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


1

Mitochondrial reactive oxygen species and cancer  

E-Print Network [OSTI]

Mitochondria produce reactive oxygen species (mROS) as a natural by-product of electron transport chain activity. While initial studies focused on the damaging effects of reactive oxygen species, a recent paradigm shift ...

Chandel, Navdeep S

2

Reactive oxygen species: a breath of life or death?  

E-Print Network [OSTI]

AP1, activator protein-1; ODD, oxygen-dependent degradationSignaling response when oxygen levels decrease (Fig. 1C;3. Halliwell B. Reactive oxygen species in living sys- tems:

Fruehauf, John P; Meyskens, Frank L Jr

2007-01-01T23:59:59.000Z

3

Aging Enhances the Production of Reactive Oxygen Species andBactericid...  

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

Enhances the Production of Reactive Oxygen Species andBactericidal Activity in Peritoneal Macrophages by Aging Enhances the Production of Reactive Oxygen Species andBactericidal...

4

Properties of Reactive Oxygen Species by Quantum Monte Carlo  

E-Print Network [OSTI]

The electronic properties of the oxygen molecule, in its singlet and triplet states, and of many small oxygen-containing radicals and anions have important roles in different fields of Chemistry, Biology and Atmospheric Science. Nevertheless, the electronic structure of such species is a challenge for ab-initio computational approaches because of the difficulties to correctly describe the statical and dynamical correlation effects in presence of one or more unpaired electrons. Only the highest-level quantum chemical approaches can yield reliable characterizations of their molecular properties, such as binding energies, equilibrium structures, molecular vibrations, charge distribution and polarizabilities. In this work we use the variational Monte Carlo (VMC) and the lattice regularized Monte Carlo (LRDMC) methods to investigate the equilibrium geometries and molecular properties of oxygen and oxygen reactive species. Quantum Monte Carlo methods are used in combination with the Jastrow Antisymmetrized Geminal Power (JAGP) wave function ansatz, which has been recently shown to effectively describe the statical and dynamical correlation of different molecular systems. In particular we have studied the oxygen molecule, the superoxide anion, the nitric oxide radical and anion, the hydroxyl and hydroperoxyl radicals and their corresponding anions, and the hydrotrioxyl radical. Overall, the methodology was able to correctly describe the geometrical and electronic properties of these systems, through compact but fully-optimised basis sets and with a computational cost which scales as $N^3-N^4$, where $N$ is the number of electrons. This work is therefore opening the way to the accurate study of the energetics and of the reactivity of large and complex oxygen species by first principles.

Andrea Zen; Bernhardt L. Trout; Leonardo Guidoni

2014-03-11T23:59:59.000Z

5

Reactive oxygen species and Udx1 during early sea urchin development Julian L. Wong, Gary M. Wessel*  

E-Print Network [OSTI]

Reactive oxygen species and Udx1 during early sea urchin development Julian L. Wong, Gary M. Wessel Abstract Sea urchin fertilization is marked by a massive conversion of molecular oxygen to hydrogen of these defective embryos. We also report an unequal distribution of reactive oxygen species between sister

Wessel, Gary M.

6

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

SciTech Connect (OSTI)

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

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

2013-01-15T23:59:59.000Z

7

Glutathione-Dependent Generation of Reactive Oxygen Species by the Peroxidase-Catalyzed Redox Cycling of Flavonoids  

Science Journals Connector (OSTI)

They may also be anti-atherosclerotic as they prevent Cu2+-catalyzed low-density lipoprotein (LDL)1 oxidative modification by scavenging reactive oxygen species (ROS) and eliminating LDL peroxyl and alkoxyl radicals (2, 3). ... fisetin ...

Giuseppe Galati; Tom Chan; Bin Wu; Peter J. O'Brien

1999-05-19T23:59:59.000Z

8

Generation of DNA-Damaging Reactive Oxygen Species via the Autoxidation of Hydrogen Sulfide under Physiologically Relevant  

E-Print Network [OSTI]

Generation of DNA-Damaging Reactive Oxygen Species via the Autoxidation of Hydrogen Sulfide under found that micromolar concentrations of H2S generated single-strand DNA cleavage. Mechanistic studies indicate that this process involved autoxidation of H2S to generate superoxide, hydrogen peroxide, and

Gates, Kent. S.

9

Controllable generation of reactive oxygen species by femtosecond-laser irradiation  

SciTech Connect (OSTI)

Femtosecond lasers have been advancing Biophotonics research in the past two decades with multiphoton microscopy, microsurgery, and photodynamic therapy. Nevertheless, laser irradiation is identified to bring photodamage to cells via reactive oxygen species (ROS) generation with unclear mechanism. Meanwhile, currently in biological researches, there is no effective method to provide controllable ROS production precisely, which originally is leaked from mitochondria during respiration and plays a key role in a lot of important cellular processes and cellular signaling pathways. In this study, we show the process of how the tightly focused femtosecond-laser induces ROS generation solely in mitochondria at the very beginning and then release to cytosol if the stimulus is intense enough. At certain weak power levels, the laser pulses induce merely moderate Ca{sup 2+} release but this is necessary for the laser to generate ROS in mitochondria. Cellular original ROS are also involved with a small contribution. When the power is above a threshold, ROS are then released to cytosol, indicating photodamage overwhelming cellular repair ability. The mechanisms in those two cases are quite different. Those results clarify parts of the mechanism in laser-induced ROS generation. Hence, it is possible to further this optical scheme to provide controllable ROS generation for ROS-related biological researches including mitochondrial diseases and aging.

Yan, Wei; He, Hao, E-mail: haohe@tju.edu.cn; Wang, Yintao; Wang, Yisen; Hu, Minglie; Wang, Chingyue [Ultrafast Laser Laboratory, Key Laboratory of Optoelectronic Information Technology (Ministry of Education), College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin (China)

2014-02-24T23:59:59.000Z

10

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

Science Journals Connector (OSTI)

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

Kyoung Ah Kang; Mei Jing Piao; Ki Cheon Kim…

2014-01-01T23:59:59.000Z

11

Assay for reactive oxygen species-induced DNA damage: measurement of the formamido and thymine glycol lesions  

Science Journals Connector (OSTI)

A 32P-postlabeling assay has been developed for the simultaneous detection of the thymine glycol lesion and the formamido remnant of pyrimidine bases in DNA exposed to reactive oxygen species (ROS). The formamido lesion is a principal lesion produced in X-irradiated DNA oligomers when oxygen is available to mediate the damage process. Production of the well-known thymine glycol lesion is less dependent on the concentration of oxygen. These two lesions have the common property that they make the phosphoester bond 3? to the modified nucleoside resistant to hydrolysis by nuclease P1. Our assay uses 32P-postlabeling to measure these lesions in the form of modified dimers obtained from DNA by nuclease P1 digestion. Appropriate carriers and internal standards have been chemically synthesized to improve the reliability and accuracy of the assay. The measurements were accomplished on 1-?g samples of DNA.

Alexander E. Maccubbin; Helen B. Patrzyc; Noreen Ersing; Edwin E. Budzinski; Jean B. Dawidzik; John C. Wallace; Herbert Iijima; Harold C. Box

1999-01-01T23:59:59.000Z

12

A role for spermine oxidase as a mediator of reactive oxygen species production in HIV-Tat-induced neuronal toxicity  

Science Journals Connector (OSTI)

Abstract Chronic oxidative stress, which occurs in brain tissues of HIV-infected patients, is involved in the pathogenesis of HIV-associated dementia. Oxidative stress can be induced by HIV-1-secreted proteins, either directly or indirectly through the release of cytotoxic factors. In particular, HIV-1 Tat is able to induce neuronal death by interacting with and activating the polyamine-sensitive subtype of the NMDA receptor (NMDAR). Here, we focused on the role of polyamine catabolism in Tat-induced oxidative stress in human neuroblastoma (SH-SY5Y) cells. First, Tat was found to induce reactive oxygen species production and to affect cell viability in SH-SY5Y cells, these effects being mediated by spermine oxidase (SMO). Second, Tat was observed to increase SMO activity as well as decreasing the intracellular spermine levels. Third, Tat-induced SMO activation was completely prevented by the NMDAR antagonist MK-801, clearly indicating an involvement of NMDAR stimulation. Finally, pretreatment of cells with N-acetylcysteine, a scavenger of H2O2, and with MK-801 was able to completely inhibit reactive oxygen species formation and to restore cell viability. Altogether, these data strongly suggest a role for polyamine catabolism-derived H2O2 in neurotoxicity as elicited by Tat-stimulated NMDAR.

Caterina Capone; Manuela Cervelli; Emanuela Angelucci; Marco Colasanti; Alberto Macone; Paolo Mariottini; Tiziana Persichini

2013-01-01T23:59:59.000Z

13

Low dose ionizing radiation produces too few reactive oxygen species to directly affect antioxidant concentrations in cells  

Science Journals Connector (OSTI)

...Radiolysis products and internal dose distribution - Calculation of...products and internal distribution of doses Low dose ionizing radiation produces too few reactive oxygen...stress is the mechanism for a wide range of negative impacts on biota living...

2012-01-01T23:59:59.000Z

14

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

SciTech Connect (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

15

Electrocatalytic Reactivity for Oxygen Reduction of Palladium...  

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

Reactivity for Oxygen Reduction of Palladium-Modified Carbon Nanotubes Synthesized in Supercritical Fluid. Electrocatalytic Reactivity for Oxygen Reduction of Palladium-Modified...

16

Formation, characterization and reactivity of adsorbed oxygen...  

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

Formation, characterization and reactivity of adsorbed oxygen on BaOPt(111). Formation, characterization and reactivity of adsorbed oxygen on BaOPt(111). Abstract: The formation...

17

Lysophosphatidic acid induces reactive oxygen species generation by activating protein kinase C in PC-3 human prostate cancer cells  

SciTech Connect (OSTI)

Highlights: •LPA induces ROS generation through LPA{sub 1} and LPA{sub 3}. •LPA induces ROS generation by activating PLC. •PKC? mediates LPA-induced ROS generation. -- Abstract: Prostate cancer is one of the most frequently diagnosed cancers in males, and PC-3 is a cell model popularly used for investigating the behavior of late stage prostate cancer. Lysophosphatidic acid (LPA) is a lysophospholipid that mediates multiple behaviors in cancer cells, such as proliferation, migration and adhesion. We have previously demonstrated that LPA enhances vascular endothelial growth factor (VEGF)-C expression in PC-3 cells by activating the generation of reactive oxygen species (ROS), which is known to be an important mediator in cancer progression. Using flow cytometry, we showed that LPA triggers ROS generation within 10 min and that the generated ROS can be suppressed by pretreatment with the NADPH oxidase (Nox) inhibitor diphenylene iodonium. In addition, transfection with LPA{sub 1} and LPA{sub 3} siRNA efficiently blocked LPA-induced ROS production, suggesting that both receptors are involved in this pathway. Using specific inhibitors and siRNA, phospholipase C (PLC) and protein kinase C (PKC) were also suggested to participate in LPA-induced ROS generation. Overall, we demonstrated that LPA induces ROS generation in PC-3 prostate cancer cells and this is mediated through the PLC/PKC/Nox pathway.

Lin, Chu-Cheng; Lin, Chuan-En; Lin, Yueh-Chien [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China)] [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Ju, Tsai-Kai [Instrumentation Center, National Taiwan University, Taipei, Taiwan, ROC (China) [Instrumentation Center, National Taiwan University, Taipei, Taiwan, ROC (China); Technology Commons, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Huang, Yuan-Li [Department of Biotechnology, Asia University, Taichung, Taiwan, ROC (China)] [Department of Biotechnology, Asia University, Taichung, Taiwan, ROC (China); Lee, Ming-Shyue [Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC (China)] [Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC (China); Chen, Jiun-Hong [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China) [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Lee, Hsinyu, E-mail: hsinyu@ntu.edu.tw [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China) [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Center for Biotechnology, National Taiwan University, Taipei, Taiwan, ROC (China); Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan, ROC (China)

2013-11-01T23:59:59.000Z

18

Mechanisms of Photochemistry and Reactive Oxygen Production by  

E-Print Network [OSTI]

photosensitizer that produces reactive oxygen species (ROS) in the presence of light; however, its properties medical and environmental contexts as well as the potential applications implied for industrial or water of transferring light energy to chemical oxidation potential in theformof

Alvarez, Pedro J.

19

Reactive Gliosis Reactive Oxygen Species: Superoxide  

E-Print Network [OSTI]

motor output. Reafferent Control in Electric Communication Reafferent Control in Electric Communication Electrocommunication; Electrical communication Definition Every motor act that an animal produces will elicit sensory the night, and sensory feedback from skeletal muscles can be used to improve motor control. On the other

20

Reactive oxygen species produced by NADPH oxidase and mitochondrial dysfunction in lung after an acute exposure to Residual Oil Fly Ashes  

SciTech Connect (OSTI)

Reactive O{sub 2} species production triggered by particulate matter (PM) exposure is able to initiate oxidative damage mechanisms, which are postulated as responsible for increased morbidity along with the aggravation of respiratory diseases. The aim of this work was to quantitatively analyse the major sources of reactive O{sub 2} species involved in lung O{sub 2} metabolism after an acute exposure to Residual Oil Fly Ashes (ROFAs). Mice were intranasally instilled with a ROFA suspension (1.0 mg/kg body weight), and lung samples were analysed 1 h after instillation. Tissue O{sub 2} consumption and NADPH oxidase (Nox) activity were evaluated in tissue homogenates. Mitochondrial respiration, respiratory chain complexes activity, H{sub 2}O{sub 2} and ATP production rates, mitochondrial membrane potential and oxidative damage markers were assessed in isolated mitochondria. ROFA exposure was found to be associated with 61% increased tissue O{sub 2} consumption, a 30% increase in Nox activity, a 33% increased state 3 mitochondrial O{sub 2} consumption and a mitochondrial complex II activity increased by 25%. During mitochondrial active respiration, mitochondrial depolarization and a 53% decreased ATP production rate were observed. Neither changes in H{sub 2}O{sub 2} production rate, nor oxidative damage in isolated mitochondria were observed after the instillation. After an acute ROFA exposure, increased tissue O{sub 2} consumption may account for an augmented Nox activity, causing an increased O{sub 2}{sup ·?} production. The mitochondrial function modifications found may prevent oxidative damage within the organelle. These findings provide new insights to the understanding of the mechanisms involving reactive O{sub 2} species production in the lung triggered by ROFA exposure. - Highlights: • Exposure to ROFA alters the oxidative metabolism in mice lung. • The augmented Nox activity contributes to the high tissue O{sub 2} consumption. • Exposure to ROFA produces alterations in mitochondrial function. • ??{sub m} decrease in state 3 may be responsible for the decreased ATP production. • Mild uncoupling prevents mitochondrial oxidative damage.

Magnani, Natalia D.; Marchini, Timoteo; Vanasco, Virginia [Instituto de Bioquímica Medicina Molecular (IBIMOL-UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires (Argentina); Tasat, Deborah R. [CESyMA, Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, San Martín, Buenos Aires (Argentina); Alvarez, Silvia [Instituto de Bioquímica Medicina Molecular (IBIMOL-UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires (Argentina); Evelson, Pablo, E-mail: pevelson@ffyb.uba.ar [Instituto de Bioquímica Medicina Molecular (IBIMOL-UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires (Argentina)

2013-07-01T23:59:59.000Z

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


21

E-Print Network 3.0 - ameliorating reactive oxygen Sample Search...  

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

structure and surface relaxation Summary: reactivity of each type of oxygen the adsorption of hydrogen over different oxygen sites is studied. Full... oxygen is the reactive...

22

Determining the Intrinsic Properties of the C1B Domain that Influence PKC Ligand Specificity and Sensitivity to Reactive Oxygen Species  

E-Print Network [OSTI]

reactive, an alternative conformation of C1B in which this residue is more exposed, and modification of C1B leads to unfolding and zinc loss. Because the regulatory domains are responsible for auto-inhibition of the kinase domain, C1B unfolding provides a...

Stewart, Mikaela D.

2013-06-04T23:59:59.000Z

23

Osseointegration of chitosan coated porous titanium alloy implant by reactive oxygen species-mediated activation of the PI3K/AKT pathway under diabetic conditions  

Science Journals Connector (OSTI)

Abstract Chitosan coated porous titanium alloy implant (CTI) is demonstrated a promising approach to improve osseointegration capacity of pure porous titanium alloy implant (TI). Since chitosan has been demonstrated to exhibit antioxidant activity, we propose CTI may ameliorate the ROS overproduction, thus reverse the poor osseointegration under diabetic conditions, and investigate the underlying mechanisms. Primary rat osteoblasts incubated on the TI and the CTI were subjected to normal serum (NS), diabetic serum (DS), DS + NAC (a potent ROS inhibitor) and DS + LY294002 (a PI3K/AKT-specific inhibitor). In vivo study was performed on diabetic sheep implanted with TI or CTI into the bone defects on crista iliaca. Results showed that diabetes-induced ROS overproduction led to osteoblast dysfunction and apoptosis, concomitant with the inhibition of AKT in osteoblasts on the TI substrate. While CTI stimulated AKT phosphorylation through ROS attenuation, thus reversed osteoblast dysfunction evidenced by improved osteoblast adhesion, increased proliferation and ALP activity, and decreased cytotoxicity and apoptotic rate, which exerted same effect to NAC treatment on the TI. These effects were further confirmed by the improved osseointegration within the CTI in vivo evidenced by Micro-CT and histological examinations. In addition, the aforementioned promotive effects afforded by CTI were abolished by blocking PI3K/AKT pathway with addition of LY294002. These results demonstrate that the chitosan coating markedly ameliorates diabetes-induced impaired bio-performance of TI via ROS-mediated reactivation of PI3K/AKT pathway, which elicits a new surface functionalization strategy for better clinical performance of titanium implant in diabetic patients.

Xiang Li; Xiang-Yu Ma; Ya-Fei Feng; Zhen-Sheng Ma; Jian Wang; Tian-Cheng Ma; Wei Qi; Wei Lei; Lin Wang

2015-01-01T23:59:59.000Z

24

MEASUREMENT OF OXYGEN CONSUMPTION AND DIFFUSION IN EXPOSED AND COVERED REACTIVE MINE TAILINGS1  

E-Print Network [OSTI]

MEASUREMENT OF OXYGEN CONSUMPTION AND DIFFUSION IN EXPOSED AND COVERED REACTIVE MINE TAILINGS1 the in situ oxygen diffusion and consumption in tailings. It provides measured values for the oxygen reaction rate Kr and the effective diffusion De coefficients based on oxygen consumption and diffusion tests

Aubertin, Michel

25

Radiation Chemistry of Ionic Liquids: Reactivity of Primary Species  

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

Liquids: Reactivity of Primary Species Liquids: Reactivity of Primary Species James F. Wishart In "Ionic Liquids as Green Solvents: Progress and Prospects" Rogers, R. D. and Seddon, K. R. , Eds.; ACS Symp. Ser. 856, Ch. 31, pp. 381-395, American Chemical Society, Washington, DC, 2003. (ISBN 0-84123-856-1) [Information about the book] Abstract: An understanding of the radiation chemistry of ionic liquids is important for development of their applications in radioactive material processing and for the application of pulse radiolysis techniques to the general study of chemical reactivity in ionic liquids. The distribution of primary radiolytic species and their reactivities determine the yields of ultimate products and the radiation stability of a particular ionic liquid. This chapter introduces some principles of radiation chemistry and the

26

Direct Observation of the Oxygenated Species during Oxygen Reduction on a  

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

27

Sunlight creates oxygenated species in water-soluble fractions...  

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

a t Sunlight creates oxygenated species in water-soluble fractions of Deepwater horizon oil Phoebe Z. Ray a , Huan Chen b , David C. Podgorski b,c , Amy M. McKenna b , Matthew A....

28

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

Science Journals Connector (OSTI)

Abstract Cheap and environmental friendly Mn–Si oxygen carriers manufactured from Mn3O4 and SiO2 by spray-drying have been investigated with respect to properties for chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU). Fifteen oxygen carriers with SiO2 content varying from 2 wt% to 75 wt% were prepared and calcined at 1050 °C and 1150 °C. The ability of material to release O2 and their reactivity towards CH4 were examined in the temperature range 900–1100 °C. Particles with a SiO2 content of more than 45 wt% and calcined at 1150 °C showed limited CLOU behaviour and poor reactivity towards CH4 at all temperatures investigated. The rest of the materials had significant CLOU properties and provided high conversion of CH4 under the experimental conditions chosen. Increasing the temperature of operation enhanced the CLOU behaviour and reactivity towards CH4. At temperatures above 950 °C, the CH4 conversion was 90–100% for these materials. Crystalline phases identified by XRD in the oxidized samples with more than 45 wt% SiO2 and calcined at 1150 °C were mainly rhodonite MnSiO3. For materials with SiO2 content below 45 wt%, braunite Mn7SiO12 was detected as the main phase in most of the samples after oxidation. This indicates that braunite Mn7SiO12 is the main active phase for oxygen transfer in CLC and CLOU, which is supported by thermodynamic calculations. The reactivity of all of the materials were also studied with syngas (50% CO and 50% H2), showing complete gas conversion at 950 °C, except for materials with a SiO2 content of more than 45 wt% and calcined at 1150 °C. The mechanical integrity and attrition resistance of the oxygen carriers were examined in a jet-cup attrition rig, and although the attrition rates varied, some reactive material showed low rates of attrition, making them very promising oxygen carrier materials for applications related to CLC and CLOU. However, measures should probably be taken to improve the crushing strength to some extent.

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

2014-01-01T23:59:59.000Z

29

Mineral-Induced Formation of Reactive Oxygen Species  

Science Journals Connector (OSTI)

...the US National Library of Medicine provides a powerful motivation...pollution. In: Environmental Medicine. Moller L (ed) Joint Industrial...toxicology: From coal mining to nanotechnology. Inhal Toxicol 14:311-324...S. National Library of Medicine, http://ghr.nlm.nih...

Martin A. A. Schoonen; Corey A. Cohn; Elizabeth Roemer; Richard Laffers; Sanford R. Simon; Thomas O’Riordan

30

Reactive oxygen species production and discontinuous gas exchange in insects  

Science Journals Connector (OSTI)

...NAN trials independently, a Kruskal-Wallis ANOVA followed by a multiple...spiracles were held open (NAHN: Kruskal-Wallis H 3 = 28.99, p 0.0001 and NAN: Kruskal-Wallis H 2 = 20.87, p 0.0001...

2012-01-01T23:59:59.000Z

31

Reactive Oxygen Species: A Breath of Life or Death?  

Science Journals Connector (OSTI)

...increased levels of ROS can be seen as the Achilles heel of cancer cell metabolism. The next decade should reveal the truth or consequences of this approach. 1 Kamata H, Hirata H. Redox regulation of cellular signalling. Cell Signal 1999;11:1-14...

John P. Fruehauf and Frank L. Meyskens, Jr.

2007-02-01T23:59:59.000Z

32

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...

Calvo, Sergio Rafael

2009-05-15T23:59:59.000Z

33

Communication: CO oxidation by silver and gold cluster cations: Identification of different active oxygen species  

SciTech Connect (OSTI)

The oxidation of carbon monoxide with nitrous oxide on mass-selected Au{sub 3}{sup +} and Ag{sub 3}{sup +} clusters has been investigated under multicollision conditions in an octopole ion trap experiment. The comparative study reveals that for both gold and silver cations carbon dioxide is formed on the clusters. However, whereas in the case of Au{sub 3}{sup +} the cluster itself acts as reactive species that facilitates the formation of CO{sub 2} from N{sub 2}O and CO, for silver the oxidized clusters Ag{sub 3}O{sub x}{sup +} (n= 1-3) are identified as active in the CO oxidation reaction. Thus, in the case of the silver cluster cations N{sub 2}O is dissociated and one oxygen atom is suggested to directly react with CO, whereas a second kind of oxygen strongly bound to silver is acting as a substrate for the reaction.

Popolan, Denisia M.; Bernhardt, Thorsten M. [Institute of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm (Germany)

2011-03-07T23:59:59.000Z

34

Oxygen Reactivity of Devolatilized Diesel Engine Particulates from Conventional and Biodiesel Fuels  

Science Journals Connector (OSTI)

Oxygen Reactivity of Devolatilized Diesel Engine Particulates from Conventional and Biodiesel Fuels ... Abatement of diesel particulates has led to an overall decrease in the fuel efficiency of diesel engines, and overcoming these losses has been one of the more challenging problems in exhaust aftertreatment. ... (16-18) Establishing a general physical basis for modeling diesel particulate oxidation is especially challenging because of the large variations in microscopic structure that it can have. ...

Andrea Strzelec; Todd J. Toops; C. Stuart Daw

2013-06-10T23:59:59.000Z

35

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

Science Journals Connector (OSTI)

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

W. Sutthisripok; S. Sattayanurak; L. Sikong

2008-10-01T23:59:59.000Z

36

Physical properties and band structure of reactive molecular beam epitaxy grown oxygen engineered HfO{sub 2{+-}x}  

SciTech Connect (OSTI)

We have conducted a detailed thin film growth structure of oxygen engineered monoclinic HfO{sub 2{+-}x} grown by reactive molecular beam epitaxy. The oxidation conditions induce a switching between (111) and (002) texture of hafnium oxide. The band gap of oxygen deficient hafnia decreases with increasing amount of oxygen vacancies by more than 1 eV. For high oxygen vacancy concentrations, defect bands form inside the band gap that induce optical transitions and p-type conductivity. The resistivity changes by several orders of magnitude as a function of oxidation conditions. Oxygen vacancies do not give rise to ferromagnetic behavior.

Hildebrandt, Erwin; Kurian, Jose; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

2012-12-01T23:59:59.000Z

37

On a Highly Reactive Fe2O3/Al2O3 Oxygen Carrier for in Situ Gasification Chemical Looping Combustion  

Science Journals Connector (OSTI)

On a Highly Reactive Fe2O3/Al2O3 Oxygen Carrier for in Situ Gasification Chemical Looping Combustion ... † State

Daofeng Mei; Alberto Abad; Haibo Zhao; Juan Adánez; Chuguang Zheng

2014-10-13T23:59:59.000Z

38

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

SciTech Connect (OSTI)

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

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

2013-11-11T23:59:59.000Z

39

Electronic structure of perovskite oxide surfaces at elevated temperatures and its correlation with oxygen reduction reactivity  

E-Print Network [OSTI]

The objective is to understand the origin of the local oxygen reduction reaction (ORR) activity on the basis of the local electronic structure at the surface of transition metal oxides at elevated temperatures and in oxygen ...

Chen, Yan, Ph. D. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

40

Oxygen and Hydroxyl Species Induce Multiple Reaction Pathways for the Partial Oxidation of Allyl Alcohol on Gold  

E-Print Network [OSTI]

, acrolein, over oxygen-precovered gold surfaces occurs via multiple reaction pathways. Utilizing temperature -dehydrogenation via interaction with an oxygen adatom or surface hydroxyl species to generate acrolein. Mediation

Henkelman, Graeme

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

Reactivity of a CaSO4-oxygen carrier in chemical-looping combustion of methane in a fixed bed reactor  

Science Journals Connector (OSTI)

Chemical-looping combustion (CLC) is a promising technology for the combustion of gas or solid fuel with efficient...2. A reactivity study of CaSO4 oxygen carrier in CLC of methane was conducted in a laboratory s...

Qilei Song; Rui Xiao; Zhongyi Deng; Laihong Shen…

2009-03-01T23:59:59.000Z

42

E-Print Network 3.0 - accumulate reactive oxygen Sample Search...  

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

Sciences, University of Manitoba Collection: Geosciences 90 Transient Studies of Oxygen Removal Pathways and Catalytic Redox Cycles during NO Decomposition on Cu-ZSM5 Summary: ....

43

ReaxFF Reactive Force Field for Solid Oxide Fuel Cell Systems with Application to Oxygen Ion Transport in Yttria-Stabilized Zirconia  

E-Print Network [OSTI]

ReaxFF Reactive Force Field for Solid Oxide Fuel Cell Systems with Application to Oxygen Ion through yttria-stabilized zirconia (YSZ) solid oxide fuel cell (SOFC) membranes. All parameters for Reax temperature, leading to applications as oxygen sensors and as membranes for high temperature solid oxide fuel

Goddard III, William A.

44

Direct and indirect photoreactions of chromophoric dissolved organic matter : roles of reactive oxygen species and iron  

E-Print Network [OSTI]

Photochemical transformations of chromophoric dissolved organic matter (CDOM) are one of the principal processes controlling its fate in coastal waters. The photochemical decomposition of CDOM leads to the formation of a ...

Goldstone, Jared Verrill, 1971-

2002-01-01T23:59:59.000Z

45

Non-thermal dielectric barrier discharge plasma induces angiogenesis through reactive oxygen species  

Science Journals Connector (OSTI)

...treatment [56]. Non-thermal plasma devices, specifically...generated at atmospheric pressure in...58]. DBD plasma characteristics...distance [58]. Non-thermal DBD plasma...effects of non-thermal atmospheric pressure plasma on bacteria...

2012-01-01T23:59:59.000Z

46

Effects of combined radiofrequency radiation exposure on levels of reactive oxygen species in neuronal cells  

Science Journals Connector (OSTI)

......typical CDMA signal of 837 MHz and a WCDMA signal of 1950 MHz were applied to the RTL...incubator with a humidified atmosphere of 5% CO2. Analysis...exposure to UMTS 1950 MHz radiation and co-exposure...reaction of menadione with plasma thiols: enhancement......

Kyoung Ah Kang; Hyung Chul Lee; Je-Jung Lee; Mi-Na Hong; Myung-Jin Park; Yun-Sil Lee; Hyung-Do Choi; Nam Kim; Young-Gyu Ko; Jae-Seon Lee

2014-03-01T23:59:59.000Z

47

Rat colonic reactive oxygen species production and DNA damage are mediated by diet and age  

E-Print Network [OSTI]

is based on the theory of decreased ROS in response to respiratory chain suppression and utilizes diphenyliodonium chloride to determine if ROS production is altered in response to a mitochondrial electron transport chain inhibitor. Although... mitochondria are thought to be a major source of ROS, literature regarding this theory is inconclusive [37]. Other sites of free radical production have been identified, each generating ROS at levels that may be specific to certain tissues. For instance, Hid...

Henderson, Cara Aletha Everett

2012-06-07T23:59:59.000Z

48

Modulation of the response to cisplatin by nitric oxide and reactive oxygen species in melanoma cells  

E-Print Network [OSTI]

Malignant melanoma causes the highest mortality rate in skin cancers. Although cisplatin has proved efficacious in the treatment of various solid tumors, melanoma seems particularly resistant to this chemotherapeutic drug. ...

Anderson, Chase Thaddeus Maceo

2013-01-01T23:59:59.000Z

49

Ca2+ Regulates Reactive Oxygen Species Production and pH during Mechanosensing in Arabidopsis Roots  

Science Journals Connector (OSTI)

...Leblanc-Fournier et al., 2008) to ethylene and jasmonate production (Mitchell...enzymes known to affect cell wall rigidity (Price et al., 2003; Bosch and Hepler, 2005...Solanum chacoense. Planta 220: 582-592. Price, N.J., Pinheiro, C., Soares...

Gabriele B. Monshausen; Tatiana N. Bibikova; Manfred H. Weisenseel; Simon Gilroy

2009-08-04T23:59:59.000Z

50

Controlling Tumor Growth by Modulating Endogenous Production of Reactive Oxygen Species  

Science Journals Connector (OSTI)

...factors trigger hydrogen peroxide (H2O2) production that leads...Materials and Methods Animals...generation of hydrogen peroxide...et al. Hydrogen peroxide...Enhanced ROS production in oncogenically...in vitro. Methods Enzymol 1984...

Alexis Laurent; Carole Nicco; Christiane Chéreau; Claire Goulvestre; Jérôme Alexandre; Arnaud Alves; Eva Lévy; Francois Goldwasser; Yves Panis; Olivier Soubrane; Bernard Weill; and Frédéric Batteux

2005-02-01T23:59:59.000Z

51

Heavy-Metal-Induced Reactive Oxygen Species: Phytotoxicity and Physicochemical Changes in Plants  

Science Journals Connector (OSTI)

Environmental contamination by hazardous environmental pollutants is a widespread and increasingly serious problem confronting society, scientists, and regulators worldwide (Debenest et al. 2010; Hajeb et al. ...

Muhammad Shahid; Bertrand Pourrut…

2014-01-01T23:59:59.000Z

52

Evidence of reactive oxygen species-mediated damage to mitochondrial DNA in children with typical autism  

E-Print Network [OSTI]

1997:77–102. 3. Lin MT, Beal MF: Mitochondrial dysfunction13:262–270. 5. Albers DS, Beal MF: Mitochondrial dysfunctionAMS, Mecocci P, Cormio A, Beal MF, Cherubini A, Cantatore P,

Napoli, Eleonora; Wong, Sarah; Giulivi, Cecilia

2013-01-01T23:59:59.000Z

53

Influence of reactive species on the lean blowout limit of an industrial DLE gas turbine burner  

Science Journals Connector (OSTI)

Abstract In order to achieve ultra-low emissions of both NOX and CO it is imperative to use a homogeneous premixed combustor. To lower the emissions further, the equivalence ratio can be lowered. By doing so, combustion is moved towards the lean blowout (LBO) limit. To improve the blowout characteristics of a burner, heat and radicals can be supplied to the flame zone. This can be achieved using a pre-chamber combustor. In this study, a central body burner, called the RPL (rich-pilot-lean) section, was used as a pre-chamber combustor to supply heat and radicals to a downscaled industrial burner. The flue gas from the RPL is mixed with the surrounding fresh mixture and form a second flame zone. This zone acts as a stabilizer for the investigated burner. The LBO limit was modeled using two perfectly stirred reactors (PSRs) in series, which allows the chemical influence on the LBO limit to be isolated. The resulting trends for the modeled LBO limit were in agreement with measured data. Increasing the equivalence ratio in the RPL section, thus increasing the energy supplied by the fuel, is a major contributor to combustion stability up to a limit where the temperature decrease is too large support combustion. For lean RPL combustion, the reactive species O, H and OH in combination affect the stability to a greater extent than the temperature alone. At rich equivalence ratios, the conversion of methane to hydrogen and carbon monoxide in the RPL section is a factor influencing the LBO limit. The results are compared with emission probe measurements that were used to investigate the LBO limit for methane and a generic syngas (10% CH4, 67.5% H2, and 22.5% CO). The syngas was also investigated after being diluted with nitrogen to a Wobbe index of 15 MJ/m3.

Ivan R. Sigfrid; Ronald Whiddon; Robert Collin; Jens Klingmann

2014-01-01T23:59:59.000Z

54

Structure and reactivity of chemisorbed species and reaction intermediates: Progress report, December 1, 1984--November 30, 1985  

SciTech Connect (OSTI)

The areas of work have supported a common theme: the structure and reactivity of chemisorbed species and reaction intermediate of importance to catalysis. A variety of tools have been to study the structure and chemistry of surface species, and to develop models and concepts of broad utility in chemisorption and catalysis. Adsorption of carbon monoxide, ammonia, hydrogen, and sulfur are discussed. Results of the research conducted or completed in the last year, as well as plans for the coming year, are summarized in this report. The results will be presented in three sections: (a) Surface Molecular Structure and Reactivity as Studied Using Electron Simulated Desorption Ion Angular Distribution (ESDIAD) and High Resolution Electron Energy Loss Spectroscopy (HREELS); (b) Neutron Inelastic Scattering Studies of Adsorption and Reaction on Catalysts; and (c) Reaction Kinetics at High Pressures over Single Crystal Catalysts.

Madey, T.E.; Kelley, R.D.

1985-08-01T23:59:59.000Z

55

Effect of Alkali and Alkaline Earth Metallic Species on Biochar Reactivity and Syngas Compositions during Steam Gasification  

Science Journals Connector (OSTI)

Effect of Alkali and Alkaline Earth Metallic Species on Biochar Reactivity and Syngas Compositions during Steam Gasification† ... Briefly, a biomass or biochar sample, held in a platinum (Pt) crucible, was ashed in air following a specially designed ashing program that raised the temperature to a final temperature of 600 °C at a very slow heating rate in order to prevent the ignition of the biomass/biochar hence to avoid the loss of AAEM species from the sample during oxidation. ... Therefore, wood may be a good fuel based on the consideration that this would potentially reduce the ash-related operation problems in a gasifier. ...

Kongvui Yip; Fujun Tian; Jun-ichiro Hayashi; Hongwei Wu

2009-07-24T23:59:59.000Z

56

Inelastic and Reactive Scattering Dynamics of Hyperthermal Oxygen Atoms on Ionic Liquid Surfaces: [emim][NTf{sub 2}] and [C{sub 12}mim][NTf{sub 2}  

SciTech Connect (OSTI)

Collisions of hyperthermal oxygen atoms, with an average translational energy of 520 kJ mol{sup -1}, on continuously refreshed ionic liquids, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([emim][NTf{sub 2}]) and 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([C{sub 12}mim][NTf{sub 2}]), were studied with the use of a beam-surface scattering technique. Time-of-flight and angular distributions of inelastically scattered O and reactively scattered OH and H{sub 2}O were collected for various angles of incidence with the use of a rotatable mass spectrometer detector. For both O and OH, two distinct scattering processes were identified, which can be empirically categorized as thermal and non-thermal. Non-thermal scattering is more probable for both O and OH products. The observation of OH confirms that at least some reactive sites, presumably alkyl groups, must be exposed at the surface. The ionic liquid with the longer alkyl chain, [C{sub 12}mim][NTf{sub 2}], is substantially more reactive than the liquid with the shorter alkyl chain, [emim][NTf{sub 2}], and proportionately much more so than would be predicted simply from stoichiometry based on the number of abstractable hydrogen atoms. Molecular dynamics models of these surfaces shed light on this change in reactivity. The scattering behavior of O is distinctly different from that of OH. However, no such differences between inelastic and reactive scattering dynamics have been seen in previous work on pure hydrocarbon liquids, in particular the benchmark, partially branched hydrocarbon, squalane (C{sub 30}H{sub 62}). The comparison between inelastic and reactive scattering dynamics indicates that inelastic scattering from the ionic liquid surfaces takes place predominantly at non-reactive sites that are effectively stiffer than the reactive alkyl chains, with a higher proportion of collisions sampling such sites for [emim][NTf{sub 2}] than for [C{sub 12}mim][NTf{sub 2}].

Wu Bohan; Zhang Jianming; Minton, Timothy K. [Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717 (United States); McKendrick, Kenneth G. [School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Slattery, John M. [Department of Chemistry, University of York, Heslington, York YO10 5DD (United Kingdom); Yockel, Scott; Schatz, George C. [Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113 (United States)

2011-05-20T23:59:59.000Z

57

Reactivity deterioration of NiO/Al{sub 2}O{sub 3} oxygen carrier for chemical looping combustion of coal in a 10 kW{sub th} reactor  

SciTech Connect (OSTI)

A relatively long-term experiment for chemical looping combustion of coal with NiO/Al{sub 2}O{sub 3} oxygen carrier was carried out in a 10 kW{sub th} continuous reactor of interconnected fluidized beds, and 100 h of operation was reached with the same batch of the oxygen carrier. The reactivity deterioration of the oxygen carriers was present during the experimental period. The reactivity deterioration of reacted oxygen carriers at different experimental stages was evaluated using X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray fluorescence spectrometer. SEM analysis showed no significant change in the morphology of the nickel-based oxygen carrier at the fuel reactor temperature {<=}940 C, but loss of surface area and porosity of reacted oxygen carriers was observed when the fuel reactor temperature exceeded 960 C. The results show that the sintering effect have mainly contributed to the reactivity deterioration of reacted oxygen carriers in the CLC process for coal, while the effects of coal ash and sulfur can be ignored. The oxidization of reduced oxygen carrier with air was an intensive exothermic process, and the high temperature of oxygen carrier particles led to sintering on the surface of oxygen carrier particles in the air reactor. Attention must be paid to control the external circulation of oxygen carrier particles in the interconnected fluidized beds in order to efficiently transport heat from the air reactor to the fuel reactor, and reduce the temperature of oxygen carrier particles in the air reactor. Improvement of reactivity deterioration of reacted oxygen carriers was achieved by the supplement of steam into the fuel reactor. Nevertheless, NiO/Al{sub 2}O{sub 3} is still one of the optimal oxygen carriers for chemical looping combustion of coal if the sintering of oxygen carrier is minimized at the suitable reactor temperature. (author)

Shen, Laihong; Wu, Jiahua; Gao, Zhengping; Xiao, Jun [Thermoenergy Engineering Research Institute, Southeast University, 2 Sipailou, Nanjing 210096 (China)

2009-07-15T23:59:59.000Z

58

Hydrous oxide species as inhibitors of oxygen reduction at platinum activated fuel cell cathodes  

Science Journals Connector (OSTI)

The successful development of a methanol/air fuel cell requires optimum performance of the air/ oxygen cathode at about 0.8 V vs RHE. ... oxygen gas reduction on platinum (the best electrocatalyst for this reacti...

L. D. Burke; J. K. Casey; J. A. Morrissey…

1994-01-01T23:59:59.000Z

59

Effect of temperature on reduction reactivity of oxygen carrier particles in a fixed bed chemical-looping combustor  

Science Journals Connector (OSTI)

In a chemical-looping combustor (CLC), gaseous fuel is oxidized...2...is separated from the exhaust gases during the combustion. In this study, NiO/bentonite particle...x formation during oxidation. Reactivity da...

Ho-Jung Ryu; Dal-Hee Bae; Gyoung-Tae Jin

2003-09-01T23:59:59.000Z

60

Effects of Several Wine Polyphenols on Lipid Peroxidation and Oxygen Activation in Rat Liver Microsomes  

Science Journals Connector (OSTI)

Lipid peroxidation (LP) and reactive oxygen species (ROS) are thought to play important roles in atherosclerosis, cancer, ageing and other diseases1. Naturally occuring polyphenols in wine, tea, vegetables, etc c...

Šárka Mat?jková; Ivan Gut

2001-01-01T23:59:59.000Z

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

Role of p53 in Sensing Oxidative DNA Damage in Response to Reactive Oxygen Species-Generating Agents  

Science Journals Connector (OSTI)

...by the base excision repair (BER) machinery. Using synthetic DNA containing 8-oxo-7,8-dihydro-2-deoxyguanosine...by the base excision repair (BER) machinery. Using synthetic DNA containing 8-oxo-7,8-dihydro-2'-deoxyguanosine...

Geetha Achanta and Peng Huang

2004-09-01T23:59:59.000Z

62

Potato Chip Intake Increases Ascorbic Acid Levels and Decreases Reactive Oxygen Species in SMP30/GNL Knockout Mouse Tissues  

Science Journals Connector (OSTI)

Kondo, Y.; Higashi, C.; Iwama, M.; Ishihara, K.; Handa, S.; Mugita, H.; Maruyama, N.; Koga, H.; Ishigami, A.Bioavailability of vitamin C from mashed potatoes and potato chips after oral administration in healthy Japanese men Br. ... Bioavailability of vitamin C from mashed potatoes and potato chips after oral administration in healthy Japanese men ... After overnight fasting, five healthy Japanese men between 22 and 27 years of age consumed 87 g mashed potatoes and 282 g potato chips. ...

Yoshitaka Kondo; Rui Sakuma; Megumi Ichisawa; Katsuyuki Ishihara; Misako Kubo; Setsuko Handa; Hiroyuki Mugita; Naoki Maruyama; Hidenori Koga; Akihito Ishigami

2014-09-02T23:59:59.000Z

63

RETRACTED ARTICLE: Non-thermal Plasma Induces Apoptosis in Melanoma Cells via Production of Intracellular Reactive Oxygen Species  

Science Journals Connector (OSTI)

Non-thermal atmospheric pressure dielectric barrier discharge (DBD) plasma may provide a novel approach to treat ... study was to evaluate the potential of DBD plasma to induce apoptosis in melanoma cells. Melano...

Rachel Sensenig; Sameer Kalghatgi; Ekaterina Cerchar…

2011-02-01T23:59:59.000Z

64

Green Tea Component, Catechin, Induces Apoptosis of Human Malignant B Cells via Production of Reactive Oxygen Species  

Science Journals Connector (OSTI)

...enhanced by As2O3 via production of intracellular ROS. Materials and Methods Cells and cell culture...H, Maeda M, et al. Production of hydrogen peroxide and methionine...phosphorylation and H2O2 production in transformed and non-transformed...

Tomonori Nakazato; Keisuke Ito; Yasuo Ikeda; and Masahiro Kizaki

2005-08-15T23:59:59.000Z

65

Temporal-Spatial Interaction between Reactive Oxygen Species and Abscisic Acid Regulates Rapid Systemic Acclimation in Plants  

Science Journals Connector (OSTI)

...plasma membrane|CE, collision energy|CV, cone voltage| INTRODUCTION...life on Earth, converting solar energy into bioavailable resources. Being sessile organisms...10) could provide further energy to drive mitochondrial respiration...

Nobuhiro Suzuki; Gad Miller; Carolina Salazar; Hossain A. Mondal; Elena Shulaev; Diego F. Cortes; Joel L. Shuman; Xiaozhong Luo; Jyoti Shah; Karen Schlauch; Vladimir Shulaev; Ron Mittler

2013-09-13T23:59:59.000Z

66

Serotonin 5-HT2B Receptor Blockade Prevents Reactive Oxygen SpeciesInduced Cardiac Hypertrophy in Mice  

E-Print Network [OSTI]

hypertrophy, ie, angiotensin II and isoproterenol infusions in mice. Angiotensin II infusion for 14 days215505) prevented the increase in cardiac superoxide generation and hypertrophy. Similarly, infusion

Boyer, Edmond

67

Sorafenib-Induced Hepatocellular Carcinoma Cell Death Depends on Reactive Oxygen Species Production In Vitro and In Vivo  

Science Journals Connector (OSTI)

...inhibited O2 production in HepG2 cells...Figure 2. ROS production by HepG2, Hepa...O2 A and B), hydrogen peroxide (C...Material and Methods. Results are...analysis of ROS production by HepG2, Hepa...O2 A) and hydrogen peroxide (B...Material and Methods. Results are...

Romain Coriat; Carole Nicco; Christiane Chéreau; Olivier Mir; Jérôme Alexandre; Stanislas Ropert; Bernard Weill; Stanislas Chaussade; François Goldwasser; and Frédéric Batteux

2012-10-01T23:59:59.000Z

68

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

E-Print Network [OSTI]

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

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

2014-04-08T23:59:59.000Z

69

Deactivation and Regeneration of Oxygen Reduction Reactivity on Double Perovskite Ba2Bi0.1Sc0.2Co1.7O6?x Cathode for Intermediate-Temperature Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

Deactivation and Regeneration of Oxygen Reduction Reactivity on Double Perovskite Ba2Bi0.1Sc0.2Co1.7O6?x Cathode for Intermediate-Temperature Solid Oxide Fuel Cells ... Most notably, cathodic polarization treatment, for example, current discharge from BBSC, can be utilized to recover the original ORR performance. ... After evaporation of water at 120 °C, a dark purple gel was recovered. ...

Wei Zhou; Jaka Sunarso; Julius Motuzas; Fengli Liang; Zhigang Chen; Lei Ge; Shaomin Liu; Anne Julbe; Zhonghua Zhu

2011-02-28T23:59:59.000Z

70

Kinetic determination of a highly reactive impregnated Fe2O3/Al2O3 oxygen carrier for use in gas-fueled Chemical Looping Combustion  

Science Journals Connector (OSTI)

Abstract The objective of this work was to determine the kinetic parameters for reduction and oxidation reactions of a highly reactive Fe-based oxygen carrier for use in Chemical Looping Combustion (CLC) of gaseous fuels containing CH4, CO and/or H2, e.g. natural gas, syngas and PSA-off gas. The oxygen carrier was prepared by impregnation of iron on alumina. The effect of both the temperature and gas concentration was analyzed in a thermogravimetric analyzer (TGA). The grain model with uniform conversion in the particle and reaction in grains following the shrinking core model (SCM) was used for kinetics determination. It was assumed that the reduction reactions were controlled by two different resistances: the reaction rate was controlled by chemical reaction in a first step, whereas the mechanism that controlled the reactions at higher conversion values was diffusion through the product layer around the grains. Furthermore, it was found that the reduction reaction mechanism was based on the interaction of Fe2O3 with Al2O3 in presence of the reacting gases to form FeAl2O4 as the only stable Fe-based phase. The reaction order values found for the reducing gases were 0.25, 0.3 and 0.6 for CH4, H2 and CO, respectively, and the activation energy took values of between 8 kJ mol?1 (for H2) and 66 kJ mol?1 (for CH4). With regard to oxidation kinetics, the reacting model assumed a reaction rate that was only controlled by chemical reaction. Values of 0.9 and 23 kJ mol?1 were found for reaction order and activation energy, respectively. Finally, the solids inventory needed in a CLC system was also estimated by considering kinetic parameters. The total solids inventory in the CLC unit took a minimum value of 150 kg MW?1 for CH4 combustion, which is a low value when compared to those of other Fe-based materials found in the literature.

A. Cabello; A. Abad; F. García-Labiano; P. Gayán; L.F. de Diego; J. Adánez

2014-01-01T23:59:59.000Z

71

Electronic Structure and Reactivity of Isomeric Oxo-Mn(V) Porphyrins:? Effects of Spin-State Crossing and pKa Modulation  

Science Journals Connector (OSTI)

Filippo De Angelis ,*†‡ Ning Jin ,‡ Roberto Car ,‡ and John T. Groves *‡ ... 1,2 Reactive oxomanganese complexes are thought to participate in the photosynthetic oxidation of water to produce oxygen. ... In recent years, fast kinetic probes of the reactivity of oxometalloporphyrin complexes13,14 and the emerging power of chemical computation in such systems15-25 have begun to provide a new level of understanding of the nature and reactivity of such oxometal species. ...

Filippo De Angelis; Ning Jin; Roberto Car; John T. Groves

2006-04-21T23:59:59.000Z

72

Studies on the Surface Oxygen Species and the Catalytic Activity for CO Oxidation of La1-xSrxCo1-xMnxO3, a Perovskite-Type Oxides Catalyst  

Science Journals Connector (OSTI)

The surface oxygen distribution the active oxygen species for CO on the perovskite-type catalyst La1-xSrxCo1-xMnxO3...and its catalytic oxidation activity with CO as probe were investigated by means of XRD, TPD a...

Rong Li; Jiantai Ma; Jingli Xu; Xia Zhou…

2000-07-01T23:59:59.000Z

73

On the origin of the selectivity of oxygen reduction of ruthenium-containing electrocatalysts in methanol-containing electrolyte  

SciTech Connect (OSTI)

The reactivity with water and methanol of oxygen-reducing (Ru{sub 1{minus}x}Mo{sub x}SeO{sub z}) and oxygen (from water)-evolving electrocatalysts (RuS{sub 2}, RuO{sub 2}), which permit electron transfer via ruthenium d-states, was studied using electrochemical techniques and differential electrochemical mass spectroscopy (DEMS). In contrast to platinum, which is depolarized by methanol, ruthenium compounds show a high reactivity with water species and an extremely low reactivity with methanol. The authors conclude that the ruthenium-centered coordination chemical reactivity with water channels electrochemical currents, thus producing kinetic selectivity. The reason for the higher reactivity with water of Ru d-states as compared to platinum is seen in the higher density of d-states near the Fermi level as shown by this comparative study.

Alonso-Vante, N.; Bogdanoff, P.; Tributsch, H.

2000-03-10T23:59:59.000Z

74

Active oxygen species and mechanism for low-temperature CO oxidation reaction on a TiO{sub 2}-supported Au catalyst prepared from Au(PPh{sub 3})(NO{sub 3}) and as-precipitated titanium hydroxide  

SciTech Connect (OSTI)

The active oxygen species and mechanism for catalytic CO oxidation with O{sub 2} on a highly active TiO{sub 2}-supported Au catalyst (denoted as Au/Ti(OH){sub 4}{sup *}), which was prepared by supporting a Au-phophine complex on as-precipitated wet titanium hydroxide followed by calcination at 673 K, have been studied by means of oxygen isotope exchange, O{sub 2} temperature-programmed desorption (O{sub 2} TPD), electron spin resonance (ESR), and Fourier-transformed infrared spectroscopy (FT-IR). Surface lattice oxygen atoms on the Au/Ti(OH){sub 4}{sup *} catalyst were inactive for oxygen exchange with O{sub 2} and CO and also for CO oxidation at room temperature. The surface lattice oxygen atoms were exchanged only with the oxygen atoms of CO{sub 2}, probably via carbonates. O{sub 2} did not dissociate to atomic oxygen on the catalyst. The catalyst showed a paramagnetic signal at g = 2.002 due to unpaired electrons trapped at oxygen vacancies mainly at the surface. O{sub 2} adsorbed on the oxygen vacancies to form superoxide O{sub 2}{sup {minus}} with g{sub 1} = 2.020, g{sub 2} = 2.010, and g{sub 3} = 2.005, which are characteristic of O{sub 2}{sup {minus}} with an angular arrangement. Upon CO exposure, all the adsorbed oxygen species disappeared. The mechanism for the catalytic CO oxidation on the active Au/Ti(OH){sub 4}{sup *} catalyst is discussed in detail and compared with mechanisms reported previously.

Liu, H.; Kozlov, A.I.; Kozlova, A.P.; Shido, Takafumi; Asakura, Kiyotaka; Iwasawa, Yasuhiro [Univ. of Tokyo (Japan)] [Univ. of Tokyo (Japan)

1999-07-25T23:59:59.000Z

75

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]

Radiation in Natural-Water Purification. Photochemistry andR.N. (1956) The purification of water on a small scale.

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

76

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]

cases (Fisher et al. , 2008; Sinton et al. , 2002b; SommerDavies and Evison, 1991; Sinton et al. , 2002b) and drinkingNZ Mumbai, India (Sinton et al. , 2002b) (Sinton et al. ,

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

77

Rehydration of the Lichen Ramalina lacera Results in Production of Reactive Oxygen Species and Nitric Oxide and a Decrease in Antioxidants  

Science Journals Connector (OSTI)

...over distilled water. This air stream...and to prevent water condensation on its inner walls...Vainio exposed to atmospheric pollutants. Physiol...as a function of water content and suggestion...D. S. 1988. Recovery of net photosynthesis...

Lior Weissman; Jacob Garty; Ayala Hochman

2005-04-01T23:59:59.000Z

78

Light-harvesting mutants show differential gene expression upon shift to high light as a consequence of photosynthetic redox and reactive oxygen species metabolism  

Science Journals Connector (OSTI)

...therefore depend on production of H2O2. It is conceivable...performance. 4. Material and methods (a) Plant growth WT...OPDA; AT-00293) or hydrogen peroxide (H2O2; AT-00185...S2), in response to hydrogen peroxide (H2O2; AT-00185...expression: (b) Abnormal production of ROS in various light-harvesting...

2014-01-01T23:59:59.000Z

79

Distinct Subpopulations of Head and Neck Cancer Cells with Different Levels of Intracellular Reactive Oxygen Species Exhibit Diverse Stemness, Proliferation, and Chemosensitivity  

Science Journals Connector (OSTI)

...outcome in locally advanced squamous cell head-neck cancer.Br J Cancer 2012;106...of antrodia cinnamomea mycelia targeting head and neck cancer initiating cells through...Haddad RI Shin DM.Recent advances in head and neck cancer.N Engl J Med 2008;359...

Ching-Wen Chang; Yu-Syuan Chen; Shiu-Huey Chou; Chia-Li Han; Yu-Ju Chen; Cheng-Chieh Yang; Chih-Yang Huang; Jeng-Fan Lo

2014-11-01T23:59:59.000Z

80

Targeting Wild-Type and Mutant p53 with Small Molecule CP-31398 Blocks the Growth of Rhabdomyosarcoma by Inducing Reactive Oxygen Species–Dependent Apoptosis  

Science Journals Connector (OSTI)

...within the single cell gate is shown at the bottom...scatter properties (small gate), and apoptotic cells...shows mitotic figures (red arrow) and apoptosis...show mitotic figures (red arrows) and apoptosis...1994;22:3551-5. 9 Woods YL Lane DP. Exploiting...

Jianmin Xu; Laura Timares; Clay Heilpern; Zhiping Weng; Changzhao Li; Hui Xu; Joseph G. Pressey; Craig A. Elmets; Levy Kopelovich; and Mohammad Athar

2010-08-15T23:59:59.000Z

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

Activation of reactive oxygen species/AMP activated protein kinase signaling mediates fisetin-induced apoptosis in multiple myeloma U266 cells  

Science Journals Connector (OSTI)

We investigated the molecular mechanisms responsible for fisetin-induced apoptosis in U266 cells. Fisetin elicited the cytotoxicity in U266 cells, manifested as an increased fraction of the cells with sub-G1 content or stained positively with TUNEL labeling. Fisetin enhanced caspase-3 activation, downregulation of Bcl-2 and Mcl-1L, and upregulation of Bax, Bim and Bad. Fisetin activated AMPK as well as its substrate acetyl-CoA carboxylase (ACC), along with a decreased phosphorylation of AKT and mTOR. Fisetin also stimulated generation of ROS in U266 cells. Conversely, compound C or N-acetyl-l-cystein blocked fisetin-induced apoptosis. Our data suggest that fisetin-induced apoptosis in U266 cells is through ROS and AMPK pathways.

Ki Young Jang; Soo-Jin Jeong; Sun-Hee Kim; Ji Hoon Jung; Ji-Hyun Kim; Wonil Koh; Chang-Yan Chen; Sung-Hoon Kim

2012-01-01T23:59:59.000Z

82

oiwa, a Female Gametophytic Mutant Impaired in a Mitochondrial Manganese-Superoxide Dismutase, Reveals Crucial Roles for Reactive Oxygen Species during Embryo Sac Development and Fertilization in Arabidopsis  

Science Journals Connector (OSTI)

...wild-type pistils (assessed by Kruskal-Wallis nonparametric one-way analysis...significance (*P 0.001, Kruskal-Wallis). A total of 69 embryo sacs...Ti-Control. Statistical Analysis The Kruskal-Wallis test on ranks was performed for...

María Victoria Martin; Diego Fernando Fiol; Venkatesan Sundaresan; Eduardo Julián Zabaleta; Gabriela Carolina Pagnussat

2013-05-07T23:59:59.000Z

83

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]

on Solar Water Disinfection, Massachusetts Institute ofSolar Disinfection For Point of Use Water Treatment in Haiti, Massachusetts

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

84

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]

solar energy flux, these wavelengths may nevertheless be important for disinfection. Thus, the advantages and

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

85

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]

2004) A novel TiO2-assisted solar photocatalytic batch-2007a) Fe3+ and TiO2 solar-light-assisted inactivation of E.

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

86

Tumor Necrosis Factor-? Increases Reactive Oxygen Species by Inducing Spermine Oxidase in Human Lung Epithelial Cells: A Potential Mechanism for Inflammation-Induced Carcinogenesis  

Science Journals Connector (OSTI)

...increasing levels of positive cell cycle regulators, as well as components...exposure to TNF-alpha, a general mediator of inflammation...molecular mechanism by which general inflammation can contribute...intratracheal administration of diesel exhaust particles. Carcinogenesis...

Naveen Babbar and Robert A. Casero, Jr.

2006-12-01T23:59:59.000Z

87

Nitric oxide production occurs downstream of reactive oxygen species in guard cells during stomatal closure induced by chitosan in abaxial epidermis of Pisum sativum  

Science Journals Connector (OSTI)

The effects of chitosan (?-1,4 linked glucosamine, a ... (NO scavenger), sodium tungstate (nitrate reductase inhibitor) or l-NAME (NO synthase inhibitor) restricted the chitosan induced stomatal closure, demonstr...

Nupur Srivastava; Vijay K. Gonugunta; Mallikarjuna R. Puli…

2009-03-01T23:59:59.000Z

88

Effects of oxysterols on cell viability, inflammatory cytokines, VEGF and reactive oxygen species production on human retinal cells: cytoprotective effects and prevention of VEGF  

E-Print Network [OSTI]

production on human retinal cells: cytoprotective effects and prevention of VEGF secretion by resveratrol B Recherche INSERM 866 (Lipides, Nutrition, Cancer) ­ Equipe Biochimie Métabolique et Nutritionnelle, and IL-8 secretion. 7-OH enhanced VEGF secretion. No cytotoxic effects were identified with 25-OH which

Paris-Sud XI, Université de

89

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]

Solar Disinfection of Drinking Water and Oral Rehydrationof Boiling to Disinfect Drinking Water in Rural Vietnam.Solar disinfection of drinking water and diarrhoea in Maasai

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

90

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]

hygiene, and/or poor sanitation, an incremental change inin areas where sanitation and hygiene are poor, improvements

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

91

Natural Ores as Oxygen Carriers in Chemical Looping Combustion  

SciTech Connect (OSTI)

Chemical looping combustion (CLC) is a combustion technology that utilizes oxygen from oxygen carriers (OC), such as metal oxides, instead of air to combust fuels. The use of natural minerals as oxygen carriers has advantages, such as lower cost and availability. Eight materials, based on copper or iron oxides, were selected for screening tests of CLC processes using coal and methane as fuels. Thermogravimetric experiments and bench-scale fixed-bed reactor tests were conducted to investigate the oxygen transfer capacity, reaction kinetics, and stability during cyclic reduction/oxidation reaction. Most natural minerals showed lower combustion capacity than pure CuO/Fe{sub 2}O{sub 3} due to low-concentrations of active oxide species in minerals. In coal CLC, chryscolla (Cu-based), magnetite, and limonite (Fe-based) demonstrated better reaction performances than other materials. The addition of steam improved the coal CLC performance when using natural ores because of the steam gasification of coal and the subsequent reaction of gaseous fuels with active oxide species in the natural ores. In methane CLC, chryscolla, hematite, and limonite demonstrated excellent reactivity and stability in 50-cycle thermogravimetric analysis tests. Fe{sub 2}O{sub 3}-based ores possess greater oxygen utilization but require an activation period before achieving full performance in methane CLC. Particle agglomeration issues associated with the application of natural ores in CLC processes were also studied by scanning electron microscopy (SEM).

Tian, Hanjing; Siriwardane, Ranjani; Simonyi, Thomas; Poston, James

2013-08-01T23:59:59.000Z

92

Reactive Maintenance  

Broader source: Energy.gov [DOE]

Reactive maintenance follows a run-it-until-it-breaks strategy where no actions or efforts are taken to maintain equipment as intended by the manufacturer. Studies indicate this is still the predominant mode of maintenance for Federal facilities.

93

A tomographic technique for the simultaneous imaging of temperature, chemical species, and pressure in reactive flows using absorption spectroscopy with frequency-agile lasers  

E-Print Network [OSTI]

This paper proposes a technique that can simultaneously retrieve distributions of temperature, concentration of chemical species, and pressure based on broad bandwidth, frequency-agile tomographic absorption spectroscopy. The technique holds...

Cai, Weiwei; Kaminski, Clemens F.

2014-01-21T23:59:59.000Z

94

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

SciTech Connect (OSTI)

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

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

2014-08-15T23:59:59.000Z

95

CO Desorption from Oxygen Species on Carbonaceous Surface: 1. Effects of the Local Structure of the Active Site and the Surface Coverage  

E-Print Network [OSTI]

in the gasification and combustion of coal. Particularly, a CO molecule release from carbonyl oxygen complexes�n,*, and Thanh N. Truong*, Department of Chemistry, UniVersity of Antioquia, Medellin, Colombia A.A. 1226, Henry Eyring Center for Theoretical Chemistry, Department of Chemistry, UniVersity of Utah, 315 South 1400 East

Truong, Thanh N.

96

Photoluminescent silicon nanocrystals synthesized by reactive laser Daria Riabinina,a  

E-Print Network [OSTI]

Photoluminescent silicon nanocrystals synthesized by reactive laser ablation Daria Riabinina reactive laser ablation in oxygen atmosphere followed by annealing. We observe a strong photoluminescence size, obtained independently by fitting photoluminescence spectra and from x-ray diffraction patterns

97

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

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

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

98

BWR oxygen control demonstration program  

SciTech Connect (OSTI)

A number of cracks have occurred recently in certain BWR piping systems. The operating environment associated with oxidizing species such as oxygen and hydrogen peroxide is considered one of the factors in the mechanism of cracking. In April 1976, NWT Corporation was contracted to perform a BWR oxygen control demonstration program. Means for reducing reactor water oxygen and hydrogen peroxide concentrations during startup and shutdown transients were defined and demonstrated at Vermont Yankee and Browns Ferry Unit 3. Results of the demonstrations and an analytical review of impacts of major system variables on oxygen transients are discussed herein.

Pearl, W.L.; Kassen, W.R.; Sawochka, S.G.

1981-05-01T23:59:59.000Z

99

Ozone-forming potential of a series of oxygenated organic compounds  

SciTech Connect (OSTI)

An incremental reactivity approach has been used to assess the relative ozone-forming potentials of various important oxygenated fuels/fuel additives, i.e., tert-butyl alcohol (TBA), dimethyl ether (DME), diethyl ether (DEE), methyl tert-butyl ether (MTBE), and ethyl tert-butyl ether (ETBE), in a variety of environments. Calculations were performed using a single-cell trajectory model, combined with the Lurmann-Carter-Coyner chemical mechanism, with (NMOC)/(NO{sub x}) ratios ranging from 4 to 20. This work provides the first quantitative assessment of the air quality impact of release of these important oxygenated compounds. ETBE and DEE are the two most reactive compounds on a per carbon equivalent basis, while TBA is the least reactive species. At a (NMOC)/(NO{sub x}) ratio of 8, which is generally typical of polluted urban areas in the United States, TBA, DME, MTBE, and ETBE all have incremental reactivities less than or equal to that of the urban NMHC mix. Thus, use of these additives in fuels may have a beneficial impact on urban ozone levels.

Japar, S.M.; Wallington, T.J.; Rudy, S.J.; Chang, Tai Y. (Ford Motor Company, Dearborn, MI (USA))

1991-03-01T23:59:59.000Z

100

Photo-excitation of carotenoids causes cytotoxicity via singlet oxygen production  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer Some photo-excited carotenoids have photosensitizing ability. Black-Right-Pointing-Pointer They are able to produce ROS. Black-Right-Pointing-Pointer Photo-excited fucoxanthin can produce singlet oxygen through energy transfer. -- Abstract: Carotenoids, natural pigments widely distributed in algae and plants, have a conjugated double bond system. Their excitation energies are correlated with conjugation length. We hypothesized that carotenoids whose energy states are above the singlet excited state of oxygen (singlet oxygen) would possess photosensitizing properties. Here, we demonstrated that human skin melanoma (A375) cells are damaged through the photo-excitation of several carotenoids (neoxanthin, fucoxanthin and siphonaxanthin). In contrast, photo-excitation of carotenoids that possess energy states below that of singlet oxygen, such as {beta}-carotene, lutein, loroxanthin and violaxanthin, did not enhance cell death. Production of reactive oxygen species (ROS) by photo-excited fucoxanthin or neoxanthin was confirmed using a reporter assay for ROS production with HeLa Hyper cells, which express a fluorescent indicator protein for intracellular ROS. Fucoxanthin and neoxanthin also showed high cellular penetration and retention. Electron spin resonance spectra using 2,2,6,6-tetramethil-4-piperidone as a singlet oxygen trapping agent demonstrated that singlet oxygen was produced via energy transfer from photo-excited fucoxanthin to oxygen molecules. These results suggest that carotenoids such as fucoxanthin, which are capable of singlet oxygen production through photo-excitation and show good penetration and retention in target cells, are useful as photosensitizers in photodynamic therapy for skin disease.

Yoshii, Hiroshi, E-mail: yoshii@nirs.go.jp [Research Center for Radiation Emergency Medicine, National Institute of Radiological Science, Chiba 263-8555 (Japan) [Research Center for Radiation Emergency Medicine, National Institute of Radiological Science, Chiba 263-8555 (Japan); Faculty of Medical Sciences, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Yoshii, Yukie, E-mail: yukiey@nirs.go.jp [Molecular Imaging Center, National Institute of Radiological Science, Chiba 263-8555 (Japan) [Molecular Imaging Center, National Institute of Radiological Science, Chiba 263-8555 (Japan); Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Asai, Tatsuya [Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan) [Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Faculty of Engineering, University of Fukui, Fukui 910-8507 (Japan); Furukawa, Takako [Molecular Imaging Center, National Institute of Radiological Science, Chiba 263-8555 (Japan) [Molecular Imaging Center, National Institute of Radiological Science, Chiba 263-8555 (Japan); Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Takaichi, Shinichi [Department of Biology, Nippon Medical School, Kawasaki, Kanagawa 211-0063 (Japan)] [Department of Biology, Nippon Medical School, Kawasaki, Kanagawa 211-0063 (Japan); Fujibayashi, Yasuhisa [Molecular Imaging Center, National Institute of Radiological Science, Chiba 263-8555 (Japan) [Molecular Imaging Center, National Institute of Radiological Science, Chiba 263-8555 (Japan); Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan)

2012-01-06T23:59:59.000Z

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

Oxygen Transport Ceramic Membranes  

SciTech Connect (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

102

Modeling Terrestrial Biogenic Sources of Oxygenated Organic Emissions  

Science Journals Connector (OSTI)

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

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

2003-07-01T23:59:59.000Z

103

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

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

104

Biodiesel Fuel Property Effects on Particulate Matter Reactivity  

SciTech Connect (OSTI)

Controlling diesel particulate emissions to meet the 2007 U.S. standard requires the use of a diesel particulate filter (DPF). The reactivity of soot, or the carbon fraction of particulate matter, in the DPF and the kinetics of soot oxidation are important in achieving better control of aftertreatment devices. Studies showed that biodiesel in the fuel can increase soot reactivity. This study therefore investigated which biodiesel fuel properties impact reactivity. Three fuel properties of interest included fuel oxygen content and functionality, fuel aromatic content, and the presence of alkali metals. To determine fuel effects on soot reactivity, the performance of a catalyzed DPF was measured with different test fuels through engine testing and thermo-gravimetric analysis. Results showed no dependence on the aromatic content or the presence of alkali metals in the fuel. The presence and form of fuel oxygen was the dominant contributor to faster DPF regeneration times and soot reactivity.

Williams, A.; Black, S.; McCormick, R. L.

2010-06-01T23:59:59.000Z

105

Sulfur behavior in chemical looping combustion with NiO/Al{sub 2}O{sub 3} oxygen carrier  

SciTech Connect (OSTI)

Chemical looping combustion (CLC) is a novel technology where CO{sub 2} is inherently separated during combustion. Due to the existence of sulfur contaminants in the fossil fuels, the gaseous products of sulfur species and the interaction of sulfur contaminants with oxygen carrier are a big concern in the CLC practice. The reactivity of NiO/Al{sub 2}O{sub 3} oxygen carrier reduction with a gas mixture of CO/H{sub 2} and H{sub 2}S is investigated by means of a thermogravimetric analyzer (TGA) and Fourier Transform Infrared spectrum analyzer in this study. An X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscope (SEM) are used to evaluate the phase characterization of reacted oxygen carrier, and the formation mechanisms of the gaseous products of sulfur species are elucidated in the process of chemical looping combustion with a gaseous fuel containing hydrogen sulfide. The results show that the rate of NiO reduction with H{sub 2}S is higher than the one with CO. There are only Ni and Ni{sub 3}S{sub 2} phases of nickel species in the fully reduced oxygen carrier, and no evidence for the existence of NiS or NiS{sub 2}. The formation of Ni{sub 3}S{sub 2} is completely reversible during the process of oxygen carrier redox. A liquid phase sintering on the external surface of reduced oxygen carriers is mainly attributed to the production of the low melting of Ni{sub 3}S{sub 2} in the nickel-based oxygen carrier reduction with a gaseous fuel containing H{sub 2}S. Due to the sintering of metallic nickel grains on the external surface of the reduced oxygen carrier, further reaction of the oxygen carrier with H{sub 2}S is constrained, and there is no increase of the sulfidation index of the reduced oxygen carrier with the cyclical reduction number. Also, a continuous operation with a syngas of carbon monoxide and hydrogen containing H{sub 2}S is carried out in a 1 kW{sub th} CLC prototype based on the nickel-based oxygen carrier, and the effect of the fuel reactor temperature on the release of gaseous products of sulfur species is investigated. (author)

Shen, Laihong; Gao, Zhengping; Wu, Jiahua; Xiao, Jun [Thermoenergy Engineering Research Institute, Southeast University, Nanjing 210096 (China)

2010-05-15T23:59:59.000Z

106

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

Science Journals Connector (OSTI)

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

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

2007-01-01T23:59:59.000Z

107

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

SciTech Connect (OSTI)

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

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

2007-09-15T23:59:59.000Z

108

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

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

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2000-10-01T23:59:59.000Z

109

Reactivating personal memory 1 RUNNING HEAD: Reactivating personal memory  

E-Print Network [OSTI]

Reactivating personal memory 1 RUNNING HEAD: Reactivating personal memory Modifying memory: Selectively enhancing and updating personal memories for a museum; Reactivating personal memory 2 Abstract Memory can be modified when reactivated

Schacter, Daniel

110

Reactivity of the Quinone Methide of Butylated hydroxytoluene in Solution  

E-Print Network [OSTI]

BHT is a common antioxidant in pharmaceutical formulations and when oxidized it forms a quinone methide (QM). QM is a highly reactive electrophilic species which can undergo nucleophilic addition. This research investigated ...

Willcockson, Maren Gulsrud

2011-08-31T23:59:59.000Z

111

OXYGEN TRANSPORT CERAMIC MEMBRANES  

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

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2001-12-01T23:59:59.000Z

112

Electrochemical behavior of reactively sputtered iron-doped nickel oxide  

SciTech Connect (OSTI)

Iron-doped nickel oxide films were deposited by reactive sputtering from elemental and alloy targets in a 20% oxygen/argon atmosphere and were characterized for use as oxygen evolution catalysts. The incorporation of iron reduced the overpotential required for oxygen evolution by as much as 300 mV at a current density of 100 mA/cm{sup 2} compared to undoped nickel oxide deposited under similar conditions. Tafel slopes were reduced from 95 mV/dec in undoped NiO{sub x} films to less than 40 mV/dec for films containing 1.6 to 5.6 mole percent (m/o) iron, indicating a change in the rate-limiting step from the primary discharge of OH{sup {minus}} ions to the recombination of oxygen radicals. Resistivity, structural, and compositional measurements indicate that high oxygen content is necessary to gain the full benefit of the iron dopant. Initial tests in KOH indicate excellent long-term stability. A film deposited from the FeNi alloy target, which exhibited low oxygen overpotentials and a Tafel slope of 35 mV/dec, had not degraded appreciably following more than 7,000 h of operation at an anodic current density of 20 mA/cm{sup 2}. Taken together, the low oxygen evolution reaction overpotentials, the excellent stability in KOH, and the relative insensitivity to iron content indicative that reactively sputtered iron-doped nickel oxide is promising as an oxygen catalyst.

Miller, E.L.; Rocheleau, R.E. [Univ. of Hawaii, Honolulu, HI (United States)

1997-09-01T23:59:59.000Z

113

OXYGEN ABUNDANCES IN CEPHEIDS  

SciTech Connect (OSTI)

Oxygen abundances in later-type stars, and intermediate-mass stars in particular, are usually determined from the [O I] line at 630.0 nm, and to a lesser extent, from the O I triplet at 615.7 nm. The near-IR triplets at 777.4 nm and 844.6 nm are strong in these stars and generally do not suffer from severe blending with other species. However, these latter two triplets suffer from strong non-local thermodynamic equilibrium (NLTE) effects and thus see limited use in abundance analyses. In this paper, we derive oxygen abundances in a large sample of Cepheids using the near-IR triplets from an NLTE analysis, and compare those abundances to values derived from a local thermodynamic equilibrium (LTE) analysis of the [O I] 630.0 nm line and the O I 615.7 nm triplet as well as LTE abundances for the 777.4 nm triplet. All of these lines suffer from line strength problems making them sensitive to either measurement complications (weak lines) or to line saturation difficulties (strong lines). Upon this realization, the LTE results for the [O I] lines and the O I 615.7 nm triplet are in adequate agreement with the abundance from the NLTE analysis of the near-IR triplets.

Luck, R. E.; Andrievsky, S. M. [Department of Astronomy, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7215 (United States); Korotin, S. N.; Kovtyukh, V. V., E-mail: luck@fafnir.astr.cwru.edu, E-mail: serkor@skyline.od.ua, E-mail: val@deneb1.odessa.ua, E-mail: scan@deneb1.odessa.ua [Department of Astronomy and Astronomical Observatory, Odessa National University, Isaac Newton Institute of Chile, Odessa Branch, Shevchenko Park, 65014 Odessa (Ukraine)

2013-07-01T23:59:59.000Z

114

Oxygen-producing inert anodes for SOM process  

DOE Patents [OSTI]

An electrolysis system for generating a metal and molecular oxygen includes a container for receiving a metal oxide containing a metallic species to be extracted, a cathode positioned to contact a metal oxide housed within the container; an oxygen-ion-conducting membrane positioned to contact a metal oxide housed within the container; an anode in contact with the oxygen-ion-conducting membrane and spaced apart from a metal oxide housed within the container, said anode selected from the group consisting of liquid metal silver, oxygen stable electronic oxides, oxygen stable crucible cermets, and stabilized zirconia composites with oxygen stable electronic oxides.

Pal, Uday B

2014-02-25T23:59:59.000Z

115

COAL SLAGGING AND REACTIVITY TESTING  

SciTech Connect (OSTI)

Union Fenosa's La Robla I Power Station is a 270-MW Foster Wheeler arch-fired system. The unit is located at the mine that provides a portion of the semianthracitic coal. The remaining coals used are from South Africa, Russia, Australia, and China. The challenges at the La Robla I Station stem from the various fuels used, the characteristics of which differ from the design coal. The University of North Dakota Energy & Environmental Research Center (EERC) and the Lehigh University Energy Research Center (LUERC) undertook a program to assess problematic slagging and unburned carbon issues occurring at the plant. Full-scale combustion tests were performed under baseline conditions, with elevated oxygen level and with redistribution of air during a site visit at the plant. During these tests, operating information, observations and temperature measurements, and coal, slag deposit, and fly ash samples were obtained to assess slagging and unburned carbon. The slagging in almost all cases appeared due to elevated temperatures rather than fuel chemistry. The most severe slagging occurred when the temperature at the sampling port was in excess of 1500 C, with problematic slagging where first-observed temperatures exceeded 1350 C. The presence of anorthite crystals in the bulk of the deposits analyzed indicates that the temperatures were in excess of 1350 C, consistent with temperature measurements during the sampling period. Elevated temperatures and ''hot spots'' are probably the result of poor mill performance, and a poor distribution of the coal from the mills to the specific burners causes elevated temperatures in the regions where the slag samples were extracted. A contributing cause appeared to be poor combustion air mixing and heating, resulting in oxygen stratification and increased temperatures in certain areas. Air preheater plugging was observed and reduces the temperature of the air in the windbox, which leads to poor combustion conditions, resulting in unburned carbon as well as slagging. A second phase of the project involved advanced analysis of the baseline coal along with an Australian coal fired at the plant. These analysis results were used in equilibrium thermodynamic modeling along with a coal quality model developed by the EERC to assess slagging, fouling, and opacity for the coals. Bench-scale carbon conversion testing was performed in a drop-tube furnace to assess the reactivity of the coals. The Australian coal had a higher mineral content with significantly more clay minerals present than the baseline coal. The presence of these clay minerals, which tend to melt at relatively low temperatures, indicated a higher potential for problematic slagging than the baseline coal. However, the pyritic minerals, comprising over 25% of the baseline mineral content, may form sticky iron sulfides, leading to severe slagging in the burner region if local areas with reducing conditions exist. Modeling results indicated that neither would present significant fouling problems. The Australian coal was expected to show slagging behavior much more severe than the baseline coal except at very high furnace temperatures. However, the baseline coal was predicted to exhibit opacity problems, as well as have a higher potential for problematic calcium sulfate-based low-temperature fouling. The baseline coal had a somewhat higher reactivity than the Australian coal, which was consistent with both the lower average activation energy for the baseline coal and the greater carbon conversion at a given temperature and residence time. The activation energy of the baseline coal showed some effect of oxygen on the activation energy, with E{sub a} increasing at the lower oxygen concentration, but may be due to the scatter in the baseline coal kinetic values at the higher oxygen level tested.

Donald P. McCollor; Kurt E. Eylands; Jason D. Laumb

2003-10-01T23:59:59.000Z

116

Artificial oxygen transport protein  

DOE Patents [OSTI]

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

Dutton, P. Leslie

2014-09-30T23:59:59.000Z

117

Oxygen Transport Ceramic Membranes  

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

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

2005-11-01T23:59:59.000Z

118

Lanthanum-promoted copper-based oxygen carriers for chemical looping combustion process  

Science Journals Connector (OSTI)

Copper-based oxygen carriers have high reactivity and favorable thermodynamic properties in the innovative chemical looping combustion (CLC), which results in the inherent...2. The major challenge of copper-based...

Yan Cao; Hou-Yin Zhao; Song P. Sit…

2014-06-01T23:59:59.000Z

119

Reactive Power Compensator.  

DOE Patents [OSTI]

A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation. 26 figs.

El-Sharkawi, M.A.; Venkata, S.S.; Chen, M.; Andexler, G.; Huang, T.

1992-07-28T23:59:59.000Z

120

Reactive power compensator  

DOE Patents [OSTI]

A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Woodinville, WA); Chen, Mingliang (Kirkland, WA); Andexler, George (Everett, WA); Huang, Tony (Seattle, WA)

1992-01-01T23:59:59.000Z

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

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

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

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

122

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

SciTech Connect (OSTI)

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

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

2012-07-01T23:59:59.000Z

123

Interactions of oxygen and ethylenewith submonolayer Ag filmssupported on Ni(111)  

SciTech Connect (OSTI)

We investigate the oxidation of, and the reaction of ethylene with, Ni(111) with and without sub-monolayer Ag adlayers as a function of temperature. The addition of Ag to Ni(111) is shown to enhance the activity towards the ethylene epoxidation reaction, and increase the temperature at which ethylene oxide is stable on the surface. We present a systematic study of the formation of chemisorbed oxygen on the Ag Ni(111) surfaces and correlate the presence and absence of O1 and O2 surface species with the reactivity towards ethylene. By characterizing the samples with low-energy electron microscopy (LEEM) in combination with X-ray photoelectron spectroscopy (XPS), we have identified specific growth of silver on step-edge sites and successfully increased the temperature at which the produced ethylene oxide remains stable, a trait which is desirable for catalysis.

Rettew, Robert [Georgia Institute of Technology; Meyer, Axel [ORNL; Senanayake, Sanjaya D [ORNL; Chen, Tsung-Liang [ORNL; Petersburg, Cole [Georgia Institute of Technology; Flege, J. Ingo [University of Bremen, Bremen, Germany; Falta, Jens [University of Bremen, Bremen, Germany; Alamgir, Faisal [ORNL

2011-01-01T23:59:59.000Z

124

Interactions of Oxygen and Ethylene with Submonolayer Ag Films Supported on Ni(111)  

SciTech Connect (OSTI)

We investigate the oxidation of, and the reaction of ethylene with, Ni(111) with and without sub-monolayer Ag adlayers as a function of temperature. The addition of Ag to Ni(111) is shown to enhance the activity towards the ethylene epoxidation reaction, and increase the temperature at which ethylene oxide is stable on the surface. We present a systematic study of the formation of chemisorbed oxygen on the Ag-Ni(111) surfaces and correlate the presence and absence of O{sup 1-} and O{sup 2-} surface species with the reactivity towards ethylene. By characterizing the samples with low-energy electron microscopy (LEEM) in combination with X-ray photoelectron spectroscopy (XPS), we have identified specific growth of silver on step-edge sites and successfully increased the temperature at which the produced ethylene oxide remains stable, a trait which is desirable for catalysis.

Alamgir, F.M.; Senanayake, S.; Rettew, R.E.; Meyer, A.; Chen, T.-L.; Petersburg, C.; Flege, J.I.; Falta, J.

2011-06-01T23:59:59.000Z

125

Interactions of Oxygen and Ethylene with Submonolayer Ag Films Supported on Ni(111)  

SciTech Connect (OSTI)

We investigate the oxidation of, and the reaction of ethylene with, Ni(111) with and without sub-monolayer Ag adlayers as a function of temperature. The addition of Ag to Ni(111) is shown to enhance the activity towards the ethylene epoxidation reaction, and increase the temperature at which ethylene oxide is stable on the surface. We present a systematic study of the formation of chemisorbed oxygen on the Ag-Ni(111) surfaces and correlate the presence and absence of O{sup 1-} and O{sup 2-} surface species with the reactivity towards ethylene. By characterizing the samples with low-energy electron microscopy (LEEM) in combination with X-ray photoelectron spectroscopy (XPS), we have identified specific growth of silver on step-edge sites and successfully increased the temperature at which the produced ethylene oxide remains stable, a trait which is desirable for catalysis.

R Rettew; A Meyer; S Senanayake; T Chen; C Petersburg; J Flege; J Falta; F Alamgir

2011-12-31T23:59:59.000Z

126

Oxyferryl Heme Reactivity  

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

Oxyferryl Heme Reactivity Using both Radiation and Photochemical Oxyferryl Heme Reactivity Using both Radiation and Photochemical Techniques A. M. English, T. Fox, G. Tsaprailis, C. W. Fenwick, J. F. Wishart, J. T. Hazzard, and G. Tollin Adv. Chem. Ser. 254, Ch. 6, pp. 81-98 Abstract: Flash photolysis and pulse radiolysis were used to generate reductants in situ to study the electron-transfer (ET) reactivity of the FeIV=O heme centers in myoglobin and cytochrome c peroxidase. Reduction of a5RuIII groups covalently bound to surface histidines allowed intramolecular RuII --> FeIV=O ET rates to be measured. Protonation of the oxene ligand was found to be largely rate determining in myoglobin, consistent with the lack of proton donors in its heme pocket. The large distance (21-23 Ã…) between surface histidines and the heme in wild-type

127

Reactivity of Acid Generators  

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

Reactivity of Acid Generators for Chemically Amplified Resists with Reactivity of Acid Generators for Chemically Amplified Resists with Low-Energy Electrons Atsuro Nakano, Takahiro Kozawa, Seiichi Tagawa, Tomasz Szreder, James F. Wishart, Toshiyuki Kai and Tsutomu Shimokawa Jpn. J. Appl. Phys., 45, L197-L200 (2006). [Find paper at the Japanese Journal of Applied Physics] Abstract: In chemically amplified resists for ionizing radiations such as electron beams and extreme ultraviolet (EUV), low-energy electrons play an important role in the pattern formation processes. The reactivity of acid generators with low-energy electrons was evaluated using solvated electrons in tetrahydrofuran, which were generated by a pulsed electron beam. The rate constants of acid generators with the solvated electrons ranged from 0.6 to 1.9 x 1011 M-1s-1

128

Oxygen enriched fireflooding  

SciTech Connect (OSTI)

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

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

1995-02-01T23:59:59.000Z

129

Reactive Power Compensating System.  

DOE Patents [OSTI]

The circuit was designed for the specific application of wind-driven induction generators. It has great potential for application in any situation where a varying reactive power load is present, such as with induction motors or generators, or for transmission network compensation.

Williams, Timothy J.; El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.

1985-01-04T23:59:59.000Z

130

Reactive power compensating system  

DOE Patents [OSTI]

The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched capacitors on each line to provide the balance of the compensation required.

Williams, Timothy J. (Redondo Beach, CA); El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Seattle, WA)

1987-01-01T23:59:59.000Z

131

Reactive Air Aluminization  

SciTech Connect (OSTI)

Ferritic stainless steels and other alloys are of great interest to SOFC developers for applications such as interconnects, cell frames, and balance of plant components. While these alloys offer significant advantages (e.g., low material and manufacturing cost, high thermal conductivity, and high temperature oxidation resistance), there are challenges which can hinder their utilization in SOFC systems; these challenges include Cr volatility and reactivity with glass seals. To overcome these challenges, protective coatings and surface treatments for the alloys are under development. In particular, aluminization of alloy surfaces offers the potential for mitigating both evaporation of Cr from the alloy surface and reaction of alloy constituents with glass seals. Commercial aluminization processes are available to SOFC developers, but they tend to be costly due to their use of exotic raw materials and/or processing conditions. As an alternative, PNNL has developed Reactive Air Aluminization (RAA), which offers a low-cost, simpler alternative to conventional aluminization methods.

Choi, Jung-Pyung; Chou, Y. S.; Stevenson, Jeffry W.

2011-10-28T23:59:59.000Z

132

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

133

Reduction Kinetics of Cu-, Ni-, and Fe-Based Oxygen Carriers Using Syngas (CO + H2) for Chemical-Looping Combustion  

Science Journals Connector (OSTI)

Reduction Kinetics of Cu-, Ni-, and Fe-Based Oxygen Carriers Using Syngas (CO + H2) for Chemical-Looping Combustion ... The reactivity of three Cu-, Fe-, and Ni-based oxygen carriers to be used in a chemical-looping combustion (CLC) system using syngas as fuel has been analyzed. ... In general, the three oxygen carriers were very reactive and suitable to be used for syngas combustion in a CLC system. ...

Alberto Abad; Francisco García-Labiano; Luis F. de Diego; Pilar Gayán; Juan Adánez

2007-05-17T23:59:59.000Z

134

Reactive Maintenance | Department of Energy  

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

Reactive Maintenance Reactive Maintenance Reactive Maintenance October 7, 2013 - 9:40am Addthis Reactive maintenance follows a run-it-until-it-breaks strategy where no actions or efforts are taken to maintain equipment as intended by the manufacturer. Studies indicate this is still the predominant mode of maintenance for Federal facilities. Advantages Reactive maintenance advantages are a double-edged sword. Federal agencies following a purely reactive maintenance strategy can expect little expenditures for manpower or system upkeep until something breaks. However, systems do break. With new equipment, Federal agencies can expect minimal incidents of failure. However, older equipment often experiences higher failure incidents and costlier repairs. Other advantages of reactive maintenance are:

135

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

E-Print Network [OSTI]

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

Pfeifer, Holger

136

Sensitive Species  

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

137

Growth Rates, Stable Oxygen Isotopes (18O), and Strontium (Sr/Ca) Composition in Two Species of Pacific Sclerosponges (Acanthocheatetes wellsi and Astrosclera willeyana) with 18O Calibration and Application to Paleoceanography  

SciTech Connect (OSTI)

The isotopic and elemental composition of sclerosponge skeletons is used to reconstruct paleoceanographic records. Yet few studies have systematically examined the natural variability in sclerosponge skeletal {delta}{sup 18}O, growth, and Sr/Ca, and how that may influence the interpretation of sclerosponge proxy records. Here, we analyzed short records in seven specimens of Acanthocheatetes wellsi (high-Mg calcite, 21 mol% Mg) from Palau, four A. wellsi (high-Mg calcite, 21 mol% Mg) from Saipan, and three Astrosclera willeyana (aragonite) sclerosponges from Saipan, as well as one long record in an A. wellsi specimen from Palau spanning 1945-2001.5. In Saipan, species-specific and mineralogical effects appear to have a negligible effect on sclerosponge {delta}{sup 18}O, facilitating the direct comparison of {delta}{sup 18}O records between species at a given location. At both sites, A. wellsi {delta}{sup 18}O and growth rates were sensitive to environmental conditions, but Sr/Ca was not sensitive to the same conditions. High-resolution {delta}{sup 18}O analyses confirmed this finding as both A. wellsi and A. willeyana deposited their skeleton in accordance with the trends in isotopic equilibrium with seawater, though with a 0.27{per_thousand} offset in the case of A. willeyana. In the high-Mg-calcite species A. wellsi, Mg may be interfering with Sr incorporation into the skeleton. On multidecadal timescales, A. wellsi sclerosponge {delta}{sup 18}O in Palau tracked the Southern Oscillation Index variability post-1977, but not pre-1977, coincident with the switch in the Pacific Decadal Oscillation (PDO) at {approx}1976. This suggests that water mass circulation in the region is influenced by El Nino-Southern Oscillation variability during positive PDO phases, but not during negative ones.

Grottoli, A.; Adkins, J; Panero, W; Reaman, D; Moots, K

2010-01-01T23:59:59.000Z

138

The structure and reactivity of adsorbates on stepped Rh and Pt surfaces investigated by LEED, HREELS, TPD, XPS and STM  

SciTech Connect (OSTI)

Defects on surfaces such as steps play an important role in surface chemistry. In order to obtain an understanding of the influence of steps in surface chemical reactions, the structure and reactivity of small molecules (O{sub 2}, CO, H{sub 2}S, and C{sub 2}H{sub 4}) on atomically stepped surfaces of RH and Pt have been investigated. The detailed structures of CO and oxygen bonded to the Rh(110) surface were determined. The CO molecules bond near the short bridge sites with the CO molecular axis tilted approximately 24{degree} from the surface normal. Oxygen atoms are bound asymmetrically in the 3-fold fcc hollow-sites to the (111) facets of the steps. The interactions of CO and oxygen on the Rh(311) surface were examined. The reaction of CO with the ordered phases of O shows two distinct reaction channels, a low temperature reaction limited channel (200 K) and a high temperature diffusion limited channel (350 K). Models of the reaction geometry and dynamics are proposed. The thermal decomposition of ethylene was examined on the Rh(311) surface. The stable decomposition species (C{sub 2}H, CH and C{sub 2}) are formed near 300 K, approximately 100 K lower on the stepped Rh(311) than on the flatter Rh(111) surface. The formation of these species at lower temperatures is attributed to the stepped nature of the surface. Finally, in situ STM was used to examine surface structural changes of a stepped Pt(111) crystal under coadsorption of sulfur and CO. This is the first direct evidence for a new mechanism by which a surface covered with an unreactive, strongly chemisorbed overlayer can form new sites, for bonding and reactions to occur, by massive surface restructuring at the step edges. This new surface phenomenon answers some of the puzzles of metal surface catalysis and its implications are described. 278 refs.

Batteas, J.D. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States). Materials Science Div.

1995-06-01T23:59:59.000Z

139

Surface Science 425 (1999) 114 Non-adiabatic charge transfer process of oxygen on  

E-Print Network [OSTI]

Surface Science 425 (1999) 1­14 Non-adiabatic charge transfer process of oxygen on metal surfaces November 1998 Abstract The dynamics of charge transfer processes of oxygen on metal surfaces a different charged oxygen species. Empirical universal potential energy functions have been constructed

Zeiri, Yehuda

140

Plants making oxygen  

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

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

Algae for Oxygen  

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

142

Photochemical Escape of Oxygen from Early Mars  

E-Print Network [OSTI]

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

Zhao, Jinjin

2015-01-01T23:59:59.000Z

143

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

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

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-07-01T23:59:59.000Z

144

Sensitive Species  

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

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. The Sensitive Species Best...

145

Atmospheric reactivity of gaseous dimethyl sulfate  

SciTech Connect (OSTI)

The atmospheric reactivity of dimethyl sulfate (DMS) with a series of atmospheric species has been investigated. Upper limits to the rate constants for the homogeneous gas-phase reactions of DMS with O{sub 3}, NH{sub 3}, and H{sub 2}O have been determined by using FTIR spectroscopy and are <1.4 {times} 10{sup {minus}21}, <1.5 {times} 10{sup {minus}21}, and <1.1 {times} 10{sup {minus}23} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}, respectively. The reactivity of DMS toward ON radicals and Cl atoms has been determined by using relative rate techniques, and the rate constants for those reactions are <5 {times} 10{sup {minus}13} and (4.2 {plus minus} 0.5) {times} 10{sup {minus}13} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}, respectively. These rate constants correspond to atmospheric lifetimes ranging from >23 days with respect to reaction with OH radicals to >33 years with respect to reaction with ozone. With the possible exception of its reaction with water, for which the calculated lifetime of DMS is >2 days, these results indicate that the atmospheric fate of DMS is not determined by its homogeneous gas-phase reactions with any of the atmosphere species studied.

Japar, S.M.; Wallington, T.J.; Andino, J.M.; Ball, J.C. (Ford Motor Co., Dearborn, MI (USA))

1990-03-01T23:59:59.000Z

146

Towards forming-free resistive switching in oxygen engineered HfO{sub 2?x}  

SciTech Connect (OSTI)

We have investigated the resistive switching behavior in stoichiometric HfO{sub 2} and oxygen-deficient HfO{sub 2?x} thin films grown on TiN electrodes using reactive molecular beam epitaxy. Oxygen defect states were controlled by the flow of oxygen radicals during thin film growth. Hard X-ray photoelectron spectroscopy confirmed the presence of sub-stoichiometric hafnium oxide and defect states near the Fermi level. The oxygen deficient HfO{sub 2?x} thin films show bipolar switching with an electroforming occurring at low voltages and low operating currents, paving the way for almost forming-free devices for low-power applications.

Sharath, S. U., E-mail: sharath@oxide.tu-darmstadt.de; Kurian, J.; Hildebrandt, E.; Alff, L. [Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Strasse 2, 64287 Darmstadt (Germany); Bertaud, T.; Walczyk, C.; Calka, P.; Zaumseil, P.; Sowinska, M.; Walczyk, D. [IHP, Im Technologiepark 25, 15236 Frankfurt Oder (Germany); Gloskovskii, A. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Schroeder, T. [IHP, Im Technologiepark 25, 15236 Frankfurt Oder (Germany); Brandenburgische Technische Universität, Konrad-Zuse-Strasse 1, 03046 Cottbus (Germany)

2014-02-10T23:59:59.000Z

147

Federal Energy Management Program: Reactive Maintenance  

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

Reactive Reactive Maintenance to someone by E-mail Share Federal Energy Management Program: Reactive Maintenance on Facebook Tweet about Federal Energy Management Program: Reactive Maintenance on Twitter Bookmark Federal Energy Management Program: Reactive Maintenance on Google Bookmark Federal Energy Management Program: Reactive Maintenance on Delicious Rank Federal Energy Management Program: Reactive Maintenance on Digg Find More places to share Federal Energy Management Program: Reactive Maintenance on AddThis.com... Sustainable Buildings & Campuses Operations & Maintenance Federal Requirements Program Management Commissioning Metering Computerized Maintenance Management Systems Maintenance Types Reactive Preventive Predictive Reliability-Centered Major Equipment Types

148

Multicycle study on chemical-looping combustion of simulated coal gas with a CaSO{sub 4} oxygen carrier in a fluidized bed reactor  

SciTech Connect (OSTI)

The cyclic test of a CaSO{sub 4}-based oxygen carrier (natural anhydrite) in alternating reducing simulated coal gas and oxidizing conditions was performed at 950{degree}C in a fluidized bed reactor at atmospheric pressure. A high concentration of CO{sub 2} was obtained in the reduction. The H{sub 2} and CO conversions and CO{sub 2} yield increased initially and final decreased significantly. The release of SO{sub 2} and H{sub 2}S during the cyclic test was found to be responsible for the decrease of reactivity of a CaSO{sub 4} oxygen carrier. The oxygen carrier conversion after the reduction reaction decreased gradually in the cyclic test. Through the comparison of mass-based reaction rates as a function of mass conversion at typical cycles, it was also evident that the reactivity of a CaSO{sub 4} oxygen carrier increased for the initial cycles but finally decreased after around 15 cycles. X-ray diffraction analysis revealed that the presence and intensity of the reduction sulfur species was in accordance with the results of gas conversion. The content of CaO was higher than expected, suggesting the formation of SO{sub 2} and H{sub 2}S during the cycles. Surface morphology analysis demonstrates that the natural anhydrite particle surface varied from impervious to porous after the cyclic test. It was also observed that the small grains on the surface of the oxygen carrier sintered in the cyclic tests. Energy-dispersive spectrum analysis also demonstrated the decrease of oxygen intensity after reduction, and CaO became the main component after the 20th oxidation. Pore structure analysis suggested that the particles agglomerated or sintered in the cyclic tests. The possible method for sulfur mitigation is proposed. Finally, some basic consideration on the design criteria of a CLC system for solid fuels using a CaSO{sub 4} oxygen carrier is discussed by the references and provides direction for future work. 49 refs., 10 figs., 5 tabs.

Qilei Song; Rui Xiao; Zhongyi Deng; Wenguang Zheng; Laihong Shen; Jun Xiao [Southeast University, Nanjing (China). Thermoenergy Engineering Research Institute

2008-11-15T23:59:59.000Z

149

Solar energy: Hydrogen and oxygen  

Science Journals Connector (OSTI)

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

John J. Farrell

1982-01-01T23:59:59.000Z

150

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

151

Metal-based reactive nanomaterials  

Science Journals Connector (OSTI)

Recent developments in materials processing and characterization resulted in the discovery of a new type of reactive materials containing nanoscaled metal components. The well-known high oxidation energies of metallic fuels can now be released very rapidly because of the very high reactive interface areas in such metal-based reactive nanomaterials. Consequently, these materials are currently being examined for an entire range of applications in energetic formulations inappropriate for conventional, micron-sized metal fuels having relatively low reaction rates. New application areas, such as reactive structural materials, are also being explored. Research remains active in manufacturing and characterization of metal-based reactive nanomaterials including elemental metal nanopowders and various nanocomposite material systems. Because of the nanometer scale of the individual particles, or phase domains, and because of the very high enthalpy of reaction between components of the nanocomposite materials, the final phase compositions, morphology, and thermodynamic properties of the reactive nanocomposite materials may be different from those of their micron-scaled counterparts. Ignition mechanisms in such materials can be governed by heterogeneous reactions that are insignificant for materials with less developed reactive interface areas. New combustion regimes are being observed that are affected by very short ignition delays combined with very high metal combustion temperatures. Current progress in this rapidly growing research area is reviewed and some potential directions for the future research are discussed.

Edward L. Dreizin

2009-01-01T23:59:59.000Z

152

Free Radical Scavenging and Antioxidant Activity of Plant Flavonoids  

Science Journals Connector (OSTI)

The occurrence of reactive oxygen species (ROS), termed as prooxidants, is a characteristic of normal aerobic organisms. The term “reactive oxygen species” collectively denotes oxygen-centered radicals such as...

Chithan Kandaswami; Elliott Middleton Jr.

1994-01-01T23:59:59.000Z

153

Oxygen in Underwater Cave  

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

154

Chemically Reactive Working Fluids | Department of Energy  

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

Chemically Reactive Working Fluids for the Capture and Transport of Concentrated Solar Thermal Energy for Power Generation Chemically Reactive Working Fluids SunShot CSP...

155

Conservation of reactive electromagnetic energy in reactive time  

E-Print Network [OSTI]

The complex Poynting theorem (CPT) is extended to a canonical time-scale domain $(t,s)$. Time-harmonic phasors are replaced by the positive-frequency parts of general fields, which extend analytically to complex time $t+is$, with $s>0$ interpreted as a time resolution scale. The real part of the extended CPT gives conservation in $t$ of a time-averaged field energy, and its imaginary part gives conservation in $s$ of a time-averaged reactive energy. In both cases, the averaging windows are determined by a Cauchy kernel of width $\\Delta t\\sim \\pm s$. This completes the time-harmonic CPT, whose imaginary part is generally supposed to be vaguely `related to' reactive energy without giving a conservation law, or even an expression, for the latter. The interpretation of $s$ as reactive time, tracking the leads and lags associated with stored capacitative and inductive energy, gives a simple explanation of the volt-ampere reactive (var) unit measuring reactive power: a var is simply one Joule per reactive second. T...

Kaiser, Gerald

2015-01-01T23:59:59.000Z

156

Internal structure, hygroscopic and reactive properties of mixed sodium  

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

Internal structure, hygroscopic and Internal structure, hygroscopic and reactive properties of mixed sodium methanesulfonate-sodium chloride particles Internal structure, hygroscopic and reactive properties of mixed sodium methanesulfonate-sodium chloride particles Print Friday, 13 May 2011 00:00 Scientists recently combined experimental approaches and molecular dynamics modeling to gain new insights into the internal structure of sea salt particles and relate it to their fundamental chemical reactivity in the atmosphere. This research shows that surface enhancement or depletion of chemical components in marine particles can occur because of the difference in the chemical nature of the species. Because the atmospheric chemistry of the salt particles takes place at the gas-particle interface, understanding their complex surfaces provides new insights about their effect on the environment and climate change. Article Link.

157

Ionic Liquids and Ionizing Radiation: Reactivity of Highly Energetic  

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

Ionizing Radiation: Reactivity of Highly Energetic Ionizing Radiation: Reactivity of Highly Energetic Species James F. Wishart J. Phys. Chem. Lett. 1, 3225-3231 (2010). [Find paper at ACS Publications] or use ACS Articles on Request View the video on this Perspective article at The Journal of Physical Chemistry Letters (5:03) Selected for the ACS Special Virtual Issue on Ionic Liquids (March 2011). Abstract: Due to their unique properties, ionic liquids present many opportunities for basic research on the interactions of radiation with materials under conditions not previously available. At the same time, there are practical applied reasons for characterizing, understanding, and being able to predict how ionic-liquid-based devices and industrial-scale systems will perform under conditions of extreme reactivity, including radiation. This

158

Impact of exhaust gas recirculation (EGR) on the oxidative reactivity of diesel engine soot  

SciTech Connect (OSTI)

This paper expands the consideration of the factors affecting the nanostructure and oxidative reactivity of diesel soot to include the impact of exhaust gas recirculation (EGR). Past work showed that soot derived from oxygenated fuels such as biodiesel carries some surface oxygen functionality and thereby possesses higher reactivity than soot from conventional diesel fuel. In this work, results show that EGR exerts a strong influence on the physical properties of the soot which leads to enhanced oxidation rate. HRTEM images showed a dramatic difference between the burning modes of the soot generated under 0 and 20% EGR. The soot produced under 0% EGR strictly followed an external burning mode with no evidence of internal burning. In contrast, soot generated under 20% EGR exhibited dual burning modes: slow external burning and rapid internal burning. The results demonstrate clearly that highly reactive soot can be achieved by manipulating the physical properties of the soot via EGR. (author)

Al-Qurashi, Khalid; Boehman, Andre L. [The EMS Energy Institute, The Pennsylvania State University, 405 Academic Activities Bldg., University Park, PA 16802 (United States)

2008-12-15T23:59:59.000Z

159

Fuel Temperature Coefficient of Reactivity  

SciTech Connect (OSTI)

A method for measuring the fuel temperature coefficient of reactivity in a heterogeneous nuclear reactor is presented. The method, which is used during normal operation, requires that calibrated control rods be oscillated in a special way at a high reactor power level. The value of the fuel temperature coefficient of reactivity is found from the measured flux responses to these oscillations. Application of the method in a Savannah River reactor charged with natural uranium is discussed.

Loewe, W.E.

2001-07-31T23:59:59.000Z

160

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (OSTI)

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

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


161

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

162

Variations in Reactivity on Different Crystallographic Orientations of Cerium Oxide  

SciTech Connect (OSTI)

Cerium oxide is a principal component in many heterogeneous catalytic processes. One of its key characteristics is the ability to provide or remove oxygen in chemical reactions. The different crystallographic faces of ceria present significantly different surface structures and compositions that may alter the catalytic reactivity. The structure and composition determine the number of coordination vacancies surrounding surface atoms, the availability of adsorption sites, the spacing between adsorption sites and the ability to remove O from the surface. To investigate the role of surface orientation on reactivity, CeO2 films were grown with two different orientations. CeO2(100) films were grown ex situ by pulsed laser deposition on Nb-doped SrTiO3(100). CeO2(111) films were grown in situ by thermal deposition of Ce metal onto Ru(0001) in an oxygen atmosphere. The chemical reactivity was characterized by the adsorption and decomposition of various molecules such as alcohols, aldehydes and organic acids. In general the CeO2(100) surface was found to be more active, i.e. molecules adsorbed more readily and reacted to form new products, especially on a fully oxidized substrate. However the CeO2(100) surface was less selective with a greater propensity to produce CO, CO2 and water as products. The differences in chemical reactivity are discussed in light of possible structural terminations of the two surfaces. Recently nanocubes and nano-octahedra have been synthesized that display CeO2(100) and CeO2(111) faces, respectively. These nanoparticles enable us to correlate reactions on high surface area model catalysts at atmospheric pressure with model single crystal films in a UHV environment.

Mullins, David R [ORNL] [ORNL; Albrecht, Peter M [ORNL] [ORNL; Calaza, Florencia C [ORNL] [ORNL

2013-01-01T23:59:59.000Z

163

Catalytic destruction of groundwater contaminants in reactive extraction wells  

DOE Patents [OSTI]

A system for remediating groundwater contaminated with halogenated solvents, certain metals and other inorganic species based on catalytic reduction reactions within reactive well bores. The groundwater treatment uses dissolved hydrogen as a reducing agent in the presence of a metal catalyst, such a palladium, to reduce halogenated solvents (as well as other substituted organic compounds) to harmless species (e.g., ethane or methane) and immobilize certain metals to low valence states. The reactive wells function by removing water from a contaminated water-bearing zone, treating contaminants with a well bore using catalytic reduction, and then reinjecting the treated effluent into an adjacent water-bearing zone. This system offers the advantages of a compact design with a minimal surface footprint (surface facilities) and the destruction of a broad suite of contaminants without generating secondary waste streams.

McNab, Jr., Walt W. (Concord, CA); Reinhard, Martin (Stanford, CA)

2002-01-01T23:59:59.000Z

164

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

165

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

166

Oxygen Transport Ceramic Membranes  

SciTech Connect (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

167

Oxygen abundances in the most oxygen-rich spiral galaxies  

E-Print Network [OSTI]

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

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

2006-01-06T23:59:59.000Z

168

Oxygen Concentration Microgradients for Cell Culture  

E-Print Network [OSTI]

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

Park, Jaehyun

2010-01-01T23:59:59.000Z

169

Oxygen Transport Membranes  

SciTech Connect (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 < 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

170

Oxygen Transport Ceramic Membranes  

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

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

2005-02-01T23:59:59.000Z

171

Joint Energy and Reactive Power Market Considering Coupled Active and Reactive Reserve Market Ensuring System Security  

Science Journals Connector (OSTI)

Reactive power market is usually held as independent from energy and reserved active power markets; however, active and reactive power are ... synchronous generator capacity curve. Therefore, reactive power market

Hamed Ahmadi; Asghar Akbari Foroud

2014-06-01T23:59:59.000Z

172

Syngas Production from Coal through Microwave Plasma Gasification: Influence of Oxygen, Steam, and Coal Particle Size  

Science Journals Connector (OSTI)

Syngas Production from Coal through Microwave Plasma Gasification: Influence of Oxygen, Steam, and Coal Particle Size ... Plasma gasification is widely applied because of its clean syngas production performance and high chemical reactivity accelerated by the free radicals produced by plasma. ... The syngas composition produced from plasma gasification at same conditions is affected by the physicochemical properties of coals. ...

Sang Jun Yoon; Jae Goo Lee

2011-11-23T23:59:59.000Z

173

Controlled oxygen vacancy induced p-type conductivity in HfO{sub 2-x} thin films  

SciTech Connect (OSTI)

We have synthesized highly oxygen deficient HfO{sub 2-x} thin films by controlled oxygen engineering using reactive molecular beam epitaxy. Above a threshold value of oxygen vacancies, p-type conductivity sets in with up to 6 times 10{sup 21} charge carriers per cm{sup 3}. At the same time, the band-gap is reduced continuously by more than 1 eV. We suggest an oxygen vacancy induced p-type defect band as origin of the observed behavior.

Hildebrandt, Erwin; Kurian, Jose; Mueller, Mathis M.; Kleebe, Hans-Joachim; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany); Schroeder, Thomas [IHP, 15236 Frankfurt/Oder (Germany)

2011-09-12T23:59:59.000Z

174

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

Science Journals Connector (OSTI)

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

Martin Keller; Mehdi Arjmand; Henrik Leion; Tobias Mattisson

2014-01-01T23:59:59.000Z

175

Oxygen Transport Ceramic Membranes  

SciTech Connect (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

176

Triclosan Reactivity in Chloraminated Waters  

Science Journals Connector (OSTI)

Triclosan Reactivity in Chloraminated Waters ... Triclosan, widely employed as an antimicrobial additive in many household personal care products, has recently been detected in wastewater treatment plant effluents and in source waters used for drinking water supplies. ... Chloramines used either as alternative disinfectants in drinking water treatment or formed during chlorination of nonnitrified wastewater effluents have the potential to react with triclosan. ...

Aimee E. Greyshock; Peter J. Vikesland

2006-03-16T23:59:59.000Z

177

Stabilization of Platinum Nanoparticle Electrocatalysts for Oxygen...  

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

Platinum Nanoparticle Electrocatalysts for Oxygen Reduction Using Poly(diallyldimethylammonium chloride). Stabilization of Platinum Nanoparticle Electrocatalysts for Oxygen...

178

Composite oxygen transport membrane  

DOE Patents [OSTI]

A method of producing a composite oxygen ion membrane and a composite oxygen ion membrane in which a porous fuel oxidation layer and a dense separation layer and optionally, a porous surface exchange layer are formed on a porous support from mixtures of (Ln.sub.1-xA.sub.x).sub.wCr.sub.1-yB.sub.yO.sub.3-.delta. and a doped zirconia. In the porous fuel oxidation layer and the optional porous surface exchange layer, A is Calcium and in the dense separation layer A is not Calcium and, preferably is Strontium. Preferred materials are (La.sub.0.8Ca.sub.0.2).sub.0.95Cr.sub.0.5Mn.sub.0.5O.sub.3-.delta. for the porous fuel oxidation and optional porous surface exchange layers and (La.sub.0.8Sr.sub.0.2).sub.0.95Cr.sub.0.5Fe.sub.0.5O.sub.3-.delta. for the dense separation layer. The use of such materials allows the membrane to sintered in air and without the use of pore formers to reduce membrane manufacturing costs. The use of materials, as described herein, for forming the porous layers have application for forming any type of porous structure, such as a catalyst support.

Christie, Gervase Maxwell; Lane, Jonathan A.

2014-08-05T23:59:59.000Z

179

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

SciTech Connect (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

180

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

SciTech Connect (OSTI)

We used 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, non-hollow 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 toward the oxygen reduction reaction of platinum nanowires was assessed by studying the change in the chemisorption energies of oxygen, hydroxyl, and hydroperoxyl groups, induced by converting the nanotube models to nanowires. Both ultrathin platinum nanotubes and nanowires show distinct properties compared to bulk platinum. Single-wall nanotubes and platinum nanowires with diameters larger than 1 nm show promise for use as oxygen reduction catalysts.

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

2013-03-14T23:59:59.000Z

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to obtain the most current and comprehensive results.


181

Definition: Reactive Power | Open Energy Information  

Open Energy Info (EERE)

Reactive Power Reactive Power Jump to: navigation, search Dictionary.png Reactive Power The portion of electricity that establishes and sustains the electric and magnetic fields of alternating-current equipment. Reactive power must be supplied to most types of magnetic equipment, such as motors and transformers. It also must supply the reactive losses on transmission facilities. Reactive power is provided by generators, synchronous condensers, or electrostatic equipment such as capacitors and directly influences electric system voltage. It is usually expressed in kilovars (kvar) or megavars (Mvar).[1] View on Wikipedia Wikipedia Definition In electric power transmission and distribution, volt-ampere reactive (var) is a unit used to measure reactive power in an AC electric

182

Reactive Power Support Services in Electricity Markets  

E-Print Network [OSTI]

Reactive Power Support Services in Electricity Markets Costing and Pricing of Ancillary Services Final Project Report Power Systems Engineering Research Center A National Science Foundation Industry Reactive Power Support Services in Electricity Markets Costing and Pricing of Ancillary Services Project

183

Oxygen Transport Ceramic Membranes  

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

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

2004-05-01T23:59:59.000Z

184

Oxygen to the core  

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

185

Pool octanes via oxygenates  

SciTech Connect (OSTI)

Increasingly stringent antipollution regulations placed on automobile exhaust gases with consequent reduction or complete lead ban from motor gasoline result in octane shortage at many manufacturing sites. Attractive solutions to this problem, especially in conjunction with abundant methanol supplies, are the hydration and etherification of olefins contained in light product streams from cracking unit or produced by field gas dehydrogenation. A comparison is made between oxygenates octane-volume pool contributions and established refinery technologies. Process reviews for bulk manufacture of fuel-grade isopropanol (IPA), secondary butanol (SBA), tertiary butanol (TBA), methyl tertiary butyl ether (MTBE) and tertiary amyl methyl ether (TAME) are presented together with the characteristic investment and operating data. The implantation of these processes into a typical FCCU refinery complex with the resulting octane-pool improvement possibilities is descried.

Prezelj, M.

1987-09-01T23:59:59.000Z

186

Laser spectroscopy and dynamics of transient species  

SciTech Connect (OSTI)

The goal of this program is to study the vibrational and electronic spectra and excited state dynamics of a number of transient sulfur and oxygen species. A variety of supersonic jet techniques, as well as high resolution FT-IR and intracavity dye laser spectroscopy, have been applied to these studies.

Clouthier, D.J. [Univ. of Kentucky, Lexington (United States)

1993-12-01T23:59:59.000Z

187

Reactive Ion Benjamin A. Small  

E-Print Network [OSTI]

(torr) plasma etching reactive ion etching ion milling m cm 100µm µm #12;5 Mechanics ~40 mTorrE380 kHz, 13.56 MHz ~30 sccm #12;6 Chemistry X X X X F- F- F-F- X F-F- F- F- F- R++ R++ R++ #12;7 Chemistry before opening · Silanes are explosive in the atmosphere #12;13 Bibliography Campbell, Stephen A

Garmestani, Hamid

188

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

Science Journals Connector (OSTI)

In this work we have applied optical emission spectroscopy diagnostics to investigate the characteristics of a non-thermal atmospheric pressure helium plasma jet. The discharge characteristics in the active and afterglow region of the plasma jet that are critical for biomedical applications have been investigated. The voltage-current characteristics of the plasma discharge were analyzed and the average plasma power was measured to be around 18?W. The effect of addition of small fractions of oxygen at 0.1%–0.5% on the plasma jet characteristics was studied. The addition of oxygen resulted in a decrease in plasma plume length due to the electronegativity property of oxygen. Atomic and molecular lines of selected reactive plasma species that are considered to be useful to induce biochemical reactions such as OH transitions A 2 ? + ( ? = 0 1 ) ? X 2 ? ( ? ? = 0 ) at 308?nm and A 2 ? + ( ? = 0 1 ) ? X 2 ? ( ? ? = 1 ) at 287?nm O I transitions 3p5P?3s5S0 at 777.41?nm and 3p3P?3s3S0 at 844.6?nm N2(C-B) second positive system with electronic transition C 3 ? u ? ? B 3 ? g ? in the range of 300–450?nm and N2 +(B-X) first negative system with electronic transition B 2 ? u + ? X 2 ? g + ( ? ? = 0 ) at 391.4?nm have been studied. The atomic emission lines of helium were identified including the He I transitions 3p3P0?2s3S at 388.8?nm 3p1P0? 2s1S at 501.6?nm 3d3D?2p3P0 at 587.6?nm 3d1D?2p1P0 at 667.8?nm 3s3S1?2p3P0 at 706.5?nm 3s1S0?2p1P0 at 728.1?nm and H? transition 2p-3d at 656.3?nm. Using a spectral fitting method the OH radicals at 306–312?nm the rotational and vibrational temperatures equivalent to gas temperatures of the discharge was measured and the effective non-equilibrium nature of the plasma jet was demonstrated. Our results show that in the entire active plasma region the gas temperature remains at 310?±?25?K and 340?±?25?K and it increases to 320?±?25?K and 360?±?25?K in the afterglow region of the plasma jet for pure helium and helium/oxygen (0.1%) mixture respectively. Additionally the vibrational temperatures range from 2200?±?100?K and 2500?±?100?K for pure helium and helium/oxygen (0.1%) mixture respectively. The plasma jet was tested on heat sensitive polymer films used in biomedical applications such as polyethylene terephthalate and poly-L-lactide samples continuously for several minutes without causing any physical or thermal damage to the films. The plasma jet produces significant reactive species of interest while the gas temperatures remain very low demonstrating its potential for a range of biomedical applications.

2013-01-01T23:59:59.000Z

189

Bimetallic Fe-Ni Oxygen Carriers for Chemical Looping Combustion  

SciTech Connect (OSTI)

The relative abundance, low cost, and low toxicity of iron make Fe-based oxygen carriers of great interest for chemical looping combustion (CLC), an emerging technology for clean and efficient combustion of fossil and renewable fuels. However, Fe also shows much lower reactivity than other metals (such as Ni and Cu). Here, we demonstrate strong improvement of Fe-based carriers by alloying the metal phase with Ni. Through a combination of carrier synthesis and characterization with thermogravimetric and fixed-bed reactor studies, we demonstrate that the addition of Ni results in a significant enhancement in activity as well as an increase in selectivity for total oxidation. Furthermore, comparing alumina and ceria as support materials highlights the fact that reducible supports can result in a strong increase in oxygen carrier utilization.

Bhavsar, Saurabh; Veser, Goetz

2013-11-06T23:59:59.000Z

190

Reactive composite compositions and mat barriers  

DOE Patents [OSTI]

A hazardous material storage area has a reactive multi-layer composite mat which lines an opening into which a reactive backfill and hazardous material are placed. A water-inhibiting cap may cover the hazardous material storage area. The reactive multi-layer composite mat has a backing onto which is placed an active layer which will neutralize or stabilize hazardous waste and a fronting layer so that the active layer is between the fronting and backing layers. The reactive backfill has a reactive agent which can stabilize or neutralize hazardous material and inhibit the movement of the hazardous material through the hazardous material storage area.

Langton, Christine A. (Aiken, SC); Narasimhan, Rajendran (Evans, GA); Karraker, David G. (Aiken, SC)

2001-01-01T23:59:59.000Z

191

Abscisic Acid Activation of Plasma Membrane Ca2+ Channels in Guard Cells Requires Cytosolic NAD(P)H and Is Differentially Disrupted Upstream and Downstream of Reactive Oxygen Species Production in abi1-1 and abi2-1 Protein Phosphatase 2C Mutants  

Science Journals Connector (OSTI)

...Orlandi, 1995). DPI, an inhibitor of neutrophil NADPH oxidases...oligogalacturonic acid and chitosan reduce stomatal aperture and...1986). The effect of the inhibitor diphenylene iodonium on the...Oligogalacturonic acid and chitosan reduce stomatal aperture by...

Yoshiyuki Murata; Zhen-Ming Pei; Izumi C. Mori; Julian Schroeder

192

Oxygen Electrocatalysis on Epitaxial La[subscript 0.6]Sr[subscript 0.4]CoO[subscript 3-?] Perovskite Thin Films for Solid Oxide Fuel Cells  

E-Print Network [OSTI]

Hetero-structured interfaces of oxides, which can exhibit reactivity characteristics remarkably different from bulk oxides, are interesting systems to explore in search of highly active fuel cell catalysts for oxygen ...

Crumlin, Ethan J.

193

Permeable Reactive Barriers | Department of Energy  

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

Permeable Reactive Barriers Permeable Reactive Barriers Permeable Reactive Barriers Permeable Reactive Barrier Field Projects Durango, Colorado DOE installed a PRB in October 1995 to treat ground water from a uranium mill tailings disposal site at Durango, Colorado Read more Cañon City, Colorado ESL personnel conduct tests and help evaluate performance at other PRB sites, such as Cotter Corporation's Cañon City site in Colorado. Read more Monticello, Utah Installation of a PRB hydraulically downgradient of the Monticello, Utah, millsite was completed June 30, 1999, as an Interim Remedial Action. Read more A permeable reactive barrier (PRB) is a zone of reactive material placed underground to intercept and react with a contaminant plume in ground water. Typically, PRBs are emplaced by replacing soils with reactive

194

Reactive capability limits of wind farms  

Science Journals Connector (OSTI)

Wind Energy Conversion Systems (WECS) technology can be classified into two main types: fixed speed and variable speed. Fixed speed WECS use an induction generator connected directly to the grid while variable speed WECS use a power converter to connect the generator to the grid. Fixed speed WECS require shunt capacitors for reactive power compensation, while variable speed WECS have reactive power capability. Under the Spanish grid code, wind farms have to operate in a range of power factor values. This paper determines the reactive power capability of wind farms equipped with both fixed and variable speed WECS. The reactive power capability can be represented as a reactive capability curve. In this paper, the reactive capability curve is used to calculate the additional reactive power compensation needed to meet the requirements of the Spanish grid code.

Alberto Rios Villacorta; Santiago Arnaltes Gomez; Jose Luis Rodriguez-Amenedo

2005-01-01T23:59:59.000Z

195

Oxygen Transport Ceramic Membranes  

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

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

2004-10-01T23:59:59.000Z

196

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

197

Plants and Night Oxygen Production  

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

198

Oxygen detection using evanescent fields  

DOE Patents [OSTI]

An apparatus and method for the detection of oxygen using optical fiber based evanescent light absorption. Methylene blue was immobilized using a sol-gel process on a portion of the exterior surface of an optical fiber for which the cladding has been removed, thereby forming an optical oxygen sensor. When light is directed through the optical fiber, transmitted light intensity varies as a result of changes in the absorption of evanescent light by the methylene blue in response to the oxygen concentration to which the sensor is exposed. The sensor was found to have a linear response to oxygen concentration on a semi-logarithmic scale within the oxygen concentration range between 0.6% and 20.9%, a response time and a recovery time of about 3 s, ant to exhibit good reversibility and repeatability. An increase in temperature from 21.degree. C. to 35.degree. C. does not affect the net absorption of the sensor.

Duan, Yixiang (Los Alamos, NM); Cao, Weenqing (Los Alamos, NM)

2007-08-28T23:59:59.000Z

199

Oxygen-ion-beam-driven electrostatic ion cyclotron instability of hydrogen plasma  

SciTech Connect (OSTI)

The electrostatic ion cyclotron instability of hydrogen plasma driven by an oxygen ion beam and resulting turbulent heating of both ion species is investigated. The instability growth rate exceeds the oxygen ion gyrofrequency, so that the oxygen ions may be considered as unmagnetized during the process of waves growth. As a result the instability is developed due to inverse Landau damping of the ion cyclotron waves caused by thermal motion of oxygen ions across the magnetic field. The quasilinear analysis of the turbulent heating of both ion species resulted from their interactions with ion cyclotron turbulence indicates that this instability may be responsible for the observed anisotropic heating of auroral outflowing oxygen O{sup +} ions in the ionosphere.

Chibisov, D. V.; Mikhailenko, V. S.; Stepanov, K. N. [Kharkov National University, 61108 Kharkov (Ukraine)

2009-07-15T23:59:59.000Z

200

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and initial studies on newer composition of Ti doped LSF. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. In addition, studies were also begun to obtain reliable estimates of fracture toughness and stable crack growth in specific environments. Newer composition of Ti doped LSF membranes were characterized by neutron diffraction analysis. Quench studies indicated an apparent correlation between the unit cell volume and oxygen occupancy. The studies however, indicated an anomaly of increasing Fe/Ti ratio with change in heat treatment. Ti doped LSF was also characterized for stoichiometry as a function of temp and pO{sub 2}. The non stoichiometry parameter {delta} was observed to increase almost linearly on lowering pO{sub 2} until a ideal stoichiometric composition of {delta} = 0.175 was approached.

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

2004-02-01T23:59:59.000Z

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

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect (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

202

Low Oxygen Environments in Chesapeake Bay  

E-Print Network [OSTI]

Low Oxygen Environments in Chesapeake Bay Jeremy Testa Chesapeake Biological Laboratory University of Maryland Center for Environmental Science Why we care about low oxygen? What causes low oxygen? Where and When does Chesapeake Bay lose oxygen? #12;#12;Hypoxia and Chesapeake Animals Low dissolved oxygen

Boynton, Walter R.

203

Mycobacterium tuberculosis Ser/Thr protein kinase B mediates an oxygen-dependent replication switch  

SciTech Connect (OSTI)

In the majority of cases, Mycobacterium tuberculosis (Mtb) infections are clinically latent, characterized by little or no bacterial replication and drug tolerance. Low oxygen tension is a major host factor inducing bacteriostasis, but the molecular mechanisms driving oxygen-dependent replication are poorly understood. Mtb encodes eleven serine/threonine protein kinases, a family of signaling molecules known to regulate similar replicative adaptations in other bacteria. Here, we tested the role of serine/threonine phosphorylation in the Mtb response to altered oxygen status, using an in vitro model of latency (hypoxia) and reactivation (reaeration). Broad kinase inhibition compromised survival of Mtb in hypoxia. Activity-based protein profiling and genetic mutation identified PknB as the kinase critical for surviving hypoxia. Mtb replication was highly sensitive to changes in PknB levels in aerated culture, and even more so in hypoxia. A mutant overexpressing PknB specifically in hypoxia showed a 10-fold loss in viability in low oxygen conditions. In contrast, chemically reducing PknB activity during hypoxia specifically compromised resumption of growth during reaeration. These data support a model in which PknB activity is reduced to achieve bacteriostasis, and elevated when replication resumes. Together, these data show that phosphosignaling controls replicative transitions associated with latency and reactivation, that PknB is a major regulator of these transitions, and that PknB could provide a highly vulnerable therapeutic target at every step of the Mtb life cycle - active disease, latency, and reactivation.

Ortega, Corrie; Liao, Reiling; Anderson, Lindsey N.; Rustad, Tige; Ollodart, Anja R.; Wright, Aaron T.; Sherman, David R.; Grundner, Christoph

2014-01-07T23:59:59.000Z

204

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

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

205

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/ Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Existing facilities were modified for evaluation of environmental assisted slow crack growth and creep in flexural mode. Processing of perovskites of LSC, LSF and LSCF composition were continued for evaluation of mechanical properties as a function of environment. These studies in parallel to those on the LSFCO composition is expect to yield important information on questions such as the role of cation segregation and the stability of the perovskite structure on crack initiation vs. crack growth. Studies have been continued on the La{sub 1-x}Sr{sub x}FeO{sub 3-d} composition using neutron diffraction and TGA studies. A transition from p-type to n-type of conductor was observed at relative low pO{sub 2}, at which the majority carriers changed from the holes to electrons because of the valence state decreases in Fe due to the further loss of oxygen. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport. Data obtained at 850 C show that the stoichiometry in La{sub 0.2}Sr{sub 0.8}Fe{sub 0.8}Cr{sub 0.2}O{sub 3-x} vary from {approx}2.85 to 2.6 over the pressure range studied. From the stoichiometry a lower limit of 2.6 corresponding to the reduction of all Fe{sup 4+} to Fe{sup 3+} and no reduction of Cr{sup 3+} is expected.

S. Bandopadhyay; N. Nagabhushana

2003-08-07T23:59:59.000Z

206

Recovery Act: Novel Oxygen Carriers for Coal-fueled Chemical Looping  

SciTech Connect (OSTI)

Chemical Looping Combustion (CLC) could totally negate the necessity of pure oxygen by using oxygen carriers for purification of CO{sub 2} stream during combustion. It splits the single fuel combustion reaction into two linked reactions using oxygen carriers. The two linked reactions are the oxidation of oxygen carriers in the air reactor using air, and the reduction of oxygen carriers in the fuel reactor using fuels (i.e. coal). Generally metal/metal oxides are used as oxygen carriers and operated in a cyclic mode. Chemical looping combustion significantly improves the energy conversion efficiency, in terms of the electricity generation, because it improves the reversibility of the fuel combustion process through two linked parallel processes, compared to the conventional combustion process, which is operated far away from its thermo-equilibrium. Under the current carbon-constraint environment, it has been a promising carbon capture technology in terms of fuel combustion for power generation. Its disadvantage is that it is less mature in terms of technological commercialization. In this DOE-funded project, accomplishment is made by developing a series of advanced copper-based oxygen carriers, with properties of the higher oxygen-transfer capability, a favorable thermodynamics to generate high purity of CO{sub 2}, the higher reactivity, the attrition-resistance, the thermal stability in red-ox cycles and the achievement of the auto-thermal heat balance. This will be achieved into three phases in three consecutive years. The selected oxygen carriers with final-determined formula were tested in a scaled-up 10kW coal-fueled chemical looping combustion facility. This scaled-up evaluation tests (2-day, 8-hour per day) indicated that, there was no tendency of agglomeration of copper-based oxygen carriers. Only trace-amount of coke or carbon deposits on the copper-based oxygen carriers in the fuel reactor. There was also no evidence to show the sulphidization of oxygen carriers in the system by using the high-sulfur-laden asphalt fuels. In all, the scaled-up test in 10 kW CLC facility demonstrated that the preparation method of copper-based oxygen carrier not only help to maintain its good reactivity, also largely minimize its agglomeration tendency.

Pan, Wei-Ping; Cao, Yan

2012-11-30T23:59:59.000Z

207

Layered reactive particles with controlled geometries, energies, and reactivities, and methods for making the same  

DOE Patents [OSTI]

An energetic composite having a plurality of reactive particles each having a reactive multilayer construction formed by successively depositing reactive layers on a rod-shaped substrate having a longitudinal axis, dividing the reactive-layer-deposited rod-shaped substrate into a plurality of substantially uniform longitudinal segments, and removing the rod-shaped substrate from the longitudinal segments, so that the reactive particles have a controlled, substantially uniform, cylindrically curved or otherwise rod-contoured geometry which facilitates handling and improves its packing fraction, while the reactant multilayer construction controls the stability, reactivity and energy density of the energetic composite.

Fritz, Gregory M; Knepper, Robert Allen; Weihs, Timothy P; Gash, Alexander E; Sze, John S

2013-04-30T23:59:59.000Z

208

Oxygen transfer in the implant environment  

E-Print Network [OSTI]

Temperature dependence of oxygen diffusion and consumptionRN. Influence of temperature on oxygen diffusion in hamster341-347, 1988. Cox ME. Oxygen Diffusion in Poly(dimethyl

Goor, Jared Braden

2007-01-01T23:59:59.000Z

209

OXYGEN DIFFUSION IN UO2-x  

E-Print Network [OSTI]

~ K.C. K:i.m, "Oxygen Diffusion in Hypostoichiometricsystem for enriching uo 2 in oxygen-18 or for stoichiometry+nal of Nuclear Materials OXYGEN DIFFUSION IN U0 2 _:x K.C.

Kim, K.C.

2013-01-01T23:59:59.000Z

210

Cost Effective Natural Antioxidants  

Science Journals Connector (OSTI)

Reactive oxygen species can damage nucleic acids, proteins, lipids and carbohydrates that consequently affect the immune functions causing degenerative dis...

Dhan Prakash; Neeraj Kumar

2011-01-01T23:59:59.000Z

211

PRIMARY RESEARCH PAPER Water column oxygen demand and sediment oxygen flux  

E-Print Network [OSTI]

PRIMARY RESEARCH PAPER Water column oxygen demand and sediment oxygen flux: patterns of oxygen dissolved oxygen (DO) levels often occur during summer in tidal creeks along the southeastern coast of the USA. We analyzed rates of oxygen loss as water-column biochemical oxygen demand (BOD5) and sediment

Mallin, Michael

212

Simulations of Deflagration-to-Detonation Transition in Reactive Gases |  

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

numerically generated pseudo-schlieren image numerically generated pseudo-schlieren image Weak ignition behind a reflected Mach=1.5 shock in a stoichiometric hydrogen-oxygen mixture at 0.1 atm initial pressure. Picture shows a numerically generated pseudo-schlieren image of the onset of a detonation in a turbulent boundary layer. Alexei Khokhlov, University of Chicago; Charles Bacon, Argonne National Laboratory, Joanna Austin, Andrew Knisely, University of Illinois at Urbanna-Champaign Simulations of Deflagration-to-Detonation Transition in Reactive Gases PI Name: Alexei Khokhlov PI Email: ajk@oddjob.uchicago.edu Institution: The University of Chicago Allocation Program: INCITE Allocation Hours at ALCF: 130 Million Year: 2013 Research Domain: Chemistry Hydrogen is an abundant, environmentally friendly fuel with the potential

213

Polycyclic Aromatic Triptycenes: Oxygen Substitution Cyclization Strategies  

E-Print Network [OSTI]

The cyclization and planarization of polycyclic aromatic hydrocarbons with concomitant oxygen substitution was achieved through acid catalyzed transetherification and oxygen-radical reactions. The triptycene scaffold ...

VanVeller, Brett

214

Angling chromium to let oxygen through | EMSL  

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

which enable facile oxygen anion diffusion at low temperature. Brighter spheres are strontium ions; less-bright spheres are chromium ions. Oxygen anions are barely visible, and...

215

Extracorporeal membrane oxygenation promotes long chain fatty...  

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

membrane oxygenation promotes long chain fatty acid oxidation in the immature swine heart in vivo. Extracorporeal membrane oxygenation promotes long chain fatty acid oxidation...

216

OXYGEN DIFFUSION IN HYPOSTOICHIOMETRIC URANIUM DIOXIDE  

E-Print Network [OSTI]

Research Division OXYGEN DIFFUSION IN HYPOSTOICHIOMETRIC11905 -DISCLAIMER - OXYGEN DIFFUSION IN HYPOSTOICHIOMETRICc o n e e n i g woroxygen self-diffusion coefficient

Kim, Kee Chul

2010-01-01T23:59:59.000Z

217

Platinum Monolayer Electrocatalysts for Oxygen Reduction Reaction...  

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

Platinum Monolayer Electrocatalysts for Oxygen Reduction Reaction Platinum Monolayer Electrocatalysts for Oxygen Reduction Reaction Presentation slides from the June 19, 2012, Fuel...

218

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

219

It's Elemental - The Element Oxygen  

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

220

The System Boron—Oxygen  

Science Journals Connector (OSTI)

This presentation covers the years 1985 to 1988 and, in part, to 1992. It continues the previous discussion of the system boron—oxygen in “Boron Compounds” 3rd Suppl. Vol. 2, 1987, pp. 1/184, and earlier liter...

Gert Heller

1993-01-01T23:59:59.000Z

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

Oxygen Transport Ceramic Membranes  

SciTech Connect (OSTI)

The present quarterly report describes some of the initial studies on newer compositions and also includes newer approaches to address various materials issues such as in metal-ceramic sealing. The current quarter's research has also focused on developing a comprehensive reliability model for predicting the structural behavior of the membranes in realistic conditions. In parallel to industry provided compositions, models membranes have been evaluated in varying environment. Of importance is the behavior of flaws and generation of new flaws aiding in fracture. Fracture mechanics parameters such as crack tip stresses are generated to characterize the influence of environment. Room temperature slow crack growth studies have also been initiated in industry provided compositions. The electrical conductivity and defect chemistry of an A site deficient compound (La{sub 0.55}Sr{sub 0.35}FeO{sub 3}) was studied. A higher conductivity was observed for La{sub 0.55}Sr{sub 0.35}FeO{sub 3} than that of La{sub 0.60}Sr{sub 0.40}FeO{sub 3} and La{sub 0.80}Sr{sub 0.20}FeO{sub 3}. Defect chemistry analysis showed that it was primarily contributed by a higher carrier concentration in La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. Moreover, the ability for oxygen vacancy generation is much higher in La{sub 0.55}Sr{sub 0.35}FeO{sub 3} as well, which indicates a lower bonding strength between Fe-O and a possible higher catalytic activity for La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. The program continued to investigate the thermodynamic properties (stability and phase separation behavior) and total conductivity of prototype membrane materials. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previous report listed initial measurements on a sample of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-x} prepared in-house by Praxair. Subsequently, a second sample of powder from a larger batch of sample were characterized and compared with the results from the previous batch.

S. Bandopadhyay; N. Nagabhushana; Thomas W. Eagar; Harold R. Larson; Raymundo Arroyave; X.-D Zhou; Y.-W. Shin; H.U. Anderson; Nigel Browning; Alan Jacobson; C.A. Mims

2003-11-01T23:59:59.000Z

222

Rejuvenating Permeable Reactive Barriers by Chemical Flushing  

Broader source: Energy.gov [DOE]

Final Report:Rejuvenating Permeable Reactive Barriers by Chemical Flushing,U.S. Environmental Protection Agency, Region 8 Support.August 2004

223

Exploring the reactivity of bacterial multicomponent monooxygenases  

E-Print Network [OSTI]

Chapter 1. Introduction: The Reactivity of Bacterial Multicomponent Monooxygenases Bacterial multicomponent monooxygenases constitute a remarkable family of enzymes that oxidize small, inert hydrocarbon substrates using ...

Tinberg, Christine Elaine

2010-01-01T23:59:59.000Z

224

Master Thesis in Chalmers University, Sweden The influence of MgO in CaMnO3-oxygen carrier  

E-Print Network [OSTI]

Background Chemical-looping Combustion (CLC) is an innovative fuel conversion technology inherent capture CO2 material which has high reactivity towards methane and oxygen-uncoupling ability under combustion feasible and written master thesis report Requirements Materials science (preferable), chemistry or chemical

Daraio, Chiara

225

Method for reactivating catalysts and a method for recycling supercritical fluids used to reactivate the catalysts  

DOE Patents [OSTI]

A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst. The method comprises providing a catalyst that is at least partially deactivated by fouling agents. The catalyst is contacted with a fluid reactivating agent that is at or above a critical point of the fluid reactivating agent and is of sufficient density to dissolve impurities. The fluid reactivating agent reacts with at least one fouling agent, releasing the at least one fouling agent from the catalyst. The at least one fouling agent becomes dissolved in the fluid reactivating agent and is subsequently separated or removed from the fluid reactivating agent so that the fluid reactivating agent may be reused. A system for reactivating a catalyst is also disclosed.

Ginosar, Daniel M. (Idaho Falls, ID); Thompson, David N. (Idaho Falls, ID); Anderson, Raymond P. (Idaho Falls, ID)

2008-08-05T23:59:59.000Z

226

Synergetic effects of mixed copper-iron oxides oxygen carriers in chemical looping combustion  

SciTech Connect (OSTI)

Chemical looping combustion (CLC) is an emerging technology for clean energy production from fuels. CLC produces sequestration-ready CO{sub 2}-streams without a significant energy penalty. Development of efficient oxygen carriers is essential to successfully operate a CLC system. Copper and iron oxides are promising candidates for CLC. Copper oxide possesses high reactivity but it has issues with particle agglomeration due to its low melting point. Even though iron oxide is an inexpensive oxygen carrier it has a slower reactivity. In this study, mixed metal oxide carriers containing iron and copper oxides were evaluated for coal and methane CLC. The components of CuO and Fe{sub 2}O{sub 3} were optimized to obtain good reactivity while maintaining physical and chemical stability during cyclic reactions for methane-CLC and solid-fuel CLC. Compared with single metal oxygen carriers, the optimized Cu–Fe mixed oxide oxygen carriers demonstrated high reaction rate, better combustion conversion, greater oxygen usage and improved physical stability. Thermodynamic calculations, XRD, TGA, flow reactor studies and TPR experiments suggested that there is a strong interaction between CuO and Fe{sub 2}O{sub 3} contributing to a synergistic effect during CLC reactions. The amount of oxygen release of the mixed oxide carrier in the absence of a fuel was similar to that of the single metal oxides. However, in the presence of fuels, the oxygen consumption and the reaction profiles of the mixed oxide carriers were significantly better than that of the single metal oxides. The nature of the fuel not only influenced the reactivity, but also the final reduction status of the oxygen carriers during chemical looping combustion. Cu oxide of the mixed oxide was fully reduced metallic copper with both coal and methane. Fe oxide of the mixed oxide was fully reduced Fe metal with methane but it was reduced to only FeO with coal. Possible mechanisms of how the presence of CuO enhances the reduction of Fe{sub 2}O{sub 3} are discussed.

Siriwardane, Ranjani; Tian, Hanjing; Simonyi, Thomas; Poston, James

2013-06-01T23:59:59.000Z

227

Advanced hydraulic fracturing methods to create in situ reactive barriers  

SciTech Connect (OSTI)

Many contaminated areas consist of a source area and a plume. In the source area, the contaminant moves vertically downward from a release point through the vadose zone to an underlying saturated region. Where contaminants are organic liquids, NAPL may accumulate on the water table, or it may continue to migrate downward through the saturated region. Early developments of permeable barrier technology have focused on intercepting horizontally moving plumes with vertical structures, such as trenches, filled with reactive material capable of immobilizing or degrading dissolved contaminants. This focus resulted in part from a need to economically treat the potentially large volumes of contaminated water in a plume, and in part from the availability of construction technology to create the vertical structures that could house reactive compounds. Contaminant source areas, however, have thus far remained largely excluded from the application of permeable barrier technology. One reason for this is the lack of conventional construction methods for creating suitable horizontal structures that would place reactive materials in the path of downward-moving contaminants. Methods of hydraulic fracturing have been widely used to create flat-lying to gently dipping layers of granular material in unconsolidated sediments. Most applications thus far have involved filling fractures with coarse-grained sand to create permeable layers that will increase the discharge of wells recovering contaminated water or vapor. However, it is possible to fill fractures with other compounds that alter the chemical composition of the subsurface. One early application involved development and field testing micro-encapsulated sodium percarbonate, a solid compound that releases oxygen and can create aerobic conditions suitable for biodegradation in the subsurface for several months.

Murdoch, L. [FRx Inc., Cincinnati, OH (United States); [Clemson Univ., SC (United States); Siegrist, B. [Oak Ridge National Lab., TN (United States); Vesper, S. [Univ. of Cincinnati, OH (United States)] [and others

1997-12-31T23:59:59.000Z

228

Water column oxygen demand and sediment oxygen flux: patterns of oxygen depletion in tidal creeks  

Science Journals Connector (OSTI)

Five study sites were chosen in Futch Creek, Hewletts Creek and Pages Creek,...1). Sites were chosen to reflect a range in the values of dissolved oxygen levels, chlorophyll a concentrations and nutrient (nitroge...

Tara A. MacPherson; Lawrence B. Cahoon; Michael A. Mallin

2007-07-01T23:59:59.000Z

229

Oxygen Transport Ceramic Membranes  

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

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

2004-05-01T23:59:59.000Z

230

Researchers Directly Observe Oxygen Signature in the Oxygen-evolving  

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

231

Reactive scattering of small molecules  

SciTech Connect (OSTI)

In an ultrahigh vacuum system equipped with an effusive molecular beam source, several molecular beam relaxation spectroscopy studies were performed on a stepped Pt(111) single crystal. Carbon monoxide adsorption/desorption was studied as a function of sulfur coverage. Sulfur adsorption at step sites was found to slightly decrease the sticking probability but strongly decrease the carbon monoxide interaction with the surface. The kinetics of desorption were characteristic of the tightest binding state accessible to the adsorbed carbon monoxide. Hydrogen atom recombination and desorption was studied following formaldehyde decomposition. The reaction was second order and the desorption proceeded by two pathways: one associated with the step sites and the other with the terraces. The activation energies for desorption were 25 and 19 kcal/mol for the steps and terraces, respectively and the pre-exponential factors were of the order 0.01 cm/sup 2//s. Adsorbed sulfur and high carbon monoxide surface coverages blocked the high energy hydrogen recombination pathway. The kinetics and mechanism of the hydrogen-oxygen reaction was studied in the temperature range 400 to 1000 K. The reaction proceeded by the sequential addition of hydrogen to oxygen, first to form hydroxyls and then to form water.

Gdowski, G.E.

1985-01-01T23:59:59.000Z

232

Syngas chemical looping gasification process: oxygen carrier particle selection and performance  

SciTech Connect (OSTI)

The syngas chemical looping (SCL) process coproduces hydrogen and electricity. The process involves reducing metal oxides with syngas followed by regeneration of reduced metal oxides with steam and air in a cyclic manner. Iron oxide is determined to be a desired oxygen carrier for hydrogen production considering overall properties including oxygen carrying capacity, thermodynamic properties, reaction kinetics, physical strength, melting points, and environmental effects. An iron oxide based particle can maintain good reactivity for more than 100 reduction-oxidation (redox) cycles in a thermogravimetric analyzer (TGA). The particle exhibits a good crushing strength (>20 MPa) and low attrition rate. Fixed bed experiments are carried out which reaffirm its reactivity. More than 99.75% of syngas is converted during the reduction stage. During the regeneration stage, hydrogen with an average purity of 99.8% is produced. 23 refs., 6 figs., 10 tabs.

Fanxing Li; Hyung Ray Kim; Deepak Sridhar; Fei Wang; Liang Zeng; Joseph Chen; L.-S. Fan [Ohio State University, Columbus, OH (United States). William G. Lowrie Department of Chemical and Biomolecular Engineering

2009-08-15T23:59:59.000Z

233

Apparatus and Method for Oxidation and Stabilization of Polymeric...  

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

is based on the use of reactive oxidative species (ROS), such as monatomic oxygen, and atmospheric plasma to increase the rate of oxygen diffusion to nonoxidized polymeric...

234

Reactivity of calcium sulfate from FBC systems  

Science Journals Connector (OSTI)

A relative estimate of the reactivity of calcium sulfate in a number of coal combustion ash samples was obtained, using the rate of solution in water as a parameter. Measurements were also performed on standard samples of calcium sulfate prepared in different ways, for comparison. The temperature of previous treatment appeared as the most important factor determining the reactivity of CaSO4; the grain size distribution was less important, and the duration of heating (even to 105 days) had very little influence. No correlation between specific surface of ash samples and their reactivity was apparent. Calcium sulfate in FBC ash samples was much more reactive than that contained in high-temperature ashes, and than calcium sulfate heated, alone or with various additions, at 850°C for 2 days. Of the six FBC samples tested, five showed similar behaviour, including a sample from a pressurized system; only a deposit from 96 days operation of an industrial CFBC boiler burning petroleum coke showed considerably less reactivity. Surprisingly, CaSO4 from two FBC samples placed in an oven for 60 days under sulfating conditions showed a very similar rate of solution to that of the other FBC samples, while a third sample kept in the oven for 105 days also showed no decrease in reactivity. Only when one of these samples had agglomerated (which occurred between 60 and 105 days) did it show decreased reactivity, suggesting that the agglomeration process rather than duration is significant in promoting sintering and reducing the sulfate reactivity.

Agripanea P. Iribarne; Julio V. Iribarne; Edward J. Anthony

1997-01-01T23:59:59.000Z

235

Ionizing Radiation-induced, Mitochondria-dependent Generation of Reactive Oxygen/Nitrogen  

Science Journals Connector (OSTI)

...exposing cells to ionizing radiation. In the 1-10 Gy dose range, the amount...demonstrated that ionizing radiation in the therapeutic dose range stimulates a...exposing cells to ionizing radiation. In the 1-10 Gy dose range, the amount...

J. Kevin Leach; Glenn Van Tuyle; Peck-Sun Lin; Rupert Schmidt-Ullrich; and Ross B. Mikkelsen

2001-05-15T23:59:59.000Z

236

Oxygen-Free Propane Oxidative Dehydrogenation Over Vanadium Oxide Catalysts: Reactivity and Kinetic Modelling.  

E-Print Network [OSTI]

??Propane conversion to propylene has been the subject of intensive researches. This is due to the increasing demand for propylene. Current propylene production processes suffer… (more)

Al-Ghamdi, Sameer Ali

2013-01-01T23:59:59.000Z

237

Role of Reactive Oxygen Metabolites in Crocidolite Asbestos Toxicity to Mouse Macrophages  

Science Journals Connector (OSTI)

...fibers may catalyze the production of hydroxyl radical from Superoxide ani nand hydrogen peroxide generated during...Superoxide ani n(O2' ), hydrogen peroxide (H2O2...monophosphate shunt, production of NAD(P)H, and...cytotoxicity. MATERIALS AND METHODS Reagents Crocidolite...

Lee A. Goodglick and Agnes B. Kane

1986-11-01T23:59:59.000Z

238

Z .Spectrochimica Acta Part B 56 2001 419 430 The effects of oxygen on the detection of mercury using  

E-Print Network [OSTI]

Z .Spectrochimica Acta Part B 56 2001 419 430 The effects of oxygen on the detection of mercury; accepted 27 February 2001 Abstract A systematic study of the processes associated with mercury atomic emission in a laser-induced plasma and the interactions of mercury with oxygen species is presented

Hahn, David W.

239

OXYGEN ADSORPTION ON NITROGEN CONTAINING CARBON SURFACES  

E-Print Network [OSTI]

OXYGEN ADSORPTION ON NITROGEN CONTAINING CARBON SURFACES Alejandro Montoya, Jorge O. Gil, Fanor-rich site of the carbon basal plane of graphite and then, it dissociates into oxygen atoms.1,2 Oxygen atoms at the edge of the carbon surface can form covalent bonds with oxygen. These sites can chemisorb

Truong, Thanh N.

240

Dilute Oxygen Combustion Phase I Final Report  

SciTech Connect (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 (<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

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

Dilute Oxygen Combustion Phase 2 Final Report  

SciTech Connect (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 (<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

242

Dilute oxygen combustion. Phase I report  

SciTech Connect (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) (NO{sub x}) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NO{sub x} through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NO{sub x} 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 ({approximately}1366 K) oxidant (7-27% O{sub 2} 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{sup +} 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{sup +} scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW ({approximately}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. NO{sub x} emissions increased with increasing furnace nitrogen content and furnace temperature, but remained relatively insensitive to variations in fuel injection velocity and firing rate. NO{sub x} emissions below 5{times}10{sup -3} g/MJ (10 ppm-air equivalent at 3% O{sub 2} dry) were obtained for furnace temperatures below 1533 K (2300{degree}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, with 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 utility costs alone. However, conversion of continuous steel reheat furnaces, which are responsible for most steel production, requires additional economic incentives, such as further fuel savings, increased furnace productivity, or emission credits.

NONE

1997-10-01T23:59:59.000Z

243

A reaction-based paradigm to model reactive chemical transport in groundwater with general kinetic and equilibrium reactions  

SciTech Connect (OSTI)

This paper presents a reaction-based water quality transport model in subsurface flow systems. Transport of chemical species with a variety of chemical and physical processes is mathematically described by M partial differential equations (PDEs). Decomposition via Gauss-Jordan column reduction of the reaction network transforms M species reactive transport equations into two sets of equations: a set of thermodynamic equilibrium equations representing NE equilibrium reactions and a set of reactive transport equations of M-NE kinetic-variables involving no equilibrium reactions (a kinetic-variable is a linear combination of species). The elimination of equilibrium reactions from reactive transport equations allows robust and efficient numerical integration. The model solves the PDEs of kinetic-variables rather than individual chemical species, which reduces the number of reactive transport equations and simplifies the reaction terms in the equations. A variety of numerical methods are investigated for solving the coupled transport and reaction equations. Simulation comparisons with exact solutions were performed to verify numerical accuracy and assess the effectiveness of various numerical strategies to deal with different application circumstances. Two validation examples involving simulations of uranium transport in soil columns are presented to evaluate the ability of the model to simulate reactive transport with complex reaction networks involving both kinetic and equilibrium reactions.

Zhang, Fan [ORNL; Yeh, Gour-Tsyh [University of Central Florida, Orlando; Parker, Jack C [ORNL; Brooks, Scott C [ORNL; Pace, Molly [ORNL; Kim, Young Jin [ORNL; Jardine, Philip M [ORNL; Watson, David B [ORNL

2007-01-01T23:59:59.000Z

244

Oxygen isotopic exchange: A useful tool for characterizing oxygen conducting oxides  

E-Print Network [OSTI]

Oxygen isotopic exchange: A useful tool for characterizing oxygen conducting oxides Bassat J we obtain in both cases data concerning the oxygen diffusion in the bulk and the oxygen exchange with regards to the oxygen reduction reaction. Detailed experimental and analytical processes are given

Paris-Sud XI, Université de

245

In Situ Reactivity and TOF SIMS Analysis of Surfaces Prepared...  

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

Reactivity and TOF SIMS Analysis of Surfaces Prepared by Soft and Reactive Landing of Mass Selected Ions. In Situ Reactivity and TOF SIMS Analysis of Surfaces Prepared by Soft and...

246

Structure Evolution of Graphene Oxide during Thermally Driven Phase Transformation: Is the Oxygen Content Really Preserved?  

E-Print Network [OSTI]

A mild annealing procedure was recently proposed for the scalable enhancement of graphene oxide (GO) properties with the oxygen content preserved, which was demonstrated to be attributed to the thermally driven phase separation. In this work, the structure evolution of GO with mild annealing is closely investigated. It reveals that in addition to phase separation, the transformation of oxygen functionalities also occurs, which leads to the slight reduction of GO membranes and further the enhancement of GO properties. These results are further supported by the density functional theory based calculations. The results also show that the amount of chemically bonded oxygen atoms on graphene decreases gradually and we propose that the strongly physisorbed oxygen species constrained in the holes and vacancies on GO lattice might be responsible for the preserved oxygen content during the mild annealing procedure. The present experimental results and calculations indicate that both the diffusion and transformation of...

Sun, Pengzhan; Liu, He; Wang, Kunlin; Wu, Dehai; Xu, Zhiping; Zhu, Hongwei

2014-01-01T23:59:59.000Z

247

Final Report Phase II: Performance Evaluation of Permeable Reactive  

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

Final Report Phase II: Performance Evaluation of Permeable Reactive Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Rejuvenating Permeable Reactive Barriers by Chemical Flushing Final Report - Rejuvenating Permeable Reactive Barriers by Chemical

248

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier  

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

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update More Documents & Publications Variation in Hydraulic Conductivity Over Time at the Monticello Permeable Reactive Barrier Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium Mill Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium

249

Characterization of Dual-Fuel Reactivity Controlled Compression...  

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

Dual-Fuel Reactivity Controlled Compression Ignition (RCCI) Using Hydrated Ethanol and Diesel Fuel Characterization of Dual-Fuel Reactivity Controlled Compression Ignition (RCCI)...

250

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

Science Journals Connector (OSTI)

The choice of wood char was made after comparing the oxygen concentration in the reactor’s exit stream, using different solid fuels and taking advantage of the high reactivity of the wood char, compared to other available fuels (e.g., coal or petcoke). ... The required solids inventory in the fuel reactor obtained here is lower than a previously reported investigation for a 40 wt?% CuO on ZrO2 support using petcoke as fuel (120–200 kg MWth–1)(34) and a recent study of continuous operation using a spray-dried 60 wt?% CuO on MgAl2O4 support (235 kg MWth–1 at 960 °C),(22) but is in close agreement with the values obtained by Adánez-Rubio et al.(48) for the spray-dried 60 wt?% CuO on MgAl2O4 support (39 kg MWth–1 at 930 °C). ... data of Mexican petcoke particles by a CuO/ZrO2 oxygen carrier. ...

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

2012-10-03T23:59:59.000Z

251

Consideration of spatial effects in reactivity measurements  

SciTech Connect (OSTI)

Various methods of considering spatial effects in reactivity measurements are presented. These methods are employed both at the critical (mainly fast-neutron) facilities and at the BN-600 reactor.

Matveenko, I. P., E-mail: matveenko@ippe.ru; Lititskii, V. A.; Shokod'ko, A. G. [Institute of Physics and Power Engineering (Russian Federation)

2010-12-15T23:59:59.000Z

252

Systematic approach for chemical reactivity evaluation  

E-Print Network [OSTI]

Screening Tool (RSST) and the Automatic Pressure Tracking Adiabatic Calorimeter (APTAC) were employed to evaluate the reactive systems experimentally. The RSST detected exothermic behavior and measured the overall liberated energy. The APTAC simulated...

Aldeeb, Abdulrehman Ahmed

2004-09-30T23:59:59.000Z

253

Reactivity control assembly for nuclear reactor  

DOE Patents [OSTI]

Reactivity control assembly for nuclear reactor comprises supports stacked above reactor core for holding control rods. Couplers associated with the supports and a vertically movable drive shaft have lugs at their lower ends for engagement with the supports.

Bollinger, Lawrence R. (Schenectady, NY)

1984-01-01T23:59:59.000Z

254

Fossil plant layup and reactivation conference: Proceedings  

SciTech Connect (OSTI)

The Fossil Plant Layup and Reactivation Conference was held in New Orleans, Louisiana on April 14--15, 1992. The Conference was sponsored by EPRI and hosted by Entergy Services, Inc. to bring together representatives from utilities, consulting firms, manufacturers and architectural engineers. Eighteen papers were presented in three sessions. These sessions were devoted to layup procedures and practices, and reactivation case studies. A panel discussion was held on the second day to interactively discuss layup and reactivation issues. More than 80 people attended the Conference. This report contains technical papers and a summary of the panel discussion. Of the eighteen papers, three are related to general, one is related to regulatory issues, three are related to specific equipment, four are related to layup procedures and practices, and seven are layup and reactivation case studies.

Not Available

1992-10-01T23:59:59.000Z

255

Groundwater well with reactive filter pack  

DOE Patents [OSTI]

A method and apparatus for the remediation of contaminated soil and ground water wherein a reactive pack material is added to the annular fill material utilized in standard well construction techniques.

Gilmore, Tyler J. (Pasco, WA); Holdren, Jr., George R. (Kennewick, WA); Kaplan, Daniel I. (Richland, WA)

1998-01-01T23:59:59.000Z

256

Groundwater well with reactive filter pack  

DOE Patents [OSTI]

A method and apparatus are disclosed for the remediation of contaminated soil and ground water wherein a reactive pack material is added to the annular fill material utilized in standard well construction techniques. 3 figs.

Gilmore, T.J.; Holdren, G.R. Jr.; Kaplan, D.I.

1998-09-08T23:59:59.000Z

257

A Tariff for Reactive Power - IEEE  

SciTech Connect (OSTI)

This paper describes a suggested tariff or payment for the local supply of reactive power from distributed energy resources. The authors consider four sample customers, and estimate the cost of supply of reactive power for each customer. The power system savings from the local supply of reactive power are also estimated for a hypothetical circuit. It is found that reactive power for local voltage regulation could be supplied to the distribution system economically by customers when new inverters are installed. The inverter would be supplied with a power factor of 0.8, and would be capable of local voltage regulation to a schedule supplied by the utility. Inverters are now installed with photovoltaic systems, fuel cells and microturbines, and adjustable-speed motor drives.

Kueck, John D [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator; Kirby, Brendan J [ORNL

2008-11-01T23:59:59.000Z

258

Reactive Attachment Disorder: Concepts, Treatment, and Research  

E-Print Network [OSTI]

Reactive Attachment Disorder (RAD) is a disorder characterized by controversy, both with respect to its definition and its treatment. By definition, the RAD diagnosis attempts to characterize and explain the origin of ...

Walter, Uta M.; Petr, Chris

2004-06-01T23:59:59.000Z

259

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

E-Print Network [OSTI]

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

Olson, Stephanie

2013-01-01T23:59:59.000Z

260

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

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


261

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...

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

262

Oxygen reduction on platinum : an EIS study  

E-Print Network [OSTI]

The oxygen reduction reaction (ORR) on platinum over yttria-stabilized zirconia (YSZ) is examined via electrochemical impedance spectroscopy (EIS) for oxygen partial pressures between 10-4 and 1 atm and at temperatures ...

Golfinopoulos, Theodore

2009-01-01T23:59:59.000Z

263

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

264

Imaging Oxygen Molecules Up Close | EMSL  

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

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

265

Composite oxygen ion transport element  

SciTech Connect (OSTI)

A composite oxygen ion transport element that has a layered structure formed by a dense layer to transport oxygen ions and electrons and a porous support layer to provide mechanical support. The dense layer can be formed of a mixture of a mixed conductor, an ionic conductor, and a metal. The porous support layer can be fabricated from an oxide dispersion strengthened metal, a metal-reinforced intermetallic alloy, a boron-doped Mo.sub.5Si.sub.3-based intermetallic alloy or combinations thereof. The support layer can be provided with a network of non-interconnected pores and each of said pores communicates between opposite surfaces of said support layer. Such a support layer can be advantageously employed to reduce diffusion resistance in any type of element, including those using a different material makeup than that outlined above.

Chen, Jack C. (Getzville, NY); Besecker, Charles J. (Batavia, IL); Chen, Hancun (Williamsville, NY); Robinson, Earil T. (Mentor, OH)

2007-06-12T23:59:59.000Z

266

Catalyst containing oxygen transport membrane  

SciTech Connect (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

267

Respiration, photosynthesis, and oxygen isotope fractionation in ...  

Science Journals Connector (OSTI)

Jan 25, 1971 ... Respiration, photosynthesis, and oxygen isotope fractionation in oceanic surface water1. Peter M. Kroopnick. Department of Oceanography,.

2000-01-04T23:59:59.000Z

268

Oxygen Detection via Nanoscale Optical Indicators  

E-Print Network [OSTI]

Oxygen Detection via Nanoscale Optical Indicators Ruby N. Ghosh Dept. of Physics Michigan State University East Lansing, MI, USA weekschr@msu.edu Abstract--Oxygen plays a ubiquitous role in terrestrial developed an optical technique for monitoring oxygen in both gas and liquid phases utilizing nanoscale metal

Ghosh, Ruby N.

269

8, 22252248, 2008 Detection of oxygen  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

270

Oxygen and Nitrogen Contamination During Arc Welding  

E-Print Network [OSTI]

) ) : ,- Oxygen and Nitrogen Contamination During Arc Welding T. W. Eagar Department of }faterials, mechanisms, and expected levels of oxygen and nitrogen contamination during gas tungsten arc, gas metal arc indicating the importance of dec9mposition of SiOz into silicon monoxide and oxygen are presented, indicating

Eagar, Thomas W.

271

Chemical filters by non-thermal atmospheric pressure plasmas for reactive fields  

Science Journals Connector (OSTI)

Non-thermal plasmas in electrode configurations are designed in this study and investigated at atmospheric pressure for generation of reactive fields. A combination of insulated wire electrodes and bare metal wire electrodes makes it possible to obtain a filter-like assembly of microplasmas, even in ambient air or in aqueous solutions. Oxidation and reduction fields are obtained by controlling the gas supply of hydrogen, oxygen, and water vapor, and these fields benefit various functional processes such as recycling CO2, decomposing organic molecules, and increasing the work function on metal surfaces.

Osamu Sakai; Tadasuke Morita; Yoshihiko Ueda; Noriaki Sano; Kunihide Tachibana

2011-01-01T23:59:59.000Z

272

The Mechanisms of Oxygen Reduction and Evolution Reactions in...  

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

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

273

Oxygen consumption of bovine granulosa cells in vitro.  

E-Print Network [OSTI]

??The oxygen consumption rate of granulosa cells is considered to be a key determinant of oocyte oxygenation in follicles. The oxygen status of the oocyte… (more)

Li, Dongxing

2012-01-01T23:59:59.000Z

274

Thickness Dependency of Thin Film Samaria Doped Ceria for Oxygen...  

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

Dependency of Thin Film Samaria Doped Ceria for Oxygen Sensing . Thickness Dependency of Thin Film Samaria Doped Ceria for Oxygen Sensing . Abstract: High temperature oxygen...

275

Phase II: Performance Evaluation of Permeable Reactive Barriers and  

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

Phase II: Performance Evaluation of Permeable Reactive Barriers and Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing U. S. Environmental Protection Agency Region 8 Support January 2004 Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Rejuvenating Permeable Reactive Barriers by Chemical Flushing

276

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier  

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

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update More Documents & Publications Variation in Hydraulic Conductivity Over Time at the Monticello Permeable Reactive Barrier Ground-Water Table and Chemical Changes in an Alluvial Aquifer During Sustained Pumping at the Monticello, Utah, Zero-Valent Iron Treatment Cells Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium

277

Final Report Phase II: Performance Evaluation of Permeable Reactive  

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

Final Report Phase II: Performance Evaluation of Permeable Reactive Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report - Rejuvenating Permeable Reactive Barriers by Chemical Flushing, U.S. Environmental Protection Agency Region 8 Support

278

Singlet Oxygen Singlet oxygen generation and detection are growing fields with applications in such areas as  

E-Print Network [OSTI]

Singlet Oxygen Singlet oxygen generation and detection are growing fields with applications in such areas as cancer treatment, photosensitized oxidations, and biomolecular degradation. Ground state oxygen state of an oxygen molecule is a singlet state, which can readily react with other singlet molecules

Wells, Mathew G. - Department of Physical and Environmental Sciences, University of Toronto

279

Oxygen permeation in bismuth-based materials part I: Sintering and oxygen permeation fluxes  

E-Print Network [OSTI]

1 Oxygen permeation in bismuth-based materials part I: Sintering and oxygen permeation fluxes E;2 Abstract Oxygen permeation measurements were performed on two layered bismuth based oxide ceramics. Oxygen permeability for these systems was compared to permeability of the cubic fluorite type structure

Paris-Sud XI, Université de

280

Effect of co-precipitation and impregnation on K-decorated Fe2O3/Al2O3 oxygen carrier in Chemical Looping Combustion of bituminous coal  

Science Journals Connector (OSTI)

Abstract Chemical Looping Combustion (CLC) of coal is an innovative combustion technology for CO2 inherent capture, which uses oxygen carrier (OC) to transfer lattice oxygen to coal. However, coal gasification is the rate-limiting process for CLC of coal. Although carbon conversion and gasification rate are substantially improved with oxygen carriers in the presence of alkali additives, alkali loss in oxygen carrier is still a serious problem in the process of CLC of coal. The present work focuses on the OC–potassium interaction for two preparation methods of K-decorated OC. Different contents of catalyst (K2CO3) were added into the preparation of Fe-based oxygen carrier by both co-precipitation and impregnation. And the effect of K-decorated methods on oxygen carriers was investigated in a fluidized bed reactor. For co-precipitated oxygen carriers, CO2 gas yields (fCO2) were higher and CO gas yields (fCO) were lower than the ones for impregnated oxygen carriers. Total carbon conversions for co-precipitated oxygen carriers were also higher than those for impregnated oxygen carriers, and a shorter time of fast reaction stage always corresponded to co-precipitated oxygen carrier. 9 redox cycles were also conducted to investigate the stability of oxygen carrier reactivity and the potassium loss with cycle number. It was concluded that the reactivity of co-precipitated oxygen carriers was more stable during 9 redox cycles. Especially for K10-cp (oxygen carriers of 10% potassium content by co-precipitation), fCO2 increased slightly and fCO changed very little with cycle number. According to morphological features of oxygen carriers, co-precipitation was superior to impregnation in preventing oxygen carrier particle sintering. On the other hand, although potassium contents of all K-decorated oxygen carriers decreased with cycle number, the potassium loss for co-precipitated oxygen carriers was smaller. K10-cp performed the best characteristic in avoiding potassium loss: the potassium content decreased from 8.47% (fresh oxygen carrier) to 7.79% (after 9 cycles). X-ray diffractometer (XRD) analysis showed that the potassium ferrite, K2Fe22O34, was presented in K-decorated oxygen carriers. Based on the peak intensity ratio of I K 2 Fe 22 O 34 / I Fe 2 O 3 , the higher the content of \\{K2Fe22O34\\} in K-decorated Fe2O3/Al2O3 oxygen carrier was, the larger the conversion of CO to CO2 was, and the shorter the time of fast reaction stage was. Therefore, it was inferred that \\{K2Fe22O34\\} acted as a support with catalytic effect. In addition, the content of \\{K2Fe22O34\\} was higher in co-precipitated oxygen carriers than that in impregnation oxygen carriers. It can be used to explain that why a better reactivity was always found for co-precipitated oxygen carriers.

Huijun Ge; Laihong Shen; Haiming Gu; Shouxi Jiang

2015-01-01T23:59:59.000Z

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

Dynamic modeling of the reactive twin-screw co-rotating extrusion process: experimental validation by using inlet  

E-Print Network [OSTI]

and modification.1 The co-rotating twin-screw extruder is of particular interest due to its modular geometry or removing chemical species.3,4 Furthermore, the co-rotating twin-screw extruder can handle high viscosityDynamic modeling of the reactive twin-screw co-rotating extrusion process: experimental validation

Paris-Sud XI, Université de

282

Structural, optical and electrical properties of WOxNy filmsdeposited by reactive dual magnetron sputtering  

SciTech Connect (OSTI)

Thin films of tungsten oxynitride were prepared by dual magnetron sputtering of tungsten using argon/oxygen/nitrogen gas mixtures with various nitrogen/oxygen ratios. The presence of even small amounts of oxygen had a great effect not only on the composition but on the structure of WOxNy films, as shown by Rutherford backscattering and x-ray diffraction, respectively. Significant incorporation of nitrogen occurred only when the nitrogen partial pressure exceeded 89 percent of the total reactive gas pressure. Sharp changes in the stoichiometry, deposition rate, room temperature resistivity, electrical activation energy and optical band gap were observed when the nitrogen/oxygen ratio was high.The deposition rate increased from 0.31 to 0.89 nm/s, the room temperature resistivity decreased from 1.65 x 108 to 1.82 x 10-2 ?cm, the electrical activation energy decreased from 0.97 to 0.067 eV, and the optical band gap decreased from 3.19 to 2.94 eV upon nitrogen incorporation into the films. WOxNy films were highly transparent as long as the nitrogen incorporation was low, and were brownish (absorbing) and partially reflecting as nitrogen incorporation became significant.

Mohamed, Sodky H.; Anders, Andre

2006-06-05T23:59:59.000Z

283

Application of computer modeling techniques to the kinetics of the reaction of carbon with oxygen  

SciTech Connect (OSTI)

Computer modeling techniques are applied to the kinetics of the reaction of carbon with oxygen. The rates of disappearance of oxygen, of formation of CO, CO/sub 2/ and the surface complex, measured over the temperature range 748-1173 K and the pressure range 0.5-400 Pa may be described by a mechanism involving adsorption of oxygen, formation of the strongly-bound complex, desorption of the complex and reaction of the complex with a gas-phase molecule of oxygen. The latter is shown to be an important source of CO/sub 2/ at low temperatures and higher pressures of oxygen. An important feature of the mechanism is the existence of at least two distinct types of active sites for the binding of the complex on the carbon surface, each with a characteristic reactivity. Most of the results on which the model is based were obtained using thin films of pyrolytic carbon, but some results from the oxidation of graphon are also consistent with the mechanism.

Ahmed, S.; Back, M.H.; Roscoe, J.M.

1989-01-01T23:59:59.000Z

284

Production of oxygen plasmas using radio-frequency magnetron-discharge  

Science Journals Connector (OSTI)

A new type of oxygen ion source has been developed in order to substantially prolong the lifetime of a conventional oxygen ion source for various plasma processes. In this ion source, an oxygen plasma is produced by coupling a 13.56 \\{MHz\\} radio-frequency (rf) field to a pair of rf electrodes placed in the region of a line cusp field. Two electrodes are positioned in such a way that accelerated electrons undergo magnetron type motion around them, efficiently producing a plasma around the electrodes (rf magnetron discharge). This plasma diffuses along the magnetic field line into the center region of the cusp field where the field strength is almost nil. The above process makes it possible to produce a large volume of uniform plasma. As a result, extraction of a large area oxygen-ion-beam from the new ion source is relatively easy. The lifetime of this ion source is virtually limitless, because it does not have any corrosive parts, such as a hot filament. The new ion source can be used with any kind of reactive gases as well as oxygen.

Takehisa Shibuya; Shizuyo Hashimoto; Eiji Yabe; Kazuo Takayama

1991-01-01T23:59:59.000Z

285

Muon Capture in Oxygen-16  

Science Journals Connector (OSTI)

The muon capture rate in oxygen is used as a means for measuring the induced pseudoscalar coupling constant (CP) of weak interactions. The capture rate between the JP=0+ ground state of O16 and the 0-, 1-, 2-, and 3- states of N16 are calculated as a function of CP with different nuclear models. Using the experimental values of the transition rates, we then determine CP. We find that the transition rate, and therefore CP, depends strongly on the nuclear model. We conclude that 5

Vincent Gillet and David A. Jenkins

1965-10-11T23:59:59.000Z

286

Design and synthesis of reactive separation systems  

SciTech Connect (OSTI)

During the last decade there has been a rapid upturn in interest in reactive distillation. The chemical process industry recognizes the favorable economics of carrying out reaction simultaneously with distillation for certain classes of reacting systems, and many new processes have been built based on this technology. Interest is also increasing by academics and software vendors. Systematic design methods for reactive distillation systems have only recently begun to emerge. In this report we survey the available design techniques and point out the contributions made by our group at the University of Massachusetts.

Doherty, M.F.

1992-01-01T23:59:59.000Z

287

Water reactive hydrogen fuel cell power system  

DOE Patents [OSTI]

A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into the fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

2014-11-25T23:59:59.000Z

288

Water reactive hydrogen fuel cell power system  

DOE Patents [OSTI]

A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into a fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

2014-01-21T23:59:59.000Z

289

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

Science Journals Connector (OSTI)

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

Magnus Rydén; Malin Källén; Dazheng Jing; Ali Hedayati; Tobias Mattisson; Anders Lyngfelt

2014-01-01T23:59:59.000Z

290

Formation and Reactivity of Biogenic Iron Microminerals  

SciTech Connect (OSTI)

The overall purpose of the project is to explore and quantify the processes that control the formation and reactivity of biogenic iron microminerals and their impact on the solubility of metal contaminants. The research addresses how surface components of bacterial cells, extracellular organic material, and the aqueous geochemistry of the DIRB microenvironment impacts the mineralogy, chemical state and micromorphology of reduced iron phases.

Beveridge, Terrance J.; Glasauer, Susan; Korenevsky, Anton; Ferris, F. Grant

2000-08-08T23:59:59.000Z

291

Controlling uranium reactivity March 18, 2008  

E-Print Network [OSTI]

for the last decade. Most of their work involves depleted uranium, a more common form of uraniumMarch 2008 Controlling uranium reactivity March 18, 2008 Uranium is an often misunderstood metal uranium research. In reality, uranium presents a wealth of possibilities for funda- mental chemistry. Many

Meyer, Karsten

292

Device and method for separating oxygen isotopes  

DOE Patents [OSTI]

A device and method for separating oxygen isotopes with an ArF laser which produces coherent radiation at approximately 193 nm. The output of the ArF laser is filtered in natural air and applied to an irradiation cell where it preferentially photodissociates molecules of oxygen gas containing .sup.17 O or .sup.18 O oxygen nuclides. A scavenger such as O.sub.2, CO or ethylene is used to collect the preferentially dissociated oxygen atoms and recycled to produce isotopically enriched molecular oxygen gas. Other embodiments utilize an ArF laser which is narrowly tuned with a prism or diffraction grating to preferentially photodissociate desired isotopes. Similarly, desired mixtures of isotopic gas can be used as a filter to photodissociate enriched preselected isotopes of oxygen.

Rockwood, Stephen D. (Los Alamos, NM); Sander, Robert K. (Los Alamos, NM)

1984-01-01T23:59:59.000Z

293

A survey of alternative oxygen production technologies  

Science Journals Connector (OSTI)

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

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

2001-01-01T23:59:59.000Z

294

Oxygen penetration into the bulk of palladium  

Science Journals Connector (OSTI)

Oxygen penetration into the bulk of palladium ... During heating, the reaction rate exhibited an activity maximum at 650 K, whereas no activity maximum was found during the ... ...

C. T. Campbell; D. C. Foyt; J. M. White

1977-01-01T23:59:59.000Z

295

Oxygen-Enriched Combustion | Department of Energy  

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

tip sheet discusses how an increase in oxygen in combustion air can reduce the energy loss in the exhaust gases and increase process heating system efficiency. PROCESS HEATING...

296

Renewable Oxygenate Blending Effects on Gasoline Properties  

Science Journals Connector (OSTI)

Renewable Oxygenate Blending Effects on Gasoline Properties ... National Renewable Energy Laboratory, Golden, Colorado 80401, United States ... Energy Fuels, 2011, 25 (10), ...

Earl Christensen; Janet Yanowitz; Matthew Ratcliff; Robert L. McCormick

2011-08-16T23:59:59.000Z

297

Oxygen Concentration Microgradients for Cell Culture.  

E-Print Network [OSTI]

??There is a growing need for technology that can control microscale oxygen gradients onto a tissue or culture sample in vitro. This dissertation introduces the… (more)

Park, Jaehyun

2010-01-01T23:59:59.000Z

298

Oxygen ion-beam microlithography  

DOE Patents [OSTI]

A method of providing and developing a resist on a substrate for constructing integrated circuit (IC) chips includes the following steps: of depositing a thin film of amorphous silicon or hydrogenated amorphous silicon on the substrate and exposing portions of the amorphous silicon to low-energy oxygen ion beams to oxidize the amorphous silicon at those selected portions. The nonoxidized portions are then removed by etching with RF-excited hydrogen plasma. Components of the IC chip can then be constructed through the removed portions of the resist. The entire process can be performed in an in-line vacuum production system having several vacuum chambers. Nitrogen or carbon ion beams can also be used. 5 figures.

Tsuo, Y.S.

1991-08-20T23:59:59.000Z

299

Oxygen ion-beam microlithography  

DOE Patents [OSTI]

A method of providing and developing a resist on a substrate for constructing integrated circuit (IC) chips includes the following steps: of depositing a thin film of amorphous silicon or hydrogenated amorphous silicon on the substrate and exposing portions of the amorphous silicon to low-energy oxygen ion beams to oxidize the amorphous silicon at those selected portions. The nonoxidized portions are then removed by etching with RF-excited hydrogen plasma. Components of the IC chip can then be constructed through the removed portions of the resist. The entire process can be performed in an in-line vacuum production system having several vacuum chambers. Nitrogen or carbon ion beams can also be used.

Tsuo, Y. Simon (Lakewood, CO)

1991-01-01T23:59:59.000Z

300

Cell Comp't Thermal Reactivity & Improvements | Department of...  

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

Comp't Thermal Reactivity & Improvements Cell Comp't Thermal Reactivity & Improvements Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008 on...

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

Isotope effects in methanol synthesis and the reactivity of copper...  

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

Isotope effects in methanol synthesis and the reactivity of copper formates on a CuSiO2 catalyst. Isotope effects in methanol synthesis and the reactivity of copper formates on a...

302

Design of processes with reactive distillation line diagrams  

SciTech Connect (OSTI)

On the basis of the transformation of concentration coordinates, the concept of reactive distillation lines is developed. It is applied to study the feasibility of a reactive distillation with an equilibrium reaction on all trays of a distillation column. The singular points in the distillation line diagrams are characterized in terms of nodes and saddles. Depending on the characterization of the reactive distillation line diagrams, it can be decided whether a column with two feed stages is required. On the basis of the reaction space concept, a procedure for identification of reactive distillation processes is developed, in which the reactive distillation column has to be divided into reactive and nonreactive sections. This can be necessary to overcome the limitations in separation which result from the chemical equilibrium. The concentration profile of this combined reactive/nonreactive distillation column is estimated using combined reactive/nonreactive distillation lines.

Bessling, B. [BASF Ludwigshafen (Germany). Engineering Research and Development] [BASF Ludwigshafen (Germany). Engineering Research and Development; Schembecker, G.; Simmrock, K.H. [Univ. of Dortmund (Germany). Dept. of Chemical Engineering] [Univ. of Dortmund (Germany). Dept. of Chemical Engineering

1997-08-01T23:59:59.000Z

303

Transient oxygen consumption rate measurements with the BDT?M? oxygen biosensor system  

E-Print Network [OSTI]

Oxygen consumption rate (OCR) is a reliable indicator of tissue health. Recently, the OCR of isolated human islets has been shown to predict transplant outcome in diabetic mice. The Oxygen Biosensor System (OBS) is a ...

Low, Clarke Alan

2008-01-01T23:59:59.000Z

304

Nitric oxide inhibition of soot oxidation by oxygen atoms at 298/sup 0/Ktiation  

SciTech Connect (OSTI)

Nitric oxide is observed to inhibit the rate of soot oxidation by oxygen atoms at 298 K. Small amounts of added NO reduce the rates of production of CO/sub 2/ and CO by up to 35%. The authors show experimentally that NO is not reducing the gas phase O atom concentration. Thermal description mass spectrometry is used to measure the small adsorption of NO on the soot; this NO adsorption corresponds to 1.5% of the carbon atoms on the surface of the individual soot spheres. This inhibition is interpreted in terms of a relatively small number of reactive sites on the soot at which soot gasification occurs and which are effectively blocked by NO. When considered together with our previously reported work on oxidation of soot by oxygen atoms at 298 K, these results allow a partial mechanism to be formulated for this soot oxidation process.

Wicke, B.G.; Grady, K.A.

1987-01-01T23:59:59.000Z

305

In situ gasification chemical looping combustion of a coal using the binary oxygen carrier natural anhydrite ore and natural iron ore  

Science Journals Connector (OSTI)

Abstract CaSO4 is an attractive oxygen carrier for Chemical–looping combustion (CLC), because of its high oxygen capacity and low price. But the utilization of CaSO4 oxygen carrier suffers the problems of low reactivity, deactivation caused by sulfur loss and the incomplete fuel conversion due to the thermodynamic limitations. To improve the stability and reactivity of CaSO4 oxygen carrier, a small amount of natural iron ore were added in. The kinetic behavior and thermodynamics of the reduction of the binary oxygen carrier by coal under steam atmosphere were investigated. The results show that Fe2O3 improves the performance of coal gasification and the subsequent conversion of coal syngas to CO2 and H2O. Besides, the addition of Fe2O3 reduces the chance of CaSO4 reduction to CaO by coal syngas, and the oxygen transfer capacity of CaSO4 is maintained. The optimal reaction conditions in fuel reactor are shifted from 950 °C without Fe2O3 to 900 °C with 7% Fe2O3. And the decreases in CO, SO2 and H2S environmental factors can be well up to 81.48%, 76.35% and 100%, respectively. Meanwhile, the CO2 concentration in the dry gas products increases from 81.63% up to 95.35%.

Min Zheng; Laihong Shen; Xiaoqiong Feng

2014-01-01T23:59:59.000Z

306

High density adsorbed oxygen on Rh,,111... and enhanced routes to metallic oxidation using atomic oxygen  

E-Print Network [OSTI]

High density adsorbed oxygen on Rh,,111... and enhanced routes to metallic oxidation using atomic oxygen K. D. Gibson, Mark Viste, Errol C. Sanchez, and S. J. Sibener The James Franck Institute; accepted 30 November 1998 Exposure of Rh 111 to atomic oxygen leads to the facile formation of a full

Sibener, Steven

307

Isotopes Environ. Health Stud., 2003, Vol. 39(1), pp. 4152 TREE SPECIES OF THE CENTRAL AMAZON AND  

E-Print Network [OSTI]

AND SOIL MOISTURE ALTER STABLE ISOTOPE COMPOSITION OF NITROGEN AND OXYGEN IN NITROUS OXIDE EVOLVED FROM SB RAS, Krasnoyarsk, Russia; b Department of Biological Sciences and Merriam-Powell Center; Oxygen 18; Tree species; Tropical soils INTRODUCTION The increase in the atmospheric concentration

Lehmann, Johannes

308

Reactivity control assembly for nuclear reactor. [LMFBR  

DOE Patents [OSTI]

This invention, which resulted from a contact with the United States Department of Energy, relates to a control mechanism for a nuclear reactor and, more particularly, to an assembly for selectively shifting different numbers of reactivity modifying rods into and out of the core of a nuclear reactor. It has been proposed heretofore to control the reactivity of a breeder reactor by varying the depth of insertion of control rods (e.g., rods containing a fertile material such as ThO/sub 2/) in the core of the reactor, thereby varying the amount of neutron-thermalizing coolant and the amount of neutron-capturing material in the core. This invention relates to a mechanism which can advantageously be used in this type of reactor control system.

Bollinger, L.R.

1982-03-17T23:59:59.000Z

309

Mined land reclamation by biological reactivation  

SciTech Connect (OSTI)

A mine reclamation technique, developed in Europe, restores land to full productivity within two years without topsoil replacement. The method deliberately reestablishes within one year following mining, the required biological balance between microbes, enzymes, and trace elements in the rock spoil rather than waiting five or more years for natural processes to restore balance. The technique is called Biological Reactivation (BR). This paper discusses the feasibility of BR reclamation after surface mining operations in the US. Staff of the Ohio Mining and Mineral Resources Research Institute completed an OSM-sponsored research project on BR in which physical and chemical tests characterized 140 spoil samples obtained from 10 surface mining operations. Test results indicated that Biological Reactivation technology could be effectively applied, at least in the test areas sampled within Appalachia. Preliminary estimates make clear that the new technique reduces reclamation costs on prime farmland by approximately 95% compared to topsoil segregation and replacement methods.

Gozon, J.S.; Konya, C.J.; Lukovic, S.S.; Lundquist, R.G.; Olah, J.

1982-12-01T23:59:59.000Z

310

Cell Comp't Thermal Reactivity & Improvements  

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

the role of each cell material on the safety of the battery Correlate the loss of oxygen from the charged cathode "LiNi 0.8 Co 0.15 Al 0.05 O 2 , LiNi 13 Co 13 Mn...

311

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

This quarterly technical progress report will summarize work accomplished for the Program through the fourth quarter January-March 2001 in the following task areas: Task 1 - Oxygen Enhanced Combustion, Task 2 - Oxygen Transport Membranes and Task 4 - Program Management. This report will also recap the results of the past year. The program is proceeding in accordance with the objectives for the first year. OTM material characterization was completed. 100% of commercial target flux was demonstrated with OTM disks. The design and assembly of Praxair's single tube high-pressure test facility was completed. The production of oxygen with a purity of better than 99.5% was demonstrated. Coal combustion testing was conducted at the University of Arizona. Modest oxygen enhancement resulted in NOx emissions reduction. The injector for oxygen enhanced coal based reburning was conducted at Praxair. Combustion modeling with Keystone boiler was completed. Pilot-scale combustion test furnace simulations continued this quarter.

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

2001-04-01T23:59:59.000Z

312

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

313

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

314

Use of coal as fuel for chemical-looping combustion with Ni-based oxygen carrier  

SciTech Connect (OSTI)

Chemical-looping combustion is an indirect combustion technology with inherent separation of the greenhouse gas CO{sub 2}. The feasibility of using NiO as an oxygen carrier during chemical-looping combustion of coal has been investigated experimentally at 800-960{degree}C in the present work. The experiments were carried out in a fluidized bed, where the steam acted as the gasification-fluidization medium. Coal gasification and the reaction of oxygen carrier with the water gas take place simultaneously in the reactor. The oxygen carrier particles exhibit high reactivity above 900{degree}C, and the dry basis concentration of CO{sub 2} in the exit gas of the reactor is nearly 95%. The flue gas composition as a function of the reactor temperature and cyclic reduction number is discussed. At 800-960{degree}C, the dry basis concentration of CO{sub 2} in the flue gas presents a monotonously increasing trend, whereas the dry basis concentration of CO, H{sub 2}, and CH{sub 4} decreases monotonously. The concentrations of CO{sub 2}, CO, H{sub 2}, and CH{sub 4} in the flue gas as a function of cyclic reduction number present a para-curve characteristic at 900{degree}C. With the increase of cyclic reduction number, the dry basis concentration of CO{sub 2} decreases remarkably, while the dry basis concentrations of CO, H{sub 2}, and CH{sub 4} increase rapidly. Moreover, the peak value of H{sub 2} concentration is less than that of CO. The performance of the NiO-based oxygen carriers was also evaluated using an X-ray diffractometer and a scanning electron microscope to characterize the solid residues of oxygen carrier. The results indicate that NiO is one of the suitable oxygen carriers for chemical-looping combustion of coal.

Gao, Z.P.; Shen, L.H.; Xiao, J.; Qing, C.J.; Song, Q.L. [Southeast University, Nanjing (China). Thermoenergy Engineering Research Institute

2008-12-15T23:59:59.000Z

315

XCHEM-1D: A Heat Transfer/Chemical Kinetics Computer Program for multilayered reactive materials  

SciTech Connect (OSTI)

An eXplosive CHEMical kinetics code, XCHEM, has been developed to solve the reactive diffusion equations associated with thermal ignition of energetic materials. This method-of-lines code uses stiff numerical methods and adaptive meshing to resolve relevant combustion physics. Solution accuracy is maintained between multilayered materials consisting of blends of reactive components and/or inert materials. Phase change and variable properties are included in one-dimensional slab, cylindrical and spherical geometries. Temperature-dependent thermal properties have been incorporated and the modification of thermal conductivities to include decomposition effects are estimated using solid/gas volume fractions determined by species fractions. Gas transport properties, including high pressure corrections, have also been included. Time varying temperature, heat flux, convective and thermal radiation boundary conditions, and layer to layer contact resistances have also been implemented.

Gross, R.J.; Baer, M.R.; Hobbs, M.L.

1993-10-01T23:59:59.000Z

316

Singlet oxygen luminescence detection with a fibre-coupled superconducting  

E-Print Network [OSTI]

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

Greenaway, Alan

317

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

318

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

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

319

Community Ecology & Species Assemblages  

E-Print Network [OSTI]

Tropical regions ­ most diverse More solar energy, large geographic area, more stable, better climate] Uniformity of abundance in an assemblage of species. #12;3 Region X Region Y Site 3 Site 4 Site 1 Site 2 affected by several factors: Elevation, precipitation, climate, latitude affect species distributions

Dever, Jennifer A.

320

Evidence for reactive reduced phosphorus species in the early Archean ocean  

Science Journals Connector (OSTI)

...inductively coupled plasma (ICP) mass spectrometer...outline of the study area. Fig. 2. Stratigraphic...clastic sediments or large-scale cross-bedding...of an oxidizing atmosphere, have provided a...filters to remove large solids. The solutions...analyzed on a 400-MHz Varian UnityInova...operating at 161.9 MHz in both H-coupled...

Matthew A. Pasek; Jelte P. Harnmeijer; Roger Buick; Maheen Gull; Zachary Atlas

2013-01-01T23:59:59.000Z

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

Evidence for reactive reduced phosphorus species in the early Archean ocean  

Science Journals Connector (OSTI)

...origin if lightning and geothermal sources can be eliminated...16). Phosphite from geothermal sources has been detected...together indicate a low-energy depositional setting...Earth that led to the development of life. If the source...available subsequently. Our research demonstrates the availability...

Matthew A. Pasek; Jelte P. Harnmeijer; Roger Buick; Maheen Gull; Zachary Atlas

2013-01-01T23:59:59.000Z

322

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 increased animal activity associated with increasing bottom-water oxygen concentration. We examined faunal community responses to oxygen and organic matter gradients across the lower oxygen minimum zone (OMZ

Levin, Lisa

323

Thermochemical Modeling of the Uranium-Cerium-Oxygen System  

SciTech Connect (OSTI)

The objective of the Fuel Cycle R&D Program, Advanced Fuels campaign is to provide the research and development necessary to develop low loss, high quality nuclear fuels for ultra-high burnup reactor operation. Primary work in this area will be focused on the ceramic and metallic fuel systems. The goal of the current work is to enhance the understanding of ceramic nuclear fuel thermochemistry to support fuel research and development efforts. The thermochemical behavior of oxide nuclear fuel under irradiation is dependent on the oxygen to metal ratio (O:M). In fluorite-structured fuel, the actinide metal cation is bonded with {approx}2 oxygen atoms on a crystal lattice and as the metal atoms fission, fission fragments and free oxygen are created. The resulting fission fragments will contain some oxide forming elements, however these are insufficient to bind to all the liberated oxygen and therefore, there is an average increase in O:M with fuel burnup. Some of the fission products also form species that will migrate to and react with the cladding surface in a phenomenon known as Fuel Clad Chemical Interaction (FCCI). Cladding corrosion is life-limiting so it is desirable to understand influencing factors, such as oxide thermochemistry, which can be used to guide the design and fabrication of higher burn up fuel. A phased oxide fuel thermochemical model development effort is underway within the Advanced Fuels Campaign. First models of binary oxide systems are developed. For nuclear fuel system this means U-O and transuranic systems such as Pu-O, Np-O and Am-O. Next, the binary systems will be combined to form pseudobinary systems such as U-Pu-O, etc. The model development effort requires the use of data to allow optimization based on known thermochemical parameters as a function of composition and temperature. Available data is mined from the literature and supplemented by experimental work as needed. Due to the difficulty of performing fuel fabrication development with actinide materials, fundamental studies with uranium are performed using surrogate materials as stand-ins for transuranic elements. In most cases, cerium can be used as a suitable substitute for plutonium when performing O:M and sintering kinetics studies because of identical valence states. Differences exist between the magnitude of reported thermodynamic data of (U,Pu)O{sub x} and (U,Ce)O{sub x}, however the change in oxygen potential versus O:M follows the same trend for both systems. Cerium is also a major fission product element, and thus understanding its behavior in fuel is an important issue as well.

Voit, Stewart L [ORNL; Besmann, Theodore M [ORNL

2010-10-01T23:59:59.000Z

324

Natural Ores as Oxygen Carriers in Chemical Looping Combustion  

Science Journals Connector (OSTI)

Natural Ores as Oxygen Carriers in Chemical Looping Combustion ... Chemical looping combustion (CLC) is a combustion technology that utilizes oxygen from oxygen carriers (OC), such as metal oxides, instead of air to combust fuels. ...

Hanjing Tian; Ranjani Siriwardane; Thomas Simonyi; James Poston

2013-01-02T23:59:59.000Z

325

Blood oxygen transport and depletion : the key of consummate divers  

E-Print Network [OSTI]

and Dill, D. B. (1935). Oxygen dissociation curves of birdE. (1964). A venous blood oxygen reservoir in the divingand Torrance, J. D. (1977). Oxygen-Affinity of Avian Blood.

Meir, Jessica Ulrika

2009-01-01T23:59:59.000Z

326

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

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

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

327

Kinetics and mechanisms of reactions involving small aromatic reactive intermediates  

SciTech Connect (OSTI)

Small aromatic radicals such as C{sub 6}H{sub 5}, C{sub 6}H{sub 5}O and C{sub 6}H{sub 4} are key prototype species of their homologs. C{sub 6}H{sub 5} and its oxidation product, C{sub 6}H{sub 5}O are believed to be important intermediates which play a pivotal role in hydrocarbon combustion, particularly with regard to soot formation. Despite their fundamental importance, experimental data on the reaction mechanisms and reactivities of these species are very limited. For C{sub 6}H{sub 5}, most kinetic data except its reactions with NO and NO{sub 2}, were obtained by relative rate measurements. For C{sub 6}H{sub 5}O, the authors have earlier measured its fragmentation reaction producing C{sub 5}H{sub 5} + CO in shock waves. For C{sub 6}H{sub 4}, the only rate constant measured in the gas phase is its recombination rate at room temperature. The authors have proposed to investigate systematically the kinetics and mechanisms of this important class of molecules using two parallel laser diagnostic techniques--laser resonance absorption (LRA) and resonance enhanced multiphoton ionization mass spectrometry (REMPI/MS). In the past two years, study has been focused on the development of a new multipass adsorption technique--the {open_quotes}cavity-ring-down{close_quotes} technique for kinetic applications. The preliminary results of this study appear to be quite good and the sensitivity of the technique is at least comparable to that of the laser-induced fluorescence method.

Lin, M.C. [Emory Univ., Atlanta, GA (United States)

1993-12-01T23:59:59.000Z

328

Oxygen Tension Modulates Neurite Outgrowth in PC12 Cells Through A Mechanism Involving HIF and VEGF  

E-Print Network [OSTI]

neural repair. Keywords Oxygen tension . Neurite extension .respective physiological oxygen microenvironments (Chen etet al. 2008). For example, oxygen tension differentially

Genetos, Damian C.; Cheung, Whitney K.; Decaris, Martin L.; Leach, J. Kent

2010-01-01T23:59:59.000Z

329

Long-term oxygen sensor implantation in the porcine subcutaneous environment  

E-Print Network [OSTI]

Membrane-­?Covered  Oxygen  Electrode.   Analytical  Microvascular  and  tissue  oxygen   distribution.  vitro  stability  of  an  oxygen  sensor.   Anal  Chem,  

Kumosa, Lucas Stefan

2011-01-01T23:59:59.000Z

330

Effect of temperature on reduction of CaSO{sub 4} oxygen carrier in chemical-looping combustion of simulated coal gas in a fluidized bed reactor  

SciTech Connect (OSTI)

Chemical-looping combustion (CLC) is a promising combustion technology for gaseous and solid fuel with efficient use of energy and inherent separation of CO{sub 2}. The concept of a coal-fueled CLC system using, calcium sulfate (CaSO{sub 4}) as oxygen carrier is proposed in this study. Reduction tests of CaSO{sub 4} oxygen carrier with simulated coal gas were performed in a laboratory-scale fluidized bed reactor in the temperature range of 890-950{degree}C. A high concentration of CO{sub 2} was obtained at the initial reduction period. CaSO{sub 4} oxygen carrier exhibited high reactivity initially and decreased gradually at the late period of reduction. The sulfur release during the reduction of CaSO{sub 4} as oxygen carrier was also observed and analyzed. H{sub 2} and CO{sub 2} conversions were greatly influenced by reduction temperature. The oxygen carrier conversion and mass-based reaction rates during the reduction at typical temperatures were compared. Higher temperatures would enhance reaction rates and result in high conversion of oxygen carrier. An XRD patterns study indicated that CaS was the dominant product of reduction and the variation of relative intensity with temperature is in agreement with the solid conversion. ESEM analysis indicated that the surface structure of oxygen carrier particles changed significantly from impervious to porous after reduction. EDS analysis also demonstrated the transfer of oxygen from the oxygen carrier to the fuel gas and a certain amount of sulfur loss and CaO formation on the surface at higher temperatures. The reduction kinetics of CaSO{sub 4} oxygen carrier was explored with the shrinking unreacted-core model. The apparent kinetic parameters were obtained, and the kinetic equation well predicted the experimental data. Finally, some basic considerations on the use of CaSO{sub 4} oxygen carrier in a CLC system for solid fuels were discussed.

Song, Q.L.; Xiao, R.; Deng, Z.Y.; Shen, L.H.; Xiao, J.; Zhang, M.Y. [Southeast University, Nanjing (China)

2008-12-15T23:59:59.000Z

331

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

E-Print Network [OSTI]

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

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

2007-01-11T23:59:59.000Z

332

Reactive gases evolved during pyrolysis of Devonian oil shale  

SciTech Connect (OSTI)

Computer modeling of oil shale pyrolysis is an important part of the Lawrence Livermore National Laboratory (LLNL) Oil Shale Program. Models containing detailed chemistry have been derived from an investigation of Colorado oil shale. We are currently attempting to use models to treat more completely reactions of nitrogen and sulfur compounds in the retort to better understand emissions. Batch retorting work on Devonian oil shale is proving particularly useful for this study of nitrogen/sulfur chemistry. Improved analytical methods have been developed to quantitatively determine reactive volatiles at the parts-per-million level. For example, the triple quadrupole mass spectrometer (TQMS) is used in the chemical ionization (CI) mode to provide real-time analytical data on ammonia evolution as the shale is pyrolyzed. A heated transfer line and inlet ensure rapid and complete introduction of ammonia to the instrument by preventing water condensation. Ammonia and water release data suitable for calculating kinetic parameters have been obtained from a New Albany Shale sample. An MS/MS technique with the TQMS in the electron ionization (EI) mode allows hydrogen sulfide, carbonyl sulfide, and certain trace organic sulfur compounds to be monitored during oil shale pyrolysis. Sensitivity and selectivity for these compounds have been increased by applying artificial intelligence techniques to tuning of the spectrometer. Gas evolution profiles (100 to 900/sup 0/C) are reported for hydrogen sulfide, water, ammonia, and trace sulfur species formed during pyrolysis of Devonian oil shale. Implications for retorting chemistry are discussed. 18 refs., 11 figs., 3 tabs.

Coburn, T.T.; Crawford, R.W.; Gregg, H.R.; Oh, M.S.

1986-11-01T23:59:59.000Z

333

A coupled-physics model for the vanadium oxygen fuel cell  

Science Journals Connector (OSTI)

Abstract A stationary two-dimensional model for the vanadium oxygen fuel cell is developed. The model consists of a single cell with two membranes, set up as of two half-cells and an intermediate chamber. The transport and balance of mass, momentum and charge are linked to the electrochemical reaction kinetics of the vanadium species and oxygen. The kinetic model for the cathode half-cell is extended by an empirical logistic function to describe the transient behavior of the half-cell. Additionally, experiments are conducted on a single vanadium oxygen fuel cell with 40 cm2 active membrane area. The experimental results are used to validate the simulation data. The effects of constant current discharging, polarization behavior and different flow rates on the cathode overpotential are studied by means of this model.

F.T. Wandschneider; M. Küttinger; J. Noack; P. Fischer; K. Pinkwart; J. Tübke; H. Nirschl

2014-01-01T23:59:59.000Z

334

Tetraoxygen on Reduced Ti02(110): Oxygen Adsorption and Reactions...  

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

Tetraoxygen on Reduced Ti02(110): Oxygen Adsorption and Reactions with Oxygen Vacancies. Tetraoxygen on Reduced Ti02(110): Oxygen Adsorption and Reactions with Oxygen Vacancies....

335

Reactive sticking coefficients of silane on silicon  

SciTech Connect (OSTI)

Reactive sticking coefficients (RSCs) were measured for silane and disilane on polycrystalline silicon for a wide range of temperature and flux (pressure) conditions. The data were obtained from deposition rate measurements using molecular beam scattering and a very low pressure cold wall reactor. The RSCs have non-Arrhenius temperature dependences and decreases with increasing flux at low (710/sup 0/) temperatures. A simple model involving dissociative adsorption of silane is consistent with these results. The results are compared with previous studies of the SiH/sub 4//Si(s) reaction.

Buss, R.J.; Ho, P.; Breiland, W.G.; Coltrin, M.E.

1988-09-15T23:59:59.000Z

336

Cellular-automaton model for reactive systems  

Science Journals Connector (OSTI)

A method for constructing a variety of probabilistic lattice-gas cellular automata for chemically reacting systems is described. The microscopic reactive dynamics give rise to a general fourth-order polynomial rate law for the average particle density. The reduction of the microdynamical equations to a discrete or continuous Boltzmann equation is presented. Connection between the linearized Boltzmann equations and a reaction-diffusion macroscopic equation is discussed. As an example of the general formalism a set of cellular automata rules that yield the Schlögl phenomenological model is constructed. Simulation results are presented.

David Dab; Anna Lawniczak; Jean-Pierre Boon; Raymond Kapral

1990-05-14T23:59:59.000Z

337

Theoretical and Experimental Evaluation of Chemical Reactivity  

E-Print Network [OSTI]

released and the rate of energy released for a specific reactive chemical. 2.1 DSC DSC is a popular screening tool (safe and fast) and can provide an overall indication of exothermic activity of the chemical being tested. In a DSC, a sample and a... endothermic or exothermic reaction. When the rate of heat generation in the sample exceeds a particular value, the heat supply to the sample is cut off and this additional heat gain is attributed to exothermic activity within the sample.17 From the DSC...

Wang, Qingsheng

2011-10-21T23:59:59.000Z

338

Preparation of reactive beta-dicalcium silicate  

DOE Patents [OSTI]

This invention relates to the preparation of fine particles of reactive beta-dicalcium silicate by means of a solid state process which comprises firing a mixture of calcium sulfate, silica and a reducing additive selected from the group consisting of calcium sulfide, carbon, carbon monoxide, methane and hydrogen, at a temperature of about 850.degree.-1000.degree. C. A carrier gas such as nitrogen or carbon dioxide may also be added, if desired. A high concentration of sulfur dioxide is a by-product of this process.

Shen, Ming-Shing (Laramie, WY, NJ); Chen, James M. (Rahway, NJ); Yang, Ralph T. (Amherst, NY)

1982-01-01T23:59:59.000Z

339

IAEA sodium void reactivity benchmark calculations  

SciTech Connect (OSTI)

In this paper, the IAEA-1 992 ``Benchmark Calculation of Sodium Void Reactivity Effect in Fast Reactor Core`` problem is evaluated. The proposed design is a large axially heterogeneous oxide-fueled fast reactor as described in Section 2; the core utilizes a sodium plenum above the core to enhance leakage effects. The calculation methods used in this benchmark evaluation are described in Section 3. In Section 4, the calculated core performance results for the benchmark reactor model are presented; and in Section 5, the influence of steel and interstitial sodium heterogeneity effects is estimated.

Hill, R.N.; Finck, P.J.

1992-12-01T23:59:59.000Z

340

IAEA sodium void reactivity benchmark calculations  

SciTech Connect (OSTI)

In this paper, the IAEA-1 992 Benchmark Calculation of Sodium Void Reactivity Effect in Fast Reactor Core'' problem is evaluated. The proposed design is a large axially heterogeneous oxide-fueled fast reactor as described in Section 2; the core utilizes a sodium plenum above the core to enhance leakage effects. The calculation methods used in this benchmark evaluation are described in Section 3. In Section 4, the calculated core performance results for the benchmark reactor model are presented; and in Section 5, the influence of steel and interstitial sodium heterogeneity effects is estimated.

Hill, R.N.; Finck, P.J.

1992-01-01T23:59:59.000Z

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

Density Functional Theory Study of Oxygen Reduction Activity...  

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

Study of Oxygen Reduction Activity on Ultrathin Platinum Nanotubes. Density Functional Theory Study of Oxygen Reduction Activity on Ultrathin Platinum Nanotubes. Abstract: The...

342

Oxygen Carriers for Solid Fuel Chemical Looping Combustion Process...  

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

Oxygen Carriers for Solid Fuel Chemical Looping Combustion Process Regenerable Mixed Copper-Iron-Inert Support Oxygen Carriers National Energy Technology Laboratory Contact NETL...

343

Testing Oxygen Reduction Reaction Activity with the Rotating...  

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

Testing Oxygen Reduction Reaction Activity with the Rotating Disc Electrode Technique Testing Oxygen Reduction Reaction Activity with the Rotating Disc Electrode Technique...

344

Oxygen Diffusion (OD) Dramatically Improves Wear-Resistance of...  

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

Oxygen Diffusion (OD) Dramatically Improves Wear-Resistance of Titanium Oxygen Diffusion (OD) Dramatically Improves Wear-Resistance of Titanium 2007 Diesel Engine-Efficiency &...

345

Oxygen detected in atmosphere of Saturn's moon Dione  

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

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

346

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

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

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

347

Effects of Oxygen-Containing Functional Groups on Supercapacitor...  

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

Oxygen-Containing Functional Groups on Supercapacitor Performance. Effects of Oxygen-Containing Functional Groups on Supercapacitor Performance. Abstract: Molecular dynamics (MD)...

348

Isolation, Characterization of an Intermediate in an Oxygen Atom...  

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

Characterization of an Intermediate in an Oxygen Atom-Transfer Reaction, and the Determination of the Bond Isolation, Characterization of an Intermediate in an Oxygen Atom-Transfer...

349

Direct Measurement of Oxygen Incorporation into Thin Film Oxides...  

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

Measurement of Oxygen Incorporation into Thin Film Oxides at Room Temperature Upon Ultraviolet Phton Irradiation. Direct Measurement of Oxygen Incorporation into Thin Film Oxides...

350

Oxygen Transport Studies in Nanocrystalline Ceria Films. | EMSL  

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

Transport Studies in Nanocrystalline Ceria Films. Oxygen Transport Studies in Nanocrystalline Ceria Films. Abstract: Oxygen uptake and conductivity were measured by nuclear...

351

Lattice Distortions and Oxygen Vacancies Produced in Au+-Irradiated...  

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

Lattice Distortions and Oxygen Vacancies Produced in Au+-Irradiated Nanocrystalline Cubic Zirconia. Lattice Distortions and Oxygen Vacancies Produced in Au+-Irradiated...

352

Density Functional Study of the Structure, Stability and Oxygen...  

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

Study of the Structure, Stability and Oxygen Reduction Activity of Ultrathin Platinum Nanowires. Density Functional Study of the Structure, Stability and Oxygen Reduction Activity...

353

Electron-Stimulated Production of Molecular Oxygen in Amorphous...  

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

Water. Electron-Stimulated Production of Molecular Oxygen in Amorphous Solid Water. Abstract: The low-energy, electron-stimulated production of molecular oxygen from pure amorphous...

354

Bimetallic and Ternary Alloys for Improved Oxygen Reduction Catalysis...  

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

Bimetallic and Ternary Alloys for Improved Oxygen Reduction Catalysis . Bimetallic and Ternary Alloys for Improved Oxygen Reduction Catalysis . Abstract: The research described in...

355

Advantages of Oxygenates Fuels over Gasoline in Direct Injection...  

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

Advantages of Oxygenates Fuels over Gasoline in Direct Injection Spark Ignition Engines Advantages of Oxygenates Fuels over Gasoline in Direct Injection Spark Ignition Engines...

356

LED–LED portable oxygen gas sensor  

Science Journals Connector (OSTI)

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

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

2012-12-01T23:59:59.000Z

357

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

This quarterly technical progress report will summarize work accomplished for the Program through the thirteenth quarter, April-June 2003, in the following task areas: Task 1--Oxygen Enhanced Combustion, Task 3--Economic Evaluation and Task 4--Program Management. The program is proceeding in accordance with project objectives. REI's model was modified to evaluate mixing issues in the upper furnace of a staged unit. Analysis of the results, and their potential application to this unit is ongoing. Economic evaluation continues to confirm the advantage of oxygen-enhanced combustion. A contract for a commercial demonstration has been signed with the Northeast Generation Services Company to supply oxygen and license the oxygen enhanced low NOx combustor technology for use at the 147-megawatt coal fired Mt. Tom Station in Holyoke, MA. Commercial proposals have been submitted. Economic analysis of a beta site test performance was conducted.

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

2003-08-01T23:59:59.000Z

358

Electron-impact excitation of neutral oxygen  

E-Print Network [OSTI]

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

P. S. Barklem

2006-09-25T23:59:59.000Z

359

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

360

Interactions of oxygen with Zr(0001)  

SciTech Connect (OSTI)

Interaction of oxygen with Zr(0001) have been studied using low energy electron diffraction (LEED), work function ([Delta][phi]), static and dynamic secondary ion mass spectrometry (SSIMS, DSIMS), thermal desorption spectroscopy (TDS), Auger electron spectroscopy (AES) and nuclear reaction analysis (NRA). The initial sticking coefficient of oxygen is close to unity up to [approximately]0.75 ML at 90, 293 and 473 K. Oxygen chemisorption is disordered at room temperature and below. Heating the disordered surface to [approximately]473 K causes all oxygen to move to subsurface sites. A (1x2) ordered oxygen underlayer is formed consisting of three rotated domains of (1x2) superstructure with the oxygen atoms located between the first and second planes of zirconium atoms. This structure is stable up to about 573 K, above which temperature oxygen diffuses into the bulk. AES measurements employing oxide and metal signals were used to model the growth of oxide which was found to be temperature dependent. Both NRA and AES indicate linear oxygen uptake kinetics at 90 K with abrupt passivation as the limiting thickness is reached. SSIMS ion yield data taken during the oxidation of Zr(0001) at 90, 293 and 473 K was interpretable in the context of the oxygen coverage. Dissolution into the bulk of the saturated oxide layer grown at 90 K appears to occur by an island-type mechanism rather than layer-by-layer dissolution from the oxide-metal interface. Large [Delta][phi] changes that occur upon oxidation at 90 K and temperature ramping of the saturated oxide to 300 K are attributable to reversible molecular oxygen adsorption on the oxide. The diffusion of oxygen normal to the [0001] plane of zirconium has been measured by AES: D[sub 0] = (4.14.[+-]1.92) x 10[sup [minus]2] cm[sup [minus]2] s[sup [minus]1] and E[sub a]= 199.1 [+-]2.6 kJ mol[sup [minus]1]. The fundamental vibrational frequency for the [alpha]-Zr lattice was calculated to be (6.3 [+-] 2.9) x 10[sup 13]s[sup [minus]1].

Flinn, B.J.

1992-01-01T23:59:59.000Z

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

Fluidizable zinc titanate materials with high chemical reactivity and attrition resistance  

DOE Patents [OSTI]

Highly durable and chemically reactive zinc titanate materials are prepared in a particle size range of 50 to 400 .mu.m suitable for a fluidized-bed reactor for removing reduced sulfur species in a gaseous form by granulating a mixture of fine zinc oxide and titanium oxide with inorganic and organic binders and by optional additions of small amounts of activators such as CoO and MoO.sub.3 ; and then indurating it at 800.degree. to 900.degree. C. for a time sufficient to produce attrition-resistant granules.

Gupta, Raghubir P. (Durham, NC); Gangwal, Santosh K. (Durham, NC); Jain, Suresh C. (Morgantown, WV)

1993-01-01T23:59:59.000Z

362

Oxy-combustion: Oxygen Transport Membrane Development  

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

363

Eating Invasive Species  

Science Journals Connector (OSTI)

The Institute for Applied Ecology, a nonprofit organization promoting conservation and habitat restoration, launched the Eradication by Mastication...outreach, which consists of an annual “Invasive Species Cook-off

Joseph A. Tuminello III

2014-04-01T23:59:59.000Z

364

Underground coal gasification using oxygen and steam  

SciTech Connect (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

365

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

This quarterly technical progress report will summarize work accomplished for the Program in the seventh quarter October-December 2001 in the following task areas: Task 1 - Oxygen Enhanced Combustion, Task 2 - Oxygen Transport Membranes, Task 3 - Economic Evaluation and Task 4 - Program Management. Computational fluid dynamic (CFD) modeling of oxygen injection strategies was performed during the quarter resulting in data that suggest the oxygen injection reduces NOx emissions while reducing LOI. Pilot-scale testing activities concluded at the University of Utah this quarter. Testing demonstrated that some experimental conditions can lead to NOx emissions well below the 0.15 lb/MMBtu limit. Evaluation of alternative OTM materials with improved mechanical properties continued this quarter. Powder procedure optimization continued and sintering trial began on an element with a new design. Several OTM elements were tested in Praxair's single tube high-pressure test facility under various conditions. A modified PSO1d element demonstrated stable oxygen product purity of >98% and oxygen flux of 68% of target. Updated test results and projected economic performance have been reviewed with the Utility Industrial Advisors. The economic comparison remains very favorable for O{sub 2} enhanced combustion. Discussions regarding possible Beta sites have been held with three other utilities in addition to the industrial advisors. Proposals will be prepared after the completion of full scale burner testing. Beta test cost estimating work has been initiated.

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

2002-01-01T23:59:59.000Z

366

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

This quarterly technical progress report will summarize work accomplished for the Program through the fourth quarter January-March 2002 in the following task areas: Task 1--Oxygen Enhanced Combustion, Task 2--Oxygen Transport Membranes, Task 3--Economic Evaluation and Task 4--Program Management. This report will also recap the results of the past year. The program is proceeding in accordance with the objectives for the second year. The first round of pilot scale testing with 3 bituminous coals was completed at the University of Utah. Full-scale testing equipment is in place and experiments are underway. Coal combustion lab-scale testing was completed at the University of Arizona. Modest oxygen enhancement resulted in NOx emissions reduction. Combustion modeling activities continued with pilot-scale combustion test furnace simulations. 75% of target oxygen flux was demonstrated with small PSO1 tube in Praxair's single tube high-pressure test facility. The production of oxygen with a purity of better than 99.999% was demonstrated. Economic evaluation has confirmed the advantage of oxygen-enhanced combustion. Two potential host sites have been identified.

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

2002-04-01T23:59:59.000Z

367

Deposition of Nitric Acid and Reactive Nitrogen at Harvard Forest The hourly gas-phase HNO3 concentration was measured at the Harvard Forest  

E-Print Network [OSTI]

Reactive nitrogen trace gas species play an important role in tropospheric photochemistry by stimulating gas-phase HNO3 concentration was measured at the Harvard Forest Environmental Measurement Site during radicals may be regenerated. Thus conversion of NOx radicals to HNO3 and subsequent deposition

368

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

Increased environmental regulations will require utility boilers to reduce NO{sub x} emissions to less than 0.15lb/MMBtu in the near term. Conventional technologies such as Selective Catalytic Reduction (SCR) and Selective Non-Catalytic Reduction (SNCR) are unable to achieve these lowered emission levels without substantially higher costs and major operating problems. Oxygen enhanced combustion is a novel technology that allows utilities to meet the NO{sub x} emission requirements without the operational problems that occur with SCR and SNCR. Furthermore, oxygen enhanced combustion can achieve these NO{sub x} limits at costs lower than conventional technologies. The objective of this program is to demonstrate the use of oxygen enhanced combustion as a technical and economical method of meeting the EPA State Implementation Plan for NO{sub x} reduction to less than 0.15lb/MMBtu for a wide range of boilers and coal. The oxygen enhanced coal combustion program (Task 1) focused this quarter on the specific objective of exploration of the impact of oxygen enrichment on NO{sub x} formation utilizing small-scale combustors for parametric testing. Research efforts toward understanding any limitations to the applicability of the technology to different burners and fuels such as different types of coal are underway. The objective of the oxygen transport membrane (OTM) materials development program (Task 2.1) is to ascertain a suitable material composition that can be fabricated into dense tubes capable of producing the target oxygen flux under the operating conditions. This requires that the material have sufficient oxygen permeation resulting from high oxygen ion conductivity, high electronic conductivity and high oxygen surface exchange rate. The OTM element development program (Task 2.2) objective is to develop, fabricate and characterize OTM elements for laboratory and pilot reactors utilizing quality control parameters to ensure reproducibility and superior performance. A specific goal is to achieve a material that will sinter to desired density without compromising other variables such as reaction to binder systems or phase purity. Oxygen-enhanced combustion requires a facility which is capable of supplying high purity oxygen (>99.5%) at low costs. This goal can be achieved through the thermal integration of high temperature air separation with ceramic OTM. The objective of the OTM process development program (Task 2.3) is to demonstrate successfully the program objectives on a lab-scale single OTM tube reactor under process conditions comparable to those of an optimum large-scale oxygen facility. This quarterly technical progress report will summarize work accomplished for the Program through the first quarter April--June 2000 in the following task areas: Task 1 Oxygen Enhanced Coal Combustion; Task 2 Oxygen Transport Membranes; and Task 4 Program Management.

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

2000-07-01T23:59:59.000Z

369

California Endangered Species Act Species List | Open Energy...  

Open Energy Info (EERE)

Species List Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- OtherOther: California Endangered Species Act Species ListLegal Published NA Year...

370

Physical properties of erbium implanted tungsten oxide filmsdeposited by reactive dual magnetron sputtering  

SciTech Connect (OSTI)

Amorphous and partially crystalline WO3 thin films wereprepared by reactive dual magnetron sputtering and successively implantedby erbium ions with a fluence in the range from 7.7 x 1014 to 5 x 1015ions/cm2. The electrical and optical properties were studied as afunction of the film deposition parameters and the ion fluence. Ionimplantation caused a strong decrease of the resistivity, a moderatedecrease of the index of refraction and a moderate increase of theextinction coefficient in the visible and near infrared, while theoptical band gap remained almost unchanged. These effects could belargely ascribed to ion-induced oxygen deficiency. When annealed in air,the already low resistivities of the implanted samples decreased furtherup to 70oC, whereas oxidation, and hence a strong increase of theresistivity, was observed at higher annealing temperatures.

Mohamed, Sodky H.; Anders, Andre

2006-11-08T23:59:59.000Z

371

Theoretical studies of transition metal surfaces as electrocatalysts for oxygen electroreduction  

E-Print Network [OSTI]

........................................................................... 42 5.1. Introduction ......................................................................................................... 42 5.2. Surface Structure, Changes Due to Alloying and Adsorbed Species................... 43 5.3. Electronic Structure... experiences upon alloying and when interacting with adsorbates….………………………………………….. 42 Fig. 5.2. Surface relaxation on the Pt (111) and PdCo alloys. Both the clean surface and the one with oxygen adsorbed in the fcc hollow site is shown. All distances...

Lamas, Eduardo J.

2007-09-17T23:59:59.000Z

372

Oxygen Chemistry in the Circumstellar Envelope of the Carbon-Rich Star IRC+10216  

E-Print Network [OSTI]

In this paper we study the oxygen chemistry in the C-rich circumstellar shells of IRC+10216. The recent discoveries of oxygen bearing species (water, hydroxyl radical and formaldehyde) toward this source challenge our current understanding of the chemistry in C-rich circumstellar envelopes. The presence of icy comets surrounding the star or catalysis on iron grain surfaces have been invoked to explain the presence of such unexpected species. This detailed study aims at evaluating the chances of producing O-bearing species in the C-rich circumstellar envelope only by gas phase chemical reactions. For the inner hot envelope, it is shown that although most of the oxygen is locked in CO near the photosphere (as expected for a C/O ratio greater than 1), some stellar radii far away species such as H2O and CO2 have large abundances under the assumption of thermochemical equilibrium. It is also shown how non-LTE chemistry makes very difficult the CO-->H2O,CO2 transformation predicted in LTE. Concerning the chemistry in the outer and colder envelope, we show that formaldehyde can be formed through gas phase reactions. However, in order to form water vapor it is necessary to include a radiative association between atomic oxygen and molecular hydrogen with a quite high rate constant. The chemical models explain the presence of HCO+ and predict the existence of SO and H2CS (which has been detected in a 3 mm line survey to be published). We have modeled the line profiles of H2CO, H2O, HCO+, SO and H2CS using a non-local radiative transfer model and the abundance profiles predicted by our chemical model. The results have been compared to the observations and discussed.

Marcelino Agundez; Jose Cernicharo

2006-05-25T23:59:59.000Z

373

Oxygen generator for medical applications (USIC)  

SciTech Connect (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

374

Measurement of VOC reactivities using a photochemical flow reactor  

SciTech Connect (OSTI)

A commercial ambient air monitoring instrument, the Airtrak 2000, has been modified for use as a photochemical flow reactor and used to measure the absolute and incremental reactivity of 18 single test VOCs and the incremental reactivity of six multicomponent VOC mixtures. A flow technique is a useful supplement to traditional static chamber experiments. The static chamber technique involves periodic sampling of an irradiated mixture in a photochemical chamber. Under these conditions, the irradiated mixture is always in transition. Using a flow system, a steady-state condition is established within the flow reactor that is representative, in this case, of the early stages of the smog forming process in the atmosphere. The measurement technique also allows changes in the background chamber reactivity to be monitored and taken into account. The incremental reactivity of 13 of the 18 test compounds measured is compared with previously reported results from a static chamber experiment, and the two data sets are generally in good agreement. The additivity of reactivity was tested by measuring the incremental reactivity of six multicomponent mixtures, the components being compounds measured individually in this study. The measured reactivity of a mixture was compared to that calculated from the sum of the measured reactivity of the mixture`s individual components. The results show that reactivity is additive for the concentration range studied.

Hurley, M.D.; Chang, T.Y.; Japar, S.M.; Wallington, T.J. [Ford Motor Co., Dearborn, MI (United States). Ford Research Lab.] [Ford Motor Co., Dearborn, MI (United States). Ford Research Lab.

1998-07-01T23:59:59.000Z

375

Reactive Dehydration technology for Production of Fuels and Chemicals...  

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

Catalytic and Reactive Distillation) for compact, inexpensive production of biomass-based chemicals from complex aqueous mixtures. SeparationPurification of Biomass...

376

Airborne measurement of OH reactivity during INTEX-B  

E-Print Network [OSTI]

plus OH sign), reactiv- propane ing different gases gases atisoprene (plus sign), propane (star) and propene (triangle).NMHC includes ethane, ethene, propane, propene, i-butane, n-

2009-01-01T23:59:59.000Z

377

Reactive Landing of Peptide Ions on Self-Assembled Monolayer...  

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

were characterized ex situ using time of flight-secondary ion mass spectrometry (TOF-SIMS) and infrared reflection absorption spectroscopy (IRRAS). We demonstrate that reactive...

378

Probing the structure and reactivity of gaseous ions.  

E-Print Network [OSTI]

??Studying ions in the gas phase provides the opportunity to observe their intrinsic structure and reactivity without extraneous perturbations such as solvent effects, aggregation or… (more)

Meyer, Matthew Michael

2010-01-01T23:59:59.000Z

379

Chemically Reactive Working Fluids for the Capture and Transport...  

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

Optical Waveguide Coupler Transformers for High-Power Solar Enegy Collection and Transmission Chemically Reactive Working Fluids Low-Cost Light Weigh Thin Film Solar Concentrators...

380

Monitoring Single Molecule Reactivity On a Carbon Nanotube  

E-Print Network [OSTI]

LETTERS Monitoring Single-Molecule Reactivity on a Carbondevice directly transduces single-molecule attachments andoptical methods in single-molecule research. Compared to

Collins, Philip G

2008-01-01T23:59:59.000Z

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

Physical Organic Chemistry of Reactive Intermediates | The Ames...  

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

Physical Organic Chemistry of Reactive Intermediates The Jenks group specializes in physical organic chemistry, the "how" of organic reactions. Much of the work has centered on...

382

Chemical Analysis of Complex Organic Mixtures Using Reactive...  

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

Mass Spectrometry. Abstract: Reactive nanospray desorption electrospray ionization (nano-DESI) combined with high-resolution mass spectrometry was utilized for the analysis of...

383

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

E-Print Network [OSTI]

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

Santilli, R M

2000-01-01T23:59:59.000Z

384

Investigation of different manganese ores as oxygen carriers in chemical-looping combustion (CLC) for solid fuels  

Science Journals Connector (OSTI)

Abstract The chemical-looping combustion (CLC) process is a novel solution for efficient combustion with direct capture of carbon dioxide. The process uses a metal oxide as an oxygen carrier to transfer oxygen from an air to a fuel reactor, where the fuel reacts with the solid oxygen carrier. In this work, six different manganese ores are investigated as oxygen carriers for CLC application. The chemical-looping characteristics of the oxygen carriers were evaluated in a laboratory-scale fluidized-bed reactor in the temperature range of 900–970 °C during alternating reducing and oxidizing conditions. Three of the manganese ores showed a small oxygen release in inert environment between 850 and 950 °C. During reactivity tests, the gas yield with methane increased with the temperature and complete conversion of 50% CO in H2 was obtained for all of the ores. The rates of char gasification of two fuels, namely Mexican petroleum coke and Swedish wood char, were compared for the different manganese ores at 970 °C and with 50% H2O in N2 as fluidizing gas. Ilmenite and a manufactured Mn-oxide oxygen carrier consisting of Mn3O4 and MgO-stabilized ZrO2 as support were also included for comparison. The char gasification rate and the gas conversion were higher with the manganese ores and the Mn-oxide oxygen carrier compared to ilmenite. However, the higher reactivity of the manganese ores with H2 and the ensuing decrease in H2 inhibition for manganese ores is not sufficient to explain their higher rate of char gasification. Surface analysis of partially gasified petcoke particles in the presence of manganese ores showed formation of cavities and channels as well as a uniform distribution of potassium and sodium elements. The rate of char gasification also increased with the concentration of potassium and sodium impurities in the manganese ores. Thus the results suggest that the increased rate of char conversion for manganese ores is due to alkali-catalyzed steam gasification. The increase in rate of char gasification, in combination with potentially low costs of these materials suggests that manganese ores could be interesting materials for CLC with solid fuels.

Mehdi Arjmand; Henrik Leion; Tobias Mattisson; Anders Lyngfelt

2014-01-01T23:59:59.000Z

385

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

386

Absorption process for producing oxygen and nitrogen and solution therefor  

DOE Patents [OSTI]

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

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

1990-09-25T23:59:59.000Z

387

Oxygen Toxicity Calculations by Erik C. Baker, P.E.  

E-Print Network [OSTI]

1 Oxygen Toxicity Calculations by Erik C. Baker, P.E. Management of exposure to oxygen toxicity myself using the good ole' FORTRAN programming language, I found that incorporating oxygen toxicity for others. Background Two oxygen toxicity parameters are typically "tracked" in technical diving

Read, Charles

388

Energetic neutral atoms at Mars 4. Imaging of planetary oxygen  

E-Print Network [OSTI]

Energetic neutral atoms at Mars 4. Imaging of planetary oxygen S. Barabash and M. Holmstro of the Martian oxygen exosphere/corona results in the production of planetary oxygen ions. The newborn ions start. The oxygen ions can then charge exchange with the neutral gases (H, H2, and O) of the Martian exosphere

Lukyanov, Alex

389

Nanocomposite oxygen carriers for chemical-looping combustion of sulfur-contaminated synthesis gas  

SciTech Connect (OSTI)

Chemical-looping combustion (CLC) is an emerging technology for clean combustion. We have previously demonstrated that the embedding of metal nanoparticles into a nanostructured ceramic matrix can result in unusually active and sinter-resistant nanocomposite oxygen carrier materials for CLC, which combine the high reactivity of metals with the high-temperature stability of ceramics. In the present study, we investigate the effect of H{sub 2}S in a typical coal-derived syngas on the stability and redox kinetics of Ni- and Cu-based nanostructured oxygen carriers. Both carriers show excellent structural stability and only mildly changed redox kinetics upon exposure to H{sub 2}S, despite a significant degree of sulfide formation. Surprisingly, partial sulfidation of the support results in a strong increase in oxygen carrier capacity in both cases because of the addition of a sulfide-sulfate cycle. Overall, the carriers show great potential for use in CLC of high-sulfur fuels. 21 refs., 13 figs. 1 tab.

Rahul D. Solunke; Goetz Veser [United States Department of Energy, Pittsburgh, PA (United States). National Energy Technology Laboratory

2009-09-15T23:59:59.000Z

390

EO 13112: Invasive Species  

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

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

391

CGC Trace Species Partitioning  

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

392

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

This quarterly technical progress report will summarize work accomplished for the Program through the eleventh quarter, October-December 2002, in the following task areas: Task 1 - Oxygen Enhanced Combustion, Task 2 - Oxygen Transport Membranes, Task 3 - Economic Evaluation and Task 4 - Program Management. The program is proceeding in accordance with the objectives for the third year. Pilot scale experiments conducted at the University of Utah were aimed at confirming the importance of oxygen injection strategy for different types of burners. CFD modeling at REI was used to better understand the potential for increased corrosion under oxygen enhanced combustion conditions. Data from a full-scale demonstration test in Springfield, MO were analyzed. OTM element development continued with preliminary investigation of an alternative method of fabrication of PSO1d elements. OTM process development continued with long-term testing of a PSO1d element. Economic evaluation has confirmed the advantage of oxygen-enhanced combustion. Proposals have been submitted for two additional beta test sites. A first commercial proposal has been submitted. Economic analysis of a beta site test performance was conducted.

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

2003-02-01T23:59:59.000Z

393

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

This quarterly technical progress report will summarize work accomplished for the Program through the twelfth quarter, January-March 2003, in the following task areas: Task 1--Oxygen Enhanced Combustion, Task 2--Oxygen Transport Membranes, Task 3--Economic Evaluation and Task 4--Program Management. The program is proceeding in accordance with the objectives for the third year. Pilot scale experiments conducted at the University of Utah explored both the effectiveness of oxygen addition and the best way to add oxygen with a scaled version of Riley Power's newest low NOx burner design. CFD modeling was done to compare the REI's modeling results for James River Unit 3 with the NOx and LOI results obtained during the demonstration program at that facility. Investigation of an alternative method of fabrication of PSO1d elements was conducted. OTM process development work has concluded with the completion of a long-term test of a PSO1d element Economic evaluation has confirmed the advantage of oxygen-enhanced combustion. Proposals have been submitted for two additional beta test sites. Commercial proposals have been submitted. Economic analysis of a beta site test performance was conducted.

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

2003-04-01T23:59:59.000Z

394

On the solar nickel and oxygen abundances  

E-Print Network [OSTI]

Determinations of the solar oxygen content relying on the neutral forbidden transition at 630 nm depend upon the nickel abundance, due to a Ni I blend. Here we rederive the solar nickel abundance, using the same ab initio 3D hydrodynamic model of the solar photosphere employed in the recent revision of the abundances of C, N, O and other elements. Using 17 weak, unblended lines of Ni I together with the most accurate atomic and observational data available we find log epsilon_Ni = 6.17 +/- 0.02 (statistical) +/- 0.05 (systematic), a downwards shift of 0.06 to 0.08 dex relative to previous 1D-based abundances. We investigate the implications of the new nickel abundance for studies of the solar oxygen abundance based on the [O I] 630 nm line in the quiet Sun. Furthermore, we demonstrate that the oxygen abundance implied by the recent sunspot spectropolarimetric study of Centeno & Socas-Navarro needs to be revised downwards from log epsilon_O = 8.86 +/- 0.07 to 8.71 +/- 0.10. This revision is based on the new nickel abundance, application of the best available gf-value for the 630 nm forbidden oxygen line, and a more transparent treatment of CO formation. Determinations of the solar oxygen content relying on forbidden lines now appear to converge around log epsilon_O = 8.7.

Pat Scott; Martin Asplund; Nicolas Grevesse; A. Jacques Sauval

2008-11-05T23:59:59.000Z

395

Oxygen abundance of open cluster dwarfs  

E-Print Network [OSTI]

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

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

2007-03-30T23:59:59.000Z

396

Oxygen Hydration Mechanism for the Oxygen Reduction Reaction at Pt and Pd Fuel Cell Catalysts  

Science Journals Connector (OSTI)

Oxygen Hydration Mechanism for the Oxygen Reduction Reaction at Pt and Pd Fuel Cell Catalysts ... Catalytic Reactions on the Open-Edge Sites of Nitrogen-Doped Carbon Nanotubes as Cathode Catalyst for Hydrogen Fuel Cells ... Despite significant progress made the past decade on reducing the platinum catalyst loading in the PEMFC electrodes, further ... ...

Yao Sha; Ted H. Yu; Boris V. Merinov; Pezhman Shirvanian; William A. Goddard; III

2011-02-24T23:59:59.000Z

397

Instrumentation @ Catalysis: Reactivity and Structure Group | Chemistry  

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

Instrumentation Instrumentation The Catalysis Group at BNL is leading research initiatives into the development of new tools and techniques that focus on the characterization of heterogeneous catalytic reactions and catalysts using imaging, spectroscopy and scattering techniques and integrated combinations of them under reaction conditions to unravel the morphology, chemical and structural properties, of catalysts, respectively. These efforts revolve around the use of synchrotron radiation (NSLS), electrons (CFN) and quantum tunneling tools with particular thrusts into imaging, spectroscopy and scattering. Groups Instrumentation(BNL) Three UHV chambers with diverse instrumentation for surface characterization: LEED, UPS, XPS, AES, TPD, ISS, PM-AP-IRRAS, Reactivity Cell. All the systems include ancillary instrumentation such as sputtering guns and metal evaporators. The IRRAS system was retrofitted with an ambient pressure (AP) cell on top of the UHV system. The sample can be prepared and characterized in UHV and then transfer in vacuum to the AP cell.

398

Review of existing reactive transport software  

SciTech Connect (OSTI)

Simulations of thermal and hydrological evolution following the potential emplacement of a subterranean nuclear waste repository at Yucca Mountain, NV provide data that suggest the inevitability of dependent, simultaneous chemical evolution in this system. These chemical changes will modify significantly both the magnitude and structure of local porosity and permeability; hence, they will have a dynamic feedback effect on the evolving thermal and hydrological regime. Yet, despite this intimate interdependence of transport and chemical processes, a rigorous quantitative analysis of the post- emplacement environment that incorporates this critical feedback mechanism has not been completed to date. As an initial step in this direction, the present document outlines the fundamental chemical and transport processes that must be accounted for in such an analysis, and reviews the inventory of existing software that encodes these processed in explicitly coupled form. A companion report describes the prioritization of specific capabilities that are needed for modeling post-emplacement reactive transport at Yucca Mountain.

Glassley, W., LLNL

1998-02-03T23:59:59.000Z

399

Glycolate Oxidase Modulates Reactive Oxygen Speciesâ??Mediated Signal Transduction during Nonhost Resistance in Nicotiana benthamiana and Arabidopsis  

Science Journals Connector (OSTI)

...4-methoxy-6-nitro)benzenesulfonic acid hydrate (XTT) upon the generation of O2 by NADPH...1997). Activation of the ethylene gas response pathway in Arabidopsis by the...Z. Klement, K. Rudolph, and D.C. Sands, eds (Budapest, Hungary: Akademiai...

Clemencia M. Rojas; Muthappa Senthil-Kumar; Keri Wang; Choong-Min Ryu; Amita Kaundal; Kirankumar S. Mysore

2012-01-27T23:59:59.000Z

400

Single-walled carbon nanotubes as near infrared fluorescent sensors : characterization, biological and analytical applications  

E-Print Network [OSTI]

Reactive oxygen species (ROS) have emerged as biological signaling molecules, participating in newly discovered cascades that govern cell proliferation, migration, and pathogenesis. A major challenge in understanding these ...

Jin, Hong, Ph. D. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

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

E-Print Network 3.0 - antioxidative systems detoxifying Sample...  

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

several other antioxidative systems were found... , Sandalio LM, Palma JM, Gmez M, Barroso JB. 2002. Reactive oxygen species, antioxidant systems and nitric... and their...

402

E-Print Network 3.0 - arsenic induces apoptosis Sample Search...  

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

reactive oxygen species formation... , Jenssen D (2000) Arsenic (III) and heavy metal ions induce intrachromosomal ... Source: Ma, Lena - Soil and Water Science Department,...

403

Antioxidant effects of reduced water produced by electrolysis of sodium chloride solutions  

Science Journals Connector (OSTI)

Antioxidant vitamins and enzymes such as superoxide dismutase, catalase and glutathione peroxidase are considered to function as scavengers against reactive oxygen species and to provide protection against rea...

K. Hanaoka

2001-12-01T23:59:59.000Z

404

arrest facilitating caspase: Topics by E-print Network  

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

of the agonist induced massive calcium entry, mitochondrial depolarization, and a rise in the level of reactive oxygen species that correlated with a decrease in the levels...

405

Oxygen: From Environment to Genes. The periodic occurrence of oxygen minima can powerfully influence organisms living in near  

E-Print Network [OSTI]

Oxygen: From Environment to Genes. The periodic occurrence of oxygen minima can powerfully to the winter of 2014. Their scholarly work is presented in this collection. #12;1 Oxygen: From Environment", 2013, 2014 Table of contents Page 2. Laura Lilly - Low-oxygen formation along the California current. 6

406

Inelastic neutron scattering from confined molecular oxygen  

Science Journals Connector (OSTI)

Inelastic neutron-scattering measurements were carried out on condensed bulk and confined molecular oxygen. The phase transitions of the oxygen confined in cylindrical pores with diameter of ?94?Å are suppressed below their bulk temperatures or in the case of the lowest-temperature transition to the ? phase are suppressed entirely. This last observation is possibly due to the low latent heat of transition for this transition. Both elastic and inelastic neutron-scattering data indicate a mixing of oxygen crystal phases upon confinement. Magnetic ordering fluctuations in the ? phase are found to have similar energy-dependent profiles for confined and bulk excitations showing that the magnetic correlation function decay is unaffected by the finite crystal size in confinement.

Duncan Kilburn; Paul E. Sokol; Craig M. Brown

2008-12-29T23:59:59.000Z

407

A Learning-Based Approach to Reactive Security  

E-Print Network [OSTI]

Terms--Reactive security, risk management, attack graphs, online learning, adversarial learning, game vulnerability is plugged, CISOs typically perform a cost- benefit analysis to identify which risks to address of reactive strategies in an economic model of the CISO's security cost-benefit trade- offs. Unlike previously

Song, Dawn

408

A Reactive Measurement Framework Mark Allman and Vern Paxson  

E-Print Network [OSTI]

A Reactive Measurement Framework Mark Allman and Vern Paxson International Computer Science Institute Abstract. Often when assessing complex network behavior a single measure- ment is not enough for thinking about "measurement" as a process rather than an event. We introduce reactive measurement (REM

Paxson, Vern

409

Tropospheric Reactive Nitrogen Speciation, Deposition, and Chemistry at Harvard Forest  

E-Print Network [OSTI]

and absolute contributions of nitric acid (HNO3) and NOx (nitric oxide (NO) + nitrogen dioxide (NO2)) to totalTropospheric Reactive Nitrogen Speciation, Deposition, and Chemistry at Harvard Forest A thesis. Steven C. Wofsy Cassandra Volpe Horii Tropospheric Reactive Nitrogen Speciation, Deposition

410

A Reactive Control Approach for Pipeline Inspection with an AUV  

E-Print Network [OSTI]

A Reactive Control Approach for Pipeline Inspection with an AUV Pedro K. Paim, Bruno Jouvencel and research activities, performing tasks such as survey, inspection of sub-sea pipelines and object recovery of mission. This paper proposes a reactive control approach for pipeline following by a torpedo- like

Paris-Sud XI, Université de

411

From Teleo-Reactive specifications to architectural components: A model-driven approach  

Science Journals Connector (OSTI)

The Teleo-Reactive approach designed by N.J. Nilsson offers a high-level programming model that permits the development of reactive systems, such as robotic vehicles. Teleo-Reactive programs are written in a manner that allows engineers to define the ... Keywords: Component-based software development, Model-driven software development, Reactive systems, Robotics, Teleo-Reactive programs

Pedro SáNchez; Diego Alonso; José Miguel Morales; Pedro Javier Navarro

2012-11-01T23:59:59.000Z

412

Oxygen control in makeup water for PWRs  

SciTech Connect (OSTI)

This study describes the oxygen control program and improvements to the make-up water system components of PWR nuclear plants with the ultimate goal of reducing corrosion related problems in the steam generators and other secondary system components. A PWR plant that has a vacuum degasifier has been selected to establish the basis for the program. Following the investigation of the make-up water system components, the report presents instrumentation developed for the program. Recommendations are provided for improvements to the various make-up water system components to lower the dissolved oxygen levels. 5 refs., 23 figs., 3 tabs.

Silaghy, F. (Burns and Roe, Inc., Oradell, NJ (USA))

1990-08-01T23:59:59.000Z

413

Early maturation processes in coal. Part 2: Reactive dynamics simulations using the ReaxFF reactive force field on Morwell Brown coal structures  

E-Print Network [OSTI]

Early maturation processes in coal. Part 2: Reactive dynamics simulations using the ReaxFF reactive force field on Morwell Brown coal structures Elodie Salmon a , Adri C.T. van Duin b , François Lorant Brown coal using the ReaxFF reactive force field. We find that these reactive MD simulations

Goddard III, William A.

414

Reactive barriers for {sup 137}Cs retention  

SciTech Connect (OSTI)

{sup 137}Cs was dispersed globally by cold war activities and, more recently, by the Chernobyl accident. Engineered extraction of {sup 137}Cs from soils and groundwaters is exceedingly difficult. Because the half life of {sup 137}Cs is only 30.2 years, remediation might be more effective (and less costly) if {sup 137}Cs bioavailability could be demonstrably limited for even a few decades by use of a reactive barrier. Essentially permanent isolation must be demonstrated in those few settings where high nuclear level wastes contaminated the environment with {sup 135}Cs (half life 2.3x10{sup 6} years) in addition to {sup 137}Cs. Clays are potentially a low-cost barrier to Cs movement, though their long-term effectiveness remains untested. To identify optimal clays for Cs retention Cs resorption was measured for five common clays: Wyoming Montmorillonite (SWy-1), Georgia Kaolinites (KGa-1 and KGa-2), Fithian Illite (F-Ill), and K-Metabentonite (K-Mbt). Exchange sites were pre-saturated with 0.16 M CsCl for 14 days and readily exchangeable Cs was removed by a series of LiNO{sub 3} and LiCl washes. Washed clay were then placed into dialysis bags and the Cs release to the deionized water outside the bags measured. Release rates from 75 to 139 days for SWy-1, K-Mbt and F- 111 were similar; 0.017 to 0.021% sorbed Cs released per day. Both kaolinites released Cs more rapidly (0.12 to 0.05% of the sorbed Cs per day). In a second set of experiments, clays were doped for 110 days and subjected to an extreme and prolonged rinsing process. All the clays exhibited some capacity for irreversible Cs uptake so most soils have some limited ability to act as a natural barrier to Cs migration. However, the residual loading was greatest on K-Mbt ({approximately} 0.33 wt% Cs). Thus, this clay would be the optimal material for constructing artificial reactive barriers.

KRUMHANSL,JAMES L.; BRADY,PATRICK V.; ANDERSON,HOWARD L.

2000-05-19T23:59:59.000Z

415

Flash Pyrolysis of Biomass with Reactive and Non-Reactive Gases: Summary Report for Period July 1983 through September 1984  

SciTech Connect (OSTI)

The purpose of this program is to study the conversion of biomass to liquid and gaseous hydrocarbon fuels and chemical feedstocks by a flash or rapid pyrolysis technique. During this period of study pine wood was flash pyrolyzed in atmospheres of methane and helium at a pressure of 50 psi and at temperatures up to 1050 C. The 1-inch I.D. entrained downflow tubular reactor was used in these experiments. Product yields of methane, ethane, ethylene, BTX, carbon monoxide and carbon dioxide were determined as a function of temperature and gas to wood ratio. Of particular interest were the ethylene and BTX yields. These represented as much as 29.6% and 24.6% of the carbon contained in the feed wood respectively when flash pyrolyzing in methane (flash methanolysls) and 14.7% and 9.7% when pyrolyzing in helium. In the case of flash methanolysis of wood the yields of ethylene and benzene increased with increasing methane to wood feed ratios. In the case of flash pyrolysis in helium the yields of ethylene and BTX decreased with increasing helium gas to wood feed ratios. These results indicate a mechanism by which a free radical reactive species originating from the wood interacts with the methane pyrolyzing gas to produce an enhanced yield of ethylene and benzene. The flash methanolysis of lignin extract from wood produced lower yields of ethylene, indicating the yields mainly originate from the cellulosic fractions of the wood. Some work was also performed on substituting wood ash for sillca flour (Cab-O-Sil) to allow free flow of wood particles through the entrained flow reactor. Preliminary process design and analysis indicates an economically competitive process for the flash methanolysis of wood for the production of methanol, benzene and ethylene. Future plans include completing the studies on obtaining the process chemistry of the flash methanolysis of woods, to obtain a better understanding of the enhanced ethylene and benzene yield and to investigate other biomass forms.

Steinberg M.; Fallon, P.T.; Sundaram, M.S.

1984-10-01T23:59:59.000Z

416

Atmospheric Oxygen: Isotopic Composition and Solubility Fractionation  

Science Journals Connector (OSTI)

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

P. Kroopnick; H. Craig

1972-01-07T23:59:59.000Z

417

Oxygen addition to sulfur of metal thiolates  

E-Print Network [OSTI]

, and characterized. Molecular oxygen or hydrogen peroxide reacted with (N,N'-bis(mercaptoethyl)-1,5-diazacyclooctane-nickel(II), (BME-DACO)2Ni3 +2, to produce a trimetallic, (N,N'-bismercaptoethyl-1,5-diazacyclooctane-nickel(II))-nickelate, (BME-DACO)2Ni3 2...

Soma, Takako

2012-06-07T23:59:59.000Z

418

Oxygen Limitation within a Bacterial Aggregate  

Science Journals Connector (OSTI)

...standard deviation of the average of cells exposed to 2...and Doring G. 2002. Effects of reduced mucus oxygen...Lewandowski Z. 1994. Effects of biofilm structures...Dietrich LE , Okegbe C, Price-Whelan A, Sakhtah...capability. Energy Fuels 20 :1565-1571. doi...

Aimee K. Wessel; Talha A. Arshad; Mignon Fitzpatrick; Jodi L. Connell; Roger T. Bonnecaze; Jason B. Shear; Marvin Whiteley

2014-04-01T23:59:59.000Z

419

Oxygen Transport Ceramic Membranes Quarterly Report  

E-Print Network [OSTI]

/Reaction rates in Ion 21 Transport Membranes using Isotope Tracer and Transient Kinetic Techniques CONCLUSIONS 30Oxygen Transport Ceramic Membranes Quarterly Report January 2003 ­ March 2003 Principal Authors on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane

Eagar, Thomas W.

420

Novel Membranes and Processes for Oxygen Enrichment  

SciTech Connect (OSTI)

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 "reactive oxygen species" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Why Sequence Methylotenera species?  

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

422

Endangered Species Bulletin  

E-Print Network [OSTI]

July/August 2002 Vol. XXVII No. 3 In the work that we and our partners undertake to conserve and recover vulnerable species, awareness of the efforts we take for native plants is often overshadowed by the interest received by animal species. Too often overlooked is the fact that plants provide the foundation upon which animal life, including our own, depends. Plants are not only of aesthetic value, they provide us with food, many medicines, vital ecosystem services, and a variety of other products that are essential to our economy and well being. Fortunately, we have an important partner in the protection of our nation’s imperiled flora, the Center for Plant Conservation. This edition of the

U. S. Fish; Wildlife Service

423

Reactive sticking coefficients of silane on silicon  

SciTech Connect (OSTI)

We have investigated the reaction of room-temperature silane and disilane on a hot polycrystalline silicon surface using both a collision-free molecular beam and a very low pressure CVD cell. Reactive sticking coefficients were obtained from deposition rate data over a wide range of temperatures and silane (disilane) fluxes. The RSCs are substantially less than one, ranging from 6 x 10/sup -5/ to 4 x 10/sup -2/. For silane we observed curved Arrhenius plots with slopes decreasing from approx.60 kcal mol/sup -1/ at low temperatures to approx.2 kcal mol/sup -1/ at higher temperatures. The RSCs are independent of flux (pressure) at 1040/sup 0/C, but vary as flux to the approx.-1/2 power at 710/sup 0/C. A model comprised of a dissociative adsorption mechanism with competing associative desorption and reaction was found to give reasonable agreement. For disilane, we observed RSCs that were roughly ten times higher than those for silane. We also observed a curved Arrhenius plot and a flux dependence at 710/sup 0/C for disilane. 22 refs., 5 figs.

Buss, R.J.; Ho, P.; Breiland, W.G.; Coltrin, M.E.

1987-01-01T23:59:59.000Z

424

Effect of fuel gas composition in chemical-looping combustion with Ni-based oxygen carriers. 1. Fate of sulfur  

SciTech Connect (OSTI)

Chemical-looping combustion (CLC) has been suggested among the best alternatives to reduce the economic cost of CO{sub 2} capture using fuel gas because CO{sub 2} is inherently separated in the process. For gaseous fuels, natural gas, refinery gas, or syngas from coal gasification can be used. These fuels may contain different amounts of sulfur compounds, such as H{sub 2}S and COS. An experimental investigation of the fate of sulfur during CH{sub 4} combustion in a 500 W{sub th} CLC prototype using a Ni-based oxygen carrier has been carried out. The effect on the oxygen carrier behavior and combustion efficiency of several operating conditions such as temperature and H{sub 2}S concentration has been analyzed. Nickel sulfide, Ni3S{sub 2}, was formed at all operating conditions in the fuel reactor, which produced an oxygen carrier deactivation and lower combustion efficiencies. However, the oxygen carrier recovered their initial reactivity after certain time without sulfur addition. The sulfides were transported to the air reactor where SO{sub 2} was produced as final gas product. Agglomeration problems derived from the sulfides formation were never detected during continuous operation. Considering both operational and environmental aspects, fuels with sulfur contents below 100 vppm H{sub 2}S seem to be adequate to be used in an industrial CLC plant.

Garcia-Labiano, F.; de Diego, L.F.; Gayan, P.; Adanez, J.; Abad, A.; Dueso, C. [CSIC, Zaragoza (Spain)

2009-03-15T23:59:59.000Z

425

Development and performance of Cu-based oxygen carriers for chemical-looping combustion  

SciTech Connect (OSTI)

Chemical-looping combustion (CLC) has the inherent property of separating the product CO{sub 2} from flue gases. Instead of air, it uses an oxygen carrier, usually in the form of a metal oxide, to provide oxygen for combustion. This paper focuses on the development and performance of a suitable Cu-based oxygen carrier for burning solid fuels using CLC. Carriers were made from CuO and Al{sub 2}O{sub 3} (as a support) in three different ways: mechanical mixing, wet impregnation, and co-precipitation. The reactivity of these solids was assessed by measuring their ability to oxidize CO, when in a hot bed of sand fluidized by a mixture of CO and N{sub 2}. After that, the Cu in the carrier was oxidized back to CuO by fluidizing the hot bed with air. These oxygen carriers were tested over many such cycles of reduction and oxidation. This work confirms that supporting CuO on Al{sub 2}O{sub 3} enhances the ability of the resulting particles to withstand mechanical and thermal stresses in a fluidized bed. Also, only co-precipitation produces particles that have a high loading of copper and do not agglomerate at 800-900 C. The performance of co-precipitated particles of CuO/Al{sub 2}O{sub 3} at oxidizing CO to CO{sub 2} was significantly affected by the pH of the solution in which precipitation occurred: a high pH (9.7) gave particles that reacted completely and rapidly. After 18 cycles, such a co-precipitated carrier with 82.5 wt% CuO yielded all its oxygen when oxidizing CO. X-ray analysis showed that when heated, CuO reacted with Al{sub 2}O{sub 3} to form CuAl{sub 2}O{sub 4}, which was fully reducible, so CuO experienced no loss in extent of reaction after forming this mixed oxide. An increase in operating temperature from 800 to 900 C led to the CuO providing slightly less oxygen; this was because a little of the CuO decomposed to Cu{sub 2}O between its reduction and oxidation, when the bed was fluidized by pure N{sub 2}. (author)

Chuang, S.Y.; Dennis, J.S.; Hayhurst, A.N.; Scott, S.A. [Department of Chemical Engineering, University of Cambridge, Pembroke Street, Cambridge, CB2 3RA, England (United Kingdom)

2008-07-15T23:59:59.000Z

426

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

E-Print Network [OSTI]

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

R. M. Santilli

2000-09-04T23:59:59.000Z

427

Pertechnetate (TcO4-) reduction by reactive ferrous iron forms...  

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

reduction by reactive ferrous iron forms in naturally anoxic, redox transition zone sediments from the Pertechnetate (TcO4-) reduction by reactive ferrous iron forms in naturally...

428

Metal-Pyrrolide Complexes in Three-fold Symmetry: Synthesis, Structure, Reactivity and Magnetism  

E-Print Network [OSTI]

Structure, Reactivity and Magnetism by William Hill Harman AStructure, Reactivity and Magnetism by William Hill Harmanlost time. Dave taught me magnetism and what it takes to win

Harman, William Hill

2010-01-01T23:59:59.000Z

429

Synthesis, characterization, and reactivity studies of iridium complexes bearing the ligand diphenylphosphidoboratabenzene  

E-Print Network [OSTI]

The synthesis, structure, and reactivity properties of three iridium square planar complexes bearing the anionic phosphine ligand diphenylphosphidoboratabenzene (DPB) are described. Reactivity studies show a rate enhancement ...

Arizpe, Luis (Luis Alfredo)

2011-01-01T23:59:59.000Z

430

Rapid thermal oxidation of silicon in mixtures of oxygen and nitrous oxide  

SciTech Connect (OSTI)

Oxidation in nitrous oxide by conventional hot wall furnace processing and by rapid thermal oxidation (RTO) has been a subject of much interest in recent years. RTO is a fundamentally different process than furnace oxidation, however, and the full effects of this type of processing on the oxidation kinetics are not well understood. Oxidation of silicon by RTO at a variety of pressures, temperatures, and oxidation gas mixtures has been studied. Although at lower temperatures (< 850 C) the atmospheric pressure oxidation rate in nitrous oxide is very close to that in oxygen, at higher temperatures the oxidation rate in nitrous oxide is much lower than that in oxygen. At lower pressures in a RTO process, the oxidation rate in nitrous oxide is higher than that in oxygen. The effect of the nitrogen incorporated in the oxide acting as a diffusion barrier has been proposed as the mechanism of temperature dependence for atmospheric pressure oxidation in nitrous oxide. This does not explain the effects seen at lower pressure,s however, The authors propose that some of the intermediate species produced in the decomposition of nitrous oxide into molecular nitrogen, molecular oxygen, and nitric oxide play a role in the initial stages of oxidation by RTO in nitrous oxide.

Grant, J.M.; Karim, Z. [Sharp Microelectronics Technology, Inc., Camas, WA (United States)

1996-12-01T23:59:59.000Z

431

FWS - Candidate Species List under the Endangered Species Act...  

Open Energy Info (EERE)

what a candidate species is under Section 4 of the Endangered Species Act. Author U.S. Fish and Wildlife Service Published U.S. Fish and Wildlife Service, 2011 DOI Not Provided...

432

Nitric oxide inhibition of soot oxidation by oxygen atoms at 298K  

SciTech Connect (OSTI)

Nitric oxide is observed to inhibit the rate of soot oxidation by oxygen atoms at 298K. Small amounts of added NO reduce the rates of production of CO/sub 2/ and CO by up to 35%. The authors show experimentally that NO is not reducing the gas phase O atom concentration. Thermal desorption mass spectrometry shows a small adsorption of NO on the soot; this NO adsorption corresponds to 1.5% of the carbon atoms on the surface of the individual soot spheres. This inhibition is interpreted in terms of a relatively small number of reactive sites on the soot at which soot gasification occurs and which are effectively blocked by NO.

Wicke, B.G.; Grady, K.A.

1987-08-01T23:59:59.000Z

433

Photochemical activation and reactivity of polynuclear transition metal complex molecules. Progress report, June, 1980-May 31, 1981  

SciTech Connect (OSTI)

Progress on this project during the past year has proceeded in three different but complementary directions. The first involves a continuing effort to synthesize new and unusual polynuclear transition metal complexes that (1) exhibit multi-electron transfer reactions, (2) can be expected to have long-lived excited states, and/or (3) will undergo photochemically initiated intramolecular energy transfer to produce reactive species. The second involves the electrochemical investigation of multi-electron transfer reactions of polynuclear transition metal complexes. The third is concerned with the study of the photophysics of binuclear complexes in which electron transfer could take place between a photochemically excited metal ion and the metal ion in the same molecule thereby producing two new reactive sites.

Endicott, J.F.; Lintvedt, R.L.

1981-01-01T23:59:59.000Z

434

The Economics of Oxygen Enriched Air Production Via Membranes  

E-Print Network [OSTI]

Oxygen enriched air combustion is a recognized approach to energy conservation. Conventional methods of producing oxygen enriched air: Pressure Swing Adsorption and Cryogenics, are energy-intensive and expensive. In this paper the economics of using...

Gollan, A.; Kleper, M. H.

1984-01-01T23:59:59.000Z

435

Breath is a mixture of nitrogen, oxygen, carbon dioxide, water  

E-Print Network [OSTI]

12 SCIENCE Breath is a mixture of nitrogen, oxygen, carbon dioxide, water vapour, inert gases. On the basis of proton affinity, the major constituents of air and breath (nitrogen, oxygen, carbon dioxide

436

Dopant Distribution, Oxygen Stoichiometry and Magnetism of Nanoscale...  

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

Dopant Distribution, Oxygen Stoichiometry and Magnetism of Nanoscale Sn0.99Co0.01O. Dopant Distribution, Oxygen Stoichiometry and Magnetism of Nanoscale Sn0.99Co0.01O. Abstract: In...

437

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...

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

1982-01-01T23:59:59.000Z

438

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

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

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

439

Methane Adsorption and Dissociation and Oxygen Adsorption and...  

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

Methane Adsorption and Dissociation and Oxygen Adsorption and Reaction with CO on Pd Nanoparticles on MgO(100) and on Pd(111). Methane Adsorption and Dissociation and Oxygen...

440

Inhibitive Influence of Oxygen Vacancies for Photoactivity on...  

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

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

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


441

Oxygen-induced magnetic properties and metallic behavior of a...  

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

Oxygen-induced magnetic properties and metallic behavior of a BN sheet. Oxygen-induced magnetic properties and metallic behavior of a BN sheet. Abstract: In this paper, ab initio...

442

Photo of the Week: Reactive Ion Etching | Department of Energy  

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

Reactive Ion Etching Reactive Ion Etching Photo of the Week: Reactive Ion Etching October 17, 2013 - 1:26pm Addthis Have you ever heard of Laue lenses? These multilayer lenses are used to focus high-intensity x-ray beams to show the details of nano material structures. In this photo, the drop-like domes were carved through a process called reactive ion etching, which produced the striped bubbles you see in the Laue lens. The prototype in this image helped scientists perfect the process of creating lenses so precise that scientists are able to focus x-rays to within a single nanometer. | Photo courtesy of Brookhaven National Laboratory. Have you ever heard of Laue lenses? These multilayer lenses are used to focus high-intensity x-ray beams to show the details of nano material

443

Detoxification of hydrolysate by reactive-extraction for generating biofuels  

Science Journals Connector (OSTI)

We introduce a reactive extraction to detoxify hydrolysate before fermentation to biofuels. In the selection of diluents, n-octanol showed the highest removal yield of 5-hydroxymethylfurfural (5-HMF) and levulini...

Gwi-Taek Jeong; Sung-Koo Kim; Don-Hee Park

2013-02-01T23:59:59.000Z

444

Cooperative Strategies and Reactive Search: A Hybrid Model Proposal  

Science Journals Connector (OSTI)

Cooperative strategies and reactive search are very promising techniques for solving hard optimization problems, since they reduce human intervention required to set up a method when the resolution of an unknown instance is needed. However, as far as ...

Antonio D. Masegosa; Franco Mascia; David Pelta; Mauro Brunato

2009-11-01T23:59:59.000Z

445

The Safe Storage Study for Autocatalytic Reactive Chemicals  

E-Print Network [OSTI]

In the U.S. Chemical Safety and Hazard Investigation Board (CSB) report, Improving Reactive Hazard Management, there are 37 out of 167 accidents, which occurred in a storage tank or a storage area. This fact demonstrates that thermal runaway...

Liu, Lijun

2010-10-12T23:59:59.000Z

446

Reactive Power Compensation Strategy of DGIF Wind Park  

Science Journals Connector (OSTI)

In this chapter, two different wind park reactive power compensation strategies for the DFIG wind park connected to the sub-transmission level are proposed. Except considering DFIG wind turbines as dynamic reacti...

JingJing Zhao; Yang Fu; DongDong Li…

2014-01-01T23:59:59.000Z

447

Evolution of Memory in Reactive Artificial Neural Networks  

E-Print Network [OSTI]

in the context of evolution: how reactive agents could have evolved into cognitive ones with internalized memory? This study strives to find an answer to the question by simulating neuroevolution on artificial neural networks, with the hypothesis...

Chung, Ji Ryang

2012-07-16T23:59:59.000Z

448

Reactive Support and Voltage Control Service: Key Issues and Challenges  

E-Print Network [OSTI]

Reactive Support and Voltage Control Service: Key Issues and Challenges George Gross^, Paolo of Illinois at Urbana-Champaign, Urbana, IL 61801, USA, e-mail gross@uiuc.edu ° Dipartimento di Ingegneria

Gross, George

449

Analytical methods for determining the reactivity of pyrochemical salts  

SciTech Connect (OSTI)

Pyrochemical processes used for the purification of plutonium have generated quantities of residue that contain varying amounts of reactive metals such as potassium, sodium, calcium, and magnesium. These residues are currently considered hazardous and are being managed under RCRA because of the reactivity characteristic. This designation is based solely on process knowledge. Currently there is no approved procedure for determining the reactivity of a solid with water. A method is being developed to rapidly evaluate the reactivity of pyrochemical salts with water by measuring the rate of hydrogen generation. The method was initially tested with a magnesium containing pyrochemical salt. A detection limit of approximately 0.004 g of magnesium was established. A surrogate molten salt extraction residue was also tested. Extrapolation of test data resulted in a hydrogen generation rate of 4.4 mg/(g min).

Phillips, A.G.; Stakebake, J.L.

1994-05-01T23:59:59.000Z

450

Local Control of Reactive Power by Distributed Photovoltaic Generators  

E-Print Network [OSTI]

High penetration levels of distributed photovoltaic (PV) generation on an electrical distribution circuit may severely degrade power quality due to voltage sags and swells caused by rapidly varying PV generation during cloud transients coupled with the slow response of existing utility compensation and regulation equipment. Although not permitted under current standards for interconnection of distributed generation, fast-reacting, VAR-capable PV inverters may provide the necessary reactive power injection or consumption to maintain voltage regulation under difficult transient conditions. As side benefit, the control of reactive power injection at each PV inverter provides an opportunity and a new tool for distribution utilities to optimize the performance of distribution circuits, e.g. by minimizing thermal losses. We suggest a local control scheme that dispatches reactive power from each PV inverter based on local instantaneous measurements of the real and reactive components of the consumed power and the re...

Turitsyn, Konstantin S; Backhaus, Scott; Chertkov, Misha

2010-01-01T23:59:59.000Z

451

Assessing low power reactivity levels in subcritical CANDU reactors  

SciTech Connect (OSTI)

A new technique has been developed for monitoring slow reactivity changes in Canadian deuterium uranium (CANDU) nuclear reactors during low power operation, following a sustained period of high power operation. The power doubling halving worth (PDHW) test tracks slow reactivity changes by evaluating the reactivity perturbation required by the power regulating system to halve and double reactor power over time. During low power operation of a CANDU reactor, the PDHW test is used to monitor the decay of the photoneutron precursors, so that the reactor power can be lowered using a preset amount of reactivity. The PDHW test is described in this paper and is validated by using computer simulations and operating data from a CANDU reactor.

Teare, S.W. [Corporation of the City of Mississauga, Ontario (Canada)] [Corporation of the City of Mississauga, Ontario (Canada); Shanes, F.C. [Ontario Hydro, Toronto, Ontario (Canada)] [Ontario Hydro, Toronto, Ontario (Canada); Hersey, M.W. [Pickering Nuclear Generating Station, Ontario (Canada)] [Pickering Nuclear Generating Station, Ontario (Canada)

1996-08-01T23:59:59.000Z

452

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

This quarterly technical progress report will summarize work accomplished for the Program through the second quarter July--September 2000 in the following task areas: Task 1-Oxygen Enhanced Combustion, Task 2-Oxygen Transport Membranes and Task 4-Program Management. The program is proceeding in accordance with the objectives for the first year. OTM tube characterization is well underway, the design and assembly of the high pressure permeation test facility is complete and the facility will be in full operation during the next quarter. Combustion testing has been initiated at both the University of Arizona and Praxair. Testing at the University of Arizona has experienced some delays; steps have been take to get the test work back on schedule. Completion of the first phase of the testing is expected in next quarter. Combustion modeling has been started at both REI and Praxair, preliminary results are expected in the next quarter.

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

2000-10-01T23:59:59.000Z

453

Photosynthesis and the dynamics of oxygen consumption in a ...  

Science Journals Connector (OSTI)

photosynthesis minus oxygen consumption), and gross photosynthesis at high ... The depth distribution of gross photosynthesis, as obtained by the cycling ...

1999-11-15T23:59:59.000Z

454

Oxygen-Enriched Combustion for Military Diesel Engine Generators  

Broader source: Energy.gov [DOE]

Substantial increases in brake power and considerably lower peak pressure can result from oxygen-enriched diesel combustion

455

(Electronic structure and reactivities of transition metal clusters)  

SciTech Connect (OSTI)

The following are reported: theoretical calculations (configuration interaction, relativistic effective core potentials, polyatomics, CASSCF); proposed theoretical studies (clusters of Cu, Ag, Au, Ni, Pt, Pd, Rh, Ir, Os, Ru; transition metal cluster ions; transition metal carbide clusters; bimetallic mixed transition metal clusters); reactivity studies on transition metal clusters (reactivity with H{sub 2}, C{sub 2}H{sub 4}, hydrocarbons; NO and CO chemisorption on surfaces). Computer facilities and codes to be used, are described. 192 refs, 13 figs.

Not Available

1992-01-01T23:59:59.000Z

456

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

This quarterly technical progress report will summarize work accomplished for the Program through the ninth quarter April-June 2002 in the following task areas: Task 1--Oxygen Enhanced Combustion, Task 2--Oxygen Transport Membranes, Task 3--Economic Evaluation and Task 4--Program Management. The program is proceeding in accordance with the objectives for the third year. Full-scale testing using the Industrial Boiler Simulation Facility (ISBF) at Alstom Power was completed. The pilot scale experiments to evaluate the effect of air preheat and transport air stoichiometric ratio (SR) on NOx emissions were conducted at the University of Utah. Combustion modeling activities continued with full-scale combustion test furnace simulations. An OTM element was tested in Praxair's single tube high-pressure test facility and two thermal cycles were completed. PSO1d elements of new dimension were tested resulting in a lower flux than previous PSO1d elements of different dimensions, however, no element deformation was observed. Economic evaluation has confirmed the advantage of oxygen-enhanced combustion. Two potential host beta sites have been identified and proposals submitted.

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

2002-08-01T23:59:59.000Z

457

DME-to-oxygenates process studies  

SciTech Connect (OSTI)

The feasibility of the production of hydrocarbons from dimethyl ether (DNM) has been illustrated in a fixed bed micro-reactor as well as a bench scale fluidized bed reactor by the University of Akron/EPRI DME-to-Hydrocarbon (DTG) Process. The DTG process has distinct advantages over its methanol based counterpart. Specifically, the DTG process excels in the area of higher productivity, higher per-pass conversion, and lower heat duties than the MTG process. Also of special importance is the production of oxygenates -- including MTBE, ETBE, and TAME. DME may be reacted with isobutylene to produce a mixture of MTBE and ETBE. The properties of ETBE excel over MTBE in the areas of lower RVP and higher RON. According to industrial reports, MTBE is the fastest growing chemical (1992 US capacity 135,350 BPD, with expected growth of 34%/year to 1997). Also, recent renewed interest as an octane-enhancer and as a source of oxygen has spurred a growing interest in nonrefinery synthesis routes to ETBE. TAME, with its lower RVP and higher RON has proven useful as a gasoline blending agent and octane enhancer and may also be produced directly from DME. DME, therefore, serves as a valuable feedstock in the conversion of may oxygenates with wide-scale industrial importance. It should be also noted that the interest in the utilization of DME as process feedstock is based on the favorable process economics of EPRI/UA`s liquid phase DME process.

Tartamella, T.L.; Sardesai, A.; Lee, S. [Univ. of Akron, OH (United States); Kulik, C.J. [Electric Power Research Inst., Palo Alto, CA (United States)

1994-12-31T23:59:59.000Z

458

Bridge-bonded atomic oxygen on Pt(110)  

Science Journals Connector (OSTI)

We use hybrid density-functional theory (DFT) and scanning tunneling microscopy (STM) to study oxygen adsorption on the Pt(110) surface. In the STM images oxygen appear as bright protrusions on the ridges of the “missing row” reconstructed surface. DFT calculations of binding energies for atomic oxygen on a bridge site shows a clear preference over hollow sites.

E. Janin; H. von Schenck; M. Göthelid; U. O. Karlsson; M. Svensson

2000-05-15T23:59:59.000Z

459

Oxygen Consumption Rates of Bacteria under Nutrient-Limited Conditions  

Science Journals Connector (OSTI)

...research-article Environmental Microbiology Oxygen Consumption Rates of Bacteria under Nutrient-Limited...heterotrophic bacteria was measured. The oxygen consumption and population density of batch cultures...tracked for up to 200 days. The oxygen consumption per CFU (QO2) declined by more than...

Timothy E. Riedel; William M. Berelson; Kenneth H. Nealson; Steven E. Finkel

2013-06-14T23:59:59.000Z

460

IMPROVEMENTS IN MODELLING DISSOLVED OXYGEN IN ACTIVATED SLUDGE SYSTEMS  

E-Print Network [OSTI]

1 IMPROVEMENTS IN MODELLING DISSOLVED OXYGEN IN ACTIVATED SLUDGE SYSTEMS Jacek Makinia*, Scott A in a full-scale activated sludge reactor. The Activated Sludge Model No. 1 was used to describe for dissolved oxygen. KEYWORDS Activated sludge; dispersion; dissolved oxygen dynamics; mass transfer

Wells, Scott A.

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


461

Oceanic oxygen changes as a bellwether of climate change  

E-Print Network [OSTI]

Oceanic oxygen changes as a bellwether of climate change Term paper in Biogeochemistry@ethz.ch] Tutor: Prof. Dr. Nicholas Gruber [nicholas.gruber@env.ethz.ch] Abstract The response of oceanic oxygen of climate change. Recent publications indicate that the oceanic oxygen outgassing is substaintially larger

Fischlin, Andreas

462

Fiber-optic oxygen sensor using molybdenum chloride cluster luminescence  

E-Print Network [OSTI]

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

Ghosh, Ruby N.

463

THE OXYGEN REQUIREMENTS OF SHELLFISH By Philip H. Mitchell  

E-Print Network [OSTI]

THE OXYGEN REQUIREMENTS OF SHELLFISH ~ By Philip H. Mitchell 2°7 #12;Blank page retained for pagination #12;THE OXYGEN REQUIREMENTS OF SHELLFISH. By PHILIP H. MITCHELL. J1, The respiratory exchanges to temperature changes, a smaller utili- zation of oxygen in proportion to the body weight with increase in size

464

E-Print Network 3.0 - acute oxygen sensing Sample Search Results  

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

dissolved oxygen with global warming. In coastal regimes oxygen deficits represent acute ecosystem... Ocean oxygen minima expansions and their biological impacts Lothar Stramma...

465

Oxygen-driven relaxation processes in pre-irradiated Ar cryocrystals  

E-Print Network [OSTI]

Excitations of Solid Oxygen ?in Russian?, B. I. Verkin andNUMBER 11 NOVEMBER 2006 Oxygen-driven relaxation processes? Relaxation processes in oxygen-containing Ar cryocrystals

Savchenko, E. V; Belov, A. G; Gumenchuk, G. B; Ponomaryov, A. N; Bondybey, V. E

2006-01-01T23:59:59.000Z

466

OXYGEN REDUCTION WITH CARBON SUPPORTED METALLIC CLUSTER CATALYSTS IN ALKALINE ELECTROLYTE  

E-Print Network [OSTI]

be published in the Proceedings OXYGEN REDUCTION WITH CARBONof California. LBL-11891 Oxygen Reduction with Carbonof Pt interacts with both oxygen and water more strongly

Ross Jr., Philip N.

2013-01-01T23:59:59.000Z

467

Oxygen isotope fractionation in the vacuum ultraviolet photodissociation of carbon monoxide: Wavelength, pressure and temperature dependency.  

E-Print Network [OSTI]

Oxygen isotope fractionation in the vacuum ultravioletmeasurement of the associated oxygen isotopic composition ofwavelength dependency of the oxygen isotopic composition in

Chakraborty, Subrata

2013-01-01T23:59:59.000Z

468

Reduction kinetics of Cu-, Ni-, and Fe-based oxygen carriers using syngas (CO + H{sub 2}) for chemical-looping combustion  

SciTech Connect (OSTI)

The reactivity of three Cu-, Fe-, and Ni-based oxygen carriers to be used in a chemical-looping combustion (CLC) system using syngas as fuel has been analyzed. The oxygen carriers exhibited high reactivity during reduction with fuel gases present in syngas (H{sub 2} and CO), with average values in the range 8-30% min{sup -1}. No effect of the gas products (H{sub 2}O, CO{sub 2}) on the reduction reaction rate was detected. The kinetic parameters of reaction with H{sub 2} and CO have been determined by thermogravimetric analysis. The grain model with spherical or platelike geometry in the grain was used for the kinetic determination, in which the chemical reaction controlled the global reaction rate. The activation energies determined for these reactions were low, with values ranging from 14 to 33 kJ mol{sup -1}. The reaction order depended on the reacting gas, and values from 0.5 to 1 were found. Moreover, the reactivity of the oxygen carriers when both H{sub 2} and CO are simultaneously present in the reacting gases has been analyzed, both at atmospheric and pressurized conditions. For the Cu- and Fe-based oxygen carriers, the reaction rate of the oxygen carrier with syngas corresponded to the addition of the reaction rates for the individual fuel gases, H{sub 2} and CO. For the Ni-based oxygen carrier, the reaction rate was that corresponding to the fuel gas that reacted faster with the oxygen carrier at the reacting conditions (fuel concentration, temperature, and pressure). The consequences of the behavior of the reaction of syngas and the water-gas shift (WGS) equilibrium on the design of the fuel reactor of a CLC system have been analyzed. A preliminary estimation of the solids inventory for the use of syngas in the fuel reactor of a CLC system gave values in the range of 19-34 kg MW{sup -1} when the WGS equilibrium was considered to be instantaneous. 8 figs., 4 tabs.

Alberto Abad; Francisco Garcia-Labiano; Luis F. de Diego; Pilar Gayn; Juan Adnez [Instituto de Carboquimica (CSIC), Zaragoza (Spain). Department of Energy and Environment

2007-08-15T23:59:59.000Z

469

Nanoscale study of reactive transport in catalyst layer of proton exchange membrane fuel cells with precious and non-precious catalysts using lattice Boltzmann method  

E-Print Network [OSTI]

High-resolution porous structures of catalyst layer (CL) with multicomponent in proton exchange membrane fuel cells are reconstructed using a reconstruction method called quartet structure generation set. Characterization analyses of nanoscale structures are implemented including pore size distribution, specific area and phase connectivity. Pore-scale simulation methods based on the lattice Boltzmann method are developed and used to predict the macroscopic transport properties including effective diffusivity and proton conductivity. Nonuniform distributions of ionomer in CL generates more tortuous pathway for reactant transport and greatly reduces the effective diffusivity. Tortuosity of CL is much higher than conventional Bruggeman equation adopted. Knudsen diffusion plays a significant role in oxygen diffusion and significantly reduces the effective diffusivity. Reactive transport inside the CL is also investigated. Although the reactive surface area of non-precious metal catalyst (NPMC) CL is much higher t...

Chen, Li; Kang, Qinjun; Holby, Edward F; Tao, Wen-Quan

2014-01-01T23:59:59.000Z

470

Dilute Oxygen Combustion Phase IV Final Report  

SciTech Connect (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

471

Proceedings of Healthy Buildings 2009 Paper 336 Time-Scale Analysis for Reactive Deposition of Ozone via Passive Reactive  

E-Print Network [OSTI]

Proceedings of Healthy Buildings 2009 Paper 336 Time-Scale Analysis for Reactive Deposition) homogeneous reactions with indoor pollutants. The #12;Proceedings of Healthy Buildings 2009 Paper 336 latter

Siegel, Jeffrey

472

Are hybrid species more fit than ancestral parent species in the current hybrid species habitats?  

E-Print Network [OSTI]

Are hybrid species more fit than ancestral parent species in the current hybrid species habitats? L Columbia, Vancouver, BC, Canada Introduction Hybridization is receiving renewed attention as an important). For homoploid hybridization in plants, where chromosome number remains the same, models and empirical evi- dence

Rieseberg, Loren

473

Negative ions in a radio-frequency oxygen plasma  

Science Journals Connector (OSTI)

A systematic study of a low pressure (5–200 mTorr) oxygen discharge is presented. Measurements of the electron and negative ion densities in the 13.56 MHz capacitively coupled plasma are performed by means of a microwave resonance technique in combination with photodetachment. A kinetic model is developed, incorporating volume and wall reactions of ions as well as neutral species. It is shown, by matching the experimental results with the model, that the dominant ion is O- whereas the O2- and O3- densities reach 10 to 20 % of the total negative ion density. The ratio of negative ion to electron density varies between 5 and 10 and decreases with pressure and rf power. The total negative ion density is about 5×1015 m-3, it increases with gas flow, is independent of the rf input power, and has a maximum at a pressure of 30 mTorr. The agreement between the measurements and the model is within the experimental error for a wide range of conditions. Deviations are explained by changes in the gas and wall temperatures. From the known ion density the effective ionization rate has been determined and related to the electron temperature. The ionization temperature obtained in this way varies between 2 and 4 eV and decreases with increasing gas pressure and power, as expected for the bulk electron temperature in this type of discharge.

E. Stoffels; W. W. Stoffels; D. Vender; M. Kando; G. M. W. Kroesen; F. J. de Hoog

1995-03-01T23:59:59.000Z

474

Research on fuzzy logic based dynamic boundary voltage and reactive power integrated control method  

Science Journals Connector (OSTI)

Aiming at the existing problems of conventional substation voltage and reactive power integrated control method, a new fuzzy logic based dynamic reactive power boundary voltage and reactive power integrated control method is proposed. Fuzzy logic control ... Keywords: dynamic boundary, fuzzy logic, reactive power, voltage

Zigang Xu; Fei Wang

2009-06-01T23:59:59.000Z

475

Development and Evaluation of a State-of-the-Science Reactive Plume  

E-Print Network [OSTI]

for plume rise, plume visibility, and stack opacity (5). Examples of other reactive plume models include

Zhang, Yang

476

Third (March 2006) Coring and Analysis of Zero-Valent Iron Permeable Reactive Barrier, Monticello, Utah  

Broader source: Energy.gov [DOE]

Third (March 2006) Coring and Analysis of Zero-Valent Iron Permeable Reactive Barrier, Monticello, Utah

477

Neutron spectral reactivity comparison of /sup 235/U, /sup 233/U, /sup 239/Pu  

SciTech Connect (OSTI)

In the process of storing fuel from reactors capable of breeding fissile material, it is possible that the beginning-of-life fissile loadings are not the most reactive for the fuel. In this context, it is necessary to consider the bred fissile isotopes to ensure conservative safety margins on storage of these fuels. Of particular interest for the Idaho Chemical Processing Plant were fuels consisting primarily of /sup 235/U as the fissile isotope, such as those for the Experimental Breeder Reactor (EBR-I and -II) and some light water breeder reactor (LWBR) test elements. This study examines the relative worth of additions of the isotopes /sup 239/Pu, /sup 233/U, and /sup 235/U to a /sup 235/U-fueled critical system. The equivalence relationship between fissile isotopes depends in a complex fashion on the neutron spectrum and the relative abundance of the isotopic species.

McBroom, R.C.

1987-01-01T23:59:59.000Z

478

Mn–Fe Oxides with Support of MgAl2O4, CeO2, ZrO2 and Y2O3–ZrO2 for Chemical-Looping Combustion and Chemical-Looping with Oxygen Uncoupling  

Science Journals Connector (OSTI)

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

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

2014-06-03T23:59:59.000Z

479

NETL: Gasification - Development of Ion-Transport Membrane Oxygen  

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

480

Dissolved Oxygen in Allen CreekDissolved Oxygen in Allen Creek Dissolved oxygen (DO) enters the water by diffusion from air, as a by-product of photosynthesis and  

E-Print Network [OSTI]

Dissolved Oxygen in Allen CreekDissolved Oxygen in Allen Creek Dissolved oxygen (DO) enters and rapids. There is an inverse relationship between temperature and DO, i.e. colder water holds more oxygen it supplies oxygen to aquatic organisms. Higher DO levels also give the water a better taste. Figure 2. During

Tyler, Christy

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


481

Unusual Reductive Coupling of Alkynes and Ketones:? Reactivity of Titanacycles Supported by Dimethylsilylcalix[4]arene (DMSC) Ligands  

Science Journals Connector (OSTI)

Unusual Reductive Coupling of Alkynes and Ketones:? Reactivity of Titanacycles Supported by Dimethylsilylcalix[4]arene (DMSC) Ligands ... [(DMSC)Ti{1,2,4-(Me3Si)3C6H3}] (1) mediates an unusual coupling of terminal alkynes with ketones to produce 2,7-dioxa-1-titana-4-cycloheptenes. ... The regioselectivity of the reaction is controlled by the DMSC ligand, which enforces exo-orientation of the alkyne non-H substituent in the putative intermediate (DMSC)Ti(?2-alkyne) species. ...

Oleg V. Ozerov; Carolyn P. Brock; Shana D. Carr; Folami T. Ladipo

2000-10-12T23:59:59.000Z