WorldWideScience

Sample records for oxidation state ions

  1. Ion bombardment effects on surface states in selected oxide systems: rutile and alkaline earth titanates

    International Nuclear Information System (INIS)

    Gruen, D.M.

    1978-01-01

    In this paper, the nature of the surface states of n-type TiO 2 and SrTiO 3 is discussed and the role of ion bombardment in modifying the properties of these states is elucidated. Insofar as possible, the interrelationships between oxide nonstoichiometry, surface states, ion bombardment effects and photoelectrolysis are explored

  2. Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries.

    Science.gov (United States)

    Yabuuchi, Naoaki; Nakayama, Masanobu; Takeuchi, Mitsue; Komaba, Shinichi; Hashimoto, Yu; Mukai, Takahiro; Shiiba, Hiromasa; Sato, Kei; Kobayashi, Yuki; Nakao, Aiko; Yonemura, Masao; Yamanaka, Keisuke; Mitsuhara, Kei; Ohta, Toshiaki

    2016-12-23

    Further increase in energy density of lithium batteries is needed for zero emission vehicles. However, energy density is restricted by unavoidable theoretical limits for positive electrodes used in commercial applications. One possibility towards energy densities exceeding these limits is to utilize anion (oxide ion) redox, instead of classical transition metal redox. Nevertheless, origin of activation of the oxide ion and its stabilization mechanism are not fully understood. Here we demonstrate that the suppression of formation of superoxide-like species on lithium extraction results in reversible redox for oxide ions, which is stabilized by the presence of relatively less covalent character of Mn 4+ with oxide ions without the sacrifice of electronic conductivity. On the basis of these findings, we report an electrode material, whose metallic constituents consist only of 3d transition metal elements. The material delivers a reversible capacity of 300 mAh g -1 based on solid-state redox reaction of oxide ions.

  3. Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries

    Science.gov (United States)

    Yabuuchi, Naoaki; Nakayama, Masanobu; Takeuchi, Mitsue; Komaba, Shinichi; Hashimoto, Yu; Mukai, Takahiro; Shiiba, Hiromasa; Sato, Kei; Kobayashi, Yuki; Nakao, Aiko; Yonemura, Masao; Yamanaka, Keisuke; Mitsuhara, Kei; Ohta, Toshiaki

    2016-01-01

    Further increase in energy density of lithium batteries is needed for zero emission vehicles. However, energy density is restricted by unavoidable theoretical limits for positive electrodes used in commercial applications. One possibility towards energy densities exceeding these limits is to utilize anion (oxide ion) redox, instead of classical transition metal redox. Nevertheless, origin of activation of the oxide ion and its stabilization mechanism are not fully understood. Here we demonstrate that the suppression of formation of superoxide-like species on lithium extraction results in reversible redox for oxide ions, which is stabilized by the presence of relatively less covalent character of Mn4+ with oxide ions without the sacrifice of electronic conductivity. On the basis of these findings, we report an electrode material, whose metallic constituents consist only of 3d transition metal elements. The material delivers a reversible capacity of 300 mAh g−1 based on solid-state redox reaction of oxide ions. PMID:28008955

  4. On matrix stabilisation of d- and f-transition metal ions in unstable oxidation states

    Energy Technology Data Exchange (ETDEWEB)

    Kiselev, Yurii M [Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

    2009-01-31

    The state-of-the-art in matrix stabilisation of d- and f-transition metal ions in unstable oxidation states is analysed. Main aspects of this problem concerning the genealogy of appropriate matrix systems are classified. Relevant examples are given and the data that contradict the scheme proposed are discussed. The thermodynamics of the matrix stabilisation effect is considered using the concept of isomorphic miscibility. The influence of defects and non-equilibrium on the matrix stabilisation effect is discussed. The problem of identification of the oxidation states in matrix systems is examined and various types of matrix systems are considered.

  5. On matrix stabilisation of d- and f-transition metal ions in unstable oxidation states

    International Nuclear Information System (INIS)

    Kiselev, Yurii M

    2009-01-01

    The state-of-the-art in matrix stabilisation of d- and f-transition metal ions in unstable oxidation states is analysed. Main aspects of this problem concerning the genealogy of appropriate matrix systems are classified. Relevant examples are given and the data that contradict the scheme proposed are discussed. The thermodynamics of the matrix stabilisation effect is considered using the concept of isomorphic miscibility. The influence of defects and non-equilibrium on the matrix stabilisation effect is discussed. The problem of identification of the oxidation states in matrix systems is examined and various types of matrix systems are considered.

  6. Effects of Vanadium Ions in Different Oxidation States on Myosin ATPase Extracted from the Solitary Ascidian, Halocynthia roretzi (Drasche) : Biochemistry

    OpenAIRE

    HITOSHI, MICHIBATA; YUTAKA, ZENKO; KENJI, YAMADA; MASATO, HASEGAWA; TATSURO, TERADA; TAKAHARU, NUMAKUANI; Biological Institute, Faculty of Science, Toyama University; Biological Institute, Faculty of Science, Toyama University; Biological Institute, Faculty of Science, Toyama University; Biological Institute, Faculty of Science, Toyama University; Department of Chemistry, Toyama College of Technology; Marine Biological Station, Tohoku University

    1989-01-01

    Some ascidians are known to accumulate vanadium ion within their tissues by 10^6-fold as that in sea water and store the metal ion in its reduced tetravalent and/or trivalent states. It is also well known that phosphoenzymes are inhibited by pentavalent vanadium ion over a range of 10nM to 1mM. In the present experiment we have therefore examined the effects of vanadium ions in different oxidation states on the activity of myosin ATPase extracted from the mantle of the ascidian, Halocynthia r...

  7. Negative-ion states

    International Nuclear Information System (INIS)

    Compton, R.N.

    1982-01-01

    In this brief review, we discuss some of the properties of atomic and molecular negative ions and their excited states. Experiments involving photon reactions with negative ions and polar dissociation are summarized. 116 references, 14 figures

  8. Effect of 50 and 80 MeV phosphorous ions on the contribution of interface and oxide state density in n-channel MOSFETs

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.S.; Dhole, S.D.; Kanjilal, D.; Bhoraskar, V.N. E-mail: vnb@physics.unipune.ernet.in

    1999-07-02

    n-channel depletion MOS devices were irradiated with 50 and 80 MeV phosphorous ions, with different fluences varying in the range from 10{sup 11} to 10{sup 13} ions/cm{sup 2}. The pre and post irradiation I-V characteristics were measured and the corresponding threshold shift {delta}V{sub TH} was estimated. In both the cases, the drain current I{sub D} and the threshold voltage V{sub TH} were found to decrease with the ion fluence. The increase in the threshold voltage shift {delta}V{sub TH} with the ion fluence, was greater for the devices irradiated with 80 MeV ions than those irradiated with 50 MeV ions. The interface and oxide state densities were determined through the subthreshold voltage measurements. To separate the contributions of oxide and interface states towards the threshold voltage shift, the ion irradiated MOS devices were annealed at 150 deg. C. The threshold shift during annealing initially decreased and later increased with increasing annealing period. The rate of change of the interface states during annealing was higher than that of the oxide states. It was also found that depletion mode (normally ON) MOSFETs switched operation to enhancement mode (normally OFF)

  9. Ionic conductivity of metal oxides : an essential property for all-solid-state Lithium-ion batteries

    NARCIS (Netherlands)

    Chen, C.; Eichel, R.-A.; Notten, P.H.L.

    2017-01-01

    Essential progress has been made for adopting metal oxides (MeO) in various energy storage and energy conversion applications. Among these, utilizing MeO in Lithium-ions batteries (LIBs) seems to be one of the most promising applications. In particular, conductive Li-containing oxides or

  10. Facile and efficient room temperature solid state reaction enabled synthesis of antimony nanoparticles embedded within reduced graphene oxide for enhanced sodium-ion storage

    Science.gov (United States)

    Zhang, Xiukui; Wu, Ping; Jiang, Li; Zhang, Xiaofang; Shi, Hongxia; Zhu, Xiaoshu; Wei, Shaohua; Zhou, Yiming

    2018-06-01

    Herein, a very simple and cost-effective solid state reaction method is employed to obtain, for the first time, the antimony nanoparticles embedded within reduced graphene oxide matrices (designated as Sb/rGO). By directly grinding antimony chloride and sodium hydroxide together at room temperature in the presence of graphene oxide (GO), Sb4O5Cl2 precursor was quickly obtained, which is evenly incorporated in the graphene oxide matrices. After subsequent chemical reduction by NaBH4, the Sb/rGO composite was successfully synthesized. The as-prepared Sb/rGO composite consists of uniform Sb nanoparticles of sub-20 nm, all of which have been wrapped in and protected by the rGO matrices. The Sb nanoparticles serve as a sufficient sodium ion reservoir while the rGO matrices provide highly efficient pathways for transport of sodium ions and electrons. Moreover, the volume expansion of Sb during sodiation can be buffered in the rGO matrices. As a result, the Sb/rGO composite exhibits excellent electrochemical performance in sodium-ion batteries (SIBs), including an enhanced cycling stability with a highly reversible charge capacity of 455 mA h g-1 after 45 cycles at 100 mA g-1, and a coulombic efficiency exceeding 98% during cycling. The findings in the present work pave the way to not only synthesize the designated promising electrode materials for high performance SIBs, but also thoroughly understand the solid-state reaction.

  11. Carbon contaminant in the ion processing of aluminum oxide film

    International Nuclear Information System (INIS)

    Chaug, Y.; Roy, N.

    1989-01-01

    Ion processing can induce contamination on the bombarded surface. However, this process is essential for the microelectronics device fabrication. Auger electron spectroscopy has been used to study the simultaneous deposition of carbon impurity during ion bombardment of magnetron rf-sputtering deposited aluminum oxide film. Ion bombardment on aluminum oxide results in a preferential removal of surface oxygen and a formation of a metastable state of aluminum suboxide. Cosputtered implanted carbon contaminant appears to have formed a new state of stoichiometry on the surface of the ion bombarded aluminum oxide and existed as an aluminum carbide. This phase has formed due to the interaction of the implanted carbon and the aluminum suboxide. The Ar + ion sputter etching rate is reduced for the carbon contaminated oxide. The electrical resistance of the aluminum oxide between two gold strips has been measured. It is found that the electrical resistance is also reduced due to the formation of the new stoichiometry on the surface

  12. A series of inorganic solid nitrogen sources for the synthesis of metal nitride clusterfullerenes: the dependence of production yield on the oxidation state of nitrogen and counter ion.

    Science.gov (United States)

    Liu, Fupin; Guan, Jian; Wei, Tao; Wang, Song; Jiao, Mingzhi; Yang, Shangfeng

    2013-04-01

    A series of nitrogen-containing inorganic solid compounds with variable oxidation states of nitrogen and counter ions have been successfully applied as new inorganic solid nitrogen sources toward the synthesis of Sc-based metal nitride clusterfullerenes (Sc-NCFs), including ammonium salts [(NH4)xH(3-x)PO4 (x = 0-2), (NH4)2SO4, (NH4)2CO3, NH4X (X = F, Cl), NH4SCN], thiocyanate (KSCN), nitrates (Cu(NO3)2, NaNO3), and nitrite (NaNO2). Among them, ammonium phosphates ((NH4)xH(3-x)PO4, x = 1-3) and ammonium thiocyanate (NH4SCN) are revealed to behave as better nitrogen sources than others, and the highest yield of Sc-NCFs is achieved when NH4SCN was used as a nitrogen source. The optimum molar ratio of Sc2O3:(NH4)3PO4·3H2O:C and Sc2O3:NH4SCN:C has been determined to be 1:2:15 and 1:3:15, respectively. The thermal decomposition products of these 12 inorganic compounds have been discussed in order to understand their different performances toward the synthesis of Sc-NCFs, and accordingly the dependence of the production yield of Sc-NCFs on the oxidation state of nitrogen and counter ion is interpreted. The yield of Sc3N@C80 (I(h) + D(5h)) per gram Sc2O3 by using the N2-based group of nitrogen sources (thiocyanate, nitrates, and nitrite) is overall much lower than those by using gaseous N2 and NH4SCN, indicating the strong dependence of the yield of Sc-NCFs on the oxidation state of nitrogen, which is attributed to the "in-situ" redox reaction taking place for the N2-based group of nitrogen sources during discharging. For NH3-based group of nitrogen sources (ammonium salts) which exhibits a (-3) oxidation states of nitrogen, their performance as nitrogen sources is found to be sensitively dependent on the anion, and this is understood by considering their difference on the thermal stability and/or decomposition rate. Contrarily, for the N2-based group of nitrogen sources, the formation of Sc-NCFs is independent to both the oxidation state of nitrogen (+3 or +5) and the

  13. Electrochemical investigations of ion-implanted oxide films

    International Nuclear Information System (INIS)

    Schultze, J.W.; Danzfuss, B.; Meyer, O.; Stimming, U.

    1985-01-01

    Oxide films (passive films) of 40-50 nm thickness were prepared by anodic polarization of hafnium and titanium electrodes up to 20 V. Multiple-energy ion implantation of palladium, iron and xenon was used in order to obtain modified films with constant concentration profiles of the implanted ions. Rutherford backscattering, X-ray photoelectron spectroscopy measurements and electrochemical charging curves prove the presence of implanted ions, but electrochemical and photoelectrochemical measurements indicate that the dominating effect of ion implantation is the disordering of the oxide film. The capacity of hafnium electrodes increases as a result of an increase in the dielectric constant D. For titanium the Schottky-Mott analysis shows that ion implantation causes an increase in D and the donor concentration N. Additional electronic states in the band gap which are created by the implantation improve the conductivity of the semiconducting or insulating films. This is seen in the enhancement of electron transfer reactions and its disappearance during repassivation and annealing. Energy changes in the band gap are derived from photoelectrochemical measurements; the absorption edge of hafnium oxide films decreases by approximately 2 eV because of ion implantation, but it stays almost constant for titanium oxide films. All changes in electrochemical behavior caused by ion implantation show little variation with the nature of the implanted ion. Hence the dominating effect seems to be a disordering of the oxide. (Auth.)

  14. Synthesis and characterization of some complexes with imidazole and pyrazole from saccharinate transition ions in oxidation state (II)

    International Nuclear Information System (INIS)

    Pineda Cedeno, Leslie William

    2001-01-01

    The synthesis and characterization of metal ions saccharinate of the first serie of transition with the imidazole and pyrazole molecules in water and absolute ethanol were studied. In general, it found that in this series of saccharinate of coordinated water molecules are replaced by imidazole and pyrazole molecules with different substitution patterns, generating neutral complex of molecular formula [M(Sac) 2 (L) n (H 2 O) n-4 ] and cationic complex of molecular formula [M(L) n (H 2 O) 2 ]x2Sac, [M(L) n (H 2 O) 3 ]x2Sac, [M(L) n ]x2Sac, where M = V(II), Cr(II), Mc(II), Fe(II), Co(II), Ni(II) y Zn(II); Sac = saccharinate ion; L = imidazole (imd) and pyrazole (pir) and n = 6,4,3 and 2. These compounds are soluble in DMF and insoluble in all other common solvents. In turn, synthesized compounds in water were characterized by X ray crystallography, where preliminary data of refinement cycles, generate formulas of isostructural type [M(imd) 4 (H 2 O) 2 ]x2Sac and [M(Sac) 2 (pir) 2 (H 2 O) 2 ] where M = Co(II), Ni(II). The imidazole complex crystallize in the triclinic crystal system and space group P-1, while the pyrazole complexes crystallize in the monoclinic crystal system and space group P2 (1)/n. Gradual diminution was observed in the bond distances of M-N (saccharinate ion), M-N (imidazole) and M-N (pyrazole). The complex was characterized by spectroscopic methods, magnetic and electrochemical. (author) [es

  15. Thermodynamic properties of ternary oxides in the system Ba-Fe-O using solid-state electrochemical cells with oxide and fluoride ion conducting electrolytes

    Science.gov (United States)

    Rakshit, S. K.; Parida, S. C.; Singh, Ziley; Prasad, R.; Venugopal, V.

    2004-04-01

    The standard molar Gibbs energy of formations of BaFe 12O 19(s), BaFe 2O 4(s), Ba 2Fe 2O 5(s), Ba 3Fe 2O 6(s) and Ba 5Fe 2O 8(s) have been determined using solid-state electrochemical technique employing CaF 2(s) as an electrolyte. The reversible e.m.f. values have been measured in the temperature range from 970 to 1151 K. The oxygen chemical potential corresponding to three phase equilibria involving technologically important compound BaFe 12O 19(s) has been determined using solid-state electrochemical technique employing CSZ as an electrolyte from 1048 to 1221 K. The values of Δ fGm0( T) for the above ternary oxides are given by ΔfG m0( BaFe12O19, s)/ kJ mol -1(±0.6)=-5431.3+1.5317 (T/ K) (970⩽T/ K⩽1151) ΔfG m0( BaFe2O4, s)/ kJ mol -1(±1.3)=-1461.4+0.3745 (T/ K) (970⩽T/ K⩽1151) ΔfG m0( Ba2Fe2O5, s)/ kJ mol -1(±1.4)=-2038.3+0.4433 (T/ K) (970⩽T/ K⩽1149) ΔfG m0( Ba3Fe2O6, s)/ kJ mol -1(±1.5)=-2700.1+0.6090 (T/ K) (969⩽T/ K⩽1150) and ΔfG m0( Ba5Fe2O8, s)/ kJ mol -1(±1.6)=-3984.1+0.9300 (T/ K) (973⩽T/ K⩽1150) The uncertainty estimates for Δ fGm0 includes the standard deviation in the e.m.f. and uncertainty in the data taken from the literature. An isothermal oxygen potential diagram for the system Ba-Fe-O was constructed at 1100 K based on the thermodynamic data obtained in this study.

  16. Patterning of lithium lanthanum titanium oxide films by soft lithography as electrolyte for all-solid-state Li-ion batteries

    NARCIS (Netherlands)

    Kokal, I.; Göbel, Ole; van den Ham, E.J.; ten Elshof, Johan E.; Notten, P.H.L.; Hintzen, H.T.

    2015-01-01

    The combination of sol–gel processing and soft-lithographic patterning presents a promising route towards three-dimensional (3D) micro Li-ion electrodes, and may offer a viable approach for the fabrication of all-solid-state 3D Li-ion batteries. The methods are relatively simple and therefore cheap

  17. Patterning of lithium lanthanum titanium oxide films by soft lithography as electrolyte for all-solid-state Li-ion batteries

    NARCIS (Netherlands)

    Kokal, I.; Göbel, O.F.; van den Ham, E.J.; ten Elshof, J.E.; Notten, P.H.L.; Hintzen, H.T.

    2015-01-01

    The combination of sol-gel processing and soft-lithographic patterning presents a promising route towards three-dimensional (3D) micro Li-ion electrodes, and may offer a viable approach for the fabrication of all-solid-state 3D Li-ion batteries. The methods are relatively simple and therefore cheap

  18. Sorption of uranyl ions on hydrous oxides

    International Nuclear Information System (INIS)

    Gupta, A.R.; Venkataramani, B.

    1988-01-01

    Sorption of uranyl ions on hydrous titanium oxide (HTiO), magnetite (MAG), and hydrous thorium oxide (HThO) has been studied as a function of pH. Hydrous oxides have been characterized by their pH-titration curves, intrinsic dissociation constants (pK ai * ) and point of zero charge (pH pzc ). The fraction of protonated surface hydroxyl groups as well as the surface pH (pH surf ) as a function of solution pH have been computed. The distribution of various hydrolyzed species of uranyl ions with solution pH have been compared with uranyl sorption isotherm on these oxides. Sorption edge in all the cases occurs when free hydroxyl groups are available on the surface and pH surf is sufficiently high to favor the formation of dimer-like species on the surface. A new model for the sorption process, called surface hydrolysis model, which explains these and other features of uranyl sorption on hydrous oxides has been proposed. The model visualizes the sorption process as linking of uranyl ions with two adjacent free surface hydroxyl groups without deprotonation (provided the surface pH is high for the hydrolysis of uranyl ions) and formation of dimer-like structures on the surface. The new model has been successfully applied to the present and other available data on uranyl ion sorption on hydrous oxides. (author)

  19. Ion irradiation studies of oxide ceramics

    International Nuclear Information System (INIS)

    Zinkle, S.J.

    1988-01-01

    This paper presents the initial results of an investigation of the depth-dependent microstructures of three oxide ceramics following ion implantation to moderate doses. The implantations were performed using ion species that occur as cations in the target material; for example, Mg + ions were used for MgO and MgAl 2 O 4 (spinel) irradiations. This minimized chemical effects associated with the implantation and allowed a more direct evaluation to be made of the effects of implanted ions on the microstructure. 11 refs., 14 figs

  20. 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)

  1. Paramagnetism in ion-implanted oxides

    CERN Document Server

    Mølholt, Torben Esmann; Gíslason, Hafliði Pétur; Ólafsson, Sveinn

    This thesis describes the investigation on para-magnetism in dilute ion-implanted single-crystal oxide samples studied by on- and off-line $^{57}$Fe emission Mössbauer spectroscopy. The ion-implantation of the radioactive isotopes ( $^{57}$Mn and $^{57}$Co) was performed at the ISOLDE facility at CERN in Geneva, Switzerland. The off-line measurements were performed at Aarhus University, Denmark. Mössbauer spectroscopy is a unique method, giving simultaneously local information on valence/spin state of the $^{57}$Fe probe atoms, site symmetry and magnetic properties on an atomic scale. The utilisation of emission Mössbauer spectroscopy opens up many new possibilities compared with traditional transmission Mössbauer spectroscopy. Among them is the possibility of working with a low concentration below 10$^{-4}$ –10$^{-3}$ at.%, where the implanted Mössbauer $^{57}$Fe probes are truly dilute impurities exclusively interacting with their nearest neighbours and therefore the possibility of crea...

  2. Oxide interfaces with enhanced ion conductivity

    NARCIS (Netherlands)

    Leon, C.; Santamaria, J.; Boukamp, Bernard A.

    2013-01-01

    The new field of nano-ionics is expected to yield large improvements in the performance of oxide-based energy generation and storage devices based on exploiting size effects in ion conducting materials. The search for novel materials with enhanced ionic conductivity for application in energy devices

  3. Metal ion binding to iron oxides

    Science.gov (United States)

    Ponthieu, M.; Juillot, F.; Hiemstra, T.; van Riemsdijk, W. H.; Benedetti, M. F.

    2006-06-01

    The biogeochemistry of trace elements (TE) is largely dependent upon their interaction with heterogeneous ligands including metal oxides and hydrous oxides of iron. The modeling of TE interactions with iron oxides has been pursued using a variety of chemical models. The objective of this work is to show that it is possible to model the adsorption of protons and TE on a crystallized oxide (i.e., goethite) and on an amorphous oxide (HFO) in an identical way. Here, we use the CD-MUSIC approach in combination with valuable and reliable surface spectroscopy information about the nature of surface complexes of the TE. The other objective of this work is to obtain generic parameters to describe the binding of the following elements (Cd, Co, Cu, Ni, Pb, and Zn) onto both iron oxides for the CD-MUSIC approach. The results show that a consistent description of proton and metal ion binding is possible for goethite and HFO with the same set of model parameters. In general a good prediction of almost all the collected experimental data sets corresponding to metal ion binding to HFO is obtained. Moreover, dominant surface species are in agreement with the recently published surface complexes derived from X-ray absorption spectroscopy (XAS) data. Until more detailed information on the structure of the two iron oxides is available, the present option seems a reasonable approximation and can be used to describe complex geochemical systems. To improve our understanding and modeling of multi-component systems we need more data obtained at much lower metal ion to iron oxide ratios in order to be able to account eventually for sites that are not always characterized in spectroscopic studies.

  4. Modelling of low energy ion sputtering from oxide surfaces

    International Nuclear Information System (INIS)

    Kubart, T; Nyberg, T; Berg, S

    2010-01-01

    The main aim of this work is to present a way to estimate the values of surface binding energy for oxides. This is done by fitting results from the binary collisions approximation code Tridyn with data from the reactive sputtering processing curves, as well as the elemental composition obtained from x-ray photoelectron spectroscopy (XPS). Oxide targets of Al, Ti, V, Nb and Ta are studied. The obtained surface binding energies are then used to predict the partial sputtering yields. Anomalously high sputtering yield is observed for the TiO 2 target. This is attributed to the high sputtering yield of Ti lower oxides. Such an effect is not observed for the other studied metals. XPS measurement of the oxide targets confirms the formation of suboxides during ion bombardment as well as an oxygen deficient surface in the steady state. These effects are confirmed from the processing curves from the oxide targets showing an elevated sputtering rate in pure argon.

  5. Higher Americium Oxidation State Research Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Mincher, Bruce J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Law, Jack D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Goff, George S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lumetta, Gregg J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sinkov, Sergey I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shehee, Thomas C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hobbs, David T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-12-18

    The partitioning of hexavalent Am from dissolved nuclear fuel requires the ability to efficiently oxidize Am(III) to Am(VI) and to maintain that oxidation state for a length of time sufficient to perform the separation. Several oxidants have been, or are being developed. Chemical oxidants include Ag-catalyzed ozone, Ag-catalyzed peroxydisulfate, Cu(III) periodate, and sodium bismuthate. Hexavalent americium has also now successfully been prepared by electrolysis, using functionalized electrodes. So-called auto-reduction rates of Am(VI) are sufficiently slow to allow for separations. However, for separations based on solvent extraction or ion exchange using organic resins, the high valence state must be maintained under the reducing conditions of the organic phase contact, and a holding oxidant is probably necessary. Until now, only Cu(III) periodate and sodium bismuthate oxidation have been successfully combined with solvent extraction separations. Bismuthate oxidation provided the higher DAm, since it acts as its own holding oxidant, and a successful hot test using centrifugal contactors was performed. For the other oxidants, Ag-catalyzed peroxydisulfate will not oxidize americium in nitric acid concentrations above 0.3 M, and it is not being further investigated. Peroxydisulfate in the absence of Ag catalysis is being used to prepare Am(V) in ion exchange work, discussed below. Preliminary work with Ag-catalyzed ozone has been unsuccessful for extractions of Am(VI) from 6.5 M HNO3, and only one attempt at extraction, also from 6.5 M HNO3, using the electrolytic oxidation has been attempted. However, this high acid concentration was based on the highest Am extraction efficiency using the bismuthate oxidant; which is only sparingly soluble, and thus the oxidation yield is based on bismuthate solubility. Lower acid concentrations may be sufficient with alternative oxidants and work with Ag-ozone, Cu(III) and electrolysis is on-going. Two non

  6. Oxide glass structure evolution under swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Mendoza, C.; Peuget, S.; Charpentier, T.; Moskura, M.; Caraballo, R.; Bouty, O.; Mir, A.H.; Monnet, I.; Grygiel, C.; Jegou, C.

    2014-01-01

    Highlights: • Structure of SHI irradiated glass is similar to the one of a hyper quenched glass. • D2 Raman band associated to 3 members ring is only observed in irradiated glass. • Irradiated state seems slightly different to an equilibrated liquid quenched rapidly. - Abstract: The effects of ion tracks on the structure of oxide glasses were examined by irradiating a silica glass and two borosilicate glass specimens containing 3 and 6 oxides with krypton ions (74 MeV) and xenon ions (92 MeV). Structural changes in the glass were observed by Raman and nuclear magnetic resonance spectroscopy using a multinuclear approach ( 11 B, 23 Na, 27 Al and 29 Si). The structure of irradiated silica glass resembles a structure quenched at very high temperature. Both borosilicate glass specimens exhibited depolymerization of the borosilicate network, a lower boron coordination number, and a change in the role of a fraction of the sodium atoms after irradiation, suggesting that the final borosilicate glass structures were quenched from a high temperature state. In addition, a sharp increase in the concentration of three membered silica rings and the presence of large amounts of penta- and hexacoordinate aluminum in the irradiated 6-oxide glass suggest that the irradiated glass is different from a liquid quenched at equilibrium, but it is rather obtained from a nonequilibrium liquid that is partially relaxed by very rapid quenching within the ion tracks

  7. Oxide materials as positive electrodes of lithium-ion batteries

    International Nuclear Information System (INIS)

    Makhonina, Elena V; Pervov, Vladislav S; Dubasova, Valeriya S

    2004-01-01

    The published data on oxide materials as positive electrodes for lithium-ion batteries are described systematically. The mechanisms of structural changes in cathode materials occurring during the operation of lithium-ion batteries and the problems concerned with their selection are discussed. Modern trends in optimising cathode materials and lithium-ion batteries on the whole are considered.

  8. Decoherence of superposition states in trapped ions

    CSIR Research Space (South Africa)

    Uys, H

    2010-09-01

    Full Text Available This paper investigates the decoherence of superpositions of hyperfine states of 9Be+ ions due to spontaneous scattering of off-resonant light. It was found that, contrary to conventional wisdom, elastic Raleigh scattering can have major...

  9. State of the Art ECR Ion Sources

    International Nuclear Information System (INIS)

    Xie, Z.Q.

    1997-01-01

    Electron Cyclotron Resonance (ECR) ion source which produces highly-charged ions is used in heavy ion accelerators worldwide. Applications also found in atomic physics research and industry ion implantation. ECR ion source performance continues to improve, especially in the last few years with new techniques, such as multiple-frequency plasma heating and better methods to provide extra cold electrons, combined with higher magnetic mirror fields. So far more than 1 emA of multiply-charged ions such as He 2+ and O 6+ , and 30 eμA of Au 32+ , 1.1 eμA of 238 U 48+ , and epA currents of very high charge states such as 86 Kr 35+ and 238 U 60+ have been produced

  10. 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

  11. Periodic changes in the oxidation states of the center ion in the cobalt-histidine complex induced by the BrO3- - SO32- pH-oscillator

    Science.gov (United States)

    Kurin-Csörgei, Krisztina; Poros, Eszter; Csepiova, Julianna; Orbán, Miklós

    2018-05-01

    The coupling of acid-base type pH-dependent equilibria to pH-oscillators expanded significantly the number and type of species which can participate in oscillatory chemical processes. Here, we report a new version of oscillatory phenomena that can appear in coupled oscillators. Oscillations in the oxidation states of the center ion bound in a chelate complex were generated in a combined system, when the participants of the oscillator as dynamical unit and the components of the complex formation interacted with each other through redox reaction. It was demonstrated, when the BrO3- - SO32- pH-oscillator and the Co2+ - histidine complex were mixed in a continuous stirred tank reactor, periodic changes in the pH were accompanied with periodic transitions in the oxidation number of the cobalt ion between +2 and +3. The oscillatory build up and removal of the Co(III)-complex were followed by recording the light absorption at the wavelength characteristic for this species with simultaneous monitoring the pH-oscillations. The dual role of the SO32- ion in the explanation of this observation was pointed out. Its partial and consecutive total oxidations by BrO3- give rise to and maintain sustained pH-oscillations in the combined system and its presence induces the rapid conversion of the Co2+ to a highly inert Co(III)-histidine chelate when the system jumps to and remains in the high pH-state. The oscillatory cycle is completed when the Co(III)-complex is washed out from the reactor and the reagents are replenished by the flow during the time the system spends in the acidic range of pH. The idea, to couple a core oscillator to an equilibrium through a redox reaction that takes place between the constituents of the oscillator and the target species of the linked subsystem, may be generally used to bring about forced oscillations in many other combined chemical systems.

  12. Early stages of oxidation of ion-implanted nickel at high temperature

    International Nuclear Information System (INIS)

    Peide, Z.; Grant, W.A.; Procter, R.P.M.

    1981-01-01

    The early stages of oxidation of nickel implanted with nickel, chromium, or lithium ions in oxygen at 1100 0 C have been studied using various electron-optical techniques. The unimplanted metal develops initially a fine-grained, convoluted scale having a ridged, cellular structure. Subsequently, the oxide grains increase in size significantly and oxidation becomes predominantly controlled by diffusion of Ni /sup 2+/ ions across a compact, columnar scale. Implantation of the surface with nickel ions has no significant effect on the initial oxidation behavior. However, after implantation with chromium or lithium ions, the development of the NiO scale is, in the early stages of oxidation, suppressed by formation of NiCr 2 O 4 or LiO 2 nodules, respectively. Subsequently, the implanted species are incorporated into the steady-state NiO scale where they dope the oxide and thus influence the diffusion rate of Ni /sup 2+/ ions through it. As would be predicted, the steady-state oxidation rate of chromium-implanted nickel is increased while that of lithium- implanted nickel is decreased compared with that of the unimplanted metal

  13. Catalytic oxidation of silicon by cesium ion bombardment

    International Nuclear Information System (INIS)

    Souzis, A.E.; Huang, H.; Carr, W.E.; Seidl, M.

    1991-01-01

    Results for room-temperature oxidation of silicon using cesium ion bombardment and low oxygen exposure are presented. Bombardment with cesium ions is shown to allow oxidation at O 2 pressures orders of magnitude smaller than with noble gas ion bombardment. Oxide layers of up to 30 A in thickness are grown with beam energies ranging from 20--2000 eV, O 2 pressures from 10 -9 to 10 -6 Torr, and total O 2 exposures of 10 0 to 10 4 L. Results are shown to be consistent with models indicating that initial oxidation of silicon is via dissociative chemisorption of O 2 , and that the low work function of the cesium- and oxygen-coated silicon plays the primary role in promoting the oxidation process

  14. Use of ion conductors in the pyrochemical reduction of oxides

    International Nuclear Information System (INIS)

    Miller, W.E.; Tomczuk, Z.

    1994-01-01

    An electrochemical process and electrochemical cell for reducing a metal oxide are provided. First the oxide is separated as oxygen gas using, for example, a ZrO 2 oxygen ion conductor anode and the metal ions from the reduction salt are reduced and deposited on an ion conductor cathode, for example, sodium ion reduced on a β-alumina sodium ion conductor cathode. The generation of and separation of oxygen gas avoids the problem with chemical back reaction of oxygen with active metals in the cell. The method also is characterized by a sequence of two steps where an inert cathode electrode is inserted into the electrochemical cell in the second step and the metallic component in the ion conductor is then used as the anode to cause electrochemical reduction of the metal ions formed in the first step from the metal oxide where oxygen gas formed at the anode. The use of ion conductors serves to isolate the active components from chemically reacting with certain chemicals in the cell. While applicable to a variety of metal oxides, the invention has special importance for reducing CaO to Ca o used for reducing UO 2 and PuO 2 to U and Pu. 2 figures

  15. Ion beam and dual ion beam sputter deposition of tantalum oxide films

    Science.gov (United States)

    Cevro, Mirza; Carter, George

    1994-11-01

    Ion beam sputter deposition (IBS) and dual ion beam sputter deposition (DIBS) of tantalum oxide films was investigated at room temperature and compared with similar films prepared by e-gun deposition. Optical properties ie refractive index and extinction coefficient of IBS films were determined in the 250 - 1100 nm range by transmission spectrophotometry and at (lambda) equals 632.8 nm by ellipsometry. They were found to be mainly sensitive to the partial pressure of oxygen used as a reactive gas in the deposition process. The maximum value of the refractive index of IBS deposited tantalum oxide films was n equals 2.15 at (lambda) equals 550 nm and the extinction coefficient of order k equals 2 X 10-4. Films deposited by e-gun deposition had refractive index n equals 2.06 at (lambda) equals 550 nm. Films deposited using DIBS ie deposition assisted by low energy Ar and O2 ions (Ea equals 0 - 300 eV) and low current density (Ji equals 0 - 40 (mu) A/cm2) showed no improvement in the optical properties of the films. Preferential sputtering occurred at Ea(Ar) equals 300 eV and Ji equals 20 (mu) A/cm2 and slightly oxygen deficient films were formed. Different bonding states in the tantalum-oxide films were determined by x-ray spectroscopy while composition of the film and contaminants were determined by Rutherford scattering spectroscopy. Tantalum oxide films formed by IBS contained relatively high Ar content (approximately equals 2.5%) originating from the reflected argon neutrals from the sputtering target while assisted deposition slightly increased the Ar content. Stress in the IBS deposited films was measured by the bending technique. IBS deposited films showed compressive stress with a typical value of s equals 3.2 X 109 dyn/cm2. Films deposited by concurrent ion bombardment showed an increase in the stress as a function of applied current density. The maximum was s approximately equals 5.6 X 109 dyn/cm2 for Ea equals 300 eV and Ji equals 35 (mu) A/cm2. All

  16. Ion-beam and dual-ion-beam sputter deposition of tantalum oxide films

    Science.gov (United States)

    Cevro, Mirza; Carter, George

    1995-02-01

    Ion-beam sputter deposition (IBS) and dual-ion-beam sputter deposition (DIBS) of tantalum oxide films was investigated at room temperature and compared with similar films prepared by e-gun deposition. The optical properties, i.e., refractive index and extinction coefficient, of IBS films were determined in the 250- to 1100-nm range by transmission spectrophotometry and at (lambda) equals 632.8 nm by ellipsometry. They were found to be mainly sensitive to the partial pressure of oxygen used as a reactive gas in the deposition process. The maximum value of the refractive index of IBS deposited tantalum oxide films was n equals 2.15 at (lambda) equals 550 nm and the extinction coefficient of order k equals 2 X 10-4. Films deposited by e-gun deposition had refractive index n 2.06 at (lambda) equals 550 nm. Films deposited using DIBS, i.e., deposition assisted by low energy Ar and O2 ions (Ea equals 0 to 300 eV) and low current density (Ji equals 0 to 40 (mu) A/cm2), showed no improvement in the optical properties of the films. Preferential sputtering occurred at Ea(Ar) equals 300 eV and Ji equals 20 (mu) A/cm2 and slightly oxygen deficient films were formed. Different bonding states in the tantalum-oxide films were determined by x-ray spectroscopy, whereas composition of the film and contaminants were determined by Rutherford backscattering spectroscopy (RBS). Tantalum oxide films formed by IBS contained relatively high Ar content (approximately equals 2.5%) originating from the reflected argon neutrals from the sputtering target whereas assisted deposition slightly increased the Ar content. Stress in the IBS-deposited films was measured by the bending technique. IBS-deposited films showed compressive stress with a typical value of s equals 3.2 X 109 dyn/cm2. Films deposited by concurrent ion bombardment showed an increase in the stress as a function of applied current density. The maximum was s approximately equals 5.6 X 109 dyn/cm2 for Ea equals 300 eV and Ji equals

  17. Adhesive, abrasive and oxidative wear in ion-implanted metals

    International Nuclear Information System (INIS)

    Dearnaley, G.

    1985-01-01

    Ion implantation is increasingly being used to provide wear resistance in metals and cemented tungsten carbides. Field trials and laboratory tests indicate that the best performance is achieved in mild abrasive wear. This can be understood in terms of the classification of wear modes (adhesive, abrasive, oxidative etc.) introduced by Burwell. Surface hardening and work hardenability are the major properties to be enhanced by ion implantation. The implantation of nitrogen or dual implants of metallic and interstitial species are effective. Recently developed techniques of ion-beam-enhanced deposition of coatings can further improve wear resistance by lessening adhesion and oxidation. In order to support such hard coatings, ion implantation of nitrogen can be used as a preliminary treatment. There is thus emerging a versatile group of related hard vacuum treatments involving intense beams of nitrogen ions for the purpose of tailoring metal surfaces to resist wear. (Auth.)

  18. The influence of ion implantation on the oxidation of nickel

    International Nuclear Information System (INIS)

    Goode, P.D.

    1975-11-01

    The effects of ion implantation on the oxidation of polycrystalline nickel have been studied for a range of implanted species: viz. He, Li, Ne, Ca, Ti, Ni, Co, Xe, Ce and Bi. The oxides were grown in dry oxygen at 630 0 C and the 16 O(d,p) 17 O nuclear reaction technique used to determine the amount of oxygen taken up. The influence of atomic and ionic size, valency and electronegativity of the implanted impurities was studied as also were the effects of ion bombardment damage and the influence of sputtering during implantation. Atomic size and the annealing of disorder were found to have a marked influence on oxide growth rate. The dependence of oxidation on annealing was further studied by implanting polycrystalline specimens with self ions and observing the oxide growth rate as a function of annealing temperature. A peak in the curve was found at 400 0 C and a similar peak observed at a somewhat higher temperature for oxidised single crystals. It is concluded that the oxidation rate will be influenced by those factors which alter the epitaxial relationship between metal and growing oxide. Such factors include atomic size of the implanted species, surface strain induced by implantation and changes in surface topography as a result of sputtering. In addition a model based on vacancy assisted cation migration is proposed to explain enhanced oxidation observed over a limited temperature range. (author)

  19. Indium tin oxide surface smoothing by gas cluster ion beam

    CERN Document Server

    Song, J H; Choi, W K

    2002-01-01

    CO sub 2 cluster ions are irradiated at the acceleration voltage of 25 kV to remove hillocks on indium tin oxide (ITO) surfaces and thus to attain highly smooth surfaces. CO sub 2 monomer ions are also bombarded on the ITO surfaces at the same acceleration voltage to compare sputtering phenomena. From the atomic force microscope results, the irradiation of monomer ions makes the hillocks sharper and the surfaces rougher from 1.31 to 1.6 nm in roughness. On the other hand, the irradiation of CO sub 2 cluster ions reduces the height of hillocks and planarize the ITO surfaces as smooth as 0.92 nm in roughness. This discrepancy could be explained by large lateral sputtering yield of the cluster ions and re-deposition of sputtered particles by the impact of the cluster ions on surfaces.

  20. Charge state of oxide layer of SIMOX-structures

    CERN Document Server

    Askinazi, A Y; Dmitriev, V A; Miloglyadova, L V

    2001-01-01

    The charge state of the oxide layer of the SIMOX-structures, obtained in the course of forming the oxide layers, bricked up in the silicon volume, through the oxygen ions implantation into the Si, is studied. The charge state of the given structures is studied through the method of the layer-by-layer profiling, which makes it possible to obtain the dependence of the plane zones potential on the oxide layer thickness. It is established, that during the process of the SIMOX-structures formation in the oxide layer near the boundary with the Si there appear defects, responsible for the charge. The radiation from the near-the-ultraviolet (NUV) area without the applied electric field neutralizes the given charge. The simultaneous impact of the NUV-radiation and electric field leads to the formation of significantly positive charge

  1. Air, aqueous and thermal stabilities of Ce3+ ions in cerium oxide nanoparticle layers with substrates

    KAUST Repository

    Naganuma, Tamaki

    2014-01-01

    Abundant oxygen vacancies coexisting with Ce3+ ions in fluorite cerium oxide nanoparticles (CNPs) have the potential to enhance catalytic ability, but the ratio of unstable Ce3+ ions in CNPs is typically low. Our recent work, however, demonstrated that the abundant Ce3+ ions created in cerium oxide nanoparticle layers (CNPLs) by Ar ion irradiation were stable in air at room temperature. Ce valence states in CNPs correlate with the catalytic ability that involves redox reactions between Ce3+ and Ce4+ ions in given application environments (e.g. high temperature in carbon monoxide gas conversion and immersion conditions in biomedical applications). To better understand the mechanism by which Ce3+ ions achieve stability in CNPLs, we examined (i) extra-long air-stability, (ii) thermal stability up to 500 °C, and (iii) aqueous stability of Ce 3+ ions in water, buffer solution and cell culture medium. It is noteworthy that air-stability of Ce3+ ions in CNPLs persisted for more than 1 year. Thermal stability results showed that oxidation of Ce 3+ to Ce4+ occurred at 350 °C in air. Highly concentrated Ce3+ ions in ultra-thin CNPLs slowly oxidized in water within 1 day, but stability was improved in the cell culture medium. Ce 3+ stability of CNPLs immersed in the medium was associated with phosphorus adsorption on the Ce3+ sites. This study also illuminates the potential interaction mechanisms of stable Ce3+ ions in CNPLs. These findings could be utilized to understand catalytic mechanisms of CNPs with abundant oxygen vacancies in their application environments. © The Royal Society of Chemistry 2014.

  2. Photoionization and ion cyclotron resonance studies of the ion chemistry of ethylene oxide

    Science.gov (United States)

    Corderman, R. R.; Williamson, A. D.; Lebreton, P. R.; Buttrill, S. E., Jr.; Beauchamp, J. L.

    1976-01-01

    The formation of the ethylene oxide molecular ion and its subsequent ion-molecule reactions leading to the products C2H5O(+) and C3H5O(+) have been studied using time-resolved photoionization mass spectroscopy, ion cyclotron resonance spectroscopy, and photoelectron spectroscopy. An examination of the effects of internal energy on reactivity shows that the ratio of C3H5O(+) to C2H5O(+) increases by an order of magnitude with a single quantum of vibrational energy. The formation of (C2H4O/+/)-asterisk in a collision-induced isomerization is found which yields a ring-opened structure by C-C bond cleavage. The relaxed ring-opened C2H4O(+) ion reacts with neutral ethylene oxide by CH2(+) transfer to yield an intermediate product ion C3H6O(+) which gives C3H5O(+) by loss of H.

  3. Oxidation of cyclohexane catalyzed by metal-ion-exchanged zeolites.

    Science.gov (United States)

    Sökmen, Ilkay; Sevin, Fatma

    2003-08-01

    The ion-exchange rates and capacities of the zeolite NaY for the Cu(II), Co(II), and Pb(II) metal ions were investigated. Ion-exchange equilibria were achieved in approximately 72 h for all the metal ions. The maximum ion exchange of metal ions into the zeolite was found to be 120 mg Pb(II), 110 mg Cu(II), and 100 mg Co(II) per gram of zeolite NaY. It is observed that the exchange capacity of a zeolite varies with the exchanged metal ion and the amount of metal ions exchanged into zeolite decreases in the sequence Pb(II) > Cu(II) > Co(II). Application of the metal-ion-exchanged zeolites in oxidation of cyclohexane in liquid phase with visible light was examined and it is observed that the order of reactivity of the zeolites for the conversion of cyclohexane to cyclohexanone and cyclohexanol is CuY > CoY > PbY. It is found that conversion increases by increase of the empty active sites of a zeolite and the formation of cyclohexanol is favored initially, but the cyclohexanol is subsequently converted to cyclohexanone.

  4. Vacuum arc ion charge state distributions

    International Nuclear Information System (INIS)

    Brown, I.G.; Godechot, X.

    1990-06-01

    We have measured vacuum arc ion charge state spectra for a wide range of metallic cathode materials. The charge state distributions were measured using a time-of-flight diagnostic to monitor the energetic ion beam produced by a metal vapor vacuum arc ion source. We have obtained data for 48 metallic cathode elements: Li, C, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Sr, Y, Zr, Nb, Mo, Pd, Ag, Cd, In, Sn, Ba, La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, Yb, Hf, Ta, W, Ir, Pt, Au, Pb, Bi, Th and U. The arc was operated in a pulsed mode with pulse length 0.25 msec; arc current was 100 A throughout. This array of elements extends and completes previous work by us. In this paper the measured distributions are cataloged and compared with our earlier results and with those of other workers. We also make some observations about the performance of the various elements as suitable vacuum arc cathode materials

  5. Vacuum arc ion charge-state distributions

    International Nuclear Information System (INIS)

    Brown, I.G.; Godechot, X.

    1991-01-01

    The authors have measured vacuum arc ion charge-state spectra for a wide range of metallic cathode materials. The charge-state distributions were measured using a time-of-flight diagnostic to monitor the energetic ion beam produced by a metal vapor vacuum arc ion source. They have obtained data for 48 metallic cathode elements: Li, C, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Sr, Y, Zr, Nb, Mo, Pd, Ag, Cd, In, Sn, Ba, La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, Yb, Hf, Ta, W, Ir, Pt, Au, Pb, Bi, Th, and U. The arc was operated in a pulsed mode with pulse length 0.25 ms; arc current was 100 A throughout. This array of elements extends and completes previous work by the authors. In this paper the measured distributions are cataloged and compared with their earlier results and those of other workers. They also make some observations about the performance of the various elements as suitable vacuum arc cathode materials

  6. Charge-transfer spectra of tetravalent lanthanide ions in oxides

    NARCIS (Netherlands)

    Hoefdraad, H.E.

    The charge-transfer spectra of Ce4+, Pr4+ and Tb4+ in a number of oxides are reported. It is noted that the position of the first charge-transfer band is fixed for the metal ion in an oxygen coordination of VI, but varies in VIII coordination as a function of the host lattice. It is argued that this

  7. High-temperature oxidation of ion-implanted tantalum

    International Nuclear Information System (INIS)

    Kaufmann, E.N.; Musket, R.G.; Truhan, J.J.; Grabowski, K.S.; Singer, I.L.; Gossett, C.R.

    1982-01-01

    The oxidation of ion-implanted Ta in two different high temperature regimes has been studied. Oxidations were carried out at 500 0 C in Ar/O 2 mixtures, where oxide growth is known to follow a parabolic rate law in initial stages, and at 1000 0 C in pure O 2 , where a linear-rate behavior obtains. Implanted species include Al, Ce, Cr, Li, Si and Zr at fluences of the order of 10 17 /cm 2 . Oxidized samples were studied using Rutherford backscattering, nuclear reaction analysis, Auger spectroscopy, secondary-ion mass spectroscopy, x-ray diffraction and optical microscopy. Significant differences among the specimens were noted after the milder 500 0 C treatment, specifically, in the amount of oxide formed, the degree of oxygen dissolution in the metal beneath the oxide, and in the redistribution behavior of the implanted solutes. Under the severe 1000 0 C treatment, indications of different solute distributions and of different optical features were found, whereas overall oxidation rate appeared to be unaffected by the presence of the solute. 7 figures

  8. Factors controlling the oxide ion conductivity of fluorite and perovskite structured oxides

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Lybye, D.; Bonanos, N.

    2004-01-01

    Many metal oxides of fluorite and perovskite related structures are oxide ion conductors, which have practical applications in devices such as oxygen sensors, solid oxide fuel cells (SOFC) and electrolysers. Several structural and thermodynamic parameters such as (1) critical radius of the pathway...... such parameters for fluorite and perovskite oxides by considering their sensitivities to the individual ionic radii. Based on experimental data available in the literature, it is argued that lattice distortion (lattice stress and deviation from cubic symmetry) due to ion radii mismatch determines the ionic...... conductivity to a very large extent, and that lattice distortion is of much greater importance than many other proposed parameters. In case of the perovskites, the charge of the B-site ion is also of major importance. (C) 2004 Published by Elsevier B.V....

  9. Oxidation-state maxima in plutonium chemistry

    International Nuclear Information System (INIS)

    Silver, G.L.

    2013-01-01

    Maxima in the fractions of the trivalent and hexavalent oxidation states of plutonium are inherent in the algebra of its disproportionation reactions. The maxima do not support overall disproportionation equations as satisfactory representations of aqueous plutonium. (author)

  10. New lithium-ion conducting perovskite oxides related to (Li, La)TiO3

    Indian Academy of Sciences (India)

    Unknown

    We describe the synthesis and lithium-ion conductivity of new perovskite-related oxides ... work on lithium-ion conducting perovskite oxides containing d0 cations. Keywords. ..... On the other hand, Nb/Ta compounds show a higher conductivity.

  11. Optoelectronic properties of valence-state-controlled amorphous niobium oxide

    Science.gov (United States)

    Onozato, Takaki; Katase, Takayoshi; Yamamoto, Akira; Katayama, Shota; Matsushima, Koichi; Itagaki, Naho; Yoshida, Hisao; Ohta, Hiromichi

    2016-06-01

    In order to understand the optoelectronic properties of amorphous niobium oxide (a-NbO x ), we have investigated the valence states, local structures, electrical resistivity, and optical absorption of a-NbO x thin films with various oxygen contents. It was found that the valence states of Nb ion in a-NbO x films can be controlled from 5+  to 4+  by reducing oxygen pressure during film deposition at room temperature, together with changing the oxide-ion arrangement around Nb ion from Nb2O5-like to NbO2-like local structure. As a result, a four orders of magnitude reduction in the electrical resistivity of a-NbO x films was observed with decreasing oxygen content, due to the carrier generation caused by the appearance and increase of an oxygen-vacancy-related subgap state working as an electron donor. The tunable optoelectronic properties of a-NbO x films by valence-state-control with oxygen-vacancy formation will be useful for potential flexible optoelectronic device applications.

  12. Lithium ion behavior in lithium oxide by neutron scattering studies

    International Nuclear Information System (INIS)

    Ishii, Yoshinobu; Morii, Yukio; Katano, Susumu; Watanabe, Hitoshi; Funahashi, Satoru; Ohno, Hideo; Nicklow, R.M.

    1992-01-01

    Lithium ion behavior in lithium oxide, Li 2 O, was studied in the temperature range from 293 K to 1120 K by the High-Resolution Powder Diffractometer (HRPD) installed in the JRR-3M. The diffraction patterns were analyzed with the RIETAN program. At room temperature, the thermal parameters related to the mean square of the amplitude of vibration of the lithium and the oxygen ions were 6 x 10 -21 m 2 and 4 x 10 -21 m 2 , respectively. AT 1120 K the thermal parameter of the lithium ion was 34 x 10 -21 m 2 . On the other hand, the parameter of the oxygen ion was 16 x 10 -21 m 2 . Inelastic neutron scattering studies for the lithium oxide single crystal were also carried out on the triple-axis neutron spectrometers installed at the JRR-2 and the HFIR. Although the value of a phonon energy of a transverse acoustic mode (Σ 3 ) at zone boundary was 30.6 meV at room temperature, this value was decreased to 25.1 meV at 700 K. This large softening was caused by anharmonicity of the crystal potential of lithium oxide. (author)

  13. Concept for high-charge-state ion induction accelerators

    International Nuclear Information System (INIS)

    Logan, B.G.; Perry, M.D.; Caporaso, G.J.

    1996-01-01

    This work describes a particular concept for ion induction linac accelerators using high-charge-state ions produced by an intense, short pulse laser, and compares the costs of a modular driver system producing 6.5 MJ for a variety of ion masses and charge states using a simple but consistent cost model

  14. Tunable sieving of ions using graphene oxide membranes

    Science.gov (United States)

    Abraham, Jijo; Vasu, Kalangi S.; Williams, Christopher D.; Gopinadhan, Kalon; Su, Yang; Cherian, Christie T.; Dix, James; Prestat, Eric; Haigh, Sarah J.; Grigorieva, Irina V.; Carbone, Paola; Geim, Andre K.; Nair, Rahul R.

    2017-07-01

    Graphene oxide membranes show exceptional molecular permeation properties, with promise for many applications. However, their use in ion sieving and desalination technologies is limited by a permeation cutoff of ˜9 Å (ref. 4), which is larger than the diameters of hydrated ions of common salts. The cutoff is determined by the interlayer spacing (d) of ˜13.5 Å, typical for graphene oxide laminates that swell in water. Achieving smaller d for the laminates immersed in water has proved to be a challenge. Here, we describe how to control d by physical confinement and achieve accurate and tunable ion sieving. Membranes with d from ˜9.8 Å to 6.4 Å are demonstrated, providing a sieve size smaller than the diameters of hydrated ions. In this regime, ion permeation is found to be thermally activated with energy barriers of ˜10-100 kJ mol-1 depending on d. Importantly, permeation rates decrease exponentially with decreasing sieve size but water transport is weakly affected (by a factor of <2). The latter is attributed to a low barrier for the entry of water molecules and large slip lengths inside graphene capillaries. Building on these findings, we demonstrate a simple scalable method to obtain graphene-based membranes with limited swelling, which exhibit 97% rejection for NaCl.

  15. Defects and defect generation in oxide layer of ion implanted silicon-silicon dioxide structures

    CERN Document Server

    Baraban, A P

    2002-01-01

    One studies mechanism of generation of defects in Si-SiO sub 2 structure oxide layer as a result of implantation of argon ions with 130 keV energy and 10 sup 1 sup 3 - 3.2 x 10 sup 1 sup 7 cm sup - sup 2 doses. Si-SiO sub 2 structures are produced by thermal oxidation of silicon under 950 deg C temperature. Investigations were based on electroluminescence technique and on measuring of high-frequency volt-farad characteristics. Increase of implantation dose was determined to result in spreading of luminosity centres and in its maximum shifting closer to boundary with silicon. Ion implantation was shown, as well, to result in increase of density of surface states at Si-SiO sub 2 interface. One proposed model of defect generation resulting from Ar ion implantation into Si-SiO sub 2

  16. Relationships between nitric oxide, nitroxyl ion, nitrosonium cation and peroxynitrite.

    Science.gov (United States)

    Hughes, M N

    1999-05-05

    This review is concerned mainly with the three redox-related, but chemically distinct, species NO-, NO. and NO+, with greatest emphasis being placed on the chemistry and biology of the nitroxyl ion. Biochemical routes for the formation of nitroxyl ion and methods for showing the intermediacy of this species are discussed, together with chemical methods for generating nitroxyl ion in solution. Reactions of nitroxyl ion with NO., thiols, iron centres in haem and with dioxygen are reviewed The significance of the reaction between NO- and dioxygen as a source of peroxynitrite is assessed, and attention drawn to the possible significance of the spin state of the nitroxyl ion in this context. The biological significance of nitrosation and the importance of S-nitrosothiols and certain metal nitrosyl complexes as carriers of NO+ at physiological pH is stressed. Some features in the chemistry of peroxynitrite are noted.

  17. Effect of oxide ion concentration on the electrochemical oxidation of carbon in molten LiCl

    International Nuclear Information System (INIS)

    Yun, J. W.; Choi, I. K.; Park, Y. S.; Kim, W. H.

    2001-01-01

    The continuous measurement of lithium oxide concentration was required in DOR (Direct Oxide Reduction) process, which converts spent nuclear fuel to metal form, for the reactivity monitor and effective control of the process. The concentration of lithium oxide was measured by the electrochemical method, which was based on the phenomenon that carbon atoms of glassy carbon electrode electrochemically react with oxygen ions of lithium oxide in molten LiCl medium. From the results of electrode polarization experiments, the trend of oxidation rate of carbon atoms was classified into two different regions, which were proportional and non-proportional ones, dependent on the amount of lithium oxide. Below about 2.5 wt % Li 2 O, as the carbon atom ionization rate was fast enough for reacting with diffusing lithium oxide to the surface of carbon electrode. In this concentration range, the oxidation rate of carbon atoms was controlled by the diffusion of lithium oxide, and the concentration of lithium oxide could be measured by electrochemical method. But, above 2.5 wt % Li 2 O, the oxidation rate of carbon atoms was controlled by the applied electrochemical potential, because the carbon atom ionization rate was suppressed by the huge amounts of diffusing Li 2 O. Above this concentration, the electrochemical method was not applicable to determine the concentration of lithium oxide

  18. Electronic structure and dynamics of ordered clusters with ME or RE ions on oxide surface

    Energy Technology Data Exchange (ETDEWEB)

    Kulagin, N.A., E-mail: nkulagin@bestnet.kharkov.u [Kharkiv National University for Radio Electronics, Avenue Shakespeare 6-48, 61045 Kharkiv (Ukraine)

    2011-03-15

    Selected data of ab initio simulation of the electronic structure and spectral properties of either cluster with ions of iron, rare earth or actinium group elements have been presented here. Appearance of doped Cr{sup +4} ions in oxides, Cu{sup +2} in HTSC, Nd{sup +2} in solids has been discussed. Analysis of experimental data for plasma created ordered structures of crystallites with size of about 10{sup -9} m on surface of separate oxides are given, too. Change in the spectroscopic properties of clusters and nano-structures on surface of strontium titanate crystals discussed shortly using the X-ray line spectroscopy experimental results. - Research highlights: External influence and variation of technology induce changes in valence of nl ions in compounds. Wave function of cluster presented as anti-symmetrical set of ions wave functions. The main equation describes the self-consistent field depending on state of all electrons of cluster. Level scheme of Cr{sup 4+} ions in octo- and tetra-site corresponds to doped oxides spectra after treatment. Plasma treatment effects in appearance of systems of unit crystallites with size of about 10{sup -6}-10{sup -9} m.

  19. Electronic structure and dynamics of ordered clusters with ME or RE ions on oxide surface

    International Nuclear Information System (INIS)

    Kulagin, N.A.

    2011-01-01

    Selected data of ab initio simulation of the electronic structure and spectral properties of either cluster with ions of iron, rare earth or actinium group elements have been presented here. Appearance of doped Cr +4 ions in oxides, Cu +2 in HTSC, Nd +2 in solids has been discussed. Analysis of experimental data for plasma created ordered structures of crystallites with size of about 10 -9 m on surface of separate oxides are given, too. Change in the spectroscopic properties of clusters and nano-structures on surface of strontium titanate crystals discussed shortly using the X-ray line spectroscopy experimental results. - Research highlights: → External influence and variation of technology induce changes in valence of nl ions in compounds. → Wave function of cluster presented as anti-symmetrical set of ions wave functions. → The main equation describes the self-consistent field depending on state of all electrons of cluster. → Level scheme of Cr 4+ ions in octo- and tetra-site corresponds to doped oxides spectra after treatment. → Plasma treatment effects in appearance of systems of unit crystallites with size of about 10 -6 -10 -9 m.

  20. Kinetic studies of electrochemical generation of Ag(II) ion and catalytic oxidation of selected organics

    International Nuclear Information System (INIS)

    Zawodzinski, C.; Smith, W.H.; Martinez, K.R.

    1993-01-01

    The goal of this research is to develop a method to treat mixed hazardous wastes containing selected organic compounds and heavy metals, including actinide elements. One approach is to destroy the organic via electrochemical oxidation to carbon dioxide, then recover the metal contaminants through normally accepted procedures such as ion exchange, precipitation, etc. The authors have chosen to study the electrochemical oxidation of a simple alcohol, iso-propanol. Much of the recent work reported involved the use of an electron transfer mediator, usually the silver(I)/(II) redox couple. This involved direct electrochemical generation of the mediator at the anode of a divided cell followed by homogeneous reaction of the mediator with the organic compound. In this study the authors have sought to compare the mediated reaction with direct electrochemical oxidation of the organic. In addition to silver(I)/(II) they also looked at the cobalt(II)/(III) redox coupled. In the higher oxidation state both of these metal ions readily hydrolyze in aqueous solution to ultimately form insoluble oxide. The study concluded that in a 6M nitric acid solution at room temperature iso-propanol can be oxidized to carbon dioxide and acetic acid. Acetic acid is a stable intermediate and resists further oxidation. The presence of Co(III) enhances the rate or efficiency of the reaction

  1. Ion beam synthesis of indium-oxide nanocrystals for improvement of oxide resistive random-access memories

    Science.gov (United States)

    Bonafos, C.; Benassayag, G.; Cours, R.; Pécassou, B.; Guenery, P. V.; Baboux, N.; Militaru, L.; Souifi, A.; Cossec, E.; Hamga, K.; Ecoffey, S.; Drouin, D.

    2018-01-01

    We report on the direct ion beam synthesis of a delta-layer of indium oxide nanocrystals (In2O3-NCs) in silica matrices by using ultra-low energy ion implantation. The formation of the indium oxide phase can be explained by (i) the affinity of indium with oxygen, (ii) the generation of a high excess of oxygen recoils generated by the implantation process in the region where the nanocrystals are formed and (iii) the proximity of the indium-based nanoparticles with the free surface and oxidation from the air. Taking advantage of the selective diffusivity of implanted indium in SiO2 with respect to Si3N4, In2O3-NCs have been inserted in the SiO2 switching oxide of micrometric planar oxide-based resistive random access memory (OxRAM) devices fabricated using the nanodamascene process. Preliminary electrical measurements show switch voltage from high to low resistance state. The devices with In2O3-NCs have been cycled 5 times with identical operating voltages and RESET current meanwhile no switch has been observed for non implanted devices. This first measurement of switching is very promising for the concept of In2O3-NCs based OxRAM memories.

  2. Nanosystems in Ceramic Oxides Created by Means of Ion Implantation

    OpenAIRE

    Van Huis, M.A.

    2003-01-01

    The material properties of nanometer-sized clusters are dependent on the cluster size. Changing the cluster dimensions induces structural phase transformations, metal-insulator transitions, non-linear optical properties and widening of the band gap of semiconductors. In this work, nanoclusters are created by ion implantation followed by thermal annealing. The ceramic oxides MgO and Al2O3 are used as embedding materials because of their stability and optical transparency. All clusters were cre...

  3. The problem of oxidation state stabilisation and some regularities of a Periodic system of the elements

    International Nuclear Information System (INIS)

    Kiselev, Yurii M; Tretyakov, Yuri D

    1999-01-01

    The general principles of the concept of oxidation state stabilisation are formulated. Problems associated with the preparation and provision of the highest valent forms of transition elements are considered. The empirical data concerning the synthesis of new compounds of rare-earth elements and d elements in unusually high oxidation states are analysed. The possibility of occurrence of the oxidation states + 9 and + 10 for some elements (for example, for iridium and platinum in tetraoxo ions) are discussed. Approaches to the realisation of these states are outlined and it is demonstrated that solid phases or matrices containing alkali metal cations are the most promising systems for the stabilisation of these high oxidation states. Selected thermodynamic features typical of metal halides and oxides and the regularities of the changes in the extreme oxidation states of d elements are considered. The bibliography includes 266 references.

  4. Heavy-ion induced current through an oxide layer

    International Nuclear Information System (INIS)

    Takahashi, Yoshihiro; Ohki, Takahiro; Nagasawa, Takaharu; Nakajima, Yasuhito; Kawanabe, Ryu; Ohnishi, Kazunori; Hirao, Toshio; Onoda, Shinobu; Mishima, Kenta; Kawano, Katsuyasu; Itoh, Hisayoshi

    2007-01-01

    In this paper, the heavy-ion induced current in MOS structure is investigated. We have measured the transient gate current in a MOS capacitor and a MOSFET induced by single heavy-ions, and found that a transient current can be observed when the semiconductor surface is under depletion condition. In the case of MOSFET, a transient gate current with both positive and negative peaks is observed if the ion hits the gate area, and that the total integrated charge is almost zero within 100-200 ns after irradiation. From these results, we conclude that the radiation-induced gate current is dominated by a displacement current. We also discuss the generation mechanism of the radiation-induced current through the oxide layer by device simulation

  5. Stability and electronic properties of groups IIB to VB metal ions in unusual oxidation states and the 2S /SUB 1/2/ electronic state in lithium borate glasses

    International Nuclear Information System (INIS)

    Aleksandrov, A.I.; Bubnov, N.N.; Kraevskii, S.L.; Prokof'ev, A.I.; Raspertova, Z.I.; Solinov, V.F.

    1986-01-01

    The authors study lithium borate glasses containing groups IIB to VB metal oxides. Chemically pure reagents were used to synthesize the glasses which were subjected to gamma-rays at 77 and 300 K with doses of up to 100 kR. The EST spectra were recorded on a Varian E-12 spectrometer in the 3 cm CW frequency region with a 100 kHz magnetic field modulation. It was established that after gamma-irradiation at 77 and 300 K of the lithium borate glass system containing up to 10% of cadmium, tin, thalium, and lead oxides, additional ESR lines arise in the free electron g factor region. The authors have determined the missing ESR spectra for nonactivated lithium borate glasses by studying glasses with additions of Zn, Ge, and Sb oxides

  6. Synthesis of ultrasmall Li-Mn spinel oxides exhibiting unusual ion exchange, electrochemical, and catalytic properties

    Science.gov (United States)

    Miyamoto, Yumi; Kuroda, Yoshiyuki; Uematsu, Tsubasa; Oshikawa, Hiroyuki; Shibata, Naoya; Ikuhara, Yuichi; Suzuki, Kosuke; Hibino, Mitsuhiro; Yamaguchi, Kazuya; Mizuno, Noritaka

    2015-10-01

    The efficient surface reaction and rapid ion diffusion of nanocrystalline metal oxides have prompted considerable research interest for the development of high functional materials. Herein, we present a novel low-temperature method to synthesize ultrasmall nanocrystalline spinel oxides by controlling the hydration of coexisting metal cations in an organic solvent. This method selectively led to Li-Mn spinel oxides by tuning the hydration of Li+ ions under mild reaction conditions (i.e., low temperature and short reaction time). These particles exhibited an ultrasmall crystallite size of 2.3 nm and a large specific surface area of 371 ± 15 m2 g-1. They exhibited unique properties such as unusual topotactic Li+/H+ ion exchange, high-rate discharge ability, and high catalytic performance for several aerobic oxidation reactions, by creating surface phenomena throughout the particles. These properties differed significantly from those of Li-Mn spinel oxides obtained by conventional solid-state methods.

  7. Synthesis of ultrasmall Li–Mn spinel oxides exhibiting unusual ion exchange, electrochemical, and catalytic properties

    Science.gov (United States)

    Miyamoto, Yumi; Kuroda, Yoshiyuki; Uematsu, Tsubasa; Oshikawa, Hiroyuki; Shibata, Naoya; Ikuhara, Yuichi; Suzuki, Kosuke; Hibino, Mitsuhiro; Yamaguchi, Kazuya; Mizuno, Noritaka

    2015-01-01

    The efficient surface reaction and rapid ion diffusion of nanocrystalline metal oxides have prompted considerable research interest for the development of high functional materials. Herein, we present a novel low-temperature method to synthesize ultrasmall nanocrystalline spinel oxides by controlling the hydration of coexisting metal cations in an organic solvent. This method selectively led to Li–Mn spinel oxides by tuning the hydration of Li+ ions under mild reaction conditions (i.e., low temperature and short reaction time). These particles exhibited an ultrasmall crystallite size of 2.3 nm and a large specific surface area of 371 ± 15 m2 g−1. They exhibited unique properties such as unusual topotactic Li+/H+ ion exchange, high-rate discharge ability, and high catalytic performance for several aerobic oxidation reactions, by creating surface phenomena throughout the particles. These properties differed significantly from those of Li–Mn spinel oxides obtained by conventional solid-state methods. PMID:26456216

  8. Adsorption of Cadmium Ions from Water on Double-walled Carbon Nanotubes/Iron Oxide Composite

    Directory of Open Access Journals (Sweden)

    Karima Seffah

    2017-12-01

    Full Text Available A new material (DWCNT/iron oxide for heavy metals removal was developed by combining the adsorption features of double-walled carbon nanotubes with the magnetic properties of iron oxides. Batch experiments were applied in order to evaluate adsorption capacity of the DWCNT/iron oxide composite for cadmium ions. The influence of operating parameters such as pH value, amount of adsorbent, initial adsorbate concentration and agitation speed was studied. The adsorption capacity of the DWCNT/iron oxide adsorbent for Cd2+ ions was 20.8 mg g-1, which is at the state of the art. The obtained results revealed that DWCNT/iron oxide composite is a very promising adsorbent for removal of Cd2+ ions from water under natural conditions. The advantage of the magnetic composite is that it can be used as adsorbent for contaminants in water and can be subsequently controlled and removed from the medium by a simple magnetic process.

  9. Comparison of reduction products from graphite oxide and graphene oxide for anode applications in lithium-ion batteries and sodium-ion batteries.

    Science.gov (United States)

    Sun, Yige; Tang, Jie; Zhang, Kun; Yuan, Jinshi; Li, Jing; Zhu, Da-Ming; Ozawa, Kiyoshi; Qin, Lu-Chang

    2017-02-16

    Hydrazine-reduced graphite oxide and graphene oxide were synthesized to compare their performances as anode materials in lithium-ion batteries and sodium-ion batteries. Reduced graphite oxide inherits the layer structure of graphite, with an average spacing between neighboring layers (d-spacing) of 0.374 nm; this exceeds the d-spacing of graphite (0.335 nm). The larger d-spacing provides wider channels for transporting lithium ions and sodium ions in the material. We showed that reduced graphite oxide as an anode in lithium-ion batteries can reach a specific capacity of 917 mA h g -1 , which is about three times of 372 mA h g -1 , the value expected for the LiC 6 structures on the electrode. This increase is consistent with the wider d-spacing, which enhances lithium intercalation and de-intercalation on the electrodes. The electrochemical performance of the lithium-ion batteries and sodium-ion batteries with reduced graphite oxide anodes show a noticeable improvement compared to those with reduced graphene oxide anodes. This improvement indicates that reduced graphite oxide, with larger interlayer spacing, has fewer defects and is thus more stable. In summary, we found that reduced graphite oxide may be a more favorable form of graphene for the fabrication of electrodes for lithium-ion and sodium-ion batteries and other energy storage devices.

  10. An ion cooling and state characterization apparatus for studies of molecular ion dissociative interactions

    International Nuclear Information System (INIS)

    Deng, Shihu; Vane, C R; Bannister, M E; Havener, C C; Meyer, F W; Krause, H F; Hettich, R L; Goeringer, D E; Van Berkel, G J

    2009-01-01

    An experimental capability is being developed at the Oak Ridge National Laboratory Multi-Charged Ion Research Facility (ORNL MIRF) to enable stored cooling and state characterization of molecular ions of essentially any mass. Ions selected from a variety of available sources are injected from the side into a 1.5 meter long electrostatic mirror trap, where excited internal states are cooled by radiative cooling. An electron beam target located near the middle of the ion-trap region, coupled with neutral fragment imaging detector systems at each end of the trap, permits state-specific studies of electron-molecular ion dissociation.

  11. Ion beam analysis of PECVD silicon oxide thin films

    International Nuclear Information System (INIS)

    Fernandez-Lima, F.; Rodriguez, J.A.; Pedrero, E.; Fonseca Filho, H.D.; Llovera, A.; Riera, M.; Dominguez, C.; Behar, M.; Zawislak, F.C.

    2006-01-01

    A study of ion beam analysis techniques of plasma enhanced chemical vapor deposited (PECVD) silicon oxide thin films (1 μm thick) obtained from silane (SiH 4 ) and nitrous oxide (N 2 O) is reported. The film, elemental composition and surface morphology were determined as function of the reactant gas flow ratio, R = [N 2 O]/[SiH 4 ] in the 22-110 range using the Rutherford backscattering spectrometry, nuclear reaction analysis and atomic force microscopy techniques. The density of the films was determined by combining the RBS and thickness measurements. All the experiments were done at a deposition temperature of 300 deg. C. In all the cases almost stoichiometric oxides were obtained being the impurity content function of R. It was also observed that physical properties such as density, surface roughness and shape factor increase with R in the studied interval

  12. Adsorption of lithium ion to amorphous hydrous aluminium oxide

    International Nuclear Information System (INIS)

    Wada, Hideo; Kitamura, Takao; Fujii, Ayako; Katoh, Shunsaku

    1982-01-01

    Adsorption process of lithium ion to amorphous hydrous aluminium oxide (a-HAO) was investigated by pH titration method with lithium chloride-lithium hydroxide mixed solution and X-ray diffraction analysis of a-HAO after pH titration. In the pH titration, the addition of hydroxide ion in amount from 0 to 4.0 mmol.g -1 gave no change to the pH of the solution and caused adsorption of lithium ion equivalent in amount to added hydroxide ion. X-ray diffraction analysis showed the formation of lithium hydrogenaluminate LiH (AlO 2 ) 2 .5H 2 O (LHA) in the a-HAO after pH titration. These results showed that adsorption of lithium ion by a-HAO was related to a reaction which consumed hydroxide ion and formed LHA. In order to elucidate detail process of the reaction, changes of pH, aluminium concentration and lithium concentration of the solution, respectively with time, were determined. The pH of the solution decreased in two stages. At the first stage of the pH decrease, the aluminium concentration increased whereas the lithium concentration did not change. At the second stage, the lithium concentration decreased together with the decrease of the aluminium concentration. It was inferred that adsorption of lithium ion proceeded through dissolution of a-HAO and precipitation of LHA. Theoretical adsorption capacity calculated from the above formula for LHA and aluminium content in a-HAO was 4.7 mmol.g -1 and agreed fairly well with observed value 4.0 mmol.g -1 . (author)

  13. State promotion and neutralization of ions near metal surface

    International Nuclear Information System (INIS)

    Zinoviev, A.N.

    2011-01-01

    Research highlights: → Multiply charged ion and the charge induced in the metal form a dipole. → Dipole states are promoted into continuum with decreasing ion-surface distance. → These states cross the states formed from metal atom. → Proposed model explains the dominant population of deep bound states. → Observed spectra of emitted Auger electrons prove this promotion model. -- Abstract: When a multiply charged ion with charge Z approaches the metal surface, a dipole is formed by the multiply charged ion and the charge induced in the metal. The states for such a dipole are promoted into continuum with decreasing ion-surface distance and cross the states formed from metal atom. The model proposed explains the dominant population of deep bound states in collisions considered.

  14. Manganese oxide electrode with excellent electrochemical performance for sodium ion batteries by pre-intercalation of K and Na ions.

    Science.gov (United States)

    Feng, Mengya; Du, Qinghua; Su, Li; Zhang, Guowei; Wang, Guiling; Ma, Zhipeng; Gao, Weimin; Qin, Xiujuan; Shao, Guangjie

    2017-05-22

    Materials with a layered structure have attracted tremendous attention because of their unique properties. The ultrathin nanosheet structure can result in extremely rapid intercalation/de-intercalation of Na ions in the charge-discharge progress. Herein, we report a manganese oxide with pre-intercalated K and Na ions and having flower-like ultrathin layered structure, which was synthesized by a facile but efficient hydrothermal method under mild condition. The pre-intercalation of Na and K ions facilitates the access of electrolyte ions and shortens the ion diffusion pathways. The layered manganese oxide shows ultrahigh specific capacity when it is used as cathode material for sodium-ion batteries. It also exhibits excellent stability and reversibility. It was found that the amount of intercalated Na ions is approximately 71% of the total charge. The prominent electrochemical performance of the manganese oxide demonstrates the importance of design and synthesis of pre-intercalated ultrathin layered materials.

  15. Thermodynamic Ground States of Complex Oxide Heterointerfaces

    DEFF Research Database (Denmark)

    Gunkel, F.; Hoffmann-Eifert, S.; Heinen, R. A.

    2017-01-01

    The formation mechanism of 2-dimensional electron gases (2DEGs) at heterointerfaces between nominally insulating oxides is addressed with a thermodynamical approach. We provide a comprehensive analysis of the thermodynamic ground states of various 2DEG systems directly probed in high temperature...

  16. Directing the Branching Growth of Cuprous Oxide by OH- Ions

    Science.gov (United States)

    Chen, Kunfeng; Si, Yunfei; Xue, Dongfeng

    The effect of OH- ions on the branching growth of cuprous oxide microcrystals was systematically studied by a reduction route, where copper-citrate complexes were reduced by glucose under alkaline conditions. Different copper salts including Cu(NO3)2, CuCl2, CuSO4, and Cu(Ac)2 were used in this work. The results indicate that the Cu2O branching growth habit is closely correlated to the concentration of OH- ions, which plays an important role in directing the diffusion-limited branching growth of Cu2O and influencing the reduction power of glucose. A variety of Cu2O branching patterns including 6-pod, 8-pod and 24-pod branches, have been achieved without using template and surfactant. The current method can provide a good platform for studying the growth mechanism of microcrystal branching patterns.

  17. Continuum states in ion-atom collisions

    Energy Technology Data Exchange (ETDEWEB)

    Garibotti, C.R. (Centro Atomico Bariloche and CONICET (Argentina)); Barrachina, R.O. (Centro Atomico Bariloche and CONICET (Argentina))

    1994-03-01

    We review the experimental and theoretical situation for ionization collisions of nude ions with neutral gas atoms, at intermediate and high impact energies. We consider particularly that part of the electron spectrum where emission is larger, corresponding to the joint action to the two ions. We discuss the evidence of this two-center interaction and how it is described by current theories. (orig.)

  18. Superconducting oxide thin films by ion beam sputtering

    International Nuclear Information System (INIS)

    Kobrin, P.H.; DeNatale, J.F.; Housley, R.M.; Flintoff, J.F.; Harker, A.B.

    1987-01-01

    Superconducting thin films of ternary copper oxides from the Y-Ba-Cu-O and La-Sr-Cu-O systems have been deposited by ion beam sputtering of ceramic targets. Crystallographic orientation of the polycrystalline films has been shown to vary with substrate identity, deposition temperature and annealing temperature. The onset of the superconductive transition occurs near 90K in the Y-Ba-Cu-O system. Fe impurities of < 0.2% have been found to inhibit the superconducting transition, probably by migrating to the grain boundaries

  19. Oxidation of 1,3,7-trimethylxanthine by hypochlorite ion

    Science.gov (United States)

    Kheidorov, V. P.; Ershov, Yu. A.; Chalyi, G. Yu.; Titorovich, O. V.

    2011-08-01

    The kinetics of the oxidative conversion of 1,3,7-trimethylxanthine upon treatment with hypochlorite ions (OCl-) in aqueous medium at 283-298 K and pH 8.2 was studied. The reaction order with respect to each component was determined and proved to be 1. It was established that the temperature dependence of the reaction rate follows the Arrhenius equation. The activation parameters of the reaction were measured: E a = 33.58 kJ/mol, Δ H ≠ = 31.12 kJ/mol, Δ S ≠ = -170.02 J/(K mol), Δ G ≠ = 81.45 kJ/mol. The stoichiometry of the reaction was studied, and the chemistry of the oxidative conversion of caffeine treated with OCl- is discussed.

  20. Chelation and stabilization of berkelium in oxidation state +IV

    Science.gov (United States)

    Deblonde, Gauthier J.-P.; Sturzbecher-Hoehne, Manuel; Rupert, Peter B.; An, Dahlia D.; Illy, Marie-Claire; Ralston, Corie Y.; Brabec, Jiri; de Jong, Wibe A.; Strong, Roland K.; Abergel, Rebecca J.

    2017-09-01

    Berkelium (Bk) has been predicted to be the only transplutonium element able to exhibit both +III and +IV oxidation states in solution, but evidence of a stable oxidized Bk chelate has so far remained elusive. Here we describe the stabilization of the heaviest 4+ ion of the periodic table, under mild aqueous conditions, using a siderophore derivative. The resulting Bk(IV) complex exhibits luminescence via sensitization through an intramolecular antenna effect. This neutral Bk(IV) coordination compound is not sequestered by the protein siderocalin—a mammalian metal transporter—in contrast to the negatively charged species obtained with neighbouring trivalent actinides americium, curium and californium (Cf). The corresponding Cf(III)-ligand-protein ternary adduct was characterized by X-ray diffraction analysis. Combined with theoretical predictions, these data add significant insight to the field of transplutonium chemistry, and may lead to innovative Bk separation and purification processes.

  1. Modification of oxide films by ion implantation: TiO2-films modified by Ti+ and O+ as example

    International Nuclear Information System (INIS)

    Schultze, J.W.; Elfenthal, L.; Leitner, K.; Meyer, O.

    1988-01-01

    Oxide films can be modified by ion implantation. Changes in the electrochemical properties of the films are due to the deposition profile of the implanted ion, ie doping and stoichiometric changes, as well as to the radiation damage. The latter is due to the formation of Frenkel defects and at high concentrations to a complete amorphization of the oxide film. TiOsub(x)-films with 1 + - and O + -ions into anodic oxide films on titanium. The electrode capacity shows always the behaviour of an n-type semiconductor with an almost constant flatband potential but a strong maximum donor concentration at about 3% Ti + concentration. Oxygen implantation, on the other hand, causes a small increase of donor concentration only at high concentration of O + . Electron transfer reactions show strong modifications of the electronic behaviour of the oxide film with a maximum again at 3% titanium. Photocurrent spectra prove the increasing amorphization and show interband states 2.6 eV above the VB or below the CB. During repassivation measurements at various potentials different defects formed by Ti + - and O + -implantation become mobile. A tentative model of the band structure is constructed which takes into account the interband states due to localised Ti + - and O + -ions. The modification of ion implanted oxide films is compared with the effects of other preparation techniques. (author)

  2. 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}.

  3. Charge states of ions, and mechanisms of charge ordering transitions

    Science.gov (United States)

    Pickett, Warren E.; Quan, Yundi; Pardo, Victor

    2014-07-01

    To gain insight into the mechanism of charge ordering transitions, which conventionally are pictured as a disproportionation of an ion M as 2Mn+→M(n+1)+ + M(n-1)+, we (1) review and reconsider the charge state (or oxidation number) picture itself, (2) introduce new results for the putative charge ordering compound AgNiO2 and the dual charge state insulator AgO, and (3) analyze the cationic occupations of the actual (not formal) charge, and work to reconcile the conundrums that arise. We establish that several of the clearest cases of charge ordering transitions involve no disproportion (no charge transfer between the cations, and hence no charge ordering), and that the experimental data used to support charge ordering can be accounted for within density functional-based calculations that contain no charge transfer between cations. We propose that the charge state picture retains meaning and importance, at least in many cases, if one focuses on Wannier functions rather than atomic orbitals. The challenge of modeling charge ordering transitions with model Hamiltonians isdiscussed.

  4. Magnetic properties of Pr ions in perovskite-type oxides

    International Nuclear Information System (INIS)

    Sekizawa, K.; Kitagawa, M.; Takano, Y.

    1998-01-01

    Magnetic properties of Pr ions with the controlled valence on the A and B sites of perovskite-type oxides (ABO 3 ) were investigated for two systems. PrSc 1-x Mg x O 3 and BaPr 1-x Bi x O 3 . From the magnetic susceptibility χ versus temperature T curves of PrSc 1-x Mg x O 3 , the χ-T curve for molar Pr 3+ ions on the A site and that of Pr 4+ ions were obtained. The 1/χ-T curves for both ions exhibit the crystalline electric field (CEF) effect and the effective magneticmoment μ eff above 100 K is 3.41 μ B for Pr 3- and 2.58 μ B for Pr 4+ , respectively. The χ-T curve of PrSc 0.8 Mg 0.2 O 3 is similar to that of PrBa 2 Cu 3 O y . In the BaPr 1-x Bi x O 3 system, only one intermediate phase BaPr 0.5 Bi 0.5 O 3 exists, in which Pr and Bi take an ordered arrangement on the B site. The magnetic susceptibility χ for Pr 4+ and that of Pr 3+ in the ordered arrangement with Bi 5- on the B site are much smaller than those for the A site, reflecting the strong CEF effect on the B site. Experimental χ-T curves can be well reproducedby the numerical calculation for Pr 3+ or Pr 4+ ions in the molecular field and the CEF with proper respective parameters. (orig.)

  5. A study of tritium behavior in lithium oxide by ion conductivity measurements

    International Nuclear Information System (INIS)

    Noda, Kenji; Ishii, Yoshinobu; Ohno, Hideo; Watanabe, Hitoshi

    1989-01-01

    Ion conductivity of lithium oxide (Li 2 O) irradiated with oxygen ions was measured to obtain information about the effects of irradiation on the behavior of lithium ions and tritium. The conductivity around 490 K decreased with the ion fluence, while around 440 K it increased. The decrease around 490 K and the increase around 440 K were assumed to be attributed to the F + centers and the unspecified radiation defects, respectively. From the point of view that the rate determinant in the mechanism of diffusion of lithium ions in Li 2 O leading to the ion conductivity is the same as that of tritium, the diffusivity of tritium is assumed to be as follows: the diffusivity of tritium is decreased by the F + centers in the range from 490 K to the temperature at which almost all of F + centers are recovered, while it is increased around 440 K by the unspecified radiation defects. In addition, effects of the irradiation on valence states of tritium (i.e., T + , T - ) were discussed in terms of the radiation defects. (orig.)

  6. Equilibrium charge state distributions of high energy heavy ions

    International Nuclear Information System (INIS)

    Clark, R.B.; Grant, I.S.; King, R.; Eastham, D.A.; Joy, T.

    1976-01-01

    Equilibrium charge state fractions have been measured for N, O, Ne, S, Ar and Kr ions at 1.04 MeV/nucleon after passing through various stripping materials. Further data were obtained at higher energy for S ions (4.12 MeV/nucleon) and Ar ions (4.12 and 9.6 MeV/nucleon). The mean charge fractions can be fitted to universal curves for both solid and gaseous strippers. Measurements of the equilibrium fraction of krypton ions at 1.04 MeV/nucleon passing through heavy vapours have shown that a higher average charge state is obtained than for lighter gaseous strippers. (Auth.)

  7. Origin of interface states and oxide charges generated by ionizing radiation

    International Nuclear Information System (INIS)

    Sah, C.T.

    1976-01-01

    The randomly located trivalent silicon atoms are shown to account for the thermally generated interface states at the SiO 2 -Si interface. The interface state density is greatly reduced in water containing ambients at low temperatures (450 0 C) by forming trivalent silicon hydroxide bonds. Interface states are regenerated when the /triple bond/Si-OH bonds are broken by ionizing radiation and the OH ions are drifted away. In the bulk of the oxide film, the trivalent silicon and the interstitial oxygen donor centers are shown to be responsible for the heat and radiation generated positive space charge build-up (oxide charge) in thermally grown silicon oxide

  8. Effect of ion exchange on the rate of aerobic microbial oxidation of ammonium in hyporheic zone sediments.

    Science.gov (United States)

    Yan, Ailan; Liu, Chongxuan; Liu, Yuanyuan; Xu, Fen

    2018-03-01

    Microbially mediated ammonium oxidation is a major process affecting nitrogen transformation and cycling in natural environments. This study investigated whether ion exchange process can affect microbially mediated aerobic oxidation of ammonium in a hyporheic zone (HZ) sediments from the Columbia River at US Department of Energy's Hanford site, Washington State. Experiments were conducted using synthetic groundwater and river water to investigate their effect on ammonium oxidation. Results indicated that ammonium sorption through ion exchange reactions decreased the rate of ammonium oxidation, apparently resulting from the influence of the ion exchange on dissolved ammonium concentration, thus decreasing the bioavailability of ammonium for microbial oxidation. However, with the decrease in dissolved ammonium concentration, the sorbed ammonium released back to aqueous phase, and became bioavailable so that all the ammonium in the suspensions were oxidized. Our results implied a dynamic change in ammonium oxidation rates in an environment such as at HZ where river water and groundwater with different chemical compositions exchange frequently that can affect ammonium sorption and desorption through ion exchange reactions.

  9. Group IIB-VIA semiconductor oxide cluster ions

    Science.gov (United States)

    Jayasekharan, Thankan

    2018-05-01

    Metal oxide cluster ions, MnOm± (M = Zn, Cd) and HgnOm- of various stoichiometry have been generated from solid IIB-VIA semiconductor oxides targets, (ZnO(s), CdO(s), and HgO(s)) by using pulse laser desorption ionization time of flight mass spectrometry with a laser of λ = 355 nm. Analysis of mass spectral data indicates the formation of stoichiometric cluster ions viz., (ZnO)n=1-30+ and (CdO)n=1-40+ along with -O bound anions, (ZnO)n=1-30O-, (CdO)n=1-40O- and (HgO)n=1-36O- from their respective solids. Further, metal oxoanions such as ZnOn=2,3-, CdOn=2,3,6-, and HgOn=2,3,6,7- have also been noted signifying the higher coordination ability of both Cd and Hg with O/O2/O3 species.

  10. Codeposition of deuterium ions with beryllium oxide at elevated temperatures

    CERN Document Server

    Markin, A V; Gorodetsky, A E; Negodaev, M A; Rozhanskii, N V; Scaffidi-Argentina, F; Werle, H; Wu, C H; Zalavutdinov, R K; Zakharov, A P

    2000-01-01

    Deuterium-loaded BeO films were produced by sputtering the beryllium target with 10 keV Ne ions in D sub 2 gas at a pressure of approximately 1 Pa. The sputtered beryllium reacts - on the substrate surface - with the residual oxygen, thus forming a beryllium oxide layer. Biasing the substrate negatively with respect to the target provides the simultaneous bombardment of the growing film surface with D ions formed by Ne-D sub 2 collisions. Substrate potential governs the maximum energy of ions striking the growing film surface while its size governs the flux density. According to X-ray photoelectron spectroscopy (XPS), electron probe microanalysis (EPMA) and reflection high energy electron diffraction (RHEED) data, the beryllium is deposited in the form of polycrystalline hcp-BeO layers with negligible (about 1 at.%) carbon and neon retention. Thermal desorption spectroscopy (TDS) data shows a strong deuterium bonding, with a desorption peak at 950 K, in the films deposited at -50 and -400 V substrate potentia...

  11. Thin copper oxide films prepared by ion beam sputtering with subsequent thermal oxidation: Application in chemiresistors

    Czech Academy of Sciences Publication Activity Database

    Horák, Pavel; Bejšovec, Václav; Vacík, Jiří; Lavrentiev, Vasyl; Vrňata, M.; Kormunda, M.; Daniš, S.

    2016-01-01

    Roč. 389, DEC (2016), s. 751-759 ISSN 0169-4332 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(CZ) LM2011019 Institutional support: RVO:61389005 Keywords : Copper oxide * ion beam sputtering * Van der Pauw * nuclear reaction analysis * gas sensing Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.387, year: 2016

  12. Target life time of laser ion source for low charge state ion production

    Energy Technology Data Exchange (ETDEWEB)

    Kanesue,T.; Tamura, J.; Okamura, M.

    2008-06-23

    Laser ion source (LIS) produces ions by irradiating pulsed high power laser shots onto the solid state target. For the low charge state ion production, laser spot diameter on the target can be over several millimeters using a high power laser such as Nd:YAG laser. In this case, a damage to the target surface is small while there is a visible crater in case of the best focused laser shot for high charge state ion production (laser spot diameter can be several tens of micrometers). So the need of target displacement after each laser shot to use fresh surface to stabilize plasma is not required for low charge state ion production. We tested target lifetime using Nd:YAG laser with 5 Hz repetition rate. Also target temperature and vacuum condition were recorded during experiment. The feasibility of a long time operation was verified.

  13. High Intensity High Charge State ECR Ion Sources

    CERN Document Server

    Leitner, Daniela

    2005-01-01

    The next-generation heavy ion beam accelerators such as the proposed Rare Isotope Accelerator (RIA), the Radioactive Ion Beam Factory at RIKEN, the GSI upgrade project, the LHC-upgrade, and IMP in Lanzhou require a great variety of high charge state ion beams with a magnitude higher beam intensity than currently achievable. High performance Electron Cyclotron Resonance (ECR) ion sources can provide the flexibility since they can routinely produce beams from hydrogen to uranium. Over the last three decades, ECR ion sources have continued improving the available ion beam intensities by increasing the magnetic fields and ECR heating frequencies to enhance the confinement and the plasma density. With advances in superconducting magnet technology, a new generation of high field superconducting sources is now emerging, designed to meet the requirements of these next generation accelerator projects. The talk will briefly review the field of high performance ECR ion sources and the latest developments for high intens...

  14. Facilitated ion transport in all-solid-state flexible supercapacitors.

    Science.gov (United States)

    Choi, Bong Gill; Hong, Jinkee; Hong, Won Hi; Hammond, Paula T; Park, HoSeok

    2011-09-27

    The realization of highly flexible and all-solid-state energy-storage devices strongly depends on both the electrical properties and mechanical integrity of the constitutive materials and the controlled assembly of electrode and solid electrolyte. Herein we report the preparation of all-solid-state flexible supercapacitors (SCs) through the easy assembly of functionalized reduced graphene oxide (f-RGO) thin films (as electrode) and solvent-cast Nafion electrolyte membranes (as electrolyte and separator). In particular, the f-RGO-based SCs (f-RGO-SCs) showed a 2-fold higher specific capacitance (118.5 F/g at 1 A/g) and rate capability (90% retention at 30 A/g) compared to those of all-solid-state graphene SCs (62.3 F/g at 1A/g and 48% retention at 30 A/g). As proven by the 4-fold faster relaxation of the f-RGO-SCs than that of the RGO-SCs and more capacitive behavior of the former at the low-frequency region, these results were attributed to the facilitated ionic transport at the electrical double layer by means of the interfacial engineering of RGO by Nafion. Moreover, the superiority of all-solid-state flexible f-RGO-SCs was demonstrated by the good performance durability under the 1000 cycles of charging and discharging due to the mechanical integrity as a consequence of the interconnected networking structures. Therefore, this research provides new insight into the rational design and fabrication of all-solid-state flexible energy-storage devices as well as the fundamental understanding of ion and charge transport at the interface. © 2011 American Chemical Society

  15. Steady state ion acceleration by a circularly polarized laser pulse

    International Nuclear Information System (INIS)

    Zhang Xiaomei; Shen Baifei; Cang Yu; Li Xuemei; Jin Zhangying; Wang Fengchao

    2007-01-01

    The steady state ion acceleration at the front of a cold solid target by a circularly polarized flat-top laser pulse is studied with one-dimensional particle-in-cell (PIC) simulation. A model that ions are reflected by a steady laser-driven piston is used by comparing with the electrostatic shock acceleration. A stable profile with a double-flat-top structure in phase space forms after ions enter the undisturbed region of the target with a constant velocity

  16. A microbial-mineralization-inspired approach for synthesis of manganese oxide nanostructures with controlled oxidation states and morphologies

    Energy Technology Data Exchange (ETDEWEB)

    Oba, Manabu; Oaki, Yuya; Imai, Hiroaki [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)

    2010-12-21

    Manganese oxide nanostructures are synthesized by a route inspired by microbial mineralization in nature. The combination of organic molecules, which include antioxidizing and chelating agents, facilitates the parallel control of oxidation states and morphologies in an aqueous solution at room temperature. Divalent manganese hydroxide (Mn(OH){sub 2}) is selectively obtained as a stable dried powder by using a combination of ascorbic acid as an antioxidizing agent and other organic molecules with the ability to chelate to manganese ions. The topotactic oxidation of the resultant Mn(OH){sub 2} leads to the selective formation of trivalent manganese oxyhydroxide ({beta}-MnOOH) and trivalent/tetravalent sodium manganese oxide (birnessite, Na{sub 0.55}Mn{sub 2}O{sub 4}.1.5H{sub 2}O). For microbial mineralization in nature, similar synthetic routes via intermediates have been proposed in earlier works. Therefore, these synthetic routes, which include in the present study the parallel control over oxidation states and morphologies of manganese oxides, can be regarded as new biomimetic routes for synthesis of transition metal oxide nanostructures. As a potential application, it is demonstrated that the resultant {beta}-MnOOH nanostructures perform as a cathode material for lithium ion batteries. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. A magnetic route to measure the average oxidation state of mixed-valent manganese in manganese oxide octahedral molecular sieves (OMS).

    Science.gov (United States)

    Shen, Xiong-Fei; Ding, Yun-Shuang; Liu, Jia; Han, Zhao-Hui; Budnick, Joseph I; Hines, William A; Suib, Steven L

    2005-05-04

    A magnetic route has been applied for measurement of the average oxidation state (AOS) of mixed-valent manganese in manganese oxide octahedral molecular sieves (OMS). The method gives AOS measurement results in good agreement with titration methods. A maximum analysis deviation error of +/-7% is obtained from 10 sample measurements. The magnetic method is able to (1) confirm the presence of mixed-valent manganese and (2) evaluate AOS and the spin states of d electrons of both single oxidation state and mixed-valent state Mn in manganese oxides. In addition, the magnetic method may be extended to (1) determine AOS of Mn in manganese oxide OMS with dopant "diamagnetic" ions, such as reducible V5+ (3d0) ions, which is inappropriate for the titration method due to interference of redox reactions between these dopant ions and titration reagents, such as KMnO4, (2) evaluate the dopant "paramagnetic" ions that are present as clusters or in the OMS framework, and (3) determine AOS of other mixed-valent/single oxidation state ion systems, such as Mo3+(3d3)-Mo4+(3d2) systems and Fe3+ in FeCl3.

  18. Evaluation of covalency of ions in lead-free perovskite-type dielectric oxides

    Directory of Open Access Journals (Sweden)

    Naohisa Takesue

    2017-10-01

    Full Text Available Electronic states of ions in lead-free perovskite-type dielectric oxides have been investigated with a first-principle cluster calculation. For this calculation a double-perovskite cluster model based upon the simple cubic ABO3 was used; A and B are both the cations, and O is the oxygen anion. Systematic variations of ionic species for A and B, and lengths of the model cube edge were given to the model. Results of charge transfers of the ions show that their magnitudes depend on the edge length; the lager length leads to the higher transfer magnitude. This tendency implies spatial tolerance of the ions to the clusters, and are expected to correlate with electric polarizability and dipole reversibility of this kind of oxides. The density of states and the overlap population indicate that the higher cation valence causes the higher covalency of the anions. Considering all results together provides us an idea to obtain lead-free high-performance ferroelectrics, as high as the lead-based solid solutions.

  19. Modeling all-solid-state Li-ion batteries

    NARCIS (Netherlands)

    Danilov, D.; Niessen, R.A.H.; Notten, P.H.L.

    2011-01-01

    A mathematical model for all-solid-state Li-ion batteries is presented. The model includes the charge transfer kinetics at the electrode/electrolyte interface, diffusion of lithium in the intercalation electrode, and diffusion and migration of ions in the electrolyte. The model has been applied to

  20. Generation of three-mode nonclassical vibrational states of ions

    International Nuclear Information System (INIS)

    Nguyen Ba An; Truong Minh Duc

    2002-01-01

    We propose using eight lasers with appropriate orientations and conditions to generate stable trio coherent states of an ion in a three-dimensional isotropic trap. Seven lasers whose orientations are important should be detuned to the third lower sideband of the ion vibrational motion. The eighth laser whose direction is not important should be in resonance with the ionic transition

  1. Preparation of 3D nanoporous copper-supported cuprous oxide for high-performance lithium ion battery anodes.

    Science.gov (United States)

    Liu, Dequan; Yang, Zhibo; Wang, Peng; Li, Fei; Wang, Desheng; He, Deyan

    2013-03-07

    Three-dimensional (3D) nanoporous architectures can provide efficient and rapid pathways for Li-ion and electron transport as well as short solid-state diffusion lengths in lithium ion batteries (LIBs). In this work, 3D nanoporous copper-supported cuprous oxide was successfully fabricated by low-cost selective etching of an electron-beam melted Cu(50)Al(50) alloy and subsequent in situ thermal oxidation. The architecture was used as an anode in lithium ion batteries. In the first cycle, the sample delivered an extremely high lithium storage capacity of about 2.35 mA h cm(-2). A high reversible capacity of 1.45 mA h cm(-2) was achieved after 120 cycles. This work develops a promising approach to building reliable 3D nanostructured electrodes for high-performance lithium ion batteries.

  2. Geometric Phases for Mixed States in Trapped Ions

    International Nuclear Information System (INIS)

    Lu Hongxia

    2006-01-01

    The generalization of geometric phase from the pure states to the mixed states may have potential applications in constructing geometric quantum gates. We here investigate the mixed state geometric phases and visibilities of the trapped ion system in both non-degenerate and degenerate cases. In the proposed quantum system, the geometric phases are determined by the evolution time, the initial states of trapped ions, and the initial states of photons. Moreover, special periods are gained under which the geometric phases do not change with the initial states changing of photon parts in both non-degenerate and degenerate cases. The high detection efficiency in the ion trap system implies that the mixed state geometric phases proposed here can be easily tested.

  3. Effect of calcium oxide on the efficiency of ferrous ion oxidation and total iron precipitation during ferrous ion oxidation in simulated acid mine drainage treatment with inoculation of Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Liu, Fenwu; Zhou, Jun; Jin, Tongjun; Zhang, Shasha; Liu, Lanlan

    2016-01-01

    Calcium oxide was added into ferrous ion oxidation system in the presence of Acidithiobacillus ferrooxidans at concentrations of 0-4.00 g/L. The pH, ferrous ion oxidation efficiency, total iron precipitation efficiency, and phase of the solid minerals harvested from different treatments were investigated during the ferrous ion oxidation process. In control check (CK) system, pH of the solution decreased from 2.81 to 2.25 when ferrous ions achieved complete oxidation after 72 h of Acidithiobacillus ferrooxidans incubation without the addition of calcium oxide, and total iron precipitation efficiency reached 20.2%. Efficiency of ferrous ion oxidation and total iron precipitation was significantly improved when the amount of calcium oxide added was ≤1.33 g/L, and the minerals harvested from systems were mainly a mixture of jarosite and schwertmannite. For example, the ferrous ion oxidation efficiency reached 100% at 60 h and total iron precipitation efficiency was increased to 32.1% at 72 h when 1.33 g/L of calcium oxide was added. However, ferrous ion oxidation and total iron precipitation for jarosite and schwertmannite formation were inhibited if the amount of calcium oxide added was above 2.67 g/L, and large amounts of calcium sulfate dihydrate were generated in systems.

  4. The effect on phase separation of the oxidation state of molybdenum in a Na2O-B2O3-SiO2 glass

    International Nuclear Information System (INIS)

    Kawamoto, Y.; Clemens, K.; Tomozawa, M.; Warden, J.T.

    1981-01-01

    The effect of oxidation state on phase separation was studied for 13Na 2 O, 49B 2 O 3 , 38SiO 2 (mol%) glasses containing 1 mol% Mo oxide. The glasses were melted under various conditions to vary the oxidation states of Mo ions. The oxidation states of Mo ions were determined by chemical analysis and ESR. The crystallisation tendency, the immiscibility temperature, and the phase separation morphology of the glasses were examined by DTA, x-ray diffraction, opalescence method, and replica electron microscopy. Glasses containing Mo 4+ ions have a great tendency to precipitate MoO 2 crystals. The immiscibility temperature of glass goes through a minimum when the oxidation states of Mo ions are changed. It was suggested that there is an optimum oxidation state to prevent crystallisation and to suppress the phase separation tendency of this system. (author)

  5. Solid Lithium Ion Conductors (SLIC) for Lithium Solid State Batteries

    Data.gov (United States)

    National Aeronautics and Space Administration — To identify the most lithium-ion conducting solid electrolytes for lithium solid state batteries from the emerging types of solid electrolytes, based on a...

  6. Lithium-ion transport in inorganic solid state electrolyte

    International Nuclear Information System (INIS)

    Gao Jian; Li Hong; Zhao Yu-Sheng; Shi Si-Qi

    2016-01-01

    An overview of ion transport in lithium-ion inorganic solid state electrolytes is presented, aimed at exploring and designing better electrolyte materials. Ionic conductivity is one of the most important indices of the performance of inorganic solid state electrolytes. The general definition of solid state electrolytes is presented in terms of their role in a working cell (to convey ions while isolate electrons), and the history of solid electrolyte development is briefly summarized. Ways of using the available theoretical models and experimental methods to characterize lithium-ion transport in solid state electrolytes are systematically introduced. Then the various factors that affect ionic conductivity are itemized, including mainly structural disorder, composite materials and interface effects between a solid electrolyte and an electrode. Finally, strategies for future material systems, for synthesis and characterization methods, and for theory and calculation are proposed, aiming to help accelerate the design and development of new solid electrolytes. (topical review)

  7. Solid state solubility of copper oxides in hydroxyapatite

    Science.gov (United States)

    Zykin, Mikhail A.; Vasiliev, Alexander V.; Trusov, Lev A.; Dinnebier, Robert E.; Jansen, Martin; Kazin, Pavel E.

    2018-06-01

    Samples containing copper oxide doped hydroxyapatite with the composition Ca10(PO4)6(CuxOH1-x-δ)2, x = 0.054 - 0.582, in the mixture with CuO/Cu2O were prepared by a solid-state high-temperature treatment at varying annealing temperatures and at different partial water vapor and oxygen pressures. The crystal structures of the apatite compounds were refined using powder X-ray diffraction patterns and the content of copper ions x in the apatite was determined. Copper ions enter exclusively into the apatite trigonal channels formally substituting protons of OH-groups and the hexagonal cell parameters grow approximately linearly with x, the channel volume mostly expanding while the remaining volume of the crystal lattice changing only slightly. The equilibrium copper content in the apatite increases drastically, by almost a factor of 10 with the annealing temperature rising from 800° to 1200°C. The reduction of the water partial pressure leads to a further increase of x, while the dependence of x on the oxygen partial pressure exhibits a maximum. The observed relations are consistent with the proposed chemical reactions implying the copper introduction is followed by the release of a considerable quantity of gaseous products - water and oxygen. The analysis of interatomic distances suggests that the maximum content of copper ions in the channel cannot exceed 2/3.

  8. Symplectic tomography of nonclassical states of trapped ion

    International Nuclear Information System (INIS)

    Man'ko, O.

    1996-03-01

    The marginal distribution for two types of nonclassical states of trapped ion - for squeezed and correlated states and for squeezed even and odd coherent states (squeezed Schroedinger cat states) is studied. The obtained marginal distribution for the two types of states is shown to satisfy classical dynamical equation equivalent to standard quantum evolution equation for density matrix (wave function) derived in symplectic tomography scheme. (author). 20 refs

  9. Incident ion charge state dependence of electron emission during slow multicharged ion-surface interactions

    International Nuclear Information System (INIS)

    Hughes, I.G.; Zeijlmans van Emmichoven, P.A.; Havener, C.C.; Overbury, S.H.; Robinson, M.T.; Zehner, D.M.; Meyer, F.W.

    1992-01-01

    Characteristic variations in the total electron yield γ as a function of crystal azimuthal orientation are reported for slow N 2+ , N 5+ and N 6+ ions incident on a Au(011) single crystal, together with measurements of γ as a function of incident ion velocity. Kinetic electron emission is shown to arise predominantly in close collisions between incident ions and target atoms, and potential electron emission is found to be essentially constant within our present velocity range. The incident ion charge state is shown to play no role in kinetic electron emission. Extremely fast neutralization times of the order of 10 - 15 secs are needed to explain the observations

  10. Hierarchically Nanostructured Transition Metal Oxides for Lithium‐Ion Batteries

    Science.gov (United States)

    Zheng, Mingbo; Tang, Hao; Li, Lulu; Hu, Qin; Zhang, Li; Xue, Huaiguo

    2018-01-01

    Abstract Lithium‐ion batteries (LIBs) have been widely used in the field of portable electric devices because of their high energy density and long cycling life. To further improve the performance of LIBs, it is of great importance to develop new electrode materials. Various transition metal oxides (TMOs) have been extensively investigated as electrode materials for LIBs. According to the reaction mechanism, there are mainly two kinds of TMOs, one is based on conversion reaction and the other is based on intercalation/deintercalation reaction. Recently, hierarchically nanostructured TMOs have become a hot research area in the field of LIBs. Hierarchical architecture can provide numerous accessible electroactive sites for redox reactions, shorten the diffusion distance of Li‐ion during the reaction, and accommodate volume expansion during cycling. With rapid research progress in this field, a timely account of this advanced technology is highly necessary. Here, the research progress on the synthesis methods, morphological characteristics, and electrochemical performances of hierarchically nanostructured TMOs for LIBs is summarized and discussed. Some relevant prospects are also proposed. PMID:29593962

  11. Effects of low-energy ion beam bombardment on metal oxides

    International Nuclear Information System (INIS)

    Sullivan, J.L.; Saied, S.O.; Choudhury, T.

    1993-01-01

    This paper describes a study of Ar ion bombardment damage in metal oxides. In the energy range 1 to 5 keV, preferential oxygen removal and reduction of the oxides was found to depend on ion current density, but to be independent of beam energy. (author)

  12. Comparison of oxidation resistance of copper treated by beam-line ion implantation and plasma immersion ion implantation

    International Nuclear Information System (INIS)

    An Quanzhang; Li Liuhe; Hu Tao; Xin Yunchang; Fu, Ricky K.Y.; Kwok, D.T.K.; Cai Xun; Chu, Paul K.

    2009-01-01

    Copper which has many favorable properties such as low cost, high thermal and electrical conductivity, as well as easy fabrication and joining is one of the main materials in lead frames, interconnects, and foils in flexible circuits. Furthermore, copper is one of the best antibacterial materials. However, unlike aluminum oxide or chromium oxide, the surface copper oxide layer does not render sufficient protection against oxidation. In this work, in order to improve the surface oxidation resistance of Cu, Al and N were introduced into copper by plasma immersion ion implantation (PIII) and beam-line ion implantation (BII). The implantation fluences of Al and N were 2 x 10 17 ions cm -2 and 5 x 10 16 ions cm -2 , respectively. The implanted and untreated copper samples were oxidized in air at 260 deg. C for 1 h. The X-ray diffraction (XRD), scanning electron microscopy (SEM), as well as X-ray photoelectron spectroscopy (XPS) results indicate that both implantation methods can enhance the oxidation resistance of copper but to different extent. PIII is superior to BII in enhancing the oxidation resistance of copper. The effects and possible mechanisms are discussed.

  13. Two-state ion heating at quasi-parallel shocks

    International Nuclear Information System (INIS)

    Thomsen, M.F.; Gosling, J.T.; Bame, S.J.; Onsager, T.G.; Russell, C.T.

    1990-01-01

    In a previous study of ion heating at quasi-parallel shocks, the authors showed a case in which the ion distributions downstream from the shock alternated between a cooler, denser, core/shoulder type and a hotter, less dense, more Maxwellian type. In this paper they further document the alternating occurrence of two different ion states downstream from several quasi-parallel shocks. Three separate lines of evidence are presented to show that the two states are not related in an evolutionary sense, but rather both are produced alternately at the shock: (1) the asymptotic downstream plasma parameters (density, ion temperature, and flow speed) are intermediate between those characterizing the two different states closer to the shock, suggesting that the asymptotic state is produced by a mixing of the two initial states; (2) examples of apparently interpenetrating (i.e., mixing) distributions can be found during transitions from one state to the other; and (3) examples of both types of distributions can be found at actual crossings of the shock ramp. The alternation between the two different types of ion distribution provides direct observational support for the idea that the dissipative dynamics of at least some quasi-parallel shocks is non-stationary and cyclic in nature, as demonstrated by recent numerical simulations. Typical cycle times between intervals of similar ion heating states are ∼2 upstream ion gyroperiods. Both the simulations and the in situ observations indicate that a process of coherent ion reflection is commonly an important part of the dissipation at quasi-parallel shocks

  14. Photochemical oxidants: state of the science.

    Science.gov (United States)

    Kley, D; Kleinmann, M; Sanderman, H; Krupa, S

    1999-01-01

    Atmospheric photochemical processes resulting in the production of tropospheric ozone (O(3)) and other oxidants are described. The spatial and temporal variabilities in the occurrence of surface level oxidants and their relationships to air pollution meteorology are discussed. Models of photooxidant formation are reviewed in the context of control strategies and comparisons are provided of the air concentrations of O(3) at select geographic locations around the world. This overall oxidant (O(3)) climatology is coupled to human health and ecological effects. The discussion of the effects includes both acute and chronic responses, mechanisms of action, human epidemiological and plant population studies and briefly, efforts to establish cause-effect relationships through numerical modeling. A short synopsis is provided of the interactive effects of O(3) with other abiotic and biotic factors. The overall emphasis of the paper is on identifying the current uncertainties and gaps in our understanding of the state of the science and some suggestions as to how they may be addressed.

  15. Systematic study of the ion beam mixing of oxide markers into alumina

    International Nuclear Information System (INIS)

    Cooper, E.A.; Kung, H.; Nastasi, M.

    1995-01-01

    The study of ion beam mixing of layered compositions is important in two regards: first, there is the potential of alloying the layers into a new functionally different composition and, secondly, from a fundamental aspect, it is important be able to anticipate the potential damage due to degradation of the layer structure that could be caused in these materials due to a radiation environment. The authors have completed a systematic study of ion beam mixing of thin marker layers into amorphous alumina. The degree of mixing was found to be controlled by thermodynamic factors, the nature of the marker (oxidation state), and matrix crystallinity. Ballistic mixing was observed for all markers, but the mixing of some oxide markers exhibits a thermally activated regime at higher temperatures. The experiments were conducted from a low temperature of -170 C to a maximum temperature of 75O C. 210 keV Ar was used to ion beam mix the marker layer at the various temperatures. The marker spreading was analyzed using RBS. The mixing of one marker (Fe 2 O 3 ) into crystalline alumina (sapphire) was compared to that of the amorphous alumina. It was found that the marker mixed asymmetrically into the two matrix materials, with a higher degree of mixing into the amorphous matrix. TEM cross-section results verify that there is a preference for the marker to mix into the amorphous alumina layer preferentially to the crystalline layer. The interest in ion beam mixing of marker layers in ceramic systems is motivated by the fact that layered oxides are technologically important materials for fusion reactor applications

  16. Plutonium disproportionation. Hydrolysis and local oxidation-state maxima

    International Nuclear Information System (INIS)

    Silver, G.L.

    2014-01-01

    Local maxima in the fractions of the trivalent and hexavalent oxidation states are inherent in the algebra of Pu disproportionation reactions. A new method predicts the pH and the oxidation-state fractions at maximum. Tabulated results illustrate the effects of the Pu oxidation number and Pu(IV) hydrolysis on the maxima. This method suggests a new laboratory approach for discovering Pu oxidation-state maxima. (author)

  17. Charge state of ions scattered by metal surface

    International Nuclear Information System (INIS)

    Kishinevsky, L.M.; Parilis, E.S.; Verleger, V.K.

    1976-01-01

    A model for description of charge distributions for scattering of heavy ions in the keV region, on metal surfaces developing and improving the method of Van der Weg and Bierman, and taking into account the connection between the ion charge state and scattering kinematics, is proposed. It is shown that multiple charged particles come from ions with a vacancy in the inner shell while the outer shell vacancies give only single charged ions and neutrals. The approximately linear increase of degree of ionization with normal velocity, and the non-monotonic charge dependence of the energy spectrum established by Chicherov and Buck et al is explained by considering irreversible neutralization in the depth of the metal, taking into account the connection of the charge state with the shape of trajectory and its location relative to the metal surface. The dependence of charge state on surface structure is discussed. Some new experiments are proposed. (author)

  18. 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...

  19. Oxidation potentials, Gibbs energies, enthalpies and entropies of actinide ions in aqueous solutions

    International Nuclear Information System (INIS)

    1977-01-01

    The values of the Gibbs energy, enthalpy, and entropy of different actinide ions, thermodynamic characteristics of the processes of hydration of these ions, and the presently known ionization potentials of actinides are given. The enthalpy and entropy components of the oxidation potentials of actinide elements are considered. The curves of the dependence of the Gibbs energy of ion formation on the atomic number of the element and the Frost diagrams are analyzed. The diagram proposed by Frost represents the graphical dependence of the Gibbs energy of hydrated ions on the degree of oxidation of the element. Using the Frost diagram it is easy to establish whether a given ion is stable to disproportioning

  20. Formation and effect of orientation domains in layered oxide cathodes of lithium-ion batteries

    International Nuclear Information System (INIS)

    Jarvis, Karalee A.; Wang, Chih-Chieh; Knight, James C.; Rabenberg, Lew; Manthiram, Arumugam; Ferreira, Paulo J.

    2016-01-01

    We show that in layered oxides that are employed as cathodes in lithium-ion batteries, the cation layers can order on different {111} NaCl planes within a single particle, which makes the lithium layer discontinuous across a particle. The findings challenge previous assertions that lithium undergoes 2-D diffusion in layered oxides and the data provide new insights into the decrease in rate capabilities for some layered oxides. Therefore, it is critically important to understand how these discontinuities form and how the loss of 2-D diffusion impacts the overall performance of the layered oxide cathode materials. Employing X-ray diffraction (XRD) and aberration-corrected scanning transmission electron microscopy (STEM), we find that as the material transitions from a disordered to an ordered state, it forms four orientation variants corresponding to the four {111} NaCl planes. This transition is not intrinsic to all layered oxides and appears to be more strongly affected by nickel. Furthermore, with energy dispersive spectroscopy (EDS), we show that there is an increase in the nickel concentration at the interface between each orientation variant. This reduces the rate of lithium diffusion, negatively affects the rate capability, and could be contributing to the overall capacity fade.

  1. Effect of heavy ion irradiation and α+β phase heat treatment on oxide of Zr-2.5Nb pressure tube material

    Energy Technology Data Exchange (ETDEWEB)

    Choudhuri, Gargi, E-mail: gargi@barc.gov.in [Quality Assurance Division, BARC, Mumbai, 400085 (India); Mukherjee, P.; Gayathri, N. [Variable Energy Cyclotron Centre, Kolkata, 700064 (India); Kain, V.; Kiran Kumar, M.; Srivastava, D. [Material Science Division, BARC, Mumbai, 400085 (India); Basu, S. [Solid State Physics Division, BARC, Mumbai, 400085 (India); Mukherjee, D. [Quality Assurance Division, BARC, Mumbai, 400085 (India); Dey, G.K. [Material Science Division, BARC, Mumbai, 400085 (India)

    2017-06-15

    Effect of heavy-ion irradiation on the crystalline phase transformation of oxide of Zr-2.5Nb alloys has been studied. The steam-autoclaved oxide of pressure tube is irradiated with 306 KeV Ar{sup +9} ions at a dose of 3 × 10{sup 19} Ar{sup +9}/m{sup 2}. The damage profile has been estimated using “Stopping and Range of Ions in Matter” computer program. The variation of the crystal structure along the depth of the irradiated oxide have been characterized non-destructively by Grazing Incidence X-ray Diffraction technique and compared with unirradiated-oxide. The effect of different base metal microstructures on the characteristic of oxide has also been studied. Base metal microstructure as well as the cross-sectional oxide have been characterized using transmission electron microscope. Heavy ion irradiation can significantly alter the distribution of phases in the oxide of the alloy. The difference in chemical state of alloying element has also been found between unirradiated-oxide with that of irradiated-oxide using X-ray photo electron spectroscopy. Chemical state of Nb in steam autoclaved oxide is also altered when the base metal is α + β heat treated.

  2. On kinetics and mechanism of' furfural oxidation by ions of heterovalent metals

    International Nuclear Information System (INIS)

    Krupenskij, V.I.

    1983-01-01

    Real constants of rate of furfural oxidation by Cu 2+ , Fe 3+ , Ce 4+ , Ag + , Hg 2+ 2 ions are determined, other kinetic and activation parameters of reactions are calculated, constants of stability and other thermodynamic characteristics of furfural complex with cations-oxidizers are found. Schemes of furfural transformations at one- and two-electron oxidation by ions of variable-valency metals are suggested

  3. Kinetics and mechanism of furfural oxidation by ions of heterovalent metals

    Energy Technology Data Exchange (ETDEWEB)

    Krupenskij, V.I. (Ukhtinskij Industrial' nyj Inst. (USSR))

    1983-01-01

    Real constants of rate of furfural oxidation by Cu/sup 2 +/, Fe/sup 3 +/, Ce/sup 4 +/, Ag/sup +/, Hg/sup 2 +//sub 2/ ions are determined, other kinetic and activation parameters of reactions are calculated, constants of stability and other thermodynamic characteristics of furfural complex with cations-oxidizers are found. Schemes of furfural transformations at one- and two-electron oxidation by ions of variable-valency metals are suggested.

  4. Investigation of phase stability and oxide ion performance in new perovskite-type bismuth vanadate

    International Nuclear Information System (INIS)

    Al-Alas, Ahlam; Beg, Saba; Al-Areqi, Niyazi A.S.

    2012-01-01

    Samples of the BICDVOX system, formulated as Bi 4 Cd x V 2−x O 11−(3x/2)−δ in the Cd substitution range 0 ≤ x ≤ 0.25 were synthesized using the standard solid state reaction.The correlation between phase stability and oxide ion performance were investigated by variable temperature XRPD, DSC and AC impedance spectroscopy. The substitution of V 5+ by Cd 2+ exhibited different phase transitions upon varying composition. For compositions with x ≤ 0.05, two successive transitions; α↔β↔γ are evident, while the β↔γ transition exists in the composition range 0.05 4+ → V 5+ re–oxidation results in increased defect trapping effects in the system at higher temperatures. -- Highlights: ► γ-Stabilized BICDVOX at lower dopant concentrations. ► Good oxide-ion conductivity at lower temperatures. ► High temperature-vanadium reduction with lower dopant concentrations.

  5. Determination of oxidation products in radiolysis of halophenols with pulse radiolysis, hplc, and ion chromatography

    International Nuclear Information System (INIS)

    Ye, M.; Schuler, R.H.

    1990-01-01

    This paper reports on hydroxyl radicals that react with halogen substituted phenols by several different ways. One is addition of OH radicals to the aromatic ring, which is followed by elimination of hydrogen halide, H 2 O or H - . The positions of OH radicals attack are dependent on the nature of the halogen which affects the electronic distribution in the ring. The oxidation of fluorophenols, chlorophenols and bromophenols with hydroxyl radicals in N 2 O saturated solution has been investigated with pulse radiolysis and γ-irradiation experiments. The intermediates of the reactions were studied by pulse radiolysis. The products created in the γ-irradiation of aqueous solutions of halophenols were analyzed by ion chromatography and high performance liquid chromatography (HPLC). With the combination of time-resolved and steady-state experiments a complete and detailed description of radiolytic oxidation of halophenols by hydroxyl radicals was obtained

  6. Ion-molecule reactions in the binary mixture of ethylene oxide and trioxane, 1

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Sugiura, Toshio.

    1977-01-01

    The formation mechanism of protonated molecular ions by cross-reactions in ethylene oxide-trioxane mixtures has been studied with use of a modified time-of-flight mass spectrometer. The precursors of the product ions were determined by analysis of the fine structure of their ionization efficiency curves using deuterated ethylene oxide. Protonated ethylene oxide is formed by the hydrogen atom transfer reaction of ethylene oxide molecular ion with trioxane, and protonated trioxane by the proton transfer reaction of CHO + (from ethylene oxide) with trioxane. In the ion-molecule reactions of ethylene-d 4 oxide-trioxane mixtures, appreciable isotope effect was observed. The CHO + from ethylene oxide is an important reactant ion as compared with that from trioxane in the proton transfer reaction, and CHO + from ethylene oxide was suggested as a thermal reactive ion. The order of proton affinity could be estimated from the proton transfer reactions involving CHO + . It was found that the proton affinity of trioxane is smaller than that of ethylene oxide. (auth.)

  7. Thin copper oxide films prepared by ion beam sputtering with subsequent thermal oxidation: Application in chemiresistors

    Energy Technology Data Exchange (ETDEWEB)

    Horak, P., E-mail: phorak@ujf.cas.cz [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, 250 68 Řež (Czech Republic); Bejsovec, V.; Vacik, J.; Lavrentiev, V. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, 250 68 Řež (Czech Republic); Vrnata, M. [Department of Physics and Measurements, The University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6 (Czech Republic); Kormunda, M. [Department of Physics, Jan Evangelista Purkyně University in Ústí nad Labem, České mládeže 8, 400 96 Ústí nad Labem (Czech Republic); Danis, S. [Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic)

    2016-12-15

    Highlights: • A rapid oxidation process of thin copper films. • Sheet resistance up to 10{sup 9} Ω/◊. • Mixed oxide phase at 200 °C with significant hydroxide presence. • Gas sensing response to 1000 ppm of hydrogen and methanol vapours. • Increased sensitivity with Pd and Au catalyst to hydrogen and methanol, respectively. - Abstract: Copper oxide films were prepared by thermal oxidation of thin Cu films deposited on substrates by ion beam sputtering. The subsequent oxidation was achieved in the temperature range of 200 °C–600 °C with time of treatment from 1 to 7 h (with a 1-h step) in a furnace open to air. At temperatures 250 °C–600 °C, the dominant phase formed was CuO, while at 200 °C mainly the Cu{sub 2}O phase was identified. However, the oxidation at 200 °C led to a more complicated composition − in the depth Cu{sub 2}O phase was observed, though in the near-surface layer the CuO dominant phase was found with a significant presence of Cu(OH){sub 2}. A limited amount of Cu{sub 2}O was also found in samples annealed at 600 °C. The sheet resistance R{sub S} of the as-deposited Cu sample was 2.22 Ω/□, after gradual annealing R{sub S} was measured in the range 2.64 MΩ/□–2.45 GΩ/□. The highest R{sub S} values were obtained after annealing at 300 °C and 350 °C, respectively. Oxygen depth distribution was studied using the {sup 16}O(α,α) nuclear reaction with the resonance at energy 3032 keV. It was confirmed that the higher oxidation degree of copper is located in the near-surface region. Preliminary tests of the copper oxide films as an active layer of a chemiresistor were also performed. Hydrogen and methanol vapours, with a concentration of 1000 ppm, were detected by the sensor at an operating temperature of 300 °C and 350 °C, respectively. The response of the sensors, pointed at the p-type conductivity, was improved by the addition of thin Pd or Au catalytic films to the oxidic film surface. Pd-covered films showed

  8. High charge state metal ion production in vacuum arc ion sources

    International Nuclear Information System (INIS)

    Brown, I.G.; Anders, A.; Anders, S.

    1994-01-01

    The vacuum arc is a rich source of highly ionized metal plasma that can be used to make a high current metal ion source. Vacuum arc ion sources have been developed for a range of applications including ion implantation for materials surface modification, particle accelerator injection for fundamental nuclear physics research, and other fundamental and applied purposes. Typically the source is repetitively pulsed with pulse length of order a millisecond and duty cycle or order 1% and operation of a dc embodiment has been demonstrated also. Beams have been produced from over 50 of the solid metals of the periodic table, with mean ion energy up to several hundred keV and with peak (pulsed) beam current up to several amperes. The ion charge state distribution has been extensively studied. Ion spectra have been measured for a wide range of metallic cathode materials, including Li, C, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Sr, Y, Zr, Nb, Mo, Pd, Ag, Cd, In, Sn, Sb, Ba, La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, Tm, Yb, Hf, Ta, W, Ir, Pt, Au, Pb, Bi, Th and U, as well as compound and alloy cathode materials such as TiC, SiC, UC, PbS, brass, and stainless steel. The ions generated are in general multiply-stripped with a mean charge state of from 1 to 3, depending on the particular metal species, and the charge state distribution can have components from Q = 1+ to 6+. Here the authors review the characteristics of vacuum arc ion sources from the perspective of their high charge state metal ion production

  9. The alteration of oxidation and related properties of metals by ion implantation

    International Nuclear Information System (INIS)

    Dearnaley, G.

    1981-01-01

    A review is given of the various ways in which ion implanted additives can affect the thermal oxidation of metals, for example by blocking diffusion paths for ions, by catalytic effects or by altering the plasticity of the oxide. The versatility of the process has already proved useful in the study of oxidation mechanisms. Ways of achieving a long-lasting protection are discussed in relation to the dominant mechanisms of oxidation inhibition. In many practical applications at elevated temperatures oxidation and mechanical stresses co-exist. In steels the process of oxidative wear is important under conditions of poor lubrication and implanted metallic ions have been shown to be effective. In titanium alloys fatigue cracks probably initiate at dislocation sites at which oxidation proceeds most rapidly, and hence the same implanted species can improve both types of behaviour. Successful implantation treatments for fretting fatigue in titanium and a corrosion-erosion problem in steel are described. (orig.)

  10. A high charge state heavy ion beam source for HIF

    International Nuclear Information System (INIS)

    Eylon, S.; Henestroza, E.

    1995-04-01

    A high current low emittance high charge state heavy ion beam source is being developed. This is designed to deliver HIF (heavy ion fusion) driver accelerator scale beam. Using high-charge-state beam in a driver accelerator for HIF may increase the acceleration efficiency, leading to a reduction in the driver accelerator size and cost. The proposed source system which consists of the gas beam electron stripper followed by a high charge state beam separator, can be added to existing single charge state, low emittance, high brightness ion sources and injectors. We shall report on the source physics design using 2D beam envelope simulations and experimental feasibility studies' results using a neutral gas stripper and a beam separator at the exit of the LBL 2 MV injector

  11. Quantum technologies for solid state physics using cold trapped ions

    International Nuclear Information System (INIS)

    Ferdinand Schmidt-Kaler

    2014-01-01

    The quantum states of ions are perfectly controlled, and may be used for fundamental research in quantum physics, as highlighted by the Nobel Prize given to Dave Wineland in 2012. Two directions of quantum technologies, followed by the Mainz group, have high impact on solid state physics: I) The delivery of single cold ions on demand for the deterministic doping of solid state materials with nm spatial precision to generate design-structures optimized for quantum processors. II) The simulation of solid state relevant Hamiltonians with AMO systems of one or two dimensional arrays of trapped ions. I will talk about the recent progress in both fields. http://www.quantenbit.de/#Number Sign#/publications/(author)

  12. Ion bombardment effect on surface state of metal

    International Nuclear Information System (INIS)

    Vaulin, E.P.; Georgieva, N.E.; Martynenko, T.P.

    1990-01-01

    The effect of slow argon ion bombardment on the surface microstructure of polycrystalline copper as well as the effect of surface state on sputtering of D-16 polycrystalline alloy are experimentally studied. Reduction of copper surface roughness is observed. It is shown that the D-16 alloy sputtering coefficient is sensitive to the surface state within the limits of the destructed surface layer

  13. Tunable electronic, electrical and optical properties of graphene oxide sheets by ion irradiation

    Science.gov (United States)

    Jayalakshmi, G.; Saravanan, K.; Panigrahi, B. K.; Sundaravel, B.; Gupta, Mukul

    2018-05-01

    The tunable electronic, electrical and optical properties of graphene oxide (GO) sheets were investigated using a controlled reduction by 500 keV Ar+-ion irradiation. The carbon to oxygen ratio of the GO sheets upon the ion beam reduction has been estimated using resonant Rutherford backscattering spectrometry analyses and its effect on the electrical and optical properties of GO sheets has been studied using sheet resistance measurements and photoluminescence (PL) measurements. The restoration of sp 2-hybridized carbon atoms within the sp 3 matrix is found to be increases with increasing the Ar+-ion fluences as evident from Fourier transform infrared, and x-ray absorption near-edge structure measurements. The decrease in the number of disorder-induced local density of states (LDOSs) within the π-π* gap upon the reduction causes the shifting of PL emission from near infra-red to blue region and decreases the sheet resistance. The improved electrical and optical properties of GO sheets were correlated to the decrease in the number of LDOSs within the π-π* gap. Our experimental investigations suggest ion beam irradiation is one of an effective approaches to reduce GO to RGO and to tailor its electronic, electrical and optical properties.

  14. Introducing a Simple Equation to Express Oxidation States as an Alternative to Using Rules Associated with Words Alone

    Science.gov (United States)

    Minkiewicz, Piotr; Darewicz, Malgorzata; Iwaniak, Anna

    2018-01-01

    A simple equation to calculate the oxidation states (oxidation numbers) of individual atoms in molecules and ions may be introduced instead of rules associated with words alone. The equation includes two of three categories of bonds, classified as proposed by Goodstein: number of bonds with more electronegative atoms and number of bonds with less…

  15. Lithium alloys and metal oxides as high-capacity anode materials for lithium-ion batteries

    International Nuclear Information System (INIS)

    Liang, Chu; Gao, Mingxia; Pan, Hongge; Liu, Yongfeng; Yan, Mi

    2013-01-01

    Highlights: •Progress in lithium alloys and metal oxides as anode materials for lithium-ion batteries is reviewed. •Electrochemical characteristics and lithium storage mechanisms of lithium alloys and metal oxides are summarized. •Strategies for improving electrochemical lithium storage properties of lithium alloys and metal oxides are discussed. •Challenges in developing lithium alloys and metal oxides as commercial anodes for lithium-ion batteries are pointed out. -- Abstract: Lithium alloys and metal oxides have been widely recognized as the next-generation anode materials for lithium-ion batteries with high energy density and high power density. A variety of lithium alloys and metal oxides have been explored as alternatives to the commercial carbonaceous anodes. The electrochemical characteristics of silicon, tin, tin oxide, iron oxides, cobalt oxides, copper oxides, and so on are systematically summarized. In this review, it is not the scope to retrace the overall studies, but rather to highlight the electrochemical performances, the lithium storage mechanism and the strategies in improving the electrochemical properties of lithium alloys and metal oxides. The challenges and new directions in developing lithium alloys and metal oxides as commercial anodes for the next-generation lithium-ion batteries are also discussed

  16. Splitting of the luminescent excited state of the uranyl ion

    International Nuclear Information System (INIS)

    Flint, C.D.; Sharma, P.; Tanner, P.A.

    1982-01-01

    The luminescence spectra of some uranyl compounds has been studied. It has been proposed that the splitting of the luminescent excited state of the uranyl ion is due to a descent in symmetry experienced by the uranyl ion when it is placed in a crystal field. In recent years there has been developed a highly successful model of the electronic structure of the uranyl ion. In this paper the authors use this model to interpret the luminescence spectra of a variety of uranyl compounds

  17. Charge state and slowing of fast ions in a plasma

    International Nuclear Information System (INIS)

    Nardi, E.; Zinamon, Z.

    1982-01-01

    The charge state of a projectile ion traveling through a plasma target under conditions relevant to ion-beam fusion is calculated. It is found that, at the projectile energies and target parameters considered, the projectile ionization is significantly higher than that of the same projectile species in a cold target. The resulting strong effects on the range and on the shape of the energy deposition profile are shown in several examples of full dynamic calculations

  18. Effect of magnesium ions on the initial oxidation stages of carbon steel

    International Nuclear Information System (INIS)

    Subramanian, H.; Subramanian, Veena; Rangarajan, S.; Narasimhan, S.V.; Velmurugan, S.

    2012-09-01

    Metal Ion Passivation (MIP) is a technique in which passivating ions get into the oxide of structural materials and modifies the oxide in such a way as to reduce the corrosion and corrosion release rates. Magnesium ions are found to be efficient in passivating carbon steel. This study is an attempt to understand the role of magnesium ions during the early stage of film growth on carbon steel. The study reveals that in the presence of Mg, the initial oxide film formed by the application of potential had a different electrochemical property. The microstructure of the parent alloy of steel also interacted differently with Mg during the film formation. The ferrite film was grown on carbon steel by applying 0.1 V (vs SCE) in borate buffer (pH=9, 85 deg. C). The formation and coverage of film on the surface was ascertained by measuring the steady state current density as a function of time. The steady state current density was achieved faster when Mg was present in the solution. The thin film formed was characterized by both by electrochemical impedance spectroscopy and atomic force microscopy. The formation of a passive film (at 0.1 V vs SCE) was evident in both with and without Mg cases, with total impedance of the system increasing by an order of magnitude compared to the film formed at OCP (∼ - 0.825 V vs SCE). The data was fitted to an equivalent circuit representing a metal covered with a porous film. The fit parameters were significantly different for Mg containing system and the charge transfer resistance at oxide/solution interface was observed to be two times higher. The capacitance of the film was also higher in presence of Mg indicating a thinner film. The thin films on carbon steel were characterized by AFM in semi contact mode. The surfaces were found to be covered with fine oxide. Two morphologically different regions could be identified on the surface and they were assigned as pearlite and ferrite regions. One of the most notable observations was the

  19. High ion charge states in a high-current, short-pulse, vacuum ARC ion sources

    International Nuclear Information System (INIS)

    Anders, A.; Brown, I.; MacGill, R.; Dickinson, M.

    1996-01-01

    Ions of the cathode material are formed at vacuum arc cathode spots and extracted by a grid system. The ion charge states (typically 1-4) depend on the cathode material and only little on the discharge current as long as the current is low. Here the authors report on experiments with short pulses (several μs) and high currents (several kA); this regime of operation is thus approaching a more vacuum spark-like regime. Mean ion charge states of up to 6.2 for tungsten and 3.7 for titanium have been measured, with the corresponding maximum charge states of up to 8+ and 6+, respectively. The results are discussed in terms of Saha calculations and freezing of the charge state distribution

  20. High ion charge states in a high-current, short-pulse, vacuum arc ion source

    International Nuclear Information System (INIS)

    Anders, A.; Brown, I.; MacGill, R.; Dickinson, M.

    1995-09-01

    Ions of the cathode material are formed at vacuum arc cathode spots and extracted by a grid system. The ion charge states (typically 1--4) depend on the cathode material and only little on the discharge current as long as the current is low. Here the authors report on experiments with short pulses (several micros) and high currents (several kA); this regime of operation is thus approaching a more vacuum spark-like regime. Mean ion charge states of up to 6.2 for tungsten and 3.7 for titanium have been measured, with the corresponding maximum charge states of up to 8+ and 6+, respectively. The results are discussed in terms of Saha calculations and freezing of the charge state distribution

  1. A high charge state heavy ion beam source for heavy ion fusion

    International Nuclear Information System (INIS)

    Eylon, S.; Henestroza, E.

    1996-01-01

    A high current, low emittance, high charge state heavy ion beam source is being developed. This is designed to deliver a heavy ion fusion (HIF) driver accelerator scale beam. Using a high charge state beam in a driver accelerator for HIF may increase the acceleration efficiency, leading to a reduction in the driver accelerator size and cost. The proposed source system, which consists of a gas beam electron stripper followed by a high charge state beam separator, can be added to existing single charge state, low emittance, high brightness ion sources and injectors. We shall report on the source physics design using 3D beam simulations and experimental feasibility study results using a neutral gas stripper and a beam separator at the exit of the LBL 2 MV injector. (orig.)

  2. Anodic oxidation of chloride ions in 1-butyl-3-methyl-limidazolium tetrafluoroborate ionic liquid

    International Nuclear Information System (INIS)

    Zhang, Qibo; Hua, Yixin; Wang, Rui

    2013-01-01

    Highlights: • The anodic oxidation of Cl − in BMIMBF 4 is electrochemically irreversible with diffusion controlled. • The oxidation of Cl − in BMIMBF 4 is more likely to form tri-chloride ion, Cl 3 − but not chlorine, Cl 2 . • The minute amount of Cl 2 detected after electrolysis forms according to the equilibrium of Cl 2 + Cl − ⇌ Cl 3 − . -- Abstract: The oxidation behavior of chloride ions on platinum electrodes was investigated in a natural ionic liquid, 1-butyl-3-methyl-limidazolium tetrafluoroborate (BMIMBF 4 ) in the presence of high concentrations of 1-butyl-3-methyl-limidazolium chloride (BMIMCl). Analysis of the electrode reaction was explored using cyclic voltammetry, and chronoamperometry with a platinum micro-disk electrode, and bulk potentiostatic electrolysis and UV–vis spectroscopy. The anodic oxidation of chloride ions on the platinum micro-disk electrode in the mixture was considered to be an irreversible process with diffusion controlled as revealed by cyclic voltammetry. The diffusion coefficient, D, and the number of electrons transferred, n, for anodic oxidation of Cl − in BMIMBF 4 derived from results of chronoamperometry revealed that the oxidation of chloride ions was more likely to form tri-chloride ion, Cl 3 − but not chlorine, Cl 2 . Bulk electrolysis and UV–vis spectroscopy further confirmed that the tri-chloride ion was the main product from the overall oxidation of the chloride ion

  3. Influence of surface oxidation on ion dynamics and capacitance in porous and nonporous carbon electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Dyatkin, Boris [Drexel Univ., Philadelphia, PA (United States); Zhang, Yu [Vanderbilt Univ., Nashville, TN (United States); Mamontov, Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kolesnikov, Alexander I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cheng, Yongqiang [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Meyer, III, Harry M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cummings, Peter T. [Vanderbilt Univ., Nashville, TN (United States); Gogotsi, Yury G. [Drexel Univ., Philadelphia, PA (United States)

    2016-04-07

    Here, we investigate the influence of surface chemistry and ion confinement on capacitance and electrosorption dynamics of room-temperature ionic liquids (RTILs) in supercapacitors. Using air oxidation and vacuum annealing, we produced defunctionalized and oxygen-rich surfaces of carbide-derived carbons (CDCs) and graphene nanoplatelets (GNPs). While oxidized surfaces of porous CDCs improve capacitance and rate handling abilities of ions, defunctionalized nonporous GNPs improve charge storage densities on planar electrodes. Quasi-elastic neutron scattering (QENS) and inelastic neutron scattering (INS) probed the structure, dynamics, and orientation of RTIL ions confined in divergently functionalized pores. Oxidized, ionophilic surfaces draw ions closer to pore surfaces and enhance potential-driven ion transport during electrosorption. Molecular dynamics (MD) simulations corroborated experimental data and demonstrated the significance of surface functional groups on ion orientations, accumulation densities, and capacitance.

  4. Resonant Ion Pair Formation in Electron Collisions with Ground State Molecular Ions

    International Nuclear Information System (INIS)

    Zong, W.; Dunn, G.H.; Djuric, N.; Greene, C.H.; Neau, A.; Zong, W.; Larsson, M.; Al-Khalili, A.; Neau, A.; Derkatch, A.M.; Vikor, L.; Shi, W.; Rosen, S.; Le Padellec, A.; Danared, H.; Ugglas, M. af

    1999-01-01

    Resonant ion pair formation from collisions of electrons with ground state diatomic molecular ions has been observed and absolute cross sections measured. The cross section for HD + is characterized by an abrupt threshold at 1.9thinspthinspeV and 14 resolved peaks in the range of energies 0≤E≤14 eV . The dominant mechanism responsible for the structures appears to be resonant capture and stabilization, modified by two-channel quantum interference. Data on HF + show structure correlated with photoionization of HF and with dissociative recombination of electrons with this ion. copyright 1999 The American Physical Society

  5. Ion beam analysis of oxidation and hydrogenation of switchable mirrors

    International Nuclear Information System (INIS)

    Huisman, M.C.; Jongerden, M.R.; Molen, S.J. van der; Vis, R.D.

    2001-01-01

    Thin films of Y, La or rare earth (RE) hydrides exhibit a metal insulator transition between their di- and trihydride phase. After H loading lateral diffusion samples of these materials contain an overview of all hydride phases present in the thin film phase diagram. In this paper the thin film YH x system will be investigated. The unexpected presence of a lateral oxygen profile in the YH x sample necessitates a careful interpretation of local hydrogen concentration differences. In this paper the potential of ion beam analysis will be discussed with respect to the investigation of oxidation and hydrogenation of YH x switchable mirrors. The results of the measurements will be discussed in terms of differences between bulk- and thin-film-phase diagrams of YH x . The experimental methods used are 1 H ( 4 He, 1 H) 4 He elastic recoil detection at 5 MeV and 16 O( 4 He, 4 He) 16 O resonant backscattering around 3.036 MeV

  6. Ion beam analysis of oxidation and hydrogenation of switchable mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Huisman, M.C. E-mail: huisman@nat.vu.nl; Jongerden, M.R.; Molen, S.J. van der; Vis, R.D

    2001-07-01

    Thin films of Y, La or rare earth (RE) hydrides exhibit a metal insulator transition between their di- and trihydride phase. After H loading lateral diffusion samples of these materials contain an overview of all hydride phases present in the thin film phase diagram. In this paper the thin film YH{sub x} system will be investigated. The unexpected presence of a lateral oxygen profile in the YH{sub x} sample necessitates a careful interpretation of local hydrogen concentration differences. In this paper the potential of ion beam analysis will be discussed with respect to the investigation of oxidation and hydrogenation of YH{sub x} switchable mirrors. The results of the measurements will be discussed in terms of differences between bulk- and thin-film-phase diagrams of YH{sub x}. The experimental methods used are {sup 1}H ({sup 4}He, {sup 1}H){sup 4}He elastic recoil detection at 5 MeV and {sup 16}O({sup 4}He, {sup 4}He){sup 16}O resonant backscattering around 3.036 MeV.

  7. Supercritical water oxidation of ion exchange resins: Degradation mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Leybros, A.; Roubaud, A. [CEA Marcoule, DEN DTCD SPDE LFSM, F-30207 Bagnols Sur Ceze (France); Guichardon, P. [Ecole Cent Marseille, F-13451 Marseille 20 (France); Boutin, O. [Aix Marseille Univ, UMR CNRS 6181, F-13545 Aix En Provence 4 (France)

    2010-07-01

    Spent ion exchange resins are radioactive process wastes for which there is no satisfactory industrial treatment. Supercritical water oxidation could offer a viable treatment alternative to destroy the organic structure of resins and contain radioactivity. IER degradation experiments were carried out in a continuous supercritical water reactor. Total organic carbon degradation rates in the range of 95-98% were obtained depending on operating conditions. GC-MS chromatography analyses were carried out to determine intermediate products formed during the reaction. Around 50 species were identified for cationic and anionic resins. Degradation of poly-styrenic structure leads to the formation of low molecular weight compounds. Benzoic acid, phenol and acetic acid are the main compounds. However, other products are detected in appreciable yields such as phenolic species or heterocycles, for anionic IERs degradation. Intermediates produced by intramolecular rearrangements are also obtained. A radical degradation mechanism is proposed for each resin. In this overall mechanism, several hypotheses are foreseen, according to HOO center dot radical attack sites. (authors)

  8. Steady-State Ion Beam Modeling with MICHELLE

    Science.gov (United States)

    Petillo, John

    2003-10-01

    There is a need to efficiently model ion beam physics for ion implantation, chemical vapor deposition, and ion thrusters. Common to all is the need for three-dimensional (3D) simulation of volumetric ion sources, ion acceleration, and optics, with the ability to model charge exchange of the ion beam with a background neutral gas. The two pieces of physics stand out as significant are the modeling of the volumetric source and charge exchange. In the MICHELLE code, the method for modeling the plasma sheath in ion sources assumes that the electron distribution function is a Maxwellian function of electrostatic potential over electron temperature. Charge exchange is the process by which a neutral background gas with a "fast" charged particle streaming through exchanges its electron with the charged particle. An efficient method for capturing this is essential, and the model presented is based on semi-empirical collision cross section functions. This appears to be the first steady-state 3D algorithm of its type to contain multiple generations of charge exchange, work with multiple species and multiple charge state beam/source particles simultaneously, take into account the self-consistent space charge effects, and track the subsequent fast neutral particles. The solution used by MICHELLE is to combine finite element analysis with particle-in-cell (PIC) methods. The basic physics model is based on the equilibrium steady-state application of the electrostatic particle-in-cell (PIC) approximation employing a conformal computational mesh. The foundation stems from the same basic model introduced in codes such as EGUN. Here, Poisson's equation is used to self-consistently include the effects of space charge on the fields, and the relativistic Lorentz equation is used to integrate the particle trajectories through those fields. The presentation will consider the complexity of modeling ion thrusters.

  9. Sodium-Ion Intercalated Transparent Conductors with Printed Reduced Graphene Oxide Networks.

    Science.gov (United States)

    Wan, Jiayu; Gu, Feng; Bao, Wenzhong; Dai, Jiaqi; Shen, Fei; Luo, Wei; Han, Xiaogang; Urban, Daniel; Hu, Liangbing

    2015-06-10

    In this work, we report for the first time that Na-ion intercalation of reduced graphene oxide (RGO) can significantly improve its printed network's performance as a transparent conductor. Unlike pristine graphene that inhibits Na-ion intercalation, the larger layer-layer distance of RGO allows Na-ion intercalation, leading to simultaneously much higher DC conductivity and higher optical transmittance. The typical increase of transmittance from 36% to 79% and decrease of sheet resistance from 83k to 311 Ohms/sq in the printed network was observed after Na-ion intercalation. Compared with Li-intercalated graphene, Na-ion intercalated RGO shows much better environmental stability, which is likely due to the self-terminating oxidation of Na ions on the RGO edges. This study demonstrated the great potential of metal-ion intercalation to improve the performance of printed RGO network for transparent conductor applications.

  10. Thin copper oxide films prepared by ion beam sputtering with subsequent thermal oxidation: Application in chemiresistors

    Science.gov (United States)

    Horak, P.; Bejsovec, V.; Vacik, J.; Lavrentiev, V.; Vrnata, M.; Kormunda, M.; Danis, S.

    2016-12-01

    Copper oxide films were prepared by thermal oxidation of thin Cu films deposited on substrates by ion beam sputtering. The subsequent oxidation was achieved in the temperature range of 200 °C-600 °C with time of treatment from 1 to 7 h (with a 1-h step) in a furnace open to air. At temperatures 250 °C-600 °C, the dominant phase formed was CuO, while at 200 °C mainly the Cu2O phase was identified. However, the oxidation at 200 °C led to a more complicated composition - in the depth Cu2O phase was observed, though in the near-surface layer the CuO dominant phase was found with a significant presence of Cu(OH)2. A limited amount of Cu2O was also found in samples annealed at 600 °C. The sheet resistance RS of the as-deposited Cu sample was 2.22 Ω/□, after gradual annealing RS was measured in the range 2.64 MΩ/□-2.45 GΩ/□. The highest RS values were obtained after annealing at 300 °C and 350 °C, respectively. Oxygen depth distribution was studied using the 16O(α,α) nuclear reaction with the resonance at energy 3032 keV. It was confirmed that the higher oxidation degree of copper is located in the near-surface region. Preliminary tests of the copper oxide films as an active layer of a chemiresistor were also performed. Hydrogen and methanol vapours, with a concentration of 1000 ppm, were detected by the sensor at an operating temperature of 300 °C and 350 °C, respectively. The response of the sensors, pointed at the p-type conductivity, was improved by the addition of thin Pd or Au catalytic films to the oxidic film surface. Pd-covered films showed an increased response to hydrogen at 300 °C, while Au-covered films were more sensitive to methanol vapours at 350 °C.

  11. Control of trapped-ion quantum states with optical pulses

    International Nuclear Information System (INIS)

    Rangan, C.; Monroe, C.; Bucksbaum, P.H.; Bloch, A.M.

    2004-01-01

    We present new results on the quantum control of systems with infinitely large Hilbert spaces. A control-theoretic analysis of the control of trapped-ion quantum states via optical pulses is performed. We demonstrate how resonant bichromatic fields can be applied in two contrasting ways--one that makes the system completely uncontrollable and the other that makes the system controllable. In some interesting cases, the Hilbert space of the qubit-harmonic oscillator can be made finite, and the Schroedinger equation controllable via bichromatic resonant pulses. Extending this analysis to the quantum states of two ions, a new scheme for producing entangled qubits is discovered

  12. Theory of the l-state population of Rydberg states formed in ion-solid collisions

    International Nuclear Information System (INIS)

    Kemmler, J.; Burgdoerfer, J.; Reinhold, C.O.

    1991-01-01

    The experimentally observed high-l-state population of ions excited in ion-solid interactions differs sharply from l-state populations produced in ion-atom collisions. We have studied the population dynamics of electronic excitation and transport within the framework of a classical transport theory for O 2+ (2-MeV/u) ions traversing C foils. The resulting delayed-photon-emission intensities are found to be in very good agreement with experiment. Initial phase-space conditions have been obtained from both classical-trajectory Monte Carlo calculations and random initial distributions. We find evidence that the very-high-l-state populations produced in ion-solid collisions are the result of a diffusion to high-l states under the influence of multiple scattering in the bulk of the solid

  13. Oxidation state analyses of uranium with emphasis on chemical speciation in geological media

    International Nuclear Information System (INIS)

    Ervanne, H.

    2004-01-01

    This thesis focuses on chemical methods suitable for the determination of uranium redox species in geological materials. Nd-coprecipitation method was studied for the determination of uranium oxidation states in ground waters. This method is ideally suited for the separation of uranium oxidation states in the field, which means that problems associated with the instability of U(IV) during transport are avoided. An alternative method, such as ion exchange, is recommended for the analysis of high saline and calcium- and iron-rich ground waters. U(IV)/Utot was 2.8-7.2% in ground waters in oxidizing conditions and 60-93% in anoxic conditions. From thermodynamic model calculations applied to results from anoxic ground waters it was concluded that uranium can act as redox buffer in granitic ground waters. An ion exchange method was developed for the analysis of uranium oxidation states in different solid materials of geological origin. These included uranium minerals, uraniumbearing minerals, fracture coatings and bulk rock. U(IV)/Utot was 50-70% in uraninites, 5.8-8.7% in secondary uranium minerals, 15-49% in different fracture coatings and 64- 77% in samples from deep bedrock. In the uranium-bearing minerals, U(IV)/Utot was 33-43% (allanites), 5.9% (fergusonite) and 93% (monazite). Although the ion exchange method gave reliable results, there is a risk for the conversion of uranium oxidation states during analysis of heterogeneous samples due to the redox reactions that take place in the presence of some iron compounds. This risk was investigated in a study of several common iron-bearing minerals. The risk for conversion of uranium oxidation states can be screened by sample selection and minimized with use of a redox buffer compound such as polyacrylic acid (PAA). In studies of several carboxylic acids, PAA was found to be the most suitable for extending the application of the method. The stability of uranium oxidation states during analysis and the selectivity

  14. [Ultrasound induced the formation of nitric oxide and nitrosonium ions in water and aqueous solutions].

    Science.gov (United States)

    Stepuro, I I; Adamchuk, R I; Stepuro, V I

    2004-01-01

    Nitric oxide, nitrosonium ions, nitrites, and nitrates are formed in water saturated with air under the action of ultrasound. Nitrosonium ions react with water and hydrogen peroxide to form nitrites and nitrates in sonicated solution, correspondingly. Nitric oxide is practically completely released from sonicated water into the atmosphere and reacts with air oxygen, forming NOx compounds. The oxidation of nitric oxide in aqueous medium by hydroxyl radicals and dissolved oxygen is a minor route of the formation of nitrites and nitrates in ultrasonic field.

  15. DetOx: a program for determining anomalous scattering factors of mixed-oxidation-state species.

    Science.gov (United States)

    Sutton, Karim J; Barnett, Sarah A; Christensen, Kirsten E; Nowell, Harriott; Thompson, Amber L; Allan, David R; Cooper, Richard I

    2013-01-01

    Overlapping absorption edges will occur when an element is present in multiple oxidation states within a material. DetOx is a program for partitioning overlapping X-ray absorption spectra into contributions from individual atomic species and computing the dependence of the anomalous scattering factors on X-ray energy. It is demonstrated how these results can be used in combination with X-ray diffraction data to determine the oxidation state of ions at specific sites in a mixed-valance material, GaCl(2).

  16. Microstructure of titanium oxide films synthesized by ion beam dynamic mixing

    International Nuclear Information System (INIS)

    Makino, Y.; Setsuhara, Y.; Miyake, S.

    1994-01-01

    The microstructure of titanium oxide films synthesized by the ion beam dynamic mixing (IBDM) method is investigated by glancing angle X-ray diffraction and multi-reflectance FT-IR methods. Titanium oxide films are identified as rutile phases having different degrees of (110) orientation. The IBDM rutile phase with a standard crystalline state is produced by controlling the ratio of the intensities between the (110) and (101) peaks of the rutile, I(110)/I(101), so as to approach the ratio to the value (=2.0) of ASTM standard rutile. The crystallite size of the rutile phase increases with increasing ratio of intensities of the two XRD peaks, I(110)/I(101). The increase of the crystallite size is suggested to be attributed to the increase of oxygen ion energy per Ti atom. From the dependence of the IR absorption near 500 cm -1 upon I(110)/I(101), it is indicated that the Ti-O bond strength is delicately affected by the degree of (110) orientation of the IBDM rultile phase. ((orig.))

  17. Oxidation processes on conducting carbon additives for lithium-ion batteries

    KAUST Repository

    La Mantia, Fabio; Huggins, Robert A.; Cui, Yi

    2012-01-01

    The oxidation processes at the interface between different types of typical carbon additives for lithium-ion batteries and carbonates electrolyte above 5 V versus Li/Li+ were investigated. Depending on the nature and surface area of the carbon

  18. Electron capture into excited states of multi-charged ions

    International Nuclear Information System (INIS)

    Dijkkamp, D.

    1985-01-01

    This thesis deals with charge exchange reactions in slow collisions of multi-charged ions with neutral atoms or molecules. These reactions proceed very efficiently via a curve crossing mechanism, which leads to preferential population of excited states of the ion. The subsequent decay of these states leads to the emission of characteristic radiation. From wavelength resolved measurements of the absolute intensity of this radiation, cross sections for selective population of the excited (n,l-) states of the ion were determined. In addition, for some systems the total capture cross section was measured directly by means of charge state analysis of the secondary projectile ions. The role of charge exchange processes in fusion plasmas and in astrophysical plasmas is indicated. An experimental set-up is described with emphasis on the Electron Cyclotron Resonance Ion Source that was used in the experiments. Results for collisions of C 6+ , N 6+ , O 6+ and Ne 6+ with He, H 2 and Ar are presented as well as for electron capture from Li atoms by C 4+ and He 2+ . The interaction of the iso-electronic sequence C 4+ , N 5+ , O 6+ with atomic hydrogen, molecular hydrogen and helium is studied. First results for partial and total cross sections in collisions of fully stripped carbon, nitrogen and oxygen ions with atomic hydrogen are presented. These data are of particular importance for applications in fusion diagnostics. The data indicate that calculations of both molecular and atomic orbital type yield correct results, if an extended basis set is used. (Auth.)

  19. Influence of initial state distortion in ion-atom collisions

    Energy Technology Data Exchange (ETDEWEB)

    Ciappina, M F [CONICET and Departamento de FIsica, Universidad Nacional del Sur, 8000 BahIa Blanca (Argentina); Cravero, W R [CONICET and Departamento de FIsica, Universidad Nacional del Sur, 8000 BahIa Blanca (Argentina); Garibotti, C R [CONICET and Division Colisiones Atomicas, Centro Atomico Bariloche, 8400 Bariloche (Argentina)

    2004-05-28

    We have studied the influence of initial state distortion in a single ionization by ion impact. We have taken a continuum distorted wave type distortion and by taking up to the first order in its asymptotic series expansion we build an eikonal-spherical distortion. In this way the influence of each term in the transition amplitude can be stated. This approximation can be considered an intermediate one between the eikonal initial state and the continuum distorted wave approaches for initial state distortion. We have computed doubly differential cross sections for helium ionization by protons and highly charged ions at high and intermediate impact energy. We have also discussed the contribution of the different terms in electron energy spectra, specially in the vicinity of ECC peak. Very good agreement is found with the available experimental data.

  20. Influence of initial state distortion in ion-atom collisions

    International Nuclear Information System (INIS)

    Ciappina, M F; Cravero, W R; Garibotti, C R

    2004-01-01

    We have studied the influence of initial state distortion in a single ionization by ion impact. We have taken a continuum distorted wave type distortion and by taking up to the first order in its asymptotic series expansion we build an eikonal-spherical distortion. In this way the influence of each term in the transition amplitude can be stated. This approximation can be considered an intermediate one between the eikonal initial state and the continuum distorted wave approaches for initial state distortion. We have computed doubly differential cross sections for helium ionization by protons and highly charged ions at high and intermediate impact energy. We have also discussed the contribution of the different terms in electron energy spectra, specially in the vicinity of ECC peak. Very good agreement is found with the available experimental data

  1. Nuts and Bolts of the Ion Band State Theory

    Science.gov (United States)

    Chubb, Scott R.

    2005-12-01

    The nuts and bolts of our ion band state theory of low energy nuclear reactions (LENR's) in palladium-deuteride (PdD) and palladium-hydride (PdH) are the electrons that hold together or tear apart the bonds (or lack of bonds) between deuterons (d's) or protons (p's) and the host material. In PdDx and PdHx, this bonding is strongly correlated with loading. In ambient loading conditions (x ≲ 0.6), bonding inhibits ion band state occupation. As x → 1, slight increases and decreases in loading can induce "vibrations" (which have conventionally been thought to occur from phonons) that can induce potential losses or increases of p/d. Naive assumptions about phonons fail to include these losses and increases. These effects can occur because neither H or D has core electrons and because in either PdD or PdH, the electrons near the Fermi energy have negligible overlap with the nucleus of either D or H. In the past, implicitly, we have used these facts to justify our ion band state theory. Here, we present a more formal justification, based on the relationship between H(D) ion band states (IBS's) and H(D) phonons that includes a microscopic picture that explains why occupation of IBS's can occur in PdD and PdH and how this can lead to nuclear reactions.

  2. Electrode property of single-walled carbon nanotubes in all-solid-state lithium ion battery using polymer electrolyte

    International Nuclear Information System (INIS)

    Sakamoto, Y.; Ishii, Y.; Kawasaki, S.

    2016-01-01

    Electrode properties of single-walled carbon nanotubes (SWCNTs) in an all-solid-state lithium ion battery were investigated using poly-ethylene oxide (PEO) solid electrolyte. Charge-discharge curves of SWCNTs in the solid electrolyte cell were successfully observed. It was found that PEO electrolyte decomposes on the surface of SWCNTs.

  3. Electrode property of single-walled carbon nanotubes in all-solid-state lithium ion battery using polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Y.; Ishii, Y.; Kawasaki, S., E-mail: kawasaki.shinji@nitech.ac.jp [Nagoya Institute of Technology, Gokiso, Showa, Nagoya, Aichi (Japan)

    2016-07-06

    Electrode properties of single-walled carbon nanotubes (SWCNTs) in an all-solid-state lithium ion battery were investigated using poly-ethylene oxide (PEO) solid electrolyte. Charge-discharge curves of SWCNTs in the solid electrolyte cell were successfully observed. It was found that PEO electrolyte decomposes on the surface of SWCNTs.

  4. State-selective charge transfer and excitation in ion-ion interactions at intermediate and high energies

    International Nuclear Information System (INIS)

    Samanta, R; Purkait, M

    2012-01-01

    Boundary Corrected Continuum Intermediate State (BCCIS) approximation and Classical Trajectory Monte Carlo (CTMC) methods are applied to calculate the charge transfer and excitation cross sections for ion-ion collisions.

  5. Solid state electrolytes for all-solid-state 3D lithium-ion batteries

    NARCIS (Netherlands)

    Kokal, I.

    2012-01-01

    The focus of this Ph.D. thesis is to understand the lithium ion motion and to enhance the Li-ionic conductivities in commonly known solid state lithium ion conductors by changing the structural properties and preparation methods. In addition, the feasibility for practical utilization of several

  6. Cross-sections of charge and electronic states change of particles at ion-ion and ion-molecule collisions

    International Nuclear Information System (INIS)

    Panov, M.N.; Afrosimov, V.V.; Basalaev, A.A.; Guschina, N.A.; Nikulin, V.K.

    2006-01-01

    The interactions of protons and alpha-particles with hydrocarbons are investigated. A quantum-mechanical computation of the electronic structure of all hydrocarbons from methane to butane and its fragment ions was performed in the Hartree-Fock RHF/UHF approximation using a GAMESS program (General Atomic Molecular Electron Structure System). The correlation energy was taken into account within the framework of MP2 perturbation theory. The structural parameters of the hydrocarbon molecules and their charged and neutral fragments were calculated in two cases: in the geometry of the parent molecule or of the relaxation states. The difference of the full energy of the same fragments in and out of brackets gives us the vibration excitation energies of the fragments at the moment of creation. Additional Mulliken effective charges (in electron charge units) of atoms in the fragments have been calculated. The calculations show that removing one electron from the ethane molecule without electronic excitation produced a single charged molecular ion in vibration state with binding energy of hydrogen atoms, some decimal eV. As results we obtain C 2 H 6 + and C 2 H 5 + . Additional fragmentation of hydrocarbon needs electronic excitation of produced single charged ions. Cross sections for electron capture and excitation processes in collisions between the hydrogen-like He + , B 4+ and O 7+ ions have been evaluated. The purpose of the theory within this project during the period under review was to get for the first time new data on Single-Electron Capture (SEC) and Excitation Processes (EP) in collisions of He + (1s) ions with hydrogen-like impurity ions B 4+ (1s) and O 7+ (1s) in the energy range for He + ions from 0.2 MeV to 3.0 MeV. The calculations were carried out by using the method of close-coupling equations with basis sets of eleven and ten quasimolecular two-electron states for reactions (1, 2) and (3, 4), respectively (entrance channel, seven charge transfer channels

  7. Auto transfer to Rydberg states during ion-atom collisions

    International Nuclear Information System (INIS)

    Bachau, H.; Harel, C.; Barat, M.; Roncin, P.; Bordenave-Montesquieu, A.; Moretto-Capelle, P.; Benoit-Cattin, P.; Gleizes, A.; Benhenni, M.

    1993-01-01

    Electron capture by slow multiply charged ions colliding on rare-gas targets is known to populate highly excited states of the projectile. On the basis of experimental measurement of energy and angle differential cross-sections we have shown that capture to a resonant doubly excited state may lead to Autoionizing Double Capture (ADC) as well as to True Double Capture (TDC). In this model TDC appears as a two step post-collisional process, the state populated by the collision decays to (or delutes into) a dense adjacent Rydberg series, followed by radiative deexcitation of the inner electron of the (3,n) Rydberg states. We report here new experimental observations in electron spectra measured in N 7+ +He. Auto transfer to Rydber states has also important consequences on the determination of the lifetime of the autoionizing states, some discrepancies between theoretical width values for low N 5+ (4,4) resonant states will be discussed and partially resolved

  8. Vacuum improvements for ultra high charge state ion acceleration

    International Nuclear Information System (INIS)

    Xie, Z.Q.; Lyneis, C.M.; Clark, D.J.; Guy, A.; Lundgren, S.A

    1998-06-01

    The installation of a second cryo panel has significantly improved the vacuum in the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The neutral pressure in the extraction region decreased from 1.2 x 10 -6 down to about 7 x 10 -7 Torr. The vacuum improvement reduces beam loss from charge changing collisions and enhances the cyclotron beam transmission, especially for the high charge state heavy ions. Tests with improved vacuum show the cyclotron transmission increased more than 50% (from 5.7% to 9.0%) for a Xe 27+ at 603 MeV, more than doubled for a Bi 41+ beam (from 1.9% to 4.6%) at 904 MeV and tripled for a U 47+ beam (from 1.2% to 3.6%) at 1,115 MeV. At about 5 NeV/nucleon 92 enA (2.2 pnA) for Bi 41+ and 14 enA (0.3 pnA) for U 47+ were extracted ut of the 88-Inch Cyclotron Ion beams with charge states as high as U 64+ have been produced by the LBNL AECR-U ion source and accelerated through the cyclotron for the first time. The beam losses for a variety of ultra high charge state ions were measured as a function of cyclotron pressure and compared with the calculations from the existing models

  9. Vacuum improvements for ultra high charge state ion acceleration

    International Nuclear Information System (INIS)

    Xie, Z.Q.; Lyneis, C.M.; Clark, D.J.; Guy, A.; Lundgren, S.A.

    1999-01-01

    The installation of a second cryo panel has significantly improved the vacuum in the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The neutral pressure in the extraction region decreased from 1.2 x 10 -6 down to about 7 x 10 -7 Torr. The vacuum improvement reduces beam loss from charge changing collisions and enhances the cyclotron beam transmission, especially for the high charge state heavy ions. Tests with improved vacuum show the cyclotron transmission increased more than 50% (from 5.7% to 9.0%) for a Xe 27+ at 603 MeV, more than doubled for a Bi 41+ beam (from 1.9% % to 4.6%) at 904 MeV and tripled for a U 47+ beam (from 1.2% to 3.6%) at 1115 MeV. At about 5 MeV/nucleon 92 enA (2.2 pnA) for Bi 41+ and 14 enA (0.3 pnA) for U 47+ were extracted out of the 88-Inch Cyclotron Ion beams with charge states as high as U 64+ have been produced by the LBNL AECR-U ion source and accelerated through the cyclotron for the first time. The beam losses for a variety of ultra high charge state ions were measured as a function of cyclotron pressure and compared with the calculations from the existing models. (authors)

  10. Oxide-nitride-oxide dielectric stacks with Si nanoparticles obtained by low-energy ion beam synthesis

    International Nuclear Information System (INIS)

    Ioannou-Sougleridis, V; Dimitrakis, P; Vamvakas, V Em; Normand, P; Bonafos, C; Schamm, S; Mouti, A; Assayag, G Ben; Paillard, V

    2007-01-01

    Formation of a thin band of silicon nanoparticles within silicon nitride films by low-energy (1 keV) silicon ion implantation and subsequent thermal annealing is demonstrated. Electrical characterization of metal-insulator-semiconductor capacitors reveals that oxide/Si-nanoparticles-nitride/oxide dielectric stacks exhibit enhanced charge transfer characteristics between the substrate and the silicon nitride layer compared to dielectric stacks using unimplanted silicon nitride. Attractive results are obtained in terms of write/erase memory characteristics and data retention, indicating the large potential of the low-energy ion-beam-synthesis technique in SONOS memory technology

  11. Electronically excited negative ion resonant states in chloroethylenes

    Energy Technology Data Exchange (ETDEWEB)

    Khvostenko, O.G., E-mail: khv@mail.ru; Lukin, V.G.; Tuimedov, G.M.; Khatymova, L.Z.; Kinzyabulatov, R.R.; Tseplin, E.E.

    2015-02-15

    Highlights: • Several novel dissociative negative ion channels were revealed in chloroethylenes. • The electronically excited resonant states were recorded in all chloroethylenes under study. • The states were assigned to the inter-shell types, but not to the core-excited Feshbach one. - Abstract: The negative ion mass spectra of the resonant electron capture by molecules of 1,1-dichloroethylene, 1,2-dichloroethylene-cis, 1,2-dichloroethylene-trans, trichloroethylene and tetrachloroethylene have been recorded in the 0–12 eV range of the captured electron energy using static magnetic sector mass spectrometer modified for operation in the resonant electron capture regime. As a result, several novel low-intensive dissociation channels were revealed in the compounds under study. Additionally, the negative ion resonant states were recorded at approximately 3–12 eV, mostly for the first time. These resonant states were assigned to the electronically excited resonances of the inter-shell type by comparing their energies with those of the parent neutral molecules triplet and singlet electronically excited states known from the energy-loss spectra obtained by previous studies.

  12. Carbon monoxide oxidation over three different states of copper: Development of a model metal oxide catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Jernigan, Glenn Geoffrey [California Univ., Berkeley, CA (United States). Dept. of Chemistry

    1994-10-01

    Carbon monoxide oxidation was performed over the three different oxidation states of copper -- metallic (Cu), copper (I) oxide (Cu2O), and copper (II) oxide (CuO) as a test case for developing a model metal oxide catalyst amenable to study by the methods of modern surface science and catalysis. Copper was deposited and oxidized on oxidized supports of aluminum, silicon, molybdenum, tantalum, stainless steel, and iron as well as on graphite. The catalytic activity was found to decrease with increasing oxidation state (Cu > Cu2O > CuO) and the activation energy increased with increasing oxidation state (Cu, 9 kcal/mol < Cu2O, 14 kcal/mol < CuO, 17 kcal/mol). Reaction mechanisms were determined for the different oxidation states. Lastly, NO reduction by CO was studied. A Cu and CuO catalyst were exposed to an equal mixture of CO and NO at 300--350 C to observe the production of N2 and CO2. At the end of each reaction, the catalyst was found to be Cu2O. There is a need to study the kinetics of this reaction over the different oxidation states of copper.

  13. Impact of metal-ion contaminated silica particles on gate oxide integrity

    NARCIS (Netherlands)

    Rink, Ingrid; Wali, F.; Knotter, D.M.

    2009-01-01

    The impact of metal-ion contamination (present on wafer surface before oxidation) on gate oxide integrity (GOI) is well known in literature, which is not the case for clean silica particles [1, 2]. However, it is known that particles present in ultra-pure water (UPW) decrease the random yield in

  14. Cathode and electrolyte materials for solid oxide fuel cells and ion transport membranes

    Science.gov (United States)

    Jacobson, Allan J; Wang, Shuangyan; Kim, Gun Tae

    2014-01-28

    Novel cathode, electrolyte and oxygen separation materials are disclosed that operate at intermediate temperatures for use in solid oxide fuel cells and ion transport membranes based on oxides with perovskite related structures and an ordered arrangement of A site cations. The materials have significantly faster oxygen kinetics than in corresponding disordered perovskites.

  15. Structure and reactivity of molybdenum oxide cluster ions in the gas phase

    International Nuclear Information System (INIS)

    Goncharov, V.B.; Fialko, E.F.

    2002-01-01

    A set of cluster ions of molybdenum oxides Mo x O y + (x = 1-5, y = 1-15) was prepared using a combination of the ionic cyclotron resonance method and Knudsen effusion source. Dependence of concentration of different molybdenum oxide ions on the time of retention and their interaction with carbon monoxide was studied. It is shown that Mo x O y + ions with x>3 contain cyclic fragment Mo 3 O 9 in their structure. Oxygen binding energies within ionic clusters Mo x O y + were estimated [ru

  16. Scheme for teleportation of unknown states of trapped ion

    Institute of Scientific and Technical Information of China (English)

    Chen Mei-Feng; Ma Song-She

    2008-01-01

    A scheme is presented for teleporting an unknown state in a trapped ion system.The scheme only requires a single laser beam.It allows the trap to be in any state with a few phonons,e.g.a thermal motion.Furthermore,it works in the regime,where the Rabi frequency of the laser is on the order of the trap frequency.Thus,the teleportation speed is greatly increased,which is important for decreasing the decoherence effect.This idea can also be used to teleport an unknown ionic entangled state.

  17. Oxidation under electron bombardment. A tool for studying the initial states of silicon oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Carriere, B.; Deville, J.P.; El Maachi, A.

    1987-06-01

    The exciting beam of an Auger electron spectrometer has been used to monitor the oxidation of silicon single crystals at room temperature and very low pressures of oxygen (approx. 10/sup -7/ Torr). This process allows us to build ultra-thin layers of silica on silicon (down to 30 A) but it is mostly used to investigate the mechanisms of the initial stages of oxidation. Auger spectra recorded continuously during the oxidation process provide information on (1) the nature of the silicon-oxygen chemical bonds which are interpreted through fine structure in the Auger peak, and (2) the kinetics of oxide formation which are deduced from curves of Auger signal versus time. An account is given of the contribution of these Auger studies to the description of the intermediate oxide layer during the reaction between silicon and oxygen and the influence of surface structural disorder, induced mainly by argon-ion bombardment, is discussed in terms of reactivity and oxide coverage.

  18. Comparative ion insertion study into a nanostructured vanadium oxide in aqueous salt solutions

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Q.; Ren, S. L.; Zukowski, J.; Pomeroy, M.; Soghomonian, V., E-mail: soghomon@vt.edu [Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2014-07-07

    We present a comparative study for the electrochemical insertion of different cations into a nanostructured vanadium oxide material. The oxide is hydrothemally synthesized and electrically characterized by variable temperature measurements. The electrochemical reactions are performed in aqueous chloride solutions of lithium, sodium, potassium, and ammonium, and the electrochemical behavior of various cycles are correlated with visual changes in the vanadium oxide nanosheets as observed by scanning electron microscopy. We note an increase in the specific charge per cycle in the cases of sodium and ammonium ions only, correlated with minimal physical changes to the nanosheets. The differing behavior of the various ions has implications for their use in electrical energy storage applications.

  19. Isotopic exchange rate of sodium ions between hydrous metal oxides and aqueous solutions

    International Nuclear Information System (INIS)

    Inoue, Yasushi; Yamazaki, Hiromichi

    1991-01-01

    To elucidate the kinetics of ion-exchange reaction on hydrous metal oxide, the isotopic exchange rates of sodium ions between hydrous metal oxides such as hydrous tin (IV), niobium (V), zirconium (IV) and titanium (IV) oxides, and aqueous solutions were measured radiochemically and compared with each other. The rate of reaction cannot be understood by an unified view since the rate controlling step differs with the kind of exchangers. The rate constants relevant to each exchanger such as diffusion constants and their activation energies were also determined. (author)

  20. An Electrochemical Sensor Based on Nanostructured Hollandite-type Manganese Oxide for Detection of Potassium Ions

    Directory of Open Access Journals (Sweden)

    Alex S. Lima

    2009-08-01

    Full Text Available The participation of cations in redox reactions of manganese oxides provides an opportunity for development of chemical sensors for non-electroactive ions. A sensor based on a nanostructured hollandite-type manganese oxide was investigated for voltammetric detection of potassium ions. The detection is based on the measurement of anodic current generated by oxidation of Mn(III to Mn(IV at the surface of the electrode and the subsequent extraction of the potassium ions into the hollandite structure. In this work, an amperometric procedure at an operating potential of 0.80 V (versus SCE is exploited for amperometric monitoring. The current signals are linearly proportional to potassium ion concentration in the range 4.97 × 10−5 to 9.05 × 10−4 mol L−1, with a correlation coefficient of 0.9997.

  1. Adaptation of intertidal biofilm communities is driven by metal ion and oxidative stresses

    KAUST Repository

    Zhang, Weipeng; Wang, Yong; Lee, On On; Tian, Renmao; Cao, Huiluo; Gao, Zhaoming; Li, Yongxin; Yu, Li; Xu, Ying; Qian, Pei-Yuan

    2013-01-01

    Marine organisms in intertidal zones are subjected to periodical fluctuations and wave activities. To understand how microbes in intertidal biofilms adapt to the stresses, the microbial metagenomes of biofilms from intertidal and subtidal zones were compared. The genes responsible for resistance to metal ion and oxidative stresses were enriched in both 6-day and 12-day intertidal biofilms, including genes associated with secondary metabolism, inorganic ion transport and metabolism, signal transduction and extracellular polymeric substance metabolism. In addition, these genes were more enriched in 12-day than 6-day intertidal biofilms. We hypothesize that a complex signaling network is used for stress tolerance and propose a model illustrating the relationships between these functions and environmental metal ion concentrations and oxidative stresses. These findings show that bacteria use diverse mechanisms to adapt to intertidal zones and indicate that the community structures of intertidal biofilms are modulated by metal ion and oxidative stresses.

  2. Adaptation of intertidal biofilm communities is driven by metal ion and oxidative stresses

    KAUST Repository

    Zhang, Weipeng

    2013-11-11

    Marine organisms in intertidal zones are subjected to periodical fluctuations and wave activities. To understand how microbes in intertidal biofilms adapt to the stresses, the microbial metagenomes of biofilms from intertidal and subtidal zones were compared. The genes responsible for resistance to metal ion and oxidative stresses were enriched in both 6-day and 12-day intertidal biofilms, including genes associated with secondary metabolism, inorganic ion transport and metabolism, signal transduction and extracellular polymeric substance metabolism. In addition, these genes were more enriched in 12-day than 6-day intertidal biofilms. We hypothesize that a complex signaling network is used for stress tolerance and propose a model illustrating the relationships between these functions and environmental metal ion concentrations and oxidative stresses. These findings show that bacteria use diverse mechanisms to adapt to intertidal zones and indicate that the community structures of intertidal biofilms are modulated by metal ion and oxidative stresses.

  3. Fabrication of Amorphous Indium Gallium Zinc Oxide Thin Film Transistor by using Focused Ion Beam

    Science.gov (United States)

    Zhu, Wencong

    Compared with other transparent semiconductors, amorphous indium gallium zinc oxide (a-IGZO) has both good uniformity and high electron mobility, which make it as a good candidate for displays or large-scale transparent circuit. The goal of this research is to fabricate alpha-IGZO thin film transistor (TFT) with channel milled by focused ion beam (FIB). TFTs with different channel geometries can be achieved by applying different milling strategies, which facilitate modifying complex circuit. Technology Computer-Aided Design (TCAD) was also introduced to understand the effect of trapped charges on the device performance. The investigation of the trapped charge at IGZO/SiO2 interface was performed on the IGZO TFT on p-Silicon substrate with thermally grown SiO2 as dielectric. The subgap density-of-state model was used for the simulation, which includes conduction band-tail trap states and donor-like state in the subgap. The result shows that the de-trapping and donor-state ionization determine the interface trapped charge density at various gate biases. Simulation of IGZO TFT with FIB defined channel on the same substrate was also applied. The drain and source were connected intentionally during metal deposition and separated by FIB milling. Based on the simulation, the Ga ions in SiO2 introduced by the ion beam was drifted by gate bias and affects the saturation drain current. Both side channel and direct channel transparent IGZO TFTs were fabricated on the glass substrate with coated ITO. Higher ion energy (30 keV) was used to etch through the substrate between drain and source and form side channels at the corner of milled trench. Lower ion energy (16 keV) was applied to stop the milling inside IGZO thin film and direct channel between drain and source was created. Annealing after FIB milling removed the residual Ga ions and the devices show switch feature. Direct channel shows higher saturation drain current (~10-6 A) compared with side channel (~10-7 A) because

  4. Minimization of Ion-Solvent Clusters in Gel Electrolytes Containing Graphene Oxide Quantum Dots for Lithium-Ion Batteries.

    Science.gov (United States)

    Chen, Yen-Ming; Hsu, Shih-Ting; Tseng, Yu-Hsien; Yeh, Te-Fu; Hou, Sheng-Shu; Jan, Jeng-Shiung; Lee, Yuh-Lang; Teng, Hsisheng

    2018-03-01

    This study uses graphene oxide quantum dots (GOQDs) to enhance the Li + -ion mobility of a gel polymer electrolyte (GPE) for lithium-ion batteries (LIBs). The GPE comprises a framework of poly(acrylonitrile-co-vinylacetate) blended with poly(methyl methacrylate) and a salt LiPF 6 solvated in carbonate solvents. The GOQDs, which function as acceptors, are small (3-11 nm) and well dispersed in the polymer framework. The GOQDs suppress the formation of ion-solvent clusters and immobilize PF6- anions, affording the GPE a high ionic conductivity and a high Li + -ion transference number (0.77). When assembled into Li|electrolyte|LiFePO 4 batteries, the GPEs containing GOQDs preserve the battery capacity at high rates (up to 20 C) and exhibit 100% capacity retention after 500 charge-discharge cycles. Smaller GOQDs are more effective in GPE performance enhancement because of the higher dispersion of QDs. The minimization of both the ion-solvent clusters and degree of Li + -ion solvation in the GPEs with GOQDs results in even plating and stripping of the Li-metal anode; therefore, Li dendrite formation is suppressed during battery operation. This study demonstrates a strategy of using small GOQDs with tunable properties to effectively modulate ion-solvent coordination in GPEs and thus improve the performance and lifespan of LIBs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. 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

  6. Moessbauer effect study of oxidation and coordination states of iron in some sodium borate glasse:;

    International Nuclear Information System (INIS)

    Eissa, N.A.; Sanad, A.M.; Youssef, S.M.; El-Henawii, S.A.; Gomaa, S.Sh.; Mostafa, A.G.

    1980-01-01

    A structural study of some sodium borate glasses containing iron was carried out applying ME spectroscopy. Both oxidation and coordination states of iron were investigated under the effect of gradual replacing of sodium carbonate by sodium nitrate in the glass batches. The glasses were melted in porcelain crucibles using an electrically heated furnace at 1000+-10 deg C, then were quenched on a steel plate at room temperature (R.T.). The ME source was 20 mCi radioactive Co-57 in chromium. The obtained ME spectra indicated that at lower sodium nitrate content both Fe 2+ and Fe 3+ are present in these glasses. At moderate concentrations some Fe 3+ ions were separated in a crystalline phase and the rest of the iron ions appeared as ferric ions in glassy state. At high sodium nitrate content only Fe 3+ ions in glassy state were detected. The values of the ME parameters for all iron ions indicated that all of them are in the octahedral coordination state. The density measurements confirm the separation of a crystalline phase at moderate sodium nitrate content. (author)

  7. Radioactive ion beams and techniques for solid state research

    International Nuclear Information System (INIS)

    Correia, J.G.

    1998-01-01

    In this paper we review the most recent and new applications of solid state characterization techniques using radioactive ion beams. For such type ofresearch, high yields of chemically clean ion beams of radioactive isotopesare needed which are provided by the on-line coupling of high resolution isotope separators to particle accelerators, such as the isotope separator on-line (ISOLDE) facility at CERN. These new experiments are performed by an increasing number of solid state groups. They combine nuclear spectroscopic techniques such as Moessbauer, perturbed angular correlations (PAC) and emission channeling with the traditional non-radioactive techniques liked deep level transient spectroscopy (DLTS) and Hall effect measurements. Recently isotopes of elements, not available before, were successfully used in new PAC experiments, and the first photoluminescence (PL) measurements, where the element transmutation plays the essential role on the PL peak identification, have been performed. The scope of applications of radioactive ion beams for research in solid state physics will be enlarged in the near future, with the installation at ISOLDE of a post-accelerator device providing radioactive beams with energies ranging from a few keV up to a few MeV. (orig.)

  8. Formation of Rydberg states in fast ion-atom collisions

    International Nuclear Information System (INIS)

    Schneider, D.; Kanter, E.P.; Vager, Z.; Gemmell, D.; Koch, P.; Mariani, D.; Van de Water, W.

    1983-01-01

    Previous results from beam-foil spectroscopy and from experiments using field ionization techniques have shown that a significant fraction of fast ionic projectiles traversing solid targets can be excited to high Rydberg states. We report an experimental investigation of Rydberg states formed in atomic and molecular ion beams (MeV) emerging from thin-carbon foils. Different field arrangements, including μ-wave fields, have been applied to study the effects of field ionization. The yields of electrons produced via field ionization are compared for different projectile atoms and molecules

  9. Improved oxidation resistance of group VB refractory metals by Al+ ion implantation

    International Nuclear Information System (INIS)

    Hampikian, J.M.

    1996-01-01

    Aluminum ion implantation of vanadium, niobium, and tantalum improved the metals' oxidation resistances at 500 C and 735 C. Implanted vanadium oxidized only to one-third the extent of unimplanted vanadium when exposed at 500 C to air. The oxidative weight gains of implanted niobium and tantalum proved negligible when measured at 500 C and for times sufficient to fully convert the untreated metals to their pentoxides. At 735 C, implantation of vanadium only slightly retarded its oxidation, while oxidative weight gains of niobium and tantalum were reduced by factors of 3 or more. Implanted niobium exhibited weight gain in direct proportion to oxidation time squared at 735 C. Microstructural examination of the metals implanted with selected fluences of the 180 kV aluminum ions showed the following. The solubility limit of aluminum is extended by implantation, the body centered cubic (bcc) phases being retained to ∼60 at. pct Al in all three metals. The highest fluence investigated, 2.4 x 10 22 ions/m 2 , produced an ∼400-nm layer of VAl 3 beneath the surface of vanadium, and ∼300-nm layers of an amorphous phase containing ∼70 at. pct Al beneath the niobium and tantalum surfaces. All three metals, implanted to this fluence and annealed at 600 C, contained tri-aluminides, intermetallic compounds known for their oxidation resistances. Specimens implanted to this fluence were thus selected for the oxidation measurements

  10. Ion-molecule reactions in the binary mixture of ethylene oxide and trioxane, 2

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Arakawa, Kazuo; Sugiura, Toshio.

    1978-01-01

    The ion-molecule reactions in the binary mixture of ethylene oxide and trioxane have been studied with use of a modified time-of-flight mass spectrometer. As cross-reaction product ions, C 3 H 5 O 2 + , C 3 H 6 O 2 +sup(, and C**3**H**7**O**2**)+sup( were observed under the conditions of long delay times and elevated pressure. It was found that these ions are formed by the dissociation of unstable intermediate-complex resulting from the reaction of ethylene oxide molecular ion with trioxane. It was proposed that the complex is of cyclic structure in which positive charge is delocalized. From the consideration of isotopic distribution of the product ions in ethylene-d**4** oxide-trioxane mixtures, the skeletal structures of the product ions were investigated. The rate constants of the formation reactions of C**3**H**5**O**2**)+sup(, C**3**H**6**O**2**)+sup(, and C**3**H**7**O**2**)+sup( in ethylene oxide-trioxane mixtures were found to be 2.20 x 10)-10sup(, 2.61 x 10)-10sup(, and 1.74 x 10)-10sup( cm)3sup( molecule)-1sup(s)-1 , respectively. (auth.)

  11. The air oxidation behavior of lanthanum ion implanted zirconium at 500 deg. C

    CERN Document Server

    Peng, D Q; Chen, X W; Zhou, Q G

    2003-01-01

    The beneficial effect of lanthanum ion implantation on the oxidation behavior of zirconium at 500 deg. C has been studied. Zirconium specimens were implanted by lanthanum ions using a MEVVA source at energy of 40 keV with a fluence range from 1x10 sup 1 sup 6 to 1x10 sup 1 sup 7 ions/cm sup 2 at maximum temperature of 130 deg. C, The weight gain curves were measured after being oxidized in air at 500 deg. C for 100 min, which showed that a significant improvement was achieved in the oxidation behavior of zirconium ion implanted with lanthanum compared with that of the as-received zirconium. The valence of the oxides in the scale was analyzed by X-ray photoemission spectroscopy; and then the depth distributions of the elements in the surface of the samples were obtained by Auger electron spectroscopy. Glancing angle X-ray diffraction at 0.3 deg. incident angles was employed to examine the modification of its phase transformation because of the lanthanum ion implantation in the oxide films. It was obviously fou...

  12. Novel Non-Vacuum Fabrication of Solid State Lithium Ion Battery Components

    Energy Technology Data Exchange (ETDEWEB)

    Oladeji, I. [Planar Energy Devices, Inc.; Wood, D. L. [ORNL; Wood, III, D. L.

    2012-10-19

    The purpose of this Cooperative Research and Development Agreement (CRADA) between Oak Ridge National Laboratory (ORNL) and Planar Energy Devices, Inc. was to develop large-scale electroless deposition and photonic annealing processes associated with making all-solid-state lithium ion battery cathode and electrolyte layers. However, technical and processing difficulties encountered in 2011 resulted in the focus of the CRADA being redirected solely to annealing of the cathode thin films. In addition, Planar Energy Devices de-emphasized the importance of annealing of the solid-state electrolytes within the scope of the project, but materials characterization of stabilized electrolyte layers was still of interest. All-solid-state lithium ion batteries are important to automotive and stationary energy storage applications because they would eliminate the problems associated with the safety of the liquid electrolyte in conventional lithium ion batteries. However, all-solid-state batteries are currently produced using expensive, energy consuming vacuum methods suited for small electrode sizes. Transition metal oxide cathode and solid-state electrolyte layers currently require about 30-60 minutes at 700-800°C vacuum processing conditions. Photonic annealing requires only milliseconds of exposure time at high temperature and a total of <1 min of cumulative processing time. As a result, these processing techniques are revolutionary and highly disruptive to the existing lithium ion battery supply chain. The current methods of producing all-solid-state lithium ion batteries are only suited for small-scale, low-power cells and involve high-temperature vacuum techniques. Stabilized LiNixMnyCozAl1-x-y-zO2 (NMCA) nanoparticle films were deposited onto stainless steel substrates using Planar Energy Devices’ streaming process for electroless electrochemical deposition (SPEED). Since successful SPEED trials were demonstrated by Planar Energy Devices with NMCA prior to 2010, this

  13. Oxidation states of Fe in LaNi1-xFexO3

    International Nuclear Information System (INIS)

    Goeta, A.E.; Falcon, H.; Carbonio, R.

    1994-01-01

    The distribution of oxidation states in perovskites of the type LaA 1-x B x O 3 (A and B transition metal ions) can be ''tailored'' by x variation. In particular, in LaNiO 3 it has been shown that Fe substitution for Ni foces some Ni 3+ into Ni 2+ , while some Fe 3+ changes into the unusual Fe 4+ state. In addition, the existence of mixed oxidation states of Fe and/or Ni in LaNi 1-x Fe x O 3 has been related to its catalytic activity in hydrogen peroxide decomposition. The Fe 4+ population, obtained using Moessbauer spectroscopy, was found to be constant for all the analyzed annealing temperatures for x = 0.25 concentration, where the isomer shift difference for both states is the highest and the catalytic activity is maximum. (orig.)

  14. Sintered Cathodes for All-Solid-State Structural Lithium-Ion Batteries

    Science.gov (United States)

    Huddleston, William; Dynys, Frederick; Sehirlioglu, Alp

    2017-01-01

    All-solid-state structural lithium ion batteries serve as both structural load-bearing components and as electrical energy storage devices to achieve system level weight savings in aerospace and other transportation applications. This multifunctional design goal is critical for the realization of next generation hybrid or all-electric propulsion systems. Additionally, transitioning to solid state technology improves upon battery safety from previous volatile architectures. This research established baseline solid state processing conditions and performance benchmarks for intercalation-type layered oxide materials for multifunctional application. Under consideration were lithium cobalt oxide and lithium nickel manganese cobalt oxide. Pertinent characteristics such as electrical conductivity, strength, chemical stability, and microstructure were characterized for future application in all-solid-state structural battery cathodes. The study includes characterization by XRD, ICP, SEM, ring-on-ring mechanical testing, and electrical impedance spectroscopy to elucidate optimal processing parameters, material characteristics, and multifunctional performance benchmarks. These findings provide initial conditions for implementing existing cathode materials in load bearing applications.

  15. Predissociation of high-lying Rydberg states of molecular iodine via ion-pair states

    Energy Technology Data Exchange (ETDEWEB)

    Bogomolov, Alexandr S. [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation); Grüner, Barbara; Mudrich, Marcel [Physikalisches Institut, Universität Freiburg, D-79104 Freiburg (Germany); Kochubei, Sergei A. [Institute of Semiconductor Physics, ac. Lavrent' yev ave., 13, Novosibirsk 630090 (Russian Federation); Baklanov, Alexey V. [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090 (Russian Federation)

    2014-03-28

    Velocity map imaging of the photofragments arising from two-photon photoexcitation of molecular iodine in the energy range 73 500–74 500 cm{sup −1} covering the bands of high-lying gerade Rydberg states [{sup 2}Π{sub 1/2}]{sub c}6d;0{sub g}{sup +} and [{sup 2}Π{sub 1/2}]{sub c}6d;2{sub g} has been applied. The ion signal was dominated by the atomic fragment ion I{sup +}. Up to 5 dissociation channels yielding I{sup +} ions with different kinetic energies were observed when the I{sub 2} molecule was excited within discrete peaks of Rydberg states and their satellites in this region. One of these channels gives rise to images of I{sup +} and I{sup −} ions with equal kinetic energy indicating predissociation of I{sub 2} via ion-pair states. The contribution of this channel was up to about 50% of the total I{sup +} signal. The four other channels correspond to predissociation via lower lying Rydberg states giving rise to excited iodine atoms providing I{sup +} ions by subsequent one-photon ionization by the same laser pulse. The ratio of these channels varied from peak to peak in the spectrum but their total ionic signal was always much higher than the signal of (2 + 1) resonance enhanced multi-photon ionization of I{sub 2}, which was previously considered to be the origin of ionic signal in this spectral range. The first-tier E0{sub g}{sup +} and D{sup ′}2{sub g} ion-pair states are concluded to be responsible for predissociation of Rydberg states [{sup 2}Π{sub 1/2}]{sub c}6d;0{sub g}{sup +} and [{sup 2}Π{sub 1/2}]{sub c}6d;2{sub g}, respectively. Further predissociation of these ion-pair states via lower lying Rydberg states gives rise to excited I(5s{sup 2}5p{sup 4}6s{sup 1}) atoms responsible for major part of ion signal. The isotropic angular distribution of the photofragment recoil directions observed for all channels indicates that the studied Rydberg states are long-lived compared with the rotational period of the I{sub 2} molecule.

  16. Hertzian spectroscopy application to excited states in accelerated ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard, M L

    1974-01-01

    Accelerated ion beams enables the application of optical hertzian spectrometry methods to be extended to research on the excited states of free ionic systems. The photon beat method has proved especially simple to apply in beam foil geometry because of the unidirectional beam velocity while the beam gas device is suitable for experiments of the energy level crossing type. Only the resonance technique involving direct application of high-frequency magnetic fields poses serious problems because of the high HF powers necessary. So far structure intervals have been measured in ions carrying up to three charges (seven in the special case of Lamb shift measurements) with a precision of a few percent. Study of hydrogen-like or helium-like ions of high Z allows the fundamental calculations of quantum electrodynamics to be checked with regard to the Lamb shift or the spontaneous emission theory. In more complex electronic systems, optical spectroscopy of accelerated ion beams gives wavelengths with a resolution reaching 10/sup -5/, lifetimes with an accuracy better than 10% when the cascade effects are properly studied, and Lande factors with a precision of several % under present technical conditions. The photon beat method concerns hyperfine nuclear effects in light atoms of Z < = 20. (FR)

  17. Effect of ion irradiation on the optical properties and room temperature oxidation of copper surface

    Energy Technology Data Exchange (ETDEWEB)

    Poperenko, L.V.; Ramadan Shaaban, Essam; Khanh, N.Q.; Stashchuk, V.S.; Vinnichenko, M.V.; Yurgelevich, I.V.; Nosach, D.V.; Lohner, T

    2004-05-01

    Ex situ and in situ spectroellipsometric investigation of room temperature oxidation of ion-implanted copper surface was performed. The ellipsometer is capable to measure simultaneously the ellipsometric parameters {psi} and {delta} at 88 different wavelength values in the range of 280-760 nm within a few minutes in the high precision operation mode using two zone averaging and within a fraction of a second in the one zone operation mode. The native oxide layer formed earlier on the surface of the copper was sputtered off during the aluminum ion implantation. In situ study of the growth of the newly formed native oxide layer on the ion implanted surface was carried out. Ion beam analytical measurements were performed to gain further information on the native oxide layer. The absolute number of the oxygen atoms in the native copper oxide layer was determined. The depth distribution of the implanted aluminum was extracted from Rutherford backscattering spectra. It is found that Al implantation enhanced the oxidation resistance.

  18. Effect of ion irradiation on the optical properties and room temperature oxidation of copper surface

    International Nuclear Information System (INIS)

    Poperenko, L.V.; Ramadan Shaaban, Essam; Khanh, N.Q.; Stashchuk, V.S.; Vinnichenko, M.V.; Yurgelevich, I.V.; Nosach, D.V.; Lohner, T.

    2004-01-01

    Ex situ and in situ spectroellipsometric investigation of room temperature oxidation of ion-implanted copper surface was performed. The ellipsometer is capable to measure simultaneously the ellipsometric parameters Ψ and Δ at 88 different wavelength values in the range of 280-760 nm within a few minutes in the high precision operation mode using two zone averaging and within a fraction of a second in the one zone operation mode. The native oxide layer formed earlier on the surface of the copper was sputtered off during the aluminum ion implantation. In situ study of the growth of the newly formed native oxide layer on the ion implanted surface was carried out. Ion beam analytical measurements were performed to gain further information on the native oxide layer. The absolute number of the oxygen atoms in the native copper oxide layer was determined. The depth distribution of the implanted aluminum was extracted from Rutherford backscattering spectra. It is found that Al implantation enhanced the oxidation resistance

  19. Nano-size metallic oxide particle synthesis in Fe-Cr alloys by ion implantation

    Science.gov (United States)

    Zheng, C.; Gentils, A.; Ribis, J.; Borodin, V. A.; Delauche, L.; Arnal, B.

    2017-10-01

    Oxide Dispersion Strengthened (ODS) steels reinforced with metal oxide nanoparticles are advanced structural materials for nuclear and thermonuclear reactors. The understanding of the mechanisms involved in the precipitation of nano-oxides can help in improving mechanical properties of ODS steels, with a strong impact for their commercialization. A perfect tool to study these mechanisms is ion implantation, where various precipitate synthesis parameters are under control. In the framework of this approach, high-purity Fe-10Cr alloy samples were consecutively implanted with Al and O ions at room temperature and demonstrated a number of unexpected features. For example, oxide particles of a few nm in diameter could be identified in the samples already after ion implantation at room temperature. This is very unusual for ion beam synthesis, which commonly requires post-implantation high-temperature annealing to launch precipitation. The observed particles were composed of aluminium and oxygen, but additionally contained one of the matrix elements (chromium). The crystal structure of aluminium oxide compound corresponds to non-equilibrium cubic γ-Al2O3 phase rather than to more common corundum. The obtained experimental results together with the existing literature data give insight into the physical mechanisms involved in the precipitation of nano-oxides in ODS alloys.

  20. Ion sieving in graphene oxide membranes via cationic control of interlayer spacing

    Science.gov (United States)

    Chen, Liang; Shi, Guosheng; Shen, Jie; Peng, Bingquan; Zhang, Bowu; Wang, Yuzhu; Bian, Fenggang; Wang, Jiajun; Li, Deyuan; Qian, Zhe; Xu, Gang; Liu, Gongping; Zeng, Jianrong; Zhang, Lijuan; Yang, Yizhou; Zhou, Guoquan; Wu, Minghong; Jin, Wanqin; Li, Jingye; Fang, Haiping

    2017-10-01

    Graphene oxide membranes—partially oxidized, stacked sheets of graphene—can provide ultrathin, high-flux and energy-efficient membranes for precise ionic and molecular sieving in aqueous solution. These materials have shown potential in a variety of applications, including water desalination and purification, gas and ion separation, biosensors, proton conductors, lithium-based batteries and super-capacitors. Unlike the pores of carbon nanotube membranes, which have fixed sizes, the pores of graphene oxide membranes—that is, the interlayer spacing between graphene oxide sheets (a sheet is a single flake inside the membrane)—are of variable size. Furthermore, it is difficult to reduce the interlayer spacing sufficiently to exclude small ions and to maintain this spacing against the tendency of graphene oxide membranes to swell when immersed in aqueous solution. These challenges hinder the potential ion filtration applications of graphene oxide membranes. Here we demonstrate cationic control of the interlayer spacing of graphene oxide membranes with ångström precision using K+, Na+, Ca2+, Li+ or Mg2+ ions. Moreover, membrane spacings controlled by one type of cation can efficiently and selectively exclude other cations that have larger hydrated volumes. First-principles calculations and ultraviolet absorption spectroscopy reveal that the location of the most stable cation adsorption is where oxide groups and aromatic rings coexist. Previous density functional theory computations show that other cations (Fe2+, Co2+, Cu2+, Cd2+, Cr2+ and Pb2+) should have a much stronger cation-π interaction with the graphene sheet than Na+ has, suggesting that other ions could be used to produce a wider range of interlayer spacings.

  1. Metallic oxide nano-clusters synthesis by ion implantation in high purity Fe10Cr alloy

    International Nuclear Information System (INIS)

    Zheng, Ce

    2015-01-01

    ODS (Oxide Dispersed Strengthened) steels, which are reinforced with metal dispersions of nano-oxides (based on Y, Ti and O elements), are promising materials for future nuclear reactors. The detailed understanding of the mechanisms involved in the precipitation of these nano-oxides would improve manufacturing and mechanical properties of these ODS steels, with a strong economic impact for their industrialization. To experimentally study these mechanisms, an analytical approach by ion implantation is used, to control various parameters of synthesis of these precipitates as the temperature and concentration. This study demonstrated the feasibility of this method and concerned the behaviour of alloys models (based on aluminium oxide) under thermal annealing. High purity Fe-10Cr alloys were implanted with Al and O ions at room temperature. Transmission electron microscopy observations showed that the nano-oxides appear in the Fe-10Cr matrix upon ion implantation at room temperature without subsequent annealing. The mobility of implanted elements is caused by the defects created during ion implantation, allowing the nucleation of these nanoparticles, of a few nm in diameter. These nanoparticles are composed of aluminium and oxygen, and also chromium. The high-resolution experiments show that their crystallographic structure is that of a non-equilibrium compound of aluminium oxide (cubic γ-Al 2 O 3 type). The heat treatment performed after implantation induces the growth of the nano-sized oxides, and a phase change that tends to balance to the equilibrium structure (hexagonal α-Al 2 O 3 type). These results on model alloys are fully applicable to industrial materials: indeed ion implantation reproduces the conditions of milling and heat treatments are at equivalent temperatures to those of thermo-mechanical treatments. A mechanism involving the precipitation of nano-oxide dispersed in ODS alloys is proposed in this manuscript based on the obtained experimental results

  2. Transmission electron microscopy study of the heavy-ion-irradiation-induced changes in the nanostructure of oxide dispersion strengthened steels

    Science.gov (United States)

    Rogozhkin, S. V.; Bogachev, A. A.; Orlov, N. N.; Korchuganova, O. A.; Nikitin, A. A.; Zaluzhnyi, A. G.; Kozodaev, M. A.; Kulevoy, T. V.; Kuibeda, R. P.; Fedin, P. A.; Chalykh, B. B.; Lindau, R.; Hoffman, Ya.; Möslang, A.; Vladimirov, P.; Klimenkov, M.

    2017-07-01

    Transmission electron microscopy was used to study the effect of heavy-ion irradiation on the structure and the phase state of three oxide dispersion strengthened (ODS) steels: ODS Eurofer, ODS 13.5Cr, and ODS 13.5Cr-0.3Ti (wt %). Samples were irradiated with iron and titanium ions to fluences of 1015 and 3 × 1015 cm-2 at 300, 573, and 773 K. The study of the region of maximum radiation damage shows that irradiation increases the number density of oxide particles in all samples. The fraction of fine inclusions increases in the particle size distribution. This effect is most pronounced in the ODS 13.5Cr steel irradiated with titanium ions at 300 K to a fluence of 3 × 1015 cm-2. It is demonstrated that oxide inclusions in ODS 13.5Cr-0.3Ti and ODS 13.5Cr steels are more stable upon irradiation at 573 and 773 K than upon irradiation at 300 K.

  3. Asymmetric ion transport through ion-channel-mimetic solid-state nanopores.

    Science.gov (United States)

    Guo, Wei; Tian, Ye; Jiang, Lei

    2013-12-17

    Both scientists and engineers are interested in the design and fabrication of synthetic nanofluidic architectures that mimic the gating functions of biological ion channels. The effort to build such structures requires interdisciplinary efforts at the intersection of chemistry, materials science, and nanotechnology. Biological ion channels and synthetic nanofluidic devices have some structural and chemical similarities, and therefore, they share some common features in regulating the traverse ionic flow. In the past decade, researchers have identified two asymmetric ion transport phenomena in synthetic nanofluidic structures, the rectified ionic current and the net diffusion current. The rectified ionic current is a diode-like current-voltage response that occurs when switching the voltage bias. This phenomenon indicates a preferential direction of transport in the nanofluidic system. The net diffusion current occurs as a direct product of charge selectivity and is generated from the asymmetric diffusion through charged nanofluidic channels. These new ion transport phenomena and the elaborate structures that occur in biology have inspired us to build functional nanofluidic devices for both fundamental research and practical applications. In this Account, we review our recent progress in the design and fabrication of biomimetic solid-state nanofluidic devices with asymmetric ion transport behavior. We demonstrate the origin of the rectified ionic current and the net diffusion current. We also identify several influential factors and discuss how to build these asymmetric features into nanofluidic systems by controlling (1) nanopore geometry, (2) surface charge distribution, (3) chemical composition, (4) channel wall wettability, (5) environmental pH, (6) electrolyte concentration gradient, and (7) ion mobility. In the case of the first four features, we build these asymmetric features directly into the nanofluidic structures. With the final three, we construct

  4. Inhibition of cellulase-catalyzed lignocellulosic hydrolysis by iron and oxidative metal ions and complexes.

    Science.gov (United States)

    Tejirian, Ani; Xu, Feng

    2010-12-01

    Enzymatic lignocellulose hydrolysis plays a key role in microbially driven carbon cycling and energy conversion and holds promise for bio-based energy and chemical industries. Cellulases (key lignocellulose-active enzymes) are prone to interference from various noncellulosic substances (e.g., metal ions). During natural cellulolysis, these substances may arise from other microbial activities or abiotic events, and during industrial cellulolysis, they may be derived from biomass feedstocks or upstream treatments. Knowledge about cellulolysis-inhibiting reactions is of importance for the microbiology of natural biomass degradation and the development of biomass conversion technology. Different metal ions, including those native to microbial activity or employed for biomass pretreatments, are often tested for enzymatic cellulolysis. Only a few metal ions act as inhibitors of cellulases, which include ferrous and ferric ions as well as cupric ion. In this study, we showed inhibition by ferrous/ferric ions as part of a more general effect from oxidative (or redox-active) metal ions and their complexes. The correlation between inhibition and oxidation potential indicated the oxidative nature of the inhibition, and the dependence on air established the catalytic role that iron ions played in mediating the dioxygen inhibition of cellulolysis. Individual cellulases showed different susceptibilities to inhibition. It is likely that the inhibition exerted its effect more on cellulose than on cellulase. Strong iron ion chelators and polyethylene glycols could mitigate the inhibition. Potential microbiological and industrial implications of the observed effect of redox-active metal ions on enzymatic cellulolysis, as well as the prevention and mitigation of this effect in industrial biomass conversion, are discussed.

  5. Low charge state heavy ion production with sub-nanosecond laser.

    Science.gov (United States)

    Kanesue, T; Kumaki, M; Ikeda, S; Okamura, M

    2016-02-01

    We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target.

  6. Low charge state heavy ion production with sub-nanosecond laser

    Energy Technology Data Exchange (ETDEWEB)

    Kanesue, T., E-mail: tkanesue@bnl.gov; Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Kumaki, M. [Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198 (Japan); Ikeda, S. [Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198 (Japan); Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Kanagawa 226-8503 (Japan)

    2016-02-15

    We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target.

  7. In situ oxidation state profiling of nickel hexacyanoferrate derivatized electrodes using line-imaging Raman spectroscopy and multivariate calibration

    International Nuclear Information System (INIS)

    Haight, S.M.; Schwartz, D.T.

    1999-01-01

    Metal hexacyanoferrate compounds show promise as electrochemically switchable ion exchange materials for use in the cleanup of radioactive wastes such as those found in storage basins and underground tanks at the Department of Energy's Hanford Nuclear Reservation. Reported is the use of line-imaging Raman spectroscopy for the in situ determination of oxidation state profiles in nickel hexacyanoferrate derivatized electrodes under potential control in an electrochemical cell. Line-imaging Raman spectroscopy is used to collect 256 contiguous Raman spectra every ∼5 microm from thin films (ca. 80 nm) formed by electrochemical derivatization of nickel electrodes. The cyanide stretching region of the Raman spectrum of the film is shown to be sensitive to iron oxidation state and is modeled by both univariate and multivariate correlations. Although both correlations fit the calibration set well, the multivariate (principle component regression or PCR) model's predictions of oxidation state are less sensitive to noise in the spectrum, yielding a much smoother oxidation state profile than the univariate model. Oxidation state profiles with spatial resolution of approximately 5 microm are shown for a nickel hexacyanoferrate derivatized electrode in reduced, intermediate, and oxidized states. In situ oxidation state profiles indicate that the 647.1 nm laser illumination photo-oxidizes the derivatized electrodes. This observation is confirmed using photoelectrochemical methods

  8. Role of ion-pair states in the predissociation dynamics of Rydberg states of molecular iodine.

    Science.gov (United States)

    von Vangerow, J; Bogomolov, A S; Dozmorov, N V; Schomas, D; Stienkemeier, F; Baklanov, A V; Mudrich, M

    2016-07-28

    Using femtosecond pump-probe ion imaging spectroscopy, we establish the key role of I(+) + I(-) ion-pair (IP) states in the predissociation dynamics of molecular iodine I2 excited to Rydberg states. Two-photon excitation of Rydberg states lying above the lowest IP state dissociation threshold (1st tier) is found to be followed by direct parallel transitions into IP states of the 1st tier asymptotically correlating to a pair of I ions in their lowest states I(+)((3)P2) + I(-)((1)S0), of the 2nd tier correlating to I(+)((3)P0) + I(-)((1)S0), and of the 3rd tier correlating to I(+)((1)D2) + I(-)((1)S0). Predissociation via the 1st tier proceeds presumably with a delay of 1.6-1.7 ps which is close to the vibrational period in the 3rd tier state (3rd tier-mediated process). The 2nd tier IP state is concluded to be the main precursor for predissociation via lower lying Rydberg states proceeding with a characteristic time of 7-8 ps and giving rise to Rydberg atoms I(5s(2)5p(4)6s(1)). The channel generating I((2)P3/2) + I((2)P1/2) atoms with total kinetic energy corresponding to one-photon excitation is found to proceed via a pump - dump mechanism with dramatic change of angular anisotropy of this channel as compared with earlier nanosecond experiments.

  9. Ion-ion dynamic structure factor, acoustic modes, and equation of state of two-temperature warm dense aluminum

    Science.gov (United States)

    Harbour, L.; Förster, G. D.; Dharma-wardana, M. W. C.; Lewis, Laurent J.

    2018-04-01

    The ion-ion dynamical structure factor and the equation of state of warm dense aluminum in a two-temperature quasiequilibrium state, with the electron temperature higher than the ion temperature, are investigated using molecular-dynamics simulations based on ion-ion pair potentials constructed from a neutral pseudoatom model. Such pair potentials based on density functional theory are parameter-free and depend directly on the electron temperature and indirectly on the ion temperature, enabling efficient computation of two-temperature properties. Comparison with ab initio simulations and with other average-atom calculations for equilibrium aluminum shows good agreement, justifying a study of quasiequilibrium situations. Analyzing the van Hove function, we find that ion-ion correlations vanish in a time significantly smaller than the electron-ion relaxation time so that dynamical properties have a physical meaning for the quasiequilibrium state. A significant increase in the speed of sound is predicted from the modification of the dispersion relation of the ion acoustic mode as the electron temperature is increased. The two-temperature equation of state including the free energy, internal energy, and pressure is also presented.

  10. The stopping power and energy straggling of light ions in graphene oxide foils

    Czech Academy of Sciences Publication Activity Database

    Mikšová, Romana; Macková, Anna; Malinský, Petr; Sofer, Z.

    2017-01-01

    Roč. 406, SEP (2017), s. 173-178 ISSN 0168-583X R&D Projects: GA MŠk LM2015056; GA ČR GA16-05167S Institutional support: RVO:61389005 Keywords : ion energy loss * ion energy straggling * graphene oxide Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 1.109, year: 2016

  11. Spinel-structured surface layers for facile Li ion transport and improved chemical stability of lithium manganese oxide spinel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hae Ri [Center for Energy Convergence Research, Korea Institute of Science Technology, Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 136-701 (Korea, Republic of); Seo, Hyo Ree; Lee, Boeun; Cho, Byung Won [Center for Energy Convergence Research, Korea Institute of Science Technology, Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Lee, Kwan-Young [Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 136-701 (Korea, Republic of); Oh, Si Hyoung, E-mail: sho74@kist.re.kr [Center for Energy Convergence Research, Korea Institute of Science Technology, Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2017-01-15

    Graphical abstract: Strategically-designed spinel-structured nano-scale surface layer, LiM{sub x}Mn{sup IV}{sub 1−x}O{sub 4}, featuring a high Li{sup +} ion conductivity and a good chemical stability was applied on Al-doped LiMn{sub 2}O{sub 4} spinel for the drastic improvement of the electrochemical performance at the elevated temperature as a promising cathode material for lithium rechargeable batteries. - Highlights: • Spinel-structured surface layer with a high Li-ion conductivity and a good chemical stability was prepared. • Simple wet process was developed to apply nano-scale surface layer on aluminum doped lithium manganese oxide spinel. • The properties of nano-scale surface layer were characterized by analytical tools including GITT, HR-TEM and XAS. • Materials with surface coating layer exhibit an excellent electrochemical performance at the elevated temperature. - Abstract: Li-ion conducting spinel-structured oxide layer with a manganese oxidation state close to being tetravalent was prepared on aluminum-doped lithium manganese oxide spinel for improving the electrochemical performances at the elevated temperatures. This nanoscale surface layer provides a good ionic conduction path for lithium ion transport to the core and also serves as an excellent chemical barrier for protecting the high-capacity core material from manganese dissolution into the electrolyte. In this work, a simple wet process was employed to prepare thin LiAlMnO{sub 4} and LiMg{sub 0.5}Mn{sub 1.5}O{sub 4} layers on the surface of LiAl{sub 0.1}Mn{sub 1.9}O{sub 4}. X-ray absorption studies revealed an oxidation state close to tetravalent manganese on the surface layer of coated materials. Materials with these surface coating layers exhibited excellent capacity retentions superior to the bare material, without undermining the lithium ion transport characteristics and the high rate performances.

  12. Proton and oxide ion conductivity of doped LaScO3

    DEFF Research Database (Denmark)

    Lybye, D.; Bonanos, N.

    1999-01-01

    . At temperatures below 800 degrees C and low partial pressure of oxygen, proton conduction was dominant. Above this temperature, the ionic conductivity is dominated by oxide ion transport. The protonic transport number was estimated from the conductivities measured in dry and in water-moisturised gas. An isotope......The conductivity of La0.9Sr0.1Sc0.9Mg0.1O3 has been studied by impedance spectroscopy in controlled atmospheres. The material was found to be a mixed conductor with p-type conduction at high oxygen partial pressures and a combined proton and oxide ion conductor at low oxygen partial pressures...

  13. Auto transfer to Rydberg states during ion-atom collisions

    Energy Technology Data Exchange (ETDEWEB)

    Bachau, H.; Harel, C. (Laboratoire des Collisions Atomiques, Unite Propre de Recherche 260 du CNRS, Universite Bordeaux I, 351 Cours de la Liberation, 33405 Talence (France)); Barat, M.; Roncin, P. (Laboratoire des Collisions Atomiques et Moleculaires, Unite associee 281 du CNRS, Universite de Paris Sud, Batiment 351, 91405 Orsay (France)); Bordenave-Montesquieu, A.; Moretto-Capelle, P.; Benoit-Cattin, P.; Gleizes, A.; Benhenni, M. (IRSAMC, Unite associee 770 du CNRS, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse (France))

    1993-06-05

    Electron capture by slow multiply charged ions colliding on rare-gas targets is known to populate highly excited states of the projectile. On the basis of experimental measurement of energy and angle differential cross-sections we have shown that capture to a resonant doubly excited state may lead to Autoionizing Double Capture (ADC) as well as to True Double Capture (TDC). In this model TDC appears as a two step post-collisional process, the state populated by the collision decays to (or delutes into) a dense adjacent Rydberg series, followed by radiative deexcitation of the inner electron of the (3,n) Rydberg states. We report here new experimental observations in electron spectra measured in [ital N][sup 7+]+[ital He]. Auto transfer to Rydber states has also important consequences on the determination of the lifetime of the autoionizing states, some discrepancies between theoretical width values for low [ital N][sup 5+](4,4) resonant states will be discussed and partially resolved.

  14. The ion-exchange obtaining of high purity samarium oxide

    International Nuclear Information System (INIS)

    Brzyska, W.; Soltysiak, I.; Cygan, J.

    1987-01-01

    The use of lactic acid - EDTA mixture as an eluent for the obtaining of high purity samarium oxide was studied. The studies were carried out at room temperature on cation exchange resin Wofatit KPS X 8. The best results were obtained for lactic acid (0,26 mol/dm 3 ) - EDTA (0,013 mol/dm 3 ) mixture at pH 3,3. As the result of 57% samarium concentrate elution with column load 1:3 and flow rate 0,4 cm/min, over 99% pure samarium oxide with 73% yield has been obtained. The yield of spectrally pure Sm 2 O 3 exceeded 45%. (author)

  15. Hot QCD equations of state and relativistic heavy ion collisions

    Science.gov (United States)

    Chandra, Vinod; Kumar, Ravindra; Ravishankar, V.

    2007-11-01

    We study two recently proposed equations of state obtained from high-temperature QCD and show how they can be adapted to use them for making predictions for relativistic heavy ion collisions. The method involves extracting equilibrium distribution functions for quarks and gluons from the equation of state (EOS), which in turn will allow a determination of the transport and other bulk properties of the quark gluon-plasma. Simultaneously, the method also yields a quasiparticle description of interacting quarks and gluons. The first EOS is perturbative in the QCD coupling constant and has contributions of O(g5). The second EOS is an improvement over the first, with contributions up to O[g6ln(1/g)]; it incorporates the nonperturbative hard thermal contributions. The interaction effects are shown to be captured entirely by the effective chemical potentials for the gluons and the quarks, in both cases. The chemical potential is seen to be highly sensitive to the EOS. As an application, we determine the screening lengths, which are, indeed, the most important diagnostics for QGP. The screening lengths are seen to behave drastically differently depending on the EOS considered and therefore yield a way to distinguish the two equations of state in heavy ion collisions.

  16. Investigating the capability of ToF-SIMS to determine the oxidation state of Ce

    Science.gov (United States)

    Seed Ahmed, H. A. A.; Swart, H. C.; Kroon, R. E.

    2018-04-01

    The capability of time of flight secondary ion mass spectrometry (ToF-SIMS) to determine the oxidation state of Ce ions doped in a phosphor was investigated. Two samples of SiO2:Ce (4 mol%) with known Ce3+/Ce4+ relative concentrations were subjected to ToF-SIMS measurements. The spectra were very similar and no significant differences in the relative peak intensities were observed that would readily allow one to distinguish Ce3+ from Ce4+. Although ToF-SIMS was therefore not useful to distinguish the charge state of Ce ions doped in this phosphor material, the idea in principle was also tested on two other samples, namely CeF3 and CeF4 These contain Ce as part of the host (i.e. much higher concentration) and are fluorides, which is significant because ToF-SIMS has previously been reported to be able to distinguish Eu2+ from Eu3+ in Eu doped Sr5(PO4)3F phosphor. The spectrum of CeF4 contained a small peak related to Ce4+ which was not observed in the CeF3 spectrum, yet the peak related to the Ce3+ ions was found to be much more intense in the spectrum of CeF4 than CeF3, showing that the ToF-SIMS signals cannot be directly interpreted as retaining the charge state of the ions in the original material. Nevertheless, the significant differences in the Ce-related peaks in the ToF-SIMS spectra from CeF3 and CeF4 show that the charge state of Ce may be distinguished. This study shows that while in principle ToF-SIMS may be used to distinguish the charge state of Ce ions, this depends on the sample and it would not be easy to interpret the spectra without a standard or reference.

  17. Ab initio molecular dynamics simulation of aqueous solution of nitric oxide in different formal oxidation states

    Science.gov (United States)

    Venâncio, Mateus F.; Rocha, Willian R.

    2015-10-01

    Ab initio molecular dynamics simulations were used to investigate the early chemical events involved in the dynamics of nitric oxide (NOrad), nitrosonium cation (NO+) and nitroxide anion (NO-) in aqueous solution. The NO+ ion is very reactive in aqueous solution having a lifetime of ∼4 × 10-13 s, which is shorter than the value of 3 × 10-10 s predicted experimentally. The NO+ reacts generating the nitrous acid as an intermediate and the NO2- ion as the final product. The dynamics of NOrad revealed the reversibly formation of a transient anion radical species HONOrad -.

  18. Heavy-ion transfer to high-spin states

    International Nuclear Information System (INIS)

    Lauterbach, C.

    1985-01-01

    Transfer reactions between very heavy ions, in particular about systems in which one or both collision partners are well deformed, are studied. These systems are expected to give rise to new phenomena which are related to the fact that the deformed nucleus has been Coulomb excited to a rotational or vibrational state at the time when the collision partners come into contact. In this paper the authors present results of experiments in which nuclei from the rare earth and the actinide region have been bombarded by various projectiles ranging from 34 S to 208 Pb at incident energies close to the Coulomb barrier. (Auth.)

  19. Graphene oxide layers modified by light energetic ions

    Czech Academy of Sciences Publication Activity Database

    Malinský, Petr; Macková, Anna; Mikšová, Romana; Kováčiková, Helena; Cutroneo, Mariapompea; Luxa, J.; Bouša, D.; Štrochová, B.; Sofer, Z.

    2017-01-01

    Roč. 19, č. 16 (2017), s. 10282-10291 ISSN 1463-9076 R&D Projects: GA ČR GA16-05167S; GA MŠk LM2015056 Institutional support: RVO:61389005 Keywords : graphene oxide * reduction * irradiation Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 4.123, year: 2016

  20. Non-equilibrium oxidation states of zirconium during early stages of metal oxidation

    International Nuclear Information System (INIS)

    Ma, Wen; Yildiz, Bilge; Herbert, F. William; Senanayake, Sanjaya D.

    2015-01-01

    The chemical state of Zr during the initial, self-limiting stage of oxidation on single crystal zirconium (0001), with oxide thickness on the order of 1 nm, was probed by synchrotron x-ray photoelectron spectroscopy. Quantitative analysis of the Zr 3d spectrum by the spectrum reconstruction method demonstrated the formation of Zr 1+ , Zr 2+ , and Zr 3+ as non-equilibrium oxidation states, in addition to Zr 4+ in the stoichiometric ZrO 2 . This finding resolves the long-debated question of whether it is possible to form any valence states between Zr 0 and Zr 4+ at the metal-oxide interface. The presence of local strong electric fields and the minimization of interfacial energy are assessed and demonstrated as mechanisms that can drive the formation of these non-equilibrium valence states of Zr

  1. Experimental studies of thorium ion implantation from pulse laser plasma into thin silicon oxide layers

    Science.gov (United States)

    Borisyuk, P. V.; Chubunova, E. V.; Lebedinskii, Yu Yu; Tkalya, E. V.; Vasilyev, O. S.; Yakovlev, V. P.; Strugovshchikov, E.; Mamedov, D.; Pishtshev, A.; Karazhanov, S. Zh

    2018-05-01

    We report the results of experimental studies related to implantation of thorium ions into thin silicon dioxide by pulsed plasma flux expansion. Thorium ions were generated by laser ablation from a metal target, and the ionic component of the laser plasma was accelerated in an electric field created by the potential difference (5, 10 and 15 kV) between the ablated target and a SiO2/Si (0 0 1) sample. The laser ablation system installed inside the vacuum chamber of the electron spectrometer was equipped with a YAG:Nd3  +  laser having a pulse energy of 100 mJ and time duration of 15 ns in the Q-switched regime. The depth profile of thorium atoms implanted into the 10 nm thick subsurface areas together with their chemical state as well as the band gap of the modified silicon oxide at different conditions of implantation processes were studied by means of x-ray photoelectron spectroscopy and reflected electron energy loss spectroscopy methods. Analysis of the chemical composition showed that the modified silicon oxide film contains complex thorium silicates. Depending on the local concentration of thorium atoms, the experimentally established band gaps were located in the range 6.0–9.0 eV. Theoretical studies of the optical properties of the SiO2 and ThO2 crystalline systems were performed by ab initio calculations within hybrid functional. The optical properties of the SiO2/ThO2 composite were interpreted on the basis of the Bruggeman effective medium approximation. A quantitative assessment of the yield of isomeric nuclei in ‘hot’ laser plasma at the early stages of expansion was performed. The estimates made with experimental results demonstrated that the laser implantation of thorium ions into the SiO2 matrix can be useful for further research of low-lying isomeric transitions in a 229Th isotope with energy of 7.8 +/- 0.5 eV.

  2. IBiSA_Tools: A Computational Toolkit for Ion-Binding State Analysis in Molecular Dynamics Trajectories of Ion Channels.

    Directory of Open Access Journals (Sweden)

    Kota Kasahara

    Full Text Available Ion conduction mechanisms of ion channels are a long-standing conundrum. Although the molecular dynamics (MD method has been extensively used to simulate ion conduction dynamics at the atomic level, analysis and interpretation of MD results are not straightforward due to complexity of the dynamics. In our previous reports, we proposed an analytical method called ion-binding state analysis to scrutinize and summarize ion conduction mechanisms by taking advantage of a variety of analytical protocols, e.g., the complex network analysis, sequence alignment, and hierarchical clustering. This approach effectively revealed the ion conduction mechanisms and their dependence on the conditions, i.e., ion concentration and membrane voltage. Here, we present an easy-to-use computational toolkit for ion-binding state analysis, called IBiSA_tools. This toolkit consists of a C++ program and a series of Python and R scripts. From the trajectory file of MD simulations and a structure file, users can generate several images and statistics of ion conduction processes. A complex network named ion-binding state graph is generated in a standard graph format (graph modeling language; GML, which can be visualized by standard network analyzers such as Cytoscape. As a tutorial, a trajectory of a 50 ns MD simulation of the Kv1.2 channel is also distributed with the toolkit. Users can trace the entire process of ion-binding state analysis step by step. The novel method for analysis of ion conduction mechanisms of ion channels can be easily used by means of IBiSA_tools. This software is distributed under an open source license at the following URL: http://www.ritsumei.ac.jp/~ktkshr/ibisa_tools/.

  3. Theoretical prediction of ion conductivity in solid state HfO2

    Science.gov (United States)

    Zhang, Wei; Chen, Wen-Zhou; Sun, Jiu-Yu; Jiang, Zhen-Yi

    2013-01-01

    A theoretical prediction of ion conductivity for solid state HfO2 is carried out in analogy to ZrO2 based on the density functional calculation. Geometric and electronic structures of pure bulks exhibit similarity for the two materials. Negative formation enthalpy and negative vacancy formation energy are found for YSH (yttria-stabilized hafnia) and YSZ (yttria-stabilized zirconia), suggesting the stability of both materials. Low activation energies (below 0.7 eV) of diffusion are found in both materials, and YSH's is a little higher than that of YSZ. In addition, for both HfO2 and ZrO2, the supercells with native oxygen vacancies are also studied. The so-called defect states are observed in the supercells with neutral and +1 charge native vacancy but not in the +2 charge one. It can give an explanation to the relatively lower activation energies of yttria-doped oxides and +2 charge vacancy supercells. A brief discussion is presented to explain the different YSH ion conductivities in the experiment and obtained by us, and we attribute this to the different ion vibrations at different temperatures.

  4. Photophysics of trioxatriangulenium ion. Electrophilic reactivity in the ground state and excited singlet state

    DEFF Research Database (Denmark)

    Reynisson, J.; Wilbrandt, R.; Brinck, V.

    2002-01-01

    . The physical and chemical properties of the excited singlet state of the trioxatriangulenium (TOTA(+)) carbenium ion are investigated by experimental and Computational means. The degeneracy of the lowest excited states is counteracted by Jahn-Teller-type distortion, which leads to vibronic broadening...... of the long wavelength absorption band. A strong fluorescence is observed at 520 nm (tau(n) = 14.6 ns, phi(n) = 0.12 in deaerated acetonitrile). The fluorescence is quenched by 10 aromatic electron donors predominantly via a dynamic charge transfer mechanism, but ground state complexation is shown...... triphenylenes is studied separately. Phosphorescence spectra, triplet lifetimes, and triplet-triplet absorption spectra are provided. In the discussion, TOTA(+) is compared to the unsubstituted xanthenium ion and its 9-phenyl derivative with respect to the excited state properties....

  5. Swift heavy ion induced phase transformation and thermoluminescence properties of zirconium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Lokesha, H.S. [Physics R & D Centre, PES Institute of Technology, BSK 3rd Stage, Bangalore 560085 (India); Nagabhushana, K.R., E-mail: bhushankr@gmail.com [Physics R & D Centre, PES Institute of Technology, BSK 3rd Stage, Bangalore 560085 (India); Department of Physics, PES University, BSK 3rd Stage, Bangalore 560085 (India); Singh, Fouran [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110 067 (India)

    2016-07-15

    Zirconium oxide (ZrO{sub 2}) powder is synthesized by combustion technique. XRD pattern of ZrO{sub 2} shows monoclinic phase with average crystallite size 35 nm. Pellets of ZrO{sub 2} are irradiated with 100 MeV swift Si{sup 7+}, Ni{sup 7+} and 120 MeV swift Ag{sup 9+} ions in the fluence range 3 × 10{sup 10}–3 × 10{sup 13} ions cm{sup −2}. XRD pattern show the main diffraction peak correspond to monoclinic and tetragonal phase of ZrO{sub 2} in 2θ range 27–33°. Structural phase transformation is observed for Ni{sup 7+} and Ag{sup 9+} ion irradiated samples at a fluence 1 × 10{sup 13} ions cm{sup −2} and 3 × 10{sup 12} ions cm{sup −2} respectively, since the deposited electronic energy loss exceeds an effective threshold (>12 keV nm{sup −1}). Phase transition induced by Ag{sup 9+} ion is nearly 2.9 times faster than Ni{sup 7+} ion at 1 × 10{sup 13} ions cm{sup −2}. Ag{sup 9+} ion irradiation leads two ion impact processes. Thermoluminescence (TL) glow curves exhibit two glows, a well resolved peak at ∼424 K and unresolved peak at 550 K for all SHI irradiated samples. TL response is decreased with increase of ion fluence. Beyond 3 × 10{sup 12} ions cm{sup −2}, samples don’t exhibit TL due to annihilation of defects.

  6. Effect of nitrogen ion implantation on the structural and optical properties of indium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sethi, Riti; Aziz, Anver; Siddiqui, Azher M., E-mail: amsiddiqui@jmi.ac.in [Department of Physics, Jamia Millia Islamia, New Delhi-110025 (India); Kumar, Pravin [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi-110067 (India); Khan, Sameen Ahmed [Department of Mathematics and Sciences, College of Arts and Applied Sciences (CAAS) Dhofar University, Salalah, Sultanate of Oman (Oman)

    2016-06-10

    : We report here synthesis and subsequent nitrogen ion implantation of indium oxide (In{sub 2}O{sub 3}) thin films. The films were implanted with 25 keV N{sup +} beam for different ion doses between 3E15 to 1E16 ions/cm{sup 2}. The resulting changes in structural and optical properties were investigated using XRD, SEM-EDAX and UV-Vis Spectrometry. XRD studies reveal decrease in crystallite size from 20.06 to 12.42 nm with increase in ion dose. SEM micrographs show an increase in the grain size from 0.8 to 1.35 µm with increase in ion dose because of the agglomeration of the grains. Also, from EDAX data on pristine and N-implanted thin films the presence of indium and oxygen without any traces of impurity elements could be seen. However, at lower ion doses such as 3E15 and 5E15 ions/cm{sup 2}, no evidence of the presence of nitrogen ion was seen. However, for the ion dose of 1E16 ions/cm{sup 2}, evidence of presence of nitrogen can be seen in the EDAX data. Band gap calculations reveal a decrease in band gap from 3.54 to 3.38 eV with increasing ion dose. However, the band gap was found to again show an increase to 3.58 eV at the highest ion dose owing to quantum confinement effect.

  7. Subattoampere current induced by single ions in silicon oxide layers of nonvolatile memory cells

    International Nuclear Information System (INIS)

    Cellere, G.; Paccagnella, A.; Larcher, L.; Visconti, A.; Bonanomi, M.

    2006-01-01

    A single ion impinging on a thin silicon dioxide layer generates a number of electron/hole pairs proportional to its linear energy transfer coefficient. Defects generated by recombination can act as a conductive path for electrons that cross the oxide barrier, thanks to a multitrap-assisted mechanism. We present data on the dependence of this phenomenon on the oxide thickness by using floating gate memory arrays. The tiny number of excess electrons stored in these devices allows for extremely high sensitivity, impossible with any direct measurement of oxide leakage current. Results are of particular interest for next generation devices

  8. Initial state with shear in peripheral heavy ion collisions

    Science.gov (United States)

    Magas, V. K.; Gordillo, J.; Strottman, D.; Xie, Y. L.; Csernai, L. P.

    2018-06-01

    In the present work we propose a new way of constructing the initial state for further hydrodynamic simulation of relativistic heavy ion collisions based on Bjorken-like solution applied streak by streak in the transverse plane. Previous fluid dynamical calculations in Cartesian coordinates with an initial state based on a streak by streak Yang-Mills field led for peripheral higher energy collisions to large angular momentum, initial shear flow and significant local vorticity. Recent experiments verified the existence of this vorticity via the resulting polarization of emitted Λ and Λ ¯ particles. At the same time parton cascade models indicated the existence of more compact initial state configurations, which we are going to simulate in our approach. The proposed model satisfies all the conservation laws, including conservation of a strong initial angular momentum, which is present in noncentral collisions. As a consequence of this large initial angular momentum we observe the rotation of the whole system as well as the fluid shear in the initial state, which leads to large flow vorticity. Another advantage of the proposed model is that the initial state can be given in both [t,x,y,z] and [τ ,x ,y ,η ] coordinates and thus can be tested by all 3+1D hydrodynamical codes which exist in the field.

  9. Electron capture to autoionizing states of multiply charged ions

    International Nuclear Information System (INIS)

    Mack, E.M.

    1987-01-01

    The present thesis investigates electron capture reactions resulting from slow collisions (V q+ ) and neutral gas targets (B). The energy spectra of the emitted electrons are measured; detection angle is 50 0 . Mainly, autoionizing double capture resulting from collisions with two-electron targets (He, H 2 ) is studied; then, the emitted electrons stem from doubly excited projectile states. The projectiles used are bare C 6+ , the H-like and He-like ions of C, N and O, He-like Ne 8+ and Ne-like Ar 8+ . Excited metastable projectiles used are C 5+ (2s), He-like projectiles A q+ (1s2s 3 S) and Ar 8+ (...2p 5 3s). Comparison is made with the predictions of a recently proposed extended classical barrier model, that was developed in connection with the work. This model assumes sequential capture of the electrons ('two-step' process); it predicts the realized binding enegies of the captured electrons - which may be directly determined from the autoionization spectra using only the projectile charge, the ionization potentials of the target and the collision velocity as parameters. No adjustable parameter enters into the calculations. The term energies and decay modes of the highly excited product ions themselves are studied. Generally, the autoionizing decay of these states is found to proceed preferentially to the directly adjacent lower singly excited state. Experimental evidence is presented, that triply excited states decay by successive emission of two electrons, whenever this is energetically possible. Finally, the L-MM decay in few-electron systems is considered. 314 refs.; 96 figs.; 29 tabs

  10. Oxidatively generated DNA/RNA damage in psychological stress states

    DEFF Research Database (Denmark)

    Jørgensen, Anders

    2013-01-01

    age-related somatic disorders. The overall aim of the PhD project was to investigate the relation between psychopathology, psychological stress, stress hormone secretion and oxidatively generated DNA and RNA damage, as measured by the urinary excretion of markers of whole-body DNA/RNA oxidation (8...... between the 24 h urinary cortisol excretion and the excretion of 8-oxodG/8-oxoGuo, determined in the same samples. Collectively, the studies could not confirm an association between psychological stress and oxidative stress on nucleic acids. Systemic oxidatively generated DNA/RNA damage was increased......Both non-pathological psychological stress states and mental disorders are associated with molecular, cellular and epidemiological signs of accelerated aging. Oxidative stress on nucleic acids is a critical component of cellular and organismal aging, and a suggested pathogenic mechanism in several...

  11. Oxidative dissolution of ruthenium deposits onto stainless steel by permanganate ions in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Floquet, S.; Eysseric, C.; Maurel, D. [Commissariat a l' Energie Atomique (CEA/Valrho), Bagnols-sur-Ceze (France)

    2008-07-01

    During spent nuclear fuel reprocessing ruthenium is liable to form black ruthenium deposits on the stainless steel walls of process equipments. These deposits promote corrosion and can eventually obstruct the off-gas lines. The results of decontamination of 304L stainless steel test specimens covered with RuO(OH){sub 2} . xH{sub 2}O deposits by permanganate ions in alkaline medium are described. The ruthenium deposits were dissolved by oxidation of RuO(OH){sub 2} to RuO{sub 4}{sup 2-} ions, while the permanganate ions were reduced to MnO{sub 4}{sup 2-} ions and then to manganese dioxide MnO{sub 2}. The parameters affecting the kinetics of oxidative dissolution of these deposits were examined. The results indicate that the oxidative dissolution kinetics depends on the instantaneous surface area of the deposit, and that the dissolution rate increases with the concentrations of MnO{sub 4}{sup -} and OH{sup -} ions. (orig.)

  12. 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.

  13. Metal oxide collectors for storing matter technique applied in secondary ion mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Miśnik, Maciej [Institute of Tele and Radio Technology, ul. Ratuszowa 11, 03-450 Warszawa (Poland); Gdańsk University of Technology (Poland); Konarski, Piotr [Institute of Tele and Radio Technology, ul. Ratuszowa 11, 03-450 Warszawa (Poland); Zawada, Aleksander [Institute of Tele and Radio Technology, ul. Ratuszowa 11, 03-450 Warszawa (Poland); Military University of Technology, Warszawa (Poland)

    2016-03-15

    We present results of the use of metal and metal oxide substrates that serve as collectors in ‘storing matter’, the quantitative technique of secondary ion mass spectrometry (SIMS). This technique allows separating the two base processes of secondary ion formation in SIMS. Namely, the process of ion sputtering is separated from the process of ionisation. The technique allows sputtering of the analysed sample and storing the sputtered material, with sub-monolayer coverage, onto a collector surface. Such deposits can be then analysed by SIMS, and as a result, the so called ‘matrix effects’ are significantly reduced. We perform deposition of the sputtered material onto Ti and Cu substrates and also onto metal oxide substrates as molybdenum, titanium, tin and indium oxides. The process of sputtering is carried within the same vacuum chamber where the SIMS analysis of the collected material is performed. For sputtering and SIMS analysis of the deposited material we use 5 keV Ar{sup +} beam of 500 nA. The presented results are obtained with the use of stationary collectors. Here we present a case study of chromium. The obtained results show that the molybdenum and titanium oxide substrates used as collectors increase useful yield by two orders, with respect to such pure elemental collectors as Cu and Ti. Here we define useful yield as a ratio of the number of detected secondary ions during SIMS analysis and the number of atoms sputtered during the deposition process.

  14. Kinetics and mechanism of the oxidation of thiocyanate ion by di-m ...

    African Journals Online (AJOL)

    phenanthroline)dimanganese(III,IV) perchlorate in acid medium has been investigated. The reaction follows first order in both the oxidant and the reductant. The reaction is catalysed by hydrogen ion and the rate dependence given as k2 = a + b[H+].

  15. Fluorine and chlorine determination in oxides and metals by ion chromatography

    International Nuclear Information System (INIS)

    Evseeva, T.I.; Poletaeva, I.L.; Zemlyanukhina, N.A.; Pavlova, I.V.; Rybin, A.M.; Malykh, M.Yu.; Fedorova, L.A.

    1989-01-01

    Method for simultaneous determination of fluorine and chlorine microquantitie in tantalum, uranium and plutonium oxides, based on combined methods of pyrohydrolysis (1000-1100 deg C) and two-column ion chromatography with conductometric detection is suggested. The relative root-mean-square deviation of determination error is 0.2, the fluorine and chlorine content being 5·10 -4 mass%

  16. Cadmium Sulphide-Reduced Graphene Oxide-Modified Photoelectrode-Based Photoelectrochemical Sensing Platform for Copper(II Ions.

    Directory of Open Access Journals (Sweden)

    I Ibrahim

    Full Text Available A photoelectrochemical (PEC sensor with excellent sensitivity and detection toward copper (II ions (Cu2+ was developed using a cadmium sulphide-reduced graphene oxide (CdS-rGO nanocomposite on an indium tin oxide (ITO surface, with triethanolamine (TEA used as the sacrificial electron donor. The CdS nanoparticles were initially synthesized via the aerosol-assisted chemical vapor deposition (AACVD method using cadmium acetate and thiourea as the precursors to Cd2+ and S2-, respectively. Graphene oxide (GO was then dip-coated onto the CdS electrode and sintered under an argon gas flow (50 mL/min for the reduction process. The nanostructured CdS was adhered securely to the ITO by a continuous network of rGO that also acted as an avenue to intensify the transfer of electrons from the conduction band of CdS. The photoelectrochemical results indicated that the ITO/CdS-rGO photoelectrode could facilitate broad UV-visible light absorption, which would lead to a higher and steady-state photocurrent response in the presence of TEA in 0.1 M KCl. The photocurrent decreased with an increase in the concentration of Cu2+ ions. The photoelectrode response for Cu2+ ion detection had a linear range of 0.5-120 μM, with a limit of detection (LoD of 16 nM. The proposed PEC sensor displayed ultra-sensitivity and good selectivity toward Cu2+ ion detection.

  17. Recent Advances in Antimicrobial Hydrogels Containing Metal Ions and Metals/Metal Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Fazli Wahid

    2017-11-01

    Full Text Available Recently, the rapid emergence of antibiotic-resistant pathogens has caused a serious health problem. Scientists respond to the threat by developing new antimicrobial materials to prevent or control infections caused by these pathogens. Polymer-based nanocomposite hydrogels are versatile materials as an alternative to conventional antimicrobial agents. Cross-linking of polymeric materials by metal ions or the combination of polymeric hydrogels with nanoparticles (metals and metal oxide is a simple and effective approach for obtaining a multicomponent system with diverse functionalities. Several metals and metal oxides such as silver (Ag, gold (Au, zinc oxide (ZnO, copper oxide (CuO, titanium dioxide (TiO2 and magnesium oxide (MgO have been loaded into hydrogels for antimicrobial applications. The incorporation of metals and metal oxide nanoparticles into hydrogels not only enhances the antimicrobial activity of hydrogels, but also improve their mechanical characteristics. Herein, we summarize recent advances in hydrogels containing metal ions, metals and metal oxide nanoparticles with potential antimicrobial properties.

  18. Alkali-Metal-Ion-Functionalized Graphene Oxide as a Superior Anode Material for Sodium-Ion Batteries.

    Science.gov (United States)

    Wan, Fang; Li, Yu-Han; Liu, Dai-Huo; Guo, Jin-Zhi; Sun, Hai-Zhu; Zhang, Jing-Ping; Wu, Xing-Long

    2016-06-06

    Although graphene oxide (GO) has large interlayer spacing, it is still inappropriate to use it as an anode for sodium-ion batteries (SIBs) because of the existence of H-bonding between the layers and ultralow electrical conductivity which impedes the Na(+) and e(-) transformation. To solve these issues, chemical, thermal, and electrochemical procedures are traditionally employed to reduce GO nanosheets. However, these strategies are still unscalable, consume high amounts of energy, and are expensive for practical application. Here, for the first time, we describe the superior Na storage of unreduced GO by a simple and scalable alkali-metal-ion (Li(+) , Na(+) , K(+) )-functionalized process. The various alkali metals ions, connecting with the oxygen on GO, have played different effects on morphology, porosity, degree of disorder, and electrical conductivity, which are crucial for Na-storage capabilities. Electrochemical tests demonstrated that sodium-ion-functionalized GO (GNa) has shown outstanding Na-storage performance in terms of excellent rate capability and long-term cycle life (110 mAh g(-1) after 600 cycles at 1 A g(-1) ) owing to its high BET area, appropriate mesopore, high degree of disorder, and improved electrical conductivity. Theoretical calculations were performed using the generalized gradient approximation (GGA) to further study the Na-storage capabilities of functionalized GO. These calculations have indicated that the Na-O bond has the lowest binding energy, which is beneficial to insertion/extraction of the sodium ion, hence the GNa has shown the best Na-storage properties among all comparatives functionalized by other alkali metal ions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Electrochemistry of carbonaceous materials; 1. Oxidation of Sardinian coal by Fe(III) ions

    Energy Technology Data Exchange (ETDEWEB)

    Tomat, R.; Salmaso, R.; Zecchin, S. (CNR-Instituto di Polarografia ed Elettrochimica Preparativa, Padova (Italy))

    1992-04-01

    Oxidation of subbitiminous coal (Sulcis basin, Sardinia, Italy) by Fe(III) ions in aqueous H{sub 2}SO{sub 4} solution was investigated over a wide temperature range (20-80{degree}C). Experimental results are in accord with a reaction scheme involving a reversible complex between coal particles and Fe(III) ions as a first step in the oxidation process. At low coal concentration, the reaction rate follows first-order kinetics in both coal and ferric ions (overall second order), while at sufficiently high coal concentration, the reaction rate is consistent with first-order kinetics in Fe(III) concentration, appearing to be independent of coal concentration. The kinetic results obtained give preliminary information on the advantageous use of the Fe(III)/slurried coal reaction system to depolarize the anodic compartment of an electrolysis cell, for the production of H{sub 2}. 11 refs., 5 figs.

  20. 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

  1. Oxidative degradation of ion-exchange resins in acid medium. Vol. 3

    International Nuclear Information System (INIS)

    Eskander, S.B.; Ghattas, N.K.

    1996-01-01

    Volume reduction of spent ion-exchange resins used in nuclear facilities receive increasing importance due to the increase in storage cost, unstable physical and chemical properties and their relatively high specific activity (in some cases up to 1 Ci per liter). The present study is part of research program on the treatment and immobilization of radioactive spent ion-exchange resins simulate; hydrogen peroxide was used for the oxidative degradation of spent ion-exchange resins simulate in sulphuric acid medium. Five liters ring digester developed in Karlsruhe nuclear research center-(KFK)- in germany was the chosen option to perform the oxidation process. The work reported focused on the kinetics and mechanism of the oxidation process. Heating the organic resins in sulphuric acid results in its carbonization and partial oxidation of only 1.7% of the carbon added. Results show that the oxidation reaction is a relatively slow process of first order with K value in the order of 10 -4 min -1 , and the main oxidation product was carbon dioxide. The production of carbon oxide in the off gas stream increased sharply by the addition of hydrogen peroxide to the hot sulphuric acid-resin mixture. The results obtained show that more than 97% of the carbon added was oxidized to carbon dioxide and carbon monoxide. The rate constant value (K) of this reaction was calculated to be (1.69±0.13) x 10 -2 min -1 . The results of gas chromatographic analysis indicate that no significant amounts of hazardous organic materials were detected in the off-gas streams. 6 figs., 4 tabs

  2. Utilize the spectral line pair of the same ionized state ion to measure the ion temperature of tokamak plasma

    International Nuclear Information System (INIS)

    Lin Xiaodong

    2000-01-01

    Making use of a Fabry-Perot interferometer driven by a piezoelectric crystal and selecting the suitable separation of plates, the ion temperature is defined by measuring the superimposed profile of the spectral line pair of the same ionized state ions in Tokamak. The advantage of this method is to higher spectral resolution and wider spectral range select

  3. Peculiarities in film growth of ferroelectric complex oxides in ion-plasma sputtering

    International Nuclear Information System (INIS)

    Mukhortov, V.M.; Golovko, Yu.I.; Mukhortov, Vl.M.; Dudkevich, V.P.

    1981-01-01

    Experimental investigation into the process of complex oxide film growth (using BaTiO 3 and (Ba,Sr)TiO 3 as an example) during ion-plasma sputtering has been carried out. It is shown that neutral excited atoms are knocked out of a ceramic target during its ion bombardment. Removing from the target they loss energy at the expence of collisions and at some distance hsub(cr) the oxidation reaction (BaO, TiO, TiO 2 , SrO) becomes possible. So the ''construction'' material comes in either in the form of atoms or in the form of molecules of simple oxides depending on a distance between cathode and substrate. Two mechanisms of synthesis and crystallization distinguished with dependences of growth rate, elementary cell parameters and other structure characteristics on precipitation temperature correspond to two precipitation mechanisms. Part of re-evaporation and reduction processes is discussed [ru

  4. Vanadium oxide nanotubes as cathode material for Mg-ion batteries

    DEFF Research Database (Denmark)

    Christensen, Christian Kolle; Sørensen, Daniel Risskov; Bøjesen, Espen Drath

    Vanadium oxide compounds as cathode material for secondary Li-ion batteries gained interest in the 1970’s due to high specific capacity (>250mAh/g), but showed substantial capacity fading.1 Developments in the control of nanostructured morphologies have led to more advanced materials, and recently...... vanadium oxide nanotubes (VOx-NT) were shown to perform well as a cathode material for Mg-ion batteries.2 The VOx-NTs are easily prepared via a hydrothermal process to form multiwalled scrolls of VO layer with primary amines interlayer spacer molecules.3 The tunable and relative large layer spacing 1-3 nm...... synchrotron powder X-ray diffraction measured during battery operation. These results indicate Mg-intercalation in the multiwalled VOx-NTs occurs within the space between the individual vanadium oxide layers while the underlying VOx frameworks constructing the walls are affected only to a minor degree...

  5. Facile synthesis of nanostructured transition metal oxides as electrodes for Li-ion batteries

    Science.gov (United States)

    Opra, Denis P.; Gnedenkov, Sergey V.; Sokolov, Alexander A.; Minaev, Alexander N.; Kuryavyi, Valery G.; Sinebryukhov, Sergey L.

    2017-09-01

    At all times, energy storage is one of the greatest scientific challenge. Recently, Li-ion batteries are under special attention due to high working voltage, long cycle life, low self-discharge, reliability, no-memory effect. However, commercial LIBs usage in medium- and large-scale energy storage are limited by the capacity of lithiated metal oxide cathode and unsafety of graphite anode at high-rate charge. In this way, new electrode materials with higher electrochemical performance should be designed to satisfy a requirement in both energy and power. As it known, nanostructured transition metal oxides are promising electrode materials because of their elevated specific capacity and high potential vs. Li/Li+. In this work, the perspective of an original facile technique of pulsed high-voltage plasma discharge in synthesis of nanostructured transition metal oxides as electrodes for lithium-ion batteries has been demonstrated.

  6. Method for monitoring the course of oxidation of iodide ion during radioactive iodination operation

    Energy Technology Data Exchange (ETDEWEB)

    Xuezhong, Luo

    1986-05-01

    A micro-iodine ion selective electrode is developed to follow and monitor the course of oxidation of iodide ion during radioactive iodination operation. The experimental results indicate that this method can quickly respond to the course of oxidation if the reacting liquid is greater than 30 micro liter in volume. Therefore it can be used for accurate controlling the amount of oxidzing reagent used for the reaction, for example, the amount of chloroamine T can be reduced to 1/40 of the amount ordinarily used for the preparation of angiotonin II and insulin. The effect of pH and concentration of phosphate of the reacting liquid to the oxidation reaction of I with chloroamine T is also studied.

  7. Effect of microorganisms on the plutonium oxidation states

    International Nuclear Information System (INIS)

    Lukšienė, Benedikta; Druteikienė, Rūta; Pečiulytė, Dalia; Baltrūnas, Dalis; Remeikis, Vidmantas; Paškevičius, Algimantas

    2012-01-01

    Particular microbes from substrates at the low-level radioactive waste repository in the Ignalina NPP territory were exposed to 239 Pu (IV) at low pH under aerobic conditions. Pu(III) and Pu(IV) were separated and quantitatively evaluated using the modified anion exchange method and alpha spectrometry. Tested bacteria Bacillus mycoides and Serratia marcescens were more effective in Pu reduction than Rhodococcus fascians. Fungi Paecillomyces lilacinus and Absidia spinosa var. spinosa as well as bacterium Rhodococcus fascians did not alter the plutonium oxidation state. - Highlights: ► Particular microbes from low-level radioactive waste repository were exposed to Pu (IV). ► Some tested bacteria induced slight Pu (IV) reduction at low pH under aerobic conditions. ► Tested fungi did not show peculiarities to alter Pu oxidation state. ► The modified radiochemical method was applied to differentiate Pu oxidation states.

  8. Effect of microorganisms on the plutonium oxidation states

    Energy Technology Data Exchange (ETDEWEB)

    Luksiene, Benedikta, E-mail: bena@ar.fi.lt [Center for Physical Sciences and Technology, Savanoriu ave 231, LT-02300 Vilnius (Lithuania); Druteikiene, Ruta [Center for Physical Sciences and Technology, Savanoriu ave 231, LT-02300 Vilnius (Lithuania); Peciulyte, Dalia [Nature Research Centre, Akademijos street 2, LT-08412 Vilnius (Lithuania); Baltrunas, Dalis; Remeikis, Vidmantas [Center for Physical Sciences and Technology, Savanoriu ave 231, LT-02300 Vilnius (Lithuania); Paskevicius, Algimantas [Nature Research Centre, Akademijos street 2, LT-08412 Vilnius (Lithuania)

    2012-03-15

    Particular microbes from substrates at the low-level radioactive waste repository in the Ignalina NPP territory were exposed to {sup 239}Pu (IV) at low pH under aerobic conditions. Pu(III) and Pu(IV) were separated and quantitatively evaluated using the modified anion exchange method and alpha spectrometry. Tested bacteria Bacillus mycoides and Serratia marcescens were more effective in Pu reduction than Rhodococcus fascians. Fungi Paecillomyces lilacinus and Absidia spinosa var. spinosa as well as bacterium Rhodococcus fascians did not alter the plutonium oxidation state. - Highlights: Black-Right-Pointing-Pointer Particular microbes from low-level radioactive waste repository were exposed to Pu (IV). Black-Right-Pointing-Pointer Some tested bacteria induced slight Pu (IV) reduction at low pH under aerobic conditions. Black-Right-Pointing-Pointer Tested fungi did not show peculiarities to alter Pu oxidation state. Black-Right-Pointing-Pointer The modified radiochemical method was applied to differentiate Pu oxidation states.

  9. Ion sensing properties of vanadium/tungsten mixed oxides

    International Nuclear Information System (INIS)

    Guidelli, Eder Jose; Guerra, Elidia Maria; Mulato, Marcelo

    2011-01-01

    Vanadium/tungsten mixed oxide (V 2 O 5 /WO 3 ) sensing membranes were deposited on glassy carbon substrates and used as the H + sensor of the extended gate field effect transistor (EGFET) device. X-ray diffractograms indicated a decrease of the interplanar spacing of V 2 O 5 after the insertion of WO 3 revealing that the lamellar structure is under compressive stress. The crystallinity increases with increasing WO 3 molar ratio. The film is not homogeneous, with more WO 3 material sitting at the surface. This influences the response of pH sensors using the EGFET configuration. The maximum sensitivity of 68 mV pH -1 was obtained for the sample with 5% WO 3 molar ratio. For higher WO 3 molar ratios, the behavior is not linear. It can be concluded that V 2 O 5 dominates for acidic solutions while WO 3 dominates for basic solutions. Therefore, the mixed oxide with low amount of WO 3 is the main candidate for further use as biosensor.

  10. Effects of metal ions on growth, β-oxidation system, and thioesterase activity of Lactococcus lactis.

    Science.gov (United States)

    Li, Liang; Ma, Ying

    2014-10-01

    The effects of divalent metal ions (Ca(2+), Mg(2+), Fe(2+), and Cu(2+)) on the growth, β-oxidation system, and thioesterase activity of Lactococcus lactis were investigated. Different metal ions significantly influenced the growth of L. lactis: Ca(2+) and Fe(2+) accelerated growth, whereas Cu(2+) inhibited growth. Furthermore, Mg(2+) inhibited growth of L. lactis at a low concentration but stimulated growth of L. lactis at a high concentration. The divalent metal ions had significant effects on activity of the 4 key enzymes of the β-oxidation system (acyl-CoA dehydrogenase, enoyl-CoA hydratase, L-3-hydroxyacyl-CoA dehydrogenase, and thiolase) and thioesterase of L. lactis. The activity of acyl-CoA dehydrogenases increased markedly in the presence of Ca(2+) and Mg(2+), whereas it decreased with 1 mmol/L Fe(2+) or 12 mmol/L Mg(2+). All the metal ions could induce activity of enoyl-CoA hydratase. In addition, 12 mmol/L Mg(2+) significantly stimulated activity of L-3-hydroxyacyl-CoA dehydrogenase, and all metal ions could induce activity of thiolase, although thiolase activity decreased significantly when 0.05 mmol/L Cu(2+) was added into M17 broth. Inhibition of thioesterase activity by all 4 metal ions could be reversed by 2 mmol/L Ca(2+). These results help us understand the effect of metal ions on the β-oxidation system and thioesterase activity of Lactococcus lactis. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. Development of the balance equations model for calculation of ion charge-state distribution in ECR ion sources

    International Nuclear Information System (INIS)

    Filippov, A.V.; Shirkov, G.D.; Consoli, F.; Gammino, S.; Ciavola, G.; Celona, L.; Barbarino, S.

    2008-01-01

    The investigation of the widespread model for the calculation of ion charge-state distributions (CSD) in electron cyclotron-resonance ion source based on the set of balance equations is given. The modification of this model that allows one to describe the confinement and accumulation processes of highly charged ions in ECR plasma for gas mixing case more precisely is discussed. The new approach for the time confinement calculation (ions and electrons) based on the theory of Pastukhov is offered, viz. - calculation of confinement times during two step minimization of special type functionals. The results obtained by this approach have been compared with available experimental data

  12. A computational study of adsorption of divalent metal ions on graphene oxide

    Directory of Open Access Journals (Sweden)

    Somphob Thompho

    2017-12-01

    Full Text Available Adsorption of divalent metal ions (Pb2+,Cd2+, Zn2+,Cu2+ on graphene oxide (GO was studied using density functional theory (DFT. Adsorption geometries and energies, as well as the nature of the binding energy, were calculated for the interaction of divalent metal ions with oxygen-containing groups on the surface of GO. The configurations of the complexes were modeled by placing the divalent metal ions above the center and perpendicular to the surface. Binding of Cu2+ to the GO sheet was predicted to be much stronger than that for other divalent metal ions. Calculated results show good agreement with experimental observations and provide useful information for environmental pollution cleanup.

  13. Ion sources development at GANIL for radioactive beams and high charge state ions

    International Nuclear Information System (INIS)

    Leroy, R.; Barue, C.; Canet, C.; Dupuis, M.; Flambard, J.L.; Gaubert, G.; Gibouin, S.; Huguet, Y.; Jardin, P.; Lecesne, N.; Leherissier, P.; Lemagnen, F.; Pacquet, J.Y.; Pellemoine-Landre, F.; Rataud, J.P.; Saint-Laurent, M.G.; Villari, A.C.C.; Maunoury, L.

    2001-01-01

    The GANIL laboratory has in charge the production of ion beams for nuclear and non nuclear physics. This article reviews the last developments that are underway in the fields of radioactive ion beam production, increase of the metallic ion intensities and production of highly charges ion beams. (authors)

  14. Dense ceramic membranes based on ion conducting oxides

    International Nuclear Information System (INIS)

    Fontaine, M.L.; Larring, Y.; Bredesen, R.; Norby, T.; Grande, T.

    2007-01-01

    This chapter reviews the recent progress made in the fields of high temperature oxygen and hydrogen separation membranes. Studies of membranes for oxygen separation are mainly focusing on materials design to improve flux, and to lesser extent, related to stability issues. High oxygen fluxes satisfying industrial requirements can be obtained but, for many materials, the surface exchange rate is limiting the performance. The current status on electrolyte-type and mixed proton and electron conducting membranes is outlined, highlighting materials with improved stability in typical applications as solid oxide fuel cell technology and gas separation. In our presentation more fundamental aspects related to transport properties, chemical and mechanical stability of membrane materials are also treated. It is concluded that a significantly better understanding of the long term effects of operation in chemical gradients is needed for these types of membrane materials. (authors)

  15. Hollow carbon sphere/metal oxide nanocomposites anodes for lithium-ion batteries

    International Nuclear Information System (INIS)

    Wenelska, K.; Ottmann, A.; Schneider, P.; Thauer, E.; Klingeler, R.; Mijowska, E.

    2016-01-01

    HCS (Hollow carbon spheres) covered with metal oxide nanoparticles (SnO_2 and MnO_2, respectively) were successfully synthesized and investigated regarding their potential as anode materials for lithium-ion batteries. Raman spectroscopy shows a high degree of graphitization for the HCS host structure. The mesoporous nature of the nanocomposites is confirmed by Brunauer–Emmett–Teller analysis. For both metal oxides under study, the metal oxide functionalization of HCS yields a significant increase of electrochemical performance. The charge capacity of HCS/SnO_2 is 370 mA hg"−"1 after 45 cycles (266 mA hg"−"1 in HCS/MnO_2) which clearly exceeds the value of 188 mA hg"−"1 in pristine HCS. Remarkably, the data imply excellent long term cycling stability after 100 cycles in both cases. The results hence show that mesoporous HCS/metal oxide nanocomposites enable exploiting the potential of metal oxide anode materials in Lithium-ion batteries by providing a HCS host structure which is both conductive and stable enough to accommodate big volume change effects. - Highlights: • Strategy to synthesize hollow carbon spheres decorated by metal oxides nanoparticles. • High-performance of HCS/MOx storage as mesoporous hybrid material. • The results hence demonstrate high electrochemical activity of the HCS/MOx.

  16. Dewetting of nickel oxide-films on silicon under swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Bolse, Thunu; Elsanousi, Ammar; Paulus, Hartmut; Bolse, Wolfgang

    2006-01-01

    Dewetting, occurring when a thin film on a non-wettable substrate turns into its liquid state, has gained strong interest during the last decade, since it results in nano-scale, large-area covering pattern formation. Recently we found that swift heavy ion (SHI) irradiation of thin NiO films on Si substrates at 80 K results in similar dewetting pattern, although in this case the coating has never reached its melting point. Careful inspection of the SEM images clearly revealed that the same nucleation mechanisms as observed for molten polymer films on Si (heterogeneous and homogeneous nucleation) were active. AFM shows that the circular holes formed in the early stages of the dewetting process exhibit a high and asymmetric rim-structure. RBS analysis was used to measure the coverage of the surface by the oxide films and revealed that the holes grow at constant velocity. This, and the shape of the rims, indicate that the material removed from the substrate surface piles up by plastic deformation, which points at a balance of the capillary driving forces and the hindered material dissipation

  17. Cycle Life of Commercial Lithium-Ion Batteries with Lithium Titanium Oxide Anodes in Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Xuebing Han

    2014-07-01

    Full Text Available The lithium titanium oxide (LTO anode is widely accepted as one of the best anodes for the future lithium ion batteries in electric vehicles (EVs, especially since its cycle life is very long. In this paper, three different commercial LTO cells from different manufacturers were studied in accelerated cycle life tests and their capacity fades were compared. The result indicates that under 55 °C, the LTO battery still shows a high capacity fade rate. The battery aging processes of all the commercial LTO cells clearly include two stages. Using the incremental capacity (IC analysis, it could be judged that in the first stage, the battery capacity decreases mainly due to the loss of anode material and the degradation rate is lower. In the second stage, the battery capacity decreases much faster, mainly due to the degradation of the cathode material. The result is important for the state of health (SOH estimation and remaining useful life (RUL prediction of battery management system (BMS for LTO batteries in EVs.

  18. Micro-length anodic porous niobium oxide for lithium-ion thin film battery applications

    International Nuclear Information System (INIS)

    Yoo, Jeong Eun; Park, Jiyoung; Cha, Gihoon; Choi, Jinsub

    2013-01-01

    The anodization of niobium in an aqueous mixture of H 3 PO 4 and HF in the potential range from 2.5 to 30 V for 2 h at 5 °C was performed, demonstrating that anodic porous niobium oxide film with a thickness of up to 2000 nm, including a surface dissolution layer, can be obtained by controlling the applied potential and composition of the electrolytes. Specifically, surface dissolution-free porous niobium oxide film with a thickness of 800 nm can be prepared in a low electrolyte concentration. The surface dissolution is observed when the concentration ratio of HF (wt.%):H 3 PO 4 (M) was more than 2:1. The discontinuous layers in the niobium oxide film were observed when the thickness was higher than 500 nm, which was ascribed to the large volume expansion of the niobium oxide grown from the niobium metal. The anodic porous niobium oxide film was used as the cathode for lithium-ion batteries in the potential range from 1.2 to 3.0 V at a current density of 7.28 × 10 − 6 A cm −2 . The first discharge capacity of ca. 53 μA h cm − 2 was obtained in 800 nm thick niobium oxide without a surface dissolution layer. - Highlights: ► Anodic porous niobium oxide film with a thickness of 2000 nm was obtained. ► Surface dissolution-free porous niobium oxide film was prepared. ► The niobium oxide film was used as the cathode for lithium-ion batteries

  19. In-line monitoring of an oxide ion in LiCl molten salt using a YSZ based oxide ion selective electrode

    International Nuclear Information System (INIS)

    Cho, Young Hwan; Jeon, Jong Seon; Yeon, Jei Won; Choi, In Kyu; Kim, Won Ho

    2004-01-01

    The electrode potential characteristics of a YSZ based membrane metal oxide electrode have been studied in molten LiCl at 700 .deg. C by the potentiometric method. The electrode exhibited a good potential response to log[O 2 ] and data reproducibility. The calibration plot (potential vs. log[O 2 ] was found to be linear, obeying the nernst equation. The electrode potential showed a good reversibility corresponding to increase/decrease of the oxide ion present in the molten LiCl. The physical and chemical durability appeared to be sound after several repeated uses, resulting in reproducible results. However, 'the proposed electrode' failed when metallic Li was present in the melt

  20. Assessment of all-solid-state lithium-ion batteries

    Science.gov (United States)

    Braun, P.; Uhlmann, C.; Weiss, M.; Weber, A.; Ivers-Tiffée, E.

    2018-07-01

    All-solid-state lithium-ion batteries (ASSBs) are considered as next generation energy storage systems. A model might be very useful, which describes all contributions to the internal cell resistance, enables an optimization of the cell design, and calculates the performance of an open choice of cell architectures. A newly developed one-dimensional model for ASSBs is presented, based on a design concept which employs the use of composite electrodes. The internal cell resistance is calculated by linking two-phase transmission line models representing the composite electrodes with an ohmic resistance representing the solid electrolyte (separator). Thereby, electrical parameters, i.e. ionic and electronic conductivity, electrochemical parameters, i.e. charge-transfer resistance at interfaces and lithium solid-state diffusion, and microstructure parameters, i.e. electrode thickness, particle size, interface area, phase composition and tortuosity, are considered as the most important material and design parameters. Subsequently, discharge curves are simulated, and energy- and power-density characteristics of all-solid-state cell architectures are calculated. These model calculations are discussed and compared with experimental data from literature for a high power LiCoO2-Li10GeP2S12/Li10GeP2S12/Li4Ti5O12-Li10GeP2S12 cell.

  1. Polyrhodanine modified anodic aluminum oxide membrane for heavy metal ions removal.

    Science.gov (United States)

    Song, Jooyoung; Oh, Hyuntaek; Kong, Hyeyoung; Jang, Jyongsik

    2011-03-15

    Polyrhodanine was immobilized onto the inner surface of anodic aluminum oxide (AAO) membrane via vapor deposition polymerization method. The polyrhodanine modified membrane was applied to remove heavy metal ions from aqueous solution because polyrhodanine could be coordinated with specific metal ions. Several parameters such as initial metal concentration, contact time and metal species were evaluated systematically for uptake efficiencies of the fabricated membrane under continuous flow condition. Adsorption isotherms of Hg(II) ion on the AAO-polyrhodanine membrane were analyzed with Langmuir and Freundlich isotherm models. The adsorption rate of Hg(II) ion on the membrane was obeyed by a pseudo-second order equation, indicating the chemical adsorption. The maximum removal capacity of Hg(II) ion onto the fabricated membrane was measured to be 4.2 mmol/g polymer. The AAO-polyrhodanine membrane had also remarkable uptake performance toward Ag(I) and Pb(II) ions. Furthermore, the polyrhodanine modified membrane could be recycled after recovery process. These results demonstrated that the polyrhodanine modified AAO membrane provided potential applications for removing the hazardous heavy metal ions from wastewater. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Isotopic exchange rate of cobalt ions between hydrous tin(IV) oxide and aqueous solutions

    International Nuclear Information System (INIS)

    Inoue, Yasushi; Yamazaki, Hiromichi; Itami, Akira

    1989-01-01

    The isotopic exchange rate of cobalt ions between hydrous tin(IV) oxide ion exchanger and aqueous solutions was radiochemically measured to obtain fundamental data which are useful for elucidating the ion-exchange kinetics of the material for the transition metal elements. The rate can be understood by considering that the cobalt ions were present in the exchanger as three kinds of species: (A 1 ) Free ions which can diffuse in the exchanger particles, (A 2 ) Weakly bound ions to the exchange sites which exchange rapidly with A 1 , and (B) Covalently fixed ions to the exchange sites which exchange very slowly with A 1 . At low fraction of B, the rate is controlled by the diffusion of A 1 with the effective diffusion coefficient, D eff , the values of which depend on the concentration ratios of A 2 to A 1 . When B predominates over the A species, the concentration ratios of B to A 1 affect greatly D eff . The values of D eff and their activation energy(20 kJ/mol) were also estimated

  3. Terbium(III) ions as sensitizers of oxidation of indole and its derivatives in Fenton system

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-15

    Oxidation of indole and its derivatives in the Fenton system as a source of oxidising agents, in the presence of terbium(III) ions was studied by chemiluminescence methods to get the kinetic curves of emission decay and spectral distributions of chemiluminescence. Terbium(III) ions acted as a sensitizer of the mixtures Tb(III)-Fe(II)/Fe(III)-H{sub 2}O{sub 2}-indole or its derivative (tryptophan, tryptamine, indole-3-acetic acid and indole-3-acetyl aspartic acid). For the above indolic compounds, linear dependencies of integrated intensity of chemiluminescence on concentration of indolic compound in water and in water-acetonitrile solution were obtained. The limits of detection (LOD) and quantification (LOQ) of the indolic compounds studied were found to be by one or two orders of magnitude lower in the system with terbium(III) ions than without them. - Highlights: • Chemiluminescence emitted on oxidation of indolic compounds in Fenton system. • Tb (III) ions as sensitizers of indolic compounds oxidation in solutions. • Linear relations between CL intensity and indolic compound concentration.

  4. Magnetization measurements and XMCD studies on ion irradiated iron oxide and core-shell iron/iron-oxide nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Maninder; Qiang, You; Jiang, Weilin; Pearce, Carolyn; McCloy, John S.

    2014-12-02

    Magnetite (Fe3O4) and core-shell iron/iron-oxide (Fe/Fe3O4) nanomaterials prepared by a cluster deposition system were irradiated with 5.5 MeV Si2+ ions and the structures determined by x-ray diffraction as consisting of 100% magnetite and 36/64 wt% Fe/FeO, respectively. However, x-ray magnetic circular dichroism (XMCD) indicates similar surfaces in the two samples, slightly oxidized and so having more Fe3+ than the expected magnetite structure, with XMCD intensity much lower for the irradiated core-shell samples indicating weaker magnetism. X-ray absorption spectroscopy (XAS) data lack the signature for FeO, but the irradiated core-shell system consists of Fe-cores with ~13 nm of separating oxide crystallite, so it is likely that FeO exists deeper than the probe depth of the XAS (~5 nm). Exchange bias (Hex) for both samples becomes increasingly negative as temperature is lowered, but the irradiated Fe3O4 sample shows greater sensitivity of cooling field on Hex. Loop asymmetries and Hex sensitivities of the irradiated Fe3O4 sample are due to interfaces and interactions between grains which were not present in samples before irradiation as well as surface oxidation. Asymmetries in the hysteresis curves of the irradiated core/shell sample are related to the reversal mechanism of the antiferromagnetic FeO and possibly some near surface oxidation.

  5. Shifts in oxidation states of cerium oxide nanoparticles detected inside intact hydrated cells and organelles

    Energy Technology Data Exchange (ETDEWEB)

    Szymanski, Craig J.; Munusamy, Prabhakaran; Mihai, Cosmin; Xie, Yumei; Hu, Dehong; Gilles, Marry K.; Tyliszczak, T.; Thevuthasan, Suntharampillai; Baer, Donald R.; Orr, Galya

    2015-09-01

    Cerium oxide nanoparticles (CNPs) have been shown to induce diverse biological effects, ranging from toxic to beneficial. The beneficial effects have been attributed to the potential antioxidant activity of CNPs via certain redox reactions, depending on their oxidation state or Ce3+/Ce4+ ratio. However, this ratio is strongly dependent on the environment and age of the nanoparticles and it is unclear whether and how the complex intracellular environment impacts this ratio and the possible redox reactions of CNPs. To identify any changes in the oxidation state of CNPs in the intracellular environment and better understand their intracellular reactions, we directly quantified the oxidation states of CNPs outside and inside intact hydrated cells and organelles using correlated scanning transmission x-ray and super resolution fluorescence microscopies. By analyzing hundreds of small CNP aggregates, we detected a shift to a higher Ce3+/Ce4+ ratio in CNPs inside versus outside the cells, indicating a net reduction of CNPs in the intracellular environment. We further found a similar ratio in the cytoplasm and in the lysosomes, indicating that the net reduction occurs earlier in the internalization pathway. Together with oxidative stress and toxicity measurements, our observations identify a net reduction of CNPs in the intracellular environment, which is consistent with their involvement in potentially beneficial oxidation reactions, but also point to interactions that can negatively impact the health of cells.

  6. Nanoporous titanium niobium oxide and titanium tantalum oxide compositions and their use in anodes of lithium ion batteries

    Science.gov (United States)

    Dai, Sheng; Guo, Bingkun; Sun, Xiao-Guang; Qiao, Zhenan

    2017-10-31

    Nanoporous metal oxide framework compositions useful as anodic materials in a lithium ion battery, the composition comprising metal oxide nanocrystals interconnected in a nanoporous framework and having interconnected channels, wherein the metal in said metal oxide comprises titanium and at least one metal selected from niobium and tantalum, e.g., TiNb.sub.2-x Ta.sub.xO.sub.y (wherein x is a value from 0 to 2, and y is a value from 7 to 10) and Ti.sub.2Nb.sub.10-vTa.sub.vO.sub.w (wherein v is a value from 0 to 2, and w is a value from 27 to 29). A novel sol gel method is also described in which sol gel reactive precursors are combined with a templating agent under sol gel reaction conditions to produce a hybrid precursor, and the precursor calcined to form the anodic composition. The invention is also directed to lithium ion batteries in which the nanoporous framework material is incorporated in an anode of the battery.

  7. High energy (MeV) ion-irradiated π-conjugated polyaniline: Transition from insulating state to carbonized conducting state

    International Nuclear Information System (INIS)

    Park, S.K.; Lee, S.Y.; Lee, C.S.; Kim, H.M.; Joo, J.; Beag, Y.W.; Koh, S.K.

    2004-01-01

    High energy (MeV) C 2+ , F 2+ , and Cl 2+ ions were irradiated onto π-conjugated polyaniline emeraldine base (PAN-EB) samples. The energy of an ion beam was controlled to a range of 3-4.5 MeV, with the ion dosage varying from 1x10 12 to 1x10 16 ions/cm 2 . The highest dc conductivity (σ dc ) at room temperature was measured to be ∼60 S/cm for 4.5 MeV Cl 2+ ion-irradiated PAN-EB samples with a dose of 1x10 16 ions/cm 2 . We observed the transition of high energy ion-irradiated PAN-EB samples from insulating state to conducting state as a function of ion dosage based on σ dc and its temperature dependence. The characteristic peaks of the Raman spectrum of the PAN-EB samples were reduced, while the D-peak (disordered peak) and the G peak (graphitic peak) appeared as the ion dose increased. From the analysis of the D and G peaks of the Raman spectra of the systems compared to multiwalled carbon nanotubes, ion-irradiated graphites, and annealed carbon films, the number of the clusters of hexagon rings with conducting sp 2 -bonded carbons increased with ion dosage. We also observed the increase in the size of the nanocrystalline graphitic domain of the systems with increasing ion dosage. The intensity of normalized electron paramagnelic resonance signal also increased in correlation with ion dose. The results of this study demonstrate that π-conjugated pristine PAN-EB systems changed from insulating state to carbonized conducting state through high energy ion irradiation with high ion dosage

  8. Hydrothermal synthesis of nickel oxide nanosheets for lithium-ion batteries and supercapacitors with excellent performance.

    Science.gov (United States)

    Mondal, Anjon Kumar; Su, Dawei; Wang, Ying; Chen, Shuangqiang; Wang, Guoxiu

    2013-11-01

    Nickel oxide nanosheets have been successfully synthesized by a facile ethylene glycol mediated hydrothermal method. The morphology and crystal structure of the nickel oxide nanosheets were characterized by X-ray diffraction, field-emission SEM, and TEM. When applied as electrode materials for lithium-ion batteries and supercapacitors, nickel oxide nanosheets exhibited a high, reversible lithium storage capacity of 1193 mA h g(-1) at a current density of 500 mA g(-1), an enhanced rate capability, and good cycling stability. Nickel oxide nanosheets also demonstrated a superior specific capacitance of 999 F g(-1) at a current density of 20 A g(-1) in supercapacitors. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Bloodcompatibility improvement of titanium oxide film modified by phosphorus ion implantation

    International Nuclear Information System (INIS)

    Yang, P.; Leng, Y.X.; Zhao, A.S.; Zhou, H.F.; Xu, L.X.; Hong, S.; Huang, N.

    2006-01-01

    Our recent investigation suggested that Ti-O thin film could be a newly developed antithrombotic material and its thromboresistance could be related to its physical properties of wide gap semiconductor. In this work, titanium oxide film was modified by phosphorus ion implantation and succeeding vacuum annealing. RBS were used to investigate phosphorus distribution profile. Contact angle test results show that phosphorus-doped titanium oxide film becomes more hydrophilic after higher temperature annealing, while its electric conductivity increases. Antithrombotic property of phosphorus-doped titanium oxide thin films was examined by clotting time and platelet adhesion tests. The results suggest that phosphorus doping is an effective way to improve the bloodcompatibility of titanium oxide film, and it is related to the changes of electron structure and surface properties caused by phosphorus doping

  10. Surface nanostructuring by ion-induced localized plasma expansion in zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    El-Said, A. S., E-mail: elsaid@kfupm.edu.sa, E-mail: a.s.el-said@hzdr.de [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden (Germany); Physics Department, Faculty of Science, Mansoura University, 35516 Mansoura (Egypt); Moslem, W. M. [Department of Physics, Faculty of Science, Port Said University, Port Said 42521 (Egypt); Centre for Theoretical Physics, British University in Egypt (BUE), El-Shorouk City, Cairo (Egypt); Djebli, M. [Theoretical Physics Laboratory, Faculty of Physics USTHB, B.P. 32 Bab Ezzour, 16079 Algiers (Algeria)

    2014-06-09

    Creation of hillock-like nanostructures on the surface of zinc oxide single crystals by irradiation with slow highly charged ions is reported. At constant kinetic energy, the nanostructures were only observed after irradiation with ions of potential energies above a threshold between 19.1 keV and 23.3 keV. The size of the nanostructures increases as a function of potential energy. A plasma expansion approach is used to explain the nanostructures creation. The calculations showed that the surface nanostructures became taller with the increase of ionic temperature. The influence of charged cluster formation and the relevance of their polarity are discussed.

  11. Surface nanostructuring by ion-induced localized plasma expansion in zinc oxide

    International Nuclear Information System (INIS)

    El-Said, A. S.; Moslem, W. M.; Djebli, M.

    2014-01-01

    Creation of hillock-like nanostructures on the surface of zinc oxide single crystals by irradiation with slow highly charged ions is reported. At constant kinetic energy, the nanostructures were only observed after irradiation with ions of potential energies above a threshold between 19.1 keV and 23.3 keV. The size of the nanostructures increases as a function of potential energy. A plasma expansion approach is used to explain the nanostructures creation. The calculations showed that the surface nanostructures became taller with the increase of ionic temperature. The influence of charged cluster formation and the relevance of their polarity are discussed.

  12. Phase stability of zirconium oxide films during focused ion beam milling

    Science.gov (United States)

    Baxter, Felicity; Garner, Alistair; Topping, Matthew; Hulme, Helen; Preuss, Michael; Frankel, Philipp

    2018-06-01

    Focused ion beam (FIB) is a widely used technique for preparation of electron transparent samples and so it is vital to understand the potential for introduction of FIB-induced microstructural artefacts. The bombardment of both Xe+ and Ga+ ions is observed to cause extensive monoclinic to tetragonal phase transformation in ZrO2 corrosion films, however, this effect is diminished with reduced energy and is not observed below 5 KeV. This study emphasises the importance of careful FIB sample preparation with a low energy cleaning step, and also gives insight into the stabilisation mechanism of the tetragonal phase during oxidation.

  13. Relationships among oxidation-reduction and acid-base properties of the actinides in high oxidation states

    International Nuclear Information System (INIS)

    Morss, L.R.

    1992-01-01

    The first chemical identification of plutonium, its subsequent isolation on the macroscopic scale, and more recent chemical separation schemes were achieved by taking advantage of the differences among the oxidation states of uranium, neptunium, and plutonium. Many acid-base properties modify the relative stabilities of oxidation states of the actinides. In the solid state, strongly basic compounds such as Cs 2 O yield complex oxides with oxidation states of Np(VII), Pu(VI), and Am(VI) whereas more acidic compounds such as CsF yield complex fluorides with lower oxidation states. In aqueous solution, high basicity and strongly covalent complexes favor high oxidation states. In nonaqueous solvent systems, high acidity generally favors low oxidation states. This paper elucidates and attempts to interpret the effects of these acid-base properties in a systematic fashion

  14. Multiple charge states of titanium ions in laser produced plasma

    Indian Academy of Sciences (India)

    An Nd:glass laser (KAMETRON) delivering 50 J energy (λ = 0.53 μm) in ... voltage on the deflection plates decides the energy (E/Z) of the charged particles to be ... of two ion groups viz fast ions (+22 to +12) and thermal ions (+11 to +1) as shown in ... ions survive the recombination losses in the early phase of expansion.

  15. Leakage Current Degradation Due to Ion Drift and Diffusion in Tantalum and Niobium Oxide Capacitors

    Directory of Open Access Journals (Sweden)

    Kuparowitz Martin

    2017-06-01

    Full Text Available High temperature and high electric field applications in tantalum and niobium capacitors are limited by the mechanism of ion migration and field crystallization in a tantalum or niobium pentoxide insulating layer. The study of leakage current (DCL variation in time as a result of increasing temperature and electric field might provide information about the physical mechanism of degradation. The experiments were performed on tantalum and niobium oxide capacitors at temperatures of about 125°C and applied voltages ranging up to rated voltages of 35 V and 16 V for tantalum and niobium oxide capacitors, respectively. Homogeneous distribution of oxygen vacancies acting as positive ions within the pentoxide layer was assumed before the experiments. DCL vs. time characteristics at a fixed temperature have several phases. At the beginning of ageing the DCL increases exponentially with time. In this period ions in the insulating layer are being moved in the electric field by drift only. Due to that the concentration of ions near the cathode increases producing a positively charged region near the cathode. The electric field near the cathode increases and the potential barrier between the cathode and insulating layer decreases which results in increasing DCL. However, redistribution of positive ions in the insulator layer leads to creation of a ion concentration gradient which results in a gradual increase of the ion diffusion current in the direction opposite to the ion drift current component. The equilibrium between the two for a given temperature and electric field results in saturation of the leakage current value. DCL vs. time characteristics are described by the exponential stretched law. We found that during the initial part of ageing an exponent n = 1 applies. That corresponds to the ion drift motion only. After long-time application of the electric field at a high temperature the DCL vs. time characteristics are described by the exponential

  16. Ultrasensitive colorimetric detection of Cu2+ ion based on catalytic oxidation of L-cysteine.

    Science.gov (United States)

    Yin, Kun; Li, Bowei; Wang, Xiaochun; Zhang, Weiwei; Chen, Lingxin

    2015-02-15

    As an essential element, copper ion (Cu(2+)) plays important roles in human beings for its participation in diverse metabolic processes as a cofactor and/or a structural component of enzymes. However, excessive uptake of Cu(2+) ion gives rise to the risk of certain diseases. So, it is important to develop simple ways to monitor and detect Cu(2+) ion. In this study, a simple, facile colorimetric sensor for the ultrasensitive determination of Cu(2+) ion was developed based on the following principle: L-cysteine and 1-chloro-2,4-dinitrobenzene (CDNB) could be conjugated to form the yellow product 2,4-dinitrophenylcysteine (DNPC), which was measurable at 355nm; however, upon addition of Cu(2+) ion, the absorbance of DNPC would be decreased owing to the Cu(2+) ion catalytic oxidation of L-cysteine to L-cystine in the presence of O2. Thus, the colorimetric detection of Cu(2+) ion could be achieved. The optimal pH, buffer, temperature and incubation time for the colorimetric sensor were obtained of pH 6.8 in 0.1M HEPES solution, 90 °C and 50 min, respectively. A good linearity within the range of 0.8-10 nM (r = 0.996) was attained, with a high detectability up to 0.5nM. Analyses of Cu(2+) ion in drinking water, lake water, seawater and biological samples were carried out and the method performances were found to agree well with that obtained by ICP-MS. The developed simple colorimetric sensor proved applicable for Cu(2+) ion determination in real samples with high sensitivity and selectivity. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Sponge-like reduced graphene oxide/silicon/carbon nanotube composites for lithium ion batteries

    Science.gov (United States)

    Fang, Menglu; Wang, Zhao; Chen, Xiaojun; Guan, Shiyou

    2018-04-01

    Three-dimensional sponge-like reduced graphene oxide/silicon/carbon nanotube composites were synthesized by one-step hydrothermal self-assembly using silicon nanoparticles, graphene oxide and amino modified carbon nanotubes to develop high-performance anode materials of lithium ion batteries. Scanning electron microscopy and transmission electron microscopy images show the structure of composites that Silicon nanoparticles are coated with reduced graphene oxide while amino modified carbon nanotubes wrap around the reduced graphene oxide in the composites. When applied to lithium ion battery, these composites exhibit high initial specific capacity of 2552 mA h/g at a current density of 0.05 A/g. In addition, reduced graphene oxide/silicon/carbon nanotube composites also have better cycle stability than bare Silicon nanoparticles electrode with the specific capacity of 1215 mA h/g after 100 cycles. The three-dimension sponge-like structure not only ensures the electrical conductivity but also buffers the huge volume change, which has broad potential application in the field of battery.

  18. Wet oxidative destruction of spent ion-exchange resins using hydrogen peroxide

    International Nuclear Information System (INIS)

    Srinivas, C.; Ramaswamy, M.; Theyyunni, T.K.

    1994-01-01

    Spent organic ion exchange resins are generated in large quantities during the operation of nuclear facilities. Wet oxidation as a mode of treatment of these gel-type ion exchange resins was investigated using H 2 O 2 as oxidant in the presence of CuSO 4 as catalyst. Experiments using commercial samples were conducted at 95-100 deg C under reflux conditions at atmospheric pressure. It was found that the reaction of cation resin with H 2 O 2 was instantaneous whereas with anion resin, there was a lag time. For efficient utilization of the oxidant, low rate of addition of H 2 O 2 , 0.01M concentration of CuSO 4 and neutral pH in mixed resin reactions, were found to be useful. Foaming was noted during reactions involving anion resins. This could be controlled by silicone-based agents. The residual solution left after resin oxidation is aqueous in nature and is expected to contain all the radioactivity originally present in the resin. Preliminary experiments showed that it could be efficiently trapped using available inorganic sorbents. Wet oxidation system offers a simple method of converting organic waste into environmentally acceptable inorganic products. (author). 8 refs., 6 figs., 2 tabs

  19. Reactivity of surface of metal oxide particles: from adsorption of ions to deposition of colloidal particles

    International Nuclear Information System (INIS)

    Lefevre, Gregory

    2010-01-01

    In this Accreditation to supervise research (HDR), the author proposes an overview of his research works in the field of chemistry. These works more particularly addressed the understanding of the surface reactivity of metal oxide particles and its implication on sorption and adherence processes. In a first part, he addresses the study of surface acidity-alkalinity: measurement of surface reactivity by acid-base titration, stability of metal oxides in suspension, effect of morphology on oxide-hydroxide reactivity. The second part addresses the study of sorption: reactivity of iron oxides with selenium species, sorption of sulphate ions on magnetite, attenuated total reflection infrared spectroscopy (ATR-IR). Adherence effects are addressed in the third part: development of an experimental device to study adherence in massive substrates, deposition of particles under turbulent flow. The last part presents a research project on the effect of temperature on ion sorption at solids/solutions interfaces, and on the adherence of metal oxide particles. The author gives his detailed curriculum, and indicates his various publications, teaching activities, research and administrative responsibilities

  20. 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.

  1. Catalytic reduction of nitric oxide with ammonia over transition metal ion-exchanged Y zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Sciyama, T; Arakawa, T; Matsuda, T; Yamazoe, N; Takita, Y

    1975-01-01

    The catalytic reduction of nitric oxide with ammonia was studied over transition metal ion-exchanged Y zeolite (Me-Y) catalysts. The reaction products are nitrogen, nitrous oxide, and water in all cases. Selectivities to N/sub 2/ are 60 to 80% on all the cation exchanged zeolite catalysts exhibiting a relatively minor variation with the cationic species exchanged. The copper (II)-Y catalyst exhibits low temperature activity and has an unusual catalytic activity-temperature profile with a maximum at 120/sup 0/C. The catalytic activity is enhanced considerably when a second cation, especially cobalt (II) or iron (III) is coexchanged together with Cu (II) in Y zeolite.

  2. Cation-substituted spinel oxide and oxyfluoride cathodes for lithium ion batteries

    Science.gov (United States)

    Manthiram, Arumugam; Choi, Wonchang

    2010-05-18

    The present invention includes compositions and methods of making cation-substituted and fluorine-substituted spinel cathode compositions by firing a LiMn2-y-zLiyMzO4 oxide with NH4HF2 at low temperatures of between about 300 and 700.degree. C. for 2 to 8 hours and a .eta. of more than 0 and less than about 0.50, mixed two-phase compositions consisting of a spinel cathode and a layered oxide cathode, and coupling them with unmodified or surface modified graphite anodes in lithium ion cells.

  3. Hydrogenlike nitrogen ions collision with helium into excited states

    International Nuclear Information System (INIS)

    Pan Guangyan; Yang Feng; Li Dawan; Xu Qian; Liu Huiping; Zhao Mengchun

    1991-01-01

    The emission spectra have been measured in collisions between N 6+ and He using the LHT-30 VUV Monochromator. The wavelength range is 10 nm-80 nm, the energy of N 6+ ions is 90 keV, the current of ion beam in the collision region is about 10 μA. Recently, the authors have investigated the electron capture processes and incident ions excitation in the velocity of N 6+ ions about 0.5 atomic unit. The emission spectrum of N V, N VI and N VII liens is given in collisions of N 6+ with He at 90 keV of ions energy

  4. Charge accumulation in the buried oxide of SOI structures with the bonded Si/SiO2 interface under γ-irradiation: effect of preliminary ion implantation

    International Nuclear Information System (INIS)

    Naumova, O V; Fomin, B I; Ilnitsky, M A; Popov, V P

    2012-01-01

    In this study, we examined the effect of preliminary boron or phosphorous implantation on charge accumulation in the buried oxide of SOI-MOSFETs irradiated with γ-rays in the total dose range (D) of 10 5 –5 × 10 7 rad. The buried oxide was obtained by high-temperature thermal oxidation of Si, and it was not subjected to any implantation during the fabrication process of SOI structures. It was found that implantation with boron or phosphorous ions, used in fabrication technologies of SOI-MOSFETs, increases the concentration of precursor traps in the buried oxide of SOI structures. Unlike in the case of boron implantation, phosphorous implantation leads to an increased density of states at the Si/buried SiO 2 interface during subsequent γ-irradiation. In the γ-irradiated SOI-MOSFETs, the accumulated charge density and the density of surface states in the Si/buried oxide layer systems both vary in proportion to k i ln D. The coefficients k i for as-fabricated and ion-implanted Si/buried SiO 2 systems were evaluated. From the data obtained, it was concluded that a low density of precursor hole traps was a factor limiting the positive charge accumulation in the buried oxide of as-fabricated (non-implanted) SOI structures with the bonded Si/buried SiO 2 interface. (paper)

  5. Ion-ion correlation, solvent excluded volume and pH effects on physicochemical properties of spherical oxide nanoparticles.

    Science.gov (United States)

    Ovanesyan, Zaven; Aljzmi, Amal; Almusaynid, Manal; Khan, Asrar; Valderrama, Esteban; Nash, Kelly L; Marucho, Marcelo

    2016-01-15

    One major source of complexity in the implementation of nanoparticles in aqueous electrolytes arises from the strong influence that biological environments has on their physicochemical properties. A key parameter for understanding the molecular mechanisms governing the physicochemical properties of nanoparticles is the formation of the surface charge density. In this article, we present an efficient and accurate approach that combines a recently introduced classical solvation density functional theory for spherical electrical double layers with a surface complexation model to account for ion-ion correlation and excluded volume effects on the surface titration of spherical nanoparticles. We apply the proposed computational approach to account for the charge-regulated mechanisms on the surface chemistry of spherical silica (SiO2) nanoparticles. We analyze the effects of the nanoparticle size, as well as pH level and electrolyte concentration of the aqueous solution on the nanoparticle's surface charge density and Zeta potential. We validate our predictions for 580Å and 200Å nanoparticles immersed in acid, neutral and alkaline mono-valent aqueous electrolyte solutions against experimental data. Our results on mono-valent electrolyte show that the excluded volume and ion-ion correlations contribute significantly to the surface charge density and Zeta potential of the nanoparticle at high electrolyte concentration and pH levels, where the solvent crowding effects and electrostatic screening have shown a profound influence on the protonation/deprotonation reactions at the liquid/solute interface. The success of this approach in describing physicochemical properties of silica nanoparticles supports its broader application to study other spherical metal oxide nanoparticles. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Ion assisted deposition of refractory oxide thin film coatings for improved optical and structural properties

    International Nuclear Information System (INIS)

    Sahoo, N.K.; Thakur, S.; Bhattacharyya, D.; Das, N.C.

    1999-03-01

    Ion assisted deposition technique (IAD) has emerged as a powerful tool to control the optical and structural properties of thin film coatings. Keeping in view the complexity of the interaction of ions with the films being deposited, sophisticated ion sources have been developed that cater to the need of modern optical coatings with stringent spectral and environmental specifications. In the present work, the results of ion assisted deposition (IAD) of two commonly used refractory oxides, namely TiO 2 and ZrO 2 , using cold cathode ion source (CC-102R) are presented. Through successive feedback and calibration techniques, various ion beams as well as deposition parameters have been optimized to achieve the best optical and structural film properties in the prevalent deposition geometry of the coating system. It has been possible to eliminate the unwanted optical and structural inhomogeneities from these films using and optimized set of process parameters. Interference modulated spectrophotometric and phase modulated ellipsometric techniques have been very successfully utilized to analyze the optical and structural parameters of the films. Several precision multilayer coatings have been developed and are being used for laser and spectroscopic applications. (author)

  7. Modification of mechanical properties of single crystal aluminum oxide by ion beam induced structural changes

    International Nuclear Information System (INIS)

    Ensinger, W.; Nowak, R.; Horino, Y.; Baba, K.

    1993-01-01

    The mechanical behaviour of ceramics is essentially determined by their surface qualities. As a surface modification technique, ion implantation provides the possibility to modify the mechanical properties of ceramics. Highly energetic ions are implanted into the near-surface region of a material and modify its composition and structure. Ions of aluminum, oxygen, nickel and tantalum were implanted into single-crystal α-aluminum oxide. Three-point bending tests showed that an increase in flexural strength of up to 30% could be obtained after implantation of aluminum and oxygen. Nickel and tantalum ion implantation increased the fracture toughness. Indentation tests with Knoop and Vickers diamonds and comparison of the lengths of the developed radial cracks showed that ion implantation leads to a reaction in cracking. The observed effects are assigned to radiation induced structural changes of the ceramic. Ion bombardment leads to radiation damage and formation of compressive stress. In case of tantalum implantation, the implanted near-surface zone becomes amorphous. These effects make the ceramic more resistant to fracture. (orig.)

  8. Effect of Thickness on Oxidation Behavior of Cr coated Zircaloy-4 using Arc Ion Plating

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eui Jung; Kim, Sun Jin [Hanyang University, Seoul (Korea, Republic of); Park, Jung Hwan; Kim, Hyun Gil; Jung, Yang Il; Park, Dong Jun [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Ever since the Fukushima accident, accident tolerant fuel (ATF) has been widely studied. To increase the life time and safety of nuclear claddings, there are increasing demands for protective coatings exhibiting excellent oxidation resistance. Many metal and oxide films are produced by using this method because of the high kinetic energy of the ions, ionization efficiency and deposition rate. Candidate materials for a protective layer have higher thermal neutron absorption cross sections than Zr. However, there is no systematic study of thickness effect on oxidation resistance of protective layer. In this study, Cr films with different thickness (from 1 μm to 50 μm) were deposited on the cladding surfaces by AIP. The high temperature oxidation resistance of Cr films with different thicknesses has been investigated. Uniform oxide layer with nanoporous structures have been fabricated on the surface of Zr-Nb-Sn alloy. Oxidation behavior of the pristine Zr-Nb-Sn alloy and the Zr-Nb-Sn alloy with nanostructured oxide layer evaluated by measuring weight gain (TGA).

  9. Biocompatible nanocarriers that respond to oxidative environments via interactions between chitosan and multiple metal ions

    Directory of Open Access Journals (Sweden)

    Zhang S

    2016-06-01

    Full Text Available Shichang Zhang, Liye Xia, Chenchen Ding, Lu Wen, Weihua Wan, Gang Chen Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China Abstract: Hydrogen peroxide (H2O2 functions as an early damage signal contributing to the oxidative stress response and can act as a trigger in smart oxidation-responsive drug delivery systems that are currently in development. Current H2O2-triggered oxidation-responsive polymeric systems are usually derived from chemical synthesis and rarely include natural polymers. Herein, we report two series of nanoparticle (NP complexes prepared with the biopolymer chitosan (CS and four different metal ions (Cu2+, Ca2+, Zn2+, and Fe3+, defined as CSNPs-metal complexes (Series 1 and CS-metal complexes NPs (Series 2, which responded to oxidation by dissolving upon H2O2 exposure. Experiments examining Nile red release and H2O2-triggered degradation confirmed that both series of complexes showed better sensitivity to oxidation than the CSNPs alone. Furthermore, preliminary cytotoxicity and histological observations indicated that the two series exhibited little or no cytotoxicity and generated a mild inflammatory response. Our work provides a novel and promising strategy for developing NPs for use as intelligent oxidation-responsive systems. Keywords: oxidation-responsive system, chitosan, nanoparticles, hydrogen peroxide, metal complexes

  10. Catalytic oxidative pyrolysis of spent organic ion exchange resins from nuclear power plants

    International Nuclear Information System (INIS)

    Sathi Sasidharan, N.; Deshingkar, D.S.; Wattal, P.K.; Shirsat, A.N.; Bharadwaj, S.R.

    2005-08-01

    The spent IX resins from nuclear power reactors are highly active solid wastes generated during operations of nuclear reactors. Catalytic oxidative pyrolysis of these resins can lead to high volume reduction of these wastes. Low temperature pyrolysis of transition metal ion loaded IX resins in presence of nitrogen was carried out in order to optimize catalyst composition to achieve maximum weight reduction. Thermo gravimetric analysis of the pyrolysis residues was carried out in presence of air in order to compare the oxidative characteristics of transition metal oxide catalysts. Copper along with iron, chromium and nickel present in the spent IX resins gave the most efficient catalyst combination for catalytic and oxidative pyrolysis of the residues. During low temperature catalytic pyrolysis, 137 Cesium volatility was estimated to be around 0.01% from cationic resins and around 0.1% from anionic resins. During oxidative pyrolysis at 700 degC, nearly 10 to 40% of 137 Cesium was found to be released to off gases depending upon type of resin and catalyst loaded on to it. The oxidation of pyrolytic residues at 700 degC gave weight reduction of 15% for cationic resins and 93% for anionic resins. Catalytic oxidative pyrolysis is attractive for reducing weight and volume of spent cationic resins from PHWRs and VVERs. (author)

  11. Ion irradiation-induced diffusion in bixbyite-fluorite related oxides: Dislocations and phase transformation

    Energy Technology Data Exchange (ETDEWEB)

    Rolly, Gaboriaud, E-mail: Rolly.gaboriaud@univ-poitiers.fr [Institut Pprime, CNRS-University of Poitiers, SP2MI-BP 30179, 86962 Chasseneuil-Futuroscope (France); Fabien, Paumier [Institut Pprime, CNRS-University of Poitiers, SP2MI-BP 30179, 86962 Chasseneuil-Futuroscope (France); Bertrand, Lacroix [CSIC – University of Sevilla, Avenida Américo Vespucio, 49, 41092 Sevilla (Spain)

    2014-05-01

    Ion-irradiation induced diffusion and the phase transformation of a bixbyite-fluorite related rare earth oxide thin films are studied. This work is focused on yttrium sesquioxide, Y{sub 2}O{sub 3}, thin films deposited on Si (1 0 0) substrates using the ion beam sputtering technique (IBS). As-deposited samples were annealed ant then irradiated at cryogenic temperature (80 K) with 260 keV Xe{sup 2+} at different fluences. The irradiated thin oxide films are characterized by X-ray diffraction. A cubic to monoclinic phase transformation was observed. Analysis of this phenomenon is done in terms of residual stresses. Stress measurements as a function of irradiation fluences were realised using the XRD-sin{sup 2}ψ method. Stress evolution and kinetic of the phase transformation are compared and leads to the role-played by the nucleation of point and extended defects.

  12. Swift heavy ion induced modification in morphological and physico-chemical properties of tin oxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Jaiswal, Manoj Kumar [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110 078 (India); Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Kumar, Rajesh, E-mail: rajeshkumaripu@gmail.com [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110 078 (India)

    2013-11-15

    Nanocomposite thin films of tin oxide (SnO{sub 2})/titanium oxide (TiO{sub 2}) were grown on silicon (1 0 0) substrates by electron beam evaporation deposition technique using sintered nanocomposite pellet of SnO{sub 2}/TiO{sub 2} in the percentage ratio of 95:5. Sintering of the nanocomposite pellet was done at 1300 °C for 24 h. The thicknesses of these films were measured to be 100 nm during deposition using piezo-sensor attached to the deposition chamber. TiO{sub 2} doped SnO{sub 2} nanocomposite films were irradiated by 100 MeV Au{sup 8+} ion beam at fluence range varying from 1 × 10{sup 11} ions/cm{sup 2} to 5 × 10{sup 13} ions/cm{sup 2} at Inter University Accelerator Center (IUAC), New Delhi, India. Chemical properties of pristine and ion irradiation modified thin films were characterized by Fourier Transform Infrared (FTIR) spectroscopy. FTIR peak at 610 cm{sup −1} confirms the presence of O–Sn–O bridge of tin (IV) oxide signifying the composite nature of pristine and irradiated thin films. Atomic Force Microscope (AFM) in tapping mode was used to study the surface morphology and grain growth due to swift heavy ion irradiation at different fluencies. Grain size calculations obtained from sectional analysis of AFM images were compared with results obtained from Glancing Angle X-ray Diffraction (GAXRD) measurements using Scherrer’s formulae. Phase transformation due to irradiation was observed from Glancing Angle X-ray Diffraction (GAXRD) results. The prominent 2θ peaks observed in GAXRD spectrum are at 30.67°, 32.08°, 43.91°, 44.91° and 52.35° in the irradiated films.

  13. Polydopamine-mediated surface-functionalization of graphene oxide for heavy metal ions removal

    International Nuclear Information System (INIS)

    Dong, Zhihui; Zhang, Feng; Wang, Dong; Liu, Xia; Jin, Jian

    2015-01-01

    By utilizing polydopamine (PD) nano-thick interlayer as mediator, polyethylenimine (PEI) brushes with abundant amine groups were grafted onto the surface of PD coated graphene oxide (GO) uniformly via a Michael-Addition reaction and produced a PEI–PD/GO composite nanosheets. The PEI–PD/GO composite exhibited an improved performance for adsorption of heavy metal ions as compared to PEI-coated GO and pure GO. The adsorption capacities for Cu 2+ , Cd 2+ , Pb 2+ , Hg 2+ are up to 87, 106, 197, and 110 mg/g, respectively. To further make the GO based composite operable, PEI–PD/RGO aerogel was prepared through hydrothermal and achieved a high surface area up to 373 m 2 /g. Although the adsorption capacity of PEI–PD/RGO aerogel for heavy metal ions decreases a little as compared to PEI–PD/GO composite dispersion (38, 32, 95, 113 mg/g corresponding to Cu 2+ , Cd 2+ , Pb 2+ , and Hg 2+ , respectively), it could be recycled several times in a simple way by releasing adsorbed metal ions, indicating its potential application for cleaning wastewater. - Graphical abstract: Polyethylenimine (PEI) brushes were grafted onto the surface of graphene oxide (GO) uniformly via a Michael-Addition reaction between the PEI and polydopamine interlayer coated on GO surface. The PEI–PD/GO composite exhibited an improved performance for adsorption of heavy metal ions compared to PEI-coated GO and pure GO. - Highlights: • We prepared polyethylenimine grafted polydopamine-mediated graphene oxide composites. • Introduction of PD layer increases metal ions adsorption capacity. • PEI–PD/RGO aerogel exhibited a superior adsorption performance. • PEI–PD/RGO aerogel can be recycled several times in a simple way

  14. Silicon oxide based high capacity anode materials for lithium ion batteries

    Science.gov (United States)

    Deng, Haixia; Han, Yongbong; Masarapu, Charan; Anguchamy, Yogesh Kumar; Lopez, Herman A.; Kumar, Sujeet

    2017-03-21

    Silicon oxide based materials, including composites with various electrical conductive compositions, are formulated into desirable anodes. The anodes can be effectively combined into lithium ion batteries with high capacity cathode materials. In some formulations, supplemental lithium can be used to stabilize cycling as well as to reduce effects of first cycle irreversible capacity loss. Batteries are described with surprisingly good cycling properties with good specific capacities with respect to both cathode active weights and anode active weights.

  15. The synthesis of Ag/polypyrrole coaxial nanocables via ion adsorption method using different oxidants

    Science.gov (United States)

    Qiu, Teng; Xie, Huxiao; Zhang, Jiangru; Zahoor, Amad; Li, Xiaoyu

    2011-03-01

    Ag/polypyrrole (PPy) coaxial nanocables (NCs) were synthesized by an ion adsorption method. In this method, the pre-made Ag nanowires (NWs) were dispersed in the aqueous solution of copper acetate (Cu(Ac)2), and the Cu2+ ions adsorbed onto the surface of Ag NWs can oxidize pyrrole monomers to polymerize into uniform PPy sheath outside Ag NWs after the Cu(Ac)2-treated Ag NWs were re-dispersed in the aqueous solution of pyrrole. The morphology of NCs was characterized by transmission electron microscope (TEM) and scanning electron microscope (SEM). The relationship between the thickness of polymer sheath and the concentration of Cu(Ac)2 was established. As Cu(Ac)2 which served as the oxidant can also be replaced by AgNO3 in this synthesis, the differences on the structure of polymer sheath caused by different oxidants were studied by surface-enhanced Raman scattering (SERS), high-resolution transmission electron microscope (HR-TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). Comparing with the characterization results of Ag/PPy NCs synthesized using AgNO3 as the oxidant which indicates the random arrangement of PPy chains at the interface between polymer sheath and Ag NWs, PPy chain oxidized by Cu2+ tends to show a relatively ordered conformation at the interface with the pyrrole rings identically taking the plane vertical to the surface of Ag NWs. In addition, although the main part of the polymer sheath was composed of PPy whatever kind of oxidant was used, the sheath of the NCs oxidized by Cu2+ is typical for the existence of Cu(I)-pyrrole coordinate structures with strong Cu(I)-N bond signal shown in XPS characterization.

  16. The synthesis of Ag/polypyrrole coaxial nanocables via ion adsorption method using different oxidants

    International Nuclear Information System (INIS)

    Qiu Teng; Xie Huxiao; Zhang Jiangru; Zahoor, Amad; Li Xiaoyu

    2011-01-01

    Ag/polypyrrole (PPy) coaxial nanocables (NCs) were synthesized by an ion adsorption method. In this method, the pre-made Ag nanowires (NWs) were dispersed in the aqueous solution of copper acetate (Cu(Ac) 2 ), and the Cu 2+ ions adsorbed onto the surface of Ag NWs can oxidize pyrrole monomers to polymerize into uniform PPy sheath outside Ag NWs after the Cu(Ac) 2 -treated Ag NWs were re-dispersed in the aqueous solution of pyrrole. The morphology of NCs was characterized by transmission electron microscope (TEM) and scanning electron microscope (SEM). The relationship between the thickness of polymer sheath and the concentration of Cu(Ac) 2 was established. As Cu(Ac) 2 which served as the oxidant can also be replaced by AgNO 3 in this synthesis, the differences on the structure of polymer sheath caused by different oxidants were studied by surface-enhanced Raman scattering (SERS), high-resolution transmission electron microscope (HR-TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). Comparing with the characterization results of Ag/PPy NCs synthesized using AgNO 3 as the oxidant which indicates the random arrangement of PPy chains at the interface between polymer sheath and Ag NWs, PPy chain oxidized by Cu 2+ tends to show a relatively ordered conformation at the interface with the pyrrole rings identically taking the plane vertical to the surface of Ag NWs. In addition, although the main part of the polymer sheath was composed of PPy whatever kind of oxidant was used, the sheath of the NCs oxidized by Cu 2+ is typical for the existence of Cu(I)–pyrrole coordinate structures with strong Cu(I)–N bond signal shown in XPS characterization.

  17. Reduction Rates for Higher Americium Oxidation States in Nitric Acid

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Travis Shane [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mincher, Bruce Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schmitt, Nicholas C [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-30

    The stability of hexavalent americium was measured using multiple americium concentrations and nitric acid concentrations after contact with the strong oxidant sodium bismuthate. Contrary to our hypotheses Am(VI) was not reduced faster at higher americium concentrations, and the reduction was only zero-order at short time scales. Attempts to model the reduction kinetics using zero order kinetic models showed Am(VI) reduction in nitric acid is more complex than the autoreduction processes reported by others in perchloric acid. The classical zero-order reduction of Am(VI) was found here only for short times on the order of a few hours. We did show that the rate of Am(V) production was less than the rate of Am(VI) reduction, indicating that some Am(VI) undergoes two electron-reduction to Am(IV). We also monitored the Am(VI) reduction in contact with the organic diluent dodecane. A direct comparison of these results with those in the absence of the organic diluent showed the reduction rates for Am(VI) were not statistically different for both systems. Additional americium oxidations conducted in the presence of Ce(IV)/Ce(III) ions showed that Am(VI) is reduced without the typical growth of Am(V) observed in the systems sans Ce ion. This was an interesting result which suggests a potential new reduction/oxidation pathway for Am in the presence of Ce; however, these results were very preliminary, and will require additional experiments to understand the mechanism by which this occurs. Overall, these studies have shown that hexavalent americium is fundamentally stable enough in nitric acid to run a separations process. However, the complicated nature of the reduction pathways based on the system components is far from being rigorously understood.

  18. Effect of charge state and stoichiometry on the structure and reactivity of nickel oxide clusters with CO

    Science.gov (United States)

    Johnson, Grant E.; Reilly, Nelly M.; Castleman, A. W., Jr.

    2009-02-01

    The collision induced fragmentation and reactivity of cationic and anionic nickel oxide clusters with carbon monoxide were studied experimentally using guided-ion-beam mass spectrometry. Anionic clusters with a stoichiometry containing one more oxygen atom than nickel atom (NiO2-, Ni2O3-, Ni3O4- and Ni4O5-) were found to exhibit dominant products resulting from the transfer of a single oxygen atom to CO, suggesting the formation of CO2. Of these four species, Ni2O3- and Ni4O5- were observed to be the most reactive having oxygen transfer products accounting for approximately 5% and 10% of the total ion intensity at a maximum pressure of 15 mTorr of CO. Our findings, therefore, indicate that anionic nickel oxide clusters containing an even number of nickel atoms and an odd number of oxygen atoms are more reactive than those with an odd number of nickel atoms and an even number of oxygen atoms. The majority of cationic nickel oxides, in contrast to anionic species, reacted preferentially through the adsorption of CO onto the cluster accompanied by the loss of either molecular O2 or nickel oxide units. The adsorption of CO onto positively charged nickel oxides, therefore, is exothermic enough to break apart the gas-phase clusters. Collision induced dissociation experiments, employing inert xenon gas, were also conducted to gain insight into the structural properties of nickel oxide clusters. The fragmentation products were found to vary considerably with size and stoichiometry as well as ionic charge state. In general, cationic clusters favored the collisional loss of molecular O2 while anionic clusters fragmented through the loss of both atomic oxygen and nickel oxide units. Our results provide insight into the effect of ionic charge state on the structure of nickel oxide clusters. Furthermore, we establish how the size and stoichiometry of nickel oxide clusters influences their ability to oxidize CO, an important reaction for environmental pollution abatement.

  19. A study of the local structure around Eu3+ ions in oxide glasses using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Todoroki, S.; Hirao, K.; Soga, N.

    1993-01-01

    The local structure around Eu 3+ ions in several oxide glasses (silicate, germanate and borophosphate glasses) was investigated by using 151 Eu Moessbauer spectroscopy. It was found that the isomer shift (IS) of silicate and borophosphate glasses was independent of the sodium content, but that of germanate glasses was not. This means the first coordination sphere around Eu 3+ ions in silicate glasses is insensitive to the composition of the glass matrix. It is assumed that, regardless of the sodium content, Eu 3+ ions in silicate glasses attract a certain amount of nonbridging oxygen (NBO, Si-O direct difference ) when incorporated stably into silicate glass matrix, because NBO is the only species donating negative charge. For germanate glasses, the behavior of IS is considered to be related to the resence of GeO 6/2 octahedra. On the basis of experimental results, the coordination models of Eu 3+ in these systems are proposed. (orig.)

  20. Formation of tungsten oxide nanowires by ion irradiation and vacuum annealing

    Science.gov (United States)

    Zheng, Xu-Dong; Ren, Feng; Wu, Heng-Yi; Qin, Wen-Jing; Jiang, Chang-Zhong

    2018-04-01

    Here we reported the fabrication of tungsten oxide (WO3-x ) nanowires by Ar+ ion irradiation of WO3 thin films followed by annealing in vacuum. The nanowire length increases with increasing irradiation fluence and with decreasing ion energy. We propose that the stress-driven diffusion of the irradiation-induced W interstitial atoms is responsible for the formation of the nanowires. Comparing to the pristine film, the fabricated nanowire film shows a 106-fold enhancement in electrical conductivity, resulting from the high-density irradiation-induced vacancies on the oxygen sublattice. The nanostructure exhibits largely enhanced surface-enhanced Raman scattering effect due to the oxygen vacancy. Thus, ion irradiation provides a powerful approach for fabricating and tailoring the surface nanostructures of semiconductors.

  1. On the Utility of Spinel Oxide Hosts for Magnesium-Ion Batteries.

    Science.gov (United States)

    Knight, James C; Therese, Soosairaj; Manthiram, Arumugam

    2015-10-21

    There is immense interest to develop Mg-ion batteries, but finding suitable cathode materials has been a challenge. The spinel structure has many advantages for ion insertion and has been successfully used in Li-ion batteries. We present here findings on the attempts to extract Mg from MgMn2O4-based spinels with acid (H2SO4) and with NO2BF4. The acid treatment was able to fully remove all Mg from MgMn2O4 by following a mechanism involving the disproportionation of Mn(3+), and the extraction rate decreased with increasing cation disorder. Samples with additional Mg(2+) ions in the octahedral sites (e.g., Mg1.1Mn1.9O4 and Mg1.5Mn1.5O4) also exhibit complete or near complete demagnesiation due to an additional mechanism involving ion exchange of Mg(2+) by H(+), but no Mg could be extracted from MgMnAlO4 due to the disruption of Mn-Mn interaction/contact across shared octahedral edges. In contrast, no Mg could be extracted with the oxidizing agent NO2BF4 from MgMn2O4 or Mg1.5Mn1.5O4 as the electrostatic repulsion between the divalent Mg(2+) ions prevents Mg(2+) diffusion through the 16c octahedral sites, unlike Li(+) diffusion, suggesting that spinels may not serve as potential hosts for Mg-ion batteries. The ability to extract Mg with acid in contrast to that with NO2BF4 is attributed to Mn dissolution from the lattice and the consequent reduction in electrostatic repulsion. The findings could provide insights toward the design of Mg hosts for Mg-ion batteries.

  2. Iron oxide nanoparticle-micelles (ION-micelles for sensitive (molecular magnetic particle imaging and magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Lucas W E Starmans

    Full Text Available BACKGROUND: Iron oxide nanoparticles (IONs are a promising nanoplatform for contrast-enhanced MRI. Recently, magnetic particle imaging (MPI was introduced as a new imaging modality, which is able to directly visualize magnetic particles and could serve as a more sensitive and quantitative alternative to MRI. However, MPI requires magnetic particles with specific magnetic properties for optimal use. Current commercially available iron oxide formulations perform suboptimal in MPI, which is triggering research into optimized synthesis strategies. Most synthesis procedures aim at size control of iron oxide nanoparticles rather than control over the magnetic properties. In this study, we report on the synthesis, characterization and application of a novel ION platform for sensitive MPI and MRI. METHODS AND RESULTS: IONs were synthesized using a thermal-decomposition method and subsequently phase-transferred by encapsulation into lipidic micelles (ION-Micelles. Next, the material and magnetic properties of the ION-Micelles were analyzed. Most notably, vibrating sample magnetometry measurements showed that the effective magnetic core size of the IONs is 16 nm. In addition, magnetic particle spectrometry (MPS measurements were performed. MPS is essentially zero-dimensional MPI and therefore allows to probe the potential of iron oxide formulations for MPI. ION-Micelles induced up to 200 times higher signal in MPS measurements than commercially available iron oxide formulations (Endorem, Resovist and Sinerem and thus likely allow for significantly more sensitive MPI. In addition, the potential of the ION-Micelle platform for molecular MPI and MRI was showcased by MPS and MRI measurements of fibrin-binding peptide functionalized ION-Micelles (FibPep-ION-Micelles bound to blood clots. CONCLUSIONS: The presented data underlines the potential of the ION-Micelle nanoplatform for sensitive (molecular MPI and warrants further investigation of the FibPep-ION

  3. Removal of cobalt ions from aqueous solution by an amination graphene oxide nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Fang [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000 (China); Kong, Lingtao, E-mail: ltkong@iim.ac.cn [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Huang, Jiarui [College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000 (China); Wu, Shibiao [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); School of Chemistry and Chemical Engineering, Anhui University, Hefei, Anhui 230039 (China); Zhang, Kaisheng [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Wang, Xuelong [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); School of Chemistry and Chemical Engineering, Anhui University, Hefei, Anhui 230039 (China); Sun, Bai; Jin, Zhen; Wang, Jin [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Huang, Xing-Jiu, E-mail: xjhuang@iim.ac.cn [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Liu, Jinhuai, E-mail: jhliu@iim.ac.cn [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

    2014-04-01

    Highlights: • A newly designed GO-NH{sub 2}: Higher adsorption capability than that of activated carbon. • Very quick adsorption property: More than 90% of Co(II) can be removed within 5 min. • One of the highest adsorption capabilities of today's nanomaterials for Co(II) (116.35 mg/g). • GO-NH{sub 2} membrane can remove more than 98% Co(II) from the water. - Abstract: A newly designed amination graphene oxide (GO-NH{sub 2}), a superior adsorption capability to that of activated carbon, was fabricated by graphene oxide (GO) combining with aromatic diazonium salt. The resultant GO-NH{sub 2} maintained a high surface area of 320 m{sup 2}/g. When used as an adsorbent, the GO-NH{sub 2} demonstrated a very quick adsorption property for the removal of Co(II) ions, more than 90% of Co(II) ions could be removed within 5 min for dilute solutions at 0.3 g/L adsorbent dose. The adsorption capability approaches 116.35 mg/g, which is one of the highest capabilities of today's materials. The thermodynamic parameters calculated from temperature-dependent adsorption isotherms suggested that the Co(II) ions adsorption on GO-NH{sub 2} was a spontaneous process. Considering the superior adsorption capability, the GO-NH{sub 2} filter membrane was fabricated for the removal of Co(II) ions. Membrane filtration experiments revealed that the removal capabilities of the materials for cobalt ions depended on the membrane's thickness, flow rate and initial concentration of Co(II) ions. The highest percentage removal of Co(II) exceeds 98%, indicating that the GO-NH{sub 2} is one of the very suitable membrane materials in environmental pollution management.

  4. Metal ion release from metallothioneins: proteolysis as an alternative to oxidation.

    Science.gov (United States)

    Peroza, Estevão A; dos Santos Cabral, Augusto; Wan, Xiaoqiong; Freisinger, Eva

    2013-09-01

    Metallothioneins (MTs) are among others involved in the cellular regulation of essential Zn(II) and Cu(I) ions. However, the high binding affinity of these proteins requires additional factors to promote metal ion release under physiological conditions. The mechanisms and efficiencies of these processes leave many open questions. We report here a comprehensive analysis of the Zn(II)-release properties of various MTs with special focus on members of the four main subfamilies of plant MTs. Zn(II) competition experiments with the metal ion chelator 4-(2-pyridylazo)resorcinol (PAR) in the presence of the cellular redox pair glutathione (GSH)/glutathione disulfide (GSSG) show that plant MTs from the subfamilies MT1, MT2, and MT3 are remarkably more affected by oxidative stress than those from the Ec subfamily and the well-characterized human MT2 form. In addition, we evaluated proteolytic digestion with trypsin and proteinase K as an alternative mechanism for selective promotion of metal ion release from MTs. Also here the observed percentage of liberated metal ions depends strongly on the MT form evaluated. Closer evaluation of the data additionally allowed deducing the thermodynamic and kinetic properties of the Zn(II) release processes. The Cu(I)-form of chickpea MT2 was used to exemplify that both oxidation and proteolysis are also effective ways to increase the transfer of copper ions to other molecules. Zn(II) release experiments with the individual metal-binding domains of Ec-1 from wheat grain reveal distinct differences from the full-length protein. This triggers the question about the roles of the long cysteine-free peptide stretches typical for plant MTs.

  5. To the problem on a charge state of energetic ions of radiation belts

    International Nuclear Information System (INIS)

    Panasyuk, M.I.

    1980-01-01

    Estimation of the effect of recharging processes upon formation of intensity maxima of radiation belt ions of different types is obtained as well as the ion charge states in the area of intensity maxima. Comparison of spatial position of intensity maxima of the H, He, C, O ions with the energies more than 1 MeV with the calculation results is presented. It provides the particle radial drift under the effect of sudden impulses and death at the expence of ionization losses. Application of adiabaticity criterion of the particle movement to the analysis of position of outer edge of radiation belt of heavy ions permitted to carry out estimation of the He, C, O ion charge state. He ions with the energy more than 1 MeV possess mainly the charge state of +2, C and O ions with the energy of several MeV over L=5-6 are in the ionized state almost completely, and during the drift into the depth of the belts the ion charge decreases to 3-4 over L approximately 3.5 with the energy increase. At the energies higher than several MeV the recharge processes are significant for the C and.O ions. For He ions with the energy higher 1 MeV and for H ions with more than 0.1 MeV the recharge role is not considerable

  6. Comparison of the air oxidation behaviors of Zircaloy-4 implanted with yttrium and cerium ions at 500 deg. C

    International Nuclear Information System (INIS)

    Chen, X.W.; Bai, X.D.; Xu, J.; Zhou, Q.G.; Chen, B.S.

    2002-01-01

    As a valuable process for surface modification of materials, ion implantation is eminent to improve mechanical properties, electrochemical corrosion resistance and oxidation behaviors of varieties of materials. To investigate and compare the oxidation behaviors of Zircaloy-4, implantation of yttrium ion and cerium ion were respectively employed by using an MEVVA source at the energy of 40 keV with a dose ranging from 1x10 16 to 1x10 17 ions/cm 2 . Subsequently, weight gain curves of the different specimens including as-received Zircaloy-4 and Zircaloy-4 specimens implanted with the different ions were measured after oxidation in air at 500 deg. C for 100 min. It was obviously found that a significant improvement was achieved in the oxidation behaviors of implanted Zircaloy-4 compared with that of the as-received Zircaloy-4, and the oxidation behavior of cerium-implanted Zircaloy-4 was somewhat better than that of yttrium-implanted specimen. To obtain the valence and the composition of the oxides in the scale, X-ray photoemission spectroscopy was used in the present study. Glancing angle X-ray diffraction, employed to analyze the phase transformation in the oxide films, showed that the addition of yttrium transformed the phase from monoclinic zirconia to tetragonal zirconia, yet the addition of cerium transformed the phase from monoclinic zirconia to hexagonal zirconia. In the end, the mechanism of the improvement of the oxidation behavior was discussed

  7. Fundamental degradation mechanisms of layered oxide Li-ion battery cathode materials: Methodology, insights and novel approaches

    International Nuclear Information System (INIS)

    Hausbrand, R.; Cherkashinin, G.; Ehrenberg, H.; Gröting, M.; Albe, K.; Hess, C.; Jaegermann, W.

    2015-01-01

    Graphical abstract: - Highlights: • Description of recent in operando and in situ analysis methodology. • Surface science approach using photoemission for analysis of cathode surfaces and interfaces. • Ageing and fatigue of layered oxide Li-ion battery cathode materials from the atomistic point of view. • Defect formation and electronic structure evolution as causes for cathode degradation. • Significance of interfacial energy alignment and contact potential for side reactions. - Abstract: This overview addresses the atomistic aspects of degradation of layered LiMO 2 (M = Ni, Co, Mn) oxide Li-ion battery cathode materials, aiming to shed light on the fundamental degradation mechanisms especially inside active cathode materials and at their interfaces. It includes recent results obtained by novel in situ/in operando diffraction methods, modelling, and quasi in situ surface science analysis. Degradation of the active cathode material occurs upon overcharge, resulting from a positive potential shift of the anode. Oxygen loss and eventual phase transformation resulting in dead regions are ascribed to changes in electronic structure and defect formation. The anode potential shift results from loss of free lithium due to side reactions occurring at electrode/electrolyte interfaces. Such side reactions are caused by electron transfer, and depend on the electron energy level alignment at the interface. Side reactions at electrode/electrolyte interfaces and capacity fade may be overcome by the use of suitable solid-state electrolytes and Li-containing anodes

  8. Initial state fluctuations and final state correlations in relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    Luzum, Matthew; Petersen, Hannah

    2014-01-01

    We review the phenomenology and theory of bulk observables in ultra-relativistic heavy-ion collisions, focusing on recent developments involving event-by-event fluctuations in the initial stages of a heavy-ion collision, and how they manifest in observed correlations. We first define the relevant observables and show how each measurement is related to underlying theoretical quantities. Then we review the prevailing picture of the various stages of a collision, including the state-of-the-art modeling of the initial stages of a collision and subsequent hydrodynamic evolution, as well as hadronic scattering and freeze-out in the later stages. We then discuss the recent results that have shaped our current understanding and identify the challenges that remain. Finally, we point out open issues and the potential for progress in the field. (topical review)

  9. Oxidative Stress and Heart Failure in Altered Thyroid States

    Directory of Open Access Journals (Sweden)

    Pallavi Mishra

    2012-01-01

    Full Text Available Increased or reduced action of thyroid hormone on certain molecular pathways in the heart and vasculature causes relevant cardiovascular derangements. It is well established that hyperthyroidism induces a hyperdynamic cardiovascular state, which is associated with a faster heart rate, enhanced left ventricular systolic and diastolic function whereas hypothyroidism is characterized by the opposite changes. Hyperthyroidism and hypothyroidism represent opposite clinical conditions, albeit not mirror images. Recent experimental and clinical studies have suggested the involvement of ROS tissue damage under altered thyroid status. Altered-thyroid state-linked changes in heart modify their susceptibility to oxidants and the extent of the oxidative damage they suffer following oxidative challenge. Chronic increase in the cellular levels of ROS can lead to a catastrophic cycle of DNA damage, mitochondrial dysfunction, further ROS generation and cellular injury. Thus, these cellular events might play an important role in the development and progression of myocardial remodeling and heart failure in altered thyroid states (hypo- and hyper-thyroidism. The present review aims at elucidating the various signaling pathways mediated via ROS and their modulation under altered thyroid state and the possibility of antioxidant therapy.

  10. Charge-state distribution of MeV He ions scattered from the surface atoms

    International Nuclear Information System (INIS)

    Kimura, Kenji; Ohtsuka, Hisashi; Mannami, Michihiko

    1993-01-01

    The charge-state distribution of 500-keV He ions scattered from a SnTe (001) surface has been investigated using a new technique of high-resolution high-energy ion scattering spectroscopy. The observed charge-state distribution of ions scattered from the topmost atomic layer coincides with that of ions scattered from the subsurface region and does not depend on the incident charge state but depends on the exit angle. The observed exit-angle dependence is explained by a model which includes the charge-exchange process with the valence electrons in the tail of the electron distribution at the surface. (author)

  11. Non-destructive state detection for quantum logic spectroscopy of molecular ions.

    Science.gov (United States)

    Wolf, Fabian; Wan, Yong; Heip, Jan C; Gebert, Florian; Shi, Chunyan; Schmidt, Piet O

    2016-02-25

    Precision laser spectroscopy of cold and trapped molecular ions is a powerful tool in fundamental physics--used, for example, in determining fundamental constants, testing for their possible variation in the laboratory, and searching for a possible electric dipole moment of the electron. However, the absence of cycling transitions in molecules poses a challenge for direct laser cooling of the ions, and for controlling and detecting their quantum states. Previously used state-detection techniques based on photodissociation or chemical reactions are destructive and therefore inefficient, restricting the achievable resolution in laser spectroscopy. Here, we experimentally demonstrate non-destructive detection of the quantum state of a single trapped molecular ion through its strong Coulomb coupling to a well controlled, co-trapped atomic ion. An algorithm based on a state-dependent optical dipole force changes the internal state of the atom according to the internal state of the molecule. We show that individual quantum states in the molecular ion can be distinguished by the strength of their coupling to the optical dipole force. We also observe quantum jumps (induced by black-body radiation) between rotational states of a single molecular ion. Using the detuning dependence of the state-detection signal, we implement a variant of quantum logic spectroscopy of a molecular resonance. Our state-detection technique is relevant to a wide range of molecular ions, and could be applied to state-controlled quantum chemistry and to spectroscopic investigations of molecules that serve as probes for interstellar clouds.

  12. Heavy-ion collisions and the nuclear equation of state

    International Nuclear Information System (INIS)

    Keane, D.

    1993-01-01

    The overall goal of this project is to study nucleus-nucleus collisions experimentally at intermediate and relativistic energies, with emphasis on measurement and interpretation of correlation effects that provide insight into the nuclear phase diagram and the nuclear equation of state. During the course of this reporting period, the PI returned to Kent from a 15-month leave at Lawrence Berkeley Lab, which had been devoted 100% to work on this research project. The EOS Time Projection Chamber at LBL's Bevalac accelerator has continued to be the major focus of research for all of the supported personnel; about a year ago, this detector successfully took data in production mode for the first time, and accumulated in excess of 1000 hours of beam time before the termination of the Bevalac in February 1993. Reduction and analysis of these data is currently our first priority. Effort has also been devoted to the STAR detector at the Relativistic Heavy Ion Collider, in the form of contributions to the Conceptual Design Report, work on HV control hardware and software for use with the STAR Time Projection Chamber, and tracking software development

  13. Oxide-ion and proton conducting electrolyte materials for clean energy applications: structural and mechanistic features.

    Science.gov (United States)

    Malavasi, Lorenzo; Fisher, Craig A J; Islam, M Saiful

    2010-11-01

    This critical review presents an overview of the various classes of oxide materials exhibiting fast oxide-ion or proton conductivity for use as solid electrolytes in clean energy applications such as solid oxide fuel cells. Emphasis is placed on the relationship between structural and mechanistic features of the crystalline materials and their ion conduction properties. After describing well-established classes such as fluorite- and perovskite-based oxides, new materials and structure-types are presented. These include a variety of molybdate, gallate, apatite silicate/germanate and niobate systems, many of which contain flexible structural networks, and exhibit different defect properties and transport mechanisms to the conventional materials. It is concluded that the rich chemistry of these important systems provides diverse possibilities for developing superior ionic conductors for use as solid electrolytes in fuel cells and related applications. In most cases, a greater atomic-level understanding of the structures, defects and conduction mechanisms is achieved through a combination of experimental and computational techniques (217 references).

  14. Characteristics of growth of complex ferroelectric oxide films by plasma-ion sputtering

    Science.gov (United States)

    Mukhortov, V. M.; Golovko, Yu. I.; Mukhortov, Vl. M.; Dudkevich, V. P.

    1981-02-01

    An experimental investigation was made of the process of growth of a complex oxide film, such as BaTiO3 or (Ba, Sr)TiO3, by plasma-ion sputtering. It was found that ion bombardment of a ceramic target knocked out neutral excited atoms. These atoms lost energy away from the target by collisions and at a certain critical distance hcr they were capable of oxidation to produce BaO, TiO, TiO2, and SrO. Therefore, depending on the distance between the cathode and the substrate, the “construction” material arrived in the form of atoms or molecules of simple oxides. These two (atomic and molecular) deposition mechanisms corresponded to two mechanisms of synthesis and crystallization differing in respect of the dependences of the growth rate, unit cell parameters, and other structural properties on the deposition temperature. The role of re-evaporation and of oxidation-reduction processes was analyzed.

  15. Heavy-ion collisions and the nuclear equation of state

    International Nuclear Information System (INIS)

    Keane, D.

    1992-01-01

    The overall goal of this project is to study nucleus-nucleus collisions experimentally at intermediate and relativistic energies, with emphasis on measurement and interpretation of correlation effects that provide insight into the nuclear phase diagram and the nuclear equation of state. During the past year, the PI has been on leave at Lawrence Berkeley Lab and has worked on this research project full-time. A large fraction of the effort of the PI and graduate students has gone into preparing for experiments using the Time Projection Chamber at LBL's Bevalac accelerator; in March 1992, this device successfully took data in production mode for the first time, and the first physics analysis is now under way. The PI has carried out simulations that help to define the physics performance and engineering specifications of the recently-approved STAR detector for the Relativistic Heavy Ion Collider, and has identified a new capability of this device with the potential for being an important quark-gluon plasma signature. A Postdoctoral Fellow, jointly supported by this grant and Kent State University, has been recruited to augment these efforts. Since May 1991, 11 journal papers have been published or submitted for publication; 2 conference proceedings and 9 reports or abstracts have also been published during the past year. One paper in Phys. Rev. Left., one in Phys. Rev. C, and one conference proceedings are based on the thesis project of one of the PI's Ph.D. students who is expected to graduate later this year. Partly in response to the impending closure of the Bevalac, the PI's group has recently joined the NA49 experiment at CERN

  16. Evolution of the Oxidation State of the Earth's Mantle

    Science.gov (United States)

    Danielson, L. R.; Righter, K.; Keller, L.; Christoffersen, E.; Rahman, Z.

    2015-01-01

    The oxidation state of the Earth's mantle during formation remains an unresolved question, whether it was constant throughout planetary accretion, transitioned from reduced to oxidized, or from oxidized to reduced. We investigate the stability of Fe3(+) at depth, in order to constrain processes (water, late accretion, dissociation of FeO) which may reduce or oxidize the Earth's mantle. In our previous experiments on shergottite compositions, variable fO2, T, and P less than 4 GPa, Fe3(+)/sigma Fe decreased slightly with increasing P, similar to terrestrial basalt. For oxidizing experiments less than 7GPa, Fe3(+)/sigma Fe decreased as well, but it's unclear from previous modelling whether the deeper mantle could retain significant Fe3(+). Our current experiments expand our pressure range deeper into the Earth's mantle and focus on compositions and conditions relevant to the early Earth. Preliminary multi-anvil experiments with Knippa basalt as the starting composition were conducted at 5-7 GPa and 1800 C, using a molybdenum capsule to set the fO2 near IW, by buffering with Mo-MoO3. TEM and EELS analyses revealed the run products quenched to polycrystalline phases, with the major phase pyroxene containing approximately equal to Fe3(+)/2(+). Experiments are underway to produce glassy samples that can be measured by EELS and XANES, and are conducted at higher pressures.

  17. Metal oxide nanosensors using polymeric membranes, enzymes and antibody receptors as ion and molecular recognition elements.

    Science.gov (United States)

    Willander, Magnus; Khun, Kimleang; Ibupoto, Zafar Hussain

    2014-05-16

    The concept of recognition and biofunctionality has attracted increasing interest in the fields of chemistry and material sciences. Advances in the field of nanotechnology for the synthesis of desired metal oxide nanostructures have provided a solid platform for the integration of nanoelectronic devices. These nanoelectronics-based devices have the ability to recognize molecular species of living organisms, and they have created the possibility for advanced chemical sensing functionalities with low limits of detection in the nanomolar range. In this review, various metal oxides, such as ZnO-, CuO-, and NiO-based nanosensors, are described using different methods (receptors) of functionalization for molecular and ion recognition. These functionalized metal oxide surfaces with a specific receptor involve either a complex formation between the receptor and the analyte or an electrostatic interaction during the chemical sensing of analytes. Metal oxide nanostructures are considered revolutionary nanomaterials that have a specific surface for the immobilization of biomolecules with much needed orientation, good conformation and enhanced biological activity which further improve the sensing properties of nanosensors. Metal oxide nanostructures are associated with certain unique optical, electrical and molecular characteristics in addition to unique functionalities and surface charge features which shows attractive platforms for interfacing biorecognition elements with effective transducing properties for signal amplification. There is a great opportunity in the near future for metal oxide nanostructure-based miniaturization and the development of engineering sensor devices.

  18. Metal Oxide Nanosensors Using Polymeric Membranes, Enzymes and Antibody Receptors as Ion and Molecular Recognition Elements

    Directory of Open Access Journals (Sweden)

    Magnus Willander

    2014-05-01

    Full Text Available The concept of recognition and biofunctionality has attracted increasing interest in the fields of chemistry and material sciences. Advances in the field of nanotechnology for the synthesis of desired metal oxide nanostructures have provided a solid platform for the integration of nanoelectronic devices. These nanoelectronics-based devices have the ability to recognize molecular species of living organisms, and they have created the possibility for advanced chemical sensing functionalities with low limits of detection in the nanomolar range. In this review, various metal oxides, such as ZnO-, CuO-, and NiO-based nanosensors, are described using different methods (receptors of functionalization for molecular and ion recognition. These functionalized metal oxide surfaces with a specific receptor involve either a complex formation between the receptor and the analyte or an electrostatic interaction during the chemical sensing of analytes. Metal oxide nanostructures are considered revolutionary nanomaterials that have a specific surface for the immobilization of biomolecules with much needed orientation, good conformation and enhanced biological activity which further improve the sensing properties of nanosensors. Metal oxide nanostructures are associated with certain unique optical, electrical and molecular characteristics in addition to unique functionalities and surface charge features which shows attractive platforms for interfacing biorecognition elements with effective transducing properties for signal amplification. There is a great opportunity in the near future for metal oxide nanostructure-based miniaturization and the development of engineering sensor devices.

  19. Enhancement of Oxidative Desulfurization Performance over UiO-66(Zr) by Titanium Ion Exchange.

    Science.gov (United States)

    Ye, Gan; Qi, Hui; Li, Xiaolin; Leng, Kunyue; Sun, Yinyong; Xu, Wei

    2017-07-19

    Oxidative desulfurization is considered to be one of the most promising methods for producing ultra-low-sulfur fuels because it can effectively remove refractory sulfur-containing aromatic compounds under mild conditions. In this work, the oxidative desulfurization performance over UiO-66(Zr) is greatly enhanced by Ti ion exchange. This strategy is not only efficient for UiO-66(Zr) with crystal defects but also for UiO-66(Zr) with high crystallinity. In particular, the performance of UiO-66(Zr) with high crystallinity in the oxidative desulfurization of dibenzothiophene can be improved more than 11-fold, which can be mainly attributed to the introduction of active Ti sites. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Ion exchange resins destruction in a stirred supercritical water oxidation reactor

    International Nuclear Information System (INIS)

    Leybros, A.; Roubaud, A.; Guichardon, P.; Boutin, O.

    2010-01-01

    Spent ion exchange resins (IERs) are radioactive process wastes for which there is no satisfactory industrial treatment. Supercritical water oxidation offers a viable treatment alternative to destroy the organic structure of resins, used to remove radioactivity. Up to now, studies carried out in supercritical water for IER destruction showed that degradation rates higher than 99% are difficult to obtain even using a catalyst or a large oxidant excess. In this study, a co-fuel, isopropanol, has been used in order to improve degradation rates by initiating the oxidation reaction and increasing temperature of the reaction medium. Concentrations up to 20 wt% were tested for anionic and cationic resins. Total organic carbon reduction rates higher than 99% were obtained from this process, without the use of a catalyst. The influence of operating parameters such as IERs feed concentration, nature and counterions of exchanged IERs were also studied. (authors)

  1. Raman spectroscopic study of the oxidation state of Eu in molten LiCl-KCl

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung; Yun, Jong-Il [KAIST, Daejeon(Korea, Republic of)

    2016-10-15

    Spectroscopy can provide high reliability for the quantitative analysis of such system. The molar absorptivity of Eu(II) at 325 nm is reported as about 1645 M{sup -1}cm{sup -1}, which is too high to apply to higher concentration. A high-temperature Raman spectroscopy has been set and employed for analyzing the molecular structure and coordination complex and investigating the oxidation state of europium in molten LiCl-KCl. Europium can be present in divalent state while many other lanthanides exist in trivalent state. The thermodynamic properties of europium ions have been studied using electrochemical methods, spectroscopic methods, and EPR technique. Although there has been discrepancy of the reduced amount of europium in previous works, the majority of Eu(III) is thought to be reduced to Eu(II) in molten LiCl-KCl spontaneously at relatively low concentration (< 7.5 × 10{sup -4} M). Raman spectroscopy was employed to investigate the oxidation state of EuClx in LiCl-KCl at 500 .deg. C. The Raman scattering results suggest the majority of trivalent europium is reduced to divalent state with the composition change by vaporization. The Raman bands show highly asymmetric structure, quite different from regular octahedral structure.

  2. Chemical state analysis of oxidation products on steel surface by conversion electron Moessbauer spectrometry

    International Nuclear Information System (INIS)

    Ujihira, Yusuke; Nomura, Kiyoshi

    1978-01-01

    The polished NT-70H steel (Fe: 95.97%, C: 0.56%, diameter: 5 cm, thickness: 0.5 cm) was immersed in deionized water or in solutions containing (0.25 -- 0.5) M of chloride, sulfate and nitrate ions. The chemical states of oxidation products of iron on the surface were identified through the analysis of conversion electron Moessbauer spectra (CEMS). CEMS of the steel surface, which had been dipped in deionized water, revealed that γ-FeOOH was formed on the surface. The thickness of γ-FeOOH layer increased with the increase of the duration of dipping. Dissolved oxygen in the solution played an essential role in the oxidation of iron to γ-FeOOH. Oxidation product of iron dipped in the 0.5 M sodium chloride solution was identified as γ-FeOOH. Amorphous paramagnetic iron (III) compound tended to form in the presence of hydrogen peroxide or ammonium ions in the solutions. The increase of alkalinity of the solution up to pH 12 suppressed the oxidation rate and assisted the formation of green rust, which was confirmed by the appearance of the quadrupole splitting peaks of the green rust. In the 0.25 M sodium sulfate solution, oxidation of the steel surface proceeded slowly and the quadrupole splitting peaks of Fe(OH) 2 were seen in the CEMS. The peak intensity of Fe(OH) 2 gradually decreased and that of γ-FeOOH increased by the extension of immersion of steel in the solution. Magnetite (Fe 3 O 4 ) layer was developed beneath the γ-FeOOH layer, when steel was dipped in 0.5 M sodium nitrate solution. However, the peaks of Fe 3 O 4 were not seen on CEMS of steel surface immersed in 0.5 M ammonium nitrate solution. Thus, applying the feasibility of CEMS for the characterization of oxidated compounds of iron on the steel surface formed by the immersion in solutions, the oxidation mechanism of the steel surface was discussed based upon the results of chemical state analyses. (author)

  3. Corrosion-product transport, oxidation state and remedial measures

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brett, M.E.; Tapping, R.L.

    1998-10-01

    The issues associated with monitoring and controlling corrosion-product transport (CPT) in the balance-of-plant (BOP) and steam generators (SG) of CANDU stations are briefly reviewed. Efforts are focused on minimizing corrosion of carbon steel, which is used extensively in the CANDU primary and secondary systems. Emphasis is placed on the corrosion-product oxidation state as a monitor of water chemistry effectiveness and as a monitor of system corrosion effects. The discussion is based mostly on the results of observations from Ontario Hydro plants, and their comparisons with pressurized-water reactors. The effects of low oxygen and elevated hydrazine chemistry are reviewed, as well as the effects of layup and various startup conditions. Progress in monitoring electrochemical potential (ECP) at Ontario Hydro plants and its relationship to the oxidation state of corrosion products is reviewed. Observations on CPT on the primary side of SGs are also discussed. (author)

  4. Corrosion-product transport, oxidation state and remedial measures

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brett, M.E.; Tapping, R.L.

    1998-01-01

    The issues associated with monitoring and controlling corrosion-product transport (CPT) in the balance-of-plant (BOP) and steam generators (SG) of CANDU stations are briefly reviewed. The efforts are focused on minimizing corrosion of carbon steel, which is used extensively in the CANDU primary and secondary systems. Emphasis is placed on the corrosion-product oxidation state as a monitor of water chemistry effectiveness, and as a monitor of system corrosion effects. The discussion is based mostly on the results and observations from Ontario Hydro plants, and their comparisons with PWRs. The effects of low oxygen and elevated hydrazine chemistry are reviewed, as well as the effects of lay-up and various start-up conditions. Progress in monitoring electrochemical potential (ECP) at Ontario Hydro plants and its relationship to the oxidation state of corrosion products is reviewed. Observations on corrosion-product transport on the primary side of steam generators are also discussed. (author)

  5. Influence of oxidation state on the pH dependence of hydrous iridium oxide films

    International Nuclear Information System (INIS)

    Steegstra, Patrick; Ahlberg, Elisabet

    2012-01-01

    Many electrochemical reactions taking place in aqueous solution consume or produce protons. The pH in the diffusion layer can therefore be significantly altered during the reaction and there is a need for in situ pH measurements tracing this near surface pH. In the present paper the rotating ring disc technique was used to measure near surface pH changes during oxygen reduction, utilising hydrous iridium oxide as the pH sensing probe. Before such experiments a good understanding of the pH sensing properties of these films is required and the impact of the oxidation state of the film on the pH sensing properties was investigated as well as the influence of solution redox species. The pH sensitivity (depicted by dE/dpH) was found to depend on the average oxidation state of the film in a manner resembling the cyclic voltammetry response. In all cases the pH response is “supernernstian” with more than one proton per electron. The origin of this behaviour is discussed in the context of acid-base properties of the film and the existence of both hydrous and anhydrous oxide phases. The pH response depends also on the redox properties of the solution but can be optimised for various purposes by conditioning the film at different potentials. This was clearly illustrated by adding hydrogen peroxide, an intermediate in the oxygen reduction reaction, to the solution. It was shown that hydrous iridium oxide can be used as a reliable in situ pH sensor provided that care is taken to optimise the oxidation state of the film.

  6. Pentavalent Uranium Chemistry - Synthetic Pursuit Of A Rare Oxidation State

    Energy Technology Data Exchange (ETDEWEB)

    Graves, Christopher R [Los Alamos National Laboratory; Kiplinger, Jaqueline L [Los Alamos National Laboratory

    2009-01-01

    This feature article presents a comprehensive overview of pentavalent uranium systems in non-aqueous solution with a focus on the various synthetic avenues employed to access this unusual and very important oxidation state. Selected characterization data and theoretical aspects are also included. The purpose is to provide a perspective on this rapidly evolving field and identify new possibilities for future developments in pentavalent uranium chemistry.

  7. Study of uranium oxidation states in geological material.

    Science.gov (United States)

    Pidchenko, I; Salminen-Paatero, S; Rothe, J; Suksi, J

    2013-10-01

    A wet chemical method to determine uranium (U) oxidation states in geological material has been developed and tested. The problem faced in oxidation state determinations with wet chemical methods is that U redox state may change when extracted from the sample material, thereby leading to erroneous results. In order to quantify and monitor U redox behavior during the acidic extraction in the procedure, an analysis of added isotopic redox tracers, (236)U(VI) and (232)U(IV), and of variations in natural uranium isotope ratio ((234)U/(238)U) of indigenous U(IV) and U(VI) fractions was performed. Two sample materials with varying redox activity, U bearing rock and U-rich clayey lignite sediment, were used for the tests. The Fe(II)/Fe(III) redox-pair of the mineral phases was postulated as a potentially disturbing redox agent. The impact of Fe(III) on U was studied by reducing Fe(III) with ascorbic acid, which was added to the extraction solution. We observed that ascorbic acid protected most of the U from oxidation. The measured (234)U/(238)U ratio in U(IV) and U(VI) fractions in the sediment samples provided a unique tool to quantify U oxidation caused by Fe(III). Annealing (sample heating) to temperatures above 500 °C was supposed to heal ionizing radiation induced defects in the material that can disturb U redox state during extraction. Good agreement between two independent methods was obtained for DL-1a material: an average 38% of U(IV) determined by redox tracer corrected wet chemistry and 45% for XANES. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Block Copolymer Electrolytes: Thermodynamics, Ion Transport, and Use in Solid- State Lithium/Sulfur Cells

    Science.gov (United States)

    Teran, Alexander Andrew

    Nanostructured block copolymer electrolytes containing an ion-conducting block and a modulus-strengthening block are of interest for applications in solid-state lithium metal batteries. These materials can self-assemble into well-defined microstructures, creating conducting channels that facilitate ion transport. The overall objective of this dissertation is to gain a better understanding of the behavior of salt-containing block copolymers, and evaluate their potential for use in solid-state lithium/sulfur batteries. Anionically synthesized polystyrene-b-poly(ethylene oxide) (SEO) copolymers doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt were used as a model system. This thesis investigates the model system on several levels: from fundamental thermodynamic studies to bulk characterization and finally device assembly and testing. First, the thermodynamics of neat and salt-containing block copolymers was studied. The addition of salt to these materials is necessary to make them conductive, however even small amounts of salt can have significant effects on their phase behavior, and consequently their iontransport and mechanical properties. As a result, the effect of salt addition on block copolymer thermodynamics has been the subject of significant interest over the last decade. A comprehensive study of the thermodynamics of block copolymer/salt mixtures over a wide range of molecular weights, compositions, salt concentrations and temperatures was conducted. Next, the effect of molecular weight on ion transport in both homopolymer and copolymer electrolytes were studied over a wide range of chain lengths. Homopolymer electrolytes show an inverse relationship between conductivity and chain length, with a plateau in the infinite molecular weight limit. This is due to the presence of two mechanisms of ion conduction in homopolymers; the first mechanism is a result of the segmental motion of the chains surrounding the salt ions, 2 creating a liquid

  9. Highly Efficient Adsorption of Copper Ions by a PVP-Reduced Graphene Oxide Based On a New Adsorptions Mechanism

    Institute of Scientific and Technical Information of China (English)

    Yongji Zhang; HuiJuan Chi; WenHui Zhang; Youyi Sun; Qing Liang; Yu Gu; Riya Jing

    2014-01-01

    Polyvinylpyrrolidone-reduced graphene oxide was prepared by modified hummers method and was used as adsorbent for removing Cu ions from wastewater. The effects of contact time and ions concentration on adsorption capacity were examined. The maximum adsorption capacity of 1689 mg/g was observed at an initial p H value of 3.5 after agitating for 10 min. It was demonstrated that polyvinylpyrrolidone-reduced graphene oxide had a huge adsorption capacity for Cu ions, which was 10 times higher than maximal value reported in previous works. The adsorption mechanism was also discussed by density functional theory. It demonstrates that Cu ions are attracted to surface of reduced graphene oxide by C atoms in reduced graphene oxide modified by polyvinylpyrrolidone through physisorption processes, which may be responsible for the higher adsorption capacity. Our results suggest that polyvinylpyrrolidone-reduced graphene oxide is an effective adsorbent for removing Cu ions in wastewater. It also provides a new way to improve the adsorption capacity of reduced graphene oxide for dealing with the heavy metal ion in wastewater.

  10. Solid NMR study of lithium ions accommodated in various transition metal oxides

    International Nuclear Information System (INIS)

    Kanzaki, Yasushi; Suzuki, Noriko

    2008-01-01

    Solid NMR was used to elucidate the lithium accommodation/extraction reaction in various transition metal oxides. The first study was the lithium ion exchange reaction of titanium antimonic acid (TiSbA). The effect of hydration on the selectivity of lithium ion in the solid phase was examined using 7 Li NMR. The second study was the irreversible ion exchange behavior of HNbO 3 . The selectivity for the lithium ion and the irreversible behavior were examined using 1 H and 7 Li NMR. The third study was the isotope separation between 6 Li and 7 Li in various inorganic ion exchangers. The high isotope separation coefficient was ascribed to the degree of dehydration during the ion exchange reaction. The degree of dehydration was examined by 1 H and 7 Li NMR studies. The last study was determining the mechanism of the lithium accommodation/extraction reaction of λ-MnO 2 in an aqueous solution. The different paths between the accommodation and extraction and the formation of MnO 4- during the accommodation were determined by chemical analysis. The Knight shift in the 7 Li MAS-NMR spectra of Li 0.5 MnO 2 suggested the localization of the electron density on the lithium nuclei. An XPS study also suggested the presence of an electron density on the lithium nuclei. A pH-independent redox couple was assumed to account for the accommodation/extraction reaction of lithium ions, such as Li(I)/Li(0). (author)

  11. Aqueous nitrite ion determination by selective reduction and gas phase nitric oxide chemiluminescence

    Science.gov (United States)

    Dunham, A. J.; Barkley, R. M.; Sievers, R. E.; Clarkson, T. W. (Principal Investigator)

    1995-01-01

    An improved method of flow injection analysis for aqueous nitrite ion exploits the sensitivity and selectivity of the nitric oxide (NO) chemilluminescence detector. Trace analysis of nitrite ion in a small sample (5-160 microL) is accomplished by conversion of nitrite ion to NO by aqueous iodide in acid. The resulting NO is transported to the gas phase through a semipermeable membrane and subsequently detected by monitoring the photoemission of the reaction between NO and ozone (O3). Chemiluminescence detection is selective for measurement of NO, and, since the detection occurs in the gas-phase, neither sample coloration nor turbidity interfere. The detection limit for a 100-microL sample is 0.04 ppb of nitrite ion. The precision at the 10 ppb level is 2% relative standard deviation, and 60-180 samples can be analyzed per hour. Samples of human saliva and food extracts were analyzed; the results from a standard colorimetric measurement are compared with those from the new chemiluminescence method in order to further validate the latter method. A high degree of selectivity is obtained due to the three discriminating steps in the process: (1) the nitrite ion to NO conversion conditions are virtually specific for nitrite ion, (2) only volatile products of the conversion will be swept to the gas phase (avoiding turbidity or color in spectrophotometric methods), and (3) the NO chemiluminescence detector selectively detects the emission from the NO + O3 reaction. The method is free of interferences, offers detection limits of low parts per billion of nitrite ion, and allows the analysis of up to 180 microL-sized samples per hour, with little sample preparation and no chromatographic separation. Much smaller samples can be analyzed by this method than in previously reported batch analysis methods, which typically require 5 mL or more of sample and often need chromatographic separations as well.

  12. 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.

  13. Non-noble metal graphene oxide-copper (II) ions hybrid electrodes for electrocatalytic hydrogen evolution reaction

    KAUST Repository

    Muralikrishna, S.; Ravishankar, T.N.; Ramakrishnappa, T.; Nagaraju, Doddahalli H.; Krishna Pai, Ranjith

    2015-01-01

    Non-noble metal and inexpensive graphene oxide-copper (II) ions (GO-Cu2+) hybrid catalysts have been explored for the hydrogen evolution reaction (HER). We were able to tune the binding abilities of GO toward the Cu2+ ions and hence their catalytic

  14. Role of the oxidation state of cerium on the ceria surfaces for silicate adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jihoon [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of); Moon, Jinok [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of); Clean/CMP Technology Team, Memory, Samsung Electronics, Hwaseong (Korea, Republic of); Kim, Joo Hyun; Lee, Kangchun [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of); Hwang, Junha [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of); Materials R& D Center, K.C.Tech, Anseong (Korea, Republic of); Yoon, Heesung [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of); Yi, Dong Kee, E-mail: vitalis@mju.ac.kr [Department of Chemistry, Myongji University, Yongin (Korea, Republic of); Paik, Ungyu, E-mail: upaik@hanyang.ac.kr [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of)

    2016-12-15

    Highlights: • We investigated the role of Ce oxidation state (Ce{sup 3+}/Ce{sup 4+}) on the CeO{sub 2} surfaces for the silicate adsorption. • As the Ce{sup 3+} concentration increased from 19.3 to 27.6%, the surface density of −OH group increased from 0.34 to 0.72 OH/nm{sup 2}. • The Freundlich constant for the relative adsorption capacity (K{sub F}) and adsorption intensity (1/n) indicated that CeO{sub 2} NPs with high Ce{sup 3+} concentration show higher adsorption affinity with silicate ions. - Abstract: In this study, we have investigated the role of the Ce oxidation state (Ce{sup 3+}/Ce{sup 4+}) on the CeO{sub 2} surfaces for silicate adsorption. In aqueous medium, the Ce{sup 3+} sites lead to the formation of −OH groups at the CeO{sub 2} surface through H{sub 2}O dissociation. Silicate ions can adsorb onto the CeO{sub 2} surface through interaction with the −OH groups (−Ce−OH− + −Si−O{sup −} ↔ −Ce−O−Si− + OH{sup −}). As the Ce{sup 3+} concentration increased from 19.3 to 27.6%, the surface density of −OH group increased from 0.34 to 0.72 OH/nm{sup 2}. To evaluate the adsorption behaviors of silicate ions onto CeO{sub 2} NPs, we carried out an adsorption isothermal analysis, and the adsorption isotherm data followed the Freundlich model. The Freundlich constant for the relative adsorption capacity (K{sub F}) and adsorption intensity (1/n) indicated that CeO{sub 2} NPs with high Ce{sup 3+} concentration show higher adsorption affinity with silicate ions. As a result, we have demonstrated that the Ce oxidation state (Ce{sup 3+}/Ce{sup 4+}) on the CeO{sub 2} surface can have a significant influence on the silicate adsorption.

  15. High resolution medium energy ion scattering study of silicon oxidation and oxy nitridation

    International Nuclear Information System (INIS)

    Gusev, E.P.; Lu, H.C.; Garfunkel, E.; Gustafsson, T.

    1998-01-01

    Full text: Silicon oxide is likely to remain the material of choice for gate oxides in microelectronics for the foreseeable future. As device become ever smaller and faster, the thickness of these layers in commercial products is predicted to be less than 50 Angstroms in just a few years. An understanding of such devices will therefore likely to be based on microscopic concepts and should now be investigated by atomistic techniques. With medium energy ion scattering (MEIS) using an electrostatic energy analyzer, depth profiling of thin (<60 Angstroms) silicon oxide films on Si(100) with 3 - 5 Angstroms depth resolution in the near region has been done. The growth mechanism of thin oxide films on Si(100) has been studied, using sequential oxygen isotope exposures. It is found that the oxide films are stoichiometric to within approx. 10 Angstroms of the interface. It is also found that the oxidation reactions occur at the surface, in the transition region and at interface, with only the third region being included in the conventional (Deal-Grove) model for oxide formation. Nitrogen is sometimes added to gate oxides, as it has been found empirically that his improves some of the electrical properties. The role, location and even the amount of nitrogen that exists in such films are poorly understood, and represent interesting analytical challenges. MEIS data will be presented that address these questions, measured for a number of different processing conditions. We have recently demonstrated how to perform nitrogen nano-engineering in such ultrathin gate dielectrics, and these results will also be discussed

  16. Shallow nitrogen ion implantation: Evolution of chemical state and defect structure in titanium

    Energy Technology Data Exchange (ETDEWEB)

    Manojkumar, P.A., E-mail: manoj@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Chirayath, V.A.; Balamurugan, A.K.; Krishna, Nanda Gopala; Ilango, S.; Kamruddin, M.; Amarendra, G.; Tyagi, A.K. [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Raj, Baldev [National Institute of Advanced Studies, Bangalore 560 012 (India)

    2016-09-15

    Highlights: • Low energy nitrogen ion implantation in titanium was studied. • Chemical and defect states were analyzed using SIMS, XPS and PAS. • SIMS and depth resolved XPS data showed good agreement. • Depth resolved defect and chemical states information were revealed. • Formation of 3 layers of defect states proposed to fit PAS results. - Abstract: Evolution of chemical states and defect structure in titanium during low energy nitrogen ion implantation by Plasma Immersion Ion Implantation (PIII) process is studied. The underlying process of chemical state evolution is investigated using secondary ion mass spectrometry and X-ray photoelectron spectroscopy. The implantation induced defect structure evolution as a function of dose is elucidated using variable energy positron annihilation Doppler broadening spectroscopy (PAS) and the results were corroborated with chemical state. Formation of 3 layers of defect state was modeled to fit PAS results.

  17. General regularity of the oxidation potential variations and high oxidation states in the second half of the actinide series

    International Nuclear Information System (INIS)

    Spitsyn, V.I.; Vokhmin, V.G.; Ionova, G.V.; Pershina, V.G.

    1984-01-01

    Oxidation potentials (OP) PHI(4/3), PHI(5/3), PHI(6/3), PHI(5/4) and PHI(6/5) are calculated for the members of the actinide series. A semiemperic relation combining OP with explicit terms for ground level energies of actinide ions in Russell-Saunders approximation as well as known values of formal OP relative to the normal hydrogen electrode potential are used as an extrapolation function. It is shown that an increase of PHI(4/3) OP which occurs after Bsub(k) explains a low stability of the oxidation state 4 in solutions for actinides of the second half of the series. PHI(5/3) and PHI(5/4) OP in the section starting with Cm have the minimum at Cf. PHI(6/3) OP for Cm, Bk, Cf and Es are practically the same but for Cm, Bk and Es they are smaller than PHI(5/3) OP. A principle possibility of Bk(6), Cf(6) and Es(6) preparation is shown

  18. Compatibility evaluation between La 2Mo 2O 9 fast oxide-ion conductor and Ni-based materials

    Science.gov (United States)

    Corbel, Gwenaël; Lacorre, Philippe

    2006-05-01

    The chemical reactivity of La 2NiO 4+δ and nickel metal or nickel oxide with fast oxide-ion conductor La 2Mo 2O 9 is investigated in the annealing temperature range between 600 and 1000 °C, using room temperature X-ray powder diffraction. Within the La 2NiO 4+δ/La 2Mo 2O 9 system, subsequent reaction is evidenced at relatively low annealing temperature (600 °C), with formation of La 2MoO 6 and NiO. The reaction is complete at 1000 °C. At reverse, no reaction occurs between Ni or NiO and La 2Mo 2O 9 up to 1000 °C. Together with a previous work [G. Corbel, S. Mestiri, P. Lacorre, Solid State Sci. 7 (2005) 1216], the current study shows that Ni-CGO cermets might be chemically and mechanically compatible anode materials to work with LAMOX electrolytes in solid oxide fuel cells.

  19. Electrically tunable solid-state silicon nanopore ion filter

    Directory of Open Access Journals (Sweden)

    Gracheva Maria

    2006-01-01

    Full Text Available AbstractWe show that a nanopore in a silicon membrane connected to a voltage source can be used as an electrically tunable ion filter. By applying a voltage between the heavily doped semiconductor and the electrolyte, it is possible to invert the ion population inside the nanopore and vary the conductance for both cations and anions in order to achieve selective conduction of ions even in the presence of significant surface charges in the membrane. Our model based on the solution of the Poisson equation and linear transport theory indicates that in narrow nanopores substantial gain can be achieved by controlling electrically the width of the charge double layer.

  20. Studies of the Tc oxidation states in humic acid solutions

    International Nuclear Information System (INIS)

    Wang Bo; Liu Dejun; Yao Jun

    2010-01-01

    The oxidation state is an important aspect of the speciation of Tc in groundwater that contained organic substances due to it control the precipitation, complexation, sorption and colloid formation behavior of the Tc under HWL geological disposal conditions. In present work, the oxidation states of Tc were investigated using the LaCl 3 coagulation method and solution extraction method in aqueous solutions in which the humic acid concentration range is from 0 to 20 mg L -1 and the Tc (Ⅶ) concentration range is about 10 -8 mol l -1 . The radiocounting of 99 Tc was determined using liquid scintillation spectrometry. The humic acid will influence the radiocounting ratio of 99 Tc apparently, however, the quenching effect can be restrained once keep the volume of the cocktail to about twenty times of the sample volume. The LaCl 3 coagulation methods were carried out for the investigation of Tc oxidation states in humic acid aqueous systems at about pH 8. The tetraphenylarsonium chloride (IPA)-chloroform extraction method was used also simultaneously to investigation the concentrations of Tc (Ⅳ) and Tc (Ⅶ) for the availability of the LaCl 3 precipitation method, and the experimental results demonstrate that tetravalent technetium and pertechnetate concentrations are well agreement with the LaCl 3 precipitation method. These two experimental results demonstrated that Tc (Ⅶ) is very stable in the Tc (Ⅶ)-humic acid system during a 350 days experimental period, and the Tc (Ⅳ) concentrations are very lower, that is indicate that there didn't oxidizing reactions between the Fluka humic acid and Tc (Ⅶ) in aqueous solutions under anaerobic conditions. That is means the presence of humic acids even in anaerobic groundwater is disadvantage for the retardance of radionuclides. (authors)

  1. Studies of Tc oxidation states in humic acid solutions

    International Nuclear Information System (INIS)

    Wang Bo; Liu Dejun; Yao Jun

    2011-01-01

    The oxidation state of Tc is an important aspect of the speciation in groundwater which contained organic substances due to it control the precipitation, complexation, sorption and colloid formation behavior of the Tc under HWL geological disposal conditions. In present work, the oxidation states of Tc were investigated using the LaCl 3 coagulation method and solution extraction method in aqueous solutions in which the humic acid concentration range is from 0 to 20 mg/L and the Tc (VII) concentration is about 10 -8 mol/L. The radiocounting of 99 Tc was determined using liquid scintillation spectrometry. The humic acid will influence the radiocounting ratio of 99 Tc apparently, however, the quenching effect can be restrained once keep the volume of the cocktail to about twenty times of the sample volume. The LaCl 3 coagulation method was carried out for the investigation of Tc oxidation states in humic acid aqueous systems at about pH 8. The tetraphenylarsonium chloride (TPA)-chloroform extraction method was used also simultaneously to investigation the concentrations of Tc (IV) and Tc (VII) for the availability of the LaCl 3 precipitation method, and the experimental results demonstrate that tetravalent technetium and pertechnetate concentration are well agreement with the LaCl 3 precipitation method. These two experimental results demonstrated that Tc (VII) is very stable in the Tc (VII)-humic acid system during a 350 days experimental period, and the Tc (IV) concentrations are very lower, that is indicate that there didn't oxidizing reactions between the Fluka humic acid and Tc (VII) in aqueous solutions under anaerobic conditions. That means the presence of humic acids even in anaerobic groundwater is disadvantage for the retardance of radionuclides. (authors)

  2. An Aqueous Metal-Ion Capacitor with Oxidized Carbon Nanotubes and Metallic Zinc Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Yuheng; Amal, Rose; Wang, Da-Wei, E-mail: da-wei.wang@unsw.edu.au [School of Chemical Engineering, The University of New South Wales (UNSW), Sydney, NSW (Australia)

    2016-10-03

    An aqueous metal ion capacitor comprising of a zinc anode, oxidized carbon nanotubes (oCNTs) cathode, and a zinc sulfate electrolyte is reported. Since the shuttling cation is Zn{sup 2+}, this typical metal ion capacitor is named as zinc-ion capacitor (ZIC). The ZIC integrates the divalent zinc stripping/plating chemistry with the surface-enabled pseudocapacitive cation adsorption/desorption on oCNTs. The surface chemistry and crystallographic structure of oCNTs were extensively characterized by combining X-ray photoelectron spectroscopy, Fourier-transformed infrared spectroscopy, Raman spectroscopy, and X-ray powder diffraction. The function of the surface oxygen groups in surface cation storage was elucidated by a series of electrochemical measurement and the surface-enabled ZIC showed better performance than the ZIC with an un-oxidized CNT cathode. The reaction mechanism at the oCNT cathode involves the additional reversible Faradaic process, while the CNTs merely show electric double layer capacitive behavior involving a non-Faradaic process. The aqueous hybrid ZIC comprising the oCNT cathode exhibited a specific capacitance of 20 mF cm{sup −2} (corresponding to 53 F g{sup −1}) in the range of 0–1.8 V at 10 mV s{sup −1} and a stable cycling performance up to 5000 cycles.

  3. Methods for using novel cathode and electrolyte materials for solid oxide fuel cells and ion transport membranes

    Science.gov (United States)

    Jacobson, Allan J.; Wang, Shuangyan; Kim, Gun Tae

    2016-01-12

    Methods using novel cathode, electrolyte and oxygen separation materials operating at intermediate temperatures for use in solid oxide fuel cells and ion transport membranes include oxides with perovskite related structures and an ordered arrangement of A site cations. The materials have significantly faster oxygen kinetics than in corresponding disordered perovskites.

  4. Electrocatalytic Activity of Carbonized Nanostructured Polyanilines for Oxidation Reactions: Sensing of Nitrite Ions and Ascorbic Acid

    International Nuclear Information System (INIS)

    Micić, Darko; Šljukić, Biljana; Zujovic, Zoran; Travas-Sejdic, Jadranka; Ćirić-Marjanović, Gordana

    2014-01-01

    Highlights: • Carbonized PANIs prepared from various nanostructured PANI precursors • Electroanalytical performances of carbonized PANIs evaluated using voltammetry • Study of carbonized PANIs physico-chemical properties related to electroactivity • The lowest over-potential for NO 2 − oxidation at c-PANI (+0.87 V vs. SCE) • The lowest over-potential for ascorbic acid oxidation at both c-PANI and c-PANI-SSA - Abstract: A comparative study of the electrocatalytic activity of nitrogen-containing carbon nanomaterials, prepared by the carbonization of nanostructured polyaniline (PANI) salts, for the electrooxidation reactions is presented. Nanostructured PANI salts were synthesized by the oxidative polymerization of aniline with ammonium peroxydisulfate in an aqueous solution in the presence of 5-sulfosalicylic acid (PANI-SSA), 3,5-dinitrosalicylic acid (PANI-DNSA) as well as without added acid (PANI), and subsequently carbonized to c-PANI-SSA, c-PANI-DNSA and c-PANI, respectively. Glassy carbon tip was modified with nanostructured c-PANIs and used for the investigation of sensing of nitrite and ascorbic acid in aqueous solutions as model analytes by linear sweep voltammetry. All three types of the investigated c-PANIs gave excellent response to the nitrite ions and ascorbic acid electrooxidation. The lowest peak potential for nitrite ion oxidation exhibited c-PANI (+0.87 V vs. SCE), and for ascorbic acid oxidation both c-PANI and c-PANI-SSA (ca. + 0.13 V vs. SCE). Electrochemical data were correlated with structural and textural data obtained by Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, elemental and nitrogen sorption analysis

  5. Origin of major donor states in In–Ga–Zn oxide

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Motoki; Oota, Masashi; Ishihara, Noritaka; Nonaka, Yusuke; Hirohashi, Takuya; Takahashi, Masahiro; Yamazaki, Shunpei [Semiconductor Energy Laboratory Co., Ltd., 398 Hase, Atsugi, Kanagawa 243-0036 (Japan); Obonai, Toshimitsu; Hosaka, Yasuharu; Koezuka, Junichi [Advanced Film Device Inc., 161-2 Masuzuka, Tsuga-machi, Tochigi, Tochigi 328-0114 (Japan)

    2014-12-07

    To clarify the origin of the major donor states in indium gallium zinc oxide (IGZO), we report measurement results and an analysis of several physical properties of IGZO thin films. Specifically, the concentration of H atoms and O vacancies (V{sub O}), carrier concentration, and conductivity are investigated by hard X-ray photoelectron spectroscopy, secondary ion mass spectroscopy, thermal desorption spectroscopy, and Hall effect measurements. The results of these experiments suggest that the origin of major donor states is H occupancy of V{sub O} sites. Furthermore, we use first-principles calculations to investigate the influence of the coexistence of V{sub O} and H in crystalline InGaO{sub 3}(ZnO){sub m} (m = 1). The results indicate that when H is trapped in V{sub O}, a stable complex is created that serves as a shallow-level donor.

  6. Study on the solid state chemistry of ternary uranium oxides

    International Nuclear Information System (INIS)

    Yamashita, Toshiyuki

    1988-03-01

    With the increase of burnup of uranium oxide fuels, various kinds of fission products are formed, and the oxygen atoms combined with the consumed heavy atoms are freed. The solid state chemical and/or thermodynamic properties of these elements at high temperatures are complex, and have not been well clarified. In the present report, an approach was taken that the chemical interactions between UO 2 and these fission products can be regarded as causing overlapped effects of composing ternary uranium oxides, and formation reactions and phase behavior were studied for several ternary uranium oxides with typical fission product elements such as alkaline earth metals and rare earth elements. Precise determination methods for the composition of ternary uranium oxides were developed. The estimated accuracies for x and y values in M y U 1-y O 2+x were ± 0.006 and ± 0.004, respectively. The thermodynamic properties and the lattice parameters of the phases in the Ca-U-O and Pr-U-O systems were discussed in relation to the composition determined by the methods. Crystal structure analyses of cadmium monouranates were made with X-ray diffraction method. (author) 197 refs

  7. The effect of iridium(III) ions on the formation of iron oxides in a highly alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Krehula, Stjepko, E-mail: krehul@irb.hr [Division of Materials Chemistry, Ruder Boskovic Institute, PO Box 180, HR-10002 Zagreb (Croatia); Music, Svetozar [Division of Materials Chemistry, Ruder Boskovic Institute, PO Box 180, HR-10002 Zagreb (Croatia)

    2012-03-05

    Highlights: Black-Right-Pointing-Pointer Study of the influence of Ir{sup 3+} ions on the precipitation of iron oxides. Black-Right-Pointing-Pointer Ir{sup 3+} doping in {alpha}-FeOOH caused significant changes in the microstructural properties. Black-Right-Pointing-Pointer Ir{sup 3+} doping in {alpha}-Fe{sub 2}O{sub 3} caused an increase in the Morin transition temperature. Black-Right-Pointing-Pointer Ir{sup 3+} ions caused a phase transformation {alpha}-(Fe,Ir)OOH {yields} {alpha}-(Fe,Ir){sub 2}O{sub 3} {yields} Fe{sub 3}O{sub 4} + Ir{sup 0}. - Abstract: The effect of the presence of Ir{sup 3+} ions on the formation of iron oxides in a highly alkaline precipitation system was investigated using X-ray powder diffraction (XRD), {sup 57}Fe Moessbauer and FT-IR spectroscopies, field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). Monodispersed lath-like {alpha}-FeOOH (goethite) particles precipitated by hydrothermal treatment in a highly alkaline medium with the addition of tetramethylammonium hydroxide (TMAH) were used as reference material. The presence of Ir{sup 3+} ions in the precipitation system strongly influenced the phase composition, magnetic, structural and morphological properties of obtained samples. The formation of {alpha}-Fe{sub 2}O{sub 3} (hematite) along with {alpha}-FeOOH in the first stage of hydrothermal treatment and the transformation of {alpha}-FeOOH and {alpha}-Fe{sub 2}O{sub 3} to Fe{sub 3}O{sub 4} (magnetite) by a longer hydrothermal treatment was caused by the presence of Ir{sup 3+} ions. Ir{sup 3+} for Fe{sup 3+} substitution in the structure of {alpha}-FeOOH brought about changes in unit-cell dimensions, crystallinity, particle size and shape, hyperfine magnetic field and infrared bands positions. Ir{sup 3+} for Fe{sup 3+} substitution in the structure of {alpha}-Fe{sub 2}O{sub 3} led to an increase in the temperature of the Morin transition; Moessbauer spectroscopy showed the presence of

  8. The effect of Ce ion substituted OMS-2 nanostructure in catalytic activity for benzene oxidation

    Science.gov (United States)

    Hou, Jingtao; Li, Yuanzhi; Mao, Mingyang; Zhao, Xiujian; Yue, Yuanzheng

    2014-11-01

    The nanostructure of Ce doped OMS-2 plays a very important role in its catalytic property. We demonstrate by density functional theory (DFT) calculations that the unique nanostructure of the Ce ion substituted OMS-2 with Mn vacancy in the framework is beneficial for the improvement of catalytic activity, while the nanostructure of the Ce ion substituted OMS-2 without defects are detrimental to the catalytic activity. We establish a novel and facile strategy of synthesizing these unique Ce ion substituted OMS-2 nanostructure with Mn vacancies in the framework by hydrothermal redox reaction between Ce(NO3)3 and KMnO4 with KMnO4/Ce(NO3)3 at a molar ratio of 3 : 1 at 120 °C. Compared to pure OMS-2, the produced catalyst of Ce ion substituted OMS-2 ultrathin nanorods exhibits an enormous enhancement in the catalytic activity for benzene oxidation, which is evidenced by a significant decrease (ΔT50 = 100 °C, ΔT90 = 129 °C) in the reaction temperature of T50 and T90 (corresponding to the benzene conversion = 50% and 90%), which is considerably more efficient than the expensive supported noble metal catalyst (Pt/Al2O3). We combine both theoretical and experimental evidence to provide a new physical insight into the significant effect due to the defects induced by the Ce ion substitution on the catalytic activity of OMS-2. The formation of unique Ce ion substituted OMS-2 nanostructure with Mn vacancies in the framework leads to a significant enhancement of the lattice oxygen activity, thus tremendously increasing the catalytic activity.The nanostructure of Ce doped OMS-2 plays a very important role in its catalytic property. We demonstrate by density functional theory (DFT) calculations that the unique nanostructure of the Ce ion substituted OMS-2 with Mn vacancy in the framework is beneficial for the improvement of catalytic activity, while the nanostructure of the Ce ion substituted OMS-2 without defects are detrimental to the catalytic activity. We establish a novel

  9. Molten salt oxidation of ion-exchange resins doped with toxic metals and radioactive metal surrogates

    International Nuclear Information System (INIS)

    Yang, Hee-Chul; Cho, Yong-Jun; Yoo, Jae-Hyung; Kim, Joon-Hyung; Eun, Hee-Chul

    2005-01-01

    Ion-exchange resins doped with toxic metals and radioactive metal surrogates were test-burned in a bench-scale molten salt oxidation (MSO) reactor system. The purposes of this study are to confirm the destruction performance of the two-stage MSO reactor system for the organic ion-exchange resin and to obtain an understanding of the behavior of the fixed toxic metals and the sulfur in the cationic exchange resins. The destruction of the organics is very efficient in the primary reactor. The primarily destroyed products such as carbon monoxide are completely oxidized in the secondary MSO reactor. The overall collection of the sulfur and metals in the two-stage MSO reactor system appeared to be very efficient. Over 99.5% of all the fixed toxic metals (lead and cadmium) and radioactive metal surrogates (cesium, cobalt, strontium) remained in the MSO reactor bottom. Thermodynamic equilibrium calculations and the XRD patterns of the spent salt samples revealed that the collected metals existed in the form of each of their carbonates or oxides, which are non-volatile species at the MSO system operating conditions. (author)

  10. On the electrochemistry of tin oxide coated tin electrodes in lithium-ion batteries

    International Nuclear Information System (INIS)

    Böhme, Solveig; Edström, Kristina; Nyholm, Leif

    2015-01-01

    As tin based electrodes are of significant interest in the development of improved lithium-ion batteries it is important to understand the associated electrochemical reactions. In this work it is shown that the electrochemical behavior of SnO_2 coated tin electrodes can be described based on the SnO_2 and SnO conversion reactions, the lithium tin alloy formation and the oxidation of tin generating SnF_2. The CV, XPS and SEM data, obtained for electrodeposited tin crystals on gold substrates, demonstrates that the capacity loss often observed for SnO_2 is caused by the reformed SnO_2 layer serving as a passivating layer protecting the remaining tin. Capacities corresponding up to about 80 % of the initial SnO_2 capacity could, however, be obtained by cycling to 3.5 V vs. Li"+/Li. It is also shown that the oxidation of the lithium tin alloy is hindered by the rate of the diffusion of lithium through a layer of tin with increasing thickness and that the irreversible oxidation of tin to SnF_2 at potentials larger than 2.8 V vs. Li"+/Li is due to the fact that SnF_2 is formed below the SnO_2 layer. This improved electrochemical understanding of the SnO_2/Sn system should be valuable in the development of tin based electrodes for lithium-ion batteries.

  11. Inline state of health estimation of lithium-ion batteries using state of charge calculation

    Science.gov (United States)

    Sepasi, Saeed; Ghorbani, Reza; Liaw, Bor Yann

    2015-12-01

    The determination of state-of-health (SOH) and state-of-charge (SOC) is challenging and remains as an active research area in academia and industry due to its importance for Li-ion battery applications. The estimation process poses more challenges after substantial battery aging. This paper presents an inline SOH and SOC estimation method for Li-ion battery packs, specifically for those based on LiFePO4 chemistry. This new hybridized SOC and SOH estimator can be used for battery packs. Inline estimated model parameters were used in a compounded SOC + SOH estimator consisting of the SOC calculation based on coulomb counting method as an expedient approach and an SOH observer using an extended Kalman filter (EKF) technique for calibrating the estimates from the coulomb counting method. The algorithm's low SOC and SOH estimation error, fast response time, and less-demanding computational requirement make it practical for on-board estimations. The simulation and experimental results, along with the test bed structure, are presented to validate the proposed methodology on a single cell and a 3S1P LiFePO4 battery pack.

  12. Characterization of Interface State in Silicon Carbide Metal Oxide Semiconductor Capacitors

    Science.gov (United States)

    Kao, Wei-Chieh

    Silicon carbide (SiC) has always been considered as an excellent material for high temperature and high power devices. Since SiC is the only compound semiconductor whose native oxide is silicon dioxide (SiO2), it puts SiC in a unique position. Although SiC metal oxide semiconductor (MOS) technology has made significant progress in recent years, there are still a number of issues to be overcome before more commercial SiC devices can enter the market. The prevailing issues surrounding SiC MOSFET devices are the low channel mobility, the low quality of the oxide layer and the high interface state density at the SiC/SiO2 interface. Consequently, there is a need for research to be performed in order to have a better understanding of the factors causing the poor SiC/SiO2 interface properties. In this work, we investigated the generation lifetime in SiC materials by using the pulsed metal oxide semiconductor (MOS) capacitor method and measured the interface state density distribution at the SiC/SiO2 interface by using the conductance measurement and the high-low frequency capacitance technique. These measurement techniques have been performed on n-type and p-type SiC MOS capacitors. In the course of our investigation, we observed fast interface states at semiconductor-dielectric interfaces in SiC MOS capacitors that underwent three different interface passivation processes, such states were detected in the nitrided samples but not observed in PSG-passivated samples. This result indicate that the lack of fast states at PSG-passivated interface is one of the main reasons for higher channel mobility in PSG MOSFETs. In addition, the effect of mobile ions in the oxide on the response time of interface states has been investigated. In the last chapter we propose additional methods of investigation that can help elucidate the origin of the particular interface states, enabling a more complete understanding of the SiC/SiO2 material system.

  13. IONEOS: a fast, analytic, ion equation-of-state routine

    International Nuclear Information System (INIS)

    Cranfill, C.W.; More, R.

    1978-10-01

    A routine IONEOS has been developed to compute ion pressure and specific energy along with their derivatives. The theoretical model used is due to R.D. Cowan and includes non-ideal-gas behavior. The routine is designed for use in large hydrodynamics codes as an improved procedure for splitting the total pressure and specific energy (which are usually tabulated) into ion and electron components

  14. Predicting spent fuel oxidation states in a tuff repository

    International Nuclear Information System (INIS)

    Einziger, R.E.; Woodley, R.E.

    1987-01-01

    Nevada Nuclear Waste Storage Investigations Project (NNWSI) is studying the suitability of the tuffaceous rocks at Yucca Mountain as a waste repository for spent fuel disposal. The oxidation state of the LWR spent fuel in the moist air environment of a tuff repository could be a significant factor in determining its leaching and dissolution characteristics. Predictions as to which oxidation states would be present are important in analyzing such a repository and thus the present study was undertaken. A set of TGA (thermogravimetric analysis) tests were conducted on well-controlled samples of irradiated PWR fuel with time and temperature as the only variables. The tests were conducted between 140 and 225 0 C for a duration up to 2200 hours. The weight gain curves were analyzed in terms of diffusion through a layer of U 3 O 7 , diffusion into the grains to form a solid solution, a simplified empirical representation of a combination of grain boundary diffusion and bulk grain oxidation. Reaction rate constants were determined in each case, but analysis of these data could not establish a definitive mechanism. 21 refs., 10 figs., 3 tabs

  15. Modified graphene oxide sensors for ultra-sensitive detection of nitrate ions in water.

    Science.gov (United States)

    Ren, Wen; Mura, Stefania; Irudayaraj, Joseph M K

    2015-10-01

    Nitrate ions is a very common contaminant in drinking water and has a significant impact on the environment, necessitating routine monitoring. Due to its chemical and physical properties, it is hard to directly detect nitrate ions with high sensitivity in a simple and inexpensive manner. Herein with amino group modified graphene oxide (GO) as a sensing element, we show a direct and ultra-sensitive method to detect nitrate ions, at a lowest detected concentration of 5 nM in river water samples, much lower than the reported methods based on absorption spectroscopy. Furthermore, unlike the reported strategies based on absorption spectroscopy wherein the nitrate concentration is determined by monitoring an increase in aggregation of gold nanoparticles (GNPs), our method evaluates the concentration of nitrate ions based on reduction in aggregation of GNPs for monitoring in real samples. To improve sensitivity, several optimizations were performed, including the assessment of the amount of modified GO required, concentration of GNPs and incubation time. The detection methodology was characterized by zeta potential, TEM and SEM. Our results indicate that an enrichment of modified GO with nitrate ions contributed to excellent sensitivity and the entire detection procedure could be completed within 75 min with only 20 μl of sample. This simple and rapid methodology was applied to monitor nitrate ions in real samples with excellent sensitivity and minimum pretreatment. The proposed approach paves the way for a novel means to detect anions in real samples and highlights the potential of GO based detection strategy for water quality monitoring. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. The oxidation state of sulfur in apatite: A new oxybarometer?

    Science.gov (United States)

    Fiege, A.; Konecke, B.; Kim, Y.; Simon, A. C.; Becker, U.; Parat, F.

    2016-12-01

    Oxygen fugacity (fO2) of magmatic and hydrothermal systems influences, for instance, crystallization and degassing processes as well as metal solubilities in melts and fluids. Apatite is a ubiquitous mineral in magmatic and hydrothermal environments that can record and preserve volatile zonation. It can contain several thousand μg/g of the redox sensitive element sulfur (S), making S-in-apatite a potential fO2 sensor. Despite the polyvalent properties of S (e.g., S2-, S4+, S6+), the oxidation state and incorporation mechanisms of S in the apatite structure are poorly understood. In this study, the oxidation state of S-in-apatite as a function of fO2 is investigated using X-ray absorption near-edge structures (XANES) spectroscopy at the S K-edge. Apatites crystallized from lamproitic melts at 1000°C, 300 MPa and over a broad range of fO2 and sulfur fugacities (fS2) were measured. Peaks corresponding to S6+ ( 2482 eV), S4+ ( 2478 eV) and S2- ( 2470 eV) were identified in apatite. The integrated S6+/STotal (STotal = S6+ + S4+ + S2-) peak area ratios show a distinct positive correlation with fO2, increasing from 0.17 at FMQ+0 to 0.96 at FMQ+3. Ab-initio calculations were performed to further understand the energetics and geometry of incorporation of S6+, S4+ and S2- into the apatite (F-, Cl-, OH-) end-members. The results confirm that apatite can contain three different oxidations states of S (S6+, S4+, S2-) as a function of fO2. This makes apatite probably the first geologically relevant mineral to incorporate reduced (S2-), intermediate (S4+), and oxidized (S6+) S in variable proportions. We emphasize that the strong dependence of the S oxidation state in apatite as a function of fO2 is also coupled with changing S content of apatite and co-existing melt (i.e., with changing fS2), resulting in a complex correlation between [1] apatite-melt (or fluid) partitioning, [2] redox conditions and [3] the melt and/or fluid composition, making the application of previously

  17. The role of high Rydberg states in the generation of negative ions in negative-ion discharges

    International Nuclear Information System (INIS)

    Hiskes, J.R.

    1995-01-01

    The generation of substantial yields of H - ions in a laser excited H 2 gas has been reported by Pinnaduwage and Christoforu. These H - yields have been attributed to (2 + 1) REMP photoexcitation processes leading to dissociative attachment of doubly-excited or superexcited states (SES), or dissociative attachment of high Rydberg product states. The new feature of these experiments is the implied large dissociative attachment rates, of order 10 -6 cm 3 sec -1 , values that are orders-of-magnitude larger than the dissociative attachment of the vibrationally excited levels of the ground electronic state. While these laser excitations are not directly applicable to a hydrogen negative-ion discharge, the implication of large dissociative attachment rates to the high Rydberg states may affect both the total negative-ion density and the interpretation of discharge performance. Within the discharge energetic electrons will collisionally excite the higher Rydberg states, and the relative contribution of the dissociative attachment of these states when compared with the dissociative attachment to the ground state vibrational levels, is the topic of this paper

  18. Statistical analysis on hollow and core-shell structured vanadium oxide microspheres as cathode materials for Lithium ion batteries

    Directory of Open Access Journals (Sweden)

    Xing Liang

    2018-06-01

    Full Text Available In this data, the statistical analyses of vanadium oxide microspheres cathode materials are presented for the research article entitled “Statistical analyses on hollow and core-shell structured vanadium oxides microspheres as cathode materials for Lithium ion batteries” (Liang et al., 2017 [1]. This article shows the statistical analyses on N2 adsorption-desorption isotherm and morphology vanadium oxide microspheres as cathode materials for LIBs. Keywords: Adsorption-desorption isotherm, Pore size distribution, SEM images, TEM images

  19. Techniques for enhancing the performance of high charge state ECR ion sources

    International Nuclear Information System (INIS)

    Xie, Z.Q.

    1999-01-01

    Electron Cyclotron Resonance ion source (ECRIS), which produces singly to highly charged ions, is widely used in heavy ion accelerators and is finding applications in industry. It has progressed significantly in recent years thanks to a few techniques, such as multiple-frequency plasma heating, higher mirror magnetic fields and a better cold electron donor. These techniques greatly enhance the production of highly charged ions. More than 1 emA of He 2+ and O 6+ , hundreds of eμA of O 7+ , Ne 8+ , Ar 12+ , more than 100 eμA of intermediate heavy ions with charge states up to Ne 9+ , Ar 13+ , Ca 13+ , Fe 13+ , Co 14+ and Kr 18+ , tens of eμA of heavy ions with charge states up to Xe 28+ , Au 35+ , Bi 34+ and U 34+ were produced at cw mode operation. At an intensity of about 1 eμA, the charge states for the heavy ions increased up to Xe 36+ , Au 46+ , Bi 47+ and U 48+ . More than an order of magnitude enhancement of fully stripped argon ions was achieved (I≥0.1 and h;eμA). Higher charge state ions up to Kr 35+ , Xe 46+ and U 64+ at low intensities were produced for the first time from an ECRIS. copyright 1999 American Institute of Physics

  20. Decomposition of uranyl peroxo-carbonato complex ion in the presence of metal oxides in carbonate media

    International Nuclear Information System (INIS)

    Dong-Yong Chung; Min-Sung Park; Keun-Young Lee; Eil-Hee Lee; Kwang-Wook Kim; Jei-Kwon Moon

    2015-01-01

    Uranium oxide was dissolved in the form of the uranyl peroxo-carbonato complex ion, UO 2 (O 2 )(CO 3 ) 2 4- in carbonate solutions with hydrogen peroxide. When UO 2 (O 2 )(CO 3 ) 2 4- ions lose their peroxide component, they become a stable species of uranyl tricarbonato complex ion, UO 2 (O 2 )(CO 3 ) 2 4- . The uranyl peroxo-carbonato complex self-decomposed more rapidly into the uranyl tricarbonato complex ion in the presence of a metal oxide in the carbonate solution. In this study, decomposition of the uranyl peroxo-carbonato complex in a carbonate solution was investigated in the presence of several metal oxides using absorption spectroscopy. (author)

  1. A novel vanadium oxide deposit for the cathode of asymmetric lithium-ion supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing-Mei; Hu, Chi-Chang [Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu (China); Chang, Kuo-Hsin [Department of Chemical Engineering, National Chung Cheng University, Chia-Yi (China)

    2010-12-15

    Hydrous vanadium oxide (denoted as VO{sub x}.yH{sub 2}O) deposited at 0.4 V shows promising capacitive behavior in aqueous media containing concentrated Li ions. VO{sub x}.yH{sub 2}O annealed in air at 300 C for 1 h shows highly reversible Li-ion intercalation/de-intercalation behavior with specific capacitance reaching ca. 737 and 606 F g{sup -} {sup 1} at 25 and 500 mV s{sup -1} in 12 M LiCl between -0.2 and 0.8 V. In 14 M LiCl, retention of specific capacitance is about 95% when the scan rate is increased from 25 to 500 mV s{sup -} {sup 1}. This work is the first report showing the ultrahigh rate of Li-ion intercalation/de-intercalation in VO{sub x}.yH{sub 2}O. A so-called Li-ion supercapacitor of the asymmetric type consisting of a VO{sub x}.yH{sub 2}O cathode and a WO{sub 3}{sup .}zH{sub 2}O anode is proposed here. (author)

  2. Ion Diffusion-Directed Assembly Approach to Ultrafast Coating of Graphene Oxide Thick Multilayers.

    Science.gov (United States)

    Zhao, Xiaoli; Gao, Weiwei; Yao, Weiquan; Jiang, Yanqiu; Xu, Zhen; Gao, Chao

    2017-10-24

    The layer-by-layer (LbL) assembly approach has been widely used to fabricate multilayer coatings on substrates with multiple cycles, whereas it is hard to access thick films efficiently. Here, we developed an ion diffusion-directed assembly (IDDA) strategy to rapidly make multilayer thick coatings in one step on arbitrary substrates. To achieve multifunctional coatings, graphene oxide (GO) and metallic ions were selected as the typical building blocks and diffusion director in IDDA, respectively. With diffusion of metallic ions from substrate to negatively charged GO dispersion spontaneously (i.e., from high-concentration region to low-concentration region), GO was assembled onto the substrate sheet-by-sheet via sol-gel transformation. Because metallic ions with size of subnanometers can diffuse directionally and freely in the aqueous dispersion, GO was coated on the substrate efficiently, giving rise to films with desired thickness up to 10 μm per cycle. The IDDA approach shows three main merits: (1) high efficiency with a μm-scale coating rate; (2) controllability over thickness and evenness; and (3) generality for substrates of plastics, metals and ceramics with any shapes and morphologies. With these merits, IDDA strategy was utilized in the efficient fabrication of functional graphene coatings that exhibit outstanding performance as supercapacitors, electromagnetic interference shielding textiles, and anticorrosion coatings. This IDDA approach can be extended to other building blocks including polymers and colloidal nanoparticles, promising for the scalable production and application of multifunctional coatings.

  3. Production of Oxidants by Ion Bombardment of Icy Moons in the Outer Solar System

    Directory of Open Access Journals (Sweden)

    Philippe Boduch

    2011-01-01

    Full Text Available Our groups in Brazil, France and Italy have been active, among others in the world, in performing experiments on physical-chemical effects induced by fast ions colliding with solids (frozen gases, carbonaceous and organic materials, silicates, etc. of astrophysical interest. The used ions span a very large range of energies, from a few keV to hundreds MeV. Here we present a summary of the results obtained so far on the formation of oxidants (hydrogen peroxide and ozone after ion irradiation of frozen water, carbon dioxide and their mixtures. Irradiation of pure water ice produces hydrogen peroxide whatever is the used ion and at different temperatures. Irradiation of carbon dioxide and water frozen mixtures result in the production of molecules among which hydrogen peroxide and ozone. The experimental results are discussed in the light of the relevance they have to support the presence of an energy source for biosphere on Europa and other icy moons in the outer Solar System.

  4. Experimental findings on actinide recovery utilizing oxidation by peroxydisulfate followed by ion exchange: Fuel cycle research & development

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D. T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shehee, T. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-31

    Our research seeks to determine if inorganic ion-exchange materials can be exploited to provide effective minor actinide (Am, Cm) separation from lanthanides. Previous work has established that a number of inorganic and UMOF ion-exchange materials exhibit varying affinities for actinides and lanthanides, which may be exploited for effective separations. During FY15, experimental work focused on investigating methods to oxidize americium in dilute nitric and perchloric acid with subsequent ion-exchange performance measurements of ion exchangers with the oxidized americium in dilute nitric acid. Ion-exchange materials tested included a variety of alkali titanates. Americium oxidation testing sought to determine the influence that other redox active components may have on the oxidation of AmIII. Experimental findings indicated that CeIII, NpV, and RuII are oxidized by peroxydisulfate, but there are no indications that the presence of CeIII, NpV, and RuII affected the rate or extent of americium oxidation at the concentrations of peroxydisulfate being used.

  5. Hydrothermally Processed Oxide Nanostructures and Their Lithium–ion Storage Properties

    Directory of Open Access Journals (Sweden)

    Kim Yong-Jin

    2010-01-01

    Full Text Available Abstract Y- and Si-based oxide nanopowders were synthesized by a hydrothermal reaction of Y or Si powders with NaOH or LiOH aqueous solution. Nanoparticles with different morphology such as elongated nanospheres, flower-like nanoparticles and nanowires were produced by a control of processing parameters, in particular, the starting composition of solution. The preliminary result of electrochemical examination showed that the hydrothermally processed nanowires exhibit high initial capacities of Li-ion storage: 653 mAh/g for Y2O3 nanowires as anode materials and 186 mAh/g for Li2Si2O5 nanowires as cathode materials in a Li secondary cell. Compared to the powder with elongated sphere or flower-like shapes, the nanowires showed a higher Li-ion capacity and a better cycle property.

  6. Highly Stable Aqueous Zinc-ion Storage Using Layered Calcium Vanadium Oxide Bronze Cathode

    KAUST Repository

    Xia, Chuan

    2018-02-12

    Cost-effective aqueous rechargeable batteries are attractive alternatives to non-aqueous cells for stationary grid energy storage. Among different aqueous cells, zinc-ion batteries (ZIBs), based on Zn2+ intercalation chemistry, stand out as they can employ high-capacity Zn metal as anode material. Herein, we report a layered calcium vanadium oxide bronze as cathode material for aqueous Zn batteries. For the storage of Zn2+ ions in aqueous electrolyte, we demonstrate that calcium based bronze structure can deliver a high capacity of 340 mAh g-1 at 0.2 C, good rate capability and very long cycling life (96% retention after 3000 cycles at 80 C). Further, we investigate the Zn2+ storage mechanism, and the corresponding electrochemical kinetics in this bronze cathode. Finally, we show that our Zn cell delivers an energy density of 267 Wh kg-1 at a power density of 53.4 W kg-1.

  7. Moessbauer studies of 57Fe substitution of Cu ions in superconducting oxides

    International Nuclear Information System (INIS)

    Saitovitch, E.B.

    1988-01-01

    Since the discovery of high-T c superconductivity in YBa 2 Cu 3 O 7 oxides several studies of metal ions substitutions were reported. The observed depression on T c without a systematic correlation with the charge and magnetic moment of Cu substituents claims for more detailed information about its local properties as can be revealed by 57 Fe Moessbauer spectroscopy. The results for different iron concentrations combined with modifications of the superconducting transition are discussed concerning the presence of magnetic moments on the Fe ions and the preferential occupation of Cu(1) sites, recently confirmed by neutron and electron diffraction experiments. The oxygen coordination for the different iron species are proposed on the basis of their dependence on Fe concentration, their behavior at high temperatures as well as the electron diffraction and electron microscopy measurements reported for Fe: YBa 2 Cu 3 O 7 samples. (author) [pt

  8. Highly Stable Aqueous Zinc-ion Storage Using Layered Calcium Vanadium Oxide Bronze Cathode

    KAUST Repository

    Xia, Chuan; Guo, Jing; Li, Peng; Zhang, Xixiang; Alshareef, Husam N.

    2018-01-01

    Cost-effective aqueous rechargeable batteries are attractive alternatives to non-aqueous cells for stationary grid energy storage. Among different aqueous cells, zinc-ion batteries (ZIBs), based on Zn2+ intercalation chemistry, stand out as they can employ high-capacity Zn metal as anode material. Herein, we report a layered calcium vanadium oxide bronze as cathode material for aqueous Zn batteries. For the storage of Zn2+ ions in aqueous electrolyte, we demonstrate that calcium based bronze structure can deliver a high capacity of 340 mAh g-1 at 0.2 C, good rate capability and very long cycling life (96% retention after 3000 cycles at 80 C). Further, we investigate the Zn2+ storage mechanism, and the corresponding electrochemical kinetics in this bronze cathode. Finally, we show that our Zn cell delivers an energy density of 267 Wh kg-1 at a power density of 53.4 W kg-1.

  9. A novel electrode surface fabricated by directly attaching gold nanoparticles onto NH2+ ions implanted-indium tin oxide substrate

    International Nuclear Information System (INIS)

    Liu Chenyao; Jiao Jiao; Chen Qunxia; Xia Ji; Li Shuoqi; Hu Jingbo; Li Qilong

    2010-01-01

    A new type of gold nanoparticle attached to a NH 2 + ion implanted-indium tin oxide surface was fabricated without using peculiar binder molecules, such as 3-(aminopropyl)-trimethoxysilane. A NH 2 /indium tin oxide film was obtained by implantation at an energy of 80 keV with a fluence of 5 x 10 15 ions/cm 2 . The gold nanoparticle-modified film was characterized by X-ray photoelectron spectroscopy, scanning electron microscopy and electrochemical techniques and compared with a modified bare indium tin oxide surface and 3-(aminopropyl)-trimethoxysilane linked surface, which exhibited a relatively low electron transfer resistance and high electrocatalytic activity. The results demonstrate that NH 2 + ion implanted-indium tin oxide films can provide an important route to immobilize nanoparticles, which is attractive in developing new biomaterials.

  10. Performance on the low charge state laser ion source in BNL

    Energy Technology Data Exchange (ETDEWEB)

    Okamura, M.; Alessi, J.; Beebe, E.; Costanzo, M.; DeSanto, L.; Jamilkowski, J.; Kanesue, T.; Lambiase, R.; Lehn, D.; Liaw, C. J.; McCafferty, D.; Morris, J.; Olsen, R.; Pikin, A.; Raparia, D.; Steszyn, A.; Ikeda, S.

    2015-09-07

    On March 2014, a Laser Ion Source (LIS) was commissioned which delivers high-brightness, low-charge-state heavy ions for the hadron accelerator complex in Brookhaven National Laboratory (BNL). Since then, the LIS has provided many heavy ion species successfully. The low-charge-state (mostly singly charged) beams are injected to the Electron Beam Ion Source (EBIS), where ions are then highly ionized to fit to the following accelerator’s Q/M acceptance, like Au32+. Recently we upgraded the LIS to be able to provide two different beams into EBIS on a pulse-to-pulse basis. Now the LIS is simultaneously providing beams for both the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL).

  11. Ultrafine tin oxide on reduced graphene oxide as high-performance anode for sodium-ion batteries

    International Nuclear Information System (INIS)

    Zhang, Yandong; Xie, Jian; Zhang, Shichao; Zhu, Peiyi; Cao, Gaoshao; Zhao, Xinbing

    2015-01-01

    Highlights: • A nanohybrid based on ultrafine SnO 2 and few-layered rGO has been prepared. • The nanohybrid exhibits excellent electrochemical Na-storage properties. • The rGO supplies combined conducting, buffering and dispersing effects. - Abstract: Na-ion Battery is attractive alternative to Li-ion battery due to the natural abundance of sodium resource. Searching for suitable anode materials is one of the critical issues for Na-ion battery due to the low Na-storage activity of carbon materials. In this work, we synthesized a nanohybrid anode consisting of ultrafine SnO 2 anchored on few-layered reduced graphene oxide (rGO) by a facile hydrothermal route. The SnO 2 /rGO hybrid exhibits a high capacity, long cycle life and good rate capability. The hybrid can deliver a high charge capacity of 324 mAh g SnO2 −1 at 50 mA g −1 . At 1600 mA g −1 (2.4C), it can still yield a charge capacity of 200 mAh g SnO2 −1 . After 100 cycles at 100 mA g −1 , the hybrid can retain a high charge capacity of 369 mAh g SnO2 −1 . X-ray photoelectron spectroscopy, ex situ transmission electron microscopy and electrochemical impedance spectroscopy were used to investigate the origin of the excellent electrochemical Na-storage properties of SnO 2 /rGO

  12. Deposition of indium tin oxide thin films by cathodic arc ion plating

    International Nuclear Information System (INIS)

    Yang, M.-H.; Wen, J.-C.; Chen, K.-L.; Chen, S.-Y.; Leu, M.-S.

    2005-01-01

    Indium tin oxide (ITO) thin films have been deposited by cathodic arc ion plating (CAIP) using sintered oxide target as the source material. In an oxygen atmosphere of 200 deg. C, ITO films with a lowest resistivity of 2.2x10 -4 Ω-cm were obtained at a deposition rate higher than 450 nm/min. The carrier mobility of ITO shows a maximum at some medium pressures. Although morphologically ITO films with a very fine nanometer-sized structure were observed to possess the lowest resistivity, more detailed analyses based on X-ray diffraction are attempted to gain more insight into the factors that govern electron mobility in this investigation

  13. Facile synthesis and Li-ion storage properties of porous Mn-based oxides microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Xiaojuan, E-mail: houxiaojuan@nuc.edu.cn [Key Laboratory of Instrumentation Science & Dynamic Measurement of Ministry of Education, School of Instrument and Electronics, North University of China, Taiyuan, Shanxi Province 030051 (China); Zhu, Jie [Key Laboratory of Instrumentation Science & Dynamic Measurement of Ministry of Education, School of Instrument and Electronics, North University of China, Taiyuan, Shanxi Province 030051 (China); School of Computer and Remote Sensing Information Technology, North China Institute of Aerospace Engineering, Langfang, Hebei Province 065000 (China); Shi, Shuzheng [School of Mechanical Engineering, Hebei University of Architecture, Zhangjiakou, Hebei Province 075000 (China); He, Jian; Mu, Jiliang; Geng, Wenping; Chou, Xiujian; Xue, Chenyang [Key Laboratory of Instrumentation Science & Dynamic Measurement of Ministry of Education, School of Instrument and Electronics, North University of China, Taiyuan, Shanxi Province 030051 (China)

    2017-05-15

    Highlights: • The Mn{sub 2}O{sub 3}, MnCo{sub 2}O{sub 4} and CoMn{sub 2}O{sub 4} microspheres were fabricated with the same method. • Capacities present an increasing trend as with the increasing percentage of Co element. • Plateaus present a lower trend as with the increasing percentage of Mn element. • Mn{sub 2}O{sub 3} microspheres present the most excellent cycling stability. - Abstract: Porous nanosheets assembled Mn-based oxides (Mn{sub 2}O{sub 3}, MnCo{sub 2}O{sub 4} and CoMn{sub 2}O{sub 4}) microspheres of diameters about 3–6 μm and pore size distribution mainly around 10 nm have been synthesized by the same facile solvothermal route without any surfactant followed by a calcination process. In virtue of the porous nanosheets constructed microspheres, the Mn-based oxides microspheres Mn{sub 2}O{sub 3} present specific capacities of 650 mAh/g after 100 charge and discharge cycles. Additionally among the three Mn-based oxides the representative specific capacities present an increasing trend as with the increasing percentage of Co element, the plateau of charge and discharge present a lower trend as with the increasing percentage of Mn element which is more suitable as anode materials in high output full batteries. Then the oxides with different components could be applied in different conditions such as the need for high specific capacity or high output lithium-ion batteries. Consequently the easy fabrication of microspheres and excellent electrochemical performances demonstrate Mn-based oxides’ great potential in lithium-ion batteries.

  14. Experimental apparatus for overlapping a ground-state cooled ion with ultracold atoms

    Science.gov (United States)

    Meir, Ziv; Sikorsky, Tomas; Ben-shlomi, Ruti; Akerman, Nitzan; Pinkas, Meirav; Dallal, Yehonatan; Ozeri, Roee

    2018-03-01

    Experimental realizations of charged ions and neutral atoms in overlapping traps are gaining increasing interest due to their wide research application ranging from chemistry at the quantum level to quantum simulations of solid state systems. In this paper, we describe our experimental system in which we overlap a single ground-state cooled ion trapped in a linear Paul trap with a cloud of ultracold atoms such that both constituents are in the ?K regime. Excess micromotion (EMM) currently limits atom-ion interaction energy to the mK energy scale and above. We demonstrate spectroscopy methods and compensation techniques which characterize and reduce the ion's parasitic EMM energy to the ?K regime even for ion crystals of several ions. We further give a substantial review on the non-equilibrium dynamics which governs atom-ion systems. The non-equilibrium dynamics is manifested by a power law distribution of the ion's energy. We also give an overview on the coherent and non-coherent thermometry tools which can be used to characterize the ion's energy distribution after single to many atom-ion collisions.

  15. State of the art on ion and precipitate flotation

    Energy Technology Data Exchange (ETDEWEB)

    Jung, In Ha; Yang, Myung Seung; Bae, Ki Kwang; Shon, Jong Sik; Cho, Young Hyun

    1997-08-01

    This report is contained research status of foam separation technique and thus theoretical backgrounds, the kinds of surfactants using for the foam separation technique, their characteristics, general structure and role, surfactant absorption mechanism at liquid/vapor/solid interfaces, effectiveness and efficiency were interpreted with well known models. Ion flotation and precipitate flotation which are applicable for the treatment of very low radioactive liquid wastes were analyzed on the effect of pH, foreign ions, initial concentration of metal ion through the recent presented papers. As the result of technical analysis of foam separation technique, foam separation technique seems to be applicable for the treatment of very low radioactive liquid wastes such as laundry and shower waste. (author). 42 refs., 2 tabs., 37 figs

  16. A Summary of Recent Experimental Research on Ion Energy and Charge States of Pulsed Vacuum Arcs

    International Nuclear Information System (INIS)

    Oks, Efim M.; Yushkov, Georgy Yu.; Anders, Andre

    2008-01-01

    The paper reviews the results of vacuum arc experimental investigations made collaboratively by research groups from Berkeley and Tomsk over the last two years, i.e. since the last ISDEIV in 2006. Vacuum arc plasma of various metals was produced in pulses of a few hundred microseconds duration, and the research focused on three topics: (i) the energy distribution functions for different ion charge states, (ii) the temporal development of the ion charge state distribution, and (iii) the evolution of the mean directed ion velocities during plasma expansion. A combined quadruple mass-to-charge and energy analyzer (EQP by HIDEN Ltd) and a time-of-flight spectrometer were employed. Cross-checking data by those complimentary techniques helped to avoid possible pitfalls in interpretation. It was found that the ion energy distribution functions in the plasma were independent of the ion charge state, which implies that the energy distribution on a substrate are not equal to due to acceleration in the substrate's sheath. In pulsed arc mode, the individual ion charge states fractions showed changes leading to a decrease of the mean charge state toward a steady-state value. This decrease can be reduced by lower arc current, higher pulse repetition rate and reduced length of the discharge gap. It was also found that the directed ion velocity slightly decreased as the plasma expanded into vacuum

  17. Bound states of hydrogen-like ions in Debye plasma

    International Nuclear Information System (INIS)

    Li Bowen; Jiang Jun; Kang Weimin; Yang Ningxuan; Dong Chenzhong

    2009-01-01

    The plasma screening effects on the energy levels and wave functions of hydrogen-like ions were estimated by using Debye model. The effects on n l(n=1-4, l=0-3) energy levels and wave functions of hydrogen and Fe 25+ ion versus screening lengths λ have been analyzed. Furthermore, the screening effects versus quantum number n and l has been analyzed. The results show that the screening effects increasing as n increasing and decreasing as l increasing. Last, the Eigenergies of isoelectronic series change against screening parameter λ has been discussed, it's shown that the plasma screening effects are decreasing as nuclear charge increasing. (authors)

  18. Synthesis and characterization of ruthenium fluorides and oxide fluorides with high oxidation states

    International Nuclear Information System (INIS)

    Meublat, L.

    1989-10-01

    The synthesis of ruthenium fluorides and oxide fluorides with high oxidation states was attempted from dioxide RuO 2 and tetroxide RuO 4 . Three fluorinating agents were used: fluorine, chlorine trifluoride and krypton difluoride. The reactions were achieved in anhydrous hydrogen fluoride at room temperature. Thus, the reaction of RuO 4 with CIF 3 enabled us to prepare chloryl hexafluororuthenate (V), CIO 2 + RuF 6 - , a new compound well identified by vibrational spectroscopy (infra-red and Raman), the structure of which was determined. The reaction of KrF 2 with RuO 4 gave the oxide tetrafluoride RuOF 4 , the previously published syntheses and properties of which were not in agreement with each other. This compound was definitely characterized here by chemical analysis, infra-red spectroscopy and X-ray powder diffraction. The product of thermal decomposition (70 0 C) of RuOF 4 is presumably RuF 4 since only oxygen is liberated during this decomposition. At last, the reaction of KrF 2 with RuO 2 probably leads to the formation of the new oxide fluoride RuO 2 F 4 . Indeed, no oxygen is given off during this reaction, the chemical analysis of the red-orange coloured solid residue is almost in agreement with the one proposed and its infra-red absorption spectrum indicates the presence of ruthenium-oxygen and ruthenium-terminal and bridging fluorine bonds [fr

  19. Synthesis and characterization of ruthenium fluorides and oxide fluorides with high oxidation states

    International Nuclear Information System (INIS)

    Meublat, L.

    1989-01-01

    The synthesis of ruthenium fluorides and oxide fluorides with high oxidation states was attempted from dioxide RuO 2 and tetroxide RuO 4 . Three fluorinating agents were used: fluorine, chlorine trifluoride and krypton difluoride. The reactions were achieved in anhydrous hydrogen fluoride at room temperature. Thus, the reaction of RuO 4 with CIF 3 enabled us to prepare chloryl hexafluororuthenate (V), ClO 2 + RuF 6 - , a new compound well idendified by vibrational spectroscopy (infra-red and Raman), the structure of which was determined. The reaction of KrF 2 with RuO 4 gave the oxide tetrafluoride RuOF 4 , the previously published syntheses and properties of which were not in agreement with each other. This compound was definitely characterized here by chemical analysis, infra-red spectroscopy and X-ray powder diffraction. The product of thermal decomposition (70 0 C) of RuOF 4 is presumably RuF 4 since only oxygen is liberated during this decomposition. At last, the reaction of KrF 2 with RuO 2 probably leads to the formation of the new oxide fluoride RuO 2 F 4 . Indeed, no oxygen is given off during this reaction, the chemical analysis of the red-orange coloured solid residue is almost in agreement with the one proposed and its infra-red absorption spectrum indicates the presence of ruthenium-oxygen and ruthenium-terminal and bridging fluorine bonds [fr

  20. Quantum computing with four-particle decoherence-free states in ion trap

    OpenAIRE

    Feng, Mang; Wang, Xiaoguang

    2001-01-01

    Quantum computing gates are proposed to apply on trapped ions in decoherence-free states. As phase changes due to time evolution of components with different eigenenergies of quantum superposition are completely frozen, quantum computing based on this model would be perfect. Possible application of our scheme in future ion-trap quantum computer is discussed.

  1. Self-organised nano-structuring of thin oxide-films under swift heavy ion bombardment

    International Nuclear Information System (INIS)

    Bolse, Wolfgang

    2006-01-01

    Surface instabilities and the resulting self-organisation processes play an important role in nano-technology since they allow for large-array nano-structuring. We have recently found that the occurrence of such instabilities in thin film systems can be triggered by energetic ion bombardment and the subsequent self-assembly of the surface can be nicely controlled by fine-tuning of the irradiation conditions. The role of the ion in such processes is of double nature: If the instability is latently present already in the virgin sample, but self-assembly cannot take place because of kinetic barriers, the ion impact may just supply the necessary atomic mobility. On the other hand, the surface may become instable due to the ion beam induced material modifications and further irradiation then results in its reorganisation. In the present paper, we will review recently observed nano-scale self-organisation processes in thin oxide-films induced by the irradiation with swift heavy ions (SHI) at some MeV/amu energies. The first example is about SHI induced dewetting, which is driven by capillary forces already present in the as-deposited samples. The achieved dewetting pattern show an amazing similarity to those observed for liquid polymer films on Si, although in the present case the samples were kept at 80 K and hence have never reached their melting point. The second example is about self-organised lamellae formation driven by planar stresses, which are induced by SHI bombardment under grazing incidence and result in a surface instability and anisotropic plastic deformation (hammering effect). Taking advantage of these effects and modifying the irradiation procedure, we were able to generate more complex structures like NiO-'nano-towers' of 2 μm height and 200 nm in diameter

  2. Self-assembly of metal–organic frameworks and graphene oxide as precursors for lithium-ion battery applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xia [Southwest University, Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering (China); Liu, Linlin [City University of Hong Kong, Department of Physics and Materials Science, Center of Super-Diamond and Advanced Films (COSDAF) (Hong Kong); Yuan, Ruo, E-mail: yuanruo@swu.edu.cn [Southwest University, Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering (China); Lee, Chun-Sing, E-mail: apcslee@cityu.edu.hk [City University of Hong Kong, Department of Physics and Materials Science, Center of Super-Diamond and Advanced Films (COSDAF) (Hong Kong)

    2016-10-15

    We fabricated composites of Fe{sub 2}O{sub 3}/reduced graphene oxide as lithium-ion batteries anode material with controlled structures by employing self-assembly of metal–organic frameworks (MOFs) and polymer-functionalized graphene oxide as precursors. By electrostatic interaction, the negatively charged MOFs, Prussian Blue (PB), are assembled on poly(diallyldimethylammonium chloride) (PDDA)-functionalized graphene oxide (positive charge). Then the PB cubes become FeOOH nanosheets when treated with sodium hydroxide. Upon further annealing, the FeOOH nanosheets transform to Fe{sub 2}O{sub 3} nanoparticles while the graphene oxide become reduced graphene oxide simultaneously. It was found that the composites have good performance as anode of lithium-ion battery. This work shows a new way for self-assembling MOFs and 2D materials.

  3. Effect of annealing and oxide layer thickness on doping profiles shape of ''through-oxide'' implanted P+ ions in textured silicon

    International Nuclear Information System (INIS)

    El-Dessouki, M.S.; Galloni, R.

    1987-10-01

    Phosphorous ions at energies of 60+100 KeV, and doses (4+5)x10 15 atom/cm 2 have been implanted randomly through SiO 2 layers into textured silicon crystals. The penetration profiles of the P + ions have been determined by means of differential sheet resistivity and Hall-effect, together with the anodic oxidation stripping technique. The effect of the oxide layer thickness, annealing temperature on the junction properties has been studied. The damage produced by implantation, has also been investigated using transmission electron microscope (TEM). From the mobility measurements of the free carriers as a function of depth through the junction, two minima have been observed in through oxide implanted samples. The one nearer to the Si-SiO 2 interface (at about 200A from the interface) was related to the damage produced by the recoil oxygen atoms from the oxide layer into silicon. The deeper minimum is lying at ∼ 0.2μm from the interface and was attributed to the damage produced by the implanted P + ions, which caused clusters and defect loops after annealing. This damage was observed through TEM photographs. The optimum conditions for producing shallow junction without losing much of the implanted P + ions through the oxide layer were estimated. (author). 22 refs, 7 figs, 1 tab

  4. Intestinal Oxidative State Can Alter Nutrient and Drug Bioavailability

    Directory of Open Access Journals (Sweden)

    Faria Ana

    2009-01-01

    Full Text Available Organic cations (OCs are substances of endogenous (e.g., dopamine, choline or exogenous (e.g., drugs like cimetidine origin that are positively charged at physiological ph. since many of these compounds can not pass the cell membrane freely, their transport in or out of cells must be mediated by specific transport systems. Transport by organic cation transporters (OCTs can be regulated rapidly by altering their trafficking and/or affinities in response to stimuli. However, for example, a specific disease could lead to modifications in the expression of OCTs. Chronic exposure to oxidative stress has been suggested to alter regulation and functional activity of proteins through several pathways. According to results from a previous work, oxidation-reduction pathways were thought to be involved in intestinal organic cation uptake modulation. The present work was performed in order to evaluate the influence of oxidative stressors, especially glutathione, on the intestinal organic cation absorption. For this purpose, the effect of compounds with different redox potential (glutathione, an endogenous antioxidant, and procyanidins, diet antioxidants was assessed on MPP+ (1-methyl-4-phenylpyridinium iodide uptake in an enterocyte cell line (Caco-2. Caco-2 cells were subcultured with two different media conditions (physiological: 5 mM glucose, referred as control cells; and high-glucose: 25 mM glucose, referred as HG cells. In HG cells, the uptake was significantly lower than in control cells. Redox changing interventions affected Mpp+ uptake, both in control and in high-glucose Caco-2 cells. Cellular glutathione levels could have an important impact on membrane transporter activity. The results indicate that modifications in the cellular oxidative state modulate MPP+ uptake by Caco-2 cells. Such modifications may reflect in changes of nutrient and drug bioavailability.

  5. Persistence of oxidation state III of gold in thione coordination

    Science.gov (United States)

    Jääskeläinen, Sirpa; Koskinen, Laura; Kultamaa, Matti; Haukka, Matti; Hirva, Pipsa

    2017-05-01

    Ligands N,N'-tetramethylthiourea and 2-mercapto-1-methyl-imidazole form stable Au(III) complexes [AuCl3(N,N'-tetramethylthiourea)] (1) and [AuCl3(2-mercapto-1-methyl-imidazole)] (2) instead of reducing the Au(III) metal center into Au(I), which would be typical for the attachment of sulfur donors. Compounds 1 and 2 were characterized by spectroscopic methods and by X-ray crystallography. The spectroscopic details were explained by simulation of the UV-Vis spectra via the TD-DFT method. Additionally, computational DFT studies were performed in order to find the reason for the unusual oxidation state in the crystalline materials. The preference for Au(III) can be explained via various weak intra- and intermolecular interactions present in the solid state structures. The nature of the interactions was further investigated by topological charge density analysis via the QTAIM method.

  6. Kinetic Study of Zn2+ and Cd2+ Ions Sorption by Ceric Oxide Powder

    International Nuclear Information System (INIS)

    Hassan, H.S.; Abd El-Rahman, K.M.; El Sayed, A.A.

    2008-01-01

    Ceric Oxide powder was chemically synthesized and characterized using infrared spectra and x-ray diffraction. The sorptive removal of Zinc and Cadmium ions from aqueous waste solution using synthetic ceric oxide powder was investigated using batch technique. Experiments were carried out as a function of ph, particle size, solute concentration and temperature. The uptake of zinc was found to be greater than that of cadmium. A comparison of kinetic models applied to the sorption process of each ion was evaluated for the pseudo first order, the pseudo second order, and homogeneous particle diffusion kinetic models, respectively. The results showed that both the pseudo second order and the homogeneous particle diffusion model (HPDM) were found to best correlate the experimental rate data. The numerical values of the rate constants and particle diffusion coefficients were determined from the graphical representation of the proposed models. Activation energy (Ε a ) and entropy (δ S * ) of activation for each sorption process were also calculated from the linearized form of Arrhenius equation

  7. Swift heavy ion induced de wetting of metal oxide thin films on silicon

    International Nuclear Information System (INIS)

    Bolse, T.; Paulus, H.; Bolse, W.

    2006-01-01

    We have observed that thin oxide coatings (NiO, Fe 2 O 3 ) tend to dewet their Si substrate when being bombarded with swift heavy ions (350-600 MeV Au ions) even though the irradiation was carried out about 80 K and hence, the films never reached their melting point. Scanning electron and atomic force microscopy reveal a surprising similarity of the dewetting morphologies with those observed for molten polymer films on Si, which have recently been reported by others [S. Herminghaus, K. Jakobs, K. Mecke, J. Bischof, A. Fery, M. Ibn-Elhaj, S. Schlagowsky, Science 282 (1998) 916; R. Seemann, S. Herminghaus, K. Jacobs, J. Phys.: Condens. Matter 13 (2001) 4925]. Like in that cases also here heterogeneous and homogeneous hole nucleation could be identified. Heterogeneous nucleation is less pronounced in Fe 2 O 3 /Si than in NiO/Si. The occurrence of spinodal-like dewetting cannot be detected unambiguously. The dewetting kinetics were determined by means of Rutherford backscattering spectroscopy and found to slightly differ for the two compounds. The dewetting kinetics as well as the final dewetting pattern strongly depend on the initial film thicknesses. No dewetting occurs for film thicknesses above about 150 nm, while for very small thicknesses below about 40 nm the film decays into nm-sized spherical droplets. At intermediate film thicknesses percolated networks of small oxide bridges are formed

  8. Immediate fabrication of flower-like graphene oxide by ion beam bombardment

    International Nuclear Information System (INIS)

    Cheng, Junjie; Zhang, Yuanyuan; Zhang, Guilong; Xiong, Shiquan; Pei, Renjun; Cai, Dongqing; Wu, Zhengyan

    2015-01-01

    Graphical abstract: - Highlights: • Ion beam bombardment (IBB) could modify the microstructure of graphene oxide (GO). • IBB could transform a compact multi-layered GO to a few-layered flower-like GO. • IBB could effectively improve the dispersion and the related properties of GO. • The main mechanism was proposed to be the etching and charge effects of IBB. - Abstract: An effective and convenient method using ion beam bombardment (IBB) for separating a multi-layered compact graphene oxide (GO) piece into several small few-layered loose pieces was developed, and it was found that those small GO pieces had formed a flower-like structure. Therein, the main mechanism was proposed to be the etching and charge effects of IBB. This work could provide a facile and promising approach for improving the dispersion and the related properties of GO. Furthermore, X-ray diffraction and Raman spectrum determinations demonstrated that, with the increasing fluence, IBB could effectively decrease the chemical groups in the layers of GO, resulting in the decrease of the layer distance.

  9. Immediate fabrication of flower-like graphene oxide by ion beam bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Junjie [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Division of Nanobiomedicine, Key Laboratory for Nano-Bio Interface Research, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123 (China); Zhang, Yuanyuan; Zhang, Guilong [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Xiong, Shiquan [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Pei, Renjun, E-mail: rjpei2011@sinano.ac.cn [Division of Nanobiomedicine, Key Laboratory for Nano-Bio Interface Research, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123 (China); Cai, Dongqing, E-mail: dqcai@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Wu, Zhengyan, E-mail: zywu@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China)

    2015-12-01

    Graphical abstract: - Highlights: • Ion beam bombardment (IBB) could modify the microstructure of graphene oxide (GO). • IBB could transform a compact multi-layered GO to a few-layered flower-like GO. • IBB could effectively improve the dispersion and the related properties of GO. • The main mechanism was proposed to be the etching and charge effects of IBB. - Abstract: An effective and convenient method using ion beam bombardment (IBB) for separating a multi-layered compact graphene oxide (GO) piece into several small few-layered loose pieces was developed, and it was found that those small GO pieces had formed a flower-like structure. Therein, the main mechanism was proposed to be the etching and charge effects of IBB. This work could provide a facile and promising approach for improving the dispersion and the related properties of GO. Furthermore, X-ray diffraction and Raman spectrum determinations demonstrated that, with the increasing fluence, IBB could effectively decrease the chemical groups in the layers of GO, resulting in the decrease of the layer distance.

  10. Ion beam-based characterization of multicomponent oxide thin films and thin film layered structures

    International Nuclear Information System (INIS)

    Krauss, A.R.; Rangaswamy, M.; Lin, Yuping; Gruen, D.M.; Schultz, J.A.; Schmidt, H.K.; Chang, R.P.H.

    1992-01-01

    Fabrication of thin film layered structures of multi-component materials such as high temperature superconductors, ferroelectric and electro-optic materials, and alloy semiconductors, and the development of hybrid materials requires understanding of film growth and interface properties. For High Temperature Superconductors, the superconducting coherence length is extremely short (5--15 Angstrom), and fabrication of reliable devices will require control of film properties at extremely sharp interfaces; it will be necessary to verify the integrity of thin layers and layered structure devices over thicknesses comparable to the atomic layer spacing. Analytical techniques which probe the first 1--2 atomic layers are therefore necessary for in-situ characterization of relevant thin film growth processes. However, most surface-analytical techniques are sensitive to a region within 10--40 Angstrom of the surface and are physically incompatible with thin film deposition and are typically restricted to ultra high vacuum conditions. A review of ion beam-based analytical methods for the characterization of thin film and multi-layered thin film structures incorporating layers of multicomponent oxides is presented. Particular attention will be paid to the use of time-of-flight techniques based on the use of 1- 15 key ion beams which show potential for use as nondestructive, real-time, in-situ surface diagnostics for the growth of multicomponent metal and metal oxide thin films

  11. Copper nanofiber-networked cobalt oxide composites for high performance Li-ion batteries

    Directory of Open Access Journals (Sweden)

    Shim Hee-Sang

    2011-01-01

    Full Text Available Abstract We prepared a composite electrode structure consisting of copper nanofiber-networked cobalt oxide (CuNFs@CoO x . The copper nanofibers (CuNFs were fabricated on a substrate with formation of a network structure, which may have potential for improving electron percolation and retarding film deformation during the discharging/charging process over the electroactive cobalt oxide. Compared to bare CoO x thin-film (CoO x TF electrodes, the CuNFs@CoO x electrodes exhibited a significant enhancement of rate performance by at least six-fold at an input current density of 3C-rate. Such enhanced Li-ion storage performance may be associated with modified electrode structure at the nanoscale, improved charge transfer, and facile stress relaxation from the embedded CuNF network. Consequently, the CuNFs@CoO x composite structure demonstrated here can be used as a promising high-performance electrode for Li-ion batteries.

  12. Kinetic study of Cs+ and Eu3+ ions sorption by zirconium oxide powder

    International Nuclear Information System (INIS)

    Hanafi, H.A.; Hassan, H.S.; Hamed, M.M.

    2009-01-01

    Full text: Zirconium oxide powder was chemically synthesized by sol-gel method and characterized using infrared spectra and x-ray diffraction. The sorptive removal of cesium and europium ions from aqueous waste solution using synthetic zirconium oxide powder was investigated using batch technique. Experiments were carried out as a function of pH, time and temperature. The uptake of europium was found to be greater than that of cesium. A comparison of kinetic models applied to the sorption process of each ion was evaluated for the pseudo first order, the pseudo second order, and homogeneous particle diffusion kinetic models, respectively. The results showed that both the pseudo second order and the homogeneous particle diffusion models (HPDM) were found to best correlate the experimental rate data. The numerical values of the rate constants and particle diffusion coefficients were determined from the graphical representation of the proposed models. Activation energy (Ea) and entropy (Δ S*) of activation for each sorption process were also calculated from the linearized form of Arrhenius equation. (author)

  13. High Energy Density Solid State Li-ion Battery with Enhanced Safety, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop an all solid state Li-ion battery which is capable of delivering high energy density, combined with high safety over a wide operating...

  14. Synthesizing new types of ultrathin 2D metal oxide nanosheets via half-successive ion layer adsorption and reaction

    Science.gov (United States)

    Gao, Linjie; Li, Yaguang; Xiao, Mu; Wang, Shufang; Fu, Guangsheng; Wang, Lianzhou

    2017-06-01

    Two-dimensional (2D) metal oxide nanosheets have demonstrated their great potential in a broad range of applications. The existing synthesis strategies are mainly preparing 2D nanosheets from layered and specific transition metal oxides. How to prepare the other types of metal oxides as ultrathin 2D nanosheets remains unsolved, especially for metal oxides containing alkali, alkaline earth metal, and multiple metal elements. Herein, we developed a half-successive ion layer adsorption and reaction (SILAR) method, which could synthesize those types of metal oxides as ultrathin 2D nanosheets. The synthesized 2D metal oxides nanosheets are within 1 nm level thickness and 500 m2 · g-1 level surface area. This method allows us to develop many new types of ultrathin 2D metal oxides nanosheets that have never been prepared before.

  15. Monodispersed macroporous architecture of nickel-oxide film as an anode material for thin-film lithium-ion batteries

    International Nuclear Information System (INIS)

    Wu, Mao-Sung; Lin, Ya-Ping

    2011-01-01

    A nickel-oxide film with monodispersed open macropores was prepared on a stainless-steel substrate by electrophoretic deposition of a polystyrene-sphere monolayer followed by anodic electrodeposition of nickel oxy-hydroxide. The deposited films convert to cubic nickel oxide after annealing at 400 o C for 1 h. Galvanostatic charge and discharge results indicate that the nickel-oxide film with monodispersed open macropores is capable of delivering a higher capacity than the bare nickel-oxide film, especially in high-rate charge and discharge processes. The lithiation capacity of macroporous nickel oxide reaches 1620 mA h g -1 at 1 C current discharge and decreases to 990 mA h g -1 at 15 C current discharge. The presence of monodispersed open macropores in the nickel-oxide film might facilitate the electrolyte penetration, diffusion, and migration. Electrochemical reactions between nickel oxide and lithium ions are therefore markedly improved by this tailored film architecture.

  16. Gas-phase fragmentation of coordination compounds: loss of CO(2) from inorganic carbonato complexes to give metal oxide ions

    Science.gov (United States)

    Dalgaard; McKenzie

    1999-10-01

    Using electrospray ionization mass spectrometry, novel transition metal oxide coordination complex ions are proposed as the products of the collision-induced dissociation (CID) of some carbonato complex ions through the loss of a mass equivalent to CO(2). CID spectra of [(tpa)CoCO(3)](+) (tpa = tris(2-pyridylmethyl)methylamine), [(bispicMe(2)en)Fe(&mgr;-O)(&mgr;-CO(3))Fe(bispicMe(2)en)]2+ (bispicMe(2)en = N,N'-dimethyl-N,N'-bis(2-pyridylmethy)eth- ane-1, 2-diamine) and [(bpbp)Cu(2)CO(3)](+) (bpbp(-) = bis[(bis-(2-pyridylmethyl)amino)methyl]-4-tertbutylpheno-lato(1-)), show peaks assigned to the mono- and dinuclear oxide cations, [(tpa)CoO](+), [(bispicMe(2)en)(2)Fe(2)(O)(2)]2+ and [(bpbp)Cu(2)O](+), as the dominant species. These results can be likened to the reverse of typical synthetic reactions in which metal hydroxide compounds react with CO(2) to give metal carbonato compounds. Because of the lack of available protons in the gas phase, novel oxide species rather than the more common hydroxide ions are generated. These oxide ions are relevant to the highly oxidizing species proposed in oxygenation reactions catalysed by metal oxides and metalloenzymes. Copyright 1999 John Wiley & Sons, Ltd.

  17. Proteomic indicators of oxidation and hydration state in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Jeffrey M. Dick

    2016-07-01

    Full Text Available New integrative approaches are needed to harness the potential of rapidly growing datasets of protein expression and microbial community composition in colorectal cancer. Chemical and thermodynamic models offer theoretical tools to describe populations of biomacromolecules and their relative potential for formation in different microenvironmental conditions. The average oxidation state of carbon (ZC can be calculated as an elemental ratio from the chemical formulas of proteins, and water demand per residue ( ${\\overline{n}}_{{\\mathrm{H}}_{2}\\mathrm{O}}$ n ¯ H 2 O is computed by writing the overall formation reactions of proteins from basis species. Using results reported in proteomic studies of clinical samples, many datasets exhibit higher mean ZC or ${\\overline{n}}_{{\\mathrm{H}}_{2}\\mathrm{O}}$ n ¯ H 2 O of proteins in carcinoma or adenoma compared to normal tissue. In contrast, average protein compositions in bacterial genomes often have lower ZC for bacteria enriched in fecal samples from cancer patients compared to healthy donors. In thermodynamic calculations, the potential for formation of the cancer-related proteins is energetically favored by changes in the chemical activity of H2O and fugacity of O2 that reflect the compositional differences. The compositional analysis suggests that a systematic change in chemical composition is an essential feature of cancer proteomes, and the thermodynamic descriptions show that the observed proteomic transformations in host tissue could be promoted by relatively high microenvironmental oxidation and hydration states.

  18. Composition and oxidation state of sulfur in atmospheric particulate matter

    Directory of Open Access Journals (Sweden)

    A. F. Longo

    2016-10-01

    Full Text Available The chemical and physical speciation of atmospheric sulfur was investigated in ambient aerosol samples using a combination of sulfur near-edge x-ray fluorescence spectroscopy (S-NEXFS and X-ray fluorescence (XRF microscopy. These techniques were used to determine the composition and oxidation state of sulfur in common primary emission sources and ambient particulate matter collected from the greater Atlanta area. Ambient particulate matter samples contained two oxidation states: S0 and S+VI. Ninety-five percent of the individual aerosol particles (> 1 µm analyzed contain S0. Linear combination fitting revealed that S+VI in ambient aerosol was dominated by ammonium sulfate as well as metal sulfates. The finding of metal sulfates provides further evidence for acidic reactions that solubilize metals, such as iron, during atmospheric transport. Emission sources, including biomass burning, coal fly ash, gasoline, diesel, volcanic ash, and aerosolized Atlanta soil, and the commercially available bacterium Bacillus subtilis, contained only S+VI. A commercially available Azotobacter vinelandii sample contained approximately equal proportions of S0 and S+VI. S0 in individual aerosol particles most likely originates from primary emission sources, such as aerosolized bacteria or incomplete combustion.

  19. The effect of ion implantation on the oxidation resistance of vacuum plasma sprayed CoNiCrAlY coatings

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Jie [Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences, Shanghai 200050 (China); Shanghai Institute of Ceramic, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Zhao Huayu; Zhou Xiaming [Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences, Shanghai 200050 (China); Shanghai Institute of Ceramic, Chinese Academy of Sciences, Shanghai 200050 (China); Tao Shunyan, E-mail: shunyantao@mail.sic.ac.cn [Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences, Shanghai 200050 (China); Shanghai Institute of Ceramic, Chinese Academy of Sciences, Shanghai 200050 (China); Ding Chuanxian [Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences, Shanghai 200050 (China); Shanghai Institute of Ceramic, Chinese Academy of Sciences, Shanghai 200050 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer We used ion implantation to improve the oxidation resistance of CoNiCrAlY coating. Black-Right-Pointing-Pointer The oxidation process of CoNiCrAlY coating at 1100 Degree-Sign C for 1000 h was studied. Black-Right-Pointing-Pointer The Nb ion implanted coating exhibited better oxidation resistance. Black-Right-Pointing-Pointer The influences of Nb and Al ion implantation into CoNiCrAlY coatings were evaluated. - Abstract: CoNiCrAlY coatings prepared by vacuum plasma spraying (VPS) were implanted with Nb and Al ions at a fluence of 10{sup 17} atoms/cm{sup 2}. The effects of ion implantation on the oxidation resistance of CoNiCrAlY coatings were investigated. The thermally grown oxide (TGO) formed on each specimen was characterized by XRD, SEM and EDS, respectively. The results showed that the oxidation process of CoNiCrAlY coatings could be divided into four stages and the key to obtaining good oxidation resistance was to remain high enough amount of Al and promote the lateral growth of TGO. The implantation of Nb resulted in the formation of continuous and dense Al{sub 2}O{sub 3} scale to improve the oxidation resistance. The Al implanted coating could form Al{sub 2}O{sub 3} scale at the initial stage, however, the scale was soon broken and TGO transformed to non-protective spinel.

  20. Antibacterial TiO2Coating Incorporating Silver Nanoparticles by Micro arc Oxidation and Ion Implantation

    International Nuclear Information System (INIS)

    Zhang, P.; Zhang, Z.; Li, W.

    2013-01-01

    Infection associated with titanium implants remains the most common serious complication in hard tissue replacement surgery. Since such postoperative infections are usually difficult to cure, it is critical to find optimal strategies for preventing infections. In this study, TiO 2 coating incorporating silver (Ag) nanoparticles were fabricated on pure titanium by micro arc oxidation and ion implantation. The antibacterial activity was evaluated by exposing the specimens to Staphylococcus aureus and comparing the reaction of the pathogens to Ti-MAO-Ag with Ti-MAO controls. Ti-MAO-Ag clearly inhibited bacterial colonization more than the control specimen. The coating’s antibacterial ability was enhanced by increasing the dose of silver ion implantation, and Ti-MAO-Ag 20.0 had the best antibacterial ability. In addition, cytocompatibility was assessed by culturing cell colonies on the specimens. The cells grew well on both specimens. These findings indicate that surface modification by means of this process combining MAO and silver ion implantation is useful in providing antibacterial activity and exhibits cytocompatibility with titanium implants

  1. Aluminum oxide mask fabrication by focused ion beam implantation combined with wet etching

    International Nuclear Information System (INIS)

    Liu Zhengjun; Iltanen, Kari; Chekurov, Nikolai; Tittonen, Ilkka; Grigoras, Kestutis

    2013-01-01

    A novel aluminum oxide (Al 2 O 3 ) hard mask fabrication process with nanoscale resolution is introduced. The Al 2 O 3 mask can be used for various purposes, but in this work it was utilized for silicon patterning using cryogenic deep reactive ion etching (DRIE). The patterning of Al 2 O 3 is a two-step process utilizing focused ion beam (FIB) irradiation combined with wet chemical etching. Gallium (Ga + ) FIB maskless patterning confers wet etch selectivity between the irradiated region and the non-irradiated one on the Al 2 O 3 layer, and mask patterns can easily be revealed by wet etching. This method is a modification of Ga + FIB mask patterning for the silicon etch stop, which eliminates the detrimental lattice damage and doping of the silicon substrate in critical devices. The shallow surface gallium FIB irradiated Al 2 O 3 mask protects the underlying silicon from Ga + ions. The performance of the masking capacity was tested by drawing pairs consisting of a line and an empty space with varying width. The best result was seven such pairs for 1 μm. The smallest half pitch was 59 nm. This method is capable of arbitrary pattern generation. The fabrication of a freestanding single-ended tuning fork resonator utilizing the introduced masking method is demonstrated. (paper)

  2. Disturbance of ion environment and immune regulation following biodistribution of magnetic iron oxide nanoparticles injected intravenously.

    Science.gov (United States)

    Park, Eun-Jung; Kim, Sang-Wook; Yoon, Cheolho; Kim, Younghun; Kim, Jong Sung

    2016-01-22

    Although it is expected that accumulation of metal oxide nanoparticles that can induce redox reaction in the biological system may influence ion homeostasis and immune regulation through generation of free radicals, the relationship is still unclear. In this study, mice received magnetic iron oxide nanoparticles (M-FeNPs, 2 and 4 mg/kg) a single via the tail vein, and their distribution in tissues was investigated over time (1, 4, and 13 weeks). In addition, we evaluated the effects on homeostasis of redox reaction-related elements, the ion environment and immune regulation. The iron level in tissues reached at the maximum on 4 weeks after injection and M-FeNPs the most distributed in the spleen at 13 weeks. Additionally, levels of redox reaction-related elements in tissues were notably altered since 1 week post-injection. While levels of K(+) and Na(+) in tissue tended to decrease with time, Ca(2+) levels reached to the maximum at 4 weeks post-injection. On 13 weeks post-injection, the increased percentages of neutrophils and eosinophils, the enhanced release of LDH, and the elevated secretion of IL-8 and IL-6 were clearly observed in the blood of M-FeNP-treated mice compared to the control. While expression of antigen presentation related-proteins and the maturation of dendritic cells were markedly inhibited following distribution of M-FeNPs, the expression of several chemokines, including CXCR2, CCR5, and CD123, was enhanced on the splenocytes of the treated groups. Taken together, we suggest that accumulation of M-FeNPs may induce adverse health effects by disturbing homeostasis of the immune regulation and ion environment. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. The ion dependent change in the mechanism of charge storage of chemically preintercalated bilayered vanadium oxide electrodes

    Science.gov (United States)

    Clites, Mallory; Pomerantseva, Ekaterina

    2017-08-01

    Chemical pre-intercalation is a soft chemistry synthesis approach that allows for the insertion of inorganic ions into the interlayer space of layered battery electrode materials prior to electrochemical cycling. Previously, we have demonstrated that chemical pre-intercalation of Na+ ions into the structure of bilayered vanadium oxide (δ-V2O5) results in record high initial capacities above 350 mAh g-1 in Na-ion cells. This performance is attributed to the expanded interlayer spacing and predefined diffusion pathways achieved by the insertion of charge-carrying ions. However, the effect of chemical pre-intercalation of δ-V2O5 has not been studied for other ion-based systems beyond sodium. In this work, we report the effect of the chemically preintercalated alkali ion size on the mechanism of charge storage of δ- MxV2O5 (M = Li, Na, K) in Li-ion, Na-ion, and K-ion batteries, respectively. The interlayer spacing of the δ-MxV2O5 varied depending on inserted ion, with 11.1 Å achieved for Li-preintercalated δ-V2O5, 11.4 Å for Na-preintercalated δ- V2O5, and 9.6 Å for K-preintercalated δ-V2O5. Electrochemical performance of each material has been studied in its respective ion-based system (δ-LixV2O5 in Li-ion cells, δ-NaxV2O5 in Na-ion cells, and δ-KxV2O5 in K-ion cells). All materials demonstrated high initial capacities above 200 mAh g-1. However, the mechanism of charge storage differed depending on the charge-carrying ion, with Li-ion cells demonstrating predominantly pseudocapacitive behavior and Naion and K-ion cells demonstrating a significant portion of capacity from diffusion-limited intercalation processes. In this study, the combination of increased ionic radii of the charge-carrying ions and decreased synthesized interlayer spacing of the bilayered vanadium oxide phase correlates to an increase in the portion of capacity attributed diffusion-limited charge-storage processes.

  4. Kinetic and mechanistic evaluation of tetrahydroborate ion electro-oxidation at polycrystalline gold

    International Nuclear Information System (INIS)

    Iotov, Philip I.; Kalcheva, Sasha V.; Bond, Alan M.

    2009-01-01

    The anodic oxidation of tetrahydroborate ion is studied in NaOH at stationary and rotating polycrystalline Au disk electrodes. Linear sweep and cyclic voltammetry are applied varying the scan and rotation rate from 0.005 to 51.200 V s -1 and from 52.3 to 314.1 rad s -1 , correspondingly. The effects of variation of BH 4 - and NaOH concentrations as well as of the potential limits of the ranges studied have been initially followed. Most of the experiments have been carried out with 10.9 mM NaBH 4 in 1.04 M NaOH at 293 K in the potential range from -1.300 to 0.900 V (vs. Ag/AgCl). It is found that 6 electrons are exchanged in the overall oxidation transformation. The kinetic analysis of the processes determining the two anodic peaks recorded under static conditions at scan rates lower than 0.500 V s -1 shows that 1.4 electrons are exchanged in the potential range of the first one (at ca -0.5 V), while the rate of the second one (at ca +0.3 V) is determined by a quasi-reversible 1-electron transfer reaction. A kinetic evidence for the participation of surface bound intermediates in the electro-oxidation process is provided. Two additional well outlined anodic peaks are recorded in the aforementioned potential range under specific experimental conditions. A quasi-8 electron mechanism involving four oxidation and hydrolysis steps is advanced to explain the experimental results. It accounts for the involvement of borohydride oxidation species and the Au + /Au 3+ mediator couple.

  5. Experimental efforts at NIST towards one-electron ions in circular Rydberg states

    International Nuclear Information System (INIS)

    Tan, Joseph N; Guise, Nicholas D; Brewer, Samuel M

    2011-01-01

    Experimental effort is underway at NIST to enable tests of theory with one-electron ions synthesized in circular Rydberg states from captured bare nuclei. Problematic effects that limit the accuracy of predicted energy levels for low-lying states are vanishingly small for high-angular-momentum (high-L) states; in particular, the nuclear size correction for high-L states is completely negligible for any foreseeable improvement of measurement precision. As an initial step towards realizing such states, highly charged ions are extracted from the NIST electron beam ion trap (EBIT) and steered through the electrodes of a Penning trap. The goal is to capture bare nuclei in the Penning trap for experiments to make one-electron atoms in circular Rydberg states with dipole (E1) transitions in the optical domain accessible to a frequency comb.

  6. Oxidation states of Fe and Ti in blue sapphire

    International Nuclear Information System (INIS)

    Wongrawang, P; Wongkokua, W; Monarumit, N; Thammajak, N; Wathanakul, P

    2016-01-01

    X-ray absorption near-edge spectroscopy (XANES) can be used to study the oxidation state of a dilute system such as transition metal defects in solid-state samples. In blue sapphire, Fe and Ti are defects that cause the blue color. Inter-valence charge transfer (IVCT) between Fe 2+ and Ti 4+ has been proposed to describe the optical color’s origin. However, the existence of divalent iron cations has not been thoroughly investigated. Fluorescent XANES is therefore employed to study K-edge absorptions of Fe and Ti cations in various blue sapphire samples including natural, synthetic, diffused and heat-treated sapphires. All the samples showed an Fe absorption edge at 7124 eV, corresponding to the Fe 3+ state; and Ti at 4984 eV, corresponding to Ti 4+ . From these results, we propose Fe 3+ -Ti 4+ mixed acceptor states located at 1.75 eV and 2.14 eV above the valence band of corundum, that correspond to 710 nm and 580 nm bands of UV–vis absorption spectra, to describe the cause of the color of blue sapphire. (paper)

  7. Bitwise Bell-inequality violations for an entangled state involving 2N ions

    International Nuclear Information System (INIS)

    Pope, D.T.; Milburn, G.J.

    2004-01-01

    Following on from previous work [J.-A ring . Larsson, Phys. Rev. A 67, 022108 (2003)], Bell inequalities based on correlations between binary digits are considered for a particular entangled state involving 2N trapped ions. These inequalities involve applying displacement operations to half of the ions and then measuring correlations between pairs of corresponding bits in the binary representations of the number of center-of-mass phonons of N particular ions. It is shown that the state violates the inequalities and thus displays nonclassical correlations. It is also demonstrated that it violates a Bell inequality when the displacements are replaced by squeezing operations

  8. Preparation and coherent manipulation of pure quantum states of a single molecular ion

    Science.gov (United States)

    Chou, Chin-Wen; Kurz, Christoph; Hume, David B.; Plessow, Philipp N.; Leibrandt, David R.; Leibfried, Dietrich

    2017-05-01

    Laser cooling and trapping of atoms and atomic ions has led to advances including the observation of exotic phases of matter, the development of precision sensors and state-of-the-art atomic clocks. The same level of control in molecules could also lead to important developments such as controlled chemical reactions and sensitive probes of fundamental theories, but the vibrational and rotational degrees of freedom in molecules pose a challenge for controlling their quantum mechanical states. Here we use quantum-logic spectroscopy, which maps quantum information between two ion species, to prepare and non-destructively detect quantum mechanical states in molecular ions. We develop a general technique for optical pumping and preparation of the molecule into a pure initial state. This enables us to observe high-resolution spectra in a single ion (CaH+) and coherent phenomena such as Rabi flopping and Ramsey fringes. The protocol requires a single, far-off-resonant laser that is not specific to the molecule, so many other molecular ions, including polyatomic species, could be treated using the same methods in the same apparatus by changing the molecular source. Combined with the long interrogation times afforded by ion traps, a broad range of molecular ions could be studied with unprecedented control and precision. Our technique thus represents a critical step towards applications such as precision molecular spectroscopy, stringent tests of fundamental physics, quantum computing and precision control of molecular dynamics.

  9. Novel iron oxide nanotube arrays as high-performance anodes for lithium ion batteries

    Science.gov (United States)

    Zhong, Yuan; Fan, Huiqing; Chang, Ling; Shao, Haibo; Wang, Jianming; Zhang, Jianqing; Cao, Chu-nan

    2015-11-01

    Nanostructured iron oxides can be promising anode materials for lithium ion batteries (LIBs). However, improvement on the rate capability and/or electrochemical cycling stability of iron oxide anode materials remains a key challenge because of their poor electrical conductivities and large volume expansion during cycling. Herein, the vertically aligned arrays of one-dimensional (1D) iron oxide nanotubes with 5.8 wt% carbon have been fabricated by a novel surfactant-free self-corrosion process and subsequent thermal treatment. The as-fabricated nanotube array electrode delivers a reversible capacity of 932 mAh g-1 after 50 charge-discharge cycles at a current of 0.6 A g-1. The electrode still shows a reversible capacity of 610 mAh g-1 even at a very high rate (8.0 A g-1), demonstrating its prominent rate capability. Furthermore, the nanotube array electrode also exhibits the excellent electrochemical cycling stability with a reversible capacity of 880 mAh g-1 after 500 cycles at a current of 4 A g-1. The nanotube array electrode with superior lithium storage performance reveals the promising potential as a high-performance anode for LIBs.

  10. Recent Progress in Self-Supported Metal Oxide Nanoarray Electrodes for Advanced Lithium-Ion Batteries.

    Science.gov (United States)

    Zhang, Feng; Qi, Limin

    2016-09-01

    The rational design and fabrication of electrode materials with desirable architectures and optimized properties has been demonstrated to be an effective approach towards high-performance lithium-ion batteries (LIBs). Although nanostructured metal oxide electrodes with high specific capacity have been regarded as the most promising alternatives for replacing commercial electrodes in LIBs, their further developments are still faced with several challenges such as poor cycling stability and unsatisfying rate performance. As a new class of binder-free electrodes for LIBs, self-supported metal oxide nanoarray electrodes have many advantageous features in terms of high specific surface area, fast electron transport, improved charge transfer efficiency, and free space for alleviating volume expansion and preventing severe aggregation, holding great potential to solve the mentioned problems. This review highlights the recent progress in the utilization of self-supported metal oxide nanoarrays grown on 2D planar and 3D porous substrates, such as 1D and 2D nanostructure arrays, hierarchical nanostructure arrays, and heterostructured nanoarrays, as anodes and cathodes for advanced LIBs. Furthermore, the potential applications of these binder-free nanoarray electrodes for practical LIBs in full-cell configuration are outlined. Finally, the future prospects of these self-supported nanoarray electrodes are discussed.

  11. Solid state cesium ion guns for surface studies

    International Nuclear Information System (INIS)

    Souzis, A.E.; Carr, W.E.; Kim, S.I.; Seidl, M.

    1990-01-01

    Three cesium ion guns covering the energy range of 5--5000 V are described. These guns use a novel source of cesium ions that combine the advantages of porous metal ionizers with those of aluminosilicate emitters. Cesium ions are chemically stored in a solid electrolyte pellet and are thermionically emitted from a porous thin film of tungsten at the surface. Cesium supply to the emitting surface is controlled by applying a bias across the pellet. A total charge of 10.0 C can be extracted, corresponding to greater than 2000 h of lifetime with an extraction current of 1.0 μA. This source is compact, stable, and easy to use, and produces a beam with >99.5% purity. It requires none of the differential pumping or associated hardware necessary in designs using cesium vapor and porous tungsten ionizers. It has been used in ultrahigh-vacuum (UHV) experiments at pressures of -10 Torr with no significant gas load. Three different types of extraction optics are used depending on the energy range desired. For low-energy deposition, a simple space-charge-limited planar diode with a perveance of 1x10 -7 A/V 3/2 is used. Current densities of 10.0 μA/cm 2 at the exit aperture for energies ≤20 V are typical. This type of source provides an alternative to vapor deposition with the advantage of precise flux calibration by integration of the ion current. For energies from 50 to 500 V and typical beam radii of 0.5 to 0.2 mm, a high perveance Pierce-type ion gun is used. This gun was designed with a perveance of 1x10 -9 A/V 3/2 and produces a beam with an effective temperature of 0.35 eV. For the energy range of 0.5 to 5 keV, the Pierce gun is used in conjunction with two Einzel lenses, enabling a large range of imaging ratios to be obtained. Beam radii of 60 to 300 μm are typical for beam currents of 50 nA to 1.0 μA

  12. X-ray photoelectron spectroscopy/Ar+ ion profile study of thin oxide layers on InP

    International Nuclear Information System (INIS)

    Thurgate, S.M.; Erickson, N.E.

    1990-01-01

    The effect of incremental ion bombardment on the surface layers of an aqua regia etched InP sample was studied by monitoring the components of the In 3d 5/2 and O 1s x-ray photoelectron spectroscopy (XPS) lines as the sample was bombarded with low energy (1 keV) Ar + ions. The changes in the stoichiometry of the surface produced large shifts in the position of the In 3d and O 1s lines that were not paralleled by shifts in the P 2p line. Analysis of these shifts indicated that the surface was covered with a mixture of indium hydroxide and indium phosphate, with the phosphate closer to the InP substrate. It is proposed that this layer structure is due to differences in the dissolution rates of the oxidation products in the acid etch and the effect of the distilled water rinse. It may be possible to alter the composition of such oxides by carefully tailoring the etch conditions to optimize the kinetics for the particular oxide phase required. The analysis of the XPS lines also showed that the InP substrate was damaged at very low ion doses, and finally decomposed by the ion beam. When the ion ''cleaned'' sample was exposed to oxygen, a different oxide system was produced which consisted largely of In 2 O 3 and InPO 4 [or In(PO 3 ) x ]. This model of the oxidized surface of InP is consistent with other measurements and we conclude that ion milling together with XPS and careful curve fitting can be used to find the nature of the thin oxides on InP

  13. Selective population of high-j states via heavy-ion-induced transfer reactions

    International Nuclear Information System (INIS)

    Bond, P.D.

    1982-01-01

    One of the early hopes of heavy-ion-induced transfer reactions was to populate states not seen easily or at all by other means. To date, however, I believe it is fair to say that spectroscopic studies of previously unknown states have had, at best, limited success. Despite the early demonstration of selectivity with cluster transfer to high-lying states in light nuclei, the study of heavy-ion-induced transfer reactions has emphasized the reaction mechanism. The value of using two of these reactions for spectroscopy of high spin states is demonstrated: 143 Nd( 16 O, 15 O) 144 Nd and 170 Er( 16 O, 15 Oγ) 171 Er

  14. Exogenous nitric oxide improves salt tolerance during establishment of Jatropha curcas seedlings by ameliorating oxidative damage and toxic ion accumulation.

    Science.gov (United States)

    Gadelha, Cibelle Gomes; Miranda, Rafael de Souza; Alencar, Nara Lídia M; Costa, José Hélio; Prisco, José Tarquinio; Gomes-Filho, Enéas

    2017-05-01

    Jatropha curcas is an oilseed species that is considered an excellent alternative energy source for fossil-based fuels for growing in arid and semiarid regions, where salinity is becoming a stringent problem to crop production. Our working hypothesis was that nitric oxide (NO) priming enhances salt tolerance of J. curcas during early seedling development. Under NaCl stress, seedlings arising from NO-treated seeds showed lower accumulation of Na + and Cl - than those salinized seedlings only, which was consistent with a better growth for all analyzed time points. Also, although salinity promoted a significant increase in hydrogen peroxide (H 2 O 2 ) content and membrane damage, the harmful effects were less aggressive in NO-primed seedlings. The lower oxidative damage in NO-primed stressed seedlings was attributed to operation of a powerful antioxidant system, including greater glutathione (GSH) and ascorbate (AsA) contents as well as catalase (CAT) and glutathione reductase (GR) enzyme activities in both endosperm and embryo axis. Priming with NO also was found to rapidly up-regulate the JcCAT1, JcCAT2, JcGR1 and JcGR2 gene expression in embryo axis, suggesting that NO-induced salt responses include functional and transcriptional regulations. Thus, NO almost completely abolished the deleterious salinity effects on reserve mobilization and seedling growth. In conclusion, NO priming improves salt tolerance of J. curcas during seedling establishment by inducing an effective antioxidant system and limiting toxic ion and reactive oxygen species (ROS) accumulation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  15. Oxidative decarboxylation of glycolic and phenylacetic acids with cerium(4) catalyzed by silver ions in the sulfuric acid media

    International Nuclear Information System (INIS)

    Venkatesvar Rao, G.; Nagardzhun Rao, Ch.; Sajprakash, P.K.

    1981-01-01

    Oxidative decarboxylation of glycolic and phenylacetic acids by cerium (4) in the presence of Ag + ions is studied. The Ce(4) order equals 1, glycolic acid order in the absence of a catalyst also equals 1 and is fractional (0.5) for a catalytic reaction. The phenylacetic acid order is fractional (0.75). The Ag + ion reaction order is fractional and constitutes 0.32 for glycolic and 0.36 for phenylacetic acids. The reaction mechanism is proposed [ru

  16. f-state luminescence of lanthanide and actinide ions in solution

    International Nuclear Information System (INIS)

    Beitz, J.V.

    1993-01-01

    Detailed studies of the luminescence of aquated Am 3+ are presented in the context of prior lanthanide and actinide ion work. The luminescing state of aquated Am 3+ is confirmed to be 5 D l based on observed emission and excitation spectra. The luminescence lifetime of Am 3+ in H 2 O solution is (22 ± 3) ns and (155 ± 4) ns in D 2 O solution at 295 K. Judd-Ofelt transition intensity theory qualitatively describes the observed Am 3+ relative integrated fluorescence intensities. Recent luminescence studies on complexed trivalent f-element ions in solution are reviewed as to the similarities and differences between lanthanide ion 4f state and actinide ion 5f state properties

  17. Oxidative degradation of low and intermediate level Radioactive organic wastes 2. Acid decomposition on spent Ion-Exchange resins

    International Nuclear Information System (INIS)

    Ghattas, N.K.; Eskander, S.B.

    1995-01-01

    The present work provides a simplified, effective and economic method for the chemical decomposition of radioactively contaminated solid organic waste, especially spent ion - exchange resins. The goal is to achieve volume reduction and to avoid technical problems encountered in processes used for similar purposes (incineration, pyrolysis). Factors efficiency and kinetics of the oxidation of the ion exchange resins in acid medium using hydrogen peroxide as oxidant, namely, duration of treatment and the acid to resin ratio were studied systematically on a laboratory scale. Moreover the percent composition of the off-gas evolved during the decomposition process was analysed. 3 figs., 5 tabs

  18. Photochemical methodologies for organic waste treatment: advanced oxidation process using uranyl ion with H2O2

    International Nuclear Information System (INIS)

    Naik, D.B.; Sarkar, S.K.; Mukherjee, T.

    2009-01-01

    Excited uranyl ion is able to degrade dyes such as thionine and methylene blue on irradiation with 254 nm/300 nm light. By adding H 2 O 2 along with uranyl ion, photodegradation takes place with visible light and also with enhanced rate. The hydroxyl radicals generated in the reoxidation of U(IV)/UO 2 + to UO 2 2+ are responsible for this enhanced degradation. The above advanced oxidation process (AOP) was applied to study the oxidation of 2-propanol to acetone. (author)

  19. Oxidative degradation of low and intermediate level Radioactive organic wastes 2. Acid decomposition on spent Ion-Exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Ghattas, N K; Eskander, S B [Radioisotope dept., atomic energy authority, (Egypt)

    1995-10-01

    The present work provides a simplified, effective and economic method for the chemical decomposition of radioactively contaminated solid organic waste, especially spent ion - exchange resins. The goal is to achieve volume reduction and to avoid technical problems encountered in processes used for similar purposes (incineration, pyrolysis). Factors efficiency and kinetics of the oxidation of the ion exchange resins in acid medium using hydrogen peroxide as oxidant, namely, duration of treatment and the acid to resin ratio were studied systematically on a laboratory scale. Moreover the percent composition of the off-gas evolved during the decomposition process was analysed. 3 figs., 5 tabs.

  20. Use of ion beam techniques to characterize thin plasma grown GaAs and GaAlAs oxide films

    International Nuclear Information System (INIS)

    Kauffman, R.L.; Feldman, L.C.; Chang, R.P.H.

    1978-01-01

    Thin plasma grown films of GaAs oxides and GaAlAs oxides have been analyzed using the combined techniques of Rutherford backscattering, ion-induced X-rays, and nuclear resonance profiling. The stoichiometries of the films have been quantitatively determined and can be combined with other Auger profiling results to characterize the films. The ion-induced X-ray technique has been checked against other measurements to determine its accuracy. For uniform films such as these the X-ray measurements can provide accurate quantitative results. (Auth.)

  1. Obstruction of photoinduced electron transfer from excited porphyrin to graphene oxide: a fluorescence turn-on sensing platform for iron (III ions.

    Directory of Open Access Journals (Sweden)

    Zhong De Liu

    Full Text Available A comparative research of the assembly of different porphyrin molecules on graphene oxide (GO and reduced graphene oxide (RGO was carried out, respectively. Despite the cationic porphyrin molecules can be assembled onto the surfaces of graphene sheets, including GO and RGO, to form complexes through electrostatic and π-π stacking interactions, the more obvious fluorescence quenching and the larger red-shift of the Soret band of porphyrin molecule in RGO-bound states were observed than those in GO-bound states, due to the difference of molecular flattening in degree. Further, more interesting finding was that the complexes formed between cationic porphyrin and GO, rather than RGO sheets, can facilitate the incorporation of iron (III ions into the porphyrin moieties, due to the presence of the oxygen-contained groups at the basal plane of GO sheets served as auxiliary coordination units, which can high-efficiently obstruct the electron transfer from excited porphyrin to GO sheets and result in the occurrence of fluorescence restoration. Thus, a fluorescence sensing platform has been developed for iron (III ions detection in this contribution by using the porphyrin/GO nanohybrids as an optical probe, and our present one exhibited rapid and sensitive responses and high selectivity toward iron (III ions.

  2. Determination of the oxidation states of metals and metalloids: An analytical review

    Science.gov (United States)

    Vodyanitskii, Yu. N.

    2013-12-01

    The hazard of many heavy metals/metalloids in the soil depends on their oxidation state. The problem of determining the oxidation state has been solved due to the use of synchrotron radiation methods with the analysis of the X-ray absorption near-edge structure (XANES). The determination of the oxidation state is of special importance for some hazardous heavy elements (arsenic, antimony, selenium, chromium, uranium, and vanadium). The mobility and hazard of each of these elements depend on its oxidation state. The mobilities are higher at lower oxidation states of As, Cr, V, and Se and at higher oxidation states of Sb and U. The determination of the oxidation state of arsenic has allowed revealing its fixation features in the rhizosphere of hydrophytes. The known oxidation states of chromium and uranium are used for the retention of these elements on geochemical barriers. Different oxidation states have been established for vanadium displacing iron in goethite. The determination of the oxidation state of manganese in the rhizosphere and the photosynthetic apparatus of plants is of special importance for agricultural chemists.

  3. Chaotic Dynamics Mediates Brain State Transitions, Driven by Changes in Extracellular Ion Concentrations

    DEFF Research Database (Denmark)

    Rasmussen, Rune; H. Jensen, Mogens; L. Heltberg, Mathias

    2017-01-01

    Previous studies have suggested that changes in extracellular ion concentrations initiate the transition from an activity state that characterizes sleep in cortical neurons to states that characterize wakeful- ness. However, because neuronal activity and extra- cellular ion concentrations...... are interdependent, isolating their unique roles during sleep-wake transitions is not possible in vivo. Here, we extend the Averaged-Neuron model and demonstrate that, although changes in extracellular ion concentrations occur concurrently, decreasing the conductance of calcium-dependent potassium channels initiates...... the transition from sleep to wakefulness. We find that sleep is governed by stable, self-sustained oscillations in neuronal firing patterns, whereas the quiet awake state and active awake state are both governed by irregular oscillations and chaotic dynamics; transitions between these separable awake states...

  4. All-solid-state lithium-ion and lithium metal batteries - paving the way to large-scale production

    Science.gov (United States)

    Schnell, Joscha; Günther, Till; Knoche, Thomas; Vieider, Christoph; Köhler, Larissa; Just, Alexander; Keller, Marlou; Passerini, Stefano; Reinhart, Gunther

    2018-04-01

    Challenges and requirements for the large-scale production of all-solid-state lithium-ion and lithium metal batteries are herein evaluated via workshops with experts from renowned research institutes, material suppliers, and automotive manufacturers. Aiming to bridge the gap between materials research and industrial mass production, possible solutions for the production chains of sulfide and oxide based all-solid-state batteries from electrode fabrication to cell assembly and quality control are presented. Based on these findings, a detailed comparison of the production processes for a sulfide based all-solid-state battery with conventional lithium-ion cell production is given, showing that processes for composite electrode fabrication can be adapted with some effort, while the fabrication of the solid electrolyte separator layer and the integration of a lithium metal anode will require completely new processes. This work identifies the major steps towards mass production of all-solid-state batteries, giving insight into promising manufacturing technologies and helping stakeholders, such as machine engineering, cell producers, and original equipment manufacturers, to plan the next steps towards safer batteries with increased storage capacity.

  5. The study towards high intensity high charge state laser ion sources.

    Science.gov (United States)

    Zhao, H Y; Jin, Q Y; Sha, S; Zhang, J J; Li, Z M; Liu, W; Sun, L T; Zhang, X Z; Zhao, H W

    2014-02-01

    As one of the candidate ion sources for a planned project, the High Intensity heavy-ion Accelerator Facility, a laser ion source has been being intensively studied at the Institute of Modern Physics in the past two years. The charge state distributions of ions produced by irradiating a pulsed 3 J/8 ns Nd:YAG laser on solid targets of a wide range of elements (C, Al, Ti, Ni, Ag, Ta, and Pb) were measured with an electrostatic ion analyzer spectrometer, which indicates that highly charged ions could be generated from low-to-medium mass elements with the present laser system, while the charge state distributions for high mass elements were relatively low. The shot-to-shot stability of ion pulses was monitored with a Faraday cup for carbon target. The fluctuations within ±2.5% for the peak current and total charge and ±6% for pulse duration were demonstrated with the present setup of the laser ion source, the suppression of which is still possible.

  6. Influence of vanadium oxidation states on the performance of V-Mg-Al mixed-oxide catalysts for the oxidative dehydrogenation of propane

    International Nuclear Information System (INIS)

    Schacht, L.; Navarrete, J.; Schacht, P.; Ramirez, M. A.

    2010-01-01

    V-Mg-Al mixed-oxide catalysts for oxidative dehydrogenation of propane were prepared by thermal decomposition of Mg-Al-layered double hydroxides with vanadium interlayer doping. The obtained catalysts were tested for the oxidative dehydrogenation of propane, obtaining good results in catalytic activity (conversion 16.55 % and selectivity 99.97 %) Results indicated that catalytic performance of these materials depends on how vanadium is integrated in the layered structure, which is determined by the Mg/Al ratio. Vanadium interlayer doping modifies the oxidation state of vanadium and consequently catalytic properties. Surface properties were studied by X-ray photoelectron spectroscopic and diffuse reflectance, UV-visible spectroscopy, and temperature programmed reduction. The analyses provided information about the oxidation state, before and after the reaction. From these results, it is suggested that selectivity to propylene and catalytic activity depend mainly of vanadium oxidation state. (Author)

  7. Influence of vanadium oxidation states on the performance of V-Mg-Al mixed-oxide catalysts for the oxidative dehydrogenation of propane

    Energy Technology Data Exchange (ETDEWEB)

    Schacht, L. [IPN, Escuela Superior de Fisica y Matematicas, Departamento de Ciencia de Materiales, Av. IPN s/n, Edificio 9, Col. Lindavista, 07738 Mexico D. F. (Mexico); Navarrete, J.; Schacht, P.; Ramirez, M. A., E-mail: pschacha@imp.m [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas No. 152, 07730 Mexico D. F. (Mexico)

    2010-07-01

    V-Mg-Al mixed-oxide catalysts for oxidative dehydrogenation of propane were prepared by thermal decomposition of Mg-Al-layered double hydroxides with vanadium interlayer doping. The obtained catalysts were tested for the oxidative dehydrogenation of propane, obtaining good results in catalytic activity (conversion 16.55 % and selectivity 99.97 %) Results indicated that catalytic performance of these materials depends on how vanadium is integrated in the layered structure, which is determined by the Mg/Al ratio. Vanadium interlayer doping modifies the oxidation state of vanadium and consequently catalytic properties. Surface properties were studied by X-ray photoelectron spectroscopic and diffuse reflectance, UV-visible spectroscopy, and temperature programmed reduction. The analyses provided information about the oxidation state, before and after the reaction. From these results, it is suggested that selectivity to propylene and catalytic activity depend mainly of vanadium oxidation state. (Author)

  8. Excited state fluorescence quenching of the U O2++ ion by monovalent anions

    International Nuclear Information System (INIS)

    Santarine, G.A.

    1987-01-01

    The reactions of the Uranyl ion U O 2 ++ in the excited state with the monovalent inorganic ions N O 3 - and I O 3 - in aqueous solutions at normal temperature were studied, using three techniques: Fluorescence in the steady state - Flash photolysis - Fluorescence decay after excitation. With increasing concentration of these ions it was observed a decrease in the normalized intensity and a decrease in the decay time of the fluorescence of the Uranyl ion in the solution and a corresponding appearance of the radicals N O 3 . or I O 3 . . In each case the radical was identified by its optical absorption spectrum. These results suggest that the quenching of fluorescence of the Uranyl ion in each case is owing to an electron transfer reaction. In the case of the Nitrate ion the transfer may occur after the formation of an ionic par (U O 2 + ...N O 3 ) in the ground state. Evidence for static quenching in the system Uranyl iodate was not forthcoming. A mechanism for the determination of the velocity constant (probability per ion pair per unit time) is proposed for each of the systems. (author)

  9. Peculiarities of the diffusion of silver and sodium ions in phosphate glasses with a high content of sodium oxide

    International Nuclear Information System (INIS)

    Syutkin, V.M.; Tolkatchev, V.A.

    1996-01-01

    The phosphate glasses with a high content of alkali metal ions are good ionic conductors. Despite active studies, the mechanism of ion diffusion is not so far clear. The present work discusses the characteristics of ion diffusion in phosphate glasses with a high content of sodium oxide. An effective method to study ion transport is the investigation of relaxation processes the kinetics of which depends on ion diffusion. We use the data for two types of relaxation processes the kinetics of which is determined by ion diffusion. This is the conductivity relaxation due to sodium (host) ions and the decay of radiation-induced centers controlled by silver (guest) ion diffusion. Both of the processes being actually the first-order processes display a nonexponential kinetic behavior. The relaxation law can be interpreted either as the inherently nonexponential function or as the weighted sum of exponential decay functions with a distribution of relaxation times. It has been demonstrated that on the molecular level the relaxation function should be interpreted in the frame of the scheme of parallel first-order processes. This fact allows one to formulate a number of features of ion diffusion: (i) the mean square displacement of ions does not exceed several angstrom when transport becomes non-dispersive; (ii) the diffusion coefficient of ions is the function of coordinates. In this case, a characteristic distance at which D(r) noticeably varies is no less than a hundred of angstrom; (iii) the instantaneous concentration of mobile ions is well below the overall concentration ions

  10. Manganese oxidation state mediates toxicity in PC12 cells

    International Nuclear Information System (INIS)

    Reaney, S.H.; Smith, D.R.

    2005-01-01

    The role of the manganese (Mn) oxidation state on cellular Mn uptake and toxicity is not well understood. Therefore, undifferentiated PC12 cells were exposed to 0-200 μM Mn(II)-chloride or Mn(III)-pyrophosphate for 24 h, after which cellular manganese levels were measured along with measures of cell viability, function, and cytotoxicity (trypan blue exclusion, medium lactate dehydrogenase (LDH), 8-isoprostanes, cellular ATP, dopamine, serotonin, H-ferritin, transferrin receptor (TfR), Mn-superoxide dismutase (MnSOD), and copper-zinc superoxide dismutase (CuZnSOD) protein levels). Exposures to Mn(III) >10 μM produced 2- to 5-fold higher cellular manganese levels than equimolar exposures to Mn(II). Cell viability and ATP levels both decreased at the highest Mn(II) and Mn(III) exposures (150-200 μM), while Mn(III) exposures produced increases in LDH activity at lower exposures (≥50 μM) than did Mn(II) (200 μM only). Mn(II) reduced cellular dopamine levels more than Mn(III), especially at the highest exposures (50% reduced at 200 μM Mn(II)). In contrast, Mn(III) produced a >70% reduction in cellular serotonin at all exposures compared to Mn(II). Different cellular responses to Mn(II) exposures compared to Mn(III) were also observed for H-ferritin, TfR, and MnSOD protein levels. Notably, these differential effects of Mn(II) versus Mn(III) exposures on cellular toxicity could not simply be accounted for by the different cellular levels of manganese. These results suggest that the oxidation state of manganese exposures plays an important role in mediating manganese cytotoxicity

  11. Ion-ion interactions in the denatured state contribute to the stabilization of CutA1 proteins.

    Science.gov (United States)

    Yutani, Katsuhide; Matsuura, Yoshinori; Naitow, Hisashi; Joti, Yasumasa

    2018-05-16

    In order to elucidate features of the denatured state ensembles that exist in equilibrium with the native state under physiological conditions, we performed 1.4-μs molecular dynamics (MD) simulations at 400 K and 450 K using the monomer subunits of three CutA1 mutants from Escherichia coli: an SH-free mutant (Ec0SH) with denaturation temperature (T d ) = 85.6 °C, a hydrophobic mutant (Ec0VV) with T d  = 113.3 °C, and an ionic mutant (Ec0VV_6) with T d  = 136.8 °C. The occupancy of salt bridges by the six substituted charged residues in Ec0VV_6 was 140.1% at 300 K and 89.5% at 450 K, indicating that even in the denatured state, salt bridge occupancy was high, approximately 60% of that at 300 K. From these results, we can infer that proteins from hyperthermophiles with a high ratio of charged residues are stabilized by a decrease in conformational entropy due to ion-ion interactions in the denatured state. The mechanism must be comparable to the stabilization conferred by disulfide bonds within a protein. This suggests that introduction of charged residues, to promote formation of salt bridges in the denatured state, would be a simple way to rationally design stability-enhanced mutants.

  12. Excited state populations and charge-exchange of fast ions in solids

    International Nuclear Information System (INIS)

    Miller, P.D.; Sofield, C.J.; Woods, C.J.

    1984-01-01

    Excited state populations and charge state fractions of 445 MeV Cl ions have been measured for a range of thicknesses of solid C targets. Cross sections for electron capture, loss, excitation and excited state quenching have been determined and these data are found to predict a quantitative difference between equilibrium charge state distributions from gases and solids for a special case of the Bohr-Lindhard density effect model. 8 references, 1 figure, 1 table

  13. High charge state heavy ion production from a PIG source

    International Nuclear Information System (INIS)

    Bex, L.; Clark, D.J.; Ellsworth, C.E.; Flood, W.S.; Gough, R.A.; Holley, W.R.; Meriwether, J.R.; Morris, D.

    1975-03-01

    The comparison of pulsed vs. dc arc operation for nitrogen and argon shows a shift in charge distribution toward the higher charge states for the pulsed case. Tests with various magnetic field shapes along the arc column show a significant increase in high charge state output for a uniform field compared to the case with a field low at the cathodes. (U.S.)

  14. The Adsorption of n-Octanohydroxamate Collector on Cu and Fe Oxide Minerals Investigated by Static Secondary Ion Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Alan N. Buckley

    2012-12-01

    Full Text Available The feasibility of investigating the adsorption of n-octanohydroxamate collector on copper and iron oxide minerals with static secondary ion mass spectrometry has been assessed. Secondary ion mass spectra were determined for abraded surfaces of air-exposed copper metal, malachite, pseudomalachite and magnetite that had been conditioned in aqueous potassium hydrogen n-octanohydroxamate solution, as well as for the corresponding bulk CuII and FeIII complexes. In each case, the chemical species present at the solid/vacuum interface of a similarly prepared surface were established by X-ray photoelectron spectroscopy. The most abundant positive and negative metal-containing fragment ions identified for the bulk complexes were also found to be diagnostic secondary ions for the collector adsorbed on the oxide surfaces. The relative abundances of those diagnostic ions varied with, and could be rationalised by, the monolayer or multilayer coverage of the adsorbed collector. However, the precise mass values for the diagnostic ions were not able to corroborate the different bonding in the copper and iron hydroxamate systems that had been deduced from photoelectron and vibrational spectra. Parent secondary ions were able to provide supporting information on the co-adsorption of hydroxamic acid at each conditioned surface.

  15. Enhanced coulomb counting method for estimating state-of-charge and state-of-health of lithium-ion batteries

    International Nuclear Information System (INIS)

    Ng, Kong Soon; Moo, Chin-Sien; Chen, Yi-Ping; Hsieh, Yao-Ching

    2009-01-01

    The coulomb counting method is expedient for state-of-charge (SOC) estimation of lithium-ion batteries with high charging and discharging efficiencies. The charging and discharging characteristics are investigated and reveal that the coulomb counting method is convenient and accurate for estimating the SOC of lithium-ion batteries. A smart estimation method based on coulomb counting is proposed to improve the estimation accuracy. The corrections are made by considering the charging and operating efficiencies. Furthermore, the state-of-health (SOH) is evaluated by the maximum releasable capacity. Through the experiments that emulate practical operations, the SOC estimation method is verified to demonstrate the effectiveness and accuracy.

  16. Measurement of soil carbon oxidation state and oxidative ratio by 13C nuclear magnetic resonance

    Science.gov (United States)

    Hockaday, W.C.; Masiello, C.A.; Randerson, J.T.; Smernik, R.J.; Baldock, J.A.; Chadwick, O.A.; Harden, J.W.

    2009-01-01

    The oxidative ratio (OR) of the net ecosystem carbon balance is the ratio of net O2 and CO2 fluxes resulting from photosynthesis, respiration, decomposition, and other lateral and vertical carbon flows. The OR of the terrestrial biosphere must be well characterized to accurately estimate the terrestrial CO2 sink using atmospheric measurements of changing O2 and CO2 levels. To estimate the OR of the terrestrial biosphere, measurements are needed of changes in the OR of aboveground and belowground carbon pools associated with decadal timescale disturbances (e.g., land use change and fire). The OR of aboveground pools can be measured using conventional approaches including elemental analysis. However, measuring the OR of soil carbon pools is technically challenging, and few soil OR data are available. In this paper we test three solid-state nuclear magnetic resonance (NMR) techniques for measuring soil OR, all based on measurements of the closely related parameter, organic carbon oxidation state (Cox). Two of the three techniques make use of a molecular mixing model which converts NMR spectra into concentrations of a standard suite of biological molecules of known C ox. The third technique assigns Cox values to each peak in the NMR spectrum. We assess error associated with each technique using pure chemical compounds and plant biomass standards whose Cox and OR values can be directly measured by elemental analyses. The most accurate technique, direct polarization solid-state 13C NMR with the molecular mixing model, agrees with elemental analyses to ??0.036 Cox units (??0.009 OR units). Using this technique, we show a large natural variability in soil Cox and OR values. Soil Cox values have a mean of -0.26 and a range from -0.45 to 0.30, corresponding to OR values of 1.08 ?? 0.06 and a range from 0.96 to 1.22. We also estimate the OR of the carbon flux from a boreal forest fire. Analysis of soils from nearby intact soil profiles imply that soil carbon losses associated

  17. Preparation of hydroxide ion conductive KOH–layered double hydroxide electrolytes for an all-solid-state iron–air secondary battery

    Directory of Open Access Journals (Sweden)

    Taku Tsuneishi

    2014-06-01

    Full Text Available Anion conductive solid electrolytes based on Mg–Al layered double hydroxide (LDH were prepared for application in an all-solid-state Fe–air battery. The ionic conductivity and the conducting ion species were evaluated from impedance and electromotive force measurements. The ion conductivity of LDH was markedly enhanced upon addition of KOH. The electromotive force in a water vapor concentration cell was similar to that of an anion-conducting polymer membrane. The KOH–LDH obtained was used as a hydroxide ion conductive electrolyte for all-solid-state Fe–air batteries. The cell performance of the Fe–air batteries was examined using a mixture of KOH–LDH and iron-oxide-supported carbon as the negative electrode.

  18. Oxidation processes on conducting carbon additives for lithium-ion batteries

    KAUST Repository

    La Mantia, Fabio

    2012-11-21

    The oxidation processes at the interface between different types of typical carbon additives for lithium-ion batteries and carbonates electrolyte above 5 V versus Li/Li+ were investigated. Depending on the nature and surface area of the carbon additive, the irreversible capacity during galvanostatic cycling between 2.75 and 5.25 V versus Li/Li+ could be as high as 700 mAh g-1 (of carbon). In the potential region below 5 V versus Li/Li+, high surface carbon additives also showed irreversible plateaus at about 4.1-4.2 and 4.6 V versus Li/Li+. These plateaus disappeared after thermal treatments at or above 150 °C in inert gas. The influence of the irreversible capacity of carbon additives on the overall performances of positive electrodes was discussed. © 2012 Springer Science+Business Media Dordrecht.

  19. Single-ion and single-chain magnetism in triangular spin-chain oxides

    Science.gov (United States)

    Seikh, Md. Motin; Caignaert, Vincent; Perez, Olivier; Raveau, Bernard; Hardy, Vincent

    2017-05-01

    S r4 -xC axM n2Co O9 oxides (x =0 and x =2 ) are found to exhibit magnetic responses typical of single-chain magnets (SCMs) and single-ion magnets (SIMs), two features generally investigated in coordination polymers or complexes. The compound x =0 appears to be a genuine SCM, in that blocking effects associated with slow spin dynamics yield remanence and coercivity in the absence of long-range ordering (LRO). In addition, SIM signatures of nearly identical nature are detected in both compounds, coexisting with SCM in x =0 and with LRO in x =2 . It is also observed that a SCM response can be recovered in x =2 after application of magnetic field. These results suggest that purely inorganic systems could play a valuable role in the topical issue of the interplay among SIM, SCM, and LRO phenomena in low-dimensional magnetism.

  20. Deuterium trapping in ion implanted and co-deposited beryllium oxide layers

    International Nuclear Information System (INIS)

    Markin, A.V.; Gorodetsky, A.E.; Zakharov, A.P.; Wu, C.H.

    2000-01-01

    Deuterium trapping in beryllium oxide films irradiated with 400 eV D ions has been studied by thermal desorption spectroscopy (TDS). It has been found that for thermally grown BeO films implanted in the range 300 - 900 K the total deuterium retention doesn't depend whereas TDS spectra do markedly on irradiation temperature. For R.T. implantation the deuterium is released in a wide range from 500 to 1100 K. At implantation above 600 K the main portion of retained deuterium is released in a single peak centered at about 1000 K. The similar TDS peak is measured for D/BeO co-deposited layer. In addition we correlate our implantation data on BeO with the relevant data on beryllium metal and carbon. The interrelations between deuterium retention and microstructure are discussed. (orig.)

  1. Ethylenediamine-functionalized graphene oxide incorporated acid-base ion exchange membranes for vanadium redox flow battery

    International Nuclear Information System (INIS)

    Liu, Shuai; Li, Dan; Wang, Lihua; Yang, Haijun; Han, Xutong; Liu, Biqian

    2017-01-01

    Highlights: • Ethylenediamine functionalized graphene oxide. • Layered structure of functionalized graphene oxide block vanadium ions crossover. • Protonated N-containing groups suppress vanadium ions permeation. • Ion transport channels are narrowed by electrostatic interactions. • Vanadium crossover decreased due to enhanced Donnan effect and special structure. - Abstract: As a promising large-scale energy storage battery, vanadium redox flow battery (VRFB) is urgently needed to develop cost-effective membranes with excellent performance. Novel acid-base ion exchange membranes (IEMs) are fabricated based on sulfonated poly(ether ether ketone) (SPEEK) matrix and modified graphene oxide (GO) by solution blending. N-based functionalized graphene oxide (GO-NH 2 ) is fabricated by grafting ethylenediamine onto the edge of GO via a facile method. On one hand, the impermeable layered structures effectively block ion transport pathway to restrain vanadium ions crossover. On the other hand, acid-base pairs form between −SO 3 − groups and N-based groups on the edge of GO nanosheets, which not only suppress vanadium ions contamination but also provide a narrow pathway for proton migration. The structure is beneficial for achieving an intrinsic balance between conductivity and permeability. By altering amounts of GO-NH 2 , a sequence of acid-base IEMs are characterized in detail. The single cells assembled with acid-base IEMs show self-discharge time for 160 h, capacity retention 92% after 100 cycle, coulombic efficiency 97.2% and energy efficiency 89.5%. All data indicate that acid-base IEMs have promising prospects for VRFB applications.

  2. Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation

    Science.gov (United States)

    Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

    2015-07-01

    In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time

  3. Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

    International Nuclear Information System (INIS)

    Reichel, Christian; Feldmann, Frank; Müller, Ralph; Hermle, Martin; Glunz, Stefan W.; Reedy, Robert C.; Lee, Benjamin G.; Young, David L.; Stradins, Paul

    2015-01-01

    Passivated contacts (poly-Si/SiO x /c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF 2 ), the ion implantation dose (5 × 10 14  cm −2 to 1 × 10 16  cm −2 ), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iV oc ) of 725 and 720 mV, respectively. For p-type passivated contacts, BF 2 implantations into intrinsic a-Si yield well passivated contacts and allow for iV oc of 690 mV, whereas implanted B gives poor passivation with iV oc of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved V oc of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF 2 implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with V oc of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts

  4. Possible applications of the ion beams technique for investigations in the field of equation of state

    International Nuclear Information System (INIS)

    Kanel, G.I.; Fortov, V.E.; Baumung, K.; Bluhm, H.

    1998-01-01

    The shock wave generation through the interaction of a high-power ion beam with condensed targets is considered with a goal to reveal possible ways to study the equations of state of matter using ion beams. The equation of state is thought about in an extended interpretation including the relaxation processes, such as phase transitions, chemical reactions, and stress relaxation. Advantages of the beam-driven generation of the high-energy states and possible areas of competition with more conventional technique are discussed. (orig.)

  5. Oxidation state of uranium in metamict and annealed zircon: near-infrared spectroscopic quantitative analysis

    CERN Document Server

    Zhang Ming; Ewing, R C

    2003-01-01

    Radiation and thermally induced changes in the oxidation state of uranium in metamict zircon have been systematically analysed, for the first time, using polarized near-infrared spectroscopy. The results showed that in damaged zircon U ions in crystalline domains exhibited relatively sharp, anisotropic signals from tetravalent and pentavalent U ions in crystalline domains (U sub c sub r sub y sub s sub t sub a sub l sup 4 sup + and U sub c sub r sub y sub s sub t sub a sub l sup 5 sup +). The linewidths and peak positions of the 4834 cm sup - sup 1 band (U sub c sub r sub y sub s sub t sub a sub l sup 4 sup + , E || c) and the 6668 cm sup - sup 1 band (U sub c sub r sub y sub s sub t sub a sub l sup 5 sup + , E perp. c) are a non-linear function of the self-radiation dose. They reach nearly constant values at doses greater than approx 3.5 x 10 sup 1 sup 8 alpha-events g sup - sup 1. Quantitative analysis of U sub c sub r sub y sub s sub t sub a sub l sup 4 sup + and U sub c sub r sub y sub s sub t sub a sub l...

  6. Carbonate-linked poly(ethylene oxide) polymer electrolytes towards high performance solid state lithium batteries

    International Nuclear Information System (INIS)

    He, Weisheng; Cui, Zili; Liu, Xiaochen; Cui, Yanyan; Chai, Jingchao; Zhou, Xinhong; Liu, Zhihong; Cui, Guanglei

    2017-01-01

    The classic poly(ethylene oxide) (PEO) based solid polymer electrolyte suffers from poor ionic conductivity of ambient temperature, low lithium ion transference number and relatively narrow electrochemical window (<4.0 V vs. Li + /Li). Herein, the carbonate-linked PEO solid polymer such as poly(diethylene glycol carbonate) (PDEC) and poly(triethylene glycol carbonate) (PTEC) were explored to find out the feasibility of resolving above issues. It was proven that the optimized ionic conductivity of PTEC based electrolyte reached up to 1.12 × 10 −5 S cm −1 at 25 °C with a decent lithium ion transference number of 0.39 and a wide electrochemical window about 4.5 V vs. Li + /Li. In addition, the PTEC based Li/LiFePO 4 cell could be reversibly charged and discharged at 0.05 C-rates at ambient temperature. Moreover, the higher voltage Li/LiFe 0.2 Mn 0.8 PO 4 cell (cutoff voltage 4.35 V) possessed considerable rate capability and excellent cycling performance even at ambient temperature. Therefore, these carbonate-linked PEO electrolytes were demonstrated to be fascinating candidates for the next generation solid state lithium batteries simultaneously with high energy and high safety.

  7. A state-space-based prognostics model for lithium-ion battery degradation

    International Nuclear Information System (INIS)

    Xu, Xin; Chen, Nan

    2017-01-01

    This paper proposes to analyze the degradation of lithium-ion batteries with the sequentially observed discharging profiles. A general state-space model is developed in which the observation model is used to approximate the discharging profile of each cycle, the corresponding parameter vector is treated as the hidden state, and the state-transition model is used to track the evolution of the parameter vector as the battery ages. The EM and EKF algorithms are adopted to estimate and update the model parameters and states jointly. Based on this model, we construct prediction on the end of discharge times for unobserved cycles and the remaining useful cycles before the battery failure. The effectiveness of the proposed model is demonstrated using a real lithium-ion battery degradation data set. - Highlights: • Unifying model for Li-Ion battery SOC and SOH estimation. • Extended Kalman filter based efficient inference algorithm. • Using voltage curves in discharging to have wide validity.

  8. Recoil ion charge state distributions in low energy Arq+ - Ar collisions

    International Nuclear Information System (INIS)

    Vancura, J.; Marchetti, V.; Kostroun, V.O.

    1992-01-01

    We have measured the recoil ion charge state distributions in Ar q+ -- Ar (8≤q≤16) collisions at 2.3 qkeV and 0.18qkeV by time of flight (TOF) spectroscopy. For Ar 8-16+ , recoil ion charge states up to 6+ are clearly present, indicating that the 3p subshell in the target atom is being depleted, while for Ar 10-16+ , there is evidence that target 3s electrons are also being removed. Comparison of the recoil ion charge state spectra at 2.3 and 0.18 qkeV shows that for a given projectile charge, there is very little dependence of the observed recoil target charge state distribution on projectile energy

  9. Ab initio calculation atomics ground state wave function for interactions Ion- Atom

    International Nuclear Information System (INIS)

    Shojaee, F.; Bolori zadeh, M. A.

    2007-01-01

    Ab initio calculation atomics ground state wave function for interactions Ion- Atom Atomic wave function expressed in a Slater - type basis obtained within Roothaan- Hartree - Fock for the ground state of the atoms He through B. The total energy is given for each atom.

  10. Application of powerful oxidizers in the synthesis of new high-oxidation state actinide and related species

    International Nuclear Information System (INIS)

    Yeh, S.M.

    1984-11-01

    The fluorinating and oxide scavenging ability of XeF 6 have been studied by bringing XeF 6 into interaction with oxide-fluoride compounds of the third-transition-series elements (W, Re and Os) and uranium, in their highest oxidation states. A + MOF 5 - and A + M 2 O 2 F 9 - (A = K or Cs, M = W or U) were converted to A + MF 7 - by XeF 6 , but the rhenium and osmium compounds, K + ReO 2 F 4 - and XeF 5 + OsO 3 F 3 - , resisted interaction with XeF 6 . Strong interactions between XeF 2 or KrF 2 and the solvent have been observed for their solutions in anhydrous HF. Both XeF 2 and KrF 2 are seen to be effective in breaking up the polymeric (HF)/sub n/ chains. Only weak interactions occur between cations and anions of KrF + AuF 6 - and Kr 2 F 3 + AuF 6 - in HF. The AuF 6 - anions are slightly distorted from O/sub h/ symmetry. Kr 2 F 3 + cations in HF have the same dissymmetric V-shape which occurs in crystalline salts. A low-temperature orthorhombic form, β-ReF 6 + SbF 6 - , a high-temperature rhombohedral form, α-ReF 6 + SbF 6 - , and a ReF 6 + AuF 6 - have been prepared. These compounds possess only kinetic stability at ambient temperature and at approx. 20 0 C are best represented as ReF 6 + ReF 7 MF 6 - MF 5 . Thermochemical energy evaluations indicate that the ionization potential of ReF 6 is 261 kcal mole -1 and that the fluoride-ion affinity of ReF 6 + is -214 kcal mole -1 . This is more exothermal than the corresponding process for IF 6 + (-208 kcal mole -1 ). In contrast, ReOF 5 is shown to be a better fluoro-base than IOF 5 and also is a better base than ReF 7 . ReOF 4 + MF 6 - (M = Sb, Au and As) salts are of higher thermal stability than their ReF 6 + MF 6 - analogues

  11. Optimization of ion assist beam deposition of magnesium oxide template films during initial nucleation and growth

    Energy Technology Data Exchange (ETDEWEB)

    Groves, James R [Los Alamos National Laboratory; Matias, Vladimir [Los Alamos National Laboratory; Stan, Liliana [Los Alamos National Laboratory; De Paula, Raymond F [Los Alamos National Laboratory; Hammond, Robert H [STANFORD UNIV.; Clemens, Bruce M [STANFOED UNIV.

    2010-01-01

    Recent efforts in investigating the mechanism of ion beam assisted deposition (IBAD) of biaxially textured thin films of magnesium oxide (MgO) template layers have shown that the texture develops suddenly during the initial 2 nm of deposition. To help understand and tune the behavior during this initial stage, we pre-deposited thin layers of MgO with no ion assist prior to IBAD growth of MgO. We found that biaxial texture develops for pre-deposited thicknesses < 2 nm, and that the thinnest layer tested, at 1 nm, resulted in the best qualitative RHEED image, indicative of good biaxial texture development. The texture developed during IBAD growth on the 1.5 nm pre-deposited layer is slightly worse and IBAD growth on the 2 nm pre-deposited layer produces a fiber texture. Application of these layers on an Al{sub 2}O{sub 3} starting surface, which has been shown to impede texture development, improves the overall quality of the IBAD MgO and has some of the characteristics of a biaxially texture RHEED pattern. It is suggested that the use of thin (<2 nm) pre-deposited layers may eliminate the need for bed layers like Si{sub 3}N{sub 4} and Y{sub 2}O{sub 3} that are currently thought to be required for proper biaxial texture development in IBAD MgO.

  12. Local structure and oxide-ion conduction mechanism in apatite-type lanthanum silicates.

    Science.gov (United States)

    Masson, Olivier; Berghout, Abid; Béchade, Emilie; Jouin, Jenny; Thomas, Philippe; Asaka, Toru; Fukuda, Koichiro

    2017-01-01

    The local structure of apatite-type lanthanum silicates of general formula La 9.33+x (SiO 4 ) 6 O 2+3x/2 has been investigated by combining the atomic pair distribution function (PDF) method, conventional X-ray and neutron powder diffraction (NPD) data and density functional theory (DFT) calculations. DFT was used to build structure models with stable positions of excess oxide ions within the conduction channel. Two stable interstitial positions were obtained in accordance with literature, the first one located at the very periphery of the conduction channel, neighbouring the SiO 4 tetrahedral units, and the second one closer to the channel axis. The corresponding PDFs and average structures were then calculated and tested against experimental PDFs obtained by X-ray total scattering and NPD Rietveld refinements results gathered from literature. It was shown that of the two stable interstitial positions obtained with DFT only the second one located within the channel is consistent with experimental data. This result consolidates one of the two main conduction mechanisms along the c-axis reported in the literature, namely the one involving cooperative movement of O4 and Oi ions.

  13. Simultaneous fluorescent detection of multiple metal ions based on the DNAzymes and graphene oxide.

    Science.gov (United States)

    Yun, Wen; Wu, Hong; Liu, Xingyan; Fu, Min; Jiang, Jiaolai; Du, Yunfeng; Yang, Lizhu; Huang, Yu

    2017-09-15

    A novel fluorescent detection strategy for simultaneous detection of Cu 2+ , Pb 2+ and Mg 2+ based on DNAzyme branched junction structure with three kinds of DNAzymes and graphene oxide (GO) was presented. Three fluorophores labeled DNA sequences consisted with enzyme-strand (E-DNA) and substrate strand (S-DNA) were annealed to form DNAzyme branched junction structure. In the presence of target metal ion, the DNAzyme was activated to cleave the fluorophore labeled S-DNA. The S-DNA fragments were released and adsorbed onto GO surface to quench the fluorescent signal. The detection limit was calculated to be 1 nM for Cu 2+ , 200 nM for Mg 2+ , and 0.3 nM for Pb 2+ , respectively. This strategy was successfully used for simultaneous detection of Cu 2+ , Mg 2+ and Pb 2+ in human serum. Moreover, it had potential application for simultaneous detection of multiple metal ions in environmental and biological samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Preparation of RHA-silica/graphene oxide nanocomposite for removal of nickel ions from water

    Science.gov (United States)

    Tien, Tran Thi Thuy; Tu, Tran Hoang; Thao, Huynh Nguyen Phuong; Hieu, Nguyen Huu

    2017-09-01

    In this study, silica was synthesized from rice husk ash (RHA-SiO2) by precipitation method. Graphene oxide (GO) was prepared by modified Hummers method. RHA-SiO2/GO nanocomposite was fabricated by in-situ one-step method using 3-Aminopropyltriethoxysilane (APS) as a coupling agent. The nanocomposite was characterized by using X-ray Fluorescence, X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and Brunauer-Emmett-Teller (BET) specific surface area. The adsorption of RHA-SiO2/GO for Ni2+ ions from water was investigated and compared with the precursors. Ultraviolet-visible (UV-Vis) spectroscopy was used to quantify the amount of the initial and the residual Ni2+ concentration. The maximum adsorption capacity of the nanocomposite for Ni2+ calculated from Langmuir isotherm model, which was 256.4 mg/g. In addition, the adsorption data were well-fitted to the pseudo-second-order kinetic equation. Accordingly, this study demonstrated that RHA-SiO2/GO could be used as a highly efficient adsorbent for removal Ni2+ ions from aqueous solution.

  15. TEM in situ micropillar compression tests of ion irradiated oxide dispersion strengthened alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, K.H., E-mail: kaylayano@u.boisestate.edu [Boise State University, 1910 University Drive, Boise, ID, 83725 (United States); Swenson, M.J. [Boise State University, 1910 University Drive, Boise, ID, 83725 (United States); Wu, Y. [Boise State University, 1910 University Drive, Boise, ID, 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd, Idaho Falls, ID, 83401 (United States); Wharry, J.P. [Boise State University, 1910 University Drive, Boise, ID, 83725 (United States); Purdue University, 400 Central Drive, West Lafayette, IN 47907 (United States)

    2017-01-15

    The growing role of charged particle irradiation in the evaluation of nuclear reactor candidate materials requires the development of novel methods to assess mechanical properties in near-surface irradiation damage layers just a few micrometers thick. In situ transmission electron microscopic (TEM) mechanical testing is one such promising method. In this work, microcompression pillars are fabricated from a Fe{sup 2+} ion irradiated bulk specimen of a model Fe-9%Cr oxide dispersion strengthened (ODS) alloy. Yield strengths measured directly from TEM in situ compression tests are within expected values, and are consistent with predictions based on the irradiated microstructure. Measured elastic modulus values, once adjusted for the amount of deformation and deflection in the base material, are also within the expected range. A pillar size effect is only observed in samples with minimum dimension ≤100 nm due to the low inter-obstacle spacing in the as received and irradiated material. TEM in situ micropillar compression tests hold great promise for quantitatively determining mechanical properties of shallow ion-irradiated layers.

  16. GeO2 decorated reduced graphene oxide as anode material of sodium ion battery

    International Nuclear Information System (INIS)

    Qin, Wei; Chen, Taiqiang; Hu, Bingwen; Sun, Zhuo; Pan, Likun

    2015-01-01

    Graphical abstract: Display Omitted -- Abstract: GeO 2 -reduced graphene oxide (RGO) composites were prepared by a simple freeze-drying method. After thermal annealing in N 2 atmosphere at 450 °C for 2 hours, the composites were examined as anode materials of sodium ion batteries for the first time. Their morphology, structure and electrochemical performance were characterized by field-emission scanning electron microscopy, X-ray diffraction, N 2 adsorption-desorption isotherm, cyclic voltammetry and electrochemical impedance spectroscopy, respectively. A maximum specific capacity of 330 mAh g −1 can be achieved after 50 galvanostatic charge-discharge cycles at a current density of 100 mA g −1 by tuning the RGO content in the composites. Even after 650 cycles at a high current density of 1 A g −1 , the specific capacity can still maintain at 153.7 mAh g −1 , demonstrating the excellent Na ion storage properties of the GeO 2 -RGO composites

  17. Highly stable aqueous zinc-ion storage using a layered calcium vanadium oxide bronze cathode

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Chuan; Guo, Jing; Li, Peng; Zhang, Xixiang; Alshareef, Husam N. [Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal (Saudi Arabia)

    2018-04-03

    Cost-effective aqueous rechargeable batteries are attractive alternatives to non-aqueous cells for stationary grid energy storage. Among different aqueous cells, zinc-ion batteries (ZIBs), based on Zn{sup 2+} intercalation chemistry, stand out as they can employ high-capacity Zn metal as the anode material. Herein, we report a layered calcium vanadium oxide bronze as the cathode material for aqueous Zn batteries. For the storage of the Zn{sup 2+} ions in the aqueous electrolyte, we demonstrate that the calcium-based bronze structure can deliver a high capacity of 340 mA h g{sup -1} at 0.2 C, good rate capability, and very long cycling life (96 % retention after 3000 cycles at 80 C). Further, we investigate the Zn{sup 2+} storage mechanism, and the corresponding electrochemical kinetics in this bronze cathode. Finally, we show that our Zn cell delivers an energy density of 267 W h kg{sup -1} at a power density of 53.4 W kg{sup -1}. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Fine structures of atomic excited states: precision atomic spectroscopy and electron-ion collision process

    International Nuclear Information System (INIS)

    Gao Xiang; Cheng Cheng; Li Jiaming

    2011-01-01

    Scientific research fields for future energies such as inertial confinement fusion researches and astrophysics studies especially with satellite observatories advance into stages of precision physics. The relevant atomic data are not only enormous but also of accuracy according to requirements, especially for both energy levels and the collision data. The fine structure of high excited states of atoms and ions can be measured by precision spectroscopy. Such precision measurements can provide not only knowledge about detailed dynamics of electron-ion interactions but also a bench mark examination of the accuracy of electron-ion collision data, especially incorporating theoretical computations. We illustrate that by using theoretical calculation methods which can treat the bound states and the adjacent continua on equal footing. The precision spectroscopic measurements of excited fine structures can be served as stringent tests of electron-ion collision data. (authors)

  19. Diagnosis of Lithium-Ion Batteries State-of-Health based on Electrochemical Impedance Spectroscopy Technique

    DEFF Research Database (Denmark)

    Stroe, Daniel Ioan; Swierczynski, Maciej Jozef; Stan, Ana-Irina

    2014-01-01

    Lithium-ion batteries have developed into a popular energy storage choice for a wide range of applications because of their superior characteristics in comparison to other energy storage technologies. Besides modelling the performance behavior of Lithium-ion batteries, it has become of huge...... interest to accurately diagnose their state-of-health (SOH). At present, Lithium-ion batteries are diagnosed by performing capacity or resistance (current pulse) measurements; however, in the majority of the cases, these measurements are time consuming and result in changing the state of the battery...... as well. This paper investigates the use of the electrochemical impedance spectroscopy (EIS) technique for SOH diagnosis of Lithium-ion battery cells, instead of using the aforementioned techniques, since this new method allows for online and direct measurement of the battery cell response in any working...

  20. Charge state distributions from highly charged ions channeled at a metal surface

    International Nuclear Information System (INIS)

    Folkerts, L.; Meyer, F.W.; Schippers, S.

    1994-01-01

    The vast majority of the experimental work in the field of multicharged ion-surface interactions, to date, has focused on x-ray and particularly on electron emission. These experiments include measurements of the total electron yield, the emission statistics of the electrons, and, most of all, the electron energy distributions. So far, little attention has been paid to the fate of the multicharged projectile ions after the scattering. To our knowledge, the only measurement of the charge state distribution of the scattered ions is the pioneering experiment of de Zwart et al., who measured the total yield of scattered 1+, 2+, and 3+ ions as a function of the primary charge state q (q = 1--11) for 20 key Ne, Ar, and Kr ions after reflection from a polycrystalline tungsten target. Their main finding is the sudden onset of scattered 3+ ions when inner-shell vacancies are present in the primary particles. This suggests that a certain fraction of the inner-shell vacancies survives the entire collision event, and decays via autoionization on the outgoing path. Since the projectiles scattered in the neutral charge state could not be detected in the experiment of de Zwart et al., they were not able to provide absolute charge state fractions. In our present experiment, we focus on the scattered projectiles, measuring both the final charge state and the total scattering angle with a single 2D position sensitive detector (PSD). This method gives us the number of positive, as well as neutral and negative, scattered ions, thus allowing us to extract absolute charge state fractions. Using a well-prepared single Au(110) crystal and a grazing incidence geometry, we were able to observe surface channeling along the [001] channels

  1. Effect of particle size on iron nanoparticle oxidation state

    International Nuclear Information System (INIS)

    Lombardo, Jeffrey J.; Lysaght, Andrew C.; Goberman, Daniel G.; Chiu, Wilson K.S.

    2012-01-01

    Selecting catalyst particles is a very important part of carbon nanotube growth, although the properties of these nanoscale particles are unclear. In this article iron nanoparticles are analyzed through the use of atomic force microscopy and x-ray photoelectron spectroscopy in order to understand how the size affects the chemical composition of nanoparticles and thus their physical structure. Initially, atomic force microscopy was used to confirm the presence of iron particles, and to determine the average size of the particles. Next an analytical model was developed to estimate particle size as a function of deposition time using inputs from atomic force microscopy measurement. X-ray photoelectron spectroscopy analysis was then performed with a focus on the spectra relating to the 2p Fe electrons to study the chemical state of the particles as a function of time. It was shown that as the size of nanoparticles decreased, the oxidation state of the particles changed due to a high proportion of atoms on the surface.

  2. A Review on the Synthesis of Manganese Oxide Nanomaterials and Their Applications on Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Xiaodi Liu

    2013-01-01

    Full Text Available Most recently, manganese oxides nanomaterials, including MnO and MnO2, have attracted great interest as anode materials in lithium-ion batteries (LIBs for their high theoretical capacity, environmental benignity, low cost, and special properties. Up to now, manganese oxides nanostructures with excellent properties and various morphologies have been successfully synthesized. Herein, we provide an in-depth discussion of recent development of the synthesis of manganese oxides nanomaterials and their application in the field of LIBs.

  3. Characteristics of Solid-State Calcium Ion Sensors Based on Photocurable and Selfplasticising Polyacrylate Matrices

    Directory of Open Access Journals (Sweden)

    Lee Yook Heng

    2017-11-01

    Full Text Available New membrane materials based on cross-linked poly(n-butyl acrylate (nBA, have been used successfully as calcium ion-selective membranes. These membrane materials possess selfplasticising property and hence do not require plasticisers. The photocurability and good adhesion characteristics of these polymer matrices enable workable solid-state calcium ion sensors to be fabricated by simple photocure procedures employing the calcium ionophore ETH5234 and a lipophilic additive as ion sensing components. The calcium ion-selectivity of the sensors can be controlled by varying the chemical composition of the photocured  membrane. An optimum amount of the cross-linker 2,2-hexanedioldiacrylate (HDDA and the incorporation of n-heptyl acrylate (nHA led to improvement in the calcium ion-selectivity. The best calcium ion-selectivity was obtained from a copolymer membrane with composition: nBA = 74 wt-%, nHA = 20 wt-% and HDDA = 0.1 wt-%. The selectivity coefficients of calcium over major cations were: LogKCaPot,Na= -4.4,  LogKCaPot,K = -3.6, LogKCa,PotLi = -5.9, LogKCaPot,Mg= -4.4 with a Nernstian slope (29.1 ± 0.8 mV/decade under buffered conditions. This potentiometric performance is comparable to other solid-state calcium ion sensors with various plasticised polymer membranes.

  4. Prospects for studies of ground-state proton decays with the Holifield Radioactive Ion Beam Facility

    International Nuclear Information System (INIS)

    Toth, K.S.

    1994-01-01

    By using radioactive ions from the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory it should be possible to identify many new ground-state proton emitters in the mass region from Sn to Pb. During this production and search process the limits of stability on the proton-rich side of the nuclidic chart will be delineated for a significant fraction of medium-weight elements and our understanding of the proton-emission process will be expanded and improved

  5. A Quasi-Solid-State Sodium-Ion Capacitor with High Energy Density.

    Science.gov (United States)

    Wang, Faxing; Wang, Xiaowei; Chang, Zheng; Wu, Xiongwei; Liu, Xiang; Fu, Lijun; Zhu, Yusong; Wu, Yuping; Huang, Wei

    2015-11-18

    A quasi-solid-state sodium-ion capacitor is demonstrated with nanoporous disordered carbon and macroporous graphene as the negative and positive electrodes, respectively, using a sodium-ion-conducting gel polymer electrolyte. It can operate at a cell voltage as high as 4.2 V with an energy density of record high 168 W h kg(-1). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Future prospects for ECR ion sources with improved charge state distributions

    International Nuclear Information System (INIS)

    Alton, G.D.

    1995-01-01

    Despite the steady advance in the technology of the ECR ion source, present art forms have not yet reached their full potential in terms of charge state and intensity within a particular charge state, in part, because of the narrow band width. single-frequency microwave radiation used to heat the plasma electrons. This article identifies fundamentally important methods which may enhance the performances of ECR ion sources through the use of: (1) a tailored magnetic field configuration (spatial domain) in combination with single-frequency microwave radiation to create a large uniformly distributed ECR ''volume'' or (2) the use of broadband frequency domain techniques (variable-frequency, broad-band frequency, or multiple-discrete-frequency microwave radiation), derived from standard TWT technology, to transform the resonant plasma ''surfaces'' of traditional ECR ion sources into resonant plasma ''volume''. The creation of a large ECR plasma ''volume'' permits coupling of more power into the plasma, resulting in the heating of a much larger electron population to higher energies, thereby producing higher charge state ions and much higher intensities within a particular charge state than possible in present forms of' the source. The ECR ion source concepts described in this article offer exciting opportunities to significantly advance the-state-of-the-art of ECR technology and as a consequence, open new opportunities in fundamental and applied research and for a variety of industrial applications

  7. The oxidation of uranium(IV) ions by nitrous acid in 30% tri-butyl phosphate

    International Nuclear Information System (INIS)

    Koltunov, V.S.; Marchenko, V.I.; Savilova, O.A.; Dvoeglazov, K.N.; Taylor, R.J.

    2004-01-01

    The kinetics of the oxidation of U(IV) ions by nitrous acid in a 30% TBP solution have been determined. The rate equation was found to be: - d[U(IV)] / dt = k 2a [U(IV)][HNO 2 ][HNO 3 ][H 2 O] / [HNO 3 ] 2 + β 3 [HNO 3 ][H 2 O] + β 4 [H 2 O] 2 , where, k 2a = 0.405 ± 0.055 M -1 min -1 at 55 C (β 3 ∼ 0.08; β 4 ∼ 0.007) and the activation energy was E = 112 ± 17 kJ mol -1 . The reaction mechanism appeared to involve interaction with the 1 st hydrolysis product of U(IV)-UOH 3+ . The data is compared with a previous study of the nitric acid oxidation of U(IV) in 30% TBP. This reaction is autocatalytic due to the formation of nitrous acid during the reaction. The kinetics of the decomposition of HNO 2 in 30% TBP (in the absence of U(IV)) have also been reported. (orig.)

  8. Lithium ion conductivity of molecularly compatibilized chitosan-poly(aminopropyltriethoxysilane)-poly(ethylene oxide) nanocomposites

    International Nuclear Information System (INIS)

    Fuentes, S.; Retuert, P.J.; Gonzalez, G.

    2007-01-01

    Films of composites of chitosan/poly(aminopropyltriethoxysilane)/poly(ethylene oxide) (CHI/pAPS/PEO) containing a fixed amount of lithium salt are studied. The ternary composition diagram of the composites, reporting information on the mechanic stability, the transparence and the electrical conductivity of the films, shows there is a window in which the molecular compatibility of the components is optimal. In this window, defined by the components ratios CHI/PEO 3:2, pAPS/PEO 2:3 and CHI/PEO 1:2, there is a particular composition Li x (CHI) 1 (PEO) 2 (pAPS) 1.2 for which the conductivity reaches a value of 1.7 x 10 -5 S cm -1 at near room temperature. Considering the balance between the Lewis acid and basic sites available in the component and the observed stoichiometry limits of formed polymer complexes, the conductivity values of these products may be understood by the formation of a layered structure in which the lithium ions, stabilized by the donors, poly(ethylene oxide) and/or poly(aminopropyltriethoxysilane), are intercalated in a chitosan matrix

  9. Graphene oxide-multiwalled carbon nanotubes composite as an anode for lithium ion batteries

    Directory of Open Access Journals (Sweden)

    Majchrzycki Łukasz

    2016-09-01

    Full Text Available Nowadays reduced graphene oxide (rGO is regarded as a highly interesting material which is appropriate for possible applications in electrochemistry, especially in lithium-ion batteries (LIBs. Several methods were proposed for the preparation of rGO-based electrodes, resulting in high-capacity LIBs anodes. However, the mechanism of lithium storage in rGO and related materials is still not well understood. In this work we focused on the proposed mechanism of favorable bonding sites induced by additional functionalities attached to the graphene planes. This mechanism might increase the capacity of electrodes. In order to verify this hypothesis the composite of non-reduced graphene oxide (GO with multiwalled carbon nanotubes electrodes was fabricated. Electrochemical properties of GO composite anodes were studied in comparison with similarly prepared electrodes based on rGO. This allowed us to estimate the impact of functional groups on the reversible capacity changes. As a result, it was shown that oxygen containing functional groups of GO do not create, in noticeable way, additional active sites for the electrochemical reactions of lithium storage, contrary to what has been postulated previously.

  10. Iron-antimony-based hybrid oxides as high-performance anodes for lithium-ion storage

    Science.gov (United States)

    Nguyen, Tuan Loi; Kim, Doo Soo; Hur, Jaehyun; Park, Min Sang; Yoon, Sukeun; Kim, Il Tae

    2018-06-01

    We report a facile approach to synthesize Fe-Sb-based hybrid oxides nanocomposites consisting of Sb, Sb2O3, and Fe3O4 for use as new anode materials for lithium-ion batteries. The composites are synthesized via galvanic replacement between Fe3+ and Sb at high temperature in triethylene glycol medium. The phase, morphology, and composition changes of the composites involved in the various stages of the replacement reaction are characterized using X-ray diffractometry, high-resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy. The as-prepared composites have different compositions with very small particle sizes (interfacial contact area between the nanocomposite and electrolyte, stable structure of the composites owing to a mixture of inactive phases generated by the conversion reaction between Li+ and oxide metal-whose structure serves as an electron conductor, inhibits agglomeration of Sb particles, and acts as an effective buffer against volume change of Sb during cycling-and high Li+ diffusion ability.

  11. Biochar-supported reduced graphene oxide composite for adsorption and coadsorption of atrazine and lead ions

    Science.gov (United States)

    Zhang, Ying; Cao, Bo; Zhao, Lulu; Sun, Lili; Gao, Yan; Li, Jiaojiao; Yang, Fan

    2018-01-01

    To explore potential in application for simultaneous removal of atrazine and lead ions (Pd2+), the adsorption and coadsorption of atrazine and Pd2+ is evaluated onto a novel biochar-supported reduced graphene oxide composite (RGO-BC), which has been successfully developed via slow pyrolysis of graphene oxide (GO) pretreated corn straws. Structure and morphology analysis reveal that GO nanosheets are coated on the surface of biochar (BC) mainly through π-π interactions, notably, GO nanosheets after annealing reduction can basically retain the original morphology, meanwhile, the change of physico-chemical properties on the surface endow excellent adsorption capaities of 26.10 mg g-1 for Pb2+ and 67.55 mg g-1 for atrazine. A significant difference is in sorption of Pb2+ and atrazine on RGO-BC sample in both single- and binary-solute systems. The adsorption capacity of RGO-BC still remained above 54.58 mg g-1 after four times regeneration (81% adsorption capacity remained), demonstrating a promising candidate for the application of removal contaminant in the environment.

  12. 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.

  13. Nuclear Forensics: Measurements of Uranium Oxides Using Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

    Science.gov (United States)

    2010-03-01

    Isotope Ratio Analysis of Actinides , Fission Products, and Geolocators by High- efficiency Multi-collector Thermal Ionization Mass Spectrometry...Information, 1999. Hou, Xiaolin, and Per Roos. “ Critical Comparison of radiometric and Mass Spectrometric Methods for the Determination of...NUCLEAR FORENSICS: MEASUREMENTS OF URANIUM OXIDES USING TIME-OF-FLIGHT SECONDARY ION MASS

  14. Chemical Bonding States of TiC Films before and after Hydrogen Ion Irradiation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    TiC films deposited by rf magnetron sputtering followed by Ar+ ion bombardment were irradiated with a hydrogen ion beam. X-ray photoelectron spectroscopy (XPS) was used for characterization of the chemical bonding states of C and Ti elements of the TiC films before and after hydrogen ion irradiation, in order to understand the effect of hydrogen ion irradiation on the films and to study the mechanism of hydrogen resistance of TiC films. Conclusions can be drawn that ion bombardment at moderate energy can cause preferential physical sputtering of carbon atoms from the surface of low atomic number (Z) material. This means that ion beam bombardment leads to the formation of a non-stoichiometric composition of TiC on the surface.TiC films prepared by ion beam mixing have the more excellent characteristic of hydrogen resistance. One important cause, in addition to TiC itself, is that there are many vacant sites in TiC created by ion beam mixing.These defects can easily trap hydrogen and effectively enhance the effect of hydrogen resistance.

  15. Charge state distributions for heavy ions in carbon stripper foils

    International Nuclear Information System (INIS)

    McMahan, M.A.; Lebed, R.F.; Feinberg, B.

    1989-03-01

    We have extended the database of measured charge state distributions available in the literature through measurements at the SuperHILAC using carbon stripper foils in the energy range 1.2--8.5 MeV/u. Modifying a semi-empirical model to include the effect of electronic shells, we are able to correctly predict the mean charge state to within 1/2 a charge state for 6≤Z≤92 and energies from 30 keV/u to 16 MeV/u. We have determined parameters for the widths of the distributions for each electronic shell. For distributions lying across a shell boundary, we join the two Gaussians of different widths to get an asymmetric distribution. 18 refs., 4 figs., 2 tabs

  16. Synthesis and electrochemical properties of high performance polyhedron sphere like lithium manganese oxide for lithium ion batteries

    International Nuclear Information System (INIS)

    Guo, Donglei; Wei, Xiuge; Chang, Zhaorong; Tang, Hongwei; Li, Bao; Shangguan, Enbo; Chang, Kun; Yuan, Xiao-Zi; Wang, Haijiang

    2015-01-01

    Graphical abstract: Polyhedron structured sphere-like LiMn 2 O 4 synthesized from β-MnO 2 nanorod precursor via a solid state reaction at a temperature of 800 °C exhibits excellent rate capability and cycling performance at both 25 °C and 55 °C. - Highlights: • Polyhedron sphere-like LiMn 2 O 4 was synthesized from β-MnO 2 nanorod precursor. • The polyhedron sphere-like LiMn 2 O 4 exhibits excellent rate capability and cycling performance. • The polyhedron sphere-like structure spinel LiMn 2 O 4 suppresses the dissolution of manganese ions. • The polyhedron sphere-like LiMn 2 O 4 has high diffusion coefficient of Li + . - Abstract: Polyhedron structured sphere-like lithium manganese oxide (LiMn 2 O 4 ) is successfully synthesized from β-MnO 2 nanorod precursor via a solid state reaction at a temperature of 800 °C. For comparison, LiMn 2 O 4 materials with nanorod and octahedron structures are also obtained from β-MnO 2 nanorod precursor at temperatures of 700 °C and 900 °C, respectively. The galvanostatic charge–discharge result shows that the polyhedron sphere-like LiMn 2 O 4 sample exhibits the best electrochemical performance at high rate and high temperature. After 100 cycles at 5 C, this electrode is able to maintain 94% of its capacity at 25 °C and 81% at 55 °C. This is attributed to that the polyhedron sphere-like spinel LiMn 2 O 4 can suppress the dissolution of manganese ions. Based on Brunauer Emmett Teller (BET), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), the polyhedron sphere-like LiMn 2 O 4 sample has the lowest BET surface area, largest diffusion coefficient of Li + and least charge transfer resistance. This study provides an insight into the capacity fading of LiMn 2 O 4 electrodes and the polyhedron structured sphere-like LiMn 2 O 4 can be a promising material for lithium ion batteries

  17. Oxidative stress markers in hypertensive states of pregnancy: preterm and term disease.

    Directory of Open Access Journals (Sweden)

    Lesia Olha Kurlak

    2014-08-01

    Full Text Available Discussion continues as to whether de novo hypertension in pregnancy with significant proteinuria (pre-eclampsia; PE and non-proteinuric new hypertension (gestational hypertension; GH are parts of the same disease spectrum or represent different conditions. Non-pregnant hypertension, pregnancy and PE are all associated with oxidative stress. We have established a 6 weeks post-partum clinic for women who experienced a hypertensive pregnancy. We hypothesized that PE and GH could be distinguished by markers of oxidative stress; thiobarbituric acid reactive substances (TBARS and antioxidants (ferric ion reducing ability of plasma; FRAP. Since the severity of PE and GH is greater pre-term, we also compared pre-term and term disease. Fifty-eight women had term PE, 23 pre-term PE, 60 had term GH and 6 pre-term GH, 11 pre-existing (essential hypertension (EH without PE. Limited data were available from normotensive pregnancies (n=7 and non-pregnant controls (n=14. There were no differences in postpartum TBARS or FRAP between hypertensive states; TBARS (P=0.001 and FRAP (P=0.009 were lower in plasma of non-pregnant controls compared to recently-pregnant women. Interestingly FRAP was higher in preterm than term GH (P=0.013. In PE and GH, TBARS correlated with low density lipoprotein (LDL-cholesterol (P=0.036; this association strengthened with inclusion of EH ((P=0.011. The 10 year Framingham index for cardiovascular risk was positively associated with TBARS (P=0.003.Oxidative stress profiles do not differ between hypertensive states but appear to distinguish between recently-pregnant and non-pregnant states. This suggests that pregnancy may alter vascular integrity with changes remaining 6 weeks postpartum. LDL-cholesterol is a known determinant of oxidative stress in cardiovascular disease and we have shown this association to be present in hypertensive pregnancy further emphasizing that such a pregnancy may be revealing a pre-existing cardiovascular

  18. Ladder-Shaped Ion Channel Ligands: Current State of Knowledge

    Science.gov (United States)

    Shmukler, Yuri B.; Nikishin, Denis A.

    2017-01-01

    Ciguatoxins (CTX) and brevetoxins (BTX) are polycyclic ethereal compounds biosynthesized by the worldwide distributed planktonic and epibenthic dinoflagellates of Gambierdiscus and Karenia genera, correspondingly. Ciguatera, evoked by CTXs, is a type of ichthyosarcotoxism, which involves a variety of gastrointestinal and neurological symptoms, while BTXs cause so-called neurotoxic shellfish poisoning. Both types of toxins are reviewed together because of similar mechanisms of their action. These are the only molecules known to activate voltage-sensitive Na+-channels in mammals through a specific interaction with site 5 of its α-subunit and may compete for it, which results in an increase in neuronal excitability, neurotransmitter release and impairment of synaptic vesicle recycling. Most marine ciguatoxins potentiate Nav channels, but a considerable number of them, such as gambierol and maitotoxin, have been shown to affect another ion channel. Although the extrinsic function of these toxins is probably associated with the function of a feeding deterrent, it was suggested that their intrinsic function is coupled with the regulation of photosynthesis via light-harvesting complex II and thioredoxin. Antagonistic effects of BTXs and brevenal may provide evidence of their participation as positive and negative regulators of this mechanism. PMID:28726749

  19. Ladder-Shaped Ion Channel Ligands: Current State of Knowledge

    Directory of Open Access Journals (Sweden)

    Yuri B. Shmukler

    2017-07-01

    Full Text Available Ciguatoxins (CTX and brevetoxins (BTX are polycyclic ethereal compounds biosynthesized by the worldwide distributed planktonic and epibenthic dinoflagellates of Gambierdiscus and Karenia genera, correspondingly. Ciguatera, evoked by CTXs, is a type of ichthyosarcotoxism, which involves a variety of gastrointestinal and neurological symptoms, while BTXs cause so-called neurotoxic shellfish poisoning. Both types of toxins are reviewed together because of similar mechanisms of their action. These are the only molecules known to activate voltage-sensitive Na+-channels in mammals through a specific interaction with site 5 of its α-subunit and may compete for it, which results in an increase in neuronal excitability, neurotransmitter release and impairment of synaptic vesicle recycling. Most marine ciguatoxins potentiate Nav channels, but a considerable number of them, such as gambierol and maitotoxin, have been shown to affect another ion channel. Although the extrinsic function of these toxins is probably associated with the function of a feeding deterrent, it was suggested that their intrinsic function is coupled with the regulation of photosynthesis via light-harvesting complex II and thioredoxin. Antagonistic effects of BTXs and brevenal may provide evidence of their participation as positive and negative regulators of this mechanism.

  20. Anisotropy of electronic states excited in ion-atom collisions

    International Nuclear Information System (INIS)

    Boskamp, E.B.

    1983-01-01

    The author reports coincidence measurements made on the He + + Ne and He + + He systems. The complex population amplitudes for the magnetic sublevels of the investigated excited states, Ne(2p 4 3s 2 ) 1 D and He(2p 2 ) 1 D, were completely determined and possible excitation mechanisms are described. (Auth.)

  1. Habit plane-driven P2-type manganese-based layered oxide as long cycling cathode for Na-ion batteries

    Science.gov (United States)

    Luo, Rui; Wu, Feng; Xie, Man; Ying, Yao; Zhou, Jiahui; Huang, Yongxin; Ye, Yusheng; Li, Li; Chen, RenJie

    2018-04-01

    Layered transition metal oxides are considered to be promising candidates as cathode materials for sodium-ion batteries. Herein, a facile solid-state reaction is developed to synthesize hexagons plate-like Na0.67Ni0.25Mn0.75O2+δ (denoted as P2-NNM) material with habit plane formed. The structure of this layered oxide is characterized by XRD, HR-TEM and SAED. The layered material delivers a high reversible capacity of 91.8 mAh g-1 at 0.2 C with a capacity retention of 94.4 % after 280 cycles, superior rate capability and long cycle life (84.2 % capacity retention after 1000 cycle). Ni2+ is an active ion and Ni doping alleviates the Jahn-Teller distortion, and Mn3+/Mn4+ coexist as Mn4+ is desired from the stability perspective. Particularly, CV and XPS results confirm these results. Moreover, the electrode exhibits a quasi-solid-solution reaction during the sodium extraction and insertion. This contribution demonstrates that P2-NNM is a promising cathode electrode for rechargeable long-life sodium-ion batteries.

  2. Quantum confinement-induced tunable exciton states in graphene oxide.

    Science.gov (United States)

    Lee, Dongwook; Seo, Jiwon; Zhu, Xi; Lee, Jiyoul; Shin, Hyeon-Jin; Cole, Jacqueline M; Shin, Taeho; Lee, Jaichan; Lee, Hangil; Su, Haibin

    2013-01-01

    Graphene oxide has recently been considered to be a potential replacement for cadmium-based quantum dots due to its expected high fluorescence. Although previously reported, the origin of the luminescence in graphene oxide is still controversial. Here, we report the presence of core/valence excitons in graphene-based materials, a basic ingredient for optical devices, induced by quantum confinement. Electron confinement in the unreacted graphitic regions of graphene oxide was probed by high resolution X-ray absorption near edge structure spectroscopy and first-principles calculations. Using experiments and simulations, we were able to tune the core/valence exciton energy by manipulating the size of graphitic regions through the degree of oxidation. The binding energy of an exciton in highly oxidized graphene oxide is similar to that in organic electroluminescent materials. These results open the possibility of graphene oxide-based optoelectronic device technology.

  3. Lithium-ion battery state of function estimation based on fuzzy logic algorithm with associated variables

    Science.gov (United States)

    Gan, L.; Yang, F.; Shi, Y. F.; He, H. L.

    2017-11-01

    Many occasions related to batteries demand to know how much continuous and instantaneous power can batteries provide such as the rapidly developing electric vehicles. As the large-scale applications of lithium-ion batteries, lithium-ion batteries are used to be our research object. Many experiments are designed to get the lithium-ion battery parameters to ensure the relevance and reliability of the estimation. To evaluate the continuous and instantaneous load capability of a battery called state-of-function (SOF), this paper proposes a fuzzy logic algorithm based on battery state-of-charge(SOC), state-of-health(SOH) and C-rate parameters. Simulation and experimental results indicate that the proposed approach is suitable for battery SOF estimation.

  4. Statistical electron correlation coefficients for the five lowest states of the heliumlike ions

    International Nuclear Information System (INIS)

    Thakkar, A.J.; Smith, V.H. Jr.

    1981-01-01

    Statistical correlation coefficients were introduced by Kutzelnigg, Del Re, and Berthier to provide overall measures of the difference between the electron pair density and the product of one-electron densities in atoms and molecules. Some properties of these coefficients are discussed, and it is shown that an angular correlation coefficient is experimentally accessible. Radial and angular correlation coefficients are computed from highly accurate wave functions for the 1 1 S, 2 3 S, 2 1 S, 2 3 P, and 2 1 P states of the heliumlike ions from He through Mg 10+ . It is found that positive angular correlation coefficients occur in the 2 1 P state of the two-electron positive ions but not in neutral helium. Moreover, the angular correlation coefficients for the 2 1 S and 2 3 S states of the positively charged two-electron ions show that a previously proposed reformulation of Hund's rule is incorrect

  5. A light-matter quantum interface : ion-photon entanglement and state mapping

    International Nuclear Information System (INIS)

    Stute, A.

    2012-01-01

    Quantum mechanics promises to have a great impact on computation. Motivated by the long-term vision of a universal quantum computer that speeds up certain calculations, the field of quantum information processing has been growing steadily over the last decades. Although a variety of quantum systems consisting of a few qubits have been used to implement initial algorithms successfully, decoherence makes it difficult to scale up these systems. A powerful technique, however, could surpass any size limitation: the connection of individual quantum processors in a network. In a quantum network, ''flying'' qubits coherently transfer information between the stationary nodes of the network that store and process quantum information. Ideal candidates for the physical implementation of nodes are single atoms that exhibit long storage times; optical photons, which travel at the speed of light, are ideal information carriers. For coherent information transfer between atom and photon, a quantum interface has to couple the atom to a particular optical mode. This thesis reports on the implementation of a quantum interface by coupling a single trapped 40 Ca+ ion to the mode of a high-finesse optical resonator. Single intra-cavity photons are generated in a vacuum-stimulated Raman process between two atomic states driven by a laser and the cavity vacuum field. In this Raman process, all Zeeman substates of the atom are spectroscopically resolved by tuning the frequency of the laser; via addressing specific atomic states, the polarization of the generated cavity photon is controlled, defining the photonic qubit. The electronic state of the ion is initialized, coherently manipulated, and read out via driving the quadrupole transition. With these techniques in hand, we have demonstrated two protocols for quantum communication. The first protocol, ion-photon entanglement, is regarded as a key resource of distributed quantum information processing. In our realization, we control both

  6. Systematics in Rydberg state excitations for ion-atom collisions

    International Nuclear Information System (INIS)

    Andresen, B.; Jensen, K.; Petersen, N.B.; Veje, E.

    1976-01-01

    Rydberg state excitations in the Ne + , Mg + -He collisions have been studied in the projectile energy range 10-75 keV by means of optical spectrometry in a search for systematic trends. The relative excitation cross sections for levels of a Rydberg term series are found to follow a general (nsup(x))sup(P) behaviour with P < approximately -3 varying with collision energy and particles, regardless of whether the excited state population results from direct excitation, single electron transfer, or double electron transfer. At higher collision energies P is approximately -3 as predicted by theory. Polarization of the emitted line radiation indicates that there is no general rule for the relative excitation of the different magnetic substates of the same level. A statistical distribution of excitation is found for levels within the same term when the fine structure splitting is small. (Auth.)

  7. 3D glasma initial state for relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Schenke, Björn; Schlichting, Sören

    2016-01-01

    We extend the impact-parameter-dependent Glasma model to three dimensions using explicit small-x evolution of the two incoming nuclear gluon distributions. We compute rapidity distributions of produced gluons and the early-time energy momentum tensor as a function of space-time rapidity and transverse coordinates. Finally, we study rapidity correlations and fluctuations of the initial geometry and multiplicity distributions and make comparisons to existing models for the three-dimensional initial state.

  8. Properties of the Excited States of Molecular Ions.

    Science.gov (United States)

    1981-04-13

    FIg. 1). techniques have beest applied to the study of quartet states of Oi. The four potential curves most relevant Guyon et al., using a synchrotron...8217 a’ a a C ’U ~ ~ ~ ~ ~ ~ ~ 2 2,~ C a ’I C~- C ’ 𔃺 𔃺 𔃺 ’ ’ C- ~ C-E-38- ’- u A() A09a 265 SRI INTERNATIONAL 14FNLO PARK CA MOLECULAR PHYSICS LAB F

  9. Kinetics of uranium (4) oxidation with nitrous acid in the presence of oxalate-ions in nitric and perchloric acid solutions

    International Nuclear Information System (INIS)

    Nikitenko, S.I.; Astafurova, L.N.

    1991-01-01

    Kinetics of uranium (4) oxidation with nitrous acid in the presence of oxalate-ions are studied spectrometrically. It is shown that even at small oxalate concentrations a notable effect of tetravalent uranium stabilization is observed relatively to the oxidation with nitrous acid. In case of a significant excess of oxalate-ions the oxidation rate will be considerably slower as a result of the formation of U(4) bisoxalate complex

  10. State-selective charge transfer cross sections for light ion impact of atomic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, D. R. [University of North Texas; Stancil, Phillip C. [University of Georgia, Athens; Havener, C. C. [Oak Ridge National Laboratory (ORNL)

    2015-01-01

    Owing to the utility of diagnosing plasma properties such as impurity concentration and spatial distribution, and plasma temperature and rotation, by detection of photon emission following capture of electrons from atomic hydrogen to excited states of multiply charged ions, new calculations of state-selective charge transfer involving light ions have been carried out using the atomic orbital close-coupling and the classical trajectory Monte Carlo methods. By comparing these with results of other approaches applicable in a lower impact energy regime, and by benchmarking them using key experimental data, knowledge of the cross sections can be made available across the range parameters needed by fusion plasma diagnostics.

  11. Electronic structure of molecular Rydberg states of some small molecules and molecular ion

    International Nuclear Information System (INIS)

    Sun Biao; Li Jiaming

    1993-01-01

    Based on an independent-particle-approximation (i.e. the multiple scattering self-consistent-field theory), the electronic structures of Rydberg states of the small diatomic molecules H 2 , He 2 and the He 2 + molecular ion were studied. The principal quantum number of the first state of the Rydberg series is determined from a convention of the limit of the molecular electronic configuration. The dynamics of the excited molecules and molecular ion has been elucidated. The theoretical results are in fair agreement with the existing experimental measurements, thus they can serve as a reliable basis for future refined treatment such as the configuration interaction calculation

  12. Stabilization of actinides and lanthanides in unusually high oxidation states

    International Nuclear Information System (INIS)

    Eller, P.G.; Penneman, R.A.

    1986-01-01

    Chemical environments can be chosen which stabilize actinides and lanthanides in unusually high or low oxidation states and in unusual coordination. In many cases, one can rationalize the observed species as resulting from strong charge/size influences provided by specific sites in host lattices (e.g., Tb(IV) in BaTbO 3 or Am(IV) in polytungstate anions). In other cases, the unusual species can be considered from an acid-base viewpoint (e.g., U(III) in AsF 5 /HF solution or Pu(VII) in Li 5 PuO 6 ). In still other cases, an interplay of steric and redox effects can lead to interesting comparisons (e.g., instability of double fluoride salts of Pu(V) and Pu(VI) relative to U, Np, and Am analogues). Generalized ways to rationalize compounds containing actinides and lanthanides in unusual valences (particularly high valences), including the above and numerous other examples, will form the focus of this paper. Recently developed methods for synthesizing high valent f-element fluorides using superoxidizers and superacids at low temperatures will also be described. 65 refs., 8 figs., 9 tabs

  13. Stannic oxide spherical nanoparticles: an anode material with long-term cyclability for Li-ion rechargeable batteries

    Science.gov (United States)

    Kalubarme, Ramchandra S.; Kale, Bharat B.; Gosavi, Suresh W.

    2017-08-01

    Transition metal oxides are widely used in energy storage applications. Stannic oxide nanostructures are prepared using a controlled, NaOH assisted, simple precipitation method. The morphology of the prepared material confirms the formation of fine nanoparticles having a rutile stannic oxide (SnO2) phase, with cassiterite structure, and size distribution ~20 nm. On testing, as an anode material for a Li-ion battery, stannic oxide delivers a reversible charge capacity of 957 mAh g-1 at an applied current rate of C/10. The stannic oxide shows excellent rate performance displaying capacity of 577 mAh g-1 at 10 C and capacity of 919 mAh g-1 retained after 200 cycles at an applied current rate of C/2. The super performance of stannic oxide fine particles stem from both the effective diffusion of Li-ions to reaction sites through porous channels and weaker stress/strain during Li insertion/desertion owing to its fine size.

  14. Solid oxide fuel cells fueled with reducible oxides

    Science.gov (United States)

    Chuang, Steven S.; Fan, Liang Shih

    2018-01-09

    A direct-electrochemical-oxidation fuel cell for generating electrical energy includes a cathode provided with an electrochemical-reduction catalyst that promotes formation of oxygen ions from an oxygen-containing source at the cathode, a solid-state reduced metal, a solid-state anode provided with an electrochemical-oxidation catalyst that promotes direct electrochemical oxidation of the solid-state reduced metal in the presence of the oxygen ions to produce electrical energy, and an electrolyte disposed to transmit the oxygen ions from the cathode to the solid-state anode. A method of operating a solid oxide fuel cell includes providing a direct-electrochemical-oxidation fuel cell comprising a solid-state reduced metal, oxidizing the solid-state reduced metal in the presence of oxygen ions through direct-electrochemical-oxidation to obtain a solid-state reducible metal oxide, and reducing the solid-state reducible metal oxide to obtain the solid-state reduced metal.

  15. Erratum to: Study on Chloride Ion Penetration Resistance of Rubberized Concrete Under Steady State Condition

    Directory of Open Access Journals (Sweden)

    Md Noor Nurazuwa

    2016-01-01

    In this paper, the effect of crumb rubber, CR as fine aggregate in the concrete to enhance concrete durability against chloride ion diffusion was studied. Chloride ion diffusion in rubberized concrete was tested by migration test under steady state condition. Concrete specimen with water-to-cement ratio of 0.50 was prepared to study the CR effectiveness in comparison with lower water-to-cement ratio. In addition, 10% silica fume, SF was added to provide denser concrete and to understand its effectiveness against chloride ion diffusion. Results showed that chloride transport characteristics were improved by the increasing amount of CR in all mixed due to the fact that CR has the ability to repel water. Meanwhile, rubberized concrete with w/c = 0.35 gave better resistance against chloride ion penetration compared to w/c = 0.50. This was much improved with combination of CR and SF.

  16. Adsorption of heavy metal ion from aqueous solution by nickel oxide nano catalyst prepared by different methods

    Directory of Open Access Journals (Sweden)

    Amira M. Mahmoud

    2015-03-01

    Full Text Available Environmental pollution by heavy metal is arising as the most endangering tasks to both water sources and atmosphere quality today. The treatment of heavy metals is of special concern due to their recalcitrance and persistence in the environment. To limit the spread of the heavy metals within water sources, nickel oxide nanoparticles adsorbents were synthesized and characterized with the aim of removal of one of the aggressive heavy elements, namely; lead ions. Nano nickel oxide adsorbents were prepared using NaOH and oxalic acid dissolved in ethanol as precursors. The results indicated that adsorption capacity of Pb(II ion by NiO-org catalyst is favored than that prepared using NaOH as a precipitant. Nickel oxide nanoparticles prepared by the two methods were characterized structurally and chemically through XRD, DTA, TGA, BET and FT-IR. Affinity and efficiency sorption parameters of the solid nano NiO particles, such as; contact time, initial concentration of lead ions and the dosage of NiO nano catalyst and competitive adsorption behaviors were studied. The results showed that the first-order reaction law fit the reduction of lead ion, also showed good linear relationship with a correlation coefficient (R2 larger than 0.9.

  17. Effect of swift heavy ion (SHI) irradiation on transparent conducting oxide electrodes for dye-sensitized solar cell applications

    Science.gov (United States)

    Singh, Hemant Kr.; Avasthi, D. K.; Aggarwal, Shruti

    2015-06-01

    Transparent conducting oxides (TCOs) are used as electrodes in dye-sensitized solar cells (DSSCs) because of their properties such as high transmittance and low resistivity. In the present work, the effects of swift heavy ion (SHI) irradiation on various types of TCOs are presented. The objective of this study is to investigate the effect of SHI on TCOs. For the present study, three different types of TCOs are considered, namely, (a) FTO (fluorine-doped tin oxide, SnO2:F) on a Nippon glass substrate, (b) ITO (indium tin oxide, In2O3:Sn) coated on polyethylene terephthalate (PET) on a Corning glass substrate, and (c) ITO on a Corning glass substrate. These films are irradiated with 120 MeV Ag+9 ions at fluences ranging from 3.0 × 1011 ions/cm2 to 3.0 × 1013 ions/cm2. The structural, morphological, optical and electrical properties are studied via X-ray diffraction (XRD), atomic force microscopy (AFM), UV-Vis absorption spectroscopy and four-probe resistivity measurements, respectively. The ITO-PET electrode is found to exhibit superior conductivity and transmittance properties in comparison with the others after irradiation and, therefore, to be the most suitable for solar cell applications.

  18. 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

  19. Formation of high oxide ion conductive phases in the sintered oxides of the system Bi2O3-Ln2O3 (Ln = La-Yb)

    International Nuclear Information System (INIS)

    Iwahara, H.; Esaka, T.; Sato, T.; Takahashi, T.

    1981-01-01

    The electrical conduction in various phases of the system Bi 2 O 3 -Ln 2 O 3 (Ln = La, Nd, Sm, Dy, Er, or Yb) was investigated by measuring ac conductivity and the emf of the oxygen gas concentration cell. High-oxide-ion conduction was observed in the rhombohedral and face-centered cubic (fcc) phase in these systems. The fcc phase could be stabilized over a wide range of temperature by adding a certain amount of Ln 2 O 3 . In these cases, the larger the atomic number of Ln, the lower the content of Ln 2 O 3 required to form the fcc solid solution, except in the case of Yb 2 O 3 . The oxide ion conductivity of this phase decreased with increasing content of Ln 2 O 3 . Maximum conductivity was obtained at the lower limit of the fcc solid solution formation range in each system, which was more than one order of magnitude higher than those of conventional stabilized zirconias. Lattice parameters of the fcc phase were calculated from the x-ray diffraction patterns. The relationship between the oxide ion conductivity and the lattice parameter was also discussed

  20. In-situ preparation of poly(ethylene oxide)/Li3PS4 hybrid polymer electrolyte with good nanofiller distribution for rechargeable solid-state lithium batteries

    Science.gov (United States)

    Chen, Shaojie; Wang, Junye; Zhang, Zhihua; Wu, Linbin; Yao, Lili; Wei, Zhenyao; Deng, Yonghong; Xie, Dongjiu; Yao, Xiayin; Xu, Xiaoxiong

    2018-05-01

    Nano-sized fillers in a polymer matrix with good distribution can play a positive role in improving polymer electrolytes in the aspects of ionic conductivity, mechanical property and electrochemical performance of Li-ion cells. Herein, polyethylene oxide (PEO)/Li3PS4 hybrid polymer electrolyte is prepared via a new in-situ approach. The ionic conductivities of the novel hybrid electrolytes with variable proportions are measured, and the optimal electrolyte of PEO-2%vol Li3PS4 presents a considerable ionic conductivity of 8.01 × 10-4 S cm-1 at 60 °C and an electrochemical window up to 5.1 V. The tests of DSC and EDXS reveal that the Li3PS4 nanoparticles with better distribution, as active fillers scattering in the PEO, exhibit a positive effect on the transference of lithium ion and electrochemical interfacial stabilities. Finally, the assembled solid-state LiFePO4/Li battery presents a decent cycling performance (80.9% retention rate after 325 cycles at 60 °C) and excellent rate capacities with 153, 143, 139 and 127 mAh g-1 at the discharging rate of 0.1 C, 0.2 C, 0.5 C and 1 C at 60 °C. It is fully proved that it is an advanced strategy to preparing the new organic/inorganic hybrid electrolytes for lithium-ion batteries applications.