-jen. History and Uses: Oxygen had been produced by several chemists prior to its discovery in 1774, but they failed to recognize it as a distinct element. Joseph

57

Oxygen sensitive, refractory oxide composition  

DOE Patents (OSTI)

Oxide compositions containing niobium pentoxide and an oxide selected from the group consisting of hafnia, titania, and zirconia have electrical conductivity characteristics which vary greatly depending on the oxygen content.

Holcombe, Jr., Cressie E. (Oak Ridge, TN); Smith, Douglas D. (Knoxville, TN)

1976-01-01T23:59:59.000Z

58

Regional imaging with oxygen-14  

SciTech Connect

The metabolic significance of the distribution of labeled oxygen was studied in the dog by inhalation of gas mixtures labeled with oxygen-14 (T/sub /sup 1///sub 2// = 71 seconds) maintained at a constant level of activity. Under steady-state conditions, whole-body images were developed by detection of the positron annihilation emissions with a dual head rectilinear scanner in the coincidence mode. (auth)

Russ, G.A.; Bigler, R.E.; Dahl, J.R.; Kostick, J.; McDonald, J.M.; Tilbury, R.S.; Laughlin, J.S.

1975-01-01T23:59:59.000Z

59

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.

60

EVALUATING AN INNOVATIVE OXYGEN SENSOR FOR REMOTE SUBSURFACE OXYGEN MEASUREMENTS  

Science Conference Proceedings (OSTI)

Oxygen is a primary indicator of whether anaerobic reductive dechlorination and similar redox based processes contribute to natural attenuation remedies at chlorinated solvent contaminated sites. Thus, oxygen is a viable indicator parameter for documenting that a system is being sustained in an anaerobic condition. A team of researchers investigated the adaptation of an optical sensor that was developed for oceanographic applications. The optical sensor, because of its design and operating principle, has potential for extended deployment and sensitivity at the low oxygen levels relevant to natural attenuation. The results of the research indicate this tool will be useful for in situ long-term monitoring applications, but that the traditional characterization tools continue to be appropriate for characterization activities.

Millings, M; Brian Riha, B; Warren Hyde, W; Karen Vangelas, K; Brian02 Looney, B

2006-10-12T23:59:59.000Z

Note: This page contains sample records for the topic "oxygen species ros" 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

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

62

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

63

Curcumin reduces the antimicrobial activity of ciprofloxacin against Salmonella Typhimurium and Salmonella Typhi  

E-Print Network (OSTI)

Curcumin reduces the antimicrobial activity of ciprofloxacin against Salmonella Typhimurium fragmentation, SOS response and reactive oxygen species (ROS) in the bacterial cell. Curcumin, an active increasing the proliferation of Salmonella Typhi and Salmonella Typhimurium in macrophages. In a murine model

Srinivasan, N.

64

Dilute Oxygen Combustion Phase I Final Report  

Science Conference Proceedings (OSTI)

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 (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

65

Dilute Oxygen Combustion Phase 2 Final Report  

Science Conference Proceedings (OSTI)

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 (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

66

Catalyst containing oxygen transport membrane  

Science Conference Proceedings (OSTI)

A composite oxygen transport membrane having a dense layer, a porous support layer and an intermediate porous layer located between the dense layer and the porous support layer. Both the dense layer and the intermediate porous layer are formed from an ionic conductive material to conduct oxygen ions and an electrically conductive material to conduct electrons. The porous support layer has a high permeability, high porosity, and a high average pore diameter and the intermediate porous layer has a lower permeability and lower pore diameter than the porous support layer. Catalyst particles selected to promote oxidation of a combustible substance are located in the intermediate porous layer and in the porous support adjacent to the intermediate porous layer. The catalyst particles can be formed by wicking a solution of catalyst precursors through the porous support toward the intermediate porous layer.

Christie, Gervase Maxwell; Wilson, Jamie Robyn; van Hassel, Bart Antonie

2012-12-04T23:59:59.000Z

67

Microbial oceanography of anoxic oxygen minimum zones  

E-Print Network (OSTI)

Vast expanses of oxygen-deficient and nitrite-rich water define the major oxygen minimum zones (OMZs) of the global ocean. They support diverse microbial communities that influence the nitrogen economy of the oceans, ...

Ulloa, Osvaldo

68

Microchemical systems for singlet oxygen generation  

E-Print Network (OSTI)

Chemical Oxygen-Iodine Lasers (COIL) are a technology of interest for industrial and military audiences. COILs are flowing gas lasers where the gain medium of iodine atoms is collisionally pumped by singlet delta oxygen ...

Hill, Tyrone F. (Tyrone Frank), 1980-

2008-01-01T23:59:59.000Z

69

Oxygen Sensitivity of Krypton and Lyman-? Hygrometers  

Science Conference Proceedings (OSTI)

The oxygen sensitivity of krypton and Lyman-? hygrometers is studied. Using a dewpoint generator and a controlled nitrogen/oxygen flow the extinction coefficients of five hygrometers associated with the third-order Taylor expansion of the Lambert–...

Arjan van Dijk; Wim Kohsiek; Henk A. R. de Bruin

2003-01-01T23:59:59.000Z

70

Innovative oxygen separation membrane prototype  

SciTech Connect

Improvements are still needed to gas separation processes to gain industry acceptance of coal gasification systems. The Ion Transport Membrane (ITM) technology, being developed by the US Department of Energy and its partners, offers an opportunity to lower overall plant cost and improve efficiency compared to cryogenic distillation and pressure swing adsorption methods. The technology is based on a novel class of perovskite ceramic oxides which can selectively separate oxygen ions from a stream of air at high temperature and pressure. Those ions are transported across the ITM leaving non-permeate air which can be integrated with a fuel-fired gas system, enabling co-production of power and steam along with the concentrated, high-purity oxygen. The project is at the second phase, to scale up the ITM Oxygen ceramic devices to demonstrate the technology at the 1-5 tpd capability in the Subscale Engineering Prototype. A third phase to demonstrate commercial viability extends to the end of the decade. 2 figs.

NONE

2006-08-15T23:59:59.000Z

71

The Role of Oxygen in Coal Gasification  

E-Print Network (OSTI)

Air Products supplies oxygen to a number of coal gasification and partial oxidation facilities worldwide. At the high operating pressures of these processes, economics favor the use of 90% and higher oxygen purities. The effect of inerts in the oxidant on gasifier and downstream production units also favor the use of oxygen in place of air. Factors that must be considered in selecting the optimum oxygen purity include: end use of the gasifier products, oxygen delivery pressure and the cost of capital and energy. This paper examines the major factors in oxygen purity selection for typical coal gasifiers. Examples demonstrating the effect of oxygen purity on several processes are presented: production of synthetic natural gas (SNG), integrated gasification combined-cycle (IGCC) power generation and methanol synthesis. The potential impact of a non-cryogenic air separation process currently under development is examined based on integration with a high temperature processes.

Klosek, J.; Smith, A. R.; Solomon, J.

1986-06-01T23:59:59.000Z

72

Oxygen enriched combustion system performance study  

SciTech Connect

The current study was undertaken to evaluate the performance of a pressure swing adsorption (PSA) oxygen plant to provide oxygen for industrial combustion applications. PSA oxygen plants utilize a molecular sieve material to separate air into an oxygen rich product stream and a nitrogen rich exhaust stream. These plants typically produce 90-95% purity oxygen and are located in close proximity to the point of use. In contrast, high purity (99.999%) oxygen is produced by the distillation of liquid air at a remote plant and is usually transported to the point of use either as a cryogenic liquid in a tank trailer or as a high pressure gas via pipeline. In this study, experiments were performed to the test PSA system used in conjunction with an A'' burner and comparisons were made with the results of the previous study which utilized high purity liquid oxygen. 4 refs., 6 figs., 6 tabs.

Delano, M.A. (Union Carbide Industrial Gases, Inc., Tarrytown, NY (USA)); Kwan, Y. (Energy and Environmental Research Corp., Irvine, CA (USA))

1989-07-01T23:59:59.000Z

73

The effect of oxygenate molecular structure on soot production in direct-injection diesel engines.  

DOE Green Energy (OSTI)

A combined experimental and kinetic modeling study of soot formation in diesel engine combustion has been used to study the addition of oxygenated species to diesel fuel to reduce soot emissions. This work indicates that the primary role of oxygen atoms in the fuel mixture is to reduce the levels of carbon atoms available for soot formation by fixing them in the form of CO or COz. When the structure of the oxygenate leads to prompt and direct formation of CO2, the oxygenate is less effective in reducing soot production than in cases when all fuel-bound 0 atoms produce only CO. The kinetic and molecular structure principles leading to this conclusion are described.

Westbrook, Charles K. (Lawrence Livermore National Laboratory, Livermore, CA); Pitz, William J. (Lawrence Livermore National Laboratory, Livermore, CA); Mueller, Charles J.; Martin, Glen M.; Pickett, Lyle M.

2003-06-01T23:59:59.000Z

74

Endangered Species Listing Process  

Science Conference Proceedings (OSTI)

EPRI has established an Endangered Species Advisory Committee to guide a new research effort to address electric power sector technical issues connected to U.S. Fish and Wildlife Service listing decisions on hundreds of species over the next several years. EPRI has conducted initial research into the listing process and has reached out to the U.S. Fish and Wildlife Service and other stakeholder groups in an effort to establish collegial and cooperative ties and to better understand the research gaps ...

2013-08-21T23:59:59.000Z

75

OGI School of Science & Engineering www.ogi.edu/catalog  

E-Print Network (OSTI)

oxygen species; antioxidant; plant disease. Abstract Mannitol has been hypothesized to play a role; Witteveen & Visser, 1995). Mannitol also quenches reactive oxygen species (ROS) (Smirnoff & Cumbes, 1989 of Cryptococcus neoformans by human neutrophils: evidence that fungal mannitol protects by scavenging reactive

Chapman, Michael S.

76

Forecast Technical Document Tree Species  

E-Print Network (OSTI)

Forecast Technical Document Tree Species A document listing the tree species included in the 2011 Production Forecast Tom Jenkins Justin Gilbert Ewan Mackie Robert Matthews #12;PF2011 ­ List of tree species The following is the list of species used within the Forecast System. Species are ordered alphabetically

77

Jupiter Oxygen Corporation | Open Energy Information  

Open Energy Info (EERE)

Corporation Place Schiller Park, Illinois Zip 60176 Product Illinois-based oxy-fuel combustion company involved in the capture of CO2. References Jupiter Oxygen Corporation1...

78

Insitu Oxygen Conduction Into Internal Combustion Chamber  

Insitu Oxygen Conduction Into Internal Combustion Chamber Note: The technology described above is an early stage opportunity. Licensing rights to this ...

79

Areas Participating in the Oxygenated Gasoline Program  

U.S. Energy Information Administration (EIA)

Demand and Price Outlook ... is a colorless, odorless, and poisonous gas ... oxygen by weight is to be used in the wintertime in those areas of the county that ...

80

Electrocatalyst for Oxygen Reduction with Reduced Platinum ...  

Platinum is the most efficient electrocatalyst for accelerating the oxygen reduction reaction in fuel cells. Under operating conditions, though, platinum catalysts ...

Note: This page contains sample records for the topic "oxygen species ros" 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

EO 13112: Invasive Species  

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

183 183 Federal Register / Vol. 64, No. 25 / Monday, February 8, 1999 / Presidential Documents Executive Order 13112 of February 3, 1999 Invasive Species By the authority vested in me as President by the Constitution and the laws of the United States of America, including the National Environmental Policy Act of 1969, as amended (42 U.S.C. 4321 et seq.), Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990, as amended (16 U.S.C. 4701 et seq.), Lacey Act, as amended (18 U.S.C. 42), Federal Plant Pest Act (7 U.S.C. 150aa et seq.), Federal Noxious Weed Act of 1974, as amended (7 U.S.C. 2801 et seq.), Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.), and other pertinent statutes, to prevent the introduc- tion of invasive species and provide for their control and to minimize

82

CGC Trace Species Partitioning  

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

Trace Species Partitioning as Affected Trace Species Partitioning as Affected by Cold Gas Cleanup Conditions: A Thermodynamic Analysis February 10, 2011 DOE/NETL-2011/1503 T r ace Species P ar titioning at C old G as C leanup C onditions Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name,

83

Effects of oxygen cover gas and NaOH dilution on gas generation in tank 241-SY-101 waste  

DOE Green Energy (OSTI)

Laboratory studies are reported of gas generation in heated waste from tank 241-SY-101. The rates of gas generation and the compositions of product gas were measured. Three types of tests are compared. The tests use: undiluted waste, waste diluted by a 54% addition of 2.5 M NaOH, and undiluted waste with a reactive cover gas of 30% Oxygen in He. The gas generation rate is reduced by dilution, increased by higher temperatures (which determines activation energies), and increased by reactions of Oxygen (these primarily produce H{sub 2}). Gases are generated as reduction products oxidation of organic carbon species by nitrite and oxygen.

Person, J.C.

1996-05-30T23:59:59.000Z

84

Effects of Pressure on Oxygen Sensors  

Science Conference Proceedings (OSTI)

To measure the effects of pressure on the output of a membrane oxygen sensor and a nonmembrane oxygen sensor, the authors pressure cycled a CTD sensor package in a laboratory pressure facility. The CTD sensor package was cycled from 30 to 6800 db ...

M. J. Atkinson; F. I. M. Thomas; N. Larson

1996-12-01T23:59:59.000Z

85

Oxygen Control in PWR Makeup Water  

Science Conference Proceedings (OSTI)

Three fixed-bed processes can accelerate hydrazine-oxygen reactions in PWR makeup water and reduce oxygen levels to below 5 ppb. In this comparative-test project, activated carbon based systems offered the best combination of low cost, effectiveness, and commercial availability. A second process, employing palladium-coated anion resin, is also commercially available.

1988-02-03T23:59:59.000Z

86

Oxygen ion-conducting dense ceramic  

DOE Patents (OSTI)

Preparation, structure, and properties of mixed metal oxide compositions containing at least strontium, cobalt, iron and oxygen are described. The crystalline mixed metal oxide compositions of this invention have, for example, structure represented by Sr.sub..alpha. (Fe.sub.1-x Co.sub.x).sub..alpha.+.beta. O.sub..delta. where x is a number in a range from 0.01 to about 1, .alpha. is a number in a range from about 1 to about 4, .beta. is a number in a range upward from 0 to about 20, and .delta. is a number which renders the compound charge neutral, and wherein the composition has a non-perovskite structure. Use of the mixed metal oxides in dense ceramic membranes which exhibit oxygen ionic conductivity and selective oxygen separation, are described as well as their use in separation of oxygen from an oxygen-containing gaseous mixture.

Balachandran, Uthamalingam (Hinsdale, IL); Kleefisch, Mark S. (Naperville, IL); Kobylinski, Thaddeus P. (Lisle, IL); Morissette, Sherry L. (Las Cruces, NM); Pei, Shiyou (Naperville, IL)

1997-01-01T23:59:59.000Z

87

Oxygen ion-conducting dense ceramic  

DOE Patents (OSTI)

Preparation, structure, and properties of mixed metal oxide compositions containing at least strontium, cobalt, iron and oxygen are described. The crystalline mixed metal oxide compositions of this invention have, for example, structure represented by Sr.sub..alpha. (Fe.sub.1-x Co.sub.x).sub..alpha.+.beta. O.sub..delta. where x is a number in a range from 0.01 to about 1, .alpha. is a number in a range from about 1 to about 4, .beta. is a number in a range upward from 0 to about 20, and .delta. is a number which renders the compound charge neutral, and wherein the composition has a non-perovskite structure. Use of the mixed metal oxides in dense ceramic membranes which exhibit oxygen ionic conductivity and selective oxygen separation, are described as well as their use in separation of oxygen from an oxygen-containing gaseous mixture.

Balachandran, Uthamalingam (Hinsdale, IL); Kleefisch, Mark S. (Naperville, IL); Kobylinski, Thaddeus P. (Lisle, IL); Morissette, Sherry L. (Las Cruces, NM); Pei, Shiyou (Naperville, IL)

1996-01-01T23:59:59.000Z

88

Modelling Hydrogen Reduction and Hydrodeoxygenation of Oxygenates  

Science Conference Proceedings (OSTI)

Based on Density Functional Theory (DFT) simulations, we have studied the reduction of nickel oxide and biomass derived oxygenates (catechol, guaiacol, etc.) in hydrogen. Both the kinetic barrier and thermodynamic favorability are calculated with respect to the modeled reaction pathways. In early-stage reduction of the NiO(100) surface by hydrogen, the pull-off of the surface oxygen atom and simultaneous activation of the nearby Ni atoms coordinately dissociate the hydrogen molecules so that a water molecule can be formed, leaving an oxygen vacancy on the surface. In hydrogen reaction with oxygenates catalyzed by transition metals, hydrogenation of the aromatic carbon ring normally dominates. However, selective deoxygenation is of particular interest for practical application such as biofuel conversion. Our modeling shows that doping of the transition metal catalysts can change the orientation of oxygenates adsorbed on metal surfaces. The correlation between the selectivity of reaction and the orientation of adsorption are discussed.

Zhao, Y.; Xu, Q.; Cheah, S.

2013-01-01T23:59:59.000Z

89

Oxygen Absorption in Cooling Flows  

E-Print Network (OSTI)

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

David A. Buote

2000-01-19T23:59:59.000Z

90

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect

Conventional wisdom says adding oxygen to a combustion system enhances product throughput, system efficiency, and, unless special care is taken, increases NOx emissions. This increase in NOx emissions is typically due to elevated flame temperatures associated with oxygen use leading to added thermal NOx formation. Innovative low flame temperature oxy-fuel burner designs have been developed and commercialized to minimize both thermal and fuel NOx formation for gas and oil fired industrial furnaces. To be effective these systems require close to 100% oxy-fuel combustion and the cost of oxygen is paid for by fuel savings and other benefits. For applications to coal-fired utility boilers at the current cost of oxygen, however, it is not economically feasible to use 100% oxygen for NOx control. In spite of this conventional wisdom, Praxair and its team members, in partnership with the US Department of Energy National Energy Technology Laboratory, have developed a novel way to use oxygen to reduce NOx emissions without resorting to complete oxy-fuel conversion. In this concept oxygen is added to the combustion process to enhance operation of a low NOx combustion system. Only a small fraction of combustion air is replaced with oxygen in the process. By selectively adding oxygen to a low NOx combustion system it is possible to reduce NOx emissions from nitrogen-containing fuels, including pulverized coal, while improving combustion characteristics such as unburned carbon. A combination of experimental work and modeling was used to define how well oxygen enhanced combustion could reduce NOx emissions. The results of this work suggest that small amounts of oxygen replacement can reduce the NOx emissions as compared to the air-alone system. NOx emissions significantly below 0.15 lbs/MMBtu were measured. Oxygen addition was also shown to reduce carbon in ash. Comparison of the costs of using oxygen for NOx control against competing technologies, such as SCR, show that this concept offers substantial savings over SCR and is an economically attractive alternative to purchasing NOx credits or installing other conventional technologies. In conjunction with the development of oxygen based low NOx technology, Praxair also worked on developing the economically enhancing oxygen transport membrane (OTM) technology which is ideally suited for integration with combustion systems to achieve further significant cost reductions and efficiency improvements. This OTM oxygen production technology is based on ceramic mixed conductor membranes that operate at high temperatures and can be operated in a pressure driven mode to separate oxygen with infinite selectivity and high flux. An OTM material was selected and characterized. OTM elements were successfully fabricated. A single tube OTM reactor was designed and assembled. Testing of dense OTM elements was conducted with promising oxygen flux results of 100% of target flux. However, based on current natural gas prices and stand-alone air separation processes, ceramic membranes do not offer an economic advantage for this application. Under a different DOE-NETL Cooperative Agreement, Praxair is continuing to develop oxygen transport membranes for the Advanced Boiler where the economics appear more attractive.

David R. Thompson; Lawrence E. Bool; Jack C. Chen

2004-04-01T23:59:59.000Z

91

Method of detecting oxygen partial pressure and oxygen partial pressure sensor  

DOE Patents (OSTI)

This invention is comprised of a method for detecting oxygen partial pressure and an oxygen partial pressure sensor are provided. The method for measuring oxygen partial pressure includes contacting oxygen to a solid oxide electrolyte and measuring the subsequent change in electrical conductivity of the solid oxide electrolyte. A solid oxide electrolyte is utilized that contacts both a porous electrode and a nonporous electrode. The electrical conductivity of the solid oxide electrolyte is affected when oxygen from an exhaust stream permeates through the porous electrode to establish an equilibrium of oxygen anions in the electrolyte, thereby displacing electrons throughout the electrolyte to form an electron gradient. By adapting the two electrodes to sense a voltage potential between them, the change in electrolyte conductivity due to oxygen presence can be measured.

Dees, D.W.

1991-12-31T23:59:59.000Z

92

Selective photooxidation of hydrocarbons in zeolites by oxygen  

DOE Patents (OSTI)

A selective photooxidation process for the conversion of hydrocarbon molecules to partially oxygenated derivatives, which comprises the steps of adsorbing a hydrocarbon and oxygen onto a dehydrated zeolite support matrix to form a hydrocarbon-oxygen contact pair, and subsequently exposing the hydrocarbon-oxygen contact pair to visible light, thereby forming a partially oxygenated derivative.

Frei, Heinz (Berkeley, CA); Blatter, Fritz (Berkeley, CA); Sun, Hai (Berkeley, CA)

1998-01-01T23:59:59.000Z

93

Why Sequence Methylotenera species?  

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

Methylotenera species? Methylotenera species? electron micrograph Scanning electron micrograph of cells of Methylotenera mobilis strain JLW8 grown on methylamine. Photo: Dennis Kunkel, Dennis Kunkel Microscopy, Inc. Metabolism of organic C1 compounds (compounds containing no carbon-carbon bonds) is an important part of the global carbon cycle. Methane has been recognized as one of the major C1 compounds in the environment and a major contributor to the greenhouse effect. While global emissions of other C1 compounds (methanol, methylated amines) have historically attracted less attention, recent models put their emissions on a scale similar to the scale of methane emissions. JGI plans to sequence three methylotrophs (degraders of C1 compounds) of the genus Methylotenera. Methylotrophic bacteria play a major role in maintaining the balance of C1

94

Oxygen Carriers for Solid Fuel Chemical Looping Combustion Process  

This patent-pending technology, “Regenerable Mixed Copper-Iron-Inert Support Oxygen Carriers for Solid Fuel Chemical Looping Combustion Process,” provides a metal-oxide oxygen carrier for application in fuel combustion processes that use oxygen.

95

Design optimization of oxygenated fluid pump  

E-Print Network (OSTI)

In medical emergencies, an oxygen-starved brain quickly suffers irreparable damage. In many cases, patients who stop breathing can be resuscitated but suffer from brain damage. Dr. John Kheir from Boston Children's Hospital ...

Piazzarolo, Bruno Aiala

2012-01-01T23:59:59.000Z

96

Permanent magnet hydrogen oxygen generating cells  

SciTech Connect

A generating cell for hydrogen and oxygen utilizes permanent magnets and electromagnets. Means are provided for removing gases from the electrodes. Mixing chambers are provided for water and the electrolyte used in the cell.

Harris, M.

1976-07-13T23:59:59.000Z

97

OXYGEN DIFFUSION IN HYPOSTOICHIOMETRIC URANIUM DIOXIDE  

E-Print Network (OSTI)

IN HYPOSTOICHIOMETRIC URANIUM DIOXIDE Kee Chul Kim Ph.D.727-366; Figure 1. Oxygen-uranium phase-equilibrium _ystem [18]. uranium dioxide powders and 18 0 enriched carbon

Kim, Kee Chul

2010-01-01T23:59:59.000Z

98

THE PATH OF OXYGEN IN PHOTOSYNTHESIS  

DOE Green Energy (OSTI)

An experiment is described in which an attempt is made to follow the path of oxygen in photosynthesis by the use of O{sup 18} as a tracer.

Dorough, G.D.; Calvin, M.

1950-03-31T23:59:59.000Z

99

Effects of oxygenate concentration on species mole fractions in premixed n-heptane flames  

E-Print Network (OSTI)

INAL* Department of Chemical Engineering, Izmir Institute of Technology, Gulbahce Koyu, 35437 Urla-Izmir

Senkan, Selim M.

100

Cells discover fire: Employing reactive oxygen species in development and consequences for aging  

E-Print Network (OSTI)

is requisite for breathing, $u%mox-tarjsurfactant is a complex mixture of proteins and lipids thar coats

Church, George M.

Note: This page contains sample records for the topic "oxygen species ros" 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

Rac1b and reactive oxygen species mediate MMP-3-induced EMT and genomic instability  

E-Print Network (OSTI)

. A. et al. Cell transformation by the superoxide-generating oxidase Mox1. Nature 401, 79­-82 (1999

Nelson, Celeste M.

102

Generation of reactive oxygen species by fungal NADPH oxidases is required for rice blast disease  

E-Print Network (OSTI)

utilizing all of the known techniques for NOx reduction. To be precise, the NOx formed within the flame] and several others [6, 7] have suggested certain reduction methods which are consistent with NOx formation, not solid waste. The results of NOx reduction techniques in coal combustion should be applied with caution

Talbot, Nicholas

103

Reactive oxygen species play a causal role in multiple forms of insulin resistance  

E-Print Network (OSTI)

Insulin resistance is a cardinal feature of type 2 diabetes and is characteristic of a wide range of other clinical and experimental settings. Little is known about why insulin resistance occurs in so many contexts. Do the ...

Houstis, Nicholas E

2007-01-01T23:59:59.000Z

104

Oxy-combustion: Oxygen Transport Membrane Development  

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

combustion: Oxygen Transport combustion: Oxygen Transport Membrane Development Background The mission of the U.S. Department of Energy's (DOE) 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 regulations. The EPEC R&D

105

Oxygen ion-conducting dense ceramic  

DOE Patents (OSTI)

Preparation, structure, and properties of mixed metal oxide compositions and their uses are described. Mixed metal oxide compositions of the invention have stratified crystalline structure identifiable by means of powder X-ray diffraction patterns. In the form of dense ceramic membranes, the present compositions demonstrate an ability to separate oxygen selectively from a gaseous mixture containing oxygen and one or more other volatile components by means of ionic conductivities.

Balachandran, Uthamalingam (Hinsdale, IL); Kleefisch, Mark S. (Plainfield, IL); Kobylinski, Thaddeus P. (Prospect, PA); Morissette, Sherry L. (Las Cruces, NM); Pei, Shiyou (Naperville, IL)

1998-01-01T23:59:59.000Z

106

Modern Records of Carbon and Oxygen Isotopes in Atmospheric Carbon...  

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

Modern Records of Carbon and Oxygen Isotopes in Atmospheric Carbon Dioxide and Carbon-13 in Methane Modern Records of Carbon and Oxygen Isotopes in Atmospheric Carbon Dioxide and...

107

Oxygen Nonstoichiometry, Thermo-chemical Stability and Crystal ...  

Science Conference Proceedings (OSTI)

... gas separation membranes and oxygen sensors, oxygen nonstoichiometry and crystal ... New Electric Current Effects on 8-Y Zirconia Ceramics: Pore/Bubble ...

108

Magnetism in Lithium–Oxygen Discharge Product  

SciTech Connect

Nonaqueous lithium–oxygen batteries have a much superior theoretical gravimetric energy density compared to conventional lithium-ion batteries, and thus could render long-range electric vehicles a reality. A molecular-level understanding of the reversible formation of lithium peroxide in these batteries, the properties of major/minor discharge products, and the stability of the nonaqueous electrolytes is required to achieve successful lithium–oxygen batteries. We demonstrate that the major discharge product formed in the lithium–oxygen cell, lithium peroxide, exhibits a magnetic moment. These results are based on dc-magnetization measurements and a lithium– oxygen cell containing an ether-based electrolyte. The results are unexpected because bulk lithium peroxide has a significant band gap. Density functional calculations predict that superoxide- type surface oxygen groups with unpaired electrons exist on stoichiometric lithium peroxide crystalline surfaces and on nanoparticle surfaces; these computational results are consistent with the magnetic measurement of the discharged lithium peroxide product as well as EPR measurements on commercial lithium peroxide. The presence of superoxide-type surface oxygen groups with spin can play a role in the reversible formation and decomposition of lithium peroxide as well as the reversible formation and decomposition of electrolyte molecules.

Lu, Jun; Jung, Hun-Ji; Lau, Kah Chun; Zhang, Zhengcheng; Schlueter, John A.; Du, Peng; Assary, Rajeev S.; Greeley, Jeffrey P.; Ferguson, Glen A.; Wang, Hsien-Hau; Hassoun, Jusef; Iddir, Hakim; Zhou, Jigang; Zuin, Lucia; Hu, Yongfeng; Sun, Yang-Kook; Scrosati, Bruno; Curtiss, Larry A.; Amine, Khalil

2013-05-13T23:59:59.000Z

109

Underground coal gasification using oxygen and steam  

Science Conference Proceedings (OSTI)

In this paper, through model experiment of the underground coal gasification, the effects of pure oxygen gasification, oxygen-steam gasification, and moving-point gasification methods on the underground gasification process and gas quality were studied. Experiments showed that H{sub 2} and CO volume fraction in product gas during the pure oxygen gasification was 23.63-30.24% and 35.22-46.32%, respectively, with the gas heating value exceeding 11.00 MJ/m{sup 3}; under the oxygen-steam gasification, when the steam/oxygen ratio stood at 2: 1, gas compositions remained virtually stable and CO + H{sub 2} was basically between 61.66 and 71.29%. Moving-point gasification could effectively improve the changes in the cavity in the coal seams or the effects of roof inbreak on gas quality; the ratio of gas flowing quantity to oxygen supplying quantity was between 3.1:1 and 3.5:1 and took on the linear changes; on the basis of the test data, the reasons for gas quality changes under different gasification conditions were analyzed.

Yang, L.H.; Zhang, X.; Liu, S. [China University of Mining & Technology, Xuzhou (China)

2009-07-01T23:59:59.000Z

110

Transient responses of nitrogenase to acetylene and oxygen in actinorhizal nodules and cultured Frania  

Science Conference Proceedings (OSTI)

Nitrogenase activity in root nodules of four species of actinorhizal plants showed varying declines in response to exposure to acetylene (10% v/v). Gymnostoma papuanum (S.Moore) L. Johnson. and Casuarina equisetifolia L. nodules showed a small decline (5-15%) with little or no recovery over 15 minutes. Myrica gale L. nodules showed a sharp decline followed by a rapid return to peak activity. Alnus incana ssp. rugosa (Du Roi) Clausen. nodules usually showed varying degrees of decline followed by a slower return to peak or near-peak activity. We call these effects acetylene-induced transients. Rapid increases in oxygen tension also caused dramatic transient decreases in nitrogenase activity in all species. The magnitude of the transient decrease was related to the size of the O{sub 2} partial pressure (pO{sub 2}) rise, to the proximity of the starting and ending oxygen tensions to the pO{sub 2} optimum, and to the time for which the plant was exposed to the lower pO{sub 2}. Oxygen-induced transients, induced both by step jumps in pO{sub 2} and by O{sub 2} pulses, were also observed in cultures of Frankia. The effects seen in nodules are purely a response by the bacterium and not a nodule effect per se. Oxygen-induced nitrogenase transients in actinorhizal nodules from the plant genera tested here do not appear to be a result of changes in nodule diffusion resistance.

Silvester, W.B.; Winship, L.J. (Harvard Univ., Petersham, MA (USA))

1990-02-01T23:59:59.000Z

111

Why Sequence a Thauera species?  

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

hydrogen, carbon dioxide, and oxygen, or using simple organic compounds for growth. The sequencing of Thauera sp. MZ1T will be an important contribution to the DOE systems...

112

Oxygen generator for medical applications (USIC)  

Science Conference Proceedings (OSTI)

The overall Project objective is to develop a portable, non-cryogenic oxygen generator capable of supplying medical grade oxygen at sufficient flow rates to allow the field application of the Topical Hyperbaric Oxygen Therapy (THOT{reg_sign}) developed by Numotech, Inc. This project was sponsored by the U.S. Department of Energy Global Initiatives for Proliferation Prevention (GIPP) and is managed by collaboration between Sandia National Laboratories (SNL), Numotech, Inc, and LLC SPE 'Spektr-Conversion.' The project had two phases, with the objective of Phase I being to develop, build and test a laboratory prototype of the membrane-pressure swing adsorber (PSA) system producing at 15 L/min of oxygen with a minimum of 98% oxygen purity. Phase II objectives were to further refine and identify the pre-requisites needed for a commercial product and to determine the feasibility of producing 15 L/min of oxygen with a minimum oxygen purity of 99%. In Phase I, Spektr built up the necessary infrastructure to perform experimental work and proceeded to build and demonstrate a membrane-PSA laboratory prototype capable of producing 98% purity oxygen at a flow rate of 5 L/min. Spektr offered a plausible path to scale up the process for 15 L/min. Based on the success and experimental results obtained in Phase I, Spektr performed work in three areas for Phase II: construction of a 15 L/min PSA; investigation of compressor requirements for the front end of the membrane/PSA system; and performing modeling and simulation of assess the feasibility of producing oxygen with a purity greater than 99%. Spektr successfully completed all of the tasks under Phase II. A prototype 15 L/min PSA was constructed and operated. Spektr determined that no 'off the shelf' air compressors met all of the specifications required for the membrane-PSA, so a custom compressor will likely need to be built. Modeling and simulation concluded that production of oxygen with purities greater than 99% was possible using a Membrane-PSA system.

Staiger, C. L.

2012-03-01T23:59:59.000Z

113

Why sequence psychrotolerant Acidithiobacillus species?  

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

techniques for such sites. Principal Investigators: Dopson, Mark Ume University Program: CSP 2010 Home > Sequencing > Why sequence psychrotolerant Acidithiobacillus species...

114

JGI - Why Sequence Polynucleobacter Species?  

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

Free-Living and Endosymbiotic Polynucleobacter Species? The Polynucleobacter group (Betaproteobacteria, Burkholderiaceae) is of enormous environmental relevance in freshwater...

115

Oxygen spectral line synthesis: 3D non-LTE with CO5BOLD hydrodynamical model atmospheres  

E-Print Network (OSTI)

In this work we present first results of our current project aimed at combining the 3D hydrodynamical stellar atmosphere approach with non-LTE (NLTE) spectral line synthesis for a number of key chemical species. We carried out a full 3D-NLTE spectrum synthesis of the oxygen IR 777 nm triplet, using a modified and improved version of our NLTE3D package to calculate departure coefficients for the atomic levels of oxygen in a CO5BOLD 3D hydrodynamical solar model atmosphere. Spectral line synthesis was subsequently performed with the Linfor 3D code. In agreement with previous studies, we find that the lines of the oxygen triplet produce deeper cores under NLTE conditions, due to the diminished line source function in the line forming region. This means that the solar oxygen IR 777 nm lines should be stronger in NLTE, leading to negative 3D NLTE-LTE abundance corrections. Qualitatively this result would support previous claims for a relatively low solar oxygen abundance. Finally, we outline several further steps ...

Prakapavicius, D; Kucinskas, A; Ludwig, H -G; Freytag, B; Caffau, E; Cayrel, R

2013-01-01T23:59:59.000Z

116

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

117

Oxygen scavengers - The chemistry of sulfite under hydrothermal conditions  

Science Conference Proceedings (OSTI)

Control of oxygen corrosion is critical to the reliability of steam generator systems. Mechanical deaeration and chemical oxygen scavenging effectively reduce oxygen levels in boiler feedwater systems. This paper reviews the use of sulfites to reduce oxygen and provide corrosion control throughout the boiler feedwater circuit as well as mechanical and operational oxygen reduction methods. The mechanism of oxygen pitting, electrochemical reactions, and the basis of operation of mechanical deaeration are discussed. Estimating techniques for the amount of steam required and a deaerator troubleshooting guide are included. The chemistry of sulfites is covered in detail. Also included are a functional definition of chemical oxygen scavengers and a general discussion of their various types.

Cotton, I.J.

1987-03-01T23:59:59.000Z

118

Direct Observation of Oxygen Superstructures in Manganites  

Science Conference Proceedings (OSTI)

We report the observation of superstructures associated with the oxygen 2p states in two prototypical manganites using x-ray diffraction at the oxygen K edge. In the stripe order system Bi{sub 0.31}Ca{sub 0.69}MnO{sub 3}, hole-doped O states are orbitally ordered, at the same propagation vector as the Mn orbital ordering, but no oxygen charge stripes are found at this periodicity. In La{sub 7/8}Sr{sub 1/8}MnO{sub 3}, we observe a 2p charge ordering described by alternating hole-poor and hole-rich MnO planes that is consistent with some of the recent predictions.

Grenier, S.; Tonnerre, J. M. [Institut Neel, CNRS and Universite Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9 (France); Thomas, K. J.; Hill, J. P. [Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Staub, U.; Bodenthin, Y.; Garcia-Fernandez, M. [Swiss Light Source, Paul Sherrer Institut, 5232 Villigen (Switzerland); Scagnoli, V. [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex 9 (France); Kiryukhin, V.; Cheong, S-W.; Kim, B. G. [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854 (United States)

2007-11-16T23:59:59.000Z

119

Electrolysis method for producing hydrogen and oxygen  

SciTech Connect

A novel electrolytic cell produces a mixture of highly ionized hydrogen and oxygen gases by a method combining electrolysis and radiolysis of an aqueous electrolyte. The electrolyte, which may be 25 percent of potassium hydroxide, is introduced into the cell and is simultaneously subjected to an electrolyting current and intense irradiation by electromagnetic radiation of frequency less than 10/sup -10/ meters.

Horvath, S.

1978-08-15T23:59:59.000Z

120

Novel Membranes and Processes for Oxygen Enrichment  

SciTech Connect

The overall goal of this project is to develop a membrane process that produces air containing 25-35% oxygen, at a cost of $25-40/ton of equivalent pure oxygen (EPO2). Oxygen-enriched air at such a low cost will allow existing air-fueled furnaces to be converted economically to oxygen-enriched furnaces, which in turn will improve the economic and energy efficiency of combustion processes significantly, and reduce the cost of CO{sub 2} capture and sequestration from flue gases throughout the U.S. manufacturing industries. During the 12-month Concept Definition project: We identified a series of perfluoropolymers (PFPs) with promising oxygen/nitrogen separation properties, which were successfully made into thin film composite membranes. The membranes showed oxygen permeance as high as 1,200 gpu and oxygen/nitrogen selectivity of 3.0, and the permeance and selectivity were stable over the time period tested (60 days). We successfully scaled up the production of high-flux PFP-based membranes, using MTR's commercial coaters. Two bench-scale spiral-wound modules with countercurrent designs were made and parametric tests were performed to understand the effect of feed flow rate and pressure, permeate pressure and sweep flow rate on the membrane module separation properties. At various operating conditions that modeled potential industrial operating conditions, the module separation properties were similar to the pure-gas separation properties in the membrane stamps. We also identified and synthesized new polymers [including polymers of intrinsic microporosity (PIMs) and polyimides] with higher oxygen/nitrogen selectivity (3.5-5.0) than the PFPs, and made these polymers into thin film composite membranes. However, these membranes were susceptible to severe aging; pure-gas permeance decreased nearly six-fold within two weeks, making them impractical for industrial applications of oxygen enrichment. We tested the effect of oxygen-enriched air on NO{sub x} emissions using a Bloom baffle burner at GTI. The results are positive and confirm that oxygen-enriched combustion can be carried out without producing higher levels of NOx than normal air firing, if lancing of combustion air is used and the excess air levels are controlled. A simple economic study shows that the membrane processes can produce O{sub 2} at less than $40/ton EPO{sub 2} and an energy cost of 1.1-1.5 MMBtu/ton EPO{sub 2}, which are very favorable compared with conventional technologies such as cryogenics and vacuum pressure swing adsorption processes. The benefits of integrated membrane processes/combustion process trains have been evaluated, and show good savings in process costs and energy consumption, as well as reduced CO{sub 2} emissions. For example, if air containing 30% oxygen is used in natural gas furnaces, the net natural gas savings are an estimated 18% at a burner temperature of 2,500 F, and 32% at a burner temperature of 3,000 F. With a 20% market penetration of membrane-based oxygen-enriched combustion in all combustion processes by 2020, the energy savings would be 414-736 TBtu/y in the U.S. The comparable net cost savings are estimated at $1.2-2.1 billion per year by 2020, calculated as the value of fuel savings subtracted from the cost of oxygen production. The fuel savings of 18%-32% by the membrane/oxygen-enriched combustion corresponds to an 18%-32% reduction in CO{sub 2} emissions, or 23-40 MM ton/y less CO{sub 2} from natural gas-fired furnaces by 2020. In summary, results from this project (Concept Definition phase) are highly promising and clearly demonstrate that membrane processes can produce oxygen-enriched air in a low cost manner that will lower operating costs and energy consumption in industrial combustion processes. Future work will focus on proof-of-concept bench-scale demonstration in the laboratory.

Lin, Haiqing

2011-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "oxygen species ros" 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

Kinetic Study of the Combustion of Phosphorus Containing Species  

DOE Green Energy (OSTI)

The combustion of organophosphorus compounds is of great interest for the incineration of chemical warfare agent and their use in flame inhibition as halon replacement. The thermochemical data of these species and the reactions involved at high temperature are not well known, despite some recent experimental studies. With BAC-MP4 ab initio estimations as a basis and semi-empirical estimations for many new compounds, the thermochemistry of organophosphorus compounds is studied. New group additivity values are proposed for enthalpies of formation at 298K, entropies and heat capacities of species involving pentavalent phosphorus bonded to carbon, hydrogen, oxygen, fluorine, nitrogen and sulfur atoms. The kinetic of unimolecular elimination is investigated by modeling pyrolysis experiments of DEMP, TEP and DIMP. A new combustion mechanism is described and applied to the modeling of DMMP reaction in a H{sub 2}/O{sub 2} flame.

Glaude, P.A.; Curran, H.J.; Pitz, W.J.; Westbrook, C.K.

1999-10-22T23:59:59.000Z

122

Probing Oxygen Activation Sites in Two Flavoprotein Oxidases Using Chloride as an Oxygen Surrogate  

SciTech Connect

A single basic residue above the si-face of the flavin ring is the site of oxygen activation in glucose oxidase (GOX) (His516) and monomeric sarcosine oxidase (MSOX) (Lys265). Crystal structures of both flavoenzymes exhibit a small pocket at the oxygen activation site that might provide a preorganized binding site for superoxide anion, an obligatory intermediate in the two-electron reduction of oxygen. Chloride binds at these polar oxygen activation sites, as judged by solution and structural studies. First, chloride forms spectrally detectable complexes with GOX and MSOX. The protonated form of His516 is required for tight binding of chloride to oxidized GOX and for rapid reaction of reduced GOX with oxygen. Formation of a binary MSOX-chloride complex requires Lys265 and is not observed with Lys265Met. Binding of chloride to MSOX does not affect the binding of a sarcosine analogue (MTA, methylthioactetate) above the re-face of the flavin ring. Definitive evidence is provided by crystal structures determined for a binary MSOX-chloride complex and a ternary MSOX-chloride-MTA complex. Chloride binds in the small pocket at a position otherwise occupied by a water molecule and forms hydrogen bonds to four ligands that are arranged in approximate tetrahedral geometry: Lys265:NZ, Arg49:NH1, and two water molecules, one of which is hydrogen bonded to FAD:N5. The results show that chloride (i) acts as an oxygen surrogate, (ii) is an effective probe of polar oxygen activation sites, and (iii) provides a valuable complementary tool to the xenon gas method that is used to map nonpolar oxygen-binding cavities.

Kommoju, Phaneeswara-Rao; Chen, Zhi-wei; Bruckner, Robert C.; Mathews, F. Scott; Jorns, Marilyn Schuman (Drexel-MED); (St. Louis-MED); (WU-MED)

2011-08-16T23:59:59.000Z

123

Oxygen transport by oxygen potential gradient in dense ceramic oxide membranes  

DOE Green Energy (OSTI)

Numerous studies have been conducted in recent years on the partial oxidation of methane to synthesis gas (syngas: CO + H{sub 2}) with air as the oxidant. In partial oxidation, a mixed-oxide ceramic membrane selectively transports oxygen from the air; this transport is driven by the oxygen potential gradient. Of the several ceramic materials the authors have tested, a mixed oxide based on the Sr-Fe-Co-O system has been found to be very attractive. Extensive oxygen permeability data have been obtained for this material in methane conversion experiments carried out in a reactor. The data have been analyzed by a transport equation based on the phenomenological theory of diffusion under oxygen potential gradients. Thermodynamic calculations were used to estimate the driving force for the transport of oxygen ions. The results show that the transport equation deduced from the literature describes the permeability data reasonably well and can be used to determine the diffusion coefficients and the associated activation energy of oxygen ions in the ceramic membrane material.

Maiya, P.S.; Balachandran, U.; Dusek, J.T.; Mieville, R.L. [Argonne National Lab., IL (United States). Energy Technology Div.; Kleefisch, M.S.; Udovich, C.A. [Amoco Exploration/Production, Naperville, IL (United States)

1996-05-01T23:59:59.000Z

124

Oxygen electrode in molten carbonate fuel cells  

DOE Green Energy (OSTI)

The oxygen reduction reaction on a gold electrode in lithium carbonate melt was investigated to determine the influence of partial pressure of carbon dioxide and temperature on electrode kinetics and oxygen solubility by using cyclic Voltammetry and impedance analysis techniques. During this quarter, the impedance data were analyzed by a Complex Nonlinear Least Square (CNLS) Parameter estimation program to determine the kinetic and the mass transfer related parameters such as charge transfer resistance, double layer capacitance, solution resistance, and Warburg coefficient. The estimated parameters were used to obtain the C0{sub 2} reaction orders and apparent activation energies for the exchange current density and the mass transfer parameter (D{sub o}{sup {1/2}}C{sub o}*).

Dave, B.B.; Srinivasan, S.; White, R.E.; Appleby, A.J.

1989-01-01T23:59:59.000Z

125

Electrical insulator assembly with oxygen permeation barrier  

DOE Patents (OSTI)

A high-voltage electrical insulator for electrically insulating a thermoelectric module in a spacecraft from a niobium-1% zirconium alloy wall of a heat exchanger filled with liquid lithium while providing good thermal conductivity between the heat exchanger and the thermoelectric module. The insulator has a single crystal alumina layer (SxAl[sub 2]O[sub 3], sapphire) with a niobium foil layer bonded thereto on the surface of the alumina crystal facing the heat exchanger wall, and a molybdenum layer bonded to the niobium layer to act as an oxygen permeation barrier to preclude the oxygen depleting effects of the lithium from causing undesirable niobium-aluminum intermetallic layers near the alumina-niobium interface. 3 figures.

Van Der Beck, R.R.; Bond, J.A.

1994-03-29T23:59:59.000Z

126

Electrical insulator assembly with oxygen permeation barrier  

DOE Patents (OSTI)

A high-voltage electrical insulator (21) for electrically insulating a thermoelectric module (17) in a spacecraft from a niobium-1% zirconium alloy wall (11) of a heat exchanger (13) filled with liquid lithium (16) while providing good thermal conductivity between the heat exchanger and the thermoelectric module. The insulator (21) has a single crystal alumina layer (SxAl.sub.2 O.sub.3, sapphire) with a niobium foil layer (32) bonded thereto on the surface of the alumina crystal (26) facing the heat exchanger wall (11), and a molybdenum layer (31) bonded to the niobium layer (32) to act as an oxygen permeation barrier to preclude the oxygen depleting effects of the lithium from causing undesirable niobium-aluminum intermetallic layers near the alumina-niobium interface.

Van Der Beck, Roland R. (Lansdale, PA); Bond, James A. (Exton, PA)

1994-01-01T23:59:59.000Z

127

On the reduction of oxygen from dispersed media  

E-Print Network (OSTI)

The reduction of oxygen from an organic phase dispersed in a concentrated electrolyte is investigated. Dispersed organic phases are used to enhance oxygen transport in fermenters and artificial blood substitutes. This work ...

Roushdy, Omar H., 1977-

2007-01-01T23:59:59.000Z

128

Application of Oxygen Eddy Correlation in Aquatic Systems  

Science Conference Proceedings (OSTI)

The eddy correlation technique is rapidly becoming an established method for resolving dissolved oxygen fluxes in natural aquatic systems. This direct and noninvasive determination of oxygen fluxes close to the sediment by simultaneously ...

Claudia Lorrai; Daniel F. McGinnis; Peter Berg; Andreas Brand; Alfred Wüest

2010-09-01T23:59:59.000Z

129

Analysis of Oxygenated Compounds in Hydrotreated Biomass Fast Pyrolysis Oil Distillate Fractions  

Science Conference Proceedings (OSTI)

Three hydrotreated bio-oils with different oxygen contents (8.2, 4.9, and 0.4 w/w) were distilled to produce Light, Naphtha, Jet, Diesel, and Gasoil boiling range fractions that were characterized for oxygen containing species by a variety of analytical methods. The bio-oils were originally generated from lignocellulosic biomass in an entrained-flow fast pyrolysis reactor. Analyses included elemental composition, carbon type distribution by {sup 13}C NMR, acid number, GC-MS, volatile organic acids by LC, and carbonyl compounds by DNPH derivatization and LC. Acid number titrations employed an improved titrant-electrode combination with faster response that allowed detection of multiple endpoints in many samples and for acid values attributable to carboxylic acids and to phenols to be distinguished. Results of these analyses showed that the highest oxygen content bio-oil fractions contained oxygen as carboxylic acids, carbonyls, aryl ethers, phenols, and alcohols. Carboxylic acids and carbonyl compounds detected in this sample were concentrated in the Light, Naphtha, and Jet fractions (oil or refinery intermediate streams may exist for the Diesel and Gasoil fractions. The 4.9 % oxygen sample contained almost exclusively phenolic compounds found to be present throughout the boiling range of this sample, but imparting measurable acidity primarily in the Light, Naphtha and Jet fractions. Additional study is required to understand what levels of the weakly acidic phenols could be tolerated in a refinery feedstock. The Diesel and Gasoil fractions from this upgraded oil had low acidity but still contained 3 to 4 wt% oxygen present as phenols that could not be specifically identified. These materials appear to have excellent potential as refinery feedstocks and some potential for blending into finished fuels. Fractions from the lowest oxygen content oil exhibited some phenolic acidity, but generally contained very low levels of oxygen functional groups. These materials would likely be suitable as refinery feedstocks and potentially as fuel blend components. PIONA analysis of the Light and Naphtha fractions shows benzene content of 0.5 and 0.4 vol%, and predicted (RON + MON)/2 of 63 and 70, respectively.

Christensen, Earl D.; Chupka, Gina; Luecke, Jon; Smurthwaite, Tricia D.; Alleman, Teresa L.; Iisa, Kristiina; Franz, James A.; Elliott, Douglas C.; McCormick, Robert L.

2011-10-06T23:59:59.000Z

130

Oxygen and hydrogen evolution reaction on oriented single crystals of ruthenium dioxide  

DOE Green Energy (OSTI)

A novel design for water electrolysis using a solid polymer electrolyte is being developed by General Electric. Ruthenium is one of the best electrocatalysts for the oxygen evolution reaction. There are problems connected with the significant loss in electrocatalytic activity with time. This performance degradation is presumably due to the gradual formation of an RuO/sub 2/ film. We have performed electrochemical measurements on (100), (110) and (111) oriented single crystals of RuO/sub 2/ in order to elucidate the mechanism of the electrocatalytic process. Large single crystals were grown by the vapor transport method. Our investigation has revealed several interesting differences for the various orientations. This study indicates that RuO/sub 3/ may be an important intermediate species prior to oxygen evolution and that the formation of the RuO/sub 3/ is the rate limiting process. Similar results were previously obtained for IrO/sub 2/.

Berger, L I; Pollak, F H; Canivez, Y; O'Grady, W

1979-01-01T23:59:59.000Z

131

Why Sequence Three Acidovorax Species?  

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

Three Acidovorax Species? Three Acidovorax Species? Intimate interactions between bacteria and eukaryotes have influenced the course of organismal evolution and ecological distribution. While ubiquitous, there is generally little understanding of the physiological basis of such associations, particularly when they are nonpathogenic in nature (symbiotic). Earthworms of the family Lumbricidae harbor novel symbiotic betaproteobacteria within their nephridia (excretory organ). Few symbiotic betaprotebacteria have been reported, and no other beneficial bacteria are described that specifically colonize the excretory organs of animals. To better understand the physiological and evolutionary dimensions of this symbiosis, JGI will sequence the genome of the isolated Acidovorax symbiont, and the genomes of two additional species within the genus: the

132

Probing brain oxygenation with near infrared spectroscopy  

E-Print Network (OSTI)

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

Gersten, Alexander; Raz, Amir; Fried, Robert

2011-01-01T23:59:59.000Z

133

DD4, Oxygen Plasma Exposure Effects on Indium Oxide Nanowire ...  

Science Conference Proceedings (OSTI)

Presentation Title, DD4, Oxygen Plasma Exposure Effects on Indium Oxide Nanowire ... Electronic Materials Science Challenges in Renewable Energy.

134

E.L. Grossman Chapter 10 Oxygen Isotope Stratigraphy  

E-Print Network (OSTI)

are the mineral and water respectively. Oxygen isotopic ratios are The Geologic Time Scale 2012. DOI: 10.1016/B978E.L. Grossman Chapter 10 Oxygen Isotope Stratigraphy Abstract:Variations in the 18 O/16 O ratios for global correlation. Relying on previous compilations and new data, this chapter presents oxygen isotope

Grossman, Ethan L.

135

Dilute Oxygen Combustion Phase IV Final Report  

Science Conference Proceedings (OSTI)

Novel furnace designs based on Dilute Oxygen Combustion (DOC) technology were developed under subcontract by Techint Technologies, Coraopolis, PA, to fully exploit the energy and environmental capabilities of DOC technology and to provide a competitive offering for new furnace construction opportunities. Capital cost, fuel, oxygen and utility costs, NOx emissions, oxide scaling performance, and maintenance requirements were compared for five DOC-based designs and three conventional air5-fired designs using a 10-year net present value calculation. A furnace direct completely with DOC burners offers low capital cost, low fuel rate, and minimal NOx emissions. However, these benefits do not offset the cost of oxygen and a full DOC-fired furnace is projected to cost $1.30 per ton more to operate than a conventional air-fired furnace. The incremental cost of the improved NOx performance is roughly $6/lb NOx, compared with an estimated $3/lb. NOx for equ8pping a conventional furnace with selective catalytic reduction (SCCR) technology. A furnace fired with DOC burners in the heating zone and ambient temperature (cold) air-fired burners in the soak zone offers low capital cost with less oxygen consumption. However, the improvement in fuel rate is not as great as the full DOC-fired design, and the DOC-cold soak design is also projected to cost $1.30 per ton more to operate than a conventional air-fired furnace. The NOx improvement with the DOC-cold soak design is also not as great as the full DOC fired design, and the incremental cost of the improved NOx performance is nearly $9/lb NOx. These results indicate that a DOC-based furnace design will not be generally competitive with conventional technology for new furnace construction under current market conditions. Fuel prices of $7/MMBtu or oxygen prices of $23/ton are needed to make the DOC furnace economics favorable. Niche applications may exist, particularly where access to capital is limited or floor space limitations are critical. DOC technology will continue to have a highly competitive role in retrofit applications requiring increases in furnace productivity.

Riley, M.F.

2003-04-30T23:59:59.000Z

136

Why sequence four Labyrinthulomycete species?  

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

sequence four Labyrinthulomycete species? sequence four Labyrinthulomycete species? These common marine microorganisms with the tongue-twisting name behave like fungi in the ocean ecosystem but are actually protists. Their abundance in the ocean varies with the changing seasons. They feed on non-living organic matter such as decaying algae, plants such as mangrove leaves and salt marsh grass or even animal tissues. Species that belong to the Labyrinthulomycete category all fall under a larger category of protists that also includes diatoms and brown algae. Labyrinthulomycetes help break down organic matter in the waters, and some species can also break down crude oil and tarballs. Researchers believe they also "upgrade" the quality of the debris that feed other marine organisms by adding nutrients. Long chain fatty acids produced by

137

NETL: Gasification - Development of Ion-Transport Membrane Oxygen  

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

Presentations, Papers, and Publications Presentations, Papers, and Publications ITM Oxygen Development for Advanced Oxygen Supply (Oct 2011) Ted Foster, Air Products & Chemicals, Inc. presented at the Gasification Technologies Conference, San Francisco, CA Oct 9-12, 2011. ASU/IGCC Integration Strategies (Oct 2009), David McCarthy, Air Products & Chemicals, Inc., 2009 Gasification Technologies Conference, Colorado Springs, CO. ITM Oxygen: Taking the Next Step (Oct 2009), VanEric Stein, Air Products & Chemicals, Inc., 2009 Gasification Technologies Conference, Colorado Springs, CO. ITM Oxygen: Scaling Up a Low-Cost Oxygen Supply Technology (Oct 2006) Philip Armstrong, Air Products & Chemicals, Inc., 2006 Gasification Technologies Conference, Washington, D.C. ITM Oxygen: The New Oxygen Supply for the New IGCC Market (Oct 2005)

138

(Selective carbon oxygen bond scission during reactions of oxygenates on single crystal catalysts)  

SciTech Connect

We have discovered that the carbon-oxygen bond in methanol can be selectively broken if the surface structure of the platinum catalyst is appropriately tailored. The objective of this project is to determine if variations in surface structure allow one to selectively break C-O and C-H bonds. The decomposition of a wide range of oxygenates on several carefully chosen faces of group VIII metals will be examined to see when C-O bond scission occurs and what new chemistry we can find on stepped surfaces.

1992-01-01T23:59:59.000Z

139

[Selective carbon oxygen bond scission during reactions of oxygenates on single crystal catalysts]. Progress report  

SciTech Connect

We have discovered that the carbon-oxygen bond in methanol can be selectively broken if the surface structure of the platinum catalyst is appropriately tailored. The objective of this project is to determine if variations in surface structure allow one to selectively break C-O and C-H bonds. The decomposition of a wide range of oxygenates on several carefully chosen faces of group VIII metals will be examined to see when C-O bond scission occurs and what new chemistry we can find on stepped surfaces.

1992-08-01T23:59:59.000Z

140

Oxygen stabilized zirconium-vanadium-iron alloy  

SciTech Connect

An oxygen stabilized intermetallic compound having the formula (Zr.sub.1-x Ti.sub.x).sub.2-u (V.sub.1-y Fe.sub.y)O.sub.z where x=0.0 to 0.9, y=0.01 to 0.9, z=0.25 to 0.5 and u=0 to 1. The compound is capable of reversibly sorbing hydrogen at temperatures from -196.degree. C. to 200.degree. C. at pressures down to 10.sup.-6 torr. The compound is suitable for use as a hydrogen getter in low pressure, high temperature applications such as magnetic confinement fusion devices.

Mendelsohn, Marshall H. (Woodridge, IL); Gruen, Dieter M. (Downers Grove, IL)

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxygen species ros" 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

Nongame and Endangered Species Conservation Act (Nebraska)  

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

The Game and Parks Commission is responsible for implementing and promulgating regulations to protect species named in the Endangered Species Act, as well as other endangered or threatened species...

142

Permeation of argon, carbon dioxide, helium, nitrogen and oxygen through Mylar windows  

SciTech Connect

In secondary beam lines in the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory, low mass vacuum windows are used to reduce background radiation near particle detectors. These windows are fabricated using Mylar films and are generally made as thin as possible. Mylar films as thin as 0.002 inch have been used as vacuum windows ranging in size up to 36 inch {times} 76 inch. When using Mylar for low mass window applications, permeation must be considered to achieve system design pressures. The permeation of several different gas species through both Mylar and aluminized Mylar films with thicknesses of 0.002`` and 0.005`` was studied. Testing was performed under high vacuum and a quadrupole mass spectrometer was used to identify and quantify gas species during the study. Permeability of argon, carbon dioxide, helium, nitrogen and oxygen were determined for Mylar from 20 up to 90C.

Mapes, M.; Hseuh, H.C.; Jiang, W.S.

1993-11-01T23:59:59.000Z

143

Oxygen Handling and Cooling Options in High Temperature Electrolysis Plants  

DOE Green Energy (OSTI)

Idaho National Laboratory is working on a project to generate hydrogen by high temperature electrolysis (HTE). In such an HTE system, safety precautions need to be taken to handle high temperature oxygen at ~830°C. This report is aimed at addressing oxygen handling in a HTE plant.. Though oxygen itself is not flammable, most engineering material, including many gases and liquids, will burn in the presence of oxygen under some favorable physicochemical conditions. At present, an absolute set of rules does not exist that can cover all aspects of oxygen system design, material selection, and operating practices to avoid subtle hazards related to oxygen. Because most materials, including metals, will burn in an oxygen-enriched environment, hazards are always present when using oxygen. Most materials will ignite in an oxygen-enriched environment at a temperature lower than that in air, and once ignited, combustion rates are greater in the oxygen-enriched environment. Even many metals, if ignited, burn violently in an oxygen-enriched environment. However, these hazards do not preclude the operations and systems involving oxygen. Oxygen can be safely handled and used if all the materials in a system are not flammable in the end-use environment or if ignition sources are identified and controlled. In fact, the incidence of oxygen system fires is reported to be low with a probability of about one in a million. This report is a practical guideline and tutorial for the safe operation and handling of gaseous oxygen in high temperature electrolysis system. The intent is to provide safe, practical guidance that permits the accomplishment of experimental operations at INL, while being restrictive enough to prevent personnel endangerment and to provide reasonable facility protection. Adequate guidelines are provided to govern various aspects of oxygen handling associated with high temperature electrolysis system to generate hydrogen. The intent here is to present acceptable oxygen standards and practices for minimum safety requirements. A summary of operational hazards, along with oxygen safety and emergency procedures, are provided.

Manohar S. Sohal; J. Stephen Herring

2008-07-01T23:59:59.000Z

144

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. Noble, J.

2009-10-01T23:59:59.000Z

145

Species Information System (SIS) | Data.gov  

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

Ocean Data Species Information System (SIS) Dataset Summary Description The Species Information System (SIS) consists of a web-enabled database (login required) and a public...

146

Efficiency evaluation of oxygen enrichment in energy conversion processes  

SciTech Connect

The extent to which energy conversion efficiencies can be increased by using oxygen or oxygen-enriched air for combustion was studied. Combustion of most fuels with oxygen instead of air was found to have five advantages: increases combustion temperature and efficiency, improves heat transfer at high temperatures, reduces nitrous oxide emissions, permits a high ration of exhaust gas recirculation and allows combustion of certain materials not combustible in air. The same advantages, although to a lesser degree, are apparent with oxygen-enriched air. The cost-effectiveness of the process must necessarily be improved by about 10% when using oxygen instead of air before such use could become justifiable on purely economic terms. Although such a modest increase appears to be attainable in real situations, this study ascertained that it is not possible to generally assess the economic gains. Rather, each case requires its own evaluation. For certain processes industry has already proven that the use of oxygen leads to more efficient plant operation. Several ideas for essentially new applications are described. Specifically, when oxygen is used with exhaust gas recirculation in external or internal combustion engines. It appears also that the advantages of pulse combustion can be amplified further if oxygen is used. When burning wet fuels with oxygen, direct steam generation becomes possible. Oxygen combustion could also improve processes for in situ gasification of coals, oil shales, peats, and other wet fuels. Enhanced oil recovery by fire flooding methods might also become more effective if oxygen is used. The cold energy contained in liquid oxygen can be substantially recovered in the low end of certain thermodynamic cycles. Further efforts to develop certain schemes for using oxygen for combustion appear to be justified from both the technical and economic viewpoints.

Bomelburg, H.J.

1983-12-01T23:59:59.000Z

147

Formation of Hydrogen, Oxygen, and Hydrogen Peroxide in Electron Irradiated Crystalline Water Ice  

E-Print Network (OSTI)

Water ice is abundant both astrophysically, for example in molecular clouds, and in planetary systems. The Kuiper belt objects, many satellites of the outer solar system, the nuclei of comets and some planetary rings are all known to be water-rich. Processing of water ice by energetic particles and ultraviolet photons plays an important role in astrochemistry. To explore the detailed nature of this processing, we have conducted a systematic laboratory study of the irradiation of crystalline water ice in an ultrahigh vacuum setup by energetic electrons holding a linear energy transfer of 4.3 +/- 0.1 keV mm-1. The irradiated samples were monitored during the experiment both on line and in situ via mass spectrometry (gas phase) and Fourier transform infrared spectroscopy (solid state). We observed the production of hydrogen and oxygen, both molecular and atomic, and of hydrogen peroxide. The likely reaction mechanisms responsible for these species are discussed. Additional formation routes were derived from the sublimation profiles of molecular hydrogen (90-140 K), molecular oxygen (147 -151 K) and hydrogen peroxide (170 K). We also present evidence on the involvement of hydroxyl radicals and possibly oxygen atoms as building blocks to yield hydrogen peroxide at low temperatures (12 K) and via a diffusion-controlled mechanism in the warming up phase of the irradiated sample.

Weijun Zheng; David Jewitt; Ralf I. Kaiser

2005-11-18T23:59:59.000Z

148

New Oxygen-Production Technology Proving Successful | Department of Energy  

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

Oxygen-Production Technology Proving Successful Oxygen-Production Technology Proving Successful New Oxygen-Production Technology Proving Successful April 22, 2009 - 1:00pm Addthis Washington, DC -- The Office of Fossil Energy's National Energy Technology Laboratory (NETL) has partnered with Air Products and Chemicals Inc. of Allentown, Penn. to develop the Ion Transport Membrane (ITM) Oxygen, a revolutionary new oxygen-production technology that requires less energy and offers lower capital costs than conventional technologies. ITM Oxygen will enhance the performance of integrated gasification combined cycle (IGCC) power plants, as well as other gasification-based processes. The technology will also enhance the economics of oxy-fired combustion technologies, making it an attractive option for the capture of carbon

149

Oxygen Atoms Display Novel Behavior on Common Catalyst  

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

11, 2008 11, 2008 Oxygen Atoms Display Novel Behavior on Common Catalyst Like waltzing dancers, the two atoms of an oxygen molecule usually behave identically when they separate on the surface of a catalyst. However, new research from the Environmental Molecular Sciences Laboratory reveals that on a particular catalyst, the oxygen atoms act like a couple dancing the tango: one oxygen atom plants itself while the other shimmies away, probably with energy partially stolen from the stationary one. Scientists from EMSL and Pacific Northwest National Laboratory discovered this unanticipated behavior while studying how oxygen interacts with reduced titanium oxide, a popular catalyst and a model oxide. Their research began with a slice of titanium oxide crystal, oriented so that titanium and oxygen

150

Regenerable Mixed Copper-Iron-Inert Support Oxygen Carriers  

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

Mixed Copper-Iron-Inert Support Oxygen Carriers Mixed Copper-Iron-Inert Support Oxygen Carriers for Solid Fuel Chemical Looping Combustion Process Contact NETL Technology Transfer Group techtransfer@netl.doe.gov December 2012 This patent-pending technology, "Regenerable Mixed Copper-Iron-Inert Support Oxygen Carriers for Solid Fuel Chemical Looping Combustion Process," provides a metal-oxide oxygen carrier for application in fuel combustion processes that use oxygen. This technology is available for licensing and/or further collaborative research with the U.S. Department of Energy's National Energy Technology Laboratory. Overview Patent Details U.S. Non-Provisional Patent Application No. 13/159,553; titled "Regenerable Mixed Copper-Iron-Inert Support Oxygen Carriers for Solid

151

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

152

It's Elemental - Isotopes of the Element Oxygen  

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

Nitrogen Nitrogen Previous Element (Nitrogen) The Periodic Table of Elements Next Element (Fluorine) Fluorine Isotopes of the Element Oxygen [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 16 99.757% STABLE 17 0.038% STABLE 18 0.205% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 12 1.139×10-21 seconds Proton Emission No Data Available 13 8.58 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 100.00% 14 70.620 seconds Electron Capture 100.00% 15 122.24 seconds Electron Capture 100.00% 16 STABLE - - 17 STABLE - - 18 STABLE - - 19 26.88 seconds Beta-minus Decay 100.00%

153

METHOD OF COMBINING HYDROGEN AND OXYGEN  

DOE Patents (OSTI)

A method is given for the catalytic recombination of radiolytic hydrogen and/or deulerium and oxygen resulting from the subjection or an aqueous thorium oxide or thorium oxide-uranium oxide slurry to ionizing radiation. An improved catalyst is prepared by providing paliadium nitrate in an aqueous thorium oxide sol at a concentration of at least 0.05 grams per gram of thorium oxide and contacting the sol with gaseous hydrogen to form flocculated solids. The solids are then recovered and added to the slurry to provide a palladium concentration of 100 to 1000 parts per million. Recombination is effected by the calalyst at a rate sufficient to support high nuclear reactor power densities. (AEC)

McBride, J.P.

1962-02-27T23:59:59.000Z

154

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.

155

Modeling the Oxygen - Hydrazine Reaction in PWR Secondary Feedwater  

Science Conference Proceedings (OSTI)

The proper control of oxygen in primary water reactor (PWR) secondary feedwater, using hydrazine, has been an enduring issue. The requirements on the oxygen concentration are partly opposing. Fully deoxygenated conditions in the steam generators are essential to minimize corrosion. On the other hand, some oxygen in the feedwater counteracts corrosion of carbon steel surfaces and the transport of corrosion products to the steam generators. Optimization is, therefore, essential. This work applies the frame...

2008-06-26T23:59:59.000Z

156

Dense ceramic membranes for partial oxygenation of methane  

DOE Green Energy (OSTI)

The most significant cost associated with partial oxidation of methane to syngas is that of the oxygen plant. In this paper, the authors offer a technology that is based on dense ceramic membranes and that uses air as the oxidant for methane-conversion reactions, thus eliminating the need for the oxygen plant. Certain ceramic materials exhibit both electronic and ionic conductivities (of particular interest is oxygen-ion conductivity). These materials transport not only oxygen ions (functioning as selective oxygen separators) but also electrons back from the reactor side to the oxygen/reduction interface. No external electrodes are required and if the driving potential of transport is sufficient, the partial oxidation reactions should be spontaneous. Such a system will operate without an externally applied potential. Oxygen is transported across the ceramic material in the form of oxygen anions, not oxygen molecules. In principle, the dense ceramic materials can be shaped into a hollow-tube reactor, with air passed over the outside of the membrane and methane through the inside. The membrane is permeable to oxygen at high temperatures, but not to nitrogen or any other gas. Long tubes of La-Sr-Fe-Co-O (SFC) membrane were fabricated by plastic extrusion, and thermal stability of the tubes was studied as a function of oxygen partial pressure by high-temperature XRD. Mechanical properties were measured and found to be acceptable for a reactor material. Fracture of certain SFC tubes was the consequence of an oxygen gradient that introduced a volumetric lattice difference between the inner and outer walls. However, tubes made with a particular stoichiometry (SFC-2) provided methane conversion efficiencies of >99% in a reactor. Some of the reactor tubes have operated for up to {approx} 1,000 h.

Balachandran, U.; Dusek, J.T.; Sweeney, S.M.; Mieville, R.L.; Maiya, P.S. [Argonne National Lab., IL (United States). Energy Technology Div.; Kleefisch, M.S.; Pei, S.; Kobylinski, T.P. [Amoco Research Center, Naperville, IL (United States); Bose, A.C. [USDOE Pittsburgh Energy Technology Center, PA (United States)

1994-05-01T23:59:59.000Z

157

Dilute Oxygen Combustion - Phase 3 Report  

Science Conference Proceedings (OSTI)

Dilute Oxygen Combustion (DOC) burners have been successfully installed and operated in the reheat furnace at Auburn Steel Co., Inc., Auburn, NY, under Phase 3 of the Dilute Oxygen Combustion project. Two new preheat zones were created employing a total of eight 6.5 MMBtu/hr capacity burners. The preheat zones provide a 30 percent increase in maximum furnace production rate, from 75 tph to 100 tph. The fuel rate is essentially unchanged, with the fuel savings expected from oxy-fuel combustion being offset by higher flue gas temperatures. When allowance is made for the high nitrogen level and high gas phase temperature in the furnace, measured NOx emissions are in line with laboratory data on DOC burners developed in Phase 1 of the project. Burner performance has been good, and there have been no operating or maintenance problems. The DOC system continues to be used as part of Auburn Steel's standard reheat furnace practice. High gas phase temperature is a result of the high firing density needed to achieve high production rates, and little opportunity exists for improvement in that area. However, fuel and NOx performance can be improved by further conversion on furnace zones to DOC burners, which will lower furnace nitrogen levels. Major obstacles are cost and concern about increased formation of oxide scale on the steel. Oxide scale formation may be enhanced by exposure of the steel to higher concentrations of oxidizing gas components (primarily products of combustion) in the higher temperature zones of the furnace. Phase 4 of the DOC project will examine the rate of oxide scale formation in these higher temperature zones and develop countermeasures that will allow DOC burners to be used successfully in these furnace zones.

Riley, Michael F.

2000-05-31T23:59:59.000Z

158

Dilute Oxygen Combustion Phase 3 Final Report  

SciTech Connect

Dilute Oxygen Combustion (DOC) burners have been successfully installed and operated in the reheat furnace at Auburn Steel Co., Inc., Auburn, NY, under Phase 3 of the Dilute Oxygen Combustion project. Two new preheat zones were created employing a total of eight 6.5 MMBtu/hr capacity burners. The preheat zones provide a 30 percent increase in maximum furnace production rate, from 75 tph to 100 tph. The fuel rate is essentially unchanged, with the fuel savings expected from oxy-fuel combustion being offset by higher flue gas temperatures. When allowance is made for the high nitrogen level and high gas phase temperature in the furnace, measured NOx emissions are in line with laboratory data on DOC burners developed in Phase 1 of the project. Burner performance has been good and there have been no operating or maintenance problems. The DOC system continues to be used as part of Auburn Steel?s standard reheat furnace practice. High gas phase temperature is a result of the high firing density needed to achieve high production rates, and little opportunity exists for improvement in that area. However, fuel and NOx performance can be improved by further conversion of furnace zones to DOC burners, which will lower furnace nitrogen levels. Major obstacles are cost and concern about increased formation of oxide scale on the steel. Oxide scale formation may be enhanced by exposure of the steel to higher concentrations of oxidizing gas components (primarily products of combustion) in the higher temperature zones of the furnace. Phase 4 of the DOC project will examine the rate of oxide scale formation in these higher temperature zones and develop countermeasures that will allow DOC burners to be used successfully in these furnace zones.

Riley, M.F.; Ryan, H.M.

2000-05-31T23:59:59.000Z

159

Oxygen Isotope Evidence For Past And Present Hydrothermal Regimes...  

Open Energy Info (EERE)

oxygen isotope compositions of cores and cuttings from Long Valley exploration wells show that the Bishop Tuff has been an important reservoir for both fossil and active...

160

Causes for the Ferromagnetism in Oxygen-Deficient Perovskite ...  

Science Conference Proceedings (OSTI)

Symposium, Multifunctional Oxides. Presentation Title, Causes for the Ferromagnetism in Oxygen-Deficient Perovskite Sr3YCo4O10+d and the Ultrafast Redox ...

Note: This page contains sample records for the topic "oxygen species ros" from the National Library of EnergyBeta (NLEBeta).
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161

Molecular oxygen sensors based on photoluminescent silica aerogels  

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

Molecular oxygen sensors based on photoluminescent silica aerogels Molecular oxygen sensors based on photoluminescent silica aerogels Title Molecular oxygen sensors based on photoluminescent silica aerogels Publication Type Journal Article Year of Publication 1998 Authors Ayers, Michael R., and Arlon J. Hunt Journal Journal of Non-Crystalline Solids Volume 225 Pagination 343-347 Keywords aerogel, air pressure, oxygen concentration, oxygen molecules, photoluminescence Abstract Photoluminescent silica aerogel acts as the active element of an optical sensor for molecular oxygen. The luminescent aerogel is prepared by the action of energized reducing gases on a standard silica aerogel. Intensity of aerogel photoluminescence decreases as the collision frequency between oxygen molecules and the luminescent carriers in the aerogel matrix increases. This behavior is a characteristic of many photoluminescent materials and arises from a transfer of energy from the aerogel to surrounding oxygen molecules. A sensor for oxygen concentration or air pressure can therefore be simply constructed utilizing an ultraviolet source for excitation and a suitable detector for the emitted visible signal. Stern-Volmer quenching constants for the aerogel sensing element are 1.55×10-2 Torr-1 for hydrophilic aerogel and 2.4×10-3 Torr-1 for hydrophobic aerogel.

162

Development of Ion Transport Membrane (ITM) Oxygen Technology...  

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

Ion Transport Membrane (ITM) Oxygen Technology for Integration in IGCC and Other Advanced Power Generation Systems Background The Gasification Technologies Program at the National...

163

Calorimetric Investigation of the Lithium–Manganese–Oxygen ...  

Science Conference Proceedings (OSTI)

Presentation Title, Calorimetric Investigation of the Lithium–Manganese–Oxygen Cathode Material System for Lithium Ion Batteries. Author(s), Damian M. Cupid, ...

164

Optimization of Oxygen Purity for Coal Conversion Energy Reduction  

E-Print Network (OSTI)

The conversion of coal into gaseous and liquid fuels and chemical feedstock will require large quantities of oxygen. This oxygen will be produced in large multi-train air separation plants which will consume about 350 kilowatt hours of energy for each ton of coal processed. Thus, the oxygen plants in a commercial coal conversion facility may require 150 megawatts. Design of the oxygen plants will require close attention to energy consumption. Many coal conversion processes can accept oxygen at less than the historical 99.5% purity with significant savings in energy and cost. The air separation process is reviewed with emphasis on optimum oxygen purity. An energy reduction of 8.4% can be achieved when oxygen purity is reduced from 99.5% to 95%. Oxygen is a major tonnage chemical which is also highly energy intensive. The current United States capacity of about 80 thousand tons per day places it in the top five of basic chemicals, and its energy requirement of 350 to 450 kilowatt hours per ton makes it a major energy consumer. The growing synfuels industry -- conversion of coal into hydrocarbon fuels and chemical feed-stocks -- will greatly increase the production of oxygen and presents major opportunities for energy conservation.

Baker, C. R.; Pike, R. A.

1982-01-01T23:59:59.000Z

165

Regenerable Mixed Copper-Iron-Inert Support Oxygen ...  

Regenerable Mixed Copper-Iron-Inert Support Oxygen Carriers for Solid Fuel Chemical Looping Combustion Process Contact NETL Technology Transfer Group

166

Microbial metatranscriptomics in a permanent marine oxygen minimum zone  

E-Print Network (OSTI)

Simultaneous characterization of taxonomic composition, metabolic gene content and gene expression in marine oxygen minimum zones (OMZs) has potential to broaden perspectives on the microbial and biogeochemical dynamics ...

Stewart, Frank J.

167

Effect of Dopants on Interdiffusion of Aluminum and Oxygen through ...  

Science Conference Proceedings (OSTI)

In this study, the mutual GB transport of aluminum and oxygen in RE-doped polycrystalline ... Secondary Transport Phenomena in Ceramic Membranes under ...

168

First-Principles Study of the Oxygen Evolution Reaction and ...  

Science Conference Proceedings (OSTI)

In this talk, we present our study of the mechanisms of the oxygen evolution reaction (OER) ... Secondary Transport Phenomena in Ceramic Membranes under ...

169

Oxygen Consumption Analysis for Life Prediction of Elastomers  

Science Conference Proceedings (OSTI)

Presentation Title, Oxygen Consumption Analysis for Life Prediction of Elastomers. Author(s), Elizabeth Hoffman, T. Eric Skidmore, Donald L Fisher, William L ...

170

Detailed chemical kinetic modeling of diesel combustion with oxygenated fuels  

DOE Green Energy (OSTI)

The influence of oxygenated hydrocarbons as additives to diesel fuels on ignition, NOx emissions and soot production has been examined using a detailed chemical kinetic reaction mechanism. N-heptane was used as a representative diesel fuel, and methanol, ethanol, dimethyl ether and dimethoxymethane were used as oxygenated fuel additives. It was found that addition of oxygenated hydrocarbons reduced NOx levels and reduced the production of soot precursors. When the overall oxygen content in the fuel reached approximately 25% by mass, production of soot precursors fell effectively to zero, in agreement with experimental studies. The kinetic factors responsible for these observations are discussed.

Pitz, W J; Curran, H J; Fisher, E; Glaude, P A; Marinov, N M; Westbrook, C K

1999-10-28T23:59:59.000Z

171

ORNL-grown oxygen 'sponge' presents path to better catalysts...  

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

presents path to better catalysts, energy materials This schematic depicts a new ORNL-developed material that can easily absorb or shed oxygen atoms. This schematic depicts...

172

Oxygen Exchange Kinetics on SOFC Cathode Materials: Importance ...  

Science Conference Proceedings (OSTI)

Presentation Title, Oxygen Exchange Kinetics on SOFC Cathode Materials: Importance of Ionic and Electronic Carriers. Author(s), Rotraut Merkle, Lei Wang,

173

NETL: Novel Oxygen Carriers for Coal-Fueled Chemical Looping...  

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

Chemical Looping Combustion Project No.: DE-FE0001808 NETL has partnered with Western Kentucky University to develop a series of advanced oxygen carriers for coal-fueled...

174

Exploring similarities among many species distributions  

Science Conference Proceedings (OSTI)

Collecting species presence data and then building models to predict species distribution has been long practiced in the field of ecology for the purpose of improving our understanding of species relationships with each other and with the environment. ... Keywords: HPC, parallel processing, species distribution modeling

Scott Simmerman; Jingyuan Wang; James Osborne; Kimberly Shook; Jian Huang; William Godsoe; Theodore Simons

2012-07-01T23:59:59.000Z

175

HERSCHEL MEASUREMENTS OF MOLECULAR OXYGEN IN ORION  

Science Conference Proceedings (OSTI)

We report observations of three rotational transitions of molecular oxygen (O{sub 2}) in emission from the H{sub 2} Peak 1 position of vibrationally excited molecular hydrogen in Orion. We observed the 487 GHz, 774 GHz, and 1121 GHz lines using the Heterodyne Instrument for the Far Infrared on the Herschel Space Observatory, having velocities of 11 km s{sup -1} to 12 km s{sup -1} and widths of 3 km s{sup -1}. The beam-averaged column density is N(O{sub 2}) = 6.5 x 10{sup 16} cm{sup -2}, and assuming that the source has an equal beam-filling factor for all transitions (beam widths 44, 28, and 19''), the relative line intensities imply a kinetic temperature between 65 K and 120 K. The fractional abundance of O{sub 2} relative to H{sub 2} is (0.3-7.3) x 10{sup -6}. The unusual velocity suggests an association with a {approx}5'' diameter source, denoted Peak A, the Western Clump, or MF4. The mass of this source is {approx}10 M{sub sun} and the dust temperature is {>=}150 K. Our preferred explanation of the enhanced O{sub 2} abundance is that dust grains in this region are sufficiently warm (T {>=} 100 K) to desorb water ice and thus keep a significant fraction of elemental oxygen in the gas phase, with a significant fraction as O{sub 2}. For this small source, the line ratios require a temperature {>=}180 K. The inferred O{sub 2} column density {approx_equal}5 x 10{sup 18} cm{sup -2} can be produced in Peak A, having N(H{sub 2}) {approx_equal} 4 x 10{sup 24} cm{sup -2}. An alternative mechanism is a low-velocity (10-15 km s{sup -1}) C-shock, which can produce N(O{sub 2}) up to 10{sup 17} cm{sup -2}.

Goldsmith, Paul F.; Chen, Jo-Hsin; Li Di [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Liseau, Rene; Black, John H. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden); Bell, Tom A. [Centro de Astrobiologia, CSIC-INTA, 28850 Madrid (Spain); Hollenbach, David [SETI Institute, Mountain View, CA 94043 (United States); Kaufman, Michael J. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Lis, Dariusz C. [California Institute of Technology, Cahill Center for Astronomy and Astrophysics 301-17, Pasadena, CA 91125 (United States); Melnick, Gary [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 66, Cambridge, MA 02138 (United States); Neufeld, David [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Pagani, Laurent; Encrenaz, Pierre [LERMA and UMR8112 du CNRS, Observatoire de Paris, 61 Av. de l'Observatoire, 75014 Paris (France); Snell, Ronald [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Benz, Arnold O.; Bruderer, Simon [Institute of Astronomy, ETH Zurich, Zurich (Switzerland); Bergin, Edwin [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Caselli, Paola [School of Physics and Astronomy, University of Leeds, Leeds (United Kingdom); Caux, Emmanuel [Universite de Toulouse, UPS-OMP, IRAP, Toulouse (France); Falgarone, Edith, E-mail: Paul.F.Goldsmith@jpl.nasa.gov [LRA/LERMA, CNRS, UMR8112, Observatoire de Paris and Ecole Normale Superieure, 24 rue Lhomond, 75231 Paris Cedex 05 (France)

2011-08-20T23:59:59.000Z

176

Palladium-cobalt particles as oxygen-reduction electrocatalysts  

DOE Patents (OSTI)

The present invention relates to palladium-cobalt particles useful as oxygen-reducing electrocatalysts. The invention also relates to oxygen-reducing cathodes and fuel cells containing these palladium-cobalt particles. The invention additionally relates to methods for the production of electrical energy by using the palladium-cobalt particles of the invention.

Adzic, Radoslav (East Setauket, NY); Huang, Tao (Manorville, NY)

2009-12-15T23:59:59.000Z

177

Device for measuring the total concentration of oxygen in gases  

DOE Patents (OSTI)

This invention provides a CO equilibrium in a device for measuring the total concentration of oxygen impurities in a fluid stream. To this end, the CO equilibrium is produced in an electrochemical measuring cell by the interaction of a carbon element in the cell with the chemically combined and uncombined oxygen in the fluid stream at an elevated temperature.

Isaacs, Hugh S. (Shoreham, NY); Romano, Anthony J. (Kings Park, NY)

1977-01-01T23:59:59.000Z

178

Effect of Feedwater Oxygen Control at the Vermont Yankee BWR  

Science Conference Proceedings (OSTI)

Tests in an operating BWR show that routine injection of oxygen into the feedwater to control radiation buildup is not warranted under normal operating conditions. However, since oxygen injection reduces the nickel release rate, it might be considered on a plant-by-plant basis for BWRs experiencing high nickel corrosion levels.

1985-08-02T23:59:59.000Z

179

Maintaining and Monitoring Dissolved Oxygen at Hydroelectric Projects: Status Report  

Science Conference Proceedings (OSTI)

This report is an update of EPRI's 1990 report, "Assessment and Guide for Meeting Dissolved Oxygen Water Quality Standards for Hydroelectric Plant Discharges" (GS-7001). The report provides an updated review of technologies and techniques for enhancing dissolved oxygen (DO) levels in reservoirs and releases from hydroelectric projects and state-of-the-art methods, equipment, and techniques for monitoring DO.

2002-05-28T23:59:59.000Z

180

Photolithographic patterning of polymer-encapsulated optical oxygen sensors  

Science Conference Proceedings (OSTI)

In this paper we show a novel fabrication process capable of yielding arbitrarily-shaped optical oxygen sensor patterns at micron resolution. The wafer-level process uses a thin-film sacrificial metal layer as intermediate mask, protecting the sensor ... Keywords: Optical oxygen sensor, Photolithography, PtOEPK/PS, Sensor patterning

Volker Nock; Maan Alkaisi; Richard J. Blaikie

2010-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxygen species ros" 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

NETL: News Release - New Oxygen-Production Technology Proving Successful  

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

22, 2009 22, 2009 New Oxygen-Production Technology Proving Successful Ceramic Membrane Enables Efficient, Cost-Effective Co-Production of Power and Oxygen Washington, D.C. -The Office of Fossil Energy's National Energy Technology Laboratory (NETL) has partnered with Air Products and Chemicals Inc. of Allentown, Penn. to develop the Ion Transport Membrane (ITM) Oxygen, a revolutionary new oxygen-production technology that requires less energy and offers lower capital costs than conventional technologies. ITM Oxygen will enhance the performance of integrated gasification combined cycle (IGCC) power plants, as well as other gasification-based processes. The technology will also enhance the economics of oxy-fired combustion technologies, making it an attractive option for the capture of carbon dioxide from existing coal-fired power plants.

182

Isolation and Identification of Nitrogen Species in Jet Fuel and Diesel Fuel  

Science Conference Proceedings (OSTI)

Many performance characteristics of liquid fuels-including lubricity, the ability to swell seal materials, storage stability, and thermal stability-are determined, to a large degree, by the trace polar species that the fuel contains. Because the polar fraction comprises such a small portion of the fuel matrix, it is difficult to detect these species without first isolating them from the bulk fuel. This manuscript describes the extension of previous work that established a protocol for the isolation and identification of oxygenates in jet fuels. The current work shows that a liquid-liquid extraction using methanol, followed by an isolation step using high-performance liquid chromatography (HPLC) with a silica column, can successfully separate polar nitrogen-containing species from the fuel, in addition to separating oxygenates. The analytical protocol further isolates the polar target species using a polar capillary gas chromatography (GC) column and a nontraditional oven heating program. The method is amenable to milliliter quantitites of fuel samples and produces a matrix that can be analyzed directly, using typical GC methods. The method was evaluated using spiked surrogate fuels, as well as actual petroleum-derived jet fuel samples. Furthermore, it is shown that the method also can be extended for use on diesel fuels.

Link, D.D.; Baltrus, J.P.; Zandhuis, P.H.

2007-05-01T23:59:59.000Z

183

Isolation and Identification of Nitrogen Species in Jet Fuel and Diesel Fuel  

Science Conference Proceedings (OSTI)

Many performance characteristics of liquid fuels--including lubricity, the ability to swell seal materials, storage stability, and thermal stability--are determined, to a large degree, by the trace polar species that the fuel contains. Because the polar fraction comprises such a small portion of the fuel matrix, it is difficult to detect these species without first isolating them from the bulk fuel. This manuscript describes the extension of previous work that established a protocol for the isolation and identification of oxygenates in jet fuels. The current work shows that a liquid-liquid extraction using methanol, followed by an isolation step using high-performance liquid chromatography (HPLC) with a silica column, can successfully separate polar nitrogen-containing species from the fuel, in addition to separating oxygenates. The analytical protocol further isolates the polar target species using a polar capillary gas chromatography (GC) column and a nontraditional oven heating program. The method is amenable to milliliter quantitites of fuel samples and produces a matrix that can be analyzed directly, using typical GC methods. The method was evaluated using spiked surrogate fuels, as well as actual petroleum-derived jet fuel samples. Furthermore, it is shown that the method also can be extended for use on diesel fuels.

Link, D.D.; Baltrus, J.P.; Zandhuis, P.H.

2007-05-01T23:59:59.000Z

184

Oxygen and organic matter thresholds for benthic faunal activity on the Pakistan margin oxygen minimum zone (7001100 m)  

E-Print Network (OSTI)

Oxygen and organic matter thresholds for benthic faunal activity on the Pakistan margin oxygen) on the bathyal Pakistan margin, where sediments grade from fully laminated sediment at 700 m (0.12 mL LÃ?1 O2 [5 m matter to generate abrupt faunal transitions on the Pakistan margin. & 2008 Elsevier Ltd. All rights

Levin, Lisa

185

Oxygen lines in solar granulation. I. Testing 3D models against new observations with high spatial and spectral resolution  

E-Print Network (OSTI)

Aims: we seek to provide additional tests of the line formation of theoretical 3D solar photosphere models. In particular, we set out to test the spatially-resolved line formation at several viewing angles, from the solar disk-centre to the limb and focusing on atomic oxygen lines. The purpose of these tests is to provide additional information on whether the 3D model is suitable to derive the solar oxygen abundance. We also aim to empirically constrain the NLTE recipes for neutral hydrogen collisions, using the spatially-resolved observations of the OI 777 nm lines. Methods: using the Swedish 1-m Solar Telescope we obtained high-spatial-resolution observations of five atomic oxygen lines (along with lines for other species) for five positions on the solar disk. These observations have a high spatial and spectral resolution, and a continuum intensity contrast up to 9% at 615 nm. The theoretical line profiles were computed using the 3D model, with a full 3D NLTE treatment for oxygen and LTE for the other lines...

Pereira, Tiago M D; Asplund, Martin

2009-01-01T23:59:59.000Z

186

Trace species emissions for IGFC  

SciTech Connect

The objectives of this investigation are to study both the fate and distribution of at least five significant, coal-derived trace elements commonly present in coal-gas, in terms of their vaporization during gasification, their condensation and sorption during hot-gas cleanup, as well as their effects on fuel cells, gas turbines, and ultimately the environment. The definition here of trace does not include the major contaminants of sulfur and chlorine, etc., although the simultaneous presence of such major species is always considered in our thermochemical calculations. Of course, many other elements can vaporize in trace quantities from raw coal as either volatile, molecular compounds or as metallic vapors which, besides their deleterious action on the energy conversion systems, can also be detrimental to plant and animal life when emitted into the atmosphere. Hence, an understanding is sought of how the type and quantity of significant trace species in coal-gas changes from the coal pile through cleanup subsystems and the electric generators to the exhaust stack of an integrated system.

Pigeaud, A.E.; Helble, J.J.

1994-10-01T23:59:59.000Z

187

Narrowing the estimates of species migration rates  

E-Print Network (OSTI)

of species migration rates How fast can species migrate?estimate population growth rates for each population sinceon their data 1 show that the rate of population spread is

Blois, Jessica L.

2013-01-01T23:59:59.000Z

188

Interactions of Oxygen and Hydrogen on Pd(111) surface  

DOE Green Energy (OSTI)

The coadsorption and interactions of oxygen and hydrogen on Pd(1 1 1) was studied by scanning tunneling microscopy and density functional theory calculations. In the absence of hydrogen oxygen forms a (2 x 2) ordered structure. Coadsorption of hydrogen leads to a structural transformation from (2 x 2) to a ({radical}3 x {radical}3)R30 degree structure. In addition to this transformation, hydrogen enhances the mobility of oxygen. To explain these observations, the interaction of oxygen and hydrogen on Pd(1 1 1) was studied within the density functional theory. In agreement with the experiment the calculations find a total energy minimum for the oxygen (2 x 2) structure. The interaction between H and O atoms was found to be repulsive and short ranged, leading to a compression of the O islands from (2 x 2) to ({radical}3 x {radical}3)R30 degree ordered structure at high H coverage. The computed energy barriers for the oxygen diffusion were found to be reduced due to the coadsorption of hydrogen, in agreement with the experimentally observed enhancement of oxygen mobility. The calculations also support the finding that at low temperatures the water formation reaction does not occur on Pd(1 1 1).

Demchenko, D.O.; Sacha, G.M.; Salmeron, M.; Wang, L.-W.

2008-06-25T23:59:59.000Z

189

Oxygen Reduction Reaction on Dispersed and Core-Shell Metal Alloy Catalysts: Density Functional Theory Studies  

E-Print Network (OSTI)

Pt-based alloy surfaces are used to catalyze the electrochemical oxygen reduction reaction (ORR), where molecular oxygen is converted into water on fuel cell electrodes. In this work, we address challenges due to the cost of high Pt loadings in the cathode electrocatalyst, as well as those arising from catalyst durability. We aim to develop an increased understanding of the factors that determine ORR activity together with stability against surface segregation and dissolution of Pt-based alloys. We firstly focus on the problem of determining surface atomic distribution resulting from surface segregation phenomena. We use first-principles density functional theory (DFT) calculations on PtCo and Pt3Co overall compositions, as well as adsorption of water and atomic oxygen on PtCo(111) and Pt-skin structures. The bonding between water and surfaces of PtCo and Pt-skin monolayers are investigated in terms of orbital population. Also, on both surfaces, the surface reconstruction effect due to high oxygen coverage and water co-adsorption is investigated. Although the PtCo structures show good activity, a large dissolution of Co atoms tends to occur in acid medium. To tackle this problem, we examine core-shell structures which showed improved stability and activity compared to Pt(111), in particular, one consisting of a surface Pt-skin monolayer over an IrCo or Ir3Co core, with or without a Pd interlayer between the Pt surface and the Ir-Co core. DFT analysis of surface segregation, surface stability against dissolution, surface Pourbaix diagrams, and reaction mechanisms provide useful predictions on catalyst durability, onset potential for water oxidation, surface atomic distribution, coverage of oxygenated species, and activity. The roles of the Pd interlayer in the core-shell structures that influence higher ORR activity are clarified. Furthermore, the stability and activity enhancement of new shell-anchor-core structures of Pt/Fe-C/core, Pt/Co-C/core and Pt/Ni-C/core are demonstrated with core materials of Ir, Pd3Co, Ir3Co, IrCo and IrNi. Based on the analysis, Pt/Fe-C/Ir, Pt/Co-C/Ir, Pt/Ni-C/Ir, Pt/Co-C/Pd3Co, Pt/Fe-C/Pd3Co, Pt/Co- C/Ir3Co, Pt/Fe-C/Ir3Co, Pt/Co-C/IrCo, Pt/Co-C/IrNi, and Pt/Fe-C/IrNi structures show promise in terms of both improved durability and relatively high ORR activity.

Hirunsit, Pussana

2010-08-01T23:59:59.000Z

190

Effect of in-situ oxygen on the electronic properties of graphene grown by carbon molecular beam epitaxy grown  

Science Conference Proceedings (OSTI)

We report that graphene grown by molecular beam epitaxy from solid carbon (CMBE) on (0001) SiC in the presence of unintentional oxygen exhibits a small bandgap on the order of tens of meV. The presence of bandgaps is confirmed by temperature dependent Hall effect and resistivity measurements. X-ray photoelectron spectroscopy (XPS) measurements suggest that oxygen incorporates into the SiC substrate in the form of O-Si-C and not into the graphene as graphene oxide or some other species. The effect is independent of the carrier type of the graphene. Temperature dependent transport measurements show the presence of hopping conduction in the resistivity and a concurrent disappearance of the Hall voltage. Interactions between the graphene layers and the oxidized substrate are believed to be responsible for the bandgap.

Park, Jeongho; Mitchel, W. C.; Back, Tyson C. [Air Force Research Laboratory, Materials and Manufacturing Directorate (AFRL/RXPS), Wright-Patterson AFB, Ohio 45433-7707 (United States); Elhamri, Said [Department of Physics, University of Dayton, Dayton, Ohio 45469 (United States)

2012-03-26T23:59:59.000Z

191

Low level laser therapy activates NF-kB via generation of reactive oxygen species in mouse embryonic fibroblasts  

E-Print Network (OSTI)

Despite over forty years of investigation on low-level light therapy (LLLT), the fundamental mechanisms underlying photobiomodulation remain unclear. In this study, we isolated murine embryonic fibroblasts (MEF) from ...

Hamblin, Michael R.

192

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

193

Hydrogen Production Using Hydrogenase-Containing Oxygenic Photosynthetic Organisms  

DOE Patents (OSTI)

A reversible physiological process provides for the temporal separation of oxygen evolution and hydrogen production in a microorganism, which includes the steps of growing a culture of the microorganism in medium under illuminated conditions to accumulate an endogenous substrate, depleting from the medium a nutrient selected from the group consisting of sulfur, iron, and/or manganese, sealing the culture from atmospheric oxygen, incubating the culture in light whereby a rate of light-induced oxygen production is equal to or less than a rate of respiration, and collecting an evolved gas. The process is particularly useful to accomplish a sustained photobiological hydrogen gas production in cultures of microorganisms, such as Chlamydomonas reinhardtii.

Melis, A.; Zhang, L.; Benemann, J. R.; Forestier, M.; Ghirardi, M.; Seibert, M.

2006-01-24T23:59:59.000Z

194

Magnetic resonance imaging of the cerebral metabolic rate of oxygen (CMRO?)  

E-Print Network (OSTI)

Oxygen consumption is an essential process of the functioning brain. The rate at which the brain consumes oxygen is known as the cerebral metabolic rate of oxygen (CMRO?). CMRO? is intimately related to brain health and ...

Bolar, Divya Sanam

2010-01-01T23:59:59.000Z

195

Oxygen enriched combustion system performance study. Phase 2: 100 percent oxygen enriched combustion in regenerative glass melters, Final report  

Science Conference Proceedings (OSTI)

The field test project described in this report was conducted to evaluate the energy and environmental performance of 100% oxygen enriched combustion (100% OEC) in regenerative glass melters. Additional objectives were to determine other impacts of 100% OEC on melter operation and glass quality, and to verify on a commercial scale that an on-site Pressure Swing Adsorption oxygen plant can reliably supply oxygen for glass melting with low electrical power consumption. The tests constituted Phase 2 of a cooperative project between the United States Department of Energy, and Praxair, Inc. Phase 1 of the project involved market and technical feasibility assessments of oxygen enriched combustion for a range of high temperature industrial heating applications. An assessment of oxygen supply options for these applications was also performed during Phase 1, which included performance evaluation of a pilot scale 1 ton per day PSA oxygen plant. Two regenerative container glass melters were converted to 100% OEC operation and served as host sites for Phase 2. A 75 ton per day end-fired melter at Carr-Lowrey Glass Company in Baltimore, Maryland, was temporarily converted to 100% OEC in mid- 1990. A 350 tpd cross-fired melter at Gallo Glass Company in Modesto, California was rebuilt for permanent commercial operation with 100% OEC in mid-1991. Initially, both of these melters were supplied with oxygen from liquid storage. Subsequently, in late 1992, a Pressure Swing Adsorption oxygen plant was installed at Gallo to supply oxygen for 100% OEC glass melting. The particular PSA plant design used at Gallo achieves maximum efficiency by cycling the adsorbent beds between pressurized and evacuated states, and is therefore referred to as a Vacuum/Pressure Swing Adsorption (VPSA) plant.

Tuson, G.B.; Kobayashi, H.; Campbell, M.J.

1994-08-01T23:59:59.000Z

196

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.

197

Calibration and Stability of Oxygen Sensors on Autonomous Floats  

Science Conference Proceedings (OSTI)

The calibration accuracy and stability of three Aanderaa 3835 optodes and three Seabird SBE-43 oxygen sensors were evaluated over four years using in situ and laboratory calibrations. The sensors were mostly in storage, being in the ocean for ...

Eric A. D’Asaro; Craig McNeil

198

Geothermal reservoir temperatures estimated from the oxygen isotope  

Open Energy Info (EERE)

reservoir temperatures estimated from the oxygen isotope reservoir temperatures estimated from the oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Geothermal reservoir temperatures estimated from the oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes Details Activities (3) Areas (3) Regions (0) Abstract: The oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes have been tested as a geothermometer in three areas of the western United States. Limited analyses of spring and borehole fluids and existing experimental rate studies suggest that dissolved sulfate and water are probably in isotopic equilibrium in all reservoirs of significant size with temperatures above

199

Oxygen And Carbon Isotope Ratios Of Hydrothermal Minerals From Yellowstone  

Open Energy Info (EERE)

Oxygen And Carbon Isotope Ratios Of Hydrothermal Minerals From Yellowstone Oxygen And Carbon Isotope Ratios Of Hydrothermal Minerals From Yellowstone Drill Cores Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Oxygen And Carbon Isotope Ratios Of Hydrothermal Minerals From Yellowstone Drill Cores Details Activities (3) Areas (1) Regions (0) Abstract: Oxygen and carbon isotope ratios were measured for hydrothermal minerals (silica, clay and calcite) from fractures and vugs in altered rhyolite, located between 28 and 129 m below surface (in situ temperatures ranging from 81 to 199°C) in Yellowstone drill holes. The purpose of this study was to investigate the mechanism of formation of these minerals. The Δ18O values of the thirty-two analyzed silica samples (quartz, chalcedony, α-cristobalite, and β-cristobalite) range from -7.5 to +2.8‰. About one

200

Modeling Terrestrial Biogenic Sources of Oxygenated Organic Emissions  

Science Conference Proceedings (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

Note: This page contains sample records for the topic "oxygen species ros" 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

Phosphorescent semiconductor nanocrystals and proteins for biological oxygen sensing  

E-Print Network (OSTI)

Oxygen is required for cellular respiration by all complex life making it a key metabolic profiling factor in biological systems. Tumors are defined by hypoxia (low pO2), which has been shown to influence response to ...

McLaurin, Emily J. (Emily Jane)

2011-01-01T23:59:59.000Z

202

Nano- sized strontium titanate metal oxide semiconductor oxygen gas sensors.  

E-Print Network (OSTI)

??The project focuses on strontium titanate (SrTiO3> material, a very important material for oxygen sensors. The advantages of the material are low cost and stability… (more)

Hu, Ying.

2008-01-01T23:59:59.000Z

203

IMPACT OF OXYGEN CONCENTRATION ON ZEBRA MUSSEL MORTALITY  

SciTech Connect

These tests have indicated that the bacterium Pseudomonas fluorescens strain CL0145A is effective at killing zebra mussels in environments having dissolved oxygen (DO) concentrations ranging from very low to very high. The results suggest that the highest mussel kill can be achieved in moderately to highly aerated environments, while kill may be 0-20% lower under conditions of very low oxygen. For example, under highly oxygenated conditions 97% kill was achieved while conditions having low DO produced 79% mussel kill. Service water measured in a local power plant indicated that DO concentrations were in the range of 8-9 ppm (e.g., highly aerated) within their pipes. Therefore, we will not expect to see decreases in the efficacy of CL0145A treatments due to oxygen levels within such power plant pipes.

Daniel P. Molloy

2003-01-27T23:59:59.000Z

204

CO/sub 2/ recovery from oxygen firefloods  

SciTech Connect

An additional benefit from the oxygen in-situ combustion process or fireflooding is the generation of produced gases containing a high concentration of CO/sub 2/ (>90 mole %). This CO/sub 2/ could be recovered and utilized for miscible and immiscible CO/sub 2/ flooding for EOR. This paper investigates the feasibility of recovering and marketing CO/sub 2/ from oxygen firefloods for this purpose. The expected compositions and volumes of associated gas produced from commercial oxygen in-situ combustion projects based on literature data and actual field tests are presented. In addition, the market prospects based on the transportation requirements and the costs associated with the recovery of CO/sub 2/ from an oxygen in-situ combustion project are discussed. 12 references, 2 figures, 4 tables. (JMT)

Persico, P.J.; Wetherington, J.B.; Hvizdos, L.J.

1983-06-01T23:59:59.000Z

205

Calibration and Stability of Oxygen Sensors on Autonomous Floats  

Science Conference Proceedings (OSTI)

The calibration accuracy and stability of three Aanderaa 3835 optodes and three Sea-Bird Electronics SBE-43 oxygen sensors were evaluated over four years using in situ and laboratory calibrations. The sensors were mostly in storage, being in the ...

Eric A. D'Asaro; Craig McNeil

2013-08-01T23:59:59.000Z

206

Hybrid membrane--PSA system for separating oxygen from air  

Science Conference Proceedings (OSTI)

A portable, non-cryogenic, oxygen generation system capable of delivering oxygen gas at purities greater than 98% and flow rates of 15 L/min or more is described. The system consists of two major components. The first component is a high efficiency membrane capable of separating argon and a portion of the nitrogen content from air, yielding an oxygen-enriched permeate flow. This is then fed to the second component, a pressure swing adsorption (PSA) unit utilizing a commercially available, but specifically formulated zeolite compound to remove the remainder of the nitrogen from the flow. The system is a unique gas separation system that can operate at ambient temperatures, for producing high purity oxygen for various applications (medical, refining, chemical production, enhanced combustion, fuel cells, etc . . . ) and represents a significant advance compared to current technologies.

Staiger, Chad L. (Albuquerque, NM); Vaughn, Mark R. (Albuquerque, NM); Miller, A. Keith (Albuquerque, NM); Cornelius, Christopher J. (Blackburg, VA)

2011-01-25T23:59:59.000Z

207

Effect of Oxygen Potential on Crack Growth in Alloy 617  

Science Conference Proceedings (OSTI)

Static crack growth rate increases from 4 x 10-9 m/sec to 4 x 10-8 m/sec when the oxygen concentration decreases from .001 to .0000001 atm. Proceedings ...

208

CO/sub 2/ recovery from oxygen firefloods  

SciTech Connect

The use of high purity oxygen in a fireflood project prevents the introduction of nonreactive nitrogen into the oil reservoir, and thus will significantly increase the CO/sub 2/ concentration in the produced gas. The increased CO/sub 2/ concentration would greatly simplify the recovery and processing required to utilize this CO/sub 2/ in a CO/sub 2/ flooding EOR project. The basic products produced by the reaction of oxygen with hydrocarbon fuel in the in situ combustion process are CO/sub 2/, carbon monoxide, and water. Oxygen fireflooding has technical and economic advantages over conventional fireflooding for EOR. Gas produced in an oxygen fireflood represents a major new source of high concentration CO/sub 2/ for EOR. 12 references.

Persico, P.J.; Wetherington, J.B.; Hvizdos, L.J.

1983-06-01T23:59:59.000Z

209

Reactivity and stability of platinum and platinum alloy catalysts toward the oxygen reduction reaction  

E-Print Network (OSTI)

Density functional theory (DFT) is used to study the reactivity of Pt and Pt-M (M: Pd, Co, Ni, V, and Rh) alloy catalysts towards the oxygen reduction reaction (ORR) as a function of the alloy overall composition and surface atomic distribution and compared to that on pure Pt surfaces. Reactivity is evaluated on the basis of the adsorption strength of oxygenated compounds which are intermediate species of the four-electron oxygen reduction reaction, separating the effect of the first electron-proton transfer from that of the three last electron-proton transfer steps. It is found that most homogeneous distribution PtxM catalysts thermodynamically favor the dissociation of adsorbed OOH in comparison with pure Platinum and adsorb strongly O and OH due to the strong oxyphilicity of the M elements. On the other hand, in all cases skin Platinum surfaces catalysts do not favor the dissociation of adsorbed OOH and do favor the reduction of M-O and M-OH with respect to Platinum. Considering the overall pathway of the reactions to catalyze the ORR most of the skin Platinum monolayer catalysts provide more negative free energy changes and should behave at least in a similar way than Platinum in following order: Pt3V (skin Pt) > Pt3Co (skin Pt) > Pt3Ni (skin Pt) > Pt > PtPd (skin) > Pt4Rh (skin Pt) > PtPd3 (skin ). In all cases, the reactivity is shown to be not only sensitive to the overall composition of the catalyst, but most importantly to the surface atomic distribution. Proposed electrochemical dissolution reactions of the catalyst atoms are also analyzed for the ORR catalysts, by computing the free energy changes of Platinum and bimetallic Pt-X (X: Co, Pd, Ni, and Rh) catalysts. It is found that Platinum is thermodynamically more stable than Pt-alloys in Pt3Co, Pt3Pd, Pt3Ni and Pt4Rh.

Calvo, Sergio Rafael

2007-12-01T23:59:59.000Z

210

Oxygen-permeable ceramic membranes for gas separation  

DOE Green Energy (OSTI)

Mixed-conducting oxides have a wide range of applications, including fuel cells, gas separation systems, sensors, and electrocatalytic equipment. Dense ceramic membranes made of mixed-conducting oxides are particularly attractive for gas separation and methane conversion processes. Membranes made of Sr-Fe-Co oxide, which exhibits high combined electronic and oxygen ionic conductivities, can be used to selectively transport oxygen during the partial oxidation of methane to synthesis gas (syngas, i.e., CO + H{sub 2}). The authors have fabricated tubular Sr{sub 2}Fe{sub 2}CoO{sub 6+{delta}} membranes and tested them (some for more than 1,000 h) in a methane conversion reactor that was operating at 850--950 C. An oxygen permeation flux of {approx} 10 scc/cm{sup 2} {center_dot} min was obtained at 900 C in a tubular membrane with a wall thickness of 0.75 mm. Using a gas-tight electrochemical cell, the authors have also measured the steady-state oxygen permeability of flat Sr{sub 2}Fe{sub 2}CoO{sub 6+{delta}} membranes as a function of temperature and oxygen partial pressure(pO{sub 2}). Steady-state oxygen permeability increases with increasing temperature and with the difference in pO{sub 2} on the two sides of the membrane. At 900 C, an oxygen permeability of {approx} 2.5 scc/cm{sup 2} {center_dot} min was obtained in a 2.9-mm-thick membrane. This value agrees with that obtained in methane conversion reactor experiments. Current-voltage (I-V) characteristics determined in the gas-tight cell indicate that bulk effect, rather than surface exchange effect, is the main limiting factor for oxygen permeation of {approx} 1-mm-thick Sr{sub 2}Fe{sub 2}CoO{sub 6+{delta}} membranes at elevated temperatures (> 650 C).

Balachandran, U.; Ma, B.; Maiya, P.S.; Dusek, J.T.; Mieville, R.L.; Picciolo, J.J.

1998-02-01T23:59:59.000Z

211

Reactive Air Brazing of Nicrofer-6025HT to BSCF for Oxygen ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Oxygen separation membranes can be used to provide oxygen for ... with an oxide component that promotes wetting of ceramic materials.

212

The production of carbon nanofibers and thin films on palladium catalysts from ethylene oxygen mixtures  

SciTech Connect

The characteristics of carbonaceous materials deposited in fuel rich ethylene-oxygen mixtures on three types of palladium: foil, sputtered film, and nanopowder, are reported. It was found that the form of palladium has a dramatic influence on the morphology of the deposited carbon. In particular, on sputtered film and powder, tight 'weaves' of sub-micron filaments formed quickly. In contrast, on foils under identical conditions, the dominant morphology is carbon thin films with basal planes oriented parallel to the substrate surface. Temperature, gas flow rate, reactant flow ratio (C2H4:02), and residence time (position) were found to influence both growth rate and type for all three forms of Pd. X-ray diffraction, high-resolution transmission electron microscopy, temperature-programmed oxidation, and Raman spectroscopy were used to assess the crystallinity of the as-deposited carbon, and it was determined that transmission electron microscopy and x-ray diffraction were the most reliable methods for determining crystallinity. The dependence of growth on reactor position, and the fact that no growth was observed in the absence of oxygen support the postulate that the carbon deposition proceeds by combustion generated radical species.

Phillips, Jonathan [Los Alamos National Laboratory; Doorn, Stephen [Los Alamos National Laboratory; Atwater, Mark [UNM MECH.ENG.; Leseman, Zayd [UNM MECH.ENG.; Luhrs, Claudia C [UNM ENG.MECH; Diez, Yolanda F [SPAIN; Diaz, Angel M [SPAIN

2009-01-01T23:59:59.000Z

213

On the nature and origin of acidic species in petroleum. 1. Detailed acid type distribution in a California crude oil.  

Science Conference Proceedings (OSTI)

Acidity in crude oils has long been a problem for refining. Knowledge of the detailed chemical composition of the acids responsible for corrosion can facilitate identification of problem crude oils and potentially lead to improved processing options for corrosive oils. A highly aerobically biodegraded crude from the San Joaquin Valley, which has a long history of causing corrosion problems during refining, was the subject of this study. The oil was first extracted with base, then acidified and extracted with petroleum ether. A portion of the resulting acid fraction was methylated. The unmethylated extract was analyzed by FTIR, NMR, and the methylated sample was analyzed by high-resolution mass spectrometry (HRMS). Over 96% of the ions observed in HRMS have been assigned reliable formulas. Considerably greater functionality is seen in this sample than would be presumed from the 'naphthenic acid' title typically assigned to these species. Although over 60% of the compounds contained two or more oxygens, compounds containing only oxygen heteroatoms accounted for less than 10% of the acidic compounds identified. Approximately one-half of the species contained nitrogen and about one-fourth contained sulfur. It is believed that microbial degradation is a major source of these acidic components. It was also observed that acid species with higher degrees of heteroatom substitution generally also had a higher degree of saturation than those species having less heteroatoms, possibly due to impeded migration of highly substituted, less-saturated species.

Tomczyk, N. A.; Winans, R. E.; Shinn, J. H.; Robinson, R. C.; Chemistry; Chevron Research and Technology Co.

2001-11-21T23:59:59.000Z

214

Experimental studies of oxygen isotope fractionation in the carbonic acid system at 15, 25, and 40 (degrees)C  

E-Print Network (OSTI)

In light of recent studies that show oxygen isotope fractionation in carbonate minerals to be a function of HCO3 2-; and CO3 2- concentrations, the oxygen isotope fractionation and exchange between water and components of the carbonic acid system (HCO3 2-, CO3 2-, and CO2(aq)) were investigated at 15, 25, and 40 (degrees)C. To investigate oxygen isotope exchange between HCO3 2-, CO3 -2, and H2O, NaHCO3 solutions were prepared and the pH was adjusted over a range of 2 to 12 by the addition of small amounts of HCl or NaOH. After thermal, chemical, and isotopic equilibrium was attained, BaCl2 was added to the NaHCO3 solutions. This resulted in immediate BaCO3 precipitation; thus, recording the isotopic composition of the dissolved inorganic carbon. Data from experiments at 15, 25, and 40 (degrees)C (1 atm) show that the oxygen isotope fractionation between HCO3 2-; and H2O as a function of temperature is governed by the equation: 1000 ;HCO3--H2O = 2.66 + 0.05(106T-2) + 1.18 + 0.52. where is the fractionation factor and T is in kelvins. The temperature dependence of oxygen isotope fractionation between CO32 and H2O is 1000 CO32--H2O = 2.28 + 0.03(106T-2) - 1.50 + 0.29. The oxygen isotope fractionation between CO2(aq) and H2O was investigated by acid stripping CO2(aq) from low pH solutions; these data yield the following equation: 1000 CO2(aq)-H2O = 2.52 + 0.03(106T-2) + 12.12 + 0.33. The kinetics of oxygen isotope exchange were also investigated. The half-times for exchange between HCO3- and H2O were 3.6, 1.4, and 0.25 h at 15, 25, and 40 (degrees)C, respectively. The half-times for exchange between CO2 and H2O were 1200, 170, and 41 h at 15, 25, and 40 (degrees) C, respectively. These results show that the 18O of the total dissolved inorganic carbon species can vary as much as 17 at a constant temperature. This could result in temperature independent variations in the 18O of precipitated carbonate minerals, especially in systems that are not chemically buffered.

Beck, William Cory

2004-08-01T23:59:59.000Z

215

Endangered Species Act | Open Energy Information  

Open Energy Info (EERE)

Endangered Species Act Endangered Species Act Jump to: navigation, search Statute Name Endangered Species Act Year 1973 Url Puerto-rican-parrott-TomMacKenzieUSFWS.jpg Description References The Endangered Species Act[1] Fish and Wildlife Service - ESA Overview[2] ESA Fact Sheet[3] When Congress passed the Endangered Species Act (ESA) in 1973, it recognized that our rich natural heritage is of "esthetic, ecological, educational, recreational, and scientific value to our Nation and its people." It further expressed concern that many of our nation's native plants and animals were in danger of becoming extinct. The purpose of the ESA is to protect and recover imperiled species and the ecosystems upon which they depend. It is administered by the U.S. Fish and Wildlife Service and the Commerce Department's National Marine Fisheries

216

Oxygen electrode reaction in molten carbonate fuel cells  

DOE Green Energy (OSTI)

Molten carbonate fuel cell system is a leading candidate for the utility power generation because of its high efficiency for fuel to AC power conversion, capability for an internal reforming, and a very low environmental impact. However, the performance of the molten carbonate fuel cell is limited by the oxygen reduction reaction and the cell life time is limited by the stability of the cathode material. An elucidation of oxygen reduction reaction in molten alkali carbonate is essential because overpotential losses in the molten carbonate fuel cell are considerably greater at the oxygen cathode than at the fuel anode. Oxygen reduction on a fully-immersed gold electrode in a lithium carbonate melt was investigated by electrochemical impedance spectroscopy and cyclic voltammetry to determine electrode kinetic and mass transfer parameters. The dependences of electrode kinetic and mass transfer parameters on gas composition and temperature were examined to determine the reaction orders and the activation energies. The results showed that oxygen reduction in a pure lithium carbonate melt occurs via the peroxide mechanism. A mass transfer parameter, D{sub O}{sup 1/2}C{sub O}, estimated by the cyclic voltammetry concurred with that calculated by the EIS technique. The temperature dependence of the exchange current density and the product D{sub O}{sup 1/2}C{sub O} were examined and the apparent activation energies were determined to be about 122 and 175 kJ/ mol, respectively.

Appleby, A.J.; White, R.E.

1992-07-07T23:59:59.000Z

217

SERI Aquatic Species Program: 1983 Annual Report  

DOE Green Energy (OSTI)

During 1983 research was carried out under three tasks: biological, engineering, and analysis. Biological research was aimed at screening for promising species of microalgae, macroalgae, and emergent plants that could be cultivated for energy products. Promising species were studied further to improve yields.

Not Available

1984-03-01T23:59:59.000Z

218

Method and apparatus for producing oxygenates from hydrocarbons  

DOE Patents (OSTI)

A chemical reactor for oxygenating hydrocarbons includes: a) a dielectric barrier discharge plasma cell, the plasma cell comprising a pair of electrodes having a dielectric material and void therebetween, the plasma cell comprising a hydrocarbon gas inlet feeding to the void; b) a solid oxide electrochemical cell, the electrochemical cell comprising a solid oxide electrolyte positioned between a porous cathode and a porous anode, an oxygen containing gas inlet stream feeding to the porous cathode side of the electrochemical cell; c) a first gas passageway feeding from the void to the anode side of the electrochemical cell; and d) a gas outlet feeding from the anode side of the electrochemical cell to expel reaction products from the chemical reactor. A method of oxygenating hydrocarbons is also disclosed.

Kong, Peter C. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

1995-01-01T23:59:59.000Z

219

Fuel and oxygen addition for metal smelting or refining process  

DOE Patents (OSTI)

A furnace for smelting iron ore and/or refining molten iron is equipped with an overhead pneumatic lance, through which a center stream of particulate coal is ejected at high velocity into a slag layer. An annular stream of nitrogen or argon enshrouds the coal stream. Oxygen is simultaneously ejected in an annular stream encircling the inert gas stream. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus to react with carbon monoxide gas rising from slag layer, thereby adding still more heat to the furnace. 7 figs.

Schlichting, M.R.

1994-11-22T23:59:59.000Z

220

Evolution of Photosynthesis and Biospheric Oxygenation Contingent Upon Nitrogen Fixation?  

E-Print Network (OSTI)

How photosynthesis by Precambrian cyanobacteria oxygenated Earth's biosphere remains incompletely understood. Here it is argued that the oxic transition, which took place between approximately 2.3 and 0.5 Gyr ago, required a great proliferation of cyanobacteria, and this in turn depended on their ability to fix nitrogen via the nitrogenase enzyme system. However, the ability to fix nitrogen was not a panacea, and the rate of biospheric oxygenation may still have been affected by nitrogen constraints on cyanobacterial expansion. Evidence is presented for why cyanobacteria probably have a great need for fixed nitrogen than other prokaryotes, underscoring the importance of their ability to fix nitrogen. The connection between nitrogen fixation and the evolution of photosynthesis is demonstrated by the similarities between nitrogenase and enzymes critical for the biosynthesis of (bacterio)chlorophyll. It is hypothesized that biospheric oxygenation would not have occurred if the emergence of cyanobacteria had not ...

Grula, J W

2006-01-01T23:59:59.000Z

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


221

Evaluation of oxygen-enrichment system for alternative fuel vehicles  

DOE Green Energy (OSTI)

This report presents results on the reduction in exhaust emissions achieved by using oxygen-enriched intake air on a flexible fuel vehicle (FFV) that used Indolene and M85 as test fuels. The standard federal test procedure (FTP) and the US Environmental Protection Agency`s (EPA`s) off-cycle (REP05) test were followed. The report also provides a review of literature on the oxygen membrane device and design considerations. It presents information on the sources and contributions of cold-phase emissions to the overall exhaust emissions from light-duty vehicles (LDVs) and on the various emission standards and present-day control technologies under consideration. The effects of oxygen-enriched intake air on FTP and off-cycle emissions are discussed on the basis of test results. Conclusions are drawn from the results and discussion, and different approaches for the practical application of this technology in LDVs are recommended.

Poola, R.B.; Sekar, R.R.; Ng, H.K.

1995-12-01T23:59:59.000Z

222

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,

223

Homogeneously catalyzed synthesis gas transformations to oxygenate fuels  

DOE Green Energy (OSTI)

At Brookhaven National Laboratory (BNL), the ongoing oxygenates synthesis program is addressing the catalytic synthesis gas conversion to liquid fuels and fuel additives. The major thrust of this effort is to enhance carbon conversion, reaction rates, product selectivity and overall process efficiency. To this effect, a series of liquid phase homogeneous catalysts have been developed and successfully utilized in the synthesis of methanol and other oxygenates. This paper identifies advantages and uncertainties associated with these newly developed catalysts. The effect of system parameters on the overall process scheme is discussed.

Mahajan, D.; Mattas, L.; Sanchez, J.

1992-01-01T23:59:59.000Z

224

Homogeneously catalyzed synthesis gas transformations to oxygenate fuels  

DOE Green Energy (OSTI)

At Brookhaven National Laboratory (BNL), the ongoing oxygenates synthesis program is addressing the catalytic synthesis gas conversion to liquid fuels and fuel additives. The major thrust of this effort is to enhance carbon conversion, reaction rates, product selectivity and overall process efficiency. To this effect, a series of liquid phase homogeneous catalysts have been developed and successfully utilized in the synthesis of methanol and other oxygenates. This paper identifies advantages and uncertainties associated with these newly developed catalysts. The effect of system parameters on the overall process scheme is discussed.

Mahajan, D.; Mattas, L.; Sanchez, J.

1992-04-01T23:59:59.000Z

225

Massachusetts Endangered Species Act Regulations (Massachusetts) |  

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

Endangered Species Act Regulations (Massachusetts) Endangered Species Act Regulations (Massachusetts) Massachusetts Endangered Species Act Regulations (Massachusetts) < Back Eligibility Agricultural Commercial Construction Fed. Government Fuel Distributor General Public/Consumer Industrial Installer/Contractor Institutional Investor-Owned Utility Local Government Low-Income Residential Multi-Family Residential Municipal/Public Utility Nonprofit Residential Retail Supplier Rural Electric Cooperative Schools State/Provincial Govt Systems Integrator Transportation Tribal Government Utility Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State Massachusetts Program Type Environmental Regulations Provider Department of Fish and Game

226

Process for conversion of lignin to reformulated, partially oxygenated gasoline  

DOE Patents (OSTI)

A high-yield process for converting lignin into reformulated, partially oxygenated gasoline compositions of high quality is provided. The process is a two-stage catalytic reaction process that produces a reformulated, partially oxygenated gasoline product with a controlled amount of aromatics. In the first stage of the process, a lignin feed material is subjected to a base-catalyzed depolymerization reaction, followed by a selective hydrocracking reaction which utilizes a superacid catalyst to produce a high oxygen-content depolymerized lignin product mainly composed of alkylated phenols, alkylated alkoxyphenols, and alkylbenzenes. In the second stage of the process, the depolymerized lignin product is subjected to an exhaustive etherification reaction, optionally followed by a partial ring hydrogenation reaction, to produce a reformulated, partially oxygenated/etherified gasoline product, which includes a mixture of substituted phenyl/methyl ethers, cycloalkyl methyl ethers, C.sub.7 -C.sub.10 alkylbenzenes, C.sub.6 -C.sub.10 branched and multibranched paraffins, and alkylated and polyalkylated cycloalkanes.

Shabtai, Joseph S. (Salt Lake City, UT); Zmierczak, Wlodzimierz W. (Salt Lake City, UT); Chornet, Esteban (Golden, CO)

2001-01-09T23:59:59.000Z

227

High-temperature potentiometric oxygen sensor with internal reference  

DOE Patents (OSTI)

A compact oxygen sensor is provided, comprising a mixture of metal and metal oxide an enclosure containing said mixture, said enclosure capable of isolating said mixture from an environment external of said enclosure, and a first wire having a first end residing within the enclosure and having a second end exposed to the environment. Also provided is a method for the fabrication of an oxygen sensor, the method comprising confining a metal-metal oxide solid mixture to a container which consists of a single material permeable to oxygen ions, supplying an electrical conductor having a first end and a second end, whereby the first end resides inside the container as a reference (PO.sub.2).sup.ref, and the second end resides outside the container in the atmosphere where oxygen partial pressure (PO.sub.2).sup.ext is to be measured, and sealing the container with additional single material such that grain boundary sliding occurs between grains of the single material and grains of the additional single material.

Routbort, Jules L. (Hinsdale, IL); Singh, Dileep (Naperville, IL); Dutta, Prabir K. (Worthington, OH); Ramasamy, Ramamoorthy (North Royalton, OH); Spirig, John V. (Columbus, OH); Akbar, Sheikh (Hilliard, OH)

2011-11-15T23:59:59.000Z

228

Photosynthetic hydrogen and oxygen production by green algae  

SciTech Connect

An overview of photosynthetic hydrogen and oxygen production by green algae in the context of its potential as a renewable chemical feed stock and energy carrier is presented. Beginning with its discovery by Gaffron and Rubin in 1942, motivated by curiosity-driven laboratory research, studies were initiated in the early 1970s that focused on photosynthetic hydrogen production from an applied perspective. From a scientific and technical point of view, current research is focused on optimizing net thermodynamic conversion efficiencies represented by the Gibbs Free Energy of molecular hydrogen. The key research questions of maximizing hydrogen and oxygen production by light-activated water splitting in green algae are (1) removing the oxygen sensitivity of algal hydrogenases; (2) linearizing the light saturation curves of photosynthesis throughout the entire range of terrestrial solar irradiance--including the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transport and (3) the minimum number of light reactions that are required to split water to elemental hydrogen and oxygen. Each of these research topics is being actively addressed by the photobiological hydrogen research community.

Greenbaum, E.; Lee, J.W.

1997-12-31T23:59:59.000Z

229

Photosynthetic Hydrogen and Oxygen Production by Green Algae  

SciTech Connect

Photosynthesis research at Oak Ridge National Laboratory is focused on hydrogen and oxygen production by green algae in the context of its potential as a renewable fuel and chemical feed stock. Beginning with its discovery by Gaffron and Rubin in 1942, motivated by curiosity-driven laboratory research, studies were initiated in the early 1970s that focused on photosynthetic hydrogen production from an applied perspective. From a scientific and technical point of view, current research is focused on optimizing net thermodynamic conversion efficiencies represented by the Gibbs Free Energy of molecular hydrogen. The key research questions of maximizing hydrogen and oxygen production by light-activated water splitting in green algae are: (1) removing the oxygen sensitivity of algal hydrogenases; (2) linearizing the light saturation curves of hotosynthesis throughout the entire range of terrestrial solar irradiance-including the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transpor;t and (3) constructing real-world bioreactors, including the generation of hydrogen and oxygen against workable back pressures of the photoproduced gases.

Greenbaum, E.; Lee, J.W.

1999-08-22T23:59:59.000Z

230

Direct observation of oxygen superstructures in manganites S. Grenier,1  

E-Print Network (OSTI)

Direct observation of oxygen superstructures in manganites S. Grenier,1 K. J. Thomas,2 J. P. Hill,2). [9] D. Volja, et al., cond-mat:0704.1834v1 (2007). [10] S. Grenier, et al., Phys. Rev. B 75, 085101 (Materlik, Sparks and Fisher, 1994). [14] H. L. Ju, et al., Phys. Rev. Lett. 79, 3230 (1997). [15] J. Garc

Paris-Sud XI, Université de

231

Utilization of Renewable Oxygenates as Gasoline Blending Components  

SciTech Connect

This report reviews the use of higher alcohols and several cellulose-derived oxygenates as blend components in gasoline. Material compatibility issues are expected to be less severe for neat higher alcohols than for fuel-grade ethanol. Very little data exist on how blending higher alcohols or other oxygenates with gasoline affects ASTM Standard D4814 properties. Under the Clean Air Act, fuels used in the United States must be 'substantially similar' to fuels used in certification of cars for emission compliance. Waivers for the addition of higher alcohols at concentrations up to 3.7 wt% oxygen have been granted. Limited emission testing on pre-Tier 1 vehicles and research engines suggests that higher alcohols will reduce emissions of CO and organics, while NOx emissions will stay the same or increase. Most oxygenates can be used as octane improvers for standard gasoline stocks. The properties of 2-methyltetrahydrofuran, dimethylfuran, 2-methylfuran, methyl pentanoate and ethyl pentanoate suggest that they may function well as low-concentration blends with gasoline in standard vehicles and in higher concentrations in flex fuel vehicles.

Yanowitz, J.; Christensen, E.; McCormick, R. L.

2011-08-01T23:59:59.000Z

232

Blood storage device and method for oxygen removal  

DOE Patents (OSTI)

The present invention relates to a storage device and method for the long-term storage of blood and, more particularly, to a blood storage device and method capable of removing oxygen from the stored blood and thereby prolonging the storage life of the deoxygenated blood.

Bitensky, Mark W. (Waban, MA); Yoshida, Tatsuro (Newton, MA)

2000-01-01T23:59:59.000Z

233

Characteristics of Knock in Hydrogen-Oxygen-Argon SI Engine  

DOE Green Energy (OSTI)

A promising approach for improving the efficiency of internal combustion engines is to employ a working fluid with a high specific heat ratio such as the noble gas argon. Moreover, all harmful emissions are eliminated when the intake charge is composed of oxygen, nonreactive argon, and hydrogen fuel. Previous research demonstrated indicated thermal efficiencies greater than 45% at 5.5 compression ratio in engines operating with hydrogen, oxygen, and argon. However, knock limits spark advance and increasing the efficiency further. Conditions under which knock occurs in such engines differs from typical gasoline fueled engines. In-cylinder temperatures using hydrogen-oxygen-argon are higher due to the high specific heat ratio and pressures are lower because of the low compression ratio. Better understanding of knock under these conditions can lead to operating strategies that inhibit knock and allow operation closer to the knock limit. In this work we compare knock with a hydrogen, oxygen, and argon mixture to that of air-gasoline mixtures in a variable compression ratio cooperative fuels research (CFR) engine. The focus is on stability of knocking phenomena, as well as, amplitude and frequency of the resulting pressure waves.

Killingsworth, N; Rapp, V; Flowers, D; Aceves, S; Chen, J; Dibble, R

2010-02-23T23:59:59.000Z

234

Migration Mechanisms of Oxygen Interstitial Clusters in UO2  

Science Conference Proceedings (OSTI)

Understanding the migration kinetics of radiation-induced point defects and defect clusters is a key to predicting the microstructural evolution and mass transport in nuclear fuels. Although the diffusion kinetics of point defects in UO2 is well explored both experimentally and theoretically, the kinetics of defect clusters is not well understood. In this work the migration mechanisms of oxygen interstitial clusters of size one to five atoms (1Oi – 5Oi) in UO2 are investigated by temperature-accelerated dynamics simulations without any a priori assumptions of migration mechanisms. It is found that the migration paths of oxygen interstitial clusters are complex and non-intuitive and that multiple migration paths and barriers exist for some clusters. It is also found that the cluster migration barrier does not increase with increasing cluster size and its magnitude has the following order: 2Oi < 3Oi < 1Oi < 5Oi < 4Oi. Possible finite-size effects are checked with three different sized systems. The results show good agreement with other available experimental and theoretical data. In particular, the relatively large migration barriers of cuboctahedral clusters (4Oi and 5Oi) are in good agreement with the experimentally measured oxygen diffusion activation energy in U4O9, which is thought to contain many such clusters. The cluster migration sequence may explain the interesting relationship between the oxygen diffusivity and stoichiometry in UO2+x.

Xian-Ming Bai; Anter El-Azab; Jianguo Yu; Todd R. Allen

2013-01-01T23:59:59.000Z

235

Supercritical Burning of Liquid Oxygen (LOX) Droplet with Detailed Chemistry  

E-Print Network (OSTI)

Supercritical Burning of Liquid Oxygen (LOX) Droplet with Detailed Chemistry J. DAOU,* P with diameter less than I pm vaporize before burning. A quasi-steady-like diffusion flame is then established is considered; temperature and pressure in the combustion chamber have a weak influence on the burning time

Heil, Matthias

236

Electrocatalysis of anodic and cathodic oxygen-transfer reactions  

SciTech Connect

The electrocatalysis of oxygen-transfer reactions is discussed in two parts. In Part I, the reduction of iodate (IO{sub 3}{sup {minus}}) is examined as an example of cathodic oxygen transfer. On oxide-covered Pt electrodes (PtO), a large cathodic current is observed in the presence of IO{sub 3}{sup {minus}} to coincide with the reduction of PtO. The total cathodic charge exceeds the amount required for reduction of PtO and IO{sub 3}{sup {minus}} to produce an adsorbed product. An electrocatalytic link between reduction of IO{sub 3}{sup {minus}} and reduction of PtO is indicated. In addition, on oxide-free Pt electrodes, the reduction of IO{sub 3}{sup {minus}} is determined to be sensitive to surface treatment. The electrocatalytic oxidation of CN{sup {minus}} is presented as an example of anodic oxygen transfer in Part II. The voltametric response of CN{sup {minus}} is virtually nonexistent at PbO{sub 2} electrodes. The response is significantly improved by doping PbO{sub 2} with Cu. Cyanide is also oxidized effectively at CuO-film electrodes. Copper is concluded to serve as an adsorption site for CN{sup {minus}}. It is proposed that an oxygen tunneling mechanism comparable to electron tunneling does not occur at the electrode-solution interface. The adsorption of CN{sup {minus}} is therefore considered to be a necessary prerequisite for oxygen transfer. 201 refs., 23 figs., 2 tabs.

Wels, B.R.

1990-09-21T23:59:59.000Z

237

Why sequence Comparative analysis of Aspergilli species?  

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

Comparative analysis of Aspergilli species? Comparative analysis of Aspergilli species? Aspergillus is not only one of the most important fungi for use in biotechnology it is also one of the most commonly found groups of fungi worldwide. This project seeks to sequence and annotate a series of additional Aspergillus species and Penicillium roqueforti to complement and strengthen the genomic data currently available for comparative studies. The data resulting from these species comparisonswill be of direct relevance to the DOE mission, particularly to howspecies have become adapted for utilization of specific carbon sources enabling efficientbiomass degradation. Principal Investigators: Ronald de Vries, CBS-KNAW Fungal Biodiversity Centre, the Netherlands Program: CSP 2011 Home > Sequencing > Why sequence Comparative analysis of Aspergilli

238

Aquatic Species Program (ASP): Lessons Learned  

SciTech Connect

Presentation on lessons learned from the U.S. Department of Energy?s Aquatic Species Program 1978-1996 microalgae R&D activities, presented at the 2008 AFOSR Workshop in Washington, D.C.

Jarvis, E. E.

2008-02-01T23:59:59.000Z

239

COMPUTATIONAL RESOURCES FOR BIOFUEL FEEDSTOCK SPECIES  

SciTech Connect

While current production of ethanol as a biofuel relies on starch and sugar inputs, it is anticipated that sustainable production of ethanol for biofuel use will utilize lignocellulosic feedstocks. Candidate plant species to be used for lignocellulosic ethanol production include a large number of species within the Grass, Pine and Birch plant families. For these biofuel feedstock species, there are variable amounts of genome sequence resources available, ranging from complete genome sequences (e.g. sorghum, poplar) to transcriptome data sets (e.g. switchgrass, pine). These data sets are not only dispersed in location but also disparate in content. It will be essential to leverage and improve these genomic data sets for the improvement of biofuel feedstock production. The objectives of this project were to provide computational tools and resources for data-mining genome sequence/annotation and large-scale functional genomic datasets available for biofuel feedstock species. We have created a Bioenergy Feedstock Genomics Resource that provides a web-based portal or �clearing house� for genomic data for plant species relevant to biofuel feedstock production. Sequence data from a total of 54 plant species are included in the Bioenergy Feedstock Genomics Resource including model plant species that permit leveraging of knowledge across taxa to biofuel feedstock species.We have generated additional computational analyses of these data, including uniform annotation, to facilitate genomic approaches to improved biofuel feedstock production. These data have been centralized in the publicly available Bioenergy Feedstock Genomics Resource (http://bfgr.plantbiology.msu.edu/).

Buell, Carol Robin [Michigan State University; Childs, Kevin L [Michigan State University

2013-05-07T23:59:59.000Z

240

Controlled temperature expansion in oxygen production by molten alkali metal salts  

SciTech Connect

A continuous process is set forth for the production of oxygen from an oxygen containing gas stream, such as air, by contacting a feed gas stream with a molten solution of an oxygen acceptor to oxidize the acceptor and cyclically regenerating the oxidized acceptor by releasing oxygen from the acceptor wherein the oxygen-depleted gas stream from the contact zone is treated sequentially to temperature reduction by heat exchange against the feed stream so as to condense out entrained oxygen acceptor for recycle to the process, combustion of the gas stream with fuel to elevate its temperature and expansion of the combusted high temperature gas stream in a turbine to recover power.

Erickson, Donald C. (Annapolis)

1985-06-04T23:59:59.000Z

Note: This page contains sample records for the topic "oxygen species ros" 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

IMPACT OF OXYGENATED FUEL ON DIESEL ENGINE PERFORMANCE AND EMISSIONS  

DOE Green Energy (OSTI)

As evidenced by recent lawsuits brought against operators of large diesel truck fleets [1] and by the Consent Decree brought against the heavy-duty diesel manufacturers [2], the environmental and health effects of diesel engine emissions continue to be a significant concern. Reduction of diesel engine emissions has traditionally been achieved through a combination of fuel system, combustion chamber, and engine control modifications [3]. Catalytic aftertreatment has become common on modern diesel vehicles, with the predominant device being the diesel oxidation catalytic converter [3]. To enable advanced after-treatment devices and to directly reduce emissions, significant recent interest has focused on reformulation of diesel fuel, particularly the reduction of sulfur content. The EPA has man-dated that diesel fuel will have only 15 ppm sulfur content by 2007, with current diesel specifications requiring around 300 ppm [4]. Reduction of sulfur will permit sulfur-sensitive aftertreatment devices, continuously regenerating particulate traps, NOx control catalysts, and plasma assisted catalysts to be implemented on diesel vehicles [4]. Another method of reformulating diesel fuel to reduce emissions is to incorporate oxygen in the fuel, as was done in the reformulation of gasoline. The use of methyl tertiary butyl ether (MTBE) in reformulated gasoline has resulted in contamination of water resources across the country [5]. Nonetheless, by relying on the lessons learned from MTBE, oxygenation of diesel fuel may be accomplished without compromising water quality. Oxygenation of diesel fuel offers the possibility of reducing particulate matter emissions significantly, even for the current fleet of diesel vehicles. The mechanism by which oxygen content leads to particulate matter reductions is still under debate, but recent evidence shows clearly that ''smokeless'' engine operation is possible when the oxygen content of diesel fuel reaches roughly 38% by weight [6]. The potential improvements in energy efficiency within the transportation section, particularly in sport utility vehicles and light-duty trucks, that can be provided by deployment of diesel engines in passenger cars and trucks is a strong incentive to develop cleaner burning diesel engines and cleaner burning fuels for diesel engines. Thus, serious consideration of oxygenated diesel fuels is of significant practical interest and value to society. In the present work, a diesel fuel reformulating agent, CETANERTM, has been examined in a popular light-medium duty turbodiesel engine over a range of blending ratios. This additive is a mixture of glycol ethers and can be produced from dimethyl ether, which itself can be manufactured from synthesis gas using Air Products' Liquid Phase Dimethyl Ether (LPDME TM) technology. CETANERTM is a liquid, has an oxygen content of 36 wt.%, has a cetane number over 100 and is highly miscible in diesel fuel. This combination of physical and chemical properties makes CETANERTM an attractive agent for oxygenating diesel fuel. The present study considered CETANERTM ratios from 0 to 40 wt.% in a California Air Resources Board (CARB) specification diesel fuel. Particulate matter emissions, gaseous emissions and in-cylinder pressure traces were monitored over the AVL 8-Mode engine test protocol [7]. This paper presents the results from these measurements and discusses the implications of using high cetane number oxygenates in diesel fuel reformulation.

Boehman, Andre L.

2000-08-20T23:59:59.000Z

242

Assessing Potential Acidification of Marine Archaeological Wood Based on Concentration of Sulfur Species  

DOE Green Energy (OSTI)

The presence of sulfur in marine archaeological wood presents a challenge to conservation. Upon exposure to oxygen, sulfur compounds in waterlogged wooden artifacts are being oxidized, producing sulfuric acid. This speeds the degradation of the wood, potentially damaging specimens beyond repair. Sulfur K-edge x-ray absorption spectroscopy was used to identify the species of sulfur present in samples from the timbers of the Mary Rose, a preserved 16th century warship known to undergo degradation through acidification. The results presented here show that sulfur content varied significantly on a local scale. Only certain species of sulfur have the potential to produce sulfuric acid by contact with oxygen and seawater in situ, such as iron sulfides and elemental sulfur. Organic sulfurs, such as the amino acids cysteine and methionine, may produce acid but are integral parts of the wood's structure and may not be released from the organic matrix. The sulfur species contained in the sample reflect the exposure to oxygen while submerged, and this exposure can differ greatly over time and position. A better understanding of the species pathway to acidifications required, along with its location, in order to suggest a more customized and effective preservation strategy. Waterlogged archaeological wood, frequently in the form of shipwrecks, is being excavated for historical purposes in many countries around the world. Even after extensive efforts towards preservation, scientists are discovering that accumulation of sulfate salts results in acidic conditions on the surfaces of the artifacts. Sulfuric acid degrades structural fibers in the wood by acid hydrolysis of cellulose, accelerating the decomposition of the ship timbers. Determining the sulfur content of waterlogged wood is now of great importance in maritime archaeology. Artifact preservation is often more time consuming and expensive than the original excavation; but it is key to the availability of objects for future study as well as maintaining the integrity of historical data and preserving the value of museum pieces. Sulfur occurs in a wide number of oxidation states from -2 to +6, and appears in numerous organic and inorganic compounds in nature. However, it is a very minor component of wood. Sulfur K-edge x-ray absorption spectroscopy (XAS) is a valuable technique because it has the ability to detect very low concentrations of sulfur in the specimen. XAS is also sensitive to differences in oxidation states, as well as long and short range order in molecules.

Not Available

2011-06-22T23:59:59.000Z

243

Reforming of methane with carbon dioxide to synthesize gas over supported rhodium catalysts: II. A steady-state tracing analysis: Mechanistic aspects of the carbon and oxygen reaction pathways to form CO  

SciTech Connect

Steady-state tracing techniques have been applied to investigate mechanistic aspects of the CH{sub 4} reforming reaction over CO{sub 2} over Rh supported on yttria-stabilized zirconia (YSZ) and Al{sub 2}O{sub 3} as catalysts. It was found that the surface coverage of active carbon-containing species, which are found in the reaction pathway to CO formation, is of the order of 0.2 over the Rh/Al{sub 2}O{sub 3} catalyst, while it is very small ({theta}{sub c}, < 0.02) over Rh/YSZ. The surface coverage of active oxygen-containing species which lead to the formation of CO is found to be very small over both Rh/Al{sub 2}O{sub 3} and Rh/YSZ catalysts. However, over the Rh/YSZ catalyst it was found that there exists a large reservoir of lattice oxygen species of the carrier which interact reversibly with gaseous CO{sub 2} under reforming reaction conditions. A spillover of these lattice oxygen species onto the Rh surface seems to occur, contributing to the formation of CO and H{sub 2}O. This reaction route proceeds in parallel with the reforming reaction on the Rh surface. 27 refs., 12 figs.

Efstathiou, A.M.; Kladi, A.; Tsipouriari, V.A. [Univ. of Patras (Greece)] [and others

1996-01-01T23:59:59.000Z

244

Species diversity and foundation species: Potential indicators of fisheries yields and marine ecosystem functioning.  

E-Print Network (OSTI)

systems. In Global bio- diversity assessment, Section 6.complexity controls species diversity and nutrient effectsC. S. Thornber. 2006. Predator diversity strengthens trophic

Bracken, Matthew E.S.; Bracken, B. E.; Rogers-Bennett, Laura Dr.

2007-01-01T23:59:59.000Z

245

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

246

Selectivity of the reactions of oxygenates on transition metal surfaces  

Science Conference Proceedings (OSTI)

The goal of this research has been to understand, by means of surface science studies, the elementary processes involved in the synthesis of higher oxygenates on transition metals, and the dependence of these processes upon the nature of the surface. We have completed a considerable body of work (Ph.D. thesis of J. Lynn Davis, 1988) on the reactions of alcohols, aldehydes, and carboxylic acids on clean and oxygen-containing Pd(111) surfaces. Work during the past year has focused on the surface chemistry of rhodium. We find both interesting similarities and differences between rhodium and palladium. Comparison of the two sheds light on common reaction networks among the transition metals, and on the differences between them which permit control of selectivities in catalytic reactions.

Barteau, M.A.

1989-01-01T23:59:59.000Z

247

Supramolecular quantum dot-porphyrin assemblies for biological oxygen sensing  

E-Print Network (OSTI)

Generating metabolic profiles of tumors provides a spatiotemporal map of the concentration of key species to assess and quantify tumor growth, metabolism, and response to therapy. Because the tumor microenvironment is ...

Lemon, Christopher M. (Christopher Michael)

2013-01-01T23:59:59.000Z

248

U.S. Oxygenate Plant Production of Fuel Ethanol (Thousand Barrels)  

U.S. Energy Information Administration (EIA)

U.S. Oxygenate Plant Production of Fuel Ethanol (Thousand Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 ... Fuel Ethanol Oxygenate Production;

249

Calibration, Response, and Hysteresis in Deep-Sea Dissolved Oxygen Measurements  

Science Conference Proceedings (OSTI)

Accurately measuring the dissolved oxygen concentration in the ocean has been the subject of considerable research. Traditionally, the calibration and correction of profiling oxygen measurements has centered on static, steady-state errors, ...

Bradley Edwards; David Murphy; Carol Janzen; Nordeen Larson

2010-05-01T23:59:59.000Z

250

Fundamental studies of heterostructured oxide thin film electrocatalysts for oxygen reduction at high temperatures  

E-Print Network (OSTI)

Searching for active and cost-effective catalysts for oxygen electrocatalysis is essential for the development of efficient clean electrochemical energy technologies. Perovskite oxides are active for surface oxygen exchange ...

Crumlin, Ethan J

2012-01-01T23:59:59.000Z

251

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

E-Print Network (OSTI)

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 ...

Lu, Yi-chun

252

Computational Studies on Oxygen-ionic Conduction in Rare-earth ...  

Science Conference Proceedings (OSTI)

Development of oxygen-ionic conductors which have low activation energies in ... for reducing the lower limit of operating temperatures of solid oxide fuel cells. ... electronic densities of states, oxygen migration paths and activation energies in ...

253

A Tracer Study with Oxygen-18 in Photosynthesis by Activation Analysis  

E-Print Network (OSTI)

r e e n algae. t e r m photosynthesis products containing 0WITH OXYGEN - I8 IN PHOTOSYNTHESIS BY ACTIVATION ANALYSISWITH OXYGEN-18 IN PHOTOSYNTHESIS BY ACTIVATION ANALYSIS I n

Fogelstrom-Fineman, Ingrid; Holm-Hansen, Osmund; Tolbert, Bert M.; Calvin, Melvin

1957-01-01T23:59:59.000Z

254

A DCS supervisory control of a centrifugal compessor for oxygen consumption optimization  

Science Conference Proceedings (OSTI)

In this paper, a supervisory control system for oxygen consumption optimization on a Syngas Manufacturing Process Plant is proposed. A grey-box multivariable parametric identification of the oxygen compressor system is first performed. Consequently, ...

Silvia Maria Zanoli; Luca Barboni

2009-06-01T23:59:59.000Z

255

Practical aspects of the oxygen reduction reaction (ORR)  

DOE Green Energy (OSTI)

The oxygen reduction reaction (ORR) is quite sensitive to the details of the three phase interface at which the reaction occurs. We describe here studies of the ORR at a well-defined recast Nafion/Pt microelectrode interface, emphasizing the effects of temperature and humidification on the reaction rate. We compare our results to those obtained in thin film composite electrodes used in polymer electrolyte fuel cells.

Uribe, F.A.; Springer, T.E.; Wilson, M.S.; Zawodzinski, T.A. Jr.; Gottesfeld, S.

1995-12-31T23:59:59.000Z

256

Mixed-conducting ceramic membranes for partial oxygenation of methane  

DOE Green Energy (OSTI)

The most significant cost associated with the conventional partial oxidation of methane is that of an oxygen plant. Our new technology offers a way to lower this cost, and in this paper we explore the technology that is based on dense ceramic membranes and that uses air as the oxidant for methane-conversion reactions. Mixed-conducting ceramic materials have been produced from mixed-oxide systems of the La-Sr-Fe-Co-O (SFC) type, in the form of tubes and bars. Thermodynamic stability of the tubes was studied as a function of oxygen partial pressure by high-temperature XRD. Mechanical properties were measured and found to be adequate for a reactor in the case of SFC-2: Electronic and ionic conductivities were measured; SFC-2 is unique in the sense that the ratio of ionic to electronic conductance is close to unity. Performance of the membrane tubes was good only with SFC-2. Fracture of other SFC tubes was the consequence of an oxygen gradient that introduced a volumetric lattice difference between the inner and outer walls. SFC-2 tubes provided methane conversion efficiencies of >99% in a reactor. These tubes have operated for >1000 h.

Balachandran, U.; Dusek, J.T.; Maiya, P.S.; Mieville, R.L. [Argonne National Lab., IL (United States); Kleefisch, M.S.; Udovich, C.A. [Amoco Corp., Naperville, IL (United States); Bose, A.C. [USDOE Pittsburgh Energy Technology Center, PA (United States)

1995-05-01T23:59:59.000Z

257

Formation of molecular oxygen in ultracold O + OH reaction  

SciTech Connect

We discuss the formation of molecular oxygen in ultracold collisions between hydroxyl radicals and atomic oxygen. A time-independent quantum formalism based on hyperspherical coordinates is employed for the calculations. Elastic, inelastic and reactive cross sections as well as the vibrational and rotational populations of the product O{sub 2} molecules are reported. A J-shifting approximation is used to compute the rate coefficients. At temperatures T = 10--100 mK for which the OH molecules have been cooled and trapped experimentally, the elastic and reactive rate coefficients are of comparable magnitude, while at colder temperatures, T < 1 mK, the formation of molecular oxygen becomes the dominant pathway. The validity of a classical capture model to describe cold collisions of OH and O is also discussed. While very good agreement is found between classical and quantum results at T = 0.3 K, at higher temperatures, the quantum calculations predict a higher rate coefficient than the classical model, in agreement with experimental data for the O + OH reaction. The zero-temperature limiting value of the rate coefficient is predicted to be about 6 x 10{sup -12} cm{sup 3} s{sup 01}, a value comparable to that of barrierless alkali metal atom-dimer systems and about a factor of five larger than that of the tunneling dominated F + H{sub 2} reaction.

Kendrick, Brian Kent [Los Alamos National Laboratory; Quemener, Goulven [UNLV; Balakrishman, Naduvalath [UNLV

2008-01-01T23:59:59.000Z

258

Oxygen scavenger/metal passivator reduces corrosion, toxicity  

Science Conference Proceedings (OSTI)

Haverhill Paper board, a Haverhill, MA manufacturer of recycled paperboard, generates about 120,000 lb/hr of 650 psi, 650/sup 0/F (superheated) steam. Boiler deposition and condensate return corrosion problems were always high on the list of things to avoid. A water treatment firm provided the solution with a recently developed oxygen scavenger. The new scavenger, a Chemical Processing Vaaler Award winner (Mid-November, 1986, p. 130), is a patented formulation containing methyl ethyl ketoxime (MEKO). The formulation is designed to provide protection comparable to hydrazine but without the toxicity concerns. Used in conjunction with the mechanical deaerator, MEKO scavenges the remaining 5-7 ppb of oxygen from the feed water, producing methyl ethyl ketone (MEK), N/sub 2/O, and water. High volatility gives it the ability to leave the boiler with the steam, protecting the entire generating system. MEKO also acts as a metal surface passivator, protecting iron surfaces from corrosion by forming passivated oxide films. In use since December, 1985, the MEKO-based oxygen scavenger has coupled with the other chemical and mechanical water treatment methods to maintain the boiler in operating condition. The MEKO is performing as well or better than the hydrazine at about the same cost - while avoiding the toxicity problem.

Barry, J.; Toy, D.A.

1987-07-01T23:59:59.000Z

259

Evolution of Photosynthesis and Biospheric Oxygenation Contingent Upon Nitrogen Fixation?  

E-Print Network (OSTI)

How photosynthesis by Precambrian cyanobacteria oxygenated Earth's biosphere remains incompletely understood. Here it is argued that the oxic transition, which took place between approximately 2.3 and 0.5 Gyr ago, required a great proliferation of cyanobacteria, and this in turn depended on their ability to fix nitrogen via the nitrogenase enzyme system. However, the ability to fix nitrogen was not a panacea, and the rate of biospheric oxygenation may still have been affected by nitrogen constraints on cyanobacterial expansion. Evidence is presented for why cyanobacteria probably have a great need for fixed nitrogen than other prokaryotes, underscoring the importance of their ability to fix nitrogen. The connection between nitrogen fixation and the evolution of photosynthesis is demonstrated by the similarities between nitrogenase and enzymes critical for the biosynthesis of (bacterio)chlorophyll. It is hypothesized that biospheric oxygenation would not have occurred if the emergence of cyanobacteria had not been preceded by the evolution of nitrogen fixation, and if these organisms had not also acquired the ability to fix nitrogen at the beginning of or very early in their history. The evolution of nitrogen fixation also appears to have been a precondition for the evolution of (bacterio)chlorophyll-based photosynthesis. Given that some form of chlorophyll is obligatory for true photosynthesis, and its light absorption and chemical properties make it a "universal pigment," it may be predicted that the evolution of nitrogen fixation and photosynthesis are also closely linked on other Earth- like planets.

John W. Grula

2006-05-12T23:59:59.000Z

260

Electrocatalyst for Oxygen Reduction with Reduced Platinum Oxidation and Dissolution Rates  

Platinum is the most efficient electrocatalyst for accelerating the oxygen reduction reaction in fuel cells. Under operating conditions, though, ...

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261

U.S. Product Supplied of Other Hydrocarbons/Oxygenates (Thousand ...  

U.S. Energy Information Administration (EIA)

Product Supplied for Hydrogen/Oxygenates/Renewables/Other Hydrocarbons ; U.S. Product Supplied for Crude Oil and Petroleum Products ...

262

U.S. Exports of Other Hydrocarbons/Oxygenates (Thousand Barrels ...  

U.S. Energy Information Administration (EIA)

Hydrogen/Oxygenates/Renewables/Other Hydrocarbons Supply and Disposition; U.S. Exports of Crude Oil and Petroleum Products ...

263

Atmospheric Measurements of Climate-Relevant Species  

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

Atmospheric Measurements of Climate-Relevant Species Atmospheric Measurements of Climate-Relevant Species CDIAC's data collection includes measurements of the following climate-relevant chemical species. A summary of recent greenhouse gas concentrations is also available. To determine how compounds are named, see the CDIAC "Name that compound" page. Butane (C4H10) Carbon Dioxide (CO2) Carbon Isotopes Carbon Monoxide (CO) Carbon Tetrachloride (CCl4) Chlorofluorocarbons Chloroform (CHCl3) Deuterium (2H) Ethane (C2H6) Ethyl Nitrate (C2H5ONO2) Ethyne (C2H2) Fluoroform (CHF3) Halogenated Compounds (modern records) Halons (fluorocarbons) Hydrogen (H2) Hydrochlorofluorocarbons (HCFCs) Hydrofluorocarbons (HFCs) i-Propyl Nitrate (C3H7ONO2) Methane (CH4) Methyl Bromide (CH3Br) Methyl Chloride (CH3Cl) Methyl Chloroform (CH3CCl3)

264

Oxygen production by molten alkali metal salts using multiple absorption-desorption cycles  

DOE Patents (OSTI)

A continuous chemical air separation is performed wherein oxygen is recovered with a molten alkali metal salt oxygen acceptor in a series of absorption zones which are connected to a plurality of desorption zones operated in separate parallel cycles with the absorption zones. A greater recovery of high pressure oxygen is achieved at reduced power requirements and capital costs.

Cassano, Anthony A. (Allentown, PA)

1985-01-01T23:59:59.000Z

265

Oxygen production by molten alkali metal salts using multiple absorption-desorption cycles  

DOE Patents (OSTI)

A continuous chemical air separation is performed wherein oxygen is recovered with a molten alkali metal salt oxygen acceptor in a series of absorption zones which are connected to a plurality of desorption zones operated in separate parallel cycles with the absorption zones. A greater recovery of high pressure oxygen is achieved at reduced power requirements and capital costs. 3 figs.

Cassano, A.A.

1985-07-02T23:59:59.000Z

266

Faunal responses to oxygen gradients on the Pakistan margin: A comparison of foraminiferans, macrofauna and megafauna  

E-Print Network (OSTI)

Faunal responses to oxygen gradients on the Pakistan margin: A comparison of foraminiferans Oxygen minimum zone Benthos Arabian Sea Biodiversity Deep sea a b s t r a c t The Pakistan Margin where oxygen levels were lowest. The rarity of larger animals between 300 and 700 m on the Pakistan

Levin, Lisa

267

An efficient deconvolution algorithm for estimating oxygen consumption during muscle activities  

Science Conference Proceedings (OSTI)

The reconstruction of an unknown input function from noisy measurements in a biological system is an ill-posed inverse problem. Any computational algorithm for its solution must use some kind of regularization technique to neutralize the disastrous effects ... Keywords: Bayesian inversion, Deconvolution, Mitochondrial oxygen consumption, Monte Carlo simulation, Muscle oxygen uptake, Oxygen transport and metabolism

Ranjan K. Dash; Erkki Somersalo; Marco E. Cabrera; Daniela Calvetti

2007-03-01T23:59:59.000Z

268

New Species of Cyanobacteria Forms Intracellular Carbonates  

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

New Species of Cyanobacteria New Species of Cyanobacteria Forms Intracellular Carbonates New Species of Cyanobacteria Forms Intracellular Carbonates Print Wednesday, 30 January 2013 00:00 A new species of cyanobacteria-photosynthetic bacteria that occupy a wide array of habitats-was discovered in the Mexican Lake of Alchichica where massive carbonate rocks form. Cyanobacteria have been impacting the global carbon cycle of the Earth for more than 2.3 billion years by assimilating CO2 into organic compounds and triggering calcium carbonate (CaCO3) precipitation. Despite the importance of this cyanobacteria-mediated CaCO3 biomineralization, the mechanistic details of this process are still poorly understood. Scientists agree that calcification in cyanobacteria is an extracellular process: Photosynthesizing cells commonly export the photosynthesis byproduct CO32- outside their cells where it bonds with an alkaline earth metal like Ca2+. The cyanobacteria recently found in Lake Alchichica, however, forms amorphous Ca-, Mg-, Sr- and Ba-rich carbonates intracellularly. This discovery significantly modifies the traditional view of how bacteria induce CaCO3 precipitation and may improve understanding of the fossil record by hinting at ancient traces of life in rocks, or designing new routes for sequestering CO2 or 90Sr in minerals.

269

Sequencing the Black Aspergilli species complex  

Science Conference Proceedings (OSTI)

The ~15 members of the Aspergillus section Nigri species complex (the "Black Aspergilli") are significant as platforms for bioenergy and bioindustrial technology, as members of soil microbial communities and players in the global carbon cycle, and as food processing and spoilage agents and agricultural toxigens. Despite their utility and ubiquity, the morphological and metabolic distinctiveness of the complex's members, and thus their taxonomy, is poorly defined. We are using short read pyrosequencing technology (Roche/454 and Illumina/Solexa) to rapidly scale up genomic and transcriptomic analysis of this species complex. To date we predict 11197 genes in Aspergillus niger, 11624 genes in A. carbonarius, and 10845 genes in A. aculeatus. A. aculeatus is our most recent genome, and was assembled primarily from 454-sequenced reads and annotated with the aid of >2 million 454 ESTs and >300 million Solexa ESTs. To most effectively deploy these very large numbers of ESTs we developed 2 novel methods for clustering the ESTs into assemblies. We have also developed a pipeline to propose orthologies and paralogies among genes in the species complex. In the near future we will apply these methods to additional species of Black Aspergilli that are currently in our sequencing pipeline.

Kuo, Alan; Salamov, Asaf; Zhou, Kemin; Otillar, Robert; Baker, Scott; Grigoriev, Igor

2011-03-11T23:59:59.000Z

270

Photodissociation Dynamics of Halogen Oxide Species  

E-Print Network (OSTI)

The focus of this dissertation is the study of the photodissociation dynamics of halogen oxide species (XO, X = Cl, Br, I). These radical species are known to be important in stratospheric and tropospheric ozone depletion cycles. They are also useful benchmark systems for the comparison to current theoretical methods where they provide insight into the dynamics occurring beyond the Franck-Condon region. These systems are studied using velocity map ion imaging, a technique that measures velocity and angular information simultaneously. Photofragment species are state-selectively ionized for detection using 2+1 REMPI (Resonance Enhanced Multi-Photon Ionization). The instrumentation employs a molecular beam of the XO radicals formed using pyrolitic and photolytic methods. The current work involves the measurement of fundamental physical constants of the XO species. The bond dissociation energy of IO is measured. Vibrational level dependent correlated final state branching ratios of the predissociation of the A(^2 II_3/2) state of ClO and BrO are reported, and comparison to theoretical methods is discussed.

Dooley, Kristin S.

2009-05-01T23:59:59.000Z

271

In-Cylinder Reaction Chemistry and Kinetics During Negative Valve Overlap Fuel Injection Under Low-Oxygen Conditions  

DOE Green Energy (OSTI)

Fuel injection into the negative valve overlap (NVO) period is a common method for controlling combustion phasing in homogeneous charge compression ignition (HCCI) as well as other forms of advanced combustion. During this event, at least a portion of the fuel hydrocarbons can be converted to products containing significant levels of H2 and CO, as well as other short chain hydrocarbons by means of thermal cracking, water-gas shift, and partial oxidation reactions, depending on the availability of oxygen and the time-temperature-pressure history. The resulting products alter the autoignition properties of the combined fuel mixture for HCCI. Fuel-rich chemistry in a partial oxidation environment is also relevant to other high efficiency engine concepts (e.g., the dedicated EGR (D-EGR) concept from SWRI). In this study, we used a unique 6-stroke engine cycle to experimentally investigate the chemistry of a range of fuels injected during NVO under low oxygen conditions. Fuels investigated included iso-octane, iso-butanol, ethanol, and methanol. Products from NVO chemistry were highly dependent on fuel type and injection timing, with iso-octane producing less than 1.5% hydrogen and methanol producing more than 8%. We compare the experimental trends with CHEMKIN (single zone, 0-D model) predictions using multiple kinetic mechanisms available in the current literature. Our primary conclusion is that the kinetic mechanisms investigated are unable to accurately predict the magnitude and trends of major species we observed.

Kalaskar, Vickey B [ORNL] [ORNL; Szybist, James P [ORNL] [ORNL; Splitter, Derek A [ORNL] [ORNL; Pihl, Josh A [ORNL] [ORNL; Gao, Zhiming [ORNL] [ORNL; Daw, C Stuart [ORNL] [ORNL

2013-01-01T23:59:59.000Z

272

Oxygen-Consuming Chlor-Alkali Cell Configured To Minimize Peroxide  

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

Oxygen-Consuming Chlor-Alkali Cell Oxygen-Consuming Chlor-Alkali Cell Oxygen-Consuming Chlor-Alkali Cell Configured To Minimize Peroxide Formation Oxygen-consuming zero gap chlor-alkali cell was configured to minimize peroxide formation. Available for thumbnail of Feynman Center (505) 665-9090 Email Oxygen-Consuming Chlor-Alkali Cell Configured To Minimize Peroxide Formation Oxygen-consuming zero gap chlor-alkali cell was configured to minimize peroxide formation. The cell included an ion-exchange membrane that divided the cell into an anode chamber including an anode and a cathode chamber including an oxygen gas diffusion cathode. The cathode included a single-piece of electrically conducting graphitized carbon cloth. Catalyst and polytetrafluoroethylene were attached to only one side of the cloth.

273

Cl atom recombination on silicon oxy-chloride layers deposited on chamber walls in chlorine-oxygen plasmas  

SciTech Connect

Chlorine atom recombination coefficients were measured on silicon oxy-chloride surfaces deposited in a chlorine inductively coupled plasma (ICP) with varying oxygen concentrations, using the spinning wall technique. A small cylinder embedded in the walls of the plasma reactor chamber was rapidly rotated, repetitively exposing its surface to the plasma chamber and a differentially pumped analysis chamber housing a quadruple mass spectrometer for line-of-sight desorbing species detection, or an Auger electron spectrometer for in situ surface analysis. The spinning wall frequency was varied from 800 to 30 000 rpm resulting in a detection time, t (the time a point on the surface takes to rotate from plasma chamber to the position facing the mass or Auger spectrometer), of {approx}1-40 ms. Desorbing Cl{sub 2}, due to Langmuir-Hinshelwood (LH) Cl atom recombination on the reactor wall surfaces, was detected by the mass spectrometer and also by a pressure rise in one of the differentially pumped chambers. LH Cl recombination coefficients were calculated by extrapolating time-resolved desorption decay curves to t = 0. A silicon-covered electrode immersed in the plasma was either powered at 13 MHz, creating a dc bias of -119 V, or allowed to electrically float with no bias power. After long exposure to a Cl{sub 2} ICP without substrate bias, slow etching of the Si wafer coats the chamber and spinning wall surfaces with an Si-chloride layer with a relatively small amount of oxygen (due to a slow erosion of the quartz discharge tube) with a stoichiometry of Si:O:Cl = 1:0.38:0.38. On this low-oxygen-coverage surface, any Cl{sub 2} desorption after LH recombination of Cl was below the detection limit. Adding 5% O{sub 2} to the Cl{sub 2} feed gas stopped etching of the Si wafer (with no rf bias) and increased the oxygen content of the wall deposits, while decreasing the Cl content (Si:O:Cl = 1:1.09:0.08). Cl{sub 2} desorption was detectable for Cl recombination on the spinning wall surface coated with this layer, and a recombination probability of {gamma}{sub Cl} = 0.03 was obtained. After this surface was conditioned with a pure oxygen plasma for {approx}60 min, {gamma}{sub Cl} increased to 0.044 and the surface layer was slightly enriched in oxygen fraction (Si:O:Cl = 1:1.09:0.04). This behavior is attributed to a mechanism whereby Cl LH recombination occurs mainly on chlorinated oxygen sites on the silicon oxy-chloride surface, because of the weak Cl-O bond compared to the Cl-Si bond.

Khare, Rohit; Srivastava, Ashutosh; Donnelly, Vincent M. [Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204 (United States)

2012-09-15T23:59:59.000Z

274

Method for providing oxygen ion vacancies in lanthanide oxides  

DOE Patents (OSTI)

A method for desulfurization of fuel gases resulting from the incomplete combustion of sulfur containing hydrocarbons whereby the gases are treated with lanthanide oxides containing large numbers of oxygen-ion vacancies providing ionic porosity which enhances the ability of the lanthanide oxides to react more rapidly and completely with the sulfur in the fuel gases whereby the sulfur in such gases is reduced to low levels suitable for fuels for firing into boilers of power plants generating electricity with steam turbine driven generators, gas turbines, fuel cells and precursors for liquid fuels such as methanol and the like.

Kay, D. Alan R. (4305 Lakeshore Rd., Burlington, CA); Wilson, William G. (820 Harden Dr., Pittsburgh, PA 15229)

1989-12-05T23:59:59.000Z

275

Recent advances in the kinetics of oxygen reduction  

DOE Green Energy (OSTI)

Oxygen reduction is considered an important electrocatalytic reaction; the most notable need remains improvement of the catalytic activity of existing metal electrocatalysts and development of new ones. A review is given of new advances in the understanding of reaction kinetics and improvements of the electrocatalytic properties of some surfaces, with focus on recent studies of relationship of the surface properties to its activity and reaction kinetics. The urgent need is to improve catalytic activity of Pt and synthesize new, possibly non- noble metal catalysts. New experimental techniques for obtaining new level of information include various {ital in situ} spectroscopies and scanning probes, some involving synchrotron radiation. 138 refs, 18 figs, 2 tabs.

Adzic, R.

1996-07-01T23:59:59.000Z

276

Hydrogen and oxygen concentrations in IXCs: A compilation  

DOE Green Energy (OSTI)

This paper contains four reports and two internal letters that address the estimation of hydrogen and oxygen concentrations in ion exchange columns that treat the water of the K-East and K-West Basins at Hanford. The concern is the flammability of this mixture of gases and planning for safe transport during decommissioning. A transient will occur when the hydrogen filter is temporarily blocked by a sandbag. Analyses are provided for steady-state, transients, and for both wet and dry resins.

Liljegren, L.M.; Terrones, G.T.; Melethil, P.K.

1996-06-01T23:59:59.000Z

277

Aquatic Species Program (ASP): Lessons Learned (Presentation)  

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

Aquatic Species Aquatic Species Program (ASP): Lessons Learned AFOSR Workshop Washington, D.C. February 19-21, 2008 Sponsored by Air Force Office of Science Eric E. Jarvis, Ph.D. National Renewable Energy Laboratory National Bioenergy Center eric_jarvis@nrel.gov NREL/PR-510-43232 The ASP Didn't Invent the Concept of Fuels from Algae...  Algae for methane (via anaerobic digestion) * Meier (1955); UC Berkeley 1957-59 (Oswald and Golueke) * Wastewater use, recycling of CO 2 and nutrients  Revival during Energy Crisis of 1970's * Uziel et al. (1975); Benemann et al. (1976-80) * Still focused on methane and hydrogen * Energy Research and Development Administration (ERDA) * Later DOE (SERI founded in 1977) ...But the ASP Took the Concept to the Next Level  Supported work at SERI/NREL and through

278

endangered species | OpenEI Community  

Open Energy Info (EERE)

429 Throttled (bot load) 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142234558 Varnish cache server endangered species Home Kyoung's picture Submitted by Kyoung(155) Contributor 4 September, 2012 - 21:36 Idaho Meeting #2 endangered species Fauna Fish and Wildlife Flora FWS Section 12 Section 7 The second Idaho GRR meeting was held today in Boise. Though the intent of the meeting was to focus on identifying permitting concerns, agencies and developers alike had few concerns with the current process. There were agency personnel in attendance who had not attended the first Idaho meeting, so the workshop was a great opportunity to work through the flowcharts relevant to those agencies. Syndicate content 429 Throttled (bot load) Error 429 Throttled (bot load)

279

Two Component Signal Transduction in Desulfovibrio Species  

Science Conference Proceedings (OSTI)

The environmentally relevant Desulfovibrio species are sulfate-reducing bacteria that are of interest in the bioremediation of heavy metal contaminated water. Among these, the genome of D. vulgaris Hildenborough encodes a large number of two component systems consisting of 72 putative response regulators (RR) and 64 putative histidinekinases (HK), the majority of which are uncharacterized. We classified the D. vulgaris Hildenborough RRs based on their output domains and compared the distribution of RRs in other sequenced Desulfovibrio species. We have successfully purified most RRs and several HKs as His-tagged proteins. We performed phospho-transfer experiments to verify relationships between cognate pairs of HK and RR, and we have also mapped a few non-cognate HK-RR pairs. Presented here are our discoveries from the Desulfovibrio RR categorization and results from the in vitro studies using purified His tagged D. vulgaris HKs and RRs.

Luning, Eric; Rajeev, Lara; Ray, Jayashree; Mukhopadhyay, Aindrila

2010-05-17T23:59:59.000Z

280

Methanol tolerant oxygen reduction catalysts based on transition metal sulfides  

Science Conference Proceedings (OSTI)

The oxygen reduction activity and methanol tolerance of a range of transition metal sulfide electrocatalysts have been evaluated in half-cell experiments and in a liquid-feed solid polymer electrolyte direct methanol fuel cell. These catalysts were prepared in high surface area form by direct synthesis onto various surface-functionalized carbon blacks. Of the materials tested, mixed-metal catalysts based on ReRuS and MoRuS were observed to give the best oxygen reduction activities. In addition, significant increases in performance were observed when employing sulfur-functionalized carbon black, which were attributed to the preferential deposition of active Ru sites in the catalyst-preparation process. Although the intrinsic activity of the best material tested, namely, Mo{sub 2}Ru{sub 5}S{sub 5} on sulfur-treated XC-72, was lower than Pt (by ca. 1545 mV throughout the entire polarization curve), its activity relative to Pt increased significantly in methanol-contaminated electrolytes. This was due to methanol oxidation side reactions reducing the net activity of the Pt, especially at low overpotentials.

Reeve, R.W.; Christensen, P.A.; Hamnett, A.; Haydock, S.A.; Roy, S.C. [Univ. of Newcastle, Newcastle upon Tyne (United Kingdom). Dept. of Chemistry

1998-10-01T23:59:59.000Z

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


281

Nickel-hydrogen battery with oxygen and electrolyte management features  

SciTech Connect

A nickel-hydrogen battery or cell having one or more pressure vessels containing hydrogen gas and a plurality of cell-modules therein. Each cell-module includes a configuration of cooperatively associated oxygen and electrolyte mangement and component alignment features. A cell-module having electrolyte includes a negative electrode, a positive electrode adapted to facilitate oxygen diffusion, a separator disposed between the positive and negative electrodes for separating them and holding electrolyte for ionic conductivity, an absorber engaging the surface of the positive electrode facing away from the separator for providing electrolyte to the positive electrode, and a pair of surface-channeled diffusion screens for enclosing the positive and negative electrodes, absorber, and separator and for maintaining proper alignment of these components. The screens, formed in the shape of a pocket by intermittently sealing the edges together along as many as three sides, permit hydrogen gas to diffuse therethrough to the negative electrodes, and prevent the edges of the separator from swelling. Electrolyte is contained in the cell-module, absorbhed by the electrodes, the separator and the absorber.

Sindorf, John F. (Pewaukee, WI)

1991-10-22T23:59:59.000Z

282

Radiation chemistry of alternative fuel oxygenates -- Substituted ethers  

DOE Green Energy (OSTI)

The electron beam process, an advanced oxidation and reduction technology, is based in the field of radiation chemistry. Fundamental to the development of treatment processes is an understanding of the underlying chemistry. The authors have previously evaluated the bimolecular rate constants for the reactions of methyl tert-butyl ether (MTBE) and with this study have extended their studies to include ethyl tert-butyl ether (ETBE), di-isopropyl ether (DIPE) and tert-amyl methyl ether (TAME) with the hydroxyl radical, hydrogen atom and solvated electron using pulse radiolysis. For all of the oxygenates the reaction with the hydroxyl radical appears to be of primary interest in the destruction of the compounds in water. The rates with the solvated electron are limiting values as the rates appear to be relatively low. The hydrogen atom rate constants are relatively low, coupled with the low yield in radiolysis, they concluded that these are of little significance in the destruction of the alternative fuel oxygenates (and MTBE).

Mezyk, S. P.; Cooper, W. J.; Bartels, D. M.; Tobien, T.; O'Shea, K. E.

1999-11-15T23:59:59.000Z

283

Commercialization Development of Oxygen Fired CFB for Greenhouse Gas Control  

SciTech Connect

Given that fossil fuel fired power plants are among the largest and most concentrated producers of CO{sub 2} emissions, recovery and sequestration of CO{sub 2} from the flue gas of such plants has been identified as one of the primary means for reducing anthropogenic (i.e., man-made) CO{sub 2} emissions. In 2001, ALSTOM Power Inc. (ALSTOM) began a two-phase program to investigate the feasibility of various carbon capture technologies. This program was sponsored under a Cooperative Agreement from the US Department of Energy's National Energy Technology Laboratory (DOE). The first phase entailed a comprehensive study evaluating the technical feasibility and economics of alternate CO{sub 2} capture technologies applied to Greenfield US coal-fired electric generation power plants. Thirteen cases, representing various levels of technology development, were evaluated. Seven cases represented coal combustion in CFB type equipment. Four cases represented Integrated Gasification Combined Cycle (IGCC) systems. Two cases represented advanced Chemical Looping Combined Cycle systems. Marion, et al. reported the details of this work in 2003. One of the thirteen cases studied utilized an oxygen-fired circulating fluidized bed (CFB) boiler. In this concept, the fuel is fired with a mixture of oxygen and recirculated flue gas (mainly CO{sub 2}). This combustion process yields a flue gas containing over 80 percent (by volume) CO{sub 2}. This flue gas can be processed relatively easily to enrich the CO{sub 2} content to over 96 percent for use in enhanced oil or gas recovery (EOR or EGR) or simply dried for sequestration. The Phase I study identified the O{sub 2}-fired CFB as having a near term development potential, because it uses conventional commercial CFB technology and commercially available CO{sub 2} capture enabling technologies such as cryogenic air separation and simple rectification or distillation gas processing systems. In the long term, air separation technology advancements offer significant reductions in power requirements, which would improve plant efficiency and economics for the oxygen-fired technology. The second phase consisted of pilot-scale testing followed by a refined performance and economic evaluation of the O{sub 2} fired CFB concept. As a part of this workscope, ALSTOM modified its 3 MW{sub th} (9.9 MMBtu/hr) Multiuse Test Facility (MTF) pilot plant to operate with O{sub 2}/CO{sub 2} mixtures of up to 70 percent O{sub 2} by volume. Tests were conducted with coal and petroleum coke. The test objectives were to determine the impacts of oxygen firing on heat transfer, bed dynamics, potential agglomeration, and gaseous and particulate emissions. The test data results were used to refine the design, performance, costs, and economic models developed in Phase-I for the O{sub 2}-fired CFB with CO{sub 2} capture. Nsakala, Liljedahl, and Turek reported results from this study in 2004. ALSTOM identified several items needing further investigation in preparation for large scale demonstration of the oxygen-fired CFB concept, namely: (1) Operation and performance of the moving bed heat exchanger (MBHE) to avoid recarbonation and also for cost savings compared to the standard bubbling fluid bed heat exchanger (FBHE); (2) Performance of the back-end flash dryer absorber (FDA) for sulfur capture under high CO{sub 2}/high moisture flue gas environment using calcined limestone in the fly ash and using fresh commercial lime directly in the FDA; (3) Determination of the effect of recarbonation on fouling in the convective pass; (4) Assessment of the impact of oxygen firing on the mercury, other trace elements, and volatile organic compound (VOC) emissions; and (5) Develop a proposal-level oxygen-fired retrofit design for a relatively small existing CFB steam power plant in preparation for a large-scale demonstration of the O{sub 2} fired CFB concept. Hence, ALSTOM responded to a DOE Solicitation to address all these issues with further O{sub 2} fired MTF pilot testing and a subsequent retrofit design study of oxygen firing and CO{s

Nsakala ya Nsakala; Gregory N. Liljedahl; David G. Turek

2007-03-31T23:59:59.000Z

284

Oxygen-Diffused Titanium as a Candidate Brake Rotor Material  

SciTech Connect

Titanium alloys are one of several candidate materials for the next generation of truck disk brake rotors. Despite their advantages of lightweight relative to cast iron and good strength and corrosion resistance, titanium alloys are unlikely to be satisfactory brake rotor materials unless their friction and wear behavior can be significantly improved. In this study, a surface engineering process oxygen diffusion was applied to titanium rotors and has shown very encouraging results. The oxygen diffused Ti-6Al-4V (OD-Ti) was tested on a sub-scale brake tester against a flat block of commercial brake lining material and benchmarked against several other Ti-based materials, including untreated Ti-6Al-4V, ceramic particle-reinforced Ti composites (MMCs), and a thermal-spray-coated Ti alloy. With respect to friction, the OD-Ti outperformed all other candidate materials under the imposed test conditions with the friction coefficient remaining within a desirable range of 0.35-0.50, even under the harshest conditions when the disk surface temperature reached nearly 600 ?C. In addition, the OD-Ti showed significantly improved wear-resistance over the non-treated one and was even better than the Ti-based composite materials.

Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Jolly, Brian C [ORNL

2009-01-01T23:59:59.000Z

285

CO2 Health Effects in Wildlife Species  

Science Conference Proceedings (OSTI)

The impetus for this project is the possible development of large-scale carbon dioxide (CO2) capture, transport, and storage (CCS) sites that have the potential to release CO2 into the environment and cause adverse health effects. The purpose of this project is to obtain information from the scientific literature on the effects of CO2 exposure in wildlife animal species. This report, along with previously documented information on the effects of CO2 in humans, laboratory animals, and domesticated animals...

2008-12-09T23:59:59.000Z

286

Hydrogen and Oxygen Gas Monitoring System Design and Operation  

DOE Green Energy (OSTI)

This paper describes pertinent design practices of selecting types of monitors, monitor unit placement, setpoint selection, and maintenance considerations for gas monitors. While hydrogen gas monitors and enriched oxygen atmosphere monitors as they would be needed for hydrogen production experiments are the primary focus of this paper, monitors for carbon monoxide and carbon dioxide are also discussed. The experiences of designing, installing, and calibrating gas monitors for a laboratory where experiments in support of the DOE Nuclear Hydrogen Initiative (NHI) are described along with codes, standards, and regulations for these monitors. Information from the literature about best operating practices is also presented. The NHI program has two types of activities. The first, near-term activity is laboratory and pilot-plant experimentation with different processes in the kilogram per day scale to select the most promising types of processes for future applications of hydrogen production. Prudent design calls for indoor gas monitors to sense any hydrogen leaks within these laboratory rooms. The second, longer-term activity is the prototype, or large-scale plants to produce tons of hydrogen per day. These large, outdoor production plants will require area (or “fencepost”) monitoring of hydrogen gas leaks. Some processes will have oxygen production with hydrogen production, and any oxygen releases are also safety concerns since oxygen gas is the strongest oxidizer. Monitoring of these gases is important for personnel safety of both indoor and outdoor experiments. There is some guidance available about proper placement of monitors. The fixed point, stationary monitor can only function if the intruding gas contacts the monitor. Therefore, monitor placement is vital to proper monitoring of the room or area. Factors in sensor location selection include: indoor or outdoor site, the location and nature of potential vapor/gas sources, chemical and physical data of the gases or vapors, liquids with volatility need sensors near the potential sources of release, nature and concentration of gas releases, natural and mechanical ventilation, detector installation locations not vulnerable to mechanical or water damage from normal operations, and locations that lend themselves to convenient maintenance and calibration. The guidance also states that sensors should be located in all areas where hazardous accumulations of gas may occur. Such areas might not be close to release points but might be areas with restricted air movement. Heavier than air gases are likely to accumulate in pits, trenches, drains, and other low areas. Lighter than air gases are more likely to accumulate in overhead spaces, above drop ceilings, etc. In general, sensors should be located close to any potential sources of major release of gas. The paper gives data on monitor sensitivity and expected lifetimes to support the monitor selection process. Proper selection of indoor and outdoor locations for monitors is described, accounting for the vapor densities of hydrogen and oxygen. The latest information on monitor alarm setpoint selection is presented. Typically, monitors require recalibration at least every six months, or more frequently for inhospitable locations, so ready access to the monitors is an important issue to consider in monitor siting. Gas monitors, depending on their type, can be susceptible to blockages of the detector element (i.e., dus

Lee C. Cadwallader; Kevin G. DeWall; J. Stephen Herring

2007-06-01T23:59:59.000Z

287

New Species of Cyanobacteria Forms Intracellular Carbonates  

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

New Species of Cyanobacteria Forms Intracellular Carbonates Print New Species of Cyanobacteria Forms Intracellular Carbonates Print A new species of cyanobacteria-photosynthetic bacteria that occupy a wide array of habitats-was discovered in the Mexican Lake of Alchichica where massive carbonate rocks form. Cyanobacteria have been impacting the global carbon cycle of the Earth for more than 2.3 billion years by assimilating CO2 into organic compounds and triggering calcium carbonate (CaCO3) precipitation. Despite the importance of this cyanobacteria-mediated CaCO3 biomineralization, the mechanistic details of this process are still poorly understood. Scientists agree that calcification in cyanobacteria is an extracellular process: Photosynthesizing cells commonly export the photosynthesis byproduct CO32- outside their cells where it bonds with an alkaline earth metal like Ca2+. The cyanobacteria recently found in Lake Alchichica, however, forms amorphous Ca-, Mg-, Sr- and Ba-rich carbonates intracellularly. This discovery significantly modifies the traditional view of how bacteria induce CaCO3 precipitation and may improve understanding of the fossil record by hinting at ancient traces of life in rocks, or designing new routes for sequestering CO2 or 90Sr in minerals.

288

New Species of Cyanobacteria Forms Intracellular Carbonates  

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

New Species of Cyanobacteria Forms Intracellular Carbonates Print New Species of Cyanobacteria Forms Intracellular Carbonates Print A new species of cyanobacteria-photosynthetic bacteria that occupy a wide array of habitats-was discovered in the Mexican Lake of Alchichica where massive carbonate rocks form. Cyanobacteria have been impacting the global carbon cycle of the Earth for more than 2.3 billion years by assimilating CO2 into organic compounds and triggering calcium carbonate (CaCO3) precipitation. Despite the importance of this cyanobacteria-mediated CaCO3 biomineralization, the mechanistic details of this process are still poorly understood. Scientists agree that calcification in cyanobacteria is an extracellular process: Photosynthesizing cells commonly export the photosynthesis byproduct CO32- outside their cells where it bonds with an alkaline earth metal like Ca2+. The cyanobacteria recently found in Lake Alchichica, however, forms amorphous Ca-, Mg-, Sr- and Ba-rich carbonates intracellularly. This discovery significantly modifies the traditional view of how bacteria induce CaCO3 precipitation and may improve understanding of the fossil record by hinting at ancient traces of life in rocks, or designing new routes for sequestering CO2 or 90Sr in minerals.

289

New Species of Cyanobacteria Forms Intracellular Carbonates  

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

New Species of Cyanobacteria Forms Intracellular Carbonates Print New Species of Cyanobacteria Forms Intracellular Carbonates Print A new species of cyanobacteria-photosynthetic bacteria that occupy a wide array of habitats-was discovered in the Mexican Lake of Alchichica where massive carbonate rocks form. Cyanobacteria have been impacting the global carbon cycle of the Earth for more than 2.3 billion years by assimilating CO2 into organic compounds and triggering calcium carbonate (CaCO3) precipitation. Despite the importance of this cyanobacteria-mediated CaCO3 biomineralization, the mechanistic details of this process are still poorly understood. Scientists agree that calcification in cyanobacteria is an extracellular process: Photosynthesizing cells commonly export the photosynthesis byproduct CO32- outside their cells where it bonds with an alkaline earth metal like Ca2+. The cyanobacteria recently found in Lake Alchichica, however, forms amorphous Ca-, Mg-, Sr- and Ba-rich carbonates intracellularly. This discovery significantly modifies the traditional view of how bacteria induce CaCO3 precipitation and may improve understanding of the fossil record by hinting at ancient traces of life in rocks, or designing new routes for sequestering CO2 or 90Sr in minerals.

290

Ionizing irradiation induces apoptotic damage of salivary gland acinar cells via NADPH oxidase 1-dependent superoxide generation  

Science Conference Proceedings (OSTI)

Reactive oxygen species (ROS) have important roles in various physiological processes. Recently, several novel homologues of the phagocytic NADPH oxidase have been discovered and this protein family is now designated as the Nox family. We investigated the involvement of Nox family proteins in ionizing irradiation-induced ROS generation and impairment in immortalized salivary gland acinar cells (NS-SV-AC), which are radiosensitive, and immortalized ductal cells (NS-SV-DC), which are radioresistant. Nox1-mRNA was upregulated by {gamma}-ray irradiation in NS-SV-AC, and the ROS level in NS-SV-AC was increased to approximately threefold of the control level after 10 Gy irradiation. The increase of ROS level in NS-SV-AC was suppressed by Nox1-siRNA-transfection. In parallel with the suppression of ROS generation and Nox1-mRNA expression by Nox1-siRNA, ionizing irradiation-induced apoptosis was strongly decreased in Nox1-siRNA-transfected NS-SV-AC. There were no large differences in total SOD or catalase activities between NS-SV-AC and NS-SV-DC although the post-irradiation ROS level in NS-SV-AC was higher than that in NS-SV-DC. In conclusion, these results indicate that Nox1 plays a crucial role in irradiation-induced ROS generation and ROS-associated impairment of salivary gland cells and that Nox1 gene may be targeted for preservation of the salivary gland function from radiation-induced impairment.

Tateishi, Yoshihisa [Department of Oral and Maxillofacial Surgery, Kochi Medical School, Kochi University, Kohasu, Oko-cho, Nankoku-city, Kochi 783-8505 (Japan)], E-mail: tateishi@kochi-u.ac.jp; Sasabe, Eri; Ueta, Eisaku; Yamamoto, Tetsuya [Department of Oral and Maxillofacial Surgery, Kochi Medical School, Kochi University, Kohasu, Oko-cho, Nankoku-city, Kochi 783-8505 (Japan)

2008-02-08T23:59:59.000Z

291

TY JOUR  

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

Solid phase supported profluorescent nitroxide probe for the determination Solid phase supported profluorescent nitroxide probe for the determination of aerosol borne reactive oxygen species JF Talanta A1 Mohamad Sleiman A1 Hugo Destaillats A1 Lara A Gundel KW Freeradicals Proxyl fluorescamine Dichlorofluorescin Cigarettesmoke Ozone NOx AB div class abstract svAbstract p id sp0035 Reactive oxygen species ROS and free radicals play important roles in the chemical transformation and adverse health effects of environmental aerosols This work presents a simple and sensitive method for sampling and analysis of ROS using a packed column coated with a profluorescent nitroxide scavenger proxyl fluorescamine PF Quantification was performed by extraction and analysis using HPLC with fluorescence detection For comparison the conventional

292

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

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

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.

293

Controlled temperature expansion in oxygen production by molten alkali metal salts  

DOE Patents (OSTI)

A continuous process is set forth for the production of oxygen from an oxygen containing gas stream, such as air, by contacting a feed gas stream with a molten solution of an oxygen acceptor to oxidize the acceptor and cyclically regenerating the oxidized acceptor by releasing oxygen from the acceptor wherein the oxygen-depleted gas stream from the contact zone is treated sequentially to temperature reduction by heat exchange against the feed stream so as to condense out entrained oxygen acceptor for recycle to the process, combustion of the gas stream with fuel to elevate its temperature and expansion of the combusted high temperature gas stream in a turbine to recover power. 1 fig.

Erickson, D.C.

1985-06-04T23:59:59.000Z

294

In situ global method for measurement of oxygen demand and mass transfer  

DOE Green Energy (OSTI)

Two aerobic microorganisms, Saccharomycopsis lipolytica and Brevibacterium lactofermentum, have been used in a study of mass transfer and oxygen uptake from a global perspective using a closed gas system. Oxygen concentrations in the gas and liquid were followed using oxygen electrodes, and the results allowed for easy calculation of in situ oxygen transport. The cell yields on oxygen for S. lipolytica and B. lactofermentum were 1.01 and 1.53 g/g respectively. The mass transfer coefficient was estimated as 10 h{sup {minus}1} at 500 rpm for both fermentations. The advantages with this method are noticeable since the use of model systems may be avoided, and the in situ measurements of oxygen demand assure reliable data for scale-up.

Klasson, K.T. [Oak Ridge National Lab., TN (United States). Chemical Technology Div.; Lundbaeck, K.M.O.; Clausen, E.C.; Gaddy, J.L. [Univ. of Arkansas, Fayetteville, AR (United States). Dept. of Chemical Engineering

1997-05-01T23:59:59.000Z

295

Adiposity measures and risk of cardiovascular disease  

E-Print Network (OSTI)

ratio PAI Plasminogen activator inhibitor PHS Physicians' Health Study PROMIS Pakistan Risk of Myocardial Infarction Study PSC Prospective Studies Collaboration RDR Regression dilution ratio ROS Reactive oxygen species RR Risk ratio SBP Systolic... the arterial wall where they are oxidised by macrophages and smooth muscle cells. Additional mono-nuclear cells such as monocytes are attracted to the site of damage, where they engulf LDL cholesterol and become foam cells.10,13,14 Accumulation of foam cells...

Wormser, David

2012-01-10T23:59:59.000Z

296

Neutron knockout in neutral-current neutrino-oxygen interactions  

E-Print Network (OSTI)

The ongoing and future searches for diffuse supernova neutrinos and sterile neutrinos carried out with large water-Cherenkov detectors require a precise determination of the backgrounds, especially those involving gamma rays. Of great importance, in this context, is the process of neutron knockout through neutral-current (NC) scattering of atmospheric neutrinos on oxygen. Nuclear reinteractions of the produced neutron may in fact lead to the production of gamma rays of energies high enough to mimic the processes of interest. In this Letter, we focus on the kinematical range suitable for simulations of atmospheric-neutrino interactions and provide the neutron-knockout cross sections computed using the formalism based on realistic nuclear spectral function. The role of the strange-quark contribution to the NC axial form factor is also analyzed. Based on the available experimental information, we give an estimate of the associated uncertainty.

Artur M. Ankowski; Omar Benhar

2013-05-09T23:59:59.000Z

297

Cryptic photosynthesis, Extrasolar planetary oxygen without a surface biological signature  

E-Print Network (OSTI)

On the Earth, photosynthetic organisms are responsible for the production of nearly all of the oxygen in the atmosphere. On the land, vegetation reflects in the visible, leading to a red edge which has been proposed as a biosignature for life on extrasolar planets. However, in many regions of the Earth, and particularly where surface conditions are extreme, for example in hot and cold deserts, photosynthetic organisms can be driven into and under substrates where light is still sufficient for photosynthesis. These communities exhibit no detectable surface spectral signature. The same is true of the assemblages of photosynthetic organisms at more than a few meters depth in water bodies. These communities are widespread and dominate local photosynthetic productivity. We review known cryptic photosynthetic communities and their productivity. We use a radiative transfer model to link geomicrobiology with observational astronomy and calculate the disk-averaged spectra and identify detectable features that would re...

Cockell, C S; Raven, J A

2008-01-01T23:59:59.000Z

298

Indirect Gas Species Monitoring Using Tunable Diode Lasers  

DOE Patents (OSTI)

A method for indirect gas species monitoring based on measurements of selected gas species is disclosed. In situ absorption measurements of combustion species are used for process control and optimization. The gas species accessible by near or mid-IR techniques are limited to species that absorb in this spectral region. The absorption strength is selected to be strong enough for the required sensitivity and is selected to be isolated from neighboring absorption transitions. By coupling the gas measurement with a software sensor gas, species not accessible from the near or mid-IR absorption measurement can be predicted.

Von Drasek, William A. (Oak Forest, IL); Saucedo, Victor M. (Willowbrook, IL)

2005-02-22T23:59:59.000Z

299

PRELIMINARY ESTIMATE OF THE COST OF PRODUCING ENRICHED OXYGEN-18 WATER BY DISTILLATION  

SciTech Connect

An order of magnitude estimate was made a determine the cost of producing oxygen-18 enriched water by the equilibrium distillation of water. Three isotopic purities and two production rates were considered. Costs varied from per gram for 3% oxygen-18 enriched water produced at a rate of 100 grams per day to 5 per gram for 99% oxygen-18 water produced at a rate of one gram per day. (auth)

Drury, J.S.; Klima, B.B.

1958-10-10T23:59:59.000Z

300

Aquatic species project report: FY 1991  

DOE Green Energy (OSTI)

This report summarizes the progress and research accomplishments of the Aquatic Species Project, which is managed by the National Renewable Energy Laboratory for the US Department of Energy. The project is focused on applying genetic engineering techniques to enhance the lipid, or oil, production of microalgae. Those lipids can be extracted and processed into high-energy liquid fuels such as diesel. Because microalgae require carbon dioxide, a major greenhouse'' gas, as a nutrient, project researchers also study the role that microalgae could play in a possible global climate change mitigation strategy.

Brown, L.M. (National Renewable Energy Lab., Golden, CO (United States)); Sprague, S. (USDOE, Washington, DC (United States))

1992-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxygen species ros" 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

Nanostructured Cobalt Oxide Clusters in Mesoporous Silica as Efficient Oxygen-Evolving Catalysts  

E-Print Network (OSTI)

as Efficient Oxygen- Evolving Catalysts Feng Jiao and Heinzof efficient and robust catalysts for the chemicaltransformations. Catalysts need to exhibit turnover

Jiao, Feng

2010-01-01T23:59:59.000Z

302

Distribution of Oxygen in mc-Silicon Ingots for Solar Cell Applications  

Science Conference Proceedings (OSTI)

May 1, 2007 ... Distribution of Oxygen in mc-Silicon Ingots for Solar Cell Applications by Marisa Di Sabatino, Eivind J. Øvrelid, Espen Olsen, Thorvald A. Engh ...

303

A Cost-Effective Oxygen Separation System Based on Open Gradient...  

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

Feed Systems A Cost-Effective Oxygen Separation System Based on Open Gradient Magnetic Field by Polymer Beads ITN Energy Systems, Inc. Project Number: SC0010151 Project Description...

304

Meiofaunal distributions on the Peru margin: relationship to oxygen and organic matter availability  

E-Print Network (OSTI)

oxygen and organic matter availability Carlos Neira a,e, *,and decreasing organic matter availability downslope wereleading to high food availability and quality. Food input

Neira, Carlos; Sellanes, Javier; Levin, Lisa A; Arntz, Wolf A

2001-01-01T23:59:59.000Z

305

Total organic carbon (TOC) and chemical oxygen demand (COD) - Monitoring of organic pollutants in wastewater.  

E-Print Network (OSTI)

?? Total organic carbon (TOC) and chemical oxygen demand (COD) are two methods used for measuring organic pollutants in wastewater. Both methods are widely used… (more)

Hodzic, Elvisa

2011-01-01T23:59:59.000Z

306

Task Technical Plan for Studies of Oxygen Consumption in the Catalyzed Hydrolysis of Tetraphenylborate Ion  

Science Conference Proceedings (OSTI)

This document presents the plan for studies of how dissolved oxygen affects the catalytic decomposition of the tetraphenylborate ion in alkaline aqueous solution.

Fink, S.D. [Westinghouse Savannah River Company, AIKEN, SC (United States)

1996-12-20T23:59:59.000Z

307

Cold-Start and Warm-Up Driveability Performance of Hybrid Electric Vehicles Using Oxygenated Fuels  

DOE Green Energy (OSTI)

Provides analysis and results of the driveability performance testing from four hybrid electric vehicles--Honda Civic, Toyota Prius, and two Honda Insights--that used oxygenated fuels.

Thornton, M.; Jorgensen, S.; Evans, B.; Wright, K.

2003-11-01T23:59:59.000Z

308

Low oxygen biomass-derived pyrolysis oils and methods for producing the same  

Science Conference Proceedings (OSTI)

Low oxygen biomass-derived pyrolysis oils and methods for producing them from carbonaceous biomass feedstock are provided. The carbonaceous biomass feedstock is pyrolyzed in the presence of a catalyst comprising base metal-based catalysts, noble metal-based catalysts, treated zeolitic catalysts, or combinations thereof to produce pyrolysis gases. During pyrolysis, the catalyst catalyzes a deoxygenation reaction whereby at least a portion of the oxygenated hydrocarbons in the pyrolysis gases are converted into hydrocarbons. The oxygen is removed as carbon oxides and water. A condensable portion (the vapors) of the pyrolysis gases is condensed to low oxygen biomass-derived pyrolysis oil.

Marinangeli, Richard; Brandvold, Timothy A; Kocal, Joseph A

2013-08-27T23:59:59.000Z

309

ESS 2012 Peer Review - Nitrogen-Oxygen Battery for Large Scale...  

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

2012 Frank Delnick, David Ingersoll, Karen Waldrip, Peter Feibelman NitrogenOxygen Battery A Transformational Architecture for Large Scale Energy Storage Power Sources...

310

Oxygen-resistant hydrogenases and methods for designing and making same  

SciTech Connect

The invention provides oxygen- resistant iron-hydrogenases ([Fe]-hydrogenases) for use in the production of H2. Methods used in the design and engineering of the oxygen-resistant [Fe]-hydrogenases are disclosed, as are the methods of transforming and culturing appropriate host cells with the oxygen-resistant [Fe]-hydrogenases. Finally, the invention provides methods for utilizing the transformed, oxygen insensitive, host cells in the bulk production of H.sub.2 in a light catalyzed reaction having water as the reactant.

King, Paul (Golden, CO); Ghirardi, Maria L (Lakewood, CO); Seibert, Michael (Lakewood, CO)

2009-03-10T23:59:59.000Z

311

Laboratory measurements and modeling of trace atmospheric species  

E-Print Network (OSTI)

Trace species play a major role in many physical and chemical processes in the atmosphere. Improving our understanding of the impact of each species requires a combination of laboratory exper- imentation, field measurements, ...

Sheehy, Philip M. (Philip Michael)

2005-01-01T23:59:59.000Z

312

2004 IUCN Red List of Threatened SpeciesTM A Global Species  

E-Print Network (OSTI)

standardized linear contrasts to show that this positive relationship persists when all bird species for which distribution maps published in standard ornithological handbooks (e.g., Cramp, 1977­1994; Marchant and Higgins standardized, may be entered into conventional statistical analyses. Standardization of contrasts is dependent

Reynolds, John D.

313

In Silico Modeling of Geobacter Species.  

DOE Green Energy (OSTI)

This project employed a combination of in silico modeling and physiological studies to begin the construction of models that could predict the activity of Geobacter species under different environmental conditions. A major accomplishment of the project was the development of the first genome-based models of organisms known environmental relevance. This included the modeling of two Geobacter species and two species of Pelobacter. Construction of these models required increased sophistication in the annotation of the original draft genomes as well as collection of physiological data on growth yields, cell composition, and metabolic reactions. Biochemical studies were conducted to determine whether proposed enzymatic reactions were in fact expressed. During this process we developed an Automodel Pipeline process to accelerate future model development of other environmentally relevant organisms by using bioinformatics techniques to leverage predicted protein sequences and the Genomatica database containing a collection of well-curated metabolic models. The Automodel Pipeline was also used for iterative updating of the primary Geobacter model of G. sulfurreducens to expand metabolic functions or to add alternative pathways. Although each iteration of the model does not lead to another publication, it is an invaluable resource for hypothesis development and evaluation of experimental data. In order to develop a more accurate G. sulfurreducens model, a series of physiological studies that could be analyzed in the context of the model were carried out. For example, previous field trials of in situ uranium bioremediation demonstrated that Geobacter species face an excess of electron donor and a limitation of electron acceptor near the point of acetate injection into the groundwater. Therefore, a model-based analysis of electron acceptor limitation physiology was conducted and model predictions were compared with growth observed in chemostats. Iterative studies resulted in the model accurately predicting acetate oxidation and electron acceptor reduction. The model also predicted that G. sulfurreducens must release hydrogen under electron-accepting conditions in order to maintain charge and electron balance. This prediction was borne out by subsequent hydrogen measurements. Furthermore, changes in gene expression were consistent with model predictions of flux changes around central metabolism. The model revealed multiple redundant pathways in central metabolism suggesting an apparent versatility unusual in microbial metabolism. The computational analysis led to the identification of 32 reactions that participated in eight sets of redundant pathways. The computational results guided the design of strains with mutations in key reactions to elucidate the role of the alternate pathways and obtain information on their physiological function. A total of seven strains with mutations in genes encoding five metabolic reactions were constructed and their phenotypes analyzed in 12 different environments. This analysis revealed several interesting insights on the role of the apparent redundant pathways. 13C labeling approaches were developed for further elucidation of metabolic pathways with model-driven interpretation. For example, the model was used to calculate the optimal acetate 13C labeling ratio for distinguishing flux through various pathways based on amino acid isotopomer distributions. With this method it was possible to elucidate the pathways for amino acid biosynthesis. Surprisingly, the labeling pattern of isoleucine deviated significantly from what was predicted by the metabolic reconstruction. Detailed analysis of the labeling patterns with the model led to the discovery that there are two pathways for leucine biosynthesis, including a novel citramalate pathway that was subsequently confirmed with biochemical analysis. In summary, the combined computational and experimental studies have been instrumental in further characterizing the central metabolism of members of the Geobacteraceae. Furthermore, the methods developed in these

Lovley, Derek, R.

2008-01-29T23:59:59.000Z

314

A new fibre optic pulse oximeter probe for monitoring splanchnic organ arterial blood oxygen saturation  

Science Conference Proceedings (OSTI)

A new, continuous method of monitoring splanchnic organ oxygen saturation (SpO"2) would make the early detection of inadequate tissue oxygenation feasible, reducing the risk of hypoperfusion, severe ischaemia, and, ultimately, death. In an attempt to ... Keywords: Fibre optics, Perfusion, Photoplethysmography, Pulse oximetry, Splanchnic organs

M. Hickey; N. Samuels; N. Randive; R. Langford; P. A. Kyriacou

2012-12-01T23:59:59.000Z

315

Communications: Elementary oxygen electrode reactions in the aprotic Li-air battery  

E-Print Network (OSTI)

Communications: Elementary oxygen electrode reactions in the aprotic Li-air battery J. S February 2010 We discuss the electrochemical reactions at the oxygen electrode of an aprotic Li-air battery and charge of the battery, we introduce a reaction free energy diagram and identify possible origins

Thygesen, Kristian

316

Low energy consumption method for separating gaseous mixtures and in particular for medium purity oxygen production  

DOE Patents (OSTI)

A method for the separation of gaseous mixtures such as air and for producing medium purity oxygen, comprising compressing the gaseous mixture in a first compressor to about 3.9-4.1 atmospheres pressure, passing said compressed gaseous mixture in heat exchange relationship with sub-ambient temperature gaseous nitrogen, dividing the cooled, pressurized gaseous mixture into first and second streams, introducing the first stream into the high pressure chamber of a double rectification column, separating the gaseous mixture in the rectification column into a liquid oxygen-enriched stream and a gaseous nitrogen stream and supplying the gaseous nitrogen stream for cooling the compressed gaseous mixture, removing the liquid oxygen-enriched stream from the low pressure chamber of the rectification column and pumping the liquid, oxygen-enriched steam to a predetermined pressure, cooling the second stream, condensing the cooled second stream and evaporating the oxygen-enriched stream in an evaporator-condenser, delivering the condensed second stream to the high pressure chamber of the rectification column, and heating the oxygen-enriched stream and blending the oxygen-enriched stream with a compressed blend-air stream to the desired oxygen concentration.

Jujasz, Albert J. (North Olmsted, OH); Burkhart, James A. (Olmsted Falls, OH); Greenberg, Ralph (New York, NY)

1988-01-01T23:59:59.000Z

317

071 An LTCC Clark-Type Oxygen Sensor - Programmaster.org  

Science Conference Proceedings (OSTI)

Clark-type oxygen sensors are electrochemical devices consisting an oxygen- permeable ... 030 Tricalcium Phosphate System in Drug Delivery and Bone Graft ... 039 Effect of % Boron on the Tribological Performance of Alumina Matrix ... 094 Isotopic Enrichment Studies to Determine Elemental Diffusion Profiles Through an ...

318

Pore water evolution in oilfield sandstones: constraints from oxygen isotope microanalyses of quartz cement  

E-Print Network (OSTI)

Pore water evolution in oilfield sandstones: constraints from oxygen isotope microanalyses a Department of Geology and Geophysics, University of Edinburgh, Edinburgh EH9 3JW, Scotland, UK b Shell Oxygen isotope microanalyses of authigenic quartz, in combination with temperatures of quartz

Haszeldine, Stuart

319

The effect of plutonium dioxide water surface coverage on the generation of hydrogen and oxygen  

DOE Green Energy (OSTI)

The conditions for the production of oxygen during radiolysis of water adsorbed onto plutonium dioxide powder are discussed. Studies in the literature investigating the radiolysis of water show that both oxygen and hydrogen can be generated from water adsorbed on high-purity plutonium dioxide powder. These studies indicate that there is a threshold in the amount of water below which oxygen is not generated. The threshold is associated with the number of monolayers of adsorbed water and is shown to occur at approximately two monolayers of molecularly adsorbed water. Material in equilibrium with 50% relative humidity (RH) will be at the threshold for oxygen generation. Using two monolayers of molecularly adsorbed water as the threshold for oxygen production, the total pressure under various conditions is calculated assuming stoichiometric production of hydrogen and oxygen. The specific surface area of the oxide has a strong effect on the final partial pressure. The specific surface areas resulting in the highest pressures within a 3013 container are evaluated. The potential for oxygen generation is mitigated by reduced relative humidity, and hence moisture adsorption, at the oxide surface which occurs if the oxide is warmer than the ambient air. The potential for oxygen generation approaches zero as the temperature difference between the ambient air and the material approaches 6 C.

Veirs, Douglas K. [Los Alamos National Laboratory; Berg, John M. [Los Alamos National Laboratory; Crowder, Mark L. [Savannah River National Laboratory

2012-06-20T23:59:59.000Z

320

Development of alternative oxygen production source using a zirconia solid electrolyte membrane  

SciTech Connect

The objective of this multiyear effort was the development, fabrication and testing of a zirconia oxygen production module capable of delivering approximately 100 liters/minute (LPM) of oxygen. The work discussed in this report consists of development and improvement of the zirconia cell along with manufacture of cell components, preliminary design of the final plant, additional economic analysis and industrial participation. (VC)

Suitor, J.W.; Clark, D.J.; Losey, R.W.

1990-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxygen species ros" 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

Development of alternative oxygen production source using a zirconia solid electrolyte membrane. Final report  

SciTech Connect

The objective of this multiyear effort was the development, fabrication and testing of a zirconia oxygen production module capable of delivering approximately 100 liters/minute (LPM) of oxygen. The work discussed in this report consists of development and improvement of the zirconia cell along with manufacture of cell components, preliminary design of the final plant, additional economic analysis and industrial participation. (VC)

Suitor, J.W.; Clark, D.J.; Losey, R.W.

1990-08-01T23:59:59.000Z

322

Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame  

E-Print Network (OSTI)

Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame S. E structure which, de- pending on density, may involve separate regions of carbon, oxygen and silicon burning, all propagating in a self-similar, subsonic front. The separation between these three burning regions

323

Krypton for Multi-Pane Windows: Selective Absorption of Krypton from Oxygen  

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

Krypton for Multi-Pane Windows: Selective Absorption of Krypton from Oxygen Krypton for Multi-Pane Windows: Selective Absorption of Krypton from Oxygen in an Ionic Liquid Speaker(s): John Prausnitz Waheed Afzal Date: September 18, 2012 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Robert Hart Because of its low thermal conductivity, krypton is a useful gas for the vapor space of double- (or triple-) pane windows. However krypton is more expensive than argon, currently used for most of multi-pane windows. The high price of krypton is due to the energy-intensive cryogenic process for its recovery from oxygen that is obtained from air. Ionic liquids may provide a cost-effective absorption process for separation of krypton from the oxygen stream of a liquid-air plant. The polarizability of krypton is higher than that of oxygen; therefore, krypton solubility may be

324

Prolonged cold storage of red blood cells by oxygen removal and additive usage  

DOE Patents (OSTI)

Prolonged cold storage of red blood cells by oxygen removal and additive usage. A cost-effective, 4.degree. C. storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. The improved in vivo survival and the preservation of adenosine triphosphate levels, along with reduction in hemolysis and membrane vesicle production of red blood cells stored at 4.degree. C. for prolonged periods of time, is achieved by reducing the oxygen level therein at the time of storage; in particular, by flushing the cells with an inert gas, and storing them in an aqueous solution which includes adenine, dextrose, mannitol, citrate ion, and dihydrogen phosphate ion, but no sodium chloride, in an oxygen-permeable container which is located in an oxygen-free environment containing oxygen-scavenging materials.

Bitensky, Mark W. (Boston, MA); Yoshida, Tatsuro (Newton, MA)

1998-01-01T23:59:59.000Z

325

Prolonged cold storage of red blood cells by oxygen removal and additive usage  

DOE Patents (OSTI)

Prolonged cold storage of red blood cells by oxygen removal and additive usage. A cost-effective, 4 C storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. The improved in vivo survival and the preservation of adenosine triphosphate levels, along with reduction in hemolysis and membrane vesicle production of red blood cells stored at 4 C for prolonged periods of time, is achieved by reducing the oxygen level therein at the time of storage; in particular, by flushing the cells with an inert gas, and storing them in an aqueous solution which includes adenine, dextrose, mannitol, citrate ion, and dihydrogen phosphate ion, but no sodium chloride, in an oxygen-permeable container which is located in an oxygen-free environment containing oxygen-scavenging materials. 8 figs.

Bitensky, M.W.; Yoshida, Tatsuro

1998-08-04T23:59:59.000Z

326

Vapor Phase Catalytic Upgrading of Model Biomass-Derived Oxygenate Compounds  

SciTech Connect

When biomass is converted to a liquid bio-oil through pyrolysis, it has a significantly higher oxygen content compared to petroleum fractions. In order to convert the pyrolysis products into infrastructure-compatible fuels, oxygen removal is required. Oxygen removal can be achieved by both hydrotreating (which requires the addition of hydrogen) and decarboxylation or decarbonylation, whereby oxygen is rejected as CO2 and CO, respectively. In the present contribution, a number of catalysts were tested for their activity and selectivity in deoxygenation of model biomass-derived oxygenated compounds (e.g., acetic acid, phenol). Comparison of catalytic activity of materials for different compounds, as well as material characterization results will be discussed. Materials tested will include modified zeolites and supported transition metal catalysts.

Yung, M. M.; Gomez, E.; Kuhn, J. N.

2012-01-01T23:59:59.000Z

327

THE OXYGEN PERMEATION PROPERTIES OF NANO CRYSTALLINE CEO2 THIN FILMS  

Science Conference Proceedings (OSTI)

The measurement of oxygen flux across nanocrystalline CeO{sub 2} cerium oxide thin films at intermediate temperature (650 to 800 C) is presented. Porous ceria support substrates were fabricated by sintering with carbon additions. The final dense film was deposited from an optimized sol-gel solution resulting in a mean grain size of 50 nm which displayed oxygen flux values of up to 0.014 {micro}mol/cm{sup 2}s over the oxygen partial pressure range from air to helium gas used in the measurement at 800 C. The oxygen flux characteristics confirm mixed ionic and electronic conductivity in nanocrystalline ceria films and demonstrate the role of size dependent materials properties as a design parameter in functional membranes for oxygen separation.

Brinkman, K.

2010-09-27T23:59:59.000Z

328

Oxygen suppression in boiling water reactors. Quarterly report 2, January 1--March 31, 1978  

DOE Green Energy (OSTI)

Boiling water reactors (BWR's) generally use high purity, no-additive feedwater. Primary recirculating coolant is neutral pH, and contains 100 to 300 ppB oxygen and stoichiometrically related dissolved hydrogen. However, oxygenated water increases austenitic stainless steel susceptibility to intergranular stress-corrosion cracking (IGSCC) when other requisite factors such as stress and sensitization are present. Thus, reduction or elimination of the oxygen in BWR water may preclude cracking incidents. One approach to reduction of the BWR coolant oxygen concentration is to adopt alternate water chemistry (AWC) conditions using an additive(s) to suppress or reverse radiolytic oxygen formation. Several additives are available to do this but they have seen only limited and specialized application in BWR's. The objective of this program is to perform an in-depth engineering evaluation of the potential suppression additives supported by critical experiments where required to resolve substantive uncertainties.

Burley, E.L.

1978-10-01T23:59:59.000Z

329

NETL: IEP – Oxy-Combustion CO2 Emissions Control - Oxygen-Based PC Boiler  

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

– Oxy-Combustion CO2 Emissions Control – Oxy-Combustion CO2 Emissions Control Oxygen-Based PC Boiler Project No.: FC26-04NT42207 & FC26-03NT41736 Spatial Comparison of an Air-Fired Furnace versus an Oxygen-Fired Furnace. Spatial Comparison of an Air-Fired Furnace versus an Oxygen-Fired Furnace. Foster Wheeler North America Corporation will conduct to two projects to improve carbon dioxide (CO2) capture technology by developing a conceptual pulverized coal-fired boiler system design using oxygen as the combustion medium. Using oxygen instead of air produces a flue gas with a high CO2 concentration, which will facilitate CO2 capture for subsequent sequestration. The first project will develop modeling simulations that will lead to a conceptual design that addresses costs, performance, and emissions, and

330

MHK Technologies/Oxygen Releasing and Carbon Absorbing Ocean Based  

Open Energy Info (EERE)

Releasing and Carbon Absorbing Ocean Based Releasing and Carbon Absorbing Ocean Based Renewable Energy System < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Oxygen Releasing and Carbon Absorbing Ocean Based Renewable Energy System.jpg Technology Profile Technology Description The benefits of the system developed and patented by AEEA are 1 exploitation of the greater wave energy density in the more remote off shore locations 2 usage of existing industrial fuel storage and distribution infrastructure 3 provision for a gradual transition to widespread electric vehicle use 4 avoidance of environmental destruction and visual impairment with minimal impact on commercial fishing and recreation uses 5 fostering the development of a new maritime and energy industry 6 avoidance of the high capital investment in mooring and anchoring seabed electrical cable installation and seabed restoration 7 development of flexibility by deployment of fleets of these vessels to supply widely separated market locations using coastal and national waterways and 8 provision for the addition of fleets without depletion of primary feed stocks as in nuclear energy systems 2 Fig 1 In summary the system converts wave energy from the nearly unlimited world wide

331

Oxygen sensor for monitoring gas mixtures containing hydrocarbons  

DOE Patents (OSTI)

A gas sensor measures O.sub.2 content of a reformable monitored gas containing hydrocarbons H.sub.2 O and/or CO.sub.2, preferably in association with an electrochemical power generation system. The gas sensor has a housing communicating with the monitored gas environment and carries the monitored gas through an integral catalytic hydrocarbon reforming chamber containing a reforming catalyst, and over a solid electrolyte electrochemical cell used for sensing purposes. The electrochemical cell includes a solid electrolyte between a sensor electrode that is exposed to the monitored gas, and a reference electrode that is isolated in the housing from the monitored gas and is exposed to a reference gas environment. A heating element is also provided in heat transfer communication with the gas sensor. A circuit that can include controls operable to adjust operations via valves or the like is connected between the sensor electrode and the reference electrode to process the electrical signal developed by the electrochemical cell. The electrical signal varies as a measure of the equilibrium oxygen partial pressure of the monitored gas. Signal noise is effectively reduced by maintaining a constant temperature in the area of the electrochemical cell and providing a monitored gas at chemical equilibria when contacting the electrochemical cell. The output gas from the electrochemical cell of the sensor is fed back into the conduits of the power generating system.

Ruka, Roswell J. (Pittsburgh, PA); Basel, Richard A. (Pittsburgh, PA)

1996-01-01T23:59:59.000Z

332

Conceptual Design of Oxygen-Based PC Boiler  

Science Conference Proceedings (OSTI)

Coal is presently the world's primary fuel for generating electrical power and, being more abundant and less expensive than oil or natural gas, is expected to continue its dominance into the future. Coal, however, is more carbon intensive than natural gas and oil and consequently coal-fired power plants are large point source emitters of carbon dioxide (CO{sub 2}). Since CO{sub 2} is a greenhouse gas, which may have an adverse impact on the world's climate/weather patterns, studies have been conducted to determine the feasibility and economic impact of capturing power plant CO{sub 2} emissions for pipeline transport to a sequestration/storage site. The stack gas that exhausts from a modern coal-fired power plant typically contains about 15% CO{sub 2} on a dry volume basis. Although there are numerous processes available for removing CO{sub 2} from gas streams, gas scrubbing with amine solvent is best suited for this application because of the large gas volumes and low CO{sub 2} concentrations involved. Unfortunately the energy required to regenerate the solvent for continued use as a capturing agent is large and imposes a severe energy penalty on the plant. In addition this ''back end'' or post combustion cleanup requires the addition of large vessels, which, in retrofit applications, are difficult to accommodate. As an alternative to post combustion scrubbing, Foster Wheeler (FW) has proposed that the combustion process be accomplished with oxygen rather than air. With all air nitrogen eliminated, a CO{sub 2}-water vapor rich flue gas will be generated. After condensation of the water vapor, a portion of the flue gas will be recirculated back to the boiler to control the combustion temperature and the balance of the CO{sub 2} will be processed for pipeline transport. This proposed oxygen-carbon dioxide (O{sub 2}/CO{sub 2}) combustion process eliminates the need for CO{sub 2} removal/separation and reduces the cost of supplying a CO{sub 2} rich stream for sequestration. FW has developed a conceptual design of an O{sub 2} fired boiler to determine overall plant performance and economics. Five subtasks were conducted: (1) a literature review, (2) a system design and analysis, (3) a low NOx burner design and analysis, (4) a furnace and heat recovery area design analysis, and (5) an economic analysis. The objective of the literature search is to locate any data/information relevant to the Oxygen-Based PC Boiler conceptual design. The objective of the system design and analysis task is to optimize the PC boiler plant by maximizing system efficiency within practical considerations. Simulations of the oxygen-fired plant with CO{sub 2} sequestration were conducted using Aspen Plus and were compared to a reference air-fired 460 MW plant. Flue gas recycle is used in the O{sub 2}-fired PC to control the flame temperature. Parametric runs were made to determine the effect of flame temperature on system efficiency and required waterwall material and thickness. The degree of improvement on system efficiency of various modifications including hot gas recycle, purge gas recycle, flue gas feedwater recuperation, and recycle purge gas expansion were investigated. The selected O{sub 2}-fired design case has a system efficiency of 30.6% compared to the air-fired system efficiency of 36.7%. The design O{sub 2}-fired case requires T91 waterwall material and has a waterwall surface area of only 65% of the air-fired reference case. The objective of the low NOx burner design and analysis task is to optimize the burner design to ensure stable ignition, to provide safe operation, and to minimize pollutant formation. The burners were designed and analyzed using the Fluent CFD computer program. Four burner designs were developed: (1) with no OFG and 65% flue gas recycle, (2) with 20% OFG and 65% flue gas recycle, (3) with no OFG and 56% flue gas recycle and (4) with 20% OFG and 56% flue gas recycle. A 3-D Fluent simulation was made of a single wall-fired burner and horizontal portion of the furnace from the wall to the center. Without primary gas sw

Andrew Seltzer; Zhen Fan

2005-09-01T23:59:59.000Z

333

Cryptic photosynthesis, Extrasolar planetary oxygen without a surface biological signature  

E-Print Network (OSTI)

On the Earth, photosynthetic organisms are responsible for the production of virtually all of the oxygen in the atmosphere. On the land, vegetation reflects in the visible, leading to a red edge that developed about 450 Myr ago and has been proposed as a biosignature for life on extrasolar planets. However, in many regions of the Earth, and particularly where surface conditions are extreme, for example in hot and cold deserts, photosynthetic organisms can be driven into and under substrates where light is still sufficient for photosynthesis. These communities exhibit no detectable surface spectral signature to indicate life. The same is true of the assemblages of photosynthetic organisms at more than a few metres depth in water bodies. These communities are widespread and dominate local photosynthetic productivity. We review known cryptic photosynthetic communities and their productivity. We link geomicrobiology with observational astronomy by calculating the disk-averaged spectra of cryptic habitats and identifying detectable features on an exoplanet dominated by such a biota. The hypothetical cryptic photosynthesis worlds discussed here are Earth-analogs that show detectable atmospheric biomarkers like our own planet, but do not exhibit a discernable biological surface feature in the disc-averaged spectrum.

C. S. Cockell; L. Kaltenegger; J. A. Raven

2008-09-23T23:59:59.000Z

334

A ROLE FOR MANGANESE IN OXYGEN EVOLUTION IN PHOTOSYNTHESIS  

DOE Green Energy (OSTI)

The prospects are shrinking rapidly for a future for society based on liquid hydrocarbons as a major source of energy. Among the wide array of alternative sources that are currently undergoing scrutiny, much attention is attracted to the photolysis of water to produce hydrogen and oxygen gases. Water, the starting material, does not suffer from lack of abundance, and there is every likelihood that the environmental consequences of water splitting will be negligible. Solar radiation is the obvious candiate for the ultimate energy source, but of course water cannot be photolyzed directly by the relatively low-energy wave-lengths, greater than 300 nm, that penetrate the earth's atmosphere. Nevertheless, the photolysis of water to produce O{sub 2} and reduced substances, with reduction potentials equivalent to that of H{sub 2}, is accomplished efficiently using sunlight by higher plant photosynthesis. There are even organisms that, under special conditions, will evolve H{sub 2} gas photosynthetically, but not efficiently when coupled with O{sub 2} production. To produce a molecule of O{sub 2} from water requires the removal of four electrons from two H{sub 2}O molecules.

Sauer, Kenneth

1980-01-01T23:59:59.000Z

335

Oxygen sensor for monitoring gas mixtures containing hydrocarbons  

DOE Patents (OSTI)

A gas sensor measures O{sub 2} content of a reformable monitored gas containing hydrocarbons, H{sub 2}O and/or CO{sub 2}, preferably in association with an electrochemical power generation system. The gas sensor has a housing communicating with the monitored gas environment and carries the monitored gas through an integral catalytic hydrocarbon reforming chamber containing a reforming catalyst, and over a solid electrolyte electrochemical cell used for sensing purposes. The electrochemical cell includes a solid electrolyte between a sensor electrode that is exposed to the monitored gas, and a reference electrode that is isolated in the housing from the monitored gas and is exposed to a reference gas environment. A heating element is also provided in heat transfer communication with the gas sensor. A circuit that can include controls operable to adjust operations via valves or the like is connected between the sensor electrode and the reference electrode to process the electrical signal developed by the electrochemical cell. The electrical signal varies as a measure of the equilibrium oxygen partial pressure of the monitored gas. Signal noise is effectively reduced by maintaining a constant temperature in the area of the electrochemical cell and providing a monitored gas at chemical equilibria when contacting the electrochemical cell. The output gas from the electrochemical cell of the sensor is fed back into the conduits of the power generating system. 4 figs.

Ruka, R.J.; Basel, R.A.

1996-03-12T23:59:59.000Z

336

The effects of wavelength, metals, and reactive oxygen species on the sunlight inactivation of microorganisms: observations and applications to the solar disinfection of drinking water  

E-Print Network (OSTI)

of batch-process solar disinfectors. Water Research 35(4),Batch process solar disinfection is an efficient means of disinfecting drinking water

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

337

The effects of wavelength, metals, and reactive oxygen species on the sunlight inactivation of microorganisms: observations and applications to the solar disinfection of drinking water  

E-Print Network (OSTI)

the US ASTM standard solar spectrum (1976), and for Aprilthe US ASTM standard solar spectrum (1976), and for Aprilused to simulate a solar spectrum (Figure 3.1 A, no filter).

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

338

The effects of wavelength, metals, and reactive oxygen species on the sunlight inactivation of microorganisms: observations and applications to the solar disinfection of drinking water  

E-Print Network (OSTI)

Overview. Journal of Solar Energy Engineering 129(1), 4-15.Events. Journal of Solar Energy Engineering 129(1), 100-Events. Journal of Solar Energy Engineering 129(1), Rincón,

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

339

Combustion-derived flame generated ultrafine soot generates reactive oxygen species and activates Nrf2 antioxidants differently in neonatal and adult rat lungs  

E-Print Network (OSTI)

et al. : Combustion-derived flame generated ultrafine sootacute inhalation of diffusion flame soot particles: cellularAccess Combustion-derived flame generated ultrafine soot

2013-01-01T23:59:59.000Z

340

FY 1987 Aquatic Species Program: Annual report  

DOE Green Energy (OSTI)

The goal of the Department of Energy/Solar Energy Research Institute Aquatic Species Program is to develop the technology base to produce liquid fuels from microalagae at prices competitive with conventional alternatives. Microalgae are unusual plants that can accumulate large quantities of oil and can thrive in high-salinity water, which currently has no competing uses. The algal oils, in turn, are readily converted into gasoline and diesel fuels. The best site for successful microalgae production was determined to be the US desert Southwest, with potential applications to other warm areas. Aggressive research is needed, but the improvements required are attainable. The four prime research areas in the development of this technology are growth and production, engineering design, harvesting, and conversion. Algae are selected for three criteria: tolerance to environmental fluctuations, high growth rates, and high lipid production. From 1982 to 1986, the program collected more than 3000 strains of microalgae that are more than twice as tolerant to temperature and salinity fluctuation than the initial strains. Productivity has been increased by a factor of two in outdoor culture systems since 1982, and lipid content has also been increased from 20% of body weight in 1982 to greater than 66% of body weight in 1987. Research programs are ongoing in lipid biochemistry and genetic engineering so that ultimately strains can be modified and improved to combine their best characteristics. An outdoor test facility is being built in Roswell, New Mexico.

Johnson, D.A.; Sprague, S.

1987-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxygen species ros" 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

ON THE OXYGEN ISOTOPIC COMPOSITION OF THE SOLAR SYSTEM  

SciTech Connect

The {sup 18}O/{sup 17}O ratio of the solar system is 5.2 while that of the interstellar medium (ISM) and young stellar objects is approx4. This difference cannot be explained by pollution of the Sun's natal molecular cloud by {sup 18}O-rich supernova ejecta because (1) the necessary B-star progenitors live longer than the duration of star formation in molecular clouds, (2) the delivery of ejecta gas is too inefficient and the amount of dust in supernova ejecta is too small compared to the required pollution (2% of total mass or approx20% of oxygen), and (3) the predicted amounts of concomitant short-lived radionuclides (SLRs) conflicts with the abundances of {sup 26}Al and {sup 41}Ca in the early solar system. Proposals for the introduction of {sup 18}O-rich material must also be consistent with any explanation for the origin of the observed slope-one relationship between {sup 17}O/{sup 16}O and {sup 18}O/{sup 16}O in the high-temperature components of primitive meteorites. The difference in {sup 18}O/{sup 17}O ratios can be explained by enrichment of the ISM by the {sup 17}O-rich winds of asymptotic giant branch (AGB) stars, the sequestration of comparatively {sup 18}O-rich gas from star-forming regions into long-lived, low-mass stars, and a monotonic decrease in the {sup 18}O/{sup 17}O ratio of interstellar gas. At plausible rates of star formation and gas infall, Galactic chemical evolution does not follow a slope-one line in a three-isotope plot, but instead moves along a steeper trajectory toward an {sup 17}O-rich state. Evolution of the ISM and star-forming gas by AGB winds also explains the difference in the carbon isotope ratios of the solar system and ISM.

Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii, Honolulu, HI, 96822 (United States); Krot, Alexander N.; Huss, Gary R., E-mail: gaidos@hawaii.ed, E-mail: sasha@higp.hawaii.ed, E-mail: huss@higp.hawaii.ed [Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, HI, 96822 (United States)

2009-11-10T23:59:59.000Z

342

Catalytic Synthesis of Oxygenates: Mechanisms, Catalysts and Controlling Characteristics  

DOE Green Energy (OSTI)

This research focused on catalytic synthesis of unsymmetrical ethers as a part of a larger program involving oxygenated products in general, including alcohols, ethers, esters, carboxylic acids and their derivatives that link together environmentally compliant fuels, monomers, and high-value chemicals. The catalysts studied here were solid acids possessing strong Br�������¸nsted acid functionalities. The design of these catalysts involved anchoring the acid groups onto inorganic oxides, e.g. surface-grafted acid groups on zirconia, and a new class of mesoporous solid acids, i.e. propylsulfonic acid-derivatized SBA-15. The former catalysts consisted of a high surface concentration of sulfate groups on stable zirconia catalysts. The latter catalyst consists of high surface area, large pore propylsulfonic acid-derivatized silicas, specifically SBA-15. In both cases, the catalyst design and synthesis yielded high concentrations of acid sites in close proximity to one another. These materials have been well-characterization in terms of physical and chemical properties, as well as in regard to surface and bulk characteristics. Both types of catalysts were shown to exhibit high catalytic performance with respect to both activity and selectivity for the bifunctional coupling of alcohols to form ethers, which proceeds via an efficient SN2 reaction mechanism on the proximal acid sites. This commonality of the dual-site SN2 reaction mechanism over acid catalysts provides for maximum reaction rates and control of selectivity by reaction conditions, i.e. pressure, temperature, and reactant concentrations. This research provides the scientific groundwork for synthesis of ethers for energy applications. The synthesized environmentally acceptable ethers, in part derived from natural gas via alcohol intermediates, exhibit high cetane properties, e.g. methylisobutylether with cetane No. of 53 and dimethylether with cetane No. of 55-60, or high octane properties, e.g. diisopropylether with blending octane No. of 105, and can replace aromatics in liquid fuels.

Kamil Klier; Richard G. Herman

2005-11-30T23:59:59.000Z

343

Oxygen Electrocatalysts for Water Electrolyzers and Reversible Fuel Cells: Status and Perspective  

SciTech Connect

Hydrogen production by electrochemical water electrolysis has received great attention as an alternative technology for energy conversion and storage. The oxygen electrode has a substantial effect on the performance and durability in water electrolyzers and reversible fuel cells because of its intrinsically slow kinetics for oxygen evolution/reduction and poor durability under harsh operating environments. To improve oxygen kinetics and durability of the electrode, extensive studies for highly active and stable oxygen electrocatalyst have been performed. However, due to the thermodynamic instability of transition metals in acidic media, noble metal compounds have been primarily utilized as electrocatalysts in water electrolyzers and reversible fuel cells. For water electrolyzer applications, single noble metal oxides such as ruthenium oxide and iridium oxide have been studied, and binary or ternary metal oxides have been developed to take synergestic effects of each component. On the other hand, a variety of bifunctional electrocatalysts with a combination of monofunctional electrocatalysts such as platinum for oxygen reduction and iridium oxide for oxygen evolution for reversible fuel cell applications have been mainly proposed. Practically, supported iridium oxide-on-platinum, its reverse type, and non-precious metal-supported platinum and iridium bifunctional electrocatalysts have been developed. Recent theoretical calculations and experimental studies in terms of water electrolysis and fuel cell technology suggest effective ways to cope with current major challenges of cost and durability of oxygen electrocatalysts for technical applications.

Park, Seh Kyu; Shao, Yuyan; Liu, Jun; Wang, Yong

2012-11-01T23:59:59.000Z

344

Contiguous Platinum Monolayer Oxygen Reduction Electrocatalysts on High-Stability-Low-Cost Supports  

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

Contiguous Platinum Monolayer Oxygen Reduction Contiguous Platinum Monolayer Oxygen Reduction Electrocatalysts on High-Stability-Low-Cost Supports Co-PIs: Jia Wang, Miomir Vukmirovic, Kotaro Sasaki, Brookhaven National Laboratory Yang Shao-Horn Massachusetts Institute of Technology Rachel O'Malley, David Thompsett, Sarah Ball, Graham Hard Johnson Matthey Fuel Cells Radoslav Adzic Brookhaven National Laboratory DOE Projects Kickoff Meeting September 30 , 2009 2 Project Overview Project Overview 1. Objectives: Objectives: Developing high performance fuel cell electrocatalysts for the oxygen reduction reaction (ORR) comprising contiguous Pt monolayer Pt monolayer on stable, inexpensive metal or alloy nanorods, nanowires, nanobars and

345

Removing oxygen from a solvent extractant in an uranium recovery process  

DOE Patents (OSTI)

An improvement in effecting uranium recovery from phosphoric acid solutions is provided by sparging dissolved oxygen contained in solutions and solvents used in a reductive stripping stage with an effective volume of a nonoxidizing gas before the introduction of the solutions and solvents into the stage. Effective volumes of nonoxidizing gases, selected from the group consisting of argon, carbon dioxide, carbon monoxide, helium, hydrogen, nitrogen, sulfur dioxide, and mixtures thereof, displace oxygen from the solutions and solvents thereby reduce deleterious effects of oxygen such as excessive consumption of elemental or ferrous and accumulation of complex iron phosphates or cruds.

Hurst, Fred J. (Oak Ridge, TN); Brown, Gilbert M. (Knoxville, TN); Posey, Franz A. (Concord, TN)

1984-01-01T23:59:59.000Z

346

Method for oxygen reduction in a uranium-recovery process. [US DOE patent application  

DOE Patents (OSTI)

An improvement in effecting uranium recovery from phosphoric acid solutions is provided by sparging dissolved oxygen contained in solutions and solvents used in a reductive stripping stage with an effective volume of a nonoxidizing gas before the introduction of the solutions and solvents into the stage. Effective volumes of nonoxidizing gases, selected from the group consisting of argon, carbon dioxide, carbon monoxide, helium, hydrogen, nitrogen, sulfur dioxide, and mixtures thereof, displace oxygen from the solutions and solvents thereby reduce deleterious effects of oxygen such as excessive consumption of elemental or ferrous iron and accumulation of complex iron phosphates or cruds.

Hurst, F.J.; Brown, G.M.; Posey, F.A.

1981-11-04T23:59:59.000Z

347

Simulation of the dissolved oxygen concentration and the pH value at the O2-FET  

Science Conference Proceedings (OSTI)

The O2-FET is a pH ion sensitive field effect transistor (ISFET) modified to measure dissolved oxygen via the acidification from an amperometric dissolved oxygen microsensor. A diffusion based finite elements model which describes the transactions at ... Keywords: ISFET, diffusion, dissolved oxygen, finite elements simulation

J. Wiest; S. Blank; M. Brischwein; H. Grothe; B. Wolf

2008-02-01T23:59:59.000Z

348

Appendix B: CArBon dioxide CApture teChnology SheetS Oxygen PrOductiOn  

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

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...

349

Species conservation in Idaho—going beyond the ESA  

E-Print Network (OSTI)

made to utilize Candidate Conservation Agreements (CCAs)and Candidate Conservation Agreements with Assurances (state Office of Species Conservation was made aware that FWS

Inghram, Brent J.

2005-01-01T23:59:59.000Z

350

COMBUSTION SOURCES OF UNREGULATED GAS PHASE NITROGENEOUS SPECIES  

E-Print Network (OSTI)

Nitrogeneous Species in Gas Turbine Exhaust, from Conkle, et82) Percent of Organic Gas Turbine Emissions which containnitrogen dioxide from gas turbines (from the data presented

Matthews, Ronald D.

2013-01-01T23:59:59.000Z

351

Intermediate Species Profiles in LowPressure Premixed ...  

Science Conference Proceedings (OSTI)

... kinetics are relatively sparse in comparison to the analogous hydro- carbon reactions ... the H/C/O chemistry for one-carbon and two-car- bon species ...

2013-05-04T23:59:59.000Z

352

Thermodynamics Resource for Gas-Phase and Condensed Species  

Science Conference Proceedings (OSTI)

Feb 8, 2007 ... They include thermodynamic data (heats of formation, enthalpies, entropies, and heat capacities) for gas and condensed-phase species, ...

353

Wolbachia diversity in the Porcellionides pruinosus complex of species (Crustacea  

E-Print Network (OSTI)

is a cosmopolitan woodlouse. It is known to exhibit patterns of geographical variation between populations, and has, sibling species. Introduction The cosmopolitan terrestrial isopod Porcellionides ( Metoponorthus

Cordaux, Richard

354

Investigation of the electrocatalysis for oxygen reduction reaction by Pt and binary Pt alloys: an XRD, XAS and electrochemical study  

DOE Green Energy (OSTI)

Electrocatalysis for the oxygen reduction reaction (ORR) on five binary Pt alloy electrocatalysts (PtCr/C, PtMn/C, PtFe/C, PtCo/C and PtNi/C) supported on carbon have been investigated. The electrochemical characteristics for ORR in a proton conducting fuel cell environment has been correlated with the electronic and structural parameters determined under in situ conditions using XANES and EXAFS technique respectively. Results indicate that all the alloys possess higher Pt 5d band vacancies as compared to Pt/C. There is also evidence of lattice contraction in the alloys (supported by XRD results). Further, the Pt/C shows increase in Pt 5 d band vacancies during potential transitions from 0.54 to 0.84 V vs. RHE, which has been ration@ on the basis of OH type adsorption. In contrast to this, the alloys do not exhibit such an enhancement. Detailed EXAFS analysis supports the presence of OH species on Pt/C and its relative absence in the alloys. Correlation of the electrochemical results with bond distances and d-band vacancies show a volcano type behavior with the PtCr/C on top of the curve.

Mukerjee, S.; McBreen, J. [Brookhaven National Lab., Upton, NY (United States); Srinivasan, S. [Texas A and M Univ., College Station, TX (United States). Texas Engineering Experiment Station

1995-12-31T23:59:59.000Z

355

Size Influence on the Oxygen Reduction Reaction Activity and Instability of Supported Pt Nanoparticles  

E-Print Network (OSTI)

Size-dependent oxygen reduction reaction activity (ORR) and instability of Pt nanoparticles is of great importance in proton exchange membrane fuel cell applications. In this study, the size-dependence of ORR activity on ...

Sheng, Wenchao

356

Ion implantation method for preparing polymers having oxygen erosion resistant surfaces  

DOE Patents (OSTI)

Hard surfaced polymers and the method for making them are generally described. Polymers are subjected to simultaneous multiple ion beam bombardment, that results in a hardening of the surface, improved wear resistance, and improved oxygen erosion resistance.

Lee, Eal H. (Oak Ridge, TN); Mansur, Louis K. (Clinton, TN); Heatherly, Jr., Lee (Jacksboro, TN)

1995-01-01T23:59:59.000Z

357

Method of controlled reduction of nitroaromatics by enzymatic reaction with oxygen sensitive nitroreductase enzymes  

DOE Patents (OSTI)

A method is described for the controlled reduction of nitroaromatic compounds such as nitrobenzene and 2,4,6-trinitrotoluene by enzymatic reaction with oxygen sensitive nitroreductase enzymes, such as ferredoxin NADP oxidoreductase. 6 figs.

Shah, M.M.; Campbell, J.A.

1998-07-07T23:59:59.000Z

358

Computational mass transfer moduling of flow through a photocatalytic oxygen generator  

E-Print Network (OSTI)

A self-contained, portable oxygen generator would be extraordinarily useful across a broad spectrum of industries. Both safety and energy-efficiency could be enhanced tremendously in fields such as coal mining, commercial ...

Köksal, Erin (Erin Sevim)

2008-01-01T23:59:59.000Z

359

E10: First-Principles Calculations of Oxygen Diffusion Coefficients in ...  

Science Conference Proceedings (OSTI)

B7: Synthesis and Electrical Properties of K2NiF4-Type (Ca2-xLnx)MnO4 (Ln=Nd and Sm) · B8: Monitoring Oxygen Diffusion in Gd-Doped Ceria by Null ...

360

Fundamental understanding and materials design approaches for lithium-oxygen electrochemical energy storage  

E-Print Network (OSTI)

New strategies and materials are needed to increase the energy and power capabilities of lithium storage devices for electric vehicle and grid-scale applications. Systems based on oxygen electrochemistry are promising due ...

Gallant, Betar M. (Betar Maurkah)

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxygen species ros" 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

Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants  

Office of Scientific and Technical Information (OSTI)

coating fiber bundles 13 Figure 5. Photograph of Fiber 121 as fabricated and after all thermal testing 14 Figure 6. Oxygen sensitivity of Fiber 121 at 42 C over several cycles of...

362

Land Surface Pressure Estimate from Measurements in the Oxygen A Absorption Band  

Science Conference Proceedings (OSTI)

The POLDER (polarization and directionality of the earth reflectances) instrument to be launched in 1996 carries two channels that cover the oxygen A absorption band (near IR). The authors investigate the possibility of using these measurements ...

François-Marie Bréon; Sophie Bouffiés

1996-01-01T23:59:59.000Z

363

The Formation of Labrador Sea Water. Part III: The Evolution of Oxygen and Nutrient Concentration  

Science Conference Proceedings (OSTI)

Oxygen, nutrient, and tritium concentrations observed in the western Labrador Sea in March 1976 during deep convective renewal of Labrador Sea water are analyzed to show how a newly formed water mass obtains its characteristics. Common to other ...

R. Allyn Clarke; A. R. Coote

1988-03-01T23:59:59.000Z

364

Production of Oxygen Gas and Liquid Metal by Electrochemical Decomposition of Molten Iron Oxide  

E-Print Network (OSTI)

Molten oxide electrolysis (MOE) is the electrolytic decomposition of a metal oxide, most preferably into liquid metal and oxygen gas. The successful deployment of MOE hinges upon the existence of an inert anode capable of ...

Wang, Dihua

365

Behavior of alloy 617 at 650°C in low oxygen pressure environments  

E-Print Network (OSTI)

The behavior of alloy 617 at 650°C in low oxygen partial pressure environments has been studied under static loading. Of particular interest was the crack growth rate in these conditions. For that, tests were conducted at ...

Mas, Fanny (Fanny P.)

2010-01-01T23:59:59.000Z

366

Enhanced electrocatalysis of the oxygen reduction reaction based on patterning of platinum surfaces with cyanide  

SciTech Connect

The slow rate of the oxygen reduction reaction in the phosphoric acid fuel cell is the main factor limiting its wide application. Here, we present an approach that can be used for the rational design of cathode catalysts with potential use in phosphoric acid fuel cells, or in any environments containing strongly adsorbing tetrahedral anions. This approach is based on molecular patterning of platinum surfaces with cyanide adsorbates that can efficiently block the sites for adsorption of spectator anions while the oxygen reduction reaction proceeds unhindered. We also demonstrate that, depending on the supporting electrolyte anions and cations, on the same CN-covered Pt(111) surface, the oxygen reduction reaction activities can range from a 25-fold increase to a 50-fold decrease. This behaviour is discussed in the light of the role of covalent and non-covalent interactions in controlling the ensemble of platinum active sites required for high turn over rates of the oxygen reduction reaction.

Strmcnik, D.; Escudero, M.; Kodama, K.; Stamenkovic, V. R.; Cuesta, A.; Markovic, N. M. (Materials Science Division); (Inst. de Quimica Fisica); (Toyota Central R& D Labs.)

2010-10-01T23:59:59.000Z

367

Enhanced electrocatalysis of the oxygen reduction reaction based on pattering of platinum surfaces with cyanide.  

SciTech Connect

The slow rate of the oxygen reduction reaction in the phosphoric acid fuel cell is the main factor limiting its wide application. Here, we present an approach that can be used for the rational design of cathode catalysts with potential use in phosphoric acid fuel cells, or in any environments containing strongly adsorbing tetrahedral anions. This approach is based on molecular patterning of platinum surfaces with cyanide adsorbates that can efficiently block the sites for adsorption of spectator anions while the oxygen reduction reaction proceeds unhindered. We also demonstrate that, depending on the supporting electrolyte anions and cations, on the same CN-covered Pt(111) surface, the oxygen reduction reaction activities can range from a 25-fold increase to a 50-fold decrease. This behaviour is discussed in the light of the role of covalent and non-covalent interactions in controlling the ensemble of platinum active sites required for high turn over rates of the oxygen reduction reaction.

Strmcnik, D.; Escudero-Escribano, M.; Kodama, K.; Stamenkovic, V. R.; Cuesta, A.; Markovic, N. M.; Materials Science Division; Inst. de Quimica Fisica; Toyota Central R& D Labs., Inc.

2010-08-15T23:59:59.000Z

368

From Fjords to Open Seas: Ecological Genomics of Expanding Oxygen Minimum Zones (2010 JGI User Meeting)  

Science Conference Proceedings (OSTI)

Steven Hallam of the University of British Columbia talks "From Fjords to Open Seas: Ecological Genomics of Expanding Oxygen Minimum Zones" on March 24, 2010 at the 5th Annual DOE JGI User Meeting

Hallam, Steven

2010-03-24T23:59:59.000Z

369

Method of controlled reduction of nitroaromatics by enzymatic reaction with oxygen sensitive nitroreductase enzymes  

DOE Patents (OSTI)

A method for the controlled reduction of nitroaromatic compounds such as nitrobenzene and 2,4,6-trinitrotoluene by enzymatic reaction with oxygen sensitive nitroreductase enzymes, such as ferredoxin NADP oxidoreductase.

Shah, Manish M. (Richland, WA); Campbell, James A. (Pasco, WA)

1998-01-01T23:59:59.000Z

370

The Temperature, Oxygen, and Fuel Chemistry Dependence of UO2 Dissolution Under Repository Conditions  

SciTech Connect

Description of results from single pass flowthrough tests showing the effect of dissolved oxygen and temperature on the dissolution of pure UO2 and UO2 with 8 wt% Gd2O3 doping.

Casella, Amanda J.; Hanson, Brady D.; Miller, William H.

2008-06-01T23:59:59.000Z

371

Effects of low oxygen culture on pluripotent stem cell differentiation and teratoma formation  

E-Print Network (OSTI)

Pluripotent stem cells (PSC) hold promise for the study of embryonic development and the treatment of many diseases. Most pluripotent cell research is performed in incubators with a gas-phase oxygen partial pressure (p02) ...

Millman, Jeffrey Robert

2011-01-01T23:59:59.000Z

372

Synthesis and oxygen content dependent properties of hexagonal DyMnO{sub 3 + sub delta}.  

Science Conference Proceedings (OSTI)

Oxygen deficient polycrystalline samples of hexagonal P6{sub 3}cm (space group No.185) DyMnO{sub 3+{delta}} ({delta} stoichiometric in oxygen content ({delta} = 0). Chemical expansion of the crystal lattice corresponding to these large changes of oxygen was found to be 3.48 x 10{sup -2} mol{sup -1}. Thermal expansion of stoichiometric phases were determined to be 11.6 x 10{sup -6} and 2.1 x 10{sup -6} K{sup -1} for the P6{sub 3}cm and Hex{sub 2} phases, respectively. Our measurements also indicate that the oxygen non-stoichiometry of hexagonal RMnO{sub 3+{delta}} materials may have important influence on their multiferroic properties.

Remsen, S.; Dabrowski, B.; Chmaissem, O.; Mais, J.; Szewczyk, A. (Materials Science Division); (Northern Illinois Univ.); (Polish Acad. Sci.)

2011-07-01T23:59:59.000Z

373

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

SciTech Connect

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

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

2013-07-15T23:59:59.000Z

374

Utilizing intake-air oxygen-enrichment technology to reduce cold- phase emissions  

DOE Green Energy (OSTI)

Oxygen-enriched combustion is a proven, serious considered technique to reduce exhaust hydrocarbons (HC) and carbon monoxide (CO) emissions from automotive gasoline engines. This paper presents the cold-phase emissions reduction results of using oxygen-enriched intake air containing about 23% and 25% oxygen (by volume) in a vehicle powered by a spark-ignition (SI) engine. Both engineout and converter-out emissions data were collected by following the standard federal test procedure (FTP). Converter-out emissions data were also obtained employing the US Environmental Protection Agency`s (EPA`s) ``Off-Cycle`` test. Test results indicate that the engine-out CO emissions during the cold phase (bag 1) were reduced by about 46 and 50%, and HC by about 33 and 43%, using nominal 23 and 25% oxygen-enriched air compared to ambient air (21% oxygen by volume), respectively. However, the corresponding oxides of nitrogen (NO{sub x}) emissions were increased by about 56 and 79%, respectively. Time-resolved emissions data indicate that both HC and CO emissions were reduced considerably during the initial 127 s of the cold-phase FTP, without any increase in NO, emissions in the first 25 s. Hydrocarbon speciation results indicate that all major toxic pollutants, including ozone-forming specific reactivity factors, such as maximum incremental reactivity (NUR) and maximum ozone incremental reactivity (MOIR), were reduced considerably with oxygen-enrichment. Based on these results, it seems that using oxygen-enriched intake air during the cold-phase FTP could potentially reduce HC and CO emissions sufficiently to meet future emissions standards. Off-cycle, converter-out, weighted-average emissions results show that both HC and CO emissions were reduced by about 60 to 75% with 23 or 25% oxygen-enrichment, but the accompanying NO{sub x}, emissions were much higher than those with the ambient air.

Poola, R.B.; Ng, H.K.; Sekar, R.R. [Argonne National Lab., IL (United States); Baudino, J.H. [Autoresearch Labs., Inc., Chicago, IL (United States); Colucci, C.P. [National Renewable Energy Lab., Golden, CO (United States)

1995-12-31T23:59:59.000Z

375

Electrocatalyst for oxygen reduction with reduced platinum oxidation and dissolution rates  

DOE Patents (OSTI)

The invention relates to platinum-metal oxide composite particles and their use as electrocatalysts in oxygen-reducing cathodes and fuel cells. The invention particularly relates to methods for preventing the oxidation of the platinum electrocatalyst in the cathodes of fuel cells by use of these platinum-metal oxide composite particles. The invention additionally relates to methods for producing electrical energy by supplying such a fuel cell with an oxidant, such as oxygen, and a fuel source, such as hydrogen.

Adzic, Radoslav (East Setauket, NY); Zhang, Junliang (Stony Brook, NY); Vukmirovic, Miomir (Port Jefferson Station, NY)

2011-11-22T23:59:59.000Z

376

Electrocatalyst for oxygen reduction with reduced platinum oxidation and dissolution rates  

DOE Patents (OSTI)

The invention relates to platinum-metal oxide composite particles and their use as electrocatalysts in oxygen-reducing cathodes and fuel cells. The invention particularly relates to methods for preventing the oxidation of the platinum electrocatalyst in the cathodes of fuel cells by use of these platinum-metal oxide composite particles. The invention additionally relates to methods for producing electrical energy by supplying such a fuel cell with an oxidant, such as oxygen, and a fuel source, such as hydrogen.

Adzic, Radoslav; Zhang, Junliang; Vukmirovic, Miomir

2012-11-13T23:59:59.000Z

377

Device and method for determining oxygen concentration and pressure in gases  

DOE Patents (OSTI)

Disclosed are oxygen concentration and/or pressure sensing devices and methods which incorporate photoluminescent silica aerogels. Disclosed sensors include a light proof housing for holding the photoluminescent aerogel, a source of excitation radiation (e.g., a UV source), a detector for detecting radiation emitted by the aerogel, a system for delivering a sample gas to the aerogel, and a thermocouple. Also disclosed are water resistant oxygen sensors having a photoluminescent aerogel coated with a hydrophobic material. 6 figs.

Ayers, M.R.; Hunt, A.J.

1999-03-23T23:59:59.000Z

378

Device and method for determining oxygen concentration and pressure in gases  

DOE Patents (OSTI)

Disclosed are oxygen concentration and/or pressure sensing devices and methods which incorporate photoluminescent silica aerogels. Disclosed sensors include a light proof housing for holding the photoluminescent aerogel, a source of excitation radiation (e.g., a UV source), a detector for detecting radiation emitted by the aerogel, a system for delivering a sample gas to the aerogel, and a thermocouple. Also disclosed are water resistant oxygen sensors having a photoluminescent aerogel coated with a hydrophobic material.

Ayers, Michael R. (El Cerrito, CA); Hunt, Arlon J. (Kensington, CA)

1999-01-01T23:59:59.000Z

379

Oxygen-hydrogen meter assembly for use in remote sodium sampling systems  

SciTech Connect

An assembly of an electrolytic oxygen meter and a diffusion type hydrogen meter was designed to fit into the Multipurpose Sampler hardware already installed and operating on the four FFTF sodium systems. One of the key elements in this assembly is a ceramic-metal sealed oxygen sensor which allows use of a metal tube to extend the 51 cm (20 in.) between the sampler top and the flowing sodium region.

Barton, G.B.; Bohringer, A.P.; Yount, J.A.

1980-02-01T23:59:59.000Z

380

The oxygen abundance gradient in M101: the reliability of the P method  

E-Print Network (OSTI)

We present the oxygen abundance determination for 90 HII regions in the inner parts of the grand design galaxy M101. The abundances were derived employing the P method (Pilyugin 2001a). A comparison is made with previous determinations using another calibration and direct measurements of electron temperature to derive the oxygen abundance. The results show agreement with the abundances derived from the electron temperature method and also show that the older calibration is not as accurate as the P method.

B. Cedres; M. A. Urbaneja; J. Cepa

2004-04-29T23:59:59.000Z

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


381

The oxygen abundance gradient in M101: the reliability of the P method  

E-Print Network (OSTI)

We present the oxygen abundance determination for 90 HII regions in the inner parts of the grand design galaxy M101. The abundances were derived employing the P method (Pilyugin 2001a). A comparison is made with previous determinations using another calibration and direct measurements of electron temperature to derive the oxygen abundance. The results show agreement with the abundances derived from the electron temperature method and also show that the older calibration is not as accurate as the P method.

Cedres, B; Cepa, J

2004-01-01T23:59:59.000Z

382

On the Importance of Organic Oxygen for Understanding OrganicAerosol Particles  

SciTech Connect

This study shows how aerosol organic oxygen data could provide new 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 (OM) concentration has been estimated by multiplying the measured carbon content by an assumed (OM)-to-organic carbon (OC) factor, usually 1.4. However, this factor can vary from 1.0 to 2.5 depending on location. This large 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 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-OC factor for all studied sites (urban and non-urban) averaged 1.13. 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). This analysis suggests that, 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 1 g per 100 g water.

Pang, Y.; Turpin, B.J.; Gundel, L.A.

2005-04-01T23:59:59.000Z

383

Application of oxygen-enriched combustion for locomotive diesel engines. Phase 1  

DOE Green Energy (OSTI)

A thermodynamic simulation is used to study the effects of oxygen-enriched intake air on the performance and nitrogen oxide (NO) emissions of a locomotive diesel engine. The parasitic power of the air separation membrane required to supply the oxygen-enriched air is also estimated. For a given constraint on peak cylinder pressure, the gross and net power outputs of an engine operating under different levels of oxygen enrichment are compared with those obtained when a high-boost turbocharged engine is used. A 4% increase in peak cylinder pressure can result in an increase in net engine power of approximately 13% when intake air with an oxygen content of 28% by volume is used and fuel injection timing is retarded by 4 degrees. When the engine is turbocharged to a higher inlet boost, the same increase in peak cylinder pressure improves power by only 4%. If part of the significantly higher exhaust enthalpies available as a result of oxygen enrichment are recovered, the power requirements of the air separator membrane can be met, resulting in substantial net power improvements. Oxygen enrichment reduces particulate and visible smoke emissions but increases NO emissions. However, a combination of retarded fuel injection timing and post-treatment of exhaust gases may be adequate to meet the locomotive diesel engine NO{sub x} standards. Exhaust gas after-treatment and heat recovery would be required to realize the full potential of oxygen enrichment. Economic analysis shows that oxygen-enrichment technology is economically feasible and provides high returns on investment. The study also indicates the strong influence of membrane parasitic requirements and exhaust energy recovery on economic benefits. To obtain an economic advantage while using a membrane with higher parasitic power requirements, it is necessary to recover a part of the exhaust energy.

Poola, R.B.; Sekar, R.R.; Assanis, D.N.

1996-09-01T23:59:59.000Z

384

Evaluation of oxygen utilization as an indicator of municipal solid-waste compost stability  

Science Conference Proceedings (OSTI)

This research evaluated oxygen utilization parameters as indicators of MSW compost stability. Parameters evaluated were the oxygen utilization rate (OUR), specific oxygen uptake rate (SOUR), five-day biochemical oxygen demand, and chemical oxygen demand. In addition, other suggested indicators of stability were investigated including percent volatile solids, volatile solids reduction, nitrogen content, carbon: nitrogen ratio, and reheating potential (RP). OUR is a measure of the rate of oxygen utilization by the microorganisms in the decomposition of organic matter in compost. OUR was observed to be sensitive to the degree of stabilization and decreased with increasing compost age and stability. OUR values near zero indicate that the compost microorganisms are in a state of endogenous respiration, which is characteristic of a stable compost. Therefore, OUR is an excellent indicator of stability. A number of disadvantages are associated with OUR for practical application. Therefore, other parameters were evaluated as indicators of stability based on their statistical correlation to OUR. RP exhibited the strongest correlation to OUR. In combination, RP and SOUR were the two parameters which exhibited the strongest correlation to OUR. OUR, RP, and SOUR are all measures of microbial activity which reflect the degree of organic decomposition, and therefore, stability. Based on the results of this research; OUR, RP, and SOUR are useful parameters in assessing compost stability.

Zimmerman, R.A.

1991-01-01T23:59:59.000Z

385

Role of oxygen in the film growth and giant magnetoresistance of Co/Cu multilayers  

SciTech Connect

In order to clarify the effect of oxygen in the sputtering atmosphere on the microstructure and giant magnetoresistance, Co/Cu multilayers were fabricated under a sputtering atmosphere into which regulated impurity oxygen gas was introduced. After being pumped down the sputtering chamber to the ultimate pressure (less than 1{times}10{sup {minus}10} Torr), oxygen was introduced into the chamber until its content in processing Ar gas was about 0.1 ppm to 0.1%. The magnetoresistance (MR) ratio drastically increased from less than 20% to 54% when the content of impurity oxygen was slightly increased from 20 to 80 ppm, then nearly vanished when the content became more than 200 ppm. In the former region where the MR ratio steeply increased, the root mean square roughness of the multilayers decreased from 6.5 to 4.5 Aa accompanied by a reduction in grain size as the oxygen content was increased. The partial oxidation of the multilayers is the most probable mechanism by which the flattening of the interfaces in the multilayer can be explained. We conclude that the impurity oxygen in the sputtering atmosphere serves as an obstruction of grain growth in the multilayer, not as a surfactant for the film growth. {copyright} 2001 American Institute of Physics.

Miura, Satoshi; Tsunoda, Masakiyo; Takahashi, Migaku

2001-06-01T23:59:59.000Z

386

Water Induced Surface Reconstruction of the Oxygen (2x1) covered Ru(0001)  

DOE Green Energy (OSTI)

Low temperature scanning tunneling microscopy (STM) and density functional theory (DFT) were used to study the adsorption of water on a Ru(0001) surface covered with half monolayer of oxygen. The oxygen atoms occupy hcp sites in an ordered structure with (2x1) periodicity. DFT predicts that water is weakly bound to the unmodified surface, 86 meV compared to the ~;;200 meV water-water H-bond. Instead, we found that water adsorption causes a shift of half of the oxygen atoms from hcp sites to fcc sites, creating a honeycomb structure where water molecules bind strongly to the exposed Ru atoms. The energy cost of reconstructing the oxygen overlayer, around 230 meV per displaced oxygen atom, is more than compensated by the larger adsorption energy of water on the newly exposed Ru atoms. Water forms hydrogen bonds with the fcc O atoms in a (4x2) superstructure due to alternating orientations of the molecules. Heating to 185 K results in the complete desorption of the water layer, leaving behind the oxygen honeycomb structure, which is metastable relative to the original (2x1). This stable structure is not recovered until after heating to temperatures close to 260K.

Maier, Sabine; Cabrera-Sanfelix, Pepa; Stass, Ingeborg; Sanchez-Portal, Daniel; Arnau, Andres; Salmeron, Miquel

2010-08-06T23:59:59.000Z

387

Spectroscopy of transient neutral species via negative ion photoelectron spectroscopy  

SciTech Connect

Negative ion photoelectron spectroscopy has been used to study two types of transient neutral species: bound free radicals (NO{sub 2} and NO{sub 3}) and unstable neutral species ((IHI) and (FH{sub 2})). The negative ion time-of-flight photoelectron spectrometer used for these experiments is described in detail.

Weaver, A.

1991-12-01T23:59:59.000Z

388

Spectroscopy of transient neutral species via negative ion photoelectron spectroscopy  

Science Conference Proceedings (OSTI)

Negative ion photoelectron spectroscopy has been used to study two types of transient neutral species: bound free radicals (NO{sub 2} and NO{sub 3}) and unstable neutral species ([IHI] and [FH{sub 2}]). The negative ion time-of-flight photoelectron spectrometer used for these experiments is described in detail.

Weaver, A.

1991-12-01T23:59:59.000Z

389

Proceedings of the Subcontractors' Review Meeting: Aquatic Species Program  

DOE Green Energy (OSTI)

The Aquatic Species Program (ASP) addresses the utilization of plant biomass that naturally occurs in wetland or submerged areas. Processes are being developed through this program to make use of such aquatic species, capitalizing on their inherent capacity for rapid growth as well as their extraordinary chemical compositions.

Not Available

1981-07-01T23:59:59.000Z

390

Thomson scattering diagnostic for the measurement of ion species fraction  

Science Conference Proceedings (OSTI)

Simultaneous Thomson scattering measurements of collective electron-plasma and ion-acoustic fluctuations have been utilized to determine ion species fraction from laser produced CH plasmas. The CH{sub 2} foil is heated with 10 laser beams, 500 J per beam, at the Omega Laser facility. Thomson scattering measurements are made 4 mm from the foil surface using a 30 J 2{omega} probe laser with a 1 ns pulse length. Using a series of target shots the plasma evolution is measured from 2.5 ns to 9 ns after the rise of the heater beams. Measuring the electron density and temperature from the electron-plasma fluctuations constrains the fit of the two-ion species theoretical form factor for the ion feature such that the ion temperature, plasma flow velocity and ion species fraction are determined. The ion species fraction is determined to an accuracy of {+-}0.06 in species fraction.

Ross, J S; Park, H S; Amendt, A; Divol, L; Kugland, N L; Rozmus, W; Glenzer, S H

2012-05-01T23:59:59.000Z

391

Measurement of Species Distributions in Operating Fuel Cells  

DOE Green Energy (OSTI)

Measurement and understanding of transient species distributions across and within fuel cells is a critical need for advancing fuel cell technology. The Spatially Resolved Capillary Inlet Mass Spectrometer (SpaciMS) instrument has been applied for in-situ measurement of transient species distributions within operating reactors; including diesel catalyst, air-exhaust mixing systems, and non-thermal plasma reactors. The work described here demonstrates the applicability of this tool to proton exchange membrane (PEM) and solid oxide fuel cells (SOFC) research. Specifically, we have demonstrated SpaciMS measurements of (1) transient species dynamics across a PEM fuel cell (FC) associated with load switching, (2) intra-PEM species distributions, and transient species dynamics at SOFC temperatures associated with FC load switching.

Partridge Jr, William P [ORNL; Toops, Todd J [ORNL; Parks, II, James E [ORNL; Armstrong, Timothy R. [ORNL

2004-10-01T23:59:59.000Z

392

Reintroduction of Native FishReintroduction of Native Fish Species to Coal CreekSpecies to Coal Creek  

E-Print Network (OSTI)

1 Reintroduction of Native FishReintroduction of Native Fish Species to Coal CreekSpecies to Coal Control and Reclamation ActSurface Mining Control and Reclamation Act of 1977of 1977 Coal Creek Watershed Foundation (2000)Coal Creek Watershed Foundation (2000) BackgroundBackground Fish populations in Coal Creek

Gray, Matthew

393

An inventory of invasive alien species in China 1 An inventory of invasive alien species in China  

E-Print Network (OSTI)

An inventory of invasive alien species in China 1 An inventory of invasive alien species in China, Nanjing, China 2 Nanjing Agricultural University, Nanjing, China 3 ISPRA ­ Institute for Environmental and Environment, Nanjing Forestry University, Nanjing, China 5 The First Institute of Oceanography, State Oceanic

Kratochvíl, Lukas

394

Spectroscopic and structural characterization of reduced technetium species in acetate media  

SciTech Connect

The reduction of ammonium pertechnetate by sodium borohydride in 0.1 M NaOH/glacial acetic acid has been studied. The reduction products (solids and solutions) have been characterized by UV-Visible spectroscopy, Scanning Electron Microscopy/Energy-dispersive X-ray emission spectroscopy (SEM/EDS), and X-ray absorption fine structure (XAFS) spectroscopy. UV-Visible spectra of the solution, after reduction, exhibit bands at 350 and 500 nm that have been attributed to the formation of polymeric Tc(IV) species. SEM/EDS on the solid (X-ray amorphous) indicates the absence of metallic Tc and the presence of oxygen. EXAFS measurements further indicate that the precipitate exhibits a [Tc({mu}-O){sub 2}Tc] core structure. XANES is consistent with the formation of Tc(III) and/or Tc(IV). Results infer that reduction of aqueous Tc(VII) by borohydride in the presence of acetic acid does not produce metallic Tc, but a mixture of various oxidation states of Tc near Tc(III) and Tc(IV).

Mausolf, Edward; Poineau, Frederic; Droessler, Janelle; Czerwinski, Kenneth R. (UNLV)

2011-11-17T23:59:59.000Z

395

Comparing disease expression across species: an examination of radiation and species specific disease expression in Mus musculus and Peromyscus leucopus  

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

disease expression across species: an examination of radiation and species specific disease expression across species: an examination of radiation and species specific disease expression in Mus musculus and Peromyscus leucopus William Liu 1 , Benjamin Haley 1 , Mary J. Kwasny 2 , Tatjana Paunesku 1 , Gayle Woloschak 1 1. Department of Radiation Oncology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611 2. Department of Preventative Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611 From 1969 to 1992, the Janus program at Argonne National Laboratory performed a large series of radiobiology experiments, examining the effects of varying doses of neutron and gamma radiation on two disparate species of mice, Mus musculus and Peromyscus leucopus. Much of this data has since been digitized and made freely accessible online. This study aims to revisit

396

Conversion of Mixed Oxygenates Generated from Synthesis Gas to Fuel Range Hydrocarbon  

SciTech Connect

The growing dependence in the U.S. on foreign crude oil supplies and increased concerns regarding greenhouse gas emission has generated considerable interest in research to develop renewable and environmentally friendly liquid hydrocarbon transportation fuels. One of the strategies for achieving this is to produce intermediate compounds such as alcohols and other simple oxygenates from biomass generated synthesis gas (mixture of carbon monoxide and hydrogen) and further convert them into liquid hydrocarbons. The focus of this research is to investigate the effects of mixed oxygenates intermediate product compositions on the conversion step to produce hydrocarbon liquids. A typical mixed oxygenate stream is expected to contain water (around 50%), alcohols, such as methanol and ethanol (around 35%), and smaller quantities of oxygenates such as acetaldehyde, acetic acid and ethyl acetate. However the ratio and the composition of the mixed oxygenate stream generated from synthesis gas vary significantly depending on the catalyst used and the process conditions. Zeolite catalyzed deoxygenation of methanol accompanied by chain growth is well understood under Methanol-to-Gasoline (MTG) like reaction conditions using an H-ZSM-5 zeolite as the catalyst6-8. Research has also been conducted to a limited extent in the past with higher alcohols, but not with other oxygenates present9-11. Also there has been little experimental investigation into mixtures containing substantial amounts of water. The latter is of particular interest because water separation from the hydrocarbon product would be less energy intensive than first removing it from the oxygenate intermediate stream prior to hydrocarbon synthesis, potentially reducing overall processing costs.

Ramasamy, Karthikeyan K.; Gerber, Mark A.; Lilga, Michael A.; Flake, Matthew D.

2012-08-19T23:59:59.000Z

397

Effects of Headspace and Oxygen Level on Off-gas Emissions from Wood Pellets in Storage  

SciTech Connect

Few papers have been published in the open literature on the emissions from biomass fuels, including wood pellets, during the storage and transportation and their potential health impacts. The purpose of this study is to provide data on the concentrations, emission factors, and emission rate factors of CO2, CO, and CH4 from wood pellets stored with different headspace to container volume ratios with different initial oxygen levels, in order to develop methods to reduce the toxic off-gas emissions and accumulation in storage spaces. Metal containers (45 l, 305 mm diameter by 610 mm long) were used to study the effect of headspace and oxygen levels on the off-gas emissions from wood pellets. Concentrations of CO2, CO, and CH4 in the headspace were measured using a gas chromatograph as a function of storage time. The results showed that the ratio of the headspace ratios and initial oxygen levels in the storage space significantly affected the off-gas emissions from wood pellets stored in a sealed container. Higher peak emission factors and higher emission rates are associated with higher headspace ratios. Lower emissions of CO2 and CO were generated at room temperature under lower oxygen levels, whereas CH4 emission is insensitive to the oxygen level. Replacing oxygen with inert gases in the storage space is thus a potentially effective method to reduce the biomass degradation and toxic off-gas emissions. The proper ventilation of the storage space can also be used to maintain a high oxygen level and low concentrations of toxic off-gassing compounds in the storage space, which is especially useful during the loading and unloading operations to control the hazards associated with the storage and transportation of wood pellets.

Sokhansanj, Shahabaddine [ORNL; Kuang, Xingya [University of British Columbia, Vancouver; Shankar, T.S. [University of British Columbia, Vancouver; Lim, C. Jim [University of British Columbia, Vancouver; Bi, X.T. [University of British Columbia, Vancouver; Melin, Staffan [University of British Columbia, Vancouver

2009-10-01T23:59:59.000Z

398

Synthesis and oxygen content dependent properties of hexagonal DyMnO[subscript 3+delta  

SciTech Connect

Oxygen deficient polycrystalline samples of hexagonal P6{sub 3}cm (space group No.185) DyMnO{sub 3+{delta}} ({delta} < 0) were synthesized in Ar by intentional decomposition of its perovskite phase obtained in air. The relative stability of these phases is in accord with our previous studies of the temperature and oxygen vacancy dependent tolerance factor. Thermogravimetric measurements have shown that hexagonal samples of DyMnO{sub 3+{delta}} (0 {le} {delta} {le} 0.4) exhibit unusually large excess oxygen content, which readily incorporates on heating near 300 C in various partial-pressures of oxygen atmospheres. Neutron and synchrotron diffraction data show the presence of two new structural phases at {delta} {approx} 0.25 (Hex{sub 2}) and {delta} {approx} 0.40 (Hex{sub 3}). Rietveld refinements of the Hex{sub 2} phase strongly suggest it is well modeled by the R3 space group (No.146). These phases were observed to transform back to P6{sub 3}cm above {approx} 350 C when material becomes stoichiometric in oxygen content ({delta} = 0). Chemical expansion of the crystal lattice corresponding to these large changes of oxygen was found to be 3.48 x 10{sup -2} mol{sup -1}. Thermal expansion of stoichiometric phases were determined to be 11.6 x 10{sup -6} and 2.1 x 10{sup -6} K{sup -1} for the P6{sub 3}cm and Hex{sub 2} phases, respectively. Our measurements also indicate that the oxygen non-stoichiometry of hexagonal RMnO{sub 3+{delta}} materials may have important influence on their multiferroic properties.

Remsen, S.; Dabrowski, B.; Chmaissem, O.; Mais, J.; Szewczyk, A. (NIU); (Polish)

2011-10-28T23:59:59.000Z

399

Endangered, Threatened, and Species of Special Concern (Connecticut) |  

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

Endangered, Threatened, and Species of Special Concern Endangered, Threatened, and Species of Special Concern (Connecticut) Endangered, Threatened, and Species of Special Concern (Connecticut) < Back Eligibility Agricultural Commercial Construction Fed. Government Fuel Distributor General Public/Consumer Industrial Installer/Contractor Institutional Investor-Owned Utility Local Government Low-Income Residential Multi-Family Residential Municipal/Public Utility Nonprofit Residential Retail Supplier Rural Electric Cooperative Schools State/Provincial Govt Systems Integrator Transportation Tribal Government Utility Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State Connecticut Program Type Environmental Regulations Provider Department of Energy and Environmental Protection

400

Nongame and Endangered Species Conservation Act (South Carolina) |  

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

Nongame and Endangered Species Conservation Act (South Carolina) Nongame and Endangered Species Conservation Act (South Carolina) Nongame and Endangered Species Conservation Act (South Carolina) < Back Eligibility Agricultural Commercial Construction Fed. Government Fuel Distributor General Public/Consumer Industrial Installer/Contractor Institutional Investor-Owned Utility Local Government Low-Income Residential Multi-Family Residential Municipal/Public Utility Nonprofit Residential Retail Supplier Rural Electric Cooperative Schools State/Provincial Govt Systems Integrator Transportation Tribal Government Utility Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State South Carolina Program Type Siting and Permitting Provider South Carolina Department of Natural Resources

Note: This page contains sample records for the topic "oxygen species ros" 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

Oxygen electrode reaction in molten carbonate fuel cells. Final report, September 15, 1987--September 14, 1990  

DOE Green Energy (OSTI)

Molten carbonate fuel cell system is a leading candidate for the utility power generation because of its high efficiency for fuel to AC power conversion, capability for an internal reforming, and a very low environmental impact. However, the performance of the molten carbonate fuel cell is limited by the oxygen reduction reaction and the cell life time is limited by the stability of the cathode material. An elucidation of oxygen reduction reaction in molten alkali carbonate is essential because overpotential losses in the molten carbonate fuel cell are considerably greater at the oxygen cathode than at the fuel anode. Oxygen reduction on a fully-immersed gold electrode in a lithium carbonate melt was investigated by electrochemical impedance spectroscopy and cyclic voltammetry to determine electrode kinetic and mass transfer parameters. The dependences of electrode kinetic and mass transfer parameters on gas composition and temperature were examined to determine the reaction orders and the activation energies. The results showed that oxygen reduction in a pure lithium carbonate melt occurs via the peroxide mechanism. A mass transfer parameter, D{sub O}{sup 1/2}C{sub O}, estimated by the cyclic voltammetry concurred with that calculated by the EIS technique. The temperature dependence of the exchange current density and the product D{sub O}{sup 1/2}C{sub O} were examined and the apparent activation energies were determined to be about 122 and 175 kJ/ mol, respectively.

Appleby, A.J.; White, R.E.

1992-07-07T23:59:59.000Z

402

Aerobic composting of waste activated sludge: Kinetic analysis for microbiological reaction and oxygen consumption  

SciTech Connect

In order to examine the optimal design and operating parameters, kinetics for microbiological reaction and oxygen consumption in composting of waste activated sludge were quantitatively examined. A series of experiments was conducted to discuss the optimal operating parameters for aerobic composting of waste activated sludge obtained from Kawagoe City Wastewater Treatment Plant (Saitama, Japan) using 4 and 20 L laboratory scale bioreactors. Aeration rate, compositions of compost mixture and height of compost pile were investigated as main design and operating parameters. The optimal aerobic composting of waste activated sludge was found at the aeration rate of 2.0 L/min/kg (initial composting mixture dry weight). A compost pile up to 0.5 m could be operated effectively. A simple model for composting of waste activated sludge in a composting reactor was developed by assuming that a solid phase of compost mixture is well mixed and the kinetics for microbiological reaction is represented by a Monod-type equation. The model predictions could fit the experimental data for decomposition of waste activated sludge with an average deviation of 2.14%. Oxygen consumption during composting was also examined using a simplified model in which the oxygen consumption was represented by a Monod-type equation and the axial distribution of oxygen concentration in the composting pile was described by a plug-flow model. The predictions could satisfactorily simulate the experiment results for the average maximum oxygen consumption rate during aerobic composting with an average deviation of 7.4%.

Yamada, Y. [Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry, Toyo University, Kawagoe, Saitama, 350-8585 (Japan); Kawase, Y. [Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry, Toyo University, Kawagoe, Saitama, 350-8585 (Japan)]. E-mail: bckawase@mail.eng.toyo.ac.jp

2006-07-01T23:59:59.000Z

403

Assessment of thermal swing absorption alternatives for producing oxygen enriched combustion air  

SciTech Connect

It has been established that oxygen enriched combustion (OEC) can substantially improve the thermal efficiency and productivity of a furnace. An OEC performance study by the Union Carbide Corporation found that in furnaces with flue gas temperatures above 2,000{degree}F, a high level of oxygen (O{sub 2}) enrichment (50% to 100% O{sub 2}) will result in a 40% to 60% fuel savings. The US DOE's (Department of Energy) Office of Industrial Programs (OIP) has sponsored several research development projects and engineering assessments relevant to the production of oxygen enriched air (OEA) and its use in combustion systems. In an OIP-sponsored assessment of research and development opportunities for combustion technologies, Taratec Corporation indicated that thermal swing absorption (TSA) offers a potentially viable option for producing low-cost oxygen enriched combustion air (OECA). In fact, an integrated, TSA-based oxygen enriched air production system driven by waste heat from furnace exhaust may be more energy- and cost-efficient than the alternative technologies. The study presented in this document further investigates and assesses TSA alternatives for producing low-cost OECA. 7 refs., 4 figs., 5 tabs.

Not Available

1990-04-01T23:59:59.000Z

404

Test Operation of Oxygen-Enriched Incinerator for Wastes From Nuclear Fuel Fabrication Facility  

SciTech Connect

The oxygen-enriched combustion concept, which can minimize off-gas production, has been applied to the incineration of combustible uranium-containing wastes from a nuclear fuel fabrication facility. A simulation for oxygen combustion shows the off-gas production can be reduced by a factor of 6.7 theoretically, compared with conventional air combustion. The laboratory-scale oxygen enriched incineration (OEI) process with a thermal capacity of 350 MJ/h is composed of an oxygen feeding and control system, a combustion chamber, a quencher, a ceramic filter, an induced draft fan, a condenser, a stack, an off-gas recycle path, and a measurement and control system. Test burning with cleaning paper and office paper in this OEI process shows that the thermal capacity is about 320 MJ/h, 90 % of design value and the off-gas reduces by a factor of 3.5, compared with air combustion. The CO concentration for oxygen combustion is lower than that of air combustion, while the O2 concentration in off-gas is kept above 25 vol % for a simple incineration process without any grate. The NOx concentration in an off-gas stream does not reduce significantly due to air incoming by leakage, and the volume and weight reduction factors are not changed significantly, which suggests a need for an improvement in sealing.

Kim, J.-G.; Yang, H.cC.; Park, G.-I.; Kim, I.-T.; Kim, J.-K.

2002-02-26T23:59:59.000Z

405

Oxygen-enriched diesel engine performance: A comparison of analytical and experimental results  

DOE Green Energy (OSTI)

Use of oxygen-enriched combustion air in diesel engines can lead to significant improvements in power density, as well as reductions in particulate emissions, but at the expense of higher NO{sub x} emissions. Oxygen enrichment would also lead to lower ignition delays and the opportunity to burn lower grade fuels. Analytical and experimental studies are being conducted in parallel to establish the optimal combination of oxygen level and diesel fuel properties. In this paper, cylinder pressure data acquired on a single-cylinder engine are used to generate heat release rates for operation under various oxygen contents. These derived heat release rates are in turn used to improve the combustion correlation -- and thus the prediction capability -- of the simulation code. It is shown that simulated and measured cylinder pressures and other performance parameters are in good agreement. The improved simulation can provide sufficiently accurate predictions of trends and magnitudes to be useful in parametric studies assessing the effects of oxygen enrichment and water injection on diesel engine performance. Measured ignition delays, NO{sub x} emissions, and particulate emissions are also compared with previously published data. The measured ignition delays are slightly lower than previously reported. Particulate emissions measured in this series of tests are significantly lower than previously reported. 14 refs., 10 figs., 1 tab.

Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J. (Argonne National Lab., IL (USA)); Assanis, D.N. (Illinois Univ., Urbana, IL (USA)); Schaus, J.E. (Autoresearch Labs., Inc., Chicago, IL (USA))

1990-01-01T23:59:59.000Z

406

Impact of hydrogen and oxygen defects on the lattice parameter of chemical vapor deposited zinc sulfide  

SciTech Connect

The lattice parameter of cubic chemical vapor deposited (CVD) ZnS with measured oxygen concentrations < 0.6 at.% and hydrogen impurities of < 0.015 at.% have been measured and found to vary between -0.10% and +0.09% relative to the reference lattice parameter (5.4093 Å) of oxygen-free cubic ZnS as reported in the literature. Defects other than substitutional O must be invoked to explain these observed volume changes. The structure and thermodynamic stability of a wide range of native and impurity induced defects in ZnS have been determined by Ab initio calculations. Lattice contraction is caused by S-vacancies, substitutional O on S sites, Zn vacancies, H in S vacancies, peroxy defects, and dissociated water in S-vacancies. The lattice is expanded by interstitial H, H in Zn vacancies, dihydroxy defects, interstitial oxygen, Zn and [ZnHn] complexes (n=1,…,4), interstitial Zn, and S2 dumbbells. Oxygen, though present, likely forms substitutional defects for sulfur resulting in lattice contraction rather than as interstitial oxygen resulting in lattice expansion. It is concluded based on measurement and calculations that excess zinc atoms either at anti-sites (i.e. Zn atoms on S-sites) or possibly as interstitial Zn are responsible for the relative increase of the lattice parameter of commercially produced CVD ZnS.

McCloy, John S.; Wolf, Walter; Wimmer, Erich; Zelinski, Brian

2013-01-09T23:59:59.000Z

407

Negative magnetophoresis of submicron species in magnetic nanofluids  

E-Print Network (OSTI)

In this work we studied the focusing and trapping of submicron, nonmagnetic species immersed in a magnetic nanofluid under applied magnetic fields. Focusing was achieved using two pairs of permanent magnets, which forced ...

Gonzalez, Lino A. (Lino Alberto), 1976-

2009-01-01T23:59:59.000Z

408

Halocarbon and Other Atmospheric Trace Species (HATS) | Data.gov  

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

Halocarbon and Other Atmospheric Trace Species (HATS) Halocarbon and Other Atmospheric Trace Species (HATS) Agriculture Community Menu DATA APPS EVENTS DEVELOPER STATISTICS COLLABORATE ABOUT Agriculture You are here Data.gov » Communities » Agriculture » Data Halocarbon and Other Atmospheric Trace Species (HATS) Dataset Summary Description The general mission of the Halocarbons and other Atmospheric Trace Species group is to quantify the distributions and magnitudes of sources and sinks for atmospheric nitrous oxide (N2O) and halogen containing compounds. HATS utilizes numerous types of platforms, including ground-based stations, towers, ocean vessels, aircraft, and balloons, to accomplish its mission. For a detailed mission statement, consult our FAQ. Tags {"nitrous oxide","sulfur hexaflouride",CFC-11,CFC-12,CFC-113,CCl4,CH3CCl3,CH3Cl,halon-1211,HCFC-22,HCFC-142b,halocarbons,chromatograph,aircraft,balloons,vessels,ships,towers,"natural resources",environment,air,"GHG "}

409

RESEARCH ARTICLE Open Access Species richness, distribution and genetic  

E-Print Network (OSTI)

richness for Caenorhabditis encountered to date, including both tropically cosmopolitan and geographically for different local species, although global distributions include both cosmopolitan and geographically restricted groups. Local samples for the cosmopolitan C. briggsae mirror its pan-tropical patterns

410

Final Report Parris Island Depot Invasive Plant Species  

E-Print Network (OSTI)

and Recommendations for Control Page 37 a. Chinese tallow tree (Triadicasebifera) Page 37 b. Chinaberry non-native invasive species that have been prioritized for control are Chinese tallow

Bolding, M. Chad

411

Researchers Map Where Tree Species Survive and Thrive under Climate...  

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

Researchers Map Where Tree Species Survive and Thrive under Climate Change A topology map shows the range of tree productivity from low to high biomass production (blue to red,...

412

XPS and FTIR study of Ru/Al{sub 2}O{sub 3} and Ru/TiO{sub 2} catalysts: Reduction characteristics and interaction with a methane-oxygen mixture  

SciTech Connect

The oxidation state of alumina- and titania-supported Ru catalysts has been investigated as a function of reduction temperature, as well as by following the interaction with a methane-oxygen mixture at 773 and 973 K, employing XPS and FTIR techniques. It is found that the chemical behavior of Ru depends strongly on the material on which it is supported. Over Al{sub 2}O{sub 3}, ruthenium is incompletely reduced by treatment with hydrogen at 573 and 823 K, while oxidized Ru species are also detected following exposure of the catalyst to a methane-oxygen mixture at 773 and 973 K. In contrast, over TiO{sub 2}, ruthenium is more easily reduced and is stabilized in its reduced state following hydrogen treatment at 823 K. During treatment with the methane-oxygen mixture, no reoxidation of Ru occurs. The interaction between Ru and TiO{sub 2}, which inhibits the oxidation of ruthenium under conditions of partial oxidation of methane, is related to the unique ability of the Ru/TiO{sub 2} catalyst to promote the direct route of synthesis gas formation.

Elmasides, C.; Kondarides, D.I.; Verykios, X.E. [Univ. of Patras (Greece). Dept. of Chemical Engineering; Gruenert, W. [Ruhr-Universitaet Bochum (Germany). Lehrstuhl fuer Technische Chemie

1999-06-24T23:59:59.000Z

413

Oxygen Isotope Evidence For Past And Present Hydrothermal Regimes Of Long  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Oxygen Isotope Evidence For Past And Present Hydrothermal Regimes Of Long Valley Caldera, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Oxygen Isotope Evidence For Past And Present Hydrothermal Regimes Of Long Valley Caldera, California Details Activities (3) Areas (1) Regions (0) Abstract: Whole-rock oxygen isotope compositions of cores and cuttings from Long Valley exploration wells show that the Bishop Tuff has been an important reservoir for both fossil and active geothermal systems within the caldera. The deep Clay Pit-1 and Mammoth-1 wells on the resurgent dome

414

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

415

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

416

High Rate Oxygen Reduction in Non-aqueous Electrolytes with the Addition of Perfluorinated Additives  

DOE Green Energy (OSTI)

The discharge rate capability of Li-air batteries is substantially increased by using perfluorinated compounds as oxygen carriers. The solubility of oxygen in a non-aqueous electrolyte can be significantly increased by the introduction of such compounds, which leads to the increase in the diffusion-limited current of oxygen reduction on the gas diffusion electrode in a Li-air battery. The perfluorinated compound is found to be stable within the electrochemical window of the electrolyte. A powder microelectrode and a rotating disk electrode were used to study the gas diffusion-limited current together with a rotating disk electrode. A 5 mA cm{sup -2} discharge rate is demonstrated in a lab Li-O{sub 2} cell.

Wang, Y.; Yang, X.; Zheng, D.; Qu, D.

2011-08-04T23:59:59.000Z

417

Oxygen transfer in Bi{sub 2}O{sub 3}-based solid electrolytes  

Science Conference Proceedings (OSTI)

Materials with high oxygen conductivity are found in the system Bi{sub 2}O{sub 3}-Y{sub 2}O{sub 3}-ZrO{sub 2}. The values of conductivity are higher than those of the majority of bismuth oxide-based solid electrolytes that are thermo-dynamically stable at low temperatures. Doping of bismuth oxide-based solid electrolytes with calcium fluoride results in an increase of the rate of response of electrochemical oxygen sensors. No direct correlation between dynamic and electrochemical characteristics of the sensor has been observed. Utilization of intermediate layers made of materials with mixed oxygen and electronic conductivity between the electrode and the solid electrolyte does not lead to a substantial decrease in the polarization resistance, but increases the rate of response of potentiometric sensors. Electrochemical properties of several rare earth and strontium cobalties as electrodes for bismuth oxide-based solid electrolytes have been studied.

Kharton, V.V.; Naumovich, E.N. [Belarussian State Univ., Minsk (Belarus)

1993-12-01T23:59:59.000Z

418

Correlation of Secondary Organic Aerosol with Odd Oxygen in Mexico City  

Science Conference Proceedings (OSTI)

Data collected from a mountain location within the Mexico City limits are used to demonstrate a correlation between secondary organic aerosol and odd-oxygen (O3 + NO2). Positive matrix factorization techniques are employed to separate organic aerosol components: hydrocarbon-like organic aerosol; oxidized-organic aerosol; and biomass burning organic aerosol. The measured hydrocarbon-like organic aerosol is correlated with urban CO (8±1) µg m-3 ppmv-1. The measured oxidized-organic aerosol is associated with photochemical oxidation products and correlates with odd-oxygen with an apparent slope of (70-120) µg m-3 ppmv-1. The dependence of the oxidized-organic aerosol to odd-oxygen correlation on the nature of the gas-phase hydrocarbon profile is discussed.

Herndon, Scott C.; Onasch, Timothy B.; Wood, Ezra C.; Kroll, Jesse H.; Canagaratna, M. R.; Jayne, John T.; Zavala, Miguel A.; Knighton, W. Berk; Mazzoleni, Claudio; Dubey, Manvendra K.; Ulbrich, Ingrid M.; Jimenez, Jose L.; Seila, Robert; de Gouw, Joost A.; de Foy, B.; Fast, Jerome D.; Molina, Luisa T.; Kolb, C. E.; Worsnop, Douglas R.

2008-08-05T23:59:59.000Z

419

Lance for fuel and oxygen injection into smelting or refining furnace  

DOE Patents (OSTI)

A furnace for smelting iron ore and/or refining molten iron is equipped with an overhead pneumatic lance, through which a center stream of particulate coal is ejected at high velocity into a slag layer. An annular stream of nitrogen or argon enshrouds the coal stream. Oxygen is simultaneously ejected in an annular stream encircling the inert gas stream. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus to react with carbon monoxide gas rising from slag layer, thereby adding still more heat to the furnace. 7 figures.

Schlichting, M.R.

1994-12-20T23:59:59.000Z

420

Theoretical Study of the Structure, Stability and Oxygen Reduction Activity of Ultrathin Platinum Nanowires  

Science Conference Proceedings (OSTI)

We use density functional theory to study the difference in the structure, stability and catalytic reactivity between ultrathin, 0.5- 1.0 nm diameter, platinum nanotubes and nanowires. Model nanowires were formed by inserting an inner chain of platinum atoms in small diameter nanotubes. In this way more stable, nonhollow structures were formed. The difference in the electronic structure of platinum nanotubes and nanowires was examined by inspecting the density of surface states and band structure. Furthermore, reactivity towards the oxygen reduction reaction of platinum nanowires was addressed by studying the change in the chemisorption energies of oxygen and hydroxyl groups, induced by inserting the inner chain of platinum atoms into the hollow nanotubes. Both ultrathin platinum nanotubes and nanowires show distinct properties compared to bulk platinum. Nanotubes with diameters larger than 1 nm show promise for use as oxygen reduction catalysts.

Matanovic, Ivana; Kent, Paul; Garzon, Fernando; Henson, Neil J.

2012-10-10T23:59:59.000Z

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421

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

E-Print Network (OSTI)

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

John Connell National; John W. Connell

1999-01-01T23:59:59.000Z

422

SNFP detonation phenomena of hydrogen/oxygen in spent fuel containers  

DOE Green Energy (OSTI)

Movement of spent nuclear fuels from the Hanford K Basins near the Columbia River to dry interim storage facility on the Hanford plateau will require repackaging the fuel in the basin into multi-canister overpacks (MCOs), drying of the fuel, transporting the contained fuel, hot conditioning, and finally interim storage. Each of these functions will be accomplished while the fuel is contained in the MCOs. Hydrogen and oxygen can be generated within the MCOs by several mechanisms. The principal source of hydrogen and oxygen within the MCOs is residual water from the vacuum drying and hot conditioning operations. This document assesses the detonation phenomena of hydrogen and oxygen in the spent fuel containers. Several process scenarios have been identified that could generate detonation pressures that exceed the nominal 10 atmosphere design limit of the MCOs. Only 42 grams of radiolized water are required to establish this condition.

Cooper, T.D.

1996-05-30T23:59:59.000Z

423

An Oxygen Isotope Study Of Silicates In The Larderello Geothermal Field,  

Open Energy Info (EERE)

Oxygen Isotope Study Of Silicates In The Larderello Geothermal Field, Oxygen Isotope Study Of Silicates In The Larderello Geothermal Field, Italy Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: An Oxygen Isotope Study Of Silicates In The Larderello Geothermal Field, Italy Details Activities (0) Areas (0) Regions (0) Abstract: Stable-isotope analyses were carried out on hydrothermal minerals sampled from the deep metamorphic units at Larderello, Italy. The D18O values obtained for the most retentive minerals, quartz and tourmaline, are from + 12.0‰ to + 14.7‰ and 9.9‰, respectively, and indicate deposition from an 18O-rich fluid. Calculated D18O values for these fluids range from + 5.3‰ to + 13.4‰. These values, combined with available fluid inclusion and petrographic data, are consistent with the proposed

424

Effect of oxygen on the stability of Ag islands on Si(111)-7 × 7  

SciTech Connect

We have used scanning tunneling microscopy to probe the effect of oxygen exposure on an ensemble of Ag islands separated by a Ag wetting layer on Si(111)-7 × 7. Starting from a distribution dominated by islands that are 1 layer high (measured with respect to the wetting layer), coarsening in ultrahigh vacuum at room temperature leads to growth of 2-layer islands at the expense of 1-layer islands, which is expected. If the sample is exposed to oxygen, 3-layer islands are favored, which is unexpected. There is no evidence for oxygen adsorption on top of Ag islands, but there is clear evidence for adsorption in the wetting layer. Several possible explanations are considered.

Shao, Dahai; Liu; Xiaojie; Lu, Ning; Wang, Cai-Zhuang; Ho, Kai-Ming; Tringides, Michael C.; Thiel, Patricia A.

2012-07-31T23:59:59.000Z

425

The role of oxygen-related defects and hydrogen impurities in HfO2 and ZrO2  

Science Conference Proceedings (OSTI)

We investigate the properties of oxygen-related defects and hydrogen impurities in monoclinic HfO"2 and ZrO"2 using first-principles calculations based on a hybrid functional. We examine how the formation energy of these defects depend on the Fermi level ... Keywords: Defects in semiconductors, First-principles calculations, HfO2, High-k dielectrics, Hydrogen impurities, Oxygen interstitial, Oxygen vacancy, Sources of fixed charge, ZrO2

J. L. Lyons; A. Janotti; C. G. Van de Walle

2011-07-01T23:59:59.000Z

426

MTBE, Oxygenates, and Motor Gasoline (Released in the STEO October 1999)  

Reports and Publications (EIA)

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 increase in MTBE production between 1990 and 1994. MTBE demand increased from 83,000 in 1990 to 161,000 barrels per day in 1994. The reformulated gasoline (RFG) program provided a further boost to oxygenate blending. The MTBE contained in motor gasoline increased to 269,000 barrels per day by 1997.

Information Center

1999-10-01T23:59:59.000Z

427

Similarity criteria in calculations of the energy characteristics of a cw oxygen - iodine laser  

SciTech Connect

The calculated and experimental data on the energy efficiency of a cw oxygen - iodine laser (OIL) are analysed based on two similarity criteria, namely, on the ratio of the residence time of the gas mixture in the resonator to the characteristic time of extraction of the energy stored in singlet oxygen td and on the gain-to-loss ratio {Pi}. It is shown that the simplified two-level laser model satisfactorily predicts the output characteristics of OILs with a stable resonator at {tau}{sub d} {<=} 7. Efficient energy extraction from the OIL active medium is achieved in the case of {tau}{sub d} = 5 - 7, {Pi} = 4 - 8. (lasers)

Mezhenin, A V; Azyazov, V N

2012-12-31T23:59:59.000Z

428

Test bench for studying the outlook for industrial applications of an oxygen-iodine laser  

Science Conference Proceedings (OSTI)

We report the development and tests of a chemical oxygen-iodine laser test bench based on a twisted-aerosol-flow singlet-oxygen generator and a supersonic laser model for studying the outlook for industrial applications of this laser. The maximal output power of the laser is {approx}65 kW (the average power is {approx}50 kW), corresponding to a specific output power of {approx}110 W cm{sup -2}. The maximal chemical efficiency is {approx}34%. (letters)

Adamenkov, A A; Bakshin, V V; Bogachev, A V; Buryak, E V; Vdovkin, L A; Velikanov, S D; Vyskubenko, B A; Garanin, Sergey G; Gorbacheva, E V; Grigorovich, Sergei V; Il'in, S P; Il'kaev, R I; Ilyushin, Yurii N; Kalashnik, A M; Kolobyanin, Yu V; Leonov, M L; Svischev, V V; Troshkin, M V [Russian Federal Nuclear Center 'All-Russian Scientific Research Institute of Experimental Physics', Sarov, Nizhnii Novgorod Region (Russian Federation)

2007-07-31T23:59:59.000Z

429

In Situ CO, Oxygen, and Opacity Measurement for Optimizing Combustion Control System Performance  

E-Print Network (OSTI)

The performance of a combustion control system is limited by the accuracy and reliability of the feedback provided by the stack emission flue gas monitoring system which is utilized to analyze the composition of the products of combustion. A detailed review of the latest state-of-the-art In Situ measurement techniques is provided, including: gas filter correlation spectroscopy (CO), zirconium oxide fuel cell (oxygen), and glass fiber optics based transmissometers (opacity). Recent advancements in the design and application of microprocessor-based In Situ CO, oxygen, and opacity stack emission monitoring systems are outlined, including a review of the performance capability of the latest microprocessor-based combust ion control systems.

Molloy, R. C.

1982-01-01T23:59:59.000Z

430

Oxygenate Supply/Demand Balances in the Short-Term Integrated Forecasting Model (Released in the STEO March 1998)  

Reports and Publications (EIA)

The blending of oxygenates, such as fuel ethanol and methyl tertiary butyl ether (MTBE), into motor gasoline has increased dramatically in the last few years because of the oxygenated and reformulated gasoline programs. Because of the significant role oxygenates now have in petroleum product markets, the Short-Term Integrated Forecasting System (STIFS) was revised to include supply and demand balances for fuel ethanol and MTBE. The STIFS model is used for producing forecasts in the Short-Term Energy Outlook. A review of the historical data sources and forecasting methodology for oxygenate production, imports, inventories, and demand is presented in this report.

Information Center

1998-03-01T23:59:59.000Z

431

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

E-Print Network (OSTI)

V. P. ; Nechushtai, R. Photosynthesis Research Ort, D. R. ;F. ; Editors Oxygenic Photosynthesis; The Light Reactions. [Yachandra, V. K. In Photosynthesis: Mechanisms and Effects;

Visser, Hendrik

2001-01-01T23:59:59.000Z

432

Nanostructured sorbents for capture of cadmium species in combustion environments  

SciTech Connect

The pathways of cadmium species to form a sub-micrometer-sized aerosol in a combustion system exhaust were established. Cadmium oxide was the predominant species formed in the experiments and resulted in particles of a mean size of 26-63 nm with number concentrations in the range of 2-8 x 10{sup 6} cm{sup -3}. Two different nanostructured sorbents, a solid montmorillonite (MMT) and an in situ generated agglomerated silica, were used for capture of the cadmium species. The MMT sorbent was not stable at 1000{sup o}C, and structural changes resulted. MMT did not suppress nucleation of cadmium species and partially captured it by weak physisorption as established by the leachability tests. In contrast, the in situ generated silica nanostructured agglomerates had a high surface area, suppressed nucleation of cadmium species vapors, and chemisorbed them effectively resulting in a firm binding, as compared to the MMT sorbent. There is an optimal temperature-time relationship at which the capture process is expected to be most effective. The leaching efficiency under these conditions was less than 3.2%. The nanostructured silica agglomerate size can be tuned for effective capture in existing particle control devices. 46 refs., 8 figs., 2 tabs.

Myong-Hwa Lee; Kuk Cho; Apoorva P. Shah; Pratim Biswas [Washington University in St. Louis, St. Louis, MO (United States). Aerosol and Air Quality Research Laboratory, Environmental Engineering Science Program

2005-11-01T23:59:59.000Z

433

Oxygen Surface Exchange Kinetics on Sr-Substituted Lanthanum Manganite and Ferrite Thin-Film Microelectrodes  

E-Print Network (OSTI)

The surface oxygen exchange kinetics occurring on dense La0.8Sr0.2MnO3 (65nm thick) and La0.8Sr0.2FeO3 (110nm thick) thin films were investigated by electrochemical impedance spectroscopy (EIS). Rutherford backscattering ...

la O', Gerardo Jose

434

Oxygen Reduction Activity of PtxNi1-x Alloy Nanoparticles on Multiwall Carbon Nanotubes  

E-Print Network (OSTI)

PtxNi1 - x nanoparticles (Pt:Ni; 1:0, 4:1, 3:1 and 0.7:1) of ~5 nm, were synthesized on carboxylic acid-functionalized multiwall carbon nanotubes (PtxNi1 - x NPs/MWNT). The oxygen reduction reaction (ORR) activity measurements ...

Kim, Junhyung

435

Surface structural changes of perovskite oxides during oxygen evolution in alkaline electrolyte  

E-Print Network (OSTI)

Perovskite oxides such Ba0.5Sr0.5Co0.8Fe0.8O3-6 (BSCF82) are among the most active catalysts for the oxygen evolution reaction (OER) in alkaline solution reported to date. In this work it is shown via high resolution ...

May, Kevin J. (Kevin Joseph)

2013-01-01T23:59:59.000Z

436

Tailoring Selectivity for Electrocatalytic Oxygen Evolution on Ruthenium Oxides by Zn Substitution  

SciTech Connect

Controlling gas emissions: Versatile control of the selectivity of an oxide electrocatalyst in the oxygen- and chlorine-evolution reactions was demonstrated by Zn substitution in RuO{sub 2}. The incorporation of Zn into the rutile structure alters the cation sequence along the [001] direction and modifies the structure of the active sites for both gas-evolution processes.

Petrykin, V.; Macounova, K; Shlyakhtin, O; Krtil, P

2010-01-01T23:59:59.000Z