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Sample records for oxygen ions preserves

  1. Temperature and oxygenation during organ preservation: friends or foes?

    Science.gov (United States)

    Gilbo, Nicholas; Monbaliu, Diethard

    2017-06-01

    The liberalization of donor selection criteria in organ transplantation, with the increased use of suboptimal grafts, has stimulated interest in ischemia-reperfusion injury prevention and graft reconditioning. Organ preservation technologies are changing considerably, mostly through the reintroduction of dynamic machine preservation. Here, we review the current evidence on the role of temperature and oxygenation during dynamic machine preservation. A large but complex body of evidence exists and comparative studies are few. Oxygenation seems to support an advantageous effect in hypothermic machine preservation and is mandatory in normothermic machine preservation, although in the latter, supraphysiological oxygen tensions should be avoided. High-risk grafts, such as suboptimal organs, may optimally benefit from oxygenated perfusion conditions that support metabolism and activate mechanisms of repair such as subnormothermic machine preservation, controlled oxygenated rewarming, and normothermic machine preservation. For lower risk grafts, oxygenation during hypothermic machine preservation may sufficiently reduce injuries and recharge the cellular energy to secure functional recovery after transplantation. The relationship between temperature and oxygenation in organ preservation is more complex than physiological laws would suggest. Rather than one default perfusion temperature/oxygenation standard, perfusion protocols should be tailored for specific needs of grafts of different quality.

  2. High oxygen as an additional factor in food preservation

    NARCIS (Netherlands)

    Amanatidou, A.

    2001-01-01

    In this thesis, the efficacy of high oxygen as an additional hurdle for food preservation is studied. At high oxygen conditions and at low temperature, significant impairment of growth and viability of bacterial cells is found to occur as the result of free

  3. Mixed oxygen ion/electron-conducting ceramics for oxygen separation

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, J.W.; Armstrong, T.R.; Armstrong, B.L. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-08-01

    Mixed oxygen ion and electron-conducting ceramics are unique materials that can passively separate high purity oxygen from air. Oxygen ions move through a fully dense ceramic in response to an oxygen concentration gradient, charge-compensated by an electron flux in the opposite direction. Compositions in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, perovskites where M=Sr, Ca, and Ba, and N=Mn, Ni, Cu, Ti, and Al, have been prepared and their electrical, oxygen permeation, oxygen vacancy equilibria, and catalytic properties evaluated. Tubular forms, disks, and asymmetric membrane structures, a thin dense layer on a porous support of the same composition, have been fabricated for testing purposes. In an oxygen partial gradient, the passive oxygen flux through fully dense structures was highly dependent on composition. An increase in oxygen permeation with increased temperature is attributed to both enhanced oxygen vacancy mobility and higher vacancy populations. Highly acceptor-doped compositions resulted in oxygen ion mobilities more than an order of magnitude higher than yttria-stabilized zirconia. The mixed conducting ceramics have been utilized in a membrane reactor configuration to upgrade methane to ethane and ethylene. Conditions were established to balance selectivity and throughput in a catalytic membrane reactor constructed from mixed conducting ceramics.

  4. Persufflation (gaseous oxygen perfusion) as a method of heart preservation.

    Science.gov (United States)

    Suszynski, Thomas M; Rizzari, Michael D; Scott, William E; Eckman, Peter M; Fonger, James D; John, Ranjit; Chronos, Nicolas; Tempelman, Linda A; Sutherland, David E R; Papas, Klearchos K

    2013-04-22

    Persufflation (PSF; gaseous oxygen perfusion) is an organ preservation technique with a potential for use in donor heart preservation. Improved heart preservation with PSF may improve outcomes by maintaining cardiac tissue quality in the setting of longer cold ischemia times and possibly increasing the number of donor hearts available for allotransplant. Published data suggests that PSF is able to extend the cold storage times for porcine hearts up to 14 hours without compromising viability and function, and has been shown to resuscitate porcine hearts following donation after cardiac death. This review summarizes key published work on heart PSF, including prospective implications and future directions for PSF in heart transplantation. We emphasize the potential impact of extending preservation times and expanding donor selection criteria in heart allotransplant. Additionally, the key issues that need to be addressed before PSF were to become a widely utilized preservation strategy prior to clinical heart transplantation are summarized and discussed.

  5. Reactions of atomic oxygen with the chlorate ion and the perchlorate ion

    Science.gov (United States)

    Anan'ev, Vladimir; Miklin, Mikhail; Kriger, Ludmila

    2014-06-01

    The reactions of the chlorate ion with atomic oxygen formed under photolysis of the nitrate ion introduced to potassium chlorate crystal by co-crystallization were studied by optical and infrared absorption spectroscopy. The perchlorate ion was found to form in solids as product of addition reaction of singlet atomic oxygen, formed under dissociation of the peroxynitrite ion - the product of isomerization of the excited nitrate ion. Triplet atomic oxygen does not react with the chlorate ion. The atomic oxygen formed under photolysis of the nitrate ion introduced to potassium perchlorate crystal by co-crystallization does not react with the perchlorate ion.

  6. Emission of positive oxygen ions from ion bombardment of adsorbate-covered metal surfaces

    International Nuclear Information System (INIS)

    Kaurin, M.G.

    1989-01-01

    During ion bombardment of metal surfaces, collision cascades can result in the emission of sputtered secondary ions. Recent experiments, however, have suggested that the emission of positive ions of electronegative adsorbates can result from electronic processes rather than from processes involving elastic collisions. This dissertation presents the results of experiments studying the emission of positive oxygen ions from oxygen- and carbon-monoxide-covered transition metal surfaces during bombardment by 25-250 keV ions of neon, argon, and krypton. The systems studied may be grouped into four categories. For a nickel substrate with adsorbed oxygen, the emission of positive oxygen ions proceeds through collision cascades. For titanium and niobium with adsorbed oxygen, the emission of positive oxygen ions is proportional to the primary ion velocity, consistent with emission from electronic processes; for a given primary ion velocity, the oxygen ion yield is independent of primary ion species. For substrates of molybdenum and tungsten, the oxygen yield is proportional to primary ion velocity, but the yield also depends on the primary ion species for a given primary ion velocity in a manner that is consistent with emission resulting from electronic processes. For these two groups, except for titanium, the yields during neon ion bombardment do not extrapolate (assuming linearity with primary ion velocity) to a nonzero value at zero beam velocity. The magnitude of the oxygen ion yields from these targets is not consistent with that expected if the emission were induced by secondary electrons emitted during the ion bombardment

  7. Ion measurements in premixed methane-oxygen flames

    KAUST Repository

    Alquaity, Awad; Hourani, Nadim; Chahine, May; Selim, Hatem; Sarathy, Mani; Farooq, Aamir

    2014-01-01

    Mass Spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane-oxygen-argon burner-stabilized flames. Lean, stoichiometric and rich flames at atmospheric pressure are used to study the dependence of ion chemistry

  8. Development of an oxygen carrier nanoemulsion for organ preservation

    CSIR Research Space (South Africa)

    Barnard, A

    2010-08-31

    Full Text Available high levels of chemical stability and biological inertness which makes them suitable for biological use1,2. Perfluorooctyl bromide (PFOB) is the particular PFC used in the CSIR oxygen carrier emulsion1,2....

  9. Oxygen Generating Biomaterials Preserve Skeletal Muscle Homeostasis under Hypoxic and Ischemic Conditions

    Science.gov (United States)

    2013-08-26

    injection” protocol for myogenic cell transplantation throughout large volumes of muscles in a Duchenne muscular dystrophy patient: eighteen months follow-up...Oxygen Generating Biomaterials Preserve Skeletal Muscle Homeostasis under Hypoxic and Ischemic Conditions Catherine L. Ward, Benjamin T. Corona...investigation was to determine if sodium percarbonate (SPO), an oxygen generating biomaterial, is capable of maintaining resting skeletal muscle

  10. Oxygen ion source and RFQ for Linac 1

    CERN Multimedia

    Photographic Service

    1986-01-01

    As injector to the PS Booster, Linac 1 was replaced by Linac 2 in 1980. It continued to be used for the acceleration of oxygen and sulfur ions. In 1984, its Cockcroft-Walton preinjector was replaced by an RFQ. In the foreground at the right is the oxygen ion source. A 90 deg bending magnet selects O6+ ions which are preaccelerated in an RFQ and enter Linac 1, at the far left. In the background is the proton and negative hydrogen ion source, followed by the 520 keV RFQ-1 and a bending magnet towards the entrance of Linac 1.

  11. Sorption of Molecular Oxygen by Metal-Ion Exchanger Nanocomposites

    Science.gov (United States)

    Krysanov, V. A.; Plotnikova, N. V.; Kravchenko, T. A.

    2018-03-01

    Kinetic features are studied of the chemisorption and reduction of molecular oxygen from water by metal-ion exchanger nanocomposites that differ in the nature of the dispersed metal and state of oxidation. In the Pd equilibrium sorption coefficient for oxygen dissolved in water ranges from 20 to 50, depending on the nature and oxidation state of the metal component.

  12. Thermal ion-molecule reactions in oxygen-containing molecules

    International Nuclear Information System (INIS)

    Kumakura, Minoru

    1981-02-01

    The energetics of ions and the thermal ion-molecule reactions in oxygen-containing molecules have been studied with a modified time-of-flight mass spectrometer. It was found that the translational energy of ion can be easily obtained from analysis of the decay curve using the time-of-flight mass spectrometer. The condensation-elimination reactions proceeded via cross- and homo-elimination mechanism in which the nature of intermediate-complex could be correlated with the nature of reactant ion. It was elucidated that behavior of poly-atomic oxygen-containing ions on the condensation-elimination reactions is considerably influenced by their oxonium ion structures having functional groups. In addition, the rate constants of the condensation-elimination reactions have affected with the energy state of reactant ion and the dipole moment and/or the polarizability of neutral molecule. It was clarified that the rate constants of the ion-molecule clustering reactions in poly-atomic oxygen-containing molecules such as cyclic ether of six member rings are very large and the cluster ions are stable owing to the large number of vibrational degree of freedom in the cluster ions. (author)

  13. Surface oxygen vacancy and oxygen permeation flux limits of perovskite ion transport membranes

    KAUST Repository

    Hunt, Anton; Dimitrakopoulos, Georgios; Ghoniem, Ahmed F.

    2015-01-01

    © 2015 Elsevier B.V. The mechanisms and quantitative models for how oxygen is separated from air using ion transport membranes (ITMs) are not well understood, largely due to the experimental complexity for determining surface exchange reactions

  14. Ion measurements in premixed methane-oxygen flames

    KAUST Repository

    Alquaity, Awad

    2014-07-25

    Ions are formed as a result of chemi-ionization processes in combustion systems. Recently, there has been an increasing interest in understanding flame ion chemistry due to the possible application of external electric fields to reduce emissions and improve combustion efficiency by active control of combustion process. In order to predict the effect of external electric fields on combustion plasma, it is critical to gain a good understanding of the flame ion chemistry. In this work, a Molecular Beam Mass Spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane-oxygen-argon burner-stabilized flames. Lean, stoichiometric and rich flames at atmospheric pressure are used to study the dependence of ion chemistry on equivalence ratio of premixed flames. The relative ion concentration profiles are compared qualitatively with previous methane-oxygen studies and show good agreement. The relative ion concentration data obtained in the present study can be used to validate and improve ion chemistry models for methane-oxygen flames.

  15. Interphase Evolution of a Lithium-Ion/Oxygen Battery.

    Science.gov (United States)

    Elia, Giuseppe Antonio; Bresser, Dominic; Reiter, Jakub; Oberhumer, Philipp; Sun, Yang-Kook; Scrosati, Bruno; Passerini, Stefano; Hassoun, Jusef

    2015-10-14

    A novel lithium-ion/oxygen battery employing Pyr14TFSI-LiTFSI as the electrolyte and nanostructured LixSn-C as the anode is reported. The remarkable energy content of the oxygen cathode, the replacement of the lithium metal anode by a nanostructured stable lithium-alloying composite, and the concomitant use of nonflammable ionic liquid-based electrolyte result in a new and intrinsically safer energy storage system. The lithium-ion/oxygen battery delivers a stable capacity of 500 mAh g(-1) at a working voltage of 2.4 V with a low charge-discharge polarization. However, further characterization of this new system by electrochemical impedance spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy reveals the progressive decrease of the battery working voltage, because of the crossover of oxygen through the electrolyte and its direct reaction with the LixSn-C anode.

  16. Hydrogen ion (Ph), ammonia, dissolved oxygen and nitrite ...

    African Journals Online (AJOL)

    Hydrogen ion (pH), dissolved oxygen, ammonia and nitrite concentrations were studied monthly in two systems (re-circulatory and semi-intensive of 3 m2 sizes) each for six months. The systems were each stocked with 200 g of Clarias gariepinus fingerlings. Results showed that all parameters were within acceptable limits ...

  17. Atomic oxygen ions as ionospheric biomarkers on exoplanets

    Science.gov (United States)

    Mendillo, Michael; Withers, Paul; Dalba, Paul A.

    2018-04-01

    The ionized form of atomic oxygen (O+) is the dominant ion species at the altitude of maximum electron density in only one of the many ionospheres in our Solar System — Earth's. This ionospheric composition would not be present if oxygenic photosynthesis was not an ongoing mechanism that continuously impacts the terrestrial atmosphere. We propose that dominance of ionospheric composition by O+ ions at the altitude of maximum electron density can be used to identify a planet in orbit around a solar-type star where global-scale biological activity is present. There is no absolute numerical value required for this suggestion of an atmospheric plasma biomarker — only the dominating presence of O+ ions at the altitude of peak electron density.

  18. Ring current instabilities excited by the energetic oxygen ions

    International Nuclear Information System (INIS)

    Kakad, A. P.; Singh, S. V.; Lakhina, G. S.

    2007-01-01

    The ring current instabilities driven by the energetic oxygen ions are investigated during the magnetic storm. The electrons and protons are considered to have Maxwellian distributions, while energetic oxygen ions are having loss-cone distribution. Dispersion relation for the quasielectrostatic modes with frequencies ω>ω cp (proton cyclotron frequency) and propagating obliquely to the magnetic field is obtained. Dispersion relation is studied numerically for the storm time ring current parameters and it is found that these instabilities are most prominent during intense storms when the oxygen ions become the dominant constituents of the ring current plasma. For some typical storm-time ring current parameters, these modes can produce quasielectrostatic noise in the range of 17-220 Hz, thus providing a possible explanation of the electrostatic noise observed at the inner boundary of the ring current during magnetic storms. Further, these modes can attain saturation electric fields of the order of 100-500 μV/m, and therefore, are expected to scatter O + ions into the loss-cone giving rise to their precipitation into the atmosphere, thus contributing to the ring current decay

  19. Molecular Ions in Ion Upflows and their Effects on Hot Atomic Oxygen Production

    Science.gov (United States)

    Foss, V.; Yau, A. W.; Shizgal, B.

    2017-12-01

    We present new direct ion composition observations of molecular ions in auroral ion upflows from the CASSIOPE Enhanced Polar Outflow Probe (e-POP). These observed molecular ions are N2+, NO+, and possibly O2+, and are found to occur at all e-POP altitudes starting at about 400 km, during auroral substorms and the different phases of magnetic storms, sometimes with upflow velocities exceeding a few hundred meters per second and abundances of 5-10%. The dissociative recombination of both O2+ and NO+ was previously proposed as an important source of hot oxygen atoms in the topside thermosphere [Hickey et al., 1995]. We investigate the possible effect of the observed molecular ions on the production of hot oxygen atoms in the storm and substorm-time auroral thermosphere. We present numerical solutions of the Boltzmann equation for the steady-state oxygen energy distribution function, taking into account both the production of the hot atoms and their subsequent collisional relaxation. Our result suggests the formation of a hot oxygen population with a characteristic temperature on the order of 0.3 eV and constituting 1-5% of the oxygen density near the exobase. We discuss the implication of this result in the context of magnetosphere-ionosphere-thermosphere coupling.

  20. Clinical oxygen enhancement ratio of tumors in carbon ion radiotherapy: the influence of local oxygenation changes

    DEFF Research Database (Denmark)

    Antonovic, Laura; Lindblom, Emely; Dasu, Alexandru

    2014-01-01

    , using the repairable–conditionally repairable (RCR) damage model with parameters for human salivary gland tumor cells. The clinical oxygen enhancement ratio (OER) was defined as the ratio of doses required for a tumor control probability of 50% for hypoxic and well-oxygenated tumors. The resulting OER...... was well above unity for all fractionations. For the hypoxic tumor, the tumor control probability was considerably higher if LOCs were assumed, rather than static oxygenation. The beneficial effect of LOCs increased with the number of fractions. However, for very low fraction doses, the improvement related...... to LOCs did not compensate for the increase in total dose required for tumor control. In conclusion, our results suggest that hypoxia can influence the outcome of carbon ion radiotherapy because of the non-negligible oxygen effect at the low LETs in the SOBP. However, if LOCs occur, a relatively high...

  1. An atomic oxygen device based on PIG oxygen negative ion source

    International Nuclear Information System (INIS)

    Yu Jinxiang; Cai Minghui; Han Jianwei

    2008-01-01

    It is an important research subject for the spaceflight countries to conduct equivalent simulation of 5 eV atomic oxygen effects for the spaceflight material in low earth orbit. This paper introduces an apparatus used for producing atomic oxygen, which consists of a PIG ion source with permanent magnet, two electrodes extraction system, an electron deflector, an einzel lens, an ion decelerating electrode and a sample bracket. At present it has been used on the small debris accelerator in the Center for Space Science and Applied Research, Chinese Academy of Sciences, and the producing experiments of O - are carried out. 200-300μA of O - ions are extracted at the extraction voltage of 2-3 kV. The experiments for decelerating of O - ions and erosion of kapton foil are carried out also. Because of the target room used for both the atomic oxygen device and the small debris accelerator, the facility can be used for small debris impinging and atomic erosion for spaceflight materials simultaneously. (authors)

  2. New insights into methane-oxygen ion chemistry

    KAUST Repository

    Alquaity, Awad B.S.; Chen, Bingjie; Han, Jie; Selim, Hatem; Belhi, Memdouh; Karakaya, Yasin; Kasper, Tina; Sarathy, Mani; Bisetti, Fabrizio; Farooq, Aamir

    2016-01-01

    External electric fields may reduce emissions and improve combustion efficiency by active control of combustion processes. In-depth, quantitative understanding of ion chemistry in flames enables predictive models to describe the effect of external electric fields on combustion plasma. This study presents detailed cation profile measurements in low-pressure, burner-stabilized, methane/oxygen/argon flames. A quadrupole molecular beam mass spectrometer (MBMS) coupled to a low-pressure (P =30Torr) combustion chamber was utilized to measure ion signals as a function of height above the burner. Lean, stoichiometric and rich flames were examined to evaluate the dependence of ion chemistry on flame stoichiometry. Additionally, for the first time, cataloging of flame cations is performed using a high mass resolution time-of-flight mass spectrometer (TOF-MS) to distinguish ions with the same nominal mass. In the lean and stoichiometric flames, the dominant ions were HO, CHO , CHO, CHO and CHO, whereas large signals were measured for HO, CH and CHO in the rich flame. The spatial distribution of cations was compared with results from numerical simulations constrained by thermocouple-measured flame temperatures. Across all flames, the predicted HO decay rate was noticeably faster than observed experimentally. Sensitivity analysis showed that the mole fraction of HO is most sensitive to the rate of chemi-ionization CH+O↔CHO +E. To our knowledge, this work represents the first detailed measurements of positive ions in canonical low-pressure methane flames.

  3. New insights into methane-oxygen ion chemistry

    KAUST Repository

    Alquaity, Awad B.S.

    2016-06-15

    External electric fields may reduce emissions and improve combustion efficiency by active control of combustion processes. In-depth, quantitative understanding of ion chemistry in flames enables predictive models to describe the effect of external electric fields on combustion plasma. This study presents detailed cation profile measurements in low-pressure, burner-stabilized, methane/oxygen/argon flames. A quadrupole molecular beam mass spectrometer (MBMS) coupled to a low-pressure (P =30Torr) combustion chamber was utilized to measure ion signals as a function of height above the burner. Lean, stoichiometric and rich flames were examined to evaluate the dependence of ion chemistry on flame stoichiometry. Additionally, for the first time, cataloging of flame cations is performed using a high mass resolution time-of-flight mass spectrometer (TOF-MS) to distinguish ions with the same nominal mass. In the lean and stoichiometric flames, the dominant ions were HO, CHO , CHO, CHO and CHO, whereas large signals were measured for HO, CH and CHO in the rich flame. The spatial distribution of cations was compared with results from numerical simulations constrained by thermocouple-measured flame temperatures. Across all flames, the predicted HO decay rate was noticeably faster than observed experimentally. Sensitivity analysis showed that the mole fraction of HO is most sensitive to the rate of chemi-ionization CH+O↔CHO +E. To our knowledge, this work represents the first detailed measurements of positive ions in canonical low-pressure methane flames.

  4. Tribological effects of oxygen ion implantation into stainless steel

    International Nuclear Information System (INIS)

    Evans, P.J.; Vilaithong, T.; Yu, L.D.; Monteiro, O.R.; Yu, K.M.; Brown, I.G.

    2000-01-01

    The formation of sub-surface oxide layers by hybrid metal-gas co-implantation into steel and other metals can improve their tribological properties. In this report, we compare the wear and friction performance of previously studied Al + O hybrid implants with that produced by single species oxygen ion (O + ) implantation under similar conditions. The substrates were AISI 304L stainless steel discs polished to a final mirror finish using 1 μm diamond paste, and the ion implantation was done using a conventional swept-beam technique at ion energies of 70 or 140 keV and doses of up to 1x10 17 cm -2 . The wear and friction behaviour of the implanted and unimplanted material was measured with a pin-on-disc tribometer. Here we describe the experimental procedure and results, and discuss the improvement relative to that achieved with surface layers modified by metal-gas co-implantation

  5. Oxygen ion transference number of doped lanthanum gallate

    Science.gov (United States)

    Wang, Shizhong; Wu, Lingli; Gao, Jie; He, Qiong; Liu, Meilin

    The transference numbers for oxygen ion (t O) in several LaGaO 3-based materials are determined from oxygen concentration cells using the materials as the electrolyte, including La 0.8Sr 0.2Ga 0.8Mg 0.2O 3- δ (LSGM8282), La 0.8Sr 0.2Ga 0.8Mg 0.15Co 0.05O 3- δ (LSGMC5) and La 0.8Sr 0.2Ga 0.8Mg 0.115Co 0.085O 3- δ (LSGMC8.5). Analysis indicates that the accuracy in determination of oxygen ion transference number depends on the electrode polarization resistances of the concentration cell as well as the transport properties of the materials studied. For example, the ratio of open cell voltage to Nernst potential is a good approximation to the ionic transference number for LSGM8282. However, this approximation is no longer adequate for LSGMC5 and LSGMC8.5; the effect of electrode polarization resistances must be taken into consideration in estimation of the ionic transference numbers. In particular, the ionic transference number for LSGMC5 is as high as 0.99, suggesting that it is a promising electrolyte material for low-temperature solid-state electrochemical applications.

  6. Persufflation (or gaseous oxygen perfusion) as a method of organ preservation.

    Science.gov (United States)

    Suszynski, Thomas M; Rizzari, Michael D; Scott, William E; Tempelman, Linda A; Taylor, Michael J; Papas, Klearchos K

    2012-06-01

    Improved preservation techniques have the potential to improve transplant outcomes by better maintaining donor organ quality and by making more organs available for allotransplantation. Persufflation, (PSF, gaseous oxygen perfusion) is potentially one such technique that has been studied for over a century in a variety of tissues, but has yet to gain wide acceptance for a number of reasons. A principal barrier is the perception that ex vivo PSF will cause in vivo embolization post-transplant. This review summarizes the extensive published work on heart, liver, kidney, small intestine and pancreas PSF, discusses the differences between anterograde and retrograde PSF, and between PSF and other conventional methods of organ preservation (static cold storage, hypothermic machine perfusion). Prospective implications of PSF within the broader field of organ transplantation, and in the specific application with pancreatic islet isolation and transplant are also discussed. Finally, key issues that need to be addressed before PSF becomes a more widely utilized preservation strategy are summarized and discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Oxygen ion transference number of doped lanthanum gallate

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shizhong; Wu, Lingli; Gao, Jie; He, Qiong [Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005 (China); Liu, Meilin [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States)

    2008-12-01

    The transference numbers for oxygen ion (t{sub O}) in several LaGaO{sub 3}-based materials are determined from oxygen concentration cells using the materials as the electrolyte, including La{sub 0.8}Sr{sub 0.2}Ga{sub 0.8}Mg{sub 0.2}O{sub 3-{delta}} (LSGM8282), La{sub 0.8}Sr{sub 0.2}Ga{sub 0.8}Mg{sub 0.15}Co{sub 0.05}O{sub 3-{delta}} (LSGMC5) and La{sub 0.8}Sr{sub 0.2}Ga{sub 0.8}Mg{sub 0.115}Co{sub 0.085}O{sub 3-{delta}} (LSGMC8.5). Analysis indicates that the accuracy in determination of oxygen ion transference number depends on the electrode polarization resistances of the concentration cell as well as the transport properties of the materials studied. For example, the ratio of open cell voltage to Nernst potential is a good approximation to the ionic transference number for LSGM8282. However, this approximation is no longer adequate for LSGMC5 and LSGMC8.5; the effect of electrode polarization resistances must be taken into consideration in estimation of the ionic transference numbers. In particular, the ionic transference number for LSGMC5 is as high as 0.99, suggesting that it is a promising electrolyte material for low-temperature solid-state electrochemical applications. (author)

  8. Modification of WS2 nanosheets with controllable layers via oxygen ion irradiation

    Science.gov (United States)

    Song, Honglian; Yu, Xiaofei; Chen, Ming; Qiao, Mei; Wang, Tiejun; Zhang, Jing; Liu, Yong; Liu, Peng; Wang, Xuelin

    2018-05-01

    As one kind of two-dimensional materials, WS2 nanosheets have drawn much attention with different kinds of research methods. Yet ion irradiation method was barely used for WS2 nanosheets. In this paper, the structure, composition and optical band gap (Eg) of the multilayer WS2 films deposited by chemical vapor deposition (CVD) method on sapphire substrates before and after oxygen ion irradiation with different energy and fluences were studied. Precise tailored layer-structures and a controllable optical band gap of WS2 nanosheets were achieved after oxygen ion irradiation. The results shows higher energy oxygen irradiation changed the shape from triangular shaped grains to irregular rectangle shape but did not change 2H-WS2 phase structure. The intensity of E2g1 (Г) and A1g (Г) modes decreased and have small shifts after oxygen ion irradiation. The peak frequency difference between the E2g1 (Г) and A1g (Г) modes (Δω) decreased after oxygen ion irradiation, and this result indicates the number of layers decreased after oxygen ion irradiation. The Eg decreased with the increase of the energy and the fluence of oxygen ions. The number of layers, thickness and optical band gap changed after ion irradiation with different ion fluences and energies. The results proposed a new strategy for precise control of multilayer nanosheets and demonstrated the high applicability of ion irradiation in super-capacitors, field effect transistors and other applications.

  9. Thermodynamics and Cation Diffusion in the Oxygen Ion Conductor Lsgm

    Science.gov (United States)

    Martin, M.; Schulz, O.

    Perovskite type oxides based on LaGaO3 are of large technical interest because of their high oxygen-ion conductivity. Lanthanum gallate doped with Sr on A- and Mg on B-sites, La1-xSrxGa1-yMgyO3-(x+y)/2 (LSGM), reaches higher oxygen-ion conductivities than yttria-doped zirconia (YSZ). Thus LSGM represents a promising alternative for YSZ as electrolyte in solid oxide fuel cells (SOFC). Cells using thin LSGM-layers as electrolyte are expected to operate at intermediate temperatures around 700°C for more than 30000 hours without severe degradation. A potential long term degradation effect of LSGM is kinetic demixing of the electrolyte, caused by different cation diffusion coefficients. In this paper we report on experimental studies concerning the phase diagram of LSGM and the diffusion of cations. Cation self-diffusion of 139La, 84Sr and 25Mg and cation impurity diffusion of 144Nd, 89Y and 56Fe in polycrystalline LSGM samples was investigated by secondary ion mass spectrometry (SIMS) for temperatures between 900°C and 1400°C. It was found that diffusion occurs by means of bulk and grain boundaries. The bulk diffusion coefficients are similar for all cations with activation energies which are strongly dependent on temperature. At high temperatures, the activation energies are about 5 eV, while at low temperatures values of about 2 eV are found. These results are explained by a frozen in defect structure at low temperatures. This means that the observed activation energy at low temperatures represents only the migration energy of the different cations while the observed activation energy at high temperatures is the sum of the defect formation energy and the migration energy. The migration energies for all cations are nearly identical, although 139La, 84Sr and 144Nd are occupying A-sites while 25Mg and 56Fe are occupying B-sites in the perovskite-structure. To explain these experimental findings we propose a defect cluster containing cation vacancies in both the A

  10. Preservation of high glycolytic phenotype by establishing new acute lymphoblastic leukemia cell lines at physiologic oxygen concentration

    Energy Technology Data Exchange (ETDEWEB)

    Sheard, Michael A., E-mail: msheard@chla.usc.edu [Developmental Therapeutics Program, USC-CHLA Institute for Pediatric Clinical Research, Division of Hematology-Oncology, Children' s Hospital Los Angeles, 4650 Sunset Blvd., Los Angeles, CA 90027 (United States); Ghent, Matthew V., E-mail: mattghent@gmail.com [Department of Pathology, Keck School of Medicine, University of Southern California, Health Sciences Campus, Los Angeles, CA 90089 (United States); Cabral, Daniel J., E-mail: dcabral14@gmail.com [Cancer Center and Departments of Cell Biology & Biochemistry, Pharmacology & Neuroscience, Internal Medicine and Pediatrics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430 (United States); Lee, Joanne C., E-mail: joannebarnhart@gmail.com [Cancer Center and Departments of Cell Biology & Biochemistry, Pharmacology & Neuroscience, Internal Medicine and Pediatrics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430 (United States); Khankaldyyan, Vazgen, E-mail: khangaldian@yahoo.com [Developmental Therapeutics Program, USC-CHLA Institute for Pediatric Clinical Research, Division of Hematology-Oncology, Children' s Hospital Los Angeles, 4650 Sunset Blvd., Los Angeles, CA 90027 (United States); Ji, Lingyun, E-mail: lingyun.ji@med.usc.edu [Developmental Therapeutics Program, USC-CHLA Institute for Pediatric Clinical Research, Division of Hematology-Oncology, Children' s Hospital Los Angeles, 4650 Sunset Blvd., Los Angeles, CA 90027 (United States); Wu, Samuel Q., E-mail: swu@chla.usc.edu [Medical Genetics, Children' s Hospital Los Angeles, 4650 Sunset Blvd., Los Angeles, CA 90027 (United States); Kang, Min H., E-mail: min.kang@ttuhsc.edu [Cancer Center and Departments of Cell Biology & Biochemistry, Pharmacology & Neuroscience, Internal Medicine and Pediatrics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430 (United States); and others

    2015-05-15

    Cancer cells typically exhibit increased glycolysis and decreased mitochondrial oxidative phosphorylation, and they continue to exhibit some elevation in glycolysis even under aerobic conditions. However, it is unclear whether cancer cell lines employ a high level of glycolysis comparable to that of the original cancers from which they were derived, even if their culture conditions are changed to physiologically relevant oxygen concentrations. From three childhood acute lymphoblastic leukemia (ALL) patients we established three new pairs of cell lines in both atmospheric (20%) and physiologic (bone marrow level, 5%) oxygen concentrations. Cell lines established in 20% oxygen exhibited lower proliferation, survival, expression of glycolysis genes, glucose consumption, and lactate production. Interestingly, the effects of oxygen concentration used during cell line initiation were only partially reversible when established cell cultures were switched from one oxygen concentration to another for eight weeks. These observations indicate that ALL cell lines established at atmospheric oxygen concentration can exhibit relatively low levels of glycolysis and these levels are semi-permanent, suggesting that physiologic oxygen concentrations may be needed from the time of cell line initiation to preserve the high level of glycolysis commonly exhibited by leukemias in vivo. - Highlights: • Establishing new ALL cell lines in 5% oxygen resulted in higher glycolytic expression and function. • Establishing new ALL cell lines in 5% oxygen resulted in higher proliferation and lower cell death. • The divergent metabolic phenotypes selected in 5% and 20% oxygen are semi-permanent.

  11. Preservation of high glycolytic phenotype by establishing new acute lymphoblastic leukemia cell lines at physiologic oxygen concentration

    International Nuclear Information System (INIS)

    Sheard, Michael A.; Ghent, Matthew V.; Cabral, Daniel J.; Lee, Joanne C.; Khankaldyyan, Vazgen; Ji, Lingyun; Wu, Samuel Q.; Kang, Min H.

    2015-01-01

    Cancer cells typically exhibit increased glycolysis and decreased mitochondrial oxidative phosphorylation, and they continue to exhibit some elevation in glycolysis even under aerobic conditions. However, it is unclear whether cancer cell lines employ a high level of glycolysis comparable to that of the original cancers from which they were derived, even if their culture conditions are changed to physiologically relevant oxygen concentrations. From three childhood acute lymphoblastic leukemia (ALL) patients we established three new pairs of cell lines in both atmospheric (20%) and physiologic (bone marrow level, 5%) oxygen concentrations. Cell lines established in 20% oxygen exhibited lower proliferation, survival, expression of glycolysis genes, glucose consumption, and lactate production. Interestingly, the effects of oxygen concentration used during cell line initiation were only partially reversible when established cell cultures were switched from one oxygen concentration to another for eight weeks. These observations indicate that ALL cell lines established at atmospheric oxygen concentration can exhibit relatively low levels of glycolysis and these levels are semi-permanent, suggesting that physiologic oxygen concentrations may be needed from the time of cell line initiation to preserve the high level of glycolysis commonly exhibited by leukemias in vivo. - Highlights: • Establishing new ALL cell lines in 5% oxygen resulted in higher glycolytic expression and function. • Establishing new ALL cell lines in 5% oxygen resulted in higher proliferation and lower cell death. • The divergent metabolic phenotypes selected in 5% and 20% oxygen are semi-permanent

  12. Surface oxygen vacancy and oxygen permeation flux limits of perovskite ion transport membranes

    KAUST Repository

    Hunt, Anton

    2015-09-01

    © 2015 Elsevier B.V. The mechanisms and quantitative models for how oxygen is separated from air using ion transport membranes (ITMs) are not well understood, largely due to the experimental complexity for determining surface exchange reactions at extreme temperatures (>800°C). This is especially true when fuels are present at the permeate surface. For both inert and reactive (fuels) operations, solid-state oxygen surface vacancies (δ) are ultimately responsible for driving the oxygen flux, JO2. In the inert case, the value of δ at either surface is a function of the local PO2 and temperature, whilst the magnitude of δ dictates both the JO2 and the inherent stability of the material. In this study values of δ are presented based on experimental measurements under inert (CO2) sweep: using a permeation flux model and local PO2 measurements, collected by means of a local gas-sampling probe in our large-scale reactor, we can determine δ directly. The ITM assessed was La0.9Ca0.1FeO3-δ (LCF); the relative resistances to JO2 were quantified using the pre-defined permeation flux model and local PO2 values. Across a temperature range from 825°C to 1056°C, δ was found to vary from 0.007 to 0.029 (<1%), safely within material stability limits, whilst the permeate surface exchange resistance dominates. An inert JO2 limit was identified owing to a maximum sweep surface δ, δmaxinert. The physical presence of δmaxinert is attributed to a rate limiting step shift from desorption to associative electron transfer steps on the sweep surface as PO2 is reduced. Permeate surface exchange limitations under non-reactive conditions suggest that reactive (fuel) operation is necessary to accelerate surface chemistry for future work, to reduce flux resistance and push δpast δmaxinert in a stable manner.

  13. Kinetics of oxygen exchange between bisulfite ion and water as studied by oxygen-17 nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Horner, D.A.

    1984-08-01

    The nuclear magnetic relaxation times of oxygen-17 have been measured in aqueous sodium bisulfite solutions in the pH range from 2.5 to 5 as a function of temperature, pH, and S(IV) concentration, at an ionic strength of 1.0 m. The rate law for oxygen exchange between bisulfite ion and water was obtained from an analysis of the data, and is consistent with oxygen exchange occurring via the reaction SO 2 + H 2 O right reversible H + + SHO 3 - . The value of k/sub -1/ is in agreement with relaxation measurements. Direct spectroscopic evidence was found for the existence of two isomers of bisulfite ion: one with the proton bonded to the sulfur (HSO 3 - ) and the other with the proton bonded to an oxygen (SO 3 H - ). (The symbol SHO 3 - in the above chemical equation refers to both isomeric forms of bisulfite ion.) The relative amounts of the two isomers were determined as a function of temperature, and the rate and mechanism of oxygen exchange between the two was investigated. One of the two isomers, presumably SO 3 H - , exchanges oxygens with water much more rapidly than does the other. A two-pulse sequence was developed which greatly diminished the solvent peak in the NMR spectrum

  14. Oxygen Pickup Ions Measured by MAVEN Outside the Martian Bow Shock

    Science.gov (United States)

    Rahmati, A.; Cravens, T.; Larson, D. E.; Lillis, R. J.; Dunn, P.; Halekas, J. S.; Connerney, J. E. P.; Eparvier, F. G.; Thiemann, E.; Mitchell, D. L.; Jakosky, B. M.

    2015-12-01

    The MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft entered orbit around Mars on September 21, 2014 and has since been detecting energetic oxygen pickup ions by its SEP (Solar Energetic Particles) and SWIA (Solar Wind Ion Analyzer) instruments. The oxygen pickup ions detected outside the Martian bowshock and in the upstream solar wind are associated with the extended hot oxygen exosphere of Mars, which is created mainly by the dissociative recombination of molecular oxygen ions with electrons in the ionosphere. We use analytic solutions to the equations of motion of pickup ions moving in the undisturbed upstream solar wind magnetic and motional electric fields and calculate the flux of oxygen pickup ions at the location of MAVEN. Our model calculates the ionization rate of oxygen atoms in the exosphere based on the hot oxygen densities predicted by Rahmati et al. (2014), and the sources of ionization include photo-ionization, charge exchange, and electron impact ionization. The photo-ionization frequency is calculated using the FISM (Flare Irradiance Spectral Model) solar flux model, based on MAVEN EUVM (Extreme Ultra-Violet Monitor) measurements. The frequency of charge exchange between a solar wind proton and an oxygen atom is calculated using MAVEN SWIA solar wind proton flux measurements, and the electron impact ionization frequency is calculated based on MAVEN SWEA (Solar Wind Electron Analyzer) solar wind electron flux measurements. The solar wind magnetic field used in the model is from the measurements taken by MAVEN MAG (magnetometer) in the upstream solar wind. The good agreement between our predicted pickup oxygen fluxes and the MAVEN SEP and SWIA measured ones confirms detection of oxygen pickup ions and these model-data comparisons can be used to constrain models of hot oxygen densities and photochemical escape flux.

  15. Energy deposition and ion production from thermal oxygen ion precipitation during Cassini's T57 flyby

    Science.gov (United States)

    Snowden, Darci; Smith, Michael; Jimson, Theodore; Higgins, Alex

    2018-05-01

    Cassini's Radio Science Investigation (RSS) and Langmuir Probe observed abnormally high electron densities in Titan's ionosphere during Cassini's T57 flyby. We have developed a three-dimensional model to investigate how the precipitation of thermal magnetospheric O+ may have contributed to enhanced ion production in Titan's ionosphere. The three-dimensional model builds on previous work because it calculates both the flux of oxygen through Titan's exobase and the energy deposition and ion production rates in Titan's atmosphere. We find that energy deposition rates and ion production rates due to thermal O+ precipitation have a similar magnitude to the rates from magnetospheric electron precipitation and that the simulated ionization rates are sufficient to explain the abnormally high electron densities observed by RSS and Cassini's Langmuir Probe. Globally, thermal O+ deposits less energy in Titan's atmosphere than solar EUV, suggesting it has a smaller impact on the thermal structure of Titan's neutral atmosphere. However, our results indicate that thermal O+ precipitation can have a significant impact on Titan's ionosphere.

  16. Peak Exercise Oxygen Uptake Predicts Recurrent Admissions in Heart Failure With Preserved Ejection Fraction.

    Science.gov (United States)

    Palau, Patricia; Domínguez, Eloy; Núñez, Eduardo; Ramón, José María; López, Laura; Melero, Joana; Sanchis, Juan; Bellver, Alejandro; Santas, Enrique; Bayes-Genis, Antoni; Chorro, Francisco J; Núñez, Julio

    2018-04-01

    Heart failure with preserved ejection fraction (HFpEF) is a highly prevalent syndrome with an elevated risk of morbidity and mortality. To date, there is scarce evidence on the role of peak exercise oxygen uptake (peak VO 2 ) for predicting the morbidity burden in HFpEF. We sought to evaluate the association between peak VO 2 and the risk of recurrent hospitalizations in patients with HFpEF. A total of 74 stable symptomatic patients with HFpEF underwent a cardiopulmonary exercise test between June 2012 and May 2016. A negative binomial regression method was used to determine the association between the percentage of predicted peak VO 2 (pp-peak VO 2 ) and recurrent hospitalizations. Risk estimates are reported as incidence rate ratios. The mean age was 72.5 ± 9.1 years, 53% were women, and all patients were in New York Heart Association functional class II to III. Mean peak VO 2 and median pp-peak VO 2 were 10 ± 2.8mL/min/kg and 60% (range, 47-67), respectively. During a median follow-up of 276 days [interquartile range, 153-1231], 84 all-cause hospitalizations in 31 patients (41.9%) were registered. A total of 15 (20.3%) deaths were also recorded. On multivariate analysis, accounting for mortality as a terminal event, pp-peak VO 2 was independently and linearly associated with the risk of recurrent admission. Thus, and modeled as continuous, a 10% decrease of pp-peak VO 2 increased the risk of recurrent hospitalizations by 32% (IRR, 1.32; 95%CI, 1.03-1.68; P = .028). In symptomatic elderly patients with HFpEF, pp-peak VO 2 predicts all-cause recurrent admission. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  17. Preservation of high glycolytic phenotype by establishing new acute lymphoblastic leukemia cell lines at physiologic oxygen concentration.

    Science.gov (United States)

    Sheard, Michael A; Ghent, Matthew V; Cabral, Daniel J; Lee, Joanne C; Khankaldyyan, Vazgen; Ji, Lingyun; Wu, Samuel Q; Kang, Min H; Sposto, Richard; Asgharzadeh, Shahab; Reynolds, C Patrick

    2015-05-15

    Cancer cells typically exhibit increased glycolysis and decreased mitochondrial oxidative phosphorylation, and they continue to exhibit some elevation in glycolysis even under aerobic conditions. However, it is unclear whether cancer cell lines employ a high level of glycolysis comparable to that of the original cancers from which they were derived, even if their culture conditions are changed to physiologically relevant oxygen concentrations. From three childhood acute lymphoblastic leukemia (ALL) patients we established three new pairs of cell lines in both atmospheric (20%) and physiologic (bone marrow level, 5%) oxygen concentrations. Cell lines established in 20% oxygen exhibited lower proliferation, survival, expression of glycolysis genes, glucose consumption, and lactate production. Interestingly, the effects of oxygen concentration used during cell line initiation were only partially reversible when established cell cultures were switched from one oxygen concentration to another for eight weeks. These observations indicate that ALL cell lines established at atmospheric oxygen concentration can exhibit relatively low levels of glycolysis and these levels are semi-permanent, suggesting that physiologic oxygen concentrations may be needed from the time of cell line initiation to preserve the high level of glycolysis commonly exhibited by leukemias in vivo. Copyright © 2015. Published by Elsevier Inc.

  18. Inactivation of Bacillus atrophaeus and of Aspergillus niger using beams of argon ions, of oxygen molecules and of oxygen atoms

    Energy Technology Data Exchange (ETDEWEB)

    Raballand, V; Benedikt, J; Keudell, A von [Research Group Reactive Plasmas, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Wunderlich, J [Fraunhofer Institut for Process Engineering and Packaging, Giggenhauser Strasse 35, 85354 Freising (Germany)], E-mail: Achim.vonKeudell@rub.de

    2008-06-07

    The inactivation of spores of Bacillus atrophaeus and of Aspergillus niger using beams of argon ions, of oxygen molecules and of oxygen atoms is studied. Thereby, the conditions occurring in oxygen containing low pressure plasmas are mimicked and fundamental inactivation mechanisms can be revealed. It is shown that the impact of O atoms has no effect on the viability of the spores and that no etching of the spore coat occurs up to an O atom fluence of 3.5 x 10{sup 19} cm{sup -2}. The impact of argon ions with an energy of 200 eV does not cause significant erosion for fluences up to 1.15 x 10{sup 18} cm{sup -2}. However, the combined impact of argon ions and oxygen molecules or atoms causes significant etching of the spores and significant inactivation. This is explained by the process of chemical sputtering, where an ion-induced defect at the surface of the spore reacts with either the incident bi-radical O{sub 2} or with an incident O atom. This leads to the formation of CO, CO{sub 2} and H{sub 2}O and thus to erosion.

  19. Measurements of Positively Charged Ions in Premixed Methane-Oxygen Atmospheric Flames

    KAUST Repository

    Alquaity, Awad; Han, Jie; Chahine, May; Selim, Hatem; Belhi, Memdouh; Sarathy, Mani; Bisetti, Fabrizio; Farooq, Aamir

    2016-01-01

    chemistry models are needed to understand and predict the effect of external electric fields on combustion plasmas. In this work, a molecular beam mass spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane–oxygen argon

  20. Supplementary Material for: Measurements of Positively Charged Ions in Premixed Methane-Oxygen Atmospheric Flames

    KAUST Repository

    Alquaity, Awad B. S.; Han, Jie; Chahine, May; Selim, Hatem; Belhi, Memdouh; Sarathy, Mani; Bisetti, Fabrizio; Farooq, Aamir

    2017-01-01

    chemistry models are needed to understand and predict the effect of external electric fields on combustion plasmas. In this work, a molecular beam mass spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane–oxygen argon

  1. Oxygen permeation through oxygen ion oxide-noble metal dual phase composites

    NARCIS (Netherlands)

    Chen, C.S.; Chen, C.S.; Kruidhof, H.; Bouwmeester, Henricus J.M.; Verweij, H.; Burggraaf, Anthonie; Burggraaf, A.J.

    1996-01-01

    Oxygen permeation behaviour of three composites, yttria-stabilized zirconia-palladium, erbia-stabilized bismuth oxidenoble metal (silver, gold) was studied. Oxygen permeation measurements were performed under controlled oxygen pressure gradients at elevated temperatures. Air was supplied at one side

  2. Photochemical Cycling of Reactive Oxygen Species in Hydrothermal Springs: Impacts on Biosignature Preservation

    Science.gov (United States)

    Mave, M. A.; Hinman, N. W.; Stevens, L.

    2017-12-01

    Biosignatures can be preserved via rapid entombment by aqueous minerals in a system. Wilson et al. (2000) found that high UV flux leads to increased production of reactive oxygen species (ROS), which promote iron (Fe) oxidation, and possible accumulation on microbial surfaces, leading to detectable microfossils. Hydrogen peroxide (H2O2) is a measurable ROS that serves as proxy for less stable ROS. Overall diel cycling of H2O2 is likely controlled by changes in photoreactive speciation of Fe (McKnight et al., 1988) in Fe-rich systems. To test this hypothesis, we conducted a 48-hour photochemical field study of Elk Pool in the Norris Geyser Basin at Yellowstone National Park in July, 2017 in which we measured UVA and UVB, along with H2O2 via the scopoletin fluorescence quenching method (Holm et al., 1987). Measurements were taken every few hours, and we found that maximum ROS production occurred during maximum UV irradiation. We also ran several experiments on-site in which we collected and altered spring water to either inactivate or catalyze naturally occurring reactions as well as to isolate primary mechanisms responsible for production of H2O2. Experiments were run in UV permeable Whirlpak bags and Fisherbrand tubes. Elk Pool showed only trace Fe content (pH 4) at the time of our study, so Fe-silica coated petrographic slides were added to the tube experiments (Fe-added experiments). Both sets of experiments included filtered and unfiltered spring water to differentiate biotic from abiotic mechanisms, and both UV-exposed and dark controls to separate UV-induced mechanisms for ROS formation. UV-exposed water always had greater ROS than dark experiments. Filtered spring water had higher ROS concentrations than unfiltered water, except when Fe was added. In the Fe-added experiments, unfiltered spring water had slightly greater ROS production relative to filtered water and had the lowest pH and highest aqueous Fe content after 7 hours. All Fe-added experiments showed

  3. Escape of high-energy oxygen ions through magnetopause reconnection under northward IMF

    Directory of Open Access Journals (Sweden)

    S. Kasahara

    2008-12-01

    Full Text Available During a storm recovery phase on 15 May 2005, the Geotail spacecraft repeatedly observed high-energy (>180 keV oxygen ions in the dayside magnetosheath near the equatorial plane. We focused on the time period from 11:20 UT to 13:00 UT, when Geotail observed the oxygen ions and the interplanetary magnetic field (IMF was constantly northward. The magnetic reconnection occurrence northward and duskward of Geotail is indicated by the Walén analysis and convective flows in the magnetopause boundary layer. Anisotropic pitch angle distributions of ions suggest that high-energy oxygen ions escaped from the northward of Geotail along the reconnected magnetic field lines. From the low-energy particle precipitation in the polar cap observed by DMSP, which is consistent with magnetic reconnection occurring between the magnetosheath field lines and the magnetospheric closed field lines, we conclude that these oxygen ions are of ring current origin. Our results thus suggest a new escape route of oxygen ions during northward IMF. In the present event, this escape mechanism is more dominant than the leakage via the finite Larmor radius effect across the dayside equatorial magnetopause.

  4. Performance evaluation of oxygen adsorbents using negative corona discharge–ion mobility spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Azadkish, Kamal; Jafari, Mohammad T., E-mail: jafari@cc.iut.ac.ir; Ghaziaskar, Hassan S.

    2017-02-08

    Trace amounts of oxygen was determined using negative corona discharge as an ionization source for ion mobility spectrometry. A point-in-cylinder geometry with novel design was used to establish the corona discharge without interferences of negative ions such as NO{sub X}{sup −}. The desirable background spectrum shows only electrons peak, providing the instrument capable of trace analysis of oxygen in gaseous samples. The limit of detection and linear dynamic range with high coefficient of determination (r{sup 2} = 0.9997), were obtained for oxygen as 8.5 and 28–14204 ppm, respectively. The relative standard deviations of the method for intraday and interday were obtained 4 and 11%, respectively. The satisfactory results revealed the ability of the negative corona discharge ion mobility spectrometry for investigating the performance of synthesized oxygen adsorbents in nitrogen streams. Two oxygen scavengers of MnO and Cu powder were prepared and the optimum temperature of the reactor containing MnO and Cu powder were obtained as 180 and 230 °C, respectively. Due to higher lifetime of copper powder, it was selected as the oxygen scavenger and some parameters such as: the type of adsorbent support, the size of adsorbent particles, and the amount of copper were studied for preparation of more efficient oxygen adsorbent. - Highlights: • Analysis of oxygen using negative corona discharge-ion mobility spectrometry was investigated for the first time. • Novel designed point-in-cylinder geometry was used to establish the corona discharge without interferences of negative ions. • The method was utilized to evaluate the performance of some synthesized oxygen scavengers.

  5. Supplementary Material for: Measurements of Positively Charged Ions in Premixed Methane-Oxygen Atmospheric Flames

    KAUST Repository

    Alquaity, Awad B. S.

    2017-01-01

    Cations and anions are formed as a result of chemi-ionization processes in combustion systems. Electric fields can be applied to reduce emissions and improve combustion efficiency by active control of the combustion process. Detailed flame ion chemistry models are needed to understand and predict the effect of external electric fields on combustion plasmas. In this work, a molecular beam mass spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane–oxygen argon burner-stabilized atmospheric flames. Lean and stoichiometric flames are considered to assess the dependence of ion chemistry on flame stoichiometry. Relative ion concentration profiles are compared with numerical simulations using various temperature profiles, and good qualitative agreement was observed for the stoichiometric flame. However, for the lean flame, numerical simulations misrepresent the spatial distribution of selected ions greatly. Three modifications are suggested to enhance the ion mechanism and improve the agreement between experiments and simulations. The first two modifications comprise the addition of anion detachment reactions to increase anion recombination at low temperatures. The third modification involves restoring a detachment reaction to its original irreversible form. To our knowledge, this work presents the first detailed measurements of cations and flame temperature in canonical methane–oxygen-argon atmospheric flat flames. The positive ion profiles reported here may be useful to validate and improve ion chemistry models for methane-oxygen flames.

  6. Measurements of Positively Charged Ions in Premixed Methane-Oxygen Atmospheric Flames

    KAUST Repository

    Alquaity, Awad

    2016-08-22

    Cations and anions are formed as a result of chemi-ionization processes in combustion systems. Electric fields can be applied to reduce emissions and improve combustion efficiency by active control of the combustion process. Detailed flame ion chemistry models are needed to understand and predict the effect of external electric fields on combustion plasmas. In this work, a molecular beam mass spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane–oxygen argon burner-stabilized atmospheric flames. Lean and stoichiometric flames are considered to assess the dependence of ion chemistry on flame stoichiometry. Relative ion concentration profiles are compared with numerical simulations using various temperature profiles, and good qualitative agreement was observed for the stoichiometric flame. However, for the lean flame, numerical simulations misrepresent the spatial distribution of selected ions greatly. Three modifications are suggested to enhance the ion mechanism and improve the agreement between experiments and simulations. The first two modifications comprise the addition of anion detachment reactions to increase anion recombination at low temperatures. The third modification involves restoring a detachment reaction to its original irreversible form. To our knowledge, this work presents the first detailed measurements of cations and flame temperature in canonical methane–oxygen-argon atmospheric flat flames. The positive ion profiles reported here may be useful to validate and improve ion chemistry models for methane-oxygen flames.

  7. Migration of interfacial oxygen ions modulated resistive switching in oxide-based memory devices

    Science.gov (United States)

    Chen, C.; Gao, S.; Zeng, F.; Tang, G. S.; Li, S. Z.; Song, C.; Fu, H. D.; Pan, F.

    2013-07-01

    Oxides-based resistive switching memory induced by oxygen ions migration is attractive for future nonvolatile memories. Numerous works had focused their attentions on the sandwiched oxide materials for depressing the characteristic variations, but the comprehensive studies of the dependence of electrodes on the migration behavior of oxygen ions are overshadowed. Here, we investigated the interaction of various metals (Ni, Co, Al, Ti, Zr, and Hf) with oxygen atoms at the metal/Ta2O5 interface under electric stress and explored the effect of top electrode on the characteristic variations of Ta2O5-based memory device. It is demonstrated that chemically inert electrodes (Ni and Co) lead to the scattering switching characteristics and destructive gas bubbles, while the highly chemically active metals (Hf and Zr) formed a thick and dense interfacial intermediate oxide layer at the metal/Ta2O5 interface, which also degraded the resistive switching behavior. The relatively chemically active metals (Al and Ti) can absorb oxygen ions from the Ta2O5 film and avoid forming the problematic interfacial layer, which is benefit to the formation of oxygen vacancies composed conduction filaments in Ta2O5 film thus exhibit the minimum variations of switching characteristics. The clarification of oxygen ions migration behavior at the interface can lead further optimization of resistive switching performance in Ta2O5-based memory device and guide the rule of electrode selection for other oxide-based resistive switching memories.

  8. Growth and Properties of Oxygen and Ion Doped BISMUTH(2) STRONTIUM(2) Calcium COPPER(2) Oxygen (8+DELTA) Single Crystals

    Science.gov (United States)

    Mitzi, David Brian

    1990-01-01

    A directional solidification method for growing large single crystals in the Bi_2Sr _2CaCu_2O _{8+delta} system is reported. Ion substitutions, with replacement of La for Sr and Y for Ca, as well as oxygen doping in these crystals has been explored. Ion doping results in little change of the superconducting transition for substitution levels below 20-25% (as a result of simultaneous oxygen intercalation), while beyond this level, the Meissner signal broadens and the low temperature Meissner signal decreases. Microprobe analysis and x-ray diffraction performed on these more highly substituted single crystals, provides evidence for inhomogeneity and phase segregation into regions of distinct composition. Annealing unsubstituted crystals in increasing partial pressures of oxygen reversibly depresses the superconducting transition temperature from 90K (as made) to 77K (oxygen pressure annealed) while the Hall concentrations increase from n = 3.1(3) times 10 ^{21} cm^{ -3} (0.34 holes/Cu site) to 4.6(3) times 10^{21} cm^{-3} (0.50 holes/Cu site). Further suppression of T_{c} to 72K is possible by annealing in oxygen pressures up to 100atm. No degradation of the Meissner transition or other indications of inhomogeneity or phase segregation with doping are noted, suggesting that oxygen doped Bi_2Sr _2CaCu_2O _{8+delta} is a suitable system for pursuing doping studies. The decrease in T _{c} with concentration for 0.34 <=q n <=q 0.50 indicates that a high carrier concentration regime exists where T_{c} decreases with n and suggests that this decrease does not arise from material inhomogeneity or other materials problems. The physical properties of these Bi _2Sr_2CaCu _2O_{8+delta} crystals, in this high carrier concentration regime, will be discussed.

  9. XPS study of vanadium surface oxidation by oxygen ion bombardment

    Czech Academy of Sciences Publication Activity Database

    Alov, N.; Kutsko, D.; Spirovová, Ilona; Bastl, Zdeněk

    2006-01-01

    Roč. 600, č. 8 (2006), s. 1628-1631 ISSN 0039-6028 R&D Projects: GA ČR GA104/04/0467 Institutional research plan: CEZ:AV0Z40400503 Keywords : vanadium oxide * oxide film * ion-beam oxidation * X-ray photoelectron spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.880, year: 2006

  10. Composition, structure and morphology of oxide layers formed on austenitic stainless steel by oxygen plasma immersion ion implantation

    International Nuclear Information System (INIS)

    Anandan, C.; Rajam, K.S.

    2007-01-01

    Oxygen ions were implanted in to austenitic stainless steel by plasma immersion ion implantation at 400 deg. C. The implanted samples were characterized by XPS, GIXRD, micro-Raman, AFM, optical and scanning electron microscopies. XPS studies showed the presence of Fe in elemental, as Fe 2+ in oxide form and as Fe 3+ in the form of oxyhydroxides in the substrate. Iron was present in the oxidation states of Fe 2+ and Fe 3+ in the implanted samples. Cr and Mn were present as Cr 3+ and Mn 2+ , respectively, in both the substrate and implanted samples. Nickel remained unaffected by implantation. GIXRD and micro-Raman studies showed the oxide to be a mixture of spinel and corundum structures. Optical and AFM images showed an island structure on underlying oxide. This island structure was preserved at different thicknesses. Further, near the grain boundaries more oxide growth was found. This is explained on the basis of faster diffusion of oxygen in the grain boundary regions. Measurement of total hemispherical optical aborptance, α and emittance, ε of the implanted sample show that it has good solar selective properties

  11. Ion release from magnesium materials in physiological solutions under different oxygen tensions.

    Science.gov (United States)

    Feyerabend, Frank; Drücker, Heiko; Laipple, Daniel; Vogt, Carla; Stekker, Michael; Hort, Norbert; Willumeit, Regine

    2012-01-01

    Although magnesium as degradable biomaterial already showed clinical proof of concepts, the design of new alloys requires predictive in vitro methods, which are still lacking. Incubation under cell culture conditions to obtain "physiological" corrosion may be a solution. The aim of this study was to analyse the influence of different solutions, addition of proteins and of oxygen availability on the corrosion of different magnesium materials (pure Mg, WE43, and E11) with different surface finishing. Oxygen content in solution, pH, osmolality and ion release were determined. Corrosion led to a reduction of oxygen in solution. The influence of oxygen on pH was enhanced by proteins, while osmolality was not influenced. Magnesium ion release was solution-dependent and enhanced in the initial phase by proteins with delayed release of alloying elements. The main corrosion product formed was magnesium carbonate. Therefore, cell culture conditions are proposed as first step toward physiological corrosion.

  12. Hypercapnic Acidosis Preserves Gastric Mucosal Microvascular Oxygen Saturation in a Canine Model of Hemorrhage.

    NARCIS (Netherlands)

    Schwartges, Ingo; Picker, Olaf; Beck, Christopher; Scheeren, Thomas W. L.; Schwarte, Lothar A.

    2010-01-01

    The authors aimed to clarify the effects of hypercapnic acidosis and its timing on gastric mucosal oxygenation in a canine model of hemorrhage. This was designed as a prospective, controlled, randomized animal study set in a university research laboratory. Five chronically instrumented dogs were

  13. Effects of extracellular zinc ion on the rate of oxygen consumption of ...

    African Journals Online (AJOL)

    The inhibitory effect of extracellular zinc ion on the rate of oxygen consumption of rat brain mitochondria pre-incubated in 1.0 mM Ca2+EDTA were determined. There was a significant increase [P<0.01] in the rate of oxygen consumption in the rat brain mitochondria pre-incubated in 1.0 mM. Ca2+EDTA in a succinate ...

  14. Nanocrystalline SnO2 formation by oxygen ion implantation in tin thin films

    Science.gov (United States)

    Kondkar, Vidya; Rukade, Deepti; Kanjilal, Dinakar; Bhattacharyya, Varsha

    2018-03-01

    Metallic tin thin films of thickness 100 nm are deposited on fused silica substrates by thermal evaporation technique. These films are implanted with 45 keV oxygen ions at fluences ranging from 5 × 1015 to 5 × 1016 ions cm-2. The energy of the oxygen ions is calculated using SRIM in order to form embedded phases at the film-substrate interface. Post-implantation, films are annealed using a tube furnace for nanocrystalline tin oxide formation. These films are characterized using x-ray diffraction, Raman spectroscopy, UV-vis spectroscopy and photoluminescence spectroscopy. XRD and Raman spectroscopy studies reveal the formation of single rutile phase of SnO2. The size of the nanocrystallites formed decreases with an increase in the ion fluence. The nanocrystalline SnO2 formation is also confirmed by UV-vis and photoluminescence spectroscopy.

  15. Sputtering of solid nitrogen and oxygen by keV hydrogen ions

    DEFF Research Database (Denmark)

    Ellegaard, O.; Schou, Jørgen; Stenum, B.

    1994-01-01

    Electronic sputtering of solid nitrogen and oxygen by keV hydrogen ions has been studied at two low-temperature setups. The yield of the sputtered particles has been determined in the energy regime 4-10 keV for H+, H-2+ and H-3+ ions. The yield for oxygen is more than a factor of two larger than...... that for nitrogen. The energy distributions of the sputtered N2 and O2 molecules were measured for hydrogen ions in this energy regime as well. The yields from both solids turn out to depend on the sum of the stopping power of all atoms in the ion. The yield increases as a quadratic function of the stopping power...

  16. Oxygen ion implantation induced microstructural changes and electrical conductivity in Bakelite RPC detector material

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, K. V. Aneesh, E-mail: aneesh1098@gmail.com; Ravikumar, H. B., E-mail: hbr@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Mysore-570006 (India); Ranganathaiah, C., E-mail: cr@physics.uni-mysore.ac.in [Govt. Research Centre, Sahyadri Educational Institutions, Mangalore-575007 (India); Kumarswamy, G. N., E-mail: kumy79@gmail.com [Department of Studies in Physics, Amrita Vishwa Vidyapeetham, Bangalore-560035 (India)

    2016-05-06

    In order to explore the structural modification induced electrical conductivity, samples of Bakelite Resistive Plate Chamber (RPC) detector materials were exposed to 100 keV Oxygen ion in the fluences of 10{sup 12}, 10{sup 13}, 10{sup 14} and 10{sup 15} ions/cm{sup 2}. Ion implantation induced microstructural changes have been studied using Positron Annihilation Lifetime Spectroscopy (PALS) and X-Ray Diffraction (XRD) techniques. Positron lifetime parameters viz., o-Ps lifetime and its intensity shows the deposition of high energy interior track and chain scission leads to the formation of radicals, secondary ions and electrons at lower ion implantation fluences (10{sup 12} to10{sup 14} ions/cm{sup 2}) followed by cross-linking at 10{sup 15} ions/cm{sup 2} fluence due to the radical reactions. The reduction in electrical conductivity of Bakelite detector material is correlated to the conducting pathways and cross-links in the polymer matrix. The appropriate implantation energy and fluence of Oxygen ion on polymer based Bakelite RPC detector material may reduce the leakage current, improves the efficiency, time resolution and thereby rectify the aging crisis of the RPC detectors.

  17. Study of high energy ion implantation of boron and oxygen in silicon

    International Nuclear Information System (INIS)

    Thevenin, P.

    1991-06-01

    Three aspects of high energy (0.5-3 MeV) light ions ( 11 B + and 16 O + ) implantation in silicon are examined: (1)Spatial repartition; (2) Target damage and (3) Synthesis by oxygen implantation of a buried silicon oxide layer

  18. Extraction of low-energy negative oxygen ions for thin film formation

    International Nuclear Information System (INIS)

    Vasquez, M. Jr.; Sasaki, D.; Kasuya, T.; Wada, M.; Maeno, S.

    2011-01-01

    Coextraction of low-energy positive and negative ions were performed using a plasma sputter-type ion source system driven by a 13.56 MHz radio frequency (rf) power. Titanium (Ti) atoms were sputtered out from a target and the sputtered neutrals were postionized in oxygen/argon (O 2 /Ar) plasma prior to extraction. The negative O ions were surface-produced and self-extracted. Mass spectral analyses of the extracted ion beams revealed the dependence of the ion current on the incident rf power, induced target bias and O 2 /Ar partial pressure ratio. Ti + current was found to be dependent on Ar + current and reached a saturation value with increasing O 2 partial pressure while the O - current showed a peak current at around 1:9 O 2 /Ar partial pressure ratio. Ti + current was several orders of magnitude higher than that of the O - current.

  19. Formation of oxides and segregation of mobile atoms during SIMS profiling of Si with oxygen ions

    Energy Technology Data Exchange (ETDEWEB)

    Petravic, M; Williams, J S; Svensson, B G; Conway, M [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences

    1994-12-31

    An oxygen beam is commonly used in secondary ion mass spectroscopy (SIMS) analysis to enhance the ionization probability for positive secondary ions. It has been observed, however, that this technique produces in some cases a great degradation of depth resolution. The most pronounced effects have been found for impurities in silicon under oxygen bombardment at angles of incidence smaller than {approx} 30 deg from the surface normal. A new approach is described which involved broadening of SIMS profiles for some mobile atoms, such as Cu, Ni and Au, implanted into silicon. The anomalously large broadening is explained in terms of segregation at a SiO{sub 2}/Si interface formed during bombardment with oxygen at impact angles less than 30 deg. 2 refs., 1 tab., 4 figs.

  20. Formation of oxides and segregation of mobile atoms during SIMS profiling of Si with oxygen ions

    Energy Technology Data Exchange (ETDEWEB)

    Petravic, M.; Williams, J.S.; Svensson, B.G.; Conway, M. [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences

    1993-12-31

    An oxygen beam is commonly used in secondary ion mass spectroscopy (SIMS) analysis to enhance the ionization probability for positive secondary ions. It has been observed, however, that this technique produces in some cases a great degradation of depth resolution. The most pronounced effects have been found for impurities in silicon under oxygen bombardment at angles of incidence smaller than {approx} 30 deg from the surface normal. A new approach is described which involved broadening of SIMS profiles for some mobile atoms, such as Cu, Ni and Au, implanted into silicon. The anomalously large broadening is explained in terms of segregation at a SiO{sub 2}/Si interface formed during bombardment with oxygen at impact angles less than 30 deg. 2 refs., 1 tab., 4 figs.

  1. FTIR studies of swift silicon and oxygen ion irradiated porous silicon

    International Nuclear Information System (INIS)

    Bhave, Tejashree M.; Hullavarad, S.S.; Bhoraskar, S.V.; Hegde, S.G.; Kanjilal, D.

    1999-01-01

    Fourier Transform Infrared Spectroscopy has been used to study the bond restructuring in silicon and oxygen irradiated porous silicon. Boron doped p-type (1 1 1) porous silicon was irradiated with 10 MeV silicon and a 14 MeV oxygen ions at different doses ranging between 10 12 and 10 14 ions cm -2 . The yield of PL in porous silicon irradiated samples was observed to increase considerably while in oxygen irradiated samples it was seen to improve only by a small extent for lower doses whereas it decreased for higher doses. The results were interpreted in view of the relative intensities of the absorption peaks associated with O-Si-H and Si-H stretch bonds

  2. Hydrogen and oxygen behaviors on Porous-Si surfaces observed using a scanning ESD ion microscope

    International Nuclear Information System (INIS)

    Itoh, Yuki; Ueda, Kazuyuki

    2004-01-01

    A scanning electron-stimulated desorption (ESD) ion microscope (SESDIM) measured the 2-D images of hydrogen and oxygen distribution on solid surfaces. A primary electron beam at 600 eV, with a pulse width of 220 ns, resulted in ion yields of H + and O + . This SESDIM is applied to the surface analysis of Porous-Si (Po-Si) partially covered with SiN films. During the heating of a specimen of the Po-Si at 800 deg. C under ultra-high-vacuum (UHV) conditions, the components of the surface materials were moved or diffused by thermal decomposition accompanied by a redistribution of hydrogen and oxygen. After cyclic heating of above 800 deg. C, the dynamic behaviors of H + and O + accompanied by the movements of the SiN layers were observed as images of H + and O + . This was because the H + and O + ions have been identified as composite materials by their kinetic energies

  3. Uplift of Ionospheric Oxygen Ions During Extreme Magnetic Storms

    Science.gov (United States)

    Tsurutani, Bruce T.; Mannucci, Anthony J.; Verkhoglyadova, Olga P.; Huba, Joseph; Lakhina, Gurbax S.

    2013-01-01

    Research reported earlier in literature was conducted relating to estimation of the ionospheric electrical field, which may have occurred during the September 1859 Carrington geomagnetic storm event, with regard to modern-day consequences. In this research, the NRL SAMI2 ionospheric code has been modified and applied the estimated electric field to the dayside ionosphere. The modeling was done at 15-minute time increments to track the general ionospheric changes. Although it has been known that magnetospheric electric fields get down into the ionosphere, it has been only in the last ten years that scientists have discovered that intense magnetic storm electric fields do also. On the dayside, these dawn-to-dusk directed electric fields lift the plasma (electrons and ions) up to higher altitudes and latitudes. As plasma is removed from lower altitudes, solar UV creates new plasma, so the total plasma in the ionosphere is increased several-fold. Thus, this complex process creates super-dense plasmas at high altitudes (from 700 to 1,000 km and higher).

  4. Damage induced by high energy multiply charged oxygen ions in oxide coated silicon

    Energy Technology Data Exchange (ETDEWEB)

    Dhole, S.D. [Department of Physics, University of Pune, Pune 411 007 (India)]. E-mail: sanjay@physics.unipune.ernet.in; Dahiwale, S.S. [Department of Physics, University of Pune, Pune 411 007 (India); Kulkarni, V.R. [Department of Physics, University of Pune, Pune 411 007 (India); Bogle, K.A. [Department of Physics, University of Pune, Pune 411 007 (India); Shinde, N.S. [Ecotopia Science Institute, Division of Energy Science, Nagoya University, Nagoya (Japan); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 411 007 (India)

    2006-03-15

    P-type oxide coated silicon samples of resistivity 120 {omega} cm were irradiated with 60 MeV oxygen ions of fixed charge states 4{sup +}, 5{sup +}, 6{sup +} and 7{sup +} at an equal fluence of, {phi}, {approx}10{sup 13} ions/cm{sup 2}. The induced damage was estimated by Hall voltage, Hall coefficient, carrier concentration and lifetime of minority carriers. The results indicate that Hall voltage (V {sub H}) and Hall coefficient (R {sub H}) increases, while carrier concentration (n) decreases with the charge state of impinging oxygen ions. The V {sub H} increases from 22 mV to 76.5 mV at typical current of 0.5 mA, R {sub H} from 0.42 x 10{sup 5} cm{sup 3}/C to 2.16 x 10{sup 5} cm{sup 3}/C and n decreases from 9 x 10{sup 13} cm{sup -3} to 2.88 x 10{sup 13} cm{sup -3} for the different charge states. This fact is an evidence that the oxygen ions with an individual fixed charge state passing through very thin 40 A layer of silicon dioxide, induces significant damage at the SiO{sub 2}-Si interface through the mechanism of electronic stopping power. The lifetime of minority charge carriers, {tau} (bulk property), remains constant at around 6 {mu}s for all the charge states of the 60 MeV energy oxygen ion irradiated samples at a constant fluence of, {phi}, 10{sup 13} ions/cm{sup 2}.

  5. Emission characteristics of negative oxygen ions into vacuum from cerium oxide

    International Nuclear Information System (INIS)

    Sakai, Takaaki; Fujiwara, Yukio; Kaimai, Atsushi; Yashiro, Keiji; Matsumoto, Hiroshige; Nigara, Yutaka; Kawada, Tatsuya; Mizusaki, Junichiro

    2006-01-01

    The oxygen ion emission characteristics of CeO 2 were studied under electric field in a vacuum chamber to find a candidate material for a novel ion source, 'solid oxide ion source (SOIS)'. The emission current was observed from CeO 2 under a pressure of around 10 -3 Pa, at the temperature ranging from 973 K to 1173 K. It was found that the emission current increased with temperature and applied voltage. The ions emitted from CeO 2 were confirmed to be oxygen negative ions (O - ) by the use of quadrupole mass spectrometer. The emission current decreased with time as was observed in the earlier works with other oxide ion conductors such as stabilized zirconia or other materials . To enhance the emission current from CeO 2 , an introduction of donor into CeO 2 was tested using Ce 0.992 Nb 0.008 O 2 . For comparison, effect of acceptor doping was also tested using Ce 0.9 Gd 0.1 O 1.95 . The emission current from Ce 0.9 Gd 0.1 O 1.95 was smaller than that from donor-doped and pure CeO 2. Clear enhancement of the emission current was not observed with Ce 0.992 Nb 0.008 O 2

  6. Investigation of oxygen distribution in HTSC-insulator in film structures on light ion beam

    International Nuclear Information System (INIS)

    Verbitskaya, E.M.; Grekhov, I.V.; Eremin, V.K.; Konnikov, S.G.; Linijchuk, I.A.; Razumov, S.V.; Semchinova, O.K.; Strokan, N.B.; Dyumin, A.N.; Lebedev, V.M.

    1992-01-01

    Use of nuclear reaction method on accelerated ions for profiling of oxygen concentration in thin-film HTSC structures is considered. Reaction on 16 O(d, α) 14 N deuterons, in course of which ∼ 2.6 MeV α-particles are generated, is used. Detected in experiment 2.0-2.6 MeV α-particle spectrum permits to recognstruct oxygen concentration profile in sample depth. Results obtained on YBa 2 Cu 3 O 7-δ and Y 2 BaCuO 5 film om MgO sunstrates, relating to the case of both uniform and nonuniform oxygen distribution, are presented. Resolution in the depth ∼ 200 A and accuracy of concentration measurement (relatively MgO substrate) of several percents are attained during oxygen profiling

  7. Polarisation-preserving photon frequency conversion from a trapped-ion-compatible wavelength to the telecom C-band

    Science.gov (United States)

    Krutyanskiy, V.; Meraner, M.; Schupp, J.; Lanyon, B. P.

    2017-09-01

    We demonstrate polarisation-preserving frequency conversion of single-photon-level light at 854 nm, resonant with a trapped-ion transition and qubit, to the 1550-nm telecom C band. A total photon in / fiber-coupled photon out efficiency of ˜30% is achieved, for a free-running photon noise rate of ˜60 Hz. This performance would enable telecom conversion of 854 nm polarisation qubits, produced in existing trapped-ion systems, with a signal-to-noise ratio greater than 1. In combination with near-future trapped-ion systems, our converter would enable the observation of entanglement between an ion and a photon that has travelled more than 100 km in optical fiber: three orders of magnitude further than the state-of-the-art.

  8. DISSOLVED OXYGEN REDUCTION IN THE DIII-D NEUTRAL BEAM ION SOURCE COOLING SYSTEM

    International Nuclear Information System (INIS)

    YIP, H.; BUSATH, J.; HARRISON, S.

    2004-03-01

    OAK-B135 Neutral beam ion sources (NBIS) are critical components for the neutral beam injection system supporting the DIII-D tokamak. The NBIS must be cooled with 3028 (ell)/m (800 gpm) of de-ionized and de-oxygenated water to protect the sources from overheating and failure. These ions sources are currently irreplaceable. Since the water cooled molybdenum components will oxidize in water almost instantaneously in the presence of dissolved oxygen (DO), de-oxygenation is extremely important in the NBIS water system. Under normal beam operation the DO level is kept below 5 ppb. However, during weeknights and weekends when neutral beam is not in operation, the average DO level is maintained below 10 ppb by periodic circulation with a 74.6 kW (100 hp) pump, which consumes significant power. Experimental data indicated evidence of continuous oxygen diffusion through non-metallic hoses in the proximity of the NBIS. Because of the intermittent flow of the cooling water, the DO concentration at the ion source(s) could be even higher than measured downstream, and hence the concern of significant localized oxidation/corrosion. A new 3.73 kW (5 hp) auxiliary system, installed in the summer of 2003, is designed to significantly reduce the peak and the time-average DO levels in the water system and to consume only a fraction of the power

  9. Heavy-ion induced secondary electron emission from Mg, Al, and Si partially covered with oxygen

    International Nuclear Information System (INIS)

    Weng, J; Veje, E.

    1984-01-01

    We have bombarded Mg, Al, and Si with 80 keV Ar + ions and measured the secondary electron emission yields at projectile incidence angles from 0 0 to 85 0 , with oxygen present at the target as well as under UHV conditions. The total secondary electron emission yields are found to depend fairly much on the amount of oxygen present. The three elements studied show relatively large individual variations. For all three elements, and with as well as without oxygen present, the relative secondary electron emission yield is observed to vary as 1/cos v, where v is the angle of incidence of the projectiles. This seems to indicate that the secondary electron production is initiated uniformly along the projectile path in the solid, in a region close to the surface. The results are discussed, and it is tentatively suggested, that the increase in secondary electron emission, caused by the presence of oxygen, originates from neutralization of sputtered oxygen, which initially is sitting as O 2- ions. (orig.)

  10. Electron loss from multiply protonated lysozyme ions in high energy collisions with molecular oxygen

    DEFF Research Database (Denmark)

    Hvelplund, P; Nielsen, SB; Sørensen, M

    2001-01-01

    We report on the electron loss from multiply protonated lysozyme ions Lys-Hn(n)+ (n = 7 - 17) and the concomitant formation of Lys-Hn(n+1)+. in high-energy collisions with molecular oxygen (laboratory kinetic energy = 50 x n keV). The cross section for electron loss increases with the charge state...... of the precursor from n = 7 to n = 11 and then remains constant when n increases further. The absolute size of the cross section ranges from 100 to 200 A2. The electron loss is modeled as an electron transfer process between lysozyme cations and molecular oxygen....

  11. Oxygen adsorption on Cu(111) using low energy ion scattering spectroscopy

    International Nuclear Information System (INIS)

    Zhang, F.M.; Yao, J.; Shen, Y.G.; King, B.V.; O'Connor, D.J.

    1993-01-01

    The surface structure and oxygen adsorption of Cu(l 11) have been studied by 2 keV Li + , He + and Ar + ion scattering . Incident and azimuthal dependences were measured for the clean and O-covered surfaces, and the surface geometry was analysed on the basis of the shadowing features. Experimental results under different oxygen exposures at room temperature showed that the Cu(l 11) surface undergoes a roughening transition and results in a reconstruction where Cu atoms are vertically displaced by about 0.23 Angstroms. 4 refs., 4 figs

  12. Oxygen adsorption on Cu(111) using low energy ion scattering spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, F M; Yao, J; Shen, Y G; King, B V; O` Connor, D J [Newcastle Univ., NSW (Australia). Dept. of Physics

    1994-12-31

    The surface structure and oxygen adsorption of Cu(l 11) have been studied by 2 keV Li{sup +}, He{sup +} and Ar{sup +} ion scattering . Incident and azimuthal dependences were measured for the clean and O-covered surfaces, and the surface geometry was analysed on the basis of the shadowing features. Experimental results under different oxygen exposures at room temperature showed that the Cu(l 11) surface undergoes a roughening transition and results in a reconstruction where Cu atoms are vertically displaced by about 0.23 Angstroms. 4 refs., 4 figs.

  13. Oxygen adsorption on Cu(111) using low energy ion scattering spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, F.M.; Yao, J.; Shen, Y.G.; King, B.V.; O`Connor, D.J. [Newcastle Univ., NSW (Australia). Dept. of Physics

    1993-12-31

    The surface structure and oxygen adsorption of Cu(l 11) have been studied by 2 keV Li{sup +}, He{sup +} and Ar{sup +} ion scattering . Incident and azimuthal dependences were measured for the clean and O-covered surfaces, and the surface geometry was analysed on the basis of the shadowing features. Experimental results under different oxygen exposures at room temperature showed that the Cu(l 11) surface undergoes a roughening transition and results in a reconstruction where Cu atoms are vertically displaced by about 0.23 Angstroms. 4 refs., 4 figs.

  14. Improved surface corrosion resistance of WE43 magnesium alloy by dual titanium and oxygen ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Ying [Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Wu, Guosong; Lu, Qiuyuan [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Wu, Jun [Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong (China); Xu, Ruizhen [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Yeung, Kelvin W.K., E-mail: wkkyeung@hku.hk [Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong (China); Chu, Paul K., E-mail: paul.chu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2013-02-01

    Magnesium alloys are potential biodegradable materials and have attracted much attention due to their outstanding biological performance and mechanical properties. However, their rapid degradation inside the human body cannot meet clinical needs. In order to improve the corrosion resistance, dual titanium and oxygen ion implantation is performed to modify the surface of the WE43 magnesium alloy. X-ray photoelectron spectroscopy is used to characterize the microstructures in the near surface layer and electrochemical impedance spectroscopy, potentiodynamic polarization, and immersion tests are employed to investigate the corrosion resistance of the implanted alloys in simulated body fluids. The results indicate that dual titanium and oxygen ion implantation produces a TiO{sub 2}-containing surface film which significantly enhances the corrosion resistance of WE43 magnesium alloy. Our data suggest a simple and practical means to improve the corrosion resistance of degradable magnesium alloys. - Highlights: ► Surface modification of WE43 magnesium alloy using dual ion implantation ► Dual Ti and O ion implantation produces a homogeneous TiO{sub 2}-containing surface film ► Significant improvement of the alloy corrosion resistance after the dual ion implantation.

  15. Visible-light activate Ag/WO3 films based on wood with enhanced negative oxygen ions production properties

    Science.gov (United States)

    Gao, Likun; Gan, Wentao; Cao, Guoliang; Zhan, Xianxu; Qiang, Tiangang; Li, Jian

    2017-12-01

    The Ag/WO3-wood was fabricated through a hydrothermal method and a silver mirror reaction. The system of visible-light activate Ag/WO3-wood was used to produce negative oxygen ions, and the effect of Ag nanoparticles on negative oxygen ions production was investigated. From the results of negative oxygen ions production tests, it can be observed that the sample doped with Ag nanoparticles, the concentration of negative oxygen ions is up to 1660 ions/cm3 after 60 min visible light irradiation. Moreover, for the Ag/WO3-wood, even after 60 min without irradiation, the concentration of negative oxygen ions could keep more than 1000 ions/cm3, which is up to the standard of the fresh air. Moreover, due to the porous structure of wood, the wood acted as substrate could promote the nucleation of nanoparticles, prevent the agglomeration of the particles, and thus lead the improvement of photocatalytic properties. And such wood-based functional materials with the property of negative oxygen ions production could be one of the most promising materials in the application of indoor decoration materials, which would meet people's pursuit of healthy, environment-friendly life.

  16. Radial transport of high-energy oxygen ions into the deep inner magnetosphere observed by Van Allen Probes

    Science.gov (United States)

    Mitani, K.; Seki, K.; Keika, K.; Gkioulidou, M.; Lanzerotti, L. J.; Mitchell, D. G.; Kletzing, C.

    2017-12-01

    It is known that proton is main contributor of the ring current and oxygen ions can make significant contribution during major magnetic storms. Ions are supplied to the ring current by radial transport from the plasma sheet. Convective transport of lower-energy protons and diffusive transport of higher-energy protons were reported to contribute to the storm-time and quiet-time ring current respectively [e.g., Gkioulidou et al., 2016]. However, supply mechanisms of the oxygen ions are not clear. To characterize the supply of oxygen ions to the ring current during magnetic storms, we studied the properties of energetic proton and oxygen ion phase space densities (PSDs) for specific magnetic moment (μ) during the April 23-25, 2013, geomagnetic storm observed by the Van Allen Probes mission. We here report on radial transport of high-energy (μ ≥ 0.5 keV/nT) oxygen ions into the deep inner magnetosphere during the late main phase of the magnetic storm. Since protons show little change during this period, this oxygen radial transport is inferred to cause the development of the late main phase. Enhancement of poloidal magnetic fluctuations is simultaneously observed. We estimated azimuthal mode number ≤5 by using cross wavelet analysis with ground-based observation of IMAGE ground magnetometers. The fluctuations can resonate with drift and bounce motions of the oxygen ions. The results suggest that combination of the drift and drift-bounce resonances is responsible for the radial transport of high-energy oxygen ions into the deep inner magnetosphere. We also report on the radial transport of the high-energy oxygen ions into the deep inner magnetosphere during other magnetic storms.

  17. Collisions of carbon and oxygen ions with electrons, H, H2 and He: Volume 5

    International Nuclear Information System (INIS)

    Phaneuf, R.A.; Janev, R.K.; Pindzola, M.S.

    1987-02-01

    This report provides a handbook for fusion research of recommended cross-section and rate-coefficient data for collisions of carbon and oxygen ions with electrons, hydrogen atoms and molecules, and helium atoms. Published experimental and theoretical data have been collected and evaluated, and recommended data are presented in tabular, graphical, and parametrized form. Processes considered include exciation, ionization, and charge exchange at collision energies appropriate to applications in fusion-energy research

  18. Numerical simulation of ion transport membrane reactors: Oxygen permeation and transport and fuel conversion

    KAUST Repository

    Hong, Jongsup

    2012-07-01

    Ion transport membrane (ITM) based reactors have been suggested as a novel technology for several applications including fuel reforming and oxy-fuel combustion, which integrates air separation and fuel conversion while reducing complexity and the associated energy penalty. To utilize this technology more effectively, it is necessary to develop a better understanding of the fundamental processes of oxygen transport and fuel conversion in the immediate vicinity of the membrane. In this paper, a numerical model that spatially resolves the gas flow, transport and reactions is presented. The model incorporates detailed gas phase chemistry and transport. The model is used to express the oxygen permeation flux in terms of the oxygen concentrations at the membrane surface given data on the bulk concentration, which is necessary for cases when mass transfer limitations on the permeate side are important and for reactive flow modeling. The simulation results show the dependence of oxygen transport and fuel conversion on the geometry and flow parameters including the membrane temperature, feed and sweep gas flow, oxygen concentration in the feed and fuel concentration in the sweep gas. © 2012 Elsevier B.V.

  19. Surface modification effects of fluorine-doped tin dioxide by oxygen plasma ion implantation

    Science.gov (United States)

    Tang, Peng; Liu, Cai; Zhang, Jingquan; Wu, Lili; Li, Wei; Feng, Lianghuan; Zeng, Guanggen; Wang, Wenwu

    2018-04-01

    SnO2:F (FTO), as a kind of transparent conductive oxide (TCO), exhibits excellent transmittance and conductivity and is widely used as transparency electrodes in solar cells. It's very important to modifying the surface of FTO for it plays a critical role in CdTe solar cells. In this study, modifying effects of oxygen plasma on FTO was investigated systematically. Oxygen plasma treatment on FTO surface with ion accelerating voltage ranged from 0.4 kV to 1.6 kV has been processed. The O proportion of surface was increased after ion implantation. The Fermi level of surface measurement by XPS valance band spectra was lowered as the ion accelerating voltage increased to 1.2 kV and then raised as accelerating voltage was elevated to 1.6 kV. The work function measured by Kelvin probe force microscopy increased after ion implanting, and it was consistent with the variation of Fermi level. The change of energy band structure of FTO surface mainly originated from the surface composition variation. As FTO conduction was primarily due to oxyanion hole, the carrier was electron and its concentration was reduced while O proportion was elevated at the surface of FTO, as a result, the Fermi level lowered and the work function was enlarged. It was proved that oxygen plasma treatment is an effective method to modulate the energy band structure of the surface as well as other properties of FTO, which provides much more space for interface and surface modification and then photoelectric device performance promotion.

  20. Dayside pickup oxygen ion precipitation at Venus and Mars: Spatial distributions, energy deposition and consequences

    International Nuclear Information System (INIS)

    Luhmann, J.G.; Kozyra, J.U.

    1991-01-01

    The fluxes and energy spectra of picked-up planetary O + ions incident on the dayside atmospheres of Venus and Mars are calculated using the neutral exposure models of Nagy and Cravens (1988) and the Spreiter and Stahara (1980) gasdynamic model of the magnetosheath electric and magnetic field. Cold (∼10 eV) O + ions are launched from hemispherical grids of starting points covering the daysides of the planets and their trajectories are followed until they either impact the dayside obstacle or cross the terminator plane. The impacting, or precipitating, ion fluxes are weighted according to the altitude of the hemispherical starting point grid in a manner consistent with the exosphere density models and the local photoion production rate. Maps of precipitating ion number flux and energy flux show the asymmetrical distribution of dayside energy deposition expected from this source which is unique to the weakly magnetized planets. Although the associated heating of the atmosphere and ionsphere is found to be negligible compared to that from the usual sources, backscattered or sputtered neutral oxygen atoms are produced at energies exceeding that needed for escape from the gravitational fields of both planets. These neutral winds, driven by pickup ion precipitation, represent a possibly significant loss of atmospheric constituents over the age of the solar system

  1. Study of silicon doped with zinc ions and annealed in oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Privezentsev, V. V., E-mail: v.privezentsev@mail.ru [Russian Academy of Sciences, Institute of Physics and Technology (Russian Federation); Kirilenko, E. P.; Goryachev, A. N. [Zelenograd, National Research University of Electronic Technology “MIET” (Russian Federation); Batrakov, A. A. [National Research University “MEI” (Russian Federation)

    2017-02-15

    The results of studies of the surface layer of silicon and the formation of precipitates in Czochralski n-Si (100) samples implanted with {sup 64}Zn{sup +} ions with an energy of 50 keV and a dose of 5 × 10{sup 16} cm{sup –2} at room temperature and then oxidized at temperatures from 400 to 900°C are reported. The surface is visualized using an electron microscope, while visualization of the surface layer is conducted via profiling in depth by elemental mapping using Auger electron spectroscopy. The distribution of impurity ions in silicon is analyzed using a time-of-flight secondary-ion mass spectrometer. Using X-ray photoelectron spectroscopy, the chemical state of atoms of the silicon matrix and zinc and oxygen impurity atoms is studied, and the phase composition of the implanted and annealed samples is refined. After the implantation of zinc, two maxima of the zinc concentration, one at the wafer surface and the other at a depth of 70 nm, are observed. In this case, nanoparticles of the Zn metal phase and ZnO phase, about 10 nm in dimensions, are formed at the surface and in the surface layer. After annealing in oxygen, the ZnO · Zn{sub 2}SiO{sub 4} and Zn · ZnO phases are detected near the surface and at a depth of 50 nm, respectively.

  2. Study of silicon doped with zinc ions and annealed in oxygen

    International Nuclear Information System (INIS)

    Privezentsev, V. V.; Kirilenko, E. P.; Goryachev, A. N.; Batrakov, A. A.

    2017-01-01

    The results of studies of the surface layer of silicon and the formation of precipitates in Czochralski n-Si (100) samples implanted with "6"4Zn"+ ions with an energy of 50 keV and a dose of 5 × 10"1"6 cm"–"2 at room temperature and then oxidized at temperatures from 400 to 900°C are reported. The surface is visualized using an electron microscope, while visualization of the surface layer is conducted via profiling in depth by elemental mapping using Auger electron spectroscopy. The distribution of impurity ions in silicon is analyzed using a time-of-flight secondary-ion mass spectrometer. Using X-ray photoelectron spectroscopy, the chemical state of atoms of the silicon matrix and zinc and oxygen impurity atoms is studied, and the phase composition of the implanted and annealed samples is refined. After the implantation of zinc, two maxima of the zinc concentration, one at the wafer surface and the other at a depth of 70 nm, are observed. In this case, nanoparticles of the Zn metal phase and ZnO phase, about 10 nm in dimensions, are formed at the surface and in the surface layer. After annealing in oxygen, the ZnO · Zn_2SiO_4 and Zn · ZnO phases are detected near the surface and at a depth of 50 nm, respectively.

  3. Anisotropic Oxygen Ion Diffusion in Layered PrBaCo 2 O 5+δ

    KAUST Repository

    Burriel, Mónica

    2012-02-14

    Oxygen diffusion and surface exchange coefficients have been measured on polycrystalline samples of the double perovskite oxide PrBaCo 2O 5+δ by the isotope exchange depth profile method, using a time-of-flight SIMS instrument. The measured diffusion coefficients show an activation energy of 1.02 eV, as compared to 0.89 eV for the surface exchange coefficients in the temperature range from 300 to 670 °C. Inhomogeneity was observed in the distribution of the oxygen-18 isotopic fraction from grain to grain in the ceramic samples, which was attributed to anisotropy in the diffusion and exchange of oxygen. By the use of a novel combination of electron back scattered diffraction measurements, time-of-flight, and focused ion beam SIMS, this anisotropy was confirmed by in-depth analysis of single grains of known orientation in a ceramic sample exchanged at 300 °C. Diffusion was shown to be faster in a grain oriented with the surface normal close to 100 and 010 (ab-plane oriented) than a grain with a surface normal close to 001 (c-axis oriented). The magnitude of this anisotropy is estimated to be close to a factor of 4, but this is only a lower bound due to experimental limitations. These findings are consistent with recent molecular dynamic simulations of this material where anisotropy in the oxygen transport was predicted. © 2012 American Chemical Society.

  4. Role of metal ion impurities in generation of oxygen gas within anodic alumina

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, K. [Keio Univ., Yokohama (Japan). Chemical Lab.; Habazaki, H. [Hokkaido Univ., Sapporo (Japan). Graduate School of Engineering; Skeldon, P.; Thompson, G.E.; Wood, G.C. [University of Manchester Inst. of Science and Technology (United Kingdom). Corrosion and Protection Centre

    2002-07-01

    The generation of oxygen gas within an amorphous anodic alumina film is reported. The film was formed by anodizing aluminum, which was first electropolished and then chemically polished in CrO{sub 3}-H{sub 3}PO{sub 4} solution, in sodium tungstate electrolyte. The procedure results in incorporation of mobile Cr{sup 3+} species, from the chemical polishing film, and mobile W{sup 6+} species, from the electrolyte, into the amorphous structure. The tungsten species are present in the outer 27% of the film thickness, while Cr{sup 6+} species occupy a thin layer within the tungsten-containing region. Above the Cr{sup 3+} containing layer, a band develops that contains oxygen bubbles of a few nanometres size. The oxygen is generated by oxidation of O{sup 2-} ions of the alumina. A mechanism of oxygen generation within the alumina is proposed based on the electronic band structure of the oxide, modified by the Cr{sup 3+} and W{sup 6+} species, and on the ionic transport processes during oxide growth. (author)

  5. Post oxygen treatment characteristics of coke as an anode material for Li-ion batteries.

    Science.gov (United States)

    Kim, Jae-Hun; Park, Min-Sik; Jo, Yong Nam; Yu, Ji-Sang; Jeong, Goojin; Kim, Young-Jun

    2013-05-01

    The effect of a oxygen treatment on the electrochemical characteristics of a soft carbon anode material for Li-ion batteries was investigated. After a coke carbonization process at 1000 degrees C in an argon atmosphere, the samples were treated under a flow of oxygen gas to obtain a mild oxidation effect. After this oxygen treatment, the coke samples exhibited an improved initial coulombic efficiency and cycle performance as compared to the carbonized sample. High-resolution transmission electron microscopy revealed that the carbonized cokes consisted of disordered and nanosized graphene layers and the surface of the modified carbon was significantly changed after the treatment. The chemical state of the cokes was analyzed using X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The enhanced electrochemical properties of the surface modified cokes could be attributed to the mild oxidation effect induced by the oxygen treatment. The mild oxidation process could have led to the elimination of surface imperfections and the reinforcement of a solid electrolyte interphase film, which resulted in the improved electrochemical characteristics.

  6. Anisotropic Oxygen Ion Diffusion in Layered PrBaCo 2 O 5+δ

    KAUST Repository

    Burriel, Mó nica; Peñ a-Martí nez, Juan; Chater, Richard J.; Fearn, Sarah; Berenov, Andrey V.; Skinner, Stephen J.; Kilner, John A.

    2012-01-01

    Oxygen diffusion and surface exchange coefficients have been measured on polycrystalline samples of the double perovskite oxide PrBaCo 2O 5+δ by the isotope exchange depth profile method, using a time-of-flight SIMS instrument. The measured diffusion coefficients show an activation energy of 1.02 eV, as compared to 0.89 eV for the surface exchange coefficients in the temperature range from 300 to 670 °C. Inhomogeneity was observed in the distribution of the oxygen-18 isotopic fraction from grain to grain in the ceramic samples, which was attributed to anisotropy in the diffusion and exchange of oxygen. By the use of a novel combination of electron back scattered diffraction measurements, time-of-flight, and focused ion beam SIMS, this anisotropy was confirmed by in-depth analysis of single grains of known orientation in a ceramic sample exchanged at 300 °C. Diffusion was shown to be faster in a grain oriented with the surface normal close to 100 and 010 (ab-plane oriented) than a grain with a surface normal close to 001 (c-axis oriented). The magnitude of this anisotropy is estimated to be close to a factor of 4, but this is only a lower bound due to experimental limitations. These findings are consistent with recent molecular dynamic simulations of this material where anisotropy in the oxygen transport was predicted. © 2012 American Chemical Society.

  7. Range measurements of keV hydrogen ions in solid oxygen and carbon monoxide

    International Nuclear Information System (INIS)

    Schou, J.; Soerensen, H.; Andersen, H.H.; Nielsen, M.; Rune, J.

    1984-01-01

    Ranges of 1.3-3.5 keV/atom hydrogen and deuterium molecular ions have been measured by a thin-film reflection method. The technique, used here for range measurements in solid oxygen and carbon monoxide targets, is identical to the one used previously for range measurements in hydrogen and nitrogen. The main aim was to look for phase-effects, i.e. gas-solid differences in the stopping processes. While measured ranges in solid oxygen were in agreement with known gas data, the ranges in solid carbon monoxide were up to 50% larger than those calculated from gas-stopping data. The latter result agrees with that previously found for solid nitrogen. (orig.)

  8. The Effect of Solar Wind Variations on the Escape of Oxygen Ions From Mars Through Different Channels: MAVEN Observations

    Science.gov (United States)

    Dubinin, E.; Fraenz, M.; Pätzold, M.; McFadden, J.; Halekas, J. S.; DiBraccio, G. A.; Connerney, J. E. P.; Eparvier, F.; Brain, D.; Jakosky, B. M.; Vaisberg, O.; Zelenyi, L.

    2017-11-01

    We present multi-instrument observations of the effects of solar wind on ion escape fluxes on Mars based on the Mars Atmosphere and Volatile EvolutioN (MAVEN) data from 1 November 2014 to 15 May 2016. Losses of oxygen ions through different channels (plasma sheet, magnetic lobes, boundary layer, and ion plume) as a function of the solar wind and the interplanetary magnetic field variations were studied. We have utilized the modified Mars Solar Electric (MSE) coordinate system for separation of the different escape routes. Fluxes of the low-energy (≤30 eV) and high-energy (≥30 eV) ions reveal different trends with changes in the solar wind dynamic pressure, the solar wind flux, and the motional electric field. Major oxygen fluxes occur through the tail of the induced magnetosphere. The solar wind motional electric field produces an asymmetry in the ion fluxes and leads to different relations between ion fluxes supplying the tail from the different hemispheres and the solar wind dynamic pressure (or flux) and the motional electric field. The main driver for escape of the high-energy oxygen ions is the solar wind flux (or dynamic pressure). On the other hand, the low-energy ion component shows the opposite trend: ion flux decreases with increasing solar wind flux. As a result, the averaged total oxygen ion fluxes reveal a low variability with the solar wind strength. The large standard deviations from the averages values of the escape fluxes indicate the existence of mechanisms which can enhance or suppress the efficiency of the ion escape. It is shown that the Martian magnetosphere possesses the properties of a combined magnetosphere which contains different classes of field lines. The existence of the closed magnetic field lines in the near-Mars tail might be responsible for suppression of the ion escape fluxes.

  9. Characteristics of high altitude oxygen ion energization and outflow as observed by Cluster: a statistical study

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, H.; Waara, M.; Arvelius, S.; Yamauchi, M.; Lundin, R. [Inst. of Space Physics, Kiruna (Sweden); Marghitu, O. [Max-Planck-Inst. fuer Extraterrestriche Physik, Garching (Germany); Inst. for Space Sciences, Bucharest (Romania); Bouhram, M. [Max-Planck-Inst. fuer Extraterrestriche Physik, Garching (Germany); CETP-CNRS, Saint-Maur (France); Hobara, Y. [Inst. of Space Physics, Kiruna (Sweden); Univ. of Sheffield, Sheffield (United Kingdom); Reme, H.; Sauvaud, J.A.; Dandouras, I. [Centre d' Etude Spatiale des Rayonnements, Toulouse (France); Balogh, A. [Imperial Coll. of Science, Technology and Medicine, London (United Kingdom); Kistler, L.M. [Univ. of New Hampshire, Durham (United States); Klecker, B. [Max-Planck-Inst. fuer Extraterrestriche Physik, Garching (Germany); Carlson, C.W. [Space Science Lab., Univ. of California, Berkeley (United States); Bavassano-Cattaneo, M.B. [Ist. di Fisica dello Spazio Interplanetario, Roma (Italy); Korth, A. [Max-Planck-Inst. fuer Sonnensystemforschung, Katlenburg-Lindau (Germany)

    2006-07-01

    The results of a statistical study of oxygen ion outflow using cluster data obtained at high altitude above the polar cap is reported. Moment data for both hydrogen ions (H{sup +}) and oxygen ions (O{sup +}) from 3 years (2001-2003) of spring orbits (January to May) have been used. The altitudes covered were mainly in the range 5-12 R{sub E} geocentric distance. It was found that O{sup +} is significantly transversely energized at high altitudes, indicated both by high perpendicular temperatures for low magnetic field values as well as by a tendency towards higher perpendicular than parallel temperature distributions for the highest observed temperatures. The O{sup +} parallel bulk velocity increases with altitude in particular for the lowest observed altitude intervals. O{sup +} parallel bulk velocities in excess of 60 km s{sup -1} were found mainly at higher altitudes corresponding to magnetic field strengths of less than 100 nT. For the highest observed parallel bulk velocities of O{sup +} the thermal velocity exceeds the bulk velocity, indicating that the beam-like character of the distribution is lost. The parallel bulk velocity of the H{sup +} and O{sup +} was found to typically be close to the same throughout the observation interval when the H{sup +} bulk velocity was calculated for all pitch-angles. When the H{sup +} bulk velocity was calculated for upward moving particles only the H{sup +} parallel bulk velocity was typically higher than that of O{sup +}. The parallel bulk velocity is close to the same for a wide range of relative abundance of the two ion species, including when the O{sup +} ions dominates. The thermal velocity of O{sup +} was always well below that of H{sup +}. Thus perpendicular energization that is more effective for O{sup +} takes place, but this is not enough to explain the close to similar parallel velocities. Further parallel acceleration must occur. The results presented constrain the models of perpendicular heating and parallel

  10. Characteristics of high altitude oxygen ion energization and outflow as observed by Cluster: a statistical study

    Directory of Open Access Journals (Sweden)

    H. Nilsson

    2006-05-01

    Full Text Available The results of a statistical study of oxygen ion outflow using Cluster data obtained at high altitude above the polar cap is reported. Moment data for both hydrogen ions (H+ and oxygen ions (O+ from 3 years (2001-2003 of spring orbits (January to May have been used. The altitudes covered were mainly in the range 5–12 RE geocentric distance. It was found that O+ is significantly transversely energized at high altitudes, indicated both by high perpendicular temperatures for low magnetic field values as well as by a tendency towards higher perpendicular than parallel temperature distributions for the highest observed temperatures. The O+ parallel bulk velocity increases with altitude in particular for the lowest observed altitude intervals. O+ parallel bulk velocities in excess of 60 km s-1 were found mainly at higher altitudes corresponding to magnetic field strengths of less than 100 nT. For the highest observed parallel bulk velocities of O+ the thermal velocity exceeds the bulk velocity, indicating that the beam-like character of the distribution is lost. The parallel bulk velocity of the H+ and O+ was found to typically be close to the same throughout the observation interval when the H+ bulk velocity was calculated for all pitch-angles. When the H+ bulk velocity was calculated for upward moving particles only the H+ parallel bulk velocity was typically higher than that of O+. The parallel bulk velocity is close to the same for a wide range of relative abundance of the two ion species, including when the O+ ions dominates. The thermal velocity of O+ was always well below that of H+. Thus perpendicular energization that is more effective for O+ takes place, but this is not enough to explain the close to similar parallel velocities. Further

  11. Characteristics of high altitude oxygen ion energization and outflow as observed by Cluster: a statistical study

    Directory of Open Access Journals (Sweden)

    H. Nilsson

    2006-05-01

    Full Text Available The results of a statistical study of oxygen ion outflow using Cluster data obtained at high altitude above the polar cap is reported. Moment data for both hydrogen ions (H+ and oxygen ions (O+ from 3 years (2001-2003 of spring orbits (January to May have been used. The altitudes covered were mainly in the range 5–12 RE geocentric distance. It was found that O+ is significantly transversely energized at high altitudes, indicated both by high perpendicular temperatures for low magnetic field values as well as by a tendency towards higher perpendicular than parallel temperature distributions for the highest observed temperatures. The O+ parallel bulk velocity increases with altitude in particular for the lowest observed altitude intervals. O+ parallel bulk velocities in excess of 60 km s-1 were found mainly at higher altitudes corresponding to magnetic field strengths of less than 100 nT. For the highest observed parallel bulk velocities of O+ the thermal velocity exceeds the bulk velocity, indicating that the beam-like character of the distribution is lost. The parallel bulk velocity of the H+ and O+ was found to typically be close to the same throughout the observation interval when the H+ bulk velocity was calculated for all pitch-angles. When the H+ bulk velocity was calculated for upward moving particles only the H+ parallel bulk velocity was typically higher than that of O+. The parallel bulk velocity is close to the same for a wide range of relative abundance of the two ion species, including when the O+ ions dominates. The thermal velocity of O+ was always well below that of H+. Thus perpendicular energization that is more effective for O+ takes place, but this is not enough to explain the close to similar parallel velocities. Further parallel acceleration must occur. The results presented constrain the models of perpendicular heating and parallel acceleration. In particular centrifugal acceleration of the outflowing ions, which may

  12. Oxygen ion uplift and satellite drag effects during the 30 October 2003 daytime superfountain event

    Directory of Open Access Journals (Sweden)

    B. T. Tsurutani

    2007-03-01

    Full Text Available The prompt penetration of interplanetary electric fields (IEFs to the dayside low-latitude ionosphere during the first ~2 h of a superstorm is estimated and applied to a modified NRL SAMI2 code for the 30 October 2003 event. In our simulations, the dayside ionospheric O+ is convected to higher altitudes (~600 km and higher latitudes (~±25° to 30°, forming highly displaced equatorial ionospheric anomaly (EIA peaks. This feature plus others are consistent with previously published CHAMP electron (TEC measurements and with the dayside superfountain model. The rapid upward motion of the O+ ions causes neutral oxygen (O uplift due to ion-neutral drag. It is estimated that above ~400 km altitude the O densities within the displaced EIAs can be increased substantially over quiet time values. The latter feature will cause increased drag for low-altitude satellites. This newly predicted phenomenon is expected to be typical for superstorm/IEF events.

  13. Photoluminescence of Se-related oxygen deficient center in ion-implanted silica films

    International Nuclear Information System (INIS)

    Zatsepin, A.F.; Buntov, E.A.; Pustovarov, V.A.; Fitting, H.-J.

    2013-01-01

    The results of low-temperature time-resolved photoluminescence (PL) investigation of thin SiO 2 films implanted with Se + ions are presented. The films demonstrate an intensive PL band in the violet spectral region, which is attributed to the triplet luminescence of a new variant of selenium-related oxygen deficient center (ODC). The main peculiarity of the defect energy structure is the inefficient direct optical excitation. Comparison with spectral characteristics of isoelectronic Si-, Ge- and SnODCs show that the difference in electronic properties of the new center is related to ion size factor. It was established that the dominating triplet PL excitation under VUV light irradiation is related to the energy transfer from SiO 2 excitons. A possible model of Se-related ODC is considered. -- Highlights: • The low-temperature photoluminescence of thin SiO 2 films implanted with Se + ions was studied. • The 3.4 eV PL band was attributed to triplet luminescence of Se-related ODC. • The peculiarity of SeODC electronic properties is related to ion size factor. • The dominating VUV excitation of triplet PL is related to energy transfer from SiO 2 excitons. • A possible model of Se-related ODC is considered

  14. Tumour control in ion beam radiotherapy with different ions in the presence of hypoxia: an oxygen enhancement ratio model based on the microdosimetric kinetic model

    Science.gov (United States)

    Strigari, L.; Torriani, F.; Manganaro, L.; Inaniwa, T.; Dalmasso, F.; Cirio, R.; Attili, A.

    2018-03-01

    Few attempts have been made to include the oxygen enhancement ratio (OER) in treatment planning for ion beam therapy, and systematic studies to evaluate the impact of hypoxia in treatment with the beam of different ion species are sorely needed. The radiobiological models used to quantify the OER in such studies are mainly based on the dose-averaged LET estimates, and do not explicitly distinguish between the ion species and fractionation schemes. In this study, a new type of OER modelling, based on the microdosimetric kinetic model, taking into account the specificity of the different ions, LET spectra, tissues and fractionation schemes, has been developed. The model has been benchmarked with published in vitro data, HSG, V79 and CHO cells in aerobic and hypoxic conditions, for different ion irradiation. The model has been included in the simulation of treatments for a clinical case (brain tumour) using proton, lithium, helium, carbon and oxygen ion beams. A study of the tumour control probability (TCP) as a function of oxygen partial pressure, dose per fraction and primary ion type has been performed. The modelled OER depends on both the LET and ion type, also showing a decrease for an increased dose per fraction with a slope that depends on the LET and ion type, in good agreement with the experimental data. In the investigated clinical case, a significant increase in TCP has been found upon increasing the ion charge. Higher OER variations as a function of dose per fraction have also been found for low-LET ions (up to 15% varying from 2 to 8 Gy(RBE) for protons). This model could be exploited in the identification of treatment condition optimality in the presence of hypoxia, including fractionation and primary particle selection.

  15. The obtaining and properties of asymmetric ion transport membrane for separating of oxygen from air

    Science.gov (United States)

    Solovieva, A. A.; Kulbakin, I. V.

    2018-04-01

    The bilayer oxygen-permeable membrane, consisting of a thin-film dense composite based on Co3O4 - 36 wt. % Bi2O3, and of a porous ceramic substrate of Co2SiO4, was synthesized and characterized. The way for obtaining of porous ceramic based on cobalt silicate was found, while the microstructure and the mechanical properties of porous ceramic were studied. Layered casting with post-pressing was used to cover the surface of porous support of Co2SiO4 by the Co3O4 - 36 wt. % Bi2O3 - based film. Transport properties of the asymmetric membrane have been studied, the kinetic features of oxygen transport have been established, and the characteristic thickness of the membrane has been estimated. The methods to prevent the high-temperature creep of ion transport membranes based on solid/molten oxides, which are the promising ones for obtaining of pure oxygen from air, are proposed and discussed.

  16. Si-O compound formation by oxygen ion implantation into silicon

    International Nuclear Information System (INIS)

    Hensel, E.; Wollschlaeger, K.; Kreissig, U.; Skorupa, W.; Schulze, D.; Finster, J.

    1985-01-01

    High dose oxygen ion implantation into silicon at 30 keV was performed to produce understoichiometric and stoichiometric surface oxide layers of approx. 160 nm thickness. The oxygen depth profile and oxide stoichiometry was determined by RBS and XPS. Si-O compound formation was found by IR spectroscopy and XPS in the unannealed samples as well as after target heating, furnace or flash lamp annealing. As implanted understoichiometric layers consist of random bonding like SiOsub(x) (O 2 after annealing. Unannealed stoichiometric layers are bond strained SiO 2 . The activation energies of demixing and of the annealing of bond strains are determined to 0.19 and 0.13 eV, respectively. The removing of bond strains occurs at temperatures >= 800 C in a time shorter than 1 s. The SiO 2 /Si transition region of unannealed stoichiometric layers consists of SiOsub(x) with an extent of about 10 nm. After annealing this extent diminishes to 0.8 to 1 nm in consequence of oxidation by excess oxygen from the overstoichiometric oxide region. This thickness is comparable with that of thermal oxide. (author)

  17. Structural, thermal and optical behavior of 84 MeV oxygen and 120 MeV silicon ions irradiated PES

    International Nuclear Information System (INIS)

    Samra, Kawaljeet Singh; Thakur, Sonika; Singh, Lakhwant

    2011-01-01

    In order to study structural, thermal and optical behavior, thin flat samples of polyethersulfone were irradiated with oxygen and silicon ions. The changes in properties were analyzed using different techniques viz: X-ray diffraction, thermo-gravimetric analysis, Fourier transform infrared, UV-visible and photoluminescence spectroscopy. A noticeable increase in the intensity of X-ray diffraction peaks was observed after irradiation with 84 MeV oxygen ions at low and medium fluences, which may be attributed to radiation-induced cross-linking in polymer. Fourier transform infrared and thermo-gravimetric analysis corroborated the results of X-ray diffraction analysis. No noticeable change in the Fourier transform infrared spectra of oxygen ion irradiated polyethersulfone were observed even at the highest fluence of 1 x 10 13 ions cm -2 , but after irradiation with silicon ions, a reduction in intensity of almost all characteristic bands was revealed. An increase in the activation energy of decomposition of polyethersulfone was observed after irradiation with 84 MeV oxygen ions up to medium fluences but degradation was revealed at higher fluences. Similar trends were observed by photoluminescence analysis.

  18. Depth distribution of carrier lifetime in 65 MeV oxygen ion irradiated silicon wafers

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.S. [Ecotopia Science Institute, Division of Energy Science, Nagoya University, Nagoya (Japan); Dahiwale, S.S. [Department of Physics, University of Pune, Pune 411 007 (India); Kanjilal, D. [Nuclear Science Centre, New Delhi (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 411 007 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 411 007 (India)]. E-mail: sanjay@physics.unipune.ernet.in

    2006-03-15

    CZ-grown, n-doped crystalline Si(1 1 1) of resistivity 60 {omega} cm and 140 {omega} cm were irradiated with 65 MeV energy oxygen ions, in the fluence range of 2 x 10{sup 1}-10{sup 14} ions/cm{sup 2}. The depth and spatial profile of excess minority carrier recombination time {tau} (lifetime) was measured using photoconductive decay (PCD) method. Lifetime measurements were carried out before the stopping range of impinging ions. Results show a monotonous decrease in lifetime with fluence, which is attributed to defect creation mechanism by electronic energy loss based on the thermal spike model. Also, surface modification is expected with a small loss in crystalline quality. This surface is considered to be a multi-crystalline surface with large grain boundaries that act as trapping sites for excess holes in n-Si(1 1 1). Annealing of the irradiated samples showed a near complete recovery at 750 deg. C for a period of 1 h.

  19. Laminar oxy-fuel diffusion flame supported by an oxygen-permeable-ion-transport membrane

    KAUST Repository

    Hong, Jongsup

    2013-03-01

    A numerical model with detailed gas-phase chemistry and transport was used to predict homogeneous fuel conversion processes and to capture the important features (e.g., the location, temperature, thickness and structure of a flame) of laminar oxy-fuel diffusion flames stabilized on the sweep side of an oxygen permeable ion transport membrane (ITM). We assume that the membrane surface is not catalytic to hydrocarbon or syngas oxidation. It has been demonstrated that an ITM can be used for hydrocarbon conversion with enhanced reaction selectivity such as oxy-fuel combustion for carbon capture technologies and syngas production. Within an ITM unit, the oxidizer flow rate, i.e., the oxygen permeation flux, is not a pre-determined quantity, since it depends on the oxygen partial pressures on the feed and sweep sides and the membrane temperature. Instead, it is influenced by the oxidation reactions that are also dependent on the oxygen permeation rate, the initial conditions of the sweep gas, i.e., the fuel concentration, flow rate and temperature, and the diluent. In oxy-fuel combustion applications, the sweep side is fuel-diluted with CO2, and the entire unit is preheated to achieve a high oxygen permeation flux. This study focuses on the flame structure under these conditions and specifically on the chemical effect of CO2 dilution. Results show that, when the fuel diluent is CO2, a diffusion flame with a lower temperature and a larger thickness is established in the vicinity of the membrane, in comparison with the case in which N2 is used as a diluent. Enhanced OH-driven reactions and suppressed H radical chemistry result in the formation of products with larger CO and H2O and smaller H2 concentrations. Moreover, radical concentrations are reduced due to the high CO2 fraction in the sweep gas. CO2 dilution reduces CH3 formation and slows down the formation of soot precursors, C2H2 and C2H4. The flame location impacts the species diffusion and heat transfer from the

  20. Electromagnetic ion cyclotron waves observed near the oxygen cyclotron frequency by ISEE 1 and 2

    International Nuclear Information System (INIS)

    Fraser, B.J.; Samson, J.C.; Hu, Y.D.; McPherron, R.L.; Russell, C.T.

    1992-01-01

    Pc 2 electromagnetic ion cyclotron waves at 0.1 waves at 0.1 Hz, near the oxygen cyclotron frequency, have been observed by ISEE 1 and 2 between L = 7.6 and 5.8 on an inbound near-equatorial pass in the dusk sector. The waves occurred in a thick plasmapause of width ∼ 1.5 R E and penetrated ∼1 R E into the plasmasphere. Wave onset was accompanied by significant increases in the thermal (0-100 eV) He + and the warm (0.1-16 keV/e) O + and He + heavy ion populations. The most intense waves (8 nT) were observed in the outer plasmasphere where convection drift velocities (E x B)/B 2 were largest and the Alfven velocity was a minimum. Wave polarization is predominantly left-handed with propagation almost parallel to the ambient magnetic field, and the spectral slot and polarization reversal predicted by cold plasma propagation theory are identified in the wave data. Poynting fluxes calculated during the first 15 min of the event show wave energy propagation directions both parallel and antiparallel to the field. Computations of the experimental wave spectra during the passage through the plasmapause show that the spectral slots relate to local plasma parameters, possibly suggesting an ion cyclotron wave growth source near the spacecraft. A regular wave packet structure seen over the first 30 min of the event may be attributed to the modulation of this energy source by the Pc 5 waves seen at the same time. Overall, the results are considered an example of an electromagnetic ion cyclotron wave-particle interaction occurring during the outer plasmasphere refilling process at the time of the substorm recovery phase

  1. Multiply charged ions of the oxygen - produced at interaction of laser radiation with two-element solids

    International Nuclear Information System (INIS)

    Bedilov, M.R.; Bedilov, R.M.; Kamalova, J.O.; Davletov, I.Yu.; Matnazarov, A.R.

    2007-01-01

    Full text: The interest to study of the oxygen multiply charged ions spectra produced at interaction laser radiation with one and two-element solids, is associate with possibility of creating laser and inertial thermonuclear syntheses, effective sources of multiply charged ions and nuclei atoms elements, plasma lasers, lasers on multiply charged transition, design of radiation-resistant materials and others. The present time many works is devoted to multiply charged ions, obtained from one element targets. Experimental results of study charge and energy spectra multiply charged ions of the oxygen, formed at interaction laser radiation with one and two-element solids are given in this work. Our experiments, we used installation, which is described in [1]. Neodymium laser had following parameters: wavelength 1.06 μm; intensity q = (0.1 h 1000) GW/sm 2 ; angle of incidence = 180. Were study one element Al, and two-element Al 2 O 3 , Y 2 O 3 targets by a diameter of 10 mm and thickness of 3 mm. Analysis obtained charge and energy spectra of multiply charged ions one (Al) and two-element (Al 2 O 3 , Y 2 O 3 ) targets depending on intensity of laser radiation and targets components reveal the following: - maximal charge number one element target (Al) at q 500 GW/sm 2 is equal Z max = 6 and all peaks corresponding to charge numbers Z = 1 - 6 well resolved, but two-element targets (Al 2 O 3 ) Z max ions Al decrease before 3. Also it is necessary to note that, Z max ions of the oxygen depend on target components. In case Al 2 O 3 and Y 2 O 3 maximal charge number of oxygen ions are equal Z max = 6 and 3, accordingly; - obtained charge and energy spectra of oxygen ions being included in two-element targets, are indicative of that, general regularities of the change Z max , E max and structures charge and energy spectra depending on q laser are saved. However they hang by target components; - common features and some differences of energy spectra multiply charged oxygen ions

  2. Hydraulic Permeability of Resorcinol-Formaldehyde Ion-Exchange Resin - Effects of Oxygen Uptake and Radiation

    International Nuclear Information System (INIS)

    Taylor, Paul Allen

    2009-01-01

    An ion-exchange process, using spherical resorcinol-formaldehyde (RF) resin is the baseline process for removing cesium from the dissolved salt solution in the high-level waste tanks at the U.S. Department of Energy's (DOE) Hanford site in Washington State. The RF resin is also being evaluated for use in the proposed Small Column Ion Exchange (SCIX) system, which is an alternative treatment option at DOE's Savannah River Site (SRS)in South Carolina. Testing at ORNL will determine the impact of radiation exposure and oxygen uptake by the RF resin on the hydraulic permeability of the resin. Samples of the resin will be removed periodically to measure physical properties (bead size and compressibility) and cesium capacity. The proposed full-scale treatment system at Hanford, the Waste Treatment Plant (WTP), will use an ion-exchange column containing nominally 680 gal of resin, which will treat 30 gpm of waste solution. The ion-exchange column is designed for a typical pressure drop of 6 psig, with a maximum of 9.7 psig. The lab-scale column is 3-in. clear PVC pipe and is prototypic of the proposed Hanford column. The fluid velocity in the lab-scale test will be much higher than for the full-scale column, in order to generate the maximum pressure drop expected in that column (9.7 psig). The frictional drag from this high velocity will produce similar forces on the resin in the lab-scale column as would be expected at the bottom of the full-scale column. The chemical changes in the resin caused by radiation exposure and oxygen uptake are expected to cause physical changes in the resin that could reduce the bed porosity and reduce the hydraulic permeability of the resin bed. These changes will be monitored by measuring the pressure drop through the lab-scale column and by measuring the physical properties of samples of the resin. The test loop with the lab-scale column is currently being fabricated, and operation will start by late May. Testing will be completed by the

  3. XPS studies of SiO2 surface layers formed by oxygen ion implantation into silicon

    International Nuclear Information System (INIS)

    Schulze, D.; Finster, J.

    1983-01-01

    SiO 2 surface layers of 160 nm thickness formed by 16 O + ion implantation into silicon are examined by X-ray photoelectron spectroscopy measurements into the depth after a step-by-step chemical etching. The chemical nature and the thickness of the transition layer were determined. The results of the XPS measurements show that the outer surface and the bulk of the layers formed by oxygen implantation and subsequent high temperature annealing consist of SiO 2 . There is no evidence for Si or SiO/sub x/ (0 2 and Si is similar to that of thin grown oxide layers. Only its thickness is somewhat larger than in thermal oxide

  4. Heavy Ion Formation in Titan's Ionosphere: Magnetospheric Introduction of Free Oxygen and a Source of Titan's Aerosols?

    Science.gov (United States)

    Sittler, E. C., Jr.; Ali, A.; Cooper, J. F.; Hartle, R. E.; Johnson, R. E.; Coates, A. J.; Young, D. T.

    2009-01-01

    Discovery by Cassini's plasma instrument of heavy positive and negative ions within Titan's upper atmosphere and ionosphere has advanced our understanding of ion neutral chemistry within Titan's upper atmosphere, primarily composed of molecular nitrogen, with approx.2.5% methane. The external energy flux transforms Titan's upper atmosphere and ionosphere into a medium rich in complex hydrocarbons, nitriles and haze particles extending from the surface to 1200 km altitudes. The energy sources are solar UV, solar X-rays, Saturn's magnetospheric ions and electrons, solar wind and shocked magnetosheath ions and electrons, galactic cosmic rays (CCR) and the ablation of incident meteoritic dust from Enceladus' E-ring and interplanetary medium. Here it is proposed that the heavy atmospheric ions detected in situ by Cassini for heights >950 km, are the likely seed particles for aerosols detected by the Huygens probe for altitudes <100km. These seed particles may be in the form of polycyclic aromatic hydrocarbons (PAH) containing both carbon and hydrogen atoms CnHx. There could also be hollow shells of carbon atoms, such as C60, called fullerenes which contain no hydrogen. The fullerenes may compose a significant fraction of the seed particles with PAHs contributing the rest. As shown by Cassini, the upper atmosphere is bombarded by magnetospheric plasma composed of protons, H(2+) and water group ions. The latter provide keV oxygen, hydroxyl and water ions to Titan's upper atmosphere and can become trapped within the fullerene molecules and ions. Pickup keV N(2+), N(+) and CH(4+) can also be implanted inside of fullerenes. Attachment of oxygen ions to PAH molecules is uncertain, but following thermalization O(+) can interact with abundant CH4 contributing to the CO and CO2 observed in Titan's atmosphere. If an exogenic keV O(+) ion is implanted into the haze particles, it could become free oxygen within those aerosols that eventually fall onto Titan's surface. The process

  5. Oxygen, hydrogen, ethylene and CO 2 development in lithium-ion batteries

    Science.gov (United States)

    Holzapfel, M.; Würsig, A.; Scheifele, W.; Vetter, J.; Novák, P.

    Gas evolution has been examined for different types of battery-related electrode materials via in situ differential electrochemical mass spectrometry (DEMS). Besides standard graphite also a novel silicon-based negative electrode was examined and it was shown that the evolution of hydrogen and ethylene is considerably reduced on this material compared to graphite. Oxygen evolution was proven to happen on the oxidative reaction of a Li 2O 2 electrode, besides a certain oxidation of the electrolyte. The 4.5 V plateau upon the oxidation of Li[Ni 0.2Li 0.2Mn 0.6]O 2 was likewise proven to be linked to oxygen evolution. Also in this case electrolyte oxidation was shown to be a side reaction. Layered positive electrode materials Li(Ni,Co,Al)O 2 and Li(Ni,Mn,Co)O 2 were also examined. The influence of different parameters on the CO 2 evolution in lithium-ion batteries was shown up. The amount of CO 2 formation is increased by high temperatures and cell voltages, while the addition of vinylene carbonate (VC) decreases it. Li(Ni,Mn,Co)O 2 shows much less CO 2 evolution than Li(Ni,Co,Al)O 2.

  6. Accurate and precise measurement of oxygen isotopic fractions and diffusion profiles by selective attenuation of secondary ions (SASI).

    Science.gov (United States)

    Téllez, Helena; Druce, John; Hong, Jong-Eun; Ishihara, Tatsumi; Kilner, John A

    2015-03-03

    The accuracy and precision of isotopic analysis in Time-of-Flight secondary ion mass spectrometry (ToF-SIMS) relies on the appropriate reduction of the dead-time and detector saturation effects, especially when analyzing species with high ion yields or present in high concentrations. Conventional approaches to avoid these problems are based on Poisson dead-time correction and/or an overall decrease of the total secondary ion intensity by reducing the target current. This ultimately leads to poor detection limits for the minor isotopes and high uncertainties of the measured isotopic ratios. An alternative strategy consists of the attenuation of those specific secondary ions that saturate the detector, providing an effective extension of the linear dynamic range. In this work, the selective attenuation of secondary ion signals (SASI) approach is applied to the study of oxygen transport properties in electroceramic materials by isotopic labeling with stable (18)O tracer and ToF-SIMS depth profiling. The better analytical performance in terms of accuracy and precision allowed a more reliable determination of the oxygen surface exchange and diffusion coefficients while maintaining good mass resolution and limits of detection for other minor secondary ion species. This improvement is especially relevant to understand the ionic transport mechanisms and properties of solid materials, such as the parallel diffusion pathways (e.g., oxygen diffusion through bulk, grain boundary, or dislocations) in electroceramic materials with relevant applications in energy storage and conversion devices.

  7. Simultaneous determination of artificial sweeteners, preservatives, caffeine, theobromine and theophylline in food and pharmaceutical preparations by ion chromatography.

    Science.gov (United States)

    Chen, Q C; Wang, J

    2001-12-07

    A novel ion chromatographic method was proposed for the simultaneous determination of artificial sweeteners (sodium saccharin, aspartame, acesulfame-K), preservatives (benzoic acid, sorbic acid), caffeine, theobromine and theophylline. The separation was performed on an anion-exchange analytical column operated at 40 degrees C within 45 min by an isocratic elution with 5 mM aqueous NaH2PO4 (pH 8.20) solution containing 4% (v/v) acetonitrile as eluent, and the determination by wavelength-switching ultraviolet absorbance detection. The detection limits (signal-to-noise ratio 3:1) for all analytes were below the sub-microg/ml level. Under the experimental conditions, several organic acids, including citric acid, malic acid, tartaric acid and ascorbic acid, did not interfere with the determination. The method has been successfully applied to the analysis of various food and pharmaceutical preparations, and the average recoveries for real samples ranged from 85 to 104%. The levels of all analytes determined by this method were in good agreement with those obtained by the high-performance liquid chromatographic procedure. The results also indicated that ion chromatography would be possibly a beneficial alternative to conventional high-performance liquid chromatography for the separation and determination of these compounds.

  8. Oxygen redox chemistry without excess alkali-metal ions in Na2/3[Mg0.28Mn0.72]O2.

    Science.gov (United States)

    Maitra, Urmimala; House, Robert A; Somerville, James W; Tapia-Ruiz, Nuria; Lozano, Juan G; Guerrini, Niccoló; Hao, Rong; Luo, Kun; Jin, Liyu; Pérez-Osorio, Miguel A; Massel, Felix; Pickup, David M; Ramos, Silvia; Lu, Xingye; McNally, Daniel E; Chadwick, Alan V; Giustino, Feliciano; Schmitt, Thorsten; Duda, Laurent C; Roberts, Matthew R; Bruce, Peter G

    2018-03-01

    The search for improved energy-storage materials has revealed Li- and Na-rich intercalation compounds as promising high-capacity cathodes. They exhibit capacities in excess of what would be expected from alkali-ion removal/reinsertion and charge compensation by transition-metal (TM) ions. The additional capacity is provided through charge compensation by oxygen redox chemistry and some oxygen loss. It has been reported previously that oxygen redox occurs in O 2p orbitals that interact with alkali ions in the TM and alkali-ion layers (that is, oxygen redox occurs in compounds containing Li + -O(2p)-Li + interactions). Na 2/3 [Mg 0.28 Mn 0.72 ]O 2 exhibits an excess capacity and here we show that this is caused by oxygen redox, even though Mg 2+ resides in the TM layers rather than alkali-metal (AM) ions, which demonstrates that excess AM ions are not required to activate oxygen redox. We also show that, unlike the alkali-rich compounds, Na 2/3 [Mg 0.28 Mn 0.72 ]O 2 does not lose oxygen. The extraction of alkali ions from the alkali and TM layers in the alkali-rich compounds results in severely underbonded oxygen, which promotes oxygen loss, whereas Mg 2+ remains in Na 2/3 [Mg 0.28 Mn 0.72 ]O 2 , which stabilizes oxygen.

  9. Oxygen ion uplift and satellite drag effects during the 30 October 2003 daytime superfountain event

    Directory of Open Access Journals (Sweden)

    B. T. Tsurutani

    2007-03-01

    Full Text Available The prompt penetration of interplanetary electric fields (IEFs to the dayside low-latitude ionosphere during the first ~2 h of a superstorm is estimated and applied to a modified NRL SAMI2 code for the 30 October 2003 event. In our simulations, the dayside ionospheric O+ is convected to higher altitudes (~600 km and higher latitudes (~±25° to 30°, forming highly displaced equatorial ionospheric anomaly (EIA peaks. This feature plus others are consistent with previously published CHAMP electron (TEC measurements and with the dayside superfountain model. The rapid upward motion of the O+ ions causes neutral oxygen (O uplift due to ion-neutral drag. It is estimated that above ~400 km altitude the O densities within the displaced EIAs can be increased substantially over quiet time values. The latter feature will cause increased drag for low-altitude satellites. This newly predicted phenomenon is expected to be typical for superstorm/IEF events.

  10. Uncertainty quantification of ion chemistry in lean and stoichiometric homogenous mixtures of methane, oxygen, and argon

    KAUST Repository

    Kim, Daesang

    2015-07-01

    Uncertainty quantification (UQ) methods are implemented to obtain a quantitative characterization of the evolution of electrons and ions during the ignition of methane-oxygen mixtures under lean and stoichiometric conditions. The GRI-Mech 3.0 mechanism is combined with an extensive set of ion chemistry pathways and the forward propagation of uncertainty from model parameters to observables is performed using response surfaces. The UQ analysis considers 22 uncertain rate parameters, which include both chemi-ionization, proton transfer, and electron attachment reactions as well as neutral reactions pertaining to the chemistry of the CH radical. The uncertainty ranges for each rate parameter are discussed. Our results indicate that the uncertainty in the time evolution of the electron number density is due mostly to the chemi-ionization reaction CH+O⇌HCO+ +E- and to the main CH consumption reaction CH+O2 ⇌O+HCO. Similar conclusions hold for the hydronium ion H3O+, since electrons and H3O+ account for more than 99% of the total negative and positive charge density, respectively. Surprisingly, the statistics of the number density of charged species show very little sensitivity to the uncertainty in the rate of the recombination reaction H3O+ +E- →products, until very late in the decay process, when the electron number density has fallen below 20% of its peak value. Finally, uncertainties in the secondary reactions within networks leading to the formation of minor ions (e.g., C2H3O+, HCO+, OH-, and O-) do not play any role in controlling the mean and variance of electrons and H3O+, but do affect the statistics of the minor ions significantly. The observed trends point to the role of key neutral reactions in controlling the mean and variance of the charged species number density in an indirect fashion. Furthermore, total sensitivity indices provide quantitative metrics to focus future efforts aiming at improving the rates of key reactions responsible for the

  11. Uncertainty quantification of ion chemistry in lean and stoichiometric homogenous mixtures of methane, oxygen, and argon

    KAUST Repository

    Kim, Daesang; Rizzi, Francesco; Cheng, Kwok Wah; Han, Jie; Bisetti, Fabrizio; Knio, Omar Mohamad

    2015-01-01

    Uncertainty quantification (UQ) methods are implemented to obtain a quantitative characterization of the evolution of electrons and ions during the ignition of methane-oxygen mixtures under lean and stoichiometric conditions. The GRI-Mech 3.0 mechanism is combined with an extensive set of ion chemistry pathways and the forward propagation of uncertainty from model parameters to observables is performed using response surfaces. The UQ analysis considers 22 uncertain rate parameters, which include both chemi-ionization, proton transfer, and electron attachment reactions as well as neutral reactions pertaining to the chemistry of the CH radical. The uncertainty ranges for each rate parameter are discussed. Our results indicate that the uncertainty in the time evolution of the electron number density is due mostly to the chemi-ionization reaction CH+O⇌HCO+ +E- and to the main CH consumption reaction CH+O2 ⇌O+HCO. Similar conclusions hold for the hydronium ion H3O+, since electrons and H3O+ account for more than 99% of the total negative and positive charge density, respectively. Surprisingly, the statistics of the number density of charged species show very little sensitivity to the uncertainty in the rate of the recombination reaction H3O+ +E- →products, until very late in the decay process, when the electron number density has fallen below 20% of its peak value. Finally, uncertainties in the secondary reactions within networks leading to the formation of minor ions (e.g., C2H3O+, HCO+, OH-, and O-) do not play any role in controlling the mean and variance of electrons and H3O+, but do affect the statistics of the minor ions significantly. The observed trends point to the role of key neutral reactions in controlling the mean and variance of the charged species number density in an indirect fashion. Furthermore, total sensitivity indices provide quantitative metrics to focus future efforts aiming at improving the rates of key reactions responsible for the

  12. Upwelling to Outflowing Oxygen Ions at Auroral Latitudes during Quiet Times: Exploiting a New Satellite Database

    Science.gov (United States)

    Redmon, Robert J.

    The mechanisms by which thermal O+ escapes from the top of the ionosphere and into the magnetosphere are not fully understood even with 30 years of active research. This thesis introduces a new database, builds a simulation framework around a thermospheric model and exploits these tools to gain new insights into the study of O+ ion outflows. A dynamic auroral boundary identification system is developed using Defense Meteorological Satellite Program (DMSP) spacecraft observations at 850 km to build a database characterizing the oxygen source region. This database resolves the ambiguity of the expansion and contraction of the auroral zone. Mining this new dataset, new understanding is revealed. We describe the statistical trajectory of the cleft ion fountain return flows over the polar cap as a function of activity and the orientation of the interplanetary magnetic field y-component. A substantial peak in upward moving O+ in the morning hours is discovered. Using published high altitude data we demonstrate that between 850 and 6000 km altitude, O+ is energized predominantly through transverse heating; and acceleration in this altitude region is relatively more important in the cusp than at midnight. We compare data with a thermospheric model to study the effects of solar irradiance, electron precipitation and neutral wind on the distribution of upward O+ at auroral latitudes. EUV irradiance is shown to play a dominant role in establishing a dawn-focused source population of upwelling O+ that is responsible for a pre-noon feature in escaping O+ fluxes. This feature has been corroborated by observations on platforms including the Dynamics Explorer 1 (DE-1), Polar, and Fast Auroral Snapshot SnapshoT (FAST) spacecraft. During quiet times our analysis shows that the neutral wind is more important than electron precipitation in establishing the dayside O+ upwelling distribution. Electron precipitation is found to play a relatively modest role in controlling dayside, and a

  13. Fluctuation Induced Conductivity Studies of 100 MeV Oxygen Ion Irradiated Pb Doped Bi-2223 Superconductors

    NARCIS (Netherlands)

    Banerjee, Tamalika; Kumar, Ravi; Kanjilal, D.; Ramasamy, S.

    2000-01-01

    We report on 100 MeV oxygen ion irradiation in Pb doped Bi-2223 superconductors. Resistivity measurements reveal that both grains as well as the grain boundaries are affected by such irradiation. An analysis of the excess conductivity has been made within the framework of Aslamazov-Larkin (AL) and

  14. On the influence of hydronium and hydroxide ion diffusion on the hydrogen and oxygen evolution reactions in aqueous media

    DEFF Research Database (Denmark)

    Wiberg, Gustav Karl Henrik; Arenz, Matthias

    2015-01-01

    We present a study concerning the influence of the diffusion of H+ and OH- ions on the hydrogen and oxygen evolution reactions (HER and OER) in aqueous electrolyte solutions. Using a rotating disk electrode (RDE), it is shown that at certain conditions the observed current, i.e., the reaction rate...

  15. Anisotropic Proton and Oxygen Ion Conductivity in Epitaxial Ba2In2O5 Thin Films

    DEFF Research Database (Denmark)

    Fluri, Aline; Gilardi, Elisa; Karlsson, Maths

    2017-01-01

    Solid oxide oxygen ion and proton conductors are a highly important class of materials for renewable energy conversion devices like solid oxide fuel cells. Ba2In2O5 (BIO) exhibits both oxygen ion and proton conduction, in a dry and humid environment, respectively. In a dry environment...

  16. Interactions between oxygen permeation and homogeneous-phase fuel conversion on the sweep side of an ion transport membrane

    KAUST Repository

    Hong, Jongsup

    2013-02-01

    The interactions between oxygen permeation and homogeneous fuel oxidation reactions on the sweep side of an ion transport membrane (ITM) are examined using a comprehensive model, which couples the dependency of the oxygen permeation rate on the membrane surface conditions and detailed chemistry and transport in the vicinity of the membrane. We assume that the membrane surface is not catalytic to hydrocarbon or syngas oxidation. Results show that increasing the sweep gas inlet temperature and fuel concentration enhances oxygen permeation substantially. This is accomplished through promoting oxidation reactions (oxygen consumption) and the transport of the products and reaction heat towards the membrane, which lowers the oxygen concentration and increases the gas temperature near the membrane. Faster reactions at higher fuel concentration and higher inlet gas temperature support substantial fuel conversion and lead to a higher oxygen permeation flux without the contribution of surface catalytic activity. Beyond a certain maximum in the fuel concentration, extensive heat loss to the membrane (and feed side) reduces the oxidation kinetic rates and limits oxygen permeation as the reaction front reaches the membrane. The sweep gas flow rate and channel height have moderate impacts on oxygen permeation and fuel conversion due to the residence time requirements for the chemical reactions and the location of the reaction zone relative to the membrane surface. © 2012 Elsevier B.V.

  17. Enhancement of oxygen reduction at Fe tetrapyridyl porphyrin by pyridyl-N coordination to transition metal ions

    International Nuclear Information System (INIS)

    Maruyama, Jun; Baier, Claudia; Wolfschmidt, Holger; Bele, Petra; Stimming, Ulrich

    2012-01-01

    One of the promising candidates as noble-metal-free electrode catalysts for polymer electrolyte fuel cells (PEFCs) is a carbon material with nitrogen atoms coordinating iron ions embedded on the surface (Fe-N x moiety) as the active site, although the activity is insufficient compared to conventional platinum-based electrocatalysts. In order to obtain fundamental information on the activity enhancement, a simple model of the Fe-N x active site was formed by adsorbing 5,10,15,20-Tetrakis(4-pyridyl)-21H,23H-porphine iron(III) chloride (FeTPyPCl) on the basal plane of highly oriented pyrolytic graphite (HOPG), and cathodic oxygen reduction was investigated on the surface in 0.1 M HClO 4 . The catalytic activity for oxygen reduction was enhanced by loading transition metal ions (Co 2+ , Ni 2+ , Cu 2+ ) together with FeTPyPCl. The X-ray photoelectron spectrum of the surface suggested that the metal was coordinated by the pyridine-N. The enhancement effect of the transition metals was supported by two different measurements: oxygen reduction at HOPG in 0.1 M HClO 4 dissolving FeTPyPCl and the metal ions; oxygen reduction in 0.1 M HClO 4 at the subsequently well-rinsed and dried HOPG. The ultraviolet–visible spectrum for the solution also suggested the coordination between the pyridyl-N and the metal ions. The oxygen reduction enhancement was attributed to the electronic interaction between the additional transition metal and the Fe center of the porphyrin through the coordination bonds. These results implied that the improvement of the activity of the noble-metal-free catalyst would be possible by the proper introduction of the transition metal ions around the active site.

  18. Transport of oxygen ions in Er doped La2Mo2O9 oxide ion conductors: Correlation with microscopic length scales

    Science.gov (United States)

    Paul, T.; Ghosh, A.

    2018-01-01

    We report oxygen ion transport in La2-xErxMo2O9 (0.05 ≤ x ≤ 0.25) oxide ion conductors. We have measured conductivity and dielectric spectra at different temperatures in a wide frequency range. The mean square displacement and spatial extent of non-random sub-diffusive regions are estimated from the conductivity spectra and dielectric spectra, respectively, using linear response theory. The composition dependence of the conductivity is observed to be similar to that of the spatial extent of non-random sub-diffusive regions. The behavior of the composition dependence of the mean square displacement of oxygen ions is opposite to that of the conductivity. The attempt frequency estimated from the analysis of the electric modulus agrees well with that obtained from the Raman spectra analysis. The full Rietveld refinement of X-ray diffraction data of the samples is performed to estimate the distance between different oxygen lattice sites. The results obtained from such analysis confirm the ion hopping within the spatial extent of non-random sub-diffusive regions.

  19. A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time.

    Science.gov (United States)

    Schweitzer, Mary H; Zheng, Wenxia; Cleland, Timothy P; Goodwin, Mark B; Boatman, Elizabeth; Theil, Elizabeth; Marcus, Matthew A; Fakra, Sirine C

    2014-01-22

    The persistence of original soft tissues in Mesozoic fossil bone is not explained by current chemical degradation models. We identified iron particles (goethite-αFeO(OH)) associated with soft tissues recovered from two Mesozoic dinosaurs, using transmission electron microscopy, electron energy loss spectroscopy, micro-X-ray diffraction and Fe micro-X-ray absorption near-edge structure. Iron chelators increased fossil tissue immunoreactivity to multiple antibodies dramatically, suggesting a role for iron in both preserving and masking proteins in fossil tissues. Haemoglobin (HB) increased tissue stability more than 200-fold, from approximately 3 days to more than two years at room temperature (25°C) in an ostrich blood vessel model developed to test post-mortem 'tissue fixation' by cross-linking or peroxidation. HB-induced solution hypoxia coupled with iron chelation enhances preservation as follows: HB + O2 > HB - O2 > -O2 > +O2. The well-known O2/haeme interactions in the chemistry of life, such as respiration and bioenergetics, are complemented by O2/haeme interactions in the preservation of fossil soft tissues.

  20. Theoretical and experimental investigation of carnosine and its oxygenated adducts. The reaction with the nickel ion

    Energy Technology Data Exchange (ETDEWEB)

    Pavlos, Dimitrios; Petropouleas, Panayiotis; Hatzipanayioti, Despina, E-mail: stambaki@chem.uoa.gr

    2015-11-05

    Highlights: • Study on models of neutral cations and anions of carnosine at the B3LYP/TZVP level. • The {sup 1}O{sub 2}-adducts of these models resulted in oxygenated carnosine. • Theoretical parameters correlated to experimental results for carn and carn-H{sub 2}O{sub 2}. • Theoretical models of Nickel-carn complexes have been investigated. • Isolation and characterization of the solid [Ni(carn){sub 2}(H{sub 2}O){sub 5}] have been performed. - Abstract: DFT theoretical calculations at B3LYP/TZVP or LANL2DZ level of theory, for neutral, zwitterions, protonated and anionic carnosine, were performed. Energies, the structural and spectroscopic parameters were calculated in the gas phase and aqueous medium. Additional H-bonds stabilize the ionized forms of carnosine, creating “nests” into which metal ions or bio-molecules may be sheltered. Based on Fukui functions, the reactivity of the abovementioned forms of carnosine, with {sup 1}O{sub 2}, may lead to oxygenated species. The theoretical spectroscopic parameters have been correlated to our experimental results. The effect of H{sub 2}O{sub 2} and the electrochemistry of aqueous carnosine solutions were examined. Theoretical models containing Ni(II), carnosine and water were constructed. In the isolated mauve solid, formulated [Ni(carn){sub 2}(H{sub 2}O){sub 5}], the COO−, N{sub π} and/or NH{sub 2} were bonded. When H{sub 2}O{sub 2} was added, the imidazole NMR signals disappeared. A redox couple clearly indicates one electron process, the electron coming from either the oxidation of imidazole ring or the nickel(II)/Ni(III) couple.

  1. Preferential heating of oxygen 5{sup +} ions by finite-amplitude oblique Alfvén waves

    Energy Technology Data Exchange (ETDEWEB)

    Maneva, Yana G.; Poedts, Stefaan [Centre for mathematical Plasma Astrophysics, KU Leuven, B-3001 Leuven (Belgium); Viñas, Adolfo [NASA Goddard Space Flight Center, Heliophysics Science Division, Greenbelt, 20771 MD (United States); Araneda, Jaime [Departamento de Física, Universidad de Concepción, Casilla 160 - C, Concepción (Chile)

    2016-03-25

    Minor ions in the fast solar wind are known to have higher temperatures and to flow faster than protons in the interplanetary space. In this study we combine previous research on parametric instability theory and 2.5D hybrid simulations to study the onset of preferential heating of Oxygen 5{sup +} ions by large-scale finite-amplitude Alfvén waves in the collisionless fast solar wind. We consider initially non-drifting isotropic multi-species plasma, consisting of isothermal massless fluid electrons, kinetic protons and kinetic Oxygen 5{sup +} ions. The external energy source for the plasma heating and energization are oblique monochromatic Alfvén-cyclotron waves. The waves have been created by rotating the direction of initial parallel pump, which is a solution of the multi-fluid plasma dispersion relation. We consider propagation angles θ ≤ 30°. The obliquely propagating Alfvén pump waves lead to strong diffusion in the ion phase space, resulting in highly anisotropic heavy ion velocity distribution functions and proton beams. We discuss the application of the model to the problems of preferential heating of minor ions in the solar corona and the fast solar wind.

  2. Copper ions stimulate the proliferation of hepatic stellate cells via oxygen stress in vitro.

    Science.gov (United States)

    Xu, San-qing; Zhu, Hui-yun; Lin, Jian-guo; Su, Tang-feng; Liu, Yan; Luo, Xiao-ping

    2013-02-01

    This study examined the effect of copper ions on the proliferation of hepatic stellate cells (HSCs) and the role of oxidative stress in this process in order to gain insight into the mechanism of hepatic fibrosis in Wilson's disease. LX-2 cells, a cell line of human HSCs, were cultured in vitro and treated with different agents including copper sulfate, N-acetyl cysteine (NAC) and buthionine sulfoximine (BSO) for different time. The proliferation of LX-2 cells was measured by non-radioactive cell proliferation assay. Real-time PCR and Western blotting were used to detect the mRNA and protein expression of platelet-derived growth factor receptor β subunit (PDGFβR), ELISA to determine the level of glutathione (GSH) and oxidized glutathione (GSSG), dichlorofluorescein assay to measure the level of reactive oxygen species (ROS), and lipid hydroperoxide assay to quantify the level of lipid peroxide (LPO). The results showed that copper sulfate over a certain concentration range could promote the proliferation of LX-2 cells in a time- and dose-dependent manner. The effect was most manifest when LX-2 cells were treated with copper sulfate at a concentration of 100 μmol/L for 24 h. Additionally, copper sulfate could dose-dependently increase the levels of ROS and LPO, and decrease the ratio of GSH/GSSG in LX-2 cells. The copper-induced increase in mRNA and protein expression of PDGFβR was significantly inhibited in LX-2 cells pre-treated with NAC, a precursor of GSH, and this phenomenon could be reversed by the intervention of BSO, an inhibitor of NAC. It was concluded that copper ions may directly stimulate the proliferation of HSCs via oxidative stress. Anti-oxidative stress therapies may help suppress the copper-induced activation and proliferation of HSCs.

  3. Multiple ionization and coupling effects in L-subshell ionization of heavy atoms by oxygen ions

    International Nuclear Information System (INIS)

    Pajek, M.; Banas, D.; Semaniak, J.; Braziewicz, J.; Majewska, U.; Chojnacki, S.; Czyzewski, T.; Fijal, I.; Jaskola, M.; Glombik, A.; Kretschmer, W.; Trautmann, D.; Lapicki, G.; Mukoyama, T.

    2003-01-01

    The multiple-ionization and coupling effects in L-shell ionization of atoms by heavy-ion impact have been studied by measuring the L x-ray production cross sections in solid targets of Au, Bi, Th, and U bombarded by oxygen ions in the energy range 6.4-70 MeV. The measured L x-ray spectra were analyzed using the recently proposed method accounting for the multiple-ionization effects, such as x-ray line shifting and broadening, which enables one to obtain the ionization probabilities for outer shells. The L-subshell ionization cross sections have been obtained from measured x-ray production cross sections for resolved Lα 1,2 , Lγ 1 , and Lγ 2,3 transitions using the L-shell fluorescence and Coster-Kronig yields being substantially modified by the multiple ionization in the M and N shells. In particular, the effect of closing of strong L 1 -L 3 M 4,5 Coster-Kronig transitions in multiple-ionized atoms was evidenced and discussed. The experimental ionization cross sections for the L 1 , L 2 , and L 3 subshells have been compared with the predictions of the semiclassical approximation (SCA) and the ECPSSR theory that includes the corrections for the binding-polarization effect within the perturbed stationary states approximation, the projecticle energy loss, and Coulomb deflection effects as well as the relativistic description of inner-shell electrons. These approaches were further modified to include the L-subshell couplings within the ''coupled-subshell model'' (CSM). Both approaches, when modified for the coupling effects, are in better agreement with the data. Particularly, the predictions of the SCA-CSM calculations reproduce the experimental L-subshell ionization cross section reasonably well. Remaining discrepancies are discussed qualitatively, in terms of further modifications of the L-shell decay rates caused by a change of electronic wave functions in multiple-ionized atoms

  4. Reactive-ion etching of nylon fabric meshes using oxygen plasma for creating surface nanostructures

    International Nuclear Information System (INIS)

    Salapare, Hernando S.; Darmanin, Thierry; Guittard, Frédéric

    2015-01-01

    Graphical abstract: - Highlights: • Reactive-ion etching (RIE) is employed to nylon 6,6 fabrics to achieve surface texturing and improved wettability. • FTIR spectra of the treated samples exhibited decreased transmittance of amide and carboxylic acid groups due to etching. • Etching is enhanced for higher power plasma treatments and for samples with larger mesh sizes. • Decreased crystallinity was achieved after plasma treatment. • Higher power induced higher negative DC self-bias voltage on the samples that favored anisotropic and aggressive etching. - Abstract: A facile one-step oxygen plasma irradiation in reactive ion etching (RIE) configuration is employed to nylon 6,6 fabrics with different mesh sizes to achieve surface nanostructures and improved wettability for textile and filtration applications. To observe the effects of power and irradiation time on the samples, the experiments were performed using constant irradiation time in varying power and using constant power in varying irradiation times. Results showed improved wettability after the plasma treatment. The FTIR spectra of all the treated samples exhibited decreased transmittance of the amide and carboxylic acid groups due to surface etching. The changes in the surface chemistry are supported by the SEM data wherein etching and surface nanostructures were observed for the plasma-treated samples. The etching of the surfaces is enhanced for higher power plasma treatments. The thermal analysis showed that the plasma treatment resulted in decreased crystallinity. Surface chemistry showed that the effects of the plasma treatment on the samples have no significant difference for all the mesh sizes. However, surface morphology showed that the sizes of the surface cracks are the same for all the mesh sizes but samples with larger mesh sizes exhibited enhanced etching as compared to the samples with smaller mesh sizes. Higher power induced higher negative DC self-bias voltage on the samples that

  5. Micronized Copper Wood Preservatives: Efficacy of Ion, Nano, and Bulk Copper against the Brown Rot Fungus Rhodonia placenta.

    Science.gov (United States)

    Civardi, Chiara; Schubert, Mark; Fey, Angelika; Wick, Peter; Schwarze, Francis W M R

    2015-01-01

    Recently introduced micronized copper (MC) formulations, consisting of a nanosized fraction of basic copper (Cu) carbonate (CuCO3·Cu(OH)2) nanoparticles (NPs), were introduced to the market for wood protection. Cu NPs may presumably be more effective against wood-destroying fungi than bulk or ionic Cu compounds. In particular, Cu- tolerant wood-destroying fungi may not recognize NPs, which may penetrate into fungal cell walls and membranes and exert their impact. The objective of this study was to assess if MC wood preservative formulations have a superior efficacy against Cu-tolerant wood-destroying fungi due to nano effects than conventional Cu biocides. After screening a range of wood-destroying fungi for their resistance to Cu, we investigated fungal growth of the Cu-tolerant fungus Rhodonia placenta in solid and liquid media and on wood treated with MC azole (MCA). In liquid cultures we evaluated the fungal response to ion, nano and bulk Cu distinguishing the ionic and particle effects by means of the Cu2+ chelator ammonium tetrathiomolybdate (TTM) and measuring fungal biomass, oxalic acid production and laccase activity of R. placenta. Our results do not support the presence of particular nano effects of MCA against R. placenta that would account for an increased antifungal efficacy, but provide evidence that attribute the main effectiveness of MCA to azoles.

  6. Organodioxygen complexes of some heavy metal ions and their oxygen transfer reactions

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Mei Ling; Gino Mariotto

    2003-09-01

    Several novel organodioxygen complexes of lanthanide ions, viz., lanthanum(m) and cerium(IV) have been synthesized containing a number of organic co- ligands. The complexes characterized were, [La(0 2 )(det)(N0 3 ) 2 ] (1), [La(O 2 )(tet)(NO 3 ) 2 ] (2), [La(O 2 )(C 5 H 5 N)2NO 3 ] (3), [La(O 2 )(C 6 H 18 N 3 PO) 2 (NO 3 ) 2 ] (4), [La(0 2 )(OPPh 3 ) 2 (N0 3 ) 2 ] (5), [La(O 2 ) 2 (NH 2 CH 2 CH 2 NH 2 ) 2 NO 3 ] (6), [La(O 2 )(PPh 3 ) 2 (NO 3 ) 2 ] (7) and [Ce(O 2 )(C 6 H 18 N 3 PO) 2 (NO 3 ) 3 ] (8). IR and Raman spectra revealed that (3) was a peroxo complex while the others were, in particular, superoxo type. The IR spectrum of (3) gives V 1 (O-O) at 851 cm -1 while the Raman spectra of (4), (5), (7) and (8) give V 1 (O 2 ) bands at 1046 cm -1 , 1032 cm 1 , 1100 cm -1 and 1046 cm -1 , respectively. The oxygen transfer reactions of two selected complexes were carried out under stoichiometric conditions. The complex containing a bidentate ligand, (6), was found to oxidize triphenylphosphine and trans-stilbene to their oxides while the complex containing tridentate ligand (1) was stable and inert towards oxidation. (author)

  7. Mercuric ions inhibit mitogen-activated protein kinase dephosphorylation by inducing reactive oxygen species

    International Nuclear Information System (INIS)

    Haase, Hajo; Engelhardt, Gabriela; Hebel, Silke; Rink, Lothar

    2011-01-01

    Mercury intoxication profoundly affects the immune system, in particular, signal transduction of immune cells. However, the mechanism of the interaction of mercury with cellular signaling pathways, such as mitogen activated protein kinases (MAPK), remains elusive. Therefore, the objective of this study is to investigate three potential ways in which Hg 2+ ions could inhibit MAPK dephosphorylation in the human T-cell line Jurkat: (1) by direct binding to phosphatases; (2) by releasing cellular zinc (Zn 2+ ); and (3) by inducing reactive oxygen species (ROS). Hg 2+ causes production of ROS, measured by dihydrorhodamine 123, and triggers ROS-mediated Zn 2+ release, detected with FluoZin-3. Yet, phosphatase-inhibition is not mediated by binding of Zn 2+ or Hg 2+ . Rather, phosphatases are inactivated by at least two forms of thiol oxidation; initial inhibition is reversible with reducing agents such as Tris(2-carboxyethyl)phosphine. Prolonged inhibition leads to non-reversible phosphatase oxidation, presumably oxidizing the cysteine thiol to sulfinic- or sulfonic acid. Notably, phosphatases are a particularly sensitive target for Hg 2+ -induced oxidation, because phosphatase activity is inhibited at concentrations of Hg 2+ that have only minor impact on over all thiol oxidation. This phosphatase inhibition results in augmented, ROS-dependent MAPK phosphorylation. MAPK are important regulators of T-cell function, and MAPK-activation by inhibition of phosphatases seems to be one of the molecular mechanisms by which mercury affects the immune system.

  8. Is the surface oxygen exchange rate linked to bulk ion diffusivity in mixed conducting Ruddlesden-Popper phases?

    Science.gov (United States)

    Tomkiewicz, Alex C; Tamimi, Mazin A; Huq, Ashfia; McIntosh, Steven

    2015-01-01

    The possible link between oxygen surface exchange rate and bulk oxygen anion diffusivity in mixed ionic and electronic conducting oxides is a topic of great interest and debate. While a large body of experimental evidence and theoretical analyses support a link, observed differences between bulk and surface composition of these materials are hard to reconcile with this observation. This is further compounded by potential problems with simultaneous measurement of both parameters. Here we utilize separate techniques, in situ neutron diffraction and pulsed isotopic surface exchange, to examine bulk ion mobility and surface oxygen exchange rates of three Ruddlesden-Popper phases, general form A(n-1)A(2)'B(n)O(3n+1), A(n-1)A(2)'B(n)X(3n+1); LaSrCo(0.5)Fe(0.5)O(4-δ) (n = 1), La(0.3)Sr(2.7)CoFeO(7-δ) (n = 2) and LaSr3Co(1.5)Fe(1.5)O(10-δ) (n = 3). These measurements are complemented by surface composition determination via high sensitivity-low energy ion scattering. We observe a correlation between bulk ion mobility and surface exchange rate between materials. The surface exchange rates vary by more than one order of magnitude with high anion mobility in the bulk of an oxygen vacancy-rich n = 2 Ruddlesden-Popper material correlating with rapid oxygen exchange. This is in contrast with the similar surface exchange rates which we may expect due to similar surface compositions across all three samples. We conclude that experimental limitations lead to inherent convolution of surface and bulk rates, and that surface exchange steps are not likely to be rate limiting in oxygen incorporation.

  9. Collisions of singly and doubly charged ions with oxygen molecules in the energy range 1 - 1800 (3600) eV

    International Nuclear Information System (INIS)

    Kuen, I.; Howorka, F.

    1983-01-01

    Absolute cross sections for the excitation of optically emitting states in collisions of He + , Ne + , Ar + , Kr + , B + , He ++ , Ne ++ and Ar ++ with oxygen molecules are measured, the energy range of the ion being1 - 1800 eV Lab for the singly charged and 1 - 3600 eV for the doubly charged ions. Seven important processes can be distinguished: charge exchange excitation of O 2 + band, O I, O II, X I and X II lines (X + , X ++ being the primary ion), direct excitation of X II and double charge exchange excitations. The energy dependences of the excitation cross sections are remarkably different for different processes but similar for one process with different ions. The sum total of all cross sections together for excitations which lead to light emission is on the order of a few square angstroms at 1000 eV c.m. energy. The results are of interest for surface investigations, plasma diagnostics and laser work. (Author)

  10. High Rate and Stable Li-Ion Insertion in Oxygen-Deficient LiV3O8 Nanosheets as a Cathode Material for Lithium-Ion Battery.

    Science.gov (United States)

    Song, Huanqiao; Luo, Mingsheng; Wang, Aimei

    2017-01-25

    Low performance of cathode materials has become one of the major obstacles to the application of lithium-ion battery (LIB) in advanced portable electronic devices, hybrid electric vehicles, and electric vehicles. The present work reports a versatile oxygen-deficient LiV 3 O 8 (D-LVO) nanosheet that was synthesized successfully via a facile oxygen-deficient hydrothermal reaction followed by thermal annealing in Ar. When used as a cathode material for LIB, the prepared D-LVO nanosheets display remarkable capacity properties at various current densities (a capacity of 335, 317, 278, 246, 209, 167, and 133 mA h g -1 at 50, 100, 200, 500, 1000, 2000, and 4000 mA g -1 , respectively) and excellent lithium-ion storage stability, maintaining more than 88% of the initial reversible capacity after 200 cycles at 1000 mA g -1 . The outstanding electrochemical properties are believed to arise largely from the introduction of tetravalent V (∼15% V 4+ ) and the attendant oxygen vacancies into LiV 3 O 8 nanosheets, leading to intrinsic electrical conductivity more than 1 order of magnitude higher and lithium-ion diffusion coefficient nearly 2 orders of magnitude higher than those of LiV 3 O 8 without detectable V 4+ (N-LVO) and thus contributing to the easy lithium-ion diffusion, rapid phase transition, and the excellent electrochemical reversibility. Furthermore, the more uniform nanostructure, as well as the larger specific surface area of D-LVO than N-LVO nanosheets may also improve the electrolyte penetration and provide more reaction sites for fast lithium-ion diffusion during the discharge/charge processes.

  11. Characterization of silicon oxynitride films prepared by the simultaneous implantation of oxygen and nitrogen ions into silicon

    International Nuclear Information System (INIS)

    Hezel, R.; Streb, W.

    1985-01-01

    Silicon oxynitride films about 5 nm in thickness were prepared by simultaneously implanting 5 keV oxygen and nitrogen ions into silicon at room temperature up to saturation. These films with concentrations ranging from pure silicon oxide to silicon nitride were characterized using Auger electron spectroscopy, electron energy loss spectroscopy and depth-concentration profiling. The different behaviour of the silicon oxynitride films compared with those of silicon oxide and silicon nitride with regard to thermal stability and hardness against electron and argon ion irradiation is pointed out. (Auth.)

  12. Measurement of the variable track-etch rate of hydrogen, carbon and oxygen Ions in CR-39

    International Nuclear Information System (INIS)

    Lengar, I.; Skvarc, J.; Ilic, R.

    2003-01-01

    The ratio of the track-etch rate to the bulk-etch rate for hydrogen, carbon and oxygen ions was studied for the CR-39 detector with addition of dioctylphthalate. The response was reconstructed from etch-pit growth curves obtained by the multi-step etching technique. A theoretical analysis of the correctness of the method due to the 'missing track segment' is assessed and utilisation of the results obtained for the calibration of fast neutron dosimetry is discussed. (author)

  13. Report on the FY 1999 investigational survey on the activation of oxygen electrode by ion implantation; 1999 nendo ion chunyuho ni yoru sanso denkyoku no kasseika ni kansuru kenkyu chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The oxygen electrode is important as the base electrode for water electrolysis and fuel cell, but to move it, overvoltage (activated energy) in addition to equilibrium voltage is necessary, which leads to the lowering of energy efficiency. By forming the active spot by ion implantation, the lowering of overvoltage was studied. The implantation of Ru{sup +} ion in Ruthenium dioxide thin film electrode reduced the oxygen generating overvoltage by 15-20mV. Even in the oxygen reduction, activity was also increased. The chemical composition of thin film does not change by ion implantation. The increase in activity is based on a physical change which is called the surface defect formation. The layer of ion implantation is composed of microcrystals, which is thought to contribute to the formation of any active spot. Ions were implanted in Pt electrode as a practical use material, and even in the oxygen reduction of Pt, a possibility of heightening activity by ion implantation was admitted even in the oxygen reduction of Pt. The generation of high activity oxygen by ion plantation and development of oxygen reduction electrode were established as one method as a rule. (NEDO)

  14. Facile Aluminum Reduction Synthesis of Blue TiO2 with Oxygen Deficiency for Lithium-Ion Batteries.

    Science.gov (United States)

    Zheng, Jing; Ji, Guangbin; Zhang, Peng; Cao, Xingzhong; Wang, Baoyi; Yu, Linghui; Xu, Zhichuan J

    2015-12-07

    An ultrafacile aluminum reduction method is reported herein for the preparation of blue TiO2 nanoparticles (donated as Al-TiO2 , anatase phase) with abundant oxygen deficiency for lithium-ion batteries. Under aluminum reduction, the morphology of the TiO2 nanosheets changes from well-defined rectangular into uniform round or oval nanoparticles and the particle size also decreases from 60 to 31 nm, which can aggressively accelerate the lithium-ion diffusion. Electron paramagnetic resonance (EPR) and positron annihilation lifetime spectroscopy (PALS) results reveal that plentiful oxygen deficiencies relative to the Ti(3+) species were generated in blue Al-TiO2 ; this effectively enhances the electron conductivity of the TiO2 . X-ray photoelectron spectrometry (XPS) analysis indicates that a small peak is observed for the Al-O bond, which probably plays a very important role in the stabilization of the oxygen deficiencies/Ti(3+) species. As a result, the blue Al-TiO2 possesses significantly higher capacity, better rate performance, and a longer cycle life than the white pure TiO2 . Such improvements can be attributed to the decreased particle size, as well as the existence of the oxygen deficiencies/Ti(3+) species. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Lanthanide ions (III) as sensitizers of melatonin oxidation in reaction mixtures providing reactive species of oxygen and nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kaczmarek, Małgorzata, E-mail: mkaczmar@amu.edu.pl

    2015-06-15

    Chemiluminescence (CL) of the reactive systems providing strong oxidants (reactive species of oxygen and nitrogen) containing lanthanide ions (III) and melatonin, was studied. Kinetic curves of emission decay and spectral distributions of chemiluminescence were obtained. Analysis of differences in the intensity of chemiluminescence and CL spectra proved that excitation of Tb(III) and Dy(III) ions takes place with the energy transfer from the products of melatonin oxidation: N{sup 1}-acetyl-N{sup 2}-formyl-5-methoxykynuramine (AFMK) and N{sup 1}-acetyl-5-methoxykynuramine (AMK) to the lanthanide ions. In the system Fe(II)/Fe(III)–H{sub 2}O{sub 2}–Mel–Tb(III) a linear correlation was established between the integrated CL intensity and melatonin concent. - Highlights: • Chemiluminescence (CL) of melatonin (Mel) oxidation by reactive species of oxygen and nitrogen. • Tb(III) and Dy(III) ions as sensitizers of a melatonin oxidation process. • New CL method for determination of melatonin in pharmaceutical preparations based on CL of Fe(II)/Fe(III)–H{sub 2}O{sub 2}–Mel–Tb(III) system.

  16. First-principles calculation on oxygen ion migration in alkaline-earth doped La2GeO5

    International Nuclear Information System (INIS)

    Thuy Linh, Tran Phan; Sakaue, Mamoru; Aspera, Susan Meñez; Alaydrus, Musa; Wungu, Triati Dewi Kencana; Hoang Linh, Nguyen; Kasai, Hideaki; Mohri, Takahiro; Ishihara, Tatsumi

    2014-01-01

    By using first-principles calculations based on the density functional theory, we investigated the doping effects of alkaline-earth metals (Ba, Sr and Ca) in monoclinic lanthanum germanate La 2 GeO 5 on its oxygen ion conduction. Although the lattice parameters of the doped systems changed due to the ionic radii mismatch, the crystal structures remained monoclinic. The contribution of each atomic orbital to electronic densities of states was evaluated from the partial densities of states and partial charge densities. It was confirmed that the materials behaved as ionic crystals comprising of cations of La and dopants and anions of oxygen and covalently formed GeO 4 . The doping effect on the activation barrier for oxygen hopping to the most stable oxygen vacancy site was investigated by the climbing-image nudged elastic band method. By tracing the charge density change during the hopping, it was confirmed that the oxygen motion is governed by covalent interactions. The obtained activation barriers showed excellent quantitative agreements with an experiment for the Ca- and Sr-doped systems in low temperatures as well as the qualitative trend, including the Ba-doped system. (paper)

  17. Macrophages Under Low Oxygen Culture Conditions Respond to Ion Parametric Resonance Magnetic Fields

    Science.gov (United States)

    Macrophages, when entering inflamed tissue, encounter low oxygen tension due to the impairment of blood supply and/or the massive infiltration of cells that consume oxygen. Previously, we showed that such macrophages release more bacteriotoxic hydrogen peroxide (H202) when expose...

  18. Carboxyl functionalized carbon fibers with preserved tensile strength and electrochemical performance used as anodes of structural lithium-ion batteries

    International Nuclear Information System (INIS)

    Feng, Mengjie; Wang, Shubin; Yu, Yalin; Feng, Qihang; Yang, Jiping; Zhang, Boming

    2017-01-01

    Highlights: • Carboxyl functionalized CF is acquired by simple chemical oxidation method. • These CF have preserved the tensile strength, better electrochemical properties. • The presence of H_3PO_4 prevented the turbostratic carbon from over-oxidization. • There CF can be used as anodes of multifunctional structural battery. • The preservation and improvement is result from the hindered over-oxidization. - Abstract: Carboxyl functionalized carbon fibers with preserved tensile strength and electrochemical properties were acquired through a simple chemical oxidation method, and the proposed underlying mechanism was verified. The surface of carboxyl functionalizing carbon fibers is necessary in acquiring functional groups on the surface of carbon fibers to further improve the thermal, electrical or mechanical properties of the fibers. Functionalization should preserve the tensile strength and electrochemical properties of carbon fibers, because the anodes of structural batteries need to have high strength and electrochemical properties. Functionalized with mixed H_2SO_4/HNO_3 considerably reduced the tensile strength of carbon fibers. By contrast, the appearance of H_3PO_4 preserved the tensile strength of functionalized carbon fibers, reduced the dispersion level of tensile strength values, and effectively increased the concentration of functional acid groups on the surface of carbon fibers. The presence of phosphoric acid hindered the over-oxidation of turbostratic carbon, and consequently preserved the tensile strength of carbon fibers. The increased proportion of turbostratic carbon on the surface of carbon fibers concurrently enhanced the electrochemical properties of carbon fibers.

  19. A novel ion transport membrane reactor for fundamental investigations of oxygen permeation and oxy-combustion under reactive flow conditions

    KAUST Repository

    Kirchen, Patrick

    2013-01-01

    Ion transport membrane (ITM) reactors present an attractive technology for combined air separation and fuel conversion in applications such as syngas production, oxidative coupling or oxy-combustion, with the promise of lower capital and operating costs, as well higher product selectivities than traditional technologies. The oxygen permeation rate through a given ITM is defined by the membrane temperature and oxygen chemical potential difference across it. Both of these parameters can be strongly influenced by thermochemical reactions occurring in the vicinity of the membrane, though in the literature they are often characterized in terms of the well mixed product stream at the reactor exit. This work presents the development of a novel ITM reactor for the fundamental investigation of the coupling between fuel conversion and oxygen permeation under well defined fluid dynamic and thermodynamic conditions, including provisions for spatially resolved, in-situ investigations. A planar, finite gap stagnation flow reactor with optical and probe access to the reaction zone is used to facilitate in-situ measurements and cross-validation with detailed numerical simulations. Using this novel reactor, baseline measurements are presented to elucidate the impact of the sweep gas fuel (CH4) fraction on the oxygen permeation and fuel conversion. In addition, the difference between well-mixed gas compositions measured at the reactor outlet and those measured in the vicinity of the membrane surface are discussed, demonstrating the unique utility of the reactor. © 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  20. Nuclear tracks in CR-39 produced by carbon, oxygen, aluminium and titanium ions.

    Science.gov (United States)

    Rickards, J; Romo, V; Golzarri, J I; Espinosa, G

    2002-01-01

    This work describes the response of CR-39 (allyl diglycol polycarbonate) to different ions (C, O, Al and Ti) produced by the Instituto de Fisica 3 MV 9SDH-2 Pelletron accelerator and backscattered from a thin Au film on a C support. The ion energies were chosen in series such that the ranges of the different ions in the detector were 2, 3, 4, 5, 6, 7 and 8 microm respectively for each series. Once exposed, the detectors were etched with a solution of 6.25 M KOH at 60 degrees C, and the reading was carried out using a digital image analysis system. An analysis of the measured track diameters of all the types of ions indicates that, for a given range, track kinetics are independent of type of ion, energy and stopping power.

  1. Sub-keV secondary ion mass spectrometry depth profiling: comparison of sample rotation and oxygen flooding

    International Nuclear Information System (INIS)

    Liu, R.; Wee, A.T.S.

    2004-01-01

    Following the increasingly stringent requirements in the characterization of sub-micron IC devices, an understanding of the various factors affecting ultra shallow depth profiling in secondary ion mass spectrometry (SIMS) has become crucial. Achieving high depth resolution (of the order of 1 nm) is critical in the semiconductor industry today, and various methods have been developed to optimize depth resolution. In this paper, we will discuss ultra shallow SIMS depth profiling using B and Ge delta-doped Si samples using low energy 0.5 keV O 2 + primary beams. The relationship between depth resolution of the delta layers and surface topography measured by atomic force microscopy (AFM) is studied. The effect of oxygen flooding and sample rotation, used to suppress surface roughening is also investigated. Oxygen flooding was found to effectively suppress roughening and gives the best depth resolution for B, but sample rotation gives the best resolution for Ge. Possible mechanisms for this are discussed

  2. Uptake of vaporized molybdenum and cesium tracers by molten oxide mixtures as function of free oxygen ion activity

    International Nuclear Information System (INIS)

    Carmon, B.

    1975-11-01

    Molten mixtures of oxides containing Ca, Fe, Al, Na and Si were exposed to vaporized Mo-99 and Cs-137 tracers at 1100 and 1300 deg C. Uptake values at 1300 deg C were extrapolated to short heating times. The obtained ''attachment coefficients'' for that temperature are shown to have the relationship (Mo) approximately equal to (Cs)sup(-1/2). The chemical composition of the melts and their oxygen to metal ratio found to affect the uptake of both tracers. This is associated with the cationic field strengths and the free oxygen ion activities in the mixtures. Molybdenum and cesium apparently behave like glass-network forming and glass-network modifying species, respectively. (author)

  3. Oxygen isotope systematics of chondrules in the Allende CV3 chondrite: High precision ion microprobe studies

    Digital Repository Service at National Institute of Oceanography (India)

    Rudraswami, N.G.; Ushikubo, T.; Nakashima, D.; Kita, N.T.

    grains and some of them were derived from precursors related to refractory inclusions. However, most relict olivine grains show oxygen isotope ratios that overlap with those in homogeneous chondrules. The delta sup(17)O values of four barred olivine...

  4. Removal method of fluorescent dyes as pretreatment for measurement of major ion concentrations and hydrogen and oxygen isotopic ratios

    International Nuclear Information System (INIS)

    Nakata, Kotaro; Hasegawa, Takuma; Kashiwaya, Koki; Kodama, Hiroki; Miyajima, Tohru

    2011-01-01

    The major ion concentration and isotope ratio of hydrogen and oxygen can provide important information for migration of groundwater. Sometimes, quantitative estimation of these chemical and isotopic characteristics of solution is necessary for groundwater containing fluorescent dyes, which are used in drilling borehole and tracer experiments. However, sometimes correct estimation is disturbed by dyes and they become a cause of troubles for measurement equipments. Thus development of method to remove dyes is required so that the characteristics of groundwater can be estimated without the negative effect of dyes on measurement or equipments. In this study, removal of four representative dyes (Uranin, Eosin, Naphthalenesulfonic acid sodium(NAP) and Amino G acid potassium salt (AG)) was investigated. Uranin and Eosin were found to be removed by non-ionic synthetic resin: HP2MG. 99.99% of the dyes were removed from initial solutions containing dyes with 10 mg/L after contact with resin, while the contact had little effect on ion concentrations and oxygen and hydrogen isotope ratios. Thus the chemical and isotopic characteristics of groundwater samples containing Uranin and Eosin can be obtained by using the HP2MG resin. On the other hand, the NAP and AG were found to be difficult to remove by the HP2MG resin but they were able to be removed by anion exchange resin (Dowex 1x8). Though contact of solution with Dowex 1x8 did not affect cation concentrations and hydrogen and oxygen isotope ratios, anion concentrations were changed by the contact. Therefore the Dowex 1x8 is only applicable to estimation of the cation concentrations and isotope ratio of hydrogen and oxygen. When both anion and cation concentrations from the samples were necessary, Uranin or Eosin were recommended as a tracer in drilling or tracer experiments. (author)

  5. A comparative study of 30MeV boron4+ and 60MeV oxygen8+ ion irradiated Si NPN BJTs

    International Nuclear Information System (INIS)

    Kumar, M. Vinay; Krishnaveni, S.; Yashoda, T.; Dinesh, C. M.; Krishnakumar, K. S.; Jayashree, B.; Ramani

    2015-01-01

    The impact of 30MeV boron 4+ and 60MeV oxygen 8+ ion irradiation on electrical characteristics of 2N3773 Si NPN Bipolar junction transistors (BJTs) is reported in the present study. The transistors were decapped and irradiated at room temperature. Gummel characteristics, DC current gain and Capacitance-voltage (C-V) characteristics were studied before and after irradiation at different fluences. DC current gain has decreased significantly in both boron and oxygen ion irradiation. Also the value of capacitance decreased 3-4 times with increase in fluence. Both 30MeV boron ion and 60MeV oxygen ion induced similar extent of degradation in electrical characteristics of the transistor

  6. Numerical simulation of ion transport membrane reactors: Oxygen permeation and transport and fuel conversion

    KAUST Repository

    Hong, Jongsup; Kirchen, Patrick; Ghoniem, Ahmed F.

    2012-01-01

    Ion transport membrane (ITM) based reactors have been suggested as a novel technology for several applications including fuel reforming and oxy-fuel combustion, which integrates air separation and fuel conversion while reducing complexity

  7. Incorporation of transition metal ions and oxygen generation during anodizing of aluminium alloys

    International Nuclear Information System (INIS)

    Habazaki, H.; Konno, H.; Shimizu, K.; Nagata, S.; Skeldon, P.; Thompson, G.E.

    2004-01-01

    Enrichment of nickel at the alloy/film interface and incorporation of nickel species into the anodic film have been examined for a sputtering-deposited Al-1.2at.%Ni alloy in order to assist understanding of oxygen generation in barrier anodic alumina films. Anodizing of the alloy proceeds in two stages similarly to other dilute aluminium alloys, for example Al-Cr and Al-Cu alloys, where the Gibbs free energies per equivalent for formation of alloying element oxide exceeds the value for alumina. In the first stage, a nickel-free alumina film is formed, with nickel enriching in an alloy layer, 2 nm thick, immediately beneath the anodic oxide film. In the second stage, nickel atoms are oxidized together with aluminium, with oxygen generation forming gas bubbles within the anodic oxide film. This stage commences after accumulation of about 5.4 x 10 15 nickel atoms cm -2 in the enriched alloy layer. Oxygen generation also occurs when a thin layer of the alloy, containing about 2.0 x 10 19 nickel atoms m -2 , on electropolished aluminium, is completely anodized, contrasting with thin Al-Cr and Al-Cu alloy layers on electropolished aluminium, for which oxygen generation is essentially absent. A mechanism of oxygen generation, based on electron impurity levels of amorphous alumina and local oxide compositions, is discussed in order to explain the observations

  8. Carboxyl functionalized carbon fibers with preserved tensile strength and electrochemical performance used as anodes of structural lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Mengjie [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Wang, Shubin, E-mail: shubinwang@buaa.edu.cn [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Yu, Yalin; Feng, Qihang; Yang, Jiping; Zhang, Boming [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China)

    2017-01-15

    Highlights: • Carboxyl functionalized CF is acquired by simple chemical oxidation method. • These CF have preserved the tensile strength, better electrochemical properties. • The presence of H{sub 3}PO{sub 4} prevented the turbostratic carbon from over-oxidization. • There CF can be used as anodes of multifunctional structural battery. • The preservation and improvement is result from the hindered over-oxidization. - Abstract: Carboxyl functionalized carbon fibers with preserved tensile strength and electrochemical properties were acquired through a simple chemical oxidation method, and the proposed underlying mechanism was verified. The surface of carboxyl functionalizing carbon fibers is necessary in acquiring functional groups on the surface of carbon fibers to further improve the thermal, electrical or mechanical properties of the fibers. Functionalization should preserve the tensile strength and electrochemical properties of carbon fibers, because the anodes of structural batteries need to have high strength and electrochemical properties. Functionalized with mixed H{sub 2}SO{sub 4}/HNO{sub 3} considerably reduced the tensile strength of carbon fibers. By contrast, the appearance of H{sub 3}PO{sub 4} preserved the tensile strength of functionalized carbon fibers, reduced the dispersion level of tensile strength values, and effectively increased the concentration of functional acid groups on the surface of carbon fibers. The presence of phosphoric acid hindered the over-oxidation of turbostratic carbon, and consequently preserved the tensile strength of carbon fibers. The increased proportion of turbostratic carbon on the surface of carbon fibers concurrently enhanced the electrochemical properties of carbon fibers.

  9. Influence of oxygen on the ion-beam synthesis of silicon carbide buried layers in silicon

    International Nuclear Information System (INIS)

    Artamanov, V.V.; Valakh, M.Ya.; Klyui, N.I.; Mel'nik, V.P.; Romanyuk, A.B.; Romanyuk, B.N.; Yukhimchuk, V.A.

    1998-01-01

    The properties of silicon structures with silicon carbide (SiC) buried layers produced by high-dose carbon implantation followed by a high-temperature anneal are investigated by Raman and infrared spectroscopy. The influence of the coimplantation of oxygen on the features of SiC buried layer formation is also studied. It is shown that in identical implantation and post-implantation annealing regimes a SiC buried layer forms more efficiently in CZ Si wafers or in Si (CZ or FZ) subjected to the coimplantation of oxygen. Thus, oxygen promotes SiC layer formation as a result of the formation of SiO x precipitates and accommodation of the volume change in the region where the SiC phase forms. Carbon segregation and the formation of an amorphous carbon film on the SiC grain boundaries are also discovered

  10. Solar-wind interactions with the Moon: role of oxygen ions

    International Nuclear Information System (INIS)

    Mukherjee, N.R.

    1979-01-01

    The solar-wind interacts directly with the lunar surface due to tenuous atmosphere and magnetic field. The interaction results in an almost complete absorption of the solar-wind corpuscles producing no upstream bowshock but a cavity downstream. The solar-wind oxygen ionic species induce and undergo a complex set of reactions with the elements of the lunar minerals and the solar-wind derived trapped gases. In this paper, the long-term concentration and the role of oxygen derived from the solar-wind is discussed. (Auth.)

  11. Perovskites as electrodes of solid cells in sensitive elements of oxygen ion

    International Nuclear Information System (INIS)

    Gandurska, J.; Sniezynska, I.; Marek, A.; Szwagierczak, D.; Kulawik, J.

    1997-01-01

    The perovskite family comprises many compounds used in electronic applications. In this work perovskite materials based on LaCrO 3 were investigated, destined for electrodes of solid electrolyte oxygen sensors. lanthanum chromite powders modified by calcium, strontium and aluminium were prepared by the coprecipitation-calcination technique. The powders were examined using thermal analysis, x-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy. Introductory studies of electromotive force of oxygen cells with yttria stabilized zirconia as solid electrolyte and perovskite-based electrodes proved that it is possible to replace expensive Pt electrodes by much cheaper perovskite ones. (author)

  12. Interface-modulated approach toward multilevel metal oxide nanotubes for lithium-ion batteries and oxygen reduction reaction

    Institute of Scientific and Technical Information of China (English)

    Jiashen Meng; Chaojiang Niu; Xiong Liu; Ziang Liu; Hongliang Chen; Xuanpeng Wang; Jiantao Li

    2016-01-01

    Metal oxide hollow structures with multilevel interiors are of great interest for potential applications such as catalysis,chemical sensing,drug delivery,and energy storage.However,the controlled synthesis of multilevel nanotubes remains a great challenge.Here we develop a facile interface-modulated approach toward the synthesis of complex metal oxide multilevel nanotubes with tunable interior structures through electrospinning followed by controlled heat treatment.This versatile strategy can be effectively applied to fabricate wire-in-tube and tubein-tube nanotubes of various metal oxides.These multilevel nanotubes possess a large specific surface area,fast mass transport,good strain accommodation,and high packing density,which are advantageous for lithium-ion batteries (LIBs)and the oxygen reduction reaction (ORR).Specifically,shrinkable CoMn2O4 tube-in-tube nanotubes as a lithium-ion battery anode deliver a high discharge capacity of ~565 mAh.g-1 at a high rate of 2 A.g-1,maintaining 89% of the latter after 500 cycles.Further,as an oxygen reduction reaction catalyst,these nanotubes also exhibit excellent stability with about 92% current retention after 30,000 s,which is higher than that of commercial Pt/C (81%).Therefore,this feasible method may push the rapid development of one-dimensional (1D) nanomaterials.These multifunctional nanotubes have great potential in many frontier fields.

  13. High performance electrode for electrochemical oxygen generator cell based on solid electrolyte ion transport membrane

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Wei; Shao, Zongping; Ran, Ran; Chen, Zhihao; Zeng, Pingying; Gu, Hongxia; Jin, Wanqin; Xu, Nanping [College of Chemistry and Chemical Engineering, Nanjing University of Technology, No. 5 Xin Mofan Road, Nanjing 210009, JiangSu (China)

    2007-06-30

    A double-layer composite electrode based on Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} + Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9} (BSCF + SDC) and BSCF + SDC + Ag was investigated to be a promising cathode and also anode for the electrochemical oxygen generator based on samaria doped ceria electrolyte. The Ag particles in the second layer were not only the current collector but also the improver for the oxygen adsorption at the electrode. a.c. impedance results indicated that the electrode polarization resistance, as low as 0.0058 {omega} cm{sup 2} was reached at 800 C under air. In oxygen generator cell performance test, the electrode resistance dropped to half of the value at zero current density under an applied current density of 2.34 A cm{sup -2} at 700 C, and on the same conditions the oxygen generator cell was continual working for more than 900 min with a Faradic efficiency of {proportional_to}100%. (author)

  14. Positron annihilation lifetime characterization of oxygen ion irradiated rutile TiO2

    Science.gov (United States)

    Luitel, Homnath; Sarkar, A.; Chakrabarti, Mahuya; Chattopadhyay, S.; Asokan, K.; Sanyal, D.

    2016-07-01

    Ferromagnetic ordering at room temperature has been induced in rutile phase of TiO2 polycrystalline sample by O ion irradiation. 96 MeV O ion induced defects in rutile TiO2 sample has been characterized by positron annihilation spectroscopic techniques. Positron annihilation results indicate the formation of cation vacancy (VTi, Ti vacancy) in these irradiated TiO2 samples. Ab initio density functional theoretical calculations indicate that in TiO2 magnetic moment can be induced either by creating Ti or O vacancies.

  15. Planktonic foraminiferal oxygen isotope analysis by ion microprobe technique suggests warm tropical sea surface temperatures during the Early Paleogene

    Science.gov (United States)

    Kozdon, Reinhard; Kelly, D. Clay; Kita, Noriko T.; Fournelle, John H.; Valley, John W.

    2011-09-01

    Cool tropical sea surface temperatures (SSTs) are reported for warm Paleogene greenhouse climates based on the δ18O of planktonic foraminiferal tests. These results are difficult to reconcile with models of greenhouse gas-forced climate. It has been suggested that this "cool tropics paradox" arises from postdepositional alteration of foraminiferal calcite, yielding erroneously high δ18O values. Recrystallization of foraminiferal tests is cryptic and difficult to quantify, and the compilation of robust δ18O records from moderately altered material remains challenging. Scanning electron microscopy of planktonic foraminiferal chamber-wall cross sections reveals that the basal area of muricae, pustular outgrowths on the chamber walls of species belonging to the genus Morozovella, contain no mural pores and may be less susceptible to postdepositional alteration. We analyzed the δ18O in muricae bases of morozovellids from the central Pacific (Ocean Drilling Program Site 865) by ion microprobe using 10 μm pits with an analytical reproducibility of ±0.34‰ (2 standard deviations). In situ measurements of δ18O in these domains yield consistently lower values than those published for conventional multispecimen analyses. Assuming that the original δ18O is largely preserved in the basal areas of muricae, this new δ18O record indicates Early Paleogene (˜49-56 Ma) tropical SSTs in the central Pacific were 4°-8°C higher than inferred from the previously published δ18O record and that SSTs reached at least ˜33°C during the Paleocene-Eocene thermal maximum. This study demonstrates the utility of ion microprobe analysis for generating more reliable paleoclimate records from moderately altered foraminiferal tests preserved in deep-sea sediments.

  16. Doubly versus singly positively charged oxygen ions back-scattered from a silicon surface under dynamic O2+ bombardment

    International Nuclear Information System (INIS)

    Franzreb, Klaus; Williams, Peter; Loerincik, Jan; Sroubek, Zdenek

    2003-01-01

    Mass-resolved (and emission-charge-state-resolved) low-energy ion back-scattering during dynamic O 2 + bombardment of a silicon surface was applied in a Cameca IMS-3f secondary ion mass spectrometry (SIMS) instrument to determine the bombarding energy dependence of the ratio of back-scattered O 2+ versus O + . While the ratio of O 2+ versus O + drops significantly at reduced bombarding energies, O 2+ back-scattered from silicon was still detectable at an impact energy (in the lab frame) as low as about 1.6 keV per oxygen atom. Assuming neutralization prior to impact, O 2+ ion formation in an asymmetric 16 O→ 28 Si collision is expected to take place via 'collisional double ionization' (i.e. by promotion of two outer O 2p electrons) rather than by the production of an inner-shell (O 2s or O 1s) core hole followed by Auger-type de-excitation during or after ejection. A molecular orbital (MO) correlation diagram calculated for a binary 'head-on' O-Si collision supports this interpretation

  17. Improving data quality and preserving HCD-generated reporter ions with EThcD for isobaric tag-based quantitative proteomics and proteome-wide PTM studies

    International Nuclear Information System (INIS)

    Yu, Qing; Shi, Xudong; Feng, Yu; Kent, K. Craig; Li, Lingjun

    2017-01-01

    Mass spectrometry (MS)-based isobaric labeling has undergone rapid development in recent years due to its capability for high throughput quantitation. Apart from its originally designed use with collision-induced dissociation (CID) and higher-energy collisional dissociation (HCD), isobaric tagging technique could also work with electron-transfer dissociation (ETD), which provides complementarity to CID and is preferred in sequencing peptides with post-translational modifications (PTMs). However, ETD suffers from long reaction time, reduced duty cycle and bias against peptides with lower charge states. In addition, common fragmentation mechanism in ETD results in altered reporter ion production, decreased multiplexing capability, and even loss of quantitation capability for some of the isobaric tags, including custom-designed dimethyl leucine (DiLeu) tags. Here, we demonstrate a novel electron-transfer/higher-energy collision dissociation (EThcD) approach that preserves original reporter ion channels, mitigates bias against lower charge states, improves sensitivity, and significantly improves data quality for quantitative proteomics and proteome-wide PTM studies. Systematic optimization was performed to achieve a balance between data quality and sensitivity. We provide direct comparison of EThcD with ETD and HCD for DiLeu- and TMT-labeled HEK cell lysate and IMAC enriched phosphopeptides. Results demonstrate improved data quality and phosphorylation localization accuracy while preserving sufficient reporter ion production. Biological studies were performed to investigate phosphorylation changes in a mouse vascular smooth muscle cell line treated with four different conditions. Overall, EThcD exhibits superior performance compared to conventional ETD and offers distinct advantages compared to HCD in isobaric labeling based quantitative proteomics and quantitative PTM studies. - Highlights: • EThcD was optimized for isobaric tag-labeled peptides for quantitative

  18. Improving data quality and preserving HCD-generated reporter ions with EThcD for isobaric tag-based quantitative proteomics and proteome-wide PTM studies

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Qing [School of Pharmacy, University of Wisconsin, Madison, WI 53705 (United States); Shi, Xudong [Department of Surgery, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705 (United States); Feng, Yu [School of Pharmacy, University of Wisconsin, Madison, WI 53705 (United States); Kent, K. Craig [Department of Surgery, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705 (United States); Li, Lingjun, E-mail: lingjun.li@wisc.edu [School of Pharmacy, University of Wisconsin, Madison, WI 53705 (United States); Department of Chemistry, University of Wisconsin, Madison, WI 53706 (United States)

    2017-05-22

    Mass spectrometry (MS)-based isobaric labeling has undergone rapid development in recent years due to its capability for high throughput quantitation. Apart from its originally designed use with collision-induced dissociation (CID) and higher-energy collisional dissociation (HCD), isobaric tagging technique could also work with electron-transfer dissociation (ETD), which provides complementarity to CID and is preferred in sequencing peptides with post-translational modifications (PTMs). However, ETD suffers from long reaction time, reduced duty cycle and bias against peptides with lower charge states. In addition, common fragmentation mechanism in ETD results in altered reporter ion production, decreased multiplexing capability, and even loss of quantitation capability for some of the isobaric tags, including custom-designed dimethyl leucine (DiLeu) tags. Here, we demonstrate a novel electron-transfer/higher-energy collision dissociation (EThcD) approach that preserves original reporter ion channels, mitigates bias against lower charge states, improves sensitivity, and significantly improves data quality for quantitative proteomics and proteome-wide PTM studies. Systematic optimization was performed to achieve a balance between data quality and sensitivity. We provide direct comparison of EThcD with ETD and HCD for DiLeu- and TMT-labeled HEK cell lysate and IMAC enriched phosphopeptides. Results demonstrate improved data quality and phosphorylation localization accuracy while preserving sufficient reporter ion production. Biological studies were performed to investigate phosphorylation changes in a mouse vascular smooth muscle cell line treated with four different conditions. Overall, EThcD exhibits superior performance compared to conventional ETD and offers distinct advantages compared to HCD in isobaric labeling based quantitative proteomics and quantitative PTM studies. - Highlights: • EThcD was optimized for isobaric tag-labeled peptides for quantitative

  19. Optimisation of oxygen ion transport in materials for ceramic membrane devices.

    Science.gov (United States)

    Kilner, J A

    2007-01-01

    Oxygen transport in ceramic oxide materials has received much attention over the past few decades. Much of this interest has stemmed from the desire to construct high temperature electrochemical devices for energy conversion, an example being the solid oxide fuel cell. In order to achieve high performance for these devices, insights are needed in how to achieve optimum performance from the functional components such as the electrolytes and electrodes. This includes the optimisation of oxygen transport through the crystal lattice of electrode and electrolyte materials and across the homogeneous (grain boundary) and heterogeneous interfaces that exist in real devices. Strategies are discussed for the optimisation of these quantities and current problems in the characterisation of interfacial transport are explored.

  20. A universal carbonate ion effect on stable oxygen isotope ratios in unicellular planktonic calcifying organisms

    OpenAIRE

    Ziveri, P.; Thoms, S.; Probert, I.; Geisen, M.; Langer, H.

    2012-01-01

    The oxygen isotopic composition (δ18O) of calcium carbonate of planktonic calcifying organisms is a key tool for reconstructing both past seawater temperature and salinity. The calibration of paloeceanographic proxies relies in general on empirical relationships derived from field experiments on extant species. Laboratory experiments have more often than not revealed that variables other than the target parameter influence the proxy signal, which makes proxy c...

  1. Influence of the residual oxygen in the plasma immersion ion implantation (PI3) processing of materials

    International Nuclear Information System (INIS)

    Ueda, M.; Silva, A.R.; Mello, Carina B.; Silva, G.; Reuther, H.; Oliveira, V.S.

    2011-01-01

    In this work, we investigated the effects of the contaminants present in the vacuum chamber of the PI3 system, in particular, the residual oxygen, which results in the formation of the oxide compounds on the surface and hence is responsible for the high implantation energies required to achieve reasonably thick treated layers. We used a mass spectrometer (RGA) with a quadruple filter to verify the composition of the residual vacuum and pressure of the elements present in the chamber. Initially we found a high proportion of residual oxygen in a vacuum with a pressure of 1 × 10 −3 Pa. Minimizing the residual oxygen percentage in about 80%, by efficient cleaning of the chamber walls and by improving the gas feeding process, we mitigated the formation of oxides during the PI3 process. Therefore we achieved a highly efficient PI3 processing obtaining implanted layers reaching about 50 nm, even in cases such as an aluminum alloy, where is very difficult to nitrogen implant at low energies. We performed nitrogen PI3 treatment of SS304 and Al7075 using pulses of only 3 kV and 15 × 10 −6 s at 1 kHz with an operating pressure of 1 Pa.

  2. FY 1998 annual report on the development of novel, high-activity oxygen electrode by ion-implantation; 1998 nendo ion chunyuho ni yoru shinkina kokassei sanso denkyoku no kaihatsu chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    An attempt has been made to develop an electrode material having high activity for oxygen generating reactions by ion-implantation, which is used to form the bulk defects (fine gaps at the atomic level) on the electrode surface, considered to serve as the active sites. It is found that implantation of the Co{sup +} or Zn{sup +} ion into a compound oxide electrode of Ti and Ru is accompanied by decreased overvoltage for oxygen generation by 50 to 100 mV. The Co{sup +} and Zn{sup +} ions, when implanted, cause damage of similar density in the thin film, decreasing its overvoltage to a similar extent, in spite of their different chemical properties, from which it is considered that the effect of ion implantation is not to change chemical properties of the film but to form a structural defect therein. A thin-film electrode of ruthenium dioxide, which is considered to be the oxygen generating electrode of the highest activity at present, is prepared and implanted with the Ru{sup +} ion, to observe the effect. The ion implantation also decreases the overvoltage by 50 to 70 mV, demonstrating its effect. The same principle is expected to be applicable to development of high-activity oxygen reducing electrode (electrode for fuel cell). (NEDO)

  3. Electromagnetic ion cyclotron waves observed near the oxygen cyclotron frequency by ISEE 1 and 2

    Science.gov (United States)

    Fraser, B. J.; Samson, J. C.; Hu, Y. D.; Mcpherron, R. L.; Russell, C. T.

    1992-01-01

    The first results of observations of ion cyclotron waves by the elliptically orbiting ISEE 1 and 2 pair of spacecraft are reported. The most intense waves (8 nT) were observed in the outer plasmasphere where convection drift velocities were largest and the Alfven velocity was a minimum. Wave polarization is predominantly left-handed with propagation almost parallel to the ambient magnetic field, and the spectral slot and polarization reversal predicted by cold plasma propagation theory are identified in the wave data. Computations of the experimental wave spectra during the passage through the plasmapause show that the spectral slots relate to the local plasma parameters, possibly suggesting an ion cyclotron wave growth source near the spacecraft. A regular wave packet structure seen over the first 30 min of the event is attributed to the modulation of this energy source by the Pc 5 waves seen at the same time.

  4. Oxidation of sulfur (IV by oxygen in aqueous solution: role of some metal ions

    Directory of Open Access Journals (Sweden)

    Martins Claudia R.

    1999-01-01

    Full Text Available Catalytic effect of metal ions: Cr(VI, Cr(III, Cd(II, V(V and chloride anion, on the oxidation of S(IV in aqueous solution, at concentrations of metal ions and S(IV usually found in urban atmospheres, were studied under controlled experimental conditions (pH (2.1 - 4,5, T (25.0 - 35.0 °C, air flow rate, concentration of reactants, etc.... The kinetic constant determined at 25.0 °C and pH range (2.1 - 4.5, using ultra pure water was 8.0 ± 0.5 x 10-4 s-1. This value was considered as a reference for the oxidation reaction rate. The kinetic constants determined in the presence of Cr(VI revealed that the oxidation reaction of S(IV is quite influenced by the acidity. At pH = 2.1 (K = 2.3 x 10-2 mg-1 L s-1 the reaction is carried out with a rate five times greater when compared to pH = 2.6 (K = 4.3 x 10-3 mg-1 L s-1 and thirty times greater when compared to pH = 3.4 (K= 8.0 x 10 -4 mg-1 L s-1. The following rate expression was obtained at pH = 2.6: -r(S(IV =K [Cr(VI] [S(IV] and the activation energy found was: Ea =70.3KJ/mol. No catalytic effects were observed for Cd(II or chloride ion, while inhibitory effects were observed for Cr(III and V(V ions.

  5. Generation of positive and negative oxygen ions in magnetron discharge during reactive sputtering of alumina

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Petr; Bulíř, Jiří; Lančok, Ján; Musil, Jindřich; Novotný, Michal

    2010-01-01

    Roč. 7, č. 11 (2010), s. 910-914 ISSN 1612-8850 R&D Projects: GA AV ČR IAA100100718; GA AV ČR KAN400100653; GA ČR GP202/09/P324 Institutional research plan: CEZ:AV0Z10100522 Keywords : aluminium oxide * ion-energy distribution function * magnetron * mass spectrometry * pulsed discharges Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.643, year: 2010

  6. Implantation of oxygen ions for the realization of SOS (silicon on insulator) structures: SIMOX

    International Nuclear Information System (INIS)

    Margail, J.

    1987-03-01

    Highdose oxygen implantation is becoming a serious candidate for SOI (silicon on insulator) structure realization. The fabrication condition study of these substrates allowed to show up the implantation and annealing parameter importance for microstructure, and particularly for crystal quality of silicon films. It has been shown that the use of high temperature annealings leads to high quality substrates: monocrystal silicon film without any precipitate, at the card scale; Si/Si O 2 interface formation. After annealing at 1340 O C, Hall mobilities have been measured in silicon film, and its residual doping is very low. First characteristics and performance of submicron CMOS circuits prooves the electric quality of these substrates [fr

  7. Suppression of self-organized surface nanopatterning on GaSb/InAs multilayers induced by low energy oxygen ion bombardment by using simultaneously sample rotation and oxygen flooding

    Science.gov (United States)

    Beainy, Georges; Cerba, Tiphaine; Bassani, Franck; Martin, Mickaël; Baron, Thierry; Barnes, Jean-Paul

    2018-05-01

    Time of flight secondary ion mass spectrometry (ToF-SIMS) is a well-adapted analytical method for the chemical characterization of concentration profiles in layered or multilayered materials. However, under ion beam bombardment, initially smooth material surface becomes morphologically unstable. This leads to abnormal secondary ion yields and depth profile distortions. In this contribution, we explore the surface topography and roughening evolution induced by O2+ ion bombardment on GaSb/InAs multilayers. We demonstrate the formation of nanodots and ripples patterning according to the ion beam energy. Since the latter are undesirable for ToF-SIMS analysis, we managed to totally stop their growth by using simultaneously sample rotation and oxygen flooding. This unprecedented coupling between these two latter mechanisms leads to a significant enhancement in depth profiles resolution.

  8. Fabrication of Super-Hydrophobic Microchannels via Strain-Recovery Deformations of Polystyrene and Oxygen Reactive Ion Etch.

    Science.gov (United States)

    Chakraborty, Anirban; Xiang, Mingming; Luo, Cheng

    2013-08-19

    In this article, we report a simple approach to generate micropillars (whose top portions are covered by sub-micron wrinkles) on the inner surfaces of polystyrene (PS) microchannels, as well as on the top surface of the PS substrate, based on strain-recovery deformations of the PS and oxygen reactive ion etch (ORIE). Using this approach, two types of micropillar-covered microchannels are fabricated. Their widths range from 118 μm to 132 μm, depths vary from 40 μm to 44 μm, and the inclined angles of their sidewalls are from 53° to 64°. The micropillars enable these microchannels to have super-hydrophobic properties. The contact angles observed on the channel-structured surfaces are above 162°, and the tilt angles to make water drops roll off from these channel-structured substrates can be as small as 1°.

  9. Fabrication of Super-Hydrophobic Microchannels via Strain-Recovery Deformations of Polystyrene and Oxygen Reactive Ion Etch

    Directory of Open Access Journals (Sweden)

    Anirban Chakraborty

    2013-08-01

    Full Text Available In this article, we report a simple approach to generate micropillars (whose top portions are covered by sub-micron wrinkles on the inner surfaces of polystyrene (PS microchannels, as well as on the top surface of the PS substrate, based on strain-recovery deformations of the PS and oxygen reactive ion etch (ORIE. Using this approach, two types of micropillar-covered microchannels are fabricated. Their widths range from 118 μm to 132 μm, depths vary from 40 μm to 44 μm, and the inclined angles of their sidewalls are from 53° to 64°. The micropillars enable these microchannels to have super-hydrophobic properties. The contact angles observed on the channel-structured surfaces are above 162°, and the tilt angles to make water drops roll off from these channel-structured substrates can be as small as 1°.

  10. XPS studies of SiO/sub 2/ surface layers formed by oxygen ion implantation into silicon

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, D.; Finster, J. (Karl-Marx-Universitaet, Leipzig (German Democratic Republic). Sektion Chemie); Hensel, E.; Skorupa, W.; Kreissig, U. (Zentralinstitut fuer Kernforschung, Rossendorf bei Dresden (German Democratic Republic))

    1983-03-16

    SiO/sub 2/ surface layers of 160 nm thickness formed by /sup 16/O/sup +/ ion implantation into silicon are examined by X-ray photoelectron spectroscopy measurements into the depth after a step-by-step chemical etching. The chemical nature and the thickness of the transition layer were determined. The results of the XPS measurements show that the outer surface and the bulk of the layers formed by oxygen implantation and subsequent high temperature annealing consist of SiO/sub 2/. There is no evidence for Si or SiO/sub x/ (0

  11. Cold acclimation improves chill tolerance in the migratory locust through preservation of ion balance and membrane potential

    DEFF Research Database (Denmark)

    Andersen, Mads; Folkersen, Rasmus; MacMillan, Heath Andrew

    2017-01-01

    potential (Vm). Several studies have therefore suggested a link between preservation of Vm and cellular survival after cold stress, but none has measured Vm in this context. We tested this hypothesis by acclimating locusts (Locusta migratoria) to high (31°C) and low temperature (11°C) for 4 days before...... revealed that cellular injury during cold exposure occurs when Vm becomes severely depolarized. Interestingly, we found that cellular sensitivity to hypothermic hyperkalaemia was lower in cold-acclimated locusts that were better able to defend Vm whilst exposed to high extracellular [K+]. Together...

  12. Dual-functional Memory and Threshold Resistive Switching Based on the Push-Pull Mechanism of Oxygen Ions

    KAUST Repository

    Huang, Yi-Jen

    2016-04-07

    The combination of nonvolatile memory switching and volatile threshold switching functions of transition metal oxides in crossbar memory arrays is of great potential for replacing charge-based flash memory in very-large-scale integration. Here, we show that the resistive switching material structure, (amorphous TiOx)/(Ag nanoparticles)/(polycrystalline TiOx), fabricated on the textured-FTO substrate with ITO as the top electrode exhibits both the memory switching and threshold switching functions. When the device is used for resistive switching, it is forming-free for resistive memory applications with low operation voltage (<±1 V) and self-compliance to current up to 50 μA. When it is used for threshold switching, the low threshold current is beneficial for improving the device selectivity. The variation of oxygen distribution measured by energy dispersive X-ray spectroscopy and scanning transmission electron microscopy indicates the formation or rupture of conducting filaments in the device at different resistance states. It is therefore suggested that the push and pull actions of oxygen ions in the amorphous TiOx and polycrystalline TiOx films during the voltage sweep account for the memory switching and threshold switching properties in the device.

  13. Development of a Mass Transfer Model and Its Application to the Behavior of the Cs, Sr, Ba, and Oxygen ions in an Electrolytic Reduction Process for SF

    International Nuclear Information System (INIS)

    Park, Byung Heung; Kang, Dae Seung; Seo, Chung Seok; Park, Seong Won

    2005-01-01

    Isotopes of alkali and alkaline earth metals (AM and AEM) are the main contributors to the heat load and the radiotoxicity of spent fuel (SF). These components are separated from the SF and dissolved in a molten LiCl in an electrolytic reduction process. A mass transfer model is developed to describe the diffusion behavior of Cs, Sr, and Ba in the SF into the molten salt. The model is an analytical solution of Fick's second law of diffusion for a cylinder which is the shape of a cathode in the electrolytic reduction process. And the model is also applied to depict the concentration profile of the oxygen ion which is produced by the electrolysis of Li 2 O. The regressed diffusion coefficients of the model correlating the experimentally measured data are evaluated to be greater in the order of Ba, Cs, and Sr for the metal ions and the diffusion of the oxygen ion is slower than the metal ions which implies that different mechanisms govern the diffusion of the metal ions and the oxygen ions in a molten LiCl.

  14. Effects of oxygen gas flow rate and ion beam plasma conditions on the opto-electronic properties of indium molybdenum oxide films fabricated by ion beam-assisted evaporation

    International Nuclear Information System (INIS)

    Kuo, C.C.; Liu, C.C.; Lin, C.C.; Liou, Y.Y.; He, J.L.; Chen, F.S.

    2008-01-01

    The purpose of the present work is to experimentally study the effects of the oxygen gas flow rate and ion beam plasma conditions on the properties of indium molybdenum oxide (IMO) films deposited onto the polyethersulfone (PES) substrate. Crystal structure, surface morphology, and optoelectronic properties of IMO films are examined as a function of oxygen gas flow rate and ion beam discharge voltage. Experimental results show that the IMO films consist of a cubic bixbyite B-In 2 O 3 single phase with its crystal preferred orientation alone B(222). Mo 6+ ions are therefore considered to partially substitute In 3+ sites in the deposit. Under-controlled ion bombardment during deposition enhances the reaction among those arriving oxygen and metal ion species to condense into IMO film and facilitates a decreased surface roughness of IMO film. The film with ultimate crystallinity and the lowest surface roughness is obtained when the oxygen flow rate of 3 sccm and the discharge voltage of 110 V are employed. This results in the lowest electrical resistivity due mainly to the increased Hall mobility and irrelevant to carrier concentration. The lowest electrical resistivity of 8.63 x 10 -4 ohm-cm with a 84.63% transmittance at a wavelength of 550 nm can be obtained, which satisfies the requirement of a flexible transparent conductive polymer substrate

  15. Electron stimulated desorption of positive and negative oxygen ions from YBa{sub 2}Cu{sub 3}O{sub 7} surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, A [Technion-Israel Inst. of Tech., Haifa (Israel). Solid State Inst.; Moss, S D; Paterson, P J.K. [Royal Melbourne Inst. of Tech., VIC (Australia); McCubbery, D [La Trobe Univ., Bundoora, VIC (Australia); Petravic, M [Australian National Univ., Canberra, ACT (Australia)

    1997-12-31

    The electron stimulated desorption (ESD) of positive and negative oxygen ion from superconducting YBa{sub 2}Cu{sub 3}O{sub 7} surfaces was studied. Based on ion desorption yield measurements as function of electron kinetic energy, primary excitations leading to positive and negative oxygen ion desorption are suggested. To the best of the authors` knowledge this is the first study on electron energy dependent ESD from YBa{sub 2}Cu{sub 3}O{sub 7} surfaces. The YBa{sub 2}Cu{sub 3}O{sub 7} samples were prepared from BaCO{sub 3}, Y{sub 2}O{sub 3} and CuO using standard high temperature sintering and annealing procedures. Slices 2 mm thick were cut and further annealed at 400 C in flowing oxygen for 24 hours prior to insertion into the ultrahigh vacuum (UHV) chamber for ESD. The near surface composition and chemical state of the annealed sample after exposure to air was examined by Auger and XPS analysis. These measurements suggest that the ESD experiments were performed on samples of similar near surface and bulk composition with some OH- chemisorbed groups and Cl surface contaminations and that negative and positive oxygen ion desorption may be initiated via a primary core level ionization. 10 refs., 3 figs.

  16. Electron stimulated desorption of positive and negative oxygen ions from YBa{sub 2}Cu{sub 3}O{sub 7} surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, A. [Technion-Israel Inst. of Tech., Haifa (Israel). Solid State Inst.; Moss, S.D.; Paterson, P.J.K. [Royal Melbourne Inst. of Tech., VIC (Australia); McCubbery, D. [La Trobe Univ., Bundoora, VIC (Australia); Petravic, M. [Australian National Univ., Canberra, ACT (Australia)

    1996-12-31

    The electron stimulated desorption (ESD) of positive and negative oxygen ion from superconducting YBa{sub 2}Cu{sub 3}O{sub 7} surfaces was studied. Based on ion desorption yield measurements as function of electron kinetic energy, primary excitations leading to positive and negative oxygen ion desorption are suggested. To the best of the authors` knowledge this is the first study on electron energy dependent ESD from YBa{sub 2}Cu{sub 3}O{sub 7} surfaces. The YBa{sub 2}Cu{sub 3}O{sub 7} samples were prepared from BaCO{sub 3}, Y{sub 2}O{sub 3} and CuO using standard high temperature sintering and annealing procedures. Slices 2 mm thick were cut and further annealed at 400 C in flowing oxygen for 24 hours prior to insertion into the ultrahigh vacuum (UHV) chamber for ESD. The near surface composition and chemical state of the annealed sample after exposure to air was examined by Auger and XPS analysis. These measurements suggest that the ESD experiments were performed on samples of similar near surface and bulk composition with some OH- chemisorbed groups and Cl surface contaminations and that negative and positive oxygen ion desorption may be initiated via a primary core level ionization. 10 refs., 3 figs.

  17. Ion microprobe analyses of oxygen three-isotope ratios of chondrules from the Sayh al Uhaymir 290 CH chondrite using a multiple-hole disk

    Digital Repository Service at National Institute of Oceanography (India)

    Nakashima, D.; Ushikubo, T.; Gowda, R.N.; Kita, N.T.; Valley, J.W.; Naga, K.

    Author version: Meteorit. Planet. Sci., vol.46(6); 2011; 857-874 Ion microprobe analyses of oxygen three isotope ratios of chondrules from the Sayh al Uhaymir 290 CH chondrite using a multiple-hole disk Daisuke Nakashima 1,2,* , Takayuki Ushikubo...

  18. Interactions between oxygen permeation and homogeneous-phase fuel conversion on the sweep side of an ion transport membrane

    KAUST Repository

    Hong, Jongsup; Kirchen, Patrick; Ghoniem, Ahmed F.

    2013-01-01

    concentration enhances oxygen permeation substantially. This is accomplished through promoting oxidation reactions (oxygen consumption) and the transport of the products and reaction heat towards the membrane, which lowers the oxygen concentration and increases

  19. Simultaneous Blood–Tissue Exchange of Oxygen, Carbon Dioxide, Bicarbonate, and Hydrogen Ion

    Science.gov (United States)

    Dash, Ranjan K.; Bassingthwaighte, James B.

    2014-01-01

    A detailed nonlinear four-region (red blood cell, plasma, interstitial fluid, and parenchymal cell) axially distributed convection-diffusion-permeation-reaction-binding computational model is developed to study the simultaneous transport and exchange of oxygen (O2) and carbon dioxide (CO2) in the blood–tissue exchange system of the heart. Since the pH variation in blood and tissue influences the transport and exchange of O2 and CO2 (Bohr and Haldane effects), and since most CO2 is transported as HCO3- (bicarbonate) via the CO2 hydration (buffering) reaction, the transport and exchange of HCO3- and H+ are also simulated along with that of O2 and CO2. Furthermore, the model accounts for the competitive nonlinear binding of O2 and CO2 with the hemoglobin inside the red blood cells (nonlinear O2–CO2 interactions, Bohr and Haldane effects), and myoglobin-facilitated transport of O2 inside the parenchymal cells. The consumption of O2 through cytochrome-c oxidase reaction inside the parenchymal cells is based on Michaelis–Menten kinetics. The corresponding production of CO2 is determined by respiratory quotient (RQ), depending on the relative consumption of carbohydrate, protein, and fat. The model gives a physiologically realistic description of O2 transport and metabolism in the microcirculation of the heart. Furthermore, because model solutions for tracer transients and steady states can be computed highly efficiently, this model may be the preferred vehicle for routine data analysis where repetitive solutions and parameter optimization are required, as is the case in PET imaging for estimating myocardial O2 consumption. PMID:16775761

  20. Effect of low-oxygen-concentration layer on iron gettering capability of carbon-cluster ion-implanted Si wafer for CMOS image sensors

    Science.gov (United States)

    Onaka-Masada, Ayumi; Nakai, Toshiro; Okuyama, Ryosuke; Okuda, Hidehiko; Kadono, Takeshi; Hirose, Ryo; Koga, Yoshihiro; Kurita, Kazunari; Sueoka, Koji

    2018-02-01

    The effect of oxygen (O) concentration on the Fe gettering capability in a carbon-cluster (C3H5) ion-implanted region was investigated by comparing a Czochralski (CZ)-grown silicon substrate and an epitaxial growth layer. A high Fe gettering efficiency in a carbon-cluster ion-implanted epitaxial growth layer, which has a low oxygen region, was observed by deep-level transient spectroscopy (DLTS) and secondary ion mass spectroscopy (SIMS). It was demonstrated that the amount of gettered Fe in the epitaxial growth layer is approximately two times higher than that in the CZ-grown silicon substrate. Furthermore, by measuring the cathodeluminescence, the number of intrinsic point defects induced by carbon-cluster ion implantation was found to differ between the CZ-grown silicon substrate and the epitaxial growth layer. It is suggested that Fe gettering by carbon-cluster ion implantation comes through point defect clusters, and that O in the carbon-cluster ion-implanted region affects the formation of gettering sinks for Fe.

  1. Different Reactive Oxygen Species Lead to Distinct Changes of Cellular Metal Ions in the Eukaryotic Model Organism Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Peter J. Rogers

    2011-11-01

    Full Text Available Elemental uptake and export of the cell are tightly regulated thereby maintaining the ionomic homeostasis. This equilibrium can be disrupted upon exposure to exogenous reactive oxygen species (ROS, leading to reduction or elevation of the intracellular metal ions. In this study, the ionomic composition in the eukaryotic model organism Saccharomyces cerevisiae was profiled using the inductively-coupled plasma optical emission spectrometer (ICP-OES following the treatment with individual ROS, including hydrogen peroxide, cumen hydroperoxide, linoleic acid hydroperoxide (LAH, the superoxide-generating agent menadione, the thiol-oxidising agent diamide [diazine-dicarboxylic acid-bis(dimethylamide], dimedone and peroxynitrite. The findings demonstrated that different ROS resulted in distinct changes in cellular metal ions. Aluminium (Al3+ level rose up to 50-fold after the diamide treatment. Cellular potassium (K+ in LAH-treated cells was 26-fold less compared to the non-treated controls. The diamide-induced Al3+ accumulation was further validated by the enhanced Al3+ uptake along the time course and diamide doses. Pre-incubation of yeast with individual elements including iron, copper, manganese and magnesium failed to block diamide-induced Al3+ uptake, suggesting Al3+-specific transporters could be involved in Al3+ uptake. Furthermore, LAH-induced potassium depletion was validated by a rescue experiment in which addition of potassium increased yeast growth in LAH-containing media by 26% compared to LAH alone. Taken together, the data, for the first time, demonstrated the linkage between ionomic profiles and individual oxidative conditions.

  2. Photobehavior of aqueous uranyl ion and photo-oxygenation of isobutane using light from the visible region

    International Nuclear Information System (INIS)

    Bergfeldt, T.M.; Waltz, W.L.; Xu, X; Sedlak, P.; Dreyer, U.; Mockel, H.; Lilie, J.; Stephenson, J.W.

    2003-01-01

    The photochemical and photophysical behavior of the aqueous uranyl ion [UO 2 (H 2 O) 5 ] 2+ has been studied under the influence of visible light and with added perchloric acid over the range of 0.01-4 M. In the presence of 2-methylpropane (isobutane), photo-oxygenation of isobutane occurs to yield, as the major product, 2-methyl-2-propanol (tert-butyl alcohol) along with lesser amounts of 2-methyl-2-propene (isobutene) and other C1-C8 products. The quantum yield for formation of tert-butyl alcohol is independent of light intensity at the irradiation wavelength of 415 nm and of uranyl concentration, but it increases from 0.016 ± 0.001 at 0.01 M HC1O 4 (pH 2) to 0.13 ± 0.01 at 4 M HC1O 4 . The emission spectrum from the electronically excited uranyl ion and the associated quantum yields have been measured in the presence and absence of isobutane, as a function of added perchloric acid. While in both cases the shape of the spectrum remains invariant, the quantum yields increase with increasing perchloric acid concentration. The strong dependence on added perchloric acid is interpreted within the context of the presence and interconversion of two electronically excited species, an acid form, *[UO 2 (H 2 O) 5 ] 2+ , and a base form, *[UO 2 (H 2 O) n (OH)] + . It is proposed that both forms react with isobutane to give a tert-butyl radical, and that oxidation of coordinated aqua ligands occur, the latter generating a hydroxyl radical whose reaction with isobutane rapidly leads also to a tert-butyl radical. The reaction of this alkyl radical with ground-state [UO 2 (H 2 O) 5 ] 2+ then gives rise to the stable tert-butyl alcohol product and reduced forms of uranyl ion. Based upon the values of the quantum yields and of excited-state lifetime measurements reported in the literature, a comprehensive mechanism has been developed in a quantitative manner to provide calculated values of the rate constants for the individual mechanistic steps. The calculated rate constants

  3. Optically continuous silcrete quartz cements of the St. Peter Sandstone: High precision oxygen isotope analysis by ion microprobe

    Science.gov (United States)

    Kelly, Jacque L.; Fu, Bin; Kita, Noriko T.; Valley, John W.

    2007-08-01

    A detailed oxygen isotope study of detrital quartz and authigenic quartz overgrowths from shallowly buried (ratio by laser fluorination, resulting in an average δ 18O of 10.0 ± 0.2‰ (1SD, n = 109). Twelve thin sections were analyzed by CAMECA-1280 ion microprobe (6-10 μm spot size, analytical precision better than ±0.2‰, 1SD). Detrital quartz grains have an average δ 18O of 10.0 ± 1.4‰ (1SD, n = 91) identical to the data obtained by laser fluorination. The ion microprobe data reveal true variability that is otherwise lost by homogenization of powdered samples necessary for laser fluorination. Laser fluorination uses samples that are one million times larger than the ion microprobe. Whole rock (WR) samples from the 53 rocks were analyzed by laser fluorination, giving δ 18O between 9.8‰ and 16.7‰ ( n = 110). Quartz overgrowths in thin sections from 10 rocks were analyzed by ion microprobe and average δ 18O = 29.3 ± 1.0‰ (1SD, n = 161). Given the similarity, on average, of δ 18O for all detrital quartz grains and for all quartz overgrowths, samples with higher δ 18O(WR) values can be shown to have more cement. The quartz cement in the 53 rocks, calculated by mass balance, varies from outlier at 33 vol.% cement. Eolian samples have an average of 11% cement compared to marine samples, which average 4% cement. Two models for quartz cementation have been investigated: high temperature (50-110 °C) formation from ore-forming brines related to Mississippi Valley Type (MVT) mineralization and formation as silcretes at low temperature (10-30 °C). The homogeneity of δ 18O for quartz overgrowths determined by ion microprobe rules out a systematic regional variation of temperature as predicted for MVT brines and there are no other known heating events in these sediments that were never buried to depths >1 km. The data in this study suggest that quartz overgrowths formed as silcretes in the St. Peter Sandstone from meteoric water with δ 18O values of -10

  4. Wood preservation

    Science.gov (United States)

    Kevin Archer; Stan Lebow

    2006-01-01

    Wood preservation can be interpreted to mean protection from fire, chemical degradation, mechanical wear, weathering, as well as biological attack. In this chapter, the term preservation is applied more restrictively to protection from biological hazards.

  5. Structural and compositional characterization of X-cut LiNbO3 crystals implanted with high energy oxygen and carbon ions

    International Nuclear Information System (INIS)

    Bentini, G.G.; Bianconi, M.; Cerutti, A.; Chiarini, M.; Pennestri, G.; Sada, C.; Argiolas, N.; Bazzan, M.; Mazzoldi, P.; Guzzi, R.

    2005-01-01

    High energy implantation of medium-light elements such as oxygen and carbon was performed in X-cut LiNbO 3 single crystals in order to prepare high quality optical waveguides. The compositional and damage profiles, obtained by exploiting the secondary ion mass spectrometry and Rutherford back-scattering techniques respectively, were correlated to the structural properties measured by the high resolution X-ray diffraction. This study evidences the development of tensile strain induced by the ion implantation that can contribute to the decrease of the ordinary refractive index variation through the photo-elastic effect

  6. Slags in a Large Variation Range of Oxygen Potential Based on the Ion and Molecule Coexistence Theory

    Science.gov (United States)

    Yang, Xue-Min; Li, Jin-Yan; Zhang, Meng; Chai, Guo-Min; Zhang, Jian

    2014-12-01

    A thermodynamic model for predicting sulfide capacity of CaO-FeO-Fe2O3-Al2O3-P2O5 slags in a large variation range of oxygen potential corresponding to mass percentage of FetO from 1.88 to 55.50 pct, i.e., IMCT- model, has been developed by coupling with the deduced desulfurization mechanism of the slags based on the ion and molecule coexistence theory (IMCT). The developed IMCT- model has been verified through comparing the determined sulfide capacity after Ban-ya et al.[20] with the calculated by the developed IMCT- model and the calculated by the reported sulfide capacity models such as the KTH model. Mass percentage of FetO as 6.75 pct corresponding to the mass action concentration of FetO as 0.0637 or oxygen partial as 2.27 × 10-6 Pa is the criterion for distinguishing reducing and oxidizing zones for the slags. Sulfide capacity of the slags in reducing zone is controlled by reaction ability of CaO regardless of slag oxidization ability. However, sulfide capacity of the slags in oxidizing zone shows an obvious increase tendency with the increasing of slag oxidization ability. Sulfide capacity of the slags in reducing zone keeps almost constant with variation of the simplified complex basicity (pct CaO)/((pct Al2O3) + (pct P2O5)), or optical basicity, or the mass action concentration ratios of N FeO/ N CaO, , , and . Sulfide capacity of the slags in oxidizing zone shows an obvious increase with the increasing of the simplified complex basicity (pct CaO)/((pct Al2O3) + (pct P2O5)) or optical basicity, or the aforementioned mass action concentration ratios. Thus, the aforementioned mass action concentration ratios and the corresponding mass percentage ratios of various iron oxides to basic oxide CaO are recommended to represent the comprehensive effect of various iron oxides and basic oxide CaO on sulfide capacity of the slags.

  7. A preservação do intestino delgado para transplante: a contribuição da oxigenação hiperbárica Small bowel preservation for transplantation: the contribution of the hyperbaric oxygenation

    Directory of Open Access Journals (Sweden)

    Fernando Augusto Garcia Guimarães

    2008-06-01

    oxygenation (HBO as technique of small bowel preservation for transplant and quality of the preservation. METHODS: Database Medline and Scielo were checked at www.pubmed.com and www.bireme.br, with 58 works selected. Solutions supplying oxidative substratum to the cells and adding substances to prevent or reduce the formation of reactive oxygen, is the main source of preservation. The hypothermia and solutions oxygenation are in current use. Nine papers studied the specific use of the HBO. There is no consensus on its use in experimental works. However, these papers are not comparable, due to different methodologies and types of evaluation. One also argues the complexity and the costs of the HBO. In spite of that, there are evidences that the HBO can prevent hypothermia edema, keep the tecidual oxygenation during the preservation and hinder or diminish the formation of free radicals. CONCLUSION: HBO must be considered as the unique alternative or complementary technique in the preservation of the small bowell for transplant.

  8. Synthesis of self-supported non-precious metal catalysts for oxygen reduction reaction with preserved nanostructures from the polyaniline nanofiber precursor

    DEFF Research Database (Denmark)

    Hu, Yang; Zhao, Xiao; Huang, Yunjie

    2013-01-01

    Non-precious metal catalysts (NPMCs) for the oxygen reduction reaction (ORR) are an active subject of recent research on proton exchange membrane fuel cells. In this study, we report a new approach to preparation of self-supported and nano-structured NPMCs using pre-prepared polyaniline (PANI...

  9. Anhydrous thallium hydrogen L-glutamate: polymer networks formed by sandwich layers of oxygen-coordinated thallium ions cores shielded by hydrogen L-glutamate counterions.

    Science.gov (United States)

    Bodner, Thomas; Wirnsberger, Bianca; Albering, Jörg; Wiesbrock, Frank

    2011-11-07

    Anhydrous thallium hydrogen L-glutamate [Tl(L-GluH)] crystallizes from water (space group P2(1)) with a layer structure in which the thallium ions are penta- and hexacoordinated exclusively by the oxygen atoms of the γ-carboxylate group of the hydrogen L-glutamate anions to form a two-dimensional coordination polymer. The thallium-oxygen layer is composed of Tl(2)O(2) and TlCO(2) quadrangles and is only 3 Å high. Only one hemisphere of the thallium ions participates in coordination, indicative of the presence of the 6s(2) lone pair of electrons. The thallium-oxygen assemblies are shielded by the hydrogen l-glutamate anions. Only the carbon atom of the α-carboxylate group deviates from the plane spanned by the thallium ions, the γ-carboxylate groups and the proton bearing carbon atoms, which are in trans conformation. Given the abundance of L-glutamic and L-aspartic acid in biological systems on the one hand and the high toxicity of thallium on the other hand, it is worth mentioning that the dominant structural motifs in the crystal structure of [Tl(L-GluH)] strongly resemble their corresponding analogues in the crystalline phase of [K(L-AspH)(H(2)O)(2)].

  10. X-ray photoelectron spectroscopy investigation of ion beam sputtered indium tin oxide films as a function of oxygen pressure during deposition

    International Nuclear Information System (INIS)

    Nelson, A.J.; Aharoni, H.

    1987-01-01

    X-ray photoelectron spectroscopy analysis was performed on ion beam sputter deposited films of indium tin oxide as a function of O 2 partial pressure during deposition. The oxygen partial pressure was varied over the range of 2.5 x 10 -6 --4.0 x 10 -5 Torr. Changes in composition as well as in the deconvoluted In 3d 5 /sub // 2 , Sn 3d 5 /sub // 2 , and O 1s core level spectra were observed and correlated with the variation of the oxygen partial pressure during deposition. Results show that the films become increasingly stoichiometric as P/sub =/ is increased and that the excess oxygen introduced during deposition is bound predominantly to the Sn and has little or no effect on the In--O bonding

  11. The effect of oxygen on segregation-induced redistribution of rare-earth elements in silicon layers amorphized by ion implantation

    International Nuclear Information System (INIS)

    Aleksandrov, O. V.

    2006-01-01

    A model of segregation-induced redistribution of impurities of rare-earth elements during solid-phase epitaxial crystallization of silicon layers amorphized by ion implantation is developed. This model is based on the assumption that a transition layer with a high mobility of atoms is formed at the interphase boundary on the side of a-Si; the thickness of this layer is governed by the diffusion length of vacancies in a-Si. The Er concentration profiles in Si implanted with both erbium and oxygen ions are analyzed in the context of the model. It shown that, in the case of high doses of implantation of rare-earth ions, it is necessary to take into account the formation of R m clusters (m = 4), where R denotes the atom of a rare-earth element, whereas, if oxygen ions are also implanted, formation of the complexes RO n (n = 3-6) should be taken into account; these complexes affect the transition-layer thickness and segregation coefficient

  12. Metallic and/or oxygen ion implantation into AlN ceramics as a method of preparation for its direct bonding with copper

    International Nuclear Information System (INIS)

    Barlak, M.; Borkowska, K.; Olesinska, W.; Kalinski, D.; Piekoszewski, J.; Werner, Z.; Jagielski, J.; Sartowska, B.

    2006-01-01

    Direct bonding (DB) process is recently getting an increasing interest as a method for producing high quality joints between aluminum nitride (AlN) ceramics and copper. The metallic ions were implanted using an MEVVA type TITAN implanter with unseparated beam. Oxygen ions were implanted using a semi-industrial ion implanter without mass separation equipped with a gaseous ion source. The substrate temperature did not exceed 200 o C. Ions were implanted at two acceleration voltages, i.e. 15 and 70 kV. The fluence range was between 1·E16 and 1·E18 cm -2 . After implantation, some of the samples were characterized by the Rutherford backscattering (RBS) method. In conclusion: (a) The investigations performed in the present work confirm an assumption that ion implantation is a very promising technique as a pretreatment of AlN ceramics for the formation of the joints with copper in direct bonding process. (b) It has been shown that titanium implantation gives the best results in comparison to other metals examined (Fe, Cr, Cu) but also in comparison to double Ti+O and O+Ti implantations

  13. Nuclear reaction analysis of Ge ion-implanted ZnO bulk single crystals: The evaluation of the displacement in oxygen lattices

    Energy Technology Data Exchange (ETDEWEB)

    Kamioka, K.; Oga, T.; Izawa, Y. [College of Engineering and Research Center of Ion Beam Technology, Hosei University, Koganei, Tokyo 184-8584 (Japan); Kuriyama, K., E-mail: kuri@ionbeam.hosei.ac.jp [College of Engineering and Research Center of Ion Beam Technology, Hosei University, Koganei, Tokyo 184-8584 (Japan); Kushida, K. [Department of Arts and Science, Osaka Kyouiku University, Kashiwara, Osaka 582-8582 (Japan); Kinomura, A. [National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan)

    2014-08-01

    The displacement of oxygen lattices in Ge ion-implanted ZnO bulk single crystals is studied by nuclear reaction analysis (NAR), photoluminescence (PL), and Van der Pauw methods. The Ge ion-implantation (net concentration: 2.6 × 10{sup 20} cm{sup −3}) into ZnO is performed using a multiple-step energy. The high resistivity of ∼10{sup 3} Ω cm in un-implanted samples remarkably decreased to ∼10{sup −2} Ω cm after implanting Ge-ion and annealing subsequently. NRA measurements of as-implanted and annealed samples suggest the existence of the lattice displacement of O atoms acting as acceptor defects. As O related defects still remain after annealing, these defects are not attributed to the origin of the low resistivity in 800 and 1000 °C annealed ZnO.

  14. Nuclear reaction analysis of Ge ion-implanted ZnO bulk single crystals: The evaluation of the displacement in oxygen lattices

    Science.gov (United States)

    Kamioka, K.; Oga, T.; Izawa, Y.; Kuriyama, K.; Kushida, K.; Kinomura, A.

    2014-08-01

    The displacement of oxygen lattices in Ge ion-implanted ZnO bulk single crystals is studied by nuclear reaction analysis (NAR), photoluminescence (PL), and Van der Pauw methods. The Ge ion-implantation (net concentration: 2.6 × 1020 cm-3) into ZnO is performed using a multiple-step energy. The high resistivity of ∼103 Ω cm in un-implanted samples remarkably decreased to ∼10-2 Ω cm after implanting Ge-ion and annealing subsequently. NRA measurements of as-implanted and annealed samples suggest the existence of the lattice displacement of O atoms acting as acceptor defects. As O related defects still remain after annealing, these defects are not attributed to the origin of the low resistivity in 800 and 1000 °C annealed ZnO.

  15. Passive heat exposure induced by hot water leg immersion increased oxyhemoglobin in pre-frontal cortex to preserve oxygenation and did not contribute to impaired cognitive functioning

    Science.gov (United States)

    Wijayanto, Titis; Toramoto, Sayo; Tochihara, Yutaka

    2013-07-01

    This study investigated the effects of passive heat exposure on pre-frontal cortex oxygenation and cognitive functioning, specifically to examine whether the change in pre-frontal cortex oxygenation coincided with cognitive functioning during heat exposure. Eleven male students who participated in this study immersed their lower legs to the knees in three different water temperatures, 38 °C, 40 °C, and 42 °C water in an air temperature of 28 º C and 50 % relative humidity for 60 min. After 45 min of leg immersion they performed cognitive functioning tasks assessing their short-term memory while immersing their lower legs. There were higher rectal temperature ( P 0.05). No statistical difference in cognitive functioning among the three conditions was observed with a higher increase of oxyhemoglobin during the cognitive functioning in the 42 °C condition for the left ( P = 0.05) and right ( P thermally comfortable.

  16. Growth and properties of oxygen- and ion-doped Bi2Sr2CaCu2O8+δ single crystals

    International Nuclear Information System (INIS)

    Mitzi, D.B.; Lombardo, L.W.; Kapitulnik, A.; Laderman, S.S.; Jacowitz, R.D.

    1990-01-01

    A directional solidification method for growing large single crystals in the Bi 2 Sr 2 CaCu 2 O 8+δ system is reported. Ion doping, with replacement of La for Sr and Y for Ca, as well as oxygen doping in these crystals has been explored. Doped and undoped crystals have been characterized using microprobe analysis, x-ray diffraction, thermogravimetric analysis, and magnetic and Hall measurements. Ion doping results in little change of the superconducting transition for substitution levels below 20--25%, while beyond this level the Meissner signal broadens and the low-temperature Meissner signal decreases. Microprobe analysis and x-ray diffraction performed on these more highly substituted single crystals provide evidence for inhomogeneity and phase segregation into regions of distinct composition. Annealing unsubstituted crystals in increasing partial pressures of oxygen reversibly depresses the superconducting transition temperature from 90 (as made) to 77 K (oxygen pressure annealed), while the carrier concentrations, as determined from Hall effect measurements, increase from n=3.1(3)x10 21 cm -3 (0.34 holes per Cu site) to 4.6(3)x10 21 cm -3 (0.50 holes per Cu site)

  17. Reduced hypoxic ventilatory response with preserved blood oxygenation in yoga trainees and Himalayan Buddhist monks at altitude: evidence of a different adaptive strategy?

    Science.gov (United States)

    Bernardi, Luciano; Passino, Claudio; Spadacini, Giammario; Bonfichi, Maurizio; Arcaini, Luca; Malcovati, Luca; Bandinelli, Gabriele; Schneider, Annette; Keyl, Cornelius; Feil, Paul; Greene, Richard E; Bernasconi, Carlo

    2007-03-01

    Yoga induces long-term changes in respiratory function and control. We tested whether it represents a successful strategy for high-altitude adaptation. We compared ventilatory, cardiovascular and hematological parameters in: 12 Caucasian yoga trainees and 12 control sea-level residents, at baseline and after 2-week exposure to high altitude (Pyramid Laboratory, Nepal, 5,050 m), 38 active lifestyle high-altitude natives (Sherpas) and 13 contemplative lifestyle high-altitude natives with practice of yoga-like respiratory exercises (Buddhist monks) studied at 5,050 m. At baseline, hypoxic ventilatory response (HVR), red blood cell count and hematocrit were lower in Caucasian yoga trainees than in controls. After 14 days at altitude, yoga trainees showed similar oxygen saturation, blood pressure, RR interval compared to controls, but lower HVR (-0.44 +/- 0.08 vs. -0.98 +/- 0.21 l/min/m/%SaO(2), P monks was lower than in Sherpas (-0.23 +/- 0.05 vs. -0.63 +/- 0.09 l/min/m/%SaO(2), P monks as compared to Sherpas. In conclusion, Caucasian subjects practicing yoga maintain a satisfactory oxygen transport at high altitude, with minimal increase in ventilation and with reduced hematological changes, resembling Himalayan natives. Respiratory adaptations induced by the practice of yoga may represent an efficient strategy to cope with altitude-induced hypoxia.

  18. Software preservation

    Directory of Open Access Journals (Sweden)

    Tadej Vodopivec

    2011-01-01

    Full Text Available Comtrade Ltd. covers a wide range of activities related to information and communication technologies; its deliverables include web applications, locally installed programs,system software, drivers, embedded software (used e.g. in medical devices, auto parts,communication switchboards. Also the extensive knowledge and practical experience about digital long-term preservation technologies have been acquired. This wide spectrum of activities puts us in the position to discuss the often overlooked aspect of the digital preservation - preservation of software programs. There are many resources dedicated to digital preservation of digital data, documents and multimedia records,but not so many about how to preserve the functionalities and features of computer programs. Exactly these functionalities - dynamic response to inputs - render the computer programs rich compared to documents or linear multimedia. The article opens the questions on the beginning of the way to the permanent digital preservation. The purpose is to find a way in the right direction, where all relevant aspects will be covered in proper balance. The following questions are asked: why at all to preserve computer programs permanently, who should do this and for whom, when we should think about permanent program preservation, what should be persevered (such as source code, screenshots, documentation, and social context of the program - e.g. media response to it ..., where and how? To illustrate the theoretic concepts given the idea of virtual national museum of electronic banking is also presented.

  19. Improvements of anti-corrosion and mechanical properties of NiTi orthopedic materials by acetylene, nitrogen and oxygen plasma immersion ion implantation

    International Nuclear Information System (INIS)

    Poon, Ray W.Y.; Ho, Joan P.Y.; Liu Xuanyong; Chung, C.Y.; Chu, Paul K.; Yeung, Kelvin W.K.; Lu, William W.; Cheung, Kenneth M.C.

    2005-01-01

    Nickel-titanium shape memory alloys (NiTi) are useful materials in orthopedics and orthodontics due to their unique super-elasticity and shape memory effects. However, the problem associated with the release of harmful Ni ions to human tissues and fluids has been raising safety concern. Hence, it is necessary to produce a surface barrier to impede the out-diffusion of Ni ions from the materials. We have conducted acetylene, nitrogen and oxygen plasma immersion ion implantation (PIII) into NiTi alloys in an attempt to improve the surface properties. All the implanted and annealed samples surfaces exhibit outstanding corrosion and Ni out-diffusion resistance. Besides, the implanted layers are mechanically stronger than the substrate underneath. XPS analyses disclose that the layer formed by C 2 H 2 PIII is composed of mainly TiC x with increasing Ti to C concentration ratios towards the bulk. The nitrogen PIII layer is observed to be TiN, whereas the oxygen PIII layer is composed of oxides of Ti 4+ , Ti 3+ and Ti 2+

  20. Doubly versus Singly Positively Charged Oxygen Ions Back-Scattering from a Silicon Surface under Dynamic O2+ Bombardment

    Czech Academy of Sciences Publication Activity Database

    Franzreb, K.; Williams, P.; Lörinčík, Jan; Šroubek, Zdeněk

    203-204, 1/4 (2003), s. 39-42 ISSN 0169-4332 Institutional research plan: CEZ:AV0Z2067918; CEZ:AV0Z4040901 Keywords : low-energy ion scattering * doubly charged ions * molecular orbital Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.284, year: 2003

  1. Digital preservation

    CERN Document Server

    Deegan, Marilyn

    2013-01-01

    Digital preservation is an issue of huge importance to the library and information profession right now. With the widescale adoption of the internet and the rise of the world wide web, the world has been overwhelmed by digital information. Digital data is being produced on a massive scale by individuals and institutions: some of it is born, lives and dies only in digital form, and it is the potential death of this data, with its impact on the preservation of culture, that is the concern of this book. So how can information professionals try to remedy this? Digital preservation is a complex iss

  2. K-, L- and M-shell X-ray productions induced by oxygen ions in the 0.8–1.6 MeV/amu range

    Energy Technology Data Exchange (ETDEWEB)

    Gorlachev, I., E-mail: Igor.Gorlachev@gmail.com [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Gluchshenko, N. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Ivanov, I. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); L.N. Gumilyov Eurasian National University, Mirzoyan 2, Astana (Kazakhstan); Kireyev, A. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Kozin, S.; Kurakhmedov, A. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); L.N. Gumilyov Eurasian National University, Mirzoyan 2, Astana (Kazakhstan); Platov, A. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Zdorovets, M. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Ural Federal University, Yekaterinburg 620002 (Russian Federation)

    2016-08-15

    The X-ray production cross sections induced by oxygen ions with projectile energies from 12.8 to 25.6 MeV for the elements from Al to Bi were measured. The applied approach is based on calculation of X-ray production cross sections through the cross section of Rutherford backscattering, which can be calculated with high accuracy using the Rutherford formula. The experimental results are compared to the predictions of ECPSSR and PWBA theories calculated with the ISICS code.

  3. submitter Next generation multi-scale biophysical characterization of high precision cancer particle radiotherapy using clinical proton, helium-, carbon- and oxygen ion beams

    CERN Document Server

    Dokic, Ivana; Niklas, Martin; Zimmermann, Ferdinand; Chaudhri, Naved; Krunic, Damir; Tessonnier, Thomas; Ferrari, Alfredo; Parodi, Katia; Jäkel, Oliver; Debus, Jürgen; Haberer, Thomas; Abdollahi, Amir

    2016-01-01

    The growing number of particle therapy facilities worldwide landmarks a novel era of precision oncology. Implementation of robust biophysical readouts is urgently needed to assess the efficacy of different radiation qualities. This is the first report on biophysical evaluation of Monte Carlo simulated predictive models of prescribed dose for four particle qualities i.e., proton, helium-, carbon- or oxygen ions using raster-scanning technology and clinical therapy settings at HIT. A high level of agreement was found between the in silico simulations, the physical dosimetry and the clonogenic tumor cell survival. The cell fluorescence ion track hybrid detector (Cell-Fit-HD) technology was employed to detect particle traverse per cell nucleus. Across a panel of radiobiological surrogates studied such as late ROS accumulation and apoptosis (caspase 3/7 activation), the relative biological effectiveness (RBE) chiefly correlated with the radiation species-specific spatio-temporal pattern of DNA double strand break ...

  4. Self-doped carbon architectures with heteroatoms containing nitrogen, oxygen and sulfur as high-performance anodes for lithium- and sodium-ion batteries

    International Nuclear Information System (INIS)

    Lu, Mingjie; Yu, Wenhua; Shi, Jing; Liu, Wei; Chen, Shougang; Wang, Xin; Wang, Huanlei

    2017-01-01

    Highlights: •Self-doped carbon architectures with nitrogen, oxygen, and sulfur are derived from Carrageen. •The obtained carbon materials exhibit excellent electrochemical property. •The strategy provides a one-step synthesis route to design advanced anodes for batteries. -- Abstract: Nitrogen, oxygen and sulfur tridoped porous carbons have been successfully synthesized from natural biomass algae-Carrageen by using a simultaneous carbonization and activation procedure. The doped carbons with sponge-like interconnected architecture, partially ordered graphitic structure, and abundant heteroatom doping perform outstanding features for electrochemical energy storage. When tested as lithium-ion battery anodes, a high reversible capacity of 839 mAh g −1 can be obtained at the current density of 0.1 A g −1 after 100 cycles, while a high capacity of 228 mAh g −1 can be maintained at 10 A g −1 . Tested against sodium, a high specific capacity of 227 can be delivered at 0.1 A g −1 after 100 cycles, while a high capacity of 109 mAh g −1 can be achieved at 10 A g −1 . These results turn out that the doped carbons would be potential anode materials for lithium- and sodium-ion batteries, which can be achieved by a one-step and large-scale synthesis route. Our observation indicates that heteroatom doping (especially sulfur) can significantly promote ion storage and reduce irreversible ion trapping to some extent. This work gives a general route for designing carbon nanostructures with heteroatom doping for efficient energy storage.

  5. Urine Preservative

    Science.gov (United States)

    Smith, Scott M. (Inventor); Nillen, Jeannie (Inventor)

    2001-01-01

    Disclosed is CPG, a combination of a chlorhexidine salt (such as chlorhexidine digluconate, chlorhexidine diacetate, or chlorhexidine dichloride) and n-propyl gallate that can be used at ambient temperatures as a urine preservative.

  6. Surface reactions of oxygen ions--2. Oxidation of alkenes by O/sup -/ on MgO

    Energy Technology Data Exchange (ETDEWEB)

    Aika, K.; Lunsford, J.H.

    1978-08-10

    Ethylene, propylene, 1-butene, and cis-2-butene were adsorbed on magnesium oxide containing O/sup -/ and the product distributions of their temperature-programed desorption compared with those of the desorption of possible intermediates (e.g., acetaldehyde) from untreated magnesium oxide. The results and ESR and IR spectroscopic studies suggested the alkenes reacted initially via hydrogen abstraction to form radicals; the 1-butene radical is oxidized to the alkoxide ion and forms mainly butadiene by a mechanism similar to that previously reported for alkane dehydrogenation; ethylene and propylene radicals form carboxylate ions which yield methane and carbonate ions as the main products.

  7. Influence of plasma-generated negative oxygen ion impingement on magnetron sputtered amorphous SiO2 thin films during growth at low temperatures

    International Nuclear Information System (INIS)

    Macias-Montero, M.; Garcia-Garcia, F. J.; Alvarez, R.; Gil-Rostra, J.; Gonzalez, J. C.; Gonzalez-Elipe, A. R.; Palmero, A.; Cotrino, J.

    2012-01-01

    Growth of amorphous SiO 2 thin films deposited by reactive magnetron sputtering at low temperatures has been studied under different oxygen partial pressure conditions. Film microstructures varied from coalescent vertical column-like to homogeneous compact microstructures, possessing all similar refractive indexes. A discussion on the process responsible for the different microstructures is carried out focusing on the influence of (i) the surface shadowing mechanism, (ii) the positive ion impingement on the film, and (iii) the negative ion impingement. We conclude that only the trend followed by the latter and, in particular, the impingement of O - ions with kinetic energies between 20 and 200 eV, agrees with the resulting microstructural changes. Overall, it is also demonstrated that there are two main microstructuring regimes in the growth of amorphous SiO 2 thin films by magnetron sputtering at low temperatures, controlled by the amount of O 2 in the deposition reactor, which stem from the competition between surface shadowing and ion-induced adatom surface mobility.

  8. Protection of hypoglycemia-induced neuronal death by β-hydroxybutyrate involves the preservation of energy levels and decreased production of reactive oxygen species.

    Science.gov (United States)

    Julio-Amilpas, Alberto; Montiel, Teresa; Soto-Tinoco, Eva; Gerónimo-Olvera, Cristian; Massieu, Lourdes

    2015-05-01

    Glucose is the main energy substrate in brain but in certain circumstances such as prolonged fasting and the suckling period alternative substrates can be used such as the ketone bodies (KB), beta-hydroxybutyrate (BHB), and acetoacetate. It has been shown that KB prevent neuronal death induced during energy limiting conditions and excitotoxicity. The protective effect of KB has been mainly attributed to the improvement of mitochondrial function. In the present study, we have investigated the protective effect of D-BHB against neuronal death induced by severe noncoma hypoglycemia in the rat in vivo and by glucose deprivation (GD) in cortical cultures. Results show that systemic administration of D-BHB reduces reactive oxygen species (ROS) production in distinct cortical areas and subregions of the hippocampus and efficiently prevents neuronal death in the cortex of hypoglycemic animals. In vitro results show that D-BHB stimulates ATP production and reduces ROS levels, while the nonphysiologic isomer of BHB, L-BHB, has no effect on energy production but reduces ROS levels. Data suggest that protection by BHB, not only results from its metabolic action but is also related to its capability to reduce ROS, rendering this KB as a suitable candidate for the treatment of ischemic and traumatic injury.

  9. Mechanistic insights into the interaction between energetic oxygen ions and nanosized ZnFe2O4: XAS-XMCD investigations.

    Science.gov (United States)

    Singh, Jitendra Pal; Kaur, Baljeet; Sharma, Aditya; Kim, So Hee; Gautam, Sanjeev; Srivastava, Ramesh Chandra; Goyal, Navdeep; Lim, Weol Cheol; Lin, H-J; Chen, J M; Asokan, K; Kanjilal, D; Won, Sung Ok; Lee, Ik-Jae; Chae, Keun Hwa

    2018-04-20

    The interactions of energetic ions with multi-cation compounds and their consequences in terms of changes in the local electronic structure, which may facilitate intriguing hybridization between O 2p and metal d orbitals and magnetic ordering, are the subject of debate and require a deep understanding of energy transfer processes and magnetic exchange mechanisms. In this study, nanocrystals of ZnFe2O4 were exposed to O7+ ions with an energy of 100 MeV to understand, qualitatively and quantitatively, the metal-ligand field interactions, cation migration and magnetic exchange interactions by employing X-ray absorption fine structure measurements and X-ray magnetic circular dichroism to get deeper mechanistic insights. Nanosized zinc ferrite nanoparticles (NPs) with a size of ∼16 nm synthesized in the cubic spinel phase exhibited deterioration of the crystalline phase when 100 MeV O7+ ions passed through them. However, the size of these NPs remained almost the same. The behaviour of crystal deterioration is associated with the confinement of heat in this interaction. The energy confined inside the nanoparticles promotes cation redistribution as well as the modification of the local electronic structure. Prior to this interaction, almost 42% of Zn2+ ions occupied AO4 tetrahedra; however, this value increased to 63% after the interaction. An inverse effect was observed for metal ion occupancies in BO6 octahedra. The L-edge spectra of Fe and Zn reveal that the spin and valence states of the metal ions were not affected by this interaction. This effect is also supported by K-edge measurements for Fe and Zn. The t2g/eg intensity ratio in the O K-edge spectra decreased after this interaction, which is associated with detachment of Zn2+ ions from the lattice. The extent of hybridization, as estimated from the ratio of the post-edge to the pre-edge region of the O K-edge spectra, decreased after this interaction. The metal-oxygen and metal-metal bond lengths were modified

  10. A novel ion transport membrane reactor for fundamental investigations of oxygen permeation and oxy-combustion under reactive flow conditions

    KAUST Repository

    Kirchen, Patrick; Apo, Daniel J.; Hunt, Anton; Ghoniem, Ahmed F.

    2013-01-01

    Ion transport membrane (ITM) reactors present an attractive technology for combined air separation and fuel conversion in applications such as syngas production, oxidative coupling or oxy-combustion, with the promise of lower capital and operating

  11. Dependence of ion-water distances on covalent radii, ionic radii in water and distances of oxygen and hydrogen of water from ion/water boundaries

    Czech Academy of Sciences Publication Activity Database

    Heyrovská, Raji

    2006-01-01

    Roč. 429, č. 4-6 (2006), s. 600-605 ISSN 0009-2614 R&D Projects: GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040507 Keywords : ion-water distances * covalent and ionic radius Subject RIV: BO - Biophysics Impact factor: 2.462, year: 2006

  12. Effect of oxygen on the processes of ion beam synthesis of buried SiC layers in silicon

    International Nuclear Information System (INIS)

    Artamonov, V.V.; Valakh, M.Ya.; Klyuj, N.I.; Mel'nik, V.P.; Romanyuk, A.B.; Romanyuk, B.N.; Yukhimchuk, V.A.

    1998-01-01

    The properties of Si-structures with buried silicon carbide (SiC) layers created by high dose carbon implantation into Cz-Si or Fz-Si wafers followed by high-temperature annealing were studied by Raman and infrared spectroscopy. Effect of additional oxygen implantation on the peculiarities of SiC layer formation was also studied. It was shown that under the same implantation and post-implantation annealing conditions the buried SiC layers are more effectively formed in Cz-Si or in Si subjected to additional oxygen implantation. Thus, oxygen in silicon promotes the SiC layer formation due to SiO x precipitate creation and accommodation of the crystal volume in the region where SiC phase is formed

  13. Comparison of physics model for 600 MeV protons 290 MeV·{sup n-}1 oxygen ions on carbon in MCNPX

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Arim; Kim, Dong Hyun; Jung, Nam Suk; Oh, Joo Hee [Pohang Accelerator Laboratory, POSTECH, Pohang (Korea, Republic of); Oranj, Leila Mokhtari [Pohang University of Science and Technology, Pohang (Korea, Republic of)

    2016-06-15

    With the increase in the number of particle accelerator facilities under either operation or construction, the accurate calculation using Monte Carlo codes become more important in the shielding design and radiation safety evaluation of accelerator facilities. The calculations with different physics models were applied in both of cases: using only physics model and using the mix and match method of MCNPX code. The issued conditions were the interactions of 600 MeV proton and 290 MeV·{sup n-}1 oxygen with a carbon target. Both of cross-section libraries, JENDL High Energy File 2007 (JENDL/HE-2007) and LA150, were tested in this calculation. In the case of oxygen ion interactions, the calculation results using LAQGSM physics model and JENDL/HE-2007 library were compared with D. Satoh's experimental data. Other Monte Carlo calculations using PHITS and FLUKA codes were also carried out for further benchmarking study. It was clearly found that the physics models, especially intra-nuclear cascade model, gave a great effect to determine proton-induced secondary neutron spectrum in MCNPX code. The variety of physics models related to heavy ion interactions did not make big difference on the secondary particle productions. The variations of secondary neutron spectra and particle transports depending on various physics models in MCNPX code were studied and the result of this study can be used for the shielding design and radiation safety evaluation.

  14. Direct detection of ammonium ion by means of oxygen electrocatalysis at a copper-polyaniline composite on a screen-printed electrode

    International Nuclear Information System (INIS)

    Zhybak, Mykhailo T.; Vagin, Mikhail Yu.; Beni, Valerio; Liu, Xianjie; Turner, Anthony P. F.; Dempsey, Eithne; Korpan, Yaroslav I.

    2016-01-01

    We describe a composite material for use in electrochemical oxygen reduction. A screen-printed electrode (SPE) was consecutively modified with electrodeposited copper, a Nafion membrane and electropolymerized polyaniline (PANi) to give an electrocatalytic composite of type PANi/Nafion/Cu_2O/SPE that displays good electrical conductivity at neutral pH values. It is found that the presence of ammonia causes complex formation with Cu(I), and this causes electroreduction of oxygen to result in an increased cathodic current. The finding was applied to the quantification of ammonium ions in the 1 to 1000 μM concentration range by amperometry at −0.45 V (vs. Ag/AgCl). This Faradaic phenomenon offers the advantage of direct voltammetric detection, one of the lowest known limits of detection (0.5 μM), and high sensitivity (250 mA∙M"−"1∙cm"−"2). It was applied to the determination of ammonium ion in human serum where it compared well with the photometric routine approach for clinical analysis using glutamate dehydrogenase. (author)

  15. A highly stable (SnOx-Sn)@few layered graphene composite anode of sodium-ion batteries synthesized by oxygen plasma assisted milling

    Science.gov (United States)

    Cheng, Deliang; Liu, Jiangwen; Li, Xiang; Hu, Renzong; Zeng, Meiqing; Yang, Lichun; Zhu, Min

    2017-05-01

    The (SnOx-Sn)@few layered graphene ((SnOx-Sn)@FLG) composite has been synthesized by oxygen plasma-assisted milling. Owing to the synergistic effect of rapid plasma heating and ball mill grinding, SnOx (1 ≤ x ≤ 2) nanoparticles generated from the reaction of Sn with oxygen are tightly wrapped by FLG nanosheets which are simultaneously exfoliated from expanded graphite, forming secondary micro granules. Inside the granules, the small size of the SnOx nanoparticles enables the fast kinetics for Na+ transfer. The in-situ formed FLG and residual Sn nanoparticles improve the electrical conductivity of the composite, meanwhile alleviate the aggregation of SnOx nanoparticles and relieve the volume change during the cycling, which is beneficial for the cyclic stability for the Na+ storage. As an anode material for sodium-ion batteries, the (SnOx-Sn)@FLG composite exhibits a high reversible capacity of 448 mAh g-1 at a current density of 100 mA g-1 in the first cycle, with 82.6% capacity retention after 250 cycles. Even when the current density increases to 1000 mA g-1, this composite retains 316.5 mAh g-1 after 250 cycles. With superior Na+ storage stability, the (SnOx-Sn)@FLG composite can be a promising anode material for high performance sodium-ion batteries.

  16. Influence of average ion energy and atomic oxygen flux per Si atom on the formation of silicon oxide permeation barrier coatings on PET

    Science.gov (United States)

    Mitschker, F.; Wißing, J.; Hoppe, Ch; de los Arcos, T.; Grundmeier, G.; Awakowicz, P.

    2018-04-01

    The respective effect of average incorporated ion energy and impinging atomic oxygen flux on the deposition of silicon oxide (SiO x ) barrier coatings for polymers is studied in a microwave driven low pressure discharge with additional variable RF bias. Under consideration of plasma parameters, bias voltage, film density, chemical composition and particle fluxes, both are determined relative to the effective flux of Si atoms contributing to film growth. Subsequently, a correlation with barrier performance and chemical structure is achieved by measuring the oxygen transmission rate (OTR) and by performing x-ray photoelectron spectroscopy. It is observed that an increase in incorporated energy to 160 eV per deposited Si atom result in an enhanced cross-linking of the SiO x network and, therefore, an improved barrier performance by almost two orders of magnitude. Furthermore, independently increasing the number of oxygen atoms to 10 500 per deposited Si atom also lead to a comparable barrier improvement by an enhanced cross-linking.

  17. High impact of uranyl ions on carrying-releasing oxygen capability of hemoglobin-based blood substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Li; Du, Lili; Liu, Wenyuan; Liu, Zhichao [Northwest Institute of Nuclear Technology, Xi' an, Shaanxi (China); Jia, Yi; Li, Junbai [Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing (China)

    2015-01-07

    The effect of radioactive UO{sub 2}{sup 2+} on the oxygen-transporting capability of hemoglobin-based oxygen carriers has been investigated in vitro. The hemoglobin (Hb) microspheres fabricated by the porous template covalent layer-by-layer (LbL) assembly were utilized as artificial oxygen carriers and blood substitutes. Magnetic nanoparticles of iron oxide (Fe{sub 3}O{sub 4}) were loaded in porous CaCO{sub 3} particles for magnetically assisted chemical separation (MACS). Through the adsorption spectrum of magnetic Hb microspheres after adsorbing UO{sub 2}{sup 2+}, it was found that UO{sub 2}{sup 2+} was highly loaded in the magnetic Hb microspheres, and it shows that the presence of UO{sub 2}{sup 2+} in vivo destroys the structure and oxygen-transporting capability of Hb microspheres. In view of the high adsorption capacity of UO{sub 2}{sup 2+}, the as-assembled magnetic Hb microspheres can be considered as a novel, highly effective adsorbent for removing metal toxins from radiation-contaminated bodies, or from nuclear-power reactor effluent before discharge into the environment. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Emittance preservation

    Energy Technology Data Exchange (ETDEWEB)

    Kain, V; Arduini, G; Goddard, B; Holzer, B J; Jowett, J M; Meddahi, M; Mertens, T; Roncarolo, F; Schaumann, M; Versteegen, R; Wenninger, J [European Organization for Nuclear Research, Geneva (Switzerland)

    2012-07-01

    Emittance measurements during the LHC proton run 2011 indicated a blow-up of 20 % to 30 % from LHC injection to collisions. This presentation will show the emittance preservation throughout the different parts of the LHC cycle and discuss the current limitations on emittance determination. An overview of emittance preservation through the injector complex as function of bunch intensity will also be given. Possible sources for the observed blow-up and required tests in 2012 will be presented. Possible improvements of emittance diagnostics and analysis tools for 2012 will be shown.

  19. The relative biological effectiveness for carbon and oxygen ion beams using the raster-scanning technique in hepatocellular carcinoma cell lines.

    Directory of Open Access Journals (Sweden)

    Daniel Habermehl

    Full Text Available BACKGROUND: Aim of this study was to evaluate the relative biological effectiveness (RBE of carbon (12C and oxygen ion (16O-irradiation applied in the raster-scanning technique at the Heidelberg Ion beam Therapy center (HIT based on clonogenic survival in hepatocellular carcinoma cell lines compared to photon irradiation. METHODS: Four human HCC lines Hep3B, PLC, HepG2 and HUH7 were irradiated with photons, 12C and 16O using a customized experimental setting at HIT for in-vitro trials. Cells were irradiated with increasing physical photon single doses of 0, 2, 4 and 6 Gy and heavy ion-single doses of 0, 0.125, 0.5, 1, 2, 3 Gy (12C and 16O. SOBP-penetration depth and extension was 35 mm +/-4 mm and 36 mm +/-5 mm for carbon ions and oxygen ions respectively. Mean energy level and mean linear energy transfer (LET were 130 MeV/u and 112 keV/um for 12C, and 154 MeV/u and 146 keV/um for 16O. Clonogenic survival was computated and relative biological effectiveness (RBE values were defined. RESULTS: For all cell lines and both particle modalities α- and β-values were determined. As expected, α-values were significantly higher for 12C and 16O than for photons, reflecting a steeper decline of the initial slope of the survival curves for high-LET beams. RBE-values were in the range of 2.1-3.3 and 1.9-3.1 for 12C and 16O, respectively. CONCLUSION: Both irradiation with 12C and 16O using the raster-scanning technique leads to an enhanced RBE in HCC cell lines. No relevant differences between achieved RBE-values for 12C and 16O were found. Results of this work will further influence biological-adapted treatment planning for HCC patients that will undergo particle therapy with 12C or 16O.

  20. Oxidative response of human monocytes and macrophages cultured under low oxygen culture conditions to ion parametric resonance magnetic fields.

    Science.gov (United States)

    INTRODUCTION One proposed mechanism of action of electromagnetic fields (EMFs) on biological systems is the Ion Parametric Resonance (IPR) model, which has been experimentally validated in neuronal PC-12 cells [1, 2]. It proposes that when applied EMFs are tuned to resonate with...

  1. Preparation and characterization of structures of oxygen-ion-conductive thin-film membranes; Herstellung und Charakterisierung von sauerstoffionenleitenden Duennschichtmembranstrukturen

    Energy Technology Data Exchange (ETDEWEB)

    Betz, Michael

    2010-07-01

    In power plants using Oxyfuel technology, fossil fuels are combusted with pure oxygen. This leads to carbon dioxide of high purity, which is necessary for its transport and storage. Oxygen separation by means of perovskitic membranes have great potential to decrease the efficiency losses caused by the allocation of the enormous amounts of oxygen. The aim of this work is the preparation and characterisation of thin film membranes on porous substrates and the analysis of their oxygen permeation properties. Therefore the material system A{sub 0,68}Sr{sub 0,3}Fe{sub 0,8}Co{sub 0,2}O{sub 3-{delta}} (A68SFC) was analysed, where the A-site was substituted with Lanthanides (La, Pr, Nd, Eu, Sm, Gd, Dy, Er) or alkaline earth metals (Ba, Ca). After an extensive characterisation, the selection was reduced to the substitutions with La, Pr and Nd. Other compounds could not meet the demands with regard to phase purity, chemical stability or extension behaviour. All analyses were conducted in comparison to Ba{sub 0,5}Sr{sub 0,5}Co{sub 0,8}Fe{sub 0,2}O{sub 3-{delta}} (BSCF) which is known to exhibit higher permeation rates, but is more sensitive to stability issues. The dependency of permeation rates on membrane thickness or oxygen partial pressures on both membrane surfaces is discussed by means of permeation measurements conducted on bulk BSCF membranes. These cannot be described completely by the Wagner equation. This is due to changes of the driving force originating from influences of the surface reaction kinetics and concentration polarisation on the membrane surface, which are not considered. Porous substrates for asymmetric membranes were manufactured by tape casting and warm pressing. The application of the functional layer was performed via screen printing. Permeation measurements show that the asymmetric structures exhibit higher permeation rates in comparison to bulk membranes with L=1 mm. The moderate increase can be attributed to the low gas permeability of the

  2. Growth and properties of oxygen- and ion-doped Bi2Sr2CaCu2O8+δ single crystals

    Science.gov (United States)

    Mitzi, D. B.; Lombardo, L. W.; Kapitulnik, A.; Laderman, S. S.; Jacowitz, R. D.

    1990-04-01

    A directional solidification method for growing large single crystals in the Bi2Sr2CaCu2O8+δ system is reported. Ion doping, with replacement of La for Sr and Y for Ca, as well as oxygen doping in these crystals has been explored. Doped and undoped crystals have been characterized using microprobe analysis, x-ray diffraction, thermogravimetric analysis, and magnetic and Hall measurements. Ion doping results in little change of the superconducting transition for substitution levels below 20-25%, while beyond this level the Meissner signal broadens and the low-temperature Meissner signal decreases. Microprobe analysis and x-ray diffraction performed on these more highly substituted single crystals provide evidence for inhomogeneity and phase segregation into regions of distinct composition. Annealing unsubstituted crystals in increasing partial pressures of oxygen reversibly depresses the superconducting transition temperature from 90 (as made) to 77 K (oxygen pressure annealed), while the carrier concentrations, as determined from Hall effect measurements, increase from n=3.1(3)×1021 cm-3 (0.34 holes per Cu site) to 4.6(3)×1021 cm-3 (0.50 holes per Cu site). No degradation of the Meissner transition or other indications of inhomogeneity or phase segregation with doping are noted, suggesting that oxygen-doped Bi2Sr2CaCu2O8+δ is a suitable system for pursuing doping studies. The decrease in Tc with concentration for 0.34<=n<=0.50 indicates that a high-carrier-concentration regime exists in which Tc decreases with n and suggests that this decrease does not arise from material inhomogeneity or other materials problems. An examination of the variation of Tc with the density of states and lattice constants for all of the doped and undoped superconducting samples considered here indicates that changes in Tc with doping are primarily affected by changes in the density of states (or carrier concentration) rather than by structural variation induced by the doping.

  3. Food preservation by irradiation

    International Nuclear Information System (INIS)

    Oztasiran, I.

    1984-01-01

    Irradiation is a physical process for treating food and as such it is comparable to other processing techniques such as heating or freezing foods for preservation. The energy level used in food irradiation is always below that producing radioactivity in the treated food, hence this aspect can be totally excluded in wholesomeness evaluations. Water is readily ionized and may be the primary source of ionization in foods with secondary effects on other molecules, possibly more a result of water ionization than of direct hits. In the presence of oxygen, highly reactive compounds may be produced, such as H, H 3 0+ and H 2 O 2 . Radiation at the energy flux levels used for food (<2 MeV) does not induce radioactivity. Food irradiation applications are already technically and economically feasible and that food so treated is suitable for consumption. Food irradiation techniques can play an important role for an improved preservation, storage and distribution of food products. (author)

  4. Characterization of carbon, nitrogen, oxygen and refractory metals in binary and ternary silicon-based films using ion beam methods

    International Nuclear Information System (INIS)

    Somatri-Bouamrane, R.

    1996-01-01

    Ion beam methods (non Rutherford backscattering, nuclear reactions) have been carried out in order to characterize silicon-based films. The cross sections for the reactions 12 C(α,α), 14 N(α,α), 16 O(α,α), 28 Si(α,α) and 14 N(α,p) have been measured within 2 and 7 MeV. CVD beta SiC films could be analyzed and the interface between silicon carbide and the (100) silicon substrate was studied. The epitaxial growth of the beta SiC film could be modelled by comparing the results obtained with ion beam analysis, infrared spectroscopy and electron microscopy. Moreover, the stoichiometry of low pressure CVD Me-Si-N (Me=Re, W, Ti, Ta) ternary systems was studied. The evolution of the nitrogen content in W-Si-N systems allowed to study their stability with respect to the annealing conditions. (N.T.)

  5. Ion Microprobe Measurements of Comet Dust and Implications for Models of Oxygen Isotope Heterogeneity in the Solar System

    Science.gov (United States)

    Snead, C. J.; McKeegan, K. D.; Keller, L. P.; Messenger, S.

    2017-01-01

    The oxygen isotopic compositions of anhydrous minerals in carbonaceous chondrites reflect mixing between a O-16-rich and O-17, O18-rich reservoir. The UV photodissociation of CO (i.e. selfshielding) has been proposed as a mass-independent mechanism for producing these isotopically distinct reservoirs. Self-shielding models predict the composition for the CO gas reservoir to be O-16-rich, and that the accreting primordial dust was in isotopic equilibrium with the gaseous reservoir [1, 2]. Self-shielding also predicts that cometary water, presumed to represent the O-17, O-18-rich reservoir, should be enriched in O-17 and O-18, with compositions of 200 -1000per mille, and that the interaction with this O-17, O-18-rich H2O reservoir altered the compositions of the primordial dust toward planetary values. The bulk composition of the solar nebula, which may be an approximation to the 16O-rich gaseous reservoir, has been constrained by the Genesis results [3]. However, material representing the O-17, O-18-rich end-member is rare [4], and dust representing the original accreting primordial dust has been challenging to conclusively identify in current collections. Anhydrous dust from comets, which accreted in the distal cold regions of the nebula at temperatures below approximately 30K, may provide the best opportunity to measure the oxygen isotope composition of primordial dust. Chondritic porous interplanetary dust particles (CP-IDPs) have been suggested as having cometary origins [5]; however, until direct comparisons with dust from a known comet parent body were made, link between CP-IDPs and comets remained circumstantial. Oxygen isotope analyses of particles from comet 81P/Wild 2 collected by NASA's Stardust mission have revealed surprising similarities to minerals in carbonaceous chondrites which have been interpreted as evidence for large scale radial migration of dust components from the inner solar nebula to the accretion regions of Jupiter- family comets [6

  6. Coupled Effect of Ferrous Ion and Oxygen on the Electron Selectivity of Zerovalent Iron for Selenate Sequestration.

    Science.gov (United States)

    Qin, Hejie; Li, Jinxiang; Yang, Hongyi; Pan, Bingcai; Zhang, Weiming; Guan, Xiaohong

    2017-05-02

    Although the electron selectivity (ES) of zerovalent iron (ZVI) for target contaminant and its utilization ratio (UR) decide the removal capacity of ZVI, little effort has been made to improve them. Taking selenate [Se(VI)] as a target contaminant, this study investigated the coupled influence of aeration gas and Fe(II) on the ES and UR of ZVI. Oxygen was necessary for effective removal of Se(VI) by ZVI without Fe(II) addition. Due to the application of 1.0 mM Fe(II), the ES of ZVI was increased from 3.2-3.6% to 6.2-6.8% and the UR of ZVI was improved by 5.0-19.4% under aerobic conditions, which resulted in a 100-180% increase in the Se(VI) removal capacity by ZVI. Se(VI) reduction by Fe 0 was a heterogeneous redox reaction, and the enrichment of Se(VI) on ZVI surface was the first step of electron transfer from Fe 0 core to Se(VI). Oxygen promoted the generation of iron (hydr)oxides, which facilitated the enrichment of Se(VI) on the ZVI particle surface. Therefore, the high oxygen fraction (25-50%) in the purging gas resulted in only a slight decrease in the ES of ZVI. Fe(II) addition resulted in a pH drop and promoted the generation of lepidocrocite and magnetite, which benefited Se(VI) adsorption and the following electron transfer from underlying Fe 0 to surface-located Se(VI).

  7. Tracking nuclear wave-packet dynamics in molecular oxygen ions with few-cycle infrared laser pulses

    International Nuclear Information System (INIS)

    De, S.; Bocharova, I. A.; Magrakvelidze, M.; Ray, D.; Cao, W.; Thumm, U.; Cocke, C. L.; Bergues, B.; Kling, M. F.; Litvinyuk, I. V.

    2010-01-01

    We have tracked nuclear wave-packet dynamics in doubly charged states of molecular oxygen using few-cycle infrared laser pulses. Bound and dissociating wave packets were launched and subsequently probed via a pair of 8-fs pulses of 790 nm radiation. Ionic fragments from the dissociating molecules were monitored by velocity-map imaging. Pronounced oscillations in the delay-dependent kinetic energy release spectra were observed. The occurrence of vibrational revivals permits us to identify the potential curves of the O 2 dication which are most relevant to the molecular dynamics. These studies show the accessibility to the dynamics of such higher-charged molecules.

  8. Effect of Annealing Temperature and Oxygen Flow in the Properties of Ion Beam Sputtered SnO-₂x Thin Films.

    Science.gov (United States)

    Wang, Chun-Min; Huang, Chun-Chieh; Kuo, Jui-Chao; Sahu, Dipti Ranjan; Huang, Jow-Lay

    2015-08-14

    Tin oxide (SnO 2-x ) thin films were prepared under various flow ratios of O₂/(O₂ + Ar) on unheated glass substrate using the ion beam sputtering (IBS) deposition technique. This work studied the effects of the flow ratio of O₂/(O₂ + Ar), chamber pressures and post-annealing treatment on the physical properties of SnO₂ thin films. It was found that annealing affects the crystal quality of the films as seen from both X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. In addition, the surface RMS roughness was measured with atomic force microscopy (AFM). Auger electron spectroscopy (AES) analysis was used to obtain the changes of elemental distribution between tin and oxygen atomic concentration. The electrical property is discussed with attention to the structure factor.

  9. Two-and-one-half-dimensional magnetohydrodynamic simulations of the plasma sheet in the presence of oxygen ions: The plasma sheet oscillation and compressional Pc 5 waves

    International Nuclear Information System (INIS)

    Lu Li; Liu Zhenxing; Cao Jinbin

    2002-01-01

    Two-and-one-half-dimensional magnetohydrodynamic simulations of the multicomponent plasma sheet with the velocity curl term in the magnetic equation are represented. The simulation results can be summarized as follows: (1) There is an oscillation of the plasma sheet with the period on the order of 400 s (Pc 5 range); (2) the magnetic equator is a node of the magnetic field disturbance; (3) the magnetic energy integral varies antiphase with the internal energy integral; (4) disturbed waves have a propagating speed on the order of 10 km/s earthward; (5) the abundance of oxygen ions influences amplitude, period, and dissipation of the plasma sheet oscillation. It is suggested that the compressional Pc 5 waves, which are observed in the plasma sheet close to the magnetic equator, may be caused by the plasma sheet oscillation, or may be generated from the resonance of the plasma sheet oscillation with some Pc 5 perturbation waves coming from the outer magnetosphere

  10. Transformation of sludge Si to nano-Si/SiOx structure by oxygen inward diffusion as precursor for high performance anodes in lithium ion batteries

    Science.gov (United States)

    Hua, Qiqi; Dai, Dongyang; Zhang, Chengzhi; Han, Fei; Lv, Tiezheng; Li, Xiaoshan; Wang, Shijie; Zhu, Rui; Liao, Haojie; Zhang, Shiguo

    2018-05-01

    Although several Si/C composite structures have been proposed for high-performance lithium-ion batteries (LIBs), they have still suffered from expensive and complex processes of nano-Si production. Herein, a simple, controllable oxygen inward diffusion was utilized to transform Si sludge obtained from the photovoltaic (PV) industry into the nano-Si/SiOx structure as a result of the high diffusion efficiency of O inside Si and high surface area of the sludge. After further process, a yolk/shell Si/C structure was obtained as an anode material for LIBs. This composite demonstrated an excellent cycling stability, with a high reversible capacity (˜ 1250 mAh/g for 500 cycles), by void space originally left by the SiOx accommodate inner Si expansion. We believe this is a rather simple way to convert the waste Si into a valuable nano-Si for LIB applications.

  11. Effect of Annealing Temperature and Oxygen Flow in the Properties of Ion Beam Sputtered SnO—2x Thin Films

    Directory of Open Access Journals (Sweden)

    Chun-Min Wang

    2015-08-01

    Full Text Available Tin oxide (SnO2—x thin films were prepared under various flow ratios of O2/(O2 + Ar on unheated glass substrate using the ion beam sputtering (IBS deposition technique. This work studied the effects of the flow ratio of O2/(O2 + Ar, chamber pressures and post-annealing treatment on the physical properties of SnO2 thin films. It was found that annealing affects the crystal quality of the films as seen from both X-ray diffraction (XRD and transmission electron microscopy (TEM analysis. In addition, the surface RMS roughness was measured with atomic force microscopy (AFM. Auger electron spectroscopy (AES analysis was used to obtain the changes of elemental distribution between tin and oxygen atomic concentration. The electrical property is discussed with attention to the structure factor.

  12. Oxygen-ion-migration-modulated bipolar resistive switching and complementary resistive switching in tungsten/indium tin oxide/gold memory device

    Science.gov (United States)

    Wu, Xinghui; Zhang, Qiuhui; Cui, Nana; Xu, Weiwei; Wang, Kefu; Jiang, Wei; Xu, Qixing

    2018-06-01

    In this paper, we report our investigation of room-temperature-fabricated tungsten/indium tin oxide/gold (W/ITO/Au) resistive random access memory (RRAM), which exhibits asymmetric bipolar resistive switching (BRS) behavior. The device displays good write/erase endurance and data retention properties. The device shows complementary resistive switching (CRS) characteristics after controlling the compliance current. A WO x layer electrically formed at the W/ITO in the forming process. Mobile oxygen ions within ITO migrate toward the electrode/ITO interface and produce a semiconductor-like layer that acts as a free-carrier barrier. The CRS characteristic here can be elucidated in light of the evolution of an asymmetric free-carrier blocking layer at the electrode/ITO interface.

  13. Radiolysis of N2-rich astrophysical ice by swift oxygen ions: implication for space weathering of outer solar system bodies.

    Science.gov (United States)

    Vasconcelos, F A; Pilling, S; Rocha, W R M; Rothard, H; Boduch, P

    2017-09-13

    In order to investigate the role of medium mass cosmic rays and energetic solar particles in the processing of N 2 -rich ice on frozen moons and cold objects in the outer solar system, the bombardment of an N 2  : H 2 O : NH 3  : CO 2 (98.2 : 1.5 : 0.2 : 0.1) ice mixture at 16 K employing 15.7 MeV 16 O 5+ was performed. The changes in the ice chemistry were monitored and quantified by Fourier transformed infrared spectroscopy (FTIR). The results indicate the formation of azide radicals (N 3 ), and nitrogen oxides, such as NO, NO 2 , and N 2 O, as well as the production of CO, HNCO, and OCN - . The effective formation and destruction cross-sections are roughly on the order of 10 -12 cm 2 and 10 -13 cm 2 , respectively. From laboratory molecular analyses, we estimated the destruction yields for the parent species and the formation yields for the daughter species. For N 2 , this value was 9.8 × 10 5 molecules per impact of ions, and for the most abundant new species (N 3 ), it was 1.1 × 10 5 molecules per impact of ions. From these yields, an estimation of how many species are destroyed or formed in a given timescale (10 8 years) in icy bodies in the outer solar system was calculated. This work reinforces the idea that such physicochemical processes triggered by cosmic rays, solar wind, and magnetospheric particles (medium-mass ions) in nitrogen-rich ices may play an important role in the formation of molecules (including pre-biotic species precursors such as amino acids and other "CHON" molecules) in very cold astrophysical environments, such as those in the outer region of the solar system (e.g. Titan, Triton, Pluto, and other KBOs).

  14. Giant thermally-enhanced electrostriction and polar surface phase in L a2M o2O9 oxygen ion conductors

    Science.gov (United States)

    Li, Qian; Lu, Teng; Schiemer, Jason; Laanait, Nouamane; Balke, Nina; Zhang, Zhan; Ren, Yang; Carpenter, Michael A.; Wen, Haidan; Li, Jiangyu; Kalinin, Sergei V.; Liu, Yun

    2018-04-01

    Ferroelectrics possess spontaneous electric polarization at macroscopic scales which nonetheless imposes strict limitations on the material classes. Recent discoveries of untraditional symmetry-breaking phenomena in reduced material dimensions have indicated feasibilities to extend polar properties to broader types of materials, potentially opening up the freedom for designing materials with hybrid functionalities. Here, we report the unusual electromechanical properties of L a2M o2O9 (LAMOX) oxygen ion conductors, systematically investigated at both bulk and surface length levels. We first observed giant electrostriction effects in L a2M o2O9 bulk ceramics that are thermally enhanced in concert with their low-energy oxygen-vacancy hopping dynamics. Moreover, while no clear bulk polarization was detected, the surface phases of LAMOX were found to be manifestly polar, likely originating from the coupling between the intrinsic structural flexibilities with strain gradients (i.e., flexoelectricity) and/or chemical heterogeneities present in the materials. These findings identify L a2M o2O9 as a promising electromechanical material system and suggest that the flexible structural and chemical configurations in ionically active materials could enable fundamentally different venues to accommodate electric polarization.

  15. The role of multiple ionization and subshell coupling effects in L-shell ionization of Au by oxygen ions

    International Nuclear Information System (INIS)

    Banas, D.; Braziewicz, J.; Pajek, M.; Semaniak, J.; Czyzewski, T.; Fijal, I.; Jaskola, M.; Kretschmer, W.; Mukoyama, T.; Trautmann, D.

    2002-01-01

    The ionization of L-subshell electrons in gold by the impact of 0.4-2.2 MeV amu -1 O ions was studied by observing excited Lγ(L-N, O) x-rays. We demonstrate that both the multiple ionization in outer M- and N-shells as well as the coupling effects in the L-shell play an important role in understanding the measured L-subshell ionization cross sections. The multiple ionization was found to be important in two aspects: first, the analysis of x-ray energy shifts and line broadening was crucial for proper interpretation of measured x-ray spectra; second, the additional vacancies in the M- and N-shells substantially influenced the L 1 -subshell fluorescence and Coster-Kronig (CK) yields, mainly by closing strong L 1 -L 3 M 4,5 CK transitions. The data are compared with the simplified coupled-channels calculations using the 'coupled-subshell model' (CSM) based on the semiclassical approximation (SCA), which describes both direct Coulomb ionization as well as the L-subshell couplings within the same theoretical approach. A good agreement of the present data with the theoretical predictions based on the discussed SCA-CSM approach is observed. Present findings partly explain the long-standing problem of inadequate theoretical description of L-shell ionization by heavy ion impact. (author)

  16. Oxygen isotope effect in 55Mn and 95Mo NMR spectra of the permanganate and molybdate ion

    International Nuclear Information System (INIS)

    Buckler, K.U.; Haase, A.R.; Lutz, O.; Mueller, M.; Nolle, A.

    1977-01-01

    By Fourier transform NMR spectroscopy the 55 Mn and 95 Mo resonance lines in the different permanganate and molybdate species Mn 16 Osub(4-n) 18 Osub(n) - and Mo 16 Osub(4-n) 18 Osub(n) 2- (n = 0,1,2,3,4) have been resolved in aqueous solutions of potassium permanganate and sodium molybdate. An isotopic effect on the Larmor frequency for 55 Mn of (0.59+-0.02)ppm and for 95 Mo of (0.25+-0.01)ppm to lower frequency has been found for the substitution of one 16 O atom by one 18 O atom. The relaxation rates 1/T 1 of 55 Mn in the different lines of the permanganate solution are equal within the limits of error. The oxygen exchange rate for the water-permanganate system has been evaluated. (orig.) [de

  17. PVP-coated silver nanoparticles and silver ions induce reactive oxygen species, apoptosis and necrosis in THP-1 monocytes

    DEFF Research Database (Denmark)

    Foldbjerg, Rasmus; Olesen, Ping Liu; Hougaard, Mads

    2009-01-01

    , both Ag NPs and Ag+ were shown to induce apoptosis and necrosis in THP-1 cells depending on dose and exposure time. Furthermore, the presence of apoptosis could be confirmed by the TUNEL method. A number of studies have implicated the production of reactive oxygen species (ROS) in cytotoxicity mediated...... the effect of well characterized, PVP-coated Ag NPs (69 nm ± 3 nm) and Ag+ in a human monocytic cell line (THP-1). Characterization of the Ag NPs was conducted in both stock suspension and cell media with or without serum and antibiotics. By using the flowcytometric annexin V/propidium iodide (PI) assay...... by NPs. We used the fluorogenic probe, 2′,7′-dichlorofluorescein to assess the levels of intracellular ROS during exposure to Ag NPs and Ag+. A drastic increase in ROS levels could be detected after 6–24 h suggesting that oxidative stress is an important mediator of cytotoxicity caused by Ag NPs and Ag+....

  18. Otolith oxygen isotopes measured by high-precision secondary ion mass spectrometry reflect life history of a yellowfin sole (Limanda aspera).

    Science.gov (United States)

    Matta, Mary Elizabeth; Orland, Ian J; Ushikubo, Takayuki; Helser, Thomas E; Black, Bryan A; Valley, John W

    2013-03-30

    The oxygen isotope ratio (δ(18)O value) of aragonite fish otoliths is dependent on the temperature and the δ(18)O value of the ambient water and can thus reflect the environmental history of a fish. Secondary ion mass spectrometry (SIMS) offers a spatial-resolution advantage over conventional acid-digestion techniques for stable isotope analysis of otoliths, especially given their compact nature. High-precision otolith δ(18)O analysis was conducted with an IMS-1280 ion microprobe to investigate the life history of a yellowfin sole (Limanda aspera), a Bering Sea species known to migrate ontogenetically. The otolith was cut transversely through its core and one half was roasted to eliminate organic contaminants. Values of δ(18)O were measured in 10-µm spots along three transects (two in the roasted half, one in the unroasted half) from the core toward the edge. Otolith annual growth zones were dated using the dendrochronology technique of crossdating. Measured values of δ(18)O ranged from 29.0 to 34.1‰ (relative to Vienna Standard Mean Ocean Water). Ontogenetic migration from shallow to deeper waters was reflected in generally increasing δ(18)O values from age-0 to approximately age-7 and subsequent stabilization after the expected onset of maturity at age-7. Cyclical variations of δ(18)O values within juvenile otolith growth zones, up to 3.9‰ in magnitude, were caused by a combination of seasonal changes in the temperature and the δ(18)O value of the ambient water. The ion microprobe produced a high-precision and high-resolution record of the relative environmental conditions experienced by a yellowfin sole that was consistent with population-level studies of ontogeny. Furthermore, this study represents the first time that crossdating has been used to ensure the dating accuracy of δ(18)O measurements in otoliths. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Production of an {sup 15}O beam using a stable oxygen ion beam for in-beam PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Akram, E-mail: mohammadi.akram@qst.go.jp; Yoshida, Eiji; Tashima, Hideaki; Nishikido, Fumihiko; Inaniwa, Taku; Kitagawa, Atsushi; Yamaya, Taiga

    2017-03-21

    In advanced ion therapy, the {sup 15}O ion beam is a promising candidate to treat hypoxic tumors and simultaneously monitor the delivered dose to a patient using PET imaging. This study aimed at production of an {sup 15}O beam by projectile fragmentation of a stable {sup 16}O beam in an optimal material, followed by in-beam PET imaging using a prototype OpenPET system, which was developed in the authors’ group. The study was carried out in three steps: selection of the optimal target based on the highest production rate of {sup 15}O fragments; experimental production of the beam using the optimal target in the Heavy Ion Medical Accelerator Chiba (HIMAC) secondary beam course; and realization of in-beam PET imaging for the produced beam. The optimal target evaluations were done using the Monte Carlo simulation code PHITS. The fluence and mean energy of the secondary particles were simulated and the optimal target was selected based on the production rate of {sup 15}O fragments. The highest production rate of {sup 15}O was observed for a liquid hydrogen target, 3.27% for a 53 cm thick target from the {sup 16}O beam of 430 MeV/u. Since liquid hydrogen is not practically applicable in the HIMAC secondary beam course a hydrogen-rich polyethylene material, which was the second optimal target from the simulation results, was selected as the experimental target. Three polyethylene targets with thicknesses of 5, 11 or 14 cm were used to produce the {sup 15}O beam without any degrader in the beam course. The highest production rate was measured as around 0.87% for the 11 cm thick polyethylene target from the {sup 16}O beam of 430 MeV/u when the angular acceptance and momentum acceptance were set at ±13 mrad and ±2.5%, respectively. The purity of the produced beam for the three targets were around 75%, insufficient for clinical application, but it was increased to 97% by inserting a wedge shape aluminum degrader with a thickness of 1.76 cm into the beam course and that is

  20. Production of an 15O beam using a stable oxygen ion beam for in-beam PET imaging

    Science.gov (United States)

    Mohammadi, Akram; Yoshida, Eiji; Tashima, Hideaki; Nishikido, Fumihiko; Inaniwa, Taku; Kitagawa, Atsushi; Yamaya, Taiga

    2017-03-01

    In advanced ion therapy, the 15O ion beam is a promising candidate to treat hypoxic tumors and simultaneously monitor the delivered dose to a patient using PET imaging. This study aimed at production of an 15O beam by projectile fragmentation of a stable 16O beam in an optimal material, followed by in-beam PET imaging using a prototype OpenPET system, which was developed in the authors' group. The study was carried out in three steps: selection of the optimal target based on the highest production rate of 15O fragments; experimental production of the beam using the optimal target in the Heavy Ion Medical Accelerator Chiba (HIMAC) secondary beam course; and realization of in-beam PET imaging for the produced beam. The optimal target evaluations were done using the Monte Carlo simulation code PHITS. The fluence and mean energy of the secondary particles were simulated and the optimal target was selected based on the production rate of 15O fragments. The highest production rate of 15O was observed for a liquid hydrogen target, 3.27% for a 53 cm thick target from the 16O beam of 430 MeV/u. Since liquid hydrogen is not practically applicable in the HIMAC secondary beam course a hydrogen-rich polyethylene material, which was the second optimal target from the simulation results, was selected as the experimental target. Three polyethylene targets with thicknesses of 5, 11 or 14 cm were used to produce the 15O beam without any degrader in the beam course. The highest production rate was measured as around 0.87% for the 11 cm thick polyethylene target from the 16O beam of 430 MeV/u when the angular acceptance and momentum acceptance were set at ±13 mrad and ±2.5%, respectively. The purity of the produced beam for the three targets were around 75%, insufficient for clinical application, but it was increased to 97% by inserting a wedge shape aluminum degrader with a thickness of 1.76 cm into the beam course and that is sufficiently high. In-beam PET imaging was also

  1. Effect of Caloric Restriction or Aerobic Exercise Training on Peak Oxygen Consumption and Quality of Life in Obese Older Patients with Heart Failure and Preserved Ejection Fraction A Randomized, Controlled Trial

    Science.gov (United States)

    Kitzman, Dalane W.; Brubaker, Peter; Morgan, Timothy; Haykowsky, Mark; Hundley, Gregory; Kraus, William E.; Eggebeen, Joel; Nicklas, Barbara J.

    2016-01-01

    Importance More than 80% of patients with heart failure with preserved ejection fraction (HFPEF), the most common form of HF among older persons, are overweight/obese. Exercise intolerance is the primary symptom of chronic HFPEF and a major determinant of reduced quality-of-life (QOL). Objective To determine whether caloric restriction (Diet), or aerobic exercise training (Exercise), improves exercise capacity and QOL in obese older HFPEF patients. Design Randomized, attention-controlled, 2x2 factorial trial conducted from February 2009 November 2014. Setting Urban academic medical center. Participants 100 older (67±5 years) obese (BMI=39.3±5.6kg/m2) women (n=81) and men (n=19) with chronic, stable HFPEF enrolled from 577 patients initially screened (366 excluded by inclusion / exclusion criteria, 31 for other reasons, 80 declined participation). Twenty-six participants were randomized to Exercise alone, 24 to Diet alone, 25 to Diet+Exercise, and 25 to Control; 92 completed the trial. Interventions 20 weeks of Diet and/or Exercise; Attention Control consisted of telephone calls every 2 weeks. Main Outcomes and Measures Exercise capacity measured as peak oxygen consumption (VO2, ml/kg/min; primary outcome) and QOL measured by the Minnesota Living with HF Questionnaire (MLHF) total score (co-primary outcome; score range: 0–105, higher scores indicate worse HF-related QOL). Results By main effects analysis, peak VO2 was increased significantly by both interventions: Exercise main effect 1.2 ml/kg/min (95%CI: 0.7,1.7; pDiet main effect 1.3 ml/kg/min (95%CI: 0.8,1.8; pExercise+Diet was additive (complementary) for peak VO2 (joint effect 2.5 ml/kg/min). The change in MLHF total score was non-significant with Exercise (main effect −1 unit; 95%CI: −8,5; p=0.70) and with Diet (main effect −6 units; 95%CI: −12,1; p=0.078). The change in peak VO2 was positively correlated with the change in percent lean body mass (r=0.32; p=0.003) and the change in thigh muscle

  2. Characteristics of MOSFETs fabricated in silicon-on-insulator material formed by high-dose oxygen ion implantation

    International Nuclear Information System (INIS)

    Lam, H.W.; Pinizzotto, R.F.; Yuan, H.T.; Bellavance, D.W.

    1981-01-01

    By implanting a dose of 6 x 10 17 cm -2 of 32 O 2 + at 300 keV into a silicon wafer, a buried oxide layer is formed. Crystallinity of the silicon layer above the buried oxide layer is maintained by applying a high (>200 0 C) substrate temperature during the ion implantation process. A two-step anneal cycle is found to be adequate to form the insulating buried oxide layer and to repair the implantation damage in the silicon layer on top of the buried oxide. A surface electron mobility as high as 710 cm 2 /Vs has been measured in n-channel MOSFETs fabricated in a 0.5 μm-thick epitaxial layer grown on the buried oxide wafer. A minimum subthreshold current of about 10 pA per micron of channel width at Vsub(DS)=2 V has been measured. (author)

  3. Game Changing Development Program - Next Generation Life Support Project: Oxygen Recovery From Carbon Dioxide Using Ion Exchange Membrane Electrolysis Technology

    Science.gov (United States)

    Burke, Kenneth A.; Jiao, Feng

    2016-01-01

    This report summarizes the Phase I research and development work performed during the March 13, 2015 to July 13, 2016 period. The proposal for this work was submitted in response to NASA Research Announcement NNH14ZOA001N, "Space Technology Research, Development, Demonstration, and Infusion 2014 (SpaceTech-REDDI-2014)," Appendix 14GCD-C2 "Game Changing Development Program, Advanced Oxygen Recovery for Spacecraft Life Support Systems Appendix" The Task Agreement for this Phase I work is Document Control Number: GCDP-02-TA-15015. The objective of the Phase I project was to demonstrate in laboratories two Engineering Development Units (EDU) that perform critical functions of the low temperature carbon dioxide electrolysis and the catalytic conversion of carbon monoxide into carbon and carbon dioxide. The low temperature carbon dioxide electrolysis EDU was built by the University of Delaware with Dr. Feng Jiao as the principal investigator in charge of this EDU development (under NASA Contract NNC15CA04C). The carbon monoxide catalytic conversion EDU was built by the NASA Glenn Research Center with Kenneth Burke as the principal investigator and overall project leader for the development of both EDUs. Both EDUs were successfully developed and demonstrated the critical functions for each process. The carbon dioxide electrolysis EDU was delivered to the NASA Johnson Space Center and the carbon monoxide catalytic conversion EDU was delivered to the NASA Marshall Spaceflight Center.

  4. The effect of oxygen ion beam bombardment on the properties of tin indium oxide/polyethylene terephthalate complex

    International Nuclear Information System (INIS)

    Li, Li; Liu, Honglin; Zou, Lin; Ding, Wanyu; Ju, Dongying; Chai, Weiping

    2013-01-01

    The tin indium oxide (ITO) films were deposited onto the polyethylene terephthalate (PET) surface that has been bombarded by an O ion beam. The variation of the O bombardment time resulted in the production of ITO/PET complex with different properties. Characterization by four-point probe measurement after the bending fatigue test showed that the adhesion property of the ITO/PET complex could be improved by the increase of O bombardment time while little change of electrical resistivity was observed. Scanning electron microscopy results showed that after the bending fatigue test, the nano scale seams and micro scale trenches appeared at the surface of the ITO/PET complex. The former was only the cracks of ITO film, which has little influence on the continuity and electrical resistivity of ITO film. On the contrary, the micro scale trenches were caused by the peeling off of ITO chips at the cracks, which mainly influenced the continuity and electrical resistivity of ITO film. With the increase of O bombardment time, the number and length of the micro scale trenches decreased. X-ray photoelectron spectrometry characterization showed that with the increase of O bombardment time, parts of the methylene C bonds were transformed into C=O bonds, which could be broken to form C-O-In(Sn) bonds at the initial stage of ITO film growth. By these C-O-In(Sn) crosslink bonds, the ITO film could adhere well onto the PET and the ITO/PET complex display better anti-bending fatigue property. Finally, in the context of the application of the ITO/PET complex as a flexible electrode substrate, the present work reveals a simple way to crosslink them, as well as the physicochemical mechanism happening at the interface of complex. - Highlights: • Polyethylene terephthalate (PET) surface was bombarded by N ions. • Tin indium oxide (ITO) film was deposited on bombarded PET surface. • By bombardment, methylene C bond on PET surface was broken and replaced by C=O bond. • C=O bond was

  5. The effect of oxygen ion beam bombardment on the properties of tin indium oxide/polyethylene terephthalate complex

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li; Liu, Honglin; Zou, Lin [School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028 (China); Ding, Wanyu, E-mail: dwysd_2000@163.com [School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028 (China); Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116028 (China); Ju, Dongying [Department of Material Science and Engineering, Saitama Institute of Technology, Fukaya 369-0293 (Japan); Chai, Weiping [School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028 (China)

    2013-10-31

    The tin indium oxide (ITO) films were deposited onto the polyethylene terephthalate (PET) surface that has been bombarded by an O ion beam. The variation of the O bombardment time resulted in the production of ITO/PET complex with different properties. Characterization by four-point probe measurement after the bending fatigue test showed that the adhesion property of the ITO/PET complex could be improved by the increase of O bombardment time while little change of electrical resistivity was observed. Scanning electron microscopy results showed that after the bending fatigue test, the nano scale seams and micro scale trenches appeared at the surface of the ITO/PET complex. The former was only the cracks of ITO film, which has little influence on the continuity and electrical resistivity of ITO film. On the contrary, the micro scale trenches were caused by the peeling off of ITO chips at the cracks, which mainly influenced the continuity and electrical resistivity of ITO film. With the increase of O bombardment time, the number and length of the micro scale trenches decreased. X-ray photoelectron spectrometry characterization showed that with the increase of O bombardment time, parts of the methylene C bonds were transformed into C=O bonds, which could be broken to form C-O-In(Sn) bonds at the initial stage of ITO film growth. By these C-O-In(Sn) crosslink bonds, the ITO film could adhere well onto the PET and the ITO/PET complex display better anti-bending fatigue property. Finally, in the context of the application of the ITO/PET complex as a flexible electrode substrate, the present work reveals a simple way to crosslink them, as well as the physicochemical mechanism happening at the interface of complex. - Highlights: • Polyethylene terephthalate (PET) surface was bombarded by N ions. • Tin indium oxide (ITO) film was deposited on bombarded PET surface. • By bombardment, methylene C bond on PET surface was broken and replaced by C=O bond. • C=O bond was

  6. Collisional-radiative models for hydrogen-like and helium-like carbon and oxygen ions and applications to experimental data from the TS Tokamak and the reversed field pinch RFX

    Energy Technology Data Exchange (ETDEWEB)

    Carraro, L.; Sattin, F.; Puiatty, M.E.; Scarin, P.; Valisa, M. [Associazione EURATOM-ENEA sulla Fusione, Frascati (Italy); Mattioli, M.; Demichelis, C.; Mandl, W. [Association Euratom-CEA, Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Hogan, J.T. [Oak Ridge National Lab., TN (United States)

    1996-07-01

    Collisional radiative models (CRM) are needed to simulate experimental line brightnesses and emissivities from fusion devices. CRM are built for H-like and He-like carbon and oxygen ions. The impurity ion radial distribution is obtained using a transport code with two radius dependent transport parameters: a diffusion coefficient D and an inward convection velocity V. Examples are given of the quantitative interpretation of experimental spectroscopic data from two fusion devices: the Tore Supra Tokamak and the Reversed Field Pinch RFX. (K.A.). 60 refs.

  7. Collisional-radiative models for hydrogen-like and helium-like carbon and oxygen ions and applications to experimental data from the TS Tokamak and the reversed field pinch RFX

    International Nuclear Information System (INIS)

    Carraro, L.; Sattin, F.; Puiatty, M.E.; Scarin, P.; Valisa, M.; Mattioli, M.; Demichelis, C.; Mandl, W.

    1996-07-01

    Collisional radiative models (CRM) are needed to simulate experimental line brightnesses and emissivities from fusion devices. CRM are built for H-like and He-like carbon and oxygen ions. The impurity ion radial distribution is obtained using a transport code with two radius dependent transport parameters: a diffusion coefficient D and an inward convection velocity V. Examples are given of the quantitative interpretation of experimental spectroscopic data from two fusion devices: the Tore Supra Tokamak and the Reversed Field Pinch RFX. (K.A.)

  8. Optical waveguide properties of Ca{sub 0.4}Ba{sub 0.6}Nb{sub 2}O{sub 6} crystal formed by oxygen ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tie-Jun; Zhou, Yu-Fan; Yu, Xiao-Fei; Liu, Tao; Zhang, Lian; Song, Hong-Lian; Qiao, Mei; Wang, Xue-Lin, E-mail: xuelinwang@sdu.edu.cn

    2015-07-01

    We report the fabrication of a planar optical waveguide in a Ca{sub 0.4}Ba{sub 0.6}Nb{sub 2}O{sub 6} crystal by irradiation with 6.0 MeV oxygen ions. We measured the guiding mode by the prism-coupling method at 633 nm and 1539 nm. The near-field intensity distributions were measured by the end-face coupling setup at a wavelength of 633 nm. The reflectivity calculation method (RCM) was used for reconstructing refractive index profiles. SRIM was used to simulate the electronic and nuclear stopping power caused by oxygen ion irradiation, and the finite-difference beam propagation method (FD-BPM) was used to simulate the near-field intensity distributions. Micro-Raman spectra were measured at room temperature in air to study the differences between the substrate and waveguide region.

  9. Trichomonas vaginalis induces IL-1β production in a human prostate epithelial cell line by activating the NLRP3 inflammasome via reactive oxygen species and potassium ion efflux.

    Science.gov (United States)

    Gu, Na-Yeong; Kim, Jung-Hyun; Han, Ik-Hwan; Im, Su-Jeong; Seo, Min-Young; Chung, Yong-Hoon; Ryu, Jae-Sook

    2016-07-01

    Trichomonas vaginalis is a sexually transmitted protozoan parasite that causes vaginitis in women, and urethritis and prostatitis in men. IL-1β is synthesized as immature pro-IL-1β, which is cleaved by activated caspase-1. Caspase-1 is, in turn, activated by a multi-protein complex known as an inflammasome. In this study, we investigated the inflammatory response of a prostate epithelial cell line (RWPE-1) to T. vaginalis and, specifically, the capacity of T. vaginalis to activate the NLRP3 inflammasome. RWPE-1 cells were stimulated by live T. vaginalis, and subsequent expression of pro-IL-1β, IL-1β, NLRP3, ASC and caspase-1 was determined by real-time PCR and Western blotting. IL-1β and caspase-1 production was also measured by ELISA. To evaluate the effects of NLRP3 and caspase-1 on IL-1β production, the activated RWPE-1 cells were transfected with small interfering RNAs to silence the NLRP3 and caspase-1 genes. Activation of the NLRP3 inflammasome was observed by fluorescence microscopy. Intracellular reactive oxygen species (ROS) were evaluated by spectrofluorometry. When RWPE-1 cells were stimulated with live T. vaginalis, the mRNA and protein expression of IL-1β, NLRP3, ASC, and caspase-1 increased. Moreover, silencing of NLRP3 and caspase-1 attenuated T. vaginalis-induced IL-1β secretion. The NADPH oxidase inhibitor DPI and high extracellular potassium ion suppressed the production of IL-1β, caspase-1, and the expression of NLRP3 and ASC proteins. The specific NF-κB inhibitor, Bay 11-7082, inhibited IL-1β production, and also inhibited the production of caspase-1, ASC and NLRP3 proteins. T. vaginalis induces the formation of the NLRP3 inflammasome in human prostate epithelial cells via ROS and potassium ion efflux, and this results in IL-1β production. This is the first evidence for activation of the NLRP3 inflammasome in the inflammatory response by prostate epithelial cells infected with T. vaginalis. Prostate 76:885-896, 2016. © 2016 Wiley

  10. Simple methods for in vitro pollen germination and pollen preservation of selected species of the genus Agave

    Directory of Open Access Journals (Sweden)

    Sigifredo López Díaz

    2008-01-01

    Full Text Available Simple methods to evaluate the viability and to preserve Agave tequilana Weber var. azul and A. angustifolia Haw pollen were established. Pollen viability was assessed by improving a growing media and evaluating three common pollen germination media components: sucrose, boric acid, and calcium ion. Optimal germination of pollen was obtained at 0.300 M sucrose, 0.324 mM boric acid, and 1.219 mM calcium nitrate and incubated at a temperature of 25°C. Agave pollen was preserved in olive oil and organic solvents. Olive oil, which is immiscible with water, provides an anhydrous environment and limits available oxygen, conditions similar to those provided by some organic solvents. Fresh pollen was put into eppendorf tubes containing n-butanol, n-propanol, isopropanol, extra virgin olive oil and preserved at -20, 4, and 25°C. The germination of the preserved pollen was scored at different time periods during preservation employing the optimal germination medium. The viability of pollen grains preserved at -20°C in olive oil, proved olive oil as an efficient medium for agave pollen preservation for at least 6 months.

  11. High Selectivity Oxygen Delignification

    Energy Technology Data Exchange (ETDEWEB)

    Lucian A. Lucia

    2005-11-15

    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.

  12. Triplasmatron sources for broad and reactive ion beams

    International Nuclear Information System (INIS)

    Lejeune, C.; Grandchamp, J.P.; Kessi, O.; Gilles, J.P.

    1986-01-01

    Two alternative discharge structures, which are both convenient for the extraction of broad and reactive ion beams, are described. They have been designed in order to overcome both lifetime and beam contamination problems while preserving a high ionization efficiency and a smooth plasma uniformity. They both use a hot cathode duoplasmatron discharge to inject ionizing electrons into the main ionization chamber, according to the triplasmatron concept. The triplasmatron multipolar ion source (TMIS) uses the magnetic multipolar containment of both electrons and ions, whereas the triplasmatron reflex ion source (TRIS) uses the electrostatic and geometric containment of the ionizing electrons. The behaviour and performance of both structures are reported and discussed with a special emphasis to the operation with either oxygen or fluorocarbon gases. (author)

  13. A Study of Ion-Ion Hybrid Instability in the Mixed Plasma

    Directory of Open Access Journals (Sweden)

    Soo-Yong Kim

    1987-12-01

    Full Text Available There are more oxygen ions than hydrogen ions in the auroral field zone. We consider both analytic and numerical simulation study of the heating of hydrogen and oxygen ions by auroral electrons. With the low drift speed of electron beams, the ion-ion hybrid wave becomes unstable instead of the lower hybrid wave so that a preferential heating of oxygen ions occurs.

  14. Recent developments in persufflation for organ preservation.

    Science.gov (United States)

    Min, Catherine G; Papas, Klearchos K

    2018-06-01

    To summarize current literature and recent findings on the potential of humidified oxygenated gas perfusion (persufflation) as an alternative method for improved organ preservation. Although there are some conflicting data, the majority of the evidence suggests that persufflation, by enhancing oxygenation, can improve preservation and even rescue organs, including organs with prior exposure to warm ischemia. In some cases, persufflation produced better results than hypothermic machine perfusion. The timing of persufflation is of importance; benefits of persufflation appear to increase as the timing of its administration postprocurement decreases. This may be particularly true for tissues that are more sensitive to ischemia, such as the pancreas prior to islet isolation. Combining oxygen persufflation with nitric oxide and addition of pulsatile flow may provide further benefits and amplify its effects on improving transplant outcomes. Persufflation is a promising, relatively simple, preservation technique that enables improved oxygenation, which provides protection and improvement in the graft condition during preservation and prior to transplantation. More detailed studies are needed to optimize persufflation and evaluate its short and long-term effects in vivo.

  15. Summary of the preservation techniques and the evolution of the anammox bacteria characteristics during preservation.

    Science.gov (United States)

    Chen, Hui; Jin, Ren-Cun

    2017-06-01

    The anaerobic ammonium oxidation (anammox) process is a promising wastewater treatment method for biological nitrogen removal. A sufficient amount of active anammox sludge as a seed is crucial to the fast establishment and stability of the anammox process. Anammox bacteria is a kind of microorganism which is sensitive to the environmental conditions, e.g., oxygen, temperature. The optimum temperature and pH for the growth of the anammox bacteria are 30-40 °C and 6.7-8.3. A proper preservation technique allows fast start-up of the anammox process, overcoming the long doubling time of anammox biomass. The preservation of the anammox sludge is influenced by various factors, e.g., preservation techniques, duration, temperature, substrates, and protective agents. During preservation, the characteristics of the anammox biomass, including the bioactivity, heme c content, extracellular polymeric substances (EPS), and sludge morphology, change with time. The optimum preservation technique is not invariable and it depends on the purpose of preservation (precedence of bioactivity or quantity), the bacterial community, and other parameters. It is important for the preserved anammox biomass to achieve reactivation so that stable anammox reactors can be established as soon as possible. However, because the preservation process is complicated, the knowledge regarding preservation is far from complete, and much future work will be required to increase the understanding of preservation.

  16. Oxygen toxicity

    Directory of Open Access Journals (Sweden)

    C. A. van der Westhuizen

    1990-07-01

    Full Text Available Oxygen has been discovered about 200 years ago. Since then the vital physiological involvement of oxygen in various biologi­cal processes, mainly energy production, has been established. However, in the body molecular oxygen can be converted to toxic oxygen metabolites such as superoxide anion, hydrogen peroxide, the hydroxyl radical and singlet oxygen. These toxic metabolites are produced mainly in the mitochondria, plasma membranes and endoplasmic reticulum.

  17. Plasma immersion ion implantation for reducing metal ion release

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, C.; Garcia, J. A.; Maendl, S.; Pereiro, R.; Fernandez, B.; Rodriguez, R. J. [Centro de Ingenieria Avanzada de Superficies AIN, 31191, Cordovilla-Pamplona (Spain); Leibniz-Institut fuer Oberflaechenmodifizierung, 04318 Leipzig (Germany); Universidad de Oviedo, Departamento Quimica Fisica y Analitica (Spain); Centro de Ingenieria Avanzada de Superficies AIN, 31191, Cordovilla-Pamplona (Spain)

    2012-11-06

    Plasma immersion ion implantation of Nitrogen and Oxygen on CoCrMo alloys was carried out to improve the tribological and corrosion behaviors of these biomedical alloys. In order to optimize the implantation results we were carried experiments at different temperatures. Tribocorrosion tests in bovine serum were used to measure Co, Cr and Mo releasing by using Inductively Coupled Plasma Mass Spectrometry analysis after tests. Also, X-ray Diffraction analysis were employed in order to explain any obtained difference in wear rate and corrosion tests. Wear tests reveals important decreases in rate of more than one order of magnitude for the best treatment. Moreover decreases in metal release were found for all the implanted samples, preserving the same corrosion resistance of the unimplanted samples. Finally this paper gathers an analysis, in terms of implantation parameters and achieved properties for industrial implementation of these treatments.

  18. Oxygen Therapy

    Science.gov (United States)

    ... their breathing to dangerously low levels. Will I need oxygen when I sleep? Usually if you use supplemental oxygen during the ... your health care provider tells you you only need to use oxygen for exercise or sleep. Even if you feel “fine” off of your ...

  19. Preserving Digital Materials

    CERN Document Server

    Harvey, Ross

    2011-01-01

    This book provides a single-volume introduction to the principles, strategies and practices currently applied by librarians and recordkeeping professionals to the critical issue of preservation of digital information. It incorporates practice from both the recordkeeping and the library communities, taking stock of current knowledge about digital preservation and describing recent and current research, to provide a framework for reflecting on the issues that digital preservation raises in professional practice.

  20. Oxygen Therapy

    Directory of Open Access Journals (Sweden)

    Bonnie Solmes

    2000-01-01

    Full Text Available LTOT is prescribed for people with chronic lung disease in whom there is a decrease in the ability of the lungs to supply enough oxygen to the body. The heart is obliged to pump faster to meet the body's oxygen requirements. This may place undue stress on the heart, resulting in palpitations, dizziness and fatigue. A low oxygen level in arterial blood is also harmful to the heart, the brain and the pulmonary blood vessels. Oxygen therapy is used to break this cycle. A person with low blood oxygen will often be able to accomplish more with less fatigue with the help of supplemental oxygen therapy. Shortness of breath is a mechanical problem resulting from the effects of chronic obstructive pulmonary disease. Oxygen therapy may or may not reduce shortness of breath, but it will help the lungs and heart to function with less stress.

  1. Mechanism for Burgess Shale-type preservation

    DEFF Research Database (Denmark)

    Gaines, Robert R.; Hammarlund, Emma U.; Hou, Xianguang

    2012-01-01

    Exceptionally preserved fossil biotas of the Burgess Shale and a handful of other similar Cambrian deposits provide rare but critical insights into the early diversification of animals. The extraordinary preservation of labile tissues in these geographically widespread but temporally restricted......-oxygen bottom water conditions at the sites of deposition resulted in reduced oxidant availability. Subsequently, rapid entombment of fossils in fine-grained sediments and early sealing of sediments by pervasive carbonate cements at bed tops restricted oxidant flux into the sediments. A permeability barrier...

  2. Environmental education on wood preservatives and preservative ...

    African Journals Online (AJOL)

    The development and use of wood preservatives in Nigeria should address not only the cost and demand functions but also the potential hazards in environmental equations. Forest products specialists are often asked about the perceived risks and environmental costs of treated wood products. Evidently, the civil society is ...

  3. Studies on coordination chemistry and bioactivity of complexes of a bidentate oxygen-oxygen donor ligand, 1,2-dibenzoylhydrazine, with Cr3+, Co2+, Ni2+, Cu2+ and Zn2+ Ions

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Lai Wee Wong; Crouse, Karen A.; Ali, A.M.; Yamin, B.M.; Fun, H.-K.

    2003-08-01

    A new bidentate ligand, 1,2-dibenzoylhydrazine (DBHz), with OO donor sequences, was prepared. Several complexes of DBHz containing Cr(JJI), Fe(UI), Co(U), Ni(JJ), Cu(II) and Zn(TJ) ions have been synthesized and characterized by CHN analyses, IR, molar conductivity and UV/Visible spectroscopic studies. All of the compounds were tested for their antibacterial, antifungal and anticancer properties. DBHz was very effective against Pseudomonas aeruginosa, Bacillus subtilis mutant and Bacillus subtilis wild type bacteria. It was also effective against Saccaromyces cereiviceae, Candida albicans, Candida albicans lypolytica and Aspergillus ochraceous fungi. The free ligand, DBHz, in particular, was strongly active against colon cancer cell lines (HT-29), with a CD 50 value of 2.5 /μg/ml. (author)

  4. The absence of ion-regulatory suppression in the gills of the aquatic air-breathing fish Trichogaster lalius during oxygen stress.

    Science.gov (United States)

    Huang, Chun-Yen; Lin, Hsueh-Hsi; Lin, Cheng-Huang; Lin, Hui-Chen

    2015-01-01

    The strategy for most teleost to survive in hypoxic or anoxic conditions is to conserve energy expenditure, which can be achieved by suppressing energy-consuming activities such as ion regulation. However, an air-breathing fish can cope with hypoxic stress using a similar adjustment or by enhancing gas exchange ability, both behaviorally and physiologically. This study examined Trichogaster lalius, an air-breathing fish without apparent gill modification, for their gill ion-regulatory abilities and glycogen utilization under a hypoxic treatment. We recorded air-breathing frequency, branchial morphology, and the expression of ion-regulatory proteins (Na(+)/K(+)-ATPase and vacuolar-type H(+)-ATPase) in the 1(st) and 4(th) gills and labyrinth organ (LO), and the expression of glycogen utilization (GP, glycogen phosphorylase protein expression and glycogen content) and other protein responses (catalase, CAT; carbonic anhydrase II, CAII; heat shock protein 70, HSP70; hypoxia-inducible factor-1α, HIF-1α; proliferating cell nuclear antigen, PCNA; superoxidase dismutase, SOD) in the gills of T. lalius after 3 days in hypoxic and restricted conditions. No morphological modification of the 1(st) and 4(th) gills was observed. The air-breathing behavior of the fish and CAII protein expression both increased under hypoxia. Ion-regulatory abilities were not suppressed in the hypoxic or restricted groups, but glycogen utilization was enhanced within the groups. The expression of HIF-1α, HSP70 and PCNA did not vary among the treatments. Regarding the antioxidant system, decreased CAT enzyme activity was observed among the groups. In conclusion, during hypoxic stress, T. lalius did not significantly reduce energy consumption but enhanced gas exchange ability and glycogen expenditure. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Mass preserving image registration

    DEFF Research Database (Denmark)

    Gorbunova, Vladlena; Sporring, Jon; Lo, Pechin Chien Pau

    2010-01-01

    The paper presents results the mass preserving image registration method in the Evaluation of Methods for Pulmonary Image Registration 2010 (EMPIRE10) Challenge. The mass preserving image registration algorithm was applied to the 20 image pairs. Registration was evaluated using four different...

  6. Modes of fossil preservation

    Science.gov (United States)

    Schopf, J.M.

    1975-01-01

    The processes of geologic preservation are important for understanding the organisms represented by fossils. Some fossil differences are due to basic differences in organization of animals and plants, but the interpretation of fossils has also tended to be influenced by modes of preservation. Four modes of preservation generally can be distinguished: (1) Cellular permineralization ("petrifaction") preserves anatomical detail, and, occasionally, even cytologic structures. (2) Coalified compression, best illustrated by structures from coal but characteristic of many plant fossils in shale, preserves anatomical details in distorted form and produces surface replicas (impressions) on enclosing matrix. (3) Authigenic preservation replicates surface form or outline (molds and casts) prior to distortion by compression and, depending on cementation and timing, may intergrade with fossils that have been subject to compression. (4) Duripartic (hard part) preservation is characteristic of fossil skeletal remains, predominantly animal. Molds, pseudomorphs, or casts may form as bulk replacements following dissolution of the original fossil material, usually by leaching. Classification of the kinds of preservation in fossils will aid in identifying the processes responsible for modifying the fossil remains of both animals and plants. ?? 1975.

  7. Food preservation by irradiation

    International Nuclear Information System (INIS)

    Labots, H.; Huis in 't Veld, G.J.P.; Verrips, C.T.

    1985-01-01

    After a review of several methods for the preservation of food and the routes of food infections, the following chapters are devoted to the preservation by irradiation. Applications and legal aspects of food irradiation are described. Special reference is made to the international situation. (Auth.)

  8. Self-preserving cosmetics.

    Science.gov (United States)

    Varvaresou, A; Papageorgiou, S; Tsirivas, E; Protopapa, E; Kintziou, H; Kefala, V; Demetzos, C

    2009-06-01

    Preservatives are added to products for two reasons: first, to prevent microbial spoilage and therefore to prolong the shelf life of the product; second, to protect the consumer from a potential infection. Although chemical preservatives prevent microbial growth, their safety is questioned by a growing segment of consumers. Therefore, there is a considerable interest in the development of preservative-free or self-preserving cosmetics. In these formulations traditional/chemical preservatives have been replaced by other cosmetic ingredients with antimicrobial properties that are not legislated as preservatives according to the Annex VI of the Commission Directive 76/768/EEC and the amending directives (2003/15/EC, 2007/17/EC and 2007/22/EC). 'Hurdle Technology', a technology that has been used for the control of product safety in the food industry since 1970s, has also been applied for the production of self-preserving cosmetics. 'Hurdle Technology' is a term used to describe the intelligent combination of different preservation factors or hurdles to deteriorate the growth of microorganisms. Adherence to current good manufacturing practice, appropriate packaging, careful choice of the form of the emulsion, low water activity and low or high pH values are significant variables for the control of microbial growth in cosmetic formulations. This paper describes the application of the basic principles of 'Hurdle Technology' in the production of self-preserving cosmetics. Multifunctional antimicrobial ingredients and plant-derived essential oils and extracts that are used as alternative or natural preservatives and are not listed in Annex VI of the Cosmetic Directive are also reported.

  9. Pancreas preservation for pancreas and islet transplantation

    Science.gov (United States)

    Iwanaga, Yasuhiro; Sutherland, David E.R.; Harmon, James V.; Papas, Klearchos K.

    2010-01-01

    Purpose of review To summarize advances and limitations in pancreas procurement and preservation for pancreas and islet transplantation, and review advances in islet protection and preservation. Recent findings Pancreases procured after cardiac death, with in-situ regional organ cooling, have been successfully used for islet transplantation. Colloid-free Celsior and histidine-tryptophan-ketoglutarate preservation solutions are comparable to University of Wisconsin solution when used for cold storage before pancreas transplantation. Colloid-free preservation solutions are inferior to University of Wisconsin solution for pancreas preservation prior to islet isolation and transplantation. Clinical reports on pancreas and islet transplants suggest that the two-layer method may not offer significant benefits over cold storage with the University of Wisconsin solution: improved oxygenation may depend on the graft size; benefits in experimental models may not translate to human organs. Improvements in islet yield and quality occurred from pancreases treated with inhibitors of stress-induced apoptosis during procurement, storage, isolation or culture. Pancreas perfusion may be desirable before islet isolation and transplantation and may improve islet yields and quality. Methods for real-time, noninvasive assessment of pancreas quality during preservation have been implemented and objective islet potency assays have been developed and validated. These innovations should contribute to objective evaluation and establishment of improved pancreas preservation and islet isolation strategies. Summary Cold storage may be adequate for preservation before pancreas transplants, but insufficient when pancreases are processed for islets or when expanded donors are used. Supplementation of cold storage solutions with cytoprotective agents and perfusion may improve pancreas and islet transplant outcomes. PMID:18685343

  10. Chronopolis Digital Preservation Network

    Directory of Open Access Journals (Sweden)

    David Minor

    2010-07-01

    Full Text Available The Chronopolis Digital Preservation Initiative, one of the Library of Congress’ latest efforts to collect and preserve at-risk digital information, has completed its first year of service as a multi-member partnership to meet the archival needs of a wide range of domains.Chronopolis is a digital preservation data grid framework developed by the San Diego Supercomputer Center (SDSC at UC San Diego, the UC San Diego Libraries (UCSDL, and their partners at the National Center for Atmospheric Research (NCAR in Colorado and the University of Maryland's Institute for Advanced Computer Studies (UMIACS.Chronopolis addresses a critical problem by providing a comprehensive model for the cyberinfrastructure of collection management, in which preserved intellectual capital is easily accessible, and research results, education material, and new knowledge can be incorporated smoothly over the long term. Integrating digital library, data grid, and persistent archive technologies, Chronopolis has created trusted environments that span academic institutions and research projects, with the goal of long-term digital preservation.A key goal of the Chronopolis project is to provide cross-domain collection sharing for long-term preservation. Using existing high-speed educational and research networks and mass-scale storage infrastructure investments, the partnership is leveraging the data storage capabilities at SDSC, NCAR, and UMIACS to provide a preservation data grid that emphasizes heterogeneous and highly redundant data storage systems.In this paper we will explore the major themes within Chronopolis, including:a The philosophy and theory behind a nationally federated data grid for preservation. b The core tools and technologies used in Chronopolis. c The metadata schema that is being developed within Chronopolis for all of the data elements. d Lessons learned from the first year of the project.e Next steps in digital preservation using Chronopolis: how we

  11. Effects of oxygen gas flow rates and Ga contents on structural properties of Ga-doped ZnO films prepared by ion-plating with a DC arc discharge

    International Nuclear Information System (INIS)

    Terasako, Tomoaki; Nomoto, Junichi; Makino, Hisao; Yamamoto, Naoki; Shirakata, Sho; Yamamoto, Tetsuya

    2015-01-01

    Structural properties of highly c-axis oriented polycrystalline Ga-doped ZnO (GZO) films prepared by ion-plating with a DC arc discharge were studied in terms of the oxygen gas flow rate (F O2 ) introduced into the chamber during the deposition process and the Ga 2 O 3 content in the GZO sintered pellet. The X-ray diffraction (XRD) measurements revealed that the GZO films have the residual compressive stress along the a-axis direction (in-plane) and the tensile stress along the c-axis direction (out-of-plane). The increase in F O2 or the increase in Ga 2 O 3 content was effective for relaxing the in-plane compressive stress induced by the so-called atomic peening effect. The positive correlation between the carrier concentration (n) and the primitive cell volume (V) would be due to the incorporation of Ga atoms substituting Zn sites (Ga Zn s) together with the generation of n-type intrinsic defects or complex defects. - Highlights: • Films of Ga-doped ZnO (GZO) films were deposited by ion-plating with a DC arc discharge. • Structural properties of GZO films were examined by X-ray diffraction measurements. • GZO films had the residual compressive stress along the a-axis direction. • There was the correlation between the carrier concentration and the cell volume.

  12. Effects of oxygen gas flow rates and Ga contents on structural properties of Ga-doped ZnO films prepared by ion-plating with a DC arc discharge

    Energy Technology Data Exchange (ETDEWEB)

    Terasako, Tomoaki, E-mail: terasako.tomoaki.mz@ehime-u.ac.jp [Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama-shi, Ehime 790-8577 (Japan); Nomoto, Junichi; Makino, Hisao; Yamamoto, Naoki [Research Institute, Kochi University of Technology, 185 Miyanokuchi, Tosayamada-cho, Kami-shi, Kochi 782-8502 (Japan); Shirakata, Sho [Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama-shi, Ehime 790-8577 (Japan); Yamamoto, Tetsuya [Research Institute, Kochi University of Technology, 185 Miyanokuchi, Tosayamada-cho, Kami-shi, Kochi 782-8502 (Japan)

    2015-12-01

    Structural properties of highly c-axis oriented polycrystalline Ga-doped ZnO (GZO) films prepared by ion-plating with a DC arc discharge were studied in terms of the oxygen gas flow rate (F{sub O2}) introduced into the chamber during the deposition process and the Ga{sub 2}O{sub 3} content in the GZO sintered pellet. The X-ray diffraction (XRD) measurements revealed that the GZO films have the residual compressive stress along the a-axis direction (in-plane) and the tensile stress along the c-axis direction (out-of-plane). The increase in F{sub O2} or the increase in Ga{sub 2}O{sub 3} content was effective for relaxing the in-plane compressive stress induced by the so-called atomic peening effect. The positive correlation between the carrier concentration (n) and the primitive cell volume (V) would be due to the incorporation of Ga atoms substituting Zn sites (Ga{sub Zn}s) together with the generation of n-type intrinsic defects or complex defects. - Highlights: • Films of Ga-doped ZnO (GZO) films were deposited by ion-plating with a DC arc discharge. • Structural properties of GZO films were examined by X-ray diffraction measurements. • GZO films had the residual compressive stress along the a-axis direction. • There was the correlation between the carrier concentration and the cell volume.

  13. Measurements of the total energy lost per electron-ion pair lost in low-pressure inductive argon, helium, oxygen and nitrogen discharge

    International Nuclear Information System (INIS)

    Lee, Young-Kwang; Ku, Ju-Hwan; Chung, Chin-Wook

    2011-01-01

    Experimental measurements of the total energy lost per electron-ion pair lost, ε T , were performed in a low-pressure inductive atomic gases (Ar, He) and molecular gases (O 2 , N 2 ) discharge. The value of ε T was determined from a power balance based on the electropositive global (volume-averaged) model. A floating harmonic method was employed to measure ion fluxes and electron temperatures at the discharge wall. In the pressure range 5-50 mTorr, it was found that the measured ε T ranged from about 70 to 150 V for atomic gases, but from about 180 to 1300 V for molecular gases. This difference between atomic and molecular discharge is caused by additional collisional energy losses of molecular gases. For argon discharge, the stepwise ionization effect on ε T was observed at relatively high pressures. For different gases, the measured ε T was evaluated with respect to the electron temperature, and then compared with the calculation results, which were derived from collisional and kinetic energy loss. The measured ε T and their calculations showed reasonable agreement.

  14. Optimization of preservation activities and preservation engineering (1)

    International Nuclear Information System (INIS)

    Aoki, Takayuki; Mimaki, Hidehito; Oda, Mitsuyuki

    2004-01-01

    In order to deal with the optimization of preservation activities and 'preservation engineering' which makes it possible, the relation between general society and preservation, the content and the structure of preservation activities, and the viewpoint and the approach of the optimization of the preventive preservation are described. The optimization of the preventive preservation is shown respectively in the four stages of planning, implementation, result evaluation and countermeasure. (K. Kato)

  15. VT Historic Preservation Grant

    Data.gov (United States)

    Vermont Center for Geographic Information — The State-funded Historic Preservation Grant Program helps municipalities and non-profit organizations rehabilitate the historic buildings that are a vital part of...

  16. Preservation of Built Environments

    DEFF Research Database (Denmark)

    Pilegaard, Marie Kirstine

    When built environments and recently also cultural environments are to be preserved, the historic and architectural values are identified as the key motivations. In Denmark the SAVE system is used as a tool to identify architectural values, but in recent years it has been criticized for having...... architectural value in preservation work as a matter of maintaining the buildings -as keeping them "alive" and allowing this to continue in the future. The predominantly aesthetic preservation approach will stop the buildings' life process, which is the same as - "letting them die". Finnebyen in Aarhus...... is an example of a residential area, where the planning authority currently has presented a preservational district plan, following guidelines from the SAVE method. The purpose is to protect the area's architectural values in the future. The predominantly aesthetic approach is here used coupled to the concept...

  17. Radiation preservation of maize

    International Nuclear Information System (INIS)

    Wasito.

    1980-01-01

    Radiation preservation of maize was carried out. Radiation doses and sources, shielding materials, packaging materials, chemical radiation effects, biological radiation effects, were discussed. Experimental methods, samples and accessories were also presented. (SMN)

  18. Digital preservation for heritages

    CERN Document Server

    Lu, Dongming

    2011-01-01

    ""Digital Preservation for Heritages: Technologies and Applications"" provides a comprehensive and up-to-date coverage of digital technologies in the area of cultural heritage preservation, including digitalization, research aiding, conservation aiding, digital exhibition, and digital utilization. Processes, technical frameworks, key technologies, as well as typical systems and applications are discussed in the book. It is intended for researchers and students in the fields of computer science and technology, museology, and archaeology. Dr. Dongming Lu is a professor at College of Computer Sci

  19. Indiana Pavement Preservation Program

    OpenAIRE

    Ong, Ghim Ping (Raymond); Nantung, Tommy E.; Sinha, Kumares C.

    2010-01-01

    State highway agencies are facing immense pressure to maintain roads at acceptable levels amidst the challenging financial and economic situations. In recent years, pavement preservation has been sought as a potential alternative for managing the pavement assets, believing that it would provide a cost-effective solution in maintaining infrastructural conditions and meeting user expectations. This study explores the potential of pavement preservation concepts in managing the agency‘s pavement ...

  20. Oxygen isotopic distribution along the otolith growth axis by secondary ion mass spectrometry: Applications for studying ontogenetic change in the depth inhabited by deep-sea fishes

    Science.gov (United States)

    Shiao, Jen-Chieh; Itoh, Shoichi; Yurimoto, Hisayoshi; Iizuka, Yoshiyuki; Liao, Yun-Chih

    2014-02-01

    This study using tuna otoliths as working standards established a high lateral resolution and precision analysis to measure δ18Ootolith by secondary ion mass spectrometry. This analytical approach of the ion probe was applied to deep-sea fishes to reconstruct the likely depths inhabited by the fishes at different life history stages based on the measured δ18Ootolith values as a proxy of water temperature. Dramatic increases up to 5-6‰ in δ18Ootolith, representing a temperature decrease of approximately 20 °C, were detected in a blind cusk eel (Barathronus maculatus) otolith and in the otoliths of Synaphobranchus kaupii during leptocephalus metamorphosis to glass eel, inferred from the drop of otolith Sr/Ca ratios and increase of otolith growth increment width. δ18Ootolith profiles clearly divided the fish's life history into a planktonic stage in the mixed layer of the ocean and a benthic stage on the deep-sea ocean bottom. The habitat shift signal was recorded within a 150 μm width of otolith growth zone, which was too narrow to be clearly detected by mechanical drilling and conventional isotopic ratio mass spectrometry. However, variations down to -7‰ were found in δ18Ootolith profiles as the result of Cs2+ beam sputter in the core and larval portions of the otoliths. Carbon mapping by electron probe microanalyzer and staining by toluidine blue suggested abundant proteins existed in the areas with anomaly negative δ18Ootolith values, which cannot be interpreted as a habitat change but due to the isotopic fractionation by O emission from the proteins. These results implied that careful design and understanding of the chemical composition of the analytical areas or tracks on the heterogeneous otolith was essential for highly accurate and precise analysis.

  1. Plasma-Oxygen Interaction During Thin Films Deposition by Laser ...

    African Journals Online (AJOL)

    In this contribution we study the effect of the oxygen pressure on the plasma dynamics during the ablation of oxides materials into an oxygen gas. The study was done using fast imaging and ion probe techniques. Both techniques revealed that a threshold oxygen pressure is needed to initiate the plume oxygen interaction.

  2. Limitations of potentiometric oxygen sensors operating at low oxygen levels

    DEFF Research Database (Denmark)

    Lund, Anders; Jacobsen, Torben; Hansen, Karin Vels

    2011-01-01

    The electrochemical processes that limit the range of oxygen partial pressures in which potentiometric oxygen sensors can be used, were analysed using a theoretical and an experimental approach. Electrochemical impedance spectroscopy was performed on porous Pt/yttria stabilised zirconia (YSZ......) electrodes between 10−6 and 0.2 bar and at temperatures between 500 and 950 °C. The flow of oxide ions and electron holes through a sensor cell, with a YSZ electrolyte, were calculated under similar conditions. The oxygen permeation of the sensor cell was insignificant at an oxygen partial pressure of 10......−6 bar for an inlet flow rate higher than 2 L h−1 between 600 and 800 °C. The polarisation resistance measured between 10−6 and 10−4 bar was found to be inversely proportional to the oxygen partial pressure, nearly temperature independent and inversely proportional to the inlet gas flow rate, which shows...

  3. High rate performance of LiMn2O4 cathodes for lithium ion batteries synthesized by low temperature oxygen plasma assisted sol–gel process

    International Nuclear Information System (INIS)

    Chen, C.-L.; Chiu, K.-F.; Chen, Y.-R.; Chen, C.C.; Lin, H.C.; Chiang, H.Y.

    2013-01-01

    Nano-crystalline LiMn 2 O 4 thin films have been synthesized by the sol–gel process at low temperature (623 K). The low temperature prepared films are treated by a direct current pulsed oxygen plasma, and tested as cathodes for lithium batteries. The plasma treated films are able to sustain charge–discharge cycles under significant high current density of up to 5.4 A/g corresponding to 45 C for battery operation. The capacity ratio for discharging at 1.2 A/g and 0.024 A/g is over 65%, indicating low internal resistance, which meets the requirement of fast charge and discharge for electric vehicles. The stable high current density performances can be attributed to the formation of a dense surface morphology that is induced by the plasma irradiation. The formation of the surface morphology results in the more uniform current distribution on the film surface, which decreases the interface charge transfer resistances as measured by the electrochemical impedance spectra. - Highlights: • A low temperature process has been used to synthesize LiMn 2 O 4 thin films. • Plasma treatment can reduce the interface charge transfer resistances for LiMn 2 O 4 . • LiMn 2 O 4 cathodes treated by plasma treatment can deliver high rate capability

  4. Coordination polymers of Fe(iii) and Al(iii) ions with TCA ligand: distinctive fluorescence, CO2 uptake, redox-activity and oxygen evolution reaction.

    Science.gov (United States)

    Dhara, Barun; Sappati, Subrahmanyam; Singh, Santosh K; Kurungot, Sreekumar; Ghosh, Prasenjit; Ballav, Nirmalya

    2016-04-28

    Fe and Al belong to different groups in the periodic table, one from the p-block and the other from the d-block. In spite of their different groups, they have the similarity of exhibiting a stable 3+ oxidation state. Here we have prepared Fe(iii) and Al(iii) based coordination polymers in the form of metal-organic gels with the 4,4',4''-tricarboxyltriphenylamine (TCA) ligand, namely Fe-TCA and Al-TCA, and evaluated some important physicochemical properties. Specifically, the electrical conductivity, redox-activity, porosity, and electrocatalytic activity (oxygen evolution reaction) of the Fe-TCA system were noted to be remarkably higher than those of the Al-TCA system. As for the photophysical properties, almost complete quenching of the fluorescence originating from TCA was observed in case of the Fe-TCA system, whereas for the Al-TCA system a significant retention of fluorescence with red-shifted emission was observed. Quantum mechanical calculations based on density functional theory (DFT) were performed to unravel the origin of such discriminative behaviour of these coordination polymer systems.

  5. Training for Preservation Management

    Directory of Open Access Journals (Sweden)

    Mirjam M. Foot

    1999-05-01

    Full Text Available In August 1997 the first of a series of summer schools in Preservation Management was held at the Archivschule in Marburg (Germany. The school was organised by the ECPA, the LIBER Division on Preservation, ICA and the Archivschule itself and was aimed at archivists and librarians in management positions from European institutions. It dealt with managerial, organisational and financial aspects of preservation and required active participation by those attending. Apart from introductory sessions by the teaching staff at the Archivschule, a large part of the course took the form of working groups, discussions, assignments and role play, to which participants were expected to take their own experience and problems. The school was conducted in German. Topics, spread over five days, ranged from preservation in the context of the core activities of libraries and archives; planning of preservation projects; general management issues, such as resource management, budgeting, priority setting, communication and effecting change; to more detailed considerations of day-to-day issues, such as storage, disaster control, microfilming and digitising, mass conservation processes, and moulds and fungi.

  6. Oxygen diffusion in monazite

    Science.gov (United States)

    Cherniak, D. J.; Zhang, X. Y.; Nakamura, M.; Watson, E. B.

    2004-09-01

    We report measurements of oxygen diffusion in natural monazites under both dry, 1-atm conditions and hydrothermal conditions. For dry experiments, 18O-enriched CePO4 powder and monazite crystals were sealed in Ag-Pd capsules with a solid buffer (to buffer at NNO) and annealed in 1-atm furnaces. Hydrothermal runs were conducted in cold-seal pressure vessels, where monazite grains were encapsulated with 18O-enriched water. Following the diffusion anneals, oxygen concentration profiles were measured with Nuclear Reaction Analysis (NRA) using the reaction 18O(p,α)15N. Over the temperature range 850-1100 °C, the Arrhenius relation determined for dry diffusion experiments on monazite is given by: Under wet conditions at 100 MPa water pressure, over the temperature range 700-880 °C, oxygen diffusion can be described by the Arrhenius relationship: Oxygen diffusion under hydrothermal conditions has a significantly lower activation energy for diffusion than under dry conditions, as has been found the case for many other minerals, both silicate and nonsilicate. Given these differences in activation energies, the differences between dry and wet diffusion rates increase with lower temperatures; for example, at 600 °C, dry diffusion will be more than 4 orders of magnitude slower than diffusion under hydrothermal conditions. These disparate diffusivities will result in pronounced differences in the degree of retentivity of oxygen isotope signatures. For instance, under dry conditions (presumably rare in the crust) and high lower-crustal temperatures (∼800 °C), monazite cores of 70-μm radii will preserve O isotope ratios for about 500,000 years; by comparison, they would be retained at this temperature under wet conditions for about 15,000 years.

  7. Cancer and fertility preservation

    DEFF Research Database (Denmark)

    Lambertini, Matteo; Del Mastro, Lucia; Pescio, Maria C

    2016-01-01

    In the last years, thanks to the improvement in the prognosis of cancer patients, a growing attention has been given to the fertility issues. International guidelines on fertility preservation in cancer patients recommend that physicians discuss, as early as possible, with all patients...... of reproductive age their risk of infertility from the disease and/or treatment and their interest in having children after cancer, and help with informed fertility preservation decisions. As recommended by the American Society of Clinical Oncology and the European Society for Medical Oncology, sperm...... data have become available, and several issues in this field are still controversial and should be addressed by both patients and their treating physicians.In April 2015, physicians with expertise in the field of fertility preservation in cancer patients from several European countries were invited...

  8. Optimization of preservation activities and preservation engineering (2)

    International Nuclear Information System (INIS)

    Aoki, Takayuki; Mimaki, Hidehito; Oda, Mitsuyuki

    2004-01-01

    In order to deal with the optimization of preservation activities and 'preservation engineering' which makes it possible, the viewpoint and the approach of the optimization of the ex post facto preservation and the content to be possessed in 'preservation engineering' are described. The optimization of the ex post facto preservation is shown respectively in the four stages of planning, implementation, result evaluation and countermeasure. (K. Kato)

  9. Advanced Digital Preservation

    CERN Document Server

    Giaretta, David

    2011-01-01

    There is growing recognition of the need to address the fragility of digital information, on which our society heavily depends for smooth operation in all aspects of daily life. This has been discussed in many books and articles on digital preservation, so why is there a need for yet one more? Because, for the most part, those other publications focus on documents, images and webpages -- objects that are normally rendered to be simply displayed by software to a human viewer. Yet there are clearly many more types of digital objects that may need to be preserved, such as databases, scientific da

  10. Effects of oxygen concentration on atmospheric pressure dielectric barrier discharge in Argon-Oxygen Mixture

    Science.gov (United States)

    Li, Xuechun; Li, Dian; Wang, Younian

    2016-09-01

    A dielectric barrier discharge (DBD) can generate a low-temperature plasma easily at atmospheric pressure and has been investigated for applications in trials in cancer therapy, sterilization, air pollution control, etc. It has been confirmed that reactive oxygen species (ROS) play a key role in the processes. In this work, we use a fluid model to simulate the plasma characteristics for DBD in argon-oxygen mixture. The effects of oxygen concentration on the plasma characteristics have been discussed. The evolution mechanism of ROS has been systematically analyzed. It was found that the ground state oxygen atoms and oxygen molecular ions are the dominated oxygen species under the considered oxygen concentrations. With the oxygen concentration increasing, the densities of electrons, argon atomic ions, resonance state argon atoms, metastable state argon atoms and excited state argon atoms all show a trend of decline. The oxygen molecular ions density is high and little influenced by the oxygen concentration. Ground state oxygen atoms density tends to increase before falling. The ozone density increases significantly. Increasing the oxygen concentration, the discharge mode begins to change gradually from the glow discharge mode to Townsend discharge mode. Project supported by the National Natural Science Foundation of China (Grant No. 11175034).

  11. SMART PACKAGING FOR FOOD PRESERVATION

    Directory of Open Access Journals (Sweden)

    Raquel Rodríguez-Sauceda

    2014-07-01

    Full Text Available One of the biggest challenges of the food industry is the preservation of its products, that is, to prevent them from being attacked by microorganisms that decompose them hauling economic losses and severe health damage to the consumer. Today, competition in the food industry is very high and any company that does not offer the quality products is doomed to fail. Consumers demand more and the industry still stands offering what is asked: quality, security and safety. The package, in addition to fulfilling its core functions is becoming a means of sophisticated interactions with content and a record of relevant information for both the end consumer and intermediate players in the value chain and concepts are born of active and intelligent packaging. A smart container is defined as a system that monitors the condition of the packaged product, being able to register and provide information about product quality or condition of the container, showing the possible "abnormal" practices that have suffered the product or the container during the entire supply chain, such as transportation or storage. These systems monitor the mechanisms of altered food due to physiological, chemical and biological processes that respond and communicate changes in the status of the product as time-temperature, Oxygen, Carbon dioxide, microbial growth, etc. There are different types of smart packaging such as time-temperature indicators, color indicators, indicators of pathogens and indicators of leaks, to name a few. Through literature review, arguments that demonstrate the usefulness and necessity of the use of smart packaging to preserve the quality and safety of the product it contains, from manufacturing to the time it is used by consumers were found, as these besides communicating or providing information about their state, acting as a marketing tool.

  12. Singlet Oxygen at the Laundromat

    Science.gov (United States)

    Keeports, David

    1995-09-01

    Singlet molecular oxygen is an interesting molecule both visually and theoretically, since its red chemiluminescence can be analyzed by the application of simple molecular orbital theory. It can be produced from the reaction of hydrogen peroxide from either chlorine gas or hypochlorite ion from household bleach. Here we demostrate how to produce it using simple laundry cleansers.

  13. Ion channeling

    International Nuclear Information System (INIS)

    Erramli, H.; Blondiaux, G.

    1994-01-01

    Channeling phenomenon was predicted, many years ago, by stark. The first channeling experiments were performed in 1963 by Davies and his coworkers. Parallely Robinson and Oen have investigated this process by simulating trajectories of ions in monocrystals. This technique has been combined with many methods like Rutherford Backscattering Spectrometry (R.B.S.), Particles Induced X-rays Emission (P.I.X.E) and online Nuclear Reaction (N.R.A.) to localize trace elements in the crystal or to determine crystalline quality. To use channeling for material characterization we need data about the stopping power of the incident particle in the channeled direction. The ratios of channeled to random stopping powers of silicon for irradiation in the direction have been investigated and compared to the available theoretical results. We describe few applications of ion channeling in the field of materials characterization. Special attention is given to ion channeling combined with Charged Particle Activation Analysis (C.P.A.A.) for studying the behaviour of oxygen atoms in Czochralski silicon lattices under the influence of internal gettering and in different gaseous atmospheres. Association between ion channeling and C.P.A.A was also utilised for studying the influence of the growing conditions on concentration and position of carbon atoms at trace levels in the MOVPE Ga sub (1-x) Al sub x lattice. 6 figs., 1 tab., 32 refs. (author)

  14. Normothermic perfusion: a new paradigm for organ preservation.

    Science.gov (United States)

    Brockmann, Jens; Reddy, Srikanth; Coussios, Constantin; Pigott, David; Guirriero, Dino; Hughes, David; Morovat, Alireza; Roy, Debabrata; Winter, Lucy; Friend, Peter J

    2009-07-01

    Transplantation of organs retrieved after cardiac arrest could increase the donor organ supply. However, the combination of warm ischemia and cold preservation is highly detrimental to the reperfused organ. Our objective was to maintain physiological temperature and organ function during preservation and thereby alleviate this injury and allow successful transplantation. We have developed a liver perfusion device that maintains physiological temperature with provision of oxygen and nutrition. Reperfusion experiments suggested that this allows recovery of ischemic damage. In a pig liver transplant model, we compared the outcome following either conventional cold preservation or warm preservation. Preservation periods of 5 and 20 hours and durations of warm ischemia of 40 and 60 minutes were tested. After 20 hours preservation without warm ischemia, post-transplant survival was improved (27%-86%, P = 0.026), with corresponding differences in transaminase levels and histological analysis. With the addition of 40 minutes warm ischemia, the differences were even more marked (cold vs. warm groups 0% vs. 83%, P = 0.001). However, with 60 minutes warm ischemia and 20 hours preservation, there were no survivors. Analysis of hemodynamic and liver function data during perfusion showed several factors to be predictive of posttransplant survival, including bile production, base excess, portal vein flow, and hepatocellular enzymes. Organ preservation by warm perfusion, maintaining physiological pressure and flow parameters, has enabled prolonged preservation and successful transplantation of both normal livers and those with substantial ischemic damage. This technique has the potential to address the shortage of organs for transplantation.

  15. Prevention of ischemia-reperfusion lung injury during static cold preservation by supplementation of standard preservation solution with HEMO2life® in pig lung transplantation model.

    Science.gov (United States)

    Glorion, M; Polard, V; Favereau, F; Hauet, T; Zal, F; Fadel, E; Sage, E

    2017-10-25

    We describe the results of adding a new biological agent HEMO 2 life ® to a standard preservation solution for hypothermic static lung preservation aiming to improve early functional parameters after lung transplantation. HEMO 2 life ® is a natural oxygen carrier extracted from Arenicola marina with high oxygen affinity developed as an additive to standard organ preservation solutions. Standard preservation solution (Perfadex ® ) was compared with Perfadex ® associated with HEMO 2 life ® and with sham animals after 24 h of hypothermic preservation followed by lung transplantation. During five hours of lung reperfusion, functional parameters and biomarkers expression in serum and in bronchoalveolar lavage fluid (BALF) were measured. After five hours of reperfusion, HEMO 2 life ® group led to significant improvement in functional parameters: reduction of graft vascular resistance (p preservation improves early graft function after prolonged cold ischemia in lung transplantation.

  16. Integral-preserving integrators

    International Nuclear Information System (INIS)

    McLaren, D I; Quispel, G R W

    2004-01-01

    Ordinary differential equations having a first integral may be solved numerically using one of several methods, with the integral preserved to machine accuracy. One such method is the discrete gradient method. It is shown here that the order of the method can be bootstrapped repeatedly to higher orders of accuracy. The method is illustrated using the Henon-Heiles system. (letter to the editor)

  17. Foodstuffs preservation by ionization

    International Nuclear Information System (INIS)

    1991-12-01

    This document contains all the papers presented at the meeting on foodstuffs preservation by ionization. These papers deal especially with the food ionization process, its development and the view of the food industry on ionization. Refs and figs (F.M.)

  18. Preserving food with radiation

    International Nuclear Information System (INIS)

    Thomas, A.C

    1978-01-01

    Food irradiation is becoming an increasingly more important method of food preservataion. The irradiation process and its advangages are briefly described, and its use in the preservation of poultry and various kinds of fruits is discussed. Fruit export is hampered by restrictions due to infestation. Radiation disinfestation will therefore be of great advantage and may lead to a growth in export markets

  19. Preserve America News

    Science.gov (United States)

    phone number. Whether or not you're able to let us know ahead of time, however, we hope you can join us Amache Preservation Society in Colorado and the Friends of Mount Hope Cemetery in New York. This brings Places: Breathing New Life into Our Communities." Read about this informative session. National

  20. POLARISATION PRESERVING OPTICAL FIBRE

    DEFF Research Database (Denmark)

    2000-01-01

    . This cladding structure provides polarisation preserving properties to the optical fibre. Optical fibres using this technology may have claddings with elements placed non-periodically as well as in a two-dimensional periodic lattice - such as cladding providing Photonic Band Gap (PBG) effects....

  1. Wood preservative testing

    Science.gov (United States)

    Rebecca Ibach; Stan T. Lebow

    2012-01-01

    Most wood species used in commercial and residential construction have little natural biological durability and will suffer from biodeterioration when exposed to moisture. Historically, this problem has been overcome by treating wood for outdoor use with toxic wood preservatives. As societal acceptance of chemical use changes, there is continual pressure to develop and...

  2. Preservation in New Buildings

    Directory of Open Access Journals (Sweden)

    Christopher Kitching

    2000-06-01

    Full Text Available In the United Kingdom (as in many other countries increasing attention is being paid to the importance of each library and archive having a written preservation strategy endorsed by its governing body. So increasingly we are asking: where does „preservation“ begin and what are its top priorities? Some would say preservation begins with the definition of collecting policies to ensure that only relevant items are acquired in the first place, and therefore that no unnecessary costs are incurred on the long-term care of unwanted and unconsulted items. Others might argue that the first priority must be the careful appraisal of existing holdings to determine their preservation and conservation requirements and to prioritise their treatment. Or should preservation begin with damage-limitation: restricting the physical handling of books and documents, on the one hand by providing whenever possible surrogate copies in digital formats or microform, and on the other hand by offering at least basic protection through appropriate boxing and packaging? This, surely, goes hand-in-hand with the education of staff and readers about the importance of treating rare or unique materials with proper respect.

  3. Preserving the Seminar Experience

    Science.gov (United States)

    Ramsey, David; Evans, Jocelyn; Levy, Meyer

    2016-01-01

    This article presents a new approach to online graduate education. With hopes of recruiting a larger cohort in order to preserve a graduate program struggling with low enrollment, we began offering a limited number of seats to students who would attend class in real time but from remote locations, using a videoconferencing platform. Unlike…

  4. Effect of oxygen gas and annealing treatment for magnetically enhanced reactive ion etched (Ba0.65,Sr0.35)TiO3 thin films

    International Nuclear Information System (INIS)

    Zhang Baishun; Quan Zuci; Zhang Tianjin; Guo Tao; Mo Shaobo

    2007-01-01

    Sol-gel-derived (Ba 0.65 ,Sr 0.35 )TiO 3 (BST) thin films were etched in CF 4 /Ar and CF 4 /Ar/O 2 plasmas using magnetically enhanced reactive ion etching technology. Experimental results show that adding appropriate O 2 to CF 4 /Ar can better the etching effects of BST films for the increase of etching rate and decrease of etched residues. The maximum etching rate is 8.47 nm/min when CF 4 /Ar/O 2 gas-mixing ratio is equal to 9/36/5. X-ray photoelectron spectroscopy (XPS) data confirm accumulation of reaction products on the etched surface due to low volatility of reaction products such as Ba and Sr fluorides, and these residues could be removed by annealing treatment. The exact peak positions and chemical shifts of the interested elements were deduced by fitting XPS narrow-scan spectra with symmetrical Gaussian-Lorentzian product function for Ba 3d, Sr 3d, and O 1s peaks, meanwhile asymmetrical Gaussian-Lorentzian sum function was used to fit Ti 2p doublet to adjust the multiple splitting and/or shake-up process of transition-metal Ti cations. Compared to the unetched counterparts, the etched Ba 3d 5/2 , Ba 3d 3/2 , Sr 3d 5/2 , Sr 3d 3/2 , Ti 2p 3/2 , Ti 2p 1/2 , and O 1s peaks shift towards higher binding energy regions by amounts of 1.31, 1.30, 0.60, 0.79, 0.09, 0.46, and 0.50 eV, respectively. While the etched Ti 2p 3/2 and Ti 2p 1/2 peaks have small chemical shifts for two reasons. One is that Ti fluoride (TiF z ) is mostly removed from the etched surface because of its higher volatility in the process of thermal desorption. The other is that there is a shift compensation between TiF z and the etched BST matrix in which Ti 4+ cations are partially reduced to form Ti x+ (0 0.65 ,Sr 0.35 )Ti 0.97 O 2.86 , (Ba 0.70 ,Sr 0.30 )Ti 0.24 O 1.39 , and (Ba 0.68 ,Sr 0.32 )Ti 0.95 O 2.74 , and then the average valence of Ti cations is estimated to be +3.84, +3.25, and +3.66 with respect to the electroneutrality principle, respectively. It is inferred that electrical

  5. Blood conservation with membrane oxygenators and dipyridamole.

    Science.gov (United States)

    Teoh, K H; Christakis, G T; Weisel, R D; Madonik, M M; Ivanov, J; Wong, P Y; Mee, A V; Levitt, D; Benak, A; Reilly, P

    1987-07-01

    Cardiopulmonary bypass induces platelet activation and dysfunction, which result in platelet deposition and depletion. Reduced platelet numbers and abnormal platelet function may contribute to postoperative bleeding. A membrane oxygenator may preserve platelets and reduce bleeding more than a bubble oxygenator, and the antiplatelet agent dipyridamole may protect platelets intraoperatively and reduce bleeding postoperatively. A prospective randomized trial was performed in 44 patients undergoing elective coronary artery bypass grafting to assess the effects of the membrane oxygenator and dipyridamole on platelet counts, platelet activation products, and postoperative bleeding. Patients who were randomized to receive a bubble oxygenator and no dipyridamole had the lowest postoperative platelet counts, the greatest blood loss, and the most blood products transfused. Platelet counts were highest and blood loss was least in patients randomized to receive a membrane oxygenator and dipyridamole (p less than .05). A bubble oxygenator with dipyridamole and a membrane oxygenator without dipyridamole resulted in intermediate postoperative platelet counts and blood loss. Arterial thromboxane B2 and platelet factor 4 concentrations were elevated on cardiopulmonary bypass in all groups. Both the membrane oxygenator and dipyridamole were independently effective (by multivariate analysis) in preserving platelets. Optimal blood conservation was achieved with a membrane oxygenator and dipyridamole.

  6. DNA preservation in silk.

    Science.gov (United States)

    Liu, Yawen; Zheng, Zhaozhu; Gong, He; Liu, Meng; Guo, Shaozhe; Li, Gang; Wang, Xiaoqin; Kaplan, David L

    2017-06-27

    The structure of DNA is susceptible to alterations at high temperature and on changing pH, irradiation and exposure to DNase. Options to protect and preserve DNA during storage are important for applications in genetic diagnosis, identity authentication, drug development and bioresearch. In the present study, the stability of total DNA purified from human dermal fibroblast cells, as well as that of plasmid DNA, was studied in silk protein materials. The DNA/silk mixtures were stabilized on filter paper (silk/DNA + filter) or filter paper pre-coated with silk and treated with methanol (silk/DNA + PT-filter) as a route to practical utility. After air-drying and water extraction, 50-70% of the DNA and silk could be retrieved and showed a single band on electrophoretic gels. 6% silk/DNA + PT-filter samples provided improved stability in comparison with 3% silk/DNA + filter samples and DNA + filter samples for DNA preservation, with ∼40% of the band intensity remaining at 37 °C after 40 days and ∼10% after exposure to UV light for 10 hours. Quantitative analysis using the PicoGreen assay confirmed the results. The use of Tris/borate/EDTA (TBE) buffer enhanced the preservation and/or extraction of the DNA. The DNA extracted after storage maintained integrity and function based on serving as a functional template for PCR amplification of the gene for zinc finger protein 750 (ZNF750) and for transgene expression of red fluorescence protein (dsRed) in HEK293 cells. The high molecular weight and high content of a crystalline beta-sheet structure formed on the coated surfaces likely accounted for the preservation effects observed for the silk/DNA + PT-filter samples. Although similar preservation effects were also obtained for lyophilized silk/DNA samples, the rapid and simple processing available with the silk-DNA-filter membrane system makes it appealing for future applications.

  7. Ion mixing and numerical simulation of different ions produced in the ECR ion source

    International Nuclear Information System (INIS)

    Shirkov, G.D.

    1996-01-01

    This paper is to continue theoretical investigations and numerical simulations in the physics of ECR ion sources within the CERN program on heavy ion acceleration. The gas (ion) mixing effect in ECR sources is considered here. It is shown that the addition of light ions to the ECR plasma has three different mechanisms to improve highly charged ion production: the increase of confinement time and charge state of highly ions as the result of ion cooling; the concentration of highly charged ions in the central region of the source with high energy and density of electrons; the increase of electron production rate and density of plasma. The numerical simulations of lead ion production in the mixture with different light ions and different heavy and intermediate ions in the mixture with oxygen, are carried out to predict the principal ECR source possibilities for LHC applications. 18 refs., 23 refs

  8. Characterization of carbon, nitrogen, oxygen and refractory metals in binary and ternary silicon-based films using ion beam methods; Caracterisation des elements: carbone, azote, oxygene et metal refractaire dans des depots binaires et ternaires a base de silicium par methodes d'analyse utilisant les faisceaux d'ions

    Energy Technology Data Exchange (ETDEWEB)

    Somatri-Bouamrane, R. [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire]|[Universite Claude Bernard, 69 - Lyon (France)

    1996-12-19

    Ion beam methods (non Rutherford backscattering, nuclear reactions) have been carried out in order to characterize silicon-based films. The cross sections for the reactions {sup 12}C({alpha},{alpha}), {sup 14}N({alpha},{alpha}), {sup 16}O({alpha},{alpha}), {sup 28}Si({alpha},{alpha}) and {sup 14}N({alpha},p) have been measured within 2 and 7 MeV. CVD beta SiC films could be analyzed and the interface between silicon carbide and the (100) silicon substrate was studied. The epitaxial growth of the beta SiC film could be modelled by comparing the results obtained with ion beam analysis, infrared spectroscopy and electron microscopy. Moreover, the stoichiometry of low pressure CVD Me-Si-N (Me=Re, W, Ti, Ta) ternary systems was studied. The evolution of the nitrogen content in W-Si-N systems allowed to study their stability with respect to the annealing conditions. (N.T.)

  9. Oxygen Vacancies and Stacking Faults Introduced by Low-Temperature Reduction Improve the Electrochemical Properties of Li2MnO3 Nanobelts as Lithium-Ion Battery Cathodes.

    Science.gov (United States)

    Sun, Ya; Cong, Hengjiang; Zan, Ling; Zhang, Youxiang

    2017-11-08

    Among the Li-rich layered oxides Li 2 MnO 3 has significant theoretical capacity as a cathode material for Li-ion batteries. Pristine Li 2 MnO 3 generally has to be electrochemically activated in the first charge-discharge cycle which causes very low Coulombic efficiency and thus deteriorates its electrochemical properties. In this work, we show that low-temperature reduction can produce a large amount of structural defects such as oxygen vacancies, stacking faults, and orthorhombic LiMnO 2 in Li 2 MnO 3 . The Rietveld refinement analysis shows that, after a reduction reaction with stearic acid at 340 °C for 8 h, pristine Li 2 MnO 3 changes into a Li 2 MnO 3 -LiMnO 2 (0.71/0.29) composite, and the monoclinic Li 2 MnO 3 changes from Li 2.04 Mn 0.96 O 3 in the pristine Li 2 MnO 3 (P-Li 2 MnO 3 ) to Li 2.1 Mn 0.9 O 2.79 in the reduced Li 2 MnO 3 (R-Li 2 MnO 3 ), indicating the production of a large amount of oxygen vacancies in the R-Li 2 MnO 3 . High-resolution transmission electron microscope images show that a high density of stacking faults is also introduced by the low-temperature reduction. When measured as a cathode material for Li-ion batteries, R-Li 2 MnO 3 shows much better electrochemical properties than P-Li 2 MnO 3 . For example, when charged-discharged galvanostatically at 20 mA·g -1 in a voltage window of 2.0-4.8 V, R-Li 2 MnO 3 has Coulombic efficiency of 77.1% in the first charge-discharge cycle, with discharge capacities of 213.8 and 200.5 mA·h·g -1 in the 20th and 30th cycles, respectively. In contrast, under the same charge-discharge conditions, P-Li 2 MnO 3 has Coulombic efficiency of 33.6% in the first charge-discharge cycle, with small discharge capacities of 80.5 and 69.8 mA·h·g -1 in the 20th and 30th cycles, respectively. These materials characterizations, and electrochemical measurements show that low-temperature reduction is one of the effective ways to enhance the performances of Li 2 MnO 3 as a cathode material for Li-ion batteries.

  10. Oxygen safety

    Science.gov (United States)

    ... sure you have working smoke detectors and a working fire extinguisher in your home. If you move around the house with your oxygen, you may need more than one fire extinguisher in different locations. Smoking can be very dangerous. No one should smoke ...

  11. Oxygen therapy - infants

    Science.gov (United States)

    ... breathe increased amounts of oxygen to get normal levels of oxygen in their blood. Oxygen therapy provides babies with the extra oxygen. Information Oxygen is a gas that the cells in your body need to work properly. The ...

  12. Food preservation by irradiation

    International Nuclear Information System (INIS)

    Kooij, J. van

    1981-01-01

    Twenty-five years of development work on the preservation of food by irradiation have shown that this technology has the potential to reduce post-harvest losses and to produce safe foods. The technological feasibility has been established but general acceptance of food irradiation by national regulatory bodies and consumers requires attention. The positive aspects of food preservation by irradiation include: the food keeps its freshness and its physical state, agents which cause spoilage (bacteria, etc.) are eliminated, recontamination does not take place, provided packaging materials are impermeable to bacteria and insects. It inhibits sprouting of root crops, kills insects and parasites, inactivates bacteria, spores and moulds, delays ripening of fruit, improves the technological properties of food. It makes foods biologically safe, allows the production of shelf-stable foods and is excellent for quarantine treatment, and generally improves food hygiene. The dose ranges needed for effective treatment are given

  13. How to preserve foods

    International Nuclear Information System (INIS)

    Balek, V.; Vadassova, J.

    1979-01-01

    The use of gamma and fast electron radiations for food preservation is described. Examples are given of the application of ionizing radiation for retarding potato germination, onion growth, and fruit ripening, for limiting the action of microorganisms, and removing salmonella from meat products. The method has remarkable prospects although it may not be considered to be a general-purpose method. Geographic and economic conditions should always be taken into consideration. (J.P.)

  14. Preservation and gamma irradiation

    International Nuclear Information System (INIS)

    Ramiere, R.

    1991-01-01

    The paper reviews briefly the application of gamma radiation to preservation of cultural objects for disinsectization, disinfection and strengthening of materials such as wood or stone by impregnation with a liquid resin and in situ polymerization. As heavy equipment is required two facilities are specialized a 1000 T Bq cobalt 60 source at Grenoble (France) and 100 T Bq one at Rostoky (Czechoslovakia). Examples of treated objects are given [fr

  15. Beneficial bread without preservatives

    OpenAIRE

    Denkova, Zapryana; Denkova, Rositsa

    2014-01-01

    Besides their inherent nutritional value functional foods contain substances that have beneficial impact on the functioning of organs and systems in the human body and reduce the risk of disease. Bread and bakery goods are basic foods in the diet of contemporary people. Preservatives are added to the composition of foods in order to ensure their microbiological safety, but these substances affect directly the balance of microflora in the tract. A great problem is mold and bacterial spoilage (...

  16. Fertility preservation 2

    Science.gov (United States)

    De Vos, Michel; Smitz, Johan; Woodruff, Teresa K

    2014-01-01

    Enhanced long-term survival rates of young women with cancer and advances in reproductive medicine and cryobiology have culminated in an increased interest in fertility preservation methods in girls and young women with cancer. Present data suggest that young patients with cancer should be referred for fertility preservation counselling quickly to help with their coping process. Although the clinical application of novel developments, including oocyte vitrification and oocyte maturation in vitro, has resulted in reasonable success rates in assisted reproduction programmes, experience with these techniques in the setting of fertility preservation is in its infancy. It is hoped that these and other approaches, some of which are still regarded as experimental (eg, ovarian tissue cryopreservation, pharmacological protection against gonadotoxic agents, in-vitro follicle growth, and follicle transplantation) will be optimised and become established within the next decade. Unravelling the complex mechanisms of activation and suppression of follicle growth will not only expand the care of thousands of women diagnosed with cancer, but also inform the care of millions of women confronted with reduced reproductive fitness because of ageing. PMID:25283571

  17. Grain preservation in SSSR

    International Nuclear Information System (INIS)

    Trisviatski, L.A.

    1973-01-01

    First the importance of cereals collected in the S.S.S.R., the reason why the government had to put in practice a storage chain, composed of large capacity store houses (200 000 metric tonnes, or more) is reminded. When climatic conditions result in wet harvested grains, cereals are dried either in state enterprise dryers (32 to 50 tonnes/hour) or in kolkhozes' dryers (2 to 16 tonnes/hour). A new type of drying with recycling, has been developped, economizing 10 to 15 p. 100. Then the possibilities offered by the technique of partial drying of very wet grains are studied and the preservation processes using fresh ventilation, or hot ventilation with drying effect are described. The question of silage of wet grains destined to animal consumption is then examined as well as preservation by sodium pyrosulfide; the use of propionic acid, little developped in SSSR, is studied now, just as storage with inert gas. The struggle technics against insects, either with chemical agents, or with irradiation are described. Finally the modalities of technicians formation, specialized in preservation, are discussed [fr

  18. Common Laundry Detergent Ingredient May Help Preserve Muscle Tissue After Severe Injury

    Science.gov (United States)

    ... Yoo JJ, Harrison BS, Christ GJ. Oxygen Generating Biomaterials Preserve Skeletal Muscle Homeostasis under Hypoxic and Ischemic ... scientific news and resources on diseases of the bones, joints, muscles, and skin from the NIAMS. Click ...

  19. Determination of viability of preserved skin in low temperature

    International Nuclear Information System (INIS)

    Yang Hong Chang; Hao Zheng Ming; Zao Xiao Chun

    1999-01-01

    The skin from fresh human cadavers was stored in 4-18 degree C refrigerator. Before it was grafted for treatment of burn patients, it was quickly put into 40 degree C water and bring back to a former condition. The survival rate of skin was related with time and temperature of store. We used oxygen consumption to observe the change of viability of preserved skin. Oxygen consumption of skin was observed with apparatus made in the 304th Hospital of Peoples Liberation Army. The operating temperature was 5 - 45 degree C. Determination range was 0 - 199 mm Hg, resolving power of digital display was I mm Hg, instrumental error < 0.5 s'. Fresh human cadavers skin was made into 0.3 - 0.4 mm thick piece. Cleaned with NaCl 0.9% for three time. Then it was kept in neomycin solution for fifteen minutes. Then cut into 0.5 x 0.5 cm slices and stored in neomycin (2mg/ml). The skin was stored in 4 degree C refrigerator for five different periods (1, 2, 3, 5 and 7 days). Then the Oxygen consumption was determined immediately. The oxygen consumption was also determined before and after it was stored for 24 hours. After the skin was stored in 4 and -18 degree C for 24 hours the oxygen consumption was determined immediately. The prepared skin, which was stored in ordinary refrigerator, was useful and simple. The preserved skin was grafted onto the bum patient and survival rate was high and in short time. But the result showed the viability of preserved skin reduced with time. The result showed that the oxygen consumption of skin, which was stored at 4 degree C, on the fifth day was 62.23% and on day 7 was 30.5%. The study showed that the preserved skin which was stored at 4 degree C for five days was better while the vitality of skin evidently reduced after seven days and the survival rate was low. The oxygen consumption of preserved skin that was stored in -18 degree C refrigerator for 24 hours was 100%. But in 4 degree C refrigerator it was 89.1%. The result showed that the

  20. Training development for pavement preservation.

    Science.gov (United States)

    2013-05-01

    This research project strives to help the Iowa Department of Transportation (DOT) fully achieve the full benefits of pavement : preservation through training on proper selection, design, and application of pavement preservation treatments. In some ca...

  1. ACHP | Tribal Historic Preservation Officers

    Science.gov (United States)

    preservation of significant historic properties. Those functions include identifying and maintaining Working with Section 106 Federal, State, & Tribal Programs Training & Education Publications Search skip specific nav links Home arrow Historic Preservation Programs & Officers arrow THPOs

  2. Preservative treatments for building components

    Science.gov (United States)

    Stan Lebow

    2007-01-01

    The wood species most commonly used in construction have little natural durability Thus, they are treated with preservatives when used in conditions that favor biodeterioration. The type of preservative used varies with the type of wood product, exposure condition, and specific agent of deterioration. This paper discusses the characteristics of several preservative...

  3. Preserving the Manhattan Project

    Science.gov (United States)

    Kelly, Cynthia

    2014-03-01

    When future generations look back on the 20th century, few events will rival the harnessing of nuclear energy as a turning point in world history, science and society. Yet, the Department of Energy has not always embraced its Manhattan Project origins. The presentation will focus on the progress made over the last 20 years to preserve the properties and first-hand accounts that for decades have been threatened with demolition and indifference. Since the mid-1950s, most remaining Manhattan Project properties at the Los Alamos National Laboratory had been abandoned. Among them was a cluster of wooden buildings called the ``V Site.'' This is where scientists assembled the ``Gadget,'' the world's first atomic device tested on July 16, 1945. Regardless of its significance, the ``V Site'' buildings like all the rest were slated for demolition. The Advisory Council on Historic Preservation (ACHP) toured the properties in November 1998. Most could not believe that the world's first atomic bomb was designed in such humble structures. The properties were declared to be ``monumental in their lack of monumentality.'' A Save America's Treasures grant for 700,000 was awarded to restore the properties. To raise the required matching funds, I left the Federal government and soon founded the Atomic Heritage Foundation. The presentation will trace the progress made over the last decade to generate interest and support nationwide to preserve the Manhattan Project heritage. Saving both the physical properties and first-hand accounts of the men and women have been a priority. Perhaps our most significant achievement may be legislation now under consideration by Congress to create a Manhattan Project National Historical Park. Seventy years later, the Manhattan Project is finally getting the recognition it deserves.

  4. Fertility Preservation in Girls

    Directory of Open Access Journals (Sweden)

    Jennia Michaeli

    2012-01-01

    Full Text Available Children that undergo treatment for cancer are at risk of suffering from subfertility or hormonal dysfunction due to the detrimental effects of radiotherapy and chemotherapeutic agents on the gonads. Cryopreservation of ovarian tissue prior to treatment offers the possibility of restoring gonadal function after resumption of therapy. Effective counseling and management of pediatric patients is crucial for preserving their future reproductive potential. The purpose of this article is to review recent literature and to revise recommendations we made in a 2007 article. Pediatric hemato-oncology, reproductive endocrinology, surgery, anesthesia and bioethics perspectives are discussed and integrated to propose guidelines for offering ovarian cryopreservation to premenarcheal girls with cancer.

  5. Radiation preservation of spices

    International Nuclear Information System (INIS)

    Badshah, A.; Tasnim, A.; Khan, M.; Sattar, A.; Khan, I.

    1989-01-01

    The use of gamma irradiation for preservation of red hot pepper has been explained in report, as it can kill the harmful organisms without altering the organolpetic properties. The sample were dried and reduced to pass through 20 mesh. The samples were irradiated at different dose levels of 0, 2.5, 5.0, 7.5 and 10.0 KGy and results have been shown after different time intervals. Radiation and packaging treatments resulted normaly no effect on the color of dry fruits. (A.B)

  6. Preserving Transactional Data

    OpenAIRE

    Sara Day Thomson

    2017-01-01

    This paper is an adaptation of a longer report commissioned by the UK Data Service. The longer report contributes to on-going support for the Big Data Network – a programme funded by the Economic and Social Research Council (ESRC). The longer report can be found at doi:10.7207/twr16-02. This paper discusses requirements for preserving transactional data and the accompanying challenges facing the companies and institutions who aim to re-use these data for analysis or research. It present...

  7. Excitation of atoms and molecules in collisions with highly charged ions

    International Nuclear Information System (INIS)

    Watson, R.L.

    1992-01-01

    This report discusses research of multicharged nitrogen, oxygen and carbon monoxide molecular ions produced with collision with multicharged argon ions. Properties like ionization, dissociation, and excitation are investigated

  8. Mutual preservation of entanglement

    International Nuclear Information System (INIS)

    Veitia, Andrzej; Jing, Jun; Yu, Ting; Wong, Chee Wei

    2012-01-01

    We study a generalized double Jaynes–Cummings (JC) model where two entangled pairs of two-level atoms interact indirectly. We show that there exist initial states of the qubit system so that two entangled pairs are available at all times. In particular, the minimum entanglement in the pairs as a function of the initial state is studied. Finally, we extend our findings to a model consisting of multi-mode atom–cavity interactions. We use a non-Markovian quantum state diffusion (QSD) equation to obtain the steady-state density matrix for the qubits. We show that the multi-mode model also displays dynamical preservation of entanglement. -- Highlights: ► Entanglement dynamics is studied in a generalized double Jaynes–Cummings model. ► We show that for certain initial states, the atoms remain entangled at all times. ► We extend the results to the case of multi-mode atom–cavity interactions. ► The model suggest that indirect interaction may help to preserve entanglement.

  9. Preservation technologies for fresh meat - a review.

    Science.gov (United States)

    Zhou, G H; Xu, X L; Liu, Y

    2010-09-01

    Fresh meat is a highly perishable product due to its biological composition. Many interrelated factors influence the shelf life and freshness of meat such as holding temperature, atmospheric oxygen (O(2)), endogenous enzymes, moisture, light and most importantly, micro-organisms. With the increased demand for high quality, convenience, safety, fresh appearance and an extended shelf life in fresh meat products, alternative non-thermal preservation technologies such as high hydrostatic pressure, superchilling, natural biopreservatives and active packaging have been proposed and investigated. Whilst some of these technologies are efficient at inactivating the micro-organisms most commonly related to food-borne diseases, they are not effective against spores. To increase their efficacy against vegetative cells, a combination of several preservation technologies under the so-called hurdle concept has also been investigated. The objective of this review is to describe current methods and developing technologies for preserving fresh meat. The benefits of some new technologies and their industrial limitations is presented and discussed.

  10. An Innovative Hyperbaric Hypothermic Machine Perfusion Protects the Liver from Experimental Preservation Injury

    Directory of Open Access Journals (Sweden)

    Ferdinando A. Giannone

    2012-01-01

    Full Text Available Purpose. Hypothermic machine perfusion systems seem more effective than the current static storage to prevent cold ischemic liver injury. Thus, we test an innovative hyperbaric hypothermic machine perfusion (HHMP, which combines hyperbaric oxygenation of the preservation solution and continuous perfusion of the graft. Methods. Rat livers were preserved with Celsior solution according to 4 different modalities: normobaric static preservation; hyperbaric static preservation at 2 atmosphere absolute (ATA; normobaric dynamic preservation, with continuous perfusion; hyperbaric dynamic preservation, with continuous perfusion at 2 ATA. After 24 h cold preservation, we assessed different parameters. Results. Compared to baseline, livers preserved with the current static storage showed severe ultrastructural damage, glycogen depletion and an increased oxidative stress. Normobaric perfused livers showed improved hepatocyte ultrastructure and ameliorated glycogen stores, but they still suffered a significant oxidative damage. The addition of hyperbaric oxygen produces an extra benefit by improving oxidative injury and by inducing endothelial NO synthase (eNOS gene expression. Conclusions. Preservation by means of the present innovative HHMP reduced the liver injury occurring after the current static cold storage by lowering glycogen depletion and oxidative damage. Interestingly, only the use of hyperbaric oxygen was associated to a blunted oxidative stress and an increased eNOS gene expression.

  11. Preserving reptiles for research

    Science.gov (United States)

    Gotte, Steve W.; Jacobs, Jeremy F.; Zug, George R.; Dodd, C. Kenneth

    2016-01-01

    What are voucher specimens and why do we collect them? Voucher specimens are animals and/or their parts that are deposited in a research museum to document the occurrence of a taxon at a specific location in space and time (Pleijel et al., 2008; Reynolds and McDiarmid, 2012). For field biologists, vouchers are the repeatable element of a field study as they allow other biologists, now and in the future, to confirm the identity of species that were studied. The scientific importance of a voucher specimen or series of specimens is that other people are afforded the opportunity to examine the entire animal and confirm or correct identifications. A photographic record is somewhat useful for recording the occurrence of a species, but such records can be insufficient for reliable confirmation of specific identity. Even if a photo shows diagnostic characters of currently recognized taxa, it may not show characters that separate taxa that may be described in the future. Substantial cryptic biodiversity is being found in even relatively well-known herpetofaunas (Crawford et al., 2010), and specimens allow researchers to retroactively evaluate the true diversity in a study as understanding of taxonomy evolves. They enable biologists to study the systematic relationships of populations by quantifying variation in different traits. Specimens are also a source of biological data such as behaviour, ecology, epidemiology, and reproduction through examination of their anatomy, reproductive and digestive tracts, and parasites (Suarez and Tsutsui, 2004). Preserving reptiles as vouchers is not difficult, although doing it properly requires care, effort, and time. Poorly preserved vouchers can invalidate the results and conclusions of your study because of the inability to confirm the identity of your study animals. Good science requires repeatability of observations, and the absence of vouchers or poorly preserved ones prevents such confirmation. Due to space restrictions, we are

  12. Production of an accelerated oxygen-14 beam

    International Nuclear Information System (INIS)

    Powell, J.; O'Neil, J.P.; Cerny, Joseph

    2003-01-01

    BEARS is an ongoing project to provide a light-ion radioactive-beam capability at the 88-Inch Cyclotron at LBNL. Light radioactive isotopes are produced at a 10 MeV proton medical cyclotron, transported 350 m via a high-speed gas transport capillary, cryogenically separated, and injected into the 88-Inch Cyclotron's ion source. The first radioactive beam successfully accelerated was carbon-11 and beams of intensity more than 10 8 ions/s have been utilized for experiments. Development of oxygen-14 as the second BEARS beam presented considerable technical challenges, both due to its short half-life of 71 s and the radiation chemistry of oxygen in the target. The usual techniques developed for medical uses of oxygen-15 involve the addition of significant amounts of carrier oxygen, something that would overload the ion source. As a solution, oxygen-14 is produced as water in a carrier-free form, and is chemically converted in two steps to carbon dioxide, a form readily usable by the BEARS. This system has been built and is operational, and initial tests of accelerating an oxygen-14 beam have been performed

  13. Recombination and detachment in oxygen discharges: the role of metastable oxygen molecules

    International Nuclear Information System (INIS)

    Gudmundsson, J T

    2004-01-01

    A global (volume averaged) model of oxygen discharges is used to study the transition from a recombination dominated discharge to a detachment dominated discharge. The model includes the metastable oxygen molecules O 2 (a 1 Δ g ) and O 2 (b 1 Σ g + ) and the three Herzberg states O 2 (A 3 Σ u + , A' 3 Δ u , c 1 Σ u - ). Dissociative attachment of the oxygen molecule in the ground state O 2 ( 3 Σ g - ) and the metastable oxygen molecule O 2 (a 1 Δ g ) are the dominating channels for creation of the negative oxygen ion O - . At high pressures, dissociative attachment of the Herzberg states contributes significantly to the creation of the negative oxygen ion, O - . The detachment by a collision of the metastable oxygen molecule O 2 (b 1 Σ g + ) with the oxygen ion, O - , is a significant loss process for the O - at pressures above 10 mTorr. Its contribution to the loss is more significant at a lower applied power, but at the higher pressures it is always significant. Detachment by collision with O( 3 P) is also an important loss mechanism for O - . We find that ion-ion recombination is the dominating loss process for negative ions in oxygen discharges at low pressures and calculate the critical pressure where the contributions of recombination reactions and detachment reactions are equal. This critical pressure depends on the applied power, increases with applied power and is in the range 5-14 mTorr in the pressure and power range investigated

  14. Ion structure and sequence of ion formation in acetylene flames

    Energy Technology Data Exchange (ETDEWEB)

    Larionova, I.A.; Fialkov, B.S.; Kalinich, K.YA.; Fialkov, A.B.; Ospanov, B.S.

    1993-06-01

    Results of a study of the ion composition of acetylene-air flames burning at low pressures are reported. Data on ion formation are compared for flames of saturated hydrocarbons, oxygen-containing fuels, and acetylene. It is shown that the characteristics of ion formation in the flame front and directly ahead of it are similar to those observed in flames of other fuels. These characteristics, however, are different in the low-temperature region. 9 refs.

  15. Relativisitic heavy ion collisions

    International Nuclear Information System (INIS)

    Tannenbaum, M.J.

    1987-01-01

    Some of the objectives and observables of Relativistic Heavy Ion Physics are presented. The first experimental results from oxygen interactions at CERN, 200 GeV/c per nucleon, and BNL, 14.5 GeV/c per nucleon are shown. The data indicate more energy emission than was originally predicted. 25 refs., 19 figs

  16. Food preservation by irradiation

    International Nuclear Information System (INIS)

    Gottschalk, M.

    1978-01-01

    In November, 1977, an International Symposium on Food Preservation by Irradiation was held at Wageningen, the Netherlands. About 200 participants attended the Symposium which was organised by the International Atomic Energy Agency, the Food and Agriculture Organization of the United Nations and the World Health Organization; a reflection of the active interest which is being shown in food irradiation processing, particularly among developing countries. The 75 papers presented provided an excellent review of the current status of food irradiation on a wide range of different topics, and the Symposium also afforded the valuable opportunity for informal discussion among the participants and for developing personal contacts. A brief survey of the salient aspects discussed during the course of the meeting are reported on. (orig.) [de

  17. Oxidized graphene as an electrode material for rechargeable metal-ion batteries – a DFT point of view

    International Nuclear Information System (INIS)

    Dobrota, Ana S.; Pašti, Igor A.; Skorodumova, Natalia V.

    2015-01-01

    Graphical abstract: - Abstract: In line with a growing interest in the use of graphene-based materials for energy storage applications and active research in the field of rechargeable metal-ion batteries we have performed a DFT based computational study of alkali metal atoms (Li, Na and K) interaction with an oxidized graphene. The presence of oxygen surface groups (epoxy and hydroxyl) alters the chemisorption properties of graphene. In particular, we observe that the epoxy groups are redox active and enhance the alkali metal adsorption energies by a factor of 2 or more. When an alkali metal atom interacts with hydroxyl-graphene the formation of metal-hydroxide is observed. In addition to a potential boost of metal ion storage capability, oxygen functional groups also prevent the precipitation of the metal phase. By simulating lithiation/de-lithiation process on epoxy-graphenes, it was concluded that the oxidized graphene can undergo structural changes during battery operation. Our results suggest that the content and the type of oxygen surface groups should be carefully tailored to maximize the performance of metal-ion batteries. This is mainly related to the control of the oxidation level in order to provide enough active centers for metal ion storage while preserving sufficient electrical conductivity

  18. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... Provider Pocket Guides Provider Guides Fertility Preservation for Women Diagnosed with Cancer Fertility Preservation for Men Diagnosed ... Patient Pocket Guides Patient Guides Fertility Preservation for Women Diagnosed with Cancer Fertility Preservation for Men Diagnosed ...

  19. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... for Women Diagnosed with Cancer Fertility Preservation for Men Diagnosed with Cancer Fertility Preservation for Children Diagnosed ... for Women Diagnosed with Cancer Fertility Preservation for Men Diagnosed with Cancer Fertility Preservation for Children Diagnosed ...

  20. Oxygen Reduction on Platinum

    DEFF Research Database (Denmark)

    Nesselberger, Markus

    . The influence of the ion adsorption strength, which is observed in the “particle size studies” on the oxygen reduction rate on Pt/C catalysts, is further investigated under similar reaction conditions by infrared spectroscopy. The designed in situ electrochemical ATR-FTIR setup features a high level...... of instrument automation and online data treatment, and provides welldefined mass transport conditions enabling kinetic measurements. A modified electrochemical / spectroscopic interface is presented allowing the exclusive investigation of the Pt/C catalyst layer. Three types of potential dependent adsorption...... adsorption on Pt does not block the ORR directly. Instead, the onset of oxide formation with the concomitant conversion of the anion adsorbate layer is the decisive blocking mechanism....

  1. Ebselen Preserves Tissue-Engineered Cell Sheets and their Stem Cells in Hypothermic Conditions.

    Science.gov (United States)

    Katori, Ryosuke; Hayashi, Ryuhei; Kobayashi, Yuki; Kobayashi, Eiji; Nishida, Kohji

    2016-12-14

    Clinical trials have been performed using autologous tissue-engineered epithelial cell sheets for corneal regenerative medicine. To improve stem cell-based therapy for convenient clinical practice, new techniques are required for preserving reconstructed tissues and their stem/progenitor cells until they are ready for use. In the present study, we screened potential preservative agents and developed a novel medium for preserving the cell sheets and their stem/progenitor cells; the effects were evaluated with a luciferase-based viability assay. Nrf2 activators, specifically ebselen, could maintain high ATP levels during preservation. Ebselen also showed a strong influence on maintenance of the viability, morphology, and stem cell function of the cell sheets preserved under hypothermia by protecting them from reactive oxygen species-induced damage. Furthermore, ebselen drastically improved the preservation performance of human cornea tissues and their stem cells. Therefore, ebselen shows good potential as a useful preservation agent in regenerative medicine as well as in cornea transplantation.

  2. Preserving Employee Privacy in Wellness.

    Science.gov (United States)

    Terry, Paul E

    2017-07-01

    The proposed "Preserving Employee Wellness Programs Act" states that the collection of information about the manifested disease or disorder of a family member shall not be considered an unlawful acquisition of genetic information. The bill recognizes employee privacy protections that are already in place and includes specific language relating to nondiscrimination based on illness. Why did legislation expressly intending to "preserve wellness programs" generate such antipathy about wellness among journalists? This article argues that those who are committed to preserving employee wellness must be equally committed to preserving employee privacy. Related to this, we should better parse between discussions and rules about commonplace health screenings versus much less common genetic testing.

  3. Ion-ion collisions

    International Nuclear Information System (INIS)

    Salzborn, Erhard; Melchert, Frank

    2000-01-01

    Collisions between ions belong to the elementary processes occurring in all types of plasmas. In this article we give a short overview about collisions involving one-electron systems. For collisions involving multiply-charged ions we limit the discussion to one specific quasi-one-electron system. (author)

  4. Measuring the oxygen profile and permeation flux across an ion transport KAUST Repository

    Hunt, Anton; Dimitrakopoulos, Georgios; Kirchen, Patrick; Ghoniem, Ahmed F.

    2014-01-01

    A novel ion transport membrane laboratory reactor is introduced which can sample gases at the La0.9Ca0.1FeO3 -δ membrane surface at high temperature flux conditions. Experimental data (spatial profiles and operating condition sensitivity) is presented and used to validate detailed 1D and 2D numerical models under inert (CO2 sweep) operating conditions; the numerical models account for mass transfer resistances to the membrane surface. Bypassing the mass transfer resistances experimentally allows for direct parameterization of a three resistance oxygen flux model; a unique solution method based on bespoke experimental datasets to find surface exchange reaction rate constants is demonstrated. Membrane operating regimes and oxygen off-stoichiometric coefficients can thus be determined highlighting the importance of surface exchange studies and the obvious requirement to reduce sweep surface P O2 through oxyfuel reaction integration and/or flow field adjustments. A more complex first-order flux model is also proposed and tested incorporating the surface oxygen ion concentrations in the surface exchange reactions; this is found to give similar material parameters to the simpler zero-order model studied in the literature for this particular case. © 2014 Elsevier B.V.

  5. Measuring the oxygen profile and permeation flux across an ion transport KAUST Repository

    Hunt, Anton

    2014-10-01

    A novel ion transport membrane laboratory reactor is introduced which can sample gases at the La0.9Ca0.1FeO3 -δ membrane surface at high temperature flux conditions. Experimental data (spatial profiles and operating condition sensitivity) is presented and used to validate detailed 1D and 2D numerical models under inert (CO2 sweep) operating conditions; the numerical models account for mass transfer resistances to the membrane surface. Bypassing the mass transfer resistances experimentally allows for direct parameterization of a three resistance oxygen flux model; a unique solution method based on bespoke experimental datasets to find surface exchange reaction rate constants is demonstrated. Membrane operating regimes and oxygen off-stoichiometric coefficients can thus be determined highlighting the importance of surface exchange studies and the obvious requirement to reduce sweep surface P O2 through oxyfuel reaction integration and/or flow field adjustments. A more complex first-order flux model is also proposed and tested incorporating the surface oxygen ion concentrations in the surface exchange reactions; this is found to give similar material parameters to the simpler zero-order model studied in the literature for this particular case. © 2014 Elsevier B.V.

  6. Sterilization by oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Adir Jose; Mansano, Ronaldo Domingues; Andreoli Pinto, Terezinha de Jesus; Ruas, Ronaldo; Silva Zambon, Luis da; Silva, Monica Valero da; Verdonck, Patrick Bernard

    2004-07-31

    The use of polymeric medical devices has stimulated the development of new sterilization methods. The traditional techniques rely on ethylene oxide, but there are many questions concerning the carcinogenic properties of the ethylene oxide residues adsorbed on the materials after processing. Another common technique is the gamma irradiation process, but it is costly, its safe operation requires an isolated site and it also affects the bulk properties of the polymers. The use of a gas plasma is an elegant alternative sterilization technique. The plasma promotes an efficient inactivation of the micro-organisms, minimises the damage to the materials and presents very little danger for personnel and the environment. Pure oxygen reactive ion etching type of plasmas were applied to inactivate a biologic indicator, the Bacillus stearothermophilus, to confirm the efficiency of this process. The sterilization processes took a short time, in a few minutes the mortality was complete. In situ analysis of the micro-organisms' inactivating time was possible using emission spectrophotometry. The increase in the intensity of the 777.5 nm oxygen line shows the end of the oxidation of the biologic materials. The results were also observed and corroborated by scanning electron microscopy.

  7. Nuclear knowledge preservation

    International Nuclear Information System (INIS)

    Bettencourt, Marcia Pires da Luz

    2009-01-01

    The nuclear technology has encouraged the world development and brought a number of benefits to society. These benefits occurred in important social sectors such as Agriculture, Industry, Health Sciences, Environmental Sciences and the production of energy. The research in the nuclear area is justified, accordingly, as an important factor for science development, technology and innovation. Despite the importance of nuclear energy, there is a collapse in the generation, transmission and sharing of nuclear knowledge. The threat of regression in this area is evidenced by the difficulty of generating new knowledge and practices regarding the maintenance of some critical areas. This project focuses its attention on studying, specifically, the lack of young engineers and technical professionals to replace the older, considered this, an alarming situation. Therefore, it is necessary to identify and record the key skills of experienced workers, through a set of tools to elicitation (capture) this knowledge, as expertise is mainly with people, and is lost when they leave the organization. Against, the Knowledge Management provides methodologies for the process of stimulating the creation, collection and knowledge dissemination process, in order to achieve strategic objectives. This study aims to contribute to the building of a model for the Brazilian nuclear knowledge preservation and, therefore, contributes to the maintenance and innovation of activities in this area. (author)

  8. User Experience and Heritage Preservation

    Science.gov (United States)

    Orfield, Steven J.; Chapman, J. Wesley; Davis, Nathan

    2011-01-01

    In considering the heritage preservation of higher education campus buildings, much of the attention gravitates toward issues of selection, cost, accuracy, and value, but the model for most preservation projects does not have a clear method of achieving the best solutions for meeting these targets. Instead, it simply relies on the design team and…

  9. Production of an accelerated oxygen-14 beam

    CERN Document Server

    Powell, J; Cerny, J

    2003-01-01

    BEARS is an ongoing project to provide a light-ion radioactive-beam capability at the 88-Inch Cyclotron at LBNL. Light radioactive isotopes are produced at a 10 MeV proton medical cyclotron, transported 350 m via a high-speed gas transport capillary, cryogenically separated, and injected into the 88-Inch Cyclotron's ion source. The first radioactive beam successfully accelerated was carbon-11 and beams of intensity more than 10 sup 8 ions/s have been utilized for experiments. Development of oxygen-14 as the second BEARS beam presented considerable technical challenges, both due to its short half-life of 71 s and the radiation chemistry of oxygen in the target. The usual techniques developed for medical uses of oxygen-15 involve the addition of significant amounts of carrier oxygen, something that would overload the ion source. As a solution, oxygen-14 is produced as water in a carrier-free form, and is chemically converted in two steps to carbon dioxide, a form readily usable by the BEARS. This system has bee...

  10. Exercise physiology in heart failure and preserved ejection fraction.

    Science.gov (United States)

    Haykowsky, Mark J; Kitzman, Dalane W

    2014-07-01

    Recent advances in the pathophysiology of exercise intolerance in patients with heart failure with preserved ejection fraction (HFPEF) suggest that noncardiac peripheral factors contribute to the reduced peak V(o2) (peak exercise oxygen uptake) and to its improvement after endurance exercise training. A greater understanding of the peripheral skeletal muscle vascular adaptations that occur with physical conditioning may allow for tailored exercise rehabilitation programs. The identification of specific mechanisms that improve whole body and peripheral skeletal muscle oxygen uptake could establish potential therapeutic targets for medical therapies and a means to follow therapeutic response. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Effect of melatonin on kidney cold ischemic preservation injury

    Science.gov (United States)

    Aslaner, Arif; Gunal, Omer; Turgut, Hamdi Taner; Celik, Erdal; Yildirim, Umran; Demirci, Rojbin Karakoyun; Gunduz, Umut Riza; Calis, Hasan; Dogan, Sami

    2013-01-01

    Melatonin is a potent free radical scavenger of reactive oxygen species, nitric oxide synthase inhibitor and a well-known antioxidant secreted from pineal gland. This hormone has been reported to protect tissue from oxidative damage. In this study, we aim to investigate the effect of melatonin on kidney cold ischemia time when added to preservation solution. Thirty male Wistar albino rats were divided equally into three groups; Ringer Lactate (RL) solution, University of Wisconsin (UW) solution with and without melatonin. The serum Lactate Dehydrogenase (LDH) activities of the preservation solutions at 2nd, 24th, 36th, and 48th hours were determined. Tissue malondialdehyde (MDA) levels were also measured and a histological examination was performed at 48th hour. Melatonin that added to preservation solution prevented enzyme elevation and decreased lipid peroxidation in preservation solution when compared to the control group (p<0.05). The histological examination revealed that UW solution containing melatonin significantly prevented the kidney from pathological injury (p<0.05). Melatonin added to preservation solutions such as UW solution seemed to protect the tissue preserved effectively from cold ischemic injury for up to 48 hour. PMID:24179573

  12. Contact dermatitis caused by preservatives.

    Science.gov (United States)

    Yim, Elizabeth; Baquerizo Nole, Katherine L; Tosti, Antonella

    2014-01-01

    Preservatives are biocidal chemicals added to food, cosmetics, and industrial products to prevent the growth of microorganisms. They are usually nontoxic and inexpensive and have a long shelf life. Unfortunately, they commonly cause contact dermatitis. This article reviews the most important classes of preservatives physicians are most likely to encounter in their daily practice, specifically isothiazolinones, formaldehyde and formaldehyde-releasers, iodopropynyl butylcarbamate, methyldibromoglutaronitrile, and parabens. For each preservative mentioned, the prevalence of sensitization, clinical presentation of contact dermatitis, patch testing concentrations, cross reactions, and related legislation will be discussed. Mandatory labeling of preservatives is required in some countries, but not required in others. Until policies are made, physicians and patients must be proactive in identifying potential sensitizers and removing their use. We hope that this article will serve as a guide for policy makers in creating legislation and future regulations on the use and concentration of certain preservatives in cosmetics and industrial products.

  13. Measurement of negative ion mobilities in O2 and O3 mixtures at atmospheric pressure

    International Nuclear Information System (INIS)

    Itoh, H.; Norimoto, K.; Hayashi, T.

    1998-01-01

    Mobility measurements of negative molecular oxygen ions in pure oxygen and in an oxygen-ozone mixture are reported. A cascaded gap consisting of an ion drift gap and an ion detection gap was used in the experiment. The ion detection gap was formed by a positive point and a grounded plane electrode was operated at atmospheric pressure. The zero field mobility of negative molecular oxygen ions was determined to be 2.07+-0.02 cm 2 /V.s. A somewhat higher value of oxygen mobility was found at higher electric field/pressure ratios; this is presumed to be due to negative ozone ions. When changing the electric field/pressure ratio the mobility of negative oxygen ions in oxygen-ozone mixtures becomes smaller than that in pure oxygen; this is probably due to the cumulative effect of other particles produced by silent discharges. (J.U.)

  14. Binding energies of cluster ions

    International Nuclear Information System (INIS)

    Parajuli, R.; Matt, S.; Scheier, P.; Echt, O.; Stamatovic, A.; Maerk, T.D.

    2002-01-01

    The binding energy of charged clusters may be measured by analyzing the kinetic energy released in the metastable decay of mass selected parent ions. Using finite heat bath theory to determine the binding energies of argon, neon, krypton, oxygen and nitrogen from their respective average kinetic energy released were carried out. A high-resolution double focussing two-sector mass spectrometer of reversed Nier-Johnson type geometry was used. MIKE ( mass-analysed ion kinetic energy) were measured to investigate decay reactions of mass-selected ions. For the inert gases neon (Ne n + ), argon (Ar n + ) and krypton (Kr n + ), it is found that the binding energies initially decrease with increasing size n and then level off at a value above the enthalpy of vaporization of the condensed phase. Oxygen cluster ions shown a characteristic dependence on cluster size (U-shape) indicating a change in the metastable fragmentation mechanism when going from the dimer to the decamer ion. (nevyjel)

  15. Hot oxygen atoms: Their generation and chemistry

    International Nuclear Information System (INIS)

    Ferrieri, R.A.; Chu, Yung Y.; Wolf, A.P.

    1987-01-01

    Oxygen atoms with energies between 1 and 10 eV have been produced through ion beam sputtering from metal oxide targets. Argon ion beams were used on Ta 2 O 5 and V 2 O 5 . Results show that some control may be exerted over the atom's kinetic energy by changing the target. Reactions of the hot O( 3 P) with cis- and trans-butenes were investigated

  16. Ion implantation

    International Nuclear Information System (INIS)

    Dearnaley, Geoffrey

    1975-01-01

    First, ion implantation in semiconductors is discussed: ion penetration, annealing of damage, gettering, ion implanted semiconductor devices, equipement requirements for ion implantation. The importance of channeling for ion implantation is studied. Then, some applications of ion implantation in metals are presented: study of the corrosion of metals and alloys; influence or ion implantation on the surface-friction and wear properties of metals; hyperfine interactions in implanted metals

  17. Effect of melatonin on kidney cold ischemic preservation injury

    OpenAIRE

    Aslaner, Arif; Gunal, Omer; Turgut, Hamdi Taner; Celik, Erdal; Yildirim, Umran; Demirci, Rojbin Karakoyun; Gunduz, Umut Riza; Calis, Hasan; Dogan, Sami

    2013-01-01

    Melatonin is a potent free radical scavenger of reactive oxygen species, nitric oxide synthase inhibitor and a well-known antioxidant secreted from pineal gland. This hormone has been reported to protect tissue from oxidative damage. In this study, we aim to investigate the effect of melatonin on kidney cold ischemia time when added to preservation solution. Thirty male Wistar albino rats were divided equally into three groups; Ringer Lactate (RL) solution, University of Wisconsin (UW) soluti...

  18. Dopamine improves hypothermic machine preservation of the liver.

    Science.gov (United States)

    Minor, Thomas; Lüer, Bastian; Efferz, Patrik

    2011-10-01

    Hypothermic machine preservation (HMP) is currently reconsidered as alternative to standard cold storage of organs from non-heart-beating donors. The present study was aimed at investigating the possible synergistic effect of HMP and the addition of dopamine to the circulating perfusate during preservation. Cardiac arrest was induced in male Wistar rats (250-300 g) by phrenotomy. Thirty minutes later livers were flushed via the portal vein and subjected to 20 h of HMP at 5ml/min at 4°C. During HMP the preservation solution was equilibrated with 100% oxygen and dopamine was added at 0, 10, 50 or 100 μM (D0, D10, D50, D100; n=6 resp.). Graft viability was assessed thereafter upon warm reperfusion in vitro for 2h. During HMP, D50 and D100 significantly reduced hepatic release of ALT to about 50%. No influence of dopamine was found on vascular resistance, oxygen uptake or lactate production at any concentration. D50 significantly reduced enzyme release during reperfusion (∼50%), enhanced bile flow and oxygen consumption. D10 was less effective while D100 even rose enzyme release compared with D0. Enhanced oxygen free radical mediated lipid peroxidation (LPO), found in the tissue of D0 livers was significantly reduced by D50; D50 significantly abrogated molecular upregulation of vWillebrand factor upon reperfusion suggesting vascular protection of the endothelial cell. Efficiency of HMP might be increased by stimulating livers with dopamine during ex vivo preservation, limiting vascular side effects and improving functional recovery upon early reperfusion. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Food preservation by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-02-15

    As shortages of food and energy still continue to constitute the major threats to the well-being of the human race, all actions aiming at overcoming these problems must be assigned vital importance. Of the two complementary ways of solving the food problem (i.e., increasing the production of food and decreasing the spoilage of food) a novel method designed to contribute to the latter purpose has been discussed at this symposium hosted by The Netherlands and held under the aegis of the Food and Agriculture Organization of the United Nations, the International Atomic Energy Agency and the World Health Organization. Progress made since the last symposium of this kind (Bombay, India, 1972) was reviewed from the technological, economic and wholesomeness points of view by participants from 39 countries (60% of the latter were of the developing world). From the reports presented on the use of radiations to control physiological changes in plants, feasibility of radiation preservation of potatoes, onions, garlic, as well as of some tropical and subtropical fruits (mangoes, papayas, litchis and avocado) was confirmed. For potatoes, onions and mangoes, optimal conditions of treatment and storage were established on a larger scale, combined with sizeable consumer trials. Combinations of ionizing radiation with chemicals (salycilic acid, for potatoes), and physical agents (ultraviolet rays, for papayas) have been reported to be successful against the incidence of rot. A considerable number of papers dealt with the control of microbiological spoilage of foods. Work since 1972 has shown that radurization of fruits and vegetables (bananas, mangoes, dried dates, endive, chickory, onions, soup-greens), meat, poultry, marine products (mackerel, cod and plaice fillets, shrimps), decontamination of food ingredients and food technology aids (enzyme preparations, proteins, starch, spices), radappertization of meat and animal feedstuffs as well as combination treatments with salt, heat

  20. Food preservation by irradiation

    International Nuclear Information System (INIS)

    1978-01-01

    As shortages of food and energy still continue to constitute the major threats to the well-being of the human race, all actions aiming at overcoming these problems must be assigned vital importance. Of the two complementary ways of solving the food problem (i.e., increasing the production of food and decreasing the spoilage of food) a novel method designed to contribute to the latter purpose has been discussed at this symposium hosted by The Netherlands and held under the aegis of the Food and Agriculture Organization of the United Nations, the International Atomic Energy Agency and the World Health Organization. Progress made since the last symposium of this kind (Bombay, India, 1972) was reviewed from the technological, economic and wholesomeness points of view by participants from 39 countries (60% of the latter were of the developing world). From the reports presented on the use of radiations to control physiological changes in plants, feasibility of radiation preservation of potatoes, onions, garlic, as well as of some tropical and subtropical fruits (mangoes, papayas, litchis and avocado) was confirmed. For potatoes, onions and mangoes, optimal conditions of treatment and storage were established on a larger scale, combined with sizeable consumer trials. Combinations of ionizing radiation with chemicals (salycilic acid, for potatoes), and physical agents (ultraviolet rays, for papayas) have been reported to be successful against the incidence of rot. A considerable number of papers dealt with the control of microbiological spoilage of foods. Work since 1972 has shown that radurization of fruits and vegetables (bananas, mangoes, dried dates, endive, chickory, onions, soup-greens), meat, poultry, marine products (mackerel, cod and plaice fillets, shrimps), decontamination of food ingredients and food technology aids (enzyme preparations, proteins, starch, spices), radappertization of meat and animal feedstuffs as well as combination treatments with salt, heat

  1. Autoionizing states in highly ionized oxygen, fluorine and silicon

    International Nuclear Information System (INIS)

    Forester, J.P.; Peterson, R.S.; Griffin, P.M.; Pegg, D.J.; Haselton, H.H.; Liao, K.H.; Sellin, I.A.; Mowat, J.R.; Thoe, R.S.

    1975-01-01

    Autoionizing states in high Z 3-electron ions associated with core excited configurations of the type 1s2snl and 1s2pnl are reported. The electron decay-in-flight spectra of lithium-like oxygen, fluorine, and silicon ions are presented. Initial beam energies of 6.75-MeV oxygen and fluorine ions and 22.5-MeV silicon ions were used. Stripping and excitation were done by passing the beams through a thin carbon foil. The experimental technique is described. 4 figs, 1 table, 7 refs

  2. Ceria Based Composite Membranes for Oxygen Separation

    DEFF Research Database (Denmark)

    Gurauskis, Jonas; Ovtar, Simona; Kaiser, Andreas

    2014-01-01

    Mixed ionic-electronic conducting membranes for oxygen gas separation are attracting a lot of interest due to their promising potential for the pure oxygen and the syngas production. Apart from the need for a sufficiently high oxygen permeation fluxes, the prolonged stability of these membranes...... under the large oxygen potential gradients at elevated temperatures is decisive for the future applications. The gadolinium doped cerium oxide (CGO) based composite membranes are considered as promising candidates due to inherent stability of CGO phase. The CGO matrix is a main oxygen ion transporter......; meanwhile the primary role of a secondary phase in this membrane is to compensate the low electronic conductivity of matrix at intended functioning conditions. In this work thin film (15-20 μm) composite membranes based on CGO matrix and LSF electronic conducting phase were fabricated and evaluated...

  3. Contamination versus preservation of cosmetics

    DEFF Research Database (Denmark)

    Lundov, Michael Dyrgaard; Moesby, Lise; Zachariae, Claus

    2009-01-01

    Cosmetics with high water content are at a risk of being contaminated by micro-organisms that can alter the composition of the product or pose a health risk to the consumer. Pathogenic micro-organisms such as Staphylococcus aureus and Pseudomonas aeruginosa are frequently found in contaminated...... cosmetics. In order to avoid contamination of cosmetics, the manufacturers add preservatives to their products. In the EU and the USA, cosmetics are under legislation and all preservatives must be safety evaluated by committees. There are several different preservatives available but the cosmetic market...

  4. Oxygen flooding and sample cooling during depth profiling of HfSiON thin films

    Energy Technology Data Exchange (ETDEWEB)

    Miwa, Shiro [Materials Analysis Center, Materials Laboratories, Sony Corporation, 4-16-1 Okata, Atsugi 243-0021 (Japan)], E-mail: Shiro.Miwa@jp.sony.com

    2008-12-15

    A combination of oxygen flooding and. Cs primary ion bombardment can suppress the enhancement of the secondary ion signal at the surface and at the interface of a thin HfSiON layer on a Si substrate. The surface concentration of both Cs and O during Cs primary ion bombardment with oxygen flooding was higher than that without oxygen flooding, as confirmed by X-ray photoelectron spectroscopy. When the sample was cooled to about -150 deg. C, the enhancement of the secondary ion signal could be suppressed at a lower oxygen pressure.

  5. Polarization preservation and control in a figure-8 ring

    Energy Technology Data Exchange (ETDEWEB)

    Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Lin, Fanglei [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Kondratenko, A. M. [GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058; Kondratenko, M. A. [GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058; Filatov, Yuri [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); GOO Zaryad, Russkaya st., 41, Novosibirsk, 630058

    2016-02-01

    We present a complete scheme for managing the polarization of ion beams in Jefferson Lab's proposed Medium-energy Electron-Ion Collider (MEIC). It provides preservation of the ion polarization during all stages of beam acceleration and polarization control in the collider's experimental straights. We discuss characteristic features of the spin motion in accelerators with Siberian snakes and in accelerators of figure-8 shape. We propose 3D spin rotators for polarization control in the MEIC ion collider ring. We provide polarization calculations in the collider with the 3D rotator for deuteron and proton beams. The main polarization control features of the figure-8 design are summarized.

  6. Theory and measurements of emittance preservation in plasma wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Frederico, Joel

    2016-12-01

    In this dissertation, we examine the preservation and measurement of emittance in the plasma wakefield acceleration blowout regime. Plasma wakefield acceleration (PWFA) is a revolutionary approach to accelerating charged particles that has been demonstrated to have the potential for gradients orders of magnitude greater than traditional approaches. The application of PWFA to the design of a linear collider will make new high energy physics research possible, but the design parameters must first be shown to be competitive with traditional methods. Emittance preservation is necessary in the design of a linear collider in order to maximize luminosity. We examine the conditions necessary for circular symmetry in the PWFA blowout regime, and demonstrate that current proposals meet these bounds. We also present an application of beam lamentation which describes the process of beam parameter and emittance matching. We show that the emittance growth saturates as a consequence of energy spread in the beam. The initial beam parameters determine the amount of emittance growth, while the contribution of energy spread is negligible. We also present a model for ion motion in the presence of a beam that is much more dense than the plasma. By combining the model of ion motion and emittance growth, we find the emittance growth due to ion motion is minimal in the case of marginal ion motion. In addition, we present a simulation that validates the ion motion model, which is under further development to examine emittance growth of both marginal and pronounced ion motion. Finally, we present a proof-of-concept of an emittance measurement which may enable the analysis of emittance preservation in future PWFA experiments.

  7. Federal Support for Preserve America

    Science.gov (United States)

    Mississippi's Heritage Tourism Industry Post Hurricane Katrina also received a $150,000 Preserve America Grant Arkansas Delta, one for music, one for African-American history, and one for agriculture. The project will

  8. Cultural Preservation Program for Alaska

    Science.gov (United States)

    Barbaran, Francisco Ramon

    2011-01-01

    In this technical report, an innovative cultural preservation program for implementation in Athabascan villages is presented. The parameters for success in implementing such a project is discussed based on a workshop with Athabascan elders.

  9. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... options further? Fertility Preservation - Where Does It Fit? Options for Fertility Preservation The following diagram gives a brief description of fertility preservation options available to children diagnosed with cancer before and ...

  10. Hereditary History Preserving Bisimilarity Is Undecidable

    DEFF Research Database (Denmark)

    Jurdzinski, Marcin; Nielsen, Mogens

    2000-01-01

    History preserving bisimilarity (hp-bisimilarity) and hereditary history preserving bisimilarity (hhp-bisimilarity) are behavioural equivalences taking into account causal relationships between events of concurrent systems. Their prominent feature is being preserved under action refinement...

  11. Fertility Preservation for Children Diagnosed with Cancer

    Science.gov (United States)

    ... Skip to main content SaveMyFertility An Online Fertility Preservation Toolkit for Patients and Their Providers Open menu ... with Cancer You are here Home » Patients Fertility Preservation for Children Diagnosed with Cancer Fertility Preservation for ...

  12. Oxygen depletion of bismuth molybdates

    Energy Technology Data Exchange (ETDEWEB)

    Yong, L.K.; Howe, R.F.; Keulks, G.W.; Hall, W.K.

    1978-05-01

    Pure ..cap alpha..-phase bismuth molybdate (Bi/sub 2/Mo/sub 3/O/sub 12/), which is known to be weakly active for selective oxidation, and pure ..gamma..-phase bismuth molybdate (Bi/sub 2/MoO/sub 6/), which has good activity, were subjected to oxidation-reduction cycles with known amounts of hydrogen and oxygen, at 300/sup 0/-570/sup 0/C and with evacuation steps between treatments. The volume of oxygen consumed during reoxidation was equal to half the hydrogen consumed during the reduction on the ..cap alpha..-phase, which indicated that no hydrogen was retained during reduction. For the ..gamma..-phase, the oxygen consumption was greater than half of the hydrogen consumption and it increased with extent of reduction. The excess oxygen was apparently consumed by filling anion vacancies formed during outgassing subsequent to the reduction step. ESR spectroscopy and temperature-programed oxidation-reduction indicated that lattice oxide ions which bridge between bismuth and molybdenum layers of the koechlinite structure become more labile when the catalyst is in a partially reduced state, and that this effect is greater in the ..gamma..- than the ..cap alpha..-phase. Table and 15 references.

  13. Glow discharge in singlet oxygen

    International Nuclear Information System (INIS)

    Vagin, N.P.; Ionin, A.A.; Klimachev, Yu.M.; Sinitsyn, D.V.; Yuryshev, N.N.; Kochetov, I.V.; Napartovich, A.P.

    2003-01-01

    Currently, there is no experimental data on the plasma balance in gas mixtures with a high content of singlet delta oxygen O 2 ( 1 Δ g ). These data can be obtained by studying the parameters of an electric discharge in singlet oxygen produced by a chemical generator. The O 2 ( 1 Δ g ) molecules significantly change the kinetics of electrons and negative ions in plasma. Hence, the discharge conditions at low and high O 2 ( 1 Δ g ) concentrations are very different. Here, the parameters of the positive column of a glow discharge in a gas flow from a chemical singlet-oxygen generator are studied. It is experimentally shown that, at an O 2 ( 1 Δ g ) concentration of 50% and at pressures of 1.5 and 2 torr, the electric field required to sustain the discharge is considerably lower than in the case when all of the oxygen molecules are in the ground state. A theoretical model of the glow discharge is proposed whose predictions are in good agreement with the experimental data

  14. Artificial oxygen transport protein

    Science.gov (United States)

    Dutton, P. Leslie

    2014-09-30

    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.

  15. Catalyst containing oxygen transport membrane

    Science.gov (United States)

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

    2012-12-04

    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.

  16. Analyzing the dependence of oxygen incorporation current density on overpotential and oxygen partial pressure in mixed conducting oxide electrodes.

    Science.gov (United States)

    Guan, Zixuan; Chen, Di; Chueh, William C

    2017-08-30

    The oxygen incorporation reaction, which involves the transformation of an oxygen gas molecule to two lattice oxygen ions in a mixed ionic and electronic conducting solid, is a ubiquitous and fundamental reaction in solid-state electrochemistry. To understand the reaction pathway and to identify the rate-determining step, near-equilibrium measurements have been employed to quantify the exchange coefficients as a function of oxygen partial pressure and temperature. However, because the exchange coefficient contains contributions from both forward and reverse reaction rate constants and depends on both oxygen partial pressure and oxygen fugacity in the solid, unique and definitive mechanistic assessment has been challenging. In this work, we derive a current density equation as a function of both oxygen partial pressure and overpotential, and consider both near and far from equilibrium limits. Rather than considering specific reaction pathways, we generalize the multi-step oxygen incorporation reaction into the rate-determining step, preceding and following quasi-equilibrium steps, and consider the number of oxygen ions and electrons involved in each. By evaluating the dependence of current density on oxygen partial pressure and overpotential separately, one obtains the reaction orders for oxygen gas molecules and for solid-state species in the electrode. We simulated the oxygen incorporation current density-overpotential curves for praseodymium-doped ceria for various candidate rate-determining steps. This work highlights a promising method for studying the exchange kinetics far away from equilibrium.

  17. ECR ion source for variable energy cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Bose, D K; Taki, G S; Nabhiraj, P Y; Pal, G; Dasgupta, B; Mallik, C; Das, S K; Bandopadhaya, D K; Bhandari, R K [Variable Energy Cyclotron Centre, Calcutta (India)

    1995-09-01

    Some performance characteristics of 6.4 GHz two stage ECR ion source which was under development at this centre is presented. The present ion source will facilitate acceleration of light heavy ions with the existing k=130 variable energy cyclotron. Multiply charged heavy ion (MCHI) beam from the source will also be utilized for atomic physics studies. Oxygen beam has already been used for ion implantation studies. The external injection system under development is nearing completion. Heavy ion beam from cyclotron is expected by end of 1995. (author).

  18. Ex-vivo machine perfusion for kidney preservation.

    Science.gov (United States)

    Hamar, Matyas; Selzner, Markus

    2018-06-01

    Machine perfusion is a novel strategy to decrease preservation injury, improve graft assessment, and increase organ acceptance for transplantation. This review summarizes the current advances in ex-vivo machine-based kidney preservation technologies over the last year. Ex-vivo perfusion technologies, such as hypothermic and normothermic machine perfusion and controlled oxygenated rewarming, have gained high interest in the field of organ preservation. Keeping kidney grafts functionally and metabolically active during the preservation period offers a unique chance for viability assessment, reconditioning, and organ repair. Normothermic ex-vivo kidney perfusion has been recently translated into clinical practice. Preclinical results suggest that prolonged warm perfusion appears superior than a brief end-ischemic reconditioning in terms of renal function and injury. An established standardized protocol for continuous warm perfusion is still not available for human grafts. Ex-vivo machine perfusion represents a superior organ preservation method over static cold storage. There is still an urgent need for the optimization of the perfusion fluid and machine technology and to identify the optimal indication in kidney transplantation. Recent research is focusing on graft assessment and therapeutic strategies.

  19. Organic carbon production, mineralisation and preservation on the Peruvian margin

    Science.gov (United States)

    Dale, A. W.; Sommer, S.; Lomnitz, U.; Montes, I.; Treude, T.; Liebetrau, V.; Gier, J.; Hensen, C.; Dengler, M.; Stolpovsky, K.; Bryant, L. D.; Wallmann, K.

    2015-03-01

    Carbon cycling in Peruvian margin sediments (11 and 12° S) was examined at 16 stations, from 74 m water depth on the middle shelf down to 1024 m, using a combination of in situ flux measurements, sedimentary geochemistry and modelling. Bottom water oxygen was below detection limit down to ca. 400 m and increased to 53 μM at the deepest station. Sediment accumulation rates decreased sharply seaward of the middle shelf and subsequently increased at the deep stations. The organic carbon burial efficiency (CBE) was unusually low on the middle shelf (60%) at the deep oxygenated sites. In line with other studies, CBE was elevated under oxygen-deficient waters in the mid-water oxygen minimum zone. Organic carbon rain rates calculated from the benthic fluxes alluded to efficient mineralisation of organic matter in the water column compared to other oxygen-deficient environments. The observations at the Peruvian margin suggest that a lack of oxygen does not greatly affect the degradation of organic matter in the water column but promotes the preservation of organic matter in sediments.

  20. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... You are here Home » Patients Fertility Preservation for Children Diagnosed with Cancer Fertility Preservation for Children Diagnosed with Cancer Ask Your Doctor Information for ...

  1. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... Home » Patients Fertility Preservation for Children Diagnosed with Cancer Fertility Preservation for Children Diagnosed with Cancer Ask Your Doctor Information for Patients Many adult ...

  2. Cancer therapy with ions

    International Nuclear Information System (INIS)

    Mandrillon, P.

    1993-01-01

    The treatment of tumours with charged particles, ranging from protons to 'light ions' (Carbon, Oxygen, Neon) has many advantages, but up to now has been little used because of the absence of facilities. After the successful pioneering work carried out with accelerators built for physics research, machines dedicated to this new radiotherapy are planned or already in construction. The rationale for this new radiotherapy, the accelerators and the beam delivery systems needed are presented in this paper. (orig.)

  3. Etude du mecanisme de predissociation de l'ion moleculaire de protoxyde d'azote par la mesure de l'energie cinetique des fragments de l'oxyde nitrique et de l'oxygene

    Science.gov (United States)

    Delisle, Claude

    La reaction N2 + O+ ↔ NO + + N, laquelle joue un role important dans la physique de la haute atmosphere, a ete le sujet de plusieurs etudes. Bien que cette reaction ait ete l'objet d'une quantite importante de travaux, ces derniers ne permettent toutefois pas de comprendre entierement le mecanisme d'un point de vue quantique, particulierement les niveaux d'energie excites des fragments qui permettent cette reaction. Puisque cette reaction n'est pas tres facile a reproduire en laboratoire, nous avons utilise la spectroscopie laser sur faisceaux d'ions rapides afin d'explorer les limites de dissociation de l'ion moleculaire intermediaire de cette reaction, a savoir l'ion N2O+. Le faisceau d'ions N2O+ rapides, apres excitation de l'ion moleculaire vers un niveau predissocie de l'etat A2Sigma+, se dissocie pour produire les fragments ioniques O+ et NO+. Par la mesure de la variation du nombre de fragments ioniques en fonction de l'energie cinetique des ions N2O+, nous avons enregistre les spectres de predissociation de l'ion N2O+. Lorsque c'etait possible, nous avons procede a l'analyse de ces spectres de dissociation afin d'en tirer les constantes moleculaires. Pour certaines des transitions rotationnelles intenses, nous avons mesure l'energie cinetique acquise par les fragments lors de la predissociation de l'ion N 2O+. Afin d'analyser les distributions en energie cinetique, nous avons developpe une simulation de l'experience en considerant, entre autres choses, la position des niveaux de vibration et de rotation des fragments diatomiques de chacune des limites de dissociation de N2O+. Les resultats de l'analyse sont exprimes en termes de population des niveaux de vibration des fragments diatomiques pour une distribution donnee de la population des niveaux de rotation des fragments. Les resultats ainsi obtenus, montrent que les fragments diatomiques sont produits dans des niveaux de vibration fortement excites. De tels niveaux d'excitation ne correspondent pas aux

  4. Fertility preservation in Turner syndrome.

    Science.gov (United States)

    Grynberg, Michaël; Bidet, Maud; Benard, Julie; Poulain, Marine; Sonigo, Charlotte; Cédrin-Durnerin, Isabelle; Polak, Michel

    2016-01-01

    Premature ovarian insufficiency is a relatively rare condition that can appear early in life. In a non-negligible number of cases the ovarian dysfunction results from genetic diseases. Turner syndrome (TS), the most common sex chromosome abnormality in females, is associated with an inevitable premature exhaustion of the follicular stockpile. The possible or probable infertility is a major concern for TS patients and their parents, and physicians are often asked about possible options to preserve fertility. Unfortunately, there are no recommendations on fertility preservation in this group. The severely reduced follicle pool even during prepubertal life represents the major limit for fertility preservation and is the root of numerous questions regarding the competence of gametes or ovarian tissue crybanked. In addition, patients suffering from TS show higher than usual rates of spontaneous abortion, fetal anomaly, and maternal morbidity and mortality, which should be considered at the time of fertility preservation and before reutilization of the cryopreserved gametes. Apart from fulfillment of the desire of becoming genetic parents, TS patients may be potential candidates for egg donation, gestational surrogacy, and adoption. The present review discusses the different options for preserving female fertility in TS and the ethical questions raised by these approaches. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  5. Ion source with plasma cathode

    International Nuclear Information System (INIS)

    Yabe, E.

    1987-01-01

    A long lifetime ion source with plasma cathode has been developed for use in ion implantation. In this ion source, a plasma of a nonreactive working gas serves as a cathode in place of a thermionic tungsten filament used in the Freeman ion source. In an applied magnetic field, the plasma is convergent, i.e., filamentlike; in zero magnetic field, it turns divergent and spraylike. In the latter case, the plasma exhibits a remarkable ability when the working gas has an ionization potential larger than the feed gas. By any combination of a working gas of either argon or neon and a feed gas of AsF 5 or PF 5 , the lifetime of this ion source was found to be more than 90 h with an extraction voltage of 40 kV and the corresponding ion current density 20 mA/cm 2 . Mass spectrometry results show that this ion source has an ability of generating a considerable amount of As + and P + ions from AsF 5 and PF 5 , and hence will be useful for realizing a fully cryopumped ion implanter system. This ion source is also eminently suitable for use in oxygen ion production

  6. Interplay between O2 and SnO2: oxygen ionosorption and spectroscopic evidence for adsorbed oxygen.

    Science.gov (United States)

    Gurlo, Alexander

    2006-10-13

    Tin dioxide is the most commonly used material in commercial gas sensors based on semiconducting metal oxides. Despite intensive efforts, the mechanism responsible for gas-sensing effects on SnO(2) is not fully understood. The key step is the understanding of the electronic response of SnO(2) in the presence of background oxygen. For a long time, oxygen interaction with SnO(2) has been treated within the framework of the "ionosorption theory". The adsorbed oxygen species have been regarded as free oxygen ions electrostatically stabilized on the surface (with no local chemical bond formation). A contradiction, however, arises when connecting this scenario to spectroscopic findings. Despite trying for a long time, there has not been any convincing spectroscopic evidence for "ionosorbed" oxygen species. Neither superoxide ions O(2)(-), nor charged atomic oxygen O,(-) nor peroxide ions O(2)(2-) have been observed on SnO(2) under the real working conditions of sensors. Moreover, several findings show that the superoxide ion does not undergo transformations into charged atomic oxygen at the surface, and represents a dead-end form of low-temperature oxygen adsorption on reduced metal oxide.

  7. Adhesion of silver films to ion-bombarded alumina

    International Nuclear Information System (INIS)

    Erck, R.A.; Fenske, G.R.

    1990-01-01

    This paper reports on silver films deposited on alumina substrates using ion bombardment. Adhesion strength was measured as a function of deposition conditions, sputter-cleaning time, and bombarding ion species, using a pull-type adhesion tester. Argon- and argon/oxygen-ion sputtering produced large increases in adhesion strength, with the greatest increases occurring for oxygen-ion bombardment. Adhesion strength increased monotonically as a function of ion sputtering time. At a given deposition rate, further enhancement of adhesion is seen with concurrent ion bombardment

  8. Preservation theorems on finite structures

    International Nuclear Information System (INIS)

    Hebert, M.

    1994-09-01

    This paper concerns classical Preservation results applied to finite structures. We consider binary relations for which a strong form of preservation theorem (called strong interpolation) exists in the usual case. This includes most classical cases: embeddings, extensions, homomorphisms into and onto, sandwiches, etc. We establish necessary and sufficient syntactic conditions for the preservation theorems for sentences and for theories to hold in the restricted context of finite structures. We deduce that for all relations above, the restricted theorem for theories hold provided the language is finite. For the sentences the restricted version fails in most cases; in fact the ''homomorphism into'' case seems to be the only possible one, but the efforts to show that have failed. We hope our results may help to solve this frustrating problem; in the meantime, they are used to put a lower bound on the level of complexity of potential counterexamples. (author). 8 refs

  9. Blogs as Objects of Preservation

    DEFF Research Database (Denmark)

    Stepanyan, Karen; Gkotsis, George; Kalb, Hendrik

    2012-01-01

    challenge for the digital preservation community. While the methodological frameworks for selecting these properties provide a good foundation, a continued discussion is necessary for further clarifying and improving the available methods. This paper advances earlier work by building on the exist......challenge for the digital preservation community. While the methodological frameworks for selecting these properties provide a good foundation, a continued discussion is necessary for further clarifying and improving the available methods. This paper advances earlier work by building...... analysis) and, subsequently, improve the final reformulation of the properties. To demonstrate the applicability of the modified framework, the paper presents a use case of a blog preservation initiative that is informed by stakeholder interviews and evaluation of structural and technological foundations...

  10. Tuning of optical and electrical properties of wide band gap Fe:SnO{sub 2}/Li:NiO p-n junctions using 80 MeV oxygen ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Mistry, Bhaumik V.; Joshi, U.S. [Gujarat University, Department of Physics, School of Sciences, Ahmedabad (India); Avasthi, D.K. [Inter University Accelerator Centre, New Delhi (India)

    2016-12-15

    Electrical and optical properties of pristine and swift heavy ion (SHI) irradiated p-n junction diode have been investigated for advanced electronics application. Fe:SnO{sub 2}/Li:NiO p-n junction was fabricated by using pulsed laser deposition on c-sapphire substrate. The optical band gaps of Fe:SnO{sub 2} and Li:NiO films were obtained to be 3.88 and 3.37 eV, respectively. The current-voltage characteristics of the oxide-based p-n junction showed a rectifying behaviour with turn-on voltage of 0.95 V. The oxide-based p-n junction diode was irradiated to 80 MeV O{sup +6} ions with 1 x 10{sup 12} ions/cm{sup 2} fluence. Decrease in grain size due to SHI irradiation is confirmed by the grazing angle X-ray diffraction and atomic force microscopy. In comparison with the pristine p-n junction diode, O{sup +6} ion irradiated p-n junction diode shows the increase of surface roughness and decrease of percentage transmittance in visible region. For irradiated p-n junction diode, current-voltage curve has still rectifying behaviour but exhibits lower turn-on voltage than that of virgin p-n junction diode. (orig.)

  11. Active preservation - otherwise no archives

    International Nuclear Information System (INIS)

    Norberg, E.

    1996-01-01

    The role and history of national and regional archives in Sweden is discussed. It is noted that large portions of our cultural heritage can not be set aside for long-term preservation due to several facts: Some events are never documented, Important records are never set aside, Important information is stored on media that are not suitable for long-term preservation, Information can not be accessed due to inadequate search aids, Eliminations are made due to lack of space. Strategies for an action plan to save valuable material are briefly outlined, and the importance of international cooperation is stressed

  12. Yeasts preservation: alternatives for lyophilisation

    OpenAIRE

    Nyanga, Loveness K.; Nout, Martinus J. R.; Smid, Eddy J.; Boekhout, Teun; Zwietering, Marcel H.

    2012-01-01

    The aim of the study was to compare the effect of two low-cost, low technology traditional methods for drying starter cultures with standard lyophilisation. Lyophilised yeast cultures and yeast cultures preserved in dry rice cakes and dry plant fibre strands were examined for viable cell counts during 6 months storage at 4 and 25 °C. None of the yeast cultures showed a significant loss in viable cell count during 6 months of storage at 4 °C upon lyophilisation and preservation in dry rice cak...

  13. Polarization-preserving holey fibers

    DEFF Research Database (Denmark)

    Broeng, Jes; Mogilevtsev, Dmitri; Libori, Stig E. Barkou

    2001-01-01

    In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization......In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization...

  14. Active preservation - otherwise no archives

    Energy Technology Data Exchange (ETDEWEB)

    Norberg, E [National Swedish Archives, Stockholm (Sweden)

    1996-12-01

    The role and history of national and regional archives in Sweden is discussed. It is noted that large portions of our cultural heritage can not be set aside for long-term preservation due to several facts: Some events are never documented, Important records are never set aside, Important information is stored on media that are not suitable for long-term preservation, Information can not be accessed due to inadequate search aids, Eliminations are made due to lack of space. Strategies for an action plan to save valuable material are briefly outlined, and the importance of international cooperation is stressed.

  15. 36 CFR 910.32 - Historic preservation.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Historic preservation. 910.32... DEVELOPMENT AREA Standards Uniformly Applicable to the Development Area § 910.32 Historic preservation... Preservation Plan of the Corporation, are specified for preservation, shall be acomplished (a) in accordance...

  16. ACHP | Summary of the Preserve America Initiative

    Science.gov (United States)

    Initiative Preserve America: Explore and Enjoy Our Heritage (logo) Summary of the Preserve America Initiative Preserve America is a White House initiative that encourages and supports community efforts to preserve and enjoy our priceless cultural and natural heritage. The goals of the initiative include a greater shared

  17. Transport of Alkali Metal Ions through a Liquid Membrane System ...

    African Journals Online (AJOL)

    crown-6, [K(MF18C6)](picrate) was determined by X-ray crystallography and showed that each potassium ion is eight-coordinate; each K+ ion is coordinated to the six oxygen atoms of the crown, to the phenolate oxygen atom and to one of the ...

  18. Comparison of Tissue Preservation using Formalin and Ethanol as Preservative Formula

    OpenAIRE

    See Woan Shian; Arifin Soenggono; Sawkar Vijay Pramod

    2016-01-01

    Background: Tissue preservation can be performed through embalming, by providing the chemical embalming fluid to the human remains. Formalin’s preservative formula is the foundation for modern methods of embalming. Unfortunately, this preservative formula has several disadvantages. While Ethanol’s preservative formula is a considerable agent to replace formalin’s preservative formula. The aim of this study was to compare the tissue preservation using formalin and ethanol as preservative formu...

  19. Local quantum channels preserving classical correlations

    International Nuclear Information System (INIS)

    Guo Zhihua; Cao Huaixin

    2013-01-01

    The aim of this paper is to discuss local quantum channels that preserve classical correlations. First, we give two equivalent characterizations of classical correlated states. Then we obtain the relationships among classical correlation-preserving local quantum channels, commutativity-preserving local quantum channels and commutativity-preserving quantum channels on each subsystem. Furthermore, for a two-qubit system, we show the general form of classical correlation-preserving local quantum channels. (paper)

  20. Biogeochemistry: Oxygen burrowed away

    NARCIS (Netherlands)

    Meysman, F.J.R.

    2014-01-01

    Multicellular animals probably evolved at the seafloor after a rise in oceanic oxygen levels. Biogeochemical model simulations suggest that as these animals started to rework the seafloor, they triggered a negative feedback that reduced global oxygen.

  1. Oxygen transport membrane

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof.......The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof....

  2. Evaluation of a pyridoxylated hemoglobin polyoxyethylene conjugate solution as a perfusate for small intestine preservation.

    Science.gov (United States)

    Liu, H; Agishi, T; Kawai, T; Hayashi, T; Fujita, S; Fuchinoue, S; Takahashi, K; Teraoka, S; Ota, K

    1992-01-01

    A new type of artificial blood, pyridoxylated hemoglobin-polyoxyethylene conjugate (PHP) solution, (developed by PHP research group of the department of health and welfare of Japan, and produced by Ajinomoto Co., Inc. Tokyo) as an oxygen-carrying component, has been recently devised using hemoglobin obtained from hemolyzed human erythrocytes. Recently, the studies using this solution as a preservation solution were performed in some instances. To examine the mechanism of improved viability using this solution as a preservation solution, we developed a model of orthotopic small intestine transplantation (OIT) in the rat. As a baseline study, we compared parameters of viability of the grafts preserved in Collins and UW solution to those preserved in PHP solution including a survival rate, a serum level total protein and albumin, and a change in body weight after transplantation. In our study, the simple hypothermia storage together with intestinal perfusion preservation with PHP solution was performed. Animals were divided into 6, 12, and 24 hr preservation groups. All of the rats survived after 6 hr preservation following transplantation. However, in 12 hr storage, five of six rats in PHP solution preservation survived and recovery in body weight after grafting was better than those with Collins and UW solution. We conclude that the PHP solution is, therefore, considered to possibly be a more suitable perfusate for small intestine preservation than Collins and UW solution.

  3. A revolution in food preservation

    International Nuclear Information System (INIS)

    1986-01-01

    A brief consumer guide to food irradiation is presented. Aspects covered include some of the advantages of food irradiation compared to other methods of food preservation, the type of radiation used, the mechanism of action, some practical applications, safety and future benefits. (UK)

  4. Hardcore Heritage: imagination for preservation

    NARCIS (Netherlands)

    Rietveld, E.; Rietveld, R.

    2017-01-01

    Should the practice of the historic preservation of built and landscape heritage necessarily be based on conservation? Monuments, listed buildings, landscapes, and other forms of built heritage, are typically regarded as immutable and untouchable—objects to be “conserved”—and as a result tend to

  5. 2007 Preserve America Presidential Awards

    Science.gov (United States)

    aviation history museum that emphasizes people and culture as well as technology and events. With a the Private Preservation category, the two winners are: The History Channel, Save Our History Save Our History were Abbe Raven, president and CEO, A&E Television Networks; and Nancy Dubuc

  6. Yeasts preservation: alternatives for lyophilisation

    NARCIS (Netherlands)

    Nyanga, L.K.; Nout, M.J.R.; Smid, E.J.; Boekhout, T.; Zwietering, M.H.

    2012-01-01

    The aim of the study was to compare the effect of two low-cost, low technology traditional methods for drying starter cultures with standard lyophilisation. Lyophilised yeast cultures and yeast cultures preserved in dry rice cakes and dry plant fibre strands were examined for viable cell counts

  7. Beyond the Scope of Preservation?

    DEFF Research Database (Denmark)

    Rikke, Stenbro,; Riesto, Svava

    2014-01-01

    Why are some parts of the built environment protected as national heritage and others not? Listing is the most restrictive tool of Norwegian and Danish preservation in the built environment and creates a specific version of the past told through buildings and sites. The heritage authorities in both...

  8. Proterozoic atmospheric oxygen

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene

    2014-01-01

    This article is concerned with the evolution of atmospheric oxygen concentrations through the Proterozoic Eon. In particular, this article will seek to place the history of atmospheric oxygenation through the Proterozoic Eon in the context of the evolving physical environment including the history...... of continental growth and volcanic outgassing, as well as biogeochemical processing of elements within the oceans. The author will seek to explore constraints on the history of oxygenation and understand which processes have regulated oxygen through this eon....

  9. Oxygen evolution reaction catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  10. [Domiciliary oxygen therapy].

    Science.gov (United States)

    Abdel Kafi, S

    2010-09-01

    In Belgium, oxygen therapy is becoming more and more accessible. When oxygen is needed for short periods or for special indications as palliative care, an agreement between mutual insurance companies and pharmacists allows the practitioner the home installation of gazeous oxygen cylinder or of oxygen concentrator. When long term oxygen therapy (LTOT) is indicated for patients with respiratory insufficiency, the pneumologist must first ask the INAMI the authorization to install one of the following modalities: oxygen concentrator with or without demand oxygen delivery cylinder and liquid oxygen. The goal of LTOT is to increase survival and quality of life. The principal and well accepted indication for LTOT is severe hypoxemia. The beneficial effects of oxygen therapy limited at night or on exertion are controversial. In order to increase patient's autonomy, oxygen can be prescribed for ambulation, respecting prescription's rules. At each step of oxygen therapy implementing (indication, choice of the device and follow-up) the patient under oxygen may benefit from a joint approach between the general practitioner and the chest specialist.

  11. Aircraft Oxygen Generation

    Science.gov (United States)

    2012-02-01

    An Oxygen Enriched Air System for the AV-8A Harrier (NADC-81198-60).” 70 Horch , T., et. al. “The F-16 Onboard Oxygen Generating System: Performance...Only and Safety Privileged). Horch , T., Miller, R., Bomar, J., Tedor, J., Holden, R., Ikels, K., & Lozano, P. (1983). The F-16 Onboard Oxygen

  12. Hybrid Food Preservation Program Improves Food Preservation and Food Safety Knowledge

    Science.gov (United States)

    Francis, Sarah L.

    2014-01-01

    The growing trend in home food preservation raises concerns about whether the resulting food products will be safe to eat. The increased public demand for food preservation information led to the development of the comprehensive food preservation program, Preserve the Taste of Summer (PTTS). PTTS is a comprehensive hybrid food preservation program…

  13. Lanthanide ions induce hydrolysis of hemoglobin-bound 2,3-diphosphoglycerate (2,3-DPG), conformational changes of globin and bidirectional changes of 2,3-DPG-hemoglobin's oxygen affinity.

    Science.gov (United States)

    Cheng, Y; Lin, H; Xue, D; Li, R; Wang, K

    2001-02-14

    The changes in structure and function of 2,3-diphosphoglycerate-hemoglobin (2,3-DPG-Hb) induced by Ln(3+) binding were studied by spectroscopic methods. The binding of lanthanide cations to 2,3-DPG is prior to that to Hb. Ln(3+) binding causes the hydrolysis of either one from the two phosphomonoester bonds in 2,3-DPG non-specifically. The results using the ultrafiltration method indicate that Ln(3+) binding sites for Hb can be classified into three categories: i.e. positive cooperative sites (N(I)), non-cooperative strong sites (N(S)) and non-cooperative weak sites (N(W)) with binding constants in decreasing order: K(I)>K(S)>K(W). The total number of binding sites amounts to about 65 per Hb tetramer. Information on reaction kinetics was obtained from the change of intrinsic fluorescence in Hb monitored by stopped-flow fluorometry. Fluctuation of fluorescence dependent on Ln(3+) concentration and temperature was observed and can be attributed to the successive conformational changes induced by Ln(3+) binding. The results also reveal the bidirectional changes of the oxygen affinity of Hb in the dependence on Ln(3+) concentration. At the range of [Ln(3+)]/[Hb]<2, the marked increase of oxygen affinity (P(50) decrease) with the Ln(3+) concentration can be attributed to the hydrolysis of 2,3-DPG, while the slight rebound of oxygen affinity in higher Ln(3+) concentration can be interpreted by the transition to the T-state of the Hb tetramer induced by Ln(3+) binding. This was indicated by the changes in secondary structure characterized by the decrease of alpha-helix content.

  14. Chemistry of ice: Migration of ions and gases by directional freezing of water

    Directory of Open Access Journals (Sweden)

    Umer Shafique

    2016-09-01

    Full Text Available Redistribution of anions and cations creates an electrical imbalance in ice grown from electrolyte solutions. Movement of acidic and basic ions in cooling solutions can permanently change the pH of frozen and unfrozen parts of the system, largely. The extent of pH change associated with freezing is determined by solute concentration and the extent of cooling. In the present work, redistribution of hydrogen, hydroxyl, carbonate, and bicarbonate ions was studied during directional freezing in batch aqueous systems. Controlled freezing was employed vertically as well as radially in acidic and basic solutions. In each case, the ions substantially migrated along with moving freezing front. Conductometry and pH-metry were employed to monitor the moving ions. Besides, some other experiments were carried out with molecular gases, such as oxygen, carbon dioxide, and chlorine and an azeotropic mixture like water–ethanol. Findings can be used to understand possible changes that can occur in preserving materials by freezing.

  15. Oxygen configurations in silica

    International Nuclear Information System (INIS)

    Chelikowsky, James R.; Chadi, D. J.; Binggeli, N.

    2000-01-01

    We propose a transition state for oxygen in silica. This state is produced by the insertion of an oxygen molecule into the Si-O-Si bond, i.e., it consists of producing a Si-O-O-O-Si bond. This state allows molecular oxygen diffusion in silica without breaking the molecular O 2 bond and it is energetically more stable than a peroxy configuration. This configuration may allow for exchange of molecular oxygen with the oxygen in the silica framework. (c) 2000 The American Physical Society

  16. Low-level efficacy of cosmetic preservatives

    DEFF Research Database (Denmark)

    Lundov, M D; Johansen, J D; Zachariae, C

    2011-01-01

    Preservation using combinations of preservatives has several advantages. This study shows that the concentration of some of the most frequently used allergenic preservatives can be markedly lowered when they are combined with phenoxyethanol. The antimicrobial efficacy of cosmetic preservatives...... of the preservatives indicated additive effects against the microorganisms. No combination of preservatives showed any inhibitory action on each other. Challenge tests with different concentrations and combinations were performed in a cosmetic cream. Diazolidinyl urea and MCI/MI alone were ineffective against C....... albicans in a challenge test at concentrations up to 16 times higher than the observed MIC values. When combining phenoxyethanol with either one of the allergenic preservatives diazolidinyl urea, MCI/MI or MI, the cosmetic cream was adequately preserved at concentrations well below the preservatives' MIC values as well...

  17. Speculations on the existence of hydride ions in proton conducting oxides

    DEFF Research Database (Denmark)

    Poulsen, F.W.

    2001-01-01

    The chemical and physical nature of the hydride ion is briefly treated. Several reactions of the hydride ion in oxides or oxygen atmosphere are given, A number of perovskites and inverse perovskites are listed. which contain the H- ion on the oxygen or B-anion sites in the archetype ABO(3) System...

  18. Cellular radiobiology of heavy-ion beams

    International Nuclear Information System (INIS)

    Tobias, C.A.; Blakely, E.A.; Ngo, F.Q.H.; Roots, R.J.; Yang, T.C.

    1981-01-01

    Progress is reported in the following areas of this research program: relative biological effectiveness and oxygen enhancement ratio of silicon ion beams; heavy ion effects on the cell cycle; the potentiation effect (2 doses of high LET heavy-ion radiations separated by 2 to 3 hours); potentially lethal damage in actively growing cells and plateau growth cells; radiation induced macromolecular lesions and cellular radiation chemistry; lethal effects of dual radiation; and the development of a biophysical repair/misrepair model

  19. The bare uranyl(2+) ion, UO22+

    International Nuclear Information System (INIS)

    Cornehl, H.H.; Heinemann, C.; Marcalo, J.; Pires de Matos, A.; Schwarz, H.

    1996-01-01

    Ion-molecule reactions between U 2+ and oxygen donors or charge-stripping collisions between singly charged UO 2 2 ions and O 2 collision partners generate uranyl(2+) ions in the gas phase. These do not readily dissociate into singly charged fragments. The standard enthalpy of formation for UO 2 2+ is estimated to be 371±60 kcal mol -1 , in accord with the results of ab initio calculations. (orig.)

  20. Orbital preservation in a maxillectomy

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Katsuhiko; Nishikawa, Hitomi; Kumagai, Masahiko; Dosaka, Yoshihiro; Kuroda, Toru; Atago, Yoshihiro; Nishio, Masamichi [Sapporo National Hospital (Japan)

    1999-07-01

    In the past 9 years, 38 patients of the maxillary cancer were treated by a combination of radiation and surgery. Sixteen patients showed the orbital involvement as confirmed by a CT scan and/or MRI. An orbital excenteration was necessary in 6 patients, due mainly to deep intraorbital invasion, while in 10, the orbital contents were preserved despite the involvement of the orbital capsule. The local rate of the orbital region in the latter patients evaluated at 48 months after the initial surgery was 44%. For the treatment of the recurrence at the orbital capsule. The application of gold grain (Au{sup 198}) thus appeared to be a useful tool for further preserving the eye. (author)

  1. Orbital preservation in a maxillectomy

    International Nuclear Information System (INIS)

    Tanaka, Katsuhiko; Nishikawa, Hitomi; Kumagai, Masahiko; Dosaka, Yoshihiro; Kuroda, Toru; Atago, Yoshihiro; Nishio, Masamichi

    1999-01-01

    In the past 9 years, 38 patients of the maxillary cancer were treated by a combination of radiation and surgery. Sixteen patients showed the orbital involvement as confirmed by a CT scan and/or MRI. An orbital excenteration was necessary in 6 patients, due mainly to deep intraorbital invasion, while in 10, the orbital contents were preserved despite the involvement of the orbital capsule. The local rate of the orbital region in the latter patients evaluated at 48 months after the initial surgery was 44%. For the treatment of the recurrence at the orbital capsule. The application of gold grain (Au 198 ) thus appeared to be a useful tool for further preserving the eye. (author)

  2. INCORRECT PRESERVATION OF AMPUTATED DIGITS

    Directory of Open Access Journals (Sweden)

    Uroš Ahčan

    2004-09-01

    Full Text Available Background. A decision to replant is critically dependent on the condition of the amputated digit and the way it was preserved during transport. The most common error is exposing the amputated digit to very low temperatures. Preservation directly on ice, on cooling devices in portable refrigerators, or on top of packets of frozen meat often result in a frozen and therefore unusable body digit.Methods. An inquiry questionnaire on correct methods of preservation of amputated digits was conducted on a sample of 30 lay persons, 30 medical students, and 15 physicians.Three simulations of most frequently used methods of preservation of amputated digit were conducted (the correct method; directly on ice; on cooling devices of portable refrigerators. Environment temperature of the (simulated amputated digits stored was measured.In a retrospective study, hospital records of patients treated at the Clinical department of plastic surgery and burns in Ljubljana between 1998 and 2002 were examined. We determined the number of replantations performed, gender of the patients, their age, the mechanism of the injury, the success rate of the replantation, and the duration of hospitalisation. In five case described in detail, we present an inadequate treatment of the amputated digits.Results. The results of the questionnaire survey show that no less than 86.7% of lay person respondents would have treated the injuries in an incorrect way; same holds for 43.4% students of medicine, and 33.3% of practicing physicians.The temperature of the simulated amputated digit remained above 5°C throughout the simulated correct treatment. When preserved directly on ice on or coolant bodies, the temperature dropped below the freezing point and never climbed above 0°C throughout the duration of the simulation (150 minutes.Between years 1998 and 2002, Clinical department of plastic surgery and burns at the University clinical centre Ljubljana admitted 124 injured persons with

  3. Nuclear Knowledge Preservation in Croatia

    International Nuclear Information System (INIS)

    Pleslic, S.; Novosel, N.

    2006-01-01

    Since the International Atomic Energy Agency (IAEA, Vienna, Austria) was founded in 1957 as an autonomous intergovernmental organization, it was authorized for exchange of technical and scientific information on peaceful uses of atomic energy. 35 years ago the International Nuclear Information System (INIS) was established from IAEA as an international bibliographic database in the nuclear field and in nuclear related areas. INIS as an instrument for a comprehensive and systematic dissemination of all information and knowledge becomes a big technological and science information system with 134 Members (114 countries and 20 international organizations). In INIS Membership Arrangements all Members are responsible for the collection, selection, description of information and providing the Agency with the full text of each item of non-conventional literature. Participation of each Member is important because decentralized information management is an operational philosophy of INIS. During all these years status of nuclear power changed significantly in the world. Some developing countries started to develop nuclear power programme and some developed countries showed tendency to decrease use of nuclear power. Anyway, expert knowledge accumulated over decades and the achievements in the field of nuclear science and technology have to be preserved and later transferred to future generations. It became obvious that the INIS is practically a pioneer in the area of nuclear knowledge preservation with well defined goals of knowledge preservation: selection of the most valuable information to convey to the future, ensuring that it remains accessible, readable and understandable and management of technological change. Main components of knowledge preservation are: selection of information for preservation including evaluation and prioritisation by value, use and risk, information capture (purchasing, copy, digitise, web links), describing, classifying, store and access

  4. Preserved entropy and fragile magnetism.

    Science.gov (United States)

    Canfield, Paul C; Bud'ko, Sergey L

    2016-08-01

    A large swath of quantum critical and strongly correlated electron systems can be associated with the phenomena of preserved entropy and fragile magnetism. In this overview we present our thoughts and plans for the discovery and development of lanthanide and transition metal based, strongly correlated systems that are revealed by suppressed, fragile magnetism, quantum criticality, or grow out of preserved entropy. We will present and discuss current examples such as YbBiPt, YbAgGe, YbFe2Zn20, PrAg2In, BaFe2As2, CaFe2As2, LaCrSb3 and LaCrGe3 as part of our motivation and to provide illustrative examples.

  5. Preservation of food and radiation

    International Nuclear Information System (INIS)

    Kasamatsu, Tomomichi

    1975-01-01

    In the application of radiation to preservation of food, there are some methods; sterilization, elimination of noxious insects, prevention of germination and control of maturation. The former two utilize the lethal effect of radiation to the living things and the latter two utilize the injurious effect on the metabolism of the living things. At present, irradiation to potato is most widely permitted for the purpose of prevention of germination, and the irradiation with 15 Krad (maximum) is allowed to preserve potato for 8 months in Japan. In the other hand, a large quantity of doses, such as 4.5 to 5.6 Mrad, is necessary to sterilize completely for industrial use, degeneration of food component and high cost come into question. In addition, food is directly taken into the mouth of human being, therefore, wholesomeness, legal permission and determination of dose must be examined. (Tsukamoto, Y.)

  6. Oxygen transport by oxygen potential gradient in dense ceramic oxide membranes

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-05-01

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

  7. Food Preservation by Irradiation (Rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Urrows, Grace M.

    1968-01-01

    Up to 30% of food harvests are lost in some parts of the world because of animal pests and microorganisms. Nuclear techniques can help reduce and extend the shelf life of these foods. Around 55 countries now have food irradiation programs. The use of radiation is the most recent step in man's attempts to preserve some of his harvest for the lean part of the year.

  8. Technical Information/Website Preservation

    Science.gov (United States)

    PintoRey, Christian R.

    2010-01-01

    This document reviews the work of the author in NASA's Motivating Undergraduates in Science and Technology (MUST) internship. The intern worked on the Space Shuttles hydraulic systems (i.e., Auxiliary Power Units (APU's) and Hydraulic Pump Units (HPU's)), and website preservation of the hydraulic technology captured in websites relating to the coming.the Space Shuttle Retirement. Several figures and pictures show an overview of the orbiter's hydraulic systems

  9. New method of preserving food

    Energy Technology Data Exchange (ETDEWEB)

    Carrard, G. (Australian Atomic Energy Commission Research Establishment, Lucas Heights)

    1983-07-01

    The use of gamma radiation for food preservation is discussed. Investigations at the AAEC include: the eradication of fruit-fly larvae in oranges, tomatoes and avocadoes; treatment of shrimps; extending the shelf life of mushrooms and potatoes; treatment of imported beans to prevent germination; killing of bacterial spores with a combination of pressure and gamma radiation; and the treatment of beehives containing honey-bee larvae with foulbrood.

  10. New method of preserving food

    International Nuclear Information System (INIS)

    Carrard, G.

    1983-01-01

    The use of gamma radiation for food preservation is discussed. Investigations at the AAEC include: the eradication of fruit-fly larvae in oranges, tomatoes and avocadoes; treatment of shrimps; extending the shelf life of mushrooms and potatoes; treatment of imported beans to prevent germination; killing of bacterial spores with a combination of pressure and gamma radiation; and the treatment of beehives containing honey-bee larvae with foulbrood

  11. ULTRAVIOLET TECHNOLOGY FOR FOOD PRESERVATION

    OpenAIRE

    Guedes, AMM; Novello, D; Mendes, GMD; Cristianini, M

    2009-01-01

    ULTRAVIOLET TECHNOLOGY FOR FOOD PRESERVATION This literature review article had as objective to gather information about ultraviolet (UV) technology utilization on the food industry, its effects and potential application. Aspects as the origin, concept and applications of the technology on the equipment industry and running mechanisms were approached. The application of UV radiation on food decontamination is still little used due its low penetration, but it is known that it can be easily app...

  12. The ZEUS data preservation project

    International Nuclear Information System (INIS)

    Malka, Janusz; Wichmann, Katarzyna

    2012-01-01

    A project to allow long term access and physics analysis of ZEUS data (ZEUS data preservation) has been established in collaboration with the DESY-IT group. In the ZEUS approach the analysis model is based on the Common Ntuple project, under development since 2006. The real data and all presently available Monte Carlo samples are being preserved in a flat ROOT ntuple format. There is ongoing work to provide the ability to simulate new, additional Monte Carlo samples also in the future. The validation framework of such a scheme using virtualisation techniques is being explored. The goal is to validate the frozen ZEUS software against future changes in hardware and operating system. A cooperation between ZEUS, DESY-IT and the library was established for document digitisation and long-term preservation of collaboration web pages. Part of the ZEUS internal documentation has already been stored within the HEP documentation system INSPIRE. Existing digital documentation, needed to perform physics analysis also in the future, is being centralised and completed.

  13. Phase-preserved optical elevator.

    Science.gov (United States)

    Luo, Yuan; Zhang, Baile; Han, Tiancheng; Chen, Zhi; Duan, Yubo; Chu, Chia-Wei; Barbastathis, George; Qiu, Cheng Wei

    2013-03-25

    The unique superiority of transformation optics devices designed from coordinate transformation is their capability of recovering both ray trajectory and optical path length in light manipulation. However, very few experiments have been done so far to verify this dual-recovery property from viewpoints of both ray trajectory and optical path length simultaneously. The experimental difficulties arise from the fact that most previous optical transformation optics devices only work at the nano-scale; the lack of intercomparison between data from both optical path length and ray trajectory measurement in these experiments obscured the fact that the ray path was subject to a subwavelength lateral shift that was otherwise not easily perceivable and, instead, was pointed out theoretically [B. Zhang et al. Phys. Rev. Lett. 104, 233903, 2010]. Here, we use a simple macroscopic transformation optics device of phase-preserved optical elevator, which is a typical birefringent optical phenomenon that can virtually lift an optical image by a macroscopic distance, to demonstrate decisively the unique optical path length preservation property of transformation optics. The recovery of ray trajectory is first determined with no lateral shift in the reflected ray. The phase preservation is then verified with incoherent white-light interferometry without ambiguity and phase unwrapping.

  14. Polyenergy ion beam synthesis of buried oxynitride layer in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Barabanenkov, M.Yu. E-mail: barab@ipmt-hpm.ac.ru; Agafonov, Yu.A.; Mordkovich, V.N.; Pustovit, A.N.; Vyatkin, A.F.; Zinenko, V.I

    2000-11-01

    The efficiency of silicon oxynitride synthesis in silicon crystals implanted with substoichiometric doses of oxygen and nitrogen ions is investigated both experimentally and theoretically. Si crystals are implanted with oxygen and nitrogen ions with doses of 1.5 and 4.5x10{sup 17} cm{sup -2}, respectively, at fixed oxygen ion energy of 150 keV and nitrogen ion energies varied from 80 to 180 keV. The samples annealed at 1200 deg C for 2 h were analysed by secondary ion mass spectroscopy (SIMS). Theoretically, a `diffusion-alternative sinks' model is applied to the annealing stage of ion beam synthesis of a buried layer of a new phase in solids. It is shown that the maximum of the ternary phase production is attained when nitrogen ions are implanted deeper than oxygen ions. An explanation of this fact is given in terms of that (i) the segregation of oxygen and nitrogen species on the surface of oxide nuclei removes the kinetic restriction of nuclei growth, characteristic of oxide growth, at the expense of only oxygen atoms, and (ii) the higher the implantation energy the smoother the shape of ion range distribution in the target, which, in its turn, causes the predominance of the impurity sink over the impurity diffusion.

  15. Polyenergy ion beam synthesis of buried oxynitride layer in silicon

    International Nuclear Information System (INIS)

    Barabanenkov, M.Yu.; Agafonov, Yu.A.; Mordkovich, V.N.; Pustovit, A.N.; Vyatkin, A.F.; Zinenko, V.I.

    2000-01-01

    The efficiency of silicon oxynitride synthesis in silicon crystals implanted with substoichiometric doses of oxygen and nitrogen ions is investigated both experimentally and theoretically. Si crystals are implanted with oxygen and nitrogen ions with doses of 1.5 and 4.5x10 17 cm -2 , respectively, at fixed oxygen ion energy of 150 keV and nitrogen ion energies varied from 80 to 180 keV. The samples annealed at 1200 deg C for 2 h were analysed by secondary ion mass spectroscopy (SIMS). Theoretically, a `diffusion-alternative sinks' model is applied to the annealing stage of ion beam synthesis of a buried layer of a new phase in solids. It is shown that the maximum of the ternary phase production is attained when nitrogen ions are implanted deeper than oxygen ions. An explanation of this fact is given in terms of that (i) the segregation of oxygen and nitrogen species on the surface of oxide nuclei removes the kinetic restriction of nuclei growth, characteristic of oxide growth, at the expense of only oxygen atoms, and (ii) the higher the implantation energy the smoother the shape of ion range distribution in the target, which, in its turn, causes the predominance of the impurity sink over the impurity diffusion

  16. Ion Colliders

    CERN Document Server

    Fischer, W

    2014-01-01

    High-energy ion colliders are large research tools in nuclear physics to study the Quark-Gluon-Plasma (QGP). The range of collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead and uranium. Asymmetric collision combinations (e.g. protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders, the Relativistic Heavy Ion Collider (RHIC) at BNL, and the Large Hadron Collider (LHC) at CERN.

  17. Recoil ions

    International Nuclear Information System (INIS)

    Cocke, C.L.; Olson, R.E.

    1991-01-01

    The collision of a fast moving heavy ion with a neutral atomic target can produce very highly charged but slowly moving target ions. This article reviews experimental and theoretical work on the production and use of recoil ions beyond the second ionization state by beams with specific energies above 0.5 MeV/amu. A brief historical survey is followed by a discussion of theoretical approaches to the problem of the removal of many electrons from a neutral target by a rapid, multiply charged projectile. A discussion of experimental techniques and results for total and differential cross sections for multiple ionization of atomic and molecular targets is given. Measurements of recoil energy are discussed. The uses of recoil ions for in situ spectroscopy of multiply charged ions, for external beams of slow, highly charged ions and in ion traps are reviewed. Some possible future opportunities are discussed. (orig.)

  18. DNA damage in preserved specimens and tissue samples: a molecular assessment

    Directory of Open Access Journals (Sweden)

    Cantin Elizabeth

    2008-10-01

    Full Text Available Abstract The extraction of genetic information from preserved tissue samples or museum specimens is a fundamental component of many fields of research, including the Barcode of Life initiative, forensic investigations, biological studies using scat sample analysis, and cancer research utilizing formaldehyde-fixed, paraffin-embedded tissue. Efforts to obtain genetic information from these sources are often hampered by an inability to amplify the desired DNA as a consequence of DNA damage. Previous studies have described techniques for improved DNA extraction from such samples or focused on the effect of damaging agents – such as light, oxygen or formaldehyde – on free nucleotides. We present ongoing work to characterize lesions in DNA samples extracted from preserved specimens. The extracted DNA is digested to single nucleosides with a combination of DNase I, Snake Venom Phosphodiesterase, and Antarctic Phosphatase and then analyzed by HPLC-ESI-TOF-MS. We present data for moth specimens that were preserved dried and pinned with no additional preservative and for frog tissue samples that were preserved in either ethanol, or formaldehyde, or fixed in formaldehyde and then preserved in ethanol. These preservation methods represent the most common methods of preserving animal specimens in museum collections. We observe changes in the nucleoside content of these samples over time, especially a loss of deoxyguanosine. We characterize the fragmentation state of the DNA and aim to identify abundant nucleoside lesions. Finally, simple models are introduced to describe the DNA fragmentation based on nicks and double-strand breaks.

  19. Korteweg-deVries-Burgers (KdVB) equation in a five component cometary plasma with kappa described electrons and ions

    Science.gov (United States)

    Michael, Manesh; Willington, Neethu T.; Jayakumar, Neethu; Sebastian, Sijo; Sreekala, G.; Venugopal, Chandu

    2016-12-01

    We investigate the existence of ion-acoustic shock waves in a five component cometary plasma consisting of positively and negatively charged oxygen ions, kappa described hydrogen ions, hot solar electrons, and slightly colder cometary electrons. The KdVB equation has been derived for the system, and its solution plotted for different kappa values, oxygen ion densities, as well as the temperature ratios for the ions. It is found that the amplitude of the shock wave decreases with increasing kappa values. The strength of the shock profile decreases with increasing temperatures of the positively charged oxygen ions and densities of negatively charged oxygen ions.

  20. Oxygen etching mechanism in carbon-nitrogen (CNx) domelike nanostructures

    International Nuclear Information System (INIS)

    Acuna, J. J. S.; Figueroa, C. A.; Kleinke, M. U.; Alvarez, F.; Biggemann, D.

    2008-01-01

    We report a comprehensive study involving the ion beam oxygen etching purification mechanism of domelike carbon nanostructures containing nitrogen. The CN x nanodomes were prepared on Si substrate containing nanometric nickel islands catalyzed by ion beam sputtering of a carbon target and assisting the deposition by a second nitrogen ion gun. After preparation, the samples were irradiated in situ by a low energy ion beam oxygen source and its effects on the nanostructures were studied by x-ray photoelectron spectroscopy in an attached ultrahigh vacuum chamber, i.e., without atmospheric contamination. The influence of the etching process on the morphology of the samples and structures was studied by atomic force microscopy and field emission gun-secondary electron microscopy, respectively. Also, the nanodomes were observed by high resolution transmission electron microscopy. The oxygen atoms preferentially bond to carbon atoms by forming terminal carbonyl groups in the most reactive parts of the nanostructures. After the irradiation, the remaining nanostructures are grouped around two well-defined size distributions. Subsequent annealing eliminates volatile oxygen compounds retained at the surface. The oxygen ions mainly react with nitrogen atoms located in pyridinelike structures

  1. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... fertility preservation is important. These key points can help start the conversation: Cancer and cancer treatment may ... several resources listed on the reverse that can help you locate a fertility preservation specialist to discuss ...

  2. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... fertility preservation center closest to you Visit the Pediatric Oncofertility Research Foundation Visit the Patient Navigator Website ... Ginsberg JP. New advances in fertility preservation for pediatric cancer patients. Curr Opin Pediatr. 2010;23:9- ...

  3. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... Cancer Ask Your Doctor Information for Patients Many adult survivors of childhood cancer feel fertility preservation and ... Fertility preservation and adolescent cancer patients: lessons from adult survivors of childhood cancer and their parents. Cancer ...

  4. 76 FR 60754 - Preserving the Open Internet

    Science.gov (United States)

    2011-09-30

    ...-201] Preserving the Open Internet AGENCY: Federal Communications Commission. ACTION: Final rule..., 2011, a document establishing rules to preserve the open Internet. Inadvertently the wrong paragraph... alleging violations of the open Internet rules. Federal Communications Commission. Matt Warner, Attorney...

  5. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... available and having your child see a reproductive specialist in a timely manner can improve their future ... Can you refer us to a fertility preservation specialist to discuss my child’s options further? Fertility Preservation - ...

  6. A Holistic Approach to Bit Preservation

    DEFF Research Database (Denmark)

    Zierau, Eld Maj-Britt Olmütz

    2011-01-01

    This thesis presents three main results for a holistic approach to bit preservation, where the ultimate goal is to find the optimal bit preservation strategy for specific digital material that must be digitally preserved. Digital material consists of sequences of bits, where a bit is a binary digit...... which can have the value 0 or 1. Bit preservation must ensure that the bits remain intact and readable in the future, but bit preservation is not concerned with how bits can be interpreted as e.g. an image. A holistic approach to bit preservation includes aspects that influence the final choice of a bit...... a holistic approach and include aspects of digital representation, confidentiality, availability, bit safety and costs when defining requirements for the bit preservation. Analysis of such requirements and choice of the final bit preservation solution can be supported by the three main results presented...

  7. Prolonged platelet preservation by transient metabolic suppression

    NARCIS (Netherlands)

    Badlou, Bahram Alamdary

    2006-01-01

    Introduction: Different clinical studies have shown that transfusion of stored platelets results in better haemostasis in patients with thrombocytopenia with and without a platelet function defect. Objectives: Current preservation procedures aim to optimally preserve the metabolic status of

  8. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... JP, Kolon TF. Fertility Preservation in Children and Adolescents With Cancer . Urology. 2016;91:190-6. Loren ... 10. Nieman CL, et al. Fertility preservation and adolescent cancer patients: lessons from adult survivors of childhood ...

  9. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... be fertility preservation options available and having your child see a reproductive specialist in a timely manner ... there are options for preserving fertility in your child diagnosed with cancer. You may be focused on ...

  10. Integrated turbomachine oxygen plant

    Science.gov (United States)

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

    2014-06-17

    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.

  11. Ambient oxygen promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Ho Joong Sung

    2011-05-01

    Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

  12. Simultaneous sampling of tissue oxygenation and oxygen consumption in skeletal muscle.

    Science.gov (United States)

    Nugent, William H; Song, Bjorn K; Pittman, Roland N; Golub, Aleksander S

    2016-05-01

    Under physiologic conditions, microvascular oxygen delivery appears to be well matched to oxygen consumption in respiring tissues. We present a technique to measure interstitial oxygen tension (PISFO2) and oxygen consumption (VO2) under steady-state conditions, as well as during the transitions from rest to activity and back. Phosphorescence Quenching Microscopy (PQM) was employed with pneumatic compression cycling to achieve 1 to 10 Hz sampling rates of interstitial PO2 and simultaneous recurrent sampling of VO2 (3/min) in the exteriorized rat spinotrapezius muscle. The compression pressure was optimized to 120-130 mmHg without adverse effect on the tissue preparation. A cycle of 5s compression followed by 15s recovery yielded a resting VO2 of 0.98 ± 0.03 ml O2/100 cm(3)min while preserving microvascular oxygen delivery. The measurement system was then used to assess VO2 dependence on PISFO2 at rest and further tested under conditions of isometric muscle contraction to demonstrate a robust ability to monitor the on-kinetics of tissue respiration and the compensatory changes in PISFO2 during contraction and recovery. The temporal and spatial resolution of this approach is well suited to studies seeking to characterize microvascular oxygen supply and demand in thin tissues. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Photoionization cross section of atomic and molecular oxygen

    International Nuclear Information System (INIS)

    Pareek, P.N.

    1983-01-01

    Photoionization cross sections of atomic oxygen and dissociative photoionization cross sections of molecular oxygen were measured from their respective thresholds to 120 angstrom by use of a photoionization mass spectrometer in conjunction with a spark light source. The photoionization cross sections O 2 + parent ion and O + fragment ion from neutral O 2 were obtained by a technique that eliminated the serious problem of identifying the true abundances of O + ions. These ions are generally formed with considerable kinetic energy and, because most mass spectrometers discriminate against energetic ions, true O + abundances are difficult to obtain. In the present work the relative cross sections for producing O + ions are obtained and normalized against the total cross sections in a spectral region where dissociative ionization is not possible. The fragmentation cross sections for O + were then obtained by subtraction of O 2 + cross sections from the known total photoionization cross sections. The results are compared with the previously published measurements. The absolute photoionization cross section of atomic oxygen sigma 8 /sub +/ was measured at 304 A. The actual number density of oxygen atoms within the ionization region was obtained by measuring the fraction of 0 2 molecules dissociated. This sigma/sub +/ at 304 angstrom was used to convert the relative photoinization cross sections, measured as a function of wavelength using a calibrated photodiode, to absolute cross sections. The results are compared with previous measurements and calculated cross sections. angstrom Rydberg series converging to the OII 4 P state was observed

  14. Preservation management for libraries, archives and museums

    CERN Document Server

    Gorman, G E

    2006-01-01

    Memory institutions such as libraries, archives, galleries and museums all share pressing concerns about preserving heritage. This book charts the diversity of preservation management in the contemporary information landscape, and offers guidance on preservation methods for the sustainability of collections from a range of international experts.

  15. Orthogonality preserving infinite dimensional quadratic stochastic operators

    International Nuclear Information System (INIS)

    Akın, Hasan; Mukhamedov, Farrukh

    2015-01-01

    In the present paper, we consider a notion of orthogonal preserving nonlinear operators. We introduce π-Volterra quadratic operators finite and infinite dimensional settings. It is proved that any orthogonal preserving quadratic operator on finite dimensional simplex is π-Volterra quadratic operator. In infinite dimensional setting, we describe all π-Volterra operators in terms orthogonal preserving operators

  16. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... website. Skip to main content SaveMyFertility An Online Fertility Preservation Toolkit for Patients and Their Providers Open ... Diagnosed with Cancer You are here Home » Patients Fertility Preservation for Children Diagnosed with Cancer Fertility Preservation ...

  17. Fertility Preservation for Children Diagnosed with Cancer

    Medline Plus

    Full Text Available ... Skip to main content SaveMyFertility An Online Fertility Preservation Toolkit for Patients and Their Providers Open menu ... with Cancer You are here Home » Patients Fertility Preservation for Children Diagnosed with Cancer Fertility Preservation for ...

  18. 32 CFR 174.18 - Historic preservation.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Historic preservation. 174.18 Section 174.18... Historic preservation. (a) The transfer, lease, or sale of National Register-eligible historic property to... the regulations implementing the National Historic Preservation Act (36 CFR 800.5(a)(2)(vii)). One way...

  19. 76 FR 74721 - Preserving the Open Internet

    Science.gov (United States)

    2011-12-01

    ...; Report No. 2936] Preserving the Open Internet AGENCY: Federal Communications Commission. ACTION: Final... for broadband service to preserve and reinforce Internet freedom and openness. DATES: Oppositions to... applicability. Subject: In the Matter of Preserving the Open Internet, Broadband Industry Practices, published...

  20. Comprehensive preserving technique for Chinese chestnut storage

    International Nuclear Information System (INIS)

    Chen Yuntang; Yang Baoan; Zhang Jianwei; Li Qiufang

    2003-01-01

    Chinese chestnut can be preserved for a long time by using a comprehensive preserving technique, which consists of casing, irradiating, treating with preserving agent and controlling environment conditions. The shelftime of the treated chestnuts reaches 11 months keeping no insects, no germination and good quality for eating with the good fruit ratio of 97.5% and water losing ratio of 3.8%

  1. A holistic approach to bit preservation

    DEFF Research Database (Denmark)

    Zierau, Eld

    2012-01-01

    Purpose: The purpose of this paper is to point out the importance of taking a holistic approach to bit preservation when setting out to find an optimal bit preservation solution for specific digital materials. In the last decade there has been an increasing awareness that bit preservation, which ...

  2. Energized Oxygen : Speiser Current Sheet Bifurcation

    Science.gov (United States)

    George, D. E.; Jahn, J. M.

    2017-12-01

    A single population of energized Oxygen (O+) is shown to produce a cross-tail bifurcated current sheet in 2.5D PIC simulations of the magnetotail without the influence of magnetic reconnection. Treatment of oxygen in simulations of space plasmas, specifically a magnetotail current sheet, has been limited to thermal energies despite observations of and mechanisms which explain energized ions. We performed simulations of a homogeneous oxygen background, that has been energized in a physically appropriate manner, to study the behavior of current sheets and magnetic reconnection, specifically their bifurcation. This work uses a 2.5D explicit Particle-In-a-Cell (PIC) code to investigate the dynamics of energized heavy ions as they stream Dawn-to-Dusk in the magnetotail current sheet. We present a simulation study dealing with the response of a current sheet system to energized oxygen ions. We establish a, well known and studied, 2-species GEM Challenge Harris current sheet as a starting point. This system is known to eventually evolve and produce magnetic reconnection upon thinning of the current sheet. We added a uniform distribution of thermal O+ to the background. This 3-species system is also known to eventually evolve and produce magnetic reconnection. We add one additional variable to the system by providing an initial duskward velocity to energize the O+. We also traced individual particle motion within the PIC simulation. Three main results are shown. First, energized dawn- dusk streaming ions are clearly seen to exhibit sustained Speiser motion. Second, a single population of heavy ions clearly produces a stable bifurcated current sheet. Third, magnetic reconnection is not required to produce the bifurcated current sheet. Finally a bifurcated current sheet is compatible with the Harris current sheet model. This work is the first step in a series of investigations aimed at studying the effects of energized heavy ions on magnetic reconnection. This work differs

  3. Oxygen Isotopes in Chondritic Interplanetary Dust: Parent-Bodies and Nebular Oxygen Reservoirs

    International Nuclear Information System (INIS)

    Aleon, J; McKeegan, K D; Leshin, L

    2006-01-01

    Planetary objects have preserved various amounts of oxygen issued from isotopically different oxygen reservoirs reflecting their origin and physico-chemical history. An 16 O-rich component is preserved in refractory inclusions (CAIs) whereas meteorites matrices are enriched in an 16 O-poor component. The origin of these components is still unclear. The most recent models are based on isotope selective photodissociation of CO in a 16 O-rich nebula/presolr cloud resulting in a 16 O-poor gas in the outer part of the nebula. However because most meteorite components are thought to be formed in the inner 3AU of the solar nebula, the precise isotopic composition of outer solar system components is yet unknown. In that respect, the oxygen isotopic composition of cometary dust is a key to understand the origin of the solar system. The Stardust mission will bring back to the Earth dust samples from comet Wild2, a short period comet from the Jupiter family. A precise determination of the oxygen isotope composition of Wild2 dust grains is essential to decipher the oxygen reservoirs of the outer solar system. However, Stardust samples may be extremely fragmented upon impact in the collector. In addition, interplanetary dust particles (IDPs) collected in the stratosphere are likely to contain comet samples. Therefore, they started to investigate the oxygen isotopic composition of a suite of chondritic interplanetary dust particles that includes IDPs of potential cometary origin using a refined procedure to increase the lateral resolution for the analysis of Stardust grains or IDP subcomponents down to ∼ 3 (micro)m. High precision data for 4 IDPs were previously reported, here they have measured 6 additional IDPs

  4. Ion colliders

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions (77Asb1, 81Bou1). The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  5. Ion colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, W.

    2011-12-01

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions [77Asb1, 81Bou1]. The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  6. Radiation preservation of cooked foods

    International Nuclear Information System (INIS)

    Aurangzeb; Bibi, N.; Badshah, A.; Khan, I.

    1989-01-01

    The preservation of irradiated cooked food has been explained in this report under vacuum conditions. The samples were irradiated at dose levels of 7.5 and 10.0 LGy. Measurement of fungal count was carried immediately after irradiation and after each 15 days of storage life upto 60 days of time interval. The samples were evaluated organolepticaly as well. It has been observed that no significance difference was observed among samples of irradiated and vacuum packed controls during storage for 45 days. (A.B.)

  7. Polarization preservation in the AGS

    International Nuclear Information System (INIS)

    Ratner, L.G.

    1983-01-01

    The successful operation of a high energy polarized beam at the Argonne Zero Gradient Synchrotron (ZGS) with the concommitant development of depolarizing resonance correction techniques has led to the present project of commissioning such a beam at the Brookhaven Alternating Gradient Synchrotron (AGS). A description of the project was presented at the 1981 National Accelerator Conference. I would like to now present a more detailed description of how we plan to preserve the polarization during acceleration, and to present our game plan for tuning through some 50 resonances and reaching our goal of a 26 GeV polarized proton beam with greater than 60% polarization

  8. Tensor Train Neighborhood Preserving Embedding

    Science.gov (United States)

    Wang, Wenqi; Aggarwal, Vaneet; Aeron, Shuchin

    2018-05-01

    In this paper, we propose a Tensor Train Neighborhood Preserving Embedding (TTNPE) to embed multi-dimensional tensor data into low dimensional tensor subspace. Novel approaches to solve the optimization problem in TTNPE are proposed. For this embedding, we evaluate novel trade-off gain among classification, computation, and dimensionality reduction (storage) for supervised learning. It is shown that compared to the state-of-the-arts tensor embedding methods, TTNPE achieves superior trade-off in classification, computation, and dimensionality reduction in MNIST handwritten digits and Weizmann face datasets.

  9. Effect of oxygen pressure on sensitivity of CR-39 used for astronauts radiation dosimetry

    International Nuclear Information System (INIS)

    Murai, T.; Yabe, S.; Nagamatsu, A.; Tawara, H.; Kumagai, H.; Miyazawa, Y.; Kitajo, K.; Kodaira, S.; Yasuda, N.

    2006-01-01

    The personal radiation dosimeters for astronauts are exposed to low-pressure oxygen gas (0.29 atmospheres) during extra-vehicle activities. CR-39 plastic track detectors are one of the typical passive dosimeters for space radiation monitoring. We investigated change in track formation sensitivity of the antioxidant-doped CR-39 plastic with which oxygen gas comes in contact at different pressures up to 2 atmospheres for 1h to 10 days. The oxygen effect on sensitivity was measured for the C, Si and Fe ions (10-200 keV/μm) from the HIMAC heavy ion accelerator. The sensitivity is obviously sensitive to oxygen pressure at heavy-ion exposures, but not sensitive to the experience of oxygen atmosphere before and after the ion exposures. The maximum sensitivity is obtained at 0.29 atmospheres. The present experimental data suggested that the effect depends on LET of incident particles. (author)

  10. Modelling the Costs of Preserving Digital Assets

    DEFF Research Database (Denmark)

    Kejser, Ulla Bøgvad; Nielsen, Anders Bo; Thirifays, Alex

    2012-01-01

    Information is increasingly being produced in digital form, and some of it must be preserved for the longterm. Digital preservation includes a series of actively managed activities that require on-going funding. To obtain sufficient resources, there is a need for assessing the costs...... and the benefits accrued by preserving the assets. Cost data is also needed for optimizing activities and comparing the costs of different preservation alternatives. The purpose of this study is to analyse generic requirements for modelling the cost of preserving digital assets. The analysis was based...

  11. Oxygen nonstoichiometry and defects in Mn-doped Gd2Ti2O7+x

    International Nuclear Information System (INIS)

    Porat, O.; Tuller, H.L.

    1996-01-01

    The oxygen nonstoichiometry in Mn-doped Gd 2 Ti 2 O 7 , Gd 2 (Ti 0.975 Mn 0.025 ) 2 O 7+x , was measured electrochemically, as a function of temperature and oxygen partial pressure, with the aid of an oxygen titration cell. The analysis of the data shows that the defect equilibrium can be described by considering the dominant point defects to be neutral oxygen interstitials, doubly charged oxygen vacancies, and trivalent and quadrivalent Mn ions substituted in the Ti sites. The enthalpies for the formation of neutral oxygen interstitials and trivalent Mn are determined

  12. OAIS and Distributed Digital Preservation in Practice

    DEFF Research Database (Denmark)

    Zierau, Eld

    The aim of the paper is to illustrate how the distributed aspects of digital preservation can be aligned in practice, with the concepts and principles of the Open Archival Information System (OAIS) Reference Model. There has been a growing awareness within the digital preservation community...... of the need for cooperation between organizations to address digital preservation requirements. One common example is that replicas of preservation copies of digital objects need to be independently preserved (e.g., stored, managed, monitored, documented) to ensure that at least one correct replica...... will survive for as long as needed. Such independence can be achieved through distributed digital preservation that relies upon specific agreements between participating and contributing organizations. The OAIS Reference Model does not address the challenges of distributed digital preservation in detail...

  13. Preservation of forest wood chips

    Energy Technology Data Exchange (ETDEWEB)

    Kofman, P.D.; Thomsen, I.M.; Ohlsson, C.; Leer, E.; Ravn Schmidt, E.; Soerensen, M.; Knudsen, P.

    1999-01-01

    As part of the Danish Energy Research Programme on biomass utilisation for energy production (EFP), this project concerns problems connected to the handling and storing of wood chips. In this project, the possibility of preserving wood chips of the Norway Spruce (Picea Abies) is addressed, and the potential improvements by anaerobic storage are tested. Preservation of wood chips aims at reducing dry matter losses from extensive heating during storage and to reduce production of fungal spores. Fungal spores pose a health hazards to workers handling the chips. Further the producers of wood chips are interested in such a method since it would enable them to give a guarantee for the delivery of homogeneous wood chips also during the winter period. Three different types of wood chips were stored airtight and further one of these was stored in accordance with normal practise and use as reference. The results showed that airtight storage had a beneficial impact on the quality of the chips: no redistribution of moisture, low dry matter losses, unfavourable conditions for microbial activity of most fungi, and the promotion of yeasts instead of fungi with airborne spores. Likewise the firing tests showed that no combustion problems, and no increased risk to the environment or to the health of staff is caused by anaerobic storage of wood chips. In all, the tests of the anaerobic storage method of forest wood chips were a success and a large-scale test of the method will be carried out in 1999. (au)

  14. Preserving information in neural transmission.

    Science.gov (United States)

    Sincich, Lawrence C; Horton, Jonathan C; Sharpee, Tatyana O

    2009-05-13

    Along most neural pathways, the spike trains transmitted from one neuron to the next are altered. In the process, neurons can either achieve a more efficient stimulus representation, or extract some biologically important stimulus parameter, or succeed at both. We recorded the inputs from single retinal ganglion cells and the outputs from connected lateral geniculate neurons in the macaque to examine how visual signals are relayed from retina to cortex. We found that geniculate neurons re-encoded multiple temporal stimulus features to yield output spikes that carried more information about stimuli than was available in each input spike. The coding transformation of some relay neurons occurred with no decrement in information rate, despite output spike rates that averaged half the input spike rates. This preservation of transmitted information was achieved by the short-term summation of inputs that geniculate neurons require to spike. A reduced model of the retinal and geniculate visual responses, based on two stimulus features and their associated nonlinearities, could account for >85% of the total information available in the spike trains and the preserved information transmission. These results apply to neurons operating on a single time-varying input, suggesting that synaptic temporal integration can alter the temporal receptive field properties to create a more efficient representation of visual signals in the thalamus than the retina.

  15. Towards Interoperable Preservation Repositories: TIPR

    Directory of Open Access Journals (Sweden)

    Priscilla Caplan

    2010-07-01

    Full Text Available Towards Interoperable Preservation Repositories (TIPR is a project funded by the Institute of Museum and Library Services to create and test a Repository eXchange Package (RXP. The package will make it possible to transfer complex digital objects between dissimilar preservation repositories.  For reasons of redundancy, succession planning and software migration, repositories must be able to exchange copies of archival information packages with each other. Every different repository application, however, describes and structures its archival packages differently. Therefore each system produces dissemination packages that are rarely understandable or usable as submission packages by other repositories. The RXP is an answer to that mismatch. Other solutions for transferring packages between repositories focus either on transfers between repositories of the same type, such as DSpace-to-DSpace transfers, or on processes that rely on central translation services.  Rather than build translators between many dissimilar repository types, the TIPR project has defined a standards-based package of metadata files that can act as an intermediary information package, the RXP, a lingua franca all repositories can read and write.

  16. Brief concept of hip preservation

    Directory of Open Access Journals (Sweden)

    Sanjeev S. Madan

    2017-12-01

    Full Text Available Restoration of the anatomy of the hip joint and biomechanics across it, carry the immense importance to prevent future osteoarthritis of the joint. The aim of this review is to provide the brief concept of the methods to preserve the hip, especially in young adults. Attempts to preserve the hips start with the intense preoperative planning of the corrective procedure. Different parameters regarding the femur and acetabulum in all 3 dimensions need to be assessed. Especially, measurement of the anteversion of the femur and acetabulum is a significant step to avoid osteoarthritis. In addition, the suprapelvic and infrapelvic (spine and lower limb lengths alignment needs to be considered in the planning. Correction of the femoral side of the hip needs the understanding of the blood supply of the proximal femur which carries the risk of avascular necrosis more so with intracapsular osteotomies. Acetabular reorientation, to re-distribute the forces over the weight bearing part, can be carried out with re-directional osteotomy such as periacetabular osteotomy. It needs the understanding of the acetabular anatomy and the force distribution in it. To conclude, correction of both femoral and acetabular side parameters need to be considered in decision making depending on the alterations due to various etiologies causing the hip disorders.

  17. Distributed privacy preserving data collection

    KAUST Repository

    Xue, Mingqiang

    2011-01-01

    We study the distributed privacy preserving data collection problem: an untrusted data collector (e.g., a medical research institute) wishes to collect data (e.g., medical records) from a group of respondents (e.g., patients). Each respondent owns a multi-attributed record which contains both non-sensitive (e.g., quasi-identifiers) and sensitive information (e.g., a particular disease), and submits it to the data collector. Assuming T is the table formed by all the respondent data records, we say that the data collection process is privacy preserving if it allows the data collector to obtain a k-anonymized or l-diversified version of T without revealing the original records to the adversary. We propose a distributed data collection protocol that outputs an anonymized table by generalization of quasi-identifier attributes. The protocol employs cryptographic techniques such as homomorphic encryption, private information retrieval and secure multiparty computation to ensure the privacy goal in the process of data collection. Meanwhile, the protocol is designed to leak limited but non-critical information to achieve practicability and efficiency. Experiments show that the utility of the anonymized table derived by our protocol is in par with the utility achieved by traditional anonymization techniques. © 2011 Springer-Verlag.

  18. Determining the Source of Water Vapor in a Cerium Oxide Electrochemical Oxygen Separator to Achieve Aviator Grade Oxygen

    Science.gov (United States)

    Graf, John; Taylor, Dale; Martinez, James

    2014-01-01

    More than a metric ton of water is transported to the International Space Station (ISS) each year to provide breathing oxygen for the astronauts. Water is a safe and compact form of stored oxygen. The water is electrolyzed on ISS and ambient pressure oxygen is delivered to the cabin. A much smaller amount of oxygen is used each year in spacesuits to conduct Extra Vehicular Activities (EVAs). Space suits need high pressure (>1000 psia) high purity oxygen (must meet Aviator Breathing Oxygen "ABO" specifications, >99.5% O2). The water / water electrolysis system cannot directly provide high pressure, high purity oxygen, so oxygen for EVAs is transported to ISS in high pressure gas tanks. The tanks are relatively large and heavy, and the majority of the system launch weight is for the tanks and not the oxygen. Extracting high purity oxygen from cabin air and mechanically compressing the oxygen might enable on-board production of EVA grade oxygen using the existing water / water electrolysis system. This capability might also benefit human spaceflight missions, where oxygen for EVAs could be stored in the form of water, and converted into high pressure oxygen on-demand. Cerium oxide solid electrolyte-based ion transport membranes have been shown to separate oxygen from air, and a supported monolithic wafer form of the CeO2 electrolyte membrane has been shown to deliver oxygen at pressures greater than 300 psia. These supported monolithic wafers can withstand high pressure differentials even though the membrane is very thin, because the ion transport membrane is supported on both sides (Fig 1). The monolithic supported wafers have six distinct layers, each with matched coefficients of thermal expansion. The wafers are assembled into a cell stack which allows easy air flow across the wafers, uniform current distribution, and uniform current density (Fig 2). The oxygen separation is reported to be "infinitely selective" to oxygen [1] with reported purity of 99.99% [2

  19. Ion beam induces nitridation of silicon

    International Nuclear Information System (INIS)

    Petravic, M.; Williams, J.S.; Conway, M.

    1998-01-01

    High dose ion bombardment of silicon with reactive species, such as oxygen and nitrogen, has attracted considerable interest due to possible applications of beam-induced chemical compounds with silicon. For example, high energy oxygen bombardment of Si is now routinely used to form buried oxide layers for device purposes, the so called SIMOX structures. On the other hand, Si nitrides, formed by low energy ( 100 keV) nitrogen beam bombardment of Si, are attractive as oxidation barriers or gate insulators, primarily due to the low diffusivity of many species in Si nitrides. However, little data exists on silicon nitride formation during bombardment and its angle dependence, in particular for N 2 + bombardment in the 10 keV range, which is of interest for analytical techniques such as SIMS. In SIMS, low energy oxygen ions are more commonly used as bombarding species, as oxygen provides stable ion yields and enhances the positive secondary ion yield. Therefore, a large body of data can be found in the literature on oxide formation during low energy oxygen bombardment. Nitrogen bombardment of Si may cause similar effects to oxygen bombardment, as nitrogen and oxygen have similar masses and ranges in Si, show similar sputtering effects and both have the ability to form chemical compounds with Si. In this work we explore this possibility in some detail. We compare oxide and nitride formation during oxygen and nitrogen ion bombardment of Si under similar conditions. Despite the expected similar behaviour, some large differences in compound formation were found. These differences are explained in terms of different atomic diffusivities in oxides and nitrides, film structural differences and thermodynamic properties. (author)

  20. Oxygen enrichment incineration

    International Nuclear Information System (INIS)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested

  1. Oxygen enrichment incineration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested.

  2. Proton-bound cluster ions in ion mobility spectrometry

    Science.gov (United States)

    Ewing, R. G.; Eiceman, G. A.; Stone, J. A.

    1999-01-01

    Gaseous oxygen and nitrogen bases, both singly and as binary mixtures, have been introduced into ion mobility spectrometers to study the appearance of protonated molecules, and proton-bound dimers and trimers. At ambient temperature it was possible to simultaneously observe, following the introduction of molecule A, comparable intensities of peaks ascribable to the reactant ion (H2O)nH+, the protonated molecule AH+ and AH+ H2O, and the symmetrical proton bound dimer A2H+. Mass spectral identification confirmed the identifications and also showed that the majority of the protonated molecules were hydrated and that the proton-bound dimers were hydrated to a much lesser extent. No significant peaks ascribable to proton-bound trimers were obtained no matter how high the sample concentration. Binary mixtures containing molecules A and B, in some cases gave not only the peaks unique to the individual compounds but also peaks due to asymmetrical proton bound dimers AHB+. Such ions were always present in the spectra of mixtures of oxygen bases but were not observed for several mixtures of oxygen and nitrogen bases. The dimers, which were not observable, notable for their low hydrogen bond strengths, must have decomposed in their passage from the ion source to the detector, i.e. in a time less than approximately 5 ms. When the temperature was lowered to -20 degrees C, trimers, both homogeneous and mixed, were observed with mixtures of alcohols. The importance of hydrogen bond energy, and hence operating temperature, in determining the degree of solvation of the ions that will be observed in an ion mobility spectrometer is stressed. The possibility is discussed that a displacement reaction involving ambient water plays a role in the dissociation.

  3. Influence of oxygen concentration on ethylene removal using dielectric barrier discharge

    Science.gov (United States)

    Takahashi, Katsuyuki; Motodate, Takuma; Takaki, Koichi; Koide, Shoji

    2018-01-01

    Ethylene gas is decomposed using a dielectric barrier discharge plasma reactor for long-period preservation of fruits and vegetables. The oxygen concentration in ambient gas is varied from 2 to 20% to simulate the fruit and vegetable transport container. The experimental results show that the efficiency of ethylene gas decomposition increases with decreasing oxygen concentration. The reactions of ethylene molecules with ozone are analyzed by Fourier transform infrared spectrometry. The analysis results show that the oxidization process by ozone is later than that by oxygen atoms. The amount of oxygen atoms that contribute to ethylene removal increases with decreasing oxygen concentration because the reaction between oxygen radicals and oxygen molecules is suppressed at low oxygen concentrations. Ozone is completely removed and the energy efficiency of C2H4 removal is increased using manganese dioxide as a catalyst.

  4. Is my network module preserved and reproducible?

    Directory of Open Access Journals (Sweden)

    Peter Langfelder

    2011-01-01

    Full Text Available In many applications, one is interested in determining which of the properties of a network module change across conditions. For example, to validate the existence of a module, it is desirable to show that it is reproducible (or preserved in an independent test network. Here we study several types of network preservation statistics that do not require a module assignment in the test network. We distinguish network preservation statistics by the type of the underlying network. Some preservation statistics are defined for a general network (defined by an adjacency matrix while others are only defined for a correlation network (constructed on the basis of pairwise correlations between numeric variables. Our applications show that the correlation structure facilitates the definition of particularly powerful module preservation statistics. We illustrate that evaluating module preservation is in general different from evaluating cluster preservation. We find that it is advantageous to aggregate multiple preservation statistics into summary preservation statistics. We illustrate the use of these methods in six gene co-expression network applications including 1 preservation of cholesterol biosynthesis pathway in mouse tissues, 2 comparison of human and chimpanzee brain networks, 3 preservation of selected KEGG pathways between human and chimpanzee brain networks, 4 sex differences in human cortical networks, 5 sex differences in mouse liver networks. While we find no evidence for sex specific modules in human cortical networks, we find that several human cortical modules are less preserved in chimpanzees. In particular, apoptosis genes are differentially co-expressed between humans and chimpanzees. Our simulation studies and applications show that module preservation statistics are useful for studying differences between the modular structure of networks. Data, R software and accompanying tutorials can be downloaded from the following webpage: http

  5. Innovative oxide materials for electrochemical energy conversion and oxygen separation

    Science.gov (United States)

    Belousov, V. V.

    2017-10-01

    Ion-conducting solid metal oxides are widely used in high-temperature electrochemical devices for energy conversion and oxygen separation. However, liquid metal oxides possessing unique electrochemical properties still remain of limited use. The review demonstrates the potential for practical applications of molten oxides. The transport properties of molten oxide materials are discussed. The emphasis is placed on the chemical diffusion of oxygen in the molten oxide membrane materials for electrochemical energy conversion and oxygen separation. The thermodynamics of these materials is considered. The dynamic polymer chain model developed to describe the oxygen ion transport in molten oxides is discussed. Prospects for further research into molten oxide materials are outlined. The bibliography includes 145 references.

  6. Negative secondary ion emission from oxidized surfaces

    International Nuclear Information System (INIS)

    Gnaser, H.; Kernforschungsanlage Juelich G.m.b.H.

    1984-01-01

    The emission of negative secondary ions from 23 elements was studied for 10 keV O 2 + and 10 keV In + impact at an angle of incidence of 45 0 . Partial oxidation of the sample surfaces was achieved by oxygen bombardment and/or by working at a high oxygen partial pressure. It was found that the emission of oxide ions shows an element-characteristic pattern. For the majority of the elements investigated these features are largely invariant against changes of the surface concentration of oxygen. For the others admission of oxygen strongly changes the relative intensities of oxide ions: a strong increase of MO 3 - signals (M stands for the respective element) is accompanied by a decrease of MO - and M - intensities. Different primary species frequently induce changes of both the relative and the absolute negative ion intensities. Carbon - in contrast to all other elements - does not show any detectable oxide ion emission but rather intense cluster ions Csub(n) - (detected up to n=12) whose intensities oscillate in dependence on n. (orig./RK)

  7. ion irradiation

    Indian Academy of Sciences (India)

    Swift heavy ions interact predominantly through inelastic scattering while traversing any polymer medium and produce excited/ionized atoms. Here samples of the polycarbonate Makrofol of approximate thickness 20 m, spin coated on GaAs substrate were irradiated with 50 MeV Li ion (+3 charge state). Build-in ...

  8. Ion microprobes

    International Nuclear Information System (INIS)

    Coles, J.N.; Long, J.V.P.

    1977-01-01

    An ion microprobe is described that has an ion extraction arrangement comprising two separate paths for ions and electrons diverging from a common point. A cone shaped or pyramidal guard electrode surrounds each path the apex angles being equal and coinciding with the said point. The guard electrodes are positioned to lie tangentially to each other and to a planar surface including the said point. An aperture is provided for the two paths at the apexes of both guard electrodes, and electrical connections between the guard electrodes enable the same potential to be applied to both guard electrodes. Means are provided for generating oppositely polarised electric fields within the guard electrodes, together with means for causing a focused ion beam to strike the common point without suffering astigmatism. The means for causing a focused ion beam to strike the said point includes an ion gun for directing an ion beam along one of the paths and means to provide an axial accelerating field there along. Optical viewing means are also provided. Existing designs enable only ions or electrons, but not both, to be extracted at any one time. (U.K.)

  9. Renal vein oxygen saturation in renal artery stenosis

    DEFF Research Database (Denmark)

    Nielsen, K; Rehling, M; Henriksen, Jens Henrik Sahl

    1992-01-01

    Renal vein oxygen-saturation was measured in 56 patients with arterial hypertension and unilateral stenosis or occlusion of the renal artery. Oxygen-saturation in blood from the ischaemic kidney (84.4%, range 73-93%) was significantly higher than that from the 'normal' contralateral kidney (81...... than its blood flow. This is probably due to decreased filtration fraction and filtered sodium with subsequent reduction in absolute tubular re-absorption of sodium ions....

  10. Confinement of multiply charged ions in an ECRH mirror plasma

    International Nuclear Information System (INIS)

    Petty, C.C.

    1989-06-01

    This thesis is an experimental study of multiply charged ions in the Constance B mirror experiment. By measuring the ion densities, end loss fluxes and ion temperatures, the parallel confinement times for the first five charge states of oxygen and neon plasmas are determined. The parallel ion confinement times increase with charge state and peak on axis, both indications of an ion-confining potential dip created by the hot electrons. The radial profile of ion end loss is usually hollow due to large ion radial transport (τ paralleli ∼ τ perpendiculari ), with the peak fluxes occurring at the edge of the electron cyclotron resonance zone. Several attempts are made to increase the end loss of selected ion species. Using minority ICRH, the end loss flux of resonant ions increases by 20% in cases when radial transport induced by ICRH is not too severe. A large antenna voltage can also extinguish the plasma. By adding helium to an oxygen plasma, the end loss of O 6+ increases by 80% due to decreased ion radial transport. An ion model is developed to predict the ion densities, end loss fluxes and confinement times in the plasma center using the ion particle balance equations, the quasineutrality condition and theoretical confinement time formulas. The model generally agrees with the experimental data for oxygen and neon plasmas to within experimental error. Under certain conditions spatial diffusion appears to determine the parallel ion confinement time of the highest charge states. For oxygen plasmas during ICRH, the measured parallel confinement time of the resonant ions is much shorter than their theoretical value, probably due to rf diffusion of the ions into the loss cone. 58 refs., 101 figs., 16 tabs

  11. Structural Changes in Polymer Films by Fast Ion Implantation

    Science.gov (United States)

    Parada, M. A.; Minamisawa, R. A.; Muntele, C.; Muntele, I.; De Almeida, A.; Ila, D.

    2006-11-01

    In applications from food wrapping to solar sails, polymers films can be subjected to intense charged panicle bombardment and implantation. ETFE (ethylenetetrafluoroethylene) with high impact resistance is used for pumps, valves, tie wraps, and electrical components. PFA (tetrafluoroethylene-per-fluoromethoxyethylene) and FEP (tetrafluoroethylene-hexa-fluoropropylene) are sufficiently biocompatible to be used as transcutaneous implants since they resist damage from the ionizing space radiation, they can be used in aerospace engineering applications. PVDC (polyvinyllidene-chloride) is used for food packaging, and combined with others plastics, improves the oxygen barrier responsible for the food preservation. Fluoropolymers are also known for their radiation dosimetry applications, dependent on the type and energy of the radiation, as well as of the beam intensity. In this work ETFE, PFA, FEP and PVDC were irradiated with ions of keV and MeV energies at several fluences and were analyzed through techniques as RGA, OAP, FTIR, ATR and Raman spectrophotometry. CF3 is the main specie emitted from PFA and FEP when irradiated with MeV protons. H and HF are released from ETFE due to the broken C-F and C-H bonds when the polymer is irradiated with keV Nitrogen ions and protons. At high fluence, especially for keV Si and N, damage due to carbonization is observed with the formation of hydroperoxide and polymer dehydroflorination. The main broken bonds in PVDC are C-O and C-Cl, with the release of Cl and the formation of double carbon bonds. The ion fluence that causes damage, which could compromise fluoropolymer film applications, has been determined.

  12. First-Principles Study on Cathode Properties of Li2MTiO4 (M = V, Cr, Mn, Fe, Co, and Ni) with Oxygen Deficiency for Li-Ion Batteries

    Science.gov (United States)

    Hamaguchi, Motoyuki; Momida, Hiroyoshi; Oguchi, Tamio

    2018-04-01

    We study the cathode properties of Li2MTiO4 (M = V, Cr, Mn, Fe, Co, and Ni) for Li-ion batteries by performing first-principles calculations. Formation energies and voltages for Li2-xMTiO4 (0 ≤ x ≤ 2) models with rock-salt-based structures considering several Li concentrations (2 - x) are calculated. Two dominant charge/discharge reaction mechanisms associated with redox reactions of M and O are found mainly in the ranges of lower and higher x, respectively. In the higher-x region, the O redox reactions can destabilize atomic structures, because the electron removal from O-p states produces high peaks at the fermi level in the density of states. The structural stability of O using the models with O deficiency is calculated, and the result shows that O can dissociate much more easily than Li in the higher-x region. The critical Li concentration at which the vacancy formation energy of O becomes lower than that of Li is estimated, and the critical x value decreases with increasing number of 3d electrons as M changes from V to Ni. The calculated voltages of Li2MTiO4 with O deficiency are lower than those without O deficiency, showing that the O dissociation degrades battery performances. Our systematic study for the series of M predicts that Li2CrTiO4 may be the best cathode material considering its cathode properties of high voltage and stability against O dissociation.

  13. The C2H3O+ chemi-ion acetyl cation or O-protonated ketene

    DEFF Research Database (Denmark)

    Egsgaard, H.; Carlsen, L.

    1995-01-01

    The C2H3O+ chemi-ion sampled from a premixed methane/oxygen flame has been demonstrated to be the acetyl cation based on ion-molecule reactions with isoprene and 1,3-dioxolane.......The C2H3O+ chemi-ion sampled from a premixed methane/oxygen flame has been demonstrated to be the acetyl cation based on ion-molecule reactions with isoprene and 1,3-dioxolane....

  14. Organic carbon production, mineralization and preservation on the Peruvian margin

    Science.gov (United States)

    Dale, A. W.; Sommer, S.; Lomnitz, U.; Montes, I.; Treude, T.; Gier, J.; Hensen, C.; Dengler, M.; Stolpovsky, K.; Bryant, L. D.; Wallmann, K.

    2014-09-01

    Carbon cycling in Peruvian margin sediments (11° S and 12° S) was examined at 16 stations from 74 m on the inner shelf down to 1024 m water depth by means of in situ flux measurements, sedimentary geochemistry and modeling. Bottom water oxygen was below detection limit down to ca. 400 m and increased to 53 μM at the deepest station. Sediment accumulation rates and benthic dissolved inorganic carbon fluxes decreased rapidly with water depth. Particulate organic carbon (POC) content was lowest on the inner shelf and at the deep oxygenated stations (< 5%) and highest between 200 and 400 m in the oxygen minimum zone (OMZ, 15-20%). The organic carbon burial efficiency (CBE) was unexpectedly low on the inner shelf (< 20%) when compared to a global database, for reasons which may be linked to the frequent ventilation of the shelf by oceanographic anomalies. CBE at the deeper oxygenated sites was much higher than expected (max. 81%). Elsewhere, CBEs were mostly above the range expected for sediments underlying normal oxic bottom waters, with an average of 51 and 58% for the 11° S and 12° S transects, respectively. Organic carbon rain rates calculated from the benthic fluxes alluded to a very efficient mineralization of organic matter in the water column, with a Martin curve exponent typical of normal oxic waters (0.88 ± 0.09). Yet, mean POC burial rates were 2-5 times higher than the global average for continental margins. The observations at the Peruvian margin suggest that a lack of oxygen does not affect the degradation of organic matter in the water column but promotes the preservation of organic matter in marine sediments.

  15. Persufflation Improves Pancreas Preservation When Compared With the Two-Layer Method

    Science.gov (United States)

    Scott, W.E.; O'Brien, T.D.; Ferrer-Fabrega, J.; Avgoustiniatos, E.S.; Weegman, B.P.; Anazawa, T.; Matsumoto, S.; Kirchner, V.A.; Rizzari, M.D.; Murtaugh, M.P.; Suszynski, T.M.; Aasheim, T.; Kidder, L.S.; Hammer, B.E.; Stone, S.G.; Tempelman, L.; Sutherland, D.E.R.; Hering, B.J.; Papas, K.K.

    2010-01-01

    Islet transplantation is emerging as a promising treatment for patients with type 1 diabetes. It is important to maximize viable islet yield for each organ due to scarcity of suitable human donor pancreata, high cost, and the high dose of islets required for insulin independence. However, organ transport for 8 hours using the two-layer method (TLM) frequently results in lower islet yields. Since efficient oxygenation of the core of larger organs (eg, pig, human) in TLM has recently come under question, we investigated oxygen persufflation as an alternative way to supply the pancreas with oxygen during preservation. Porcine pancreata were procured from non–heart-beating donors and preserved by either TLM or persufflation for 24 hours and fixed. Biopsies were collected from several regions of the pancreas, sectioned, stained with hematoxylin and eosin, and evaluated by a histologist. Persufflated tissues exhibited distended capillaries due to gas perfusion and significantly less autolysis/cell death than regions not exposed to persufflation or tissues exposed to TLM. The histology presented here suggests that after 24 hours of preservation, persufflation dramatically improves tissue health when compared with TLM. These results indicate the potential for persufflation to improve viable islet yields and extend the duration of preservation, allowing more donor organs to be utilized. PMID:20692396

  16. Amorphous carbon nitrogenated films prepared by plasma immersion ion implantation and deposition

    International Nuclear Information System (INIS)

    Rangel, Elidiane C.; Durrant, Steven F.; Rangel, Rita C.C.; Kayama, Milton E.; Landers, Richard; Cruz, Nilson C. da

    2006-01-01

    In this work, an investigation was conducted on amorphous hydrogenated-nitrogenated carbon films prepared by plasma immersion ion implantation and deposition. Glow discharge was excited by radiofrequency power (13.56 MHz, 40 W) whereas the substrate-holder was biased with 25 kV negative pulses. The films were deposited from benzene, nitrogen and argon mixtures. The proportion of nitrogen in the chamber feed (R N ) was varied against that of argon, while keeping the total pressure constant (1.3 Pa). From infrared reflectance-absorbance spectroscopy it was observed that the molecular structure of the benzene is not preserved in the film. Nitrogen was incorporated from the plasma while oxygen arose as a contaminant. X-ray photoelectron spectroscopy revealed that N/C and O/C atomic ratios change slightly with R N . Water wettability decreased as the proportion of N in the gas phase increased while surface roughness underwent just small changes. Nanoindentation measurements showed that film deposition by means of ion bombardment was beneficial to the mechanical properties of the film-substrate interface. The intensity of the modifications correlates well with the degree of ion bombardment

  17. Need of Reactor Dosimetry Preservation

    International Nuclear Information System (INIS)

    Ilieva, Krassimira

    2011-01-01

    The nuclear safety requirements and philosophy have changed by the development of new nuclear systems and this imposes special research and development activity. Reactor dosimetry which is applied for determination of neutron field parameters and neutron flux responses in different regions of the reactor system plays an important role in determining of radiation exposure on reactor system elements as reactor vessel, internals, shielding; dose determination for material damage study; for conditioning of irradiation; dose determination for medicine and industry application; induced activity determination for decommissioning purposes. The management of nuclear knowledge has emerged as a growing challenge in recent years. The need to preserve and transfer nuclear knowledge is compounded by recent trends such as ageing of the nuclear workforce, declining student numbers in nuclear related fields, and the threat of losing accumulated nuclear knowledge. (author)

  18. Correlation-Preserving Photo Collage.

    Science.gov (United States)

    Liu, Lingjie; Zhang, Hongjie; Jing, Guangmei; Guo, Yanwen; Chen, Zhonggui; Wang, Wenping

    2017-05-12

    A new method is presented for producing photo collages that preserve content correlation of photos. We use deep learning techniques to find correlation among given photos to facilitate their embedding on the canvas, and develop an efficient combinatorial optimization technique to make correlated photos stay close to each other. To make efficient use of canvas space, our method first extracts salient regions of photos and packs only these salient regions. We allow the salient regions to have arbitrary shapes, therefore yielding informative, yet more compact collages than by other similar collage methods based on salient regions. We present extensive experimental results, user study results, and comparisons against the state-of-the-art methods to show the superiority of our method.

  19. Privacy-Preserving Trajectory Collection

    DEFF Research Database (Denmark)

    Gidofalvi, Gyozo; Xuegang, Huang; Pedersen, Torben Bach

    2008-01-01

    In order to provide context--aware Location--Based Services, real location data of mobile users must be collected and analyzed by spatio--temporal data mining methods. However, the data mining methods need precise location data, while the mobile users want to protect their location privacy....... To remedy this situation, this paper first formally defines novel location privacy requirements. Then, it briefly presents a system for privacy--preserving trajectory collection that meets these requirements. The system is composed of an untrusted server and clients communicating in a P2P network. Location...... data is anonymized in the system using data cloaking and data swapping techniques. Finally, the paper empirically demonstrates that the proposed system is effective and feasible....

  20. Radiations to preserve world heritage

    International Nuclear Information System (INIS)

    Hurel, T.

    2017-01-01

    This article details the use of radiation to preserve the archaeological and artistic heritage. Gamma radiations are used to kill living organisms (insects, fungi and moulds) and to solidify styren-polyester resins that may be injected in wood items to reinforce them. Neutron irradiations are used to reveal the structure of an item and to get information on the materials the item is made of. Both irradiations are non-destructive. Carbon 14 dating is efficient to age items but beyond 50.000 years the method becomes ineffective and other methods like thermoluminescence take over. For instance it is the thermoluminescence method applied on flints found on the Jebel Irhoud site (Morocco) that has allowed to push back the age of the first Homo Sapiens by 100.000 years to reach 300.000 years. (A.C.)