Science.gov

Sample records for radioactive metal ions

  1. Radioactive ion detector

    DOEpatents

    Bower, K.E.; Weeks, D.R.

    1997-08-12

    Apparatus for detecting the presence, in aqueous media, of substances which emit alpha and/or beta radiation and determining the oxidation state of these radioactive substances, that is, whether they are in cationic or anionic form. In one embodiment, a sensor assembly has two elements, one comprised of an ion-exchange material which binds cations and the other comprised of an ion-exchange material which binds anions. Each ion-exchange element is further comprised of a scintillation plastic and a photocurrent generator. When a radioactive substance to which the sensor is exposed binds to either element and emits alpha or beta particles, photons produced in the scintillation plastic illuminate the photocurrent generator of that element. Sensing apparatus senses generator output and thereby indicates whether cationic species or anionic species or both are present and also provides an indication of species quantity. 2 figs.

  2. Radioactive ion detector

    DOEpatents

    Bower, Kenneth E. (Los Alamos, NM); Weeks, Donald R. (Saratoga, CA)

    1997-01-01

    Apparatus for detecting the presence, in aqueous media, of substances which emit alpha and/or beta radiation and determining the oxidation state of these radioactive substances, that is, whether they are in cationic or anionic form. In one embodiment, a sensor assembly has two elements, one comprised of an ion-exchange material which binds cations and the other comprised of an ion-exchange material which binds anions. Each ion-exchange element is further comprised of a scintillation plastic and a photocurrent generator. When a radioactive substance to which the sensor is exposed binds to either element and emits alpha or beta particles, photons produced in the scintillation plastic illuminate the photocurrent generator of that element. Sensing apparatus senses generator output and thereby indicates whether cationic species or anionic species or both are present and also provides an indication of species quantity.

  3. Alkali metal ions through glass: a possible radioactive waste management application 

    E-print Network

    Jones, Robert Allan

    1996-01-01

    method of separating radioactive cesium (stored as a nitrate) from high level radioactive waste. This objective was not completely met because of mechanical failures with the special cesium glass. The focus was then made on learning more about soda...

  4. Sources of radioactive ions

    SciTech Connect

    Alonso, J.R.

    1985-05-01

    Beams of unstable nuclei can be formed by direct injection of the radioactive atoms into an ion source, or by using the momentum of the primary production beam as the basis for the secondary beam. The effectiveness of this latter mechanism in secondary beam formation, i.e., the quality of the emerging beam (emittance, intensity, energy spread), depends critically on the nuclear reaction kinematics, and on the magnitude of the incident beam energy. When this beam energy significantly exceeds the energies typical of the nuclear reaction process, many of the qualities of the incident beam can be passed on to the secondary beam. Factors affecting secondary beam quality are discussed, along with techniques for isolating and purifying a specific secondary product. The ongoing radioactive beam program at the Bevalac is used as an example, with applications, present performance and plans for improvements.

  5. Charge Breeding of Radioactive Ions

    E-print Network

    Wenander, F J C

    2013-01-01

    Charge breeding is a technique to increase the charge state of ions, in many cases radioactive ions. The singly charged radioactive ions, produced in an isotope separator on-line facility, and extracted with a low kinetic energy of some tens of keV, are injected into a charge breeder, where the charge state is increased to Q. The transformed ions are either directed towards a dedicated experiment requiring highly charged ions, or post-accelerated to higher beam energies. In this paper the physics processes involved in the production of highly charged ions will be introduced, and the injection and extraction beam parameters of the charge breeder defined. A description of the three main charge-breeding methods is given, namely: electron stripping in gas jet or foil; external ion injection into an electron-beam ion source/trap (EBIS/T); and external ion injection into an electron cyclotron resonance ion source (ECRIS). In addition, some preparatory devices for charge breeding and practical beam delivery aspects ...

  6. Metal Ion Sources for Ion Beam Implantation

    SciTech Connect

    Zhao, W. J.; Zhao, Z. Q.; Ren, X. T.

    2008-11-03

    In this paper a theme touched upon the progress of metal ion sources devoted to metal ion beam implantation (MIBI) will be reviewed. A special emphasis will be given to some kinds of ion sources such as ECR, MEVVA and Cluster ion sources. A novel dual hollow cathode metal ion source named DUHOCAMIS will be introduced and discussed.

  7. Method for decontamination of radioactive metal surfaces

    DOEpatents

    Bray, L.A.

    1996-08-13

    Disclosed is a method for removing radioactive contaminants from metal surfaces by applying steam containing an inorganic acid and cerium IV. Cerium IV is applied to contaminated metal surfaces by introducing cerium IV in solution into a steam spray directed at contaminated metal surfaces. Cerium IV solution is converted to an essentially atomized or vapor phase by the steam.

  8. Method for decontamination of radioactive metal surfaces

    DOEpatents

    Bray, Lane A. (Richland, WA)

    1996-01-01

    Disclosed is a method for removing radioactive contaminants from metal surfaces by applying steam containing an inorganic acid and cerium IV. Cerium IV is applied to contaminated metal surfaces by introducing cerium IV in solution into a steam spray directed at contaminated metal surfaces. Cerium IV solution is converted to an essentially atomized or vapor phase by the steam.

  9. Metal Ions in Neuroscience

    PubMed Central

    Ragan, C. Ian

    1997-01-01

    Metal ions are believed to participate in many neurodegenerative conditions. In excitotoxic cell death there is convincing evidence for the participation of Ca2+ and Zn2+ ions although the exact molecular mechanisms by which these metals exert their effects are unclear. Only in one instance has the metal binding site of metalloenzymes been exploited for therapeutic purposes and this is the use of Li+ in the treatment of bipolar affective disorder. Again the exact molecular target is not clear but is likely to involve a Mg2+-dependent enzyme of an intracellular signalling pathway. In Parkinson's disease, the selective loss of dopaminergic neurones in the substantia nigra may be caused by radical-mediated damage and there is good evidence to suggest that Fe2+ or 3+ is important in promoting formation of radical species. The evidence that free radicals are important in mediating other neurodegenerative conditions is less strong but still substantial enough to suggest that removal of reactive oxygen species or preventing their formation may be a valid approach to therapy. PMID:18475782

  10. Method of handling radioactive alkali metal waste

    DOEpatents

    Wolson, Raymond D. (Lockport, IL); McPheeters, Charles C. (Plainfield, IL)

    1980-01-01

    Radioactive alkali metal is mixed with particulate silica in a rotary drum reactor in which the alkali metal is converted to the monoxide during rotation of the reactor to produce particulate silica coated with the alkali metal monoxide suitable as a feed material to make a glass for storing radioactive material. Silica particles, the majority of which pass through a 95 mesh screen or preferably through a 200 mesh screen, are employed in this process, and the preferred weight ratio of silica to alkali metal is 7 to 1 in order to produce a feed material for the final glass product having a silica to alkali metal monoxide ratio of about 5 to 1.

  11. Radioactive metal tracer investigation of Pd2Si formation

    NASA Astrophysics Data System (ADS)

    Farmer, J.; Wandt, M. A. E.; Pretorius, R.

    1990-04-01

    A radioactive metal tracer technique has been developed with a view to identify the dominant diffusing species and the diffusion mechanism during silicide growth.The position of a thin band of radioactive metal, originally at the silicon/metal interface, is determined after silicide formation by alternate use of Rutherford backscattering spectrometry, ? spectrometry, and Ar ion sputter etching. Application of this procedure to the formation of Pd2Si yields a 109Pd activity profile, the position and shape of which indicates that mainly silicon moves during this reaction, while the observed spreading of the profile points to some palladium vacancy diffusion. The data obtained with this approach demonstrate that the technique is well suited for the determination of the predominantly diffusing species, and confirm results of other inert marker and 31Si tracer diffusion experiments.

  12. Radioactive scrap metal decontamination technology assessment report

    SciTech Connect

    Buckentin, J.M.; Damkroger, B.K.; Schlienger, M.E.

    1996-04-01

    Within the DOE complex there exists a tremendous quantity of radioactive scrap metal. As an example, it is estimated that within the gaseous diffusion plants there exists in excess of 700,000 tons of contaminated stainless steel. At present, valuable material is being disposed of when it could be converted into a high quality product. Liquid metal processing represents a true recycling opportunity for this material. By applying the primary production processes towards the material`s decontamination and re-use, the value of the strategic resource is maintained while drastically reducing the volume of material in need of burial. Potential processes for the liquid metal decontamination of radioactively contaminated metal are discussed and contrasted. Opportunities and technology development issues are identified and discussed. The processes compared are: surface decontamination; size reduction, packaging and burial; melting technologies; electric arc melting; plasma arc centrifugal treatment; air induction melting; vacuum induction melting; and vacuum induction melting and electroslag remelting.

  13. Radioactive Ion Beam Production Capabilities At The Holifield Radioactive Ion Beam Facility

    SciTech Connect

    Beene, J. R.; Dowling, D. T.; Gross, C. J.; Juras, R. C.; Liu, Y.; Meigs, M. J.; Mendez, A. J. II; Nazarewicz, W.; Sinclair, J. W.; Stracener, D. W.; Tatum, B. A.

    2011-06-01

    The Holifield Radioactive Ion Beam Facility (HRIBF) is a national user facility for research with radioactive ion beams (RIBs) that has been in routine operation since 1996. It is located at Oak Ridge National Laboratory (ORNL) and operated by the ORNL Physics Division. The principal mission of the HRIBF is the production of high quality beams of shortlived radioactive isotopes to support research in nuclear structure physics and nuclear astrophysics. HRIBF is currently unique worldwide in its ability to provide neutron-rich fission fragment beams post-accelerated to energies above the Coulomb barrier for nuclear reactions. HRIBF produces RIBs by the isotope separator on-line (ISOL) technique using a particle accelerator system that consists of the Oak Ridge Isochronous Cyclotron (ORIC) driver accelerator, one of the two Injectors for Radioactive Ion Species (IRIS1 or IRIS2) production systems, and the 25-MV tandem electrostatic accelerator that is used for RIB post-acceleration. ORIC provides a light ion beam (proton, deuteron, or alpha) which is directed onto a thick target mounted in a target-ion source (TIS) assembly located on IRIS1 or IRIS2. Radioactive atoms that diffuse from the target material are ionized, accelerated, mass selected, and transported to the tandem accelerator where they are further accelerated to energies suitable for nuclear physics research. RIBs are transported through a beam line system to various experimental end stations including the Recoil Mass Spectrometer (RMS) for nuclear structure research, and the Daresbury Recoil Separator (DRS) for nuclear astrophysics research. HRIBF also includes two off-line ion source test facilities, one low-power on-line ISOL test facility (OLTF), and one high-power on-line ISOL test facility (HPTL). This paper provides an overview and status update of HRIBF, describes the recently completed $4.7M IRIS2 addition and incorporation of laser systems for beam production and purification, and discusses a proposed replacement of the ORIC driver accelerator.

  14. Method for electrochemical decontamination of radioactive metal

    DOEpatents

    Ekechukwu, Amy A. (Augusta, GA)

    2008-06-10

    A decontamination method for stripping radionuclides from the surface of stainless steel or aluminum material comprising the steps of contacting the metal with a moderately acidic carbonate/bicarbonate electrolyte solution containing sodium or potassium ions and thereafter electrolytically removing the radionuclides from the surface of the metal whereby radionuclides are caused to be stripped off of the material without corrosion or etching of the material surface.

  15. INEL metal recycle radioactive scrap metal survey report

    SciTech Connect

    Funk, D.M.

    1994-09-01

    DOE requested that inventory and characterization of radioactive scrap metal (RSM) be conducted across the DOE complex. Past studies have estimated the metal available from unsubstantiated sources. In meetings held in FY-1993, with seven DOE sites represented and several DOE-HQ personnel present, INEL personnel discovered that these numbers were not reliable and that large stockpiles did not exist. INEL proposed doing in-field measurements to ascertain the amount of RSM actually available. This information was necessary to determine the economic viability of recycling and to identify feed stock that could be used to produce containers for radioactive waste. This inventory measured the amount of RSM available at the selected DOE sites. Information gathered included radionuclide content and chemical form, general radiation field, alloy type, and mass of metal.

  16. Pure radioactive Ga ion beams provided by new laser ion source for nuclear research at ORNL

    E-print Network

    Pure radioactive Ga ion beams provided by new laser ion source for nuclear research at ORNL pure beams of radioactive nuclei far from stability. · Beams of neutron-rich Ga isotopes were delivered to the Low-energy Radioactive Ion Beam Spectroscopy Station (LeRIBSS) with previously unattainable purity

  17. Development of the Holifield Radioactive Ion Beam Facility

    SciTech Connect

    Tatum, B.A.

    1997-08-01

    The Holifield Radioactive Ion Beam Facility (HRIBF) construction project has been completed and the first radioactive ion beam has been successfully accelerated. The project, which began in 1992, has involved numerous facility modifications. The Oak Ridge Isochronous Cyclotron has been converted from an energy booster for heavy ion beams to a light ion accelerator with internal ion source. A target-ion source and mass analysis system have been commissioned as key components of the facility`s radioactive ion beam injector to the 25MV tandem electrostatic accelerator. Beam transport lines have been completed, and new diagnostics for very low intensity beams have been developed. Work continues on a unified control system. Development of research quality radioactive beams for the nuclear structure and nuclear astrophysics communities continues. This paper details facility development to date.

  18. METAL IONS: Physiological function and Pathological rle

    E-print Network

    Morante, Silvia

    METAL IONS: Physiological function and Pathological rôle #12;METAL IONS ARE ESSENTIAL CELL COMPONENTS At least one-third of all proteins encoded in the human genome contain metal ions They can easily of biological processes Their ionization state influences how easily metal can get into cells (e.g.: Fe++ cross

  19. Evaluation of radioactive scrap metal recycling

    SciTech Connect

    Nieves, L.A.; Chen, S.Y.; Kohout, E.J.; Nabelssi, B.; Tilbrook, R.W.; Wilson, S.E.

    1995-12-01

    This report evaluates the human health risks and environmental and socio-political impacts of options for recycling radioactive scrap metal (RSM) or disposing of and replacing it. Argonne National Laboratory (ANL) is assisting the US Department of Energy (DOE), Office of Environmental Restoration and Waste Management, Oak Ridge Programs Division, in assessing the implications of RSM management alternatives. This study is intended to support the DOE contribution to a study of metal recycling being conducted by the Task Group on Recycling and Reuse of the Organization for Economic Cooperation and Development. The focus is on evaluating the justification for the practice of recycling RSM, and the case of iron and steel scrap is used as an example in assessing the impacts. To conduct the evaluation, a considerable set of data was compiled and developed. Much of this information is included in this document to provide a source book of information.

  20. Ion beam modification of metals

    NASA Astrophysics Data System (ADS)

    Dearnaley, G.

    1990-04-01

    Energetic ions beams may be used in various ways to modify and so improve the tribological properties of metals. These methods include: — ion implantation of selected additive species; — ion beam mixing of thin deposited coatings; — ion-beam-assisted deposition of thicker overlay coatings. The first of these techniques has been widely used to modify the electronic properties of semiconductors, but has since been extended for the treatment of all classes of material. Tool steels can be strengthened by the ion implantation of nitrogen or titanium, to produce fine dispersions of hard second-phase precipitates. Solid solution strengthening, by combinations of substitutional and interstitial species, such as yttrium and nitrogen, has also been successful. Both ion beam mixing (IBM) and ion-beam-assisted deposition (IBAD) use a combination of coating and ion bombardment. In the first case, the objective is to intermix the coating and substrate by the aid of radiation-enhanced diffusion. In the latter case, the coating is densified and modified during deposition and the process can be continued in order to build up overlay coatings several ?m in thickness. The surface can then be tailored, for instance to provide a hard and adherent ceramic such as silicon nitride, boron nitride or titanium nitride. It is an advantage that all the above processes can be applied at relatively low temperatures, below about 200° C, thereby avoiding distortion of precision components. Ion implantation is also being successfully applied for the reduction of corrosion, especially at high temperatures or in the atmosphere and to explore the mechanisms of oxidation. Ion-assisted coatings, being compact and adherent, provide a more substantial protection against corrosion: silicon nitride and boron nitride are potentially useful in this respect. Examples will be given of the successful application of these methods for the surface modification of metals and alloys, and developments in the equipment now available for industrial application of ion beams will also be reviewed.

  1. Metal ion-containing epoxies

    NASA Technical Reports Server (NTRS)

    Stoakley, D. M.; St.clair, A. K.

    1982-01-01

    A variety of metallic and organometallic complexes to be used as potential additives for an epoxy used by the aerospace industry as a composite matrix resin were investigated. A total of 9 complexes were screened for compatibility and for their ability to accelerate or inhibit the cure of a highly crosslinkable epoxy resin. Methods for combining the metallic complexes with the resin were investigated, gel times recorded, and cure exotherms studied by differential scanning calorimetry. Glass transition temperatures of cured metal ion containing epoxy castings were determined by thermomechanical analysis. Thermal stabilities of the castings were determined by thermogravimetric analysis. Mechanical strength and stiffness of these doped epoxies were also measured.

  2. Titanate-based adsorbents for radioactive ions entrapment from water.

    PubMed

    Yang, Dongjiang; Liu, Hongwei; Zheng, Zhanfeng; Sarina, Sarina; Zhu, Huaiyong

    2013-03-21

    This feature article reviews some titanate-based adsorbents for the removal of radioactive wastes (cations and anions) from water. At the beginning, we discuss the development of the conventional ion-exchangeable titanate powders for the entrapment of radioactive cations, such as crystalline silicotitanate (CST), monosodium titanate (MST), peroxotitanate (PT). Then, we specially emphasize the recent progress in the uptake of radioactive ions by one-dimensional (1D) sodium titanate nanofibers and nanotubes, which includes the synthesis and phase transformation of the 1D nanomaterials, adsorption ability (capacity, selectivity, kinetics, etc.) of radioactive cations and anions, and the structural evolution during the adsorption process. PMID:23412572

  3. Titanate-based adsorbents for radioactive ions entrapment from water

    NASA Astrophysics Data System (ADS)

    Yang, Dongjiang; Liu, Hongwei; Zheng, Zhanfeng; Sarina, Sarina; Zhu, Huaiyong

    2013-02-01

    This feature article reviews some titanate-based adsorbents for the removal of radioactive wastes (cations and anions) from water. At the beginning, we discuss the development of the conventional ion-exchangeable titanate powders for the entrapment of radioactive cations, such as crystalline silicotitanate (CST), monosodium titanate (MST), peroxotitanate (PT). Then, we specially emphasize the recent progress in the uptake of radioactive ions by one-dimensional (1D) sodium titanate nanofibers and nanotubes, which includes the synthesis and phase transformation of the 1D nanomaterials, adsorption ability (capacity, selectivity, kinetics, etc.) of radioactive cations and anions, and the structural evolution during the adsorption process.

  4. Mechanistic Enzyme Models: Pyridoxal and Metal Ions.

    ERIC Educational Resources Information Center

    Hamilton, S. E.; And Others

    1984-01-01

    Background information, procedures, and results are presented for experiments on the pyridoxal/metal ion model system. These experiments illustrate catalysis through Schiff's base formation between aldehydes/ketones and primary amines, catalysis by metal ions, and the predictable manner in which metal ions inhibit or catalyze reactions. (JN)

  5. Reversible photodeposition and dissolution of metal ions

    DOEpatents

    Foster, Nancy S. (Boulder, CO); Koval, Carl A. (Golden, CO); Noble, Richard D. (Boulder, CO)

    1994-01-01

    A cyclic photocatalytic process for treating waste water containing metal and organic contaminants. In one embodiment of the method, metal ions are photoreduced onto the photocatalyst and the metal concentrated by resolubilization in a smaller volume. In another embodiment of the method, contaminant organics are first oxidized, then metal ions removed by photoreductive deposition. The present invention allows the photocatalyst to be recycled until nearly complete removal of metal ions and organic contaminants is achieved.

  6. Metallic ions in the equatorial ionosphere

    NASA Technical Reports Server (NTRS)

    Aikin, A. C.; Goldberg, R. A.

    1972-01-01

    Four positive ion composition measurements of the equatorial E region made at Thumba, India, are presented. During the day, the major ions between 90 and 125 km are NO(+) and O2(+). A metallic ion layer centered at 92 km is observed, and found to contain Mg(+), Fe(+), Ca(+), K(+), Al(+), and Na(+) ions. The layer is explained in terms of a similarly shaped latitude distribution of neutral atoms which are photoionized and charge-exchanged with NO(+) and O2(+). Three body reactions form molecular metallic ions which are rapidly lost by dissociative ion-electron recombination. Nighttime observations show downward drifting of the metallic ion layer caused by equatorial dynamo effects. These ions react and form neutral metals which exchange charges with NO(+) and O2(+) to produce an observed depletion of those ions within the metallic ion region.

  7. Rational Design of Metal Ion Sequestering Agents

    SciTech Connect

    Raymond, Kenneth N.

    2000-09-30

    The discriminate bonding of metal ions is a challenge to the synthetic chemist and a phenomenon of considerable practical importance.1 An important feature of many technical applications is the specific or preferential binding of a single metal ion in the presence of many metals. Examples range from large-volume uses (e.g. ferric EDTA as a plant food, calcium complexing agents as water softeners or anticaking formulations) to very high technology applications (technetium complexation in radiopharmaceuticals, synthetic metalloenzymes). We are interested in efficient and discriminate binding of actinides for waste stream remediation. Actinides represent a major and long-lived contaminant in nuclear waste. While the separation of actinides from other radioactive components of waste, such as Sr and Cs, is relatively well established, the separation of actinides from each other and in complex solutions (e.g. those found in tank wastes) is not as well resolved. The challenge of designing metal-specific (actinide) ligands is facilitated by examples from nature. Bacteria synthesize Fe(III)-specific ligands, called siderophores, to sequester Fe(III) from the environment and return it to the cell. The similarities between Fe(III) and Pu(IV) (their charge-to-size ratios and acidity), make the siderophores prototypical for designing actinide-specific ligands. The chelating groups present in siderophores are usually hydroxamic acids and catecholamides. We have developed derivatives of these natural products which have improved properties. The catechol derivatives are the 2,3-dihydroxyterephthalamides (TAMs), and 3,4-dihydroxysulfonamides (SFAMs), and the hydroxamic acid derivatives are three isomers of hydroxypyridinones, 1,2- HOPO, 3,2-HOPO, and 3,4-HOPO. All of these ligands are attached to molecular backbones by amides and a very important feature of HOPO and CAM ligands is a strong hydrogen bonds formed between the amide proton and the adjacent phenolic oxygen in the metal complex, thereby enhancing the stability (Figure 1).

  8. Protein-Transition Metal Ion Networks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins obtained from agricultural sources were blended with divalent metal ions. Feather keratin, egg albumin, and wheat gluten showed increases of 2-3 times in modulus with addition of divalent transition metal ions Cu2+ and Zn2+. Increasing concentrations of ions resulted in increased stiffnes...

  9. In-Trap Spectroscopy of Charge-Bred Radioactive Ions

    NASA Astrophysics Data System (ADS)

    Lennarz, A.; Grossheim, A.; Leach, K. G.; Alanssari, M.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Crespo López-Urrutia, J. R.; Gallant, A. T.; Holl, M.; Kwiatkowski, A. A.; Lassen, J.; Macdonald, T. D.; Schultz, B. E.; Seeraji, S.; Simon, M. C.; Andreoiu, C.; Dilling, J.; Frekers, D.

    2014-08-01

    In this Letter, we introduce the concept of in-trap nuclear decay spectroscopy of highly charged radioactive ions and describe its successful application as a novel spectroscopic tool. This is demonstrated by a measurement of the decay properties of radioactive mass A=124 ions (here, In124 and Cs124) in the electron-beam ion trap of the TITAN facility at TRIUMF. By subjecting the trapped ions to an intense electron beam, the ions are charge bred to high charge states (i.e., equivalent to the removal of N-shell electrons), and an increase of storage times to the level of minutes without significant ion losses is achieved. The present technique opens the venue for precision spectroscopy of low branching ratios and is being developed in the context of measuring electron-capture branching ratios needed for determining the nuclear ground-state properties of the intermediate odd-odd nuclei in double-beta (??) decay.

  10. EBIS charge breeder for radioactive ion beams at ATLAS.

    SciTech Connect

    Ostroumov, P.; Kondrashev, S.; Pardo, R.; Savard, G.; Vondrasek, R.; Alessi, J.; Beebe, E.; Pikin, A.

    2010-07-01

    The construction of the Californium Rare Isotope Breeder Upgrade (CARIBU) for the Argonne National Laboratory ATLAS facility is completed and its commissioning is being performed. In its full capacity, the CARIBU facility will use fission fragments from a 1 Curie (Ci) {sup 252}Cf source. The ions will be thermalized and collected into a low-energy ion beam by a helium gas catcher, mass analyzed by an isobar separator, and charge bred to higher charge states for acceleration in ATLAS. To reach energies E/A 10 MeV/u, one should inject ions with charge-to-mass ratio (q/A) {ge} 1/7 into the ATLAS linac. In the first stage, the existing Electron Cyclotron Resonance (ECR) ion source will be used as a charge breeder. The maximum intensity of radioactive ion beams at the output of the gas catcher will not exceed 10{sup 7} ions per second. A charge breeder based on an Electron Beam Ion Source (EBIS) has significant advantages over the ECR option for ion beam intensities up to about 10{sup 9} ions per second, providing 3-4 times higher efficiency and significantly better purity of highly charged radioactive ion beams for further acceleration. The proposed EBIS project for CARIBU will heavily utilize state-of-the-art EBIS technology recently developed at Brookhaven National Laboratory. This will allow us to reduce both the project cost and timescale, simultaneously insuring reliable technical realization of the cutting-edge technology. Several parameters of the CARIBU EBIS charge breeder (EBIS-CB) will be relaxed with respect to the BNL EBIS in favor of higher reliability and lower cost. Technical performance of the CARIBU charge breeder will not suffer from such a relaxation and will provide high efficiency for a whole range of radioactive ion beams. The goal of this paper is to present the initial design of the EBIS charge breeder for radioactive ion beams at ATLAS.

  11. EBIS charge breeder for radioactive ion beams at ATLAS

    SciTech Connect

    Ostroumov, P.; Alessi, J.; Kondrashev, S.; Pardo, R.; Savard, G.; Vondrasek, R.; Beebe, E.; Pikin, A.

    2010-07-20

    The construction of the Californium Rare Isotope Breeder Upgrade (CARIBU) for the Argonne National Laboratory ATLAS facility is completed and its commissioning is being performed. In its full capacity, the CARIBU facility will use fission fragments from a 1 Curie (Ci) {sup 252}Cf source. The ions will be thermalized and collected into a low-energy ion beam by a helium gas catcher, mass analyzed by an isobar separator, and charge bred to higher charge states for acceleration in ATLAS. To reach energies E/A 10 MeV/u, one should inject ions with charge-to-mass ratio (q/A) {ge} 1/7 into the ATLAS linac. In the first stage, the existing Electron Cyclotron Resonance (ECR) ion source will be used as a charge breeder. The maximum intensity of radioactive ion beams at the output of the gas catcher will not exceed 10{sup 7} ions per second. A charge breeder based on an Electron Beam Ion Source (EBIS) has significant advantages over the ECR option for ion beam intensities up to about 10{sup 9} ions per second, providing 3-4 times higher efficiency and significantly better purity of highly charged radioactive ion beams for further acceleration. The proposed EBIS project for CARIBU will heavily utilize state-of-the-art EBIS technology recently developed at Brookhaven National Laboratory. This will allow us to reduce both the project cost and timescale, simultaneously insuring reliable technical realization of the cutting-edge technology. Several parameters of the CARIBU EBIS charge breeder (EBIS-CB) will be relaxed with respect to the BNL EBIS in favor of higher reliability and lower cost. Technical performance of the CARIBU charge breeder will not suffer from such a relaxation and will provide high efficiency for a whole range of radioactive ion beams. The goal of this paper is to present the initial design of the EBIS charge breeder for radioactive ion beams at ATLAS.

  12. EBIS charge breeder for radioactive ion beams at ATLAS

    NASA Astrophysics Data System (ADS)

    Ostroumov, P.; Kondrashev, S.; Pardo, R.; Savard, G.; Vondrasek, R.; Alessi, J.; Beebe, E.; Pikin, A.

    2010-07-01

    The construction of the Californium Rare Isotope Breeder Upgrade (CARIBU) for the Argonne National Laboratory ATLAS facility is completed and its commissioning is being performed. In its full capacity, the CARIBU facility will use fission fragments from a 1 Curie (Ci) 252Cf source. The ions will be thermalized and collected into a low-energy ion beam by a helium gas catcher, mass analyzed by an isobar separator, and charge bred to higher charge states for acceleration in ATLAS. To reach energies E/A 10 MeV/u, one should inject ions with charge-to-mass ratio (q/A) >= 1/7 into the ATLAS linac. In the first stage, the existing Electron Cyclotron Resonance (ECR) ion source will be used as a charge breeder. The maximum intensity of radioactive ion beams at the output of the gas catcher will not exceed 107 ions per second. A charge breeder based on an Electron Beam Ion Source (EBIS) has significant advantages over the ECR option for ion beam intensities up to about 109 ions per second, providing 3-4 times higher efficiency and significantly better purity of highly charged radioactive ion beams for further acceleration. The proposed EBIS project for CARIBU will heavily utilize state-of-the-art EBIS technology recently developed at Brookhaven National Laboratory. This will allow us to reduce both the project cost and timescale, simultaneously insuring reliable technical realization of the cutting-edge technology. Several parameters of the CARIBU EBIS charge breeder (EBIS-CB) will be relaxed with respect to the BNL EBIS in favor of higher reliability and lower cost. Technical performance of the CARIBU charge breeder will not suffer from such a relaxation and will provide high efficiency for a whole range of radioactive ion beams. The goal of this paper is to present the initial design of the EBIS charge breeder for radioactive ion beams at ATLAS.

  13. Liquid metal ion source and alloy

    DOEpatents

    Clark, Jr., William M. (Thousand Oaks, CA); Utlaut, Mark W. (Saugus, CA); Behrens, Robert G. (Los Alamos, NM); Szklarz, Eugene G. (Los Alamos, NM); Storms, Edmund K. (Los Alamos, NM); Santandrea, Robert P. (Santa Fe, NM); Swanson, Lynwood W. (McMinnville, OR)

    1988-10-04

    A liquid metal ion source and alloy, wherein the species to be emitted from the ion source is contained in a congruently vaporizing alloy. In one embodiment, the liquid metal ion source acts as a source of arsenic, and in a source alloy the arsenic is combined with palladium, preferably in a liquid alloy having a range of compositions from about 24 to about 33 atomic percent arsenic. Such an alloy may be readily prepared by a combustion synthesis technique. Liquid metal ion sources thus prepared produce arsenic ions for implantation, have long lifetimes, and are highly stable in operation.

  14. Charge breeding simulations for radioactive ion beam production

    SciTech Connect

    Variale, V.; Raino, A. C.; Clauser, T.

    2012-02-15

    The charge breeding technique is used for radioactive ion beam (RIB) production in order of optimizing the re-acceleration of the radioactive element ions produced by a primary beam in a thick target. Charge breeding is achieved by means of a device capable of increasing the ion charge state from 1+ to a desired value n+. In order to get high intensity RIB, experiments with charge breeding of very high efficiency could be required. To reach this goal, the charge breeding simulation could help to optimize the high charge state production efficiency by finding more proper parameters for the radioactive 1+ ions. In this paper a device based on an electron beam ion source (EBIS) is considered. In order to study that problem, a code already developed for studying the ion selective containment in an EBIS with RF quadrupoles, BRICTEST, has been modified to simulate the ion charge state breeding rate for different 1+ ion injection conditions. Particularly, the charge breeding simulations for an EBIS with a hollow electron beam have been studied.

  15. Charge breeding simulations for radioactive ion beam production.

    PubMed

    Variale, V; Rainò, A C; Clauser, T

    2012-02-01

    The charge breeding technique is used for radioactive ion beam (RIB) production in order of optimizing the re-acceleration of the radioactive element ions produced by a primary beam in a thick target. Charge breeding is achieved by means of a device capable of increasing the ion charge state from 1+ to a desired value n+. In order to get high intensity RIB, experiments with charge breeding of very high efficiency could be required. To reach this goal, the charge breeding simulation could help to optimize the high charge state production efficiency by finding more proper parameters for the radioactive 1+ ions. In this paper a device based on an electron beam ion source (EBIS) is considered. In order to study that problem, a code already developed for studying the ion selective containment in an EBIS with RF quadrupoles, BRICTEST, has been modified to simulate the ion charge state breeding rate for different 1+ ion injection conditions. Particularly, the charge breeding simulations for an EBIS with a hollow electron beam have been studied. PMID:22380242

  16. Versatile high current metal ion implantation facility

    SciTech Connect

    Brown, I.G.; Dickinson, M.R.; Galvin, J.E.; Godechot, X.; MacGill, R.A.

    1991-06-01

    A metal ion implantation facility has been developed with which high current beams of practically all the solid metals of the periodic table can be produced. A multi-cathode, broad beam, metal vapor vacuum arc ion source is used to produce repetitively pulsed metal ion beams at an extraction voltage of up to 100 kV, corresponding to an ion energy of up to several hundred keV because of the ion-charge state multiplicity, and with a beam current of up to several amperes peak pulsed and several tens of mA time averaged delivered onto a downstream target. Implantation is done in a broad-beam mode, with a direct line-of-sight from ion source to target. Here we summarize some of the features of the ion source and the implantation facility that has been built up around it. 28 refs., 5 figs.

  17. Ion beam analysis of radioactive samples

    NASA Astrophysics Data System (ADS)

    Raepsaet, C.; Khodja, H.; Bossis, P.; Pipon, Y.; Roudil, D.

    2009-06-01

    The nuclear microprobe facility of the Pierre Süe Laboratory is fitted with two microbeam lines. One is dedicated to non-active samples. The other one, located in a controlled shielded area, offers the unique feature of being devoted to radioactive samples. Operational since 1998, it is strongly linked to nuclear research programs and has been dimensioned to accept radioactive but non-contaminant radioactive samples, including small quantities of UOX or MOX irradiated fuel. The samples, transported in a shipping cask, are unloaded and handled in hot cells with slaved arms. The analysis chamber, situated in a concrete cell, is equipped with charged particle detectors and a Si(Li) X-ray detector, shielded in order to reduce the radioactive noise produced by the sample, allowing ERDA, RBS, NRA and PIXE. After a description of the facility, including the sample handling in the hot cells and the analysis chamber, we will give an overview of the various experimental programs which have been performed, with an emphasis on the determination of the hydrogen distribution and local content in nuclear fuel cladding tubes.

  18. Method for making radioactive metal articles having small dimensions

    DOEpatents

    Ohriner, Evan K. (Knoxville, TN)

    2000-01-01

    A method for making a radioactive article such as wire, includes the steps of providing a metal article having a first shape, such a cylinder, that is either radioactive itself or can be converted to a second, radioactive isotope by irradiation; melting the metal article one or more times; optionally adding an alloying metal to the molten metal in order to enhance ductility or other properties; placing the metal article having the first shape (e.g., cylindrical) into a cavity in the interior of an extrusion body (e.g., a cylinder having a cylindrical cavity therein); extruding the extrusion body and the article having the first shape located in the cavity therein, resulting in an elongated extrusion body and an article having a second shape; removing the elongated extrusion body, for example by chemical means, leaving the elongated inner article substantially intact; optionally repeating the extrusion procedure one or more times; and then drawing the elongated article to still further elongate it, into wire, foil, or another desired shape. If the starting metal is enriched in a radioactive isotope or a precursor thereof, the end product can provide a more intense radiation source than conventionally manufactured radioactive wire, foil, or the like.

  19. COMPUTATIONAL DESIGN OF METAL ION SEQUESTERING AGENTS

    EPA Science Inventory

    Organic ligands that exhibit a high degree of metal ion recognition are essential precursors for developing separation processes and sensors for metal ions. Since the beginning of the nuclear era, much research has focused on discovering ligands that target specific radionuclides...

  20. PROTEIN-TRANSITION METAL ION NETWORKS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins obtained from agricultural sources were blended with divalent metal ions. Feather keratin, egg albumin, and wheat gluten had low, medium, and high levels of aspartic and glutamic acid, respectively, and FT-IR showed that the divalent transition metal ions Mn2+, Cu2+, and Zn2+ were tightly ...

  1. Pseudo ribbon metal ion beam source

    SciTech Connect

    Stepanov, Igor B. Ryabchikov, Alexander I.; Sivin, Denis O.; Verigin, Dan A.

    2014-02-15

    The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beam extraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ion beam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ion beam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface.

  2. Separation of metal ions from aqueous solutions

    DOEpatents

    Almon, Amy C. (Augusta, GA)

    1994-01-01

    A process and apparatus for quantitatively and selectively separating metal ions from mixtures thereof in aqueous solution. The apparatus includes, in combination, a horizontal electrochemical flow cell containing flow bulk electrolyte solution and an aqueous, metal ion-containing solution, the cell containing a metal mesh working electrode, a counter electrode positioned downstream from the working electrode, an independent variable power supply/potentiostat positioned outside of the flow cell and connected to the electrodes, and optionally a detector such as a chromatographic detector, positioned outside the flow cell. This apparatus and its operation has significant application where trace amounts of metal ions are to be separated.

  3. Spin Observables in Reactions with Radioactive Ion Beams

    SciTech Connect

    Galindo-Uribarri, Alfredo {nmn}; Urrego Blanco, Juan Pablo

    2007-01-01

    Polarization observables in nuclear reactions with exotic nuclei will provide important information concerning structural properties of nuclei and reaction mechanisms. We are currently engaged in exploring the use of polarization observables with radioactive ion beams and in the development of a polarized cryogenic target.

  4. Neutron Transfer Reactions with Neutron-rich Radioactive Ion Beams

    SciTech Connect

    Cizewski, Jolie; Grzywacz-Jones, Kate L; Pain, Steven D; Thomas, Jeffrey S; Baktash, Cyrus; Bardayan, Daniel W; Blackmon, Jeff C; Gross, Carl J; Liang, J Felix; Shapira, Dan; Smith, Michael Scott; KOZUB, RAYMOND L; Moazen, Brian H; Nesaraja, Caroline D; Carter, H Kennon; Johnson, Micah; Fitzgerald, Ryan; Visser, Dale William; Greife, Uwe; Livesay, Jake; Catford, Wilton N; Ma, Zhanwen

    2005-10-01

    Initial measurements are presented of the (d,p) reactions on neutron-rich N = 50 isotones along the r-process path of nucleosynthesis with radioactive ion beams of {sup 82}Ge and {sup 84}Se. Prospects for measurements with unstable {sup 130,132}Sn beams are discussed.

  5. Radioactive decays of highly-charged ions

    NASA Astrophysics Data System (ADS)

    Gao, B. S.; Najafi, M. A.; Atanasov, D. R.; Blaum, K.; Bosch, F.; Brandau, C.; Chen, X. C.; Dillmann, I.; Dimopoulou, Ch.; Faestermann, Th.; Geissel, H.; Gernhäuser, R.; Hillenbrand, P.-M.; Kovalenko, O.; Kozhuharov, C.; Litvinov, S. A.; Litvinov, Yu. A.; Maier, L.; Nolden, F.; Piotrowski, J.; Sanjari, M. S.; Scheidenberger, C.; Spillmann, U.; Steck, M.; Stöhlker, Th.; Trageser, Ch.; Tu, X. L.; Weick, H.; Winckler, N.; Xu, H. S.; Yamaguchi, T.; Yan, X. L.; Zhang, Y. H.; Zhou, X. H.

    2015-05-01

    Access to stored and cooled highly-charged radionuclides offers unprecedented opportunities to perform high-precision investigations of their decays. Since the few-electron ions, e.g. hydrogen- or helium-like ions, are quantum mechanical systems with clear electronic ground state configurations, the decay studies of such ions are performed under well-defined conditions and allow for addressing fundamental aspects of the decay process. Presented here is a compact review of the relevant experiments conducted at the Experimental Storage Ring ESR of GSI. A particular emphasis is given to the investigations of the two-body beta decay, namely the bound-state ?-decay and its time-mirrored counterpart, orbital electron-capture.

  6. Expansion of the radioactive ion beam program at Argonne

    NASA Astrophysics Data System (ADS)

    Clark, J. A.

    2011-01-01

    The Argonne Tandem Linear Accelerator System (ATLAS) at Argonne National Laboratory (ANL) provides a wide range of stable ion beams and radioactive beams which have contributed to our understanding of nuclear structure and reactions. Until now, most radioactive ion beams at ATLAS were produced in flight using light-ion reactions such as (p, n), (d, n), (d, p), (d,3He), and (3He,n). Within the next few months, the radioactive ion beam program at ATLAS will acquire much extended, new capabilities with the commissioning of a new facility: the CAlifornium Rare Isotope Breeder Upgrade (CARIBU). CARIBU will supply ion beams of 252Cf fission fragments, which are thermalized in a gas catcher. The singly- and doubly-charged ions extracted from the gas catcher will be mass-separated and either delivered to a low-energy experimental area, or charge bred with a modified ECR source and subsequently reaccelerated by the ATLAS facility. Properties of hundreds of these neutron-rich nuclides will be investigated using ion traps, decay stations, the newly commissioned HELical Orbit Spectrometer (HELIOS), and other available experimental equipment such as Gammasphere and the FMA. HELIOS was constructed to take advantage of rare ion beams, such as those provided by CARIBU, through light-ion transfer reactions in inverse kinematics, and represents a new approach to the study of direct reactions in inverse kinematics which avoids kinematic broadening. Experiments are currently being conducted with HELIOS, and first results with the d(28Si,p) and d(12B,p) reactions have shown excellent energy resolution.

  7. ISOLATION OF RADIOACTIVE METALS FROM LIQUID WASTES

    EPA Science Inventory

    Metals are present in many waste streams, and pose challenges with regard to their disposal. Release of metals into the environment presents both human health and ecological concerns. As a result, efforts are directed at reducing their toxicity, bioavailability, and environment...

  8. The Scientific program with RIBRAS (Radioactive Ion Beams in Brasil)

    SciTech Connect

    Lichtenthaeler, R.; Lepine-Szily, A.; Guimaraes, V.; Faria, P. N. de; Mendes, D. R. Jr.; Pires, K. C. C.; Morcelle, V.; Hussein, M. S.; Barioni, A.; Condori, R. Pampa; Morais, M. C.; Alcantara Nunez, J.; Camargo, O. Jr.; Otani, Y.; Leistenschneider, E.; Scarduelli, V.; Benjamim, E. A.; Arazi, A.; Assuncao, M.

    2009-06-03

    The Radioactive Ion Beams Facility (RIBRAS) is in operation since 2004 at the Pelletron Accelerator Laboratory of the University of Sao Paulo and consists of two superconducting solenoids capable of producing low energy secondary beams of light exotic nuclei. Measurements of the elastic scattering, breakup and transfer reactions with radioactive projectiles such as {sup 6}He,{sup 8}Li,{sup 7}Be on several targets have been performed. A review of the research program carried on along the last four years using the RIBRAS facility is presented.

  9. Charge breeding of radioactive ions with EBIS and EBIT

    E-print Network

    Wenander, Fredrik

    2010-01-01

    A charge state breeder, which transforms externally injected singly charged ions to a higher charge state q+, is an important tool which has applications within atomic, nuclear and even particle physics. The charge breeding concept of radioactive ions has already been demonstrated at REX-ISOLDE/CERN with the use of an Electron beam Ion Source (EBIS) and at several facilities employing Electron Resonance Cyclotron Ion Sources (ECRIS). As will be demonstrated in this paper, EBIS and Electron Beam Ion Traps (EBIT), are well suited for the task as they are capable of delivering clean, highly charged beams within a short transformation time. The increasing demand for highly charged ions of all kind of elements and isotopes, stable and radioactive, to be used for low-energy experiments such as TITAN at TRIUMF and MATS at FAIR, but also for post-acceleration to higher energies, is now pushing the development of the breeders. The next challenge will be to satisfy the needs, for example space-charge capacity, of the s...

  10. Radioactively Contaminated Scrap Metal An International Approach to Monitoring, Interception & Managing

    E-print Network

    Radioactively Contaminated Scrap Metal An International Approach to Monitoring, Interception of uncontrolled radioactive source incidents. Aside from radiation exposure to workers and the public, this unwanted radioactive scrap material causes environmental and facility contamination with cleanup costs

  11. Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials

    DOEpatents

    Wang, Yifeng; Miller, Andy; Bryan, Charles R.; Kruichak, Jessica Nicole

    2015-11-17

    Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials are described. For example, a method of capturing and immobilizing radioactive nuclei includes flowing a gas stream through an exhaust apparatus. The exhaust apparatus includes a metal fluorite-based inorganic material. The gas stream includes a radioactive species. The radioactive species is removed from the gas stream by adsorbing the radioactive species to the metal fluorite-based inorganic material of the exhaust apparatus.

  12. Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials

    SciTech Connect

    Wang, Yifeng; Miller, Andy; Bryan, Charles R; Kruichar, Jessica Nicole

    2015-04-07

    Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials are described. For example, a method of capturing and immobilizing radioactive nuclei includes flowing a gas stream through an exhaust apparatus. The exhaust apparatus includes a metal fluorite-based inorganic material. The gas stream includes a radioactive species. The radioactive species is removed from the gas stream by adsorbing the radioactive species to the metal fluorite-based inorganic material of the exhaust apparatus.

  13. An ion source module for the Beijing Radioactive Ion-beam Facility

    SciTech Connect

    Cui, B. Huang, Q.; Tang, B.; Ma, R.; Chen, L.; Ma, Y.

    2014-02-15

    An ion source module is developed for Beijing Radioactive Ion-beam Facility. The ion source module is designed to meet the requirements of remote handling. The connection and disconnection of the electricity, cooling and vacuum between the module and peripheral units can be executed without on-site manual work. The primary test of the target ion source has been carried out and a Li{sup +} beam has been extracted. Details of the ion source module and its primary test results are described.

  14. Uptake of metal ions on humic acids

    SciTech Connect

    Pehlivan, E.; Arslan, G.

    2006-09-15

    The kinetics, the sorption capacities, pH and temperature dependence of sorption of humic acids (HAs) of Turkish brown coals with respect to Zn(II), Cu(II), Ni(II), Co(II) and Pb(II) ions were investigated, and the roles of the carboxylic and phenolic groups in the adsorption of metals ion on HAs were searched in this work. These metal ions are able to form complex compounds with carboxylic and phenolic groups of HAs. Adsorption equilibrium was achieved in between 50 and 60 min for all studied cations. HAs extracted from different brown coals have been characterized by chemical and physical methods. The chemical properties of HAs showed differences depending on the source from which they were obtained. The sorption of metals on the surface of HAs depends strongly on the pH, and sorption decreases with decreasing pH. Maximum removal of metal ions was demonstrated at pH values of 4.1-5.0. The Langmuir adsorption isotherm was used to describe observed sorption phenomena. The {Delta}G{sup 0} became negative as the temperature increased, and so the equilibrium constant decreased slightly. The investigation proved that the HAs are suitable materials for the studied heavy metal ion removal from aqueous solution and could be considered as potential material for purification of effluent polluted with toxic metal ions.

  15. Nuclear astrophysics at the Holifield Radioactive Ion Beam Facility

    SciTech Connect

    Smith, M.S.

    1994-12-31

    The potential for understanding spectacular stellar explosions such as novae, supernovae, and X-ray bursts will be greatly enhanced by the availability of the low-energy, high-intensity, accelerated beams of proton-rich radioactive nuclei currently being developed at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. These beams will be utilized in absolute cross section measurements of crucial (p, {gamma}) capture reactions in efforts to resolve the substantial qualitative uncertainties in current models of explosive stellar hydrogen burning outbursts. Details of the nuclear astrophysics research program with the unique HRIBF radioactive beams and a dedicated experimental endstation--centered on the Daresbury Recoil Separator--will be presented.

  16. Metal-ion recycle technology for metal electroplating waste waters

    SciTech Connect

    Sauer, N.N.; Smith, B.F.

    1993-06-01

    As a result of a collaboration with Boeing Aerospace, the authors have begun a program to identify suitable treatments or to develop new treatments for electroplating baths. The target baths are mixed-metal or alloy baths that are being integrated into the Boeing electroplating complex. These baths, which are designed to replace highly toxic chromium and cadmium baths, contain mixtures of two metals, either nickel-tungsten, nickel-zinc, or zinc-tin. This report reviews the literature and details currently available on emerging technologies that could affect recovery of metals from electroplating baths under development by Boeing Aerospace. This literature survey summarizes technologies relevant to the recovery of metals from electroplating processes. The authors expanded the scope to investigate single metal ion recovery technologies that could be applied to metal ion recovery from alloy baths. This review clearly showed that the electroplating industry has traditionally relied on precipitation and more recently on electrowinning as its waste treatment methods. Despite the almost ubiquitous use of precipitation to remove contaminant metal ions from waste electroplating baths and rinse waters, this technology is clearly no longer feasible for the electroplating industry for several reasons. First, disposal of unstabilized sludge is no longer allowed by law. Second, these methods are no longer adequate as metal-removal techniques because they cannot meet stringent new metal discharge limits. Third, precious resources are being wasted or discarded because these methods do not readily permit recovery of the target metal ions. As a result, emerging technologies for metal recovery are beginning to see application to electroplating waste recycle. This report summarizes current research in these areas. Included are descriptions of various membrane technologies, such as reverse osmosis and ultrafiltration, ion exchange and chelating polymer technology, and electrodialysis.

  17. Liquid metal ion source and alloy

    SciTech Connect

    Clark, W.M. Jr.; Utlaut, M.W.; Storms, E.K.; Behrens, R.G.; Szklarz, E.G.; Swanson, L.W.; Santandrea, R.P.

    1988-10-04

    A liquid metal ion source is described comprising: emission means for emitting positively charged ions of an elemental chemical species; and source means for supplying the species to be emitted to the emission means, the species being supplied in a congruently vaporizing non-eutectic alloy of the elemental chemical species and at least one other element.

  18. ION EXCHANGE SOFTENING: EFFECTS ON METAL CONCENTRATIONS

    EPA Science Inventory

    A corrosion control pipe loop study to evaluate the effect of ion exchange water softening on metal leaching from household plumbing materials was conducted on two different water qualities having different pH's and hardness levels. The results showed that removing hardness ions ...

  19. The Use of Induction Melting for the Treatment of Metal Radioactive Waste - 13088

    SciTech Connect

    Zherebtsov, Alexander; Pastushkov, Vladimir; Poluektov, Pavel; Smelova, Tatiana; Shadrin, Andrey

    2013-07-01

    The aim of the work is to assess the efficacy of induction melting metal for recycling radioactive waste in order to reduce the volume of solid radioactive waste to be disposed of, and utilization of the metal. (authors)

  20. The SPES radioactive ion beam project of INFN

    NASA Astrophysics Data System (ADS)

    de Angelis, Giacomo; Spes Collaboration; Prete, G.; Andrighetto, A.; Manzolaro, M.; Corradetti, S.; Scarpa, D.; Rossignoli, M.; Monetti, A.; Lollo, M.; Calderolla, M.; Vasquez, J.; Zafiropoulos, D.; Sarchiapone, L.; Benini, D.; Favaron, P.; Rigato, M.; Pegoraro, R.; Maniero, D.; Calabretta, L.; Comunian, M.; Maggiore, M.; Lombardi, A.; Piazza, L.; Porcellato, A. M.; Roncolato, C.; Bisoffi, G.; Pisent, A.; Galatà, A.; Giacchini, M.; Bassato, G.; Canella, S.; Gramegna, F.; Valiente, J.; Bermudez, J.; Mastinu, P. F.; Esposito, J.; Wyss, J.; Russo, A.; Zanella, S.

    2014-07-01

    The SPES Radioactive Ion Beam facility at INFN-LNL is presently in the construction phase. The facility is based on the Isol (Isotope separation on-line) method with an UCx Direct Target able to sustain a power of 10 kW. The primary proton beam is provided by a high current Cyclotron accelerator with energy of 35-70 MeV and a beam current of 0.20.5 mA. Neutron-rich radioactive ions are produced by proton induced Uranium fission at an expected fission rate of the order of 1013 fissions per second. After ionization and selection the exotic isotopes are re-accelerated by the ALPI superconducting Linac at energies of 10A MeV for masses in the region A = 130 amu. The expected secondary beam rates are of the order of 107 - 109 pps. Aim of the SPES project is to provide a facility for high intensity radioactive ion beams for nuclear physics research as well as to develop an interdisciplinary research center based on the cyclotron proton beam.

  1. The SPES Radioactive Ion Beam facility of INFN

    NASA Astrophysics Data System (ADS)

    de Angelis, G.; Spes Collaboration; Prete, G.; Andrighetto, A.; Manzolaro, M.; Corradetti, S.; Scarpa, D.; Rossignoli, M.; Monetti, A.; Lollo, M.; Calderolla, M.; Vasquez, J.; Zafiropoulos, D.; Sarchiapone, L.; Benini, D.; Favaron, P.; Rigato, M.; Pegoraro, R.; Maniero, D.; Calabretta, L.; Comunian, M.; Maggiore, M.; Lombardi, A.; Piazza, L.; Porcellato, A. M.; Roncolato, C.; Bisoffi, G.; Pisent, A.; Galatà, A.; Giacchini, M.; Bassato, G.; Canella, S.; Gramegna, F.; Valiente, J.; Bermudez, J.; Mastinu, P. F.; Esposito, J.; Wyss, J.; Russo, A.; Zanella, S.

    2015-02-01

    A new Radioactive Ion Beam (RIB) facility (SPES) is presently under construction at the Legnaro National Laboratories of INFN. The SPES facility is based on the ISOL method using an UCx Direct Target able to sustain a power of 10 kW. The primary proton beam is provided by a high current Cyclotron accelerator with energy of 40 MeV and a beam current of 0.2-0.5 mA. Neutron-rich radioactive ions are produced by proton induced fission at an expected fission rate of the order of 1013 fissions per second. After ionization and selection the exotic isotopes are re-accelerated by the ALPI superconducting LINAC at energies of 10A MeV for masses in the region A=130 amu. The expected secondary beam rates are of the order of 107 - 109 pps. Aim of the SPES facility is to deliver high intensity radioactive ion beams of neutron rich nuclei for nuclear physics research as well as to be an interdisciplinary research center for radio-isotopes production for medicine and for neutron beams.

  2. The SPES Radioactive-Ion Beam Facility of INFN

    NASA Astrophysics Data System (ADS)

    de Angelis, G.; Prete, G.; Andrighetto, A.; Manzolaro, M.; Corradetti, S.; Scarpa, D.; Rossignoli, M.; Monetti, A.; Lollo, M.; Calderolla, M.; Vasquez, J.; Zafiropoulos, D.; Sarchiapone, L.; Benini, D.; Favaron, P.; Rigato, M.; Pegoraro, R.; Maniero, D.; Comunian, M.; Maggiore, M.; Lombardi, A.; Piazza, L.; Porcellato, A. M.; Roncolato, C.; Bisoffi, G.; Pisent, A.; Galatà, A.; Giacchini, M.; Bassato, G.; Canella, S.; Gramegna, F.; Valiente, J.; Bermudez, J.; Mastinu, P. F.; Esposito, J.; Wyss, J.; Russo, A.; Zanella, S.; Calabretta, L.

    2015-11-01

    A new radioactive-ion beam (RIB) facility (SPES) is presently under construction at the Legnaro National Laboratories of INFN. The SPES facility is based on the ISOL method using a UCx direct target able to sustain a power of 10 kW. The primary proton beam will be provided by a high-current cyclotron accelerator with energy of 35-70 MeV and a beam current of 0.2-0.5 mA. Neutron-rich radioactive ions will be produced by proton-induced fission on a uranium target at an expected fission rate of the order of 1013 fissions per second. After ionization and selection the exotic isotopes will be re-accelerated by the ALPI superconducting LINAC at energies of 10A MeV for masses in the region A=130 amu. The expected secondary beam rates are of the order of 107-109 pps. The aim of the SPES facility is to deliver high-intensity radioactive-ion beams of neutron-rich nuclei for nuclear physics research, as well as to be an interdisciplinary research center for radioisotope production for medicine and for neutron beams.

  3. Bioavailability of Metal Ions and Evolutionary Adaptation

    PubMed Central

    Hong Enriquez, Rolando P.; Do, Trang N.

    2012-01-01

    The evolution of life on earth has been a long process that began nearly 3.5 × 109 years ago. In their initial moments, evolution was mainly influenced by anaerobic environments; with the rise of O2 and the corresponding change in bioavailability of metal ions, new mechanisms of survival were created. Here we review the relationships between ancient atmospheric conditions, metal ion bioavailability and adaptation of metals homeostasis during early evolution. A general picture linking geochemistry, biochemistry and homeostasis is supported by the reviewed literature and is further illustrated in this report using simple database searches. PMID:25371266

  4. Metal-ion rescue revisited: Biochemical detection of site-bound metal ions important for RNA folding

    E-print Network

    Das, Rhiju

    Metal-ion rescue revisited: Biochemical detection of site-bound metal ions important for RNA-dimensional architectures of RNA molecules, divalent metal ions populate specific locations, shedding their water molecules make essential contributions to function. Defining the locations of these site-bound metal ions remains

  5. Metal vapor vacuum arc ion sources

    SciTech Connect

    Brown, I.G.; Dickinson, M.R.; Galvin, J.E.; Godechot, X.; MacGill, R.A.

    1990-06-01

    We have developed a family of metal vapor vacuum are (MEVVA) high current metal ion sources. The sources were initially developed for the production of high current beams of metal ions for heavy ion synchrotron injection for basic nuclear physics research; more recently they have also been used for metal ion implantation. A number of different embodiments of the source have been developed for these specific applications. Presently the sources operate in a pulsed mode, with pulse width of order 1 ms and repetition rate up to 100 pps. Beam extraction voltage is up to 100 kV, and since the ions produced in the vacuum arc plasma are in general multiply ionized the ion energy is up to several hundred keV. Beam current is up to several Amperes peak and around 10 mA time averaged delivered onto target. Nearly all of the solid metals of the Periodic Table have been use to produce beam. A number of novel features have been incorporated into the sources, including multiple cathodes and the ability to switch between up to 18 separate cathode materials simply and quickly, and a broad beam source version as well as miniature versions. here we review the source designs and their performance. 45 refs., 7 figs.

  6. Liquid metal ion source for cluster ions of metals and alloys: design and characteristics

    NASA Astrophysics Data System (ADS)

    Bhaskar, N. D.; Klimcak, C. M.; Frueholz, R. P.

    1990-01-01

    Currently liquid metal ion sources (LMISs) are of great interest for a wide variety of applications—ion implantation, ion microlithography, thrusters for electric space propulsion, etc. A novel application of the LMIS is for the production of metallic cluster ions. In our laboratory we have designed and optimized the performance of a LMIS for the production of cluster ions of alkali metals. Using liquid rubidium (Rb) we have observed copious production of singly charged cluster ions (Rb+N, N=1-100). As expected the largest fraction of the emission consists of atomic ions. For low source current (<5 ?A) about 80% of the total emission current is that of Rb+. The remaining 20% consists of Rb+2 and Rb+3. However, for large emission currents (>80 ?A) we observe cluster ions as large as Rb+100. We study the mass distribution using the time-of-flight technique.

  7. Intense metal ion beam source for heavy ion fusion

    SciTech Connect

    Brown, I.G.

    1986-05-01

    We have developed an ion source which can produce high current beams of metal ions. The source uses a metal vapor vacuum arc discharge as the plasma medium from which the ions are extracted, so we have called this source the MEVVA ion source. The metal plasma is created simply and efficiently and no carrier gas is required. Beams have been produced from metallic elements spanning the periodic table from lithium through uranium, at extraction voltages from 10 to 60 kV and with beam currents as high as 1.1 Amperes (electrical current in all charge states). A brief description of the source is given and its possible application as an ion source for heavy ion fusion is considered. Beams such as C/sup +/ (greater than or equal to99% of the beam in this species and charge state), Cr/sup 2 +/ (80%), and Ta/sup 3+,4+,5+/ (mixed charge states) have been produced. Beam emittance measurements and ways of increasing the source brightness are discussed.

  8. Computational Design of Metal Ion Sequestering Agents

    SciTech Connect

    Hay, Benjamin P.; Rapko, Brian M.

    2006-06-01

    Organic ligands that exhibit a high degree of metal ion recognition are essential precursors for developing separation processes and sensors for metal ions. Since the beginning of the nuclear era, much research has focused on discovering ligands that target specific radionuclides. Members of the Group 1A and 2A cations (e.g., Cs, Sr, Ra) and the f-block metals (actinides and lanthanides) are of primary concern to DOE. Although there has been some success in identifying ligand architectures that exhibit a degree of metal ion recognition, the ability to control binding affinity and selectivity remains a significant challenge. The traditional approach for discovering such ligands has involved lengthy programs of organic synthesis and testing that, in the absence of reliable methods for screening compounds before synthesis, have resulted in much wasted research effort.

  9. Nuclear Structure Studies with Stable and Radioactive Beams: The SPES radioactive ion beam project

    NASA Astrophysics Data System (ADS)

    de Angelis, G.; SPES Collaboration; Prete, G.; Andrighetto, A.; Manzolaro, M.; Corradetti, S.; Scarpa, D.; Rossignoli, M.; Monetti, A.; Lollo, M.; Calderolla, M.; Vasquez, J.; Zafiropoulos, D.; Sarchiapone, L.; Benini, D.; Favaron, P.; Rigato, M.; Pegoraro, R.; Maniero, D.; Calabretta, L.; Comunian, M.; Maggiore, M.; Lombardi, A.; Piazza, L.; Porcellato, A. M.; Roncolato, C.; Bisoffi, G.; Pisent, A.; Galatà, A.; Giacchini, M.; Bassato, G.; Canella, S.; Gramegna, F.; Valiente, J.; Bermudez, J.; Mastinu, P. F.; Esposito, J.; Wyss, J.; Russo, A.; Zanella, S.

    2015-04-01

    A new Radioactive Ion Beam (RIB) facility (SPES) is presently under construction at the Legnaro National Laboratories of INFN. The SPES facility is based on the ISOL method using an UCx Direct Target able to sustain a power of 10 kW. The primary proton beam is provided by a high current Cyclotron accelerator with energy of 35-70 MeV and a beam current of 0.2-0.5 mA. Neutron-rich radioactive ions are produced by proton induced fission on an Uranium target at an expected fission rate of the order of 1013 fissions per second. After ionization and selection the exotic isotopes are re-accelerated by the ALPI superconducting LINAC at energies of 10A MeV for masses in the region A=130 amu. The expected secondary beam rates are of the order of 107 - 109 pps. Aim of the SPES facility is to deliver high intensity radioactive ion beams of neutron rich nuclei for nuclear physics research as well as to be an interdisciplinary research centre for radio-isotopes production for medicine and for neutron beams.

  10. Materials science and biophysics applications at the ISOLDE radioactive ion beam facility

    E-print Network

    Wahl, U

    2011-01-01

    The ISOLDE isotope separator facility at CERN provides a variety of radioactive ion beams, currently more than 800 different isotopes from ~65 chemical elements. The radioisotopes are produced on-line by nuclear reactions from a 1.4 GeV proton beam with various types of targets, outdiffusion of the reaction products and, if possible, chemically selective ionisation, followed by 60 kV acceleration and mass separation. While ISOLDE is mainly used for nuclear and atomic physics studies, applications in materials science and biophysics account for a significant part (currently ~15%) of the delivered beam time, requested by 18 different experiments. The ISOLDE materials science and biophysics community currently consists of ~80 scientists from more than 40 participating institutes and 21 countries. In the field of materials science, investigations focus on the study of semiconductors and oxides, with the recent additions of nanoparticles and metals, while the biophysics studies address the toxicity of metal ions i...

  11. Metal vapor arc ion plating

    DOEpatents

    Bertram, L.A.; Fisher, R.W.; Mattox, D.M.; Zanner, F.J.

    1986-09-09

    A method and apparatus for ion plating are described. The apparatus uses more negative than a first electrode voltage in a vacuum arc remelt system to attract low energy ions from the anode electrode to the article to be plated. 2 figs.

  12. MEVVA ion source for high current metal ion implantation

    SciTech Connect

    Brown, I.; Washburn, J.

    1986-07-01

    The MEVVA (Metal Vapor Vacuum Arc) ion source is a new kind of source which can produce high current beams of metal ions. Beams of a wide range of elements have been produced, spanning the periodic table from lithium up to and including uranium. The source extraction voltage is up to 60 kV, and we are increasing this up to 120 kV. A total ion beam current of over 1 Ampere has been extracted from the present embodiment of the concept, and this is not an inherent limit. The ion charge state distribution varies with cathode material and arc current, and beams like Li/sup +/, Co/sup +,2+,3+/ and U/sup 3+,4+,5+,6+/ for example, are typical; thus the implantation energy can be up to several hundred kilovolts without additional acceleration. The ion source has potential applications for ion implantation and ion beam mixing for achievement of improved corrosion resistance or wear resistance in metals or surface modification of ceramic materials and semiconductors. Here we outline the source and its performance, and describe some very preliminary implantation work using this source.

  13. ISOL science at the Holifield Radioactive Ion Beam Facility

    NASA Astrophysics Data System (ADS)

    Beene, J. R.; Bardayan, D. W.; Galindo Uribarri, A.; Gross, C. J.; Jones, K. L.; Liang, J. F.; Nazarewicz, W.; Stracener, D. W.; Tatum, B. A.; Varner, R. L.

    2011-02-01

    The Holifield Radioactive Ion Beam Facility (HRIBF) provides high-quality Isotope Separator Online beams of short-lived, radioactive nuclei for nuclear structure and reaction studies, astrophysics research, and interdisciplinary applications. The primary driver, the Oak Ridge Isochronous Cyclotron, produces rare isotopes by bombarding highly refractory targets with light ions. The radioactive isotopes are ionized, formed into a beam, mass selected, injected into the 25 MV tandem, accelerated, and used in experiments. This paper reviews the HRIBF and its users' science. Note that this manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up irrevocable, world-wide license to publish or reproduce the published form of the manuscript, or allow others to do so, for United States Government purposes.

  14. Metal ions affecting the skin and eyes.

    PubMed

    Lansdown, Alan B G

    2011-01-01

    The skin and eyes remain in constant exposure to the surrounding environment and are subject to accidental, occupational, and biological risks at all times, Normal development, homeostasis, and repair following injury depend upon appropriate levels of calcium, zinc, magnesium, copper, iron, and minute amounts of other trace metals. Both tissues exist in a permanent state of dynamic equilibrium with the environment whereby cells lost through natural wear and tear are replaced through genetically regulated mitotic patterns. Normal functional requirements of the constituent tissues depend on critical balances between trace metals, metal ion gradients, and specific carrier proteins which are modulated by upregulation of growth factors, cytokines, hormones, and subcellular regulators acting by autocrine, paracrine, and endocrine mechanisms. Metal ion gradients in epidermal tissues serve critical functions in basal cell proliferation, post-mitotic migration, and functional differentiation in normal homeostasis and in repair following injury. Toxic mechanisms reflect imbalances in trace metals or interaction between xenobiotic and trace metals through competitive binding key carrier proteins and metabolic pathways leading to trace metal imbalances and functional impairment. Alternatively, toxic injuries result through direct cytotoxic action of metal ions on cell membranes, intercellular communication, RNA and DNA damage, and mutagenic change. Arsenic is the only primary carcinogen in the skin following ingestion or topical exposure; beryllium, aluminum, and zirconium are a cause of granuloma. Aluminum as a cause for breast cancer is equivocal. Metal toxicities in the eye result from direct accidental or occupational exposure and systemic uptake of neurotoxic metals and their action on the retina and optic nerve. Calcium, zinc, magnesium, and iron are essential trace elements in eye development and physiology but silver, gold, lead, and mercury are absorbed through optic membranes or from the circulation to accumulate in the vitreous leading to local or systemic action. Lead, mercury, cadmium, aluminum, and other xenobiotic metals are implicated in structural and physiological damage in the mammalian eye. Thallium shows an affinity for melanin. PMID:21473382

  15. Reactivity and Infrared Spectroscopy of Gaseous Hydrated Trivalent Metal Ions

    E-print Network

    Cohen, Ronald C.

    trivalent rare earth metal ions containing yttrium and all naturally abundant lanthanide metals are formedReactivity and Infrared Spectroscopy of Gaseous Hydrated Trivalent Metal Ions Matthew F. Bush sizes that differs by only a few water molecules for each metal ion. The effective turnover size

  16. Cluster SIMS using metal cluster complex ions

    NASA Astrophysics Data System (ADS)

    Fujiwara, Yukio; Kondou, Kouji; Teranishi, Yoshikazu; Watanabe, Kouji; Nonaka, Hidehiko; Saito, Naoaki; Itoh, Hiroshi; Fujimoto, Toshiyuki; Kurokawa, Akira; Ichimura, Shingo; Tomita, Mitsuhiro

    2008-12-01

    Metal cluster complexes are chemically synthesized organometallic compounds, which have a wide range of chemical compositions with high molecular weight. Using a metal cluster complex ion source, sputtering characteristics of silicon bombarded with normally incident Ir 4(CO) 7+ ions were investigated. Experimental results showed that the sputtering yield at 10 keV was 36, which is higher than that with Ar + ions by a factor of 24. In addition, secondary ion mass spectrometry (SIMS) of boron-delta-doped silicon samples and organic films of poly(methyl methacrylate) (PMMA) was performed. Compared with conventional O 2+ ion beams, Ir 4(CO) 7+ ion beams improved depth resolution by a factor of 2.5 at the same irradiation conditions; the highest depth resolution of 0.9 nm was obtained at 5 keV, 45° with oxygen flooding of 1.3 × 10 -4 Pa. Furthermore, it was confirmed that Ir 4(CO) 7+ ion beams significantly enhanced secondary ion intensity in high-mass region.

  17. Novel metal ion surface modification technique

    SciTech Connect

    Brown, I.G.; Godechot, X.; Yu, K.M.

    1990-10-01

    We describe a method for applying metal ions to the near-surface region of solid materials. The added species can be energetically implanted below the surface or built up as a surface film with an atomically mixed interface with the substrate; the metal ion species can be the same as the substrate species or different from it, and more than one kind of metal species can be applied, either simultaneously or sequentially. Surface structures can be fabricated, including coatings and thin films of single metals, tailored alloys, or metallic multilayers, and they can be implanted or added onto the surface and ion beam mixed. We report two simple demonstrations of the method: implantation of yttrium into a silicon substrate at a mean energy of 70 keV and a dose of 1 {times} 10{sup 16} atoms/cm{sup 2}, and the formation of a titanium-yttrium multilayer structure with ion beam mixing to the substrate. 17 refs., 3 figs.

  18. Direct reaction experimental studies with beams of radioactive tin ions

    NASA Astrophysics Data System (ADS)

    Jones, K. L.; Ahn, S.; Allmond, J. M.; Ayres, A.; Bardayan, D. W.; Baugher, T.; Bazin, D.; Beene, J. R.; Berryman, J. S.; Bey, A.; Bingham, C.; Burcher, S.; Cartegni, L.; Cerizza, G.; Chae, K. Y.; Cizewski, J. A.; Gade, A.; Galindo-Uribarri, A.; Garcia-Ruiz, R. F.; Grzywacz, R.; Howard, M. E.; Kozub, R. L.; Liang, J. F.; Manning, B.; Matoš, M.; McDaniel, S.; Miller, D.; Nesaraja, C. D.; O'Malley, P. D.; Padgett, S.; Padilla-Rodal, E.; Pain, S. D.; Pittman, S. T.; Radford, D. C.; Ratkiewicz, A.; Schmitt, K. T.; Shore, A.; Smith, M. S.; Stracener, D. W.; Stroberg, S. R.; Tostevin, J.; Varner, R. L.; Weisshaar, D.; Wimmer, K.; Winkler, R.

    2015-10-01

    The tin chain of isotopes provides a unique region in which to investigate the evolution of single-particle structure, spreading from N = 50 at 100Sn, through 10 stable isotopes and the N = 82 shell closure at 132Sn out into the r-process path. Direct reactions performed on radioactive ion beams are sensitive spectroscopic tools for studying exotic nuclei. Here we present one experiment knocking out neutrons from tin isotopes that are already neutron deficient and two reactions that add a neutron to neutron-rich 130Sn. Both techniques rely on selective particle identification and the measurement of ? rays in coincidence with charged ions. We present the goals of the two experiments and the particle identification for the channels of interest. The final results will be presented in future publications.

  19. Intense metal-ion-beam production using an impregnated-electrode-type liquid-metal ion source

    NASA Astrophysics Data System (ADS)

    Ishikawa, Junzo; Tsuji, Hiroshi; Aoyama, Yuji; Takagi, Toshinori

    1990-01-01

    The properties of liquid-metal ion sources are very sensitive to their tip structure. Because the impregnated-electrode-type liquid-metal ion source has a porous tip, it generates more than 300-?A ion currents of various metals including relatively high vapor-pressure metals such as Li, Cu, Ga, Ge, Ag, In, and Au, from which ions can be stably extracted. The large beam divergence, a common disadvantage in liquid-metal ion sources, can be overcome by designing new lens systems to efficiently transport the ion beam for both high- and low-energy applications. In addition, the ion beam current can be multiplied by using multiple emission cusps; thus, a germanium ion current of 1.3 mA was obtained by a three-point emission source. Therefore, the impregnated-electrode-type liquid-metal ion source can be utilized as a metal ion source for general applications.

  20. Intense metal-ion-beam production using an impregnated-electrode-type liquid-metal ion source

    SciTech Connect

    Ishikawa, J.; Tsuji, H.; Aoyama, Y.; Takagi, T. )

    1990-01-01

    The properties of liquid-metal ion sources are very sensitive to their tip structure. Because the impregnated-electrode-type liquid-metal ion source has a porous tip, it generates more than 300-{mu}A ion currents of various metals including relatively high vapor-pressure metals such as Li, Cu, Ga, Ge, Ag, In, and Au, from which ions can be stably extracted. The large beam divergence, a common disadvantage in liquid-metal ion sources, can be overcome by designing new lens systems to efficiently transport the ion beam for both high- and low-energy applications. In addition, the ion beam current can be multiplied by using multiple emission cusps; thus, a germanium ion current of 1.3 mA was obtained by a three-point emission source. Therefore, the impregnated-electrode-type liquid-metal ion source can be utilized as a metal ion source for general applications.

  1. Cryogenic molecular separation system for radioactive (11)C ion acceleration.

    PubMed

    Katagiri, K; Noda, A; Suzuki, K; Nagatsu, K; Boytsov, A Yu; Donets, D E; Donets, E D; Donets, E E; Ramzdorf, A Yu; Nakao, M; Hojo, S; Wakui, T; Noda, K

    2015-12-01

    A (11)C molecular production/separation system (CMPS) has been developed as part of an isotope separation on line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive (11)C ion beams. In the ISOL system, (11)CH4 molecules will be produced by proton irradiation and separated from residual air impurities and impurities produced during the irradiation. The CMPS includes two cryogenic traps to separate specific molecules selectively from impurities by using vapor pressure differences among the molecular species. To investigate the fundamental performance of the CMPS, we performed separation experiments with non-radioactive (12)CH4 gases, which can simulate the chemical characteristics of (11)CH4 gases. We investigated the separation of CH4 molecules from impurities, which will be present as residual gases and are expected to be difficult to separate because the vapor pressure of air molecules is close to that of CH4. We determined the collection/separation efficiencies of the CMPS for various amounts of air impurities and found desirable operating conditions for the CMPS to be used as a molecular separation device in our ISOL system. PMID:26724018

  2. Functional Identification of Catalytic Metal Ion Binding Sites within RNA

    E-print Network

    Herschlag, Dan

    elucidation of metal ion interactions with both the enzyme and the substrate(s). In the Tetrahymena group I the ligands of catalytic metal ions within RNA. In applying this strategy to the Tetrahymena group I intron

  3. Material Removes Heavy Metal Ions From Water

    NASA Technical Reports Server (NTRS)

    Philipp, Warren H., Jr.; Street, Kenneth W.; Hill, Carol; Savino, Joseph M.

    1995-01-01

    New high capacity ion-exchange polymer material removes toxic metal cations from contaminated water. Offers several advantages. High sensitivities for such heavy metals as lead, cadmium, and copper and capable of reducing concentrations in aqueous solutions to parts-per-billion range. Removes cations even when calcium present. Material made into variety of forms, such as thin films, coatings, pellets, and fibers. As result, adapted to many applications to purify contaminated water, usually hard wherever found, whether in wastewater-treatment systems, lakes, ponds, industrial plants, or homes. Another important feature that adsorbed metals easily reclaimed by either destructive or nondestructive process. Other tests show ion-exchange polymer made inexpensively; easy to use; strong, flexible, not easily torn; and chemically stable in storage, in aqueous solutions, and in acidic or basic solution.

  4. High-current pulsed ion source for metallic ions

    SciTech Connect

    Gavin, B.; Abbott, S.; MacGill, R.; Sorensen, R.; Staples, J.; Thatcher, R.

    1981-03-01

    A new sputter-ion PIG source and magnet system, optimized for intermediate charge states, q/A of 0.02 to 0.03, is described. This source will be used with the new Wideroe-based injector for the SuperHILAC. Pulsed electrical currents of several emA of heavy metal ions have been produced in a normalized emittance area of .05..pi.. cm-mr. The source system is comprised of two electrically separate anode chambers, one in operation and one spare, which can be selected by remote control. The entire source head is small and quickly removable.

  5. The role of metal ion-ligand interactions during divalent metal ion adsorption.

    PubMed

    Eldridge, Daniel S; Crawford, Russell J; Harding, Ian H

    2015-09-15

    A suite of seven different divalent metal ions (Ca(II), Cd(II), Cu(II), Mg(II), Ni(II), Pb(II), Zn(II)) was adsorbed from solution onto two Fe2O3 samples, quartz SiO2 and three different amphoteric polystyrene latices (containing amine and carboxyl functional groups). For the metal oxides, a high correlation was observed between the pH at which 50% of the metal was removed from solution (pH50) and the first hydrolysis constant for the metal ion (pK1). For the polystyrene latices, a much higher correlation was observed between the pH50 and pKc (equilibrium constant describing metal-carboxyl affinity) as opposed to pK1. These observations provide evidence of a strong relationship that exists between a metal's affinity for a particular ligand in solution and for that metal ion's affinity for the same ligand present as part of an adsorbing surface. The isoelectric point of the amphoteric latex surface can be increased by decreasing the carboxyl content of the latex surface. For all 7 metal ions, this resulted in a substantial decrease, for any given pH, in adsorption. We suggest that this may be partly due to the decreased carboxyl content, but is dominantly attributable to the presence of less favorable electrostatic conditions. This, in turn, demonstrates that electrostatics play a controlling role in metal ion adsorption onto amphoteric latex surfaces and, in addition to the nature of the metal ion, also controls the pH at which adsorption takes place. PMID:26001134

  6. Assessment of recycling or disposal alternatives for radioactive scrap metal

    SciTech Connect

    Murphie, W.E.; Lilly, M.J. III; Nieves, L.A.; Chen, S.Y.

    1993-10-01

    The US Department of Energy, Office of Environmental Restoration and Waste Management, is participating with the Organization for Economic Cooperation and Development (OECD) is an evaluation of management alternatives for radioactive scarp metals. For this purpose, Argonne National Laboratory is assessing alternatives for radioactive scrap metals. For this purpose, Argonne National Laboratory is assessing environmental and societal implications of recycling and/or disposal process alternatives (with metal replacement). Findings will be presented in a report from the OECD Task Group. This paper focuses on the radiological risk assessment and dose estimate sensitivity analysis. A ``tiered`` concept for release categories, with and without use restrictions, is being developed. Within the tiers, different release limits may be indicated for specific groupings of radionuclides. Depending on the spectrum of radionuclides that are present and the level of residual activity after decontamination and/or smelting, the scrap may be released for unrestricted public use or for specified public uses, or it may be recycled within the nuclear industry. The conversatism of baseline dose estimates is examined, and both more realistic parameter values and protective measures for workers are suggested.

  7. Engineering of microorganisms towards recovery of rare metal ions.

    PubMed

    Kuroda, Kouichi; Ueda, Mitsuyoshi

    2010-06-01

    The bioadsorption of metal ions using microorganisms is an attractive technology for the recovery of rare metal ions as well as removal of toxic heavy metal ions from aqueous solution. In initial attempts, microorganisms with the ability to accumulate metal ions were isolated from nature and intracellular accumulation was enhanced by the overproduction of metal-binding proteins in the cytoplasm. As an alternative, the cell surface design of microorganisms by cell surface engineering is an emerging strategy for bioadsorption and recovery of metal ions. Cell surface engineering was firstly applied to the construction of a bioadsorbent to adsorb heavy metal ions for bioremediation. Cell surface adsorption of metal ions is rapid and reversible. Therefore, adsorbed metal ions can be easily recovered without cell breakage, and the bioadsorbent can be reused or regenerated. These advantages are suitable for the recovery of rare metal ions. Actually, the cell surface display of a molybdate-binding protein on yeast led to the enhanced adsorption of molybdate, one of the rare metal ions. An additional advantage is that the cell surface display system allows high-throughput screening of protein/peptide libraries owing to the direct evaluation of the displayed protein/peptide without purification and concentration. Therefore, the creation of novel metal-binding protein/peptide and engineering of microorganisms towards the recovery of rare metal ions could be simultaneously achieved. PMID:20393699

  8. Metal ions in the atmosphere of Neptune.

    PubMed

    Lyons, J R

    1995-02-01

    Microwave propagation experiments performed with Voyager 2 at Neptune revealed sharp layers of electrons in Neptune's lower ionosphere with densities of approximately 10(4) per cubic centimeter. These layers are reminiscent of the sporadic-E layers in the Earth's ionosphere, and when taken together with data from the other giant planets, these data confirm the importance of the magnetic field in layer formation. A photochemical model that incorporates species produced by meteoroid ablation predicts that singly ionized magnesium is the most likely metal to be found in the layers, although laboratory data on the kinetics of metallic atoms and ions in a reducing environment are lacking. The metal chemistry discussed here is directly relevant to the abundant metals observed at the impact site of the G fragment of comet Shoemaker Levy 9 on Jupiter. PMID:7839139

  9. Ohmic model for electrodeposition of metallic ions

    NASA Astrophysics Data System (ADS)

    Gliozzi, A. S.; Alexe-Ionescu, A. L.; Barbero, G.

    2015-10-01

    An ohmic model to describe the electrodeposition of metallic ions on the electrodes is proposed. We assume that the ionic distribution is homogeneous across the electrolytic cell, and that the ionic current is due to the bulk electric field. The nucleation in the electrodeposition is supposed to be well described by a kinetic equation at the electrode, taking into account the neutralization of metallic ions on the electrodes. Two cases are considered. In the first case the characteristic time describing the neutralization of the ions is supposed to be negligible with respect to the flight time of the ions across the cell. In this framework the bulk electric field coincides with the external electric field, and our analysis gives analytical formulae for the surface density of deposited ions and for the electric current in the external circuit. The case where the two characteristic times are comparable, and the effective electric field in the bulk depends on the surface deposition, is considered too. In this case the ordinary differential equations describing the ionic distribution and the adsorption phenomenon have to be solved numerically. The agreement between the presented model and the experimental results published by several groups is reasonably good.

  10. Assessment of recycling or disposal alternatives for radioactive scrap metal

    SciTech Connect

    Murphie, W.E.; Lilly, M.J. III; Nieves, L.A.; Chen, S.Y.

    1993-11-01

    The US Department of Energy, Office of Environmental Restoration and Waste Management, Oak Ridge Programs Division, is participating with the Organization for Economic Cooperation and Development in providing analytical support for evaluation of management alternatives for radioactive scrap metals. For this purpose, Argonne National Laboratory is assessing environmental and societal implications of recycling and/or disposal process alternatives. This effort includes development of inventory estimates for contaminated metals; investigation of scrap metal market structure, processes, and trends; assessment of radiological and nonradiological effects of recycling; and investigation of social and political factors that are likely to either facilitate or constrain recycling opportunities. In addition, the option of scrap metal disposal is being assessed, especially with regard to the environmental and health impacts of replacing these metals if they are withdrawn from use. This paper focuses on the radiological risk assessment and dose estimate sensitivity analysis. A {open_quotes}tiered{close_quotes} concept for release categories, with and without use restrictions, is being developed. Within the tiers, different release limits may be indicated for specific groupings of radionuclides. Depending on the spectrum of radionuclides that are present and the level of residual activity after decontamination and/or smelting, the scrap may be released for unrestricted public use or for specified public uses, or it may be recycled within the nuclear industry. The conservatism of baseline dose estimates is examined, and both more realistic parameter values and protective measures for workers are suggested.

  11. Effects of Metal Ion Adduction on the Gas-Phase Conformations of Protein Ions

    NASA Astrophysics Data System (ADS)

    Flick, Tawnya G.; Merenbloom, Samuel I.; Williams, Evan R.

    2013-11-01

    Changes in protein ion conformation as a result of nonspecific adduction of metal ions to the protein during electrospray ionization (ESI) from aqueous solutions were investigated using traveling wave ion mobility spectrometry (TWIMS). For all proteins examined, protein cations (and in most cases anions) with nonspecific metal ion adducts are more compact than the fully protonated (or deprotonated) ions with the same charge state. Compaction of protein cations upon nonspecific metal ion binding is most significant for intermediate charge state ions, and there is a greater reduction in collisional cross section with increasing number of metal ion adducts and increasing ion valency, consistent with an electrostatic interaction between the ions and the protein. Protein cations with the greatest number of adducted metal ions are no more compact than the lowest protonated ions formed from aqueous solutions. These results show that smaller collisional cross sections for metal-attached protein ions are not a good indicator of a specific metal-protein interaction in solution because nonspecific metal ion adduction also results in smaller gaseous protein cation cross sections. In contrast, the collisional cross section of ?-lactalbumin, which specifically binds one Ca2+, is larger for the holo-form compared with the apo-form, in agreement with solution-phase measurements. Because compaction of protein cations occurs when metal ion adduction is nonspecific, elongation of a protein cation may be a more reliable indicator that a specific metal ion-protein interaction occurs in solution.

  12. Surrogate reactions for neutron capture with radioactive ion beams

    NASA Astrophysics Data System (ADS)

    Cizewski, Jolie A.

    2012-10-01

    Neutron capture reactions are responsible for most of the elements heavier than iron, through either the slow or rapid processes of nucleosynthesis. The r process in particular proceeds through very short-lived nuclei on which neutron capture reaction measurements will never be possible. Knowledge of neutron capture cross sections on short-lived nuclei is also important for applications such as nuclear energy, nuclear forensics, and stockpile stewardship science. When the level density at the neutron separation energy is relatively low, for example near closed neutron shells, direct neutron capture often dominates and direct neutron transfer reactions can provide the spectroscopic information needed to calculate the direct capture. However, when the level density is higher, a compound nucleus is formed and statistical mechanisms dominate the decay. While the formation of the compound nucleus can be calculated with optical models, modeling of the decay is less robust. Because of the importance of neutron capture on nuclei away from stability, there have been efforts to validate surrogate reactions for neutron capture that exploit the availability of beams of radioactive nuclei that interact with light targets where reaction products are measured in coincidence with gamma radiation. This talk would summarize efforts to validate a surrogate for neutron capture and the techniques being developed to measure these reactions with beams of radioactive ions.

  13. On the Metal Ion Selectivity of Oxoacid Extractants

    SciTech Connect

    Hay, Benjamin; Chagnes, Alexandre; Cote, Gerard

    2013-01-01

    Relationships between metal chelate stability, ligand basicity, and metal ion acidity are reviewed and the general applicability is illustrated by linear correlations between aqueous stability constants and ligand pKa values for 35 metals with 26 ligands. The results confirm that most individual ligands of this type exhibit a stability ordering that correlates with the Lewis acidity of the metal ion. It is concluded that the general metal ion selectivity exhibited by liquid-liquid oxoacid extractants such as carboxylic acids, -diketones, and alkylphosphoric acids reflects the intrinsic affinity of the metal ion for the negative oxygen donor ligand.

  14. Liquid metal alloy ion source based metal ion injection into a room-temperature electron beam ion source

    SciTech Connect

    Thorn, A.; Ritter, E.; Zschornack, G.; Ullmann, F.; Pilz, W.; Bischoff, L.

    2012-02-15

    We have carried out a series of measurements demonstrating the feasibility of using the Dresden electron beam ion source (EBIS)-A, a table-top sized, permanent magnet technology based electron beam ion source, as a charge breeder. Low charged gold ions from an AuGe liquid metal alloy ion source were injected into the EBIS and re-extracted as highly charged ions, thereby producing charge states as high as Au{sup 60+}. The setup, the charge breeding technique, breeding efficiencies as well as acceptance and emittance studies are presented.

  15. Analysis of metallic pigments by ion microbeam

    NASA Astrophysics Data System (ADS)

    Pelicon, P.; Klanjšek-Gunde, M.; Kunaver, M.; Sim?i?, J.; Budnar, M.

    2002-05-01

    Metallic paints consist of metallic flakes dispersed in a resinous binder, i.e. a light-element polymer matrix. The spatial distribution and orientation of metallic flakes inside the matrix determines the covering efficiency of the paint, glossiness, and its angular-dependent properties such as lightness flop or color flop (two-tone). Such coatings are extensively used for a functional (i.e. security) as well as decorative purpose. The ion microbeam analysis of two types of silver paint with imbedded metallic flakes has been performed to determine the spatial distribution of the aluminum flakes in paint layer. The average sizes of the aluminum flakes were 23 ?m (size distribution 10-37) and 49 ?m (size distribution 34-75), respectively. The proton beam with the size of 2×2 ?m 2 at Ljubljana ion microprobe has been used to scan the surface of the pigments. PIXE mapping of Al K? map shows lateral distribution of the aluminum flakes, whereas the RBS slicing method reveals tomograms of the flakes in uppermost 7 ?m of the pigment layer. The series of point analysis aligned over the single flake reveal the flake angle in respect to the polymer matrix surface. The angular sensitivity is well below 1 angular degree.

  16. Transparent monolithic metal ion containing nanophase aerogels

    SciTech Connect

    Risen, W. M., Jr.; Hu, X.; Ji, S.; Littrell, K.

    1999-12-01

    The formation of monolithic and transparent transition metal containing aerogels has been achieved through cooperative interactions of high molecular weight functionalized carbohydrates and silica precursors, which strongly influence the kinetics of gelation. After initial gelation, subsequent modification of the ligating character of the system, coordination of the group VIII metal ions, and supercritical extraction afford the aerogels. The structures at the nanophase level have been probed by photon and electron transmission and neutron scattering techniques to help elucidate the basis for structural integrity together with the small entity sizes that permit transparency in the visible range. They also help with understanding the chemical reactivities of the metal-containing sites in these very high surface area materials. These results are discussed in connection with new reaction studies.

  17. Polarized proton target for radioactive ion beam experiments

    NASA Astrophysics Data System (ADS)

    Sakaguchi, Satoshi; Uesaka, Tomohiro; Wakui, Takashi; Kawahara, Tomomi; Tateishi, Kenichiro; Chebotaryov, Sergey; Milman, Evgeniy; Sakai, Hideyuki

    2014-09-01

    The world of atomic nuclei is enriched by the strong spin-dependent interaction in nuclear force. For studying roles of such interactions, one of the best approaches is the direct reaction of spin-polarized light ions. From more than half century ago, a number of scattering experiments using polarized proton/deuteron beams have been performed in all over the world. A polarized target for radioactive-ion beam experiments will enable us to apply this powerful approach to the field of unstable nuclei. At RIKEN and CNS, Univ. of Tokyo, we have constructed a solid polarized proton target based on a unique polarizing method. The target has an advantage of the operation under a low magnetic field of 0.1 T, which allows the detection of low-energy recoil protons in the inverse kinematics. Currently achieved polarization is about 20%. The target has already been applied to RI-beam experiments at intermediate energies such as 70-200 MeV/nucleon. In this talk, we will introduce the overview of the polarized target system and present status of the experimental programs such as study of spin-orbit interaction in proton elastic scattering and determination of spin-orbit splitting by (p,2p) knock-out reaction. New physics opportunities expected with low-energy beams will also be covered.

  18. A gas jet target for radioactive ion beam experiments

    NASA Astrophysics Data System (ADS)

    Chipps, K. A.; Bardayan, D. W.; Blackmon, J. C.; Browne, J.; Couder, M.; Erikson, L. E.; Greife, U.; Hager, U.; Kontos, A.; Lemut, A.; Linhardt, L. E.; Meisel, Z.; Montes, F.; Pain, S. D.; Robertson, D.; Sarazin, F.; Schatz, H.; Schmitt, K. T.; Smith, M. S.; Vetter, P.; Wiescher, M.

    2013-04-01

    New radioactive ion beam (RIB) facilities, like FRIB in the US or FAIR in Europe, will push further away from stability and enable the next generation of nuclear physics experiments. Thus, the need for improved RIB targets is more crucial than ever: developments in exotic beams should coincide with developments in targets for use with those beams, in order for nuclear physics to remain on the cutting edge. Of great importance to the future of RIB physics are scattering, transfer and capture reaction measurements of rare, exotic, and unstable nuclei on light targets such as hydrogen and helium. These measurements require targets that are dense, highly localized, and pure, and conventional targets often suffer too many drawbacks to allow for such experimental designs. Targets must also accommodate the use of large area, highly-segmented silicon detector arrays, high-efficiency gamma arrays, and novel heavy ion detectors to efficiently measure the reaction products. To address this issue, the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) Collaboration led by the Colorado School of Mines (CSM) is in the process of designing, building and testing a supersonic gas jet target for use at existing and future RIB facilities. The gas jet target provides a high density and high purity of target nuclei within a tightly confined region, without the use of windows or backing materials. The design also enables the use of multiple state-of-the-art detection systems.

  19. A gas jet target for radioactive ion beam experiments

    SciTech Connect

    Chipps, K. A.; Greife, U.; Hager, U.; Sarazin, F.; Bardayan, D. W.; Pain, S. D.; Schmitt, K. T.; Smith, M. S.; Blackmon, J. C.; Linhardt, L. E.; Browne, J.; Kontos, A.; Meisel, Z.; Montes, F.; Schatz, H.; Erikson, L. E.; Lemut, A.; and others

    2013-04-19

    New radioactive ion beam (RIB) facilities, like FRIB in the US or FAIR in Europe, will push further away from stability and enable the next generation of nuclear physics experiments. Thus, the need for improved RIB targets is more crucial than ever: developments in exotic beams should coincide with developments in targets for use with those beams, in order for nuclear physics to remain on the cutting edge. Of great importance to the future of RIB physics are scattering, transfer and capture reaction measurements of rare, exotic, and unstable nuclei on light targets such as hydrogen and helium. These measurements require targets that are dense, highly localized, and pure, and conventional targets often suffer too many drawbacks to allow for such experimental designs. Targets must also accommodate the use of large area, highly-segmented silicon detector arrays, high-efficiency gamma arrays, and novel heavy ion detectors to efficiently measure the reaction products. To address this issue, the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) Collaboration led by the Colorado School of Mines (CSM) is in the process of designing, building and testing a supersonic gas jet target for use at existing and future RIB facilities. The gas jet target provides a high density and high purity of target nuclei within a tightly confined region, without the use of windows or backing materials. The design also enables the use of multiple state-of-the-art detection systems.

  20. Metal ion binding to iron oxides

    NASA Astrophysics Data System (ADS)

    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.

  1. Study of Nuclear Reactions with 11C and 15O Radioactive Ion Beams

    SciTech Connect

    Lee, Dongwon

    2007-05-14

    Nuclear reaction study with radioactive ion beams is one of the most exciting research topics in modern nuclear physics. The development of radioactive ion beams has allowed nuclear scientists and engineers to explore many unknown exotic nuclei far from the valley of nuclear stability, and to further our understanding of the evolution of the universe. The recently developed radioactive ion beam facility at the Lawrence Berkeley National Laboratory's 88-inch cyclotron is denoted as BEARS and provides {sup 11}C, {sup 14}O and {sup 15}O radioactive ion beams of high quality. These moderate to high intensity, proton-rich radioactive ion beams have been used to explore the properties of unstable nuclei such as {sup 12}N and {sup 15}F. In this work, the proton capture reaction on {sup 11}C has been evaluated via the indirect d({sup 11}C, {sup 12}N)n transfer reaction using the inverse kinematics method coupled with the Asymptotic Normalization Coefficient (ANC) theoretical approach. The total effective {sup 12}N {yields} {sup 11}C+p ANC is found to be (C{sub eff}{sup 12{sub N}}){sup 2} = 1.83 {+-} 0.27 fm{sup -1}. With the high {sup 11}C beam intensity available, our experiment showed excellent agreement with theoretical predictions and previous experimental studies. This study also indirectly confirmed that the {sup 11}C(p,{gamma}) reaction is a key step in producing CNO nuclei in supermassive low-metallicity stars, bypassing the slow triple alpha process. The newly developed {sup 15}O radioactive ion beam at BEARS was used to study the poorly known level widths of {sup 16}F via the p({sup 15}O,{sup 15}O)p reaction. Among the nuclei in the A=16, T=1 isobaric triad, many states in {sup 16}N and {sup 16}O have been well established, but less has been reported on {sup 16}F. Four states of {sup 16}F below 1 MeV have been identified experimentally: 0{sup -}, 1{sup -}, 2{sup -}, and 3{sup -} (E{sub x} = 0.0, 0.19, 0.42, and 0.72 MeV, respectively). Our study utilized R-matrix analysis and found that the 0- state has a level width of 23.1 {+-} 2.2 keV, and that the broader 1- state has a width of 91.1 {+-} 9.9 keV. The level width of the 2{sup -} state is found to be 3.3 {+-} 0.6 keV which is much narrower than the compiled value of 40 {+-} 30 keV, while a width of 14.1 {+-} 1.7 keV for the 3{sup -} state is in good agreement with the reported value (< 15 keV). These experimental level widths of all four levels are also in accordance with theoretical predictions using single particle shell model calculation.

  2. How do metal ions direct ribozyme folding?

    NASA Astrophysics Data System (ADS)

    Denesyuk, Natalia A.; Thirumalai, D.

    2015-10-01

    Ribozymes, which carry out phosphoryl-transfer reactions, often require Mg2+ ions for catalytic activity. The correct folding of the active site and ribozyme tertiary structure is also regulated by metal ions in a manner that is not fully understood. Here we employ coarse-grained molecular simulations to show that individual structural elements of the group I ribozyme from the bacterium Azoarcus form spontaneously in the unfolded ribozyme even at very low Mg2+ concentrations, and are transiently stabilized by the coordination of Mg2+ ions to specific nucleotides. However, competition for scarce Mg2+ and topological constraints that arise from chain connectivity prevent the complete folding of the ribozyme. A much higher Mg2+ concentration is required for complete folding of the ribozyme and stabilization of the active site. When Mg2+ is replaced by Ca2+ the ribozyme folds, but the active site remains unstable. Our results suggest that group I ribozymes utilize the same interactions with specific metal ligands for both structural stability and chemical activity.

  3. Analysis of disposition alternatives for radioactively contaminated scrap metal

    SciTech Connect

    Nieves, L.A.; Chen, S.Y.; Kohout, E.J.; Nabelssi, B.; Tilbrook, R.W.; Wilson, S.E.

    1997-01-01

    Millions of tonnes of slightly radioactive, scrap iron and steel, stainless steel, and copper are likely to become available as nuclear and other facilities and equipment are withdrawn from service. Disposition of this material is an international policy issue under consideration currently. The major alternatives for managing this material are to either develop a regulatory process for decontamination and recycling that will safeguard human health or to dispose of the scrap and replace the metal stocks. To evaluate the alternatives, we estimate quantities of scrap arising from nuclear power plant decommissioning, evaluate potential price impacts of recycling on regional markets, and assess the health and environmental impacts of the management alternatives. We conclude that decontaminating and recycling the scrap is the superior alternative.

  4. Characterization of low temperature metallic magnetic calorimeters having gold absorbers with implanted $^{163}$Ho ions

    E-print Network

    L. Gastaldo; P. Ranitzsch; F. von Seggern; J. -P. Porst; S. Schäfer; C. Pies; S. Kempf; T. Wolf; A. Fleischmann; C. Enss; A. Herlert; K. Johnston

    2012-06-25

    For the first time we have investigated the behavior of fully micro-fabricated low temperature metallic magnetic calorimeters (MMCs) after undergoing an ion-implantation process. This experiment had the aim to show the possibility to perform a high precision calorimetric measurement of the energy spectrum following the electron capture of $^{163}$Ho using MMCs having the radioactive $^{163}$Ho ions implanted in the absorber. The implantation of $^{163}$Ho ions was performed at ISOLDE-CERN. The performance of a detector that underwent an ion-implantation process is compared to the one of a detector without implanted ions. The results show that the implantation dose of ions used in this experiment does not compromise the properties of the detector. In addition an optimized detector design for future $^{163}$Ho experiments is presented.

  5. Behavior of metal ions in bioelectrochemical systems: A review

    NASA Astrophysics Data System (ADS)

    Lu, Zhihao; Chang, Dingming; Ma, Jingxing; Huang, Guangtuan; Cai, Lankun; Zhang, Lehua

    2015-02-01

    Bioelectrochemical systems (BESs) have been focused on by many researchers to treat wastewater and recover energy or valuable chemicals from wastes. In BESs, metal ions play an important role in the conductivity of solution, reactors' internal resistance, power generation, chemical production and activity of microorganisms. Additionally, the metal ions are also involved in anodic or cathodic reaction processes directly or indirectly in BESs. This paper reviews the behavior of metal ions in BESs, including (1) increase of the conductivity of electrolyte and decrease of internal resistance, (2) transfer for desalination, (3) enhancement or inhibition of the biocatalysis in anode, (4) improvement of cathodic performance by metal ions through electron acceptance or catalysis in cathodic process and (5) behavior of metal ions on membranes. Moreover, the perspectives of BESs removing heavy metal ions in wastewater or solid waste are discussed to realize recovery, reduction and detoxification simultaneously.

  6. Predicting relative toxicity of metal ions to bacteria (Microtox{reg_sign}) using ion characteristics

    SciTech Connect

    McCloskey, J.T.; Newman, M.C.; Clark, S.B.

    1995-12-31

    The use of predictive effects models with metals has received little attention in toxicology. The purpose of this study was to predict the relative toxicity of individual metal ions and metal mixtures using ion characteristics. The concentration of metal resulting in a 50% reduction in light output (EC50) in marine bacteria (Vibrio fischeri) was determined for several metals using the Microtox{reg_sign} Toxicity Analyzer. Trends in metal toxicity were predicted by combining metal speciation calculations with empirical models based on metal ion characteristics. These trends were consistent for nine divalent metals (Ca{prime} Cd, Cu, Hg, Mg, Mn, Ni, Pb and Zn) whether the media mimicked salt water (NaC, medium) or freshwater (NaNO{sub 3} medium). When expanding the study to include an additional 14 mono-, di-, and trivalent metal ions, ion characteristics were still useful for predicting the relative toxicity of metal ions to bacteria. The prediction of nonadditive toxic effects using metal mixtures was also possible based on ion characteristics. Overall, models based on ion characteristics show much promise for predicting the relative toxicity of metal ions using the Microtox{reg_sign} assay.

  7. Separation of traces of metal ions from sodium matrices

    NASA Technical Reports Server (NTRS)

    Korkisch, J.; Orlandini, K. A.

    1969-01-01

    Method for isolating metal ion traces from sodium matrices consists of two extractions and an ion exchange step. Extraction is accomplished by using 2-thenoyltrifluoracetone and dithizone followed by cation exchange.

  8. Direct reaction measurements with a (132)Sn radioactive ion beam

    SciTech Connect

    Jones, K. L.; Chae, K. Y.; Kapler, R.; Ma, Zhanwen; Moazen, Brian; Cizewski, J. A.; Hatarik, Robert; Pain, S. D.; Swan, T. P.; Nunes, F. M.; Adekola, Aderemi S; Bardayan, Daniel W; Blackmon, Jeff C; Chae, Kyung Yuk; Liang, J Felix; Nesaraja, Caroline D; Pain, Steven D; Shapira, Dan; Smith, Michael Scott; Chipps, Kelly A; Erikson, Luke; Livesay, R. J.; Harlin, Christopher W; Patterson, N. P.; Thomas, J. S.; Kozub, R. L.; Shriner, Jr., John F

    2011-01-01

    The (d,p) neutron transfer and (d,d) elastic scattering reactions were measured in inverse kinematics using a radioactive ion beam of {sup 132}Sn at 630 MeV. The elastic scattering data were taken in a region where Rutherford scattering dominated the reaction, and nuclear effects account for less than 8% of the elastic scattering cross section. The magnitude of the nuclear effects, in the angular range studied, was found to be independent of the optical potential used, allowing the transfer data to be normalized in a reliable manner. The neutron-transfer reaction populated a previously unmeasured state at 1363 keV, which is most likely the single-particle 3p{sub 1/2} state expected above the N=82 shell closure. The data were analyzed using finite-range adiabatic-wave calculations and the results compared with the previous analysis using the distorted-wave Born approximation. Angular distributions for the ground and first-excited states are consistent with the previous tentative spin and parity assignments. Spectroscopic factors extracted from the differential cross sections are similar to those found for the one-neutron states beyond the benchmark doubly magic nucleus {sup 208}Pb.

  9. Direct reaction measurements with a 132Sn radioactive ion beam

    SciTech Connect

    Jones, Katherine L.; Nunes, Filomena M.; Adekola, Aderemi S.; Bardayan, Dan W.; Blackmon, Jeff; Chae, K. Y.; Chipps, Kelly A.; Cizewski, Jolie A.; Erikson, Luke E.; Harlin, C.; Hatarik, R.; Kapler, R.; Kozub, Raymond L.; Liang, J. F.; Livesay, Ronald J.; Ma, Zhongguo J.; Moazen, B. H.; Nesaraja, Caroline D.; Pain, Steven D.; Patterson, N. P.; Shapira, Dan; Shriner, Jr., John F.; Smith, Michael S.; Swan, Thomas P.; Thomas, Jeff S.

    2011-09-01

    The (d,p) neutron transfer and (d,d) elastic scattering reactions were measured in inverse kinematics using a radioactive ion beam of 132Sn at 630 MeV. The elastic scattering data were taken in a region where Rutherford scattering dominated the reaction, and nuclear effects account for less than 8% of the elastic scattering cross section. The magnitude of the nuclear effects, in the angular range studied, was found to be independent of the optical potential used, allowing the transfer data to be normalized in a reliable manner. The neutron-transfer reaction populated a previously unmeasured state at 1363 keV, which is most likely the single-particle 3p1/2 state expected above the N = 82 shell closure. The data were analyzed using finite-range adiabatic-wave calculations and the results compared with the previous analysis using the distorted-wave Born approximation. Angular distributions for the ground and first-excited states are consistent with the previous tentative spin and parity assignments. Spectroscopic factors extracted from the differential cross sections are similar to those found for the one-neutron states beyond the benchmark doubly magic nucleus 208Pb.

  10. State promotion and neutralization ?f ions near metal surface

    NASA Astrophysics Data System (ADS)

    Zinoviev, A. N.

    2011-05-01

    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.

  11. Ion implantation of krypton in sputter-deposited metal matrices

    SciTech Connect

    Tingey, G.L.; McClanahan, E.D.; Nesbitt, J.F.

    1980-06-01

    Krypton 85 has been successfully stored in a metal matrix by bombarding the metal surface with krypton ions while the metal is being deposited by sputtering. The krypton is thus incorporated into the metal in concentrations approaching 200 cm/sup 3/ of Kr(STP)cm/sup 3/ of deposit. Cost estimates of a facility to perform this work are given. (GHT)

  12. Plasma immersion surface modification with metal ion plasma

    SciTech Connect

    Brown, I.G.; Yu, K.M. ); Godechot, X. Societe Anonyme d'Etudes et Realisations Nucleaires , 94 - Limeil-Brevannes )

    1991-04-01

    We describe here a novel technique for surface modification in which metal plasma is employed and by which various blends of plasma deposition and ion implantation can be obtained. The new technique is a variation of the plasma immersion technique described by Conrad and co-workers. When a substrate is immersed in a metal plasma, the plasma that condenses on the substrate remains there as a film, and when the substrate is then implanted, qualitatively different processes can follow, including' conventional' high energy ion implantation, recoil implantation, ion beam mixing, ion beam assisted deposition, and metallic thin film and multilayer fabrication with or without species mixing. Multiple metal plasma guns can be used with different metal ion species, films can be bonded to the substrate through ion beam mixing at the interface, and multilayer structures can be tailored with graded or abrupt interfaces. We have fabricated several different kinds of modified surface layers in this way. 22 refs., 4 figs.

  13. Plasma immersion ion implantation for reducing metal ion release

    SciTech Connect

    Diaz, C.; Garcia, J. A.; Maendl, S.; Pereiro, R.; Fernandez, B.; Rodriguez, R. J.

    2012-11-06

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

  14. Porous metal oxide microspheres from ion exchange resin

    NASA Astrophysics Data System (ADS)

    Picart, S.; Parant, P.; Caisso, M.; Remy, E.; Mokhtari, H.; Jobelin, I.; Bayle, J. P.; Martin, C. L.; Blanchart, P.; Ayral, A.; Delahaye, T.

    2015-07-01

    This study is devoted to the synthesis and the characterization of porous metal oxide microsphere from metal loaded ion exchange resin. Their application concerns the fabrication of uranium-americium oxide pellets using the powder-free process called Calcined Resin Microsphere Pelletization (CRMP). Those mixed oxide ceramics are one of the materials envisaged for americium transmutation in sodium fast neutron reactors. The advantage of such microsphere precursor compared to classical oxide powder is the diminution of the risk of fine dissemination which can be critical for the handling of highly radioactive powders such as americium based oxides and the improvement of flowability for the filling of compaction chamber. Those millimetric oxide microspheres incorporating uranium and americium were synthesized and characterizations showed a very porous microstructure very brittle in nature which occurred to be adapted to shaping by compaction. Studies allowed to determine an optimal heat treatment with calcination temperature comprised between 700-800 °C and temperature rate lower than 2 °C/min. Oxide Precursors were die-pressed into pellets and then sintered under air to form regular ceramic pellets of 95% of theoretical density (TD) and of homogeneous microstructure. This study validated thus the scientific feasibility of the CRMP process to prepare bearing americium target in a powder free manner.

  15. Insight into the mechanisms of metal ion binding in hexagonal tungsten bronze

    NASA Astrophysics Data System (ADS)

    Kennedy, Shane; Smith, Suzanne; Avdeev, Maxim; Fuchs, Alex

    2006-03-01

    Tungsten trioxides and their alkali-metal-intercalated products MzWO3+ show potential for application in electrodes, as ion exchangers, catalysts and the treatment of radioactive waste. Hexagonal tungsten bronze (HTB) was selected for the present work because its structure features hexagonal channels, of diameter ˜0.54 nm, that may be useful for selective and reversible binding of metal ions. X-ray and neutron powder diffraction were used to provide an insight into the mechanisms of metal ion binding of the Mo doped HTB's. Combined Rietveld refinement of the X-ray and neutron diffraction shows that doping with Mo degrades the crystallinity of HTB, in particular by creating a high degree of disorder in the a-b planes. Structural information combined with solution chemistry indicates several potential mechanisms of binding and metal ion exchange sites. This type of investigation provides invaluable information for new strategies in the design of inorganic sorbents and their optimization for metal ion separation.

  16. European research activities on charge state breeding related to radioactive ion beam facilities.

    PubMed

    Lamy, T; Angot, J; Thuillier, T

    2008-02-01

    European effort on charge breeders is mainly dedicated to present and future Radioactive Ion Beam facilities. The main projects are High Intensity and Energy-ISOLDE at CERN, SPIRAL2 at GANIL, and EURISOL. Most of the experimental developments are funded by the European programs EURONS (European Nuclear Structure) and EURISOL (European Isotope Separation On-Line Radioactive Ion Beam Facility). Two ion source types (electron beam ion source and electron cyclotron resonance ion source) have been adapted to accept the injection and the capture of an ion beam, in order to increase its charge with the highest efficiency within the shortest time. Both charge breeders have advantages and disadvantages with regard to their use in a Radioactive Ion Beam facility. The most important parameters studied are acceptance (in emittance and intensity) of the charge breeder, efficiency, and charge breeding time of a specific n+ charge state, emittance of the extracted n+ beam. The charge breeder parameters are studied with different 1+ ion sources dedicated to 1+ radioactive ion beam production, and the tuning procedure of the charge breeder as a beam line section of a specific accelerator is established and measured too. PMID:18315164

  17. Source of Metal Ions Based on Penning Discharge

    NASA Astrophysics Data System (ADS)

    Kolodko, D. V.; Mamedov, N. V.; Sinelnikov, D. N.; Khodachenko, G. V.; Kaziev, A. V.; Tumarkin, A. V.; Pisarev, A. A.

    The deposition flux in magnetron discharges comprises two components: neutral particles and ions. In order to study the deposition process in detail, one needs to separate these components. Producing thin films by ion flux only requires development of a special ion source. The source of metal ions with Penning discharge was designed, numerically simulated and assembled. The characteristics of the ion source were determined experimentally.

  18. Recent developments of SOLEROO: Australia's first high energy radioactive Ion Beam capability

    NASA Astrophysics Data System (ADS)

    Carter, I. P.; Dasgupta, M.; Hinde, D. J.; Luong, D. H.; Williams, E.; Ramachandran, K.; Cook, K. J.; Muirhead, A. G.; Marshall, S.; Tunningley, T.

    2015-04-01

    The first measurements of the Australian National University's new radioactive ion beam capability were carried out using elastic scattering of a 8Li radioactive beam from a 197Au target. The purpose of this experiment was to test the radioactive ion beam capability as a complete system, which uses a pair of twin position-sensitive parallel plate avalanche counters as tracking detectors along with a highly pixelated double sided Si detector array. The tracking detector system allows us to have extremely high purity secondary radioactive ion beams by electronically tagging the reaction products of interest, thus allowing complete separation from the unwanted contaminant beam species of similar mass and charge. Here, some recent developments and characteristics of this system are presented.

  19. Ion implantation enhanced metal-Si-metal photodetectors

    SciTech Connect

    Sharma, A.K.; Scott, K.A.M.; Brueck, S.R.J. . Center for High Technology Materials); Zolper, J.C.; Myers, D.R. )

    1994-05-01

    The quantum efficiency and frequency response of simple Ni-Si-Ni metal-semiconductor-metal (MSM) photodetectors at long wavelengths are significantly enhanced with a simple, ion-implantation step to create a highly absorbing region [approximately] 1 [mu]m below the Si surface. The internal quantum efficiency is improved by a factor of [approximately] 3 at 860 nm (to 64%) and a full factor of ten at 1.06 [mu]m (to 23%) as compared with otherwise identical unimplanted devices. Dark currents are only slightly affected by the implantation process and are as low as 630 pA for a 4.5-[mu]m gap device at 10-V bias. Dramatic improvement in the impulse response is observed, 100 ps vs. 600 ps, also at 10-V bias and 4.5-[mu]m gap, due to the elimination of carrier diffusion tails in the implanted devices. Due to its planar structure, this device is fully VLSI compatible. Potential applications include optical interconnections for local area networks and multi-chip modules.

  20. On the onset voltage of liquid metal ion sources

    NASA Astrophysics Data System (ADS)

    Mair, G. L. R.

    1989-09-01

    Various formulae for the onset voltage corresponding to liquid metal ion sources (LMIS) of different design are compared to a wide range of experimental data. Provided the correct formula is used in each particular case, the agreement between theory and experiment is satisfactory. Predicting the source starting voltage correctly is of use in ion source and ion column design.

  1. Development of a lithium liquid metal ion source for MeV ion beam analysis

    SciTech Connect

    Read, P.M.; Maskrey, J.T.; Alton, G.D.

    1988-01-01

    Lithium liquid metal ion sources are an attractive complement to the existing gaseous ion sources that are extensively used for ion beam analysis. This is due in part to the high brightness of the liquid metal ion source and in part to the availability of a lithium ion beam. High brightness is of particular importance to MeV ion microprobes which are now approaching current density limitations on targets determined by the ion source. The availability of a lithium beam provides increased capabilities for hydrogen profiling and high resolution Rutherford backscattering spectrometry. This paper describes the design and performance of a lithium liquid metal ion source suitable for use on a 5MV Laddertron accelerator. Operational experience with the source and some of its uses for ion beam analysis are discussed. 8 refs., 2 figs.

  2. Reusable chelating resins concentrate metal ions from highly dilute solutions

    NASA Technical Reports Server (NTRS)

    Bauman, A. J.; Weetal, H. H.; Weliky, N.

    1966-01-01

    Column chromatographic method uses new metal chelating resins for recovering heavy-metal ions from highly dilute solutions. The absorbed heavy-metal cations may be removed from the chelating resins by acid or base washes. The resins are reusable after the washes are completed.

  3. Alkali metal ion battery with bimetallic electrode

    SciTech Connect

    Boysen, Dane A; Bradwell, David J; Jiang, Kai; Kim, Hojong; Ortiz, Luis A; Sadoway, Donald R; Tomaszowska, Alina A; Wei, Weifeng; Wang, Kangli

    2015-04-07

    Electrochemical cells having molten electrodes having an alkali metal provide receipt and delivery of power by transporting atoms of the alkali metal between electrode environments of disparate chemical potentials through an electrochemical pathway comprising a salt of the alkali metal. The chemical potential of the alkali metal is decreased when combined with one or more non-alkali metals, thus producing a voltage between an electrode comprising the molten the alkali metal and the electrode comprising the combined alkali/non-alkali metals.

  4. Applications of the MEVVA high current metal ion source

    SciTech Connect

    Brown, I.G.

    1986-08-01

    A new kind of ion source has been developed in which a metal vapor vacuum arc (MEVVA) is used to produce the plasma from which the ion beam is extracted. The novel and exciting feature of this source is the very high metal ion beam current attainable. A total ion beam current of over 1 Ampere has been extracted from the embodiment of the concept that we're presently using, and this is not a limit of the method. The source was developed to upgrade the uranium ion beam intensity of the Bevatron, LBL's heavy ion synchrotron, for basic nuclear physics research. Other important applications include its use within the Heavy Ion Fusion research effort; for ion implantation; and for other basic research uses. In this paper the source is described briefly, its performance outlined, and its poential and limitations for a variety of applications is discussed.

  5. Detection of toxic metal ions with near-infrared compounds

    NASA Astrophysics Data System (ADS)

    Casay, Guillermo A.; Czuppon, Tibor; Evans, Lawrence, III; Patonay, Gabor

    1994-10-01

    The determination of toxic metal ions in water using near-infrared compounds synthesized in our laboratories will be reported. Several near-infrared tetrasubstituted chloroaluminum 2,3-naphthalocyanine derivatives with spectral characteristics (absorbance and fluorescence) between 700 nm and 1000 nm have been used in these investigations. In the presence of metal ions the NIR dye's absorbance maximum undergoes a bathochromic shift of about 25 nm accompanied by changes in the fluorescence spectra along with molecular lifetime. The response of the NIR dye in the presence of several concentrations of toxic metal ions will be reported. The fluorescence intensity generated by the complex formed by the metal ion and the dye was monitored by (a) a modified commercially available spectrofluorometer and (b) an NIR instrument developed in our laboratories. The fluorescence intensity changes measured with the probe in the presence of metal ions can be used to construct a calibration curve for the monitoring of contaminants' metal ions in the environment. The effect of metal ions on the lifetime of the NIR dye as compared to the uncomplexed dye will be reported. The NIR instrument consists of a semiconductor laser diode, the NIR dye and a detector. The output wavelength of a 780 nm diode (used as the excitation source) matched the absorbance of these dyes and improved the detection limits of the analytes. Long term stability of the probe was investigated by a week-long period of observation. After one week the intensity varies by only 2%, suggesting suitably for long storage.

  6. Impregnated-electrode-type liquid metal ion source

    SciTech Connect

    Ishikawa, J.; Takagi, T.

    1984-12-01

    An impregnated-electrode-type liquid metal ion source has been developed in which a sintered porous tungsten tip is used. The flow rate of the liquid metal can be controlled by selecting the diameters of the tungsten powders to be sintered (10 and 100 ..mu..m). Since the liquid metal can be stably supplied to the tip head, stable operation in a wide range from low (a few ..mu..A) to high ion current (a few hundred ..mu..A) is possible for various metals such as gallium and gold. Moreover, it is also a potential ion source with liquid metals such as silver with high vapor pressure at the melting point. A new method of holding and directly heating the main component of the ion source by means of knife-edged electrodes with a spring is extremely effective for high temperature operation.

  7. Catalysis using hydrous metal oxide ion exchangers

    DOEpatents

    Dosch, R.G.; Stephens, H.P.; Stohl, F.V.

    1983-07-21

    In a process which is catalyzed by a catalyst comprising an active metal on a carrier, said metal being active as a catalyst for the process, an improvement is provided wherein the catalyst is a hydrous, alkali metal or alkaline earth metal titanate, zirconate, niobate or tantalate wherein alkali or alkaline earth metal cations have been exchanged with a catalytically effective amount of cations of said metal.

  8. Catalysis using hydrous metal oxide ion exchanges

    DOEpatents

    Dosch, Robert G. (Albuquerque, NM); Stephens, Howard P. (Albuquerque, NM); Stohl, Frances V. (Albuquerque, NM)

    1985-01-01

    In a process which is catalyzed by a catalyst comprising an active metal on a carrier, said metal being active as a catalyst for the process, an improvement is provided wherein the catalyst is a hydrous, alkali metal or alkaline earth metal titanate, zirconate, niobate or tantalate wherein alkali or alkaline earth metal cations have been exchanged with a catalytically effective amount of cations of said metal.

  9. Metal ion adsorption at the ionic liquid-mica interface.

    PubMed

    McDonald, Samila; Elbourne, Aaron; Warr, Gregory G; Atkin, Rob

    2015-12-23

    Mica has been employed in many studies of ionic liquid (IL) interfaces on account of its atomic smoothness and well defined surface properties. However, until now it has been unclear whether ions dissolved in ILs can compete with the IL cation and adsorb to mica charge sites. In this work amplitude modulated atomic force microscopy (AM-AFM) has been used to probe metal ion adsorption at the interface of mica with propylammonium nitrate (PAN), a room temperature IL. Lithium, sodium, potassium, magnesium and calcium nitrate salts were added to PAN at a concentration of ?60 mM. Aluminum nitrate was also investigated, but only at 5 mM because its solubility in PAN is much lower. The AM-AFM images obtained when the metal ions were present are strikingly different to that of pure PAN, indicating that the ions compete effectively with the propylammonium cation and adsorb to negatively charged sites on the mica surface despite their much lower concentration. This is a consequence of electrostatic attractions between the mica charge sites and the metal ions being significantly stronger than for the propylammonium cation; compared to the metal ions the propylammonium charged group is relatively constrained sterically. A distinct honeycomb pattern is noted for the PAN + Al(3+) system, less obviously for the divalent ions and not at all for monovalent ions. This difference is attributed to the strength of electrostatic interactions between metal ions and mica charge sites increasing with the ion charge, which means that divalent and (particularly) trivalent ions are located more precisely above the charged sites of the mica lattice. The images obtained allow important distinctions between metal ion adsorption at mica-water and mica-PAN interfaces to be made. PMID:26661934

  10. Progress in metal ion separation and preconcentration : an overview.

    SciTech Connect

    Bond, A. H.

    1998-05-19

    A brief historical perspective covering the most mature chemically-based metal ion separation methods is presented, as is a summary of the recommendations made in the 1987 National Research Council (NRC) report entitled ''Separation and Purification: Critical Needs and Opportunities''. A review of Progress in Metal Ion Separation and Preconcentration shows that advances are occurring in each area of need cited by the NRC. Following an explanation of the objectives and general organization of this book, the contents of each chapter are briefly summarized and some future research opportunities in metal ion separations are presented.

  11. Separation of platinum group metal ions by Donnan dialysis

    SciTech Connect

    Brajter, K.; Slonawska, K.; Cox, J.A.

    1985-10-01

    Separations of metal ions on the basis of Donnan dialysis across anion-exchange membranes should be possible if the receiver electrolyte composition favors the formation of selected anionic complexes of the sample metal ions. Moreover, such a separation has the possibility of being better suited from some applications than batch or column experiments with anion-exchange resins. The above hypothesis are tested on the platinum-group metal ions, Pt(IV), Rh(III), Pd(II), Ir(III), and Ir(IV). 13 references, 4 tables.

  12. An Animal Model Using Metallic Ions to Produce Autoimmune Nephritis

    PubMed Central

    Ramírez-Sandoval, Roxana; Luévano-Rodríguez, Nayeli; Rodríguez-Rodríguez, Mayra; Pérez-Pérez, María Elena; Saldívar-Elias, Sergio; Gurrola-Carlos, Reinaldo; Avalos-Díaz, Esperanza; Bollain-y-Goytia, Juan José

    2015-01-01

    Autoimmune nephritis triggered by metallic ions was assessed in a Long-Evans rat model. The parameters evaluated included antinuclear autoantibody production, kidney damage mediated by immune complexes detected by immunofluorescence, and renal function tested by retention of nitrogen waste products and proteinuria. To accomplish our goal, the animals were treated with the following ionic metals: HgCl2, CuSO4, AgNO3, and Pb(NO3)2. A group without ionic metals was used as the control. The results of the present investigation demonstrated that metallic ions triggered antinuclear antibody production in 60% of animals, some of them with anti-DNA specificity. Furthermore, all animals treated with heavy metals developed toxic glomerulonephritis with immune complex deposition along the mesangium and membranes. These phenomena were accompanied by proteinuria and increased concentrations of urea. Based on these results, we conclude that metallic ions may induce experimental autoimmune nephritis. PMID:26064998

  13. Incorporation of impurity metal ions in electrolytic manganese dioxide

    SciTech Connect

    Tamura, Hiroki; Ishizeki, Kenji; Nagayama, Masaichi; Furuichi, Ryusaburo . Faculty of Engineering)

    1994-08-01

    The amounts of impurity metal ions incorporated into electrolytic manganese dioxide (EMD) during its preparation were measured as a function of metal ion concentration and current densities. The amount of incorporated ions increased in proportion to the concentration in solution, and at a fixed concentration it was different from ion to ion: Ni[sup 2+] < Zn[sup 2+] < Co[sup 2+] < Cu[sup 2+] < Fe[sup 2+] < Pb[sup 2+]. The specific surface area of the formed EMD was larger for impurity ions with higher incorporation affinity. Further, the adsorption of ions on the surface of a ready-made manganese dioxide sample (ICI2) was examined, and modeling of the adsorption behavior was attempted. The amounts of adsorbed ions at a fixed concentration in solution and pH 0.7 (where EMD is produced) were obtained by the ion-adsorption model. There was a strong correlation between the amount incorporated and the amount of adsorption, suggesting a mechanism in which EMD is contaminated through adsorption on its new growing surface. The increase in specific surface area of EMD with contaminants was interpreted to be due to a suppression of the growth of EMD at the adsorbed foreign ion sites, resulting in EMD with many defects or smaller particle sizes. The opposite effect of current density on incorporation for the two groups of metal ions was discussed.

  14. Metal ion acquisition in Staphylococcus aureus: overcoming nutritional immunity

    PubMed Central

    Cassat, James E.

    2013-01-01

    Transition metals are essential nutrients to virtually all forms of life, including bacterial pathogens. In Staphylococcus aureus, metal ions participate in diverse biochemical processes such as metabolism, DNA synthesis, regulation of virulence factors, and defense against oxidative stress. As an innate immune response to bacterial infection, vertebrate hosts sequester transition metals in a process that has been termed “nutritional immunity.” To successfully infect vertebrates, S. aureus must overcome host sequestration of these critical nutrients. The objective of this review is to outline the current knowledge of staphylococcal metal ion acquisition systems, as well as to define the host mechanisms of nutritional immunity during staphylococcal infection. PMID:22048835

  15. Proceedings of the workshop on prospects for research with radioactive beams from heavy ion accelerators

    SciTech Connect

    Nitschke, J.M.

    1984-04-01

    The SuperHILAC Users Executive Committee organized a workshop on Prospects for Research with Radioactive Beams from Heavy Ion Accelerators. The main purpose of the workshop was to bring together a diverse group of scientists who had already done experients with radioactive beams or were interested in their use in the future. The topics of the talks ranged from general nuclear physics, astrophysics, production of radioactive beams and high energy projectile fragmentation to biomedical applications. This publication contains the abstracts of the talks given at the workshop and copies of the viewgraphs as they were supplied to the editor.

  16. Probing the Role of Metal Ions in RNA Catalysis: Kinetic and Thermodynamic Characterization of a Metal Ion Interaction with the 2-Moiety of the Guanosine

    E-print Network

    Herschlag, Dan

    Probing the Role of Metal Ions in RNA Catalysis: Kinetic and Thermodynamic Characterization of a Metal Ion Interaction with the 2-Moiety of the Guanosine Nucleophile in the Tetrahymena Group I Ribozyme: Deciphering the role of individual metal ions in RNA catalysis is a tremendous challenge, as numerous metal

  17. Ion-exchange material and method of storing radioactive wastes

    DOEpatents

    Komarneni, S.; Roy, D.M.

    1983-10-31

    A new cation exchanger is a modified tobermorite containing aluminum isomorphously substituted for silicon and containing sodium or potassium. The exchanger is selective for lead, rubidium, cobalt, and cadmium and is selective for cesium over calcium or sodium. The tobermorites are compatible with cement and are useful for the long-term fixation and storage of radioactive nuclear wastes.

  18. Industrial Application of Radioactive Ion Beams at the RIKEN RI Beam Factory

    SciTech Connect

    Kambara, Tadashi; Yoshida, Atsushi; Yanagisawa, Yoshiyuki; Kameda, Daisuke; Fukuda, Naoki; Ohnishi, Tetsuya; Kubo, Toshiyuki; Uemoto, Ryuji; Nagano, Akira; Uno, Hiroyuki

    2011-12-13

    The Radioactive Ion Beam Factory (RIBF) at RIKEN is a heavy-ion accelerator facility that can provide intensive beams of radioactive isotopes (RI beam) produced at in-flight RI-beam separators. While the facility is used for experiments of various basic research fields, a new project has been started to open the facility to non-academic proposals from industry. We show an overview of the RIBF and the project of industrial use, and present a utilization of an RI-beam for development of wear diagnostics of industrial materials.

  19. Extracting metal ions with diphosphonic acid, or derivative thereof

    DOEpatents

    Horwitz, Earl P. (Argonne, IL); Gatrone, Ralph C. (Argonne, IL); Nash, Kenneth L. (Argonne, IL)

    1994-01-01

    Thermodynamically-unstable complexing agents which are diphosphonic acids and diphosphonic acid derivatives (or sulphur containing analogs), like carboxyhydroxymethanediphosphonic acid and vinylidene-1,1-diphosphonic acid, are capable of complexing with metal ions, and especially metal ions in the II, III, IV, V and VI oxidation states, to form stable, water-soluble metal ion complexes in moderately alkaline to highly-acidic media. However, the complexing agents can be decomposed, under mild conditions, into non-organic compounds which, for many purposes are environmentally-nondamaging compounds thereby degrading the complex and releasing the metal ion for disposal or recovery. Uses for such complexing agents as well as methods for their manufacture are also described.

  20. Extracting metal ions with diphosphonic acid, or derivative thereof

    DOEpatents

    Horwitz, E.P.; Gatrone, R.C.; Nash, K.L.

    1994-07-26

    Thermodynamically-unstable complexing agents which are diphosphonic acids and diphosphonic acid derivatives (or sulfur containing analogs), like carboxyhydroxymethanediphosphonic acid and vinylidene-1,1-diphosphonic acid, are capable of complexing with metal ions, and especially metal ions in the II, III, IV, V and VI oxidation states, to form stable, water-soluble metal ion complexes in moderately alkaline to highly-acidic media. However, the complexing agents can be decomposed, under mild conditions, into non-organic compounds which, for many purposes are environmentally-nondamaging compounds thereby degrading the complex and releasing the metal ion for disposal or recovery. Uses for such complexing agents as well as methods for their manufacture are also described. 1 fig.

  1. Predicting the relative toxicity of metal ions using ion characteristics: Microtox{reg_sign} bioluminescence assay

    SciTech Connect

    McCloskey, J.T.; Newman, M.C.; Clark, S.B.

    1996-10-01

    Quantitative structure-activity relationships have been used to predict the relative toxicity of organic compounds. Although not as common, ion characteristics have also proven useful for predicting the relative toxicity of metal ions. The purpose of this study was to determine if the relative toxicity of metal ions using the Microtox{reg_sign} bioassay was predictable using ion characteristics. Median effect concentrations (EC50s) were determined for 20 metals in a NaNO{sub 3} medium, which reflected freshwater speciation conditions, using the Microtox bacterial assay. The log of EC50 values was modeled using several ion characteristics, and Akaike`s Information Criterion was calculated to determine which ion characteristics provided the best fit. Whether modeling total ion or free ion EC50 values, the one variable which best modeled EC50s was the softness index, while a combination of {chi}{sub m}{sup 2}r ({chi}{sub m} = electronegativity, r = Pauling ionic radius) and {vert_bar}log K{sub OH}{vert_bar} was the best two-variable model. Other variables, including {Delta}E{sub 0} and {chi}{sub m}{sup 2}r (one-variable models) and (AN/{Delta}IP, {Delta}E{sub 0}) and ({chi}{sub m}{sup 2}r, Z{sup 2}/r) (two-variable models), also gave adequate fits. Modeling with speciated (free ion) versus unspeciated (total ion) EC50 values did not improve fits. Modeling mono-, di-, and trivalent metal ions separately improved the models. The authors conclude that ion characteristics can be used to predict the relative toxicity of metal ions whether in freshwater (NaNO{sub 3} medium) or saltwater (NaCl medium) speciation conditions and that this approach can be applied to metal ions varying widely in both valence and binding tendencies.

  2. Smart textile device using ion polymer metal compound.

    PubMed

    Nakamura, Taro; Ihara, Tadashi

    2013-01-01

    We have developed a smart textile device that detects angular displacement of attached surface using ion polymer metal compound. The device was composed of ion polymer metal compound (IPMC) which was fabricated from Nafion resin by heat-press and chemical gold plating. The generated voltage from IPMC was measured as a function of bending angle. Fabricated IPMC device was weaved into a cotton cloth and multidirectional movements were detected. PMID:24109750

  3. Multiple roles of metal ions in large ribozymes.

    PubMed

    Donghi, Daniela; Schnabl, Joachim

    2011-01-01

    Since the discovery of catalytic RNA molecules (ribozymes), intense research has been devoted to understand their structure and activity. Among RNA molecules, the large ribozymes, namely group I and group II introns and RNase P, are of special importance. The first two ribozymes are known for their ability to perform self-splicing while RNase P is responsible for the 5'-end maturation of tRNA in bacteria, archea, and eukaryotes. All three groups of ribozymes show a significant requirement for metal ions in order to establish the active tertiary structure that enables catalysis. The primary role of both monovalent and divalent metal ions is to screen the negative charge associated with the phosphate sugar backbone, but the metal ions also play an active role in catalysis. Biochemical and biophysical investigations, supported by recent findings from X-ray crystal structures, allow clarifying and rationalizing both the structural and catalytic roles of metal ions in large ribozymes. In particular, the "two-metal-ion mechanism", describing how metal ions in the active center take part in catalysis, has been largely corroborated. PMID:22010273

  4. Detection of Metallic Compounds in Rocket Plumes Using Ion Probes

    NASA Technical Reports Server (NTRS)

    Dunn, Robert W.

    1998-01-01

    This grant experimentally verified that ion probes can consistently detect metallic compounds in a hybrid rocket plume. Two electrostatic detection methods were tested. The first method used an unbiased ion probe. It responded to collisions or near collisions with charged particulates. The amplitude of the response to metallic ions always exceeded that of the combustion products. The second device was a cylindrical Gaussian surface that surrounded, but did not touch, the plume. A charge imbalance in the plume induced a current in cylinder that was detected by a sensitive amplifier. The probe was more sensitive to metallic compounds than the cylinder. However, the Gaussian cylinder demonstrated sufficient sensitivity to warrant serious future consideration. Since the cylinder is nonintrusive, it is particularly attractive. Apparently, ions formed during combustion transfer to the metallic impurities. The formation of these metallic ions slows the ion recombination rate and helps preserve charges in the plume. The electrostatic detectors, in turn, respond to the charges carried by the metallic impurities.

  5. MODELING AN ION EXCHANGE PROCESS FOR CESIUM REMOVAL FROM ALKALINE RADIOACTIVE WASTE SOLUTIONS

    SciTech Connect

    Smith, F; Luther Hamm, L; Sebastian Aleman, S; Johnston Michael, J

    2008-08-26

    The performance of spherical Resorcinol-Formaldehyde ion-exchange resin for the removal of cesium from alkaline radioactive waste solutions has been investigated through computer modeling. Cesium adsorption isotherms were obtained by fitting experimental data using a thermodynamic framework. Results show that ion-exchange is an efficient method for cesium removal from highly alkaline radioactive waste solutions. On average, two 1300 liter columns operating in series are able to treat 690,000 liters of waste with an initial cesium concentration of 0.09 mM in 11 days achieving a decontamination factor of over 50,000. The study also tested the sensitivity of ion-exchange column performance to variations in flow rate, temperature and column dimensions. Modeling results can be used to optimize design of the ion exchange system.

  6. Quantum ion-acoustic wave oscillations in metallic nanowires

    SciTech Connect

    Moradi, Afshin

    2015-05-15

    The low-frequency electrostatic waves in metallic nanowires are studied using the quantum hydrodynamic model, in which the electron and ion components of the system are regarded as a two-species quantum plasma system. The Poisson equation as well as appropriate quantum boundary conditions give the analytical expressions of dispersion relations of the surface and bulk quantum ion-acoustic wave oscillations.

  7. Structural Metals in the Group I Intron: A Ribozyme with a Multiple Metal Ion Core

    SciTech Connect

    Stahley,M.; Adams, P.; Wang, J.; Strobel, S.

    2007-01-01

    Metal ions play key roles in the folding and function for many structured RNAs, including group I introns. We determined the X-ray crystal structure of the Azoarcus bacterial group I intron in complex with its 5' and 3' exons. In addition to 222 nucleotides of RNA, the model includes 18 Mg2+ and K+ ions. Five of the metals bind within 12 Angstroms of the scissile phosphate and coordinate the majority of the oxygen atoms biochemically implicated in conserved metal-RNA interactions. The metals are buried deep within the structure and form a multiple metal ion core that is critical to group I intron structure and function. Eight metal ions bind in other conserved regions of the intron structure, and the remaining five interact with peripheral structural elements. Each of the 18 metals mediates tertiary interactions, facilitates local bends in the sugar-phosphate backbone or binds in the major groove of helices. The group I intron has a rich history of biochemical efforts aimed to identify RNA-metal ion interactions. The structural data are correlated to the biochemical results to further understand the role of metal ions in group I intron structure and function.

  8. Detection of Heavy Metal Ions Based on Quantum Point Contacts

    E-print Network

    Tao, Nongjian

    quantum phenomena begin to emerge, which offer not only exciting opportunities to study fundamental chem on many living organisms and the consequence of heavy metal ions not being biodegradable. To date, heavy because they provide an early detection of trace metal contaminants while minimizing errors, labor

  9. Michigan state upgrade to produce intense radioactive ion beams by fragmentation technique

    SciTech Connect

    Lubkin, G.B.

    1997-05-01

    This article describes the planned upgrading of accelerator facilities to produce intense radioactive ion beams, by a fragmentation technique, for experimental simulation of nucleosynthesis in novas and supernovas. (AIP) {ital 1997 American Institute of Physics.} {copyright} {ital 1997} {ital American Institute of Physics}

  10. Effect of Metal Ions on Melanin – Local Anaesthetic Drug Complexes

    PubMed Central

    Buszman, Ewa; Betlej, Bo?ena; Wrze?niok, Dorota; Radwa?ska-Wala, Bo?ena

    2003-01-01

    The affinity of melanin biopolymers for metal ions, drugs and other organic compounds is an important factor in the etiology of toxic retinopathy, hiperpigmentation, otic lesions and irreversible extrapyramidal disorders. The aim of the presented work was to examine the interaction of local anaesthetic drugs used in ophthalmology with model DOPA-melanin in the presence of metal ions. It has been demonstrated that the analyzed drugs form complexes with melanin biopolymer. Based on the .values of association constants,, the following order of drugs affinity to melanin was found: tetracaine > procaine >> bupivacaine > lidocaine. It has also been shown that Cu2+ and Zn2+ ions administered to DOPA-melanin before complexing with drugs decrease the total amount of local anaesthetics bound to melanin. The blocking of some active centers in melanin molecules by metal ions, which potentially exist in living systems, may change the clinical therapeutic efficiency of the analyzed local anaesthetic drugs. PMID:18365047

  11. Behavior of actinide ions during sludge washing of alkaline radioactive.

    SciTech Connect

    Bond, A. H.; Nash, K. L.; Gelis, A. V.; Jensen, M. P.; Sullivan, J. C.; Rao, L.

    1999-11-15

    It is difficult to accurately predict actinide behavior during the alkaline leaching of Hanford's radioactive sludges due to the diverse chemical and radiolytic conditions existing in these wastes. The results of Pu dissolution during experimental washing of sludge simulants from the BiPO{sub 4} Redox, and PUREX processes shows that {le} 2.l% Pu is dissolved during contact with alkaline media, but up to 65.5% Pu may be dissolved in acidic media. The dissolution of Cr, Fe, Nd, and Mn has also been observed, and the results of solid state, radioanalytical, and spectroscopic investigations are detailed.

  12. Production and Applications of Metal-cluster-complex Ion Beams

    NASA Astrophysics Data System (ADS)

    Fujiwara, Yukio; Kondou, Kouji; Teranishi, Yoshikazu; Watanabe, Kouji; Nonaka, Hidehiko; Saito, Naoaki; Itoh, Hiroshi; Fujimoto, Toshiyuki; Kurokawa, Akira; Ichimura, Shingo; Tomita, Mitsuhiro

    A new ion source using massive molecules called metal cluster complexes has been developed. Metal cluster complexes are chemically-synthesized organometallic compounds, which have a wide range of chemical compositions with high molecular weight. The ion source is compact enough to be installed in commonly used secondary ion mass spectrometry (SIMS) systems. Using the ion source, sputtering characteristics of silicon bombarded with normally incident Ir4(CO)7+ ions were investigated. Experimental results showed that the sputtering yield at 10 keV was 36, which is higher than that with Ar+ ions by a factor of 24. In addition, SIMS analyses of boron-delta-doped silicon samples and organic films of poly(methyl methacrylate) (PMMA) were performed. Compared with conventional O2+ ion beams, Ir4(CO)7+ ion beams improved depth resolution by a factor of 2.5 at the same irradiation conditions; the highest depth resolution of 0.9 nm was obtained at 5 keV, 45° with oxygen flooding of 1.3×10-4 Pa. Furthermore, experimental results confirmed that Ir4(CO)7+ ion beams significantly enhanced secondary ion intensity in high-mass region.

  13. A vacuum spark ion source: High charge state metal ion beams

    NASA Astrophysics Data System (ADS)

    Yushkov, G. Yu.; Nikolaev, A. G.; Oks, E. M.; Frolova, V. P.

    2016-02-01

    High ion charge state is often important in ion beam physics, among other reasons for the very practical purpose that it leads to proportionately higher ion beam energy for fixed accelerating voltage. The ion charge state of metal ion beams can be increased by replacing a vacuum arc ion source by a vacuum spark ion source. Since the voltage between anode and cathode remains high in a spark discharge compared to the vacuum arc, higher metal ion charge states are generated which can then be extracted as an ion beam. The use of a spark of pulse duration less than 10 ?s and with current up to 10 kA allows the production of ion beams with current of several amperes at a pulse repetition rate of up to 5 pps. We have demonstrated the formation of high charge state heavy ions (bismuth) of up to 15 + and a mean ion charge state of more than 10 +. The physics and techniques of our vacuum spark ion source are described.

  14. Titanates deliver metal ions to human monocytes.

    PubMed

    Wataha, John C; Hobbs, David T; Wong, Jacqueline J; Dogan, Sami; Zhang, Hai; Chung, K-H; Elvington, Mark C

    2010-04-01

    Amorphous peroxotitantes (APT) are insoluble titanium-based particles that bind a variety of metal compounds with high affinity; these particles could be sequestered locally in a solid phase to deliver metal-based drugs. Previous studies have confirmed the 'biodelivery' of metals from metal-APT complexes to fibroblasts, but not monocytes. Our goal in the current study was to use monocytic cytokine secretion to assess delivery of gold or platinum-based compounds from APT to human THP1 monocytes. Cytokine secretion was not triggered by APT alone or metal-APT complexes. In monocytes activated by lipopolysaccharide (LPS), APT alone enhanced or suppressed IL1beta or IL6 secretion, yet TNFalpha secretion was unaffected. Complexes of APT and Au(III) or cis-platin altered LPS-activated IL6 or IL1beta secretion most, TNFalpha least. Our results suggest that the APT deliver metals to monocytes. PMID:19941042

  15. Removal of metal ions from aqueous solution

    DOEpatents

    Jackson, Paul J. (Los Alamos, NM); Delhaize, Emmanuel (Los Alamos, NM); Robinson, Nigel J. (Durham, GB2); Unkefer, Clifford J. (Los Alamos, NM); Furlong, Clement (Seattle, WA)

    1990-01-01

    A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly (.gamma.-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly (.gamma.-glutamylcysteinyl)glycines having a particular number of monomer repeat units for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form.

  16. Removal of metal ions from aqueous solution

    DOEpatents

    Jackson, Paul J. (both Los Alamos, NM); Delhaize, Emmanuel (both Los Alamos, NM); Robinson, Nigel J. (Durham, GB2); Unkefer, Clifford J. (Los Alamos, NM); Furlong, Clement (Seattle, WA)

    1990-11-13

    A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly (.gamma.-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly (.gamma.-glutamylcysteinyl)glycines having a particular number of monomer repeat unit for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heayv metals from solution. This also results in the removal of the metals from the column in a concentrated form.

  17. RATIONAL DESIGN OF METAL ION SEQUESTERING AGENTS

    EPA Science Inventory

    An enormous amount of radioactive and toxic chemical waste remains at over one hundred sites managed by the Department of Energy. Despite the investment of large sums, major goals associated with the cleanup remain unmet. It is our thesis that economically practical accomplishmen...

  18. Process for modifying the metal ion sorption capacity of a medium

    DOEpatents

    Lundquist, Susan H. (White Bear Township, MN)

    2002-01-01

    A process for modifying a medium is disclosed that includes treating a medium having a metal ion sorption capacity with a solution that includes: A) an agent capable of forming a complex with metal ions; and B) ions selected from the group consisting of sodium ions, potassium ions, magnesium ions, and combinations thereof, to create a medium having an increased capacity to sorb metal ions relative to the untreated medium.

  19. Does Ion Release Differ Between Hip Resurfacing and Metal-on-metal THA?

    PubMed Central

    Moroni, Antonio; Cadossi, Matteo; Baldini, Nicola; Giannini, Sandro

    2008-01-01

    Modern metal-on-metal hip resurfacing was introduced as a bone-preserving method of joint reconstruction for young and active patients; however, the large diameter of the bearing surfaces is of concern for potential increased metal ion release. We hypothesized there were no differences in serum concentrations of chromium, cobalt, and molybdenum between patients who had metal-on-metal hip resurfacing (Group A; average head diameter, 48 mm; median followup, 24 months) and patients who had 28-mm metal-on-metal THA (Group B; median followup, 25 months). Serum concentrations also were compared with concentrations in healthy subjects. We identified no differences in ion levels between Groups A and B. A distinction was made according to gender. Women showed a higher chromium release in Group A whereas men had a higher cobalt release in Group B. Values obtained from Group A were higher than those of the control subjects. Our data suggest metal-on-metal bearings for THA should not be rejected because of concern regarding potential increased metal ion release; however, patients with elevated ion levels, even without loosening or toxicity, could be at higher risk and should be followed up periodically. Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18196364

  20. Thin layer activation-based evaluation of tribological behaviour of light ion-implanted metallic samples

    NASA Astrophysics Data System (ADS)

    Racolta, P. M.; Popa-Simil, L.; Alexandreanu, B.; Mateescu, L.

    1997-05-01

    In our Cyclotron Laboratory wear and/or corrosion studies of metallic machine parts are performed on a routine basis by using the Charged Particle Surface Activation method, also commonly known as the Thin Layer Activation (TLA) technique. In principle, this method consists of an ion beam irradiation of the surface of interest (typically using proton and deuteron beams), followed by in-situ radioactivity monitoring, on a testing bench or in normal running conditions. The observed changes in radioactivity are then transformed in mass losses, by using a specific calibration procedure. In spite of the high reliability of the method, which allows fast and accurate determinations under real operating conditions, the issue of possible influence of ion bombardment upon the tribologic properties of irradiated components had yet to be clarified. To do that, a dedicated set-up was designed so as to ensure a simultaneous irradiation of the disk-shaped samples at various incident beam energies and doses. Since the expected structural modifications were associated not only to ion-induced damages, but also to the local heating, we tried to outline the contribution of each of the two above-mentioned effects. Consequently, the microstructure effects have been investigated by both electronic and metallography microscopy. The Vickers micro-hardness test has been taken before and after irradiation of each sample. Two main outcomes can be reported: the use of radioactive labelling for wear and corrosion control using MeV beams with doses below 10 17 ions/cm 2 of light particles such as protons and deuterons does not lead to significant changes of the tribologic properties of the studied machine part; and besides, wear diagrams (wear levels vs. running time) for Carbon Steel Alloy (OL-45 in Romanian standard, 0.45% carbon) and {Cu63}/{Zn37} brass irradiated at different doses (10 17 - 10 18 ions/cm 2) have been obtained.

  1. Structural modifications in biosynthetic melanins induced by metal ions.

    PubMed

    Palumbo, A; d'Ischia, M; Misuraca, G; Prota, G; Schultz, T M

    1988-02-17

    A number of transition metal ions with a wide distribution in biological systems, e.g., Cu2+, Co2+ and Zn2+, are shown to affect markedly the chemical properties of melanins formed by the tyrosinase-catalysed oxidation of dopa. Acid decarboxylation and permanganate degradation provide evidence that melanins prepared in the presence of metal ions contain a high content of carboxyl groups arising from the incorporation of 5,6-dihydroxyindole-2-carboxylic acid (DICA) into the pigment polymer. Naturally occurring melanins from cephalopod ink and B16 mouse melanoma were found to be much more similar to melanins prepared in the presence of metal ions than to standard melanins prepared in the absence of metal ions. These results suggest that the presence of carboxylated indole units in natural melanins is probably due to the intervention in the biochemical pathway of metal ions which, as recently shown, catalyse the formation of DICA versus 5,6-dihydroxyindole in the rearrangement of dopachrome. PMID:3124888

  2. Precision mass measurements at TITAN with radioactive ions

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, A. A.; Macdonald, T. D.; Andreoiu, C.; Bale, J. C.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Ettenauer, S.; Gallant, A. T.; Grossheim, A.; Lennarz, A.; Mané, E.; Pearson, M. R.; Schultz, B. E.; Simon, M. C.; Simon, V. V.; Dilling, J.

    2013-12-01

    Measurements of the atomic mass further our understanding in many disciplines from metrology to physics beyond the standard model. The accuracy and precision of Penning trap mass spectrometry have been well demonstrated at TITAN, including measurements of neutron-rich calcium and potassium isotopes to investigate three-body forces in nuclear structure and within the island of inversion to study the mechanism of shell quenching and deformation. By charge breeding ions, TITAN has enhanced the precision of the measurement technique. The precision achieved in the measurement of the superallowed ?-emitter 74Rb in the 8+ charge state rivaled earlier measurements with singly charged ions in a fraction of the time. By breeding 78Rb to the same charge state, the ground state could be easily distinguished from the isomer. Further developments led to threshold charge breeding, which permitted capturing and measuring isobarically and elementally pure ion samples in the Penning trap. This was demonstrated via the Q-value determination of 71Ge. An overview of the TITAN facility and recent results are presented herein.

  3. Metal ion binding and the folding of the hairpin ribozyme.

    PubMed Central

    Wilson, Timothy J; Lilley, David M J

    2002-01-01

    The hairpin ribozyme comprises two formally unpaired loops carried on two arms of a four-way helical RNA junction. Addition of divalent metal ions brings about a conformational transition into an antiparallel structure in which there is an intimate association between the loops to generate the active form of the ribozyme. In this study, we have used fluorescence resonance energy transfer to analyze the global folding of the complete ribozyme, and the simple four-way junction derived from it, over a wide concentration range of divalent and monovalent metal ions. The simple junction undergoes an ion-induced rotation into an antiparallel form. In the presence of a constant background concentration of sodium ions, the magnesium-ion-induced transition is characterized by noncooperative binding with a Hill coefficient n = 1. By contrast, the magnesium-ion-induced folding of the complete ribozyme is more complex, involving two distinct binding phases. The first phase occurs in the micromolar range, and involves the cooperative binding of at least three magnesium ions. This can also be achieved by high concentrations of sodium ions, and is therefore likely to be due to diffuse binding of cations at the junction and the interface of the loop-loop interaction. The second phase occurs in the millimolar range, and can only be induced by divalent metal ions. This transition occurs in response to the noncooperative, site-specific binding of magnesium ions. We observe a good correlation between the extent of ion-induced folding and cleavage activity. PMID:12022226

  4. Development of boron and phosphorus liquid metal ion sources for the focused ion beam system

    SciTech Connect

    Higuchi-Rusli, R.

    1986-01-01

    The approach taken here was to develop and build dual carbon filament liquid metal ion sources along with the test bed system. Pd/sub 73/B/sub 27/ and Pt/sub 58/B/sub 42/ binary alloys were selected as p-type dopant sources, and Cu/sub 3/P binary alloy was used as n-type dopant source. Three emitters with different tip radii were used in the present investigation. The results indicate that Pd/sub 73/B/sub 27/ alloy is a good candidate for a boron liquid metal ion source. This conclusion was derived in this investigation from a lifetime test result with 2.5 ..mu..m emitter of more than 120 hours. Pt/sub 58/B/sub 42/ alloy is not a suitable alloy source for a boron liquid metal ion source despite the higher mole fraction of boron to be used as a source of ionizing species. Cu/sub 3/P alloy is a good candidate for a phosphorus liquid metal ion source. Any apparent chemical interactions were found by metallographic technique, although AES result shows emitter element in the spectrum of collected beam current. A combination of rhenium and graphite ribbon as liquid metal ion source emitter and heater used in this investigation is the only possible approach to produce a long lifetime boron and phosphorus liquid metal ion source.

  5. Ion Irradiation-induced nano-crystallization metallic glasses (amorphous metal

    E-print Network

    Tran, Minh Hong

    2013-02-28

    This project idea is proposed in order to develop the understanding of the mechanisms responsible for Nano-crystal phase formation when metallic glasses (amorphous) is exposed under the high energy ion irradiation and is quantified the resulting...

  6. New type of metal ion source: Surface diffusion Li{sup +} ion source

    SciTech Connect

    Medvedev, V.K.; Suchorski, Y.; Block, J.H.

    1995-03-01

    A surface diffusion metal ion source, a new type of metal ion source, is explored. In this device a field desorption process is used to achieve an almost monoenergetic continuous flux of Li{sup +} ions from a [111]-oriented W field emitter. Earlier difficulties with the continuous supply of adatoms, required to produce measurable desorption rates, were overcome by making use of solid state surface diffusion from the Li multilayer reservoir at the shank of the field emitter. The high density of the ion beam (an ion current of 10{sup {minus}12} A was achieved from a W trimer), the extremely narrow energy distribution (full width at half-maximum of 0.25 eV) and the stable geometric form of the emitter itself during the operation are advantages of the new ion source which may be important in different areas of nanotechnology. {copyright} {ital 1995} {ital American} {ital Vacuum} {ital Society}

  7. Membrane Interactions and Metal Ion Effects on Bilayer Permeation of the Lipophilic Ion Modulator DP-109

    E-print Network

    Jelinek, Raz

    are ascribed to interactions of the tested compounds with the phospholipid bilayers (11, 13-15). The colorMembrane Interactions and Metal Ion Effects on Bilayer Permeation of the Lipophilic Ion Modulator describe the application of a colorimetric phospholipid/ polydiacetylene (PDA) biomimetic membrane assay

  8. A New Droplet Breakup Model for Dimer Ion Formation from a Gallium Liquid Metal Ion Source

    NASA Astrophysics Data System (ADS)

    Hornsey, Richard; Ishitani, Tohru

    1990-06-01

    It is demonstrated that energy distribution curves for Ga2+ found in the literature are inconsistent with existing models of cluster ion formation in liquid metal ion sources (LMIS). A new model for the rapid breakup of metastable droplets away from the emitting area is proposed to explain gallium dimer ion formation. Simple calculations are performed to establish the feasibility of this mechanism, and the practical application of this model is discussed in detail.

  9. Metal ion levels and revision rates in metal-on-metal hip resurfacing arthroplasty: a comparative study.

    PubMed

    Robinson, Patrick G; Wilkinson, Andrew J; Meek, Robert M D

    2014-01-01

    Metal-on-metal (MoM) bearings in hip surgery are related to increased blood levels of metal ions. The nature of the relationship between ion levels and failure is still not fully understood. This study compares three cohorts of patients, 120 patients in each cohort, treated with a hip resurfacing arthroplasty, grouped by brand and diameter of femoral component on average four years postoperatively: Birmingham Hip Resurfacing ?50 mm, Durom resurfacing ?50 mm and Durom resurfacing <50 mm. The median blood ion levels of cobalt and chromium were significantly lower in the cohort with the large Durom resurfacing than the other two cohorts (P<0.05). The large BHR and large Durom HRA had revision rates of 3.3%. The small Durom HRA had a revision rate of 8.3%. Elevated blood ion levels can indicate a failing MoM bearing. The large BHR and large Durom HRA have similar revision rates yet the large Durom HRA had significantly lower metal ion levels. When similar ion levels were reported for BHR and small Durom the latter had significantly higher revision rates. This suggests ion levels do not absolutely predict the rate of HRA failure. Since MoM generation of metal ions is not the sole reason of failure, regular clinical and radiographic follow-up should also be in place for patients with these joints. PMID:24500833

  10. Metal plasma immersion ion implantation and deposition: A review

    SciTech Connect

    Anders, A.

    1996-09-01

    Metal Plasma Immersion Ion Implantation and Deposition (MePIIID) is a hybrid process combining cathodic arc deposition and plasma immersion ion implantation. The properties of metal plasma produced by vacuum arcs are reviewed and the consequences for MePIIID are discussed. Different version of MePIIID are described and compared with traditional methods of surface modification such as ion beam assisted deposition (IBAD). MePIIID is a very versatile approach because of the wide range of ion species and energies used. In one extreme case, films are deposited with ions in the energy range 20--50 eV, and at the other extreme, ions can be implanted with high energy (100 keV or more) without film deposition. Novel features of the technique include the use of improved macroparticle filters; the implementation of several plasma sources for multi-element surface modification; tuning of ion energy during implantation and deposition to tailor the substrate-film intermixed layer and structure of the growing film; simultaneous pulsing of the plasma potential (positive) and substrate bias (negative) with a modified Marx generator; and the use of high ion charge states.

  11. Beam dynamics of a liquid-metal ion source

    NASA Astrophysics Data System (ADS)

    Whealton, J. H.; Meszaros, P. S.; Rothe, K. E.; Raridon, R. J.; Ryan, P. M.

    1990-01-01

    rms emittance growth of liquid-metal ion sources is studied. Processes included are nonlinear expansion through extractor and accelerator fringe fields, nonlinear beam space charge, plasma effects near needle, and waves [either ion acoustic or space charge limited as considered by Dudnikov (private communication, 1988)]. This investigation consists of 2-D analysis of appropriate Vlasov-Poisson equations in both steady-state and time-dependent formulations. Various geometries will be considered such as some used by Alton of ORNL.

  12. Comet Encke: Meteor metallic ion identification by mass spectrometer

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.; Aikin, A. C.

    1972-01-01

    Metal ions including Na-40(+), Mg-24(+), Si-28(+), K-39(+), Ca-40(+), Sc-45(+), Cr-52(+), Fe-56(+), and Ni-58(+) were detected in the upper atmosphere during the beta Taurids meteor shower. Abundances of these ions relative to Si(+) show agreement in most instances with chondrites. A notable exception is 45(+), which is Sc(+), is 100 times more abundant than neutral scandium found in chondrites.

  13. Adsorbent for metal ions and method of making and using

    DOEpatents

    White, L.R.; Lundquist, S.H.

    1999-08-10

    A method comprises the step of spray-drying a solution or slurry comprising (alkali metal or ammonium) (metal) hexacyanoferrate particles in a liquid, to provide monodisperse, substantially spherical particles in a yield of at least 70 percent of theoretical yield and having a particle size in the range of 1 to 500 micrometers, said particles being active towards Cs ions. The particles, which can be of a single salt or a combination of salts, can be used free flowing, in columns or beds, or entrapped in a nonwoven, fibrous web or matrix or a cast porous membrane, to selectively remove Cs ions from aqueous solutions. 2 figs.

  14. Adsorbent for metal ions and method of making and using

    DOEpatents

    White, Lloyd R. (Minneapolis, MN); Lundquist, Susan H. (White Bear Township, MN)

    1999-01-01

    A method comprises the step of spray-drying a solution or slurry comprising (alkali metal or ammonium) (metal) hexacyanoferrate particles in a liquid, to provide monodisperse, substantially spherical particles in a yield of at least 70 percent of theoretical yield and having a particle size in the range of 1 to 500 micrometers, said particles being active towards Cs ions. The particles, which can be of a single salt or a combination of salts, can be used free flowing, in columns or beds, or entrapped in a nonwoven, fibrous web or matrix or a cast porous membrane, to selectively remove Cs ions from aqueous solutions.

  15. Adsorbent for metal ions and method of making and using

    DOEpatents

    White, Lloyd R. (Minneapolis, MN); Lundquist, Susan H. (White Bear Township, MN)

    2000-01-01

    A method comprises the step of spray-drying a solution or slurry comprising (alkali metal or ammonium) (metal) hexacyanoferrate particles in a liquid, to provide monodisperse, substantially spherical particles in a yield of at least 70 percent of theoretical yield and having a particle size in the range of 1 to 500 micrometers, said particles being active towards Cs ions. The particles, which can be of a single salt or a combination of salts, can be used free flowing, in columns or beds, or entrapped in a nonwoven, fibrous web or matrix or a cast porous membrane, to selectively remove Cs ions from aqueous solutions.

  16. Smart responsive microcapsules capable of recognizing heavy metal ions.

    PubMed

    Pi, Shuo-Wei; Ju, Xiao-Jie; Wu, Han-Guang; Xie, Rui; Chu, Liang-Yin

    2010-09-15

    Smart responsive microcapsules capable of recognizing heavy metal ions are successfully prepared with oil-in-water-in-oil double emulsions as templates for polymerization in this study. The microcapsules are featured with thin poly(N-isopropylacrylamide-co-benzo-18-crown-6-acrylamide) (P(NIPAM-co-BCAm)) membranes, and they can selectively recognize special heavy metal ions such as barium(II) or lead(II) ions very well due to the "host-guest" complexation between the BCAm receptors and barium(II) or lead(II) ions. The stable BCAm/Ba(2+) or BCAm/Pb(2+) complexes in the P(NIPAM-co-BCAm) membrane cause a positive shift of the volume phase transition temperature of the crosslinked P(NIPAM-co-BCAm) hydrogel to a higher temperature, and the repulsion among the charged BCAm/Ba(2+) or BCAm/Pb(2+) complexes and the osmotic pressure within the P(NIPAM-co-BCAm) membranes result in the swelling of microcapsules. Induced by recognizing barium(II) or lead(II) ions, the prepared microcapsules with P(NIPAM-co-BCAm) membranes exhibit isothermal and significant swelling not only in outer and inner diameters but also in the membrane thickness. The proposed microcapsules in this study are highly attractive for developing smart sensors and/or carriers for detection and/or elimination of heavy metal ions. PMID:20656104

  17. Adsorption characteristics of metal ions on chitosan chemically modified by D-galactose

    SciTech Connect

    Kondo, Kazuo; Sumi, Hisaharu; Matsumoto, Michiaki

    1996-07-01

    The adsorption characteristics of metal ions on chitosan chemically modified by D-galactose were examined. The pH dependency on the distribution ratio was found to be affected by the valency of the metal ion, and the apparent adsorption equilibrium constants of the metal ions were determined. The order of adsorption of the metal ions is Ga > In > Nd > Eu for the trivalent metal ions and Cu > Ni > Co for the divalent metal ions. It is believed that amino and hydroxyl groups in the chitosan act as a chelating ligand.

  18. Improved scales for metal ion softness and toxicity.

    PubMed

    Kinraide, Thomas B

    2009-03-01

    Ten scales relating to chemical hardness or softness of metal ions were compiled. These included eight published scales such as those of Pearson, Ahrland, Klopman, and Misono. Another scale consisted of the logs of the solubility products of metal sulfides, and yet another was a consensus scale constructed from -log K values for metal ion binding to seven soft ligands. These 10 scales were normalized and averaged. The resulting consensus scale for softness (sigma(Con)) appeared to be superior to any of the 10 scales used in its construction based on correlations among the scales. Other possible indicators of softness were examined, including the standard electrode potential (E(0)) and the bulk metal density (rho(Metal)), both of which were also superior to most of the 10 scales just mentioned. Vales for sigma(Con) may be computed from E(0), rho(Metal), and the first ionization potential (I(P)), R(2) = 0.867, for the equation sigma(Con) = aE(0)I(P) + brho(Metal). A consensus scale for toxicity (T(Con)) derived from studies with many different taxa correlated well (R(2) = 0.807) with sigma(Con) computed from the preceding equation, but incorporation of ion charge (Z) into the following equation, T(Con) = asigma(Con) + bsigma(Con)Z + cZ, increased R(2) to 0.923. Substitution of other softness scales for sigma(Con) into equations to predict T(Con) reduced the value of R(2). Thus, sigma(Con) appears to be a superior scale for metal ion softness and toxicity, the latter being an interactive function of both softness and charge. PMID:18980392

  19. DUHOCAMIS: a dual hollow cathode ion source for metal ion beams.

    PubMed

    Zhao, W J; Müller, M W O; Janik, J; Liu, K X; Ren, X T

    2008-02-01

    In this paper we describe a novel ion source named DUHOCAMIS for multiply charged metal ion beams. This ion source is derived from the hot cathode Penning ion gauge ion source (JINR, Dubna, 1957). A notable characteristic is the modified Penning geometry in the form of a hollow sputter electrode, coaxially positioned in a compact bottle-magnetic field along the central magnetic line of force. The interaction of the discharge geometry with the inhomogeneous but symmetrical magnetic field enables this device to be operated as hollow cathode discharge and Penning discharge as well. The main features of the ion source are the very high metal ion efficiency (up to 25%), good operational reproducibility, flexible and efficient operations for low charged as well as highly charged ions, compact setup, and easy maintenance. For light ions, e.g., up to titanium, well-collimated beams in the range of several tens of milliamperes of pulsed ion current (1 ms, 10/s) have been reliably performed in long time runs. PMID:18315181

  20. DUHOCAMIS: A dual hollow cathode ion source for metal ion beams

    SciTech Connect

    Zhao, W. J.; Mueller, M. W. O.; Janik, J.; Liu, K. X.; Ren, X. T.

    2008-02-15

    In this paper we describe a novel ion source named DUHOCAMIS for multiply charged metal ion beams. This ion source is derived from the hot cathode Penning ion gauge ion source (JINR, Dubna, 1957). A notable characteristic is the modified Penning geometry in the form of a hollow sputter electrode, coaxially positioned in a compact bottle-magnetic field along the central magnetic line of force. The interaction of the discharge geometry with the inhomogeneous but symmetrical magnetic field enables this device to be operated as hollow cathode discharge and Penning discharge as well. The main features of the ion source are the very high metal ion efficiency (up to 25%), good operational reproducibility, flexible and efficient operations for low charged as well as highly charged ions, compact setup, and easy maintenance. For light ions, e.g., up to titanium, well-collimated beams in the range of several tens of milliamperes of pulsed ion current (1 ms, 10/s) have been reliably performed in long time runs.

  1. Heavy metal ions are potent inhibitors of protein folding

    SciTech Connect

    Sharma, Sandeep K.; Goloubinoff, Pierre; Christen, Philipp

    2008-07-25

    Environmental and occupational exposure to heavy metals such as cadmium, mercury and lead results in severe health hazards including prenatal and developmental defects. The deleterious effects of heavy metal ions have hitherto been attributed to their interactions with specific, particularly susceptible native proteins. Here, we report an as yet undescribed mode of heavy metal toxicity. Cd{sup 2+}, Hg{sup 2+} and Pb{sup 2+} proved to inhibit very efficiently the spontaneous refolding of chemically denatured proteins by forming high-affinity multidentate complexes with thiol and other functional groups (IC{sub 50} in the nanomolar range). With similar efficacy, the heavy metal ions inhibited the chaperone-assisted refolding of chemically denatured and heat-denatured proteins. Thus, the toxic effects of heavy metal ions may result as well from their interaction with the more readily accessible functional groups of proteins in nascent and other non-native form. The toxic scope of heavy metals seems to be substantially larger than assumed so far.

  2. Observation of doubly-charged dimer ion emission in liquid-metal-ion sources

    NASA Astrophysics Data System (ADS)

    Ishitani, T.; Umemura, K.; Kawanami, Y.

    1989-08-01

    Liquid-metal-ion sources (LMIS's) emit atomic and cluster ions. In the mass analysis of LMIS's using Au-Sb and Pt-Sb alloys, the doubly-charged dimer ions Sb 2+2 are observed as well as the doubly-charged diatomic ions AuSb 2+ and PtSb 2+. The flux abundance of Sb 2+2 in Sb + +Sb 2+2 for a Au-Sb alloy is approximately 20%, which is larger by one order of magnitude than that for a Pt-Au alloy. It is predicted that the stability of cluster ions is strongly affected by the electrostatic field near the ion emitter. The formation mechanism of M 2+2 ions is discussed using mass spectra and energy distribution curves.

  3. Charge state breeding for the acceleration of radioactive ions at TRIUMF

    SciTech Connect

    Ames, F.; Baartman, R.; Bricault, P.; Jayamanna, K.; McDonald, M.; Lamy, T.

    2010-02-15

    A 14.5 GHz electron cyclotron resonance ion source (PHOENIX from Pantechnik) has been set up at the Isotope Separation and ACceleration (ISAC) facility at TRIUMF for the charge state breeding of radioactive ions. After extensive testing and optimization on a test bench it has been moved on-line and put into operation. During a first test in 2008 a beam of {sup 80}Rb{sup 14+} was successfully created from {sup 80}Rb{sup 1+} and accelerated by the ISAC postaccelerator. Further tests with different stable and radioactive isotopes from the ISAC on-line sources and from a test source with stable Cs have been carried out. Until now an efficiency of 1.4% for {sup 124}Cs{sup 20+} has been obtained.

  4. A Negative-Surface Ionization for Generation of Halogen Radioactive Ion Beams

    SciTech Connect

    Zaim, H.

    2001-04-16

    A simple and efficient negative surface ionization source has been designed, fabricated and initially tested for on-line generation of radioactive ion beams of the halogens (Cl, Br, I, and At) for use in the nuclear-structure and nuclear-astrophysics research programs at the Holifield Radioactive Ion Beam Facility. The source utilizes a solid, spherical geometry LaB{sub 6} surface ionizer for forming highly electronegative atoms and molecules. Despite its widely publicized propensity for being easily poisoned, no evidences of this effect were experienced during testing of the source. Nominal efficiencies of 15% for Br{sup {minus}} beam generation were obtained during off-line evaluation of the source with AlBr3 feed material when account is taken of the fractional dissociation of the molecule. Principles of operation, design features, operational parameter data, initial performance results, and beam quality data (emittance) are presented in this article.

  5. Layered metal sulfides: Exceptionally selective agents for radioactive strontium removal

    PubMed Central

    Manos, Manolis J.; Ding, Nan; Kanatzidis, Mercouri G.

    2008-01-01

    In this article, we report the family of robust layered sulfides K2xMnxSn3-xS6 (x = 0.5–0.95) (KMS-1). These materials feature hexagonal [MnxSn3-xS6]2x? slabs of the CdI2 type and contain highly mobile K+ ions in their interlayer space that are easily exchangeable with other cations and particularly strontium. KMS-1 display outstanding preference for strontium ions in highly alkaline solutions containing extremely large excess of sodium cations as well as in acidic environment where most alternative adsorbents with oxygen ligands are nearly inactive. The implication of these results is that simple layered sulfides should be considered for the efficient remediation of certain nuclear wastes. PMID:18316731

  6. Droplet and cluster ion emission from Ga and In liquid metal ion sources

    NASA Astrophysics Data System (ADS)

    Hornsey, Richard; Ishitani, Tohru

    1990-10-01

    There is at present a need to model the emission of droplets from liquid metal ion sources (LMIS), in order to account for such additional phenomena as cluster-ion emissions; knowledge of the droplets' initial sizes and droplets is required for the prediction of cluster ion voltage deficits. A simple model is developed in which the droplets are envisioned as forming from the breakoff of the tip sphere from the LMIS apical jet. The scheme is demonstrated to be useful in the derivation of qualitative variations of LMIS mass loss, Ga and In dimer ion voltage deficits, and energy spreads with current.

  7. A design of large current ion gun employing liquid metal ion source

    NASA Astrophysics Data System (ADS)

    Mori, Yuzo; Wang, Hui; Endo, Katsuyoshi; Yamauchi, Kazuto; Ide, Takashi

    1990-07-01

    A lens system for a large current liquid metal ion source has been designed by a numerical computer simulation method. As a computed result, the lens system can focus an ion beam having an emission angle of 60° to a beam having a radius of 1.8 mm at 1 m from the ion source. Following the simulated result, the lens system was constructed and tested. When the total ion current extracted from the ion source was less than 10 ?A, more than 95% of the total ion was focused to a beam with a radius of about 2 mm at 1 m from the ion source, which agreed well with the computer simulation result. When the total ion current became more than 10 ?A, the minimum radius of the focused ion beam at 1 m from the ion source gradually increased with it. However, even if the total ion current was more than 50 ?A, almost 80% of it could be obtained on a 1×1 cm2 target at 1 m from the ion source.

  8. Metal ion bombardment of onion skin cell wall

    SciTech Connect

    Sangyuenyongpipat, S.; Vilaithong, T.; Yu, L.D.; Verdaguer, A.; Ratera, I.; Ogletree, D.F.; Monteiro, O.R.; Brown, I.G.

    2004-05-10

    Ion bombardment of living cellular material is a novel subfield of ion beam surface modification that is receiving growing attention from the ion beam and biological communities. Although it has been demonstrated that the technique is sound, in that an adequate fraction of the living cells can survive both the vacuum environment and energetic ion bombardment, there remains much uncertainty about the process details. Here we report on our observations of onion skin cells that were subjected to ion implantation, and propose some possible physical models that tend to support the experimental results. The ion beams used were metallic (Mg, Ti, Fe, Ni, Cu), mean ion energy was typically 30keV, and the implantation fluence was in the range 1014 1016 ions/cm2. The cells were viewed using Atomic Force Microscopy, revealing the formation of microcrater-like structures due to ion bombardment. The implantation depth profile was measured with Rutherford backscattering spectrometry and compared to the results of the TRIM, T-DYN and PROFILE computer codes.

  9. Immobilization of Metal Hexacyanoferrate Ion-Exchangers for the Synthesis of Metal Ion Sorbents-A Mini-Review.

    PubMed

    Vincent, Thierry; Vincent, Chloë; Guibal, Eric

    2015-01-01

    Metal hexacyanoferrates are very efficient sorbents for the recovery of alkali and base metal ions (including radionuclides such as Cs). Generally produced by the direct reaction of metal salts with potassium hexacyanoferrate (the precursors), they are characterized by ion-exchange and structural properties that make then particularly selective for Cs(I), Rb(I) and Tl(I) recovery (based on their hydrated ionic radius consistent with the size of the ion-exchanger cage), though they can bind also base metals. The major drawback of these materials is associated to their nanometer or micrometer size that makes them difficult to recover in large-size continuous systems. For this reason many techniques have been designed for immobilizing these ion-exchangers in suitable matrices that can be organic (mainly polymers and biopolymers) or inorganic (mineral supports), carbon-based matrices. This immobilization may proceed by in situ synthesis or by entrapment/encapsulation. This mini-review reports some examples of hybrid materials synthesized for the immobilization of metal hexacyanoferrate, the different conditionings of these composite materials and, briefly, the parameters to take into account for their optimal design and facilitated use. PMID:26610439

  10. How do energetic ions damage metallic surfaces?

    DOE PAGESBeta

    Osetskiy, Yury N.; Calder, Andrew F.; Stoller, Roger E.

    2015-02-20

    Surface modification under bombardment by energetic ions observed under different conditions in structural and functional materials and can be either unavoidable effect of the conditions or targeted modification to enhance materials properties. Understanding basic mechanisms is necessary for predicting properties changes. The mechanisms activated during ion irradiation are of atomic scale and atomic scale modeling is the most suitable tool to study these processes. In this paper we present results of an extensive simulation program aimed at developing an understanding of primary surface damage in iron by energetic particles. We simulated 25 keV self-ion bombardment of Fe thin films withmore »(100) and (110) surfaces at room temperature. A large number of simulations, ~400, were carried out allow a statistically significant treatment of the results. The particular mechanism of surface damage depends on how the destructive supersonic shock wave generated by the displacement cascade interacts with the free surface. Three basic scenarios were observed, with the limiting cases being damage created far below the surface with little or no impact on the surface itself, and extensive direct surface damage on the timescale of a few picoseconds. In some instances, formation of large vacancy loops beneath the free surface was observed, which may explain some earlier experimental observations.« less

  11. Safe disposal of radioactive iodide ions from solutions by Ag2O grafted sodium niobate nanofibers.

    PubMed

    Mu, Wanjun; Li, Xingliang; Liu, Guoping; Yu, Qianhong; Xie, Xiang; Wei, Hongyuan; Jian, Yuan

    2015-12-22

    Radioactive iodine isotopes are released into the environment by the nuclear industry and medical research institutions using radioactive materials, and have negative effects on organisms living within the ecosystem. Thus, safe disposal of radioactive iodine is necessary and crucial. For this reason, the uptake of iodide ions was investigated in Ag2O nanocrystal grafted sodium niobate nanofibers, which were prepared by forming a well-matched phase coherent interface between them. The resulting composite was applied as an efficient adsorbent for I(-) anions by forming an AgI precipitate, which also remained firmly attached to the substrates. Due to their one-dimensional morphology, the new adsorbents can be easily dispersed in liquids and readily separated after purification. This significantly enhances the adsorption efficiency and reduces the separation costs. The change in structure from the pristine sodium niobate to Ag2O anchored sodium niobate and to the used adsorbent was examined by using various characterization techniques. The effects of Ag(+) concentration, pH, equilibration time, ionic strength and competing ions on the iodide ion removal ability of the composite were studied. The Ag2O nanocrystal grafted sodium niobate adsorbent showed a high adsorption capacity and excellent selectivity for I(-) anions in basic solutions. Our results are useful for the further development of improved adsorbents for removing I(-) anions from basic wastewater. PMID:26631449

  12. Changes in blood ion levels after removal of metal-on-metal hip replacements

    PubMed Central

    Durrani, Salim K; Sampson, Barry; Panetta, Therese; Liddle, Alexander D; Sabah, Shiraz A; Chan, Newton K; Skinner, John A; Hart, Alister J

    2014-01-01

    Background and purpose In patients with metal-on-metal (MoM) hip prostheses, pain and joint effusions may be associated with elevated blood levels of cobalt and chromium ions. Since little is known about the kinetics of metal ion clearance from the body and the rate of resolution of elevated blood ion levels, we examined the time course of cobalt and chromium ion levels after revision of MoM hip replacements. Patients and methods We included 16 patients (13 female) who underwent revision of a painful MoM hip (large diameter, modern bearing) without fracture or infection, and who had a minimum of 4 blood metal ion measurements over an average period of 6.1 (0–12) months after revision. Results Average blood ion concentrations at the time of revision were 22 ppb for chromium and 43 ppb for cobalt. The change in ion levels after revision surgery varied extensively between patients. In many cases, over the second and third months after revision surgery ion levels decreased to 50% of the values measured at revision. Decay of chromium levels occurred more slowly than decay of cobalt levels, with a 9% lag in return to normal levels. The rate of decay of both metals followed second-order (exponential) kinetics more closely than first-order (linear) kinetics. Interpretation The elimination of cobalt and chromium from the blood of patients who have undergone revision of painful MoM hip arthroplasties follows an exponential decay curve with a half-life of approximately 50 days. Elevated blood levels of cobalt and chromium ions can persist for at least 1 year after revision, especially in patients with high levels of exposure. PMID:24758321

  13. Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete

    DOEpatents

    Sugama, T.; Kukacka, L.E.; Horn, W.H.

    1983-05-13

    Quick setting polymer concrete compositions are described which are mixtures of unsaturated polyesters and crosslinking monomers together with appropriate initiators and promoters in association with aggregate which may be wet and a source of bivalent metallic ions which will set to polymer concrete with excellent structural properties.

  14. Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete

    DOEpatents

    Sugama, T.; Kukacka, L.E.; Horn, W.H.

    1981-11-04

    Quick setting polymer concrete compositions which are mixtures of unsaturated polyesters and crosslinking monomers together with appropriate initiators and promoters in association with aggregate which may be wet and a source of bivalent metallic ions which will set to polymer concrete with excellent structural properties.

  15. Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete

    DOEpatents

    Sugama, Toshifumi (Mastic Beach, NY); Kukacka, Lawrence E. (Port Jefferson, NY); Horn, William H. (Brookhaven, NY)

    1985-01-01

    Quick setting polymer concrete compositions with excellent structural properties are disclosed; these polymer concrete compositions are mixtures of unsaturated polyesters and crosslinking monomers together with appropriate initiators and promoters in association with aggregate, which may be wet, and with a source of bivalent metallic ions.

  16. RADIOACTIVE MATERIAL SHIPPING PACKAGINGS AND METAL TO METAL SEALS FOUND IN THE CLOSURES OF CONTAINMENT VESSELS INCORPORATING CONE SEAL CLOSURES

    SciTech Connect

    Loftin, B; Glenn Abramczyk, G; Allen Smith, A

    2007-06-06

    The containment vessels for the Model 9975 radioactive material shipping packaging employ a cone-seal closure. The possibility of a metal-to-metal seal forming between the mating conical surfaces, independent of the elastomer seals, has been raised. It was postulated that such an occurrence would compromise the containment vessel hydrostatic and leakage tests. The possibility of formation of such a seal has been investigated by testing and by structural and statistical analyses. The results of the testing and the statistical analysis demonstrate and procedural changes ensure that hydrostatic proof and annual leakage testing can be accomplished to the appropriate standards.

  17. Broad-beam, high current, metal ion implantation facility

    SciTech Connect

    Brown, I.G.; Dickinson, M.R.; Galvin, J.E.; Godechot, X.; MacGill, R.A.

    1990-07-01

    We have developed a high current metal ion implantation facility with which high current beams of virtually all the solid metals of the Periodic Table can be produced. The facility makes use of a metal vapor vacuum arc ion source which is operated in a pulsed mode, with pulse width 0.25 ms and repetition rate up to 100 pps. Beam extraction voltage is up to 100 kV, corresponding to an ion energy of up to several hundred keV because of the ion charge state multiplicity; beam current is up to several Amperes peak and around 10 mA time averaged delivered onto target. Implantation is done in a broad-beam mode, with a direct line-of-sight from ion source to target. Here we describe the facility and some of the implants that have been carried out using it, including the seeding' of silicon wafers prior to CVD with titanium, palladium or tungsten, the formation of buried iridium silicide layers, and actinide (uranium and thorium) doping of III-V compounds. 16 refs., 6 figs.

  18. Electrospray Ionization Mass Spectrometry: From Cluster Ions to Toxic metal Ions in Biology

    SciTech Connect

    Nicholas B. Lentz

    2007-12-01

    This dissertation focused on using electrospray ionization mass spectrometry to study cluster ions and toxic metal ions in biology. In Chapter 2, it was shown that primary, secondary and quarternary amines exhibit different clustering characteristics under identical instrument conditions. Carbon chain length also played a role in cluster ion formation. In Chapters 3 and 4, the effects of solvent types/ratios and various instrumental parameters on cluster ion formation were examined. It was found that instrument interface design also plays a critical role in the cluster ion distribution seen in the mass spectrum. In Chapter 5, ESI-MS was used to investigate toxic metal binding to the [Gln{sup 11}]-amyloid {beta}-protein fragment (1-16). Pb and Cd bound stronger than Zn, even in the presence of excess Zn. Hg bound weaker than Zn. There are endless options for future work on cluster ions. Any molecule that is poorly ionized in positive ion mode can potentially show an increase in ionization efficiency if an appropriate anion is used to produce a net negative charge. It is possible that drug protein or drug/DNA complexes can also be stabilized by adding counter-ions. This would preserve the solution characteristics of the complex in the gas phase. Once in the gas phase, CID could determine the drug binding location on the biomolecule. There are many research projects regarding toxic metals in biology that have yet to be investigated or even discovered. This is an area of research with an almost endless future because of the changing dynamics of biological systems. What is deemed safe today may show toxic effects in the future. Evolutionary changes in protein structures may render them more susceptible to toxic metal binding. As the understanding of toxicity evolves, so does the demand for new toxic metal research. New instrumentation designs and software make it possible to perform research that could not be done in the past. What was undetectable yesterday will become routine tomorrow.

  19. [Spectroscopic studies on transition metal ions in colored diamonds].

    PubMed

    Meng, Yu-Fei; Peng, Ming-Sheng

    2004-07-01

    Transition metals like nickel, cobalt and iron have been often used as solvent catalysts in high pressure high temperature (HPHT) synthesis of diamond, and nickel and cobalt ions have been found in diamond lattice. Available studies indicated that nickel and cobalt ions could enter the lattice as interstitial or substitutional impurities and form complexes with nitrogen. Polarized microscopy, SEM-EDS, EPR, PL and FTIR have been used in this study to investigate six fancy color natural and synthetic diamonds in order to determine the spectroscopic characteristics and the existing forms of transition metal ions in colored diamond lattice. Cobalt-related optical centers were first found in natural chameleon diamonds, and some new nickel and cobalt-related optical and EPR centers have also been detected in these diamond samples. PMID:15766067

  20. Method for removing metal ions from solution with titanate sorbents

    DOEpatents

    Lundquist, Susan H. (White Bear Township, MN); White, Lloyd R. (Minneapolis, MN)

    1999-01-01

    A method for removing metal ions from solution comprises the steps of providing titanate particles by spray-drying a solution or slurry comprising sorbent titanates having a particle size up to 20 micrometers, optionally in the presence of polymer free of cellulose functionality as binder, said sorbent being active towards heavy metals from Periodic Table (CAS version) Groups IA, IIA, IB, IIB, IIIB, and VIII, to provide monodisperse, substantially spherical particles in a yield of at least 70 percent of theoretical yield and having a particle size distribution in the range of 1 to 500 micrometers. The particles can be used free flowing in columns or beds, or entrapped in a nonwoven, fibrous web or matrix or a cast porous membrane, to selectively remove metal ions from aqueous or organic liquid.

  1. Metal ion influence on eumelanin fluorescence and structure

    NASA Astrophysics Data System (ADS)

    Sutter, Jens-Uwe; Birch, David J. S.

    2014-06-01

    Melanin has long been thought to have an unworkably weak and complex fluorescence, but here we study its intrinsic fluorescence in order to demonstrate how metal ions can be used to control the rate of formation, constituents and structure of eumelanin formed from the well-known laboratory auto-oxidation of 3,4-dihydroxy-L-phenylalanine (L-DOPA). The effect on eumelanin absorption and fluorescence of a range of solvated metal ions is reported including Cu, Zn, Ni, Na and K. Monovalent cations and Zn have little effect, but the effect of transition metal cations can be considerable. For example, at pH 10, copper ions are shown to accelerate the onset of eumelanin formation, but not the rate of formation once it commences, and simplify the usual complex structure and intrinsic fluorescence of eumelanin in a way that is consistent with an increased abundance of 5,5-dihydroxyindole-2-carboxylic acid (DHICA). The presence of a dominant 6 ns fluorescence decay time at 480 nm, when excited at 450 nm describes a distinct photophysical species, which we tentatively assign to small oligomers. Copper is well-known to normally quench fluorescence, but increasing amounts of copper surprisingly leads to an increase in the fluorescence decay time of eumelanin, while reducing the fluorescence intensity, suggesting copper modification of the excited state. Such results have bearing on diverse areas. The most accepted morphology for melanin is that of a graphite-like sheet structure, and one which readily binds metal ions, an interaction that is thought to have an important, though as yet unclear bearing on several areas of medicine including neurology. There is also increasing interest in bio-mimicry by preparing and labelling sheet structures with metal ions for new electronic and photonic materials.

  2. Chitosan removes toxic heavy metal ions from cigarette mainstream smoke

    NASA Astrophysics Data System (ADS)

    Zhou, Wen; Xu, Ying; Wang, Dongfeng; Zhou, Shilu

    2013-09-01

    This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan. Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in different dosages. The mainstream smoke particulate matter was collected by a Cambridge filter pad, digested by a microwave digestor, and then analyzed for contents of heavy metal ions, including As(III/V), Pb(II), Cd(II), Cr(III/VI) and Ni(II), by graphite furnace atomic absorption spectrometry (GFAAS). The results showed that chitosan had a removal effect on Pb(II), Cd(II), Cr(III/VI) and Ni(II). Of these, the percent removal of Ni(II) was elevated with an increasing dosage of chitosan. Chitosan of a high deace tylation degree exhibited good binding performance toward Cd(II), Cr(III/VI) and Ni(II), though with poor efficiency for Pb(II). Except As(III/V), all the tested metal ions showed similar tendencies in the growing contents with an increasing chitosan molecular weight. Nonetheless, the percent removal of Cr(III/VI) peaked with a chitosan molecular weight of 200 kDa, followed by a dramatic decrease with an increasing chitosan molecular weight. Generally, chitosan had different removal effects on four out of five tested metal ions, and the percent removal of Cd(II), Pb(II), Cr(III/VI) and Ni(II) was approximately 55%, 45%, 50%, and 16%, respectively. In a word, chitosan used in cigarette filter can remove toxic heavy metal ions in the mainstream smoke, improve cigarette safety, and reduce the harm to smokers.

  3. Metal negative ion beam extraction from a radio frequency ion source

    SciTech Connect

    Kanda, S.; Yamada, N.; Kasuya, T.; Romero, C. F. P.; Wada, M.

    2015-04-08

    A metal ion source of magnetron magnetic field geometry has been designed and operated with a Cu hollow target. Radio frequency power at 13.56?MHz is directly supplied to the hollow target to maintain plasma discharge and induce self-bias to the target for sputtering. The extraction of positive and negative Cu ion beams have been tested. The ion beam current ratio of Cu{sup +} to Ar{sup +} has reached up to 140% when Ar was used as the discharge support gas. Cu{sup ?} ion beam was observed at 50?W RF discharge power and at a higher Ar gas pressure in the ion source. Improvement of poor RF power matching and suppression of electron current is indispensable for a stable Cu{sup ?} ion beam production from the source.

  4. Metal negative ion beam extraction from a radio frequency ion source

    NASA Astrophysics Data System (ADS)

    Kanda, S.; Yamada, N.; Kasuya, T.; Romero, C. F. P.; Wada, M.

    2015-04-01

    A metal ion source of magnetron magnetic field geometry has been designed and operated with a Cu hollow target. Radio frequency power at 13.56 MHz is directly supplied to the hollow target to maintain plasma discharge and induce self-bias to the target for sputtering. The extraction of positive and negative Cu ion beams have been tested. The ion beam current ratio of Cu+ to Ar+ has reached up to 140% when Ar was used as the discharge support gas. Cu- ion beam was observed at 50 W RF discharge power and at a higher Ar gas pressure in the ion source. Improvement of poor RF power matching and suppression of electron current is indispensable for a stable Cu- ion beam production from the source.

  5. Metal negative ion production by an RF sputter self-extraction ion source

    NASA Astrophysics Data System (ADS)

    Yamada, N.; Kasuya, T.; Kenmotsu, T.; Vasquez, M. R., Jr.; Wada, M.

    2013-02-01

    An 80 mm diameter 80 mm long RF sputter type self-extraction negative ion source equipped with a metal sputter target has been tested to investigate the performance of producing beams of negative aluminum (Al) ions. An RF power at 13.56 MHz is directly supplied to a 60 mm diameter target containing a cylindrical and ring permanent magnets to form planar magnetron magnetic field geometry. The target is self-biased to a DC potential at about -250 V with respect to the plasma, and negative ions produced at the surface are self-extracted from the target across the sheath to reach the ion beam extraction hole. Injection of cesium into the discharge enhanced the amount of Al- ions but it also enlarged the impurity ion beam current.

  6. Liquid metal ion source and alloy for ion emission of multiple ionic species

    DOEpatents

    Clark, Jr., William M. (Thousand Oaks, CA); Utlaut, Mark W. (Saugus, CA); Wysocki, Joseph A. (Oxnard, CA); Storms, Edmund K. (Los Alamos, NM); Szklarz, Eugene G. (Los Alamos, NM); Behrens, Robert G. (Los Alamos, NM); Swanson, Lynwood W. (McMinnville, OR); Bell, Anthony E. (McMinnville, OR)

    1987-06-02

    A liquid metal ion source and alloy for the simultaneous ion evaporation of arsenic and boron, arsenic and phosphorus, or arsenic, boron and phosphorus. The ionic species to be evaporated are contained in palladium-arsenic-boron and palladium-arsenic-boron-phosphorus alloys. The ion source, including an emitter means such as a needle emitter and a source means such as U-shaped heater element, is preferably constructed of rhenium and tungsten, both of which are readily fabricated. The ion sources emit continuous beams of ions having sufficiently high currents of the desired species to be useful in ion implantation of semiconductor wafers for preparing integrated circuit devices. The sources are stable in operation, experience little corrosion during operation, and have long operating lifetimes.

  7. New Metal Niobate and Silicotitanate Ion Exchangers: Development and Characterization

    SciTech Connect

    Alexandra Navrotsky; Mary Lou Balmer; Tina M. Nenoff; Yali Su

    2003-12-05

    This renewal proposal outlines our current progress and future research plans for ion exchangers: novel metal niobate and silicotitanate ion exchangers and their ultimate deployment in the DOE complex. In our original study several forms (including Cs exchanged) of the heat treated Crystalline Silicotitanates (CSTs) were fully characterized by a combination of high temperature synthesis and phase identification, low temperature synthesis and phase identification, and thermodynamics. This renewal proposal is predicated on work completed in our current EMSP program: we have shown preliminary data of a novel class of niobate-based molecular sieves (Na/Nb/M/O, M = transition metals), which show exceptionally high selectivity for divalent cations under extreme conditions (acid solutions, competing cations), in addition to novel silicotitanate phases which are also selective for divalent cations. Furthermore, these materials are easily converted by a high temperature in-situ heat treatment into a refractory ceramic waste form with low cation leachability. The new waste form is a perovskite phase, which is also a major component of Synroc, a titanate ceramic waste form used for sequestration of HLW wastes from reprocessed, spent nuclear fuel. These new niobate ion exchangers also shown orders of magnitude better selectivity for Sr2+ under acid conditions than any other material. The goal of the program is to reduce the costs associated with divalent cation waste removal and disposal, to minimize the risk of contamination to the environment during ion exchanger processing, and to provide DOE with materials for near-term lab-bench stimulant testing, and eventual deployment. The proposed work will provide information on the structure/property relationship between ion exchanger frameworks and selectivity for specific ions, allowing for the eventual ''tuning'' of framework for specific ion exchange needs. To date, DOE sites have become interested in on-site testing of these materials; ongoing discussions and initial experiments are occurring with Dr. Dean Peterman, Idaho National Engineering and Environmental Laboratory (INEEL) (location of the DOE/EM Waste Treatment Focus Area), and Dr. John Harbour, Savannah River Site (SRS). Yet the materials have not been optimized, and further research and development of the novel ion exchangers and testing conditions with simulants are needed. In addition, studies of the ion exchanger composition versus ion selectivity, ion exchange capacity and durability of final waste form are needed. This program will bring together three key institutions to address scientific hurdles of the separation process associated with metal niobate and silicotitanate ion exchangers, in particular for divalent cations (e.g., Sr2+). The program involves a joint effort between researchers at Pacific Northwest National Laboratory, who are leaders in structure/property relations in silicotitanates and in waste form development and performance assessment, Sandia National Laboratories, who discovered and developed crystalline silicotitanate ion exchangers (with Texas A&M and UOP) and also the novel class of divalent metal niobate ion exchangers, and the Thermochemistry Facility at UC Davis, who are world renowned experts in calorimetry and have already performed extensive thermodynamic studies on silicotitanate materials. In addition, Dr. Rodney Ewing of University of Michigan, an expert in radiation effects on materials, and Dr. Robert Roth of the National Institute of Standards and Technology and The Viper Group, a leader in phase equilibria development, will be consultants for radiation and phase studies. The research team will focus on three tasks that will provide both the basic research necessary for the development of highly selective ion exchange materials and also materials for short-term deployment within the DOE complex: (1) Structure/property relationships of a novel class of niobate-based molecular sieves (Na/Nb/M/O, M = transition metals), which show exceptionally high selectivity for divalent cations un

  8. Principles Governing Metal Ion Selectivity in Ion Channel Proteins

    NASA Astrophysics Data System (ADS)

    Lim, Carmay

    2014-03-01

    Our research interests are to (i) unravel the principles governing biological processes and use them to identify novel drug targets and guide drug design, and (ii) develop new methods for studying macromolecular interactions. This talk will provide an overview of our work in these two areas and an example of how our studies have helped to unravel the principles underlying the conversion of Ca2+-selective to Na+-selective channels. Ion selectivity of four-domain voltage-gated Ca2+(Cav) and sodium (Nav) channels, which is controlled by the selectivity filter (SF, the narrowest region of an open pore), is crucial for electrical signaling. Over billions of years of evolution, mutation of the Glu from domain II/III in the EEEE/DEEA SF of Ca2+-selective Cav channels to Lys made these channels Na+-selective. This talk will delineate the physical principles why Lys is sufficient for Na+/Ca2+selectivity and why the DEKA SF is more Na+-selective than the DKEA one.

  9. SIMS depth profile study using metal cluster complex ion bombardment

    NASA Astrophysics Data System (ADS)

    Tomita, M.; Kinno, T.; Koike, M.; Tanaka, H.; Takeno, S.; Fujiwara, Y.; Kondou, K.; Teranishi, Y.; Nonaka, H.; Fujimoto, T.; Kurokawa, A.; Ichimura, S.

    2007-05-01

    SIMS depth profiles using a metal cluster complex ion of Ir4 (CO)7+were studied. An unusual increase of the sputtering yield under the condition of small incident angle may be attributed to the suppression of taking oxygen from flooding O2 by the formation of a carbon cover-layer derived from Ir4 (CO)7+ion. Even though the roughness of the sputtered surface is small, the depth resolution was not improved by decreasing the cluster ion energy to less than 5 keV, because the carbon cover-layer prevents the formation of surface oxide that buffers atomic mixing. To overcome this issue, it will be necessary to eliminate carbon from the cluster ion.

  10. Between atomic and nuclear physics: radioactive decays of highly-charged ions

    NASA Astrophysics Data System (ADS)

    Atanasov, Dinko; Blaum, Klaus; Bosch, Fritz; Brandau, Carsten; Bühler, Paul; Chen, Xiangcheng; Dillmann, Iris; Faestermann, Thomas; Gao, Bingshui; Geissel, Hans; Gernhäuser, Roman; Hagmann, Siegbert; Izumikawa, Takuji; Hillenbrand, Pierre-Michel; Kozhuharov, Christophor; Kurcewicz, Jan; Litvinov, Sergey A.; Litvinov, Yuri A.; Ma, Xinwen; Münzenberg, Gottfried; Najafi, Mohammad Ali; Nolden, Fritz; Ohtsubo, Takashi; Ozawa, Akira; Cagla Ozturk, Fatma; Patyk, Zygmunt; Reed, Matthew; Reifarth, Rene; Shahab Sanjari, Mohammad; Schneider, Dieter; Steck, Markus; Stöhlker, Thomas; Sun, Baohua; Suzaki, Fumi; Suzuki, Takeshi; Trageser, Christian; Tu, Xiaolin; Uesaka, Tomohiro; Walker, Philip; Wang, Meng; Weick, Helmut; Winckler, Nicolas; Woods, Philip; Xu, Hushan; Yamaguchi, Takayuki; Yan, Xinliang; Zhang, Yuhu; FRS-ESR,the; ILIMA; SPARC; TBWD Collaborations

    2015-07-01

    Highly charged radioactive ions can be stored for extended periods of time in storage rings which allows for precision measurements of their decay modes. The straightforward motivation for performing such studies is that fully ionised nuclei or few-electron ions can be viewed as clean quantum-mechanical systems, in which the interactions of the many electrons can be either excluded or treated precisely. Thus, the influence of the electron shell on the decay probability can be investigated. Another important motivation is stellar nucleosynthesis, which proceeds at high temperatures and the involved atoms are therefore highly ionised. Presented here is a compact review of the relevant experiments conducted at heavy-ion storage rings. Furthermore, we outline the perspectives for future experiments at new-generation storage-ring facilities.

  11. Tissue localization of stable and radioactive nuclides by secondary-ion microscopy

    SciTech Connect

    Galle, P.

    1982-01-01

    Images of the distribution of a given nuclide in a section of biological tissue can be obtained at the microscopic level by ''secondary-ion mass analysis.'' In this method, the images are formed by an ion-emission microscope wherein the specimen's atoms are progressively sputtered from the surface and the ions are selectively visualied by mass spectrometry according to their mass-to-charge ratios. Such images are obtained at the cost of the destruction of the specimen, which is progressively eroded at the rate of 1-10 atomic layers per second. The spatial resolution is better than 1 ..mu..m for an imaged area 250 ..mu..m in diameter and a section thickness of 1-2000 nm;thus, the analytical images are element distributions representaive of 3-6000 atomic layers. Distributional images can be obtained for many nuclides, whether stable or radioactive, natural or artifically administered.

  12. Exploration of metal ion binding sites in RNA folds by Brownian-dynamics simulations

    E-print Network

    Westhof, Eric

    Exploration of metal ion binding sites in RNA folds by Brownian- dynamics simulations Thomas Hermann and Eric Westhof* Background: Metal ions participate in the three-dimensional folding of RNA and provide active centers in catalytic RNA molecules. The positions of metal ions are known for a few RNA

  13. Three metal ions at the active site of the Tetrahymena group I ribozyme

    E-print Network

    Herschlag, Dan

    Three metal ions at the active site of the Tetrahymena group I ribozyme Shu-ou Shan*, Aiichiro, CO, August 27, 1999 (received for review May 13, 1999) Metal ions are critical for catalysis by many RNA and protein enzymes. To understand how these enzymes use metal ions for catalysis, it is crucial

  14. Commissioning of the Daresbury Recoil Separator for nuclear astrophysics measurements at the Holifield Radioactive Ion Beam Facility

    SciTech Connect

    Smith, M.S.; Blackmon, J.C.; Koehler, P.E.

    1997-12-01

    The Daresbury Recoil Separator (DRS) has been installed for nuclear astrophysics research at Oak Ridge National Laboratory`s Holifield Radioactive Ion Beam Facility. it will be used for direct measurements of capture reactions on radioactive ions which occur in stellar explosions such as novae and X-ray bursts. The physics motivation and plans for the first measurements with radioactive beams are described, and details of the new DRS experimental equipment and preliminary results from the first commissioning experiments with stable beams are given.

  15. Development and properties of crystalline silicotitanate (CST) ion exchangers for radioactive waste applications

    SciTech Connect

    Miller, J.E.; Brown, N.E.

    1997-04-01

    Crystalline silicotitanates (CSTs) are a new class of ion exchangers that were jointly invented by researchers at Sandia National Laboratories and Texas A&M University. One particular CST, known as TAM-5, is remarkable for its ability to separate parts-per-million concentrations of cesium from highly alkaline solutions (pH> 14) containing high sodium concentrations (>5M). It is also highly effective for removing cesium from neutral and acidic solutions, and for removing strontium from basic and neutral solutions. Cesium isotopes are fission products that account for a large portion of the radioactivity in waste streams generated during weapons material production. Tests performed at numerous locations with early lab-scale TAM-5 samples established the material as a leading candidate for treating radioactive waste volumes such as those found at the Hanford site in Washington. Thus Sandia developed a Cooperative Research and Development Agreement (CRADA) partnership with UOP, a world leader in developing, commercializing, and supplying adsorbents and associated process technology to commercialize and further develop the material. CSTs are now commercially available from UOP in a powder (UOP IONSIV{reg_sign} IE-910 ion exchanger) and granular form suitable for column ion exchange operations (UOP IONSIV{reg_sign} IE-911 ion exchanger). These materials exhibit a high capacity for cesium in a wide variety of solutions of interest to the Department of Energy, and they are chemically, thermally, and radiation stable. They have performed well in tests at numerous sites with actual radioactive waste solutions, and are being demonstrated in the 100,000 liter Cesium Removal Demonstration taking place at Oak Ridge National Laboratory with Melton Valley Storage Tank waste. It has been estimated that applying CSTs to the Hanford cleanup alone will result in a savings of more than $300 million over baseline technologies.

  16. Multiply stripped ion generation in the metal vapor vacuum arc

    SciTech Connect

    Brown, I.G.; Feinberg, B.; Galvin, J.E.

    1987-09-01

    We consider the charge state distribution of ions produced in the metal vapor vacuum arc plasma discharge. A new kind of high current metal ion source in which the ion beam is extracted from a metal vapor vacuum arc plasma has been used to obtain the spectra of multiply charged ions produced within the cathode spots. The cathode materials used and the species reportetd on here are: C, Mg, Al, Si, Ti, Cr, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Rh, Pd, Ag, In, Sn, Gd, Ho, Ta, W, Pt, Au, Pb, Th, and U; the arc current was 200 A for all measurements. Charge state spectra were measured using a time-of-flight method. The arc voltage was also measured. In this paper we report on the measured charge state distributions and arc voltages and compare the distributions with the predictions of a theory in which ionization occurs in the cathode spots via stepwise ionization by electron impact. 64 refs., 10 figs., 3 tabs.

  17. New Catalytic DNA Biosensors for Radionuclides and Metal ion

    SciTech Connect

    Yi Lu

    2008-03-01

    We aim to develop new DNA biosensors for simultaneous detection and quantification of bioavailable radionuclides, such as uranium, technetium, and plutonium, and metal contaminants, such as lead, chromium, and mercury. The sensors will be highly sensitive and selective. They will be applied to on-site, real-time assessment of concentration, speciation, and stability of the individual contaminants before and during bioremediation, and for long-term monitoring of DOE contaminated sites. To achieve this goal, we have employed a combinatorial method called “in vitro selection” to search from a large DNA library (~ 1015 different molecules) for catalytic DNA molecules that are highly specific for radionuclides or other metal ions through intricate 3-dimensional interactions as in metalloproteins. Comprehensive biochemical and biophysical studies have been performed on the selected DNA molecules. The findings from these studies have helped to elucidate fundamental principles for designing effective sensors for radionuclides and metal ions. Based on the study, the DNA have been converted to fluorescent or colorimetric sensors by attaching to it fluorescent donor/acceptor pairs or gold nanoparticles, with 11 part-per-trillion detection limit (for uranium) and over million fold selectivity (over other radionuclides and metal ions tested). Practical application of the biosensors for samples from the Environmental Remediation Sciences Program (ERSP) Field Research Center (FRC) at Oak Ridge has also been demonstrated.

  18. Polymer filtration systems for dilute metal ion recovery

    SciTech Connect

    Smith, B.F.; Robison, T.W.; Jarvinen, G.D.

    1998-12-01

    Scientists at Los Alamos National Laboratory have developed a metal recovery system that meets the global treatment demands for all kinds of industrial and metal-processing streams. The Polymer Filtration (PF) System--a process that is easily operated and robust--offers metal-finishing businesses a convenient and inexpensive way to recover and recycle metal ions in-house, thus reducing materials costs, waste removal costs, and industrial liability. As a valuable economic and environmental asset, the PF System has been named a winner of a 1995 R and D 100 Award. These awards are presented annually by R and D Magazine to the one hundred most significant technical innovations of the year. The PF System is based on the use of water-soluble metal-binding polymers and on advanced ultrafiltration membranes. Customers for this technology will receive new soluble polymers, especially formulated for their waste stream, and the complete PF processing unit: a reaction reservoir, pumps, plumbing, controls, and the advanced ultrafiltration membranes, all in a skid mounted frame. Metal-bearing waste water is treated in the reaction reservoir, where the polymer binds with the metal ions under balanced acid/base conditions. The reservoir fluid is then pumped through the ultrafiltration system--a cartridge packed with ultrafiltration membranes shaped in hollow fibers. As the fluid travels inside the fiber, water and other small molecules--simple salts such as calcium and sodium, for example--pass through the porous membrane walls of the fibers and are discharged through the outlet as permeate. The polymer-bound metal, which is too large to pass through the pores, is both purified and concentrated inside the hollow fibers and is returned to the fluid reservoir for further waste water treatment.

  19. Muon Tomography as a Tool to Detect Radioactive Source Shielding in Scrap Metal Containers

    NASA Astrophysics Data System (ADS)

    Bonomi, G.; Cambiaghi, D.; Dassa, L.; Donzella, A.; Subieta, M.; Villa, V.; Zenoni, A.; Furlan, M.; Rigoni, A.; Vanini, S.; Viesti, G.; Zumerle, G.; Benettoni, M.; Checchia, P.; Gonella, F.; Pegoraro, M.; Zanuttigh, P.; Calvagno, G.; Calvini, P.; Squarcia, S.

    2014-02-01

    Muon tomography was recently proposed as a tool to inspect large volumes with the purpose of recognizing high density materials immersed in lower density matrices. The MU-STEEL European project (RFCS-CT-2010-000033) studied the application of such a technique to detect radioactive source shielding in truck containers filled with scrap metals entering steel mill foundries. A description of the muon tomography technique, of the MU-STEEL project and of the obtained results will be presented.

  20. Evaluation of the electrorefining technique for the processing of radioactive scrap metals

    SciTech Connect

    Kessinger, G.F.

    1993-10-01

    This report presents the results of a literature study performed to identify applications of the electrorefining technique to the decontamination of radioactively-contaminated scrap metal (RSM). Upon the completion of the literature search and the review of numerous references, it was concluded that there were applications of this technique that were appropriate for the decontamination of some types of RSM, especially when the desired product is a pure elemental metal of high purity. It was also concluded that this technique was not well-suited for the decontamination of RSM stainless steels and other alloys, when it was desired that the metallurgical characteristics of the alloy be present in the decontaminated product.

  1. Beam dynamics of a liquid metal ion source

    SciTech Connect

    Whealton, J.H.; Meszaros, P.S.; Rothe, K.E.; Raridon, R.J.; Ryan, P.M.

    1989-01-01

    RMS emittance growth of liquid metal ion sources is studied. Processes included are nonlinear expansion through extractor and accelerator fringe fields, nonlinear beam space charge, plasma effects near needle, and waves (either ion-acoustic or space charge limited as considered by V.I. Dudnikov). This investigation consists of 2-D analysis of appropriate Vlasov-Poisson equations in both steady-state and time-dependent formulations. Various geometries will be considered such as some used by G. Alton of ORNL. 2 refs., 7 figs.

  2. Ab Initio Calculations Applied to Problems in Metal Ion Chemistry

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Partridge, Harry; Arnold, James O. (Technical Monitor)

    1994-01-01

    Electronic structure calculations can provide accurate spectroscopic data (such as molecular structures) vibrational frequencies, binding energies, etc.) that have been very useful in explaining trends in experimental data and in identifying incorrect experimental measurements. In addition, ab initio calculations. have given considerable insight into the many interactions that make the chemistry of transition metal systems so diverse. In this review we focus on cases where calculations and experiment have been used to solve interesting chemical problems involving metal ions. The examples include cases where theory was used to differentiate between disparate experimental values and cases where theory was used to explain unexpected experimental results.

  3. The Corrosion Protection of Metals by Ion Vapor Deposited Aluminum

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1993-01-01

    A study of the corrosion protection of substrate metals by ion vapor deposited aluminum (IVD Al) coats has been carried out. Corrosion protection by both anodized and unanodized IVD Al coats has been investigated. Base metals included in the study were 2219-T87 Al, 7075-T6 Al, Titanium-6 Al-4 Vanadium (Ti-6Al-4V), 4130 steel, D6AC steel, and 4340 steel. Results reveal that the anodized IVD Al coats provide excellent corrosion protection, but good protection is also achieved by IVD Al coats that have not been anodized.

  4. Radioactive ion beam transportation for the fundamental symmetry study with laser-trapped atoms

    NASA Astrophysics Data System (ADS)

    Arikawa, Hiroshi; Ando, S.; Aoki, T.; Ezure, S.; Harada, K.; Hayamizu, T.; Inoue, T.; Ishikawa, T.; Itoh, M.; Kawamura, H.; Kato, K.; Kato, T.; Uchiyama, A.; Aoki, T.; Furukawa, T.; Hatakeyama, A.; Hatanaka, K.; Imai, K.; Murakami, T.; Nataraj, H. S.; Sato, T.; Shimizu, Y.; Wakasa, T.; Yoshida, H. P.; Sakemi, Y.

    2014-02-01

    The search for the violation of the fundamental symmetry in a radioactive atom is the promising candidate for precision tests of the standard model and its possible extensions. The subtle signal arising from the symmetry violation is enhanced in heavy atoms, such as a francium (Fr). To realize high precision measurements, a large amount of radioactive isotopes is required. The Fr is produced via a nuclear fusion reaction using a melted gold target with a 18O primary beam at Cyclotron and Radioisotope Center, Tohoku University. The maximum extraction efficiency of the Fr ion was achieved at approximately 35%. The beam line consists of an electrostatic deflector, three electrostatic quadrupole triplets to the measurement area at 10 m away from the reaction point, and several beam diagnosis systems. We optimized parameters of the beam line.

  5. Radioactive ion beam transportation for the fundamental symmetry study with laser-trapped atoms.

    PubMed

    Arikawa, Hiroshi; Ando, S; Aoki, T; Ezure, S; Harada, K; Hayamizu, T; Inoue, T; Ishikawa, T; Itoh, M; Kawamura, H; Kato, K; Kato, T; Uchiyama, A; Aoki, T; Furukawa, T; Hatakeyama, A; Hatanaka, K; Imai, K; Murakami, T; Nataraj, H S; Sato, T; Shimizu, Y; Wakasa, T; Yoshida, H P; Sakemi, Y

    2014-02-01

    The search for the violation of the fundamental symmetry in a radioactive atom is the promising candidate for precision tests of the standard model and its possible extensions. The subtle signal arising from the symmetry violation is enhanced in heavy atoms, such as a francium (Fr). To realize high precision measurements, a large amount of radioactive isotopes is required. The Fr is produced via a nuclear fusion reaction using a melted gold target with a (18)O primary beam at Cyclotron and Radioisotope Center, Tohoku University. The maximum extraction efficiency of the Fr ion was achieved at approximately 35%. The beam line consists of an electrostatic deflector, three electrostatic quadrupole triplets to the measurement area at 10 m away from the reaction point, and several beam diagnosis systems. We optimized parameters of the beam line. PMID:24593466

  6. New reaction chamber for transient field g-factor measurements with radioactive ion beams

    NASA Astrophysics Data System (ADS)

    Illana, A.; Perea, A.; Nácher, E.; Orlandi, R.; Jungclaus, A.

    2015-06-01

    A new reaction chamber has been designed and constructed to measure g-factors of short-lived excited states using the Transient Field technique in combination with Coulomb excitation in inverse kinematics. In this paper we will discuss several important aspects which have to be considered in order to successfully carry out this type of measurement with radioactive ion beams, instead of the stable beams used in a wide range of experiments in the past. The technical solutions to the problems arising from the use of such radioactive beams will be exposed in detail and the first successful experiment using the new chamber in combination with MINIBALL cluster detectors at REX-ISOLDE (CERN) will be reported on.

  7. Radioactive ion beam transportation for the fundamental symmetry study with laser-trapped atoms

    SciTech Connect

    Arikawa, Hiroshi Ando, S.; Aoki, T.; Ezure, S.; Harada, K.; Hayamizu, T.; Inoue, T.; Ishikawa, T.; Itoh, M.; Kawamura, H.; Kato, K.; Kato, T.; Uchiyama, A.; Sakemi, Y.; Aoki, T.; Furukawa, T.; Hatakeyama, A.; Hatanaka, K.; Yoshida, H. P.; Imai, K.; and others

    2014-02-15

    The search for the violation of the fundamental symmetry in a radioactive atom is the promising candidate for precision tests of the standard model and its possible extensions. The subtle signal arising from the symmetry violation is enhanced in heavy atoms, such as a francium (Fr). To realize high precision measurements, a large amount of radioactive isotopes is required. The Fr is produced via a nuclear fusion reaction using a melted gold target with a {sup 18}O primary beam at Cyclotron and Radioisotope Center, Tohoku University. The maximum extraction efficiency of the Fr ion was achieved at approximately 35%. The beam line consists of an electrostatic deflector, three electrostatic quadrupole triplets to the measurement area at 10 m away from the reaction point, and several beam diagnosis systems. We optimized parameters of the beam line.

  8. Interactions of metal ions with ? synuclein and amyloid ? peptides

    NASA Astrophysics Data System (ADS)

    Valensin, Daniela; Kozlowski, Henryk; Tessari, Isabella; Dell'Acqua, Simone; Bubacco, Luigi; Casella, Luigi; Gaggelli, Elena; Valensin, Gianni

    2014-10-01

    Amyloid ? (A?) and alfa synuclein (?S) share the ability to selectively bind copper ions (Cu(II) and Cu(I)). During the last decade large efforts have been directed to fully characterize Cu(II) binding domains in A? and ?S. On the other hand, the corresponding Cu(I) sites have been less considered. In this study we have analyzed Cu(I) interactions with peptides derived from A? and ?S, by means of CD and NMR spectroscopy. Beyond Cu(I), we have also used Ag(I) as a probe. By monitoring the metal induced effects on ?S and A? systems, the Cu(I)/Ag(I) binding domains have been identified. The corresponding protein structural rearrangements induced by the metal ions have been investigated as well. The Cu(I) coordination spheres are discussed with a particular emphasis to the role played by Met and His residues.

  9. A metallic room-temperature oxide ion conductor.

    PubMed

    Heise, Martin; Rasche, Bertold; Isaeva, Anna; Baranov, Alexey I; Ruck, Michael; Schäfer, Konrad; Pöttgen, Rainer; Eufinger, Jens-Peter; Janek, Jürgen

    2014-07-01

    Nanoparticles of Bi3 Ir, obtained from a microwave-assisted polyol process, activate molecular oxygen from air at room temperature and reversibly intercalate it as oxide ions. The closely related structures of Bi3 Ir and Bi3 IrOx (x?2) were investigated by X-ray diffraction, electron microscopy, and quantum-chemical modeling. In the topochemically formed metallic suboxide, the intermetallic building units are fully preserved. Time- and temperature-dependent monitoring of the oxygen uptake in an oxygen-filled chamber shows that the activation energy for oxide diffusion (84?meV) is one order of magnitude smaller than that in any known material. Bi3 IrOx is the first metallic oxide ion conductor and also the first that operates at room temperature. PMID:24866268

  10. Note: An ion source for alkali metal implantation beneath graphene and hexagonal boron nitride monolayers on transition metals

    SciTech Connect

    Lima, L. H. de; Cun, H. Y.; Hemmi, A.; Kälin, T.; Greber, T.

    2013-12-15

    The construction of an alkali-metal ion source is presented. It allows the acceleration of rubidium ions to an energy that enables the penetration through monolayers of graphene and hexagonal boron nitride. Rb atoms are sublimated from an alkali-metal dispenser. The ionization is obtained by surface ionization and desorption from a hot high work function surface. The ion current is easily controlled by the temperature of ionizer. Scanning Tunneling Microscopy measurements confirm ion implantation.

  11. Metal ions: supporting actors in the playbook of small ribozymes.

    PubMed

    Johnson-Buck, Alexander E; McDowell, Sarah E; Walter, Nils G

    2011-01-01

    Since the 1980s, several small RNA motifs capable of chemical catalysis have been discovered. These small ribozymes, composed of between approximately 40 and 200 nucleotides, have been found to play vital roles in the replication of subviral and viral pathogens, as well as in gene regulation in prokaryotes, and have recently been discovered in noncoding eukaryotic RNAs. All of the known natural small ribozymes - the hairpin, hammerhead, hepatitis delta virus, Varkud satellite, and glmS ribozymes--catalyze the same self-cleavage reaction as RNase A, resulting in two products, one bearing a 2'-3' cyclic phosphate and the other a 5'-hydroxyl group. Although originally thought to be obligate metalloenzymes like the group I and II self-splicing introns, the small ribozymes are now known to support catalysis in a wide variety of cations that appear to be only indirectly involved in catalysis. Nevertheless, under physiologic conditions, metal ions are essential for the proper folding and function of the small ribozymes, the most effective of these being magnesium. Metal ions contribute to catalysis in the small ribozymes primarily by stabilizing the catalytically active conformation, but in some cases also by activating RNA functional groups for catalysis, directly participating in catalytic acid-base chemistry, and perhaps by neutralizing the developing negative charge of the transition state. Although interactions between the small ribozymes and cations are relatively nonspecific, ribozyme activity is quite sensitive to the types and concentrations of metal ions present in solution, suggesting a close evolutionary relationship between cellular metal ion homeostasis and cation requirements of catalytic RNAs, and perhaps RNA in general. PMID:22010272

  12. Gamma-Ray Spectroscopy at TRIUMF-ISAC: the New Frontier of Radioactive Ion Beam Research

    SciTech Connect

    Ball, G. C.; Bandyopadhyay, D.; Bricault, P.; Chan, S.; Churchman, R.; Coombes, H.; Dombsky, M.; Garnsworthy, A.; Hackman, G.; Lassen, J.; Morton, A. C.; Pearson, C. J.; Triambak, S.; Williams, S. J.; Andreoiu, C.; Cross, D.; Austin, R. A. E.; Colosimo, S.; Kanungo, R.; Becker, J. A.

    2009-03-31

    High-resolution gamma-ray spectroscopy is essential to fully exploit the unique scientific opportunities at the next generation radioactive ion beam facilities such as the TRIUMF Isotope Separator and Accelerator (ISAC). At ISAC the 8{pi} spectrometer and its associated auxiliary detectors is optimize for {beta}-decay studies while TIGRESS an array of segmented clover HPGe detectors has been designed for studies with accelerated beams. This paper gives a brief overview of these facilities and also presents recent examples of the diverse experimental program carried out at the 8{pi} spectrometer.

  13. MRI findings following metal on metal hip arthroplasty and their relationship with metal ion levels and acetabular inclination angles.

    PubMed

    Fox, Ciara M; Bergin, Karen M; Kelly, Gabrielle E; McCoy, Gerry F; Ryan, Anthony G; Quinlan, John F

    2014-08-01

    Following the global recall of all ASR metal on metal hip products, our aim was to correlate MRI findings with acetabular inclination angles and metal ion levels in patients with these implants. Both cobalt and chromium levels were significantly higher in the presence of a periprosthetic fluid collection. There was no association between the presence of a periprosthetic mass, bone marrow oedema, trochanteric bursitis or greater levels of abductor muscle destruction for cobalt or chromium. There was no association between the level of periprosthetic tissue reaction and the acetabular inclination angle with any of the pathologies identified on MRI. The relationship between MRI pathology, metal ion levels and acetabular inclination angles in patients with ASR implants remains unclear adding to the complexity of managing patients. PMID:24793890

  14. Nanostructure operations by means of the liquid metal ion sources.

    PubMed

    Gasanov, I S; Gurbanov, I I

    2012-02-01

    Characteristics of a disperse phase of liquid metal ion source on the basis of various working substances are investigated. It is revealed that generation of the charged particles occurs in the threshold image and is simultaneously accompanied by excitation of capillary instability on a surface of the emitter. The majority of particles has the size about 2 nm (Sn) and a specific charge of 5 × 10(4) C?kg. If the working liquid possesses high viscosity (Ni), generation of nanodroplets does not occur. Gold nanoparticles are used for deposition on a surface of quartz cantilevers with the purpose of increase in sensitivity of biosensors and on an external surface of carbon nanotubes for creation pressure sensors. By means of an ion source nanostructures can be etched on a flat surface of conductive materials without difficult ion optics. PMID:22380338

  15. Reservoir-type liquid metal ion source of Al

    NASA Astrophysics Data System (ADS)

    Yamada, Hiroshi; Torii, Yasuhiro

    1986-07-01

    A liquid metal ion source of Al with a boride reservoir was developed. In this reservoir a shorter boride emitter was designed to overcome the brittleness of boride materials and some problems in supplying the Al material. This source makes possible a long continuous operation time and enhanced reliability. The fundamental performance characteristics did not change after 250 h of operation. A stable Al ion beam emission was obtained for more than 500 h and its current fluctuation was less than ±1%/3 h for a 20-30-?A source ion current. The energy spread was less than 9 eV (FWHM) for a 30-?A/sr angular current intensity.

  16. Template-directed synthesis of oligoguanylic acids - Metal ion catalysis

    NASA Technical Reports Server (NTRS)

    Bridson, P. K.; Fakhrai, H.; Lohrmann, R.; Orgel, L. E.; Van Roode, M.

    1981-01-01

    The effects of Zn(2+), Pb(2+) and other metal ions on the efficiency and stereo-selectivity of the template-directed oligomerization of guanosine 5'-phosphorimidazolide are investigated. Reactions were run in the presence of a polyC template in a 2,6-lutidine buffer, and products analyzed by high-performance liquid chromatography on an RPC-5 column. The presence of the Pb(2+) ion is found to lead to the formation of 2'-5' linked oligomers up to the 40-mer, while Zn(2+) favors the formation of predominantly 3'-5' linked oligomers up to the 35-mer. When amounts of uracil, cytidine or adenosine 5'-phosphorimidazole equal to those of the guanosine derivative are included in the reaction mixture, the incorrect base is incorporated into the oligomer about 10% of the time with a Pb(2+) catalyst, but less than 0.5% of the time with Zn(2+). The Sn(2+), Sb(3+) and Bi(3+) ions are also found to promote the formation of 2'-5' oligomers, although not as effectively as Pb(2+), while no metal ions other than Zn(2+) promote the formation of the 3'-5' oligomers. The results may be important for the understanding of the evolution of nucleic acid replication in the absence of enzymes.

  17. In vivo liberation of silver ions from metallic silver surfaces.

    PubMed

    Danscher, Gorm; Locht, Linda Jansons

    2010-03-01

    In vivo liberation of electrically charged silver atoms/silver ions from metallic silver pellets, silver grids and silver threads placed in the brain, skin and abdominal cavity was proved by way of the histochemical technique autometallography (AMG). A bio-film or "dissolution membrane" inserted between the metallic surface and macrophages was recognized on the surface of the implanted silver after a short period of time. Bio-released silver ions bound in silver-sulphur nanocrystals were traced within the first 24 h in the "dissolution membrane" and the "dissolucytotic" macrophages. In animals that had survived 10 days or more, silver nanocrystals were detected both extra- and intracellularly in places far away from the implant including regional lymph nodes, liver, kidneys and the central nervous system (CNS). The accumulated silver was always confined to lysosome-like organelles. Dissolucytotic silver was extracellularly related to collagen fibrils and fibres in connective tissue and basement membranes. Our study demonstrates that (1) the number of bio-released silver ions depends on the size of the surface of the implanted silver, (2) the spread of silver ions throughout the body takes place primarily not only through the vascular system, but also by retrograde axonal transport. It is concluded that implantation of silver or silver-plated devices is not recommendable. PMID:20033701

  18. Long-life bismuth liquid metal ion source for focussed ion beam micromachining application

    NASA Astrophysics Data System (ADS)

    Mazarov, P.; Melnikov, A.; Wernhardt, R.; Wieck, A. D.

    2008-09-01

    Liquid metal ion sources (LMISs) with Ga as ion species are widely used in focused ion beam (FIB) technology for micromachining and surface treatment on the sub-micron and nano-scale. Key features of a LMIS for investigating mechanical properties and 3D-microfabrication of materials are long life-time, high brightness, stable ion current and a highly effective milling ability for the material to be modified. In order to increase the material removal rate, heavier ions than Ga and their clusters should be applied. Bismuth (Bi) is the heaviest, non-radio-active element in the periodic table, is non-toxic and exhibits a low melting point. We have thus produced a long-life (about 1000 h) Bi LMIS with a good beam performance, applicable in any FIB system. Since Bi is the only element in this source, it is not necessary to separate it from other ions by a mass filter. Investigation of the sputtering rate of NiTi shape memory alloys using Ga and Bi LMIS showed that, for the same experimental conditions, the material removal rate with using of Bi nk+ ions in a standard FIB machine without a mass separator is about five times larger compared to Ga + ions. This use of Bi as LMIS-species is the ultimate breakthrough in sputtering applications.

  19. Two distinct modes of metal ion binding in the nuclease active site of a viral DNA-packaging terminase: insight into the two-metal-ion catalytic mechanism.

    PubMed

    Zhao, Haiyan; Lin, Zihan; Lynn, Anna Y; Varnado, Brittany; Beutler, John A; Murelli, Ryan P; Le Grice, Stuart F J; Tang, Liang

    2015-12-15

    Many dsDNA viruses encode DNA-packaging terminases, each containing a nuclease domain that resolves concatemeric DNA into genome-length units. Terminase nucleases resemble the RNase H-superfamily nucleotidyltransferases in folds, and share a two-metal-ion catalytic mechanism. Here we show that residue K428 of a bacteriophage terminase gp2 nuclease domain mediates binding of the metal cofactor Mg(2+). A K428A mutation allows visualization, at high resolution, of a metal ion binding mode with a coupled-octahedral configuration at the active site, exhibiting an unusually short metal-metal distance of 2.42 Å. Such proximity of the two metal ions may play an essential role in catalysis by generating a highly positive electrostatic niche to enable formation of the negatively charged pentacovalent phosphate transition state, and provides the structural basis for distinguishing Mg(2+) from Ca(2+). Using a metal ion chelator ?-thujaplicinol as a molecular probe, we observed a second mode of metal ion binding at the active site, mimicking the DNA binding state. Arrangement of the active site residues differs drastically from those in RNase H-like nucleases, suggesting a drifting of the active site configuration during evolution. The two distinct metal ion binding modes unveiled mechanistic details of the two-metal-ion catalysis at atomic resolution. PMID:26450964

  20. Two distinct modes of metal ion binding in the nuclease active site of a viral DNA-packaging terminase: insight into the two-metal-ion catalytic mechanism

    PubMed Central

    Zhao, Haiyan; Lin, Zihan; Lynn, Anna Y.; Varnado, Brittany; Beutler, John A.; Murelli, Ryan P.; Le Grice, Stuart F. J.; Tang, Liang

    2015-01-01

    Many dsDNA viruses encode DNA-packaging terminases, each containing a nuclease domain that resolves concatemeric DNA into genome-length units. Terminase nucleases resemble the RNase H-superfamily nucleotidyltransferases in folds, and share a two-metal-ion catalytic mechanism. Here we show that residue K428 of a bacteriophage terminase gp2 nuclease domain mediates binding of the metal cofactor Mg2+. A K428A mutation allows visualization, at high resolution, of a metal ion binding mode with a coupled-octahedral configuration at the active site, exhibiting an unusually short metal-metal distance of 2.42 Å. Such proximity of the two metal ions may play an essential role in catalysis by generating a highly positive electrostatic niche to enable formation of the negatively charged pentacovalent phosphate transition state, and provides the structural basis for distinguishing Mg2+ from Ca2+. Using a metal ion chelator ?-thujaplicinol as a molecular probe, we observed a second mode of metal ion binding at the active site, mimicking the DNA binding state. Arrangement of the active site residues differs drastically from those in RNase H-like nucleases, suggesting a drifting of the active site configuration during evolution. The two distinct metal ion binding modes unveiled mechanistic details of the two-metal-ion catalysis at atomic resolution. PMID:26450964

  1. Acetabular bone density and metal ions after metal-on-metal versus metal-on-polyethylene total hip arthroplasty; short-term results.

    PubMed

    Zijlstra, Wierd P; van der Veen, Hugo C; van den Akker-Scheek, Inge; Zee, Mark J M; Bulstra, Sjoerd K; van Raay, Jos J A M

    2014-01-01

    Information on periprosthetic acetabular bone density is lacking for metal-on-metal total hip arthroplasties. These bearings use cobalt-chromium instead of titanium acetabular components, which could lead to stress shielding and hence periprosthetic bone loss. Cobalt and chromium ions have detrimental effects on bone. It is unknown whether serum metal ion levels affect bone density clinically. We compared cementless large femoral head (mean 48 mm) metal-on-metal total hip arthroplasties (M2a-Magnum, Biomet) to cementless 28 mm metal-on-polyethylene total hip arthroplasties (Mallory-Head, Biomet) in a randomised clinical trial. We evaluated periprosthetic acetabular bone density and serum metal ion levels at 1 year postoperatively. Acetabular bone density was analyzed with dual energy x-ray absorptiometry in four horizontal regions of interest in 70 patients. After one year, acetabular bone density decreased (-3.5% to -7.8%) in three of four regions of interest in metal-on-polyethylene patients, but was retained in metal-on-metal patients. Bone density preservation was most pronounced superior to the metal-on-metal cup (+1% versus -3.7%). Serum cobalt, chromium and titanium ion levels were not related to bone density, nor to acetabular inclination or femoral head size. Oxford and Harris hip scores were similar in both groups. Contrary to our hypothesis, acetabular bone density was retained with metal-on-metal total hip arthroplasty, compared to metal-on-polyethylene arthroplasty. Bone preservation was most pronounced in the area superior to the cup. This could be a benefit during future revision surgery. PMID:24186673

  2. Molecular designs for controlling the local environments around metal ions.

    PubMed

    Cook, Sarah A; Borovik, A S

    2015-08-18

    The functions of metal complexes are directly linked to the local environment in which they are housed; modifications to the local environment (or secondary coordination sphere) are known to produce changes in key properties of the metal centers that can affect reactivity. Noncovalent interactions are the most common and influential forces that regulate the properties of secondary coordination spheres, which leads to complexities in structure that are often difficult to achieve in synthetic systems. Using key architectural features from the active sites of metalloproteins as inspiration, we have developed molecular systems that enforce intramolecular hydrogen bonds (H-bonds) around a metal center via incorporation of H-bond donors and acceptors into rigid ligand scaffolds. We have utilized these molecular species to probe mechanistic aspects of biological dioxygen activation and water oxidation. This Account describes the stabilization and characterization of unusual M-oxo and heterobimetallic complexes. These types of species have been implicated in a range of oxidative processes in biology but are often difficult to study because of their inherent reactivity. Our H-bonding ligand systems allowed us to prepare an Fe(III)-oxo species directly from the activation of O2 that was subsequently oxidized to form a monomeric Fe(IV)-oxo species with an S = 2 spin state, similar to those species proposed as key intermediates in non-heme monooxygenases. We also demonstrated that a single Mn(III)-oxo center that was prepared from water could be converted to a high-spin Mn(V)-oxo species via stepwise oxidation, a process that mimics the oxidative charging of the oxygen-evolving complex (OEC) of photosystem II. Current mechanisms for photosynthetic O-O bond formation invoke a Mn(IV)-oxyl species rather than the isoelectronic Mn(V)-oxo system as the key oxidant based on computational studies. However, there is no experimental information to support the existence of a Mn-oxyl radical. We therefore probed the amount of spin density on the oxido ligand of our complexes using EPR spectroscopy in conjunction with oxygen-17 labeling. Our findings showed that there is a significant amount of spin on the oxido ligand, yet the M-oxo bonds are best described as highly covalent and there is no indication that an oxyl radical is formed. These results offer the intriguing possibility that high-spin M-oxo complexes are involved in O-O bond formation in biology. Ligand redesign to incorporate H-bond accepting units (sulfonamido groups) simultaneously provided a metal ion binding pocket, adjacent H-bond acceptors, and an auxiliary binding site for a second metal ion. These properties allowed us to isolate a series of heterobimetallic complexes of Fe(III) and Mn(III) in which a group II metal ion was coordinated within the secondary coordination sphere. Examination of the influence of the second metal ion on the electron transfer properties of the primary metal center revealed unexpected similarities between Ca(II) and Sr(II) ions, a result with relevance to the OEC. In addition, the presence of a second metal ion was found to prevent intramolecular oxidation of the ligand with an O atom transfer reagent. PMID:26181849

  3. The beam diagnostic instruments in Beijing radioactive ion-beam facilities isotope separator on-line

    NASA Astrophysics Data System (ADS)

    Ma, Y.; Cui, B.; Ma, R.; Tang, B.; Chen, L.; Huang, Q.; Jiang, W.

    2014-02-01

    The beam diagnostic instruments for Beijing Radioactive Ion-beam Facilities Isotope Separator On-Line are introduced [B. Q. Cui, Z. H. Peng, Y. J. Ma, R. G. Ma, B. Tang, T. Zhang, and W. S. Jiang, Nucl. Instrum. Methods 266, 4113 (2008); T. J. Zhang, X. L. Guan, and B. Q. Cui, in Proceedings of APAC 2004, Gyeongju, Korea, 2004, http://www.jacow.org, p. 267]. For low intensity ion beam [30-300 keV/1 pA-10 ?A], the beam profile monitor, the emittance measurement unit, and the analyzing slit will be installed. For the primary proton beam [100 MeV/200 ?A], the beam profile scanner will be installed. For identification of the nuclide, a beam identification unit will be installed. The details of prototype of the beam diagnostic units and some experiment results will be described in this article.

  4. The beam diagnostic instruments in Beijing radioactive ion-beam facilities isotope separator on-line

    SciTech Connect

    Ma, Y. Cui, B.; Ma, R.; Tang, B.; Chen, L.; Huang, Q.; Jiang, W.

    2014-02-15

    The beam diagnostic instruments for Beijing Radioactive Ion-beam Facilities Isotope Separator On-Line are introduced [B. Q. Cui, Z. H. Peng, Y. J. Ma, R. G. Ma, B. Tang, T. Zhang, and W. S. Jiang, Nucl. Instrum. Methods 266, 4113 (2008); T. J. Zhang, X. L. Guan, and B. Q. Cui, in Proceedings of APAC 2004, Gyeongju, Korea, 2004, http://www.jacow.org , p. 267]. For low intensity ion beam [30–300 keV/1 pA–10 ?A], the beam profile monitor, the emittance measurement unit, and the analyzing slit will be installed. For the primary proton beam [100 MeV/200 ?A], the beam profile scanner will be installed. For identification of the nuclide, a beam identification unit will be installed. The details of prototype of the beam diagnostic units and some experiment results will be described in this article.

  5. Treatment and Stabilization of Potentially Pyrophoric Radioactive Metal Chips and Turnings

    SciTech Connect

    Crocker, B.R.; Grondin, R.; Yarbrough, T.

    2006-07-01

    As part of the continuing mission to decontaminate, decommission, and restore environmental quality at multiple sites throughout the U.S. Department of Energy (US DOE) nuclear complex, approximately 2,000 containers of potentially pyrophoric radioactive metal chips and turnings, weighing over 192,000 kilograms have been identified. These wastes, mostly depleted uranium (DU) and thorium metals, must be treated to remove or immobilize a wide range of hazardous and toxic regulated waste constituents without igniting the radioactive metal. Also, the treated metal wastes must be placed in an inert condition to prevent any future pyrophoric problems during storage, transportation, and disposal. All secondary wastes resulting from treatment activities must have a pathway to final disposal or destruction, in accordance with all applicable US federal and state laws, and regulations. To further this mission and to begin reducing the pyrophoric radioactive metal inventories throughout the US DOE system, a contract was awarded to Perma-Fix Environmental Services, Inc. to develop appropriate treatment methods, prove those methods in a First Article Test (FAT), and treat US DOE's existing inventory of pyrophoric radioactive metal wastes. The FAT was performed successfully between October 2002 and December 2002 using four containers of waste from the Rocky Flats Environmental Technology Site. The treated chips and turnings from this FAT were shipped for disposal at a private land disposal facility in the State of Utah. Since the FAT, two full-scale treatment projects have been performed under the contract. Between November 6, 2003 and March 4, 2004, 478 containers of Hanford DU chip wastes in mineral oil and soil matrices were treated. The treated chip waste was returned for disposal at the permitted mixed waste landfill at the Hanford Site. Between February 5, 2004, and February 25, 2005, another 222 containers of Rocky Flats DU chip waste, comprised of three distinct physical waste forms, were treated and disposed at the same land disposal facility in Utah. Complicating this task was the wide variety of hazardous and toxic contaminants, and great variability in the physical waste form. The chemical contaminants included mineral oil, polychlorinated biphenyls (PCBs), numerous volatile and semi-volatile organic contaminants, and toxic metals. Three main physical waste forms were included in the US DOE pyrophoric radioactive metal waste inventory: (1) chips and turnings in oil, (2) chips and turnings in soil, and (3) chips and turnings in sludge. The successful treatment method had to be capable of removing oil, PCBs, and volatile organics without resulting in ignition of the pyrophoric metals. After successful removal of hazardous and toxic organic contaminants, the toxic metals remaining in the waste required further stabilization to limit their potential for long-term leaching in land disposal facilities. The final waste form and its packaging also had to comply with the waste acceptance criteria of the land disposal facilities at the US DOE Hanford Site, in Richland, Washington, and the private disposal facility in Utah. This paper will describe the treatment process, the challenges encountered and overcome, the lessons learned, and final quality of the treated chip waste. Disposal and/or destruction of secondary wastes from the treatment process will also be discussed. (authors)

  6. Optical metal-organic framework sensor for selective discrimination of some toxic metal ions in water.

    PubMed

    Shahat, Ahmed; Hassan, Hassan M A; Azzazy, Hassan M E

    2013-09-01

    This paper reports the development of a facile and effective approach, based on the use of Zr-based metal-organic frameworks (UiO-66) sensor with micropores geometry, shape and particle morphology for the visual detection and removal of ultra-traces of some toxic metal ions such as Bi(III), Zn(II), Pb(II), Hg(II) and Cd(II). UiO-66 was used as selective carriers for accommodating hydrophobic chromophore probes such as dithizone (DZ) without coupling agent for sensitive and selective discrimination of trace level of toxic analytes. The developed UiO-66 sensor was utilized for the detection of ultra-traces of some toxic metal ions with the naked eye. The new sensor displays high sensitivity and selectivity of a wide range of detectable metals analytes up to 10(-10) mol dm(-3) in solution, in a rapid analyte uptake response (seconds). The developed sensor is stable, cost effective, easy to prepare, and would be useful for rapid detection and removal of ultra-traces of toxic metal ions in water samples. PMID:23953211

  7. Designated Drivers: The Differing Roles of Divalent Metal Ions in Surfactant Adsorption at the Oil-Water Interface

    E-print Network

    Richmond, Geraldine L.

    decanoate at the carbon tetrachloride-water interface. For all ions studied, the ions drive the adsorption been extensive studies modeling humic acid to understand the binding activities of metal ions.1-9 Metal In addition, metal ions, particularly transition metals, are required for catalysis in roughly one

  8. Metal Ion Binding and Enzymatic Mechanism of Methanococcus jannaschii RNase Bing Lai, Ying Li, Aoneng Cao, and Luhua Lai*

    E-print Network

    Luhua, Lai

    Metal Ion Binding and Enzymatic Mechanism of Methanococcus jannaschii RNase HII Bing Lai, Ying Li the RNA moiety in DNA:RNA hybrid in a divalent metal ion dependent manner. It is essential to understand the role of metal ion in enzymatic mechanism. One of the key points in this study is how many metal ions

  9. Sputtering of metals at ion-electron irradiation

    NASA Astrophysics Data System (ADS)

    Martynenko, Yu. V.; Korshunov, S. N.; Skorlupkin, I. D.

    2014-02-01

    It has been found that, in contrast to the commonly accepted opinion, simultaneous irradiation by 15-keV Ar+ ions and 2.5-keV electrons at temperatures above 0.5 T m ( T m is the melting temperature) induces much larger sputtering of metallic copper, nickel, and steel than irradiation only by Ar+ ions. The effect increases with the temperature. At T = 0.7 T m, the sputtering coefficients in the case of ion-electron irradiation are more than twice as large as the sputtering coefficients in the case of irradiation by Ar+ ions. The experiments on the sublimation of copper show that the sublimation rate in the case of the heating of a sample by an electron beam is higher than that in the case of heating in an electric vacuum oven. The revealed effects are explained by the electron-induced excitation of adatoms (atoms stuck over the surface, which appear owing to ion bombardment). Excited adatoms have a smaller binding energy with the surface and are sputtered more easily.

  10. Headgroup interactions and ion flotation efficiency in mixtures of a chelating surfactant, different foaming agents, and divalent metal ions.

    PubMed

    Svanedal, Ida; Boija, Susanne; Norgren, Magnus; Edlund, Håkan

    2014-06-10

    The correlation between interaction parameters and ion flotation efficiency in mixtures of chelating surfactant metal complexes and different foaming agents was investigated. We have recently shown that chelating surfactant 2-dodecyldiethylenetriaminepentaacetic acid (4-C12-DTPA) forms strong coordination complexes with divalent metal ions, and this can be utilized in ion flotation. Interaction parameters for mixed micelles and mixed monolayer formation for Mg(2+) and Ni(2+) complexes with the chelating surfactant 4-C12-DTPA and different foaming agents were calculated by Rubingh's regular solution theory. Parameters for the calculations were extracted from surface tension measurements and NMR diffusometry. The effects of metal ion coordination on the interactions between 4-C12-DTPA and the foaming agents could be linked to a previously established difference in coordination chemistry between the examined metal ions. As can be expected from mixtures of amphoteric surfactants, the interactions were strongly pH-dependent. Strong correlation was found between interaction parameter ?(?) for mixed monolayer formation and the phase-transfer efficiency of Ni(2+) complexes with 4-C12-DTPA during flotation in a customized flotation cell. In a mixture of Cu(2+) and Zn(2+), the significant difference in conditional stability constants (log K) between the metal complexes was utilized to selectively recover the metal complex with the highest log K (Cu(2+)) by ion flotation. Flotation experiments in an excess concentration of metal ions confirmed the coordination of more than one metal ion to the headgroup of 4-C12-DTPA. PMID:24824327

  11. Proceedings of the workshop on the science of intense radioactive ion beams

    SciTech Connect

    McClelland, J.B.; Vieira, D.J.

    1990-10-01

    This report contains the proceedings of a 2-1/2 day workshop on the Science of Intense Radioactive Ion Beams which was held at the Los Alamos National Laboratory on April 10--12, 1990. The workshop was attended by 105 people, representing 30 institutions from 10 countries. The thrust of the workshop was to develop the scientific opportunities which become possible with a new generation intense Radioactive Ion Beam (RIB) facility, currently being discussed within North America. The workshop was organized around five primary topics: (1) reaction physics; (2) nuclei far from stability/nuclear structure; (3) nuclear astrophysics; (4) atomic physics, material science, and applied research; and (5) facilities. Overview talks were presented on each of these topics, followed by 1-1/2 days of intense parallel working group sessions. The final half day of the workshop was devoted to the presentation and discussion of the working group summary reports, closing remarks and a discussion of future plans for this effort.

  12. No association between serum metal ions and implant fixation in large-head metal-on-metal total hip arthroplasty

    PubMed Central

    Søballe, Kjeld; Jakobsen, Stig Storgaard; Lorenzen, Nina Dyrberg; Mechlenburg, Inger; Stilling, Maiken

    2014-01-01

    Background The mechanism of failure of metal-on-metal (MoM) total hip arthroplasty (THA) has been related to a high rate of metal wear debris, which is partly generated from the head-trunnion interface. However, it is not known whether implant fixation is affected by metal wear debris. Patients and methods 49 cases of MoM THA in 41 patients (10 women) with a mean age of 52 (28–68) years were followed with stereoradiographs after surgery and at 1, 2, and 5 years to analyze implant migration by radiostereometric analysis (RSA). Patients also participated in a 5- to 7-year follow-up with measurement of serum metal ions, questionnaires (Oxford hip score (OHS) and Harris hip score (HHS)), and measurement of cup and stem positions and systemic bone mineral density. Results At 1–2 years, mean total translation (TT) was 0.04 mm (95% CI: –0.07 to 0.14; p = 0.5) for the stems; at 2–5 years, mean TT was 0.13 mm (95% CI: –0.25 to –0.01; p = 0.03), but within the precision limit of the method. For the cups, there was no statistically significant TT or total rotation (TR) at 1–2 and 2–5 years. At 2–5 years, we found 4 cups and 5 stems with TT migrations exceeding the precision limit of the method. There was an association between cup migration and total OHS < 40 (4 patients, 4 hips; p = 0.04), but there were no statistically significant associations between cup or stem migration and T-scores < –1 (n = 10), cup and stem positions, or elevated serum metal ion levels (> 7µg/L (4 patients, 6 hips)). Interpretation Most cups and stems were well-fixed at 1–5 years. However, at 2–5 years, 4 cups and 5 stems had TT migrations above the precision limits, but these patients had serum metal ion levels similar to those of patients without measurable migrations, and they were pain-free. Patients with serum metal ion levels > 7 µg/L had migrations similar to those in patients with serum metal ion levels < 7 µg/L. Metal wear debris does not appear to influence the fixation of hip components in large-head MoM articulations at medium-term follow-up. PMID:24847790

  13. Theory of Auger neutralization and deexcitation of slow ions at metal surfaces M. A. Cazalilla

    E-print Network

    Muiño, Ricardo Díez

    Theory of Auger neutralization and deexcitation of slow ions at metal surfaces M. A. Cazalilla electrons to the Auger neutralization rate of a slow ion at a metal surface has been calculated. We have considered the scattering of He on Al and studied the effect of the ion potential on the neutralization rate

  14. Pulsed ion beam treatment of metals for improved surface properties

    SciTech Connect

    Renk, T.J.; Buchheit, R.; Sorensen, R.; Thompson, M.O.; Grabowski, K.S.

    1996-12-31

    This work builds on previously reported studies using an intense pulsed ion beam to achieve a rapid melt and resolidification (RMR) of a surface metallic layer. Alloys and bi-metal combinations were treated on the RHEPP-1 facility at Sandia National Laboratories sample location, < 10 J/cm{sup 2}. Numerical modeling of thermal histories neglecting ablation have yielded predictions consistent with diagnostic measurements of treated samples. The measurements included scanning electron microscopy (SEM), Rutherford Backscattering Spectrometry (RBS), X-Ray Diffraction (XRD), and electrochemical corrosion tests. Treatment of Al-, Fe-, and Ti-based alloys with multiple beam shots indicates that the extent and nature of beam-induced modification depends on the particular alloy, and on the total number of RMR cycles. Microhardness measurements of a treated and sectioned SS-304 sample show enhancements over bulk values of as much as 50%, and extending over 100 {micro}m below the surface. In treatment of bi-metal combinations (Ion Beam Mixing), the authors have investigated overcoats on Al-, Fe, and Ti-based alloys, where the overcoat layer is applied to the substrate by conventional means such as sputter deposition. In the case of Al, it is well known that certain transition metals (Ti, Cr, Zr, Nb, Hf) can improve corrosion resistance, but are almost insoluble in Al under equilibrium conditions. They have treated samples overcoated with all the metals listed, in thickness ranging from 300 {angstrom} to 2 {micro}m RBS measurements how the overcoat to have mixed into the substrate in peak amounts ranging from 2 at% to 8% to 30%.

  15. Temperature Dependence On The Emission Characteristics Of A AuGe Liquid Metal Alloy Ion Source

    SciTech Connect

    Ganetsos, Theodore; Laskaris, Nikos; Kotsos, Bill; Bischoff, Lothar; Pilz, Wolfgang; Akhmadaliev, Chavkat

    2007-04-23

    Focused ion beam systems employing liquid metal ion sources have become of increasing importance in the microelectronics industry. Maskless ion implantation as a modern patterning technique is one of the most attractive application of Focused Ion Beams. In spite of the fact that a great deal of research has been carried out on liquid metal ion sources, surprisingly few results exist on the temperature dependence of their emission characteristics. In this article we study a AuGe liquid metal alloy ion source. The unusual results are explained in terms of the abnormal behavior of the surface tension of the alloy with temperature.

  16. Mutation of outer-shell residues modulates metal ion co-ordination strength in a metalloenzyme.

    PubMed

    Foo, Jee-Loon; Jackson, Colin J; Carr, Paul D; Kim, Hye-Kyung; Schenk, Gerhard; Gahan, Lawrence R; Ollis, David L

    2010-07-15

    The metal ion co-ordination sites of many metalloproteins have been characterized by a variety of spectroscopic techniques and small-molecule model systems, revealing many important insights into the structural determinants of metal ion co-ordination. However, our understanding of this fundamentally and practically important phenomenon remains frustratingly simplistic; in many proteins it is essentially impossible to predict metal ion specificity and the effects of remote 'outer-shell' residues on metal ion co-ordination strength are also poorly defined. This is exemplified by our inability to explain why metalloenzymes with identical metal ion co-ordination spheres, such as the closely related orthologues of bacterial PTE (phosphotriesterase) from Agrobacterium radiobacter and Pseudomonas diminuta, display different metal ion specificity and co-ordination strength. In the present study, we present a series of PTE variants that all possess identical metal ion co-ordination spheres, yet display large differences in their metal ion co-ordination strength. Using measurement of the rates of metal ion dissociation from the active site alongside analysis of structural data obtained through X-ray crystallography, we show that 'outer-shell' residues provide essential support for the metal ion ligands, in effect buttressing them in their optimal orientation. Remote mutations appear to modulate metal ion interactions by increasing or decreasing the stabilizing effects of these networks. The present study therefore provides a description of how the greater protein fold can be modified to 'tune' the strength of metal ion co-ordination and metal ion specificity, as well as reinforcing the concept of proteins as ensembles of conformational states with unique structures and biochemical properties. PMID:20459397

  17. How do coinage metal ions bind to benzene?

    NASA Astrophysics Data System (ADS)

    Dargel, Thomas K.

    1999-02-01

    The interaction of the metal ions Cu+, Ag+, and Au+ with a benzene molecule has been investigated employing various quantum chemical strategies such as density functionals, Hartree-Fock, second-order perturbation theory and coupled cluster techniques. The three coinage metal cations show interesting differences in their preferred site of complexation with the pisystem of benzene. Cu prefers a highly symmetric eta6 arrangement. In the Ag+-C6H6 complex the metal ion can change its position above the whole pi plane of benzene virtually barrier free. For Au the calculations predict as favoured site of complexation a position above the carbon backbone, i.e., at the periphery and not in the centre of the benzene ring. Unlike copper or silver, this latter site of complexation is significantly less stable in the case of gold. At our most sophisticated level of theory, the computationally predicted binding energies agree well with the experimental numbers for the copper and silver complexes. For the gold complex only an estimate is available experimentally and the calculated number probably provides the most accurate result for this property so far. 6 6

  18. New Catalytic DNA Biosensors for Radionuclides and Metal ions

    SciTech Connect

    Lu, Yi

    2003-06-01

    The goals of the project are to develop new catalytic DNA biosensors for simultaneous detection and quantification of bioavailable radionuclides and metal ions, and apply the sensors for on-site, real-time assessment of concentration, speciation and stability of the individual contaminants during and after bioremediation. A negative selection strategy was tested and validated. In vitro selection was shown to yield highly active and specific transition metal ion-dependent catalytic DNA/RNA. A fluorescence resonance energy transfer (FRET) study of in vitro selected DNA demonstrated that the trifluorophore labeled system is a simple and powerful tool in studying complex biomolecules structure and dynamics, and is capable of revealing new sophisticated structural changes. New fluorophore/quenchers in a single fluorosensor yielded improved signal to noise ratio in detection, identification and quantification of metal contaminants. Catalytic DNA fluorescent and colorimetric sensors were shown useful in sensing lead in lake water and in leaded paint. Project results were described in two papers and two patents, and won an international prize.

  19. New Catalytic DNA Biosensors for Radionuclides and Metal ions

    SciTech Connect

    Lu, Yi

    2002-06-01

    The goals of the project are to develop new catalytic DNA biosensors for simultaneous detection and quantification of bioavailable radionuclides and metal ions, and apply the sensors for on-site, real-time assessment of concentration, speciation and stability of the individual contaminants during and after bioremediation. A negative selection strategy was tested and validated. In vitro selection was shown to yield highly active and specific transition metal ion-dependent catalytic DNA/RNA. A fluorescence resonance energy transfer (FRET) study of in vitro selected DNA demonstrated that the trifluorophore labeled system is a simple and powerful tool in studying complex biomolecules structure and dynamics, and is capable of revealing new sophisticated structural changes. New fluorophore/quenchers in a single fluorosensor yielded improved signal to noise ratio in detection, identification and quantification of metal contaminants. Catalytic DNA fluorescent and colorimetric sensors were shown useful in sensing lead in lake water and in leaded paint. Project results were described in two papers and two patents, and won an international prize.

  20. Metal Ions: Driving the Orderly Assembly of Polyelectrolytes at a Hydrophobic Surface

    E-print Network

    Richmond, Geraldine L.

    Metal Ions: Driving the Orderly Assembly of Polyelectrolytes at a Hydrophobic Surface Daniel K occurring polyelectrolytes are highly tunable and depend strongly on the binding of metal ions commonly found in environmental and biological systems. While the metal complexation behaviors of many

  1. Removal of Radioactive Nuclides by Multi-Functional Microcapsules Enclosing Inorganic Ion-Exchangers and Organic Extractants

    SciTech Connect

    Mimura, H.; Akiba, K.; Onodera, Y.

    2002-02-26

    The microcapsules enclosing two kinds of functional materials, inorganic ion-exchangers and organic extractants, were prepared by taking advantage of the high immobilization ability of alginate gel polymer. The fine powders of inorganic ion-exchanger and oil drops of extractant were kneaded with sodium alginate (NaALG) solution and the kneaded sol readily gelled in a salt solution of CaCl2, BaCl2 or HCl to form spherical gel particles. The uptake properties of various nuclides, 137Cs, 85Sr, 60Co, 88Y, 152Eu and 241Am, for thirty-four specimens of microcapsules in the presence of 10-1-10-4 M HNO3 were evaluated by the batch method. The distribution coefficient (Kd) of Cs+ above 103 cm3/g was obtained for the microcapsules enclosing CuFC or AMP. The Kd of Sr2+ around 102 cm3/g was obtained for the microcapsules containing clinoptilolite, antimonic acid, zeolite A, zeolite X or titanic acid. The microcapsules enclosing DEHPA exhibited relatively large Kd values of trivalent metal ions above 103 cm3/g; for example, the Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ for a favorable microcapsule (CuFC/clinoptilolite/DEHPA/CaALG) were 1.1x104, 7.5x10, 1.1x10, 1.0x104, 1.4x104, 3.4x103 cm3/g, respectively. The uptake rates of Cs+, Y3+, Eu3+ and Am3+ for this microcapsule were rather fast; the uptake percentage above 90% was obtained after 19 h-shaking and the uptake equilibrium was attained within 1 d. The AMP/CaALG exhibited high uptake ability for Cs+ even after irradiation of 188 kGy, and DEHPA/CaALG microcapsule had similar Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ ions before and after irradiation. The microcapsules with various shapes such as spherical, columnar, fibrous and filmy forms were easily prepared by changing the way of dipping kneaded sol into gelling salt solution. The microcapsules enclosing inorganic ion-exchangers and extractants have a potential possibility for the simultaneous removal of various radioactive nuclides from waste solutions.

  2. Pollution of the Begej Canal sediment--metals, radioactivity and toxicity assessment.

    PubMed

    Dalmacija, B; Prica, M; Ivancev-Tumbas, I; van der Kooij, A; Roncevic, S; Krcmar, D; Bikit, I; Teodorovic, I

    2006-07-01

    The Begej Canal is one among a large number of canals in Vojvodina (Northern Province of Serbia and Montenegro). The paper describes a study of metal and radioactivity contamination of the Begej Canal sediment. It is also concerned with the evaluation of sediment acute toxicity based on standard test species Daphnia magna and simultaneously extracted metals and acid volatile sulfides. The quality of sediment was assessed according to Dutch standards, but the results were also compared with some Canadian and USEPA (United States Environmental Protection Agency) guidelines for sediment quality. The results showed severe pollution with chromium, copper, cadmium and zinc, whereby the anthropogenic origin of these contaminants was indicated. The tests of toxicity of sediment pore water to D. magna, gave no indication of the presence of substances in acutely toxic concentrations to this species. It can be speculated that, despite of high metal contents, the observed toxicity was low because of the high contents of clay and iron, as well as sulphide. Also, based on a comparison with the Danube sediment and Vojvodina soil in general, the data of the Begej sediment contamination with 238U and 137Cs. The 137Cs data were used for approximate dating of the sediment. No traces of contamination by nuclear power plants in the region were found, while the presence of technologically enhanced naturally occurring radioactive materials (TENORM) was proved. Conclusions based on different criteria for sediment quality assessment were in some cases contradictory. Study also showed that radioactivity aspects can be useful in sediment quality surveys. The obtained results will be invaluable for the future activities regarding integrated water management based on EC Water Framework Directive (2000/60/EC) in the Danube basin, and particularly in the region of crossborder water body of the Begej Canal. PMID:16527352

  3. Removal and recovery of metal ions from process and waste streams using polymer filtration

    SciTech Connect

    Jarvinen, G.D.; Smith, B.F.; Robison, T.W.; Kraus, K.M.; Thompson, J.A.

    1999-06-13

    Polymer Filtration (PF) is an innovative, selective metal removal technology. Chelating, water-soluble polymers are used to selectively bind the desired metal ions and ultrafiltration is used to concentrate the polymer-metal complex producing a permeate with low levels of the targeted metal ion. When applied to the treatment of industrial metal-bearing aqueous process streams, the permeate water can often be reused within the process and the metal ions reclaimed. This technology is applicable to many types of industrial aqueous streams with widely varying chemistries. Application of PF to aqueous streams from nuclear materials processing and electroplating operations will be described.

  4. Large-scale transport of metallic ions and the occurrence of thin ion layers in the polar ionosphere

    NASA Astrophysics Data System (ADS)

    Bedey, D. F.; Watkins, B. J.

    1997-05-01

    A necessary condition for the formation of thin metallic ion layers in the high-latitude ionosphere, when strong convective electric fields are present, is that these fields have a magnetically westward component. However, observations have shown that proper field direction does not guarantee the occurrence of a layer. A sufficient abundance of metallic ions is also required. We assert that the abundance of metallic ions (and hence occurrence of thin layers) is strongly influenced by large-scale ion transport, which at high latitudes is determined by the spatial and temporal structure of the large-scale convective electric field. A simple model is presented which indicates that on the dayside, ions should be lifted from the nominal background metallic layer below 100 km into the lower F region, where they flow horizontally in a narrow vertical stream (~50km) toward the nightside. Upon entering the nightside this stream of metallic ions precipitates within a limited band of geomagnetic latitudes, leading to spatially selective enhancements of ion abundance within the E region. Given an appropriately directed convective electric field, the rate of occurrence of detectable thin ion layers should be greater at those locations where precipitation has occurred and, conversely, should be less where precipitation has not occurred. We suggest that this process controls the abundance of metallic ions and therefore explains the fact that layers are sometimes absent in observations, despite the presence of westwardly directed electric fields.

  5. Recent Results of Experiments with Radioactive 21Na and 7Be ion beams

    SciTech Connect

    Greife, U.; Livesay, Jake; Jewett, Cybele; Chipps, K.; Sarazin, F.; Bardayan, Daniel W; Blackmon, Jeff C; Nesaraja, Caroline D; Smith, Michael Scott; Champagne, A. E.; Fitzgerald, R. P.; Jones, K. L.; Thomas, J. S.; Kozub, R. L.

    2007-03-01

    We report here on experiments with radioactive 21Na and 7Be beams performed by Colorado School of Mines students at the ISAC facility of TRIUMF and the Holifield Radioactive Ion Beam Facility (HRIBF) of ORNL. At TRIUMF, the DRAGON recoil separator and its segmented BGO array were used to investigate higher energy resonances in the reaction H(21Na,gamma)22Mg. Using the HRIBF we performed an experiment with a 7Be ion beam to measure scattering off Hydrogen and Carbon. Both elastic 7Be + p scattering and for the first time resonant inelastic scattering 7Be(p,p0)7Be* were observed.

  6. Inner-shell photodetachment of transition metal negative ions

    NASA Astrophysics Data System (ADS)

    Dumitriu, Ileana

    This thesis focuses on the study of inner-shell photodetachment of transition metal negative ions, specifically Fe- and Ru- . Experimental investigations have been performed with the aim of gaining new insights into the physics of negative atomic ions and providing valuable absolute cross section data for astrophysics. The experiments were performed using the X-ray radiation from the Advanced Light Source, Lawrence Berkeley National Laboratory, and the merged-beam technique for photoion spectroscopy. Negative ions are a special class of atomic systems very different from neutral atoms and positive ions. The fundamental physics of the interaction of transition metal negative ions with photons is interesting but difficult to analyze in detail because the angular momentum coupling generates a large number of possible terms resulting from the open d shell. Our work reports on the first inner-shell photodetachment studies and absolute cross section measurements for Fe- and Ru -. In the case of Fe-, an important astrophysical abundant element, the inner-shell photodetachment cross section was obtained by measuring the Fe+ and Fe2+ ion production over the photon energy range of 48--72 eV. The absolute cross sections for the production of Fe+ and Fe2+ were measured at four photon energies. Strong shape resonances due to the 3p?3d photoexcitation were measured above the 3p detachment threshold. The production of Ru+, Ru2+, and Ru3+ from Ru- was measured over 30--90 eV photon energy range The absolute photodetachment cross sections of Ru - ([Kr] 4d75s 2) leading to Ru+, Ru2+, and Ru 3+ ion production were measured at three photon energies. Resonance effects were observed due to interference between transitions of the 4 p-electrons to the quasi-bound 4p54d85s 2 states and the 4d?epsilonf continuum. The role of many-particle effects, intershell interaction, and polarization seems much more significant in Ru- than in Fe- photodetachment.

  7. Factors affecting acceptability of radioactive metal recycling to the public and stakeholders

    SciTech Connect

    Nieves, L.A.; Burke, C.J.

    1995-08-01

    The perception of risk takes place within a cultural context that is affected by individual and societal values, risk information, personal experience, and the physical environment. Researchers have found that measures of {open_quotes}voluntariness of risk assumption,{close_quotes} of {open_quotes}disaster potential,{close_quotes} and of {open_quotes}benefit{close_quotes} are important in explaining risk acceptability. A review of cross-cultural studies of risk perception and risk acceptance, as well as an informal stakeholder survey, are used to assess the public acceptability of radioactive scrap metal recycling.

  8. High-resolution mass spectrometer for liquid metal ion sources

    SciTech Connect

    Wortmann, Martin; Ludwig, Arne; Reuter, Dirk; Wieck, Andreas D.; Meijer, Jan

    2013-09-15

    Recently, a mass spectrometer for liquid metal ion sources (LMIS) has been built and set into operation. This device uses an E×B-filter as mass dispersive element and provides sufficient resolution to analyse the emission of clusters from LMIS to much higher mass ranges (>2000 amu) than commercially available mass filters for focused ion beam systems. It has also been shown that for small masses the composition of clusters from different isotopes can be resolved. Furthermore, a rather high fluence of monodisperse clusters in the range of 10{sup 6}–10{sup 7} clusters/s can be achieved with this setup. This makes it a promising tool for the preparation of mass selected clusters. In this contribution, theoretical considerations as well as technical details and the results of first measurements are presented.

  9. Metal-organic frameworks for lithium ion batteries and supercapacitors

    NASA Astrophysics Data System (ADS)

    Ke, Fu-Sheng; Wu, Yu-Shan; Deng, Hexiang

    2015-03-01

    Porous materials have been widely used in batteries and supercapacitors attribute to their large internal surface area (usually 100-1000 m2 g-1) and porosity that can favor the electrochemical reaction, interfacial charge transport, and provide short diffusion paths for ions. As a new type of porous crystalline materials, metal-organic frameworks (MOFs) have received huge attention in the past decade due to their unique properties, i.e. huge surface area (up to 7000 m2 g-1), high porosity, low density, controllable structure and tunable pore size. A wide range of applications including gas separation, storage, catalysis, and drug delivery benefit from the recent fast development of MOFs. However, their potential in electrochemical energy storage has not been fully revealed. Herein, the present mini review appraises recent and significant development of MOFs and MOF-derived materials for rechargeable lithium ion batteries and supercapacitors, to give a glimpse into these potential applications of MOFs.

  10. Controlled charge exchange between alkaline earth metals and their ions

    NASA Astrophysics Data System (ADS)

    Gacesa, Marko; Côté, Robin

    2015-05-01

    We theoretically investigate the prospects of realizing controlled charge exchange via magnetic Feshbach resonances in cold and ultracold collisions of atoms and ions. In particular, we focus on near-resonant charge exchange in heteroisotopic combinations of alkaline earth metals, such as 9Be++10 Be<-->9 Be+10Be+ , which exhibit favorable electronic and hyperfine structure. The quantum scattering calculations are performed for a range of initial states and experimentally attainable magnetic fields in standard coupled-channel Feshbach projection formalism, where higher-order corrections such as the mass-polarization term are explicitely included. In addition, we predict a number of magnetic Feshbach resonances for different heteronuclear isotopic combinations of the listed and related alkaline earth elements. Our results imply that near-resonant charge-exchange could be used to realize atom-ion quantum gates, as well as controlled charge transfer in optically trapped cold quantum gases. This work is partially supported by ARO.

  11. New Metal Niobate and Silicotitanate Ion Exchangers: Development and Characterization

    SciTech Connect

    Su, Yali; Li, Liyu; Nenoff, Tina M.; Nyman, May; Navrotsky, Alexnadra; Xu, Hongwu

    2003-09-11

    We are evaluating new metal niobate and silicotitanate ion exchangers for Cs and Sr removal and their related condensed phases as potential ceramic waste forms. The goal of the program is to provide DOE alternative materials that can exceed the solvent extraction process for removing Cs and Sr from high level wastes and technical alternatives for disposal of silicotitanate and niobate based ion exchange materials. To date we have determined the structural property relationship and thermodynamic stability of new silicotitanate and niobate based ion exchangers and their thermally converted phases. Several new phases include Na2Nb2-xMIV xO6-x(OH)x {center_dot} H2O (MIV=Ti, Zr, x=0.04 {approx} 0.4, SOMS), NaTixNb1-xO3-0.5x, Na2-xMxNb1.6Ti0.4O5.8+yx (M=Sr, Y), CsTixAl1-xSi2O6+x/2 (0 x 1), and Cc- A2TiSi6O15 (A=K, Rb, Cs) have been synthesized and characterized and results will be presented. Additionally, chemical, thermal, radiation, and thermodynamic stabilities of the new ion exchange materials and their related perovskites as potential ceramic waste forms will also be presented at the meeting.

  12. Health risk and impact evaluation for recycling of radioactive scrap metal

    SciTech Connect

    Nieves, L.A.; Chen, S.Y.; Murphie, W.E.; Lilly, M.J. III

    1994-03-01

    The DoE, Office of Environmental Restoration and Waste Management, is participating with the Organization for Economic Cooperation and Development in providing analytical support for developing international standards for recycling of radioactive scrap metals. For this purpose, Argonne National Laboratory is assessing health, environmental and societal implications of recycling and/or disposal process alternatives. This effort includes development of international inventory estimates for contaminated metals; investigation of international scrap metal markets; assessment of radiological and non-radiological human health risks; impacts on environmental quality and resources; and investigation of social and political factors. The RSM disposal option is being assessed with regard to the environmental and health impacts of replacing the metals if they are withdrawn from use. Impact estimates are developed for steel as an illustrative example because steel comprises a major portion of the scrap metal inventory. Current and potential sources of RSM include nuclear power plants, fuel cycle and weapons production facilities, industrial and medical facilities and equipment, and petroleum and phosphate rock extraction equipment. Millions of metric tons (t) of scrap iron and steel, stainless steel, and copper, as well as lesser quantities of aluminum, nickel, lead, and zirconium, are likely to become available in the future as these facilities are withdrawn from service.

  13. Electrolyte materials containing highly dissociated metal ion salts

    DOEpatents

    Lee, Hung-Sui (East Setauket, NY); Geng, Lin (Coram, NY); Skotheim, Terje A. (Shoreham, NY)

    1996-07-23

    The present invention relates to metal ion salts which can be used in electrolytes for producing electrochemical devices, including both primary and secondary batteries, photoelectrochemical cells and electrochromic displays. The salts have a low energy of dissociation and may be dissolved in a suitable polymer to produce a polymer solid electrolyte or in a polar aprotic liquid solvent to produce a liquid electrolyte. The anion of the salts may be covalently attached to polymer backbones to produce polymer solid electrolytes with exclusive cation conductivity.

  14. Electrolyte materials containing highly dissociated metal ion salts

    DOEpatents

    Lee, H.S.; Geng, L.; Skotheim, T.A.

    1996-07-23

    The present invention relates to metal ion salts which can be used in electrolytes for producing electrochemical devices, including both primary and secondary batteries, photoelectrochemical cells and electrochromic displays. The salts have a low energy of dissociation and may be dissolved in a suitable polymer to produce a polymer solid electrolyte or in a polar aprotic liquid solvent to produce a liquid electrolyte. The anion of the salts may be covalently attached to polymer backbones to produce polymer solid electrolytes with exclusive cation conductivity. 2 figs.

  15. Influence of electrode geometry on liquid metal ion source performance

    SciTech Connect

    Swanson, L.W.; Li, J.Z.

    1988-07-01

    The surface electric field distribution along the axis of a wetted needle type liquid metal ion source has been determined by numerical methods and is shown to exhibit a secondary maximum at the intersection of the cylindrical and conical sections. It is shown that the volume flow rate of the liquid metal film along the cylindrical portion of the emitter is adequate to resupply the ionized portion at the needle apex. However, a pressure minimum in the liquid film, which decreases with increasing apex cone angle, occurs at the cone/cylinder intersection and the pressure gradient formed on the conical section of the emitter opposes flow to the apex region. It is shown that, by chemically roughening the conical section of the emitter, liquid film flow via microcapillary action occurs in such a way as to provide a low flow impedance to the apex.

  16. Theoretical study of transition-metal ions bound to benzene

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Partridge, Harry; Langhoff, Stephen R.

    1992-01-01

    Theoretical binding energies are reported for all first-row and selected second-row transition metal ions (M+) bound to benzene. The calculations employ basis sets of at least double-zeta plus polarization quality and account for electron correlation using the modified coupled-pair functional method. While the bending is predominantly electrostatic, the binding energies are significantly increased by electron correlation, because the donation from the metal d orbitals to the benzene pi* orbitals is not well described at the self-consistent-field level. The uncertainties in the computed binding energies are estimated to be about 5 kcal/mol. Although the calculated and experimental binding energies generally agree to within their combined uncertainties, it is likely that the true binding energies lie in the lower portion of the experimental range. This is supported by the very good agreement between the theoretical and recent experimental binding energies for AgC6H6(+).

  17. Removal of radioactive materials and heavy metals from water using magnetic resin

    DOEpatents

    Kochen, Robert L. (Boulder, CO); Navratil, James D. (Simi Valley, CA)

    1997-01-21

    Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately.

  18. Removal of radioactive materials and heavy metals from water using magnetic resin

    DOEpatents

    Kochen, R.L.; Navratil, J.D.

    1997-01-21

    Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately. 9 figs.

  19. Effects of selected metal ions on photodegradation of organophosphorus pesticides sensitized by humic acids.

    PubMed

    Kamiya, M; Kameyama, K

    2001-10-01

    Selected metal ions having paramagnetic property were found to exert inhibition effects on aquatic photodegradation of organophosphorus pesticides sensitized by humic acids, according to the increasing order of Cr(III) < Co(II) < Mn(II) < Cu(II). Basic factors dominating the metal-ion effects were clarified on the basis of the fluorescence quenching as well as radical scavenging abilities of metal ions complexed with humic acids. PMID:11592411

  20. Structure of the alkali-metal-atom + strontium molecular ions: Towards photoassociation and formation of cold molecular ions

    SciTech Connect

    Aymar, M.; Dulieu, O.; Guerout, R.

    2011-08-14

    The potential energy curves, permanent and transition dipole moments, and the static dipolar polarizability, of molecular ions composed of one alkali-metal atom and a strontium ion are determined with a quantum chemistry approach. The molecular ions are treated as effective two-electron systems and are treated using effective core potentials including core polarization, large gaussian basis sets, and full configuration interaction. In the perspective of upcoming experiments aiming at merging cold atom and cold ion traps, possible paths for radiative charge exchange, photoassociation of a cold lithium or rubidium atom and a strontium ion are discussed, as well as the formation of stable molecular ions.

  1. Structure of the Alkali-metal-atom-Strontium molecular ions: towards photoassociation and formation of cold molecular ions

    E-print Network

    Mireille Aymar; Romain Guérout; Olivier Dulieu

    2011-02-24

    The potential energy curves, permanent and transition dipole moments, and the static dipolar polarizability, of molecular ions composed of one alkali-metal atom and a Strontium ion are determined with a quantum chemistry approach. The molecular ions are treated as effective two-electron systems and are treated using effective core potentials including core polarization, large gaussian basis sets, and full configuration interaction. In the perspective of upcoming experiments aiming at merging cold atom and cold ion traps, possible paths for radiative charge exchange, photoassociation of a cold Lithium or Rubidium atom and a Strontium ion are discussed, as well as the formation of stable molecular ions.

  2. [Relationship of biosorption capacity of heavy metal ions by Saccharomyces cerevisiae and their ionic characteristics].

    PubMed

    Chen, Can; Wang, Jian-Long

    2007-08-01

    Utilizing similar methods and ideas of QSAR in metal toxicity assessment, we tried to establish the relationship between the ion characteristics of heavy metals and the biosorption capacity by waste biomass of Saccharomyces cerevisiae, obtained from a local brewery. The biosorption experiment was carried out and the maximum biosorption capacity (q(max)) was determined by the Langmuir isotherm model. The values of q(max) decreased in order on mole basis: Pb2+ > Ag+ > Cr3+ > Cu2+ > Zn2+ > Cd2+ > Co2+ > Sr2+ > Ni2+ > Cs+. The biomass prefer to bind class B ions (Pb2+ and Ag+), then borderline ions, and last hard ions (Sr2+ and Cs+) based on the HASB principle. Twenty two parameters of physiochemical characteristics of ions were selected to correlate q(max). Linear regression analysis showed that only one parameter, i.e., the covalent index X2(m)r was correlated well to q(max) for all metal ions tested. The greater the covalent index value of metal ion was, the greater was potential to form covalent bonds with biological ligands, and the larger was the metal ion biosorption. Classification of metal ions (for divalent ion or for soft-hard ion) improved the models. More properties such as polarizing power Z2/r or the first hydrolysis constant /lgK(OH)/ or ionization potential IP were statistically significant. X2(m)r seemed to be suitable to account for metal ions containing soft ions, whereas Z2/r, /lgK(OH)/ and IP suitable for only soft ions or metal ions without soft ions. PMID:17926402

  3. Blood metal ion testing is an effective screening tool to identify poorly performing metal-on-metal bearing surfaces

    PubMed Central

    Sidaginamale, R. P.; Joyce, T. J.; Lord, J. K.; Jefferson, R.; Blain, P. G.; Nargol, A. V. F.; Langton, D. J.

    2013-01-01

    Objectives The aims of this piece of work were to: 1) record the background concentrations of blood chromium (Cr) and cobalt (Co) concentrations in a large group of subjects; 2) to compare blood/serum Cr and Co concentrations with retrieved metal-on-metal (MoM) hip resurfacings; 3) to examine the distribution of Co and Cr in the serum and whole blood of patients with MoM hip arthroplasties; and 4) to further understand the partitioning of metal ions between the serum and whole blood fractions. Methods A total of 3042 blood samples donated to the local transfusion centre were analysed to record Co and Cr concentrations. Also, 91 hip resurfacing devices from patients who had given pre-revision blood/serum samples for metal ion analysis underwent volumetric wear assessment using a coordinate measuring machine. Linear regression analysis was carried out and receiver operating characteristic curves were constructed to assess the reliability of metal ions to identify abnormally wearing implants. The relationship between serum and whole blood concentrations of Cr and Co in 1048 patients was analysed using Bland-Altman charts. This relationship was further investigated in an in vitro study during which human blood was spiked with trivalent and hexavalent Cr, the serum then separated and the fractions analysed. Results Only one patient in the transfusion group was found to have a blood Co > 2 µg/l. Blood/Serum Cr and Co concentrations were reliable indicators of abnormal wear. Blood Co appeared to be the most useful clinical test, with a concentration of 4.5 µg/l showing sensitivity and specificity for the detection of abnormal wear of 94% and 95%, respectively. Generated metal ions tended to fill the serum compartment preferentially in vivo and this was replicated in the in vitro study when blood was spiked with trivalent Cr and bivalent Co. Conclusions Blood/serum metal ion concentrations are reliable indicators of abnormal wear processes. Important differences exist however between elements and the blood fraction under study. Future guidelines must take these differences into account. PMID:23836464

  4. Amorphous Metallic Glass as New High Power and Energy Density Anodes For Lithium Ion Rechargeable Batteries

    E-print Network

    Meng, Shirley Y.

    We have investigated the use of aluminum based amorphous metallic glass as the anode in lithium ion rechargeable batteries. Amorphous metallic glasses have no long-range ordered microstructure; the atoms are less closely ...

  5. Computational study of the complexation of metal ion precursors in dendritic polymers 

    E-print Network

    Tarazona Vasquez, Francisco

    2009-05-15

    Metal ions are important for medical, environmental and catalytic applications. They are used as precursor molecules for the manufacture of metal nanocatalysts, which are promising materials for an array of biomedical, ...

  6. Prolong Restoration of the Water Quality of River Ganga Effect of Heavy Metals and Radioactive Elements.

    PubMed

    Tare, Vinod; Basu, Subhankar

    2014-04-01

    The genesis of the present research was the belief since ages and the observations made through some studies that the water of river Ganga has unique characteristics, which allows storage of water quality even on prolong storage. Very few systematic studies have been conducted to support the contention that the Ganga water indeed has some special composition that could be attributed to its unique storage capacity. It was postulated that prolong restoration of water quality depends on the ability to arrest microbial activity that is generally responsible for deterioration in water quality on prolong storage. Hence, attempt has been made to identify the parameters that are likely to influence the prolong storage of river water. Along with Ganga river water, other three major rivers, viz. Yamuna, Godavari and Narmada, were selected for comparison. Emphasis was made on estimation of heavy metals, radioactive elements, dissolved carbon and other physicochemical parameters such as temperature, pH, alkalinity, hardness and dissolved organic carbon. Based on the available information regarding the impact of heavy metals, radioactive elements vis-à-vis the chemical composition of water on microorganisms in the aquatic environment, an overall impact score for the waters of the four Indian rivers selected in the study has been assigned. PMID:26563059

  7. Analysis methods of safe Coulomb-excitation experiments with radioactive ion beams using the gosia code

    E-print Network

    M. Zieli?ska; L. P. Gaffney; K. Wrzosek-Lipska; E. Clément; T. Grahn; N. Kesteloot; P. Napiorkowski; J. Pakarinen; P. Van Duppen; N. Warr

    2015-06-16

    With the recent advances in radioactive ion beam technology, Coulomb excitation at safe energies becomes an important experimental tool in nuclear structure physics. The usefulness of the technique to extract key information on the electromagnetic properties of nuclei has been demonstrated since the 1960's with stable beam and target combinations. New challenges present themselves when studying exotic nuclei with this technique, including dealing with low statistics or number of data points, absolute and relative normalisation of the measured cross sections and a lack of complimentary experimental data, such as excited-state lifetimes and branching ratios. This paper addresses some of these common issues and presents analysis techniques to extract transition strengths and quadrupole moments utilising the least-squares fit code, {\\rmfamily \\textsc{gosia}}.

  8. New Proton-Ionizable, Calixarene-Based Ligands for Selective Metal Ion Separations

    SciTech Connect

    Bartsch, Richard A.

    2012-06-04

    The project objective was the discovery of new ligands for performing metal ion separations. The research effort entailed the preparation of new metal ion complexing agents and polymers and their evaluation in metal ion separation processes of solvent extraction, synthetic liquid membrane transport, and sorption. Structural variations in acyclic, cyclic, and bicyclic organic ligands were used to probe their influence upon the efficiency and selectivity with which metal ion separations can be performed. A unifying feature of the ligand structures is the presence of one (or more) side arm with a pendent acidic function. When a metal ion is complexed within the central cavity of the ligand, ionization of the side arm(s) produces the requisite anion(s) for formation of an overall electroneutral complex. This markedly enhances extraction/transport efficiency for separations in which movement of aqueous phase anions of chloride, nitrate, or sulfate into an organic medium would be required. Through systematic structural variations, new ligands have been developed for efficient and selective separations of monovalent metal ions (e.g., alkali metal, silver, and thallium cations) and of divalent metal ion species (e.g., alkaline earth metal, lead, and mercury cations). Research results obtained in these fundamental investigations provide important insight for the design and development of ligands suitable for practical metal ion separation applications.

  9. Bond nature of active metal ions in SiO2-based electrochemical metallization memory cells.

    PubMed

    Cho, Deok-Yong; Tappertzhofen, Stefan; Waser, Rainer; Valov, Ilia

    2013-03-01

    Electrochemical metallization cells are candidates for the next-generation non-volatile memory devices based on resistive switching. Despite the intensive studies in recent years a microscopic model of the processes in these nanoscale electrochemical systems is still missing and the physicochemical properties of the active metal ions have been rarely reported. We examined the bonding characteristics of Cu(z+) and Ag(+) ions in SiO(2)-based cells using soft X-ray absorption spectroscopy. Whereas the Ag/SiO(2) interfaces showed no chemical interaction of Ag ions, the Cu/SiO(2) showed clear signatures of partial oxidation into two ionic species of Cu(2+) and Cu(+). The analyses on the orbital hybridization strength evidently showed that the Cu(2+)-O(2-) bonds in SiO(2) are much weaker than the Cu(+)-O(2-) bonds, analogous to the case of bulk CuO and Cu(2)O. This suggests that the Cu(2+) ions should be more mobile and with a dominating role in the process of resistive switching. PMID:23354222

  10. Risk assessment for chemical pickling of metals contaminated by radioactive materials.

    PubMed

    Donzella, A; Formisano, P; Giroletti, E; Zenoni, A

    2007-01-01

    In recent years, many cases of contamination of metal scraps by unwanted radioactive materials have occurred. Moreover, international organisations are evaluating the possibility to re-use or to recycle metals coming from nuclear power plants. The metal recycling industry has started to worry about radiation exposure of workers that could be in contact with contaminated metals during each manufacturing phase. Risks are strongly dependent on the radiation source features. The aim of this study is to perform risk assessment for workers involved in chemical pickling of steel coils. Monte Carlo simulations have been performed, using the MCNP package and considering coils contaminated with (60)Co, (137)Cs, (241)Am and (226)Ra. Under the most conservative conditions (coil contaminated with 1.0 kBq g(-1) of (60)Co), the dose assessment results lower than the European dose limit for the population (1 mSv y(-1)), considering a maximum number of 10 contaminated coils handled per year. The only exception concerns the case of (241)Am, for which internal contamination could be non- negligible and should be verified in the specific cases. In every case, radiation exposure risk for people standing at 50 m from the coil is widely <1 mSv y(-1). PMID:16849378

  11. Analysis of the application of decontamination technologies to radioactive metal waste minimization using expert systems

    SciTech Connect

    Bayrakal, S.

    1993-09-30

    Radioactive metal waste makes up a significant portion of the waste currently being sent for disposal. Recovery of this metal as a valuable resource is possible through the use of decontamination technologies. Through the development and use of expert systems a comparison can be made of laser decontamination, a technology currently under development at Ames Laboratory, with currently available decontamination technologies for applicability to the types of metal waste being generated and the effectiveness of these versus simply disposing of the waste. These technologies can be technically and economically evaluated by the use of expert systems techniques to provide a waste management decision making tool that generates, given an identified metal waste, waste management recommendations. The user enters waste characteristic information as input and the system then recommends decontamination technologies, determines residual contamination levels and possible waste management strategies, carries out a cost analysis and then ranks, according to cost, the possibilities for management of the waste. The expert system was developed using information from literature and personnel experienced in the use of decontamination technologies and requires validation by human experts and assignment of confidence factors to the knowledge represented within.

  12. Most spin-1/2 transition-metal ions do have single ion anisotropy

    SciTech Connect

    Liu, Jia; Whangbo, Myung-Hwan E-mail: mike-whangbo@ncsu.edu; Koo, Hyun-Joo; Xiang, Hongjun E-mail: mike-whangbo@ncsu.edu; Kremer, Reinhard K.

    2014-09-28

    The cause for the preferred spin orientation in magnetic systems containing spin-1/2 transition-metal ions was explored by studying the origin of the easy-plane anisotropy of the spin-1/2 Cu{sup 2+} ions in CuCl{sub 2}·2H{sub 2}O, LiCuVO{sub 4}, CuCl{sub 2}, and CuBr{sub 2} on the basis of density functional theory and magnetic dipole-dipole energy calculations as well as a perturbation theory treatment of the spin-orbit coupling. We find that the spin orientation observed for these spin-1/2 ions is not caused by their anisotropic spin exchange interactions, nor by their magnetic dipole-dipole interactions, but by the spin-orbit coupling associated with their crystal-field split d-states. Our study also predicts in-plane anisotropy for the Cu{sup 2+} ions of Bi{sub 2}CuO{sub 4} and Li{sub 2}CuO{sub 2}. The results of our investigations dispel the mistaken belief that magnetic systems with spin-1/2 ions have no magnetic anisotropy induced by spin-orbit coupling.

  13. Nanoparticles reduce nickel allergy by capturing metal ions

    NASA Astrophysics Data System (ADS)

    Vemula, Praveen Kumar; Anderson, R. Rox; Karp, Jeffrey M.

    2011-05-01

    Approximately 10% of the population in the USA suffer from nickel allergy, and many are unable to wear jewellery or handle coins and other objects that contain nickel. Many agents have been developed to reduce the penetration of nickel through skin, but few formulations are safe and effective. Here, we show that applying a thin layer of glycerine emollient containing nanoparticles of either calcium carbonate or calcium phosphate on an isolated piece of pig skin (in vitro) and on the skin of mice (in vivo) prevents the penetration of nickel ions into the skin. The nanoparticles capture nickel ions by cation exchange, and remain on the surface of the skin, allowing them to be removed by simple washing with water. Approximately 11-fold fewer nanoparticles by mass are required to achieve the same efficacy as the chelating agent ethylenediamine tetraacetic acid. Using nanoparticles with diameters smaller than 500 nm in topical creams may be an effective way to limit the exposure to metal ions that can cause skin irritation.

  14. Magic wavelengths in the alkaline-earth-metal ions

    NASA Astrophysics Data System (ADS)

    Kaur, Jasmeet; Singh, Sukhjit; Arora, Bindiya; Sahoo, B. K.

    2015-09-01

    We present magic wavelengths for the n S1 /2-n P1 /2 ,3 /2 , and n S1 /2-m D3 /2 ,5 /2 transitions in Mg+, Ca+, Sr+, and Ba+ alkaline-earth-metal ions, for the principal quantum numbers n and m for the ground and first excited D states, respectively. These wavelengths are presented for linearly polarized light by plotting the dynamic polarizabilities of the n S ,n P1 /2 ,3 /2 , and m D3 /2 ,5 /2 states of the considered ions. Required dynamic polarizabilities are evaluated by employing a relativistic all-order perturbative method and their accuracies are ratified by comparing their static values with available high-precision experimental or other theoretical results. Moreover, some of the magic wavelengths identified by us in Ca+ concur with the recent measurements reported by Liu et al. [Phys. Rev. Lett. 114, 223001 (2015), 10.1103/PhysRevLett.114.223001]. Knowledge of these magic wavelengths is propitious to carry out many proposed high-precision measurements trapping the above ions in electric fields with the corresponding frequencies.

  15. Prostate cancer outcome and tissue levels of metal ions

    USGS Publications Warehouse

    Sarafanov, A.G.; Todorov, T.I.; Centeno, J.A.; MacIas, V.; Gao, W.; Liang, W.-M.; Beam, C.; Gray, Michael A.; Kajdacsy-Balla, A.

    2011-01-01

    BACKGROUND There are several studies examining prostate cancer and exposure to cadmium, iron, selenium, and zinc. Less data are available on the possible influence of these metal ions on prostate cancer outcome. This study measured levels of these ions in prostatectomy samples in order to examine possible associations between metal concentrations and disease outcome. METHODS We obtained formalin fixed paraffin embedded tissue blocks of prostatectomy samples of 40 patients with PSA recurrence, matched 1:1 (for year of surgery, race, age, Gleason grading, and pathology TNM classification) with tissue blocks from 40 patients without recurrence (n = 80). Case-control pairs were compared for the levels of metals in areas adjacent to tumors. Inductively coupled plasma-mass spectrometry (ICP-MS) was used for quantification of Cd, Fe, Zn, and Se. RESULTS Patients with biochemical (PSA) recurrence of disease had 12% lower median iron (95 ??g/g vs. 111 ??g/g; P = 0.04) and 21% lower zinc (279 ??g/g vs. 346 ??g/g; P = 0.04) concentrations in the normal-appearing tissue immediately adjacent to cancer areas. Differences in cadmium (0.489 ??g/g vs. 0.439 ??g/g; 4% higher) and selenium (1.68 ??g/g vs. 1.58 ??g/g; 5% higher) levels were not statistically significant in recurrence cases, when compared to non-recurrences (P = 0.40 and 0.21, respectively). CONCLUSIONS There is an association between low zinc and low iron prostate tissue levels and biochemical recurrence in prostate cancer. Whether these novel findings are a cause or effect of more aggressive tumors, or whether low zinc and iron prostatic levels raise implications for therapy, remains to be investigated. Copyright ?? 2011 Wiley-Liss, Inc.

  16. Novel fungus-titanate bio-nanocomposites as high performance adsorbents for the efficient removal of radioactive ions from wastewater

    NASA Astrophysics Data System (ADS)

    Xu, Mingze; Wei, Guodong; Liu, Na; Zhou, Liang; Fu, Chengwei; Chubik, M.; Gromov, A.; Han, Wei

    2013-12-01

    Reclaimable adsorbents have a critical application in the adsorption of radioactive materials. In this study, the novel bio-nanocomposites comprising fungi and titanate nanotubes are successfully synthesized by a simple and low-cost method. Morphological characterizations and composite mechanism analysis confirm that the composites are sufficiently stable to avoid dust pollution resulting from the titanate nanomaterials. Adsorption experiments demonstrate that the bio-nanocomposites are efficient adsorbents with a saturated sorption capacity as high as 120 mg g-1 (1.75 meq. g-1) for Ba2+ ions. The results suggest that the bio-nanocomposites can be used as promising radioactive adsorbents for removing radioactive ions from water caused by nuclear leakage.Reclaimable adsorbents have a critical application in the adsorption of radioactive materials. In this study, the novel bio-nanocomposites comprising fungi and titanate nanotubes are successfully synthesized by a simple and low-cost method. Morphological characterizations and composite mechanism analysis confirm that the composites are sufficiently stable to avoid dust pollution resulting from the titanate nanomaterials. Adsorption experiments demonstrate that the bio-nanocomposites are efficient adsorbents with a saturated sorption capacity as high as 120 mg g-1 (1.75 meq. g-1) for Ba2+ ions. The results suggest that the bio-nanocomposites can be used as promising radioactive adsorbents for removing radioactive ions from water caused by nuclear leakage. Electronic supplementary information (ESI) available: The experimental section and supplementary figures are shown in supplementary information. See DOI: 10.1039/c3nr03467d

  17. Nuclear reactions with 11C and 14O radioactive ion beams

    SciTech Connect

    Guo, Fanqing

    2004-12-09

    Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2x108 pps intensity on target and an 14O beam of up to 3x104 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au(11C,xn)208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of ?? decays from At isotopes as well as the presence of incomplete fusion reactions probably contribute to specific overpredictions. 15F has been investigated by the p(14O,p)14O reaction with the ERSIKTT technology. Several 14O+p runs have been performed. Excellent energy calibration was obtained using resonances from the p(14N,p)14N reaction in inverse kinematics, and comparing the results to those obtained earlier with normal kinematics. The differences between 14N+p and 14O+p in the stopping power function have been evaluated for better energy calibration. After careful calibration, the energy levels of 15F were fitted with an R-matrix calculation. Spins and parities were assigned to the two observed resonances. This new measurement of the 15F ground state supports the disappearance of the Z = 8 proton magic number for odd Z, Tz=-3/2 nuclei. It is expected that future work on proton-rich nuclides will rely heavily on RIBs and/or mass separators. Currently, radioactive ion beam intensities are sufficient for the study of a reasonable number of very proton-rich nuclides.

  18. Measurement of Two-Photon Absorption Cross Section of Metal Ions by a Mass Sedimentation Approach

    PubMed Central

    Ma, Zhuo-Chen; Chen, Qi-Dai; Han, Bing; Liu, Xue-Qing; Song, Jun-Feng; Sun, Hong-Bo

    2015-01-01

    The photo-reduction of metal ions in solution induced by femtosecond laser is an important and novel method for fabricating three-dimensional metal microstructures. However, the nonlinear absorption cross section of metal ions remains unknown because its measurement is difficult. In the present study, a method based on Two-Photon Excited Sedimentation (TPES) is proposed to measure the two-photon absorption cross section (TPACS) of metal ions in solution. The power-squared dependence of the amount of sediment on the excitation intensity was confirmed, revealing that 800?nm femtosecond laser induced reduction of metal ions was a two photon absorption process. We believe that the proposed method may be applied to measure the TPACS of several metal ions, thereby opening a new avenue towards future analysis of two-photon absorption materials. PMID:26657990

  19. Measurement of Two-Photon Absorption Cross Section of Metal Ions by a Mass Sedimentation Approach.

    PubMed

    Ma, Zhuo-Chen; Chen, Qi-Dai; Han, Bing; Liu, Xue-Qing; Song, Jun-Feng; Sun, Hong-Bo

    2015-01-01

    The photo-reduction of metal ions in solution induced by femtosecond laser is an important and novel method for fabricating three-dimensional metal microstructures. However, the nonlinear absorption cross section of metal ions remains unknown because its measurement is difficult. In the present study, a method based on Two-Photon Excited Sedimentation (TPES) is proposed to measure the two-photon absorption cross section (TPACS) of metal ions in solution. The power-squared dependence of the amount of sediment on the excitation intensity was confirmed, revealing that 800?nm femtosecond laser induced reduction of metal ions was a two photon absorption process. We believe that the proposed method may be applied to measure the TPACS of several metal ions, thereby opening a new avenue towards future analysis of two-photon absorption materials. PMID:26657990

  20. Some aspects of metallic ion chemistry and dynamics in the mesosphere and thermosphere

    NASA Technical Reports Server (NTRS)

    Mathews, J. D.

    1987-01-01

    The relationship between the formation of sporadic layers of metallic ion and the dumping of these ions into the upper mesosphere is discussed in terms of the tidal wind, classical (i.e., windshear) and other more complex, perhaps highly nonlinear layer formation mechanisms, and a possible circulation mechanism for these ions. Optical, incoherent scatter radar, rocket, and satellite derived evidence for various layer formation mechanisms and for the metallic ion circulation system is reviewed. The results of simple one dimensional numerical model calculations of sporadic E and intermediate layer formation are presented along with suggestions for more advanced models of intense or blanketing sporadic E. The flux of metallic ions dumped by the tidal wind system into the mesosphere is estimated and compared with estimates of total particle flux of meteoric origin. Possible effects of the metallic ion flux and of meteoric dust on D region ion chemistry are discussed.

  1. Perovskite-Ni composite: a potential route for management of radioactive metallic waste.

    PubMed

    Mahadik, Pooja Sawant; Sengupta, Pranesh; Halder, Rumu; Abraham, G; Dey, G K

    2015-04-28

    Management of nickel - based radioactive metallic wastes is a difficult issue. To arrest the release of hazardous material to the environment it is proposed to develop perovskite coating for the metallic wastes. Polycrystalline BaCe0.8Y0.2O3-? perovskite with orthorhombic structure has been synthesized by sol-gel route. Crystallographic analyses show, the perovskite belong to orthorhombic Pmcn space group at room temperature, and gets converted to orthorhombic Incn space group at 623K, cubic Pm3m space group (with a=4.434Å) at 1173K and again orthorhombic Pmcn space group at room temperature after cooling. Similar observations have been made from micro-Raman study as well. Microstructural studies of BaCe0.8Y0.2O3-?-NiO/Ni composites showed absence of any reaction product at the interface. This suggests that both the components (i.e. perovskite and NiO/Ni) of the composite are compatible to each other. Interaction of BaCe0.8Y0.2O3-?-NiO/Ni composites with simulated barium borosilicate waste glass melt also did not reveal any reaction product at the interfaces. Importantly, uranium from the waste glass melt was found to be partitioned within BaCe0.8Y0.2O3-? perovskite structure. It is therefore concluded that BaCe0.8Y0.2O3-? can be considered as a good coating material for management of radioactive Ni based metallic wastes. PMID:25666975

  2. Metal cation/anion adsorption on calcium carbonate: Implications to metal ion concentrations in groundwater

    SciTech Connect

    Zachara, J.M.; Cowan, C.E.; Resch, C.T.

    1990-05-01

    This chapter evaluates the sorption behavior of metallic ions on specimen calcite as a basis for determining the importance of calcite relative to other subsurface sorbents, such as layer silicates and oxides, in controlling metal ion concentration in calcareous groundwaters. A review of the literature shows the sorption of both metallic cations and anions on calcite over ranges in pH and CO{sub 2} partial pressure to be consistent with a surface-exchange process where cations exchange with surface Ca and anions exchange with surface CO{sub 3}. A general surface-exchange model was developed to account for the effects of Ca and CO{sub 3} concentrations, pH, and calcite surface area on cation and anion sorption onto calcite. The model was applied to recently developed experimental sorption data of Zn and SeO{sub 3} on specimen calcite in equilibrium CaCO{sub 3}(aq) suspensions. The surface-exchange model was able to describe the effects of pH on both cation and anion sorption, and provided good predictions of the effects of variable CO{sub 2}(g) pressure on Zn sorption and of PO{sub 4} on SeO{sub 3} sorption. The surface-exchange model, combined with sorption constants for other phases, was used to calculate Cd sorption to a hypothetical aquifer material containing a mixture of sorbents. The sorbent concentrations were fixed to those expected in groundwater zones. The multi-sorbent calculation documented the importance of calcite as a sorbent for metallic ions in groundwater.93 refs., 18 figs., 5 tabs.

  3. MeRNA: a Database of Metal Ion Binding Sites in RNAStructures

    SciTech Connect

    Stefan, Liliana R.; Zhang, Rui; Levitan, Aaron G.; Hendrix, DonnaF.; Brenner, Steven E.; Holbrook, Stephen R.

    2005-10-05

    Metal ions are essential for the folding of RNA into stable tertiary structures and for the catalytic activity of some RNA enzymes. To aid in the study of the roles of metal ions in RNA structural biology, we have created MeRNA (Metals in RNA), a comprehensive compilation of all metal binding sites identified in RNA three-dimensional structures available from the Protein Data Bank (PDB) and Nucleic Acid Database (NDB). Currently, our database contains information relating to binding of 9764 metal ions corresponding to 23 distinct elements; in 256 RNA structures. The metal ion locations were confirmed and ligands characterized using original literature references. MeRNA includes eight manually identified metal-ion binding motifs, which are described in the literature. MeRNA is searchable by PDB identifier, metal ion, method of structure determination, resolution and R-values for X-ray structure, and distance from metal to any RNA atom or to water. New structures with their respective binding motifs will be added to the database as they become available. The MeRNA database will further our understanding of the roles of metal ions in RNA folding and catalysis and have applications in structural and functional analysis, RNA design and engineering.

  4. Process for the displacement of cyanide ions from metal-cyanide complexes

    DOEpatents

    Smith, Barbara F. (Los Alamos, NM); Robinson, Thomas W. (Los Alamos, NM)

    1997-01-01

    The present invention relates to water-soluble polymers and the use of such water-soluble polymers in a process for the displacement of the cyanide ions from the metal ions within metal-cyanide complexes. The process waste streams can include metal-cyanide containing electroplating waste streams, mining leach waste streams, mineral processing waste streams, and related metal-cyanide containing waste streams. The metal ions of interest are metals that give very strong complexes with cyanide, mostly iron, nickel, and copper. The physical separation of the water-soluble polymer-metal complex from the cyanide ions can be accomplished through the use of ultrafiltration. Once the metal-cyanide complex is disrupted, the freed cyanide ions can be recovered for reuse or destroyed using available oxidative processes rendering the cyanide nonhazardous. The metal ions are released from the polymer, using dilute acid, metal ion oxidation state adjustment, or competing chelating agents, and collected and recovered or disposed of by appropriate waste management techniques. The water-soluble polymer can then be recycled. Preferred water-soluble polymers include polyethyleneimine and polyethyleneimine having a catechol or hydroxamate group.

  5. Grid-controlled metal ion sources for heavy ion fusion accelerators

    SciTech Connect

    Len, L.K.; Humphries, S. Jr.; Burkart, C.

    1986-01-01

    A variety of metal ions can be generated using vacuum arcs, but due to the nature of these arcs, the flux generated fluctuates in time. We have successfully employed electrostatically biased grids to control the plasma and to provide a well-behaved, space charge limited ion source. The grid prevents the plasma from entering the extraction gap before the main voltage pulse is applied. The extracted ion current is space charge limited, resulting in a constant output current even though the ion flux from the vacuum arc source varies considerably. There are several advantages over other conventional sources, for instance, thermionic sources are faced with heating problems especially for large area configurations, while gas-injection sources cause prefill problems because they take too long to reach equilibrium. We have performed extraction experiments with aluminium and indium arc sources. We have extracted 300 mA of pure Al/sup +/ at 30 kV for 10 ..mu..s. The normalized beam emittance has been measured to be 8 /times/ 10/sup /minus/7/ ..pi..-m-rad. 3 refs., 5 figs.

  6. Radiation and Electromagnetic Induction Data Fusion for Detection of Buried Radioactive Metal Waste - 12282

    SciTech Connect

    Long, Zhiling; Wei, Wei; Turlapaty, Anish; Du, Qian; Younan, Nicolas H.; Waggoner, Charles

    2012-07-01

    At the United States Army's test sites, fired penetrators made of Depleted Uranium (DU) have been buried under ground and become hazardous waste. Previously, we developed techniques for detecting buried radioactive targets. We also developed approaches for locating buried paramagnetic metal objects by utilizing the electromagnetic induction (EMI) sensor data. In this paper, we apply data fusion techniques to combine results from both the radiation detection and the EMI detection, so that we can further distinguish among DU penetrators, DU oxide, and non- DU metal debris. We develop a two-step fusion approach for the task, and test it with survey data collected on simulation targets. In this work, we explored radiation and EMI data fusion for detecting DU, oxides, and non-DU metals. We developed a two-step fusion approach based on majority voting and a set of decision rules. With this approach, we fuse results from radiation detection based on the RX algorithm and EMI detection based on a 3-step analysis. Our fusion approach has been tested successfully with data collected on simulation targets. In the future, we will need to further verify the effectiveness of this fusion approach with field data. (authors)

  7. Spindependent screening and Auger neutralization of He + ions in metals M. Alducin*

    E-print Network

    Muiño, Ricardo Díez

    Spin­dependent screening and Auger neutralization of He + ions in metals M. Alducin* Donostia electron densities of the medium. In a second step, the rates for Auger neutralization of a He + ion polarization of the emitted yield is measured when a He + projectile is neutralized in front of a metal surface

  8. Spin-dependent screening and Auger neutralization of He+ ions in metals

    E-print Network

    Muiño, Ricardo Díez

    Spin-dependent screening and Auger neutralization of He+ ions in metals M. Alducin* Donostia electron densities of the medium. In a second step, the rates for Auger neutralization of a He+ ion polarization of the emitted yield is measured when a He+ projectile is neutralized in front of a metal surface

  9. An unconventional origin of metal-ion rescue and inhibition in the Tetrahymena group I

    E-print Network

    Herschlag, Dan

    An unconventional origin of metal-ion rescue and inhibition in the Tetrahymena group I ribozyme metal ions. Herein we report that, in the Tetrahymena group I ribozyme reaction, the deleterious effect@cmgm+stanford+edu+ Abbreviations: E: the Tetrahymena L-21 ScaI ribozyme; G: gua- nosine; SA: generically, the oligonucleotide

  10. Analysis of Supercritical-Extracted Chelated Metal Ions From Mixed Organic-Inorganic Samples

    NASA Technical Reports Server (NTRS)

    Sinha, Mahadeva P. (Inventor)

    1996-01-01

    Organic and inorganic contaminants of an environmental sample are analyzed by the same GC-MS instrument by adding an oxidizing agent to the sample to oxidize metal or metal compounds to form metal ions. The metal ions are converted to chelate complexes and the chelate complexes are extracted into a supercritical fluid such as CO2. The metal chelate extract after flowing through a restrictor tube is directly injected into the ionization chamber of a mass spectrometer, preferably containing a refractory metal filament such as rhenium to fragment the complex to release metal ions which are detected. This provides a fast, economical method for the analysis of metal contaminants in a sample and can be automated. An organic extract of the sample in conventional or supercritical fluid solvents can be detected in the same mass spectrometer, preferably after separation in a supercritical fluid chromatograph.

  11. Caging Metal Ions with Visible Light-Responsive Nanopolymersomes

    PubMed Central

    2015-01-01

    Polymersomes are bilayer vesicles that self-assemble from amphiphilic diblock copolymers, and provide an attractive system for the delivery of biological and nonbiological molecules due to their environmental compatibility, mechanical stability, synthetic tunability, large aqueous core, and hyperthick hydrophobic membrane. Herein, we report a nanoscale photoresponsive polymersome system featuring a meso-to-meso ethyne-bridged bis[(porphinato)zinc] (PZn2) fluorophore hydrophobic membrane solute and dextran in the aqueous core. Upon 488 nm irradiation in solution or in microinjected zebrafish embryos, the polymersomes underwent deformation, as monitored by a characteristic red-shifted PZn2 emission spectrum and confirmed by cryo-TEM. The versatility of this system was demonstrated through the encapsulation and photorelease of a fluorophore (FITC), as well as two different metal ions, Zn2+ and Ca2+. PMID:25518002

  12. High energy metal ion implantation using `Magis`, a novel, broad-beam, Marx-generator-based ion source

    SciTech Connect

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

    1996-08-01

    Ion energy of the beam formed by an ion source is proportional to extractor voltage and ion charge state. Increasing the voltage is difficult and costly for extraction voltage over 100 kV. Here we explore the possibility of increasing the charge states of metal ions to facilitate high-energy, broad beam ion implantation at a moderate voltage level. Strategies to enhance the ion charge state include operating in the regimes of high-current vacuum sparks and short pulses. Using a time-of-flight technique we have measured charge states as high as 7+ (73 kA vacuum spark discharge) and 4+ (14 kA short pulse arc discharge), both for copper, with the mean ion charge states about 6.0 and 2.5, respectively. Pulsed discharges can conveniently be driven by a modified Marx generator, allowing operation of ``Magis`` with a single power supply (at ground potential) for both plasma production and ion extraction.

  13. New Metal Niobate and Silicotitanate Ion Exchangers: Development and Characterization

    SciTech Connect

    Su, Yali; Nenoff, Tina M.; Navrotsky, Alexandra

    2002-06-01

    This project is a continuing EMSP project entitled ''New Silicotitanate Waste Forms: Development and Characterization.'' In our original study, the phase selection and chemical durability of silicotitanates (including commercially available IE-911) as a function of temperature (500 to 1000 C) was fully characterized by a combination of techniques including XRD, TEM, SEM, NMR, Raman spectroscopy, XAFS, XANES, and by thermodynamic studies. In addition, work on this program led to new discoveries not anticipated in the originally proposed research. Of particular importance was the discovery of a new ion exchange material that is selective for divalent cations under extreme conditions (e.g., acid solutions, competing cations), thus providing an alternative for removing Sr from mixed wastes. This material is converted easily by high-temperature, in situ heat treatment into a perovskite phase, which is also a major component of Synroc, a titanate ceramic waste form used for sequestration of high-level waste (HLW) from reprocessed, spent nuclear fuel. This renewal project is based on the current needs in separation of cesium and strontium and the results obtained from our previous EMSP work. The purpose of this project is to deliver pertinent information that can be used to make rational decisions on selection of separation processes for cesium, strontium, and actinides. The objectives of this project are: (1) to establish the structure/property relationship between inorganic ion exchanger materials and their ability to selectively separate divalent cations under extreme operating conditions-This includes optimizing stoichiometry, synthesis, and pretreatment conditions for metal niobate and silicotitanate ion exchangers for maximum strontium and actinide-surrogate selectivity. (2) to fully characterize the phase relationships, structures, and thermodynamic and kinetic stabilities of these new phases and their related condensed phases (as potential ceramic waste forms) (3) to understand the chemical and thermodynamic stabilities of silicotitanate ion exchangers based on an in-depth comprehension of local bonding configurations and thermochemistry (4) to apply fundamental understanding to tailoring an ion exchanger that is ideally suited for a DOE needs and therefore has the potential for short-term deployment in the DOE complex

  14. New Metal Niobate and Silicotitanate Ion Exchangers: Development and Characterization

    SciTech Connect

    Su, Yali; Nenoff, Tina M.; Navrotsky, Alexandra

    2001-06-01

    This project is a continuing EMSP project entitled ''New Silicotitanate Waste Forms: Development and Characterization.'' In our original study, the phase selection and chemical durability of silicotitanates (including commercially available IE-911) as a function of temperature (500 to 1000 C) was fully characterized by a combination of techniques including XRD, TEM, SEM, NMR, Raman spectroscopy, XAFS, XANES, and by thermodynamic studies. In addition, work on this program led to new discoveries not anticipated in the originally proposed research. Of particular importance was the discovery of a new ion exchange material that is selective for divalent cations under extreme conditions (e.g., acid solutions, competing cations), thus providing an alternative for removing Sr from mixed wastes. This material is converted easily by high-temperature, in situ heat treatment into a perovskite phase, which is also a major component of Synroc, a titanate ceramic waste form used for sequestration of high-level waste (HLW) from reprocessed, spent nuclear fuel. This renewal project is based on the current needs in separation of cesium and strontium and the results obtained from our previous EMSP work. The purpose of this project is to deliver pertinent information that can be used to make rational decisions on selection of separation processes for cesium, strontium, and actinides. The objectives of this project are: (1) to establish the structure/property relationship between inorganic ion exchanger materials and their ability to selectively separate divalent cations under extreme operating conditions-This includes optimizing stoichiometry, synthesis, and pretreatment conditions for metal niobate and silicotitanate ion exchangers for maximum strontium and actinide-surrogate selectivity. (2) to fully characterize the phase relationships, structures, and thermodynamic and kinetic stabilities of these new phases and their related condensed phases (as potential ceramic waste forms) (3) to understand the chemical and thermodynamic stabilities of silicotitanate ion exchangers based on an in-depth comprehension of local bonding configurations and thermochemistry (4) to apply fundamental understanding to tailoring an ion exchanger that is ideally suited for a DOE needs and therefore has the potential for short-term deployment in the DOE complex.

  15. Viscoplasticity of simulated high-level radioactive waste glass containing platinum group metal particles

    NASA Astrophysics Data System (ADS)

    Uruga, Kazuyoshi; Usami, Tsuyoshi; Tsukada, Takeshi; Komamine, Satoshi; Ochi, Eiji

    2014-09-01

    The shear rate dependency of the viscosity of three simulated high-level radioactive waste glasses containing 0, 1.2 and 4.5 wt% platinum group metals (PGMs) was examined at a temperature range of 1173-1473 K by a rotating viscometer. Shear stress when the shear rate equals zero, i.e. yield stress, was also measured by capillary method. The viscosity of the glass containing no PGM was shear rate-independent Newtonian fluid. On the other hand, the apparent viscosity of the glasses containing PGMs increased with decreasing shear rate, and nonzero amount of yield stresses were detected from both glasses. The viscosity and yield stress of the glass containing 4.5 wt% PGMs was roughly one to two orders of magnitude greater than the glass containing 1.2 wt% PGMs. These viscoplastic properties were numerically expressed by Casson equation.

  16. Fernald`s dilemma: Do we recycle the radioactively contaminated metals, or do we bury them?

    SciTech Connect

    Yuracko, K.L.; Hadley, S.W.; Perlack, R.D.

    1996-06-01

    During the past five years, a number of U.S. Department of Energy (DOE) funded efforts have demonstrated the technical efficacy of converting various forms of radioactive scrap metal (RSM) into useable products. From the development of large accelerator shielding blocks, to the construction of low level waste containers, technology has been applied to this fabrication process in a safe and stakeholder supported manner. The potential health and safety risks to both workers and the public have been addressed. The question remains; can products be fabricated from RSM in a cost efficient and market competitive manner? This paper presents a methodology for use within DOE to evaluate the costs and benefits of recycling and reusing some RSM, rather than disposing of this RSM in an approved burial site. This life cycle decision methodology, developed by both the Oak Ridge National Laboratory (ORNL) and DOE Fernald is the focus of the following analysis.

  17. An artificial tongue fluorescent sensor array for identification and quantitation of various heavy metal ions.

    PubMed

    Xu, Wang; Ren, Changliang; Teoh, Chai Lean; Peng, Juanjuan; Gadre, Shubhankar Haribhau; Rhee, Hyun-Woo; Lee, Chi-Lik Ken; Chang, Young-Tae

    2014-09-01

    Herein, a small-molecule fluorescent sensor array for rapid identification of seven heavy metal ions was designed and synthesized, with its sensing mechanism mimicking that of a tongue. The photoinduced electron transfer and intramolecular charge transfer mechanism result in combinatorial interactions between sensor array and heavy metal ions, which lead to diversified fluorescence wavelength shifts and emission intensity changes. Upon principle component analysis (PCA), this result renders clear identification of each heavy metal ion on a 3D spatial dispersion graph. Further exploration provides a concentration-dependent pattern, allowing both qualitative and quantitative measurements of heavy metal ions. On the basis of this information, a "safe-zone" concept was proposed, which provides rapid exclusion of versatile hazardous species from clean water samples based on toxicity characteristic leaching procedure standards. This type of small-molecule fluorescent sensor array could open a new avenue for multiple heavy metal ion detection and simplified water quality analysis. PMID:25144824

  18. A lithium liquid metal ion source suitable for high voltage terminal applications

    SciTech Connect

    Read, P.M.; Maskrey, J.T.; Alton, G.D.

    1989-01-01

    Liquid metal ion sources offer potential improvement in lateral resolution over conventionally used gaseous sources for MeV microprobe applications because of their intrinsic brightnesses. The use of a Li liquid metal ion source is particularly attractive because of the increased sensitivity of lithium for detecting hydrogen (hydrogen profiling) and for detecting near surface contaminants through high-resolution Rutherford backscattering spectrometry. However, the technical difficulty of occasional sparking between the needle and extraction electrode requires that the needle of the Li liquid metal ion source be rewetted before reignition can be effected; this problem makes Li liquid metal ion sources of the usual design risky for operation in the insulated high-voltage terminals of accelerators used in such applications. We have designed a reliable, long-lived, Li liquid-metal ion source which has provisions for overcoming this limitation. The design features and performance characteristics of the source are described in this report. 9 refs., 4 figs.

  19. A lithium liquid metal ion source suitable for high voltage terminal applications

    NASA Astrophysics Data System (ADS)

    Read, P. M.; Maskrey, J. T.; Alton, G. D.

    1990-01-01

    Liquid metal ion sources offer potential improvement in lateral resolution over conventionally used gaseous sources for MeV microprobe applications because of their intrinsic brightnesses. The use of a Li liquid metal ion source is particularly attractive because of the increased sensitivity of lithium for detecting hydrogen (hydrogen profiling) and for detecting near-surface contaminants through high-resolution Rutherford backscattering spectrometry. However, the technical difficulty of occasional sparking between the needle and extraction electrode requires that the needle of the Li liquid metal ion source be rewetted before reignition can be effected; this problem makes Li liquid metal ion sources of the usual design risky for operation in the insulated high-voltage terminals of accelerators used in such applications. We have designed a reliable, long-lived, Li liquid-metal ion source which has provisions for overcoming this limitation. The design features and performance characteristics of the source are described in this article.

  20. Transport of radioactive ion beams and related safety issues: The {sup 132}Sn{sup +} case study

    SciTech Connect

    Osswald, F. Bouquerel, E.; Boutin, D.; Dinkov, A.; Sellam, A.

    2014-12-15

    The transport of intense radioactive ion beam currents requires a careful design in order to limit the beam losses, the contamination and thus the dose rates. Some investigations based on numerical models and calculations have been performed in the framework of the SPIRAL 2 project to evaluate the performance of a low energy beam transport line located between the isotope separation on line (ISOL) production cell and the experiment areas. The paper presents the results of the transverse phase-space analysis, the beam losses assessment, the resulting contamination, and radioactivity levels. They show that reasonable beam transmission, emittance growth, and dose rates can be achieved considering the current standards.

  1. Nitrogen ion implantation in metals - A comparison of Experimental Results and Computer Simulations

    NASA Astrophysics Data System (ADS)

    Sanghera, Harpreet; Sullivan, John

    2000-04-01

    The aim of this work is to investigate the effects of ion energy, current density and dose on low energy nitrogen ion implantation profiles in metal surfaces. For this purpose, metal (Al, Fe, Cu and Au) bulk samples, with a purity of 99.9energies of 2, 3, 4 and 5 keV with current densities of 1 mA/cm2 and 5 mA/cm2 for each ion energy. The ion fluences for these experiments range from 6xE16 and 3xE17 ions/cm2. The chemical composition and chemical structure of the implanted metals were investigated by XPS and Angle Resolved X-ray Photoelectron Spectroscopy (ARXPS). The concentration profiles of nitrogen ions implanted into metals were measured by X-ray Photoelectron Spectroscopy (XPS) and these were compared with the profiles created using computer simulation codes SUSPRE and SATVAL.

  2. Sunflower stalks as adsorbents for the removal of metal ions from wastewater

    SciTech Connect

    Sun, G.; Shi, W.

    1998-04-01

    Sunflower stalks as adsorbents for the removal of metal ions such as copper, cadmium, zinc, and chromium ions in aqueous solutions were studied with equilibrium isotherms and kinetic adsorptions. The maximum adsorptions of four heavy metals are 29.3 mg/g (Cu{sup 2+}), 30.73 mg/g (Zn{sup 2+}), 42.18 mg/g (Cd{sup 2+}), and 25.07 mg/g (Cr{sup 3+}), respectively. Particle sizes of sunflower stalks affected the adsorption of metal ions; the finer size of particles showed better adsorption to the ions. Temperature also plays an interesting role in the adsorption of different metal ions. Copper, zinc, and cadmium exhibited lower adsorption on sunflower stalks at higher temperature, while chromium showed the opposite phenomenon. The adsorption rates of copper, cadmium, and chromium are quite rapid. Within 60 min of operation about 60--80% of these ions were removed from the solutions.

  3. Metal-clad optical waveguide fluorescence device for the detection of heavy metal ions

    NASA Astrophysics Data System (ADS)

    Margheri, Giancarlo; Giorgetti, Emilia; Marsili, Paolo; Zoppi, Angela; Lascialfari, Luisa; Cicchi, Stefano

    2014-07-01

    We developed Hg-sensing chips by decorating the external surface of metal-clad optical waveguides with a monolayer of Hg-sensitive fluorescent molecular probes. The emission properties of the original water-soluble form of the molecule were previously found to be selectively quenched in the presence of Hg ions. The fabricated samples were tested with optical waveguide fluorescence spectroscopy by putting them in contact with a 5-?M water solution of Hg ions and recording the emission spectra versus incubation time. The estimate of the limit of detection was 150 nM. A preliminary evaluation of the selectivity of the structure was also performed by using Cd as possible interfering analytes.

  4. Arrays of Metal Nanostructures Produced by Focussed Ion Beam

    NASA Astrophysics Data System (ADS)

    Luches, P.; di Bona, A.; Contri, S. F.; Gazzadi, G. C.; Vavassori, P.; Albertini, F.; Casoli, F.; Nasi, L.; Fabbrici, S.; Valeri, S.

    2007-12-01

    We present a study of the magnetic properties of arrays of nanostructures produced in a focussed ion beam-scanning electron microscope dual beam system. The single magnetic units have been isolated either by direct removal of parts of the metallic film or by local modification of the film magnetic properties. The final quality of the shape and the residual damage strictly depend on beam parameters (spot size and pixel dwell time) and on the swelling properties of the patterned materials. On square Fe(001) elements with a well-defined intrinsic (magnetocristalline) and shape- and size- induced (shape plus configurational) anisotropy we show that the overall magnetic anisotropy is not a mere superposition of the individual contributions. We also demonstrate that with ion irradiation doses below the milling threshold L10 FePt films with perpendicular magnetic anisotropy undergo a transition from the magnetically hard L10 phase to the magnetically soft A1 phase leading to an out-of-plane to in-plane spin reorientation. The magnetic properties of the planar arrays obtained by local modification of the film are compared to arrays of sculpted structures of the same material.

  5. Multidiagnostics analysis of ion dynamics in ultrafast laser ablation of metals over a large fluence range

    SciTech Connect

    Anoop, K. K.; Polek, M. P.; Bruzzese, R.; Amoruso, S.; Harilal, Sivanandan S.

    2015-02-28

    The ions dynamics in ultrafast laser ablation of metals is studied over a fluence range spanning from the ablation threshold up to ~75 J/cm2 by means of three established diagnostic techniques. Langmuir probe, Faraday cup and spectrally resolved ICCD imaging simultaneously monitor the laser-produced plasma ions produced during ultrafast laser ablation of a copper target. The fluence dependence of ion yield is analyzed observing the occurrence of three different regimes. Moreover, the specific ion yield shows a maximum at about 4-5 J/cm2, followed by a gradual reduction and a transition to a high-fluence regime above ~50 J/cm2. The fluence variation of the copper ions angular distribution is also analyzed, observing a gradual increase of forward peaking of Cu ions for fluences up to ~10 J/cm2. Then, a broader ion component is observed at larger angles for fluences larger than ~10 J/cm2. Finally, an experimental characterization of the ions angular distribution for several metallic targets (Mg, Al, Cr, Fe, Cu, and W) is carried out at a relatively high fluence of ~66 J/cm2. Interestingly, the ion emission from the volatile metals show a narrow forward peaked distribution and a high peak ion yield compared to the refractory metals. Moreover, the width of ion angular distributions presents a striking correlation with the peak ion yield.

  6. Focused ion beam milling and scanning electron microscopy characterization of polymer+metal hybrids

    E-print Network

    North Texas, University of

    Focused ion beam milling and scanning electron microscopy characterization of polymer+metal hybrids dispersion on the surfaces of the microhybrids. Focus ion beam (FIB) milling was used to create a transversal cut in the material. SEM imaging was performed before, during and after ion milling to investigate

  7. Formation of metallic nanostructures on the surface of ion- exchange glass by focused electron beam

    NASA Astrophysics Data System (ADS)

    Komissarenko, F. E.; Zhukov, M. V.; Mukhin, I. S.; Golubok, A. O.; Sidorov, A. I.

    2015-11-01

    This paper presents a new method for formation of metallic nanostructures on the surface of ion-exchange glass. The method is based on the interaction of a focused electron beam with ions in ion-exchange glass. In experiments nanostructures with different shapes were obtained, depending on the electrons irradiation conditions.

  8. METAL INTERACTIONS AT SULFIDE MINERAL SURFACES: PART 3, METAL AFFINITIES IN SINGLE AND MULTIPLE ION ADSORPTION REACTIONS

    EPA Science Inventory

    Adsorption reactions of both single ions and multiple ion mixtures with sulfide minerals (chalcocite, galena, pyrite, and sphalerite) were investigated in the metal concentration range of 0.0001 to 0.00001 M. Chromium (III), iron (III), barium (II), cadmium (II), copper (II), nic...

  9. Conditions of accumulation of radioactive metals in the process of differentiation of ultrabasic alkaline-carbonatite rock associations

    NASA Astrophysics Data System (ADS)

    Kogarko, L. N.

    2014-07-01

    The distribution of radioactive elements in alkaline rocks from Polar Siberia and Ukraine shows that U and Th are markedly concentrated in carbonatite complex and nepheline syenite as final products of magma fractionation. Peralkaline nepheline syenites from Polar Siberia are characterized by very high contents of radioactive elements, which are close to the economic level. Radioactive elements are also concentrated in rocks of the carbonatite complex. For example, some soevites contain up to 294 × 10-4%U and 916 × 10-4% Th. In late dolomite carbonatites, the contents of radioactive elements are appreciably lower. The Th/U ratio in alkaline rocks of Polar Siberia is close to the chondrite value in primary high-Mg rocks and increases in late derivatives: phoscorite, calcite and dolomite carbonatites. The main amount of radioactive elements is contained in rare-metal accessory minerals: perovskite, pyrochlore, calzirtite, and apatite. Rock-forming minerals are distinguished by very low concentrations of radioactive elements. In alkaline series of the Chernigovka massif (Ukraine), U and Th also accumulate in the course of crystal fractionation, especially in phoscorites from the carbonatite complex. Mantle xenoliths and alkaline rocks from Ukraine reveal uranium specialization. Most likely, the discrepancy in fractionation of radioactive elements between Polar Siberia and Ukraine is caused by different geodynamic regimes of these provinces. The Mesozoic alkaline magmatism of Polar Siberia is a part of the Siberian superplume, whereas the Proterozoic alkaline complex in Ukraine is related to subduction of the oceanic crust.

  10. Synthesis, characterization and application of titanium oxide nanocomposites for removal of radioactive cesium, cobalt and europium ions.

    PubMed

    Borai, E H; Breky, M M E; Sayed, M S; Abo-Aly, M M

    2015-07-15

    New nanocomposite material containing TiO2/Poly (acrylamide-styrene sodium sulfonate) [TiO2/(P (AAm-SSS)] was prepared by in-situ intercalative polymerization of poly acrylamide (PAAm) and styrene sodium sulfonate (SSS) in the presence of TiO2 nanoparticles as inorganic filler. N, N-methylene bis acrylamide (MBA) was used as a cross linker. The polymerization process was performed using ?-radiation as reaction initiator. Moreover, new nanocomposite material containing poly styrene-TiO2 (PS-TiO2) was also prepared by ionic polymerization method. Styrene was catalytically polymerized by Ti(4+) via an ionic polymerization route to produce polystyrene (PS). The structure characteristics of the nanocomposites were investigated by XRD, TGA, SEM, surface area, and FTIR. The nanoparticles and nanocomposites were investigated for removal of some metal ions from aqueous solutions. The effective key parameters on the sorption behavior of radioactive cesium (Cs(+)), cobalt (Co(2+)) and europium (Eu(3+)) were investigated using batch equilibrium technique with respect to solution pH and contact time. The obtained results revealed that the equilibrium for Cs(+), Co(2+) and Eu(3)(+) is reached at 2-3 h for all nanocomposites. The data indicated that there is no significant change in the uptake between TiO2 nanoparticles and TiO2-PS. On the contrary, the uptake process is significantly improved using TiO2/(P (AAm-SSS) nanocomposite and the maximum experimental retention capacities for Cs(+), Co(2+) and Eu(3+) were found to be 120, 100.9 and 85.7 mg/g, respectively. PMID:25797394

  11. Thermal-electric coupled-field finite element modeling and experimental testing of high-temperature ion sources for the production of radioactive ion beams

    NASA Astrophysics Data System (ADS)

    Manzolaro, M.; Meneghetti, G.; Andrighetto, A.; Vivian, G.; D'Agostini, F.

    2016-02-01

    In isotope separation on line facilities the target system and the related ion source are two of the most critical components. In the context of the selective production of exotic species (SPES) project, a 40 MeV 200 ?A proton beam directly impinges a uranium carbide target, generating approximately 1013 fissions per second. The radioactive isotopes produced in this way are then directed to the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work both the surface ion source and the plasma ion source adopted for the SPES facility are presented and studied by means of numerical thermal-electric models. Then, numerical results are compared with temperature and electric potential difference measurements, and finally the main advantages of the proposed simulation approach are discussed.

  12. Metal ions and protein aggregation: the case fo Prion protein and -amyloids

    E-print Network

    Morante, Silvia

    Metal ions and protein aggregation: the case fo Prion protein and -amyloids Silvia Morante community, is the structural rôle played by metals in intra-molecular and inter-molecular interactions. Metals are essential elements for many of the fundamental activities of cells. Storing, metabolism

  13. Radioactivity levels and heavy metals in the urban soil of Central Serbia.

    PubMed

    Milenkovic, B; Stajic, J M; Gulan, Lj; Zeremski, T; Nikezic, D

    2015-11-01

    Radioactivity concentrations and heavy metal content were measured in soil samples collected from the area of Kragujevac, one of the largest cities in Serbia. The specific activities of (226)Ra, (232)Th, (40)K and (137)Cs in 30 samples were measured by gamma spectrometry using an HPGe semiconductor detector. The average values?±?standard deviations were 33.5?±?8.2, 50.3?±?10.6, 425.8?±?75.7 and 40.2?±?26.3 Bq kg(-1), respectively. The activity concentrations of (226)Ra, (232)Th and (137)Cs have shown normal distribution. The annual effective doses, radium equivalent activities, external hazard indexes and excess lifetime cancer risk were also estimated. A RAD7 device was used for measuring radon exhalation rates from several samples with highest content of (226)Ra. The concentrations of As, Co, Cr, Cu, Mn, Ni, Pb and Zn were measured, as well as their EDTA extractable concentrations. Wide ranges of values were obtained, especially for Cr, Mn, Ni, Pb and Zn. The absence of normal distribution indicates anthropogenic origin of Cr, Ni, Pb and Zn. Correlations between radionuclide activities, heavy metal contents and physicochemical properties of analysed soil were determined by Spearman correlation coefficient. Strong positive correlation between (226)Ra and (232)Th was found. PMID:26087932

  14. Does bearing size influence metal ion levels in large-head metal-on-metal total hip arthroplasty? A comparison of three total hip systems

    PubMed Central

    2014-01-01

    Background The purpose of the study was twofold: first, to determine whether there is a statistically significant difference in the metal ion levels among three different large-head metal-on-metal (MOM) total hip systems. The second objective was to assess whether position of the implanted prostheses, patient demographics or factors such as activity levels influence overall blood metal ion levels and whether there is a difference in the functional outcomes between the systems. Methods In a cross-sectional cohort study, three different metal-on-metal total hip systems were assessed: two monoblock heads, the Durom socket (Zimmer, Warsaw, IN, USA) and the Birmingham socket (Smith and Nephew, Memphis, TN, USA), and one modular metal-on-metal total hip system (Pinnacle, Depuy Orthopedics, Warsaw, IN, USA). Fifty-four patients were recruited, with a mean age of 59.7 years and a mean follow-up time of 41 months (12 to 60). Patients were evaluated clinically, radiologically and biochemically. Statistical analysis was performed on all collected data to assess any differences between the three groups in terms of overall blood metal ion levels and also to identify whether there was any other factor within the group demographics and outcomes that could influence the mean levels of Co and Cr. Results Although the functional outcome scores were similar in all three groups, the blood metal ion levels in the larger monoblock large heads (Durom, Birmingham sockets) were significantly raised compared with those of the Pinnacle group. In addition, the metal ion levels were not found to have a statistically significant relationship to the anteversion or abduction angles as measured on the radiographs. Conclusions When considering a MOM THR, the use of a monoblock large-head system leads to higher elevations in whole blood metal ions and offers no advantage over a smaller head modular system. PMID:24472283

  15. Radioactive Ion Beams at ISOLDE/CERN Recent Developments and Perspectives

    SciTech Connect

    U. Georg; J.R.J. Bennett; U.C. Bergmann; R. Catherall; P. Drumm; V.N. Fedoseyev; T. Giles; O.C. Jonsson; A.R. Junghans; U. Koester; E. Kugler; J. Lettry; V.I. Mishin; T. Nilsson; H. Ravn; K.-H. Schmidt; H. Simon; C. Tamburella

    1999-12-31

    Since the move of ISOLDE from CERN's synchrocyclotron (SC) to the Proton Synchrotron Booster (PSB) in 1992 extensive work has been devoted to the development of new beams, i.e. the production of new isotopes, beams of higher intensity and the ionization of further elements. Most of these developments were driven by the particular needs of the physics community proposing new experiments. The main achievements were the adaption of liquid metal targets to the pulsed proton beam to prevent shockwaves and splashing inside the target container and systematic studies on the time structure of the release of the isotopes from the target. Furthermore the work on laser ion-sources already started at ISOLDE-2 was continued, the so-called RIST target was developed, and most recently first tests on the isotope production while increasing the proton energy from 1 GeV to 1.4 GeV were done. The latter topics are discussed in this paper.

  16. Radioactive ion beams at ISOLDE/CERN recent developments and perspectives

    SciTech Connect

    Georg, U.; Catherall, R.; Giles, T.; Jonsson, O. C.; Koester, U.; Kugler, E.; Lettry, J.; Nilsson, T.; Ravn, H.; Simon, H.; Tamburella, C.; Bennett, J. R. J.; Drumm, P.; Bergmann, U. C.; Fedoseyev, V. N.; Junghans, A. R.; Mishin, V. I.; Schmidt, K.-H.

    1999-11-16

    Since the move of ISOLDE from CERN's synchrocyclotron (SC) to the Proton Synchrotron Booster (PSB) in 1992 extensive work has been devoted to the development of new beams, i.e. the production of new isotopes, beams of higher intensity and the ionization of further elements. Most of these developments were driven by the particular needs of the physics community proposing new experiments. The main achievements were the adaption of liquid metal targets to the pulsed proton beam to prevent shockwaves and splashing inside the target container and systematic studies on the time structure of the release of the isotopes from the target. Furthermore the work on laser ion-sources already started at ISOLDE-2 was continued, the so-called RIST target was developed, and most recently first tests on the isotope production while increasing the proton energy from 1 GeV to 1.4 GeV were done. The latter topics are discussed in this paper.

  17. Metal-Mediated Peptide Ion Conformations in the Gas Phase John A. Taraszka, Jianwei Li, and David E. Clemmer*

    E-print Network

    Clemmer, David E.

    Metal-Mediated Peptide Ion Conformations in the Gas Phase John A. Taraszka, Jianwei Li, and David E, 1999; In Final Form: February 24, 2000 The influence of metal cations and source temperature-resolution ion mobility techniques. Cross sections for non-metalated [ICA-nH]n- (n ) 2-6) ions show a distinct

  18. Does a Single Metal Ion Bridge the A-9 and Scissile Phosphate Groups in the Catalytically Active

    E-print Network

    Scott, William

    ERRATUM Does a Single Metal Ion Bridge the A-9 and Scissile Phosphate Groups in the Catalytically±41 Figure 3 of the above paper shows the divalent metal ion coordinated to the pro-S nonbridging phosphate. The metal ion should in fact be bound by the pro-R oxygens of these phosphates, as is now shown

  19. Development of Neutron Detectors for the Next Generation of Radioactive Ion-Beam Facilities

    E-print Network

    Pär-Anders Söderström

    2009-05-13

    The next generation of radioactive ion beam facilities, which will give experimental access to many exotic nuclei, are presently being developed. These facilities will make it possible to study very short lived exotic nuclei with extreme values of isospin far from the line of beta stability. Such nuclei will be produced with very low cross sections and to study them, new detector arrays are being developed. At the SPIRAL facility in GANIL a neutron detector array, the Neutron Wall, is located. In this work the Neutron Wall has been characterized regarding neutron detection efficiency and discrimination between neutrons and gamma rays. The possibility to increase the efficiency by increasing the high voltage of the photomultiplier tubes has also been studied. For SPIRAL2 a neutron detector array, NEDA, is being developed. NEDA will operate in a high gamma-ray background environment which puts a high demand on the quality of discrimination between neutrons and gamma rays. To increase the quality of the discrimination methods pulse-shape discrimination techniques utilizing digital electronics have been developed and evaluated regarding bit resolution and sampling frequency of the ADC. The conclusion is that an ADC with a bit resolution of 12 bits and a sampling frequency of 100 MS/s is adequate for pulse-shape discrimination of neutrons and gamma rays for a neutron energy range of 0.3-12 MeV.

  20. A gas-jet transport and catcher technique for on-line production of radioactive ion beams using an electron cyclotron resonance ion-source

    SciTech Connect

    Naik, V.; Chakrabarti, A.; Bhattacharjee, M.; Karmakar, P.; Bandyopadhyay, A.; Dechoudhury, S.; Mondal, M.; Pandey, H. K.; Lavanyakumar, D.; Mandi, T. K.; Dutta, D. P.; Kundu Roy, T.; Bhowmick, D.; Sanyal, D.; Srivastava, S. C. L.; Ray, A.; Ali, Md. S.; Bhattacharjee, S.

    2013-03-15

    Radioactive ion beams (RIB) have been produced on-line, using a gas-jet recoil transport coupled Electron Cyclotron Resonance (ECR) ion-source at the VECC-RIB facility. Radioactive atoms/molecules carried through the gas-jet were stopped in a catcher placed inside the ECR plasma chamber. A skimmer has been used to remove bulk of the carrier gas at the ECR entrance. The diffusion of atoms/molecules through the catcher has been verified off-line using stable isotopes and on-line through transmission of radioactive reaction products. Beams of {sup 14}O (71 s), {sup 42}K (12.4 h), {sup 43}K (22.2 h), and {sup 41}Ar (1.8 h) have been produced by bombarding nitrogen and argon gas targets with proton and alpha particle beams from the K130 cyclotron at VECC. Typical measured intensity of RIB at the separator focal plane is found to be a few times 10{sup 3} particles per second (pps). About 3.2 Multiplication-Sign 10{sup 3} pps of 1.4 MeV {sup 14}O RIB has been measured after acceleration through a radiofrequency quadrupole linac. The details of the gas-jet coupled ECR ion-source and RIB production experiments are presented along with the plans for the future.

  1. Performance of the Recoil Mass Spectrometer and its detector systems at the Holifield Radioactive Ion Beam Facility

    NASA Astrophysics Data System (ADS)

    Gross, C. J.; Ginter, T. N.; Shapira, D.; Milner, W. T.; McConnell, J. W.; James, A. N.; Johnson, J. W.; Mas, J.; Mantica, P. F.; Auble, R. L.; Das, J. J.; Blankenship, J. L.; Hamilton, J. H.; Robinson, R. L.; Akovali, Y. A.; Baktash, C.; Batchelder, J. C.; Bingham, C. R.; Brinkman, M. J.; Carter, H. K.; Cunningham, R. A.; Davinson, T.; Fox, J. D.; Galindo-Uribarri, A.; Grzywacz, R.; Liang, J. F.; MacDonald, B. D.; MacKenzie, J.; Paul, S. D.; Piechaczek, A.; Radford, D. C.; Ramayya, A. V.; Reviol, W.; Rudolph, D.; Rykaczewski, K.; Toth, K. S.; Weintraub, W.; Williams, C.; Woods, P. J.; Yu, C.-H.; Zganjar, E. F.

    2000-08-01

    The recently commissioned Recoil Mass Spectrometer (RMS) at the Holifield Radioactive Ion Beam Facility (HRIBF) is described. Consisting of a momentum separator followed by an E-D-E Rochester-type mass spectrometer, the RMS is the centerpiece of the nuclear structure endstation at the HRIBF. Designed to transport ions with rigidities near K=100, the RMS has acceptances of ±10% in energy and ±4.9% in mass-to-charge ratio. Recent experimental results are used to illustrate the detection capabilities of the RMS, which is compatible with many detectors and devices.

  2. Computational scheme for the prediction of metal ion binding by a soil fulvic acid

    USGS Publications Warehouse

    Marinsky, J.A.; Reddy, M.M.; Ephraim, J.H.; Mathuthu, A.S.

    1995-01-01

    The dissociation and metal ion binding properties of a soil fulvic acid have been characterized. Information thus gained was used to compensate for salt and site heterogeneity effects in metal ion complexation by the fulvic acid. An earlier computational scheme has been modified by incorporating an additional step which improves the accuracy of metal ion speciation estimates. An algorithm is employed for the prediction of metal ion binding by organic acid constituents of natural waters (once the organic acid is characterized in terms of functional group identity and abundance). The approach discussed here, currently used with a spreadsheet program on a personal computer, is conceptually envisaged to be compatible with computer programs available for ion binding by inorganic ligands in natural waters.

  3. Recoil in vacuum for Te ions: Calibration, models, and applications to radioactive-beam g-factor measurements

    SciTech Connect

    Stuchbery, A. E.; Stone, N. J.

    2007-09-15

    In the light of new g factor results for the stable isotopes between {sup 122}Te and {sup 130}Te, the calibration and modeling of the recoil-in-vacuum (RIV) interaction for Te ions is reexamined, and the recent radioactive-beam g factor measurement on {sup 132}Te by the RIV technique is reevaluated. The implications for further RIV g-factor measurements in the {sup 132}Sn region are discussed.

  4. Electric Double-Layer Effects Induce Separation of Aqueous Metal Ions.

    PubMed

    Ji, Qinghua; An, Xiaoqiang; Liu, Huijuan; Guo, Lin; Qu, Jiuhui

    2015-11-24

    Metal ion separation is crucial to environmental decontamination, chromatography, and metal recovery and recycling. Theoretical studies have suggested that the ion distributions in the electric double-layer (EDL) region depend on the nature of the ions and the characteristics of the charged electrode surface. We believe that rational design of the electrode material and device structure will enable EDL-based devices to be utilized in the separation of aqueous metal ions. On the basis of this concept, we fabricate an EDL separation (EDLS) device based on sandwich-structured N-functionalized graphene sheets (CN-GS) for selective separation of aqueous toxic heavy metal ions. We demonstrate that the EDLS enables randomly distributed soluble ions to form a coordination-driven layer and electrostatic-driven layer in the interfacial region of the CN-GS/solution. Through tuning the surface potential of the CN-GS, the effective separation of heavy metal ions (coordination-driven layer) from alkali or alkaline earth metal ions (electrostatic-driven layer) can be achieved. PMID:26481603

  5. Calculated distortions induced by metal-ion binding to simple oligonucleotide systems: Implications for toxicity

    SciTech Connect

    Turner, J.E.; Hingerty, B.E.; England, M.W.; Jacobson, K.B.

    1990-01-01

    We have previously published detailed results of calculations of the binding of the metal ions, Cd{sup 2+} and Ca{sup 2+}, to the dinucleoside monophosphate GpC in water. These ions, which have the same charge and radius, differ enormously in their toxicity to man and other biological systems. Our calculations showed contrasting behavior in the binding of these two metal ions to GpC. We suggest the hypothesis that structural distortions calculated for metal ions binding to simple nucleic-acid systems might serve as a indicator of an ion's potential ability to alter molecular activity and hence to be toxic to an organism. Furthermore, the degree of distortion might be correlated with the degree of toxicity as measured by some suitable criteria. The present paper reports the results of binding calculations for a number of other metal ions, of different valence states, with several dinucleoside monophosphates in water. A general trend of distortion with the type of binding of the metal ions is found. We are seeking quantitative measures of distortion to correlate with indicators of acute toxicity that we have measured for 24 metal ions using mice, Drosophila, and CHO cells. 3 refs., 3 figs.

  6. Determination of metal ion concentrations by SERS using 2,2'-bipyridyl complexes.

    PubMed

    Docherty, Julie; Mabbott, Samuel; Smith, W Ewen; Reglinski, John; Faulds, Karen; Davidson, Christine; Graham, Duncan

    2015-10-01

    Surface enhanced Raman scattering (SERS) can generate characteristic spectral "fingerprints" from metal complexes, thus providing the potential for the development of methods of analysis for the identification and quantitation of a range of metal ions in solution. The advantages include sensitivity and the use of one ligand for several metals without the need for a specific chromophore. Aqueous solutions of Fe(II), Ni(II), Zn(II), Cu(II), Cr(III) and Cd(II) in the presence of excess 2,2'-bipyridyl (bipy) were analysed using SERS. Specific marker bands enabled the identification of each metal ion and the limit of detection for each metal ion was estimated. Two of the ions, Zn(II) and Cu(II), could be detected below the World Health Organisation's (WHO) recommended limits for drinking water at levels of 0.22 and 0.6 mg L(-1), respectively. PMID:26312259

  7. Metal ion complexation by ionizable crown ethers. Progress report, January 1, 1991--December 31, 1993

    SciTech Connect

    Bartsch, R.A.

    1993-07-01

    Cyclic and acyclic polyether compounds with pendent carboxylic acid, phosphonic acid monoethyl ester, sulfonic acid, phosphinic acid and hydroxamic acid groups have been synthesized. The proton-ionizable polyethers can come with and without lipophilic groups. Two types of lipophilic di-ionizable lariat ethers have been prepared. Conformations of proton-ionizable lariat ethers have been probed. Competitive alkali metal cation transport by syn-(decyl)dibenzo-16-crown-5-oxyacetic acid and lipophilic proton-ionizable dibenzo lariat ethers in polymer-supported liquid membranes was studied. Complexation of alkali metal cations with ionized lariat ethers was studied. Condensation polymerization of cyclic and acyclic dibenzo polyethers containing pendent mono-ionizable groups with formaldehyde produces novel ion exchange resins with both ion exchange sites for metal ion complexation and polyether binding sites for metal ion recognition. Resins prepared from lariat ether dibenzo phosphonic acid monoethyl esters show strong sorption of divalent heavy metal cations with selectivity for Pb{sup 2+}.

  8. Metal Ion Concentrations in Body Fluids after Implantation of Hip Replacements with Metal-on-Metal Bearing – Systematic Review of Clinical and Epidemiological Studies

    PubMed Central

    Hartmann, Albrecht; Hannemann, Franziska; Lützner, Jörg; Seidler, Andreas; Drexler, Hans; Günther, Klaus-Peter; Schmitt, Jochen

    2013-01-01

    Introduction The use of metal-on-metal (MoM) total hip arthroplasty (THA) increased in the last decades. A release of metal products (i.e. particles, ions, metallo-organic compounds) in these implants may cause local and/or systemic adverse reactions. Metal ion concentrations in body fluids are surrogate measures of metal exposure. Objective To systematically summarize and critically appraise published studies concerning metal ion concentrations after MoM THA. Methods Systematic review of clinical trials (RCTs) and epidemiological studies with assessment of metal ion levels (cobalt, chromium, titanium, nickel, molybdenum) in body fluids after implantation of metalliferous hip replacements. Systematic search in PubMed and Embase in January 2012 supplemented by hand search. Standardized abstraction of pre- and postoperative metal ion concentrations stratified by type of bearing (primary explanatory factor), patient characteristics as well as study quality characteristics (secondary explanatory factors). Results Overall, 104 studies (11 RCTs, 93 epidemiological studies) totaling 9.957 patients with measurement of metal ions in body fluids were identified and analyzed. Consistently, median metal ion concentrations were persistently elevated after implantation of MoM-bearings in all investigated mediums (whole blood, serum, plasma, erythrocytes, urine) irrespective of patient characteristics and study characteristics. In several studies very high serum cobalt concentrations above 50 µg/L were measured (detection limit typically 0.3 µg/L). Highest metal ion concentrations were observed after treatment with stemmed large-head MoM-implants and hip resurfacing arthroplasty. Discussion Due to the risk of local and systemic accumulation of metallic products after treatment with MoM-bearing, risk and benefits should be carefully balanced preoperatively. The authors support a proposed „time out“ for stemmed large-head MoM-THA and recommend a restricted indication for hip resurfacing arthroplasty. Patients with implanted MoM-bearing should receive regular and standardized monitoring of metal ion concentrations. Further research is indicated especially with regard to potential systemic reactions due to accumulation of metal products. PMID:23950923

  9. Properties of microsolvated ions: from the microenvironment of chromophore and alkali metal ions in proteins to negative ions in water clusters.

    PubMed

    Nielsen, Steen Brøndsted; Andersen, Lars H

    2006-12-01

    Here we discuss the fascinating chemistry and physics of microsolvated ions that bridge the transition from bare ions in gas phase to ions in solution. Such ions occur in many situations in biochemistry and are crucial for several functions; metal ions, for example, must remove their water shell to pass through ion pumps in membranes. Furthermore, only a few water molecules are buried in the hydrophobic pockets of proteins where they are bound to charged amino acid residues or ionic chromophores. Another aspect is the reactivity of microsolvated ions and the importance in atmospheric, organic and inorganic chemistry. We close by a discussion of the stability of molecular dianions, and how hydration affects the electronic binding energy. There is a vast literature on microsolvated ions, and in this review we are far from being comprehensive, rather we mainly bring examples of our own work. PMID:16697516

  10. Characterization of Metal Ion ­ Colloid Interaction: Impact On Colloid-facilitated Transport

    NASA Astrophysics Data System (ADS)

    Specht, C. H.; Schmitt, D.; Kaulisch, E.-M.; Frimmel, F. H.

    It is generally accepted, that metal transport in natural aquatic systems strongly de- pends on the metal binding form. Besides complex formation with well defined inor- ganic and organic ligands, the interaction with colloidal particles and soil material is one of the most important reactions of metal ions in aquatic systems. Mobile colloids compete with the stationary soil matrix for binding of metal ions and might facili- tate their transport. Important representatives for mineral and organic colloids are clay minerals and natural organic matter (NOM), respectively. In this work, the interaction of metal ions with clay minerals and NOM is characterized by coupling of asymmetric flow field-flow fractionation AF4 to inductively coupled plasma ­ mass spectrometry (ICPMS). A method for separating mineral from organic colloids is presented, which allows to quantify the amount of metals being bound to either colloid. For different metal ions (Cu, Zn, Pb, Pt) and a metalloid (As) a different extent of binding to either colloid was found.The information obtained from the AF4-ICPMS measurements was useful for the understanding of the observations from column experiments which were conducted to quantify the colloid-facilitated metal transport. In column experiments, the transport of the mineral colloids itself and the influence of NOM onto the colloid transport were investigated. Furthermore, the dependance of colloid transport from the ionic strength and the pH value was elucidated. In order to get information about the co-transport of metal ions by organic and mineral colloids, metal ions were adsorbed onto the colloidal material and a distribution coef- ficient of the metal ions between the colloidal phase and the solution was determined. The colloidal suspension containing both, "free" and adsorbed metal ions were then injected onto the column. The direct metal breakthrough caused by colloidal trans- port was detected at the column outlet. The results clearly revealed that the amount of metal ions being transported agreed well with the amount of colloids being mobile and the amount of metal ions being bound to the colloids. Particle mobility is strongly affected by the ionic strength of the eluent and by organic coatings. In the presence of NaCl organic coatings enhanced particle mobility, whereas in the presence of CaCl2 it was reduced.

  11. Multidiagnostic analysis of ion dynamics in ultrafast laser ablation of metals over a large fluence range

    NASA Astrophysics Data System (ADS)

    Anoop, K. K.; Polek, M. P.; Bruzzese, R.; Amoruso, S.; Harilal, S. S.

    2015-02-01

    The dynamics of ions in ultrafast laser ablation of metals is studied over fluences ranging from the ablation threshold up to ?75 J/cm2 by means of three well-established diagnostic techniques. Langmuir probe, Faraday cup, and spectrally resolved intensified charge coupled device imaging simultaneously monitored the ions produced during ultrafast laser ablation of a pure copper target with 800 nm, ?50 fs, Ti: Sapphire laser pulses. The fluence dependence of ion yield is analyzed, resulting in the observance of three different regimes. The specific ion yield shows a maximum at about 4-5 J/cm2, followed by a gradual reduction and a transition to a high-fluence regime above ?50 J/cm2. The fluence dependence of the copper ions angular distribution is also analyzed, observing a gradual increase in forward-peaking of Cu ions for fluences up to ?10 J/cm2. A broader ion component is observed at larger angles for fluences larger than ?10 J/cm2. Finally, an experimental characterization of the ionic angular distribution for several metallic targets (Mg, Al, Cr, Fe, Cu, and W) is carried out at a relatively high fluence of ?66 J/cm2. Interestingly, the ion emission from the volatile metals shows a narrow, forward-peaked distribution, and a high peak ion yield compared to the refractory metals. Moreover, the width of ionic angular distributions presents a striking correlation with the peak ion yield.

  12. Direct observation of ion transfer in contact charging between a metal and a polymer

    NASA Astrophysics Data System (ADS)

    Mizes, H. A.; Conwell, E. M.; Salamida, D. P.

    1990-04-01

    Triboelectric charging between metals and insulators is usually thought to involve electron transfer. Doping some polymers with a small amount of salt can significantly change their charging properties, even reversing the sign to which they charge upon contact with a given metal. We show by means of secondary-ion mass spectrometry that ions of the salt are transferred across the interface in contacts between a doped polymer and a metal. Specifically, we observe a transfer of bromine ions when polystyrene doped with a small amount of the salt cetylpyridinium bromide is contacted to an indium surface.

  13. Novel Metal Ion Based Estrogen Mimics for Molecular Imaging

    SciTech Connect

    Rajagopalan, Raghavan

    2006-01-30

    The overall objective of the SBIR Phase I proposal is to prepare and evaluate a new class of {sup 99m}Tc or {sup 94m}Tc containing estrogen-like small molecules ('estrogen mimics') for SPECT or PET molecular imaging of estrogen receptor positive (ER+) tumors. In this approach, the metal ion is integrated into the estrone skeleton by isosteric substitution of a carbon atom in the steroidal structure to give new class of mimics that are topologically similar to the native estrogen (Fig. 1). Although both N{sub 2}S{sub 2} and N{sub 3}S mimics 1 and 2 were considered as target structures, molecular modeling study revealed that the presence of the acetyl group at position-15 in the N{sub 3}S mimic 2 causes steric hinderance toward binding of 2 to SHBG. Therefore, initial efforts were directed at the synthesis and evaluation of the N{sub 2}S{sub 2} mimic 1.

  14. Interaction between ATP, metal ions, glycine, and several minerals

    NASA Technical Reports Server (NTRS)

    Rishpon, J.; Ohara, P. J.; Lawless, J. G.; Lahav, N.

    1982-01-01

    Interactions between ATP, glycine and montmorillonite and kaolinite clay minerals in the presence of various metal cations are investigated. The adsorption of adenine nucleotides on clays and Al(OH)3 was measured as a function of pH, and glycine condensation was followed in the presence of ATP, ZnCl2, MgCl2 and either kaolinite or montmorillonite. The amounts of ATP and ADP adsorbed are found to decrease with increasing Ph, and to be considerably enhanced in experiments with Mg(2+)- and Zn(2+)-montmorillonite with respect to Na(+)-montmorillonite. The effects of divalent cations are less marked in kaolinite. Results for Al(OH)3 show the importance of adsorption at clay platelet edges at high pH. The decomposition of ATP during drying at high temperature is observed to be inhibited by small amounts of clay, vacuum, or Mg(2+) or Zn(2+) ions, and to be accompanied by peptide formation in the presence of glycine. Results suggest the importance of Zn(2+) and Mg(2+) in chemical evolution.

  15. Process for carbonaceous material conversion and recovery of alkali metal catalyst constituents held by ion exchange sites in conversion residue

    DOEpatents

    Sharp, David W. (Seabrook, TX)

    1980-01-01

    In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered for the particles by contacting or washing them with an aqueous solution containing calcium or magnesium ions in an alkali metal recovery zone at a low temperature, preferably below about 249.degree. F. During the washing or leaching process, the calcium or magnesium ions displace alkali metal ions held by ion exchange sites in the particles thereby liberating the ions and producing an aqueous effluent containing alkali metal constituents. The aqueous effluent from the alkali metal recovery zone is then recycled to the conversion process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst.

  16. Cross-reactive fluorescent indicators for analysis of metal-ion mixtures

    SciTech Connect

    Chadha, S.; Tabacco, M.B.; Walt, D.R.

    1997-12-31

    The conventional approach to optical sensing of metal ions has been to use metal-binding indicators containing selective binding sites linked to a chromogenic or fluorescent tag. The one analyte-one sensor approach tends to be tedious and time consuming, especially where multiple ions need to be determined. Most metallofluorescent indicators lack sufficient binding discrimination between metal ions to be effective for analysis of mixtures. In this paper we present an approach which exploits the cross-reactivity of semi-selective metallofluorescent indicators, combined with multivariate analysis, to model a binding pattern for multiple metal ions. Mixtures of metal ions have different cross-reactive binding patterns with each metallofluorescent indicator. A pattern recognition algorithm capable of modeling these binding patterns allows concentrations of individual metal ions to be determined. The fluorescence responses of the indicators and formation of the metal complexes are pH dependent, therefore calibration was performed at different pH values in the 4-9 pH range. The application of these semi-selective indicators to the development of optical array sensors for continuous, on-site monitoring in multicomponent media is discussed is a useful alternative to the one analyte-one sensor paradigm.

  17. Elastomeric Nanocomposite Foams for the Removal of Heavy Metal Ions from Water.

    PubMed

    Chavan, Asmita A; Li, Hongbo; Scarpellini, Alice; Marras, Sergio; Manna, Liberato; Athanassiou, Athanassia; Fragouli, Despina

    2015-07-15

    We report the fabrication and utilization of elastomeric polymer nanocomposite foams for the efficient removal of Pb2+ and Hg2+ heavy metal ions from polluted water. The polydimethylsiloxane (PDMS) foams are properly modified in order to become hydrophilic and allow the polluted water to penetrate in their volume. The ZnSe colloidal nanocrystals (NCs) that decorate the surface of the foams, act as active components able to entrap the metal ions. In this way, after the dipping of the nanocomposite foams in water polluted with Pb2+ or Hg2+, a cation exchange reaction takes place, and the heavy metal ions are successfully removed. The removal capacity for the Pb2+ ions exceeds 98% and the removal of Hg2+ ions approaches almost 100% in the studied concentrations region of 20-40 ppm. The reaction is concluded after 24 h, but it should be noticed that after the first hour, more than 95% of both the metal ions is removed. The color of the foams changes upon heavy metal ions entrapment, providing thus the opportunity of an easy detection of the presence of the ions in water. Taking into account that the fabricated foams provide good elastic properties and resistance to heat, they can be used in different conditions of water remediation. PMID:26133912

  18. Heterogeneous processes affecting metal ion transport in the presence of organic ligands: Reactive transport modeling

    NASA Astrophysics Data System (ADS)

    Kantar, Cetin

    2007-04-01

    The development of models to accurately simulate metal ion transport through saturated systems under variable chemical conditions, e.g., in systems containing organic ligands (L) such as natural organic matter (NOM), has two essential aspects: (1) establishing the ability to simulate metal ion sorption to aquifer solids over a range of metal/ligand ratios; and (2) to incorporate this ability to simulate metal speciation over a range in chemical conditions (e.g., pH, ligand activity) into mass transport models. Modeling approaches to evaluate metal ion sorption and transport in the presence of NOM include: (1) isotherm-based transport models, and (2) multicomponent (MC) transport models. The accuracy of transport models depends on how well the chemical interactions affecting metal ion transport in the presence of organic ligands (e.g., metal/ligand complexation) are described in transport equations. The isotherm-based transport models often fail to accurately describe metal ion transport in the presence of NOM since these models treat NOM as a single solute despite the fact that NOM is a multicomponent mixture of subcomponents with different chemical and polyfunctional behavior. On the other hand, the calculations presented in this study suggest that a multicomponent reactive transport model, in conjunction with a mechanistic modeling approach for the description of metal ion binding by NOM in a manner conducive to the application of surface complexation modeling (SCM), can effectively be used as an important predictive tool in simulating metal ion sorption and transport under variable chemical conditions in the presence of NOM.

  19. Chromium and cobalt ion concentrations in blood and serum following various types of metal-on-metal hip arthroplasties

    PubMed Central

    2013-01-01

    Background and purpose Widely different metal ion concentrations in blood and serum have been reported with metal-on-metal (MoM) implants. We reviewed the literature on blood and serum ion concentrations of chromium (Cr) and cobalt (Co) following various MoM hip arthroplasties. Methods Studies were searched for in the Medline database, Embase, and the Cochrane Database of Systematic Reviews. Highest mean or median ion concentrations of Cr and Co after a minimum of 1 year of follow-up were extracted and grouped according to sample- and articulation type, and average values were calculated. Results 43 studies were included and 16 different MoM implants were identified. For the different types of bearings, average ion concentrations and range were calculated from the mean or median ion concentration. The average Cr concentration ranged between 0.5 and 2.5 ?g/L in blood and between 0.8 and 5.1 ?g/L in serum. For Co, the range was 0.7–3.4 ?g/L in blood and 0.3–7.5 ?g/L in serum. Interpretation When the average blood ion concentrations calculated for the different implants, together with the concentrations measured in the individual studies, were compared with the upper acceptable limit for Cr and Co in blood, no clear pattern was recognized. Furthermore, we were unable to detect any clear difference in ion concentrations between different types of implants (THA and resurfacing). PMID:23594249

  20. Ion microscopy of the thyroid gland: a method for imaging stable and radioactive iodine

    SciTech Connect

    Berry, J.P.; Escaig, F.; Lange, F.; Galle, P.

    1986-07-01

    Analytical ion microscopy has been applied to the study of distribution of stable and radioactive iodine in the thyroid gland. Analytical images, each of them representing the distribution of one isotope of iodine, can easily be obtained in a few seconds from an Epon section with a resolution of 0.5 micron. In thyroids of normal rats, intrafollicular and intracytoplasmic stable 127I can be clearly distinguished. After thyreostimulin injection, a rapid and important redistribution of 127I is observed which reflects an intense cytoplasmic reabsorption of intrafollicular iodine. After injection of a long-lived isotope of iodine, 129I, the progressive incorporation of this isotope has been observed and the images of the natural iodine 129I have been compared to the images of 127I. An unusual iodine distribution has been observed in proliferating cells of an autonomous nodule. The very high sensitivity of this method makes possible the study of intracellular and extracellular stable iodine in the thyroid gland in a number of physiological and pathological conditions; its ability for isotopic analysis in microscopic volumes offers new possibilities for kinetic studies of iodine metabolism. However, in the present state of the art the specimen cannot be studied at the ultrastructural level as it is with other methods, and some difficulties remain in qualitative analysis such as the contamination of spectra with organic mass fragments which makes difficult the study of some elements such as sulfur. In addition, the matrix effect on ionization efficiency or on sputtering rate makes quantitative analysis difficult. In the future, image processing systems will be needed for a better quantitative interpretation.

  1. Plastic flow produced by single ion impacts on metals.

    SciTech Connect

    Birtcher, R. C.

    1998-10-30

    Single ion impacts have been observed using in situ transmission electron microscopy and video recording with a time resolution of 33 milliseconds. Gold was irradiated at 50 K and room temperature. Single ion impacts produce holes, modify existing holes, and extrude material into the initial specimen hole and holes formed by other ion impacts. The same behavior is observed at both temperatures. At both temperatures, ion impacts result in craters and ejected material. Ion impacts produce more small craters than large ones for all ion masses, while heavier mass ions produce more and larger craters than lighter mass ions. This comparison is affected by the ion energy. As the energy of an ion is increased, the probability for deposition near the surface decreases and fewer craters are formed. For a given ion mass, crater production depends on the probability for displacement cascade production in the near surface region. Crater and holes are stable at room temperature, however, ion impacts near an existing crater may cause flow of material into the crater either reshaping or annihilating it. Holes and craters result from the explosive outflow of material from the molten zone of near-surface cascades. The outflow may take the form of molten material, a solid lid or an ejected particle. The surface is a major perturbation on displacement cascades resulting from ion impacts.

  2. Journal of Molecular Structure 890 (2008) 289294 The linkage between ribosomal crystallography, metal ions,

    E-print Network

    Yonath, Ada E.

    2008-01-01

    Journal of Molecular Structure 890 (2008) 289­294 The linkage between ribosomal crystallography linkage between ribosomal crystallography, metal ions, heteropolytungstates and functional flexibility Accepted 19 March 2008 Available online 7 April 2008 Keywords: Ribosome Ribosomal functional flexibility

  3. Effect of pH and metal ions on DPPH radical scavenging activity of tea.

    PubMed

    P?kal, Anna; Pyrzynska, Krystyna

    2015-02-01

    The 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assay is commonly applied for the estimation of antioxidant activity of plant extracts. This article discusses the effect of a sample pH and the presence of metal ions on the results obtained using DPPH method for several tea infusions. Higher radical quenching was observed in less acidic media. The impact of metal ions depends of the types of metal ion and its concentration. Quercetin and epigallocatechin gallate were less efficient in the reaction with DPPH in the presence of Al(III). Desalting process using cation-exchange resin Dowex 50Wx8 decreased the content of metal ions in all studied tea infusions. The DPPH scavenging activity of the effluents after this process were higher than those of the primary extracts and this may be related to the actual antioxidant capacity of these samples. PMID:25578761

  4. Factorial experimental design for recovering heavy metals from sludge with ion-exchange resin.

    PubMed

    Lee, I Hsien; Kuan, Yu-Chung; Chern, Jia-Ming

    2006-12-01

    Wastewaters containing heavy metals are usually treated by chemical precipitation method in Taiwan. This method can remove heavy metals form wastewaters efficiently, but the resultant heavy metal sludge is classified as hazardous solid waste and becomes another environmental problem. If we can remove heavy metals from sludge, it becomes non-hazardous waste and the treatment cost can be greatly reduced. This study aims at using ion-exchange resin to remove heavy metals such as copper, zinc, cadmium, and chromium from sludge generated by a PCB manufacturing plant. Factorial experimental design methodology was used to study the heavy metal removal efficiency. The total metal concentrations in the sludge, resin, and solution phases were measured respectively after 30 min reaction with varying leaching agents (citric acid and nitric acid); ion-exchange resins (Amberlite IRC-718 and IR-120), and temperatures (50 and 70 degrees C). The experimental results and statistical analysis show that a stronger leaching acid and a higher temperature both favor lower heavy metal residues in the sludge. Two-factors and even three-factor interaction effects on the heavy metal sorption in the resin phase are not negligible. The ion-exchange resin plays an important role in the sludge extraction or metal recovery. Empirical regression models were also obtained and used to predict the heavy metal profiles with satisfactory results. PMID:16843592

  5. Radioactive scrap metal (RSM) inventory & tracking system and prototype RSM field survey

    SciTech Connect

    Thomas, T.R.

    1994-09-01

    Based on very preliminary information, it has been estimated that the radioactive scrap metal (RSM) inventories at DOE facilities amount to about 1.5 million tons and a much larger amount will be generated from decontamination and decommissioning of surplus DOE facilities. To implement a national DOE program for beneficial reuse of RSM, it will be necessary to known the location and characteristics of RSM inventories that are available and will be generated to match them with product demands. It is the intent of this task to provide a standardized methodology via a RSM database for recording, tracking, and reporting data on RSM inventories. A multiple relational database in dBASE IV was designed and a PC-based code was written in Clipper 5.0 syntax to expedite entry, editing, querying, and reporting of RSM survey data. The PC based-code, the multiple relational database files, and other external files used by the code to generate reports and queries constitute a customized software application called the RSM Inventory & Tracking System (RSM I&TS). A prototype RSM field survey was conducted at the Nevada Test Site (NTS) to demonstrate the field use of the RSM I&TS and logistics of conducting the survey. During the demonstration, about 50 tons of RSM were sized, characterized, sorted, and packaged in transport containers.

  6. Silica coated magnetite nanoparticles for removal of heavy metal ions from polluted waters

    E-print Network

    Dash, Monika

    2013-01-01

    Magnetic removal of Hg2+ and other heavy metal ions like Cd2+, Pb2+ etc. using silica coated magnetite particles from polluted waters is a current topic of active research to provide efficient water recycling and long term high quality water. The technique used to study the bonding characteristics of such kind of nanoparticles with the heavy metal ions is a very sensitive hyperfine specroscopy technique called the perturbed angular correlation technique (PAC).

  7. Pure ion current collection in ion sensitive probe measurement with a metal mesh guard electrode for evaluation of ion temperature in magnetized plasma

    NASA Astrophysics Data System (ADS)

    Hsieh, Tung-Yuan; Kawamori, Eiichirou; Nishida, Yasushi

    2013-02-01

    This paper presents a new design of ion sensitive probe (ISP) that enables collection of pure ion current for accurate measurement of the perpendicular ion temperature in magnetized plasmas. The new type of ISP resolves a longstanding issue widely observed in ISP type measurements, namely, that the current-voltage characteristic is smeared by an unexpected electron current in the standard ISP model. The new ISP is equipped with a fine scale metal mesh on the sensor entrance to prevent electrons from flowing to the sensor, a phenomenon considered to be caused by the space-charge effect. The new ISP successfully measured the ion temperature of electron cyclotron resonance plasmas.

  8. Pure ion current collection in ion sensitive probe measurement with a metal mesh guard electrode for evaluation of ion temperature in magnetized plasma.

    PubMed

    Hsieh, Tung-Yuan; Kawamori, Eiichirou; Nishida, Yasushi

    2013-02-01

    This paper presents a new design of ion sensitive probe (ISP) that enables collection of pure ion current for accurate measurement of the perpendicular ion temperature in magnetized plasmas. The new type of ISP resolves a longstanding issue widely observed in ISP type measurements, namely, that the current-voltage characteristic is smeared by an unexpected electron current in the standard ISP model. The new ISP is equipped with a fine scale metal mesh on the sensor entrance to prevent electrons from flowing to the sensor, a phenomenon considered to be caused by the space-charge effect. The new ISP successfully measured the ion temperature of electron cyclotron resonance plasmas. PMID:23464206

  9. Pure ion current collection in ion sensitive probe measurement with a metal mesh guard electrode for evaluation of ion temperature in magnetized plasma

    SciTech Connect

    Hsieh, Tung-Yuan; Kawamori, Eiichirou; Nishida, Yasushi

    2013-02-15

    This paper presents a new design of ion sensitive probe (ISP) that enables collection of pure ion current for accurate measurement of the perpendicular ion temperature in magnetized plasmas. The new type of ISP resolves a longstanding issue widely observed in ISP type measurements, namely, that the current-voltage characteristic is smeared by an unexpected electron current in the standard ISP model. The new ISP is equipped with a fine scale metal mesh on the sensor entrance to prevent electrons from flowing to the sensor, a phenomenon considered to be caused by the space-charge effect. The new ISP successfully measured the ion temperature of electron cyclotron resonance plasmas.

  10. Importance of diffuse metal ion binding to RNA.

    PubMed

    Tan, Zhi-Jie; Chen, Shi-Jie

    2011-01-01

    RNAs are highly charged polyanionic molecules. RNA structure and function are strongly correlated with the ionic condition of the solution. The primary focus of this article is on the role of diffusive ions in RNA folding. Due to the long-range nature of electrostatic interactions, the diffuse ions can contribute significantly to RNA structural stability and folding kinetics. We present an overview of the experimental findings as well as the theoretical developments on the diffuse ion effects in RNA folding. This review places heavy emphasis on the effect of magnesium ions. Magnesium ions play a highly efficient role in stabilizing RNA tertiary structures and promoting tertiary structural folding. The highly efficient role goes beyond the mean-field effect such as the ionic strength. In addition to the effects of specific ion binding and ion dehydration, ion-ion correlation for the diffuse ions can contribute to the efficient role of the multivalent ions such as the magnesium ions in RNA folding. PMID:22010269

  11. High-energy metal ion implantation for reduction of surface resistivity of alumina ceramic

    SciTech Connect

    Gushenets, V. I.; Nikolaev, A. G.; Oks, E. M.; Savkin, K. P.; Yushkov, G. Yu.; Brown, I. G.

    2012-02-15

    In this work, the possibility to increase the surface conductivity of ceramic insulators through their treatment with accelerated metal ion beams produced by a MevvaV.Ru vacuum arc source is demonstrated. The increase in surface conductivity is made possible due to experimental conditions in which an insulated collector is charged by beam ions to a potential many times lower than the accelerating voltage, and hence, than the average beam ion energy. The observed effect of charge neutralization of the accelerated ion beam is presumably associated with electrons knocked out of the electrodes of the accelerating system of the source and of the walls of the vacuum chamber by the accelerated ions.

  12. Infrared Spectroscopy of Metal Ion Complexes: Models for Metal Ligand Interactions and Solvation

    NASA Astrophysics Data System (ADS)

    Duncan, Michael

    2006-03-01

    Weakly bound complexes of the form M^+-Lx (M=Fe, Ni, Co, etc.; L=CO2, C2H2, H2O, benzene, N2) are prepared in supersonic molecular beams by laser vaporization in a pulsed-nozzle cluster source. These species are mass analyzed and size-selected in a reflectron time-of-flight mass spectrometer. Clusters are photodissociated at infrared wavelengths with a Nd:YAG pumped infrared optical parametric oscillator/amplifier (OPO/OPA) laser or with a tunable infrared free-electron laser. M^+-(CO2)x complexes absorb near the free CO2 asymmetric stretch near 2349 cm-1 but with an interesting size dependent variation in the resonances. Small clusters have blue-shifted resonances, while larger complexes have additional bands due to surface CO2 molecules not attached to the metal. M^+(C2H2)n complexes absorb near the C-H stretches in acetylene, but resonances in metal complexes are red-shifted with repect to the isolated molecule. Ni^+ and Co^+ complexes with acetylene undergo intracluster cyclization reactions to form cyclobutadiene. Transition metal water complexes are studied in the O-H stretch region, and partial rotational structure can be measured. M^+(benzene) and M^+(benzene)2 ions (M=V, Ti, Al) represent half-sandwich and sandwich species, whose spectra are measured near the free benzene modes. These new IR spectra and their assignments will be discussed as well as other new IR spectra for similar complexes.

  13. Effects of metal ions on the catalytic degradation of dicofol by cellulase.

    PubMed

    Zhai, Zihan; Yang, Ting; Zhang, Boya; Zhang, Jianbo

    2015-07-01

    A new technique whereby cellulase immobilized on aminated silica was applied to catalyze the degradation of dicofol, an organochlorine pesticide. In order to evaluate the performance of free and immobilized cellulase, experiments were carried out to measure the degradation efficiency. The Michaelis constant, Km, of the reaction catalyzed by immobilized cellulase was 9.16 mg/L, and the maximum reaction rate, Vmax, was 0.40 mg/L/min, while that of free cellulase was Km=8.18 mg/L, and Vmax=0.79 mg/L/min, respectively. The kinetic constants of catalytic degradation were calculated to estimate substrate affinity. Considering that metal ions may affect enzyme activity, the effects of different metal ions on the catalytic degradation efficiency were explored. The results showed that the substrate affinity decreased after immobilization. Monovalent metal ions had no effect on the reaction, while divalent metal ions had either positive or inhibitory effects, including activation by Mn2+, reversible competition with Cd2+, and irreversible inhibition by Pb2+. Ca2+ promoted the catalytic degradation of dicofol at low concentrations, but inhibited it at high concentrations. Compared with free cellulase, immobilized cellulase was affected less by metal ions. This work provided a basis for further studies on the co-occurrence of endocrine-disrupting chemicals and heavy metal ions in the environment. PMID:26141889

  14. Selective fluorescence sensors for detection of nitroaniline and metal Ions based on ligand-based luminescent metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Yu, Zongchao; Wang, Fengqin; Lin, Xiangyi; Wang, Chengmiao; Fu, Yiyuan; Wang, Xiaojun; Zhao, Yongnan; Li, Guodong

    2015-12-01

    Metal-organic frameworks (MOFs) are porous crystalline materials with high potential for applications in fluorescence sensors. In this work, two solvent-induced Zn(II)-based metal-organic frameworks, Zn3L3(DMF)2 (1) and Zn3L3(DMA)2(H2O)3 (2) (L=4,4?-stilbenedicarboxylic acid), were investigated as selective sensing materials for detection of nitroaromatic compounds and metal ions. The sensing experiments show that 1 and 2 both exhibit selective fluorescence quenching toward nitroaniline with a low detection limit. In addition, 1 exhibits high selectivity for detection of Fe3+ and Al3+ by significant fluorescence quenching or enhancement effect. While for 2, it only exhibits significant fluorescence quenching effect for Fe3+. The results indicate that 1 and 2 are both promising fluorescence sensors for detecting and recognizing nitroaniline and metal ions with high sensitivity and selectivity.

  15. New Catalytic DNA Biosensors for Radionuclides and Metal ions

    SciTech Connect

    Lu, Yi

    2005-06-01

    In vitro selection for DNAzymes that are catalytically active with UO22+ ions as the metal cofactor has been completed. The 10th generation pool of DNA was cloned and sequenced. A total of 84 clones were sequenced and placed into families based on sequence alignments. Selected members of each family were 5-labeled with 32P and amplified using PCR. Activity assays were conducted using the isotopically labeled DNAzymes in order to determine which sequences were the most active. The secondary structures of the two most active sequences, called Clone 13 and Clone 39, were determined using the computer program Mfold. A cleavage rate of approximately 1 min-1 in the presence of 10 uM UO22+ was observed for both clones. Clone 39 was determined to be the best candidate for truncation to create a trans-cleaving DNAzyme, based on its secondary structure. An enzyme strand, called 39E, and a substrate strand, called 39DS, were designed by truncating the cis-cleaving DNAzyme. An alternative enzyme strand, called 39Ec, was also assayed with the 39DS substrate. This strand was designed so that the two binding arms were perfectly complimentary, unlike 39E, which formed three mismatched base pairs with 39DS. Both 39E and 39Ec were found to be active, with a rate of approximately 1 min-1 in the presence of 10 uM UO22+. A preliminary UO22+ binding curve was obtained for the 39Ec/39DS trans-cleaving system. The enzyme is active with UO22+ concentrations as low as 1 nM. Based on the preliminary binding curve data, the apparent UO22+ binding constant is approximately 330 nM, and kmax is approximately 1 min-1.

  16. Submicro and Nano Structured Porous Materials for the Production of High-Intensity Exotic Radioactive Ion Beams

    E-print Network

    Fernandes, Sandrina; Stora, Thierry

    2010-01-01

    ISOLDE, the CERN Isotope Separator On-line DEvice is a unique source of low energy beams of radioactive isotopes - atomic nuclei that have too many or too few neutrons to be stable. The facility is like a small ‘chemical factory’, giving the possibility of changing one element to another, by selecting the atomic mass of the required isotope beam in the mass separator, rather as the ‘alchemists’ once imagined. It produces a total of more than 1000 different isotopes from helium to radium, with half-lives down to milliseconds, by impinging a 1.4 GeV proton beam from the Proton Synchrotron Booster (PSB) onto special targets, yielding a wide variety of atomic fragments. Different components then extract the nuclei and separate them according to mass. The post-accelerator REX (Radioactive beam EXperiment) at ISOLDE accelerates the radioactive beams up to 3 MeV/u for many experiments. A wide international user radioactive ion beam (RIB) community investigates fundamental aspects of nuclear physics, particle...

  17. The use of ion flotation for detoxification of metal-contaminated waters and process effluents

    SciTech Connect

    Doyle, F.M.; Duyvesteyn, S.; Sreenivasarao, K.

    1995-12-31

    Toxic metals entering surface or ground water from sources such as metal finishing shop spills and abandoned mines can pose a significant threat to public health and the environment. Ion flotation and similar foam separation techniques show great promise for treating dilute, metal-contaminated solutions, and could also be used to treat effluents from many minerals and metallurgical processing operations prior to discharge. In ion flotation, an appropriate collector is added to the solution to form hydrophobic complexes with the metal ions. These metal-bearing species are then removed by flotation, usually with trace addition of a frother to stabilize the foam. In an effort to better understand the underlying scientific and engineering principles that determine the performance of ion flotation, the removal of Cu(II), Pb(II), Cd(II), Cr(III) and Cr(VI) has been studied using laboratory scale flotation columns in batch mode. The effects of the superficial air velocity, solution and froth height, nature of the collector, collector:metal-ion ratio, ionic strength and several frothers at low concentrations on the flotation kinetics are reported. Finally, results are presented on methods that might allow regeneration of collector and recovery of by-product metal from the foam product.

  18. Evaluation of dry ashing in conjunction with ion chromatographic determination of transition metal ions in pig feed samples.

    PubMed

    Van paemel, Marleen R; De Rycke, Herman; Millet, Sam; Hesta, Myriam; Janssens, Geert P J

    2005-03-23

    The contents of transition metal ions iron, copper, zinc, and manganese were simultaneously determined in pig feed using an ion chromatographic technique (IC) preceded by dry ashing. Employing ion exchange, the ions were separated on an IonPac CS5A column used in combination with a pyridine-2,6-dicarboxylic acid based eluent. The separation was followed by spectrophotometric detection after postcolumn reaction with 4-(2-pyridylazo)resorcinol. Dry ashing parameters were varied to assess their role in potential analyte loss. Quantitative recoveries (>95%) were obtained for all analytes with a dry ashing method that included a moderate temperature-time regime and ash leaching support in the form of sonication and heat treatment. The use of HCl as leaching acid and the presence of alkaline earths in the matrix solution did not interfere with the chromatographic separation. PMID:15769106

  19. The emission characteristics of an indium needle-type liquid metal ion source

    NASA Astrophysics Data System (ADS)

    Hornsey, R. I.

    1989-09-01

    Operational data for an indium needle-type liquid metal ion source are presented. Detailed comparisons are drawn between these characteristics and those of a similar gallium source. The behaviours of the two sources are found to be strikingly similar, indicating a common mechanism of ion emission.

  20. Spin{polarized electron excitation during the neutralization of He + ions in metals

    E-print Network

    Muiño, Ricardo Díez

    Spin{polarized electron excitation during the neutralization of He + ions in metals M. Alducin a R Abstract Spin{resolved electron spectra collected during the neutralization of spin{polarized He + ions as on the neutralization process itself. The interpretation of such electron spectra, however, requires a deep

  1. Short Communication Kinetics and thermodynamics of heavy metal ions sequestration onto novel

    E-print Network

    Gong, Jian Ru

    Short Communication Kinetics and thermodynamics of heavy metal ions sequestration onto novel of Cadmium and Mercury ions. " Kinetics and thermodynamics of biosorption. " Biosorption feasible, spontaneous and endothermic. a r t i c l e i n f o Article history: Received 6 January 2012 Received

  2. Titanium alloy mini-implants for orthodontic anchorage: Immediate loading and metal ion release q

    E-print Network

    Meyers, Marc A.

    Titanium alloy mini-implants for orthodontic anchorage: Immediate loading and metal ion release q devices in orthodontics. The early load is nec- essary to simplify the mini-implant methodology, but can: Titanium alloy; Mini-implant; Orthodontic anchorage; Ion release 1. Introduction Anchorage has long been

  3. Metallic LiMo3Se3 Nanowire Film Sensors for Electrical Detection of Metal Ions in Water

    E-print Network

    Osterloh, Frank

    Metallic LiMo3Se3 Nanowire Film Sensors for Electrical Detection of Metal Ions in Water Mark AllenVis, California 95616 ReceiVed February 5, 2008. ReVised Manuscript ReceiVed March 30, 2008 LiMo3Se3 nanowire film sensors were fabricated by drop-coating a 0.05% (mass) aqueous nanowire solution onto microfabricated

  4. Property enchancement of polyimide films by way of the incorporation of lanthanide metal ions

    NASA Technical Reports Server (NTRS)

    Thompson, David W.

    1993-01-01

    Lanthanide metal ions were incorporated into the polyimide derived from 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA) and 1,3-bis(aminophenoxy) benzene (APB) in an attempt to produce molecular level metal-polymer composites. The lanthanide series of metal ions (including aluminum, scandium, and yttrium) provide discrete and stable metal ions in the 3+ oxidation state. Throughout the series there is a uniform variation in ionic size ranging from 50 pm for aluminum to a maximum of 103.4 pm for cerium and gradually decreasing again to 84.8 pm for lutetium. The high charge-to-size ratio for these ions as well as the ability to obtain large coordination numbers makes them excellent candidates for interacting with the polymer substructure. The distinct lack of solubility of simple lanthanide salts such as the acetates and halides has made it difficult to obtain metal ions distributed in the polymer framework as discrete ions or metal complexes rather than microcomposites of metal clusters. (Lanthanum nitrates are quite soluble, but the presence of the strongly oxidizing nitrate ion leads to serious degradation of the polymer upon thermal curing. This work was successful at extending the range of soluble metals salts by using chelating agents derived from the beta-diketones dipivaloylmethane, dibenzoylmethane, trifluoroacetylacetone, and hexafluoroacetylacetone. Metal acetates which are insoluble in dimethylacetamide dissolve readily in the presence of the diketones. Addition of the polyimide yields a homogeneous resin which is then cast into a clear film. Upon curing clear films were obtained with the dibenzoylmethane and trifluoroacetylacetone ligands. The dipavaloylmethane precipitates the metal during the film casting process, and hexafluoroacetylacetone gives cured films which are deformed and brittle. These clear films are being evaluated for the effect of the metal ions on the coefficient of thermal expansion, resistance to atomic oxygen, and on selective gas permeability. Much more commonly than above, polyimide films are prepared by casting the film as the poly(amic acid) precursor which is then converted to the imidized form during the thermal cure cycle. Very limited success was achieved in the past in adding lanthanide metal ions to the amide precursors because of gellation and lack of solubility. With the use of the diketone ligands cited above, the solubility and gellation problems were overcome. However, the films after curing were clear but unacceptably brittle. Attempts to overcome this cure embrittlement problem are in progress.

  5. Poultry litter-based activated carbon for removing heavy metal ions in water.

    PubMed

    Guo, Mingxin; Qiu, Guannan; Song, Weiping

    2010-02-01

    Utilization of poultry litter as a precursor material to manufacture activated carbon for treating heavy metal-contaminated water is a value-added strategy for recycling the organic waste. Batch adsorption experiments were conducted to investigate kinetics, isotherms, and capacity of poultry litter-based activated carbon for removing heavy metal ions in water. It was revealed that poultry litter-based activated carbon possessed significantly higher adsorption affinity and capacity for heavy metals than commercial activated carbons derived from bituminous coal and coconut shell. Adsorption of metal ions onto poultry litter-based carbon was rapid and followed Sigmoidal Chapman patterns as a function of contact time. Adsorption isotherms could be described by different models such as Langmuir and Freundlich equations, depending on the metal species and the coexistence of other metal ions. Potentially 404 mmol of Cu2+, 945 mmol of Pb2+, 236 mmol of Zn2+, and 250-300 mmol of Cd2+ would be adsorbed per kg of poultry litter-derived activated carbon. Releases of nutrients and metal ions from litter-derived carbon did not pose secondary water contamination risks. The study suggests that poultry litter can be utilized as a precursor material for economically manufacturing granular activated carbon that is to be used in wastewater treatment for removing heavy metals. PMID:19783133

  6. Coloring a Superabsorbent Polymer with Metal Ions: An Undergraduate Chemistry Experiment

    ERIC Educational Resources Information Center

    Yaung, Jing-Fun; Chen, Yueh-Huey

    2009-01-01

    A novel undergraduate chemistry experiment involving superabsorbent polymers commonly used in diapers and other personal care products is described. Students observe the removal of divalent transition-metal ions from aqueous solutions by the polymers. With the procedures provided, students are able to color the superabsorbent polymers with metal

  7. Rare-earth neutral metal injection into an electron beam ion trap plasma

    SciTech Connect

    Magee, E. W. Beiersdorfer, P.; Brown, G. V.; Hell, N.

    2014-11-15

    We have designed and implemented a neutral metal vapor injector on the SuperEBIT high-energy electron beam ion trap at the Lawrence Livermore National Laboratory. A horizontally directed vapor of a europium metal is created using a thermal evaporation technique. The metal vapor is then spatially collimated prior to injection into the trap. The source's form and quantity constraints are significantly reduced making plasmas out of metal with vapor pressures ?10{sup ?7} Torr at ?1000?°C more obtainable. A long pulsed or constant feed metal vapor injection method adds new flexibility by varying the timing of injection and rate of material being introduced into the trap.

  8. Metal ions affecting the pulmonary and cardiovascular systems.

    PubMed

    Corradi, Massimo; Mutti, Antonio

    2011-01-01

    Some metals, such as copper and manganese, are essential to life and play irreplaceable roles in, e.g., the functioning of important enzyme systems. Other metals are xenobiotics, i.e., they have no useful role in human physiology and, even worse, as in the case of lead, may be toxic even at trace levels of exposure. Even those metals that are essential, however, have the potential to turn harmful at very high levels of exposure, a reflection of a very basic tenet of toxicology--"the dose makes the poison." Toxic metal exposure may lead to serious risks to human health. As a result of the extensive use of toxic metals and their compounds in industry and consumer products, these agents have been widely disseminated in the environment. Because metals are not biodegradable, they can persist in the environment and produce a variety of adverse effects. Exposure to metals can lead to damage in a variety of organ systems and, in some cases, metals also have the potential to be carcinogenic. Even though the importance of metals as environmental health hazards is now widely appreciated, the specific mechanisms by which metals produce their adverse effects have yet to be fully elucidated. The unifying factor in determining toxicity and carcinogenicity for most metals is the generation of reactive oxygen and nitrogen species. Metal-mediated formation of free radicals causes various modifications to nucleic acids, enhanced lipid peroxidation, and altered calcium and sulfhydryl homeostasis. Whilst copper, chromium, and cobalt undergo redox-cycling reactions, for metals such as cadmium and nickel the primary route for their toxicity is depletion of glutathione and bonding to sulfhydryl groups of proteins. This chapter attempts to show that the toxic effects of different metallic compounds may be manifested in the pulmonary and cardiovascular systems. The knowledge of health effects due to metal exposure is necessary for practising physicians, and should be assessed by inquiring about present and past occupational history and environmental exposure. PMID:21473377

  9. Selective adsorption of metal ions by chemically-modified MCM-41

    NASA Astrophysics Data System (ADS)

    Lam, Koon Fung

    Selective adsorbents were developed for removal and recovery of heavy metals from aqueous medium. As heavy metals interact with surface moieties differently depending on their chemical properties, tailor-made adsorbents were synthesized for metal separation from aqueous solution based on different adsorption mechanisms. This is the first comprehensive study in the design of adsorbent for selective adsorption of metal ions based on a nanostructured material, MCM-41. Adsorption mechanism studies by FTIR and XPS found that hard-soft acid-base principle, surface complexation and ion-exchange were the main interactions between metal ions and surface functional groups. The adsorption selectivity of SH-MCM-41 obeys the hard-soft acid-base principle. It was suitable for separation of hard and soft metal ions such as Ag+ and Cu 2+. Stability constants could be as the guideline for predicting the adsorption of NH2-MCM-41 which was able to separate metals with different complexing ability. Furthermore, ion-exchange mechanism governs the adsorption of COONa-MCM-41 and it was capable of separating cationic metals from metallic oxyanions. Factors such as functional group loading, amount of adsorbent, solution pH and metal composition of solution could affect both adsorption capacity and selectivity of the adsorbents depending on the adsorption mechanisms. By identifying the adsorption mechanism, the selective adsorbents was designed for precious metal recovery and toxic metal separation. It was found that both SH-MCM-41 and NH2-MCM-41 were able to remove gold in the presence of other metals and these adsorbents were efficient to adsorb trace amount of gold from the solution. The regenerable NH2-MCM-41 could be re-used for five times without loss of performance. On the other hand, NH2-MCM-41 was used to separate toxic cadmium ions from Ni-Cd solution. It was found that the addition of EDTA improved the adsorption selectivity. NH2-MCM-41 only remove Cd2+ at pH5.0 while the adsorbent removed Ni2+ at pH3.0. This introduces an opportunity to recover both metal ions from spent Ni-Cd battery wastes.

  10. Single-metal-ion-based molecular building blocks (MBBs) approach to the design and synthesis of metal organic assemblies

    NASA Astrophysics Data System (ADS)

    Brant, Jacilynn A.; Liu, Yunling; Sava, Dorina F.; Beauchamp, Derek; Eddaoudi, Mohamed

    2006-08-01

    The single-metal-ion-based molecular building blocks (MBBs) approach for the construction of metal-organic assemblies, in which hetero-coordinated single metal ions are rendered rigid and directional via nitrogen-oxygen chelation with judiciously selected ligands, has been implemented. Single-metal-ion-based MBBs of the general formula MN x(CO 2) y constitute the building units of metal-organic frameworks (MOFs) and metal-organic polyhedra (MOPs) presented herein. The octahedral MBB, MN 2(CO 2) 4, can occur as two structural isomers depending on the positioning of nitrogen atoms. The MN 2(CO 2) 4 MBBs contain two rings of heterochelation, and depending on the position of the oxygen atoms involved in heterochelation it is possible to generate three different building units (BUs) from the cis-MN 2(CO 2) 4 MBB and two BUs from the trans-MN 2(CO 2) 4 MBB. Assembly of the different BUs derived from the cis-MN 2(CO 2) 4 MBB, through a bifunctional ligand such as 2,5-pyridinedicarboxylic acid, permits the construction of diverse assemblies, such as a metal-organic 2D Kagomé lattice, a discrete octahedron, and a 3D diamondoid-like network. The fac-MN 3(CO 2) 3 MBB mediates a BU with the appropriate geometry to facilitate the formation of a metal-organic cube, and the BU resulting from the mer-MN 3(CO 2) 3 MBB is T-shaped. Tetrahedral building units (TBUs) can be derived either from MN 4(CO 2) 2 or MN 4(CO 2) 4 MBBs, from which zeolite-like MOFs have been constructed. Foremost, rationalization and systemization of such findings offer great potential toward the pursuit of the logical synthesis of functional metal-organic assemblies.

  11. Adherence of ion beam sputter deposited metal films on H-13 steel

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.

    1980-01-01

    An electron bombardment argon ion source was used to sputter deposit 17 different metal and metal oxide films ranging in thickness from 1 to 8 micrometers on H-13 steel substrates. The film adherence to the substrate surface was measured using a tensile test apparatus. Comparisons in bond strength were made between ion beam, ion plating, and RF deposited films. A protective coating to prevent heat checking in H-13 steel dies used for aluminum die casting was studied. The results of exposing the coated substrates to temperatures up to 700 degrees are presented.

  12. Percolation of gallium dominates the electrical resistance of focused ion beam deposited metals

    SciTech Connect

    Faraby, H.; DiBattista, M.; Bandaru, P. R.

    2014-04-28

    Metal deposition through focused ion beam (FIB) based systems is thought to result in material composed of the primary metal from the metallo-organic precursor in addition to carbon, oxygen, and gallium. We determined, through electrical resistance and chemical composition measurements on a wide range of FIB deposited platinum and tungsten lines, that the gallium ion (Ga{sup +}) concentration in the metal lines plays the dominant role in controlling the electrical resistivity. Effective medium theory, based on McLachlan's formalisms, was used to describe the relationship between the Ga{sup +} concentration and the corresponding resistivity.

  13. Effects of CoCr metal wear debris generated from metal-on-metal hip implants and Co ions on human monocyte-like U937 cells.

    PubMed

    Posada, Olga M; Tate, Rothwelle J; Grant, M Helen

    2015-03-01

    Hip resurfacing with cobalt-chromium (CoCr) alloy was developed as a surgical alternative to total hip replacement. However, the biological effects of nanoparticles generated by wear at the metal-on-metal articulating surfaces has limited the success of such implants. The aim of this study was to investigate the effects of the combined exposure to CoCr nanoparticles and cobalt ions released from a resurfacing implant on monocytes (U937 cells) and whether these resulted in morphology changes, proliferation alterations, toxicity and cytokine release. The interaction between prior exposure to Co ions and the cellular response to nanoparticulate debris was determined to simulate the situation in patients with metal-on-metal implants receiving a second implant. Effects on U937 cells were mainly seen after 120h of treatment. Prior exposure to Co ions increased the toxic effects induced by the debris, and by Co ions themselves, suggesting the potential for interaction in vivo. Increased TNF-? secretion by resting cells exposed to nanoparticles could contribute to osteolysis processes in vivo, while increased IFN-? production by activated cells could represent cellular protection against tissue damage. Data suggest that interactions between Co ions and CoCr nanoparticles would occur in vivo, and could threaten the survival of a CoCr metal implant. PMID:25433333

  14. The Gellyfish: an in-situ equilibrium-based sampler for determining multiple free metal ion concentrations in marine ecosystems

    EPA Science Inventory

    Free metal ions are usually the most bioavailable and toxic metal species to aquatic organisms, but they are difficult to measure because of their extremely low concentrations in the marine environment. Many of the current methods for determining free metal ions are complicated a...

  15. Predicting relative toxicity and interactions of divalent metal ions: Microtox{reg_sign} bioluminescence assay

    SciTech Connect

    Newman, M.C.; McCloskey, J.T.

    1996-03-01

    Both relative toxicity and interactions between paired metal ions were predicted with least-squares linear regression and various ion characteristics. Microtox{reg_sign} 15 min EC50s (expressed as free ion) for Ca(II), Cd(II), Cu(II), Hg(II), Mg(II), Mn(II), Ni(II), Pb(II), and Zn(II) were most effectively modeled with the constant for the first hydrolysis (K{sub H} for M{sup n+} + H{sub 2}O {yields} MOH{sup a{minus}1} + H{sup +}) although other ion characteristics were also significant in regression models. The {vert_bar}log K{sub H}{vert_bar} is correlated with metal ion affinity to intermediate ligands such as many biochemical functional groups with O donor atoms. Further, ordination of metals according to ion characteristics, e.g., {vert_bar}log K{sub H}{vert_bar} facilitated prediction of paired metal interactions. Pairing metals with strong tendencies to complex with intermediate or soft ligands such as those with O or S donor atoms resulted in strong interactions.

  16. Evaluation of dynamic ion exchange for the isolation of metal ions for characterization by mass and. cap alpha. spectrometry

    SciTech Connect

    Cassidy, R.M.; Miller, F.C.; Knight, C.H.; Roddick, J.C.; Sullivan, R.W.

    1986-06-01

    A /sup 140/La tracer has been used to identify the sources of cross-contamination when conventional high-performance liquid chromatography was used to collect metal ion fractions for subsequent analysis by ..cap alpha.. spectrometry or mass spectrometry. Major sources of memory effects identified were normal band broadening, sorption onto metal surfaces, and retention within sample valves; secondary sorption effects within the column and isotopic exchange with sorbed metal ions were not important sources of memory effects. On the basis of these results a recommended procedure was developed that gives cross-contamination levels of less than or equal to 0.006%. Sample preparation techniques for the ..cap alpha.. spectrometric and mass spectrometric analyses of the collected fractions are discussed, and some examples are given of applications to analytical problems in geochemistry and the nuclear industry. Good sample recoveries were obtained for the sample range studied (0.1-500 ng).

  17. Highly ordered three-dimensional macroporous carbon spheres for determination of heavy metal ions

    SciTech Connect

    Zhang, Yuxiao; Zhang, Jianming; Liu, Yang; Huang, Hui; Kang, Zhenhui

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Highly ordered three dimensional macroporous carbon spheres (MPCSs) were prepared. Black-Right-Pointing-Pointer MPCS was covalently modified by cysteine (MPCS-CO-Cys). Black-Right-Pointing-Pointer MPCS-CO-Cys was first time used in electrochemical detection of heavy metal ions. Black-Right-Pointing-Pointer Heavy metal ions such as Pb{sup 2+} and Cd{sup 2+} can be simultaneously determined. -- Abstract: An effective voltammetric method for detection of trace heavy metal ions using chemically modified highly ordered three dimensional macroporous carbon spheres electrode surfaces is described. The highly ordered three dimensional macroporous carbon spheres were prepared by carbonization of glucose in silica crystal bead template, followed by removal of the template. The highly ordered three dimensional macroporous carbon spheres were covalently modified by cysteine, an amino acid with high affinities towards some heavy metals. The materials were characterized by physical adsorption of nitrogen, scanning electron microscopy, and transmission electron microscopy techniques. While the Fourier-transform infrared spectroscopy was used to characterize the functional groups on the surface of carbon spheres. High sensitivity was exhibited when this material was used in electrochemical detection (square wave anodic stripping voltammetry) of heavy metal ions due to the porous structure. And the potential application for simultaneous detection of heavy metal ions was also investigated.

  18. Ordering of metal-ion toxicities in different species--extrapolation to man

    SciTech Connect

    England, M.W.; Turner, J.E.; Hingerty, B.E.; Jacobson, K.B. )

    1989-01-01

    Our previous attempts to predict the toxicities of 24 metal ions for a given species, using physicochemical parameters associated with the ions, are summarized. In our current attempt we have chosen indicators of toxicity for biological systems of increasing levels of complexity--starting with individual biological molecules and ascending to mice as representative of higher-order animals. The numerical values for these indicators have been normalized to a scale of 100 for Mg{sup 2+} (essentially nontoxic) and 0 for Cd{sup 2+} (very toxic). To give predicted toxicities to humans, extrapolations across biological species have been made for each of the metal ions considered. The predicted values are then compared with threshold limit values (TLV) from the literature. Both methods for predicting toxicities have their advantages and disadvantages, and both have limited success for metal ions. However, the second approach suggests that the TLV for Cu{sup 2+} should be lower than that currently recommended.

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

    PubMed

    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. PMID:24212283

  20. Effect of metal ions on melanin--local anaesthetic drug complexes.

    PubMed

    Buszman, Ewa; Betlej, Bozena; Wrze?niok, Dorota; Radwa?ska-Wala, Bozena

    2003-01-01

    The affinity of melanin biopolymers for metal ions, drugs and other organic compounds is an important factor in the etiology of toxic retinopathy, hiperpigmentation, otic lesions and irreversible extrapyramidal disorders. The aim of the presented work was to examine the interaction of local anaesthetic drugs used in ophthalmology with model DOPA-melanin in the presence of metal ions. It has been demonstrated that the analyzed drugs form complexes with melanin biopolymer. Based on the .values of association constants,, the following order of drugs affinity to melanin was found: tetracaine > procaine > bupivacaine > lidocaine. It has also been shown that Cu(2+) and Zn(2+) ions administered to DOPA-melanin before complexing with drugs decrease the total amount of local anaesthetics bound to melanin. The blocking of some active centers in melanin molecules by metal ions, which potentially exist in living systems, may change the clinical therapeutic efficiency of the analyzed local anaesthetic drugs. PMID:18365047

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

    PubMed Central

    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. PMID:24212283

  2. First results of Trojan horse method using radioactive ion beams: {sup 18}F(p,?) at astrophysical energies

    SciTech Connect

    Cherubini, S.; Spitaleri, C.; Puglia, S.; Rapisarda, G.; Romano, S.; Gulino, M.; La Cognata, M.; Lamia, L.; Kubono, S.; Wakabayashi, Y.; Yamaguchi, H.; Hayakawa, S.; Kurihara, Y.; Binh, D.; Bishop, S.; Coc, A.; De Séréville, N.; Hammache, F.

    2014-05-02

    The abundance of {sup 18}F in Nova explosions is considered to be an important piece of information for the understanding of this astrophysical phenomenon. It is then necessary to study the nuclear processess that both produce and destroy this isotope in Novae. Among these latter reactions, the {sup 18}F(p,?){sup 15}O is one of the most important {sup 18}F destruction channels. Here we report on an experiment performed using the CRIB apparatus of the Center for Nuclear Study of the University of Tokyo. This was the first experiment that used the Trojan Horse method applied to a Radioactive Ion Beam induced reaction.

  3. Reaction dynamics induced by the radioactive ion beam 7Be on medium-mass and heavy targets

    NASA Astrophysics Data System (ADS)

    Mazzocco, M.; Boiano, A.; Boiano, C.; La Commara, M.; Manea, C.; Parascandolo, C.; Pierroutsakou, D.; Stefanini, C.; Strano, E.; Torresi, D.; Acosta, L.; Di Meo, P.; Fernandez-Garcia, J. P.; Glodariu, T.; Grebosz, J.; Guglielmetti, A.; Keeley, N.; Lay, J. A.; Marquinez-Duran, G.; Martel, I.; Mazzocchi, C.; Molini, P.; Nicoletto, M.; Pakou, A.; Parkar, V. V.; Rusek, K.; Sánchez-Benítez, A. M.; Sandoli, M.; Sava, T.; Sgouros, O.; Signorini, C.; Silvestri, R.; Soramel, F.; Soukeras, V.; Stiliaris, E.; Stroe, L.; Toniolo, N.; Zerva, K.

    2015-10-01

    We studied the reaction dynamics induced at Coulomb barrier energies by the weakly-bound Radioactive Ion Beam 7Be (S? = 1.586 MeV) on medium-mass (58Ni) and heavy (208Pb) targets. The experiments were performed at INFN-LNL (Italy), where a 2-3×105 pps 7Be secondary beam was produced with the RIB in-flight facility EXOTIC. Charged reaction products were detected by means of high-granularity silicon detectors in rather wide angular ranges. The contribution presents an up-to-date status of the data analysis and theoretical interpretation for both systems.

  4. First Results with TIGRESS and Accelerated Radioactive Ion Beams from ISAC: Coulomb Excitation of {sup 20,21,29}Na

    SciTech Connect

    Schumaker, M. A.; Svensson, C. E.; Demand, G. A.; Finlay, P.; Green, K. L.; Grinyer, G. F.; Leach, K. G.; Millar, B. A.; Phillips, A. A.; Sumithrarachchi, C. S.; Triambak, S.; Wong, J.; Hurst, A. M.; Wu, C. Y.; Becker, J. A.; Stoyer, M. A.; Cline, D.; Hayes, A. B.; Whitbeck, A.; Hackman, G.

    2009-03-10

    The TRIUMF-ISAC Gamma-Ray Escape Suppressed Spectrometer (TIGRESS) is a state-of-the-art {gamma}-ray spectrometer being constructed at the ISAC-II radioactive ion beam facility at TRIUMF. TIGRESS will be comprised of twelve 32-fold segmented high-purity germanium (HPGe) clover-type {gamma}-ray detectors, with BGO/CsI(Tl) Compton-suppression shields, and is currently operational at ISAC-II in an early-implementation configuration of six detectors. Results have been obtained for the first experiments performed using TIGRESS, which examined the A = 20, 21, and 29 isotopes of Na by Coulomb excitation.

  5. Trojan Horse method and radioactive ion beams: study of $^{18}$F(p,$\\alpha$)$^{15}$O reaction at astrophysical energies

    E-print Network

    Gulino, M; Rapisarda, G G; Kubono, S; Lamia, L; La Cognata, M; Yamaguchi, H; Hayakawa, S; Wakabayashi, Y; Iwasa, N; Kato, S; Komatsubara, H; Teranishi, T; Coc, A; De Séréville, N; Hammache, F; Spitaleri, C

    2012-01-01

    The Trojan Horse Method was applied for the first time to a Radioactive Ion Beam induced reaction to study the reaction $^{18}$F(p,$\\alpha$)$^{15}$O via the three body reaction $^{18}$F(d,$\\alpha$ $^{15}$O)n at the low energies relevant for astrophysics. The abundance of $^{18}$F in Nova explosions is an important issue for the understanding of this astrophysical phenomenon. For this reason it is necessary to study the nuclear reactions that produce or destroy $^{18}$F in Novae. $^{18}$F(p,$\\alpha$)$^{15}$O is one of the main $^{18}$F destruction channels. Preliminary results are presented in this paper.

  6. Trojan Horse method and radioactive ion beams: study of $^{18}$F(p,$?$)$^{15}$O reaction at astrophysical energies

    E-print Network

    M. Gulino; S. Cherubini; G. G. Rapisarda; S. Kubono; L. Lamia; M. La Cognata; H. Yamaguchi; S. Hayakawa; Y. Wakabayashi; N. Iwasa; S. Kato; H. Komatsubara; T. Teranishi; A. Coc; N. De Séréville; F. Hammache; C. Spitaleri

    2012-10-31

    The Trojan Horse Method was applied for the first time to a Radioactive Ion Beam induced reaction to study the reaction $^{18}$F(p,$\\alpha$)$^{15}$O via the three body reaction $^{18}$F(d,$\\alpha$ $^{15}$O)n at the low energies relevant for astrophysics. The abundance of $^{18}$F in Nova explosions is an important issue for the understanding of this astrophysical phenomenon. For this reason it is necessary to study the nuclear reactions that produce or destroy $^{18}$F in Novae. $^{18}$F(p,$\\alpha$)$^{15}$O is one of the main $^{18}$F destruction channels. Preliminary results are presented in this paper.

  7. Measurement of radioactivity and heavy metal levels in edible vegetables and their impact on Kuala Selangor communities of Peninsular Malaysia.

    PubMed

    Asaduzzaman, Kh; Khandaker, M U; Amin, Y M; Zainuddin, Z; Farook, M S; Bradley, D A

    2015-11-01

    Vegetable is an essential daily diet item for the people of Malaysia. This work addressed the radiation and heavy metal exposure scenarios through the consumption of vegetables. Kuala Selangor is located in Sungai Selangor estuary in the west coast of Peninsular Malaysia, which is susceptible to pollution load due to the presence of large-scale industrial and human activities. Radioactivity and heavy metals level in human diet is of particular concern for the assessment of possible radiological and chemical hazards to human health. Therefore, a comprehensive study was carried out to determine the radioactivity levels ((226)Ra, (228)Ra and (40)K) and heavy metal concentrations (Cr, As, Cd, Mn, Mg, Al, Sr, Rb, Sb, Ba, Hg, Fe, Ni, Zn, Cu, Bi and Pb) in 10 varieties of vegetable collected from different farmlands in Kuala Selangor region. The committed doses for (226)Ra, (228)Ra and (40)K due to consumption of vegetables were found 16.6±1.3, 23.6±1.7 and 58±5 µSv y(-1), respectively, with a total of 98±8 µSv y(-1). This dose imposes no significant threat to human health. The estimated cancer risk shows that probability of increase in cancer risk from daily intake of vegetables is only a minor fraction of International Commission on Radiological Protection values. The concentrations of heavy metal were below the daily intake recommended by the international organisations. PMID:25935008

  8. Surface phenomena in liquid metal alloys with application to development of a liquid metal ion source of B and As

    SciTech Connect

    Bozack, M.J.

    1985-01-01

    A liquid metal ion (LMI) source is a low volatility liquid metal film which flows to the apex of a solid needle support structure. Subsequent application of a high electric field deforms the liquid and results in ion emission. Considerable interest has been shown in development of LMI sources capable of producing a variety of technologically important ions. For implantation of silicon, for example, B is the preferred p-type dopant, while As and P are the preferred n-type dopants. It has been difficult to construct long-lived ion sources based upon these species because B possesses a high melting point and reacts strongly with most refractory metal supports, while As and P have high vapor pressures. To overcome these difficulties, the material and thermochemical properties of liquid metal alloy surfaces were studied. A number of successful contact systems were identified for B, while the development of a LMI source of As was completely solved. To lower the chemical reactivity of B alloys, it was necessary to utilize nonmetallic support structures. In these cases wettability of B based alloys is governed by surface segregation of low-level, low-surface tension impurities within the alloys that inhibit reaction between the alloy and substrate. Coating the substrate with a material having a high affinity to carbon (e.g., B, or Si) acts to tie up the segregated material and promote wetting.

  9. Modified agricultural waste biomass with enhanced responsive properties for metal-ion remediation: a green approach

    NASA Astrophysics Data System (ADS)

    Mahajan, Garima; Sud, Dhiraj

    2012-12-01

    Dalbergia sissoo pods, a lignocellulosic nitrogenous waste biomass, was evaluated for sequestering of Cr(VI) from synthetic wastewater. Dalbergia sissoo pods (DSP) were used in three different forms, viz. natural (DSPN), impregnated in the form of hydrated beads (DSPB), and in carbonized form (DSPC) for comparative studies. Batch experiments were performed for the removal of hexavalent chromium. Effects of pH adsorbent dose, initial metal-ion concentration, stirring speed, and contact time were investigated. The removal of metal ions was dependent on the physico-chemical characteristics of the adsorbent, adsorbate concentration, and other studied process parameters. Maximum metal removal for Cr(VI) was observed at pH 2.0. The experimental data were analyzed based on Freundlich and Langmuir adsorption isotherms. Kinetic studies indicated that the adsorption of metal ions followed a pseudo-second-order equation.

  10. Photoinduced charge accumulation by metal ion-coupled electron transfer.

    PubMed

    Bonn, Annabell G; Wenger, Oliver S

    2015-10-01

    An oligotriarylamine (OTA) unit, a Ru(bpy)3(2+) photosensitizer moiety (Ru), and an anthraquinone (AQ) entity were combined to a molecular dyad (Ru-OTA) and a molecular triad (AQ-Ru-OTA). Pulsed laser excitation at 532 nm led to the formation of charge-separated states of the type Ru(-)-OTA(+) and AQ(-)-Ru-OTA(+) with lifetimes of ?10 ns and 2.4 ?s, respectively, in de-aerated CH3CN at 25 °C. Upon addition of Sc(OTf)3, very long-lived photoproducts were observed. Under steady-state irradiation conditions using a flux of (6.74 ± 0.21) × 10(15) photons per second at 450 nm, the formation of twofold oxidized oligotriarylamine (OTA(2+)) was detected in aerated CH3CN containing 0.02 M Sc(3+), as demonstrated unambiguously by comparison with UV-Vis absorption spectra obtained in the course of chemical oxidation with Cu(2+). Photodriven charge accumulation on the OTA unit of Ru-OTA and AQ-Ru-OTA is possible due to the lowering of the O2 reduction potential caused by the interaction of superoxide with the strong Lewis acid Sc(3+). The presence of the anthraquinone unit in AQ-Ru-OTA accelerates the rate-determining reaction step for charge accumulation by a factor of 10 compared to the Ru-OTA dyad. This is attributed to the formation of Sc(3+)-stabilized anthraquinone radical anion intermediates in the triad. Possible mechanistic pathways leading to charge accumulation are discussed. Photodriven charge accumulation is of key importance for solar fuels because their production will have to rely on multi-electron chemistry rather than single-electron reaction steps. Our study is the first to demonstrate that metal ion-coupled electron transfer (MCET) can be exploited to accumulate charges on a given molecular unit using visible light as an energy input. The approach of using a combination of intra- and intermolecular electron transfer reactions which are enabled by MCET is conceptually novel, and the fundamental insights gained from our study are relevant in the greater context of solar energy conversion. PMID:26312416

  11. FINAL REPORT. RATIONAL DESIGN OF METAL ION SEQUESTERING AGENTS

    EPA Science Inventory

    The purpose of this project has been to study the fundamental coordination chemistry of the actinides, uranium, thorium, plutonium and americium, and the non-radioactive analogues, cerium, iron, neodymium, and gadolinium, used as actinide models. Using a biomimetic approach we ha...

  12. Biodegradable radioactive implants for glaucoma filtering surgery produced by ion implantation

    NASA Astrophysics Data System (ADS)

    Assmann, W.; Schubert, M.; Held, A.; Pichler, A.; Chill, A.; Kiermaier, S.; Schlösser, K.; Busch, H.; Schenk, K.; Streufert, D.; Lanzl, I.

    2007-04-01

    A biodegradable, ?-emitting implant has been developed and successfully tested which prevents fresh intraocular pressure increase after glaucoma filtering surgery. Ion implantation has been used to load the polymeric implants with the ?-emitter 32P. The influence of ion implantation and gamma sterilisation on degradation and 32P-fixation behavior has been studied by ion beam and chemical analysis. Irradiation effects due to the applied ion fluence (1015 ions/cm2) and gamma dose (25 kGy) are found to be tolerable.

  13. Poly(ether) urethane reactivity with metal-ion in calcification and environmental stress cracking.

    PubMed

    Thoma, R J

    1987-04-01

    Since their introduction to the biomedical community in 1967, polyurethanes have been used in a number of biomedical applications. In chronic applications evidence is now available which suggests that polyurethanes may be subject to various cracking phenomena. Environmental stress cracking and calcification are two phenomena resulting in poly(ether)urethane cracking, which have been shown to be enhanced by ion complexation. Much evidence now exists which defines the ability of poly(ether)urethanes to selectively extract ions, especially calcium ion from solution. Metal ion binding appears to enhance environmental stress cracking and appears to be a first step in the process of calcification. PMID:3506954

  14. The use of aluminum nitride to improve Aluminum-26 Accelerator Mass Spectrometry measurements and production of Radioactive Ion Beams

    NASA Astrophysics Data System (ADS)

    Janzen, Meghan S.; Galindo-Uribarri, Alfredo; Liu, Yuan; Mills, Gerald D.; Romero-Romero, Elisa; Stracener, Daniel W.

    2015-10-01

    We present results and discuss the use of aluminum nitride as a promising source material for Accelerator Mass Spectrometry (AMS) and Radioactive Ion Beams (RIBs) science applications of 26Al isotopes. The measurement of 26Al in geological samples by AMS is typically conducted on Al2O3 targets. However, Al2O3 is not an ideal source material because it does not form a prolific beam of Al- required for measuring low-levels of 26Al. Multiple samples of aluminum oxide (Al2O3), aluminum nitride (AlN), mixed Al2O3-AlN as well as aluminum fluoride (AlF3) were tested and compared using the ion source test facility and the stable ion beam (SIB) injector platform at the 25-MV tandem electrostatic accelerator at Oak Ridge National Laboratory. Negative ion currents of atomic and molecular aluminum were examined for each source material. It was found that pure AlN targets produced substantially higher beam currents than the other materials and that there was some dependence on the exposure of AlN to air. The applicability of using AlN as a source material for geological samples was explored by preparing quartz samples as Al2O3 and converting them to AlN using a carbothermal reduction technique, which involved reducing the Al2O3 with graphite powder at 1600 °C within a nitrogen atmosphere. The quartz material was successfully converted to AlN. Thus far, AlN proves to be a promising source material and could lead towards increasing the sensitivity of low-level 26Al AMS measurements. The potential of using AlN as a source material for nuclear physics is also very promising by placing 26AlN directly into a source to produce more intense radioactive beams of 26Al.

  15. Analysis of Accumulating Ability of Heavy Metals in Lotus (Nelumbo nucifera) Improved by Ion Implantation

    NASA Astrophysics Data System (ADS)

    Zhang, Jianhua; Wang, Naiyan; Zhang, Fengshou

    2012-05-01

    Heavy metals have seriously contaminated soil and water, and done harm to public health. Academician WANG Naiyan proposed that ion-implantation technique should be exploited for environmental bioremediation by mutating and breeding plants or microbes. By implanting N+ into Taikonglian No.1, we have selected and bred two lotus cultivars, Jingguang No.1 and Jingguang No.2. The present study aims at analyzing the feasibility that irradiation can be used for remediation of soil and water from heavy metals. Compared with parent Taikonglian No.1, the uptaking and accumulating ability of heavy metals in two mutated cultivars was obviously improved. So ion implantation technique can indeed be used in bioremediation of heavy metals in soil and water, but it is hard to select and breed a cultivar which can remedy the soil and water from all the heavy metals.

  16. A 1-dodecanethiol-based phase transfer protocol for the highly efficient extraction of noble metal ions from aqueous phase.

    PubMed

    Chen, Dong; Cui, Penglei; Cao, Hongbin; Yang, Jun

    2015-03-01

    A 1-dodecanethiol-based phase-transfer protocol is developed for the extraction of noble metal ions from aqueous solution to a hydrocarbon phase, which calls for first mixing the aqueous metal ion solution with an ethanolic solution of 1-dodecanethiol, and then extracting the coordination compounds formed between noble metal ions and 1-dodecanethiol into a non-polar organic solvent. A number of characterization techniques, including inductively coupled plasma atomic emission spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis demonstrate that this protocol could be applied to extract a wide variety of noble metal ions from water to dichloromethane with an efficiency of >96%, and has high selectivity for the separation of the noble metal ions from other transition metals. It is therefore an attractive alternative for the extraction of noble metals from water, soil, or waste printed circuit boards. PMID:25766023

  17. Method for mobilization of hazardous metal ions in soils

    DOEpatents

    Dugan, Patrick R. (Idaho Falls, ID); Pfister, Robert M. (Powell, OH)

    1995-01-01

    A microbial process for removing heavy metals such as bismuth, cadmium, lead, thorium, uranium and other transuranics from soils and sediments, utilizing indigenous, or isolates of indigenous, microorganisms and reducing agents, such as cysteine or sodium thioglycollate, or complexing agents such as the amino acid glycine, to effect the mobilization or release of the metals from the soil particles.

  18. Development of dithizone based fibre optic evanescent wave sensor for heavy metal ion detection in aqueous environments

    NASA Astrophysics Data System (ADS)

    Bhavsar, K.; Prabhu, R.; Pollard, P.

    2013-06-01

    Detection of highly toxic heavy metal ions requires rapid, simple, sensitive and selective detection methods in the environment. Optical fibre based sensing facilitates the remote, continuous and in-situ detection approaches in the environment. Herein, we report the development of a dithizone based fibre optic sensor with a simple procedure to detect heavy metal ions in the aqueous environment using an evanescent wave sensing approach. The chromogenic ligand dithizone and its spectral specificity with metal ions has been elaborated in this work.

  19. Multi-cathode metal vapor arc ion source

    DOEpatents

    Brown, Ian G. (1088 Woodside Rd., Berkeley, CA 94708); MacGill, Robert A. (645 Kern St., Richmond, CA 94805)

    1988-01-01

    An ion generating apparatus utilizing a vacuum chamber, a cathode and an anode in the chamber. A source of electrical power produces an arc or discharge between the cathode and anode. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma is directed to an extractor which separates the electrons from the plasma, and accelerates the ions to produce an ion beam. One embodiment of the appaatus utilizes a multi-cathode arrangement for interaction with the anode.

  20. Human topoisomerase II? uses a two-metal-ion mechanism for DNA cleavage

    PubMed Central

    Deweese, Joseph E.; Burgin, Alex B.; Osheroff, Neil

    2008-01-01

    The DNA cleavage reaction of human topoisomerase II? is critical to all of the physiological and pharmacological functions of the protein. While it has long been known that the type II enzyme requires a divalent metal ion in order to cleave DNA, the role of the cation in this process is not known. To resolve this fundamental issue, the present study utilized a series of divalent metal ions with varying thiophilicities in conjunction with DNA cleavage substrates that replaced the 3?-bridging oxygen of the scissile bond with a sulfur atom (i.e. 3?-bridging phosphorothiolates). Rates and levels of DNA scission were greatly enhanced when thiophilic metal ions were included in reactions that utilized sulfur-containing substrates. Based on these results and those of reactions that employed divalent cation mixtures, we propose that topoisomerase II? mediates DNA cleavage via a two-metal-ion mechanism. In this model, one of the metal ions makes a critical interaction with the 3?-bridging atom of the scissile phosphate. This interaction greatly accelerates rates of enzyme-mediated DNA cleavage, and most likely is needed to stabilize the leaving 3?-oxygen. PMID:18653531

  1. Anion-intercalated layered double hydroxides modified test strips for detection of heavy metal ions.

    PubMed

    Wang, Nan; Sun, Jianchao; Fan, Hai; Ai, Shiyun

    2016-02-01

    In this work, a novel approach for facile and rapid detection of heavy metal ions using anion-intercalated layered double hydroxides (LDHs) modified test strips is demonstrated. By intercalating Fe(CN)6(4-) or S(2-) anions into the interlayers of LDHs on the filter paper, various heavy metal ions can be easily detected based on the color change before and after reaction between the anions and the heavy metal ions. Upon the dropping of heavy metal ions solutions to the test strips, the colors of the test strips changed instantly, which can be easily observed by naked eyes. With the decrease of the concentration, the color depth changed obviously. The lowest detection concentration can be up to 1×10(-6)molL(-1). Due to the easily intercalation of anions into the interlayer of the LDHs on test trips, this procedure provides a general method for the construction of LDHs modified test strips for detection of heavy metal ions. The stability of the prepared test strips is investigated. Furthermore, all the results were highly reproducible. The test strips may have potential applications in environmental monitoring fields. PMID:26653453

  2. Mechanism of Metal Ion Activation of the Diphtheria Toxin Repressor DtxR

    NASA Astrophysics Data System (ADS)

    D'Aquino, J. Alejandro; Ringe, Dagmar

    2006-08-01

    The diphtheria toxin repressor, DtxR, is a metal ion-activated transcriptional regulator that has been linked to the virulence of Corynebacterium diphtheriae. Structure determination has shown that there are two metal ion binding sites per repressor monomer, and site-directed mutagenesis has demonstrated that binding site 2 (primary) is essential for recognition of the target DNA repressor, leaving the role of binding site 1 (ancillary) unclear (1 - 3). Calorimetric techniques have demonstrated that while binding site 1 (ancillary) has high affinity for metal ion with a binding constant of 2 × 10-7, binding site 2 (primary) is a low affinity binding site with a binding constant of 6.3 × 10-4. These two binding sites act independently and their contribution can be easily dissected by traditional mutational analysis. Our results clearly demonstrate that binding site 1 (ancillary) is the first one to be occupied during metal ion activation, playing a critical role in stabilization of the repressor. In addition, structural data obtained for the mutants Ni-DtxR(H79A,C102D), reported here and the previously reported DtxR(H79A) (4) has allowed us to propose a mechanism of metal ion activation for DtxR.

  3. FTIR spectroscopy structural analysis of the interaction between Lactobacillus kefir S-layers and metal ions

    NASA Astrophysics Data System (ADS)

    Gerbino, E.; Mobili, P.; Tymczyszyn, E.; Fausto, R.; Gómez-Zavaglia, A.

    2011-02-01

    FTIR spectroscopy was used to structurally characterize the interaction of S-layer proteins extracted from two strains of Lactobacillus kefir (the aggregating CIDCA 8348 and the non-aggregating JCM 5818) with metal ions (Cd +2, Zn +2, Pb +2 and Ni +2). The infrared spectra indicate that the metal/protein interaction occurs mainly through the carboxylate groups of the side chains of Asp and Glut residues, with some contribution of the NH groups belonging to the peptide backbone. The frequency separation between the ?COO - anti-symmetric and symmetric stretching vibrations in the spectra of the S-layers in presence of the metal ions was found to be ca. 190 cm -1 for S-layer CIDCA 8348 and ca. 170 cm -1 for JCM 5818, denoting an unidentate coordination in both cases. Changes in the secondary structures of the S-layers induced by the interaction with the metal ions were also noticed: a general trend to increase the amount of ?-sheet structures and to reduce the amount of ?-helices was observed. These changes allow the proteins to adjust their structure to the presence of the metal ions at minimum energy expense, and accordingly, these adjustments were found to be more important for the bigger ions.

  4. Metal ion-induced lateral aggregation of filamentous viruses fd and M13.

    PubMed Central

    Tang, Jay X; Janmey, Paul A; Lyubartsev, Alexander; Nordenskiöld, Lars

    2002-01-01

    We report a detailed comparison between calculations of inter-filament interactions based on Monte-Carlo simulations and experimental features of lateral aggregation of bacteriophages fd and M13 induced by a number of divalent metal ions. The general findings are consistent with the polyelectrolyte nature of the virus filaments and confirm that the solution electrostatics account for most of the experimental features observed. One particularly interesting discovery is resolubilization for bundles of either fd or M13 viruses when the concentration of the bundle-inducing metal ion Mg(2+) or Ca(2+) is increased to large (>100 mM) values. In the range of Mg(2+) or Ca(2+) concentrations where large bundles of the virus filaments are formed, the optimal attractive interaction energy between the virus filaments is estimated to be on the order of 0.01 kT per net charge on the virus surface when a recent analytical prediction to the experimentally defined conditions of resolubilization is applied. We also observed qualitatively distinct behavior between the alkali-earth metal ions and the divalent transition metal ions in their action on the charged viruses. The understanding of metal ions-induced reversible aggregation based on solution electrostatics may lead to potential applications in molecular biology and medicine. PMID:12080143

  5. Arc discharge ion source for europium and other refractory metals implantation.

    PubMed

    Turek, M; Prucnal, S; Dro?dziel, A; Pyszniak, K

    2009-04-01

    The best method for the impurity doping to the host material is the ion implantation. Due to high melting point of the rare earth standard metal ion sources are useless. One of the solution is to use chemical compounds of rare earths characterized by low melting point. In this paper we describe the novel design of the ion source suitable for refractory metal (e.g., rare earths) ion implantation. The dependencies of Eu(+) current on cathode and arc currents as well as on hydrogen flow are presented. Europium (III) chloride as the source of the europium atoms was used. Europium ions were produced during collisions of evaporated and decomposed EuCl(3) molecules with fast electrons. The typical current of the europium ion beam extracted from the ion source was 25 microA for the extraction voltage of 25 kV. The ion source works without maintenance breaks for approximately 50 h, which enables high dose implantation. The presented ion source needs neither advanced high power supplies nor high vacuum regime. PMID:19405653

  6. Prevalence of Pseudotumor in Patients After Metal-On-Metal Hip Arthroplasty Evaluated with Metal Ion Analysis and MARS-MRI.

    PubMed

    Sutphen, Sean A; MacLaughlin, Lewis H; Madsen, Adam A; Russell, Jackie H; McShane, Michael A

    2016-01-01

    The purpose of this study is to quantify the prevalence of pseudotumors in patients with well-functioning and painful metal-on-metal total hip arthroplasty, to characterize the pseudotumor with the use of MARS-MRI, and to assess the relationship between pseudotumors and metal ions. We retrospectively reviewed 102 single surgeon patients. The results showed that 68.6% developed pseudotumor with 60.9% of the asymptomatic group developing pseudotumor. The symptomatic group had a higher proportion of patients with elevated serum cobalt levels (P=0.035). There was no difference found with elevated metal ions and prevalence of pseudotumor, but elevated cobalt levels were associated with larger pseudotumor size (P=0.001). The available evidence indicated that most patients that develop pseudotumors are asymptomatic, and that elevated serum cobalt levels may be associated with symptoms and pseudotumor size. PMID:26253484

  7. Selection of allosteric ?-lactamase mutants featuring an activity regulation by transition metal ions

    PubMed Central

    Mathonet, Pascale; Barrios, Humberto; Soumillion, Patrice; Fastrez, Jacques

    2006-01-01

    Libraries of phage-displayed ?-lactamase mutants in which up to three loops have been engineered by genetic introduction of random peptide sequences or by randomization of the wild-type sequence have been submitted to selection protocols designed to find mutants in which binding of transition metal ions to the engineered secondary binding site leads to significant effects on the enzymatic activity. A double-selection protocol was applied: The phage-displayed libraries were first selected for transition metal ions affinity by panning on IMAC support, then a second selection step was applied to isolate mutants that have retained significant catalytic activity. The analysis of the kinetic properties of mutants in the presence of nickel, copper, or zinc ions allowed isolation of a few mutants whose activity was either enhanced or inhibited by factors up to three and >10, respectively, in a metal-specific manner. A remarkable mutant exhibiting differential allosteric regulation depending on the metal was found. Its activity was activated by nickel ion binding, inhibited by cupric ion binding, and nearly unaffected by zinc ions. These observations point to an interesting potential for up- or down-regulation of activity within a monomeric enzyme by binding to an “allosteric site” relatively remote from the active site. PMID:16963642

  8. Identification of Metals (Heavy and Radioactive) in Drinking Water by an Indirect Analysis Method Based on Scale Tests

    PubMed Central

    Rajkovic, Miloš B.; Lacnjevac, Caslav M.; Ralevic, Nebojsa R.; Stojanovi?, Mirjana D.; Toskovi?, Dragan V.; Pantelic, Gordana K.; Ristic, Nikola M.; Jovanic, Sasa

    2008-01-01

    The analysis of water quality, regarding the content of metals, especially heavy and radioactive ones, has been carried out in an indirect way, by testing scale formed in a hot-water heater, using water from the water-supply network of the city of Belgrade – the district of New Belgrade. The determination of the composition and the structure of the scale has resulted in its complete identification, and its crystallochemical formula has been defined. It has unequivocally been established that the obtained results are within the tolerance boundary with the results acquired by a conventional analysis of water, when it is a matter of very low concentrations. The presence of radioactive elements of uranium and strontium in a scale sample has been found and the way of their penetrating its composition and structure has been explained. Applying the fractional extraction method, uranium has been established to be of an anthropogenic origin.

  9. Carbon dots rooted agarose hydrogel hybrid platform for optical detection and separation of heavy metal ions.

    PubMed

    Gogoi, Neelam; Barooah, Mayuri; Majumdar, Gitanjali; Chowdhury, Devasish

    2015-02-11

    A robust solid sensing platform for an on-site operational and accurate detection of heavy metal is still a challenge. We introduce chitosan based carbon dots rooted agarose hydrogel film as a hybrid solid sensing platform for detection of heavy metal ions. The fabrication of the solid sensing platform is centered on simple electrostatic interaction between the NH3+ group present in the carbon dots and the OH- groups present in agarose. Simply on dipping the hydrogel film strip into the heavy metal ion solution, in particular Cr6+, Cu2+, Fe3+, Pb2+, Mn2+, the strip displays a color change, viz., Cr6+?yellow, Cu2+?blue, Fe3+?brown, Pb2+?white, Mn2+?tan brown. The optical detection limit of the respective metal ion is found to be 1 pM for Cr6+, 0.5 ?M for Cu2+, and 0.5 nM for Fe3+, Pb2+, and Mn2+ by studying the changes in UV-visible reflectance spectrum of the hydrogel film. Moreover, the hydrogel film finds applicability as an efficient filtration membrane for separation of these quintet heavy metal ions. The strategic fundamental feature of this sensing platform is the successful capability of chitosan to form colored chelates with transition metals. This proficient hybrid hydrogel solid sensing platform is thus the most suitable to employ as an on-site operational, portable, cheap colorimetric-optical detector of heavy metal ion with potential skill in their separation. Details of the possible mechanistic insight into the colorimetric detection and ion separation are also discussed. PMID:25567035

  10. A theoretical and experimental study of liquid-metal ion sources and their application to focused ion-beam technology

    SciTech Connect

    Puretz, J.

    1988-01-01

    A key parameter of liquid metal ion source (LMIS) operation is the current-voltage (I(V)) relationship. Some issues surrounding this relationship, which is complicated by severe space-charge near the emitter, are examined for a LMIS. A simple technique is introduced which relies on the principle of momentum conservation within a simple diode structure and enables the solution of space charge problems without resorting to the Poisson equation. As an illustration of this approach, the result of Stern-Gossling-Fowler is easily derived. This method is then applied to the problem of modeling the I(V) characteristic of a LMIS. A simple and physically intuitive criterion is derived which demonstrates that the ratio of the viscous drag force on the emitter to the force of the ion beam impinging on the collector determine whether the ion current is dominated by the flow of liquid metal or by the space charge in the beam. This explains, for the first time, how these two factors are related. Another result is that, contrary to currently accepted thinking, it is not the flow impedance per se which influences the ion current but the product of the film thickness and the flow impedance. Since the advent of LMIS, the understanding of their fundamental properties and their application to focused ion beam (FIB) technology have followed parallel developments. One of the goals of the research presented in this dissertation has been to expand the applications of the liquid metal ion source. The major difficulties encountered during their fabrication, testing and operation are due primarily to contamination by oxygen, carbon bearing gases and backsputtering of material to the source, particularly from the extraction electrode.

  11. Industrial applications of ion implantation into metal surfaces

    SciTech Connect

    Williams, J.M.

    1987-07-01

    The modern materials processing technique, ion implantation, has intriguing and attractive features that stimulate the imaginations of scientists and technologists. Success of the technique for introducing dopants into semiconductors has resulted in a stable and growing infrastructure of capital equipment and skills for use of the technique in the economy. Attention has turned to possible use of ion implantation for modification of nearly all surface related properties of materials - optical, chemical and corrosive, tribological, and several others. This presentation provides an introduction to fundamental aspects of equipment, technique, and materials science of ion implantation. Practical and economic factors pertaining to the technology are discussed. Applications and potential applications are surveyed. There are already available a number of ion-implanted products, including ball-and-roller bearings and races, punches-and-dies, injection screws for plastics molding, etc., of potential interest to the machine tool industry.

  12. Craters produced on metals by single ion impacts.

    SciTech Connect

    Birtcher, R. C.

    1998-12-23

    Single ion impacts have been observed using in-situ transmission electron microscopy during irradiation. In addition to internal defects, single-ion impacts create surface craters as large as 12 nm on In, Ag, Pb and Au. Crater formation rates have been determined from video recordings with a time-resolution of 33 milliseconds. The cratering rate for Xe ions increases linearly with increasing target mass density above a threshold density of approximately 7 gm/cm{sup 3}. The cratering rate increases as the ion mass is increased. These results suggest that cratering requires a high energy-density, near-surface displacement cascade. TRIM calculations have been made in an effort to establish a near-surface energy-density criterion for cratering.

  13. Influence of several metal ions on the gelation activation energy of silicon tetraethoxide

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    1990-01-01

    The effects of nine metal cations Li(+), Na(+), Mg(2+), Ca(2+), Sr(2+), Cu(2+), Al(3+), La(3+), and Y(3+) on silica gel formation has been investigated by studying the hydrolysis and polycondensation of silicon tetraethoxide (TEOS) in the presence of metal nitrates. The influence of water:TEOS mole ratio, metal ion concentration, and the reaction temperature has been investigated. The overall activation energy for gel formation has been determined from the temperature dependence of the time of gelation for each system. The activation energy for -Si-O-Si- network formation is found to be 54.5 kJ/mol. The gel formation time as well as the activation energy sharply increase in the presence of Cu(2+), Al(3+), La(3+) and Y(3+). In contrast, the presence of Li(+), Na(+), Mg(2+), Ca(2+), or Sr(2+) lowers the gelation time, but has no appreciable effect on the activation energy. This difference may be attributed to the participation or nonparticipation of the metal ions in the formation of the three-dimensional polymeric network during the polycondensation step. The concentration of metal ion Mg(2+), Ca(2+), Y(3+) or the water:TEOS mole ratio had no appreaciable effect on the gelation activation energy. A simple test has been proposed to determine whether a metal ion would act as a network intermediate or modifier in silica and other glassy networks.

  14. Influence of several metal ions on the gelation activation energy of silicon tetraethoxide

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    1988-01-01

    The effects of nine metal cations (Li(+), Na(+), Mg(2+), Ca(2+), Sr(2+), Cu(2+), Al(3+), La(3+), and Y(3+) on silica gel formation has been investigated by studying the hydrolysis and polycondensation of silicon tetraethoxide (TEOS) in the presence of metal nitrates. The influence of water: TEOS mole ratio, metal ion concentration, and the reaction temperature has been investigated. The overall activation energy for gel formation has been determined from the temperature dependence of the time of gelation for each system. The activation energy for -Si-O-Si- network formation is found to be 54.5 kJ/mol. The gel formation time as well as the activation energy sharply increase in the presence of Cu(2+), Al(3+), La(3+) and Y(3+). In contrast, the presence of Li(+), Na(+), Mg(2+), Ca(2+), or, Sr(2+) lowers the gelation time, but has no appreciable effect on the activation energy. This difference may be attributed to the participation or nonparticipation of the metal ions in the formation of the three-dimensional polymeric network during the polycondensation step. The concentration of metal ion (Mg(2+), Ca(2+), Y(3+) or the water: TEOS mole ratio had no appreciable effect on the gelation activation energy. A simple test has been proposed to determine whether a metal ion would act as a network intermediate or modifier in silica and other glassy networks.

  15. Supercharging with Trivalent Metal Ions in Native Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Flick, Tawnya G.; Williams, Evan R.

    2012-11-01

    Addition of 1.0 mM LaCl3 to aqueous ammonium acetate solutions containing proteins in their folded native forms can result in a significant increase in the molecular ion charging obtained with electrospray ionization as a result of cation adduction. In combination with m-nitrobenzyl alcohol, molecular ion charge states that are greater than the number of basic sites in the protein can be produced from these native solutions, even for lysozyme, which is conformationally constrained by four intramolecular disulfide bonds. Circular dichroism spectroscopy indicates that the conformation of ubiquitin is not measurably affected with up to 1.0 M LaCl3, but ion mobility data indicate that the high charge states that are formed when 1.0 mM LaCl3 is present are more unfolded than the low charge states formed without this reagent. These and other results indicate that the increased charging is a result of La3+ preferentially adducting onto compact or more native-like conformers during ESI and the gas-phase ions subsequently unfolding as a result of increased Coulomb repulsion. Electron capture dissociation of these high charge-state ions formed from these native solutions results in comparable sequence coverage to that obtained for ions formed from denaturing solutions without supercharging reagents, making this method a potentially powerful tool for obtaining structural information in native mass spectrometry.

  16. Designing antimicrobial bioactive glass materials with embedded metal ions synthesized by the sol-gel method.

    PubMed

    Palza, Humberto; Escobar, Blanca; Bejarano, Julian; Bravo, Denisse; Diaz-Dosque, Mario; Perez, Javier

    2013-10-01

    Bioactive glasses (SiO2-P2O5-CaO) having tailored concentrations of different biocide metal ions (copper or silver) were produced by the sol-gel method. All the particles release phosphorous ions when immersed in water and simulated body fluid (SBF). Moreover, a surface layer of polycrystalline hydroxy-carbonate apatite was formed on the particle surfaces after 10 day immersion in SBF as confirmed by X-ray diffraction and scanning electron microscopy (SEM) showing the bioactive materials. Samples with embedded either copper or silver ions were able to further release the biocide ions with a release rate that depends on the metal embedded and the dissolution medium: water or SBF. This biocide ion release from the samples explains the antimicrobial effect of our active particles against Escherichia coli DH5? ampicillin-resistant (Gram-negative) and Streptococcus mutans (Gram-positive) as determined by the Minimum Bactericidal Concentration (MBC) method. The antimicrobial behavior of the particles depends on the bacteria and the biocide ion used. Noteworthy, although samples with copper are able to release more metal ion than samples with silver, they present higher MBC showing the high effect of silver against these bacteria. PMID:23910279

  17. Method for intercalating alkali metal ions into carbon electrodes

    DOEpatents

    Doeff, M.M.; Ma, Y.; Visco, S.J.; DeJonghe, L.

    1995-08-22

    A low cost, relatively flexible, carbon electrode for use in a secondary battery is described. A method is provided for producing same, including intercalating alkali metal salts such as sodium and lithium into carbon.

  18. Method for intercalating alkali metal ions into carbon electrodes

    DOEpatents

    Doeff, Marca M. (Hayward, CA); Ma, Yanping (Berkeley, CA); Visco, Steven J. (Berkeley, CA); DeJonghe, Lutgard (Lafayette, CA)

    1995-01-01

    A low cost, relatively flexible, carbon electrode for use in a secondary battery is described. A method is provided for producing same, including intercalating alkali metal salts such as sodium and lithium into carbon.

  19. Metal-air cell with ion exchange material

    DOEpatents

    Friesen, Cody A.; Wolfe, Derek; Johnson, Paul Bryan

    2015-08-25

    Embodiments of the invention are related to anion exchange membranes used in electrochemical metal-air cells in which the membranes function as the electrolyte material, or are used in conjunction with electrolytes such as ionic liquid electrolytes.

  20. Immobilized metal ion affinity partitioning, a method combining metal-protein interaction and partitioning of proteins in aqueous two-phase systems.

    PubMed

    Birkenmeier, G; Vijayalakshmi, M A; Stigbrand, T; Kopperschläger, G

    1991-02-22

    Immobilized metal ions were used for the affinity extraction of proteins in aqueous two-phase systems composed of polyethylene glycol (PEG) and dextran or PEG and salt. Soluble chelating polymers were prepared by covalent attachment of metal-chelating groups to PEG. The effect on the partitioning of proteins of such chelating PEG derivatives coordinated with different metal ions is demonstrated. The proteins studied were alpha 2-macroglobulin, tissue plasminogen activator, superoxide dismutase and monoclonal antibodies. The results indicate that immobilized metal ion affinity partitioning provides excellent potential for the extraction of proteins. PMID:1710621

  1. Refining technology for the recycling of stainless steel radioactive scrap metals, FY 94 bi-annual report

    SciTech Connect

    Mizia, R.E.; Atteridge, D.G.; Buckentin, J.; Carter, J.; Davis, H.L.; Devletian, J.H.; Scholl, M.R.; Turpin, R.B.; Webster, S.L.

    1994-08-01

    The research addressed under this project is the recycling of metallic nuclear-related by-product materials under the direction of Westinghouse Idaho Nuclear Company (WINCO). The program addresses the recycling of radioactive scrap metals (RSM) for beneficial re-use within the DOE complex; in particular, this program addresses the recycling of stainless steel RSM. It is anticipated that various stainless steel components under WINCO control at the Idaho Falls Engineering Laboratory (INEL), such as fuel pool criticality barriers and fuel storage racks will begin to be recycled in FY94-95. The end product of this recycling effort is expected to be waste and overpack canisters for densified high level waste for the Idaho Waste Immobilization Facility and/or the Universal Canister System for dry (interim) storage of spent fuel. The specific components of this problem area that are presently being, or have been, addressed by CAAMSEC are: (1) the melting/remelting of stainless steel RSM into billet form; (2) the melting/remelting initial research focus will be on the use of radioactive surrogates to study; (3) the cost effectiveness of RSM processing oriented towards privatization of RSM reuse and/or resale. Other components of this problem that may be addressed under program extension are: (4) the melting/remelting of carbon steel; (5) the processing of billet material into product form which shall meet all applicable ASTM requirements; and, (6) the fabrication of an actual prototypical product; the present concept of an end product is a low carbon Type 304/316 stainless steel cylindrical container for densified and/or vitrified high level radioactive waste and/or the Universal Canister System for dry (interim) storage of spent fuel. The specific work reported herein covers the melting/remelting of stainless steel {open_quotes}scrap{close_quotes} metal into billet form and the study of surrogate material removal effectiveness by various remelting techniques.

  2. Serum metal ion concentrations in paediatric patients following total knee arthroplasty using megaprostheses.

    PubMed

    Friesenbichler, Jörg; Sadoghi, Patrick; Maurer-Ertl, Werner; Szkandera, Joanna; Glehr, Mathias; Ogris, Kathrin; Wolf, Matthias; Weger, Christian; Leithner, Andreas

    2014-01-01

    The purpose of this study was to determine the concentrations of cobalt, chromium, and molybdenum in the serum of paediatric tumour patients after fixed hinge total knee arthroplasty. Further, these metal ion levels were compared with serum metal ion levels of patients with other orthopaedic devices such as hip and knee prostheses with metal-on-metal or metal-on-polyethylene articulation to find differences between anatomical locations, abrasion characteristics, and bearing surfaces. After an average follow-up of 108 months (range: 67 to 163) of 11 paediatric patients with fixed hinge total knee arthroplasty, the mean concentrations for Co and Cr were significantly increased while Mo was within the limits compared to the upper values from the reference laboratory. Furthermore, these serum concentrations were significantly higher compared to patients with a standard rotating hinge device (P = 0.002 and P < 0.001) and preoperative controls (P < 0.001). On the other hand, the serum levels of patients following MoM THA or rotating hinge arthroplasty using megaprostheses were higher. Therefore, periodic long-term follow-ups are recommended due to the rising concerns about systemic metal ion exposure in the literature. Upon the occurrence of adverse reactions to metal debris the revision of the fixed hinge implant should be considered. PMID:25276819

  3. Serum Metal Ion Concentrations in Paediatric Patients following Total Knee Arthroplasty Using Megaprostheses

    PubMed Central

    Friesenbichler, Jörg; Sadoghi, Patrick; Maurer-Ertl, Werner; Szkandera, Joanna; Glehr, Mathias; Ogris, Kathrin; Wolf, Matthias; Weger, Christian; Leithner, Andreas

    2014-01-01

    The purpose of this study was to determine the concentrations of cobalt, chromium, and molybdenum in the serum of paediatric tumour patients after fixed hinge total knee arthroplasty. Further, these metal ion levels were compared with serum metal ion levels of patients with other orthopaedic devices such as hip and knee prostheses with metal-on-metal or metal-on-polyethylene articulation to find differences between anatomical locations, abrasion characteristics, and bearing surfaces. After an average follow-up of 108 months (range: 67 to 163) of 11 paediatric patients with fixed hinge total knee arthroplasty, the mean concentrations for Co and Cr were significantly increased while Mo was within the limits compared to the upper values from the reference laboratory. Furthermore, these serum concentrations were significantly higher compared to patients with a standard rotating hinge device (P = 0.002 and P < 0.001) and preoperative controls (P < 0.001). On the other hand, the serum levels of patients following MoM THA or rotating hinge arthroplasty using megaprostheses were higher. Therefore, periodic long-term follow-ups are recommended due to the rising concerns about systemic metal ion exposure in the literature. Upon the occurrence of adverse reactions to metal debris the revision of the fixed hinge implant should be considered. PMID:25276819

  4. FINAL REPORT. REMOVAL OF RADIOACTIVE CATIONS AND ANIONS FROM POLLUTED WATER USING LIGAND-MODIFIED COLLOID-ENHANCED ULTRAFILTRATION

    EPA Science Inventory

    The purpose of this project was to develop, optimize, and evaluate new separation methods for removal of hazardous (radionuclides and toxic non-radioactive contaminants) metal ions from either ground water or aqueous waste solutions produced during Decontamination and Decommissio...

  5. Method for mobilization of hazardous metal ions in soils

    DOEpatents

    Dugan, P.R.; Pfister, R.M.

    1995-06-27

    A microbial process is revealed for removing heavy metals such as bismuth, cadmium, lead, thorium, uranium and other transuranics from soils and sediments. The method utilizes indigenous, or isolates of indigenous, microorganisms and reducing agents, such as cysteine or sodium thioglycollate, or complexing agents such as the amino acid glycine, to effect the mobilization or release of the metals from the soil particles. 5 figs.

  6. Depth concentrations of deuterium ions implanted into some pure metals and alloys

    NASA Astrophysics Data System (ADS)

    Didyk, A. Yu.; Wi?niewski, R.; Kitowski, K.; Kulikauskas, V.; Wilczynska, T.; Hofman, A.; Shiryaev, A. A.; Zubavichus, Ya. V.

    2012-01-01

    Pure metals (Cu, Ti, Zr, V, Pd) and diluted Pd alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh) were implanted by 25-keV deuterium ions at fluences in the range (1.2-2.3) × 1022 m-2. The post-treatment depth distributions of deuterium ions were measured 10 days and three months after the implantation by using Elastic Recoil Detection Analysis (ERDA) and Rutherford Backscattering (RBS). Comparison of the obtained results allowed us to make conclusions about relative stability of deuterium and hydrogen gases in pure metals and diluted Pd alloys. Very high diffusion rates of implanted deuterium ions in V and Pd pure metals and Pd alloys were observed. Small-angle X-ray scattering revealed formation of nanosized defects in implanted corundum and titanium.

  7. Dysregulation of transition metal ion homeostasis is the molecular basis for cadmium toxicity in Streptococcus pneumoniae

    PubMed Central

    Begg, Stephanie L.; Eijkelkamp, Bart A.; Luo, Zhenyao; Couñago, Rafael M.; Morey, Jacqueline R.; Maher, Megan J.; Ong, Cheryl-lynn Y.; McEwan, Alastair G.; Kobe, Bostjan; O’Mara, Megan L.; Paton, James C.; McDevitt, Christopher A.

    2015-01-01

    Cadmium is a transition metal ion that is highly toxic in biological systems. Although relatively rare in the Earth’s crust, anthropogenic release of cadmium since industrialization has increased biogeochemical cycling and the abundance of the ion in the biosphere. Despite this, the molecular basis of its toxicity remains unclear. Here we combine metal-accumulation assays, high-resolution structural data and biochemical analyses to show that cadmium toxicity, in Streptococcus pneumoniae, occurs via perturbation of first row transition metal ion homeostasis. We show that cadmium uptake reduces the millimolar cellular accumulation of manganese and zinc, and thereby increases sensitivity to oxidative stress. Despite this, high cellular concentrations of cadmium (~17?mM) are tolerated, with negligible impact on growth or sensitivity to oxidative stress, when manganese and glutathione are abundant. Collectively, this work provides insight into the molecular basis of cadmium toxicity in prokaryotes, and the connection between cadmium accumulation and oxidative stress. PMID:25731976

  8. Bio-functionalized silver nanoparticles for selective colorimetric sensing of toxic metal ions and antimicrobial studies

    NASA Astrophysics Data System (ADS)

    Vinod Kumar, V.; Anbarasan, S.; Christena, Lawrence Rene; SaiSubramanian, Nagarajan; Philip Anthony, Savarimuthu

    2014-08-01

    Hibiscus Sabdariffa (Gongura) plant extracts (leaves (HL) and stem (HS) were used for the first time in the green synthesis of bio-functionalized silver nanoparticles (AgNPs). The bio-functionality of AgNPs has been successfully utilized for selective colorimetric sensing of potentially health and environmentally hazardous Hg2+, Cd2+ and Pb2+ metal ions at ppm level in aqueous solution. Importantly, clearly distinguishable colour for all three metal ions was observed. The influence of extract preparation condition and pH were also explored on the formation of AgNPs. Both selectivity and sensitivity differed for AgNPs synthesized from different parts of the plant. Direct correlation between the stability of green synthesized AgNPs at different pH and its antibacterial effects has been established. The selective colorimetric sensing of toxic metal ions and antimicrobial effect of green synthesized AgNPs demonstrated the multifunctional applications of green nanotechnology.

  9. Depth concentrations of deuterium ions implanted into some pure metals and alloys

    E-print Network

    A. Yu. Didyk; R. Wi?niewski; K. Kitowski; V. Kulikauskas; T. Wilczynska; A. A. Shiryaev; Ya. V. Zubavichus

    2011-02-04

    Pure metals (Cu, Ti, Zr, V, Pd) and diluted Pd-alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh) were implanted by 25 keV deuterium ions at fluences in the range (1.2{\\div}2.3)x1022 D+/m2. The post-treatment depth distributions of deuterium ions were measured 10 days and three months after the implantation using Elastic Recoil Detection Analysis (ERDA) and Rutherford Backscattering (RBS). Comparison of the obtained results allowed to make conclusions about relative stability of deuterium and hydrogen gases in pure metals and diluted Pd alloys. Very high diffusion rates of implanted deuterium ions from V and Pd pure metals and Pd alloys were observed. Small-angle X-ray scattering revealed formation of nanosized defects in implanted corundum and titanium.

  10. Particle concentration effect: adsorption of divalent metal ions on coffee grounds.

    PubMed

    Utomo, Handojo Djati; Hunter, Keith A

    2010-03-01

    The adsorption of divalent metal ions Cu2+, Pb2+, Zn2+, and Cd2+ on coffee grounds as a function of coffee grounds concentration was studied in which adsorption density decreased as the concentration of coffee grounds (C(s)) increased. Adsorption studies were conducted by equilibrating aqueous solutions of each metal ion at concentrations in the range 19-291 micromol L(-1) with coffee suspensions in the concentration range 0.971-8.738 g L(-1), with the initial pH adjusted to 5.0+/-0.1 using NaOH or HNO3. Metastable Equilibrium Adsorption theory did not adequately explain the adsorption phenomenon, except at low concentrations of coffee grounds and trace metal ions. Instead the results indicated that flocculation might reduce the surface availability thus reducing the adsorption density. The flocculation theory was confirmed after a further experiment adding dispersant sodium hexa-meta-phosphate (NaHMP) to the suspension. PMID:19660940

  11. On the electrochemical deposition and dissolution of divalent metal ions.

    PubMed

    Pinto, Leandro M C; Quaino, Paola; Santos, Elizabeth; Schmickler, Wolfgang

    2014-01-13

    The deposition of Cu(2+) and Zn(2+) from aqueous solution has been investigated by a combination of classical molecular dynamics, density functional theory, and a theory developed by the authors. For both cases, the reaction proceeds through two one-electron steps. The monovalent ions can get close to the electrode surface without losing hydration energy, while the divalent ions, which have a stronger solvation sheath, cannot. The 4s orbital of Cu interacts strongly with the sp band and more weakly with the d band of the copper surface, while the Zn?4s orbital couples only to the sp band of Zn. At the equilibrium potential for the overall reaction, the energy of the intermediate Cu(+) ion is only a little higher than that of the divalent ion, so that the first electron transfer can occur in an outer-sphere mode. In contrast, the energy of the Zn(+) ion lies too high for a simple outer-sphere reaction to be favorable; in accord with experimental data this suggests that this step is affected by anions. PMID:24376128

  12. Metallic ions in the upper atmosphere of Mars from the passage of comet C/2013 A1 (Siding Spring)

    NASA Astrophysics Data System (ADS)

    Benna, M.; Mahaffy, P. R.; Grebowsky, J. M.; Plane, J. M. C.; Yelle, R. V.; Jakosky, B. M.

    2015-06-01

    We report the first in situ detection of metal ions in the upper atmosphere of Mars resulting from the ablation of dust particles from comet Siding Spring. This detection was carried out by the Neutral Gas and Ion Mass Spectrometer on board the Mars Atmosphere and Volatile Evolution Mission. Metal ions of Na, Mg, Al, K, Ti, Cr, Mn, Fe, Co, Ni, Cu, and Zn, and possibly of Si, and Ca, were identified in the ion spectra collected at altitudes of ~185 km. The measurements revealed that Na+ was the most abundant species, and that the remaining metals were depleted with respect to the CI (type 1 carbonaceous Chondrites) abundance of Na+. The temporal profile and abundance ratios of these metal ions suggest that the combined effects of dust composition, partial ablation, differential upward transport, and differences in the rates of formation and removal of these metal ions are responsible for the observed depletion.

  13. Improvements in estimated entropies and related thermodynamic data for aqueous metal ions.

    PubMed

    Johnson, David A; Nelson, Peter G

    2012-06-01

    New estimated standard entropies for some aqueous metal ions are obtained by taking account of magnetic and symmetry contributions. By combining them with an analysis of literature data, improved experimental and estimated values are derived for the standard enthalpies and Gibbs energies of formation of the aqueous ions of titanium, vanadium, chromium, manganese, cerium, and praseodymium. Separate entropy correlations are used for each primary coordination number, and the size dependence is represented by the reciprocal of the metal-oxygen distance in that coordination. The new scheme is consistent with recent work on the coordination of Hg(2+)(aq), Pb(2+)(aq), and tripositive rare earth ions. It differs from its predecessors in indicating a larger variation of the standard molar entropies of aqueous ions with coordination number. The value of S(?)(Be(2+), aq) is discussed in this context. PMID:22621251

  14. Identification of nonprotein ligands to the metal ions bound to glutamine synthetase

    SciTech Connect

    Eads, C.D.; LoBrutto, R.; Kumar, A.; Villafranca, J.J.

    1988-01-12

    Electron paramagnetic resonance (EPR) was used to study the environment of Mn/sup 2 +/ bound to the tight (n/sub 1/) metal ion binding site of glutamine synthetase in the presence of analogues of the tetrahedral adduct, L-methionine (S)-sulfoximine (Met(O)(NM)-S) and L-methionine (R)-sulfoximine (Met(O)(NH)-R). The Mn/sup 2 +/ EPR spectrum in the presence of Met(O)(NH)-S is identical with the previously published spectrum obtained from a mixture of isomers and is characteristic of a highly octahedral metal ion environment with a small zero field splitting. The presence of Met(O)(NH)-R produces and EPR spectrum that appears characteristic of a more distorted metal ion environment, with a larger zero field splitting. These data demonstrate that the two isomers interact differently with the enzyme-bound Mn/sup 2 +/. Broadening of the Mn/sup 2 +/ EPR spectrum in the presence of Met(O)NH) is observed in /sup 17/O-enriched water due to superhyperfine coupling of water to the metal ion. Superhyperfine coupling due to the /sup 14/N nucleus of the imine nitrogen of the sulfoximine moiety of Met(O)(NH)-S but not of Met-(O)(NH)-R has been detected by electron spin-echo envelope modulation spectroscopy. Two intense peaks are evident in the presence of Met(O)(NH)-S with frequencies at 1.7 and 3.3 MHz. These peaks are absent when (/sup 15/N)imine-labeled Met(O)(NH) is used, indicating the presence of the sulfoximine nitrogen of Met(O)(NH)-S in the inner coordination sphere of the metal ion. Taken together, these results suggest a model of the active site in which the metal ion is directly involved in the catalytic mechanism, serving to stabilize the tetrahedral adduct formed from ammonia and ..gamma..-glutamyl phosphate.

  15. Gluteal muscle fatty atrophy is not associated with elevated blood metal ions or pseudotumors in patients with a unilateral metal-on-metal hip replacement.

    PubMed

    Reito, Aleksi; Elo, Petra; Nieminen, Jyrki; Puolakka, Timo; Eskelinen, Antti

    2016-02-01

    Background and purpose - There are no international guidelines to define adverse reaction to metal debris (ARMD). Muscle fatty atrophy has been reported to be common in patients with failing metal-on-metal (MoM) hip replacements. We assessed whether gluteal muscle fatty atrophy is associated with elevated blood metal ion levels and pseudotumors. Patients and methods - 263 consecutive patients with unilateral ASR XL total hip replacement using a posterior approach and with an unoperated contralateral hip were included in the study. All patients had undergone a standard screening program at our institution, including MRI and blood metal ion measurement. Muscle fatty atrophy was graded as being absent, mild, moderate, or severe in each of the gluteal muscles. Results - The prevalance of moderate-to-severe gluteal muscle atrophy was low (12% for gluteus minimus, 10% for gluteus medius, and 2% for gluteus maximus). Muscle atrophy was neither associated with elevated blood metal ion levels (>?5 ppb) nor with the presence of a clear (solid- or mixed-type) pseudotumor seen in MRI. A combination of moderate-to-severe atrophy in MRI, elevated blood metal ion levels, and MRI-confirmed mixed or solid pseudotumor was rare. Multivariable regression revealed that "preoperative diagnosis other than osteoarthrosis" was the strongest predictor of the presence of fatty atrophy. Interpretation - Gluteal muscle atrophy may be a clinically significant finding with influence on hip muscle strength in patients with MoM hip replacement. However, our results suggest that gluteal muscle atrophy seen in MRI is not associated with either the presence or severity of ARMD, at least not in patients who have been operated on using the posterior approach. PMID:26427902

  16. Evaluation of the biological effect of Ti generated debris from metal implants: ions and nanoparticles.

    PubMed

    Soto-Alvaredo, J; Blanco, E; Bettmer, J; Hevia, D; Sainz, R M; López Cháves, C; Sánchez, C; Llopis, J; Sanz-Medel, A; Montes-Bayón, M

    2014-09-01

    Metallic implants placed in humans exhibit wear and corrosion that result in the liberation of metal-containing by-products. In the case of titanium (Ti) containing implants, the metal containing debris may exist in a number of states, including metallic particles produced by mechanical wear and the products of metal corrosion in biological environments, such as the joints and surrounding fluids and tissues. In addition, these constituents may dissolve in both intracellular and extracellular solutions generating Ti ions. Both species, ions and nanoparticles, show different cellular toxicities. In this work we have evaluated the possible evolution of TiO2 nanoparticles (NPs) into soluble Ti metal ions by contact with biological fluids. For this aim, an in vitro study to address quantitative Ti solubilisation from TiO2 nanoparticles (with a diameter of 21 nm) after incubation with human serum at different concentrations has been conducted. Total Ti determination revealed low solubilisation rates ranging from 0.53 to 0.82% after just one week of incubation in the serum. The incubated serum was then subjected to speciation analysis by anion exchange liquid chromatography using an inductively coupled plasma mass spectrometer (ICP-MS) as an elemental detector for Ti monitoring. The obtained results revealed a significant increase in the Ti signal associated with the fraction of the protein transferrin and preferentially with one of the metal binding sites of the protein, the N-lobe. Thus, the effect of Ti at the cellular level has been evaluated by considering that it can be present either as ions or as nanoparticles using two different cells lines: human enterocytes HT29 and murine osteoblasts MC3T3. Significant toxicity was found at the highest concentration assayed (50 ?g mL(-1)) for both Ti species (ions and NPs) and slightly higher for the ionic species at lower concentrations (1 and 10 ?g mL(-1)). PMID:25001216

  17. Metal ions to control the morphology of semiconductor nanoparticles: copper selenide nanocubes.

    PubMed

    Li, Wenhua; Zamani, Reza; Ibáñez, Maria; Cadavid, Doris; Shavel, Alexey; Morante, Joan Ramon; Arbiol, Jordi; Cabot, Andreu

    2013-03-27

    Morphology is a key parameter in the design of novel nanocrystals and nanomaterials with controlled functional properties. Here, we demonstrate the potential of foreign metal ions to tune the morphology of colloidal semiconductor nanoparticles. We illustrate the underlying mechanism by preparing copper selenide nanocubes in the presence of Al ions. We further characterize the plasmonic properties of the obtained nanocrystals and demonstrate their potential as a platform to produce cubic nanoparticles with different composition by cation exchange. PMID:23470030

  18. Efficient qubit detection using alkaline-earth-metal ions and a double stimulated Raman adiabatic process

    SciTech Connect

    Moeller, Ditte; Soerensen, Jens L.; Thomsen, Jakob B.; Drewsen, Michael

    2007-12-15

    We present a scheme for robust and efficient projection measurement of a qubit consisting of the two magnetic sublevels in the electronic ground state of alkaline-earth-metal ions. The scheme is based on two stimulated Raman adiabatic passages involving four partially coherent laser fields. We show how the efficiency depends on experimentally relevant parameters: Rabi frequencies, pulse widths, laser linewidths, one- and two-photon detunings, residual laser power, laser polarization, and ion motion.

  19. Homogeneous Liquid-Liquid Extraction of Metal Ions with a Functionalized Ionic Liquid.

    PubMed

    Hoogerstraete, Tom Vander; Onghena, Bieke; Binnemans, Koen

    2013-05-16

    Binary mixtures of the ionic liquid betainium bis(trifluoromethylsulfonyl)imide and water show an upper critical solution temperature. This solvent system has been used to extract metal ions by phase-transition extraction, using zwitterionic betaine as extractant. The system is efficient for the extraction of trivalent rare-earth, indium and gallium ions. This new type of metal extraction system avoids problems associated with the use of viscous ionic liquids, namely, the difficulty of intense mixing of the aqueous and ionic liquid phases by stirring. PMID:26282975

  20. Solvent extraction, membranes, and ion exchange in hydrometallurgical dilute metals separation

    SciTech Connect

    Tavlarides, L.L.; Bae, J.H.; Lee, C.K.

    1987-01-01

    The separation methods which are used in the hydro-metallurgical field are reviewed and compared. Some processes in solvent extraction in use for recovery of crucial metals which are important to the US defense and economy are presented. Various commercial extractants are reviewed and categorized. Other methods such as liquid membranes and ions exchange resins used for dilute metal ions separation are summarized. These methods are compared with solvent extraction. Problems to overcome in the future development of these separation methods are also identified and discussed in this paper.

  1. Structured copolymers and their use as absorbents, gels and carriers of metal ions

    DOEpatents

    Hedstrand, David M. (Midland, MI); Helmer, Bradley J. (Midland, MI); Tomalia, Donald A. (Midland, MI)

    1996-01-01

    Dense star polymers or dendrimers having a highly branched interior structure capable of associating or chelating with metal ions are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell. The modified dendrimers are useful for dispersing metal ions in a non-aqueous polymer matrix. Also dense star polymers or dendrimers having a highly branched hydrophilic interior structure are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell, which modified polymers are useful as gels and surfactants.

  2. Structured copolymers and their use as absorbents, gels and carriers of metal ions

    DOEpatents

    Hedstrand, D.M.; Helmer, B.J.; Tomalia, D.A.

    1996-10-01

    Dense star polymers or dendrimers having a highly branched interior structure capable of associating or chelating with metal ions are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell. The modified dendrimers are useful for dispersing metal ions in a non-aqueous polymer matrix. Also dense star polymers or dendrimers having a highly branched hydrophilic interior structure are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell, which modified polymers are useful as gels and surfactants.

  3. Hollow Nanostructured Metal Silicates with Tunable Properties for Lithium Ion Battery Anodes.

    PubMed

    Yu, Seung-Ho; Quan, Bo; Jin, Aihua; Lee, Kug-Seung; Kang, Soon Hyung; Kang, Kisuk; Piao, Yuanzhe; Sung, Yung-Eun

    2015-11-25

    Hollow nanostructured materials have attracted considerable interest as lithium ion battery electrodes because of their good electrochemical properties. In this study, we developed a general procedure for the synthesis of hollow nanostructured metal silicates via a hydrothermal process using silica nanoparticles as templates. The morphology and composition of hollow nanostructured metal silicates could be controlled by changing the metal precursor. The as-prepared hierarchical hollow nanostructures with diameters of ?100-200 nm were composed of variously shaped primary particles such as hollow nanospheres, solid nanoparticles, and thin nanosheets. Furthermore, different primary nanoparticles could be combined to form hybrid hierarchical hollow nanostructures. When hollow nanostructured metal silicates were applied as anode materials for lithium ion batteries, all samples exhibited good cyclic stability during 300 cycles, as well as tunable electrochemical properties. PMID:26536816

  4. Assembly of Nanoions via Electrostatic Interactions: Ion-Like Behavior of Charged Noble Metal Nanoclusters

    PubMed Central

    Yao, Qiaofeng; Luo, Zhentao; Yuan, Xun; Yu, Yue; Zhang, Chao; Xie, Jianping; Lee, Jim Yang

    2014-01-01

    The assembly of ultrasmall metal nanoclusters (NCs) is of interest to both basic and applied research as it facilitates the determination of cluster structures and the customization of cluster physicochemical properties. Here we present a facile and general approach to assemble noble metal NCs by selectively inducing electrostatic interactions between negatively-charged metal NCs and divalent cations. The charged metal NCs, which have well-defined sizes, charges and structures; and behave similarly to multivalent anions, can be considered as nanoions. These nanoions exhibit step-like assembly behavior when interacting with the counter cations – assembly only occurs when the solubility product (Ksp) between the carboxylate ions on the NC surface and the divalent cations is exceeded. The assembly here is distinctively different from the random aggregation of colloidal particles by counter ions. The nanoions would assemble into fractal-like monodisperse spherical particles with a high order of regularity that mimic the assembly of ionic crystals. PMID:24457992

  5. Metal Ion Speciation and Dissolved Organic Matter Composition in Soil Solutions

    NASA Astrophysics Data System (ADS)

    Benedetti, M. F.; Ren, Z. L.; Bravin, M.; Tella, M.; Dai, J.

    2014-12-01

    Knowledge of the speciation of heavy metals and the role of dissolved organic matter (DOM) in soil solution is a key to understand metal mobility and ecotoxicity. In this study, soil column-Donnan membrane technique (SC-DMT) was used to measure metal speciation of Cd, Cu, Ni, Pb, and Zn in eighteen soil solutions, covering a wide range of metal sources and concentrations. DOM composition in these soil solutions was also determined. Our results show that in soil solution Pb and Cu are dominant in complex form, whereas Cd, Ni and Zn mainly exist as free ions; for the whole range of soil solutions, only 26.2% of DOM is reactive and consists mainly of fulvic acid (FA). The metal speciation measured by SC-DMT was compared to the predicted ones obtained via the NICA-Donnan model using the measured FA concentrations. The free ion concentrations predicted by speciation modelling were in good agreement with the measurements. Diffusive gradients in thin-films gels (DGT) were also performed to quantify the labile metal species in the fluxes from solid phase to solution in fourteen soils. The concentrations of metal species detected by DGT were compared with the free ion concentrations measured by DMT and the maximum concentrations calculated based on the predicted metal speciation in SC-DMT soil solutions. It is concluded that both inorganic species and a fraction of FA bound species account for the amount of labile metals measured by DGT, consistent with the dynamic features of this technique. The comparisons between measurements using analytical techniques and mechanistic model predictions provided mutual validation in their performance. Moreover, we show that to make accurate modelling of metal speciation in soil solutions, the knowledge of DOM composition is the crucial information, especially for Cu; like in previous studies the modelling of Pb speciation is not optimal and an updated of Pb generic binding parameters is required to reduce model prediction uncertainties.

  6. Metal Ions May Suppress or Enhance Cellular Differentiation in Candida albicans and Candida tropicalis Biofilms? †

    PubMed Central

    Harrison, Joe J.; Ceri, Howard; Yerly, Jerome; Rabiei, Maryam; Hu, Yaoping; Martinuzzi, Robert; Turner, Raymond J.

    2007-01-01

    Candida albicans and Candida tropicalis are polymorphic fungi that develop antimicrobial-resistant biofilm communities that are characterized by multiple cell morphotypes. This study investigated cell type interconversion and drug and metal resistance as well as community organization in biofilms of these microorganisms that were exposed to metal ions. To study this, Candida biofilms were grown either in microtiter plates containing gradient arrays of metal ions or in the Calgary Biofilm Device for high-throughput susceptibility testing. Biofilm formation and antifungal resistance were evaluated by viable cell counts, tetrazolium salt reduction, light microscopy, and confocal laser scanning microscopy in conjunction with three-dimensional visualization. We discovered that subinhibitory concentrations of certain metal ions (CrO42?, Co2+, Cu2+, Ag+, Zn2+, Cd2+, Hg2+, Pb2+, AsO2?, and SeO32?) caused changes in biofilm structure by blocking or eliciting the transition between yeast and hyphal cell types. Four distinct biofilm community structure types were discerned from these data, which were designated “domed,” “layer cake,” “flat,” and “mycelial.” This study suggests that Candida biofilm populations may respond to metal ions to form cell-cell and solid-surface-attached assemblages with distinct patterns of cellular differentiation. PMID:17557844

  7. Mechanism of Metal Ion Activation of the Diphtheria Toxin Repressor DtxR

    SciTech Connect

    D'Aquino,J.; Tetenbaum-Novatt, J.; White, A.; Berkovitch, F.; Ringe, D.

    2005-01-01

    The diphtheria toxin repressor (DtxR) is a metal ion-activated transcriptional regulator that has been linked to the virulence of Corynebacterium diphtheriae. Structure determination has shown that there are two metal ion binding sites per repressor monomer, and site-directed mutagenesis has demonstrated that binding site 2 (primary) is essential for recognition of the target DNA repressor, leaving the role of binding site 1 (ancillary) unclear. Calorimetric techniques have demonstrated that although binding site 1 (ancillary) has high affinity for metal ion with a binding constant of 2 x 10{sup -7}, binding site 2 (primary) is a low-affinity binding site with a binding constant of 6.3 x 10{sup -4}. These two binding sites act in an independent fashion, and their contribution can be easily dissected by traditional mutational analysis. Our results clearly demonstrate that binding site 1 (ancillary) is the first one to be occupied during metal ion activation, playing a critical role in stabilization of the repressor. In addition, structural data obtained for the mutants Ni-DtxR(H79A, C102D), reported here, and the previously reported DtxR(H79A) have allowed us to propose a mechanism of metal activation for DtxR.

  8. Potentiometric and spectroscopic study of the interaction of 3d transition metal ions with inositol hexakisphosphate

    NASA Astrophysics Data System (ADS)

    Veiga, Nicolás; Macho, Israel; Gómez, Kerman; González, Gabriel; Kremer, Carlos; Torres, Julia

    2015-10-01

    Among myo-inositol phosphates, the most abundant in nature is the myo-inositol hexakisphosphate, InsP6. Although it is known to be vital to cell functioning, the biochemical research into its metabolism needs chemical and structural analysis of all the protonation, complexation and precipitation processes that it undergoes in the biological media. In view of its high negative charge at physiological level, our group has been leading a thorough research into the InsP6 chemical and structural behavior in the presence of the alkali and alkaline earth metal ions essential for life. The aim of this article is to extend these studies, dealing with the chemical and structural features of the InsP6 interaction with biologically relevant 3d transition metal ions (Fe(II), Fe(III), Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)), in a non-interacting medium and under simulated physiological conditions. The metal-complex stability constants were determined by potentiometry, showing under ligand-excess conditions the formation of mononuclear species in different protonation states. Under metal ion excess, polymetallic species were detected for Fe(II), Fe(III), Zn(II) and Cu(II). Additionally, the 31P NMR and UV-vis spectroscopic studies provided interesting structural aspects of the strong metal ion-InsP6 interaction.

  9. Shot-to-shot reproducibility in the emission of fast highly charged metal ions from a laser ion source

    SciTech Connect

    Krasa, J.; Velyhan, A.; Margarone, D.; Krousky, E.; Laska, L.; Jungwirth, K.; Rohlena, K.; Ullschmied, J.; Parys, P.; Ryc, L.; Wolowski, J.

    2012-02-15

    The generation of fast highly charged metal ions with the use of the sub-nanosecond Prague Asterix Laser System, operated at a fundamental wavelength of 1315 nm, is reported. Particular attention is paid to shot-to-shot reproducibility in the ion emission. Au and Pd targets were exposed to intensities up to 5 x 10{sup 16} W/cm{sup 2}. Above the laser intensity threshold of {approx}3 x 10{sup 14} W/cm{sup 2} the plasma is generated in a form of irregular bursts. The maximum energy of protons constituting the leading edge of the fastest burst reaches a value up to 1 MeV. The fast ions in the following bursts have energy gradually decreasing with the increasing burst number, namely, from a value of about 0.5 MeV/charge regardless of the atomic number and mass of the ionized species.

  10. Promoting the Adsorption of Metal Ions on Kaolinite by Defect Sites: A Molecular Dynamics Study

    PubMed Central

    Li, Xiong; Li, Hang; Yang, Gang

    2015-01-01

    Defect sites exist abundantly in minerals and play a crucial role for a variety of important processes. Here molecular dynamics simulations are used to comprehensively investigate the adsorption behaviors, stabilities and mechanisms of metal ions on defective minerals, considering different ionic concentrations, defect sizes and contents. Outer-sphere adsorbed Pb2+ ions predominate for all models (regular and defective), while inner-sphere Na+ ions, which exist sporadically only at concentrated solutions for regular models, govern the adsorption for all defective models. Adsorption quantities and stabilities of metal ions on kaolinite are fundamentally promoted by defect sites, thus explaining the experimental observations. Defect sites improve the stabilities of both inner- and outer-sphere adsorption, and (quasi) inner-sphere Pb2+ ions emerge only at defect sites that reinforce the interactions. Adsorption configurations are greatly altered by defect sites but respond weakly by changing defect sizes or contents. Both adsorption quantities and stabilities are enhanced by increasing defect sizes or contents, while ionic concentrations mainly affect adsorption quantities. We also find that adsorption of metal ions and anions can be promoted by each other and proceeds in a collaborative mechanism. Results thus obtained are beneficial to comprehend related processes for all types of minerals. PMID:26403873

  11. Increasing Mechanical Strength of Gelatin Hydrogels by Divalent Metal Ion Removal

    NASA Astrophysics Data System (ADS)

    Xing, Qi; Yates, Keegan; Vogt, Caleb; Qian, Zichen; Frost, Megan C.; Zhao, Feng

    2014-04-01

    The usage of gelatin hydrogel is limited due to its instability and poor mechanical properties, especially under physiological conditions. Divalent metal ions present in gelatin such as Ca2+ and Fe2+ play important roles in the gelatin molecule interactions. The objective of this study was to determine the impact of divalent ion removal on the stability and mechanical properties of gelatin gels with and without chemical crosslinking. The gelatin solution was purified by Chelex resin to replace divalent metal ions with sodium ions. The gel was then chemically crosslinked by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). Results showed that the removal of divalent metal ions significantly impacted the formation of the gelatin network. The purified gelatin hydrogels had less interactions between gelatin molecules and form larger-pore network which enabled EDC to penetrate and crosslink the gel more efficiently. The crosslinked purified gels showed small swelling ratio, higher crosslinking density and dramatically increased storage and loss moduli. The removal of divalent ions is a simple yet effective method that can significantly improve the stability and strength of gelatin hydrogels. The in vitro cell culture demonstrated that the purified gelatin maintained its ability to support cell attachment and spreading.

  12. Increasing Mechanical Strength of Gelatin Hydrogels by Divalent Metal Ion Removal

    PubMed Central

    Xing, Qi; Yates, Keegan; Vogt, Caleb; Qian, Zichen; Frost, Megan C.; Zhao, Feng

    2014-01-01

    The usage of gelatin hydrogel is limited due to its instability and poor mechanical properties, especially under physiological conditions. Divalent metal ions present in gelatin such as Ca2+ and Fe2+ play important roles in the gelatin molecule interactions. The objective of this study was to determine the impact of divalent ion removal on the stability and mechanical properties of gelatin gels with and without chemical crosslinking. The gelatin solution was purified by Chelex resin to replace divalent metal ions with sodium ions. The gel was then chemically crosslinked by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). Results showed that the removal of divalent metal ions significantly impacted the formation of the gelatin network. The purified gelatin hydrogels had less interactions between gelatin molecules and form larger-pore network which enabled EDC to penetrate and crosslink the gel more efficiently. The crosslinked purified gels showed small swelling ratio, higher crosslinking density and dramatically increased storage and loss moduli. The removal of divalent ions is a simple yet effective method that can significantly improve the stability and strength of gelatin hydrogels. The in vitro cell culture demonstrated that the purified gelatin maintained its ability to support cell attachment and spreading. PMID:24736500

  13. The Application of LC-ICP-MS to Study Metal Ion Homeostasis in Biological Systems 

    E-print Network

    McCormick, Sean P.

    2014-12-10

    THE APPLICATION OF LC-ICP-MS TO STUDY METAL ION HOMEOSTASIS IN BIOLOGICAL SYSTEMS A Dissertation by SEAN PATRICK MCCORMICK Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements... homeostasis can cause different diseases in humans. All essential metals in the cell can be implicated in one or more disease states. Iron-related diseases fall under two categories, namely iron deficiency and iron overload. Anemia is the most prevalent...

  14. Biosensor and chemical sensor probes for calcium and other metal ions

    DOEpatents

    Vo-Dinh, Tuan (Knoxville, TN); Viallet, Pierre (Perpignan, FR)

    1996-01-01

    The present invention relates to chemical sensor and biosensor probes for measuring low concentration of metals and metal ions in complex samples such as biological fluids, living cells, and environmental samples. More particularly the present invention relates to a gel-based Indo-1 and Fura-2 chemical sensor probes for the measurement of low concentrations of calcium, cadmium, magnesium and the like. Also disclosed is a detector device using the sensors of the present invention.

  15. Using Metal Complex Ion-Molecule Reactions in a Miniature Rectilinear Ion Trap Mass Spectrometer to Detect Chemical Warfare Agents

    NASA Astrophysics Data System (ADS)

    Graichen, Adam M.; Vachet, Richard W.

    2013-06-01

    The gas-phase reactions of a series of coordinatively unsaturated [Ni(L)n]y+ complexes, where L is a nitrogen-containing ligand, with chemical warfare agent (CWA) simulants in a miniature rectilinear ion trap mass spectrometer were investigated as part of a new approach to detect CWAs. Results show that upon entering the vacuum system via a poly(dimethylsiloxane) (PDMS) membrane introduction, low concentrations of several CWA simulants, including dipropyl sulfide (simulant for mustard gas), acetonitrile (simulant for the nerve agent tabun), and diethyl phosphite (simulant for nerve agents sarin, soman, tabun, and VX), can react with metal complex ions generated by electrospray ionization (ESI), thereby providing a sensitive means of detecting these compounds. The [Ni(L)n]2+ complexes are found to be particularly reactive with the simulants of mustard gas and tabun, allowing their detection at low parts-per-billion (ppb) levels. These detection limits are well below reported exposure limits for these CWAs, which indicates the applicability of this new approach, and are about two orders of magnitude lower than electron ionization detection limits on the same mass spectrometer. The use of coordinatively unsaturated metal complexes as reagent ions offers the possibility of further tuning the ion-molecule chemistry so that desired compounds can be detected selectively or at even lower concentrations.

  16. Metal ion release from bearing wear and corrosion with 28 mm and large-diameter metal-on-metal bearing articulations: a follow-up study.

    PubMed

    Vendittoli, P-A; Roy, A; Mottard, S; Girard, J; Lusignan, D; Lavigne, M

    2010-01-01

    We have updated our previous randomised controlled trial comparing release of chromium (Cr) and cobalt (Co) ions and included levels of titanium (Ti) ions. We have compared the findings from 28 mm metal-on-metal total hip replacement, performed using titanium CLS/Spotorno femoral components and titanium AlloFit acetabular components with Metasul bearings, with Durom hip resurfacing using a Metasul articulation or bearing and a titanium plasma-sprayed coating for fixation of the acetabular component. Although significantly higher blood ion levels of Cr and Co were observed at three months in the resurfaced group than in total hip replacement, no significant difference was found at two years post-operatively for Cr, 1.58 microg/L and 1.62 microg/L respectively (p = 0.819) and for Co, 0.67 microg/L and 0.94 microg/L respectively (p = 0.207). A steady state was reached at one year in the resurfaced group and after three months in the total hip replacement group. Interestingly, Ti, which is not part of the bearing surfaces with its release resulting from metal corrosion, had significantly elevated ion levels after implantation in both groups. The hip resurfacing group had significantly higher Ti levels than the total hip replacement group for all periods of follow-up. At two years the mean blood levels of Ti ions were 1.87 microg/L in hip resurfacing and and 1.30 microg/L in total hip replacement (p = 0.001). The study confirms even with different bearing diameters and clearances, hip replacement and 28 mm metal-on-metal total hip replacement produced similar Cr and Co metal ion levels in this randomised controlled trial study design, but apart from wear on bearing surfaces, passive corrosion of exposed metallic surfaces is a factor which influences ion concentrations. Ti plasma spray coating the acetabular components for hip resurfacing produces significantly higher release of Ti than Ti grit-blasted surfaces in total hip replacement. PMID:20044673

  17. Highly sensitive sensors for alkali metal ions based on complementary-metal-oxide-semiconductor-compatible silicon nanowires

    NASA Astrophysics Data System (ADS)

    Zhang, Guo-Jun; Agarwal, Ajay; Buddharaju, Kavitha D.; Singh, Navab; Gao, Zhiqiang

    2007-06-01

    Highly sensitive sensors for alkali metal ions based on complementary-metal-oxide- semiconductor-compatible silicon nanowires (SiNWs) with crown ethers covalently immobilized on their surface are presented. A densely packed organic monolayer terminated with amine groups is introduced to the SiNW surface via hydrosilylation. Amine-modified crown ethers, acting as sensing elements, are then immobilized onto the SiNWs through a cross-linking reaction with the monolayer. The crown ether-functionalized SiNWs recognize Na+ and K+ according to their complexation ability to the crown ethers. The SiNW sensors are highly selective and capable of achieving an ultralow detection limit down to 50nM, over three orders of magnitude lower than that of conventional crown ether-based ion-selective electrodes.

  18. Reactions of flavosemiquinone radicals in the presence of metal ions

    NASA Astrophysics Data System (ADS)

    Porkhun, V. I.; Sivko, A. N.; Porkhun, E. V.; Rakhimov, A. I.

    2014-06-01

    The rate constants of disproportionation of flavosemiquinone radicals were obtained by pulsed spectroscopy. The yield of the flavosemiquinone radical increased when Mohr's salt was introduced in the aqueous solutions of riboflavin. The spectral kinetic characteristics of complexes of flavosemiquinone radical anions with Zn2+ and Cd2+ ions were determined.

  19. Dense Metal Plasma in a Solenoid for Ion Beam Neutralization

    SciTech Connect

    Anders, Andre; Kauffeldt, Marina; Oks, Efim M.; Roy, Prabir K.

    2010-10-30

    Space-charge neutralization is required to compress and focus a pulsed, high-current ion beam on a target for warm dense matter physics or heavy ion fusion experiments. We described approaches to produce dense plasma in and near the final focusing solenoid through which the ion beam travels, thereby providing an opportunity for the beam to acquire the necessary space-charge compensating electrons. Among the options are plasma injection from pulsed vacuum arc sources located outside the solenoid, and using a high current (> 4 kA) pulsed vacuum arc plasma from a ring cathode near the edge of the solenoid. The plasma distribution is characterized by photographic means, by an array of movable Langmuir probes, by a small single probe, and by evaluating Stark broadening of the Balmer H beta spectral line. In the main approach described here, the plasma is produced at several cathode spots distributed azimuthally on the ring cathode. It is shown that the plasma is essentially hollow, as determined by the structure of the magnetic field, though the plasma density exceeds 1014 cm-3 in practically all zones of the solenoid volume if the ring electrode is placed a few centimeters off the center of the solenoid. The plasma is non-uniform and fluctuating, however, since its density exceeds the ion beam density it is believed that this approach could provide a practical solution to the space charge neutralization challenge.

  20. Construction and evaluation of a metal ion biosensor

    NASA Astrophysics Data System (ADS)

    Tescione, Lia; Belfort, Georges

    1993-01-01

    E. coli, genetically engineered with a mercury(II)-sensitive promoter and the lux genes from Vibrio fischeri, were used as microbial sensors for the detection of mercury. Evaluation of this genetic construction was carried out by determining the effects of various parameters on cell suspensions maintained at constant conditions in a small vessel. The strongest light intensities and quickest induction times occurred with cells in the mid-exponential growth phase maintained at 280 C, concentrated to 1 x 10(exp 9) cells/mL, mixed at very fast speeds, and aerated at 2 vvm (volume of air per volume of culture per minute) during light measurement in the small vessel. The sensitivity of these cells to the mercuric ion lied in the range of 0.02-4 micrometer (4-800 ppb) and the total response time was on the order of one hour, depending on the above parameters. The cells exhibited great specificity for mercury. The cells have almost equal specificity for organic and inorganic form of the mercuric ion and responded more weakly to the mercurous ion. A simple, inexpensive, durable miniature probe was constructed and operated using the optimum parameters found in the small vessel as a guide. The range of sensitivity to the mercuric ion detected in the probe was 0.01-4 micrometer when aeration was provided.

  1. Metal ion dependence of cooperative collapse transitions in RNA.

    PubMed

    Moghaddam, Sarvin; Caliskan, Gokhan; Chauhan, Seema; Hyeon, Changbong; Briber, R M; Thirumalai, D; Woodson, Sarah A

    2009-10-30

    Positively charged counterions drive RNA molecules into compact configurations that lead to their biologically active structures. To understand how the valence and size of the cations influences the collapse transition in RNA, small-angle X-ray scattering was used to follow the decrease in the radius of gyration (R(g)) of the Azoarcus and Tetrahymena ribozymes in different cations. Small, multivalent cations induced the collapse of both ribozymes more efficiently than did monovalent ions. Thus, the cooperativity of the collapse transition depends on the counterion charge density. Singular value decomposition of the scattering curves showed that folding of the smaller and more thermostable Azoarcus ribozyme is well described by two components, whereas collapse of the larger Tetrahymena ribozyme involves at least one intermediate. The ion-dependent persistence length, extracted from the distance distribution of the scattering vectors, shows that the Azoarcus ribozyme is less flexible at the midpoint of transition in low-charge-density ions than in high-charge-density ions. We conclude that the formation of sequence-specific tertiary interactions in the Azoarcus ribozyme overlaps with neutralization of the phosphate charge, while tertiary folding of the Tetrahymena ribozyme requires additional counterions. Thus, the stability of the RNA structure determines its sensitivity to the valence and size of the counterions. PMID:19712681

  2. Metal Ion Dependence of Cooperative Collapse Transitions in RNA

    SciTech Connect

    Moghaddam, Sarvin; Caliskan, Gokhan; Chauhan, Seema; Hyeon, Changbong; Briber, R.M.; Thirumalai, D.; Woodson, Sarah A.

    2010-10-12

    Positively charged counterions drive RNA molecules into compact configurations that lead to their biologically active structures. To understand how the valence and size of the cations influences the collapse transition in RNA, small-angle X-ray scattering was used to follow the decrease in the radius of gyration (R{sub g}) of the Azoarcus and Tetrahymena ribozymes in different cations. Small, multivalent cations induced the collapse of both ribozymes more efficiently than did monovalent ions. Thus, the cooperativity of the collapse transition depends on the counterion charge density. Singular value decomposition of the scattering curves showed that folding of the smaller and more thermostable Azoarcus ribozyme is well described by two components, whereas collapse of the larger Tetrahymena ribozyme involves at least one intermediate. The ion-dependent persistence length, extracted from the distance distribution of the scattering vectors, shows that the Azoarcus ribozyme is less flexible at the midpoint of transition in low-charge-density ions than in high-charge-density ions. We conclude that the formation of sequence-specific tertiary interactions in the Azoarcus ribozyme overlaps with neutralization of the phosphate charge, while tertiary folding of the Tetrahymena ribozyme requires additional counterions. Thus, the stability of the RNA structure determines its sensitivity to the valence and size of the counterions.

  3. Construction and evaluation of a metal ion biosensor

    SciTech Connect

    Tescione, L.; Belfort, G. . Dept. of Chemical Engineering)

    1993-10-01

    Escherichia coli, genetically engineered with a mercury (II)-sensitive promoter and the lux genes from Vibrio fischeri, were used as microbial bioluminescent sensors for the detection of mercury. Evaluation of this genetic construction was carried out by determining the effects of various parameters on cell suspensions maintained at constant conditions in a small 100-mL vessel. The strongest light intensities and quickest induction times occurred with cells in the midexponential growth phase maintained at 28C, concentrated to 1 [times] 10[sup 9] cells/mL, mixed at very fast speeds, and aerated at 2 vvm during light measurement in the small vessel. The cells were sensitive to the mercuric ion in the range of 20 nM to 4 [mu]M, and the total response time was on the order of 1 hour, depending on the above parameters. The cells exhibited great specificity for mercury. The cells had almost equal specificity for organic and inorganic forms of the mercuric ion and responded more weakly to the mercurous ion. A simple, inexpensive, durable miniature probe was constructed and operated using the optimum parameters found in the small vessel as a guide. The range of sensitivity to the mercuric ion detected in the probe was 10 nM to 4 [mu]M when aeration was provided.

  4. Effect of heavy metals ions on enzyme activity in the Mediterranean mussel, Donax trunculus

    SciTech Connect

    Mizrahi, L.; Achituv, Y. )

    1989-06-01

    Heavy metal ions strongly are bound by sulfhydryl groups of proteins. Sulfhydryl binding changes the structure and enzymatic activities of proteins and causes toxic effects evident at the whole organism level. Heavy metal ions like Cd, Cu, Hg, Zn, and Pb in sufficiently high concentrations might kill organisms or cause other adverse effects that changing aquatic community structures. Bivalves are known to be heavy metal accumulators. The aim of the present study was to examine the effects of different concentrations of each of five heavy metal ions on the activity of four enzymes in D. trunculus. As it is known that heavy metals inhibit the activity of a wide range of enzymes, the authors chose representative examples of dehydrogenases (lactate and malate dehydrogenases), respiratory enzyme (cytochrome oxidase) and digestive enzyme ({alpha}-amylase). The acute effects of different concentrations of selected metals were examined. These concentrations were higher than those found usually in the locality where the animals occur, but might be encountered during a given event of pollution.

  5. Recovery of dilute metal ions by biosorption on river algae and its component

    SciTech Connect

    Fujita, Toyohisa; Kogita, Hiroki; Mamiya, Mitsuo; Yen, W.T.

    1995-12-31

    Green algae taken from an acidic mine drainage and blue-green algae take from an alkaline hot spring stream were collected and tested for their ability to recover or remove dilute metal ions. Experimental results demonstrated that unwashed blue-green algae and washed green algae effectively adsorbed base metals ions and eluted the at pH 1. It was also found that washed and dried algae adsorbed precious metal ions more effectively than unwashed algae. For example, the washed and dried blue-green algae was capable of adsorbing 0.31 kg of gold pre kg of algae. The gold from tetrachloroaurate solution which was adsorbed on washed blue-green algae was found to change to a metallic state following initial metal binding. In the case of a dilute gold complex solution leached with thiourea, only a small amount of gold could be captured by algae. Further experiments were conducted on components of the algae, such as alginic acid, agar, cellulose and chitin and mixtures of these components, in order to determine their contribution to metal adsorption characteristics. However, a mixture of these two components demonstrated both good adsorption and desorption characteristics indicating an interaction between the individual components.

  6. Paul trapping of radioactive 6He+ions and direct observation of their beta-decay

    E-print Network

    X. Flechard; E. Lienard; A. Mery; D. Rodriguez; G. Ban; D. Durand; F. Duval; M. Herbane; M. Labalme; F. Mauger; O. Naviliat-Cuncic; J. C. Thomas; Ph. Velten

    2008-10-10

    We demonstrate that abundant quantities of short-lived beta unstable ions can be trapped in a novel transparent Paul trap and that their decay products can directly be detected in coincidence. Low energy 6He+ (807 ms half-life) ions were extracted from the SPIRAL source at GANIL, then decelerated, cooled and bunched by means of the buffer gas cooling technique. More than 10^8 ions have been stored over a measuring period of six days and about 10^5 decay coincidences between the beta particles and the 6Li^{++} recoiling ions have been recorded. The technique can be extended to other short-lived species, opening new possibilities for trap assisted decay experiments.

  7. Co-luminescence of ions and molecules in nanoparticles of metal complexes

    NASA Astrophysics Data System (ADS)

    Ermolaev, Valerii L.; Sveshnikova, E. B.

    2012-09-01

    The features of co-luminescence (sensitized luminescence) of lanthanide ions and dye molecules inserted in nanoparticles of complexes formed by trivalent metals with ?-diketones are discussed. The mechanisms of energy transfer in these nanoparticles that lead to sensitization of Ln3+ ion luminescence and dye molecule fluorescence are considered. It is shown that the process of nanoparticle formation and their morphology in aqueous solutions can be studied by analyzing the mechanism of their co-luminescence and co-fluorescence. Examples of chemical, biological and medicinal applications of nanoparticles containing lanthanide ions and dye molecules with enhanced luminescence brightness are given. The bibliography includes 131 references.

  8. Micrometer-Scale Machining of Metals and Polymers Enabled by Focused Ion Beam Sputtering

    SciTech Connect

    Adams, D.P.; Benavides, G.L.; Vasile, M.J.

    1998-12-22

    This work combines focused ion beam sputtering and ultra-precision machining for microfabrication of metal alloys and polymers. Specifically, micro-end mills are made by Ga ion beam sputtering of a cylindrical tool shank. Using an ion energy of 20keV, the focused beam defines the tool cutting edges that have submicrometer radii of curvature. We demonstrate 25 {micro}m diameter micromilling tools having 2, 4 and 5 cutting edges. These tools fabricate fine channels, 26-28 microns wide, in 6061 aluminum, brass, and polymethyl methacrylate. Micro-tools are structurally robust and operate for more than 5 hours without fracture.

  9. Self-sputtering far above the runaway threshold: an extraordinary metal ion generator

    SciTech Connect

    Andersson, Joakim; Anders, Andre

    2008-12-16

    When self-sputtering is driven far above the runaway threshold voltage, energetic electrons are made available to produce"excess plasma" far from the magnetron target. Ionization balance considerations show that the secondary electrons deliver the necessary energy to the"remote" zone. Thereby, such a system can be an extraordinarily prolific generator of useable metal ions. Contrary to other known sources, the ion current to a substrate can exceed the discharge current. For gasless self-sputtering of copper, the useable ion current scales exponentially with the discharge voltage.

  10. Ion beam effects of 26.0 MeV Cu7+ ions in thin metallic and insulating films during Heavy Ion ERDA measurements

    NASA Astrophysics Data System (ADS)

    Mavhungu, H.; Msimanga, M.; Hlatshwayo, T.

    2015-04-01

    We report on an investigation carried out to determine effects of the probing beam on the structure of typical metallic and insulating thin films during Elastic Recoil Detection Analysis (ERDA) using a heavy ion beam. Metallic niobium nitride (NbN) and insulating calcium fluoride (CaF2) thin films (used as test samples) were irradiated by 26.0 MeV 63Cu7+ ions to fluences of 1.70 × 1014 ions/cm2 and 2.70 × 1014 ions/cm2, respectively. The effects of irradiation on the structural properties of the films were studied using Rutherford Backscattering Spectrometry (RBS), X-ray diffraction (XRD) and Atomic Force Microscopy (AFM). RBS results showed a significant (18%) reduction in the thickness of the CaF2 film due to electronic sputtering compared to only 1% reduction in the NbN film. XRD results showed no significant peak shifts in both films, but rather formation of unidentified peaks in the insulating film. AFM results indicated a substantial decrease in the average surface roughness of the insulating film and only a nominal increase in that of the metallic film. Results of electronic sputtering yield measurements carried out by ERDA are explained in terms of both the Coulomb explosion and the inelastic thermal spike models.

  11. Negative ions of transition metal-halogen clusters

    NASA Astrophysics Data System (ADS)

    Pradhan, Kalpataru; Gutsev, Gennady L.; Jena, Purusottam

    2010-10-01

    A systematic density functional theory based study of the structure and spectroscopic properties of neutral and negatively charged MXn clusters formed by a transition metal atom M (M =Sc,Ti,V) and up to seven halogen atoms X (X =F,Cl,Br) has revealed a number of interesting features: (1) Halogen atoms are bound chemically to Sc, Ti, and V for n ?nmax, where the maximal valence nmax equals to 3, 4, and 5 for Sc, Ti, and V, respectively. For n >nmax, two halogen atoms became dimerized in the neutral species, while dimerization begins at n =5, 6, and 7 for negatively charged clusters containing Sc, Ti, and V. (2) Magnetic moments of the transition metal atoms depend strongly on the number of halogen atoms in a cluster and the cluster charge. (3) The number of halogen atoms that can be attached to a metal atom exceeds the maximal formal valence of the metal atom. (4) The electron affinities of the neutral clusters abruptly rise at n =nmax, reaching values as high as 7 eV. The corresponding anions could be used in the synthesis of new salts, once appropriate counterions are identified.

  12. Using Hydrogen Balloons to Display Metal Ion Spectra

    ERIC Educational Resources Information Center

    Maynard, James H.

    2008-01-01

    We have optimized a procedure for igniting hydrogen-filled balloons containing metal salts to obtain the brightest possible flash while minimizing the quantity of airborne combustion products. We report air quality measurements in a lecture hall immediately after the demonstration. While we recommend that this demonstration be done outdoors or in…

  13. Improved Scales for Metal Ion Softness and Toxicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ten scales relating to chemical hardness or softness were compiled. These included eight published scales such as those of Pearson, Ahrland, Klopman, and Misono. Another scale consisted of the -logs of the solubility products of metal sulfides, and yet another was a consensus scale constructed fro...

  14. Density Functional Theory Study on the Interactions of Metal Ions with Long Chain Deprotonated Carboxylic Acids.

    PubMed

    Mehandzhiyski, Aleksandar Y; Riccardi, Enrico; van Erp, Titus S; Koch, Henrik; Åstrand, Per-Olof; Trinh, Thuat T; Grimes, Brian A

    2015-10-01

    In this work, interactions between carboxylate ions and calcium or sodium ions are investigated via density functional theory (DFT). Despite the ubiquitous presence of these interactions in natural and industrial chemical processes, few DFT studies on these systems exist in the literature. Special focus has been placed on determining the influence of the multibody interactions (with up to 4 carboxylates and one metal ion) on an effective pair-interaction potential, such as those used in molecular mechanics (MM). Specifically, DFT calculations are employed to quantify an effective pair-potential that implicitly includes multibody interactions to construct potential energy curves for carboxylate-metal ion pairs. The DFT calculated potential curves are compared to a widely used molecular mechanics force field (OPLS-AA). The calculations indicate that multibody effects do influence the energetic behavior of these ionic pairs and the extent of this influence is determined by a balance between (a) charge transfer from the carboxylate to the metal ions which stabilizes the complex and (b) repulsion between carboxylates, which destabilizes the complex. Additionally, the potential curves of the complexes with 1 and 2 carboxylates and one counterion have been examined to higher separation distance (20 Å) by the use of relaxed scan optimization and constrained density functional theory (CDFT). The results from the relaxed scan optimization indicate that near the equilibrium distance, the charge transfer between the metal ion and the deprotonated carboxylic acid group is significant and leads to non-negligible differences between the DFT and MM potential curves, especially for calcium. However, at longer separation distances the MM calculated interaction potential functions converge to those calculated with CDFT, effectively indicating the approximate domain of the separation distance coordinate where charge transfer between the ions is occurring. PMID:26331433

  15. 1388 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 35, NO. 5, OCTOBER 2007 Ion-Shading Effects During Metal Etch

    E-print Network

    Chen, Francis F.

    Metal Etch in Plasma Processing Tsitsi G. Madziwa-Nussinov, Member, IEEE, Donald Arnush, and Francis F shading, ion tra- jectories, metal etch, plasma processing. I. INTRODUCTION PLASMA etching [1] are of critical importance for plasma etching, since positive ions are accelerated toward the surface when

  16. Treatment of Radioactive Metallic Waste from Operation of Nuclear Power Plants by Melting - The German Way for a Consistent Recycling to Minimize the Quantity of Radioactive Waste from Operation and Dismantling for Disposal - 12016

    SciTech Connect

    Wegener, Dirk; Kluth, Thomas

    2012-07-01

    During maintenance of nuclear power plants, and during their decommissioning period, a large quantity of radioactive metallic waste will accrue. On the other hand the capacity for final disposal of radioactive waste in Germany is limited as well as that in the US. That is why all procedures related to this topic should be handled with a maximum of efficiency. The German model of consistent recycling of the radioactive metal scrap within the nuclear industry therefore also offers high capabilities for facilities in the US. The paper gives a compact overview of the impressive results of melting treatment, the current potential and further developments. Thousands of cubic metres of final disposal capacity have been saved. The highest level of efficiency and safety by combining general surface decontamination by blasting and nuclide specific decontamination by melting associated with the typical effects of homogenization. An established process - nationally and internationally recognized. Excellent connection between economy and ecology. (authors)

  17. Hybrid metallic ion-exchanged waveguides for SPR biological sensing

    NASA Astrophysics Data System (ADS)

    de Bonnault, S.; Bucci, D.; Zermatten, P.. J.; Charette, P. G.; Broquin, J. E.

    2015-02-01

    Glass substrates have been used for decades to create biosensors due to their biocompatibility, low thermal conductivity, and limited fluorescence. Among the different types of sensors, those based on surface plasmon resonance (SPR) allow exploitation of the sensing lightwave at the vicinity of the sensor surface where small entities such as DNA or proteins are located. In this paper, ion-exchanged waveguides and SPR are combined to create a multianalyte optical sensor integrated onto glass. First the principle of operation is introduced, then the theoretical analysis and design of the sensing element. Simulations have been carried out using the Aperiodic Fourier Modal Method (AFMM) and a custom software that handles ion-exchange index-profiles. Fabrication and characterization processes are also presented. Finally the first experimental spectra are displayed and discussed. The sensor presents a bulk sensibility of 5000nm/RIU.

  18. Direct optical excitation of a fullerene-incarcerated metal ion

    E-print Network

    Mark A G Jones; Kyriakos Porfyrakis; G Andrew D Briggs; Robert A Taylor; Arzhang Ardavan

    2006-04-20

    The endohedral fullerene Er3N@C80 shows characteristic 1.5 micron photoluminescence at cryogenic temperatures associated with radiative relaxation from the crystal-field split Er3+ 4I13/2 manifold to the 4I15/2 manifold. Previous observations of this luminescence were carried out by photoexcitation of the fullerene cage states leading to relaxation via the ionic states. We present direct non-cage-mediated optical interaction with the erbium ion. We have used this interaction to complete a photoluminescence-excitation map of the Er3+ 4I13/2 manifold. This ability to interact directly with the states of an incarcerated ion suggests the possibility of coherently manipulating fullerene qubit states with light.

  19. The possible role of metal ions and clays in prebiotic chemistry

    NASA Technical Reports Server (NTRS)

    Lawless, J. G.; Edelson, E. H.

    1980-01-01

    Eight homoionic bentonites were prepared using alkali, alkaline earth, and transition metal ions as counterions. The interaction of the clays with 5'-AMP was studied and it was found that the alkali metal-substituted clays did not remove any nucleotide from dilute solution, and that zinc-bentonite adsorbed the most (98%). In addition, study of the interaction of seven other nucleotides with zinc-bentonite showed that the purine nucleotides were more strongly absorbed than the pyrimidine nucleotides. Langmuir isotherms were obtained for these systems and the adsorption data were explained by the adsorption coefficient and the accessibility of metal for binding.

  20. Cooperative interactions of metal nanoparticles in the ion-exchange matrix with oxygen dissolved in water

    NASA Astrophysics Data System (ADS)

    Khorolskaya, S. V.; Polyanskii, L. N.; Kravchenko, T. A.; Konev, D. V.

    2014-06-01

    The kinetics of the reduction of molecular oxygen dissolved in water with nanocomposites consisting of an ion-exchange matrix and copper nanoparticles deposited in it in various amounts was studied. As the metal content in the polymer increased, the amount of reduced oxygen initially increased and then reached the limiting value. At a certain metal content, ionization of individual particles with formation of metal counterions changes to the oxidation of particles assembly giving layers of oxide products. The mechanism changes at the percolation threshold of the electron conductivity of the nanocomposite and determines the maximum amount of absorbed oxygen.