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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

Effect of different intravenous iron preparations on lymphocyte intracellular reactive oxygen species generation and subpopulation survival.  

E-Print Network [OSTI]

IV iron compounds induced greater intracellular ROS generation,IV iron preparations on intracellular reactive oxygen species generationIV iron preparations on intracellular immune cell ROS generation

Gupta, Ajay; Zhuo, Jiaying; Zha, Junli; Reddy, Srinivasa; Olp, Jonathan; Pai, Amy

2010-01-01T23:59:59.000Z

3

RESUS-D-12-00285 Mild hypothermia reduces per-ischemic reactive oxygen species production4  

E-Print Network [OSTI]

this dysfunction through per-ischemic3 inhibition of reactive oxygen species (ROS) generation.4 Methods: First, ROS ischemic injuries through complex events2 involving reactive oxygen species (ROS) generation 1, 2RESUS-D-12-00285 1 2 3 Mild hypothermia reduces per-ischemic reactive oxygen species production4

Paris-Sud XI, Université de

4

Lycopene cyclase paralog CruP protects against reactive oxygen species in oxygenic  

E-Print Network [OSTI]

, quenching singlet oxygen generated during the water-splitting process of photo- synthesis (10, 11). VariousLycopene cyclase paralog CruP protects against reactive oxygen species in oxygenic photosynthetic cyclase. Instead, we show that CruP aids in preventing accumulation of reactive oxygen species (ROS

Wurtzel, Eleanore

5

S-nitrosothiols and reactive oxygen species in plant disease resistance and development   

E-Print Network [OSTI]

Nitric oxide (NO) as well as reactive oxygen species (ROS) play an important role in defence signalling in plants. After successful recognition of an invading pathogen, an increase in ROS occurs, the ’oxidative burst’; ...

Brzezek, Kerstin

2014-06-28T23:59:59.000Z

6

Reactive oxygen species deglycosilate glomerular a-dystroglycan  

E-Print Network [OSTI]

Reactive oxygen species deglycosilate glomerular a-dystroglycan NPJ Vogtla¨nder1 , WPM Tamboer1 open. Reactive oxygen species (ROS) are known to degrade and depolymerize carbohydrates, and to playDa in skeletal muscle, ranging from 120 kDa in brain to 190 kDa in the Torpedo electric organ.8

Campbell, Kevin P.

7

INHIBITION OF CASPASE-LIKE ACTIVITIES PREVENTS THE APPEARANCE OF REACTIVE OXYGEN SPECIES AND DARK-INDUCED APOPTOSIS  

E-Print Network [OSTI]

cells revealed by SYTOX-green staining, and the generation of reactive oxygen species (ROS), we usedINHIBITION OF CASPASE-LIKE ACTIVITIES PREVENTS THE APPEARANCE OF REACTIVE OXYGEN SPECIES AND DARK viability; Dunaliella tertiolecta; phosphatidylserine; phytoplankton; reactive oxygen species; unicellular

Berges, John A.

8

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

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

Isoquinoline-1,3,4-trione Derivatives Inactivate Caspase-3 by Generation of Reactive Oxygen Species*S  

E-Print Network [OSTI]

Isoquinoline-1,3,4-trione Derivatives Inactivate Caspase-3 by Generation of Reactive Oxygen Species that ROS can be generated by reaction of isoquinoline-1,3,4-trione derivatives with DTT. Oxygen- pounds can irreversibly inactivate caspase-3 in a 1,4-dithio- threitol (DTT)- and oxygen-dependent manner

Tian, Weidong

11

Direct Observation of the Oxygenated Species during Oxygen Reduction...  

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

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...

12

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

13

Reactive Gliosis Reactive Oxygen Species: Superoxide  

E-Print Network [OSTI]

. By sensing the electric signals generated by other 3368 Reactive Gliosis #12;individuals, mormyrids are alsoReactive Gliosis Glial Scar Reactive Oxygen Species: Superoxide Anions Neuroinflammation motor output. Reafferent Control in Electric Communication Reafferent Control in Electric Communication

14

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

SciTech Connect (OSTI)

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

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

2009-08-15T23:59:59.000Z

15

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

16

IGF-I enhances cellular senescence via the reactive oxygen species-p53 pathway  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer Cellular senescence plays an important role in tumorigenesis and aging process. Black-Right-Pointing-Pointer We demonstrated IGF-I enhanced cellular senescence in primary confluent cells. Black-Right-Pointing-Pointer IGF-I enhanced cellular senescence in the ROS and p53-dependent manner. Black-Right-Pointing-Pointer These results may explain the underlying mechanisms of IGF-I involvement in tumorigenesis and in regulation of aging. -- Abstract: Cellular senescence is characterized by growth arrest, enlarged and flattened cell morphology, the expression of senescence-associated {beta}-galactosidase (SA-{beta}-gal), and by activation of tumor suppressor networks. Insulin-like growth factor-I (IGF-I) plays a critical role in cellular growth, proliferation, tumorigenesis, and regulation of aging. In the present study, we show that IGF-I enhances cellular senescence in mouse, rat, and human primary cells in the confluent state. IGF-I induced expression of a DNA damage marker, {gamma}H2AX, the increased levels of p53 and p21 proteins, and activated SA-{beta}-gal. In the confluent state, an altered downstream signaling of IGF-I receptor was observed. Treatment with a reactive oxygen species (ROS) scavenger, N-acetylcystein (NAC) significantly suppressed induction of these markers, indicating that ROS are involved in the induction of cellular senescence by IGF-I. In p53-null mouse embryonic fibroblasts, the IGF-I-induced augmentation of SA-{beta}-gal and p21 was inhibited, demonstrating that p53 is required for cellular senescence induced by IGF-I. Thus, these data reveal a novel pathway whereby IGF-I enhances cellular senescence in the ROS and p53-dependent manner and may explain the underlying mechanisms of IGF-I involvement in tumorigenesis and in regulation of aging.

Handayaningsih, Anastasia-Evi; Takahashi, Michiko; Fukuoka, Hidenori; Iguchi, Genzo; Nishizawa, Hitoshi; Yamamoto, Masaaki; Suda, Kentaro [Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan)] [Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan); Takahashi, Yutaka, E-mail: takahash@med.kobe-u.ac.jp [Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan)] [Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan)

2012-08-24T23:59:59.000Z

17

Apoptosis induction by silica nanoparticles mediated through reactive oxygen species in human liver cell line HepG2  

SciTech Connect (OSTI)

Silica nanoparticles are increasingly utilized in various applications including agriculture and medicine. In vivo studies have shown that liver is one of the primary target organ of silica nanoparticles. However, possible mechanisms of hepatotoxicity caused by silica nanoparticles still remain unclear. In this study, we explored the reactive oxygen species (ROS) mediated apoptosis induced by well-characterized 14 nm silica nanoparticles in human liver cell line HepG2. Silica nanoparticles (25–200 ?g/ml) induced a dose-dependent cytotoxicity in HepG2 cells. Silica nanoparticles were also found to induce oxidative stress in dose-dependent manner indicated by induction of ROS and lipid peroxidation and depletion of glutathione (GSH). Quantitative real-time PCR and immunoblotting results showed that both the mRNA and protein expressions of cell cycle checkpoint gene p53 and apoptotic genes (bax and caspase-3) were up-regulated while the anti-apoptotic gene bcl-2 was down-regulated in silica nanoparticles treated cells. Moreover, co-treatment of ROS scavenger vitamin C significantly attenuated the modulation of apoptotic markers along with the preservation of cell viability caused by silica nanoparticles. Our data demonstrated that silica nanoparticles induced apoptosis in human liver cells, which is ROS mediated and regulated through p53, bax/bcl-2 and caspase pathways. This study suggests that toxicity mechanisms of silica nanoparticles should be further investigated at in vivo level. -- Highlights: ? We explored the mechanisms of toxicity caused by silica NPs in human liver HepG2 cells. ? Silica NPs induced a dose-dependent cytotoxicity in HepG2 cells. ? Silica NPs induced ROS generation and oxidative stress in a dose-dependent manner. ? Silica NPs were also modulated apoptosis markers both at mRNA and protein levels. ? ROS mediated apoptosis induced by silica NPs was preserved by vitamin C.

Ahmad, Javed [Department of Zoology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia)] [Department of Zoology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Ahamed, Maqusood, E-mail: maqusood@gmail.com [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia)] [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia); Akhtar, Mohd Javed [Fibre Toxicology, CSIR-Indian Institute of Toxicology Research, Lucknow-226001 (India)] [Fibre Toxicology, CSIR-Indian Institute of Toxicology Research, Lucknow-226001 (India); Alrokayan, Salman A. [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia)] [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia); Siddiqui, Maqsood A.; Musarrat, Javed; Al-Khedhairy, Abdulaziz A. [Department of Zoology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia)] [Department of Zoology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia)

2012-03-01T23:59:59.000Z

18

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

SciTech Connect (OSTI)

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

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

2011-10-15T23:59:59.000Z

19

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...

20

NADPH oxidase-mediated generation of reactive oxygen species: A new mechanism for X-ray-induced HeLa cell death  

SciTech Connect (OSTI)

Oxidative damage is an important mechanism in X-ray-induced cell death. Radiolysis of water molecules is a source of reactive oxygen species (ROS) that contribute to X-ray-induced cell death. In this study, we showed by ROS detection and a cell survival assay that NADPH oxidase has a very important role in X-ray-induced cell death. Under X-ray irradiation, the upregulation of the expression of NADPH oxidase membrane subunit gp91{sup phox} was dose-dependent. Meanwhile, the cytoplasmic subunit p47{sup phox} was translocated to the cell membrane and localized with p22{sup phox} and gp91{sup phox} to form reactive NADPH oxidase. Our data suggest, for the first time, that NADPH oxidase-mediated generation of ROS is an important contributor to X-ray-induced cell death. This suggests a new target for combined gene transfer and radiotherapy.

Liu Qing [Department of Radiobiology, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd., Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, 509 Nanchang Rd., Lanzhou 730000 (China); He Xiaoqing [First Affiliated Hospital of Lanzhou University, 1 Donggang West Rd., Lanzhou 730000 (China); Liu Yongsheng [Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural, 1 Xujiaping Rd., Lanzhou 730046 (China); Du Bingbing; Wang Xiaoyan [College of Medicine, Lanzhou University, 222, South Tianshui Rd., Lanzhou 730000 (China); Zhang Weisheng [Gansu Province People's Hospital, 160 Donggang West Rd., Lanzhou 730000 (China); Jia Pengfei [Institute of Cell Biology, School of Life Science, Lanzhou University, 222, South Tianshui Rd., Lanzhou 730000 (China); Dong Jingmei [Institute of Sports Medicine, Lanzhou City University, Jiefang Rd., Lanzhou 730070 (China); Ma Jianxiu [College of Medicine, Northwest University for Nationalities, 1 Northwest New Village, Lanzhou 730030 (China); Wang Xiaohu [Department of Radiology, Gansu Province Cancer Hospital, 2 Xiaoxihu East Rd., Lanzhou 730050 (China); Li Sha [Department of Radiology, Lanzhou General Hospital of PLA, 98 Xiaoxihu West Rd., 730050 (China); Zhang Hong [Department of Radiobiology, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd., Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, 509 Nanchang Rd., Lanzhou 730000 (China)], E-mail: zhangh@impcas.ac.cn

2008-12-19T23:59:59.000Z

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


21

Depletion of hepatoma-derived growth factor-related protein-3 induces apoptotic sensitization of radioresistant A549 cells via reactive oxygen species-dependent p53 activation  

SciTech Connect (OSTI)

Highlights: •HRP-3 is a radiation- and anticancer drug-responsive protein in A549 cells. •Depletion of HRP-3 induces apoptosis of radio- and chemoresistant A549 cells. •Depletion of HRP-3 promotes ROS generation via inhibition of the Nrf2/HO-1 pathway. •Depletion of HRP-3 enhances ROS-dependent p53 activation and PUMA expression. -- Abstract: Biomarkers based on functional signaling have the potential to provide greater insight into the pathogenesis of cancer and may offer additional targets for anticancer therapeutics. Here, we identified hepatoma-derived growth factor-related protein-3 (HRP-3) as a radioresistance-related gene and characterized the molecular mechanism by which its encoded protein regulates the radio- and chemoresistant phenotype of lung cancer-derived A549 cells. Knockdown of HRP-3 promoted apoptosis of A549 cells and potentiated the apoptosis-inducing action of radio- and chemotherapy. This increase in apoptosis was associated with a substantial generation of reactive oxygen species (ROS) that was attributable to inhibition of the Nrf2/HO-1 antioxidant pathway and resulted in enhanced ROS-dependent p53 activation and p53-dependent expression of PUMA (p53 upregulated modulator of apoptosis). Therefore, the HRP-3/Nrf2/HO-1/ROS/p53/PUMA cascade is an essential feature of the A549 cell phenotype and a potential radiotherapy target, extending the range of targets in multimodal therapies against lung cancer.

Yun, Hong Shik; Hong, Eun-Hee [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of) [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Lee, Su-Jae [Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of)] [Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Baek, Jeong-Hwa [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of) [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of); Lee, Chang-Woo [Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of)] [Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of); Yim, Ji-Hye; Um, Hong-Duck [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)] [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Hwang, Sang-Gu, E-mail: sgh63@kcch.re.kr [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)] [Division of Radiation Cancer Biology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)

2013-09-27T23:59:59.000Z

22

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

23

Properties of reactive oxygen species by quantum Monte Carlo  

SciTech Connect (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{sup 3} ? N{sup 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.

Zen, Andrea [Dipartimento di Fisica, La Sapienza - Università di Roma, Piazzale Aldo Moro 2, 00185 Rome (Italy); Trout, Bernhardt L. [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, Massachusetts 02139 (United States); Guidoni, Leonardo, E-mail: leonardo.guidoni@univaq.it [Dipartimento di Scienze Fisiche e Chimiche, Università degli studi de L'Aquila, Via Vetoio, 67100 Coppito, L'Aquila (Italy)

2014-07-07T23:59:59.000Z

24

Generation of reactive oxygen species by a persulfide (BnSSH) Tonika Chatterji,  

E-Print Network [OSTI]

Generation of reactive oxygen species by a persulfide (BnSSH) Tonika Chatterji, Kripa Keerthi generate reactive oxygen species under biologically rele- vant conditions via the sequence of reactions by reactive oxygen species generated in this manner may contribute to the cytotoxic properties of leinamycin

Gates, Kent. S.

25

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

26

E-Print Network 3.0 - active oxygen species Sample Search Results  

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

Powered by Explorit Topic List Advanced Search Sample search results for: active oxygen species Page: << < 1 2 3 4 5 > >> 1 Ecological requirements of damselflies in Dutch...

27

SNP in TXNRD2 Associated With Radiation-Induced Fibrosis: A Study of Genetic Variation in Reactive Oxygen Species Metabolism and Signaling  

SciTech Connect (OSTI)

Purpose: The aim of the study was to identify noninvasive markers of treatment-induced side effects. Reactive oxygen species (ROS) are generated after irradiation, and genetic variation in genes related to ROS metabolism might influence the level of radiation-induced adverse effects (AEs). Methods and Materials: 92 breast cancer (BC) survivors previously treated with hypofractionated radiation therapy were assessed for the AEs subcutaneous atrophy and fibrosis, costal fractures, lung fibrosis, pleural thickening, and telangiectasias (median follow-up time 17.1 years). Single-nucleotide polymorphisms (SNPs) in 203 genes were analyzed for association to AE grade. SNPs associated with subcutaneous fibrosis were validated in an independent BC survivor material (n=283). The influence of the studied genetic variation on messenger ribonucleic acid (mRNA) expression level of 18 genes previously associated with fibrosis was assessed in fibroblast cell lines from BC patients. Results: Subcutaneous fibrosis and atrophy had the highest correlation (r=0.76) of all assessed AEs. The nonsynonymous SNP rs1139793 in TXNRD2 was associated with grade of subcutaneous fibrosis, the reference T-allele being more prevalent in the group experiencing severe levels of fibrosis. This was confirmed in another sample cohort of 283 BC survivors, and rs1139793 was found significantly associated with mRNA expression level of TXNRD2 in blood. Genetic variation in 24 ROS-related genes, including EGFR, CENPE, APEX1, and GSTP1, was associated with mRNA expression of 14 genes previously linked to fibrosis (P?.005). Conclusion: Development of subcutaneous fibrosis can be associated with genetic variation in the mitochondrial enzyme TXNRD2, critically involved in removal of ROS, and maintenance of the intracellular redox balance.

Edvardsen, Hege, E-mail: hege.edvardsen@rr-research.no [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway) [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); Landmark-Høyvik, Hege [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway) [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); Reinertsen, Kristin V. [National Resource Centre for Late Effects after Cancer Treatment, OUS Radiumhospitalet, Oslo (Norway)] [National Resource Centre for Late Effects after Cancer Treatment, OUS Radiumhospitalet, Oslo (Norway); Zhao, Xi [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway) [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); Grenaker-Alnæs, Grethe Irene; Nebdal, Daniel [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway)] [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); Syvänen, Ann-Christine [Department of Medical Sciences, Uppsala University, Uppsala (Sweden)] [Department of Medical Sciences, Uppsala University, Uppsala (Sweden); Rødningen, Olaug [Department of Medical Genetics, OUS Ullevaal, Oslo (Norway)] [Department of Medical Genetics, OUS Ullevaal, Oslo (Norway); Alsner, Jan; Overgaard, Jens [Department of Experimental Clinical Oncology, Ahus University Hospital (Norway)] [Department of Experimental Clinical Oncology, Ahus University Hospital (Norway); Borresen-Dale, Anne-Lise [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway) [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); Fosså, Sophie D. [K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway) [K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); National Resource Centre for Late Effects after Cancer Treatment, OUS Radiumhospitalet, Oslo (Norway); Kristensen, Vessela N. [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway) [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); Department of Clinical Molecular Biology (EpiGen), Division of Medicine, Ahus University Hospital (Norway)

2013-07-15T23:59:59.000Z

28

Reactive oxygen species mediate Cr(VI)-induced carcinogenesis through PI3K/AKT-dependent activation of GSK-3?/?-catenin signaling  

SciTech Connect (OSTI)

Cr(VI) compounds are known human carcinogens that primarily target the lungs. Cr(VI) produces reactive oxygen species (ROS), but the exact effects of ROS on the signaling molecules involved in Cr(VI)-induced carcinogenesis have not been extensively studied. Chronic exposure of human bronchial epithelial cells to Cr(VI) at nanomolar concentrations (10–100 nM) for 3 months not only induced cell transformation, but also increased the potential of these cells to invade and migrate. Injection of Cr(VI)-stimulated cells into nude mice resulted in the formation of tumors. Chronic exposure to Cr(VI) increased levels of intracellular ROS and antiapoptotic proteins. Transfection with catalase or superoxide dismutase (SOD) prevented Cr(VI)-mediated increases in colony formation, cell invasion, migration, and xenograft tumors. While chronic Cr(VI) exposure led to activation of signaling cascades involving PI3K/AKT/GSK-3?/?-catenin and PI3K/AKT/mTOR, transfection with catalase or SOD markedly inhibited Cr(VI)-mediated activation of these signaling proteins. Inhibitors specific for AKT or ?-catenin almost completely suppressed the Cr(VI)-mediated increase in total and active ?-catenin proteins and colony formation. In particular, Cr(VI) suppressed autophagy of epithelial cells under nutrition deprivation. Furthermore, there was a marked induction of AKT, GSK-3?, ?-catenin, mTOR, and carcinogenic markers in tumor tissues formed in mice after injection with Cr(VI)-stimulated cells. Collectively, our findings suggest that ROS is a key mediator of Cr(VI)-induced carcinogenesis through the activation of PI3K/AKT-dependent GSK-3?/?-catenin signaling and the promotion of cell survival mechanisms via the inhibition of apoptosis and autophagy. - Highlights: • Chronic exposure to Cr(VI) induces carcinogenic properties in BEAS-2B cells. • ROS play an important role in Cr(VI)-induced tumorigenicity of BEAS-2B cells. • PI3K/AKT/GSK-3?/?-catenin signaling involved in Cr(VI) carcinogenesis. • The inhibition of apoptosis and autophagy contributes to Cr(VI) carcinogenesis.

Son, Young-Ok; Pratheeshkumar, Poyil; Wang, Lei; Wang, Xin; Fan, Jia; Kim, Dong-Hern; Lee, Ju-Yeon; Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); School of Dentistry and Institute of Oral Biosciences, Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States)

2013-09-01T23:59:59.000Z

29

Inhibition of NADPH cytochrome P450 reductase by the model sulfur mustard vesicant 2-chloroethyl ethyl sulfide is associated with increased production of reactive oxygen species  

SciTech Connect (OSTI)

Inhalation of vesicants including sulfur mustard can cause significant damage to the upper airways. This is the result of vesicant-induced modifications of proteins important in maintaining the integrity of the lung. Cytochrome P450s are the major enzymes in the lung mediating detoxification of sulfur mustard and its metabolites. NADPH cytochrome P450 reductase is a flavin-containing electron donor for cytochrome P450. The present studies demonstrate that the sulfur mustard analog, 2-chloroethyl ethyl sulfide (CEES), is a potent inhibitor of human recombinant cytochrome P450 reductase, as well as native cytochrome P450 reductase from liver microsomes of saline and {beta}-naphthoflavone-treated rats, and cytochrome P450 reductase from type II lung epithelial cells. Using rat liver microsomes from {beta}-naphthoflavone-treated rats, CEES was found to inhibit CYP 1A1 activity. This inhibition was overcome by microsomal cytochrome P450 reductase from saline-treated rats, which lack CYP 1A1 activity, demonstrating that the CEES inhibitory activity was selective for cytochrome P450 reductase. Cytochrome P450 reductase also generates reactive oxygen species (ROS) via oxidation of NADPH. In contrast to its inhibitory effects on the reduction of cytochrome c and CYP1A1 activity, CEES was found to stimulate ROS formation. Taken together, these data demonstrate that sulfur mustard vesicants target cytochrome P450 reductase and that this effect may be an important mechanism mediating oxidative stress and lung injury.

Gray, Joshua P. [Department of Science, United States Coast Guard Academy, New London, CT (United States); Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ (United States); Mishin, Vladimir [Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ (United States); Heck, Diane E. [Department of Environmental Health Science, New York Medical College, Valhalla, NY (United States); Laskin, Debra L. [Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ (United States); Laskin, Jeffrey D., E-mail: jlaskin@eohsi.rutgers.ed [Environmental and Occupational Medicine, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ (United States)

2010-09-01T23:59:59.000Z

30

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.

31

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

32

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

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

Green fluorescent protein based indicators of dynamic redox changes and reactive oxygen species  

E-Print Network [OSTI]

attached a singlet oxygen generator to the C-terminal ofencoded singlet oxygen generators, which is currentlyassays. A. Singlet oxygen generator and sensor are tethered;

Dooley, Colette

2006-01-01T23:59:59.000Z

35

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

E-Print Network [OSTI]

-heptane/oxygenate mixtures were 2.7 and 3.4. Three different fuel oxygenates (i.e. MTBE, methanol, and ethanol) were tested tertiary-butyl ether (MTBE), ethyl tertiary-butyl ether (ETBE), and tertiary amyl methyl ether (TAME)) were considered as possible fuel oxygenates. MTBE and ethanol are the most common oxygenates currently used

Senkan, Selim M.

36

Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway  

SciTech Connect (OSTI)

Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

Wang, Yi-Fen; Shyu, Huey-Wen [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China)] [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Chang, Yi-Chuang [Department of Nursing, Fooyin University, Kaohsiung, Taiwan (China)] [Department of Nursing, Fooyin University, Kaohsiung, Taiwan (China); Tseng, Wei-Chang [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China)] [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Huang, Yeou-Lih [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China)] [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Lin, Kuan-Hua; Chou, Miao-Chen; Liu, Heng-Ling [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China)] [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China); Chen, Chang-Yu, E-mail: mt037@mail.fy.edu.tw [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China)] [Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan (China)

2012-03-01T23:59:59.000Z

37

Up-regulation of cytosolic phospholipase A{sub 2}{alpha} expression by N,N-diethyldithiocarbamate in PC12 cells; involvement of reactive oxygen species and nitric oxide  

SciTech Connect (OSTI)

Disulfiram (an alcohol-aversive drug) and related compounds are known to provoke several side effects involving behavioral and neurological complications. N,N-diethyldithiocarbamate (DDC) is considered as one of the main toxic species of disulfiram and acts as an inhibitor of superoxide dismutase. Since arachidonic acid (AA) formation is regulated by reactive oxygen species (ROS) and related to toxicity in neuronal cells, we investigated the effects of DDC on AA release and expression of the {alpha} type of cytosolic phospholipase A{sub 2} (cPLA{sub 2}{alpha}) in PC12 cells. Treatment with 80-120 {mu}M DDC that causes a moderate increase in ROS levels without cell toxicity stimulated cPLA{sub 2}{alpha} mRNA and its protein expression. The expression was mediated by extracellular-signal-regulated kinase (ERK1/2), one of the mitogen-activated protein kinases. Treatment with N {sup G} nitro-L-arginine methyl ester (an inhibitor of nitric oxide synthase, 1 mM) and oxy-hemoglobin (a scavenger of nitric oxide, 2 mg/mL) abolished the DDC-induced responses (ERK1/2 phosphorylation and cPLA{sub 2}{alpha} expression). We also showed DDC-induced up-regulation of the mRNA expression of lipocortin 1, an inhibitor of PLA{sub 2}. Furthermore, DDC treatment of the cells enhanced Ca{sup 2+}-ionophore-induced AA release in 30 min, although the effect was limited. Changes in AA metabolism in DDC-treated cells may have a potential role in mediating neurotoxic actions of disulfiram. In this study, we show the first to demonstrate the up-regulation of cPLA{sub 2}{alpha} expression by DDC treatment in neuronal cells.

Akiyama, Nobuteru [Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8675 (Japan); Nabemoto, Maiko [Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8675 (Japan); Hatori, Yoshio [Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8675 (Japan); Nakamura, Hiroyuki [Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8675 (Japan); Hirabayashi, Tetsuya [Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8675 (Japan); Fujino, Hiromichi [Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8675 (Japan); Saito, Takeshi [Department of Health Sciences, Hokkaido University School of Medicine, Sapporo 060-0812 (Japan); Murayama, Toshihiko [Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba 260-8675 (Japan)]. E-mail: murayama@p.chiba-u.ac.jp

2006-09-01T23:59:59.000Z

38

Phenethyl Isothiocyanate (PEITC) Decreases Specficity Protein (SP) Tanscription Factors through an ROS-dependent Mechanism  

E-Print Network [OSTI]

include hydrogen peroxide (H2O2), ozone (O3), peroxynitrite (ONOO-) and hydroxide (OH) [1]. ROS normally exist in all cells that undergo aerobic respiration. Endogenous sources of ROS in cells includes mitochondria, peroxisomes and cytochrome P450..., catalase and GPx. SOD catalyzes the dismutation of superoxide into oxygen and hydrogen peroxide [42]. There are three forms of SOD found in humans: cytosolic Cu/Zn-SOD, mitochondrial Mn-SOD and extracellular SOD (EC-SOD) [43, 9 44]. SOD...

Guthrie, Aaron S 1987-

2012-12-05T23:59:59.000Z

39

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.

40

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

SciTech Connect (OSTI)

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

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

2011-09-15T23:59:59.000Z

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


41

Cadmium induces carcinogenesis in BEAS-2B cells through ROS-dependent activation of PI3K/AKT/GSK-3?/?-catenin signaling  

SciTech Connect (OSTI)

Cadmium has been widely used in industry and is known to be carcinogenic to humans. Although it is widely accepted that chronic exposure to cadmium increases the incidence of cancer, the mechanisms underlying cadmium-induced carcinogenesis are unclear. The main aim of this study was to investigate the role of reactive oxygen species (ROS) in cadmium-induced carcinogenesis and the signal transduction pathways involved. Chronic exposure of human bronchial epithelial BEAS-2B cells to cadmium induced cell transformation, as evidenced by anchorage-independent growth in soft agar and clonogenic assays. Chronic cadmium treatment also increased the potential of these cells to invade and migrate. Injection of cadmium-stimulated cells into nude mice resulted in the formation of tumors. In contrast, the cadmium-mediated increases in colony formation, cell invasion and migration were prevented by transfection with catalase, superoxide dismutase-1 (SOD1), or SOD2. In particular, chronic cadmium exposure led to activation of signaling cascades involving PI3K, AKT, GSK-3?, and ?-catenin and transfection with each of the above antioxidant enzymes markedly inhibited cadmium-mediated activation of these signaling proteins. Inhibitors specific for AKT or ?-catenin almost completely suppressed the cadmium-mediated increase in total and active ?-catenin proteins and colony formation. Moreover, there was a marked induction of AKT, GSK-3?, ?-catenin, and carcinogenic markers in tumor tissues formed in mice after injection with cadmium-stimulated cells. Collectively, our findings suggest a direct involvement of ROS in cadmium-induced carcinogenesis and implicate a role of AKT/GSK-3?/?-catenin signaling in this process. -- Highlights: ? Chronic exposure to cadmium induces carcinogenic properties in BEAS-2B cells. ? ROS involved in cadmium-induced tumorigenicity of BEAS-2B cells. ? Cadmium activates ROS-dependent AKT/GSK-3?/?-catenin-mediated signaling. ? ROS-dependent signaling as potential therapeutic targets in cadmium carcinogenesis.

Son, Young-Ok; Wang, Lei; Poyil, Pratheeshkumar; Budhraja, Amit; Hitron, J. Andrew; Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States)] [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States) [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States); School of Dentistry and Institute of Oral Biosciences (BK21 program), Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States)] [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States)

2012-10-15T23:59:59.000Z

42

Photochemical Transformation of Carboxylated Multiwalled Carbon Nanotubes: Role of Reactive Oxygen Species  

E-Print Network [OSTI]

in consumer and industrial products (e.g., electronics, composite materials, and sporting equipment) mayPhotochemical Transformation of Carboxylated Multiwalled Carbon Nanotubes: Role of Reactive Oxygen investigated the photochemical transformation of carboxylated multiwalled carbon nanotubes (COOH

Alvarez, Pedro J.

43

Moderate extracellular acidification inhibits capsaicin-induced cell death through regulating calcium mobilization, NF-{kappa}B translocation and ROS production in synoviocytes  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer Moderate extracellular acidification regulates intracellular Ca{sup 2+} mobilization. Black-Right-Pointing-Pointer Moderate acidification activates NF-{kappa}B nuclear translocation in synoviocytes. Black-Right-Pointing-Pointer Moderate acidification depresses the ROS production induced by capsaicin. Black-Right-Pointing-Pointer Moderate acidification inhibits capsaicin-caused synoviocyte death. -- Abstract: We previously show the expression of transient receptor potential vanilloid 1 (TRPV1) in primary synoviocytes from collagen-induced arthritis (CIA) rats. Capsaicin and lowered extracellular pH from 7.4 to 5.5 induce cell death through TRPV1-mediated Ca{sup 2+} entry and reactive oxygen species (ROS) production. However, under the pathological condition in rheumatoid arthritis, the synovial fluid is acidified to a moderate level (about pH 6.8). In the present study, we examined the effects of pH 6.8 on the TRPV1-mediated cell death. Our finding is different or even opposite from what was observed at pH 5.5. We found that the moderate extracellular acidification (from pH 7.4 to 6.8) inhibited the capsaicin-induced Ca{sup 2+} entry through attenuating the activity of TRPV1. In the mean time, it triggered a phospholipse C (PLC)-related Ca{sup 2+} release from intracellular stores. The nuclear translocation of NF-{kappa}B was found at pH 6.8, and this also depends on PLC activation. Moreover, the capsaicin-evoked massive ROS production and cell death were depressed at pH 6.8, both of which are dependent on the activation of PLC and NF-{kappa}B. Taken together, these results suggested that the moderate extracellular acidification inhibited the capsaicin-induced synoviocyte death through regulating Ca{sup 2+} mobilization, activating NF-{kappa}B nuclear translocation and depressing ROS production.

Hu, Fen; Yang, Shuang; Zhao, Dan; Zhu, Shuyan; Wang, Yuxiang [Department of Biophysics, School of Physics and Key Laboratory of Bioactive Materials of Education Ministry, Nankai University, Tianjin 300071 (China)] [Department of Biophysics, School of Physics and Key Laboratory of Bioactive Materials of Education Ministry, Nankai University, Tianjin 300071 (China); Li, Junying, E-mail: jyli04@nankai.edu.cn [Department of Biophysics, School of Physics and Key Laboratory of Bioactive Materials of Education Ministry, Nankai University, Tianjin 300071 (China)] [Department of Biophysics, School of Physics and Key Laboratory of Bioactive Materials of Education Ministry, Nankai University, Tianjin 300071 (China)

2012-07-20T23:59:59.000Z

44

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

E-Print Network [OSTI]

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

Jonathan Phillips; Chun Ku Chen; Randell Mills

2004-02-06T23:59:59.000Z

45

A novel synthetic analog of militarin, MA-1 induces mitochondrial dependent apoptosis by ROS generation in human lung cancer cells  

SciTech Connect (OSTI)

A synthetic Militarin analog-1[(2R,3R,4R,5R)-1,6-bis(4-(2,4,4-trimethylpentan-2-yl)phenoxy) hexane-2,3,4,5-tetraol] is a novel derivative of constituents from Cordyceps militaris, which has been used to treat a variety of chronic diseases including inflammation, diabetes, hyperglycemia and cancers. Here, we report for the first time the synthesis of Militarin analog-1 (MA-1) and the apoptotic mechanism of MA-1 against human lung cancer cell lines. Treatment with MA-1 significantly inhibited the viability of 3 human lung cancer cell lines. The inhibition of viability and growth in MA-1-treated A549 cells with an IC{sub 50} of 5 ?M were mediated through apoptosis induction, as demonstrated by an increase in DNA fragmentation, sub-G{sub 0}/G{sub 1}-DNA fraction, nuclear condensation, and phosphatidylserine exposure. The apoptotic cell death caused mitochondrial membrane permeabilization through regulation of expression of the Bcl-2 family proteins, leading to cytochrome c release in a time-dependent manner. Subsequently, the final stage of apoptosis, activation of caspase-9/-3 and cleavage of poly (ADP ribose) polymerase, was induced. Furthermore, A549 lung cancer cells were more responsive to MA-1 than a bronchial epithelial cell line (BEAS-2B), involving the rapid generation of reactive oxygen species (ROS), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) activation. The pharmacological inhibition of ROS generation and JNK/p38 MAPK exhibited attenuated DNA fragmentation in MA-1-induced apoptosis. Oral administration of MA-1 also retarded growth of A549 orthotopic xenografts. In conclusion, the present study indicates that the new synthetic derivative MA-1 triggers mitochondrial apoptosis through ROS generation and regulation of MAPKs and may be a potent therapeutic agent against human lung cancer. - Highlights: • We report a novel synthesized derivative, militarin analog-1 (MA-1). • MA-1-induced cancer cell death was triggered by the ROS generation through MAPKs. • The MA-1-induced cell death was also modulated by the mitochondria-mediated pathway. • The apoptotic cancer cell death by MA-1 was also exhibited in orthotopic xenografts. • Our findings suggest MA-1 as a clinically useful agent for human lung cancer.

Yoon, Deok Hyo; Lim, Mi-Hee [Department of Biochemistry, Kangwon National University, Chuncheon 200-701 (Korea, Republic of); Lee, Yu Ran [Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747 (Korea, Republic of); Sung, Gi-Ho [Mushroom Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Suwon 404-707 (Korea, Republic of); Lee, Tae-Ho [R and D Center, Dong-A Pharmaceutical Co, Ltd, Yongin 446-905 (Korea, Republic of); Jeon, Byeong Hwa [Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747 (Korea, Republic of); Cho, Jae Youl [Department of Genetic Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Song, Won O. [Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824 (United States); Park, Haeil [College of Pharmacy, Kangwon National University, Chuncheon 200-701 (Korea, Republic of); Choi, Sunga, E-mail: sachoi@cnu.ac.kr [Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747 (Korea, Republic of); Kim, Tae Woong, E-mail: tawkim@kangwon.ac.kr [Department of Biochemistry, Kangwon National University, Chuncheon 200-701 (Korea, Republic of)

2013-12-15T23:59:59.000Z

46

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

47

TGF-{beta}1 increases invasiveness of SW1990 cells through Rac1/ROS/NF-{kappa}B/IL-6/MMP-2  

SciTech Connect (OSTI)

Research highlights: {yields} Rac1 mediates TGF-{beta}1-induced SW1990 invasion through MMP-2 secretion and activation. {yields} NADPH-generated ROS act downstream of Rac1 in TGF-{beta}1-challenged SW1990 cells. {yields} TGF-{beta}1-stimulated ROS activate NF-{kappa}B in SW1990 cells. {yields} NF{kappa}B-induced IL-6 release is required for secretion and activation of MMP-2 in SW1990 cells. -- Abstract: Human pancreatic cancer invasion and metastasis have been found to correlate with increased levels of active matrix metalloproteinase 2 (MMP-2). The multifunctional cytokine transforming growth factor beta 1 (TGF-{beta}1) has been shown to increase both secretion of MMP-2 and invasion by several pancreatic cancer cell types. In the present study, we investigated the signaling pathway involved in TGF-{beta}1-promoted MMP-2 secretion and invasion by human pancreatic cancer cells SW1990. Using specific inhibitors, we found that stimulation of these tumor cells with TGF-{beta}1 induced secretion and activation of the collagenase MMP-2, which was required for TGF-{beta}1-stimulated invasion. Our results also indicate that signaling events involved in TGF-{beta}1-enhanced SW1990 invasiveness comprehend activation of Rac1 followed by generation of reactive oxygen species through nicotinamide adenine dinucleotide phosphate-oxidase, activation of nuclear factor-kappa beta, release of interleukin-6, and secretion and activation of MMP-2.

Binker, Marcelo G. [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada) [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); CBRHC Research Center, Buenos Aires (Argentina); Binker-Cosen, Andres A. [CBRHC Research Center, Buenos Aires (Argentina)] [CBRHC Research Center, Buenos Aires (Argentina); Gaisano, Herbert Y. [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada)] [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); Cosen, Rodica H. de [CBRHC Research Center, Buenos Aires (Argentina)] [CBRHC Research Center, Buenos Aires (Argentina); Cosen-Binker, Laura I., E-mail: laura.cosen.binker@utoronto.ca [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); CBRHC Research Center, Buenos Aires (Argentina)

2011-02-04T23:59:59.000Z

48

Arsenic and chromium in drinking water promote tumorigenesis in a mouse colitis-associated colorectal cancer model and the potential mechanism is ROS-mediated Wnt/?-catenin signaling pathway  

SciTech Connect (OSTI)

Exposure to carcinogenic metals, such as trivalent arsenic [As(III)] and hexavalent chromium [Cr(VI)], through drinking water is a major global public health problem and is associated with various cancers. However, the mechanism of their carcinogenicity remains unclear. In this study, we used azoxymethane/dextran sodium sulfate (AOM/DSS)-induced mouse colitis-associated colorectal cancer model to investigate their tumorigenesis. Our results demonstrate that exposure to As(III) or Cr(VI), alone or in combination, together with AOM/DSS pretreatment has a promotion effect, increasing the colorectal tumor incidence, multiplicity, size, and grade, as well as cell inflammatory response. Two-dimensional differential gel electrophoresis coupled with mass spectrometry revealed that As(III) or Cr(VI) treatment alone significantly changed the density of proteins. The expression of ?-catenin and phospho-GSK was increased by treatment of carcinogenic metals alone. Concomitantly, the expression of NADPH oxidase1 (NOX1) and the level of 8-OHdG were also increased by treatment of carcinogenic metals alone. Antioxidant enzymes, such as superoxide dismutase (SOD) and catalase, were decreased. Similarly, in an in vitro system, exposure of CRL-1807 to carcinogenic metals increased reactive oxygen species (ROS) generation, the expression of ?-catenin, phospho-GSK, and NOX1. Inhibition of ROS generation by addition of SOD or catalase inhibited ?-catenin expression and activity. Our study provides a new animal model to study the carcinogenicity of As(III) and Cr(VI) and suggests that As(III) and Cr(VI) promote colorectal cancer tumorigenesis, at least partly, through ROS-mediated Wnt/?-catenin signaling pathway. -- Highlights: ? Carcinogenic metals in drinking water promote colorectal tumor formation in vivo. ? Carcinogenic metals induce ?-catenin activation in vivo and in vitro. ? ROS generation induced by carcinogenic metals mediated ?-catenin activation.

Wang, Xin; Mandal, Ardhendu K. [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States)] [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Saito, Hiroshi [Department of Surgery and Physiology, Lucille P. Markey Cancer Center, University of Kentucky, Lexington, KY 40536 (United States)] [Department of Surgery and Physiology, Lucille P. Markey Cancer Center, University of Kentucky, Lexington, KY 40536 (United States); Pulliam, Joseph F.; Lee, Eun Y. [Pathology and Laboratory Medicine, University of Kentucky, Lexington, KY 40536 (United States)] [Pathology and Laboratory Medicine, University of Kentucky, Lexington, KY 40536 (United States); Ke, Zun-Ji; Lu, Jian; Ding, Songze [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States)] [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Li, Li [Department of Family Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)] [Department of Family Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Shelton, Brent J.; Tucker, Thomas [Markey Cancer Control Program, University of Kentucky, Lexington, KY 40504 (United States)] [Markey Cancer Control Program, University of Kentucky, Lexington, KY 40504 (United States); Evers, B. Mark [Department of Surgery and Physiology, Lucille P. Markey Cancer Center, University of Kentucky, Lexington, KY 40536 (United States)] [Department of Surgery and Physiology, Lucille P. Markey Cancer Center, University of Kentucky, Lexington, KY 40536 (United States); Zhang, Zhuo [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States)] [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Shi, Xianglin, E-mail: xshi5@uky.edu [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States)] [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States)

2012-07-01T23:59:59.000Z

49

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]

singlet oxygen. Environmental Science & Technology 41(13),Oxygen Mediated Inactivation. Environmental Science & TechnologyOxygen Mediated Inactivation. Environmental Science & Technology

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

50

Perlick: ENERGY STAR Referral (HP48RO-S)  

Broader source: Energy.gov [DOE]

DOE referred Perlick refrigerator HP48RO-S to EPA, brand manager of the ENERGY STAR program, for appropriate action after DOE testing revealed that the model does not meet ENERGY STAR requirements.

51

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

52

Application of the Supported Fluorescent Probe Proxyl Fluorescamine to the Measurement of Free Radicals in Cigarette Smoke and Secondary Organic Aerosols  

E-Print Network [OSTI]

oxygen species formation. Environmental Science and TechnologyOxygen Species (ROS). Aerosol Science and Technology 2008,oxygen species concentrations in Flushing, New York. Aerosol Science and Technology

Sleiman, Mohamad

2013-01-01T23:59:59.000Z

53

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]

contained in transparent plastic bottles: characterizing thepolyethylene terephthalate) plastic bottle, oxygenating themethod requires only plastic bottles, considered by many of

Fisher, Michael Benjamin

2011-01-01T23:59:59.000Z

54

Epithelial–mesenchymal transition during oncogenic transformation induced by hexavalent chromium involves reactive oxygen species-dependent mechanism in lung epithelial cells  

SciTech Connect (OSTI)

Hexavalent chromium [Cr(VI)] is an important human carcinogen associated with pulmonary diseases and lung cancer. Exposure to Cr(VI) induces DNA damage, cell morphological change and malignant transformation in human lung epithelial cells. Despite extensive studies, the molecular mechanisms remain elusive, it is also not known if Cr(VI)-induced transformation might accompany with invasive properties to facilitate metastasis. We aimed to study Cr(VI)-induced epithelial–mesenchymal transition (EMT) and invasion during oncogenic transformation in lung epithelial cells. The results showed that Cr(VI) at low doses represses E-cadherin mRNA and protein expression, enhances mesenchymal marker vimentin expression and transforms the epithelial cell into fibroblastoid morphology. Cr(VI) also increases cell invasion and promotes colony formation. Further studies indicated that Cr(VI) uses multiple mechanisms to repress E-cadherin expression, including activation of E-cadherin repressors such as Slug, ZEB1, KLF8 and enhancement the binding of HDAC1 in E-cadherin gene promoter, but DNA methylation is not responsible for the loss of E-cadherin. Catalase reduces Cr(VI)-induced E-cadherin and vimentin protein expression, attenuates cell invasion in matrigel and colony formation on soft agar. These results demonstrate that exposure to a common human carcinogen, Cr(VI), induces EMT and invasion during oncogenic transformation in lung epithelial cells and implicate in cancer metastasis and prevention. - Graphical abstract: Epithelial–mesenchymal transition during oncogenic transformation induced by hexavalent chromium involves reactive oxygen species-dependent mechanisms in lung epithelial cells. - Highlights: • We study if Cr(VI) might induce EMT and invasion in epithelial cells. • Cr(VI) induces EMT by altering E-cadherin and vimentin expression. • It also increases cell invasion and promotes oncogenic transformation. • Catalase reduces Cr(VI)-induced EMT, invasion and transformation.

Ding, Song-Ze, E-mail: dingsongze@hotmail.com [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Yang, Yu-Xiu; Li, Xiu-Ling [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Michelli-Rivera, Audrey [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Han, Shuang-Yin [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Wang, Lei; Pratheeshkumar, Poyil; Wang, Xin; Lu, Jian; Yin, Yuan-Qin; Budhraja, Amit; Hitron, Andrew J. [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States)

2013-05-15T23:59:59.000Z

55

Expression and rearrangement of the ROS1 gene in human glioblastoma cells  

SciTech Connect (OSTI)

The human ROS1 gene, which possibly encodes a growth factor receptor, was found to be expressed in human tumor cell lines. In a survey of 45 different human cell lines, the authors found ROS1 to be expressed in glioblastoma-derived cell lines at high levels and not to be expressed at all, or expressed at very low levels, in the remaining cell lines. The ROS1 gene was present in normal copy numbers in all cell lines that expressed the gene. However, in one particular glioblastoma line, they detected a potentially activating mutation at the ROS1 locus.

Birchmeier, C.; Sharma, S.; Wigler, M.

1987-12-01T23:59:59.000Z

56

Oxygen analyzer  

DOE Patents [OSTI]

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

Benner, William H. (Danville, CA)

1986-01-01T23:59:59.000Z

57

Oxygen analyzer  

DOE Patents [OSTI]

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

Benner, W.H.

1984-05-08T23:59:59.000Z

58

Oxygen Discharge and Post-Discharge Kinetics Experiments and Modeling for the Electric Oxygen-Iodine Laser System  

E-Print Network [OSTI]

Oxygen Discharge and Post-Discharge Kinetics Experiments and Modeling for the Electric Oxygen a low-pressure oxygen/helium/nitric oxide discharge. In the electric discharge oxygen-iodine laser (ElectricOIL) the discharge production of atomic oxygen, ozone, and other excited species adds levels

Carroll, David L.

59

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

SciTech Connect (OSTI)

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

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

1995-04-01T23:59:59.000Z

60

Penetration Deep into Tissues of Reactive Oxygen Species Generated in Floating-Electrode Dielectric Barrier Discharge (FE-DBD): in Vitro Agarose Gel Model Mimicking an Open Wound  

E-Print Network [OSTI]

In this manuscript we present an in vitro model based on agarose gel that can be used to simulate a dirty, oily, bloody, and morphologically complex surface of, for example, an open wound. We show this models effectiveness in simulating depth of penetration of reactive species generated in plasma deep into tissue of a rat and confirm the penetration depths with agarose gel model. We envision that in the future such a model could be used to study plasma discharges (and other modalities) and minimize the use of live animals: plasma can be optimized on the agarose gel wound model and then finally verified using an actual wound.

Dobrynin, Danil; Friedman, Gary; Fridman, Alexander

2013-01-01T23:59:59.000Z

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


61

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

62

Effects of oxygen on fracturing fluids  

SciTech Connect (OSTI)

The stability of polysaccharide gels at high temperature is limited by such factors as pH, mechanical degradation, and oxidants. Oxygen is unavoidably placed in fracturing fluids through dissolution of air. To prevent premature degradation of the fracturing fluid by this oxidant, oxygen scavengers are commonly used. In this paper, the effects of oxygen and various oxygen scavengers on gel stability will be presented. Mechanical removal of oxygen resulted in surprisingly stable fracturing gels at 275 F. However, chemical removal of oxygen gave mixed results. Test data from sodium thiosulfate, sodium sulfite, and sodium erythorbate used as oxygen scavengers/gel stabilizers showed that the efficiency of oxygen removal from gels did not directly coincide with the viscosity retention of the gel, and large excesses of additives were necessary to provide optimum gel stabilization. The inability of some oxygen scavengers to stabilize the gel was the result of products created from the interaction of oxygen with the oxygen scavenger, which in turn, produced species that degraded the gel. The ideal oxygen scavenger should provide superior gel stabilization without creating detrimental side reaction products. Of the materials tested, sodium thiosulfate appeared to be the most beneficial.

Walker, M.L.; Shuchart, C.E.; Yaritz, J.G.; Norman, L.R.

1995-11-01T23:59:59.000Z

63

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

64

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

65

Biochem. J. (2008) 411, 531541 (Printed in Great Britain) doi:10.1042/BJ20071534 531 Endosomal NADPH oxidase regulates c-Src activation following  

E-Print Network [OSTI]

-dependent mechanism of c-Src activation following H/R injury and found that ROS (reactive oxygen species) generated generate O2 ·- by transferring an electron from NADPH to molecular oxygen. The active form of th, hypoxia/reoxygenation, NADPH oxidase, Rac1, reactive oxygen species. INTRODUCTION ROS (reactive oxygen

Engelhardt, John F.

2008-01-01T23:59:59.000Z

66

Identification of an Archean marine oxygen oasis  

SciTech Connect (OSTI)

The early Earth was essentially anoxic. A number of indicators suggest the presence of oxygenic photosynthesis 2700 3000 million years (Ma) ago, but direct evidence for molecular oxygen (O2) in seawater has remained elusive. Here we report rare earth element (REE) analyses of 2800 million year old shallowmarine limestones and deep-water iron-rich sediments at Steep Rock Lake, Canada. These show that the seawater from which extensive shallow-water limestones precipitated was oxygenated, whereas the adjacent deeper waters where iron-rich sediments formed were not. We propose that oxygen promoted limestone precipitation by oxidative removal of dissolved ferrous iron species, Fe(II), to insoluble Fe(III) oxyhydroxide, and estimate that at least 10.25 M oxygen concentration in seawater was required to accomplish this at Steep Rock. This agrees with the hypothesis that an ample supply of dissolved Fe(II) in Archean oceans would have hindered limestone formation. There is no direct evidence for the oxygen source at Steep Rock, but organic carbon isotope values and diverse stromatolites in the limestones suggest the presence of cyanobacteria. Our findings support the view that during the Archean significant oxygen levels first developed in protected nutrient-rich shallow marine habitats. They indicate that these environments were spatially restricted, transient, and promoted limestone precipitation. If Archean marine limestones in general reflect localized oxygenic removal of dissolved iron at the margins of otherwise anoxic iron-rich seas, then early oxygen oases are less elusive than has been assumed.

Riding, Dr Robert E [University of Tennessee (UT); Fralick, Dr Philip [Lakehead University, Canada; Liang, Liyuan [ORNL

2014-01-01T23:59:59.000Z

67

Ethanol increases matrix metalloproteinase-12 expression via NADPH oxidase-dependent ROS production in macrophages  

SciTech Connect (OSTI)

Matrix metalloproteinase-12 (MMP-12), an enzyme responsible for degradation of extracellular matrix, plays an important role in the progression of various diseases, including inflammation and fibrosis. Although most of those are pathogenic conditions induced by ethanol ingestion, the effect of ethanol on MMP-12 has not been explored. In the present study, we investigated the effect of ethanol on MMP-12 expression and its potential mechanisms in macrophages. Here, we demonstrated that ethanol treatment increased MMP-12 expression in primary murine peritoneal macrophages and RAW 264.7 macrophages at both mRNA and protein levels. Ethanol treatment also significantly increased the activity of nicotinamide adenine dinucleotide (NADPH) oxidase and the expression of NADPH oxidase-2 (Nox2). Pretreatment with an anti-oxidant (N-acetyl cysteine) or a selective inhibitor of NADPH oxidase (diphenyleneiodonium chloride (DPI)) prevented ethanol-induced MMP-12 expression. Furthermore, knockdown of Nox2 by small interfering RNA (siRNA) prevented ethanol-induced ROS production and MMP-12 expression in RAW 264.7 macrophages, indicating a critical role for Nox2 in ethanol-induced intracellular ROS production and MMP-12 expression in macrophages. We also showed that ethanol-induced Nox2 expression was suppressed by transient transfection with dominant negative I?B-? plasmid or pretreatment with Bay 11-7082, a selective inhibitor of NF-?B, in RAW 264.7 macrophages. In addition, ethanol-induced Nox2 expression was also attenuated by treatment with a selective inhibitor of p38 MAPK, suggesting involvement of p38 MAPK/NF-?B pathway in ethanol-induced Nox2 expression. Taken together, these results demonstrate that ethanol treatment elicited increase in MMP-12 expression via increase in ROS production derived from Nox2 in macrophages. - Highlights: • Ethanol increases ROS production through up-regulation of Nox2 in macrophages. • Enhanced oxidative stress contributes to ethanol-induced MMP-12 expression. • p38 MAPK/NF-?B signaling pathway modulates ethanol-induced Nox2 expression.

Kim, Mi Jin; Nepal, Saroj; Lee, Eung-Seok; Jeong, Tae Cheon [College of Pharmacy, Yeungnam University, Gyeongsanbuk-do 712-749 (Korea, Republic of); Kim, Sang-Hyun [Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Park, Pil-Hoon, E-mail: parkp@yu.ac.kr [College of Pharmacy, Yeungnam University, Gyeongsanbuk-do 712-749 (Korea, Republic of)

2013-11-15T23:59:59.000Z

68

Solid state oxygen sensor  

DOE Patents [OSTI]

Solid state oxygen sensors are provided with a yttria-doped zirconia as an electrolyte and use the electrochemical oxygen pumping of the zirconia electrolyte. A linear relationship between oxygen concentration and the voltage arising at a current plateau occurs when oxygen accessing the electrolyte is limited by a diffusion barrier. A diffusion barrier is formed herein with a mixed electronic and oxygen ion-conducting membrane of lanthanum-containing perovskite or zirconia-containing fluorite. A heater may be used to maintain an adequate oxygen diffusion coefficient in the mixed conducting layer.

Garzon, Fernando H. (Sante Fe, NM); Chung, Brandon W. (Los Alamos, NM); Raistrick, Ian D. (Los Alamos, NM); Brosha, Eric L. (Los Alamos, NM)

1996-01-01T23:59:59.000Z

69

Transport and metabolism of symplastic and apoplastic ascorbate during oxidative stress   

E-Print Network [OSTI]

Reactive oxygen species (ROS) are produced continuously in plants and act as important signalling molecules in many cellular processes including stress and defence responses. ROS can arise from external sources as well ...

Parsons, Harriet T

2009-01-01T23:59:59.000Z

70

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...

71

Magnetic interaction in oxygenated alpha Fe-phthalocyanines  

SciTech Connect (OSTI)

Alpha iron phthalocyanines (?-FePc) oxygenated at low temperatures were investigated with the help of {sup 57}Fe Mössbauer spectroscopy, magnetization measurements (SQUID) and X-ray diffractometry (XRD). Mössbauer spectroscopy revealed that upon oxygenation of ?-FePc, new species were formed which could be associated with Fe{sup III}Pc oxygen adducts. Unexpectedly, magnetically split spectrum of oxygenated ?-FePc was observed below 20 K. In-field Mössbauer spectra in a 5 T external magnetic field at 5K and magnetization measurements indicate antiferromagnetic coupling in oxygenated ?-FePc.

Kuzmann, Ern?, E-mail: kuzmann@caesar.elte.hu; Homonnay, Zoltán; Horváth, Attila [Institute of Chemistry, Eötvös Loránd University, P.O. Box 32, 1512 Budapest (Hungary); Pechousek, Jiri; Cuda, Jan; Machala, Libor; Zoppellaro, Giorgio; Zboril, Radek [Regional Centre of Advanced Technologies and Materials, Departments of Experimental Physics and Physical Chemistry, Faculty of Science Palacky University, 17. Listopadu 1192/12, 771 46 Olomouc (Czech Republic); Yin, Houping; Wei, Yen [Department of Chemistry, Drexel University, Philadelphia, PA 19104 (United States); Klencsár, Zoltán [Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, 1117 (Hungary); Kubuki, Shiro [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachi-Oji, Tokyo 192-0397 (Japan); Nath, Amar [Department of Chemistry, University of North Carolina, Asheville, NC 28804 (United States)

2014-10-27T23:59:59.000Z

72

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

73

Oxygen partial pressure sensor  

DOE Patents [OSTI]

A method for detecting oxygen partial pressure and an oxygen partial pressure sensor are provided. The method for measuring oxygen partial pressure includes contacting oxygen to a solid oxide electrolyte and measuring the subsequent change in electrical conductivity of the solid oxide electrolyte. A solid oxide electrolyte is utilized that contacts both a porous electrode and a nonporous electrode. The electrical conductivity of the solid oxide electrolyte is affected when oxygen from an exhaust stream permeates through the porous electrode to establish an equilibrium of oxygen anions in the electrolyte, thereby displacing electrons throughout the electrolyte to form an electron gradient. By adapting the two electrodes to sense a voltage potential between them, the change in electrolyte conductivity due to oxygen presence can be measured. 1 fig.

Dees, D.W.

1994-09-06T23:59:59.000Z

74

E-Print Network 3.0 - adipogenesis mechanism profile Sample Search...  

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

reactive oxygen species (ROS) in diabetes is the underlying mechanism of endothelial injury... of the key mechanisms by which HO-1 is involved in diabetes and the metabolic...

75

Integrated turbomachine oxygen plant  

SciTech Connect (OSTI)

An integrated turbomachine oxygen plant includes a turbomachine and an air separation unit. One or more compressor pathways flow compressed air from a compressor through one or more of a combustor and a turbine expander to cool the combustor and/or the turbine expander. An air separation unit is operably connected to the one or more compressor pathways and is configured to separate the compressed air into oxygen and oxygen-depleted air. A method of air separation in an integrated turbomachine oxygen plant includes compressing a flow of air in a compressor of a turbomachine. The compressed flow of air is flowed through one or more of a combustor and a turbine expander of the turbomachine to cool the combustor and/or the turbine expander. The compressed flow of air is directed to an air separation unit and is separated into oxygen and oxygen-depleted air.

Anand, Ashok Kumar; DePuy, Richard Anthony; Muthaiah, Veerappan

2014-06-17T23:59:59.000Z

76

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; Krumpelt, Michael; Wang, Xiaoping; Carter, J. David

2005-07-12T23:59:59.000Z

77

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.

Carter, J. David; Wang, Xiaoping; Vaughey, John; Krumpelt, Michael

2004-11-23T23:59:59.000Z

78

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

79

E-Print Network 3.0 - active oxygen content Sample Search Results  

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

Powered by Explorit Topic List Advanced Search Sample search results for: active oxygen content Page: << < 1 2 3 4 5 > >> 1 Reactivity and coverage of active surface species...

80

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

Note: This page contains sample records for the topic "oxygen species ros" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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81

Atomic Oxygen in the Comae of Comets  

E-Print Network [OSTI]

We report on the detection of atomic oxygen lines in the spectra of 8 comets. These forbidden lines are a result of the photodissociation of the parent oxygen-bearing species directly into an excited state. We used high resolution spectra obtained at the McDonald Observatory 2.7m telescope to resolve the cometary oxygen lines from the telluric oxygen lines and from other cometary emissions. We find that the relative intensities of the two red lines (6300.304 and 6363.776A) are consistent with theory. The green line (5577.339A) has an intensity which is about 10% of the sum of the intensities of the two red lines. We show that collisional quenching may be important in the inner coma. If we assume the relative excitation rates of potential parents which have appeared in the literature, then H2O would be the parent of the cometary green oxygen line. However, those rates have been questioned. We measured the width of the three oxygen lines and find that the green line is wider than either of the two red lines. The finding of a wider line could imply a different parent for the green and red lines. However, the constancy of the green to red line flux ratio suggests the parent is the same for these lines but that the exciting photons have different energies.

Anita L. Cochran

2008-07-03T23:59:59.000Z

82

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

83

Regulation of Singlet Oxygen Generation Using Single-Walled Carbon Zhiwen Tang,  

E-Print Network [OSTI]

Regulation of Singlet Oxygen Generation Using Single-Walled Carbon Nanotubes Zhi Zhu, Zhiwen TangDNA aptamer, and single-walled carbon nanotubes (SWNTs) for controllable singlet oxygen (1 O2) generation. 1 O to tissue oxygen to generate highly reactive 1 O2, an aggressive chemical species, which can react rapidly

Tan, Weihong

84

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

85

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

86

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

87

High Selectivity Oxygen Delignification  

SciTech Connect (OSTI)

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

Lucian A. Lucia

2005-11-15T23:59:59.000Z

88

Catalase and NO CATALASE ACTIVITY1 Promote Autophagy-Dependent Cell Death in ArabidopsisC W OPEN  

E-Print Network [OSTI]

, Sweden Programmed cell death often depends on generation of reactive oxygen species, which can with reactive oxygen species could allow catalase to act as a molecular link between reactive oxygen species oxygen species (ROS) and PCD (Jones and Dangl, 2006). Since the discovery more than two decades ago of HR

Schierup, Mikkel Heide

89

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...

90

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

91

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

92

Evidence for Thiol-Dependent Production of Oxygen Radicals by 4-Methyl-5-pyrazinyl-3H-1,2-dithiole-3-thione  

E-Print Network [OSTI]

to a peroxide species that undergoes a trace metal-catalyzed, Fenton-type reaction to generate oxygen radicalsEvidence for Thiol-Dependent Production of Oxygen Radicals by 4-Methyl-5-pyrazinyl-3H-1,2-dithiole the conversion of molecular oxygen to reactive oxygen radicals. Using a plasmid-based assay that monitors DNA

Gates, Kent. S.

93

Antioxidants reduce endoplasmic reticulum stress and improve protein secretion  

E-Print Network [OSTI]

and in vivo. The findings indicate that reactive oxygen species are a signal generated by misfolded protein oxygen species improves protein folding and cell survival and may provide an avenue to treat and,themolecularpathwaysthatcouplethese processes are poorly understood (1). Reactive oxygen species (ROS) originate during oxygen-using cellular

Bedwell, David M.

94

E4F1 deficiency results in oxidative stress-mediated cell death of leukemic cells  

E-Print Network [OSTI]

, histiocytic sarcoma HSC, hematopoietic stem cell PET, positon emission tomography ROS, reactive oxygen species OCR, oxygen consumption rate shRNA, short hairpin RNA inserm-00610191,version1-21Jul2011 #12;Abstract

Boyer, Edmond

95

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

96

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

97

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

98

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

99

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

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

Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005, United States h i g h l i g h t s * Oxidation seen in water-soluble oil fraction after exposure...

100

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

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


101

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

102

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

103

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

104

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

105

Direct Observation of the Oxygenated Species during Oxygen Reduction on a  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesDataTranslocation of Shewanella Oneidensisthe Size(110).Using

106

Contiguous Platinum Monolayer Oxygen Reduction Electrocatalysts...  

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

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

107

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...

108

Atomic oxygen patterning from a biomedical needle-plasma source  

SciTech Connect (OSTI)

A “plasma needle” is a cold plasma source operating at atmospheric pressure. Such sources interact strongly with living cells, but experimental studies on bacterial samples show that this interaction has a surprising pattern resulting in circular or annular killing structures. This paper presents numerical simulations showing that this pattern occurs because biologically active reactive oxygen and nitrogen species are produced dominantly where effluent from the plasma needle interacts with ambient air. A novel solution strategy is utilised coupling plasma produced neutral (uncharged) reactive species to the gas dynamics solving for steady state profiles at the treated biological surface. Numerical results are compared with experimental reports corroborating evidence for atomic oxygen as a key bactericidal species. Surface losses are considered for interaction of plasma produced reactants with reactive solid and liquid interfaces. Atomic oxygen surface reactions on a reactive solid surface with adsorption probabilities above 0.1 are shown to be limited by the flux of atomic oxygen from the plasma. Interaction of the source with an aqueous surface showed hydrogen peroxide as the dominant species at this interface.

Kelly, Seán; Turner, Miles M. [School of Physical Science and National Centre for Plasma Science and Technology, Dublin City University, Dublin (Ireland)] [School of Physical Science and National Centre for Plasma Science and Technology, Dublin City University, Dublin (Ireland)

2013-09-28T23:59:59.000Z

109

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

110

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

111

High Selectivity Oxygen Delignification  

SciTech Connect (OSTI)

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

Arthur J. Ragauskas

2005-09-30T23:59:59.000Z

112

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

E-Print Network [OSTI]

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

Lam, Raymond H. W.

113

The first step in the development of text mining technology for cancer risk assessment: identifying and organizing scientific evidence in risk assessment literature  

E-Print Network [OSTI]

, excretion Inhalation Blood/air partition Urinary elimination Bioaccumulation/ Lipophility Toxicokinetics Reactive oxygen species (ROS) Superoxide dismutase Oxidative species Oxidative metabolism Activation or deactivation Cytochrome P450 Epoxide hydrolase...

Korhonen, Anna; Silins, Ilona; Sun, Lin; Stenius, Ulla

2009-09-22T23:59:59.000Z

114

Purinergic receptors responsible for ATP-dependent ROS production and activation of inflammasomes in gingival epithelial cells  

E-Print Network [OSTI]

D. S. Kumararatne. 1997. ATP-induced killing of mycobacteria24. Cruz, C.M. , et al. , ATP activates a reactive oxygenYilmaz, O. , et al. , ATP scavenging by the intracellular

Ho, Marcus

2012-01-01T23:59:59.000Z

115

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

116

Oxygen-reducing catalyst layer  

DOE Patents [OSTI]

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

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

2011-03-22T23:59:59.000Z

117

Electrochemical studies of quinone oxygen  

SciTech Connect (OSTI)

Asphaltenes are a chemically complex mixture of aromatic and heteroaromatic compounds. This material contains oxygen in various functional groups. The distribution includes esters, carboxylic acids, phenolic and most probably quinone type oxygen functionalities. The present work details the complete electrochemical behaviour of quinone type oxygen. The method is quinone specific. A condensed aromatic quinone, 9,10-anthraquinone, was selected as representative of complex quinones. By this method quinones can be determined in the presence of other oxygen functional groups, alcohols, carboxylic acids, ethers, and other carbonyls.

Deanhardt, M.L. (Lander College, Greenwood, SC (US)); Mushrush, G.W.; Stalick, W.M. (Chemistry Dept., George mason Univ., Fairfax, VA (US)); Watkins, J.M. Jr. (Naval Research Lab., Fuels Section, Code 6180, Washington, DC (US))

1990-02-01T23:59:59.000Z

118

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

119

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

120

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

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


121

NADPH oxidase/ROS-dependent PYK2 activation is involved in TNF-?-induced matrix metalloproteinase-9 expression in rat heart-derived H9c2 cells  

SciTech Connect (OSTI)

TNF-? plays a mediator role in the pathogenesis of chronic heart failure contributing to cardiac remodeling and peripheral vascular disturbances. The implication of TNF-? in inflammatory responses has been shown to be mediated through up-regulation of matrix metalloproteinase-9 (MMP-9). However, the detailed mechanisms of TNF-?-induced MMP-9 expression in rat embryonic-heart derived H9c2 cells are largely not defined. We demonstrated that in H9c2 cells, TNF-? induced MMP-9 mRNA and protein expression associated with an increase in the secretion of pro-MMP-9. TNF-?-mediated responses were attenuated by pretreatment with the inhibitor of ROS (N-acetyl-L-cysteine, NAC), NADPH oxidase [apocynin (APO) or diphenyleneiodonium chloride (DPI)], MEK1/2 (U0126), p38 MAPK (SB202190), JNK1/2 (SP600125), NF-?B (Bay11-7082), or PYK2 (PF-431396) and transfection with siRNA of TNFR1, p47{sup phox}, p42, p38, JNK1, p65, or PYK2. Moreover, TNF-? markedly induced NADPH oxidase-derived ROS generation in these cells. TNF-?-enhanced p42/p44 MAPK, p38 MAPK, JNK1/2, and NF-?B (p65) phosphorylation and in vivo binding of p65 to the MMP-9 promoter were inhibited by U0126, SB202190, SP600125, NAC, DPI, or APO. In addition, TNF-?-mediated PYK2 phosphorylation was inhibited by NAC, DPI, or APO. PYK2 inhibition could reduce TNF-?-stimulated MAPKs and NF-?B activation. Thus, in H9c2 cells, we are the first to show that TNF-?-induced MMP-9 expression is mediated through a TNFR1/NADPH oxidase/ROS/PYK2/MAPKs/NF-?B cascade. We demonstrated that NADPH oxidase-derived ROS generation is involved in TNF-?-induced PYK2 activation in these cells. Understanding the regulation of MMP-9 expression and NADPH oxidase activation by TNF-? on H9c2 cells may provide potential therapeutic targets of chronic heart failure. - Highlights: • TNF-? induces MMP-9 secretion and expression via a TNFR1-dependent pathway. • TNF-? induces ROS/PYK2-dependent MMP-9 expression in H9c2 cells. • TNF-? induces MMP-9 expression via a NADPH oxidase/ROS-dependent NF-?B signaling. • TNF-? activates MAPK phosphorylation through NADPH oxidase/ROS generation.

Yang, Chuen-Mao, E-mail: chuenmao@mail.cgu.edu.tw [Department of Physiology and Pharmacology and Health Aging Research Center, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Heart Failure Center, Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan (China); Lee, I-Ta [Department of Physiology and Pharmacology and Health Aging Research Center, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Department of Anesthetics, Chang Gung Memorial Hospital at Linkou and College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Hsu, Ru-Chun; Chi, Pei-Ling; Hsiao, Li-Der [Department of Physiology and Pharmacology and Health Aging Research Center, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China)

2013-10-15T23:59:59.000Z

122

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

123

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

124

A Chemical Kinetic Modeling Study of the Effects of Oxygenated Hydrocarbons on Soot Emissions from Diesel Engines  

SciTech Connect (OSTI)

A detailed chemical kinetic modeling approach is used to examine the phenomenon of suppression of sooting in diesel engines by addition of oxygenated hydrocarbon species to the fuel. This suppression, which has been observed experimentally for a few years, is explained kinetically as a reduction in concentrations of soot precursors present in the hot products of a fuel-rich diesel ignition zone when oxygenates are included. Oxygenates decrease the overall equivalence ratio of the igniting mixture, producing higher ignition temperatures and more radical species to consume more soot precursor species, leading to lower soot production. The kinetic model is also used to show how different oxygenates, ester structures in particular, can have different soot-suppression efficiencies due to differences in molecular structure of the oxygenated species.

Westbrook, C K; Pitz, W J; Curran, H J

2005-11-14T23:59:59.000Z

125

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

126

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

127

Mixed oxygen ion/electron-conducting ceramics for oxygen separation  

SciTech Connect (OSTI)

Solid mixed-conducting electrolytes in the series La{sub l-x}A{sub x}Co{sub l-y}Fe{sub y}O{sub 3-{delta}} (A = Sr,Ca,Ba) are potentially useful as passive membranes to separate high purity oxygen from air and as cathodes in fuel cells. All of the compositions studied exhibited very high electrical conductivities. At lower temperatures, conductivities increased with increasing temperature, characterized by activation energies of 0.05 to 0.16 eV that are consistent with a small polaron (localized electronic carrier) conduction mechanism. At higher temperatures, electronic conductivities tended to decrease with increasing temperature, which is attributed to decreased electronic carrier populations associated with lattice oxygen loss. Oxygen ion conductivities were higher than that of yttria stabilized zirconia and increased with the cobalt content and also increased with the extent of divalent A-site substitution. Thermogravimetric studies were conducted to establish the extent of oxygen vacancy formation as a function of temperature, oxygen partial pressure, and composition. These vacancy populations strongly depend on the extent of A-site substitution. Passive oxygen permeation rates were established for each of the compositions as a function of temperature and oxygen partial pressure gradient. For 2.5 mm thick membranes in an oxygen vs nitrogen partial pressure gradient, oxygen fluxes at 900 C ranged from approximately 0.3 sccm/cm{sup 2} for compositions high in iron and with low amounts of strontium A-site substitution to approximately 0.8 sccm/cm{sup 2} for compositions high in cobalt and strontium. A-site substitution with calcium instead of strontium resulted in substantially lower fluxes.

Stevenson, J.W.; Armstrong, B.L.; Armstrong, T.R.; Bates, J.L.; Pederson, L.R.; Weber, W.J.

1995-05-01T23:59:59.000Z

128

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

129

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

130

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.

131

H6 and mBDCA-5p-H6 in oxygen-saturated DMF solution. An increase in the limiting current as  

E-Print Network [OSTI]

of molecular rec- ognition of an in situ­generated reactive oxygen species has the potential to be incorporatedH6 and mBDCA-5p-H6 in oxygen-saturated DMF solution. An increase in the limiting current as well) is consistent with a greater number of electrons transferred during reduction of oxygen in the presence of m

Weiss, Benjamin P.

132

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

133

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

134

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

135

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

136

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

137

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...

138

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

139

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...

140

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

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


141

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...

142

Oxygen Concentration Microgradients for Cell Culture  

E-Print Network [OSTI]

for technology that can control microscale oxygen gradientstechnology is the ability to rapidly generate and alter oxygentechnology should enable numerous studies in the field of biology where oxygen

Park, Jaehyun

2010-01-01T23:59:59.000Z

143

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

144

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

145

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.

146

Identification and antioxidant characterisation of thioredoxin-like1 from Apis cerana cerana  

E-Print Network [OSTI]

and protecting organisms against toxic reactive oxygen species. Compared with the well-studied Trxs in Mammalia / oxidative stress 1. INTRODUCTION "Reactive oxygen species (ROS)" is a collective term for H2O2 and oxygen often affected (Del et al. 2005). Lipid oxidation results in the generation of many harmful secondary

147

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.

148

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

149

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

150

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

151

Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways  

SciTech Connect (OSTI)

Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G{sub 2}/M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45?. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-? or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ? The mode of NaF-induced cell death and the mechanisms involved were examined. ? NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ? NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ? JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ? ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

Nguyen Ngoc, Tam Dan [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of)] [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Son, Young-Ok [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States)] [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lim, Shin-Saeng [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of) [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States)] [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Kim, Jong-Ghee [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of)] [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Heo, Jung Sun [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of)] [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Choe, Youngji [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of)] [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Jeon, Young-Mi, E-mail: young@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of)] [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lee, Jeong-Chae, E-mail: leejc88@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of) [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

2012-03-15T23:59:59.000Z

152

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

153

Oxygen uptake of benthic systems  

E-Print Network [OSTI]

mg/hr/sq m between standard and maximum mixing. Hanes and Irvine (23) made a determination of the effects of temperature on quiescent oxygen uptake rates by covering sludge with aerated water and allowing the supernatant to be totally de- pleted.... ECTROLTSIS STSTDI FOA MEMURIRC BOO. FIGURE 2. SWITCH ELECTROQE IN CONTACT WITH ELECTROIYTE. OXYGEN GENERATOR OFF. FIGURE 3. SWIICH ELECI'RODE NOT IN CONTACT' WITH -' ECTROLYTE. 0 0 0 a 0 0 0 ~ O0 0 o 0 0 o o 0 0 0 0 PIERRE A. HIGH SPEED NIXINC...

Priebe, William Franklin

1972-01-01T23:59:59.000Z

154

Determination of oxygen in molten alkali halide salts by proton activation analysis  

SciTech Connect (OSTI)

The authors have recently used a lanthanum fluoride precipitation method to separate /sup 18/F produced from proton activation of /sup 18/O in alkali chloride and fluoride salts. The procedure was developed for studying dissolved oxide species in alkali halide melts. Determination of oxygen in these systems is important for research in batteries and in extractive metallurgy utilizing molten salts as solvents. The details are given oxygen determination in alkali chloride and fluoride systems.

Wai, C.M.; Dysart, M.E.

1986-12-01T23:59:59.000Z

155

Characterization of Morphine Self-Administration Following Spinal Cord Injury  

E-Print Network [OSTI]

-related peptide (CGRP), pro-inflammatory cytokines, reactive oxygen species (ROS), NO, and proteases (Kreutzberg, 1996; Aloisi, 2001; Dong & Benveniste, 2001; Fleming et al., 2006; Carlson et al., 1998; Lieberman et al., 1989; Priller et al., 1995; Rischke...

Woller, Sarah Ann

2013-07-16T23:59:59.000Z

156

TARGET SPECIES Table 1. Terrestrial target species.  

E-Print Network [OSTI]

that have only one or a very few number of key ecological functions. Functional specialist species could = Critical functional link species, species that are the only ones that perform a specific ecological Merganser Boreal Toad Wolverine FS Horned Grebe Long-toed Salamander CFLS BIRDS House Finch CFLS Northern

157

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

158

Asymmetric cancer cell division regulated by AKT Ipsita Dey-Guhaa,b,1  

E-Print Network [OSTI]

Cancer Cells in Vitro. We began by studying MCF7, a highly proliferative, aneuploid, ER+ /HER2- human that slowly pro- liferating MCF7 cells might produce low levels of reactive oxygen species (ROS stem cells and cancer stem cells produce low levels of ROS (5­7). We stained MCF7 cells with 5-(and-6

Albeck, John

159

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

160

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

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


161

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.

162

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

163

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

164

Oxygen transport in the internal xenon plasma of a dispenser hollow cathode  

SciTech Connect (OSTI)

Reactive gases such as oxygen and water vapor modify the surface morphology of BaO dispenser cathodes and degrade the electron emission properties. For vacuum cathodes operating at fixed temperature, the emission current drops rapidly when oxygen adsorbs on top of the low work function surface. Previous experiments have shown that plasma cathodes are more resistant to oxygen poisoning and can operate with O{sub 2} partial pressures one to two orders of magnitude higher than vacuum cathodes before the onset of poisoning occurs. Plasma cathodes used for electric thrusters are typically operated with xenon; however, gas phase barium, oxygen, and tungsten species may be found in small concentrations. The densities of these minor species are small compared with the plasma density, and thus, their presence in the discharge does not significantly alter the xenon plasma parameters. It is important, however, to consider the transport of these minor species as they may deposit on the emitter surface and affect the electron emission properties. In this work, we present the results of a material transport model used to predict oxygen fluxes to the cathode surface by solving the species conservation equations in a cathode with a 2.25?mm diameter orifice operated at a discharge current of 15?A, a Xe flow rate of 3.7 sccm, and 100?ppm of O{sub 2}. The dominant ionization process for O{sub 2} is resonant charge exchange with xenon ions. Ba is effectively recycled in the plasma; however, BaO and O{sub 2} are not. The model shows that the oxygen flux to the surface is not diffusion-limited; therefore, the high resistance to oxygen poisoning observed in plasma cathodes likely results from surface processes not considered here.

Capece, Angela M., E-mail: acapece@pppl.gov; Shepherd, Joseph E. [California Institute of Technology, Pasadena, California 91125 (United States); Polk, James E.; Mikellides, Ioannis G. [Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, California 91109 (United States)

2014-04-21T23:59:59.000Z

165

AN ELECTRICAL OXYGEN-TEMPERATURE METER  

E-Print Network [OSTI]

426 AN ELECTRICAL OXYGEN-TEMPERATURE METER FOR FISHERY BIOLOGISTS SEP 2 1196: vuUiJo HIM. . SPECIAL and Wildlife, Daniel H. Janzen, Director AN ELECTRICAL OXYGEN-TEMPERATURE METER FOR FISHERY BIOLOGISTS -temperature meter 11 Maintenance and trouble -shooting 12 #12;AN ELECTRICAL OXYGEN-TEMPERATURE METER

166

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.

167

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

168

Modulation of mixed-phase titania photoluminescence by oxygen adsorption  

SciTech Connect (OSTI)

We investigate the effect of oxygen (O{sub 2}) adsorption on photoluminescence properties of mixed-phase titania nanoparticle films deposited by femtosecond pulsed laser deposition, aiming to assess preliminary conclusions about the feasibility of opto-chemical sensing based on titania. We evidence that O{sub 2} produces opposite responses in rutile and anatase photoluminescence efficiency, highlighting interesting potentialities for future double-parametric optical sensing based on titania. The results evidence an important role of lattice oxygen atoms, suggesting that the standard Schottky barrier mechanism driving the response toward gas species in most used metal-oxide sensors (e.g., tin dioxide) is not the only active mechanism in titania.

Pallotti, D.; Orabona, E.; Amoruso, S.; Maddalena, P. [Dipartimento di Fisica, Universitá degli Studi di Napoli “Federico II,” Via Cintia, I-80126 Napoli (Italy); Institute for Superconductors, Oxides and Innovative Materials and Devices, CNR-SPIN, U.O.S. Napoli, Via Cintia, I-80126 Napoli (Italy); Lettieri, S., E-mail: stefano.lettieri@spin.cnr.it [Institute for Superconductors, Oxides and Innovative Materials and Devices, CNR-SPIN, U.O.S. Napoli, Via Cintia, I-80126 Napoli (Italy)

2014-07-21T23:59:59.000Z

169

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

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

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

170

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

171

Experimental Effects of Atomic Oxygen on the Development of an Electric Discharge Oxygen Iodine Laser  

E-Print Network [OSTI]

state I. Conventionally, a two-phase (gas-liquid) chemistry singlet oxygen generator (SOG) producesExperimental Effects of Atomic Oxygen on the Development of an Electric Discharge Oxygen Iodine of the electric discharge iodine laser continues, the role of oxygen atoms downstream of the discharge region

Carroll, David L.

172

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

173

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

174

OXYGEN 18 EXCHANGE REACTIONS OF ALDEHYDES AND KETONES  

E-Print Network [OSTI]

OXYGEN 18 EXCHANGE REACTIONS OF ALDEHYDES AND KETONES TWO-eng-48 OXYGEN 18 EXCHANGE REACTIONS OF ALDEHYDES AND KETONES

Byrn, Marianne; Calvin, Melvin

1965-01-01T23:59:59.000Z

175

Gate Voltage Control of Oxygen Diffusion on Graphene Dr. Jorge O. Sofo  

E-Print Network [OSTI]

Gate Voltage Control of Oxygen Diffusion on Graphene Dr. Jorge O. Sofo Associate Professor conductivity (twice that of diamond). Due to Carbon's affinity for tetrahedral bonding, its surface is amenable atoms. Our research focuses on the attachment and diffusion of different atomic species to the surface

Bjørnstad, Ottar Nordal

176

To identify genes associated with the cytokinin-induced enhanced drought tolerance, we analyzed the transcriptome  

E-Print Network [OSTI]

antenna and the oxygen-evolving complex (OEC). The core is comprised of the reaction center proteins D1 chetalase; NPQ, non-photochemical quenching; OEC, oxygen- evolving complex; PGR5, PROTON GRADIENT REGULATION 5; PQ, plastoquinone; qP, photochemical quenching; ROS, reactive oxygen species; RuBP, ribulose-1

Blumwald, Eduardo

177

WANG ET AL. VOL. 6 ' NO. 6 ' 50705077 ' 2012 www.acsnano.org  

E-Print Network [OSTI]

"on" state), they become actively phototoxic and generate reactive oxygen species (ROS) including singlet oxygen for PDT upon light illumi- nation;4,5 The AuNRs also serve as ultraeffi- cient energy the targeted release of singlet oxygen.1,3 This lack of specificity has resulted in unavoidable da- mage

Tan, Weihong

178

The CRG1 gene required for resistance to the singlet oxygen-generating cercosporin toxin in Cercospora nicotianae encodes a putative  

E-Print Network [OSTI]

The CRG1 gene required for resistance to the singlet oxygen-generating cercosporin toxin electron or energy transfer to generate reactive oxygen species such as superoxide (OÅÀ 2 ) and singlet gene is involved in cellular resistance to the perylenequinone toxin, cercosporin, that generates

Daub, Margaret

179

ENDANGERED SPECIES RESEARCH Endang Species Res  

E-Print Network [OSTI]

include thermal expansion of the warming oceans along with melting of glaciers and ice caps (Church et al considerably this century, potentially affecting species that rely on coastal habitat. The Northwestern

Aberdeen, University of

180

Myocardial Reloading after Extracorporeal Membrane Oxygenation...  

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

Protein Synthesis. Abstract: Extracorporeal membrane oxygenation (ECMO) unloads the heart providing a bridge to recovery in children after myocardial stunning. Mortality after...

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


181

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

182

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

183

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

184

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

185

New Oxygen-Production Technology Proving Successful  

Broader source: Energy.gov [DOE]

The Office of Fossil Energy's National Energy Technology Laboratory has partnered with Air Products and Chemicals Inc. of Allentown, Penn. to develop the Ion Transport Membrane (ITM) Oxygen, a revolutionary new oxygen-production technology that requires less energy and offers lower capital costs than conventional technologies.

186

Oxygen and Nitrogen Contamination During Arc Welding  

E-Print Network [OSTI]

) ) : ,- Oxygen and Nitrogen Contamination During Arc Welding T. W. Eagar Department of }faterials, shielded metal arc, self-shielded metal arc, and submerged arc welding are reviewed. Calcu- lations upon heating is also discussed. Introduction Oxygen and nitrogen ~ontamination of weld metal

Eagar, Thomas W.

187

Modelling Hydrogen Reduction and Hydrodeoxygenation of Oxygenates  

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

188

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

189

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

190

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

191

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

192

Oxygen buffering of Kilauea volcanic gases and the oxygen fugacity of Kilauea basalt  

SciTech Connect (OSTI)

Volcanic gases collected during episode 1 of the Puu Oo eruption along the east rift zone of Kilauea Volcano, Hawaii, have uniform C-O-H-S-Cl-F compositions that are sharply depleted in CO[sub 2]. The CO[sub 2]-poor gases are typical of Type II volcanic gases (GERLACH and GRAEBER, 1985) and were emitted from evolved magma stored for a prolonged period of time in the east rift zone after releasing CO[sub 2]-rich gases during an earlier period of temporary residence in the summit magma chamber. The samples are remarkably free of contamination by atmospheric gases and meteoric water. Thermodynamic evaluation of the analytical data shows that the episode 1 gases have equilibrium compositions appropriate for temperatures between 935 and 1032[degrees]C. Open- and closed-system equilibrium models of species distributions for the episode 1 gases show unequivocally that coexisting lavas buffered the gas oxygen fugacities during cooling. These models indicate that the F[sub o[sub 2

Gerlach, T.M. (Geological Survey, Vancouver, WA (United States))

1993-02-01T23:59:59.000Z

193

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

194

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

195

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

196

Turbulent dispersal promotes species coexistence  

E-Print Network [OSTI]

drive all other species to extinction. However, empiricalA will always drive species B to extinction (unless f A = fductivity species (species B) to extinction (Fig. 2a). In

Berkley, Heather A; Kendall, Bruce E.; Mitarai, Satoshi; Siegel, David A

2010-01-01T23:59:59.000Z

197

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

198

ENDANGERED SPECIES PETITION MANAGEMENT GUIDANCE  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . 3 a. Petitions to List, Reclassify, or Delist Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 A. Petitions to List, Reclassify, or Delist Species

199

Characterization of an oxygen suspension used for intravenous infusion  

E-Print Network [OSTI]

Oxygenated fluid mixture can be used to treat critically ill patients suffering from asphyxia, lung injury, and cardiac arrest. This oxygenated fluid delivered intravenously re-oxygenates the bloodstream, allowing for more ...

Peña, Kristen Helen

2012-01-01T23:59:59.000Z

200

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

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


201

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...

202

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

203

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

204

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

205

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....

206

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...

207

Selective reduction of NOx in oxygen rich environments with plasma...  

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

reduction of NOx in oxygen rich environments with plasma-assisted catalysis: Catalyst development and mechanistic studies Selective reduction of NOx in oxygen rich environments...

208

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 &...

209

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...

210

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...

211

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)...

212

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...

213

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...

214

Fractionation of Oxygen Isotopes in Phosphate during its Interactions...  

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

Fractionation of Oxygen Isotopes in Phosphate during its Interactions with Iron Oxides. Fractionation of Oxygen Isotopes in Phosphate during its Interactions with Iron Oxides....

215

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...

216

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...

217

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...

218

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...

219

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...

220

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

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


221

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

222

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

223

Injectable polymer for in vivo oxygen sensing  

E-Print Network [OSTI]

This thesis documents the synthesis and characterization of an elastomeric polymer that is oxygen sensitive and can be interrogated using Magnetic Resonance Imaging (MRI) or Magnetic Resonance (MR) technology to report the ...

Imaad, Syed M. (Syed Muhammad)

2013-01-01T23:59:59.000Z

224

Oxygen Enriched Combustion System Performance Study  

E-Print Network [OSTI]

}ched combustlon systems are technically, envlronmentally and economically feasible and offer significant energy savings and/or productivity improvement, and then to verify the performance of selected systems in research furnaces. Tests of several commercial... for 35 - 100 percent oxygen. The absolute levels of the NO x emissions also depended on the furnace temperature. INTRODUCTION Oxygen enriched combustion has been found to have significant energy saving potential in industrial furnace applications...

Chen, S. L.; Kwan, Y.; Abele, A. R.; Silver, L. S.; Kobayashi, H.

225

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

226

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

227

Magnetism in Lithium–Oxygen Discharge Product  

SciTech Connect (OSTI)

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

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

2013-05-13T23:59:59.000Z

228

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

229

Photocatalytic reactions of oxygenates on tropospheric oxide particles  

SciTech Connect (OSTI)

Oxygenates such as ethanol and tert-butyl methyl ether (MTBE) are finding increased use as additives to fuels. The relative merits of ethanol and MTBE have become the focus of intense debate with their ultimate fate as fugitive emissions representing one aspect of this controversy. Both species are known to react homogeneously with photogenerated OH radicals. Here we show that both can also photoreact on suspended solid particulates in the atmosphere with rates comparable to those of OH reactions. Heterogeneous reactions of ethanol yield acetaldehyde and those of MTBE give isobutene and formaldehyde (carcinogenic). Experiments by spectroscopic and kinetic techniques show that the active phases in fly ash are Fe and Ti oxides. In addition, the effects of humidity and alkali addition on the activity and selectivity of these reactions are also discussed. This work appears to be the first demonstration that volatile organic compounds can react as fast by a heterogeneous mechanism as by a homogeneous one in the atmosphere.

Idriss, H.; Seebauer, E.G.; Miller, A. [Univ. of Illinois, Urbana, IL (United States)

1996-10-01T23:59:59.000Z

230

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

231

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

232

Preservation of a species  

E-Print Network [OSTI]

To put it simply, humans are going extinct. I identify the source of the problem as an imperceptible societal trend to eliminate the experience that authenticates us as a living species: failure. We've unanimously designated ...

Witt, Sarah (Sarah Elizabeth)

2011-01-01T23:59:59.000Z

233

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

234

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

235

Forecast Technical Document Tree Species  

E-Print Network [OSTI]

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

236

Dissecting Oxygenic Photosynthesis: The Evolution of the "Z"-Scheme  

E-Print Network [OSTI]

of the "period four oxygen clock" and the structure of the oxygen-evolving center. After a brief mention the maximum quantum yield, i.e., the number of oxygen molecules evolved per photon of light absorbed11CHAPTER Dissecting Oxygenic Photosynthesis: The Evolution of the "Z"-Scheme for Thylakoid

Govindjee

237

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

238

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

239

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

240

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

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


241

Oxygenates du`jour...MTBE? Ethanol? ETBE?  

SciTech Connect (OSTI)

There are many different liquids that contain oxygen which could be blended into gasoline. The ones that have been tried and make the most sense are in the alcohol (R-OH) and ether (R-O-R) chemical family. The alcohols considered are: methanol (MeOH), ethanol (EtOH), tertiary butyl alcohol (TBA). The ethers are: methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), tertiary amyl ethyl ether (TAEE), di-isopropyl ether (DIPE). Of the eight oxygenates listed above, the author describes the five that are still waiting for widespread marketing acceptance (methanol, TBA, TAME, TAEE, and DIPE). He then discusses the two most widely used oxygenates in the US, MTBE and ethanol, along with the up-and-coming ethanol ether, ETBE. Selected physical properties for all of these oxygenates can be found in Table 2 at the end of this paper. A figure shows a simplified alcohol/ether production flow chart for the oxygenates listed above and how they are interrelated.

Wolfe, R.

1995-12-31T23:59:59.000Z

242

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

243

Oxygen-Reducing Biocathodes Operating with Passive Oxygen Transfer in Microbial Fuel Cells  

E-Print Network [OSTI]

Oxygen-Reducing Biocathodes Operating with Passive Oxygen Transfer in Microbial Fuel Cells Xue Xia, Justin C. Tokash, Fang Zhang, Peng Liang, Xia Huang,*, and Bruce E. Logan*,, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, P

244

Manipulation of in vivo iron levels can alter resistance to oxidative stress without affecting ageing in the nematode C. elegans  

E-Print Network [OSTI]

by reactive oxygen species (ROS) (Harman, 1956; Sohal and Weindruch, 1996). Thus, far, extensive experimental.2. Iron as a generator of oxidative damage Iron plays a central role in many essential cellular processes including oxygen transport, xenobiotic detoxification, and mito- chondrial energy metabolism. Iron

Gems, David

245

Visible Light Sensitized Inactivation of MS-2 Bacteriophage by a  

E-Print Network [OSTI]

and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, Civil and Environmental and Technology, Rice University, Houston, Texas 77005 Received May 3, 2010. Revised manuscript received July 20, through which reactive oxygen species (ROS) such as singlet oxygen (1 O2

Alvarez, Pedro J.

246

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

247

Interaction of light with the ZnO surface: Photon induced oxygen "breathing," oxygen vacancies, persistent photoconductivity,  

E-Print Network [OSTI]

Interaction of light with the ZnO surface: Photon induced oxygen "breathing," oxygen vacancies donation of oxygen vacancies. Our findings suggest that the observed decomposition of the ZnO lattice may. The formation of oxygen-vacancy rich surface is suggested to induce surface delta doping, causing accumulation

Shalish, Ilan

248

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

249

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

E-Print Network [OSTI]

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

Houstis, Nicholas E

2007-01-01T23:59:59.000Z

250

Aging Enhances the Production of Reactive Oxygen Species andBactericidal  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUCProductstwrmrAre theAdministratorCFM LEAPAgenda Agenda LargeTransfers

251

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

252

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

253

Plants & Animals Invasive Species  

E-Print Network [OSTI]

& Climate Exotic Species Ecology Environmental Policy Reference Fire ant Ant Seed predation Computational, guaranteed results! SwissFrenchSchool.ch AFM Tips by NanoAndMore AFM Tips For Any Application. Fast Delivery. Free Samples! NanoAndMore.com/Tips Related Stories Ants Are Experienced Fungus

Alvarez, Nadir

254

Invasive Species Conservation Biology  

E-Print Network [OSTI]

dependent on such waters" ­ Non-indigenous Aquatic Nuisance Prevention and Control Act of 1990 · ­ Alien · Major impacts · Examples (Global, Great Lakes) · Invasion Success · Control #12;Terminology of Invasive species · What is the difference between exotic, non-indigenous, non-native, alien, nuisance, and invasive

Gottgens, Hans

255

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

SciTech Connect (OSTI)

Three hydrotreated bio-oils with different oxygen contents (8.2, 4.9, and 0.4 w/w) were distilled to produce Light, Naphtha, Jet, Diesel, and Gasoil boiling range fractions that were characterized for oxygen containing species by a variety of analytical methods. The bio-oils were originally generated from lignocellulosic biomass in an entrained-flow fast pyrolysis reactor. Analyses included elemental composition, carbon type distribution by {sup 13}C NMR, acid number, GC-MS, volatile organic acids by LC, and carbonyl compounds by DNPH derivatization and LC. Acid number titrations employed an improved titrant-electrode combination with faster response that allowed detection of multiple endpoints in many samples and for acid values attributable to carboxylic acids and to phenols to be distinguished. Results of these analyses showed that the highest oxygen content bio-oil fractions contained oxygen as carboxylic acids, carbonyls, aryl ethers, phenols, and alcohols. Carboxylic acids and carbonyl compounds detected in this sample were concentrated in the Light, Naphtha, and Jet fractions (<260 C boiling point). Carboxylic acid content of all of the high oxygen content fractions was likely too high for these materials to be considered as fuel blendstocks although potential for blending with crude oil or refinery intermediate streams may exist for the Diesel and Gasoil fractions. The 4.9 % oxygen sample contained almost exclusively phenolic compounds found to be present throughout the boiling range of this sample, but imparting measurable acidity primarily in the Light, Naphtha and Jet fractions. Additional study is required to understand what levels of the weakly acidic phenols could be tolerated in a refinery feedstock. The Diesel and Gasoil fractions from this upgraded oil had low acidity but still contained 3 to 4 wt% oxygen present as phenols that could not be specifically identified. These materials appear to have excellent potential as refinery feedstocks and some potential for blending into finished fuels. Fractions from the lowest oxygen content oil exhibited some phenolic acidity, but generally contained very low levels of oxygen functional groups. These materials would likely be suitable as refinery feedstocks and potentially as fuel blend components. PIONA analysis of the Light and Naphtha fractions shows benzene content of 0.5 and 0.4 vol%, and predicted (RON + MON)/2 of 63 and 70, respectively.

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

2011-10-06T23:59:59.000Z

256

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.

257

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

258

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

259

Oxygen isotope exchange between water and semiquinones  

SciTech Connect (OSTI)

A reaction is described that can be utilized to produce /sup 17/O-labeled anion radicals that yield strong well resolved ESR signals exhibiting splitting from the /sup 17/O nucleus. The oxygen anthraquinone has been studied, and the results are reported herein. 7 references, 1 figure.

Stevenson, G.R.; Wang, Z.Y.; Reiter, R.C.; Peters, S.J.

1988-09-14T23:59:59.000Z

260

The influence of surface properties on the plasma dynamics in radio-frequency driven oxygen plasmas: Measurements and simulations  

SciTech Connect (OSTI)

Plasma parameters and dynamics in capacitively coupled oxygen plasmas are investigated for different surface conditions. Metastable species concentration, electronegativity, spatial distribution of particle densities as well as the ionization dynamics are significantly influenced by the surface loss probability of metastable singlet delta oxygen (SDO). Simulated surface conditions are compared to experiments in the plasma-surface interface region using phase resolved optical emission spectroscopy. It is demonstrated how in-situ measurements of excitation features can be used to determine SDO surface loss probabilities for different surface materials.

Greb, Arthur; Niemi, Kari; O'Connell, Deborah; Gans, Timo [York Plasma Institute, Department of Physics, University of York, York, YO10 5DD (United Kingdom)] [York Plasma Institute, Department of Physics, University of York, York, YO10 5DD (United Kingdom)

2013-12-09T23:59:59.000Z

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


261

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

262

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

263

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

264

OXYGEN TRANSFER IN TRICKLING FILTERS By BruceE. Logan~  

E-Print Network [OSTI]

OXYGEN TRANSFER IN TRICKLING FILTERS By BruceE. Logan~ ABSTRACT: Insufficientoxygen transfer can result in anaerobic biofilmsand odor generation during biochemicaloxygen demand (BOD) removal plastic media trickling filters occurs by diffusion of oxygen through thin fluid films, previous models

265

Design, measurement, and analysis of oxygenated fluid pump system  

E-Print Network [OSTI]

The author sought out the opportunity to design and implement a system for pumping oxygenated fluid and mixing it with saline, for the purpose of providing sufficient levels of oxygen for patients undergoing forms of ...

Mason, Alexander M., IV (Alexander Martin)

2012-01-01T23:59:59.000Z

266

Label-free oxygen-metabolic photoacoustic microscopy in vivo  

E-Print Network [OSTI]

tomography (PET) using radioactively labeled oxy- gen. Many other pathological and physiological functions of oxygen consumption instead of the static oxygen concentration.11 If the region of interest has well

Wang, Lihong

267

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

268

Optical Perfusion and Oxygenation Characterization in a Liver Phantom  

E-Print Network [OSTI]

Continuous monitoring of blood perfusion and oxygenation is essential in assessing the health of a transplanted organ. Particularly, monitoring the perfusion and oxygenation of the organ during the two-week period after the transplant procedure...

King, Travis J.

2012-02-14T23:59:59.000Z

269

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...

270

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...

271

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...

272

Nanoscale Phase Separation, Cation Ordering, and Surface Oxygen...  

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

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

273

On the reduction of oxygen from dispersed media  

E-Print Network [OSTI]

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

Roushdy, Omar H., 1977-

2007-01-01T23:59:59.000Z

274

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

275

Electrical insulator assembly with oxygen permeation barrier  

DOE Patents [OSTI]

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

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

1994-03-29T23:59:59.000Z

276

A miniature inexpensive, oxygen sensing element  

SciTech Connect (OSTI)

An exhaustive study was conducted to determine the feasibility of Nernst-type oxygen sensors based on ceramics containing Bi{sub 2}O{sub 3}. The basic sensor design consisted of a ceramic sensing module sealed into a metal tube. The module accommodated an internal heater and thermocouple. Thermal-expansion-matched metals, adhesives, and seals were researched and developed, consistent with sequential firings during sensor assembly. Significant effort was devoted to heater design/testing and to materials' compatibility with Pt electrodes. A systematic approach was taken to develop all sensor components which led to several design modifications. Prototype sensors were constructed and exhaustively tested. It is concluded that development of Nerst-type oxygen sensors based on Bi{sub 2}O{sub 3} will require much further effort and application of specialized technologies. However, during the course of this 3-year program much progress was reported in the literature on amperometric-type oxygen sensors, and a minor effort was devoted here to this type of sensor based on Bi{sub 2}O{sub 3}. These studies were made on Bi{sub 2}O{sub 3}-based ceramic samples in a multilayer-capacitor-type geometry and amperometric-type oxygen sensing was demonstrated at very low temperatures ({approximately} 160{degree}C). A central advantage here is that these types of sensors can be mass-produced very inexpensively ({approximately} 20--50 cents per unit). Research is needed, however, to develop an optimum diffusion-limiting barrier coating. In summary, the original goals of this program were not achieved due to unforeseen problems with Bi{sub 2}O{sub 3}-based Nernst sensors. However, a miniature amperometric sensor base on Bi{sub 2}O{sub 3} was demonstrated in this program, and it is now seen that this latter sensor is far superior to the originally proposed Nernst sensor. 6 refs., 24 figs.

Arenz, R.W.

1991-10-07T23:59:59.000Z

277

Oxygen stabilized zirconium vanadium intermetallic compound  

DOE Patents [OSTI]

An oxygen stabilized intermetallic compound having the formula Zr.sub.x OV.sub.y where x=0.7 to 2.0 and y=0.18 to 0.33. The compound is capable of reversibly sorbing hydrogen at temperatures from -196.degree. C. to 450.degree. C. at pressures down to 10.sup.-6 Torr. The compound is also capable of selectively sorbing hydrogen from gaseous mixtures in the presence of CO and CO.sub.2.

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

1982-01-01T23:59:59.000Z

278

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

279

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

280

Quasi-Reversible Oxygen Exchange of Amorphous IGZO Thin Films  

E-Print Network [OSTI]

MRSEC Quasi-Reversible Oxygen Exchange of Amorphous IGZO Thin Films NSF Grant # 1121262 A. U. Adler of varying oxygen partial pressure. Oxygen exchange was confirmed by 18O tracer diffusion (time of carrier content vs. pO2) analysis should be applicable for studying the underlying carrier generation

Shahriar, Selim

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


281

Oxygen Reduction DOI: 10.1002/anie.201403264  

E-Print Network [OSTI]

Oxygen Reduction DOI: 10.1002/anie.201403264 Dramatic Increase in the Oxygen Reduction Reaction solvation) is used to predict how the energies and barriers for the mechanistic steps of the oxygen. In these electro- chemical devices, H2 (generated e.g. from solar energy conversion) reacts with O2 to produce

Goddard III, William A.

282

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.

283

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

284

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.

285

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

286

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...

287

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...

288

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

289

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

290

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

291

E-Print Network 3.0 - active oxygen control Sample Search Results  

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

Powered by Explorit Topic List Advanced Search Sample search results for: active oxygen control Page: << < 1 2 3 4 5 > >> 1 Oxygen Modulation via Microfluidic Devices Oxygen...

292

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

293

Exotic Species What's the Problem?  

E-Print Network [OSTI]

of introduced species as "the stealth destroyers of the American environment" (McDonald 1999: A15). Another seeds, eggs, spores, or other biological material capable of propagating that species

Callender, Craig

294

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

295

FORMATION OF MOLECULAR OXYGEN AND OZONE ON AMORPHOUS SILICATES  

SciTech Connect (OSTI)

Oxygen in the interstellar medium is seen in the gas phase, in ices (incorporated in H{sub 2}O, CO, and CO{sub 2}), and in grains such as (Mg{sub x} Fe{sub 1-x} )SiO{sub 3} or (Mg{sub x} Fe{sub 1-x} ){sub 2}SiO{sub 4}, 0 < x < 1. In this investigation, we study the diffusion of oxygen atoms and the formation of oxygen molecules and ozone on the surface of an amorphous silicate film. We find that ozone is formed at low temperature (<30 K), and molecular oxygen forms when the diffusion of oxygen atoms becomes significant, at around 60 K. This experiment, besides being the first determination of the diffusion energy barrier (1785 {+-} 35 K) for oxygen atoms on a silicate surface, suggests bare silicates as a possible storage place for oxygen atoms in low-A{sub v} environments.

Jing Dapeng; He Jiao; Vidali, Gianfranco [Physics Department, Syracuse University, Syracuse, NY 13244 (United States); Brucato, John Robert; Tozzetti, Lorenzo [Osservatorio Astrofisico di Arcetri, INAF, I-50125 Florence (Italy); De Sio, Antonio [Department of Physics and Astronomy, University of Florence, I-50125 Florence (Italy)

2012-09-01T23:59:59.000Z

296

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

SciTech Connect (OSTI)

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

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

2014-09-30T23:59:59.000Z

297

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

298

How Plants Do It: Light, Oxygen, Action!  

SciTech Connect (OSTI)

Plants have been doing it with ease for millions of years, and yet science has yet to fully comprehend how: Photosynthesis. It's a fundamental process of all plant life on Earth, using the simple and abundant ingredients of water and light to create food and enrich the planet's atmosphere with life-giving oxygen. In this talk, Professor Yachandra discusses how understanding the process of photosynthesis holds the key to a whole new level of mastery of how energy is produced, with enormous implications for the economy and the environment.

Yachandra, Vittal (University of California, Berkeley) [University of California, Berkeley

2008-08-26T23:59:59.000Z

299

SUPPORTED DENSE CERAMIC MEMBRANES FOR OXYGEN SEPARATION  

SciTech Connect (OSTI)

Mixed-conducting membranes have the ability to conduct oxygen with perfect selectivity at elevated temperatures, which makes them an extremely attractive alternative for oxygen separation and membrane reactor applications. The ability to reliably fabricate these membranes in thin or thick films would enable solid-state divisional limitations to be minimized, thus providing higher oxygen flux. Based on that motivation, the overall objective for this project is to develop and demonstrate a strategy for the fabrication of supported Wick film ceramic mixed conducting membranes, and improve the understanding of the fundamental issues associated with reliable fabrication of these membranes. The project has focused on the mixed-conducting ceramic composition SrCo{sub 0.5}FeO{sub x} because of its superior permeability and stability in reducing atmospheres. The fabrication strategy employed involves the deposition of SrCo{sub 0.5}FeO{sub x} thick films onto porous supports of the same composition. In the second year of this project, we completed characterization of the sintering and phase behavior of the porous SrCo{sub 0.5}FeO{sub x} supports, leading to a standard support fabrication methodology. Using a doctor blade method, pastes made from aerosol-derived SrCo{sub 0.5}FeO{sub x} powder dispersed with polyethylene glycol were applied to the supports, and the sintering behavior of the thick film membranes was examined in air and nitrogen atmospheres. It has been demonstrated that the desired crystalline phase content can be produced in the membranes, and that the material in the membrane layer can be highly densified without densifying the underlying support. However, considerable cracking and opening of the film occurred when films densified to a high extent. The addition of MgO into the SrCo{sub 0.5}FeO{sub x} supports was shown to inhibit support sintering so that temperatures up to 1300 C, where significant liquid formation occurs, could be used for film sintering. This successfully reduced cracking, however the films retained open porosity. The investigation of this concept will be continued in the final year of the project. Investigation of a metal organic chemical vapor deposition (MOCVD) method for defect mending in dense membranes was also initiated. An appropriate metal organic precursor (iron tetramethylheptanedionate) was identified whose deposition can be controlled by access to oxygen at temperatures in the 280-300 C range. Initial experiments have deposited iron oxide, but only on the membrane surface; thus refinement of this method will continue.

Timothy L. Ward

2000-06-30T23:59:59.000Z

300

Oxygen stabilized zirconium-vanadium-iron alloy  

DOE Patents [OSTI]

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

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

1982-01-01T23:59:59.000Z

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


301

Jupiter Oxygen Corporation | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 - 429 Throttled (botOpen6 Climate ZoneJeromeCounty isJupiter Oxygen Corporation

302

Oxygen Handling and Cooling Options in High Temperature Electrolysis Plants  

SciTech Connect (OSTI)

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

Manohar S. Sohal; J. Stephen Herring

2008-07-01T23:59:59.000Z

303

Oxygen Abundance Measurements of SHIELD Galaxies  

E-Print Network [OSTI]

We have derived oxygen abundances for 8 galaxies from the Survey of HI in Extremely Low-mass Dwarfs (SHIELD). The SHIELD survey is an ongoing study of very low-mass galaxies, with M$_{\\rm HI}$ between 10$^{6.5}$ and 10$^{7.5}$ M$_{\\odot}$, that were detected by the Arecibo Legacy Fast ALFA (ALFALFA) survey. H$\\alpha$ images from the WIYN 3.5m telescope show that these 8 SHIELD galaxies each possess one or two active star-forming regions which were targeted with long-slit spectral observations using the Mayall 4m telescope at KPNO. We obtained a direct measurement of the electron temperature by detection of the weak [O III] $\\lambda$4363 line in 2 of the HII regions. Oxygen abundances for the other HII regions were estimated using a strong-line method. When the SHIELD galaxies are plotted on a B-band luminosity-metallicity diagram they appear to suggest a slightly shallower slope to the relationship than normally seen. However, that offset is systematically reduced when the near-infrared luminosity is used ins...

Haurberg, Nathalie C; Cannon, John M; Marshall, Melissa V

2015-01-01T23:59:59.000Z

304

OXYGEN DEPLETION IN THE INTERSTELLAR MEDIUM: IMPLICATIONS FOR GRAIN MODELS AND THE DISTRIBUTION OF ELEMENTAL OXYGEN  

SciTech Connect (OSTI)

This paper assesses the implications of a recent discovery that atomic oxygen is being depleted from diffuse interstellar gas at a rate that cannot be accounted for by its presence in silicate and metallic oxide particles. To place this discovery in context, the uptake of elemental O into dust is considered over a wide range of environments, from the tenuous intercloud gas and diffuse clouds sampled by the depletion observations to dense clouds where ice mantles and gaseous CO become important reservoirs of O. The distribution of O in these contrasting regions is quantified in terms of a common parameter, the mean number density of hydrogen (n{sub H}). At the interface between diffuse and dense phases (just before the onset of ice-mantle growth) as much as {approx}160 ppm of the O abundance is unaccounted for. If this reservoir of depleted oxygen persists to higher densities it has implications for the oxygen budget in molecular clouds, where a shortfall of the same order is observed. Of various potential carriers, the most plausible appears to be a form of O-bearing carbonaceous matter similar to the organics found in cometary particles returned by the Stardust mission. The 'organic refractory' model for interstellar dust is re-examined in the light of these findings, and it is concluded that further observations and laboratory work are needed to determine whether this class of material is present in quantities sufficient to account for a significant fraction of the unidentified depleted oxygen.

Whittet, D. C. B. [New York Center for Astrobiology, and Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, NY 12180 (United States)

2010-02-20T23:59:59.000Z

305

Electrochemical oxygen pumps. Final CRADA report.  

SciTech Connect (OSTI)

All tasks of the Work Plan of ISTC Project 2277p have been completed, thus: (1) techniques of chemical synthesis were developed for more than ten recipes of electrolyte based on cerium oxide doped with 20 mole% of gadolinium (CeGd)O{sub 2}, doped by more than 10 oxide systems including 6 recipes in addition to the Work Plan; (2) electric conductivity and mechanical strength of CeGd specimens with additions of oxide systems were performed, two candidate materials for the electrolyte of electrochemical oxygen pump (pure CeGd and CeGd doped by 0.2 wt% of a transition metal) were chosen; (3) extended studies of mechanical strength of candidate material specimens were performed at room temperature and at 400, 600, 800 C; (4) fixtures for determination of mechanical strength of tubes by external pressure above 40 atmospheres at temperature up to 700 C were developed and fabricated; and (5) technology of slip casting of tubes from pure (Ce,Gd)O{sub 2} and of (Ce,Gd)O{sub 2} doped by 0.2 wt% of a transition metal, withstanding external pressure of minimum 40 atmospheres at temperature up to 700 C was developed, a batch of tubes was sent for testing to Argonne National Laboratory; (6) technology of making nanopowder from pure (Ce,Gd)O{sub 2} was developed based on chemical synthesis and laser ablation techniques, a batch of nanopowder with the weight 1 kg was sent for testing to Argonne National Laboratory; (7) a business plan for establishing a company for making powders of materials for electrochemical oxygen pump was developed; and (8) major results obtained within the Project were reported at international conferences and published in the Russian journal Electrochemistry. In accordance with the Work Plan a business trip of the following project participants was scheduled for April 22-29, 2006, to Tonawanda, NY, USA: Manager Victor Borisov; Leader of technology development Gennady Studenikin; Leader of business planning Elena Zadorozhnaya; Leader of production Vasily Lepalovsky; and Translator Vladimir Litvinov. During this trip project participants were to discuss with the project Technical Monitor J.D. Carter and representative of Praxair Inc. J. Chen the results of project activities (prospects of transition metal-doped material application in oxygen pumps), as well as the prospects of cooperation with Praxair at the meeting with the company management in the following fields: (1) Deposition of thin films of oxide materials of complex composition on support by magnetron and ion sputtering, research of coatings properties; (2) Development of block-type structure technology (made of porous and dense ceramics) for oxygen pump. The block-type structure is promising because when the size of electrolyte block is 2 x 2 inches and assembly height is 10 inches (5 blocks connected together) the area of active surface is ca. 290 square inches (in case of 8 slots), that roughly corresponds to one tube with diameter 1 inch and height 100 inches. So performance of the system made of such blocks may be by a factor of two or three higher than that of tube-based system. However one month before the visit, J. Chen notified us of internal changes at Praxair and the cancellation of the visit to Tonawanda, NY. During consultations with the project Technical Monitor J.D. Carter and Senior Project Manager A. Taylor a decision was made to extend the project term by 2 quarters to prepare proposals for follow-on activities during this extension (development of block-type structures made of dense and porous oxide ceramics for electrochemical oxygen pumps) using the funds that were not used for the trip to the US.

Carter, J. D.

2009-10-01T23:59:59.000Z

306

Nitrogen-doped carbon-supported cobalt-iron oxygen reduction catalyst  

DOE Patents [OSTI]

A Fe--Co hybrid catalyst for oxygen reaction reduction was prepared by a two part process. The first part involves reacting an ethyleneamine with a cobalt-containing precursor to form a cobalt-containing complex, combining the cobalt-containing complex with an electroconductive carbon supporting material, heating the cobalt-containing complex and carbon supporting material under conditions suitable to convert the cobalt-containing complex and carbon supporting material into a cobalt-containing catalyst support. The second part of the process involves polymerizing an aniline in the presence of said cobalt-containing catalyst support and an iron-containing compound under conditions suitable to form a supported, cobalt-containing, iron-bound polyaniline species, and subjecting said supported, cobalt-containing, iron bound polyaniline species to conditions suitable for producing a Fe--Co hybrid catalyst.

Zelenay, Piotr; Wu, Gang

2014-04-29T23:59:59.000Z

307

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

E-Print Network [OSTI]

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

Weijun Zheng; David Jewitt; Ralf I. Kaiser

2005-11-18T23:59:59.000Z

308

Activation of ROS/NF-{kappa}B and Ca{sup 2+}/CaM kinase II are necessary for VCAM-1 induction in IL-1{beta}-treated human tracheal smooth muscle cells  

SciTech Connect (OSTI)

Histone acetylation regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs) plays a critical role in the expression of inflammatory genes, such as vascular cell adhesion molecule-1 (VCAM-1). Oxidative processes have been shown to induce VCAM-1 expression. Here, we investigated the mechanisms underlying IL-1{beta}-induced VCAM-1 expression in human tracheal smooth muscle cells (HTSMCs). Our results showed that IL-1{beta} enhanced HTSMCs-monocyte adhesion through up-regulation of VCAM-1, which was inhibited by pretreatment with selective inhibitors of PKC{alpha} (Goe6976), c-Src (PP1), NADPH oxidase [diphenylene iodonium (DPI) and apocynin (APO)], intracellular calcium chelator (BAPTA/AM), PI-PLC (U73122), CaM (calmidazolium chloride), CaM kinase II (KN62), p300 (garcinol), NF-{kappa}B (Bay11-7082), HDAC (trichostatin A), and ROS scavenger [N-acetyl-L-cysteine (NAC)] or transfection with siRNAs of MyD88, PKC{alpha}, Src, p47{sup phox}, p300, and HDAC4. Moreover, IL-1{beta} stimulated NF-{kappa}B and CaMKII phosphorylation through MyD88-dependent PI-PLC/PKC{alpha}/c-Src/ROS and PI-PLC/Ca{sup 2+}/CaM pathways, respectively. Activation of NF-{kappa}B and CaMKII may eventually lead to the acetylation of histone residues and phosphorylation of histone deacetylases. These findings suggested that IL-1{beta} induced VCAM-1 expression via these multiple signaling pathways in HTSMCs. Blockade of these pathways may reduce monocyte adhesion via VCAM-1 suppression and attenuation of the inflammatory responses in airway diseases.

Luo, S.-F. [Department of Internal Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Chang, C.-C.; Lee, I-T. [Department of Physiology and Pharmacology, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Lee, C.-W. [Department of Nursing, Division of Basic Medical Sciences, Chang Gung Institute of Technology, Chia-Yi, Taiwan (China); Lin, W.-N. [Department of Physiology and Pharmacology, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Lin, C.-C. [Department of Anesthetics, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Yang, C.-M. [Department of Physiology and Pharmacology, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China)], E-mail: chuenmao@mail.cgu.edu.tw

2009-05-15T23:59:59.000Z

309

The effect of monomolecular films on oxygen transfer across an air-water interface  

E-Print Network [OSTI]

Rate 8. Effect of Aquasave Monolayer on Oxygen Uptake Rate 9. Effect of Isopropyl Alcohol on Oxygen Uptake Rate 10. Effect of Isopropyl Alcohol on Oxygen Uptake Rate 11. Effect of Isopropyl Alcohol on Oxygen Uptake Rate 12. Effect of Kerosene... on Oxygen Uptake Rate 13. Effect of Kerosene on Oxygen Uptake Rate 14. Effect of n-Pentanol on Oxygen Uptake Rate 15. Effect of n-Pentanol on Oxygen Uptake Rate 16. Effect of Hexane on Oxygen Uptake Rate 17. Effect of Hexane on Oxygen Uptake Rate 18...

Mahmoud, Tariq Ahmad

1967-01-01T23:59:59.000Z

310

Oxygen-Enriched Combustion for Military Diesel Engine Generators...  

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

Combustion for Military Diesel Engine Generators Oxygen-Enriched Combustion for Military Diesel Engine Generators Substantial increases in brake power and considerably lower peak...

311

Palladium-Cobalt Particles As Oxygen-Reduction Electrocatalysts...  

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

Hydrogen and Fuel Cell Hydrogen and Fuel Cell Find More Like This Return to Search Palladium-Cobalt Particles As Oxygen-Reduction Electrocatalysts Brookhaven National Laboratory...

312

Catalytic reduction system for oxygen-rich exhaust  

DOE Patents [OSTI]

Non-thermal plasma gas treatment is combined with selective catalytic reduction to enhance NO{sub x} reduction in oxygen-rich vehicle engine exhausts. 8 figs.

Vogtlin, G.E.; Merritt, B.T.; Hsiao, M.C.; Wallman, P.H.; Penetrante, B.M.

1999-04-13T23:59:59.000Z

313

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

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

the efficiency of solid oxide fuel cells can be improved. Citation: Edmondson PD, WJ Weber, F Namavar, and Y Zhang.2011."Lattice Distortions and Oxygen Vacancies Produced in...

314

active oxygen probe: Topics by E-print Network  

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

CERN Preprints Summary: I present here the results of the first principles studies of the adsorption energetics of the intermediates of the oxygen electro-reduction reaction (ORR)...

315

Optical dissolved oxygen sensor utilizing molybdenum chloride cluster phosphorescence  

E-Print Network [OSTI]

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

Ghosh, Ruby N.

316

Table 33. Oxygenated Motor Gasoline Prices by Grade, Sales Type...  

Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

- - - - - - - - - - - - See footnotes at end of table. 33. Oxygenated Motor Gasoline Prices by Grade, Sales Type, PAD District, and State 116 Energy Information...

317

Table 33. Oxygenated Motor Gasoline Prices by Grade, Sales Type...  

Gasoline and Diesel Fuel Update (EIA)

Information Administration Petroleum Marketing Annual 1995 Table 33. Oxygenated Motor Gasoline Prices by Grade, Sales Type, PAD District, and State (Cents per Gallon...

318

Microbial metatranscriptomics in a permanent marine oxygen minimum zone  

E-Print Network [OSTI]

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

Stewart, Frank J.

319

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

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

2009 - Poster Session August 3 rd , Hyatt Regency Dearborn Hotel Virtual Oxygen Sensor Innovative NOx and PM Emission Control Technologies J. Seebode, E. Stlting,...

320

Modeling Oxygen Transport in Three-Dimensional Capillary Networks.  

E-Print Network [OSTI]

??The purpose of this thesis was to examine how the use of real 3-dimensional (3D) capillary network geometries affect models of oxygen transport to tissue.… (more)

Fraser, Graham M

2012-01-01T23:59:59.000Z

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


321

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

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

Precursor Transport Through the Hydrogen Electron-Stimulated Production of Molecular Oxygen in Amorphous Solid Water on Pt(111): Precursor Transport Through the Hydrogen...

322

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. Abstract: In a recent work, we have shown that chemically synthesized...

323

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

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

High temperature oxygen sensors are widely used for exhaust gas monitoring in automobiles. This particular study explores the use of thin film single crystalline samaria...

324

Korean oxygenates rule sparks MTBE capacity plans  

SciTech Connect (OSTI)

The Korean government`s strict standard for gasoline sold domestically is expected to have a significant impact on the methyl tert-butyl ether (MTBE) market. The mandate-requiring gasoline oxygen content of 0.5% this year, 0.75% by 1996, and 1.0% by 1998-has sparked a rush by Korean refineries to build new MTBE plants. If expansion plans are carried out, Korea`s MTBE capacity will increase from 280,000 m.t./year to 650,000 m.t./year by 1996, far surpassing predicted demand. Honam Oil, part of the Lucky Group, plans startup of a 100,000-m.t./year unit at Yeochon by early 1996. In addition, by the end of 1996 Ssangyong Oil will bring a 100,000-m.t./year unit onstream.

Kim, Hyung-Jin

1994-06-15T23:59:59.000Z

325

Dilute Oxygen Combustion - Phase 3 Report  

SciTech Connect (OSTI)

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

Riley, Michael F.

2000-05-31T23:59:59.000Z

326

Dilute Oxygen Combustion Phase 3 Final Report  

SciTech Connect (OSTI)

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

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

2000-05-31T23:59:59.000Z

327

Ordering and oxygen content effects in YBa sub 2 (Cu sub 1 minus x Fe sub x ) sub 3 O sub 7 samples observed by high-temperature Moessbauer spectroscopy  

SciTech Connect (OSTI)

We report here {ital in} {ital situ} high-temperature {sup 57}Fe Moessbauer measurements on YBa{sub 2}(Cu{sub 1{minus}{ital x}}Fe{sub {ital x}}){sub 3}O{sub 7} samples in controlled oxygen atmosphere, in air, or in vacuum. In these conditions, fundamental information can be obtained related to the thermal stability of the different Fe species, as well as the mechanism of oxygen loss.

Saitovitch, E.B.; Scorzelli, R.B.; Azevedo, I.S.; dos Santos, C.A. (Centro Brasileiro de Pesquisas F isicas, Rua Dr. Xavier Sigaud, 150, 22290, Rio de Janeiro-RJ, Brasil (BR))

1990-05-01T23:59:59.000Z

328

Hypolimnetic Oxygen Depletion in Eutrophic Lakes Beat Muller,*,  

E-Print Network [OSTI]

Hypolimnetic Oxygen Depletion in Eutrophic Lakes Beat Muller,*, Lee D. Bryant,, Andreas Matzinger obtained from 11 eutrophic lakes and suggests a model describing the consumption of dissolved oxygen (O2) in the hypolimnia of eutrophic lakes as a result of only two fundamental processes: O2 is consumed (i) by settled

Wehrli, Bernhard

329

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

E-Print Network [OSTI]

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

Macalady, Jenn

330

Unexpected Nondissociative Binding of N2O on Oxygen Vacancies...  

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

Nondissociative Binding of N2O on Oxygen Vacancies on a Rutile TiO2(110)-1×1 . Unexpected Nondissociative Binding of N2O on Oxygen Vacancies on a Rutile TiO2(110)-1×1 ....

331

Singlet oxygen luminescence detection with a fibre-coupled superconducting  

E-Print Network [OSTI]

Singlet oxygen luminescence detection with a fibre-coupled superconducting nanowire single luminescence detection Fibre-based singlet oxygen luminescence detection References Superconducting Detector, is an intermediate in many biological processes. We employ a superconducting nanowire single-photon detector (SNSPD

Greenaway, Alan

332

Palladium-cobalt particles as oxygen-reduction electrocatalysts  

DOE Patents [OSTI]

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

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

2009-12-15T23:59:59.000Z

333

Instructions for use Removal of Oxygen and Nitrogen from Niobium  

E-Print Network [OSTI]

Instructions for use #12;------ Removal of Oxygen and Nitrogen from Niobium by External Gettering of Energy Science and Technology, Kyoto University Yoshida-Honmachi, Sakyo-ku, Kyoto 606-01 Japan Keywords External Gettering, Purification of Niobium, Thermodynamics of Impurities, Oxygen Diffusion, Purity

Tachizawa, Kazuya

334

HERSCHEL MEASUREMENTS OF MOLECULAR OXYGEN IN ORION  

SciTech Connect (OSTI)

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

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

2011-08-20T23:59:59.000Z

335

Direct tuyere injection of oxygen for enhanced coal combustion  

SciTech Connect (OSTI)

Injecting oxygen directly into the tuyere blowpipe can enhance the ignition and combustion of injected pulverized coal, allowing the efficient use of higher coal rates at high furnace production levels. The effects of direct oxygen injection have been estimated from an analysis of the factors controlling the dispersion, heating, ignition, and combustion of injected coal. Injecting ambient temperature oxygen offers mechanical improvements in the dispersion of coal but provides little thermochemical benefit over increased blast enrichment. Injecting hot oxygen through a novel, patented thermal nozzle lance offers both mechanical and thermochemical benefits over increased enrichment or ambient oxygen injection. Plans for pilot-scale and commercial-scale testing of this new lance are described.

Riley, M.F. [Praxair, Inc., Tarrytown, NY (United States)

1996-12-31T23:59:59.000Z

336

Nanoparticulate-catalyzed oxygen transfer processes  

DOE Patents [OSTI]

Nanoparticulates of oxygen transfer materials that are oxides of rare earth metals, combinations of rare earth metals, and combinations of transition metals and rare earth metals are used as catalysts in a variety of processes. Unexpectedly large thermal efficiencies are achieved relative to micron sized particulates. Processes that use these catalysts are exemplified in a multistage reactor. The exemplified reactor cracks C6 to C20 hydrocarbons, desulfurizes the hydrocarbon stream and reforms the hydrocarbons in the stream to produce hydrogen. In a first reactor stage the steam and hydrocarbon are passed through particulate mixed rare earth metal oxide to crack larger hydrocarbon molecules. In a second stage, the steam and hydrocarbon are passed through particulate material that desulfurizes the hydrocarbon. In a third stage, the hydrocarbon and steam are passed through a heated, mixed transition metal/rare earth metal oxide to reform the lower hydrocarbons and thereby produce hydrogen. Stages can be alone or combined. Parallel reactors can provide continuous reactant flow. Each of the processes can be carried out individually.

Hunt, Andrew T. (Atlanta, GA); Breitkopf, Richard C. (Dunwoody, GA)

2009-12-01T23:59:59.000Z

337

Relaxation behavior of oxygen deficient strontium manganite  

SciTech Connect (OSTI)

Conduction behavior of nanocrystalline oxygen deficient ceramic-SrMnO{sub 3–?}(??0.14) has been studied. The structural analysis of nano-SrMnO{sub 2.86} follows hexagonal unit cell structure with P6{sub 3}/mmc (194) space group belonging to 6/mmm point group with 4H – layered type hexagonal-cubic layers. The system have lattice parameters; a = 5.437(92) Å, c = 9.072(92) Å, c/a?1.66 (85) with ? =90° ?= 120° and cell volume, V= 232.35(18). The relaxation times estimated from complex impedance and modulus relaxation spectrum, show the thermally activated system with corresponding activation energies as 0.66 eV and 0.51 eV The stretching factor ‘?’ from the scaled modulus spectrum shows the poly-dispersive non-Debye nature of the system. The hopping number ‘n’ shows the influence of ionic charge carriers which controls the conduction mechanism of nano-SrMnO{sub 2.86}.

Pandey, Namita, E-mail: namita205@gmail.com; Thakur, Awalendra Kumar, E-mail: namita205@gmail.com [Department of Physics, Indian Institute of Technology-Patna, Patna- 800013 (India)

2014-04-24T23:59:59.000Z

338

Faraday Discuss., 1997, 108, 115130 Excited state dynamics in clusters of oxygen  

E-Print Network [OSTI]

Faraday Discuss., 1997, 108, 115�130 Excited state dynamics in clusters of oxygen Runjun Li, Karl A clusters of oxygen. Oxygen clusters and liquid oxygen have a com- plicated chemistry due to numerous low) dynamics of small anionic clusters of oxygen. We Ðnd that the dynamics of the neutral DPD pathway

Continetti, Robert E.

339

deficiencies are considered an abiotic stress for plants  

E-Print Network [OSTI]

) #12; hypothesized that higher concentrations of N result in higher levels of AA and proteins > with additional proteins being made, it can give rise to additional secondary metabolites, but also other defense compounds lack of N = higher levels of reactive oxygen species (ROS) > damage photosynthetic machinery #12

Constabel, Peter

340

Published Ahead of Print 28 July 2014. 10.1128/AAC.03683-14.  

E-Print Network [OSTI]

of s rendered stationary-phase Esch- erichia coli more sensitive to the bactericidal antibiotic gentamicin (Gm reporter, 3=-(p-hydroxyphenyl) fluorescein (HPF) dye, and Amplex Red showed that Gm generated more reactive oxygen species (ROS) in the mutant. HPF measurements can be distorted by cell elon- gation, but Gm did

Matin, A.C.

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


341

Sigma S-Dependent Antioxidant Defense Protects Stationary-Phase Escherichia coli against the Bactericidal Antibiotic Gentamicin  

E-Print Network [OSTI]

elucidated. Loss of s rendered stationary-phase Esch- erichia coli more sensitive to the bactericidal. Use of the psfiA genetic reporter, 3=-(p-hydroxyphenyl) fluorescein (HPF) dye, and Amplex Red showed that Gm generated more reactive oxygen species (ROS) in the mutant. Gm did not cause cell elongation

Matin, A.C.

342

Original Contribution SUPEROXIDE DISMUTASE MIMETICS ELEVATE SUPEROXIDE DISMUTASE  

E-Print Network [OSTI]

damage from reactive oxygen species (ROS), particularly superoxide and its derivatives. This predicts. Where life span was reduced by the superoxide generators paraquat and plumbagin, EUK-8 treatment increased life span in a dose-dependent fashion. Yet in the absence of a superoxide generator, treatment

Gems, David

343

Intracellular Delivery Using Fluorophore-CPP Conjugates and Light: Mechanisms and Implications  

E-Print Network [OSTI]

PM Plasma membrane PTD Protein transduction domain RB Rose Bengal RBC Red blood cell RNO p-dimethylnitrosoaniline ROS Reactive oxygen species sh-RNA short hairpin RNA SPPS Solid phase peptide synthesis vii TAT Trans activator... ....................................................................................... 56 2.4.1 Peptide synthesis .................................................................................... 56 ix 2.4.2 Cell-based assays .................................................................................... 57 2...

Muthukrishnan, Nandhini

2014-05-02T23:59:59.000Z

344

Miniature Enzyme-Based Electrodes for Detection of Hydrogen Peroxide Release from Alcohol-Injured Hepatocytes  

E-Print Network [OSTI]

generated by hepatocytes has not been undertaken to the best of our knowledge. Hydrogen peroxide (H2O2Miniature Enzyme-Based Electrodes for Detection of Hydrogen Peroxide Release from Alcohol clinical and experimental studies, it has been found that the production of reactive oxygen species (ROS

Ferrara, Katherine W.

345

In vitro cellular responses to silicon carbide particles manufactured through the Acheson process: impact of physico-chemical features on pro-inflammatory and pro-  

E-Print Network [OSTI]

1 In vitro cellular responses to silicon carbide particles manufactured through the Acheson process ROS: Reactive Oxygen Species SiC: Silicon carbide SSA: Specific Surface Area TNF: Tumor Necrosis carbide (SiC) an industrial-scale product manufactured through the Acheson process, is largely employed

Paris-Sud XI, Université de

346

Oxygen diffusion, surface exchange and oxygen semi-permeation performances of Ln2NiO4+ membranes (Ln = La, Pr and Nd)  

E-Print Network [OSTI]

Oxygen diffusion, surface exchange and oxygen semi-permeation performances of Ln2NiO4+ membranes the rate determining step (rds) in oxygen semi-permeation of dense Ln2NiO4+ membranes (with Ln = La, Pr and Nd), a specific setup has been designed, which allowed measuring the oxygen semi-permeation flux

Paris-Sud XI, Université de

347

Oxygen Modulation via Microfluidic Devices Oxygen is a key but under-studied metabolic variable. It influences biological phenomena as diverse as  

E-Print Network [OSTI]

Oxygen Modulation via Microfluidic Devices Oxygen is a key but under-studied metabolic variable methods to modulate oxygen are crude and inefficient. Our lab has developed a suite of devices which can rapidly alter oxygen conditions surrounding cells in both position and time.[1-3]. Moreover, because

Ben-Arie, Jezekiel

348

Flammability of selected heat resistant alloys in oxygen gas mixtures  

SciTech Connect (OSTI)

Within recent years, the use of oxygen has increased in applications where elevated temperatures and corrosion may be significant factors. In such situations, traditional alloys used in oxygen systems will not be adequate. Where alternative alloys must be utilized, based upon environmental requirements, it is essential that they may be characterized with respect to their ignition and combustion resistance in oxygen. Promoted ignition and promoted ignition-combustion are terms which have been used to describe a situation where a substance with low oxygen supports the combustion of a compatibility ignites and more ignition resistant material. In this paper, data will be presented on the promoted ignition-combustion behavior of selected heat resistant engineering alloys that may be considered for gaseous oxygen applications in severe environments. In this investigation, alloys have been evaluated via both flowing and static (fixed volume) approaches using a rod configuration. Oxygen-nitrogen gas mixtures with compositions ranging from approximately 40 to 99.7% oxygen at pressures of 3.55 to 34.6 MPa were used in the comparative studies.

Zawierucha, R.; McIlroy, K.; Million, J.F. [Praxair, Inc., Tonawanda, NY (United States)

1995-12-31T23:59:59.000Z

349

Increased intrapulmonary retention of radiolabeled neutrophils in early oxygen toxicity  

SciTech Connect (OSTI)

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

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

1988-02-01T23:59:59.000Z

350

Measuring oxygen reduction/evolution reactions on the nanoscale  

SciTech Connect (OSTI)

The efficiency of fuel cells and metal-air batteries is significantly limited by the activation of oxygen reduction and evolution reactions (ORR/OER). Despite the well-recognized role of oxygen reaction kinetics on the viability of energy technologies, the governing mechanisms remain elusive and until now addressable only by macroscopic studies. This lack of nanoscale understanding precludes optimization of material architecture. Here we report direct measurements of oxygen reduction/evolution reactions and oxygen vacancy diffusion on oxygen-ion conductive solid surfaces with sub-10 nanometer resolution. In electrochemical strain microscopy (ESM), the biased scanning probe microscopy tip acts as a moving, electrocatalytically active probe exploring local electrochemical activity. The probe concentrates an electric field in a nanometer-scale volume of material, and bias-induced, picometer-level surface displacements provide information on local electrochemical processes. Systematic mapping of oxygen activity on bare and Pt-functionalized yttria-stabilized zirconia (YSZ) surfaces is demonstrated. This approach allows directly visualization of ORR/OER activation process at the triple-phase boundary, and can be extended to broad spectrum of oxygen-conductive and electrocatalytic materials.

Kalinin, Sergei V [ORNL; Jesse, Stephen [ORNL; Kumar, Amit [ORNL; Morozovska, A. N. [National Academy of Science of Ukraine, Kiev, Ukraine; Ciucci, Francesco [Harvard-Smithsonian Center for Astrophysics

2011-01-01T23:59:59.000Z

351

Alien Species and Evolution: The Evolutionary Ecology of Exotic Plants, Animals, Microbes and Interacting Native Species  

E-Print Network [OSTI]

Review: Alien Species and Evolution: The EvolutionaryGermany George W. Cox. Alien Species and Evolution: TheRecycled, acid-free paper. Alien Species and Evolution leads

Nehrbass, Nana

2005-01-01T23:59:59.000Z

352

Influence of geometry on liquid oxygen magnetohydrodynamics  

SciTech Connect (OSTI)

Magnetic fluid actuators have performed well in industrial applications, but have a limited temperature range due to the freezing point of the carrier fluid. Liquid oxygen (LOX) presents a pure, paramagnetic fluid suitable for use in a cryogenic magnetic fluid system; therefore, it is a potential solution to increasing the thermal range of magnetic fluid technology without the need for magnetic particles. The current study presents experimental work regarding the influence of geometry on the dynamics of a LOX slug in a 1.9 mm quartz tube when pulsed by a solenoid in a closed volume. A numerical analysis calculated the optimal solenoid geometry and balanced the magnetic, damping, and pressure forces to determine optimal slug lengths. Three configurations comprised the experiment: (1) a 24-gauge wire solenoid with an optimized 2.7 cm length slug, (2) a 30-gauge wire solenoid with an optimized 1.3 cm length slug, and (3) a 30-gauge wire solenoid with a nonoptimized 2.5 cm length slug. Typically, the hydrodynamic breakdown limit is calculated and used to determine the system range; however the experiment showed that the hydrodynamic breakdown limit was never reached by the slug. This implied that, instead, the system range should factor in a probabilistic risk of failure calculated as a function of the induced pressure change from its oscillations. The experimental data were also used to establish a nondimensional relationship between the maximum displacement and initial magnetic pressure on the slug. The average initial velocity of the slug was found to be proportional to the initial magnetic pressure, Mason number, and slug length. The results of this study can be used in the design and optimization of a LOX fluid system for space or low-temperature applications. (author)

Boulware, Jeffrey C.; Ban, Heng [Department of Mechanical and Aerospace Engineering, Utah State University, 4130 Old Main Hill, Logan, UT 84322-4130 (United States); Jensen, Scott; Wassom, Steve [Space Dynamics Laboratory, Utah State University Research Foundation, 1695 North Research Park Way, North Logan, UT 84341 (United States)

2010-11-15T23:59:59.000Z

353

Boron nitride nanosheets as oxygen-atom corrosion protective coatings  

SciTech Connect (OSTI)

The research of two-dimensional nanomaterials for anticorrosion applications is just recently burgeoning. Herein, we demonstrate the boron nitride nanosheets (BNNSs) coatings for protecting polymer from oxygen-atom corrosion. High-quality BNNSs, which are produced by an effective fluid dynamics method with multiple exfoliation mechanisms, can be assembled into coatings with controlled thickness by vacuum filtration. After exposed in atom oxygen, the naked polymer is severely corroded with remarkable mass loss, while the BNNSs-coated polymer remains intact. Barrier and bonding effects of the BNNSs are responsible for the coating's protective performance. These preliminary yet reproducible results pave a way for resisting oxygen-atom corrosion.

Yi, Min [Beijing Key Laboratory for Powder Technology Research and Development, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Plasma Laboratory, Ministry-of-Education Key Laboratory of Fluid Mechanics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Shen, Zhigang, E-mail: shenzhg@buaa.edu.cn [Beijing Key Laboratory for Powder Technology Research and Development, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Plasma Laboratory, Ministry-of-Education Key Laboratory of Fluid Mechanics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); School of Material Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Zhao, Xiaohu [Plasma Laboratory, Ministry-of-Education Key Laboratory of Fluid Mechanics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Liang, Shuaishuai [Beijing Key Laboratory for Powder Technology Research and Development, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Liu, Lei [Beijing Key Laboratory for Powder Technology Research and Development, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); School of Material Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China)

2014-04-07T23:59:59.000Z

354

THERMOCHEMICAL CONVERSION OF FERMENTATION-DERIVED OXYGENATES TO FUELS  

SciTech Connect (OSTI)

At present ethanol generated from renewable resources through fermentation process is the dominant biofuel. But ethanol suffers from undesirable fuel properties such as low energy density and high water solubility. The production capacity of fermentation derived oxygenates are projected to rise in near future beyond the current needs. The conversion of oxygenates to hydrocarbon compounds that are similar to gasoline, diesel and jet fuel is considered as one of the viable option. In this chapter the thermo catalytic conversion of oxygenates generated through fermentation to fuel range hydrocarbons will be discussed.

Ramasamy, Karthikeyan K.; Wang, Yong

2013-06-01T23:59:59.000Z

355

Production of Ultra-Cold-Neutrons in Solid ?-Oxygen  

E-Print Network [OSTI]

Our recent neutron scattering measurements of phonons and magnons in solid \\alpha-oxygen have led us to a new understanding of the production mechanismen of ultra-cold-neutrons (UCN) in this super-thermal converter. The UCN production in solid \\alpha-oxygen is dominated by the excitation of phonons. The contribution of magnons to UCN production becomes only slightly important above E >10 meV and at E >4 meV. Solid \\alpha-oxygen is in comparison to solid deuterium less effcient in the down-scattering of thermal or cold neutrons into the UCN energy regime.

E. Gutsmiedl; A. Frei; F. Boehle; A. Maier; S. Paul; H. Schober; A. Orecchini

2010-07-30T23:59:59.000Z

356

Hydrogen Production Using Hydrogenase-Containing Oxygenic Photosynthetic Organisms  

DOE Patents [OSTI]

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

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

2006-01-24T23:59:59.000Z

357

Solid phases of spatially nanoconfined oxygen: A neutron scattering study  

SciTech Connect (OSTI)

We present a comprehensive neutron scattering study on solid oxygen spatially confined in 12 nm wide alumina nanochannels. Elastic scattering experiments reveal a structural phase sequence known from bulk oxygen. With decreasing temperature cubic ?-, orthorhombic ?- and monoclinic ?-phases are unambiguously identified in confinement. Weak antiferromagnetic ordering is observed in the confined monoclinic ?-phase. Rocking scans reveal that oxygen nanocrystals inside the tubular channels do not form an isotropic powder. Rather, they exhibit preferred orientations depending on thermal history and the very mechanisms, which guide the structural transitions.

Kojda, Danny [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin (Germany) [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin (Germany); Freie Universität Berlin, 14195 Berlin (Germany); Wallacher, Dirk; Hofmann, Tommy, E-mail: tommy.hofmann@helmholtz-berlin.de [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin (Germany)] [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin (Germany); Baudoin, Simon; Hansen, Thomas [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France)] [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France); Huber, Patrick [Technische Universität Hamburg-Harburg, 21073 Hamburg (Germany)] [Technische Universität Hamburg-Harburg, 21073 Hamburg (Germany)

2014-01-14T23:59:59.000Z

358

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

359

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

E-Print Network [OSTI]

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

Bolar, Divya Sanam

2010-01-01T23:59:59.000Z

360

Seasonal and interannual oxygen variability on the Washington and Oregon continental shelves  

E-Print Network [OSTI]

A. Pe~ na (2013), Declining oxygen on the British ColumbiaE. , and L. I. Gordon (1992), Oxygen solubility in seawater:10.1002/2014JC010254 Key Points: Oxygen model presented for

2015-01-01T23:59:59.000Z

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


361

Atomic oxygen flux determined by mixed-phase Ag/Ag2O deposition...  

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

oxygen flux determined by mixed-phase AgAg2O deposition. Atomic oxygen flux determined by mixed-phase AgAg2O deposition. Abstract: The flux of atomic oxygen generated in a...

362

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

E-Print Network [OSTI]

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

Chan, Sharleen

363

Advances in studying bioinorganic reaction mechanisms: isotopic probes of activated oxygen  

E-Print Network [OSTI]

Advances in studying bioinorganic reaction mechanisms: isotopic probes of activated oxygen intermediates in metalloenzymes Justine P Roth Metalloenzymes catalyze reactions of molecular oxygen and its reduced forms through the controlled formation of metal- bound, activated oxygen intermediates

Roth, Justine P.

364

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

E-Print Network [OSTI]

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

McEnulty, Tess

2012-01-01T23:59:59.000Z

365

High-Velocity Oxygen Fuel Thermal Spray of Fe-Based Amorphous Alloy: a Numerical and Experimental Study  

E-Print Network [OSTI]

High-Velocity Oxygen Fuel Thermal Spray of Fe-Basedusing a high velocity oxygen fuel (HVOF) spray processstructure. [12] High velocity oxygen fuel (HVOF) thermal

Ajdelsztajn, L.; Dannenberg, J.; Lopez, J.; Yang, N.; Farmer, J.; Lavernia, E. J.

2009-01-01T23:59:59.000Z

366

Insect Conservation under the Endangered Species Act  

E-Print Network [OSTI]

the trend toward species extinction, whatever the cost." 'protection for species on the verge of extinction. 43. Id.about the extinction of any species 3 1 and, unlike earlier

Lugo, Ezequiel

2006-01-01T23:59:59.000Z

367

Chytridiomycosis as a cause of species extinction?  

E-Print Network [OSTI]

Chytridiomycosis as a cause of species extinction? Yimin Du Penny Langhammer Yijun Lou John population declines, species extinctions ­ Biodiversity loss · Theoretical ­ Host extinction generally to amphibian species Stuart et al. 2004. Science 306: 17831786 #12;Batrachochytrium dendrobatidis (Bd

Linder, Tamás

368

Nongame and Endangered Species Conservation Act (Nebraska)  

Broader source: Energy.gov [DOE]

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

369

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

SciTech Connect (OSTI)

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

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

1994-08-01T23:59:59.000Z

370

Influence of oxygen pressure and aging on LaAlO{sub 3} films grown by pulsed laser deposition on SrTiO{sub 3} substrates  

SciTech Connect (OSTI)

The crystal structures of LaAlO{sub 3} films grown by pulsed laser deposition on SrTiO{sub 3} substrates at oxygen pressure of 10{sup ?3} millibars or 10{sup ?5} millibars, where kinetics of ablated species hardly depend on oxygen background pressure, are compared. Our results show that the interface between LaAlO{sub 3} and SrTiO{sub 3} is sharper when the oxygen pressure is lower. Over time, the formation of various crystalline phases is observed while the crystalline thickness of the LaAlO{sub 3} layer remains unchanged. X-ray scattering as well as atomic force microscopy measurements indicate three-dimensional growth of such phases, which appear to be fed from an amorphous capping layer present in as-grown samples.

Park, Jihwey; Aeppli, Gabriel [London Centre for Nanotechnology, University College London, London WC1H 0AH (United Kingdom); Soh, Yeong-Ah, E-mail: yeongahsoh@gmail.com [London Centre for Nanotechnology, University College London, London WC1H 0AH (United Kingdom); Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom); David, Adrian; Lin, Weinan [Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371 (Singapore); Wu, Tom [Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia)

2014-02-24T23:59:59.000Z

371

A method of determining the dissolved oxygen in the moisture of a porous medium and some oxygen diffusion studies  

E-Print Network [OSTI]

this dissolved oxygen The sample chamber apparatus gives ocnsplcte seal of the bottle from the atmosphere The ohsabor does not require a large ameunt Of nitrogen Sb remove all the oxygen from it, It is easily portable and light in weight The proposed method... METHOD QF DETRHRIUIHO THE DISSOLVED OXmEK IE THE MOISTURE OF A POROUS ERDD% @AD SMfE QXYOEB DKFFUSIOE STUDIES ' INTRO DUO fQRF, I Oxygen, bas been known to be important in plant growth fox maay years There has been a great deal of xesearoh...

Runkles, Jack Ralph

1952-01-01T23:59:59.000Z

372

E-Print Network 3.0 - activity peak oxygen Sample Search Results  

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

Yttria-stabilized zirconia, a well known oxygen ion... including fuel cells, oxygen pumps, and chemical gas sensors because of a number of superior properties... such as heat...

373

E-Print Network 3.0 - adjuvant hyperbaric oxygen Sample Search...  

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

Ph.D., Editor Summary: . Hyperbaric oxygen is the definitive treat- ment for carbon monoxide poisoning.47 However, pro- ponents... III, Putnam RW, Dean JB: Hyperbaric oxygen and...

374

E-Print Network 3.0 - apneic oxygenation combined Sample Search...  

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

the same day were combined for data analysis. The oxygen concentration gradient in the agar... Oxygen sensation and social feeding mediated by a C. elegans guanylate cyclase...

375

High-Temperature Zirconia Oxygen Sensor with Sealed Metal/Metal...  

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

High-Temperature Zirconia Oxygen Sensor with Sealed MetalMetal Oxide Internal Reference High-Temperature Zirconia Oxygen Sensor with Sealed MetalMetal Oxide Internal Reference...

376

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

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

reactive oxygen Search Powered by Explorit Topic List Advanced Search Sample search results for: accumulate reactive oxygen Page: << < 1 2 3 4 5 > >> 1 CLINICAL CONCEPTS AND...

377

Low-Oxygen Induction of Normally Cryptic psbA Genes in Cyanobacteria...  

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

Oxygen Induction of Normally Cryptic psbA Genes in Cyanobacteria. Low-Oxygen Induction of Normally Cryptic psbA Genes in Cyanobacteria. Abstract: Microarray analysis indicated...

378

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

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

Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen simulation Page: << < 1 2 3 4 5 > >> 1 Influence of oxygen on the interfacial...

379

E-Print Network 3.0 - adjunctive hyperbaric oxygen Sample Search...  

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

hyperbaric oxygen Search Powered by Explorit Topic List Advanced Search Sample search results for: adjunctive hyperbaric oxygen Page: << < 1 2 3 4 5 > >> 1 TO: UMRSMAS Divers FR:...

380

Microfluidic advantage : novel techniques for protein folding and oxygen control in cell cultures  

E-Print Network [OSTI]

Novel Techniques for Protein Folding and Oxygen Control inTemperature Jump System to Study Fast Protein FoldingNovel Techniques for Protein Folding and Oxygen Control in

Polinkovsky, Mark E.; Polinkovsky, Mark E.

2012-01-01T23:59:59.000Z

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


381

Impact of ethanol and butanol as oxygenates on SIDI engine efficiency...  

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

as oxygenates on SIDI engine efficiency and emissions using steady-state and transient test procedures Impact of ethanol and butanol as oxygenates on SIDI engine efficiency and...

382

E-Print Network 3.0 - achieving fast oxygen Sample Search Results  

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

Bulletin Collection: Environmental Sciences and Ecology 51 Oxygen diffusion in titanite: Lattice diffusion and fast-path diffusion in single crystals Summary: Oxygen...

383

Vehicle Technologies Office Merit Review 2014: Intake Air Oxygen Sensor  

Broader source: Energy.gov [DOE]

Presentation given by Robert Bosch at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about intake air oxygen sensors.

384

In-situ generation of oxygen-releasing metal peroxides  

DOE Patents [OSTI]

A method for remediation of contaminants in soil and groundwater is disclosed. The method generates oxygen releasing solids in groundwater or soil by injecting an aqueous energetic oxidant solution containing free radicals, oxidative conditions can be created within or ahead of a contaminant plume. Some contaminants may be remediated directly by reaction with the free radicals. Additionally and more importantly, the free radicals create an oxidative condition whereby native or injected materials, especially metals, are converted to peroxides. These peroxides provide a long-term oxygen reservoir, releasing oxygen relatively slowly over time. The oxygen can enhance microbial metabolism to remediate contaminants, can react with contaminant metals either to form immobile precipitants or to mobilize other metals to permit remediation through leaching techniques. Various injection strategies for injecting the energetic oxidant solution are also disclosed.

Looney, Brian B. (Aiken, SC); Denham, Miles E. (Aiken, SC)

2007-01-09T23:59:59.000Z

385

Reaction of adsorption substitution of oxygen on a cracking catalyst  

SciTech Connect (OSTI)

In an investigation of catalysts for methanol synthesis and carbon monoxide conversion, the authors have observed, for the first time, the reaction of adsorption substitution of strongly bound oxygen on catalysts containing zeolites and compounds of lanthanum and cerium.

Vishnetskaya, M.V.; Takhtarova, G.N.; Topchieva, K.V.

1986-04-01T23:59:59.000Z

386

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

E-Print Network [OSTI]

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

Hu, Ying.

2008-01-01T23:59:59.000Z

387

Phosphorescent semiconductor nanocrystals and proteins for biological oxygen sensing  

E-Print Network [OSTI]

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

McLaurin, Emily J. (Emily Jane)

2011-01-01T23:59:59.000Z

388

Dissolution of oxygen reduction electrocatalysts in acidic environment  

E-Print Network [OSTI]

Platinum (Pt) alloy nanoparticles are used as catalysts in electrochemical cells to reduce oxygen to water and to oxidize hydrogen; the overall reaction converts chemical energy into electrical energy. These nanocatalysts are deposited on a carbon...

Gu, Zhihui

2009-05-15T23:59:59.000Z

389

A DIGITAL CONTROL SYSTEM FOR OPTIMAL OXYGEN TRANSFER  

E-Print Network [OSTI]

A DIGITAL CONTROL SYSTEM FOR OPTIMAL OXYGEN TRANSFER EFFICIENCY Arnold Schwarzenegger Governor system ............................. 10 5.2 Types of aeration processes of fine bubble diffusers for sub-surface aeration ............ 13 5.5 Process design considerations

390

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

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

only at the bridging oxygen vacancies, with one O atom healing a vacancy and other O atom bonding at the neighboring Ti site as an adatom. Majority (81%) of O adatoms are found...

391

Oxygen Vacancies and Ferromagnetism in CoxTi–x–y...  

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

Vacancies and Ferromagnetism in CoxTi–x–y. Oxygen Vacancies and Ferromagnetism in CoxTi–x–y. Abstract: Abstract: Cobalt-doped titanium dioxide, or CTO, has...

392

Oxygen Enrichment in the Process and Chemical Industries  

E-Print Network [OSTI]

The rapid escalation in energy prices during recent years has resulted in a resurgence of interest in the energy-saving aspects of oxygen enrichment techniques available to the process and chemical industries. Important side benefits which may...

Milne, R. T.

1984-01-01T23:59:59.000Z

393

Hybrid membrane--PSA system for separating oxygen from air  

DOE Patents [OSTI]

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

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

2011-01-25T23:59:59.000Z

394

Enhancing SNCR-aided combustion with oxygen addition  

DOE Patents [OSTI]

NOx emissions from combustion are reduced, NOx reduction efficiency by SNCR is improved, and other efficiencies are realized, by injecting oxygen into a fuel-rich combustion zone under controlled conditions.

Kobayashi, Hisashi; Wu, Kuang Tsai; Bool III, Lawrence E.

2004-03-09T23:59:59.000Z

395

Massachusetts Endangered Species Act Regulations (Massachusetts)  

Broader source: Energy.gov [DOE]

The regulations that accompany the Massachusetts Endangered Species Act list three categories of animals and plants in need of protection: endangered, threatened, and species of special concern....

396

Oxygen enhanced switching to combustion of lower rank fuels  

DOE Patents [OSTI]

A furnace that combusts fuel, such as coal, of a given minimum energy content to obtain a stated minimum amount of energy per unit of time is enabled to combust fuel having a lower energy content, while still obtaining at least the stated minimum energy generation rate, by replacing a small amount of the combustion air fed to the furnace by oxygen. The replacement of oxygen for combustion air also provides reduction in the generation of NOx.

Kobayashi, Hisashi; Bool III, Lawrence E.; Wu, Kuang Tsai

2004-03-02T23:59:59.000Z

397

Method for making oxygen-reducing catalyst layers  

DOE Patents [OSTI]

Methods are provided for making oxygen-reducing catalyst layers, which include simultaneous or sequential stops of physical vapor depositing an oxygen-reducing catalytic material onto a substrate, the catalytic material comprising a transition metal that is substantially free of platinum; and thermally treating the catalytic material. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

O'Brien, Dennis P.; Schmoeckel, Alison K.; Vernstrom, George D.; Atanasoski, Radoslav; Wood, Thomas E.; O'Neill, David G.

2010-06-22T23:59:59.000Z

398

Oxygenation cost estimates for Cherokee, Douglas, and Norris reservoirs  

SciTech Connect (OSTI)

The capital and annual costs associated with reoxygenation of the turbine releases at Cherokee, Douglas and Norris Reservoirs using the small bubble injection technique developed for Ft. Patrick Henry Dam were computed. The weekly average dissolved oxygen (DO) deficits were computed for each reservoir for an average year (based on 16 years of records). The total annual cost of an oxygen supply and injection system for each reservoir is presented. 5 refs., 6 figs., 5 tabs.

Fain, T.G.

1980-10-01T23:59:59.000Z

399

Determination of carbon, nitrogen, and oxygen in high purity magnesium  

E-Print Network [OSTI]

DETERMINATION OF CARBON, NITROGEN, AND OXYGEN IN HIGH PURITY MAGNESIUM A Thesis by NEIL GERARD ROCHE Submitted to the Graduate College of Texas A8cM University in partial i'ulfillment of the requirement for the degree of MASTER OF SCIENCE... December 1981 Major Subject: Chemistry DETERMINATION OF CARBON, NITROGEN, AND OXYGEN IN HIGH PURITY MAGNESIUM A Thesis by NEIL GERARD ROCHE Approved as to style and content by: E. A. Schweikert (Chairman of Committee) G. J. Bastiaans (Member) L...

Roche, Neil Gerard

2012-06-07T23:59:59.000Z

400

Oxygen consumption by asphalt films and resulting viscosity changes  

E-Print Network [OSTI]

OXYGEN CONSUMPTION BY ASPHALT FILNS AND RESULTING VISCOSITY CHANGES A Thesis by FRANK LEE CARTER, JR. Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... Nay 1965 Major Subject: Chemistry OXYGEN CONSUMPTION BY ASPHALT FILMS AND RESULTING VISCOSITY CHANGES A Thesis by FRANK LEE CARTER, JR. Approved as to style and content by: (Chairm of Committee) (H o Depa ( mb ) (Membe May 1965...

Carter, Frank Lee

2012-06-07T23:59:59.000Z

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


401

LIFE Chamber Chemical Equilibrium Simulations with Additive Hydrogen, Oxygen, and Nitrogen  

SciTech Connect (OSTI)

In order to enable continuous operation of a Laser Inertial confinement Fusion Energy (LIFE) engine, the material (fill-gas and debris) in the fusion chamber must be carefully managed. The chamber chemical equilibrium compositions for post-shot mixtures are evaluated to determine what compounds will be formed at temperatures 300-5000K. It is desired to know if carbon and or lead will deposit on the walls of the chamber, and if so: at what temperature, and what elements can be added to prevent this from happening. The simulation was conducted using the chemical equilibrium solver Cantera with a Matlab front-end. Solutions were obtained by running equilibrations at constant temperature and constant specific volume over the specified range of temperatures. It was found that if nothing is done, carbon will deposit on the walls once it cools to below 2138K, and lead below 838K. Three solutions to capture the carbon were found: adding pure oxygen, hydrogen/nitrogen combo, and adding pure nitrogen. The best of these was the addition of oxygen which would readily form CO at around 4000K. To determine the temperature at which carbon would deposit on the walls, temperature solutions to evaporation rate equations needed to be found. To determine how much carbon or any species was in the chamber at a given time, chamber flushing equations needed to be developed. Major concerns are deposition of carbon and/or oxygen on the tungsten walls forming tungsten oxides or tungsten carbide which could cause embrittlement and cause failure of the first wall. Further research is needed.

DeMuth, J A; Simon, A J

2009-09-03T23:59:59.000Z

402

Invasive species Invasive species have been described as the second-greatest  

E-Print Network [OSTI]

····· Invasive species Invasive species have been described as the second-greatest extinction species a major cause of animal extinctions, or has the extinction threat of invasive species been exaggerated? By what mechanisms have invasive species driven animal species to extinction? Are certain animal

Davis, Mark A.

403

Species measurements in a hypersonic, hydrogen-air, combustion wake  

SciTech Connect (OSTI)

A continuously sampling, time-of-flight mass spectrometer has been used to measure relative species concentrations in a two-dimensional, hydrogen-air combustion wake at mainstream Mach numbers exceeding 5. The experiments, in a free piston shock tunnel, yielded distributions of hydrogen, oxygen, nitrogen, water, and nitric oxide at stagnation enthalpies ranging from 5.6 MJ/kg to 12.2 MJ/kg and at a distance of approximately 100s times the thickness of the initial hydrogen jet. The amount of hydrogen mixed in stoichiometric proportions was approximately independent of the stagnation enthalpy, despite the fact that the proportion of hydrogen in the wake was increased with stagnation enthalpy. Roughly 50% of the mixed hydrogen underwent combustion at the highest enthalpy. The proportion of hydrogen reacting to water could be approximately predicted using reaction rates based on mainstream temperatures.

Skinner, K.A.; Stalker, R.J. [Univ. of Queensland, Brisbane, Queensland (Australia)] [Univ. of Queensland, Brisbane, Queensland (Australia)

1996-09-01T23:59:59.000Z

404

Oxidative stress and oxidative damage in chemical carcinogenesis  

SciTech Connect (OSTI)

Reactive oxygen species (ROS) are induced through a variety of endogenous and exogenous sources. Overwhelming of antioxidant and DNA repair mechanisms in the cell by ROS may result in oxidative stress and oxidative damage to the cell. This resulting oxidative stress can damage critical cellular macromolecules and/or modulate gene expression pathways. Cancer induction by chemical and physical agents involves a multi-step process. This process includes multiple molecular and cellular events to transform a normal cell to a malignant neoplastic cell. Oxidative damage resulting from ROS generation can participate in all stages of the cancer process. An association of ROS generation and human cancer induction has been shown. It appears that oxidative stress may both cause as well as modify the cancer process. Recently association between polymorphisms in oxidative DNA repair genes and antioxidant genes (single nucleotide polymorphisms) and human cancer susceptibility has been shown.

Klaunig, James E., E-mail: jklauni@indiana.edu; Wang Zemin; Pu Xinzhu; Zhou Shaoyu

2011-07-15T23:59:59.000Z

405

Metformin prevents methylglyoxal-induced apoptosis of mouse Schwann cells  

SciTech Connect (OSTI)

Methylglyoxal (MG) is involved in the pathogenesis of diabetic complications via the formation of advanced glycation end products (AGEs) and reactive oxygen species (ROS). To clarify whether the antidiabetic drug metformin prevents Schwann cell damage induced by MG, we cultured mouse Schwann cells in the presence of MG and metformin. Cell apoptosis was evaluated using Hoechst 33342 nuclear staining, caspase-3 activity, and c-Jun-N-terminal kinase (JNK) phosphorylation. Intracellular ROS formation was determined by flow cytometry, and AMP-activated kinase (AMPK) phosphorylation was also examined. MG treatment resulted in blunted cell proliferation, an increase in the number of apoptotic cells, and the activation of caspase-3 and JNK along with enhanced intracellular ROS formation. All of these changes were significantly inhibited by metformin. No significant activation of AMPK by MG or metformin was observed. Taken together, metformin likely prevents MG-induced apoptotic signals in mouse Schwann cells by inhibiting the formation of AGEs and ROS.

Ota, Kimiko [Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya (Japan); Nakamura, Jiro [Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya (Japan); Li, Weiguo [Department of Cellular Biology and Anatomy, School Medical College of Georgia, Augusta, GA (United States); Kozakae, Mika [Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya (Japan); Watarai, Atsuko [Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya (Japan); Nakamura, Nobuhisa [Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya (Japan); Yasuda, Yutaka [Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya (Japan); Nakashima, Eirtaro [Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya (Japan); Naruse, Keiko [Department of Internal Medicine, School of Denistry, Aichi Gakuin University, Nagoya (Japan); Watabe, Kazuhiko [Department of Molecular Neuropathology, Tokyo Metropolitan Institute for Neuroscience, Tokyo (Japan); Kato, Koichi [Division of Endocrinology, Metabolism and Diabetology, Department of Internal Medicine, Aichi Medical University, Aichi (Japan); Oiso, Yutaka [Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya (Japan); Hamada, Yoji [Department of Metabolic Medicine, Nagoya University School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466-8550 (Japan)]. E-mail: yhama@med.nagoya-u.ac.jp

2007-05-25T23:59:59.000Z

406

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

407

Comparison of species-specific oxygen isotope paleotemperature equations: Sensitivity analysis using planktonic foraminifera from the Cariaco Basin, Venezuela  

E-Print Network [OSTI]

using planktonic foraminifera from the Cariaco Basin, Venezuela Katherine E. Wejnert a, , Robert C, Venezuela a b s t r a c ta r t i c l e i n f o Article history: Received 6 December 2011 Received in revised biweekly sediment trap samples collected in Cariaco Basin, Venezuela between 2003 and 2008. Sixteen

Meyers, Steven D.

408

The JET Hydrogen-Oxygen Recombination Sensor – A Safety Device for Hydrogen Isotope Processing Systems  

E-Print Network [OSTI]

The JET Hydrogen-Oxygen Recombination Sensor – A Safety Device for Hydrogen Isotope Processing Systems

409

A mathematical simulation of oxygen and lactic acid transport in skeletal muscle subject to periodic ischemia  

E-Print Network [OSTI]

oxidative processes . However, as Jobis and Chance point out, the 21 22 23 oxygen utilization of respiring cells w111 become oxygen dependent at some critical partial pressure of oxygen (p02) such that as the p02 falls so will the oxygen consumpt1on rate...

Artigue, Ronald Stephen

1974-01-01T23:59:59.000Z

410

E-Print Network 3.0 - atomic oxygen beams Sample Search Results  

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

beams Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen beams...

411

Dissolved Oxygen Sensing in a Flow Stream using Molybdenum Chloride Optical Indicators  

E-Print Network [OSTI]

Dissolved Oxygen Sensing in a Flow Stream using Molybdenum Chloride Optical Indicators Reza Loloee1@msu.edu Abstract--Dissolved oxygen concentration is considered the most important water quality variable in fish culture. Reliable and continuous (24/7) oxygen monitoring of dissolved oxygen (DO) in the 1 ­ 11 mg

Ghosh, Ruby N.

412

Oxygen Consumption by Germinating Seeds Advisor: Dr. Neil Budko (n.v.budko@tudelft.nl)  

E-Print Network [OSTI]

Oxygen Consumption by Germinating Seeds Advisor: Dr. Neil Budko (n.v.budko@tudelft.nl) Problem) by the Fytagoras B.V. (Leiden): "Seed germination in most seeds depends on the availability of oxygen. Living seeds commences. The availability of oxygen to the embryo in the seed depends on the oxygen concentration around

Vuik, Kees

413

Controlled oxygen doping of GaN using plasma assisted molecular-beam epitaxy  

E-Print Network [OSTI]

Controlled oxygen doping of GaN using plasma assisted molecular-beam epitaxy A. J. Ptak, L. J-assisted molecular-beam epitaxy to study the dependence of oxygen incorporation on polarity and oxygen partial pressure. Oxygen incorporates at a rate ten times faster on nitrogen-polar GaN than on the Ga polarity

Myers, Tom

414

E-Print Network 3.0 - atomic oxygen beam Sample Search Results  

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

beam Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen beam...

415

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

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

interactions Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen interactions...

416

Ocean oxygen minima expansions and their biological impacts Lothar Stramma a,, Sunke Schmidtko a,b  

E-Print Network [OSTI]

Ocean oxygen minima expansions and their biological impacts Lothar Stramma a,Ã?, Sunke Schmidtko a Keywords: Deoxygenation Oxygen minimum zones Ecosystem changes Hypoxia Tropical ocean Tropical Atlantic dissolved oxygen with global warming. In coastal regimes oxygen deficits represent acute ecosystem

Levin, Lisa

417

E-Print Network 3.0 - atomic oxygen densities Sample Search Results  

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

densities Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen densities...

418

Turbulent Oxygen Flames in Type Ia Supernovae A. J. Aspden1  

E-Print Network [OSTI]

Turbulent Oxygen Flames in Type Ia Supernovae A. J. Aspden1 , J. B. Bell1 , and S. E. Woosley2 oxygen flames. The two aims of the paper are to examine the response of the inductive oxygen flame to intense levels of turbulence, and to explore the possibility of transition to detonation in the oxygen

419

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

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

interaction Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen interaction...

420

Oxygen sublattice defect in cobalt oxide : formation, migration, charge localization and thermodynamic processes  

E-Print Network [OSTI]

643 Oxygen sublattice defect in cobalt oxide : formation, migration, charge localization of oxygen defects in CoO using classical simulations. The charge localization in the oxygen vacancy has]. The defect concentration in the oxygen sublattice is several orders of magnitude smaller, but never- theless

Paris-Sud XI, Université de

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


421

Deep-Sea Research II 47 (2000) 227}257 Variations in bioturbation across the oxygen  

E-Print Network [OSTI]

Deep-Sea Research II 47 (2000) 227}257 Variations in bioturbation across the oxygen minimum zone 1999; received in revised form 25 March 1999; accepted 30 March 1999 Abstract Oxygen minimum zones) along a transect across the oxygen minimum zone (OMZ) on the Oman margin. Bottom-water oxygen

Levin, Lisa

422

E-Print Network 3.0 - atomic oxygen density Sample Search Results  

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

density Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen density...

423

Oxygen electrode reaction in molten carbonate fuel cells  

SciTech Connect (OSTI)

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

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

1992-07-07T23:59:59.000Z

424

Oxygen abundance in the Sloan Digital Sky Survey  

E-Print Network [OSTI]

We present two samples of $\\hii$ galaxies from the Sloan Digital Sky Survey (SDSS) spectroscopic observations data release 3. The electron temperatures($T_e$) of 225 galaxies are calculated with the photoionized $\\hii$ model and $T_e$ of 3997 galaxies are calculated with an empirical method. The oxygen abundances from the $T_e$ methods of the two samples are determined reliably. The oxygen abundances from a strong line metallicity indicator, such as $R_{23}$, $P$, $N2$, and $O3N2$, are also calculated. We compared oxygen abundances of $\\hii$ galaxies obtained with the $T_e$ method, $R_{23}$ method, $P$ method, $N2$ method, and $O3N2$method. The oxygen abundances derived with the $T_e$ method are systematically lower by $\\sim$0.2 dex than those derived with the $R_{23}$ method, consistent with previous studies based on $\\hii$ region samples. No clear offset for oxygen abundance was found between $T_e$ metallicity and $P$, $N2$ and $O3N2$ metallicity. When we studied the relation between N/O and O/H, we found that in the metallicity regime of $\\zoh > 7.95$, the large scatter of the relation can be explained by the contribution of small mass stars to the production of nitrogen. In the high metallicity regime, $\\zoh > 8.2$, nitrogen is primarily a secondary element produced by stars of all masses.

F. Shi; X. Kong; F. Z. Cheng

2006-03-10T23:59:59.000Z

425

Ranking species in mutualistic networks  

E-Print Network [OSTI]

Understanding the architectural subtleties of ecological networks, believed to confer them enhanced stability and robustness, is a subject of outmost relevance. Mutualistic interactions have been profusely studied and their corresponding bipartite networks, such as plant-pollinator networks, have been reported to exhibit a characteristic "nested" structure. Assessing the importance of any given species in mutualistic networks is a key task when evaluating extinction risks and possible cascade effects. Inspired in a recently introduced algorithm --similar in spirit to Google's PageRank but with a built-in non-linearity-- here we propose a method which --by exploiting their nested architecture-- allows us to derive a sound ranking of species importance in mutualistic networks. This method clearly outperforms other existing ranking schemes and can become very useful for ecosystem management and biodiversity preservation, where decisions on what aspects of ecosystems to explicitly protect need to be made.

Domínguez-García, Virginia

2015-01-01T23:59:59.000Z

426

Carolyn Penstein Ros Language Technologies Institute  

E-Print Network [OSTI]

process does the steam undergo in the Turbines ? Student: condensation System: Steam undergoes Isentropic Expansion in a turbines that converts the heat energy of the steam into work by rotating the blades. What in a turbine, it's moisture level increases. Does this affect the extent to which the Quality is acceptable

Rose, Carolyn Penstein

427

Chemisorption and catalysis by metal clusters. II. Chemisorption of carbon monoxide and of oxygen by supported osmium clusters derived from Os/sub 3/(CO)/sub 12/ and from Os/sub 6/(CO)/sub 18/  

SciTech Connect (OSTI)

Carbon monoxide and oxygen have been chemisorbed at 293 K on the high-nuclearity carbonyl-protected clusters (the various species A) obtained by heating in vacuo to 523 K Os/sub 3/(CO)/sub 12/ or Os/sub 6/(CO)/sub 18/ impregnated on silica, alumina, or titania. The adsorption isotherms have a conventional appearance, but most are composed of a primary and a secondary region. Material adsorbed in the secondary region is removed by evacuation at room temperature whereas that adsorbed in the primary region is removed by evacuation at elevated temperatures. For species A/alumina and the species A/titania the primary region is complete and the secondary region commences when the pressure over the adsorbent is 0.2 Torr. Species A/silica gave no secondary region in oxygen adsorption. Adsorption and subsequent temperature-programmed desorption of (/sup 18/O)CO occurred without any dilution by (/sup 16/O)CO, indicating that ligand-(/sup 16/O)CO and adsorbed-(/sup 18/O)CO do not exchange even at elevated temperatures. The two species A/aluminas catalyzed oxygen isotope exchange at 293 K. From the experimental evidence it is deduced that carbon monoxide and oxygen each adsorbs molecularly in both the primary and the secondary regions. In the primary region carbon monoxide adsorption occurs at osmium sites on the cluster framework, whereas in the secondary region it occurs at ligand-carbon bonded to osmium. For oxygen, adsorption in the primary region is again at osmium sites on the cluster framework but that in the secondary region is at osmium sites of the cluster framework suitably modified as a result of the support-cluster interaction.

Hunt, D.J.; Jackson, S.D.; Moyes, R.B.; Wells, P.B.; Whyman, R.

1984-04-01T23:59:59.000Z

428

The effect of an evaporation suppressant upon the liquid film oxygen transfer coefficient  

E-Print Network [OSTI]

" ? By Winkler Method 32 Oxygen Transfer Coefficient At 21'C Using Distilled Water Without "Aquasave" ? By Winkler Method 33 Oxygen Transfer Coefficient At 36'C Using Distilled Water With "Aquasave" ? By Winkler Method 34 Oxygen Transfer Coefficient At 36'C... Using Distilled Water Without "Aquasave" ? By Winkler Method 35 Oxygen Transfer Coefficient At 21'C Using Blended Water With "Aquasave" ? By D. O. Meter 37 10. Oxygen Transfer Coefficient At 21'C Using Blended Water Without "Aquasave" ? By D. 0...

Amad, Mohamad Towfic

1967-01-01T23:59:59.000Z

429

CRADA Final Report: Ionically Conductive Membranes Oxygen Separation  

SciTech Connect (OSTI)

Scientists at the Lawrence Berkeley National Laboratory (LBNL) in a collaborative effort with Praxair Corporation developed a bench-top oxygen separation unit capable of producing ultra-high purity oxygen from air. The device is based on thin-film electrolyte technology developed at LBNL as part of a solid oxide fuel cell program. The two teams first demonstrated the concept using planar ceramic disks followed by the development of tubular ceramic structures for the bench-top unit. The highly successful CRADA met all technical milestones on time and on budget. Due to the success of this program the industrial partner and the team at LBNL submitted a grant proposal for further development of the unit to the Advanced Technology Program administered by the National Institute of Standar~s. This proposal was selected for funding, and now the two teams are developing a precommercial oxygen separation unit under a 3-year, $6 million dollar program.

Visco, Steven J.

2001-10-29T23:59:59.000Z

430

Transition metal-promoted oxygen ion conductors as oxidation catalyst  

SciTech Connect (OSTI)

A novel metal oxide composite catalyst for the complete oxidation of carbon monoxide and hydrocarbons was prepared by combining oxygen ion conducting materials with active transition metals. The oxygen ion conductors used were typical fluorite-type oxides, such as ceria, zirconia, and others. Active base metal catalysts, such as copper, were used as additives to promote the catalytic properties of oxygen ion conductors. The intimate contact of the two kinds of materials gave rise to a highly active oxidation catalyst. On Cu-Ce-O composite catalysts, 95% of carbon monoxide was oxidized by air at {approximately} 100 C. Complete methane oxidation on the same catalyst took place at {approximately} 550 C. When the stoichiometric amount of sulfur dioxide was sued to oxidize carbon monoxide, 96% of sulfur dioxide was reduced to elemental sulfur at temperatures above 460 C with 99% of sulfur dioxide conversion. This type of composite catalyst also showed excellent resistance to water poisoning.

Liu, W.; Sarofim, A. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering; Flytzani-Stephanopoulos, M. [Tufts Univ., Medford, MA (United States). Dept. of Chemical Engineering

1994-12-31T23:59:59.000Z

431

Fuel and oxygen addition for metal smelting or refining process  

DOE Patents [OSTI]

A furnace 10 for smelting iron ore and/or refining molten iron 20 is equipped with an overhead pneumatic lance 40, through which a center stream of particulate coal 53 is ejected at high velocity into a slag layer 30. An annular stream of nitrogen or argon 51 enshrouds the coal stream. Oxygen 52 is simultaneously ejected in an annular stream encircling the inert gas stream 51. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus 84 to react with carbon monoxide gas rising from slag layer 30, thereby adding still more heat to the furnace.

Schlichting, Mark R. (Chesterton, IN)

1994-01-01T23:59:59.000Z

432

Fuel and oxygen addition for metal smelting or refining process  

DOE Patents [OSTI]

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

Schlichting, M.R.

1994-11-22T23:59:59.000Z

433

Evolution of Photosynthesis and Biospheric Oxygenation Contingent Upon Nitrogen Fixation?  

E-Print Network [OSTI]

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

Grula, J W

2006-01-01T23:59:59.000Z

434

New oxygen radical source using selective sputtering of oxygen atoms for high rate deposition of TiO{sub 2} films  

SciTech Connect (OSTI)

We have developed a new oxygen radical source based on the reactive sputtering phenomena of a titanium target for high rate deposition of TiO{sub 2} films. In this oxygen radical source, oxygen radicals are mainly produced by two mechanisms: selective sputter-emission of oxygen atoms from the target surface covered with a titanium oxide layer, and production of high-density oxygen plasma in the space near the magnetron-sputtering cathode. Compared with molecular oxygen ions, the amount of atomic oxygen radicals increased significantly with an increase in discharge current so that atomic oxygen radicals were mainly produced by this radical source. It should be noted that oxygen atoms were selectively sputtered from the target surface, and titanium atoms sputter-emitted from the target cathode were negligibly small. The amount of oxygen radicals supplied from this radical source increased linearly with increasing discharge current, and oxygen radicals of 1 Multiplication-Sign 10{sup 15} atoms/s/cm{sup 2} were supplied to the substrate surface at a discharge current of 1.2 A. We conclude that our newly developed oxygen radical source can be a good tool to achieve high rate deposition and to control the structure of TiO{sub 2} films for many industrial design applications.

Yasuda, Yoji; Lei, Hao; Hoshi, Yoichi [Department of Electronics and Information Technology, Tokyo Polytechnic University, Kanagawa 243-0297 (Japan); State Key Laboratory for Corrosion and Protection, Surface Engineering of Materials Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Department of Electronics and Information Technology, Tokyo Polytechnic University, Kanagawa 243-0297 (Japan)

2012-11-15T23:59:59.000Z

435

Soot formation in laminar premixed methane/oxygen flames at atmospheric pressure  

SciTech Connect (OSTI)

Flame structure and soot formation were studied within soot-containing laminar premixed methane/oxygen flames at atmospheric pressure. The following measurements were made: soot volume fractions by laser extinction, soot temperatures by multiline emission, gas temperatures (where soot was absent) by corrected fine-wire thermocouples, soot structure by thermophoretic sampling and transmission electron microscope (TEM), major gas species concentrations by sampling and gas chromatography, and gas velocities by laser velocimetry. Present measurements of gas species concentrations were in reasonably good agreement with earlier measurements due to Ramer et al. as well as predictions based on the detailed mechanisms of Frenklach and co-workers and Leung and Lindstedt; the predictions also suggest that H atom concentrations are in local thermodynamic equilibrium throughout the soot formation region. Using this information, it was found that measured soot surface growth rates could be correlated successfully by predictions based on the hydrogen-abstraction/carbon-addition (HACA) mechanisms of both Frenklach and co-workers and Colket and Hall, extending an earlier assessment of these mechanisms for premixed ethylene/air flames to conditions having larger H/C ratios and acetylene concentrations. Measured primary soot particle nucleation rates were somewhat lower than the earlier observations for laminar premixed ethylene/air flames and were significantly lower than corresponding rates in laminar diffusion flames, for reasons that still must be explained.

Xu, F.; Lin, K.C.; Faeth, G.M. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Aerospace Engineering] [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Aerospace Engineering

1998-10-01T23:59:59.000Z

436

Strength in Numbers: Setting Quantitative Criteria for Listing Species under the Endangered Species Act  

E-Print Network [OSTI]

the trend toward species extinction, whatever the cost." 9 'to any species at a "measurable risk" of extinction. H.R.dan- ger of extinction while those species that are listed

Robbins, Kalyani

2009-01-01T23:59:59.000Z

437

Catalytic ignition of fuel/oxygen/nitrogen mixtures over platinum  

SciTech Connect (OSTI)

Ignition of fuel/oxygen/nitrogen mixtures over platinum wire is experimentally studied by using microcalorimetry and by restricting the flow to the low Reynolds number range so that axisymmetry prevails. The fuels studied are propane, butane, propylene, ethylene, carbon monoxide, and hydrogen. Parameters investigated include flow velocity, fuel type and concentration, and oxygen concentration. The catalytic ignition temperatures of the various fuels are accurately determined over extensive ranges of fuel/oxygen/nitrogen concentrations. Results show two distinctly opposite ignition trends depending on the nature of the fuel. That is, the ignition temperature of lean propane/air and butane/air mixtures decreases as their fuel concentration is increased, while the reverse trend is observed for lean mixtures of propylene, ethylene, carbon monoxide, and hydrogen with air. Furthermore, the ignition of propane depends primarily on fuel concentration, while the ignition of carbon monoxide depends on fuel and oxygen concentrations to a comparable extent. These results are explained on the basis of hierarchical surface adsorption strengths of the different reactants in effecting catalytic ignition. Additional phenomena of interest are observed and discussed.

Cho, P.; Law, C.K.

1986-11-01T23:59:59.000Z

438

ChemicalChemical StratigraphyStratigraphy Oxygen, Carbon, Strontium,  

E-Print Network [OSTI]

2/25/2009 1 ChemicalChemical StratigraphyStratigraphy Oxygen, Carbon, Strontium, Sulphur Isotopes Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department evolves over time, with the geological time line running from right to left in this graph. The increased

Miami, University of

439

Characteristics of Knock in Hydrogen-Oxygen-Argon SI Engine  

SciTech Connect (OSTI)

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

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

2010-02-23T23:59:59.000Z

440

High-temperature potentiometric oxygen sensor with internal reference  

DOE Patents [OSTI]

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

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

2011-11-15T23:59:59.000Z

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


441

A DIGITAL CONTROL SYSTEM FOR OPTIMAL OXYGEN TRANSFER  

E-Print Network [OSTI]

A DIGITAL CONTROL SYSTEM FOR OPTIMAL OXYGEN TRANSFER EFFICIENCY Arnold Schwarzenegger Governor operations improvement (i.e., operators training, cleaning frequency and methods, process upgrade, etc audits specialist ­ Henryk Melcer Brown & Caldwell, process designer ­ Rod Reardon Camp, Dresser, and Mc

442

Oxygen and nitrogen diffusion in ?-hafnium from first principles  

SciTech Connect (OSTI)

We use a combination of density functional theory and multistate diffusion formalism to analyze the diffusion of oxygen and nitrogen in technologically important hafnium metal. Comparing the local density approximation and the Perdew-Burke-Ernzerhof version of the generalized gradient approximation, we find that a better description of the hafnium lattice in the latter results in the correct sequence of stable and transition states for oxygen interstitials leading to essentially quantitative agreement with experiment. For oxygen diffusion, we find an isotropic temperature-dependent diffusion coefficient of D=0.082e{sup ?2.04/k{sub B}T}cm{sup 2}s{sup ?1} utilizing interstitial sites with hexahedral and octahedral coordination. For the diffusivity of nitrogen, we find that an additional stable interstitial site, the crowdion site, exists and that the diffusion coefficient is D=0.15e{sup ?2.68/k{sub B}T}cm{sup 2}s{sup ?1}. Our results also reproduce the experimental observation that nitrogen diffusivity is lower than that of oxygen in hafnium.

O'Hara, Andrew; Demkov, Alexander A., E-mail: demkov@physics.utexas.edu [Department of Physics, The University of Texas at Austin, Austin, Texas 78712 (United States)

2014-05-26T23:59:59.000Z

443

An oxygen reduction electrocatalyst based on carbon nanotubegraphene complexes  

E-Print Network [OSTI]

such as platinum or its alloys are routinely used in fuel cells because of their high activity. Carbon alloys) for the oxygen reduction reaction (ORR) in acidic media for proton-exchange membrane fuel cells1, and designing catalysts with both optimal activity and stability for ORR in acidic solutions all remain

Pennycook, Steve

444

ORIGINAL PAPER Electrochemical reduction of oxygen with iron phthalocyanine  

E-Print Network [OSTI]

bio- fuel cells) has been increasing [1­6]. The common point for all the biological systems is need Recent interest in electricity production using microbial fuel cells makes it important to better applications in neutral media. Keywords Microbial fuel cells Á Oxygen reduction Á Iron phthalocyanine Á Redox

445

Fault Tolerant Oxygen Control of a Diesel Engine Air System  

E-Print Network [OSTI]

Fault Tolerant Oxygen Control of a Diesel Engine Air System Rainer Nitsche Matthias Bitzer control problem of a Diesel engine air system having a jammed Exhaust Gas Recirculation (EGR) valve of the air system. Keywords: Fault tolerant control, Diesel engine, Air system, Model-based trajectory

Paris-Sud XI, Université de

446

ORIGINAL PAPER Sex differences in circulatory oxygen transport parameters  

E-Print Network [OSTI]

aerobic energy demands, and suggests that the higher [Hb] of female fish may com- pensate for the smaller has commenced, and so their stored energy reserves must satisfy the energetic demands of the migra rMV. These findings reject the hypothesis that all aspects of the circulatory oxygen trans- port

Hinch, Scott G.

447

Process for conversion of lignin to reformulated, partially oxygenated gasoline  

DOE Patents [OSTI]

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

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

2001-01-09T23:59:59.000Z

448

Utilization of Renewable Oxygenates as Gasoline Blending Components  

SciTech Connect (OSTI)

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

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

2011-08-01T23:59:59.000Z

449

Methane Activation with Rhenium Catalysts. 1. Bidentate Oxygenated Ligands  

E-Print Network [OSTI]

Methane Activation with Rhenium Catalysts. 1. Bidentate Oxygenated Ligands Jason M. Gonzales, Jonas, California 90089 ReceiVed July 31, 2006 Trends in methane activation have been explored for rhenium complexes proceeds with methane activation through a barrier of less than 35 kcal mol-1 . Study

Goddard III, William A.

450

RESPONSE TO OXYGEN DEFICIENCY SENSING EQUIPMENT IN LABORATORIES  

E-Print Network [OSTI]

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

Jia, Songtao

451

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

SciTech Connect (OSTI)

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

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

2001-11-21T23:59:59.000Z

452

Subtask 3.12 - Oxygen-Fired CFBC  

SciTech Connect (OSTI)

Traditionally, air is used as the source of oxygen for firing a combustion system. A fully oxygen-fired circulating fluidized-bed combustion (CFBC) system would result in the production of a flue gas stream consisting of mostly carbon dioxide and water. The concentrated carbon dioxide stream would be available for sequestering or other purposes. Temperatures in an oxygen-blown CFBC system would be controlled by a combination of flue gas recycle, solids recirculation, and by appropriately sizing and locating the amount of heat-transfer surface required. Flue gas recycle provides the additional gas required for adequate fluidization and circulation of solids replacing the nitrogen that would be present in an air-blown system. The amount of flue gas recycle will determine how much of the remaining heat from the coal combustion will have to be removed. If the amount of flue gas recycle required by increasing solids recirculation and oxygen staging is limited, introducing the pure oxygen at multiple locations in the combustor to result in a more even temperature profile should result in a more compact system, thus reducing initial capital costs for construction. The overall efficiency of the process should be greater than that of an air-blown system since less fuel is required for the creation of the same amount of energy. The Energy & Environmental Research Center (EERC) is in a unique position to advance this technology. It has a world-class CFBC pilot plant, has experience with firing a wide range of fuels in our air-fired CFBC pilot plant, has prior experience with oxygen-firing a slagging furnace system in a pulverized coal-fired mode with a bituminous coal, and has all of the components required for oxygen-firing right next to the CFBC pilot plant already in place. An engineering study was performed to identify methods, an overall appropriate configuration, and an operating strategy for a fully oxygen-fired CFBC pilot plant by: (1) developing a plan to optimize the amount of flue gas recycle required to control bed temperature; (2) determining how to best utilize the heat-transfer surfaces in a CFBC pilot plant, such as increased external bed surface, to more beneficially use increased solids recycle; (3) identifying appropriate methods for staged addition of the oxygen/recycled flue gas streams to maintain a good temperature profile in the combustor; and (4) determining the level of effort required to convert the EERC CFBC pilot plant to one that is oxygen-blown. The EERC additionally used its experience to consider what would be required for firing a wide range of fuels from biomass to low-rank coals to high-rank coals and petroleum cokes. These proposed modifications will be performed based upon obtaining the required funding.

Douglas Hajicek; Mark Musich; Ann Henderson

2007-02-28T23:59:59.000Z

453

eschweizerbartxxx Interactions between alien species and restoration  

E-Print Network [OSTI]

eschweizerbartxxx Interactions between alien species and restoration of large-river ecosystems-river ecosystems that are the subject of restoration efforts also typically are heavily invaded by alien species interactions that link alien species and river restoration. Most obviously, restoration may be aimed

Pace, Michael L.

454

Million Species EXTINCTION RISK FROM CLIMATE CHANGE  

E-Print Network [OSTI]

Saving Million Species EXTINCTION RISK FROM CLIMATE CHANGE Edited by Lee Hannah ISLANDPRESS-in-Publication Data Saving a million species : extinction risk from climate change / edited by LeeHannah. p. cm. ISBN, extinction, extinction risk, biodiversity,freshwater, marine, biology, coral bleaching, species area

Poff, N. LeRoy

455

Electrocatalysis of anodic and cathodic oxygen-transfer reactions  

SciTech Connect (OSTI)

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

Wels, B.R.

1990-09-21T23:59:59.000Z

456

Oxygen and Nitrogen in Isolated Dwarf Irregular Galaxies  

E-Print Network [OSTI]

We present long slit optical spectroscopy of 67 HII regions in 21 dwarf irregular galaxies to investigate the enrichment of oxygen, nitrogen, neon, sulfur, and argon in low mass galaxies. Oxygen abundances are obtained via direct detection of the temperature sensitive emission lines for 25 HII regions; for the remainder of the sample, oxygen abundances are estimated from strong line calibrations. The direct abundance determinations are compared to the strong-line abundance calibrations of both McGaugh (1991) and Pilyugin (2000). Global oxygen and nitrogen abundances for this sample of dwarf irregular galaxies are examined in the context of open and closed box chemical evolution models. While several galaxies are consistent with closed box chemical evolution, the majority of this sample have an effective yield ~1/4 of the expected yield for a constant star formation rate and Salpeter IMF, indicating that either outflow of enriched gas or inflow of pristine gas has occurred. The effective yield strongly correlates with M_H/L_B in the sense that gas-rich galaxies are more likely to be closed systems. However, the effective yield does not appear to correlate with other global parameters such as dynamical mass, absolute magnitude, star formation rate or surface brightness. A correlation is found between the observed nitrogen-to-oxygen ratio and the color of the underlying stellar population; redder dwarf irregular galaxies have higher N/O ratios than blue dwarf irregular galaxies. The relative abundance ratios are interpreted in the context of delayed release of nitrogen and varied star formation histories.

L. van Zee; M. P. Haynes

2005-09-22T23:59:59.000Z

457

Normal muscle oxygen consumption and fatigability in sickle cell patients despite reduced microvascular oxygenation and hemorheological abnormalities  

E-Print Network [OSTI]

1 Normal muscle oxygen consumption and fatigability in sickle cell patients despite reduced hypothesized that muscle metabolism and fatigability could be impaired in sickle cell patients, no study has profile at rest between 16 healthy subjects (AA), 20 sickle cell-hemoglobin C disease (SC) patients and 16

Paris-Sud XI, Université de

458

IMPACT OF OXYGENATED FUEL ON DIESEL ENGINE PERFORMANCE AND EMISSIONS  

SciTech Connect (OSTI)

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

Boehman, Andre L.

2000-08-20T23:59:59.000Z

459

OXYGEN CONSUMPTION OF NORMAL AND GREEN OYSTERS 1 PAUL S. GALTSOFF, Ph. D., In Charge, Oyster Fishery Investigations  

E-Print Network [OSTI]

OXYGEN CONSUMPTION OF NORMAL AND GREEN OYSTERS 1 $ By PAUL S. GALTSOFF, Ph. D., In Charge, Oyster _ ~ethod _ Oxygen consumption of normal oyster _ Effect of oxygen tension on oxygen con- sumption _ Page 489 Increased rate of metabolism _ 490 Experiments with green oysters _ 493 Oxygen consumption

460

In Situ Bioreduction of Uranium (VI) to Submicromolar Levels and Reoxidation by Dissolved Oxygen  

SciTech Connect (OSTI)

Groundwater within Area 3 of the U.S. Department of Energy (DOE) Environmental Remediation Sciences Program (ERSP) Field Research Center at Oak Ridge, TN (ORFRC) contains up to 135 {micro}M uranium as U(VI). Through a series of experiments at a pilot scale test facility, we explored the lower limits of groundwater U(VI) that can be achieved by in-situ biostimulation and the effects of dissolved oxygen on immobilized uranium. Weekly 2 day additions of ethanol over a 2-year period stimulated growth of denitrifying, Fe(III)-reducing, and sulfate-reducing bacteria, and immobilization of uranium as U(IV), with dissolved uranium concentrations decreasing to low levels. Following sulfite addition to remove dissolved oxygen, aqueous U(VI) concentrations fell below the U.S. Environmental Protection Agency maximum contaminant limit (MCL) for drinking water (<30 {micro}g L{sup -1} or 0.126 {micro}M). Under anaerobic conditions, these low concentrations were stable, even in the absence of added ethanol. However, when sulfite additions stopped, and dissolved oxygen (4.0-5.5 mg L{sup -1}) entered the injection well, spatially variable changes in aqueous U(VI) occurred over a 60 day period, with concentrations increasing rapidly from <0.13 to 2.0 {micro}M at a multilevel sampling (MLS) well located close to the injection well, but changing little at an MLS well located further away. Resumption of ethanol addition restored reduction of Fe(III), sulfate, and U(VI) within 36 h. After 2 years of ethanol addition, X-ray absorption near-edge structure spectroscopy (XANES) analyses indicated that U(IV) comprised 60-80% of the total uranium in sediment samples. At the completion of the project (day 1260), U concentrations in MLS wells were less than 0.1 {micro}M. The microbial community at MLS wells with low U(VI) contained bacteria that are known to reduce uranium, including Desulfovibrio spp. and Geobacter spp., in both sediment and groundwater. The dominant Fe(III)-reducing species were Geothrix spp.

Wu, Weimin [ORNL; Carley, Jack M [ORNL; Luo, Jian [Stanford University; Ginder-Vogel, Matthew A. [Stanford University; Cardenas, Erick [Michigan State University, East Lansing; Leigh, Mary Beth [Michigan State University, East Lansing; Hwang, Chaichi [Miami University, Oxford, OH; Kelly, Shelly D [Argonne National Laboratory (ANL); Ruan, Chuanmin [ORNL; Wu, Liyou [University of Oklahoma, Norman; Van Nostrand, Joy [University of Oklahoma, Norman; Gentry, Terry J [ORNL; Lowe, Kenneth Alan [ORNL; Mehlhorn, Tonia L [ORNL; Carroll, Sue L [ORNL; Luo, Wensui [ORNL; Fields, Matthew Wayne [Miami University, Oxford, OH; Gu, Baohua [ORNL; Watson, David B [ORNL; Kemner, Kenneth M [Argonne National Laboratory (ANL); Marsh, Terence [Michigan State University, East Lansing; Tiedje, James [Michigan State University, East Lansing; Zhou, Jizhong [University of Oklahoma, Norman; Fendorf, Scott [Stanford University; Kitanidis, Peter K. [Stanford University; Jardine, Philip M [ORNL; Criddle, Craig [ORNL

2007-01-01T23:59:59.000Z

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


461

Plant Species Biology (2003) 18, 123127 2003 The Society for the Study of Species Biology  

E-Print Network [OSTI]

and Genetics, Graduate School of Environmental Earth Science, Hokkaido University, Sapporo 060-0810, JapanPlant Species Biology (2003) 18, 123­127 © 2003 The Society for the Study of Species Biology Blackwell Science, LtdOxford, UKPSBPlant Species Biology1442-1984The Society for the Study of Species

Tomimatsu,, Hiroshi

2003-01-01T23:59:59.000Z

462

Effects of Hydration and Oxygen Vacancy on CO2 Adsorption and...  

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

Hydration and Oxygen Vacancy on CO2 Adsorption and Activation on ?-Ga2O3(100). Effects of Hydration and Oxygen Vacancy on CO2 Adsorption and Activation on ?-Ga2O3(100)....

463

Active Oxygen Vacancy Site for Methanol Synthesis from CO2 Hydrogenati...  

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

Oxygen Vacancy Site for Methanol Synthesis from CO2 Hydrogenation on In2O3(110): A DFT Study. Active Oxygen Vacancy Site for Methanol Synthesis from CO2 Hydrogenation on...

464

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

465

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

E-Print Network [OSTI]

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

Crumlin, Ethan J

2012-01-01T23:59:59.000Z

466

Direct Electrolysis of Molten Lunar Regolith for the Production of Oxygen and Metals on the Moon  

E-Print Network [OSTI]

The feasibility of producing oxygen by direct electrolysis of the molten lunar regolith at 1600 C was investigated and the generation of usable oxygen gas at the anode and concomitant production of iron and silicon at the ...

Sirk, Aislinn H.

467

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

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

with ground-state atomic oxygen O(3P) has been investigated... It was suggested that the UV dissociates ozone into atomic oxygen, which is responsible for the degradation... be...

468

Surface structure of ?-Cr2O3(0001) after activated oxygen...  

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

Surface structure of ?-Cr2O3(0001) after activated oxygen exposure. Surface structure of ?-Cr2O3(0001) after activated oxygen exposure. Abstract: The surface structure...

469

E-Print Network 3.0 - arabian sea oxygen Sample Search Results  

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

oxygen Search Powered by Explorit Topic List Advanced Search Sample search results for: arabian sea oxygen Page: << < 1 2 3 4 5 > >> 1 The origin of summer monsoon rainfall at New...

470

Growth of Epitaxial Thin Pd(111) Films on Pt(111) and Oxygen...  

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

Growth of Epitaxial Thin Pd(111) Films on Pt(111) and Oxygen-Terminated FeO(111) Surfaces . Growth of Epitaxial Thin Pd(111) Films on Pt(111) and Oxygen-Terminated FeO(111)...

471

A Mechanism of Photo-Induced Desorption of Oxygen Atoms From...  

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

of Photo-Induced Desorption of Oxygen Atoms From MgO Nano-Crystals. A Mechanism of Photo-Induced Desorption of Oxygen Atoms From MgO Nano-Crystals. Abstract: In a series of recent...

472

Development, testing, and application of quantitative oxygenation imaging from magnetic susceptibility by MRI  

E-Print Network [OSTI]

The healthy brain consumes 20% of total oxygen used by the body under normal conditions. Continuous oxygen delivery to neural tissue is needed to maintain normal brain function and viability. Reliable measurements of brain ...

Fan, Audrey Peiwen

2014-01-01T23:59:59.000Z

473

Ultrafast vectorial and scalar dynamics of ionic clusters: Azobenzene solvated by oxygen  

SciTech Connect (OSTI)

The ultrafast dynamics of clusters of trans-azobenzene anion (A{sup -}) solvated by oxygen molecules was investigated using femtosecond time-resolved photoelectron spectroscopy. The time scale for stripping off all oxygen molecules from A{sup -} was determined by monitoring in real time the transient of the A{sup -} rise, following an 800 nm excitation of A{sup -} (O{sub 2}){sub n}, where n=1-4. A careful analysis of the time-dependent photoelectron spectra strongly suggests that for n>1 a quasi-O{sub 4} core is formed and that the dissociation occurs by a bond cleavage between A{sup -} and conglomerated (O{sub 2}){sub n} rather than a stepwise evaporation of O{sub 2}. With time and energy resolutions, we were able to capture the photoelectron signatures of transient species which instantaneously rise (<100 fs) then decay. The transient species are assigned as charge-transfer complexes: A{center_dot}O{sub 2}{sup -} for A{sup -}O{sub 2} and A{center_dot}O{sub 4}{sup -}{center_dot}(O{sub 2}){sub n-2} for A{sup -}(O{sub 2}){sub n}, where n=2-4. Subsequent to an ultrafast electron recombination, A{sup -} rises with two distinct time scales: a subpicosecond component reflecting a direct bond rupture of the A{sup -}-(O{sub 2}){sub n} nuclear coordinate and a slower component (1.6-36 ps, increasing with n) attributed to an indirect channel exhibiting a quasistatistical behavior. The photodetachment transients exhibit a change in the transition dipole direction as a function of time delay. Rotational dephasing occurs on a time scale of 2-3 ps, with a change in the sign of the transient anisotropy between A{sup -}O{sub 2} and the larger clusters. This behavior is a key indicator of an evolving cluster structure and is successfully modeled by calculations based on the structures and inertial motion of the parent clusters.

Paik, D. Hern; Baskin, J. Spencer; Kim, Nam Joon; Zewail, Ahmed H. [Laboratory for Molecular Sciences, California Institute of Technology, Pasadena, California 91125 and Physical Biology Center for Ultrafast Science and Technology, California Institute of Technology, Pasadena, California 91125 (United States)

2006-10-07T23:59:59.000Z

474

Toxicological and performance aspects of oxygenated motor vehicle fuels  

SciTech Connect (OSTI)

At the request of the Environmental Protection Agency, the committee reviewed a draft of a federal report that assesses the effects of oxygenated fuels on public health, air quality, fuel economy, engine performance, and water quality. The committee determined that much of the federal report adequately represents what is known about the effects of methyl tertiary-butyl ether (MTBE) -- the most commonly used additive in the federal oxygenated-fuels program -- on health, the environment, and motor vehicles. MTBE, a chemical added to gasoline to reduce carbon monoxide pollution, appears not to pose a substantial human health risk, but more-definitive data are needed to assess short-term health effects and to determine whether this additive is effective in reducing carbon monoxide pollution in cold environments.

NONE

1996-12-31T23:59:59.000Z

475

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

476

Evaluation of Advanced PSA and Oxygen Combustion System for Industrial Furnace Applications  

E-Print Network [OSTI]

M. A. Delano Union Carbide Corp. Tarrytown, NY ABSTRACT EVALUATION OF ADVANCED PSA AND OXYGEN COMBUSTION SYSTEM FOR INDUSTRIAL FURNACE APPLICATIONS D. Lagree Union Carbide Corp. Tonawanda, NY The performance of a pilot scale advanced PSA... oxygen generation system and a low NO x oxygen burner was evaluated for industrial furnace applications. The PSA system employs a two-bed vacuum cycle design with a capacity of 1.3 TPD at 90% O 2 purity. The oxygen generated from the PSA system...

Delano, M. A.; Lagree, D.; Kwan, Y.

477

Hydrogen Production from Methane Using Oxygen-permeable Ceramic Membranes  

E-Print Network [OSTI]

is the existence of hot spots in the catalyst bed due to the reaction exothermicity [1]. This hydrogen production process could be cost-effective if oxygen is provided by sources other than air separation plant. CO2 reforming (or dry reforming) of methane... information about equilibrium product compositions and equilibrium constants at different temperatures were provided by one of the former students in Dr Susan Williams’ research group [8]. Syngas can also be produced by coal gasification. The syngas...

Faraji, Sedigheh

2010-06-08T23:59:59.000Z