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1

Trapping radioactive ions  

NASA Astrophysics Data System (ADS)

Trapping devices for atomic and nuclear physics experiments with radioactive ions are becoming more and more important at accelerator facilities. While about ten years ago only one online Penning trap experiment existed, namely ISOLTRAP at ISOLDE/CERN, meanwhile almost every radioactive beam facility has installed or plans an ion trap setup. This article gives an overview on ion traps in the operation, construction or planing phase which will be used for fundamental studies with short-lived radioactive nuclides such as mass spectrometry, laser spectroscopy and nuclear decay spectroscopy. In addition, this article summarizes the use of gas cells and radiofrequency quadrupole (Paul) traps at different facilities as a versatile tool for ion beam manipulation like retardation, cooling, bunching, and cleaning.

Kluge, H.-J.; Blaum, K.

2004-12-01

2

Radioactive ion detector  

DOEpatents

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.

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

1997-01-01

3

Radioactive ion detector  

DOEpatents

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.

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

1997-08-12

4

Managing potentially radioactive scrap metal  

SciTech Connect

The National Council on Radiation Protection and Measurements published NCRP Report No. 141 on November 19, 2002. Contract DE-FG02-98CH10945 provided the sole support for this report titled ''Managing Potentially Radioactive Scrap Metal.'' Some preliminary work supported by the U.S. Environmental Protection Agency that led to an NCRP Letter Report provided some background information for this work. NCRP Report No. 141 provides recommendations on the methodologies and techniques available to the United States for disposing of radioactive, contaminated scrap metals.

None

2002-11-19

5

Radioactive Ion Beams and Radiopharmaceuticals  

NASA Astrophysics Data System (ADS)

Experiments performed at radioactive ion beam facilities shed new light on nuclear physics and nuclear structure, as well as nuclear astrophysics, materials science and medical science. The many existing facilities, as well as the new generation of facilities being built and those proposed for the future, are a testament to the high interest in this rapidly expanding field. The opportunities inherent in radioactive beam facilities have enabled the search for radioisotopes suitable for medical diagnosis or therapy. In this article, an overview of the production techniques and the current status of RIB facilities and proposals will be presented. In addition, accelerator-generated radiopharmaceuticals will be reviewed.

Laxdal, R. E.; Morton, A. C.; Schaffer, P.

2014-02-01

6

Decontaimination of radioactive metals  

SciTech Connect

This patent describes a method of extracting technetium and actinide radiocontaminants from radiocontaminated nickel comprising the steps: fabricating a nickel electrode contaminated with technetium and actinides; and then anodically dissolving the electrode contaminated with technetium and actinides in a oxidizing acid electrolyte solution to produce a solution containing actinide ions and at least 30 grams/liter of nickel and to oxidize the technetium to produce pertechnetate anions; and then removing pertechnetate anions and actinides by counter-current solvent extraction with a barren solution containing TOPO, D[sub 2]EHPA or mixtures thereof dissolved in an organic solvent, to produce a decontaminated, nickel containing raffinate, and a contaminated, loaded solvent stream; and then stripping the technetium values from the contaminated, loaded solvent stream with hydrochloric acid; passing the decontaminated, nickel containing raffinate through an absorbent for organic solvent; and then electrowinning the raffinate in an electrolysis cell with acidic electrolyte to remove residual actinides present, and to recover cathodic nickel.

Snyder, T.S.; Gass, W.R.; Worcester, S.A.; Ayers, L.J.

1992-10-20

7

Metal Ion Sources for Ion Beam Implantation  

SciTech Connect

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.

Zhao, W. J.; Zhao, Z. Q.; Ren, X. T. [Institute of Heavy Ion Physics and State Key Labarotary in Nuclear Physics and Nuclear Technology, Peking University, Beijing 100871 (China)

2008-11-03

8

A radioactive metal processing industry perspective source.  

PubMed

The current U.S. economic environment for the disposition of radioactive waste, including very-low-activity metals, is currently experiencing relatively low radioactive disposal costs and readily available disposal space. Despite the recent market increase in demand for recycled scrap metal commodities, there is still little change in the behavior of the nuclear industry (including radioactive waste processors and radioactive scrap metal recyclers) to pursue the recycling of potentially contaminated scrap metal. The relatively low cost of traditional radioactive waste disposal combined with the perceived risks associated with recycling of previously contaminated metals means that most U.S. radioactive facility managers and stakeholders will elect not to recycle. Current technology exists and precedence has been set for prescreening (by means of bulk radioactive assay techniques) scrap metal that is not contaminated and diverting it to industrial landfills for disposal. Other processes also allow some radiologically contaminated metals to be melted and recast into products with low, but acceptable, activity levels for restricted use in the nuclear industry. A new concept is being considered that would create a centralized licensed facility for the process and disposition of "very-low-activity" metals for "directed first use." The advantages to this type of approach would include a standardized method for licensing the clearance process. PMID:17033461

Johnson, A

2006-11-01

9

The ORNL Radioactive Ion Beam Project  

Microsoft Academic Search

On June 30, 1992, the Holifield Heavy Ion Research Facility (HHIRF) was shut down as an operating national users' facility for heavy ion physics research and became a construction project to reconfigure the existing accelerator system and develop a first generation radioactive ion beam (RIB) facility. During its 11 years of operation, the HHIRF had over 600 users, of which

D. K. Olsen; G. D. Alton; R. L. Auble; C. Baktash; D. T. Dowling; J. D. Garrett; D. L. Haynes; C. M. Jones; R. C. Juras; M. J. Meigs; G. D. Mills; S. W. Mosko; R. L. Robinson; B. A. Tatum; H. Blosser; L. Lee; F. Marti; H. K. Carter; J. Kormicki; P. Mantica; L. Rayburn; C. A. Reed

1992-01-01

10

The ORNL Radioactive Ion Beam Project  

Microsoft Academic Search

On June 30, 1992, the Holifield Heavy Ion Research Facility (HHIRF) was shut down as an operating national users` facility for heavy ion physics research and became a construction project to reconfigure the existing accelerator system and develop a first generation radioactive ion beam (RIB) facility. During its 11 years of operation, the HHIRF had over 600 users, of which

D. K. Olsen; G. D. Alton; R. L. Auble; C. Baktash; D. T. Dowling; J. D. Garrett; D. L. Haynes; C. M. Jones; R. C. Juras; M. J. Meigs; G. D. Mills; S. W. Mosko; R. L. Robinson; B. A. Tatum; H. Blosser; L. Lee; F. Marti; H. K. Carter; J. Kormicki; P. Mantica; L. Rayburn; C. A. Reed; J. Dellwo; H. Wollnik

1992-01-01

11

Method for decontamination of radioactive metal surfaces  

DOEpatents

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.

Bray, Lane A. (Richland, WA)

1996-01-01

12

Method for decontamination of radioactive metal surfaces  

DOEpatents

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.

Bray, L.A.

1996-08-13

13

Metal ion release from metal implants  

Microsoft Academic Search

Metal ion release from metallic materials, e.g. stainless steel, cobalt–chromium alloy, titanium, and titanium alloys, implanted into human body was reviewed in this paper. Surface oxide films on metallic materials play an important role as an inhibitor of ion release and they change with the release in vivo. Low concentration of dissolved oxygen, inorganic ions, proteins, and cells may accelerate

T. Hanawa

2004-01-01

14

Radioactive-ion-beam research at Livermore  

NASA Astrophysics Data System (ADS)

The ability to produce secondary radioactive heavy ion beams which can be isolated, focused, and transported to a secondary target can enable reaction studies and other research with the approximately more than 1300 nuclei with decay lifetimes approximately more than 1 microsec. Current research in secondary beam production and future applications in astrophysics, nuclear structure, heavy ion physics, and radiotherapy are examined as well as associated spin off and technology transfer in applied physics.

Haight, R. C.; Mathews, G. J.; Ward, R. A.; Woosley, S. E.

1983-06-01

15

INEL metal recycle radioactive scrap metal survey report  

Microsoft Academic Search

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

Funk

1994-01-01

16

Radioactive scrap metal decontamination technology assessment report  

SciTech Connect

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.

Buckentin, J.M.; Damkroger, B.K.; Schlienger, M.E. [Sandia National Labs., Albuquerque, NM (United States). Liquid Metal Processing Lab.

1996-04-01

17

Hydrogen production during processing of radioactive sludge containing noble metals.  

National Technical Information Service (NTIS)

Hydrogen was produced when radioactive sludge from Savannah River Site radioactive waste containing noble metals was reacted with formic acid. This will occur in a process tank in the Defense Waste Facility at SRS when waste is vitrified. Radioactive slud...

B. C. Ha D. M. Ferrara N. E. Bibler

1992-01-01

18

A Novel Radioactive Isotope Ion Target SCRIT  

SciTech Connect

Electron scattering is a superior method to investigate the internal structure, such as charge distribution, of atomic nuclei. Most of the radii of nuclei were determined unambiguously by that. However, radioactive isotopes (RI) which recently came up to a major research interest have not been accessible due to the difficulty in making fixed targets and taking measurements before they decay. We proposed a conceptually new target called SCRIT (Self-Confining Radioactive Isotope ion Target) as opposed to a collider method. The luminosity expected for SCRIT is inevitably low (typically on the order of 1.E+27/cm{sup 2}/s) and a large acceptance detector system is required. We plan to perform a coincidence measurement using an electron arm and a recoil ion detector which needs to be developed. Current status of the ion trapping with a prototype SCRIT and the background measurement results in an electron storage ring will be discussed.

Kurita, Kazuyoshi [Department of Physics, Rikkyo University, Nishi-Ikebukuro Toshima, Tokyo, 171-8501 (Japan); Cycltron Center, RIKEN, Wako, Saitama, 351-0198 (Japan); Masuda, Tetsuya [Department of Physics, Rikkyo University, Nishi-Ikebukuro Toshima, Tokyo, 171-8501 (Japan); Koseki, Tadashi [Accelerator Division I, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801 (Japan); Noda, Akira; Shirai, Toshiyuki; Tongu, Hiromu [Center for Beam Science, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011 (Japan); Furukawa, Yukihiro; Tamae, Tadaaki [Laboratory of Nuclear Science, Tohoku University, Mikamine, Taihaku, Sendai, 982-0826 (Japan); Ito, Sachiko; Emoto, Takashi; Nakamura, Masato; Wakasugi, Masanori; Yano, Yasushige [Cycltron Center, RIKEN, Wako, Saitama, 351-0198 (Japan); Ohnishi, Tetsuya; Suda, Toshimi; Takeda, Hiroyuki; Wang Shuo [RI Beam Science Laboratory, RIKEN, Wako, Saitama, 351-0198 (Japan)

2006-11-20

19

Advances in metal ion sources  

SciTech Connect

Beams of metallic ion species can be produced by the ECR (electron cyclotron resonance) ion source and by the MEVVA (metal vapor vacuum arc) ion source. Although the ECR source is fundamentally a gaseous ion source, metal ion beams can be produced by introducing metallic feed material into the plasma discharge using a number of techniques. The ion charge states can be very high, which is a significant advantage to most applications. The MEVVA ion source, on the other hand, is specifically a metal ion source. It has produced metallic ion beams from virtually all the solid metallic elements at a current of typically hundreds of milliamperes; the ions produced are in general multiply ionized, but not as highly stripped as those generated in the ECR source. Although the MEVVA source at present operates in a pulsed mode with a low duty cycle (less than or equal to 1%), work is in progress to increase the duty cycle significantly. In this paper the operation and performance of the LBL ECR and MEVVA ion sources, with respect to metal ion generation, are described.

Brown, I.G.

1988-05-01

20

Evaluation of radioactive scrap metal recycling  

Microsoft Academic Search

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

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

1995-01-01

21

Radioactive scrap metal decontamination technology assessment report.  

National Technical Information Service (NTIS)

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 mate...

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

1996-01-01

22

Radioactive Ion Beam Production Capabilities at the Holifield Radioactive Ion Beam Facility  

SciTech Connect

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 HRIBF is the production of high-quality beams of short-lived 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.

Beene, James R [ORNL; Dowling, Darryl T [ORNL; Gross, Carl J [ORNL; Juras, Raymond C [ORNL; Liu, Yuan [ORNL; Meigs, Martha J [ORNL; Mendez, II, Anthony J [ORNL; Nazarewicz, Witold [ORNL; Sinclair, John William [ORNL; Stracener, Daniel W [ORNL; Tatum, B Alan [ORNL

2011-01-01

23

Laser ion sources for radioactive beams (invited).  

PubMed

Resonant ionisation laser ion sources are nowadays extensively used, when available, at many leading on-line facilities. Moreover, new laser ion sources are now under development in most of the recent on-line facility projects under construction worldwide. This success is mainly due to the reliability, the ionization efficiency and the high purity that this type of source can achieve for the production of radioactive species and for a large range of chemical elements. Laser ion sources for radioactive beams gather many different systems such as dye laser or all-solid state titanium:sapphire laser systems, high or low repetition rates, hot cavities or gas cells, additional selectivity by using chemical techniques, or the LIST technique (laser ion source trap). In this paper, the physics of laser ion sources will be described with the current limitations and challenges for the future. An overview of the laser ion source facilities will be given, with an emphasis on the ongoing developments and perspectives on LIS. PMID:22380257

Lecesne, N

2012-02-01

24

Laser ion sources for radioactive beams (invited)  

NASA Astrophysics Data System (ADS)

Resonant ionisation laser ion sources are nowadays extensively used, when available, at many leading on-line facilities. Moreover, new laser ion sources are now under development in most of the recent on-line facility projects under construction worldwide. This success is mainly due to the reliability, the ionization efficiency and the high purity that this type of source can achieve for the production of radioactive species and for a large range of chemical elements. Laser ion sources for radioactive beams gather many different systems such as dye laser or all-solid state titanium:sapphire laser systems, high or low repetition rates, hot cavities or gas cells, additional selectivity by using chemical techniques, or the LIST technique (laser ion source trap). In this paper, the physics of laser ion sources will be described with the current limitations and challenges for the future. An overview of the laser ion source facilities will be given, with an emphasis on the ongoing developments and perspectives on LIS.

Lecesne, N.

2012-02-01

25

Ion beam modification of metals  

Microsoft Academic Search

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,

G. Dearnaley

1990-01-01

26

Laser ion source development at Holifield Radioactive Ion Beam Facility  

NASA Astrophysics Data System (ADS)

This report describes the efforts made to develop a resonant-ionization laser ion source based on tunable Ti:sapphire lasers for nuclear physics and astrophysics research at Holifield Radioactive Ion Beam Facility. Three Ti:sapphire lasers have been upgraded with individual pump lasers to eliminate laser power losses due to synchronization delays. Ionization schemes for 14 elements have been obtained. Off-line studies show that the overall efficiency of the laser ion source can be as high as 40%. TaC surface coatings have been investigated for minimizing surface and bulk trapping of the atoms of interest.

Liu, Y.; Gottwald, T.; Havener, C. C.; Howe, J. Y.; Kiggans, J.; Mattolat, C.; Vane, C. R.; Wendt, K.; Beene, J. R.

2012-02-01

27

A radioactive target/ion source for material research  

NASA Astrophysics Data System (ADS)

A radioactive target/ion source for material research has been developed at China Institute of Atomic Energy, China. With a proton ion beam from the HI-13 tandem as the primary beam, the low intensity radioactive ion beam is generated on line. The first aim of the source is to produce a radioactive ion beam of 62Zn+ which will serve as nuclear probe in material research. The main features and current status of the source are presented in this article.

Cui, B.; Li, L.; Ma, Y.; Wang, R.; Jiang, W.

2004-05-01

28

Method for electrochemical decontamination of radioactive metal  

DOEpatents

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.

Ekechukwu, Amy A. (Augusta, GA)

2008-06-10

29

Fabrication of radioactive stents by ion implantation  

NASA Astrophysics Data System (ADS)

Worldwide about one million patients require treatment of stenosed coronary arteries annually. Often a tubular stainless steel mesh (stent) is implanted to mechanically support the injured vessel. Restenosis, an abundant complication (20%-30%) can be prevented, if the vessel is treated with ionizing radiation. Stents can deliver radiation if they are made radioactive. The radio isotope 32P is well suited when ion implanted. Radioactive ions sources require high efficiency to keep the radioactive inventory small. Reliability, ease of operation, and maintenance are mandatory. A small emittance is important to minimize losses during mass separation and beam transport. A 2.45 GHz ECR source was developed for the implantation of 32P. The source consists of two coils for the axial and a permanent hexapole for the radial confinement. The microwaves are fed in radially by a loop connected to a silver plated brass tube surrounding the plasma chamber. The plasma chamber is made from Pyrex. Neutron activated phosphorus, containing 30 ppm 32P, is introduced from the rear end on a rod. As support gas D2 is used. By this 32P+ can be separated from (31PD)+. The extraction is done in two steps: 60 kV-30 kV-ground. Mass separation is accomplished by a double focusing 90° magnet (radius 500 mm). During four years of operation about 1000 radioactive stents per year have been provided for animal experiments and clinical trials. Only one maintenance to exchange the extraction system due to degradation of high voltage stability was required so far.

Huttel, Erhard; Kaltenbaek, Johann; Schloesser, Klaus; Schweickert, Hermann

2002-02-01

30

Evaluation of radioactive scrap metal recycling  

SciTech Connect

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.

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

1995-12-01

31

Scrap metals industry perspective on radioactive materials.  

PubMed

With more than 80 reported/confirmed accidental melts worldwide since 1983 and still counting, potential contamination by radioactive materials remains as a major concern among recycled scrap and steel companies. Some of these events were catastrophic and have cost the industry millions of dollars in business and, at the same time, resulted in declining consumer confidence. It is also known that more events with confirmed radioactive contamination have occurred that involve mining of old steel slag and skull dumps. Consequently, the steel industry has since undergone massive changes that incurred unprecedented expenses through the installation of radiation monitoring systems in hopes of preventing another accidental melt. Despite such extraordinary efforts, accidental melts continue to occur and plague the industry. One recent reported/confirmed event occurred in the Republic of China in 2004, causing the usual lengthy shutdown for expensive decontamination efforts before the steel mill could resume operations. With this perspective in mind, the metal industry has a long-standing opposition to the release of radioactive materials of any kind to commerce for fear of contamination and the potential consequences. PMID:17033460

Turner, Ray

2006-11-01

32

Development of metallic ion beams using ECRIS  

Microsoft Academic Search

The low energy metallic ion beams find wide applications in various research fields of the materials science. Several metallic ion beams have been developed successfully using the electron cyclotron resonance (ECR) ion source based low energy ion beam facility (LEIBF) at Inter University Accelerator Centre (IUAC), New Delhi. These metallic ion beams were developed by different techniques and utilized for

P. Kumar; G. Rodrigues; P. S. Lakshmy; D. Kanjilal; Beer Pal Singh; R. Kumar

2006-01-01

33

Target Development for Radioactive Ion Beam Generation  

NASA Astrophysics Data System (ADS)

Development of ion beams of short-lived isotopes is crucial for modern nuclear structure and nuclear astrophysics. For example, ^82Ge,^130+xSn, ^92,94,95Sr beams are of interest but impurities and low intensities have prevented them from being useful. The code HSC-5 [1], with an extensive thermochemical database, predicts which chemical compounds may be transported within the target-ion source. The code also allows us to predict stability of target materials as function of temperature and pressure. So, a number of new targets have been fabricated and tested for use at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory, based on the ISOL technique. Recent results from off-line and on-line tests at HRIBF and CERN-ISOLDE will be presented. This research was sponsored by the NNSA under Stewardship Science Academic Alliance program through DOE Cooperative Agreement # DE-FC03-3NA00143. [1] HSC Chemistry for Windows - Chemical Reaction and Equilibrium Software with extensive Thermochemical Database, Outokumpu Research Oy, Pori, Finnland

Kronenberg, A.; Carter, H. K.; Stracener, D. W.; Bilheux, J. C.; Cizewski, J. A.; Koester, U.

2004-10-01

34

Target Development for Radioactive Ion Beam Generation  

NASA Astrophysics Data System (ADS)

Development of ion beams of short-lived isotopes is crucial for modern nuclear structure and nuclear astrophysics. For example, ^82Ge, ^130+xSn, ^92,94,95Sr beams are of interest but impurities and low intensities have prevented them from being useful. The code HSC-5 [1], with an extensive thermochemical database predicts which chemical compounds may be transported within the target-ion source. The code also allows us to predict stability of target materials as function of temperature and pressure. So, a number of new targets have been fabricated and tested for use at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory, based on the ISOL technique. Recent results from off-line and on-line tests at HRIBF and CERN-ISOLDE will be presented. This research was sponsored by the NNSA under Stewardship Science Academic Alliance program through DOE Cooperative Agreement # DE-FC03-3NA00143. [1] HSC Chemistry for Windows Chemical Reaction and Equilibrium Software with extensive Thermochemical Database, Outokumpu Research Oy, Pori, Finnland

Kronenberg, A.; Carter, H. K.; Stracener, D.; Bilheux, J.; Cizewski, J. A.; Koester, U.

2004-11-01

35

The production and generation of radioactive ion beams (RIBs)  

SciTech Connect

There is a strong interest in physics with radioactive ion beams, which has triggered a number of projects where nuclear physics installations are upgraded with accelerators for low charge state radioactive beams. A survey of the status of these projects is given with emphasis on the low energy linacs, which are limiting the acceptance and transmission of these low current ion beams.

Schempp, A. [Institut fuer Angewandte Physik, J. W. Goethe-Universitaet, D-60054 Frankfurt (Germany)

1999-06-10

36

Development of the Holifield Radioactive Ion Beam Facility  

SciTech Connect

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.

Tatum, B.A.

1997-08-01

37

Assessment of recycling or disposal alternatives for radioactive scrap metal  

Microsoft Academic Search

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

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

1993-01-01

38

A radioactive ion beam facility using photofission  

NASA Astrophysics Data System (ADS)

Use of a high-power electron linac as the driver accelerator for a Radioactive Ion Beam (RIB) facility is proposed. An electron beam of 30 MeV and 100 kW can produce nearly 5×10 13 fissions/s from an optimized 235U target and about 60% of this from a natural uranium target. An electron beam can be readily transmitted through a thin window at the exit of the accelerator vacuum system and transported a short distance through air to a water-cooled Bremsstrahlung-production target. The Bremsstrahlung radiation can, in turn, be transported through air to the isotope-production target. This separates the accelerator vacuum system, the Bremsstrahlung target and the isotope-production target, reducing remote handling problems. The electron beam can be scanned over a large target area to reduce the power density on both the Bremsstrahlung and isotope-production targets. These features address one of the most pressing technological challenges of a high-power RIB facility, namely the production of high yields of neutron-rich ions with reasonable power density in the target. The cost of an electron linac of the required specifications, including the facility shielding, is significantly less than the cost of any other primary-beam accelerator that could produce a comparable fission yield. A high-power electron linac could also be used with a multifoil helium-jet target. A large number of thin uranium foils could be irradiated with the scanned Bremsstrahlung beam and the fission fragments captured in aerosol-loaded helium and transported to an ion source that is well removed from the intense radiation fields of the primary target. The fission yield would be less than 1% of that available from a thick target, but this approach might be the easiest technical solution to obtain useable yields with manageable radiation-safety problems.

Diamond, William T.

1999-08-01

39

Ion beam modification of metals  

NASA Astrophysics Data System (ADS)

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.

Dearnaley, G.

1990-04-01

40

Titanate-based adsorbents for radioactive ions entrapment from water  

NASA Astrophysics Data System (ADS)

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.

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

2013-02-01

41

Metal ion-containing epoxies  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

42

Metal ion coordination studies on a silica-based ion exchange resin before and after heating.  

SciTech Connect

Work designed to assess the potential of using a single material to sorb highly charged metal ions from aqueous solution and then microencapsulate and chemical fix those sorbed metal ions in vitreous silica is described. The basis for these studies is a chemically functionalized porous silica that is termed Diphosil. Diphosil was created by Chiarizia and coworkers (Solv. Extr. Ion Exch. 1996, 14(6), 1977-1100) as an ion exchange resin that strongly sorbs actinide and other highly charged metal ions from acid solutions. We have determined the maximum metal ion loading for Diphosil and shown that it sorbs trivalent ions from concentrated phosphoric acid. Using FT-IR analysis, we have shown that heating metal ion-loaded Diphosil in air converts its organic content primarily into carbon dioxide and water vapor. We have carried out studies on luminescence dynamics and spectroscopy, powder x-ray diffraction, and optical microscopy of metal ion-loaded Diphosil prior to and following heating in air. All of the results of our investigations are consistent with microencapsulation and chemical fixation of metal ions sorbed into Diphosil when that material is heated to 1273 K. In consequence, Diphosil is a promising basis for a single material approach to reducing nuclear waste volume by removing longlived alpha emitters from high level liquid radioactive waste and generating a vitreous silica nuclear waste form for the removed radionuclides that is suitable for geologic disposal.

Beitz, J. V.; Williams, C. W.; Chemistry

2001-07-31

43

The production of accelerated radioactive ion beams  

SciTech Connect

During the last few years, substantial work has been done and interest developed in the scientific opportunities available with accelerated radioactive ion beams (RIBs) for nuclear physics, astrophysics, and applied research. This interest has led to the construction, development, and proposed development of both first- and second-generation RIB facilities in Asia, North America, and Europe; international conferences on RIBs at Berkeley and Louvain-la-Neuve; and many workshops on specific aspects of RIB production and science. This paper provides a discussion of both the projectile fragmentation, PF, and isotope separator on-line, ISOL, approach to RIB production with particular emphasis on the latter approach, which employs a postaccelerator and is most suitable for nuclear structure physics. The existing, under construction, and proposed facilities worldwide are discussed. The paper draws heavily from the CERN ISOLDE work, the North American IsoSpin Laboratory (ISL) study, and the operating first-generation RIB facility at Louvain-la-Neuve, and the first-generation RIB project currently being constructed at ORNL.

Olsen, D.K.

1993-11-01

44

Ion Exchange Characteristics of Palladium and Ruthenium from a Simulated Radioactive Liquid Waste  

Microsoft Academic Search

Radioactive high-level liquid wastes contain significant quantities of platinum group metals (PGM), such as palladium [Pd(II)], rhodium [Rh(III)], and ruthenium [Ru(III)]. The PGM are produced as fission products in nuclear reactors. In this study, batch and column experiments were carried out to investigate the ion exchange characteristics of Pd(II) and Ru(III), including the effects of the ionic group of ion

S. H. Lee; H. Chung

2003-01-01

45

Tokai Radioactive Ion Accelerator Complex (TRIAC): present and future  

SciTech Connect

Tokai Radioactive Ion Accelerator Complex (TRIAC) is the low-energy accelerator complex for re-accelerating short-lived radioactive ion beams (RIBs) in Japan. After the introduction of the present status of the TRIAC, considered as future extension of the present TRIAC activity, we are going to discuss our experimental proposal to investigate the beta-decay properties of neutron-rich rare isotopes involved in the 3{sup rd} peak in the r-process element abundance.

Jeong, S. C. [Tokai Campus, High Energy Accelerator Research Organization (KEK), Shirakata Shirane 2-4, Tokai, Ibaraki 319-1195 (Japan)

2010-04-30

46

Mechanistic Enzyme Models: Pyridoxal and Metal Ions.  

ERIC Educational Resources Information Center

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)

Hamilton, S. E.; And Others

1984-01-01

47

Thermochemical Processing of Radioactive Waste Using Powder Metal Fuels.  

National Technical Information Service (NTIS)

Problematic radioactive wastes were generated during various activities of both industrial facilities and research institutions usually in relative small amounts. These can be spent ion exchange resins, inorganic absorbents, wastes from research nuclear r...

M. I. Ojovan I. A. Sobolev S. A. Dmitriev

2004-01-01

48

Metallic ions in the equatorial ionosphere  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

49

Rational design of metal ion sequestering agents. 1998 annual progress report  

Microsoft Academic Search

'This project addresses fundamental issues and requirements in developing hazardous metal ion separation technologies needed in the treatment and disposal of radioactive and chemical toxic waste. It encompasses the synthesis of new agents, followed by their characterization and evaluation, with the aim to optimize their metal ion sequestering properties for use in applied technologies. This research is focused on the

1998-01-01

50

Search for sterile neutrinos at radioactive ion beam facilities  

NASA Astrophysics Data System (ADS)

We propose applications of Radioactive Ion Beam facilities to investigate physics beyond the Standard Model. In particular, we focus upon the search for sterile neutrinos by means of a low energy beta-beam with a Lorentz boost factor of 1. In the considered setup, collected 8Li radioactive ions are sent inside a 4? detector filled with a liquid scintillator, with inverse-beta decay as neutrino detection channel. We provide exclusion curves for the sterile neutrino mixing parameters, based upon the 3+1 formalism, depending upon the achievable ion intensity. The proposed experiment represents a possible alternative to clarify the current anomalies observed in neutrino experiments.

Espinoza, Catalina; Lazauskas, Rimantas; Volpe, Cristina

2013-07-01

51

Method for making radioactive metal articles having small dimensions  

DOEpatents

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.

Ohriner, Evan K. (Knoxville, TN)

2000-01-01

52

Managing the disposition of potentially radioactive scrap metal.  

PubMed

In 2002, the National Council on Radiation Protection and Measurements (NCRP) issued Report No. 141, Managing Potentially Radioactive Scrap Metal. The report evaluates management policy and related issues regarding scrap metal generated in regulated facilities that have been under radiological control or have radiological concerns. It has been estimated that more than 9 million metric tons of scrap metal of all types that have been associated with the production or use of radioactive materials will be generated during the coming decades at various facilities across the United States. Currently, disposition of such metal has encountered particular obstacles, primarily because of the lack of a consistent disposition policy, systematic regulatory provisions, and, above all, public understanding. Without clarity in the regulatory passage, much of the scrap metal, including metal that has not been contaminated, could be mischaracterized as low-level radioactive waste, resulting in a costly disposition operation. NCRP Report No. 141 identifies this general category of metal as "potentially radioactive scrap metal" (PRSM) and discusses the viable disposition options for facilitating its management. Because much of the PRSM has been found to contain very low residual radioactivity or even none at all, one consideration is to release such metal outside of the radiological control framework. This would require the development and implementation of a set of strict release standards in the United States that would necessarily be risk-based and supported by a comprehensive management scheme. Developing a policy of this kind, however, would entail the resolution of many issues, not the least of which would be public acceptance, including that of the metal industry, of the possible recycling of PRSM in the general commerce. PMID:17033456

Chen, S Y

2006-11-01

53

Fabrication of radioactive stents by ion implantation  

Microsoft Academic Search

Worldwide about one million patients require treatment of stenosed coronary arteries annually. Often a tubular stainless steel mesh (stent) is implanted to mechanically support the injured vessel. Restenosis, an abundant complication (20%-30%) can be prevented, if the vessel is treated with ionizing radiation. Stents can deliver radiation if they are made radioactive. The radio isotope 32P is well suited when

Erhard Huttel; Johann Kaltenbaek; Klaus Schloesser; Hermann Schweickert

2002-01-01

54

Ion beam analysis of radioactive samples  

NASA Astrophysics Data System (ADS)

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.

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

2009-06-01

55

Charge breeding simulations for radioactive ion beam production.  

PubMed

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

Variale, V; Rainò, A C; Clauser, T

2012-02-01

56

Charge breeding simulations for radioactive ion beam production  

NASA Astrophysics Data System (ADS)

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.

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

2012-02-01

57

Liquid metal ion source and alloy  

DOEpatents

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.

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

58

Laser Ion Source Operation at the TRIUMF Radioactive Ion Beam Facility  

NASA Astrophysics Data System (ADS)

The TRIUMF Resonant Ionization Laser Ion Source (RILIS) for radioactive ion beam production is presented, with target ion source, laser beam transport, laser system and operation. In this context aspects of titanium sapphire (TiSa) laser based RILIS and facility requirements are discussed and results from the first years of TRILIS RIB delivery are given.

Lassen, J.; Bricault, P.; Dombsky, M.; Lavoie, J. P.; Gillner, M.; Gottwald, T.; Hellbusch, F.; Teigelhöfer, A.; Voss, A.; Wendt, K. D. A.

2009-03-01

59

Scrap metal management issues associated with naturally occurring radioactive material  

SciTech Connect

Certain industrial processes sometimes generate waste by-products that contain naturally occurring radioactive material (NORM) at elevated concentrations. Some industries, including the water treatment, geothermal energy, and petroleum industries, generate scrap metal that may be contaminated with NORM wastes. Of these three industries, the petroleum industry probably generates the largest quantity of NORM-contaminated equipment, conservatively estimated at 170,000 tons per year. Equipment may become contaminated when NORM-containing scale or sludge accumulates inside water-handling equipment. The primary radionuclides of concern in these NORM wastes are radium-226 and radium-228. NORM-contaminated equipment generated by the petroleum industry currently is managed several ways. Some equipment is routinely decontaminated for reuse; other equipment becomes scrap metal and may be disposed of by burial at a licensed landfill, encapsulation inside the wellbore of an abandoned well, or shipment overseas for smelting. In view of the increased regulatory activities addressing NORM, the economic burden of managing NORM-contaminated wastes, including radioactive scrap metal, is likely to continue to grow. Efforts to develop a cost-effective strategy for managing radioactive scrap metal should focus on identifying the least expensive disposition options that provide adequate protection of human health and the environment. Specifically, efforts should focus on better characterizing the quantity of radioactive scrap available for recycle or reuse, the radioactivity concentration levels, and the potential risks associated with different disposal options.

Smith, K.P.; Blunt, D.L.

1995-08-01

60

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...

61

Versatile high current metal ion implantation facility  

SciTech Connect

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.

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

1991-06-01

62

?-delayed neutron spectroscopy using trapped radioactive ions.  

PubMed

A novel technique for ?-delayed neutron spectroscopy has been demonstrated using trapped ions. The neutron-energy spectrum is reconstructed by measuring the time of flight of the nuclear recoil following neutron emission, thereby avoiding all the challenges associated with neutron detection, such as backgrounds from scattered neutrons and ? rays and complicated detector-response functions. (137)I(+) ions delivered from a (252)Cf source were confined in a linear Paul trap surrounded by radiation detectors, and the ?-delayed neutron-energy spectrum and branching ratio were determined by detecting the ?(-) and recoil ions in coincidence. Systematic effects were explored by determining the branching ratio three ways. Improvements to achieve higher detection efficiency, better energy resolution, and a lower neutron-energy threshold are proposed. PMID:23496704

Yee, R M; Scielzo, N D; Bertone, P F; Buchinger, F; Caldwell, S; Clark, J A; Deibel, C M; Fallis, J; Greene, J P; Gulick, S; Lascar, D; Levand, A F; Li, G; Norman, E B; Pedretti, M; Savard, G; Segel, R E; Sharma, K S; Sternberg, M G; Van Schelt, J; Zabransky, B J

2013-03-01

63

Neutron Transfer Reactions with Neutron-rich Radioactive Ion Beams  

SciTech Connect

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.

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

2005-10-01

64

Spin Observables in Reactions with Radioactive Ion Beams  

SciTech Connect

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.

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

2007-01-01

65

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...

66

Nuclear astrophysics and the Daresbury Recoil Separator at the Holifield Radioactive Ion Beam Facility.  

National Technical Information Service (NTIS)

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 oc...

M. S. Smith

1997-01-01

67

Radioactive ion beam facilities in Europe  

NASA Astrophysics Data System (ADS)

The past two decades have seen extraordinarily rapid development of radioactive beam physics throughout the world and in particular in Europe. The important scientific advances have stemmed from a large number of facilities. Previously existing stable beam machines have been adapted to produce rare isotope beams and dedicated facilities have come on-line. This talk gives an overview of the present European installations highlighting their complementary nature. The European roadmap calls for the construction of two next generation facilities: FAIR making use of projectile fragmentation and EURISOL based on the ISOL technique. The future FAIR facility will be described and the path towards EURISOL presented in the light of the construction of "intermediate" generation facilities SPIRAL2, HIE ISOLDE and SPES and results from the ongoing EURISOL Design Study.

Blumenfeld, Y.

2008-10-01

68

Ion sources for initial use at the Holifield Radioactive Ion Beam Facility  

SciTech Connect

The Holifield Radioactive Ion Beam Facility (HRIBF) now under construction at the Oak Ridge National Laboratory will use the 25-MV tandem accelerator for the acceleration of radioactive ion beams to energies appropriate for research in nuclear physics; negative ion beams are, therefore, required for injection into the tandem accelerator. Because charge exchange is an efficient means for converting initially positive ion beams to negative ion beams, both positive and negative ion sources are viable options for use at the facility; the choice of the type of ion source will depend on the overall efficiency for generating the radioactive species of interest. A high-temperature version of the CERN-ISOLDE positive ion source has been selected and a modified version of the source designed and fabricated for initial use at the HRIBF because of its low emittance, relatively high ionization efficiencies and species versatility, and because it has been engineered for remote installation, removal and servicing as required for safe handling in a high-radiation-level ISOL facility. Prototype plasma-sputter negative ion sources and negative surface-ionization sources are also under design consideration for generating negative radioactive ion beams from high-electron-affinity elements. The design features of these sources and expected efficiencies and beam qualities (emittances) will be described in this report.

Alton, G.D.

1993-12-31

69

Separation of metal ions from aqueous solutions  

DOEpatents

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.

Almon, Amy C. (Augusta, GA)

1994-01-01

70

Pseudo ribbon metal ion beam source.  

PubMed

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. PMID:24593634

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

2014-02-01

71

Assessment of recycling or disposal alternatives for radioactive scrap metal  

Microsoft Academic Search

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

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

1993-01-01

72

Risk and impact tradeoffs in radioactive scrap metal management  

Microsoft Academic Search

Two management alternatives for radioactive scrap metal were evaluated: (1) recycling and reuse, and (2) disposal and replacement. The human health risks, environmental impacts, and sociopolitical issues potentially associated with these alternatives were assessed in an international context. For each alternative, the health risks from workplace and transportation accidents are greater in magnitude than the risks from potential exposure to

L. A. Nieves; S. Y. Chen

1995-01-01

73

Heavy metal ions removal by chelating resin  

Microsoft Academic Search

Purpose – Preparation of chelating resin to be used in the removal of heavy metal ions from solutions. Design\\/methodology\\/approach – Chelating resin based on poly (glycidyl-methacrylate-co-N, N-methylene-bis-acrylamide) containing ethylenediamine was synthesised and used in removal of heavy metals from solutions. Findings – The optimal pH values for adsorption of different metal ions occur in the range 4.0-10.0 depending on the

N. M. Abd El-Moniem; M. R. El-Sourougy; D. A. F. Shaaban

2005-01-01

74

Development of metallic ion beams using ECRIS  

NASA Astrophysics Data System (ADS)

The low energy metallic ion beams find wide applications in various research fields of the materials science. Several metallic ion beams have been developed successfully using the electron cyclotron resonance (ECR) ion source based low energy ion beam facility (LEIBF) at Inter University Accelerator Centre (IUAC), New Delhi. These metallic ion beams were developed by different techniques and utilized for the synthesis of the metal nanoparticles inside various host matrices. The special emphasis was put on the development of the nickel (Ni) and iron (Fe) ion beams using volatile compounds. The hydrocarbon cluster beams were also observed in the charge state distribution (CSD) of the ECR plasma produced by the dissociation of the vapors from the volatile compound of iron. Ni and Fe ion beams were utilized to make a dilute magnetic semiconductor phase (nickel in silicon and iron in silicon) by implantation method. The ion beams extracted from the metallic ECR plasma have been analyzed in energy and momentum using a high mass resolution dipole magnet. Studies of the CSD of the output metallic ion beams and the co-relations among various source parameters are presented.

Kumar, P.; Rodrigues, G.; Lakshmy, P. S.; Kanjilal, D.; Singh, Beer Pal; Kumar, R.

2006-11-01

75

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

SciTech Connect

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)

Zherebtsov, Alexander; Pastushkov, Vladimir; Poluektov, Pavel; Smelova, Tatiana; Shadrin, Andrey [JSC 'VNIINM', Rogova st., 5, 123098, Moscow (Russian Federation)] [JSC 'VNIINM', Rogova st., 5, 123098, Moscow (Russian Federation)

2013-07-01

76

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

SciTech Connect

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.

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. [Instituto de Fisica da Universidade de Sao Paulo, C.P. 66318, 05389-970 Sao Paulo (Brazil); Benjamim, E. A. [Universidad de Santiago de Compostela, Depto. Fisica Particulas, Facultad Fisica, Campus Sur s/n 15786 Santiago de Compostela (Spain) (Spain); Moro, A. M. [Departamento de FAMN, Universidad de Sevilla, Apdo 1065, E-41080, Sevilla (Spain); Arazi, A. [Laboratorio Tandar, Departamento de Fisica, Comision Nacional de Energia Atomica, Av. del Libertador 8250, (1429), Buenos Aires (Argentina); Assuncao, M. [UNIFESP-Campus de Diadema, SP (Brazil)] (and others)

2009-06-03

77

Selection and design of ion sources for use at the Holifield Radioactive Ion Beam Facility  

SciTech Connect

The Holifield Radioactive Ion beam Facility now under construction at the Oak Ridge National Laboratory will use the 25-MV tandem accelerator for the acceleration of radioactive ion beams to energies appropriate for research in nuclear physics; negative ion beams are, therefore, required for injection into the tandem accelerator. Because charge exchange is an efficient means for converting initially positive ion beams to negative ion beams, both positive and negative ion sources are viable options for use at the facility. The choice of the type of ion source will depend on the overall efficiency for generating the radioactive species of interest. Although direct-extraction negative ion sources are clearly desirable, the ion formation efficiencies are often too low for practical consideration; for this situation, positive ion sources, in combination with charge exchange, are the logical choice. The high-temperature version of the CERN-ISOLDE positive ion source has been selected and a modified version of the source designed and fabricated for initial use at the facility because of its low emittance, relatively high ionization efficiencies and species versatility, and because it has been engineered for remote installation, removal and servicing as required for safe handling in a high-radiation-level ISOL facility. The source will be primarily used to generate ion beams from elements with intermediate to low electron affinities. Prototype plasma-sputter negative ion sources and negative surface-ionization sources are under design consideration for generating radioactive ion beams from high-electron-affinity elements. The design features of these sources and expected efficiencies and beam qualities (emittances) will be described in this report.

Alton, G.D.; Haynes, D.L.; Mills, G.D.; Olsen, D.K.

1993-12-31

78

Sorption of metal ions on alumina  

SciTech Connect

The adsorption of metal ions on aluminas is of great interest in different fields such as geochemistry, oceanography, limnology, and pollution control. Precipitation and adsorption of metal ions (Co(II), Ni(II), Cu(II), and Cr(III)) on {gamma}-alumina were investigated experimentally. A surface chemical reaction model to calculate concentrations of aluminum ions, metal ions, and pH as variables depending on amount of alumina, volume of liquid and gas phase, initial metal concentration, and amount of acid or base added is presented. In the case of Co(II) the pH dependence of rest concentrations with and without alumina is equal; adsorption may be disregarded. For the other ions adsorption is important. Considering the charge of the surface does not improve the fit. In the pH region, where adsorption leads to lower rest concentrations than precipitation, adsorption may be described by a Henry isotherm.

Baumgarten, E.; Kirchhausen-Duesing, U. [Heinrich-Heine Univ. Duesseldorf (Germany). Inst. fuer Physikalische Chemie und Elektrochemie] [Heinrich-Heine Univ. Duesseldorf (Germany). Inst. fuer Physikalische Chemie und Elektrochemie

1997-10-01

79

Fusion Induced By Medium-Mass Radioactive Ion Beams  

NASA Astrophysics Data System (ADS)

The use of radioactive ion beams in nuclear physics experiments has increased rapidly in recent years. A variety of short-lived nuclei and beam energies are available. With medium-mass, neutron-rich radioactive nuclei, the influence of neutron excess on fusion and compound nucleus survival can be explored. This can improve our understanding on how to synthesize new neutron-rich heavy nuclei. Fusion induced by medium-mass, neutron-rich radioactive nuclei, 38S, 132,134Sn, and 134Te has been measured. Enhanced fusion cross sections were observed in these measurements. However, in most of the cases the enhancement is due to the lowering of the barrier by the larger nuclear sizes except for 134Sn induced fusion. Results from these experiments and future plans are discussed.

Liang, J. F.

2006-08-01

80

Immobilized calcein for metal ion preconcentration  

SciTech Connect

A technique is demonstrated for the preparation of immobilized calcein, (2',7',((bis(carboxymethyl)amino)methyl)-fluorescein), to be used for metal ion preconcentration. The calcein is of particular interest as a reagent for transition metals. The preconcentration is demonstrated for cobalt, copper, and nickel ions. Fluorescence spectra of the calcein at various pH values were obtained. Values were determined for the conditional binding constants of immobilized and dissolved calcein with the transition metal ions as a function of pH.

Not Available

1984-04-01

81

First online production of radioactive ion beams at VECC  

NASA Astrophysics Data System (ADS)

Radioactive ion beams (RIB) have been recently accelerated for the first time at the VECC-RIB facility. Beams of 14O (71 s), 42K (12.4 h), 43K (22 h) and 41Ar (1.8 h) have been produced by bombarding 1 atm nitrogen and argon gas targets with 1 micro-ampere proton and alpha particle beams from the K130 cyclotron. Radioactive atoms were transported 15 m away to the ECR ion-source using a gas-jet transport system. Typical measured intensity of RIB at the separator focal plane is few times 103 pps. About 3300 pps of 1.4 MeV 14O was measured after acceleration through a 3.4 m long RFQ linac. The details of the gas-jet coupled ECR and RIB production experiments are presented.

Naik, Vaishali; Chakrabarti, Alok; Bhattacharjee, Mahuwa; Karmakar, Prasanta; Bhattacharjee, Sampa; Bandyopadhyay, Arup; Dechoudhury, Siddhartha; Kumar, Dodi Lavanya; Mondal, Manas; Pandey, H. K.; Mandi, T. K.; Dutta, D. P.; Roy, Tapatee Kundu; Bhowmik, Debasis; Sanyal, Dirtha; Ray, Ayan; Sabir Ali, Md.; Srivastava, S. C. L.; Nabhiraj, P. Y.

2013-12-01

82

Transport of radioactive ions in soil by electrokinetics  

SciTech Connect

An electrokinetic approach is being evaluated for in situ soil remediation at the Hanford Site in Richland, Washington. This approach uses an applied electric field to induce transport of both radioactive and hazardous waste ions in soil. The work discussed in this paper involves the development of a new method to monitor the movement of the radioactive ions within the soil during the electrokinetic process. A closed cell and a gamma counter were used to provide iii situ measurements of {sup 137}Cs and {sup 60}Co movement in Hanford soil. Preliminary results show that for an applied potential of 200 V over approximately 200 hr, {sup 137}Cs and {sup 60}60 were transported a distance of 4 to 5 in. The monitoring technique demonstrated the feasibility of using electrokinetics for soil separation applications.

Buehler, M.F.; Surma, J.E.; Virden, J.W.

1994-10-01

83

Reducing metal ion release following hip resurfacing arthroplasty.  

PubMed

Recent guidelines have suggested that routine postoperative care of patients with metal-on-metal hip prostheses should involve metal ion analysis. This study sought to investigate the relationship between bearing surface wear rates of metal components and serum metal ion analysis and also to quantify the incidence of excessive increases in serum metal ion concentrations post-hip resurfacing arthroplasty. PMID:21435493

Langton, David J; Joyce, Thomas J; Mangat, Navjeet; Lord, James; Van Orsouw, Maarten; De Smet, Koen; Nargol, Antoni V F

2011-04-01

84

Metal-ion recycle technology for metal electroplating waste waters  

SciTech Connect

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.

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

1993-06-01

85

Scrap metal management issues associated with naturally occurring radioactive material  

Microsoft Academic Search

Certain industrial processes sometimes generate waste by-products that contain naturally occurring radioactive material (NORM) at elevated concentrations. Some industries, including the water treatment, geothermal energy, and petroleum industries, generate scrap metal that may be contaminated with NORM wastes. Of these three industries, the petroleum industry probably generates the largest quantity of NORM-contaminated equipment, conservatively estimated at 170,000 tons per year.

K. P. Smith; D. L. Blunt

1995-01-01

86

Uptake of metal ions on humic acids  

SciTech Connect

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.

Pehlivan, E.; Arslan, G. [Selcuk University, Konya (Turkey)

2006-09-15

87

Serum metal ion levels after second-generation metal-on-metal total hip arthroplasty  

Microsoft Academic Search

Introduction  Metal-on-metal bearings for total hip arthroplasty are increasing in popularity. However, metal ion toxicity, metal hypersensitivity,\\u000a and metal carcinogenicity are the causes concern for patients with metal-on-metal hip replacement. We investigated serum levels\\u000a of cobalt and chromium ions in patients with successfully implanted second-generation metal-on-metal total hip arthroplasty\\u000a (THA) using PINNACLE-A (DePuy, Warsaw, IN, USA).\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  Thirty-three patients underwent

Takao Imanishi; Masahiro Hasegawa; Akihiro Sudo

2010-01-01

88

Transparent monolithic metal ion containing nanophase aerogels  

Microsoft Academic Search

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

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

1999-01-01

89

Ion Beam Studies of Hydrogen in Metals.  

National Technical Information Service (NTIS)

Methods based on ion implantation and nuclear reaction analysis were used to investigate the behavior of hydrogen isotopes in metals. The binding enthalpy of deuterium (D) at irradiation effects, He bubbles, D sub 2 bubbles, and metal-oxide interfaces was...

S. M. Myers W. R. Wampler F. Besenbacher S. L. Robinson N. R. Moody

1984-01-01

90

Reactions of fulvic acid with metal ions  

Microsoft Academic Search

Fulvic acid is a water-soluble humic material that occurs widely in soils and waters and that tends to form water-soluble and water-insoluble complexes with a variety of metal ions, some of which are toxic. This paper presents information on the conditions under which the different types of FA-metal complexes are formed.

M. Schnitzer; H. Kerndorff

1981-01-01

91

Ion exchange of alkali metals on hydrous titanium dioxide in neutral and alkaline solutions  

Microsoft Academic Search

Selectivity of hydrous titanium dioxide as an ion exchanger for alkali metal and tetraalkylammonium ions, has been studied using radioactive indicators:22Na and137Cs. The equilibrium distribution of trace amounts of sodium and cesium ions between the exchanger and aqueous solutions containing macroamounts of other univalent cations was studied over the temperature range of 15 to 80°C. The selectivity sequence in slightly

A. Bilewicz; R. Dybczynski; J. Narbutt

1991-01-01

92

ISOL science at the Holifield Radioactive Ion Beam Facility  

NASA Astrophysics Data System (ADS)

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.

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

93

Upgraded vacuum arc ion source for metal ion implantation.  

PubMed

Vacuum arc ion sources have been made and used by a large number of research groups around the world over the past twenty years. The first generation of vacuum arc ion sources (dubbed "Mevva," for metal vapor vacuum arc) was developed at Lawrence Berkeley National Laboratory in the 1980s. This paper considers the design, performance parameters, and some applications of a new modified version of this kind of source which we have called Mevva-V.Ru. The source produces broad beams of metal ions at an extraction voltage of up to 60 kV and a time-averaged ion beam current in the milliampere range. Here, we describe the Mevva-V.Ru vacuum arc ion source that we have developed at Tomsk and summarize its beam characteristics along with some of the applications to which we have put it. We also describe the source performance using compound cathodes. PMID:22380197

Nikolaev, A G; Oks, E M; Savkin, K P; Yushkov, G Yu; Brown, I G

2012-02-01

94

Metal vapor arc ion plating  

DOEpatents

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.

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

1986-09-09

95

Mutagenicity of metal ions in bacteria.  

PubMed

The mutagenicity of 24 metal salts was investigated in plate incorporation and fluctuation assays with Salmonella TA strains or Escherichia coli WP2 uvrA pKm 101. Chromate(VI) and selenate(VI) ions were found to be mutagenic in plate incorporation assays employing conventional media. On the other hand, cadmium(II), beryllium(II), chromate(VI), and metavanadate(V) ions were detected in conventional fluctuation assays, indicating the importance of this technique in detection of metal mutagens. Modified culture media, with trimetaphosphate ions in place of orthophosphate as the sole phosphate source for bacterial growth, were also used in this study. The media modifications prevented precipitation of metals such as nickel and cadmium as their insoluble phosphates, and allowed detection of the mutagenicity of metavanadate ions in plate incorporation assays. However, the fluctuation technique using standard media was shown to detect a wider range of mutagenic metal ions than tests with modified media. It is notable that metaarsenite(III), arsenate(V), and nickel(II) ions were not found to be mutagenic in any of the assays although they are known to be carcinogenic and are mutagenic in other test systems. Their lack of mutagenicity in the modified media indicates that precipitation of these ions as orthophosphates is not the reason for their lack of activity in standard bacterial assays. PMID:3884331

Arlauskas, A; Baker, R S; Bonin, A M; Tandon, R K; Crisp, P T; Ellis, J

1985-04-01

96

Mutagenicity of metal ions in bacteria  

SciTech Connect

The mutagenicity of 24 metal salts was investigated in plate incorporation and fluctuation assays with Salmonella TA strains or Escherichia coli WP2 uvrA pKm 101. Chromate(VI) and selenate(VI) ions were found to be mutagenic in plate incorporation assays employing conventional media. On the other hand, cadmium(II), beryllium(II), chromate(VI), and metavanadate(V) ions were detected in conventional fluctuation assays, indicating the importance of this technique in detection of metal mutagens. Modified culture media, with trimetaphosphate ions in place of orthophosphate as the sole phosphate source for bacterial growth, were also used in this study. The media modifications prevented precipitation of metals such as nickel and cadmium as their insoluble phosphates, and allowed detection of the mutagenicity of metavanadate ions in plate incorporation assays. However, the fluctuation technique using standard media was shown to detect a wider range of mutagenic metal ions than tests with modified media. It is notable that metaarsenite(III), arsenate(V), and nickel(II) ions were not found to be mutagenic in any of the assays although they are known to be carcinogenic and are mutagenic in other test systems. Their lack of mutagenicity in the modified media indicates that precipitation of these ions as orthophosphates is not the reason for their lack of activity in standard bacterial assays.

Arlauskas, A.; Baker, R.S.U.; Bonin, A.M.; Tandon, R.K.; Crisp, P.T.; Ellis, J.

1985-04-01

97

Tyrosine Modification Enhances Metal Ion Binding  

PubMed Central

Tyrosine sulphation is a common modification of many proteins, and the ability to phosphorylate tyrosine residues is an intrinsic property of many growth factor receptors. We have utilized the peptide hormone cholecystokinin (CCK8), which occurs naturally in both sulphated and unsulphated forms, as a model to investigate the effect of tyrosine modification on metal ion binding. The changes in absorbance and fluorescence emission on Fe3+ ion binding indicated that tyrosine sulphation or phosphorylation increased the stoichiometry from 1 to 2, without greatly affecting the affinity (0.6–2.8 ?M at pH 6.5). Measurement of calcium binding with a calcium-selective electrode revealed that phosphorylated CCK8 bound two Ca2+ ions. CCK8 and sulphated CCK8 each bound only one Ca2+ ion with lower affinity. Binding of Ca2+, Zn2+ or Bi3+ ions to phosphorylated CCK8 did not cause any change in absorbance, but substantially increased the change in absorbance on subsequent addition of Fe3+ ions. Our results demonstrate that tyrosine modification may increase the affinity of metal ion binding to peptides, and imply that metal ions may directly regulate many signaling pathways.

BALDWIN, Graham S.; BAILEY, Michael F.; SHEHAN, B. Philip; SIMS, Ioulia; NORTON, Raymond S.

2008-01-01

98

Metal Ion Hypersensitivity in Metal-on-Metal Hip Arthroplasty  

Microsoft Academic Search

Total hip arthroplasty with use of metal-on-metal bearings has been reintroduced as an alternative to metal-on-polyethylene\\u000a bearings because of theoretical advantages such as reduced wear and a lower prevalence of osteolysis. However, we have observed\\u000a early osteolysis in nine patients (ten hips) out of 165 patients (169 hips) who had been managed with total hip replacements\\u000a using a contemporary metal-on-metal

Y.-S. Park; Y.-W. Moon; S.-J. Lim

99

Structure determination of gaseous metal and semi-metal cluster ions by ion mobility spectrometry  

Microsoft Academic Search

Gas phase ion mobility spectrometry in combination with quantum chemical calculations has proven to be extremely useful for the structure determination of cluster ions. After a short introduction into the methodology, investigations focused on clusters of different main group metals and semi-metals are reviewed. Based on the findings of different groups, it became apparent that in many cases small clusters

Patrick Weis

2005-01-01

100

Direct conversion of radioactive and chemical waste containing metals, ceramics, amorphous solids, and organics to glass  

SciTech Connect

The Glass Material Oxidation and Dissolution System (CMODS) is a new process for direct conversion of radioactive, mixed, and chemical wastes to glass. The wastes can be in the chemical forms of metals, ceramics, amorphous solids, and organics. GMODS destroys organics and it incorporates heavy metals and radionuclides into a glass. Processable wastes may include miscellaneous spent fuels (SF), SF hulls and hardware, plutonium wastes in different forms, high-efficiency particulate air (HEPA) filters, ion-exchange resins, failed equipment, and laboratory wastes. Thermodynamic calculations indicate theoretical feasibility. Small-scale laboratory experiments (< 100 g per test) have demonstrated chemical laboratory feasibility for several metals. Additional work is needed to demonstrate engineering feasibility.

Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

1994-05-02

101

Development of a radioactive ion beam test stand at LBNL  

SciTech Connect

For the on-line production of a {sup 14}O{sup +} ion beam, an integrated target--transfer line ion source system is now under development at LBNL. {sup 14}O is produced in the form of CO in a high temperature carbon target using a 20 MeV {sup 3}He beam from the LBNL 88'' Cyclotron via the reaction {sup 12}C({sup 3}He,n){sup 14}O. The neutral radioactive CO molecules diffuse through an 8 m room temperature stainless steel line from the target chamber into a cusp ion source. The molecules are dissociated, ionized and extracted at energies of 20 to 30 keV and mass separated with a double focusing bending magnet. The different components of the setup are described. The release and transport efficiency for the CO molecules from the target through the transfer line was measured for various target temperatures. The ion beam transport efficiencies and the off-line ion source efficiencies for Ar, O{sub 2} and CO are presented. Ionization efficiencies of 28% for Ar{sup +}, 1% for CO, 0.7% for O{sup +}, 0.33 for C{sup +} have been measured.

Burke, J.; Freedman, S.J.; Fujikawa, B.; Gough, R.A.; Lyneis, C.M.; Vetter, P.; Wutte, D.; Xie, Z.Q.

1998-10-05

102

Assessment of recycling or disposal alternatives for radioactive scrap metal  

SciTech Connect

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.

Murphie, W.E.; Lilly, M.J. III [USDOE Assistant Secretary for Environmental Restoration and Waste Management, Washington, DC (United States). Office of Environmental Restoration; Nieves, L.A.; Chen, S.Y. [Argonne National Lab., IL (United States)

1993-10-01

103

Nitrenium ions as ligands for transition metals  

NASA Astrophysics Data System (ADS)

Unlike N-heterocyclic carbenes (NHCs), which are now used ubiquitously in metal-based chemistry, the nitrogen-derived analogue (in which a carbon is replaced with the isoelectronic nitrogen cation, a nitrenium ion) has remained elusive as a ligand for metals. This is especially intriguing, because several other main-group analogues of NHCs have been prepared, and have been shown to coordinate with transition-metal complexes. Here, we describe the preparation of several N-heterocyclic nitrenium ions that are isoelectronic and isostructural to NHCs, and study their ligand properties. The formation of relatively strong nitrenium-metal bonds is unambiguously confirmed, in solution by selective 15N-labelling experiments, and in the solid state by X-ray crystallography. Experimental and computational studies of the electronic properties of this novel type of ligand suggest that they are poor ?-donors and good ?-acceptors.

Tulchinsky, Yuri; Iron, Mark A.; Botoshansky, Mark; Gandelman, Mark

2011-07-01

104

Assessment of recycling or disposal alternatives for radioactive scrap metal  

SciTech Connect

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.

Murphie, W.E.; Lilly, M.J. III [US Dept. of Energy, Oak Ridge, TN (United States); Nieves, L.A.; Chen, S.Y. [Argonne National Lab., IL (United States)

1993-11-01

105

Mutagenicity of metal ions in bacteria  

Microsoft Academic Search

The mutagenicity of 24 metal salts was investigated in plate incorporation and fluctuation assays with Salmonella TA strains or Escherichia coli WP2 uvrA pKm 101. Chromate(VI) and selenate(VI) ions were found to be mutagenic in plate incorporation assays employing conventional media. On the other hand, cadmium(II), beryllium(II), chromate(VI), and metavanadate(V) ions were detected in conventional fluctuation assays, indicating the importance

A. Arlauskas; R. S. U. Baker; A. M. Bonin; R. K. Tandon; P. T. Crisp; J. Ellis

1985-01-01

106

[Development of trace metal ion analysis].  

PubMed

Analyses of trace biologically essential or toxic ionic compounds found in the environment are very important. However, the lack of sensitivity and interference caused by coexisting components are often serious problems. To determine trace levels of metal ions without the above problems, new preconcentration and analytical methods have been developed. Firstly, three methods for the selective preconcentration of metal ions are shown below: 1) 3-Chloropyridazine-6-carbohydrazide was immobilized on glass beads supports to be used as a column packing material. Multi-metal ions were concentrated on the column and eluted selectively with several buffers and hydrochloric acid. The eluate was analyzed off-line by flame atomized-atomic absorption spectrometry (AAS). This method was able to determine sub-ppb levels of cupper- and cadmium-ions in environmental samples. 2) Salicylideneamino-2-thiophenol was immobilized on the supports. Aluminum ion was concentrated selectively on the column and eluted with nitric acid. The eluate was analyzed off-line by flameless-AAS or on-line by flow injection analysis using pyrocatechol violet for a post-column colorimetric reagent. These methods were able to determine ppb-ppt levels of aluminium in environmental samples and were suitable for its state-analysis. 3) Bathocuproinesulfonic acid was immobilized on the supports. Copper ion was concentrated selectively on the column and eluted with nitric acid. The eluate was analyzed on-line by flow injection analysis using bathocuproinesulfonic acid. This method was able to determine sub-ppb levels of copper in environmental samples. On the other hand, to analyze simultaneously trace metal ions and anions, capillary electrophoresis was performed using ethylenediaminetetraacetic acid as an electrolyte component. Simultaneous determination of several ions in mineral waters was achieved by the system. PMID:11019646

Kobayashi, J

2000-09-01

107

Accelerating Radioactive Ion Beams With REX-ISOLDE  

SciTech Connect

The post accelerator REX-ISOLDE is installed at the ISOLDE facility at CERN, where a broad variety of radioactive ions can be addressed. Since the end of 2001 beams at the final energy of 2.2 MeV/u are available. REX-ISOLDE uses a unique system of beam bunching and charge breeding. First a Penning trap accumulates and bunches the ions, which are delivered as a quasi-continuous beam from the ISOLDE target-ion-source, and then an electron beam ion source (EBIS) charge-breeds them to a mass-to-charge ratio below 4.5. This enables a very compact design for the following LINAC, consisting of a 4 rod RFQ, an IH structure and three 7-gap-resonators. The later ones allow a variation of the final energy between 0.8 and 2.2 MeV/u. Although the machine is still in the commissioning phase, first physics experiments have been done with neutron rich Na and Mg isotopes and 9Li. A total efficiency of several percent has already been obtained.

Ames, F.; Emhofer, S.; Habs, D.; Kester, O.; Reisinger, K.; Sieber, T. [Sektion Physik, LMU, Muenchen, D-85748 Garching (Germany); Bollen, G. [NSCL, Michigan State University, East Lansing, MI 48824 (United States); Cederkaell, J.; Forstner, O.; Wenander, F. [CERN, CH-1211 Geneva 23 (Switzerland); Huber, G.; Wolf, B. [Institut fuer Physik, J. Gutenberg-Universitaet, D-55099 Mainz (Germany); Schwalm, D.; Hahn, R. von [Max-Planck-Institut fuer Kernphysik, D-69117 Heidelberg (Germany); Bergh, P. van den; Duppen, P. van [Instituut voor Kern- en Stralingsfysica, K.U. Leuven, B-3001 Leuven (Belgium)

2003-08-26

108

Heavy metals, organics and radioactivity in soil of western Serbia.  

PubMed

Western Serbia is a region well-known for potato production. Concentrations of selected metals, polycyclic aromatic hydrocarbons (PAHs) and radioactivity were measured in the soil in order to evaluate the quality and characteristics. The examined soils (Luvisol and Pseudogley) showed unsuitable agrochemical characteristics (acid reaction, low content of organic matter and potassium). Some samples contained Ni, Mn and Cr above the maximal permissible concentration (MPC). The average concentration of total PAHs was 1.92 mg/kg, which is larger than the maximal permissible concentration in Serbia but below the threshold values in the European Union for food production. The average radioactivity of (238)U, (226)Ra, (232)Th, (40)K and the fission product (137)Cs were 60.4+/-26.2, 33.2+/-13.4, 49.1+/-18.5, 379+/-108 and 36.4+/-23.3 Bq/kg. Enhanced radioactivity in the soils was found. The total absorbed dose rate in air above the soil at 1m height calculated for western Serbia was 73.4 nGy/h and the annual effective dose was 90 microSv, which are similar to earlier reports for the study region. PMID:20060645

Dugalic, Goran; Krstic, Dragana; Jelic, Miodrag; Nikezic, Dragoslav; Milenkovic, Biljana; Pucarevic, Mira; Zeremski-Skoric, Tijana

2010-05-15

109

Effect of metal ions on positron annihilation characteristics in metal ion containing epoxies  

NASA Technical Reports Server (NTRS)

In the course of developing improved moisture-resistant epoxy resins, two different types of epoxy resins containing variable mole ratios of chromium ions per polymer repeat unit were developed. Positron annihilation characteristics have been investigated in these resins as a function of their metal ion content. In both cases, the presence of metal ions reduces the lifetime as well as the intensity of the long life component. The long life component intensity reduction is considerably more pronounced than the lifetime reduction. These results have been discussed in terms of increased unpaired electron density at Ps formation sites due to the presence of chromium ions in the matrix.

Singh, J. J.; St. Clair, A. K.; Stoakley, D. M.; Holt, W. H.; Mock, W., Jr.

1984-01-01

110

Genetically Engineered Pores Sensing Metal Ions.  

National Technical Information Service (NTIS)

Stochastic sensing with pore-forming proteins has been established as a means for sensing metal ions by using engineered forms of alpha-hemolysin as the sensor elements. The alpha-hemolysin pore is a heptamer, which has disadvantages for certain manipulat...

H. Bayley S. Conlan

2000-01-01

111

Tyrosine modification enhances metal-ion binding.  

PubMed

Tyrosine sulfation is a common modification of many proteins, and the ability to phosphorylate tyrosine residues is an intrinsic property of many growth-factor receptors. In the present study, we have utilized the peptide hormone CCK(8) (cholecystokinin), which occurs naturally in both sulfated and unsulfated forms, as a model to investigate the effect of tyrosine modification on metal-ion binding. The changes in absorbance and fluorescence emission on Fe(3+) binding indicated that tyrosine sulfation or phosphorylation increased the stoichiometry from 1 to 2, without greatly affecting the affinity (0.6-2.8 microM at pH 6.5). Measurement of Ca(2+) binding with a Ca(2+)-selective electrode revealed that phosphorylated CCK(8) bound two Ca(2+) ions. CCK(8) and sulfated CCK(8) each bound only one Ca(2+) ion with lower affinity. Binding of Ca(2+), Zn(2+) or Bi(3+) to phosphorylated CCK(8) did not cause any change in absorbance, but substantially increased the change in absorbance on subsequent addition of Fe(3+). The results of the present study demonstrate that tyrosine modification may increase the affinity of metal-ion binding to peptides, and imply that metal ions may directly regulate many signalling pathways. PMID:18636967

Baldwin, Graham S; Bailey, Michael F; Shehan, B Philip; Sims, Ioulia; Norton, Raymond S

2008-11-15

112

Variation of Radioactive Atmospheric Ion Concentration Associated With Large Earthquakes  

NASA Astrophysics Data System (ADS)

Tributsch (1978) pointed out the possibility of anomalous atmospheric ion changes preceding large earthquakes. Large and sudden changes in atmospheric ion concentration (AIC) have been observed at Kobe 8 days before the 1995 Kobe Earthquake (M7.3) in Japan (Satsutani, 1996). In order to evaluate the possibility of the short-term prediction by monitoring AIC, we have started the continuous measurement of AIC at Okayama, Japan, since 1998. Possible changes of positive large AIC have been observed prior to the 2000 western Tottori (M7.3) and 2001 Geiyo (M6.7) Earthquakes which occurred near the Okayama station. To clarify the spatial and temporal variation of AIC, we have been established the AIC measurement network since 2004 using Gerdien condensers we developed. From July 2008, a most part of these sensors has been replaced by new devices (COM SYSTEM, INC., COM-3700) for more stable observation. There are 10 stations in operation now. Meanwhile, in order to investigate the generation mechanism of atmospheric ions associated with earthquakes, we have measured the radiation of collected aerosols using three methods: PSL method, Ge-LEPS method, and radioactive half-life method with GM counter. We also monitor the Radon concentration with AIC simultaneously at three stations. Recently we observed the anomalous changes of AIC prior to the 2008 Iwate-Miyagi Nairiku Earthquake (M7.2). The results will be shown in the presentation.

Hattori, K.; Wadatsumi, K.; Furuya, R.; Yada, N.; Yamamoto, I.; Ninagawa, K.; Ideta, Y.; Nishihashi, M.

2008-12-01

113

Material Removes Heavy Metal Ions From Water  

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

114

Metal ions affecting reproduction and development.  

PubMed

Many metal ions (lead, mercury, arsenic, cadmium, chromium, nickel, vanadium, copper, lithium) exert a wide variety of adverse effects on reproduction and development, including influence on male and female subfertility or fertility, abortions, malformations, birth defects, and effects on the central nervous system. The effects produced by metal ions depend on several factors, such as timing and duration of exposure, their distribution and accumulation in various organs (e.g., the nervous system), and on the interference with specific developmental processes. Neonatal and early postnatal periods are lifespan segments during which sensitivity to metals is high; e.g., lead toxicity on the developing organism is paradigmatic of related well known and still open questions. In more recent decades, important mechanisms of action have been suggested: the endocrine disruption via impact of metal ions on reproductive hormones and the oxidative stress. While experimental data provide clear evidence of effects of many metals, human data are scant and traditionally limited to high levels of a few metal ions, like lead on male fertility. Less documented are reproductive effects for mercury, manganese, chromium, nickel, and arsenic for the same gender. More complex is the demonstration of effects on female reproduction and on pregnancy. The action of lead, arsenic, cadmium, chromium, and mercury may in fact be relevant in several stages, beginning in fetal life, during early development or maturity, and is characterized by subfertility, infertility, intrauterine growth retardation, spontaneous abortions, malformations, birth defects, postnatal death, learning and behavior deficits, and premature aging. Also, for females the evidences of specific aspects such as fertility or abortions are usually higher and clearer from animal experiments than from human studies. PMID:21473384

Apostoli, Pietro; Catalani, Simona

2011-01-01

115

Biosensors for the Detection of Heavy Metal Ions.  

National Technical Information Service (NTIS)

Phytochelatins, metallothioneins and glutathione are under investigation as biological components for the development of biosensors for heavy metal ion detection in aqueous solutions. These peptides/proteins selectively bind heavy metal ions by thiolate c...

R. Hilpert F. Binder M. H. Zenk

1989-01-01

116

Alkali metal ion-selective electrodes based on relevant alkali metal ion doped manganese oxides  

Microsoft Academic Search

Potentiometric properties of manganese oxides doped with alkali metal ions (Na+, K+, Rb+ and Cs+), which were prepared by heating mixed solutions (starting solution) of each alkali metal and Mn2+ ions, were examined. Electrodes based on mixed phases of Nao44MnO2\\/Mn2O3 and hollandite KMn8O16\\/M2O3 found by X-ray powder diffraction (XRD) exhibited Na+- and K+-selective responses with a near-Nernstian slope, respectively, when

Yukinori Tani; Yoshio Umezawa

1998-01-01

117

Low-energy radioactive ion beam production of 22Mg  

NASA Astrophysics Data System (ADS)

The 22Mg nucleus plays an important role in nuclear astrophysics, specially in the 22Mg(?,p)25Al and proton capture 22Mg(p,?)23Al reactions. It is believed that 22Mg is a waiting point in the ?p-process of nucleosynthesis in novae. We proposed a direct measurement of the 22Mg+? resonance reaction in inverse kinematics using a radioactive ion (RI) beam. A 22Mg beam of 3.73 MeV/u was produced at CRIB (Center for Nuclear Study (CNS) low-energy RI Beam) facility of the University of Tokyo located at RIKEN (Japan) in 2011. In this paper we present the results about the production of the 22Mg beam used for the direct measurement of the scattering reaction 22Mg(?,?)22Mg, and the stellar reaction 22Mg(?,p)25Al in the energy region concerning an astrophysical temperature of T9=1-3 GK.

Duy, N. N.; Kubono, S.; Yamaguchi, H.; Kahl, D.; Wakabayashi, Y.; Teranishi, T.; Iwasa, N.; Kwon, Y. K.; Khiem, L. H.; Kim, Y. H.; Song, J. S.; Hu, J.; Ayyad, Y.

2013-09-01

118

High-current pulsed ion source for metallic ions  

SciTech Connect

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.

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

1981-03-01

119

Coprecipitation of alkali metal ions with calcium carbonate  

Microsoft Academic Search

The coprecipitation of alkali metal ions (Li + , Na + , K + and Rb + ) with calcium carbonate has been studied experimentally and the following results have been obtained: 1. (1) Alkali metal ions are more easily coprecipitated with aragonite than with calcite. 2. (2) The relationship between the amounts of alkali metal ions coprecipitated with aragonite

Minoru Okumura; Yasushi Kitano

1986-01-01

120

Ligand Field Stabilization Control of Metal Ion Binding.  

National Technical Information Service (NTIS)

Specific metal ions bind to particular sites within proteins. The factors that might influence the thermodynamics of metal ion binding to proteins include metal ion radius, hard-soft acid-base effects, and ligand field stabilization energy changes. We hav...

J. M. Berg

1994-01-01

121

Fulvic acid: modifier of metal-ion chemistry  

Microsoft Academic Search

Fulvic acid, which is derived from the decay of plants and animals, is being studied for its role in the transport and toxicity of metal ions in soil and water. It is discussed in relation to the origin of humic substances and its interactions with metal ions. Techniques for investigating complexes of fulvic acid and metal ions are presented. They

Robert A. Saar; James H. Weber

1982-01-01

122

Engineering of microorganisms towards recovery of rare metal ions.  

PubMed

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

Kuroda, Kouichi; Ueda, Mitsuyoshi

2010-06-01

123

Analysis of disposition alternatives for radioactively contaminated scrap metal  

SciTech Connect

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.

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

1997-01-01

124

Porous metal filter collects radioactive strontium in hot cell operation  

SciTech Connect

The separation of a purified inorganic salt from a batch of slurry containing a high level radionuclide presented some unusual requirements at Rockwell Hanford's fission products production facility in Richland, WA. The product, radioactive strontium, is encapsulated as purified strontium fluoride after the recovered precipitate is sintered in a furnace to drive off all volatiles. The separation process required a filter to collect the finely divided strontium fluoride particles. The filter is required to withstand temperatures of 300-400/sup 0/C and maintain chemical stability in high levels of radioactivity. The filter also has to be sturdy enough to be manageable by a remote master/slave electromechanical manipulator in a hot cell. In addition, the filter must withstand a corrosive environment where the potential of traces of hydrofluoric acid exists. A uniformly permeable filter medium with low pressure drop and high particulate removal efficiency was necessary to ensure total recovery and clean filtrate. Strontium fluoride is precipitated batchwise from a reaction between sodium fluoride and strontium nitrate. After chemical adjustments are completed, the whole batch is filtered through a bank of four vacuum filters which contain a porous metal filter medium. Cylinders of sintered porous stainless steel were chosen as the filter medium because they were adaptable to the handling requirements and met the stringent separation criteria. The overall reaction-to-encapsulation operation at Rockwell Hanford has been developed to achieve better than 99% recovery of the strontium. The consistent performance of the porous metal cartridge filter medium has played an important part in maintaining this high recovery.

Fulton, J.; Hodel, A.E.

1985-03-01

125

A gas jet target for radioactive ion beam experiments  

SciTech Connect

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.

Chipps, K. A.; Greife, U.; Hager, U.; Sarazin, F. [Colorado School of Mines, Golden, CO (United States); Bardayan, D. W.; Pain, S. D.; Schmitt, K. T.; Smith, M. S. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Blackmon, J. C.; Linhardt, L. E. [Louisiana State University, Baton Rouge, LA (United States); Browne, J.; Kontos, A.; Meisel, Z.; Montes, F.; Schatz, H. [National Superconducting Cyclotron Laboratory/Michigan State University, East Lansing, MI (United States); Couder, M.; Robertson, D.; Wiescher, M. [University of Notre Dame, Notre Dame, IN (United States); Erikson, L. E. [Pacific Northwest National Laboratory, Richland, WA (United States); Lemut, A. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); and others

2013-04-19

126

Beta-delayed neutron spectroscopy using trapped radioactive ions  

NASA Astrophysics Data System (ADS)

The properties of beta-delayed neutron emission are of interest to both the basic and applied nuclear physics communities. For example, branching ratios are needed to determine how the short-lived neutron-rich isotopes synthesized in the astrophysical r process decay back to stability to become the isotopes we observe today. Also, neutron energy spectra and branching ratios are required for the design of nuclear reactors. Reliable measurements of the beta-delayed neutron properties can be performed with unprecedented precision using an ion trap surrounded by radiation detectors. When a radioactive ion decays in the trap, the recoil-daughter nucleus and emitted particles emerge from the ˜1 mm^3 trap volume with minimal scattering. These properties allow the momentum and energy of the emitted neutron to be precisely reconstructed from the nuclear recoil. Spectroscopy of beta-delayed neutrons can be performed with high efficiency, energy resolutions approaching ˜3%, and virtually no background. Results from a recent proof-of-principle experiment will be discussed. Prepared by LLNL under Contract DE-AC52-07NA27344 and ANL under Contract DE-AC02-06CH11357.

Yee, Ryan; Scielzo, N. D.; Bertone, P. F.; Buchinger, F.; Caldwell, S.; Clark, J. A.; Deibel, C. M.; Fallis, J.; Li, G.; Gulick, S.; Lascar, D.; Levand, A. F.; Norman, E. B.; Pedretti, M.; Savard, G.; Segel, R. E.; Sharma, K. S.; Sternberg, M. G.; van Schelt, J.; Zabransky, B. J.

2011-11-01

127

ORNL developments in laser ion sources for radioactive ion beam production  

NASA Astrophysics Data System (ADS)

The development of a resonant ionization laser ion source (RILIS) for the production of isotopically pure radioactive ion beams is reported. The application of the laser ion source calls for high elemental selectivity, high efficiency, and fast release of short-lived isotopes. A hot-cavity ion source and three Ti:sapphire lasers pulsed at a 10 kHz rate are employed for the RILIS. The Ti:sapphire lasers have been upgraded with individual pump lasers to eliminate intracavity Pockels cells and output losses due to synchronization delays. The development of ionization schemes for a wide range of elements is important to the success of Ti:sapphire-laser-based RILIS. In off-line studies with stable isotopes, resonant ionization of 14 elements has been studied, leading to new ionization schemes for ten elements. The absolute ionization efficiency of the hot-cavity RILIS has been measured to range from 0.9 % to 40 % for different elements. The mechanisms for ion transportation and confinement in the hot-cavity ion source have been studied using the temporal profiles of the laser-ionized ions. The hot-cavity RILIS has provided beams of neutron-rich Ga isotopes for beta decay studies and enabled the first measurement of the beta decay of the exotic Ga.

Liu, Yuan

2014-06-01

128

ORNL developments in laser ion sources for radioactive ion beam production  

NASA Astrophysics Data System (ADS)

The development of a resonant ionization laser ion source (RILIS) for the production of isotopically pure radioactive ion beams is reported. The application of the laser ion source calls for high elemental selectivity, high efficiency, and fast release of short-lived isotopes. A hot-cavity ion source and three Ti:sapphire lasers pulsed at a 10 kHz rate are employed for the RILIS. The Ti:sapphire lasers have been upgraded with individual pump lasers to eliminate intracavity Pockels cells and output losses due to synchronization delays. The development of ionization schemes for a wide range of elements is important to the success of Ti:sapphire-laser-based RILIS. In off-line studies with stable isotopes, resonant ionization of 14 elements has been studied, leading to new ionization schemes for ten elements. The absolute ionization efficiency of the hot-cavity RILIS has been measured to range from 0.9 % to 40 % for different elements. The mechanisms for ion transportation and confinement in the hot-cavity ion source have been studied using the temporal profiles of the laser-ionized ions. The hot-cavity RILIS has provided beams of neutron-rich ^{83,85,86}Ga isotopes for beta decay studies and enabled the first measurement of the beta decay of the exotic ^{86}Ga.

Liu, Yuan

2013-11-01

129

Selection of RIB targets using ion implantation at the Holifield radioactive ion beam facility  

SciTech Connect

Among several major challenges posed by generating and accelerating adequate intensities of RIBs, selection of the most appropriate target material is perhaps the most difficult because of the requisite fast and selective thermal release of minute amounts of the short-lived product atoms from the ISOL target in the presence of bulk amounts of target material. Experimental studies are under way at the Oak Ridge National Laboratory (ORNL) which are designed to measure the time evolution of implanted elements diffused from refractory target materials which are candidates for forming radioactive ion beams (RIBs) at the Holifield Radioactive Ion Beam Facility (HRIBF). The diffusion coefficients are derived by comparing experimental data with numerical solutions to a one-dimensional form of Fick`s second law for ion implanted distributions. In this report, we describe the experimental arrangement, experimental procedures, and provide time release data and diffusion coefficients for releasing ion implanted {sup 37}Cl from Zr{sub 5}Si{sub 3} and {sup 75}As, {sup 79}Br, and {sup 78}Se from Zr{sub 5}Ge{sub 3} and estimates of the diffusion coefficients for{sup 35}Cl, {sup 63}Cu, {sup 65}Cu, {sup 69}Ga and {sup 71}Ga diffused from BN; {sup 35}Cl, {sup 63}Cu, {sup 65}Cu, {sup 69}Ga, {sup 75}As, and {sup 78}Se diffused from C; {sup 35}Cl, {sup 68}Cu, {sup 69}Ga, {sup 75}As, and {sup 78}Se diffused from Ta.

Alton, G.D.; Dellwo, J.

1995-12-31

130

Metal hydrides for lithium-ion batteries  

Microsoft Academic Search

Classical electrodes for Li-ion technology operate via an insertion\\/de-insertion process. Recently, conversion electrodes have shown the capability of greater capacity, but have so far suffered from a marked hysteresis in voltage between charge and discharge, leading to poor energy efficiency and voltages. Here, we present the electrochemical reactivity of MgH2 with Li that constitutes the first use of a metal-hydride

Y. Oumellal; A. Rougier; G. A. Nazri; J.-M. Tarascon; L. Aymard

2008-01-01

131

Metal hydrides for lithium-ion batteries  

NASA Astrophysics Data System (ADS)

Classical electrodes for Li-ion technology operate via an insertion/de-insertion process. Recently, conversion electrodes have shown the capability of greater capacity, but have so far suffered from a marked hysteresis in voltage between charge and discharge, leading to poor energy efficiency and voltages. Here, we present the electrochemical reactivity of MgH2 with Li that constitutes the first use of a metal-hydride electrode for Li-ion batteries. The MgH2 electrode shows a large, reversible capacity of 1,480mAhg-1 at an average voltage of 0.5V versus Li+/Li? which is suitable for the negative electrode. In addition, it shows the lowest polarization for conversion electrodes. The electrochemical reaction results in formation of a composite containing Mg embedded in a LiH matrix, which on charging converts back to MgH2. Furthermore, the reaction is not specific to MgH2, as other metal or intermetallic hydrides show similar reactivity towards Li. Equally promising, the reaction produces nanosized Mg and MgH2, which show enhanced hydrogen sorption/desorption kinetics. We hope that such findings can pave the way for designing nanoscale active metal elements with applications in hydrogen storage and lithium-ion batteries.

Oumellal, Y.; Rougier, A.; Nazri, G. A.; Tarascon, J.-M.; Aymard, L.

2008-11-01

132

Patterned Polymer-Metal Ion Complexes  

NASA Astrophysics Data System (ADS)

The doping of polymers with metal ions has been of interest due to the possibility of tailoring their electrical, optical and mechanical properties. Such tailored polymers have potential applications in a variety of areas including flexible electronic devices and systems, optical systems such as those for holography, data storage, and mechanical systems. To extend the applications of metal doped polymers to novel micro-devices and systems, it is pertinent to develop methodologies to pattern or structure such polymers in small dimensions, often in the micro-scale. We report on the development of micro-patterned thin films of polyvinyl alcohol (PVA) doped with copper (Cu^2+) ions. The films were patterned in the micro-scale dimensions and larger by contact printing onto a substrate. Patterned Cu^2+ doped PVA films were also made by combining solution casting with micro-molding. Raman spectroscopic analysis of the developed Cu^2+ doped PVA films revealed the presence of PVA-Cu^2+ complexes. Further characterization of the Cu^2+ doped PVA films for electrical conductivity and x-ray diffraction is in progress and will be presented. The doping of PVA by other metal ions is also being explored and initial results will be presented.

Hoffpauir, Jonathan; Korivi, Naga; Ajmera, Pratul

2010-10-01

133

On the Metal Ion Selectivity of Oxoacid Extractants  

SciTech Connect

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.

Hay, Benjamin [ORNL; Chagnes, Alexandre [Chimie ParisTech; Cote, Gerard [Chimie ParisTech

2013-01-01

134

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

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

135

Effects of metal ion adduction on the gas-phase conformations of protein ions.  

PubMed

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 Ca(2+), 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. PMID:23733259

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

2013-11-01

136

Charge breeding of isotope on-line-created radioactive ions using an electron cyclotron resonance ion trap  

SciTech Connect

In the coming years huge ion-beam projects are foreseen. They deal with specific isotope on-line (ISOL) beams such as ISOL-created radioactive ions. The beam intensities are exceptionally high (>10{sup 12} ions/s), the radioactive lifetimes are short ({<=}1 s), and the ion energy is very high ({>=}150 GeV/u). In general in order to minimize the size of the accelerator one needs highly charged ISOL ions and therefore charge breeders are a must. In contrast with the CERN system, utilizing a Penning trap and an electron-beam ion source charge breeder (where the maximum ion beam cannot exceed 10{sup 6} ions/s) the Grenoble group launched in 1995 an electron cyclotron resonance (ECR) system capable of storing 10{sup 12} ions/s and delivering highly charged ISOL ions. In this article we show that this storage is possible for low-ion-energy ISOL ions following classical slowing down theory. In this case the injected ISOL ions are slowed down by ion-ion collisions which yield ion storage inside the ECR plasma, but also charge breeding by the energetic ECR electrons bombarding the slowed down ions.

Geller, R.; Lamy, T.; Sortais, P. [Laboratoire de Physique Subatomique et de Cosmologie 53, Avenue des Martyrs, F-38026 Grenoble, Cedex (France)

2006-03-15

137

Ion-beam sputtering and nanostructures of noble metals  

Microsoft Academic Search

Using the technique of ion-beam sputtering on gold (Au) and silver (Ag) metal films, metal nanoclusters vis-à-vis nanostructure materials are synthesized on silica glass substrates. Analyses of Rutherford backscattering spectra of Ar+-ion irradiated films confirm the ion-beam sputtering of metal films. Exponential decrease of experimentally measured areal density of Au atoms with the increase of ion doses has been elucidated.

P. Gangopadhyay; Sachin Kumar Srivastava; P. Magudapathy; T. N. Sairam; K. G. M. Nair; B. K. Panigrahi

2010-01-01

138

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

SciTech Connect

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.

Thorn, A.; Ritter, E.; Zschornack, G. [Fachrichtung Physik, Technische Universitaet Dresden, Helmholtzstrasse 10, D-01069 Dresden (Germany); Ullmann, F. [DREEBIT GmbH, Zur Wetterwarte 50, D-01109 Dresden (Germany); Pilz, W.; Bischoff, L. [Helmholtzzentrum Dresden-Rossendorf, Bautzner Landstrasse 400, D-01328 Dresden (Germany)

2012-02-15

139

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

PubMed

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(60 +). The setup, the charge breeding technique, breeding efficiencies as well as acceptance and emittance studies are presented. PMID:22380207

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

2012-02-01

140

The radioactive ion beams facility project for the legnaro laboratories  

SciTech Connect

In the frame work of the Italian participation to the project of a high intensity proton facility for the energy amplifier and nuclear waste transmutations, LNL is involving in the design and construction of prototypes of the injection system of the 1 GeV linac that consists of a RFQ (5 MeV, 30 mA) followed by a 100 MeV linac. This program has been already financially supported and the work is actually in progress. In this context, the LNL has been proposed a project for the construction of a second generation facility for the production of radioactive ion beams (RIBs) by using the ISOL method. The final goal consists in the production of neutron rich RIBs with masses ranging from 80 to 160 by using primary beams of protons, deuterons and light ions with energy of 100 MeV and 100 kW power. This project is proposed to be developed in about 10 years from now and intermediate milestones and experiments are foreseen and under consideration for the next INFN five year plan (1999-2003). In such period of time is proposed the construction of a proton/deuteron accelerator of 10 MeV energy and 10 mA current, consisting of a RFQ (5 MeV, 30 mA) and a linac (10 MeV, 10 mA), and of a neutron area dedicated to the RIBs production, to the BNCT applications and to the neutron physics. Some remarks on the production methods will be presented. The possibility of producing radioisotopes by means of the fission induced by neutrons will be investigated and the methods of production of neutrons will be discussed.

Tecchio, Luigi B. [Laboratori Naxionali di Legnaro, Via Romea 4, 35020 Legnaro (Italy)

1999-04-26

141

[Metal ion concentrations in patients with metal-metal bearings in prostheses].  

PubMed

Increased wear leads to elevated systemic and local metal ion concentrations for patients treated with metal-on-metal bearings. The local metal ion content in the close environment of the joint replacement (e.g. joint aspirate or tissue) is several times higher compared to the systemic metal content (e.g. in blood or serum). As a result of increased metal ion levels, local and systemic effects, such as osteolysis, pseudotumors, sensitization or in rare cases toxicity may occur. Although the definition of a specific threshold to define clinical problems is difficult due to a lack of sensitivity, the systemic metal concentration is frequently measured clinically. Currently a threshold for cobalt and chromium between 4 µg/l and 7 µg/l is under debate. Very high levels (??20 µg/l) or a steady increase over time should be a warning sign; however, metal ion levels should not be interpreted as a single diagnostic tool but rather in the entire context of the clinical, radiological and cross-sectional imaging, metal artefact reduction sequence (MARS) magnetic resonance imaging (MRI), ultrasound and computed tomography (CT) findings. PMID:23842780

Kretzer, J P; Van Der Straeten, C; Sonntag, R; Müller, U; Streit, M; Moradi, B; Jäger, S; Reinders, J

2013-08-01

142

Direct reaction measurements with a 132Sn radioactive ion beam  

SciTech Connect

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.

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

143

Modification of metallic materials and hard coatings using metal ion implantation  

Microsoft Academic Search

Ion implantation, with doses in the range 1016 to 1018 ioncm-2, modifies the surface properties of many metallic and ceramic materials. Whilst gas ion beams are currently employed extensively, metal ion implantation (MII) systems have been developed based on the vacuum metal arc and a brief review of these systems is presented. Examples of industrial applications are given using, primarily,

Yurii P Sharkeev; Boris P Gritsenko; Sergei V Fortuna; Anthony J Perry

1999-01-01

144

Production of highly charged metal ion beams from organic metal compounds at RIKEN 18 GHz ECRIS  

Microsoft Academic Search

Intense beams of highly charged metal ions (e.g., 80 ?A for Fe13+) are successfully extracted from the 18 GHz ECR Ion Source at RIKEN by feeding vapors of organic metal compounds at room temperature into the ECR plasma chamber: by MIVOC method. The beam intensity of particular metal ion is strongly dependent on the microwave power and served compounds.

T. Nakagawa; J. Ärje; Y. Miyazawa; M. Hemmi; T. Chiba; N. Inabe; M. Kase; T. Kageyama; O. Kamigaito; A. Goto; M. G Niimura; Y. Yano

1997-01-01

145

Accumulation of metal ions by pectinates  

NASA Astrophysics Data System (ADS)

The knowledge of the mechanisms which regulate the interactions of metal ions with partially methyl esterified linear polymers of ?-1,4 linked D-galacturonic acid units (pectinates), well represented in the root inner and outer apoplasm, is of great relevance to understand the processes which control their accumulation at the soil-root interface as well as their mobilization by plant metabolites. Accumulation of a metal by pectinates can be affected by the presence of other metals so that competition or distribution could be expected depending on the similar or different affinity of the metal ions towards the binding sites, mainly represented by the carboxylate groups. In order to better understand the mechanism of accumulation in the apoplasm of several metal ions, the sorption of Cd(II), Zn(II), Cu(II), Pb(II) and Cr(III) by a Ca-polygalacturonate gel, used as model of the soil-root interface, with a degree of esterification of 18% (PGAE1) and 65% (PGAE2) was studied at pH 3.0, 4.0, 5.0 and 6.0 in the presence of CaCl2 2.5 mM.. The results show that sorption increases with increasing both the initial metal concentration and pH. A similar sorption trend was evidenced for Cu(II) and Pb(II) and for Zn(II) and Cd(II), indicating that the mechanism of sorption for these two ionic couples is quite different. As an example, at pH 6.0 and an initial metal concentration equal to 2.0 mM, the amount of Cu(II) and Pb(II) sorbed was about 1.98 mg-1 of PGAE1 while that of Cd(II) and Zn(II) was about 1.2 mg-1. Cr(III) showed a rather different sorption trend and a much higher amount (2.8 mg-1of PGAE1 at pH 6.0) was recorded. The higher affinity of Cr(III) for the polysaccharidic matrix is attributable to the formation of Cr(III) polynuclear species in solution, as shown by the distribution diagrams obtained through the MEDUSA software. On the basis of these findings, the following affinity towards the PGAE1 can be assessed: Cr(III) > Cu(II) ? Pb(II) > Zn (II) ? Cd(II). Surprisingly, simultaneous sorption tests and SEM analyses indicate that a different mechanism regulates the sorption of Cu(II) and Pb(II) by PGAE1. In fact, the amount of Pb(II) sorbed (0.92 moles mg-1of PGAE1) by PGAE1 was nearly independent by the presence of Cu(II) ions, at least at the three different concentrations tested, that indicates a higher affinity of Pb(II). Such an aspect was further confirmed by exchange experiments. Samples of PGAE1 saturated with 1.96 moles mg-1of Cu(II) or 2.01 moles mg-1of Pb(II) were put in contact with 100 mL of solutions containing 97.3 moles of Pb(II) or 99.4 moles Cu(II), respectively. The exchange kinetics show that about 80% of Cu(II) was stochiometrically exchanged by Pb(II). In contrast, only about 10% of Pb(II) complexed by PGAE1 was exchanged by Cu(II). The kinetics of simultaneous sorption of all the metal ions tested indicate that Pb(II) is selectively sorbed by the PGAE1 gels. Cd(II) and Zn(II) show a similar affinity towards PGAE1. Thus, in the simultaneous presence of these ions, their selectivity towards this matrix follows the order: Pb > Cu > Cd ? Zn. Sorption of Cr(III) in the presence of the ions considered was not possible to carry out due to interference phenomena. The sorption of the same ions by 50 mg of PGAE2 evidences that the amount of Cu(II), Pb(II), and Cr(III) sorbed is markedly lower than that found for PGAE1. By considering that two carboxylic groups are involved in the complexation of a metal ion, the data show that such a stoichiometry is respected only for Pb(II). The amount of Cu(II) sorbed is about 50% lower than that of Pb(II) at all the pH values tested whereas those of Zn(II) and Cd(II) are negligible whereas that of Cr(III) is the highest. The different behaviour of Cu(II) compared to Pb(II) can be explained taking into account for both hydrophobic and steric effects of the methyl groups as well as to their different charge density. Thus, it can be concluded that the accumulation of metals at the soil-root interface strictly depends on the esterification degree of the root p

Deiana, S.; Deiana, L.; Palma, A.; Premoli, A.; Senette, C.

2009-04-01

146

Sputtered metal cluster ions: Unimolecular decomposition and collision induced fragmentation  

Microsoft Academic Search

Cluster ions are produced by ion bombardment of thick metal targets and mass selected in a Wien filter. The unimolecular decomposition of Aln+, Cun+, Mon+, Wn+, and Pbn+ is investigated under UHV conditions. The time evolution of the decay allows a glimpse into the cluster formation\\/fragmentation process. Highly excited metal cluster ions decompose mainly by evaporating single neutral atoms with

W. Begemann; S. Dreihöfer; K. H. Meiwes-Broer; H. O. Lutz

1986-01-01

147

Several Kinds of Aminoxyl Radicals and their Metal Ion Complexes  

Microsoft Academic Search

Recent results of magnetization, magnetic susceptibility and muon spin rotation\\/relaxation (?SR) measurements of some organic neutral radicals based on aminoxyl and their anion radical complexes with alkali and transition metal cations are reported. Ferromagnetic intermolecular interactions, coexistent with antiferromagnetic ones, in several carboxyaryl nitronyl nitroxide radicals are affected by inserting alkali metal ions, while the incorporation of transition metal ions

Tadashi Sugano; Stephen J. Blundell; Francis L. Pratt; Thomas Jestädt; Brendon W. Lovett; William Hayes; Peter Day

1999-01-01

148

The radioactive ion beam facility at VECC Calcutta - a status report  

NASA Astrophysics Data System (ADS)

The proposal to build a low-energy radioactive ion beam (RIB) facility at VEC Centre, Calcutta, has recently been approved. A brief description of this facility and the present status of various components of this system will be discussed.

Chakrabarti, Alok

1998-08-01

149

Advances in cement solidification technology for waste radioactive ion exchange resins: A review  

Microsoft Academic Search

Treatment and disposal of waste radioactive ion exchange resins is one of the most urgent problems for nuclear industries in China. Cement solidification technology has many advantages, such as requiring simple equipment, easy scaling-up, low working temperature, no trouble of gas cleaning and low cost. It is a suitable technology for treatment of waste radioactive resins, and has been widely

Junfeng Li; Jianlong Wang

2006-01-01

150

Securing the metal recycling chain for the steel industry by detecting orphan radioactive sources in scrap metal  

NASA Astrophysics Data System (ADS)

Experimental tests are reported for the detection of the heavy metal shielding of orphan sources hidden inside scrap metal by using a recently developed muon tomography system. Shielded sources do not trigger alarm in radiation portal commonly employed at the entrance of steel industry using scrap metal. Future systems integrating radiation portals with muon tomography inspection gates will substantially reduce the possibility of accidental melting of radioactive sources securing the use of recycled metal.

Pesente, S.; Vanini, S.; Benettoni, M.; Bonomi, G.; Calvini, P.; Checchia, P.; Conti, E.; Gonella, F.; Nebbia, G.; Squarcia, S.; Viesti, G.; Zenoni, A.; Zumerle, G.

2010-08-01

151

Securing the metal recycling chain for the steel industry by detecting orphan radioactive sources in scrap metal  

SciTech Connect

Experimental tests are reported for the detection of the heavy metal shielding of orphan sources hidden inside scrap metal by using a recently developed muon tomography system. Shielded sources do not trigger alarm in radiation portal commonly employed at the entrance of steel industry using scrap metal. Future systems integrating radiation portals with muon tomography inspection gates will substantially reduce the possibility of accidental melting of radioactive sources securing the use of recycled metal.

Pesente, S.; Benettoni, M.; Checchia, P.; Conti, E.; Gonella, F.; Nebbia, G. [INFN Sezione di Padova, via Marzolo 8, 35131 Padova Italy (Italy); Vanini, S.; Viesti, G.; Zumerle, G. [INFN Sezione di Padova, via Marzolo 8, 35131 Padova Italy (Italy); University of Padova and INFN Sezione di Padova, via Marzolo 8, 35131 Padova Italy (Italy); Bonomi, G.; Zenoni, A. [University of Brescia, via Branze 38, 25123 Brescia and INFN Sezione di Pavia, via Bassi 6, 27100 Pavia (Italy); Calvini, P.; Squarcia, S. [University of Genova and INFN Sezione di Genova, via Dodecaneso 33, 16146 Genova (Italy)

2010-08-04

152

Radioactive Ion Beams with the HHIRF (Holifield Heavy Ion Research Facility) accelerators  

SciTech Connect

Our present understanding of nuclear structure is almost completely based on facts obtained for nuclei that can be produced with stable projectiles and targets which have equilibrated for a significant fraction of the lifetime of the universe. The use of Radioactive Ion Beams (RIB) could overcome this limitation and provide unique opportunities for the study of nuclear structure with nuclei far from stability. These nuclei could answer critical issues concerning some of the most fundamental current nuclear structure themes and allow the study of entirely new phenomena, unobservable with current techniques and not derivable from our present knowledge of nuclear theory. RIB will also open new opportunities for the study of processes taking place at less equilibrated astrophysical sites, such as supernovae, cataclysmic binaries, and accreted shells of neutron stars. Widespread interest in RIB has developed in the last few years and a steering committee has recently been established to consider the construction of a large radioactive beam facility in North America. With this interest in mind, we have performed a feasibility study for a low-cost extension of the Holifield Heavy Ion Research Facility (HHIRF) accelerators which would provide access, on a short time scale, to much of the physics of proton-rich nuclei.

Meigs, M.J.; Alton, G.D.; Baktash, C.; Dowling, D.T.; Garrett, J.D.; Haynes, D.L.; Jones, C.M.; Juras, R.C.; Lane, S.N.; Lee, I.Y.; Mills, G.D.; Mosko, S.W.; Olsen, D.K.; Tatum, B.A.; Toth, K.S. (Oak Ridge National Lab., TN (USA)); Carter, H.K. (Oak Ridge Associated Universities, Inc., TN (USA))

1990-01-01

153

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

PubMed Central

Within the three-dimensional architectures of RNA molecules, divalent metal ions populate specific locations, shedding their water molecules to form chelates. These interactions help the RNA adopt and maintain specific conformations and frequently make essential contributions to function. Defining the locations of these site-bound metal ions remains challenging despite the growing database of RNA structures. Metal-ion rescue experiments have provided a powerful approach to identify and distinguish catalytic metal ions within RNA active sites, but the ability of such experiments to identify metal ions that contribute to tertiary structure acquisition and structural stability is less developed and has been challenged. Herein, we use the well-defined P4–P6 RNA domain of the Tetrahymena group I intron to reevaluate prior evidence against the discriminatory power of metal-ion rescue experiments and to advance thermodynamic descriptions necessary for interpreting these experiments. The approach successfully identifies ligands within the RNA that occupy the inner coordination sphere of divalent metal ions and distinguishes them from ligands that occupy the outer coordination sphere. Our results underscore the importance of obtaining complete folding isotherms and establishing and evaluating thermodynamic models in order to draw conclusions from metal-ion rescue experiments. These results establish metal-ion rescue as a rigorous tool for identifying and dissecting energetically important metal-ion interactions in RNAs that are noncatalytic but critical for RNA tertiary structure.

Frederiksen, John K.; Li, Nan-Sheng; Das, Rhiju; Herschlag, Daniel; Piccirilli, Joseph A.

2012-01-01

154

Silica-Polyamine Composite Materials for Heavy Metal Ion Removal, Recovery, and Recycling. II. Metal Ion Separations from Mine Wastewater and Soft Metal Ion Extraction Efficiency  

Microsoft Academic Search

Silica-polyamine composites have been synthesized which have metal ion capacities as high as 0.84 mmol\\/g for copper ions removed from aqueous solutions. In previous reports it has been demonstrated that these materials survive more than 3000 cycles of metal ion extraction, elution, and regeneration with almost no loss of capacity (less than 10%). This paper describes two modified silica-polyamine composite

ROBERT J. FISCHER; DAVID PANG; SUSAN T. BEATTY; EDWARD ROSENBERG

1999-01-01

155

The NRAMP family of metal-ion transporters.  

PubMed

The family of NRAMP metal ion transporters functions in diverse organisms from bacteria to human. NRAMP1 functions in metal transport across the phagosomal membrane of macrophages, and defective NRAMP1 causes sensitivity to several intracellular pathogens. DCT1 (NRAMP2) transport metal ions at the plasma membrane of cells of both the duodenum and in peripheral tissues, and defective DCT1 cause anemia. The driving force for the metal-ion transport is proton gradient (protonmotive force). In DCT1 the stoichiometry between metal ion and proton varied at different conditions due to a mechanistic proton slip. Though the metal ion transport by Smf1p, the yeast homolog of DCT1, is also a protonmotive force, a slippage of sodium ions was observed. The mechanism of the above phenomena could be explained by a combination between transporter and channel mechanisms. PMID:16908340

Nevo, Yaniv; Nelson, Nathan

2006-07-01

156

Mechanisms of metal ion-coupled electron transfer.  

PubMed

Redox inactive metal ions acting as Lewis acids can control electron transfer from electron donors (D) to electron acceptors (A) by binding to radical anions of electron acceptors which act as Lewis bases. Such electron transfer is defined as metal ion-coupled electron transfer (MCET). Mechanisms of metal ion-coupled electron transfer are classified mainly into two pathways, i.e., metal ion binding to electron acceptors followed by electron transfer (MB/ET) and electron transfer followed by metal ion binding to the resulting radical anions of electron acceptors (ET/MB). In the former case, electron transfer and the stronger binding of metal ions to the radical anions occur in a concerted manner. Examples are shown in each case to clarify the factors to control MCET reactions in both thermal and photoinduced electron-transfer reactions including back electron-transfer reactions. PMID:22596095

Fukuzumi, Shunichi; Ohkubo, Kei; Morimoto, Yuma

2012-05-17

157

Semicondutor quantum dots-based metal ion probes.  

PubMed

Semiconductor quantum dots (QDs) exhibit unique optical and photophysical properties that offer significant advantages over organic dyes as optical labels for chemo/bio-sensing. This review addresses the methods for metal ion detection with QDs, including photoluminescent, electrochemiluminescent, photoelectrochemical, and electrochemical approaches. The main mechanisms of direct interaction between QDs and metal ions which lead to photoluminescence being either off or on, are discussed in detail. These direct interactions provide great opportunities for developing simple yet effect metal ion probes. Different methods to design the chemically-modified QD hybrid structures through anchoring metal ion-specific groups onto the surface of QDs are summarized. Due to the spatial separation of the luminescence center and analyte recognition sites, these chemically-modified QDs offer greatly improved sensitivity and selectivity for metal ions. Several interesting applications of QD-based metal ion probes are presented, with specific emphasis on cellular probes, coding probes and sensing with logic gate operations. PMID:24270674

Wu, Peng; Zhao, Ting; Wang, Shanling; Hou, Xiandeng

2014-01-01

158

Semicondutor quantum dots-based metal ion probes  

NASA Astrophysics Data System (ADS)

Semiconductor quantum dots (QDs) exhibit unique optical and photophysical properties that offer significant advantages over organic dyes as optical labels for chemo/bio-sensing. This review addresses the methods for metal ion detection with QDs, including photoluminescent, electrochemiluminescent, photoelectrochemical, and electrochemical approaches. The main mechanisms of direct interaction between QDs and metal ions which lead to photoluminescence being either off or on, are discussed in detail. These direct interactions provide great opportunities for developing simple yet effect metal ion probes. Different methods to design the chemically-modified QD hybrid structures through anchoring metal ion-specific groups onto the surface of QDs are summarized. Due to the spatial separation of the luminescence center and analyte recognition sites, these chemically-modified QDs offer greatly improved sensitivity and selectivity for metal ions. Several interesting applications of QD-based metal ion probes are presented, with specific emphasis on cellular probes, coding probes and sensing with logic gate operations.

Wu, Peng; Zhao, Ting; Wang, Shanling; Hou, Xiandeng

2013-12-01

159

Photoluminescent graphene oxide microarray for multiplex heavy metal ion analysis.  

PubMed

An aptamer-linked graphene oxide (GO) microarray is synthesized for multiplex heavy metal ion detection. Fluorescent nanosized GO sheets are micropatterned, and specific aptamers targeting Ag(+) and Hg(2+) are immobilized on the GO array. Upon capture of the target heavy metal ions, electron transfer occurs between the GO (donors) and the heavy metal ions (acceptors), leading to fluorescence quenching of the GO. PMID:23606642

Liu, Fei; Ha, Hyun Dong; Han, Dong Ju; Seo, Tae Seok

2013-10-25

160

Optical methods for the detection of heavy metal ions  

NASA Astrophysics Data System (ADS)

The review covers an important area of the modern chemistry, namely, the detection of heavy metal ions using optical molecular detectors. The role of this method in metal ion detection and the physicochemical grounds of operation of chemosensors are discussed, and examples of detection of most abundant heavy metal ions and synthetic approaches to molecular detectors are presented. The immobilization of molecular detectors on solid substrates for the design of analytical sensor devices is described. The bibliography includes 178 references.

Uglov, A. N.; Bessmertnykh-Lemeune, A.; Guilard, R.; Averin, A. D.; Beletskaya, I. P.

2014-03-01

161

Fate of heavy metals and radioactive metals in gasification of sewage sludge  

SciTech Connect

The fates of radioactive cadmium, strontium, cesium, cobalt, arsenic, mercury, zinc, and copper spiked into sewage sludge were determined when the sludge was gasified by a process that maximizes production of char from the sludge (ChemChar process). For the most part the metals were retained in the char product in the gasifier. Small, but measurable quantities of arsenic were mobilized by gasification and slightly more than 1% of the arsenic was detected in the effluent gas. Mercury was largely mobilized from the solids in the gasifier, but most of the mercury was retained in a filter composed of char prepared from the sludge. The small amounts of mercury leaving the gasification system were found to be associated with an aerosol product generated during gasification. The metals retained in the char product of gasification were only partially leachable with 50% concentrated nitric acid.

Marrero, Thomas W.; McAuley, Brendan P.; Sutterlin, William R.; Steven Morris, J.; Manahan, Stanley E

2004-07-01

162

Research on Multi-Ion Interactions and Defects in Metals.  

National Technical Information Service (NTIS)

A summary of research on multi-ion interactions is presented. Emphasis is placed on point defects in nontransition metals and the calculation of screening charge densities, electric field gradients and lattice distortion. Multi-ion interactions in transit...

R. E. Beissner

1982-01-01

163

THE ROLES OF METAL IONS IN REGULATION BY RIBOSWITCHES  

PubMed Central

Metal ions are required by all organisms in order to execute an array of essential molecular functions. They play a critical role in many catalytic mechanisms and structural properties. Proper homeostasis of ions is critical; levels that are aberrantly low or high are deleterious to cellular physiology. To maintain stable intracellular pools, metal ion-sensing regulatory (metalloregulatory) proteins couple metal ion concentration fluctuations with expression of genes encoding for cation transport or sequestration. However, these transcriptional-based regulatory strategies are not the only mechanisms by which organisms coordinate metal ions with gene expression. Intriguingly, a few classes of signal-responsive RNA elements have also been discovered to function as metalloregulatory agents. This suggests that RNA-based regulatory strategies can be precisely tuned to intracellular metal ion pools, functionally akin to metalloregulatory proteins. In addition to these metal-sensing regulatory RNAs, there is a yet broader role for metal ions in directly assisting the structural integrity of other signal-responsive regulatory RNA elements. In this chapter, we discuss how the intimate physicochemical relationship between metal ions and nucleic acids is important for the structure and function of metal ion- and metabolite-sensing regulatory RNAs.

2012-01-01

164

Comet Encke: Meteor metallic ion identification by mass spectrometer  

NASA Technical Reports Server (NTRS)

Positive metallic ions have been measured in the earth's atmosphere between 85 and 120 km, during the period of the beta Taurids meteor shower, which is associated with Comet Encke. The ions originate during and following ablation of extraterrestrial debris by the earth's atmosphere. The enhancement of metal ion density during meteor showers is primary evidence for their extraterrestrial origin. The present results were obtained from a rocket-borne ion mass spectrometer.

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

1973-01-01

165

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

PubMed

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

Lamy, T; Angot, J; Thuillier, T

2008-02-01

166

Design and synthesis of metal ion-recognition-induced conjugated polymers: An approach to metal ion sensory materials  

Microsoft Academic Search

The synthesis and metal ion responsive properties of two 2, 2`-bipyridyl-phenylene-vinylene-based polymers is reported. These polymers are designed to be partially conjugated in their metal-free state and fully conjugated when exposed to metal ions so that the ion-induced conjugation enhancement can be transduced into a measurable signal. It is found that these polymers exhibit highly ionochromic effects with a wide

Bing Wang; Michael R. Wasielewski

1997-01-01

167

Protocols for implementing DOE authorized release of radioactive scrap metals  

Microsoft Academic Search

A process to implement the US Department of Energy`s (DOE) policy for authorized release of radioactive materials from DOE facilities is provided in the Draft Handbook for Controlling Release for Reuse or Recycle of Property Containing Residual Radioactive Material, published by DOE in 1997 and distributed to DOE field offices for interim use and implementation. The authorized release of such

S. Y. Chen; J. Arnish; S. Kamboj; L. A. Nieves

1999-01-01

168

The extension of the HHIRF accelerators to produce radioactive ion beams  

SciTech Connect

The production of medium-intensity, proton-rich, radioactive ion beams for nuclear physics, astrophysics, and applied research with the HHIRF accelerators is discussed. Radioactive atoms will be produced with fusion reactions by light-ion beams from the K = 105 Oak Ridge Isochronous Cyclotron stopping in an ISOLDE-type thick target mounted on a 300-kV high-voltage platform. These radioactive atoms will be ionized, mass separated, and charge exchanged to negative ions on the high-voltage platform prior to injection into the HHIRF 25-MV tandem accelerator. Beams of up to mass 80 will be accelerated to energies greater than 5 MeV/nucleon. For some radioactive beams, intensities greater than 1 pnA can be expected. 7 refs., 1 fig., 1 tab.

Olsen, D.K.; Alton, G.D.; Baktash, C.; Dowling, D.T.; Garrett, J.D.; Haynes, D.L.; Jones, C.M.; Juras, R.C.; Lane, S.N.; Lee, I.Y.; Meigs, M.J.; Mills, G.D.; Mosko, S.W.; Tatum, B.A.; Toth, K.S. (Oak Ridge National Lab., TN (United States)); Carter, H.K. (Oak Ridge Associated Universities, Inc., TN (United States))

1991-01-01

169

Plasma immersion ion implantation for reducing metal ion release  

NASA Astrophysics Data System (ADS)

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.

Díaz, C.; García, J. A.; Mändl, S.; Pereiro, R.; Fernández, B.; Rodríguez, R. J.

2012-11-01

170

Plasma immersion ion implantation for reducing metal ion release  

SciTech Connect

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.

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

2012-11-06

171

A biosystem for removal of metal ions from water  

SciTech Connect

The presence of heavy metal ions in ground and surface waters constitutes a potential health risk and is an environmental concern. Moreover, processes for the recovery of valuable metal ions are of interest. Bioaccumulation or biosorption is not only a factor in assessing the environmental risk posed by metal ions; it can also be used as a means of decontamination. A biological system for the removal and recovery of metal ions from contaminated water is reported here. Exopolysaccharide-producing microorganisms, including a methanotrophic culture, are demonstrated to have superior metal binding ability, compared with other microbial cultures. This paper describes a biosorption process in which dried biomass obtained from exopolysaccharide-producing microorganisms is encapsulated in porous plastic beads and is used for metal ion binding and recovery. 22 refs., 13 figs.

Kilbane, J.J. II.

1990-01-01

172

Free-ion hyperfine fields and magnetic-moment measurements on radioactive beams: progress and outlook  

NASA Astrophysics Data System (ADS)

Hyperfine fields of highly-charged heavy ions carrying many electrons are discussed in view of their utility for magnetic-moment measurements on radioactive beams by the recoil in vacuum (RIV) technique. An overview of progress is given along with a review of the foundations for ab initio calculations of the relevant free-ion hyperfine interactions.

Stuchbery, Andrew E.

2013-05-01

173

Rotational dynamics of metal azide ion pairs in dimethylsulfoxide solutions.  

PubMed

Azide ion is an excellent vibrational probe for studying ion-ion and ion-dipole interactions in solutions because its frequency is sensitively dependent on its local environments. When azide ion forms contact ion pairs with cations in dimethylsulfoxide (DMSO), free azide ion and contact ion pairs are spectrally well distinguished in FTIR spectra. Here, we investigated vibrational population relaxation, P(t), and orientational relaxation dynamics, r(t), of free azide ion and contact ion pairs (LiN3, NaN3, NH4N3, MgN3(+), and CaN3(+)) in DMSO by IR pump-probe spectroscopy. For metal azide ion pairs, the metal ion slowed down the vibrational relaxation of azide ion by acting like a thermal insulator. Biexponential behavior of r(t) was analyzed in the wobbling-in-a-cone model. The long time component of r(t) of free azide ion was found to be viscosity-dependent. The wobbling motion of azide ion within the frame of metal azide ion pairs was weakly dependent on the countercation. When the overall orientational relaxation of metal azide ion pairs was analyzed by the extended Debye-Stokes-Einstein equation, it was well described under stick or superstick boundary conditions due to a strong interaction between the metal ion and DMSO molecules. Our experimental results provide important insight in understanding the rotational dynamics of small ionic species in polar solvents when the size of the ionic species is smaller than or comparable to that of the solvent molecule. PMID:23409952

Son, Hyewon; Kwon, YoungAh; Kim, Jinwoo; Park, Sungnam

2013-03-01

174

ADSORPTION OF RADIOACTIVE METALS BY STRONGLY MAGNETIC IRON SULFIDE NANOPARTICLES PRODUCED BY SULFATE-REDUCING BACTERIA  

Microsoft Academic Search

The adsorption of a number of radioactive ions from solution by a strongly magnetic iron sulfide material was studied. The material was produced by sulfate-reducing bacteria in a novel bioreactor. The uptake was rapid and loading on the adsorbent was high due to the high surface area of the adsorbent and because many of the ions were chemisorbed. The structural

J. H. P. Watson; I. W. Croudace; P. E. Warwick; P. A. B. James; J. M. Charnock; D. C. Ellwood

2001-01-01

175

Metal Ion Release With Large-Diameter Metal-on-Metal Hip Arthroplasty  

Microsoft Academic Search

Preoperative and postoperative ion concentrations were measured in 29 metal-on-metal, large-diameter head total hip arthroplasty (LDH-THA) patients. Mean chromium, cobalt (Co), and titanium levels from LDH-THA were 1.3, 2.2, and 2.7 ?g\\/L at 12 months. The open femoral head design showed significantly higher Co concentrations than the closed design (3.0 vs 1.8 ?g\\/L, P = .037). Compared with previously published

Pascal-André Vendittoli; Traian Amzica; Alain G. Roy; Daniel Lusignan; Julien Girard; Martin Lavigne

2011-01-01

176

Microbial metal-ion reduction and Mars: extraterrestrial expectations?  

Microsoft Academic Search

Dissimilatory metal-ion-reducing bacteria (DMRB) can couple the reduction of a variety of different metal ions to cellular respiration and growth. The excitement of this metabolic group lies not only in the elucidation of a new type of metabolism, but also in the potential use of these abilities for the removal of toxic organics, and in their ability to reduce (and

Kenneth H. Nealson; B. Lea Cox

2002-01-01

177

Vegetable waste-based sensors for metal ion determination  

Microsoft Academic Search

Last studies on metal adsorption have shown important interactions between different vegetable wastes and metal ions. Recently, yohimbe bark and grape stalks have been used as biosorption materials in the recovery and preconcentration of chromium(VI) ions. In the present work, both vegetable residues coming from pharmaceutical and wine industries, respectively, are selected for the development of vegetable waste-based sensors for

Núria Fiol; Florencio de la Torre; Patrick Demeyere; Antonio Florido; Isabel Villaescusa

2007-01-01

178

Immobilized Metal Ion Affinity Chromatography (IMAC) Chemistry and Bioseparation Applications  

Microsoft Academic Search

This review discusses the principles of immobilized metal ion affinity chromatography (IMAC) and its applications to protein separations. IMAC functions by binding the accessible electron-donating pendant groups of a protein - such as histidine, cysteine, and tryptophan - to a metal ion which is held by a chelating group covalently attached on a stationary support. A common chelating group is

Jon W. Wong; Robert L. Albright; Nien-Hwa L. Wang

1991-01-01

179

Metal ion release kinetics from nanoparticle silicone composites  

Microsoft Academic Search

Metal ion release kinetics from silver and copper nanoparticle silicone composites generated by laser ablation in liquids are investigated. The metal ion transport mechanism is studied by using different model equations and their fit to experimental data. Results indicate that during the first 30days of immersion, Fickian diffusion is the dominant transport mechanism. After this time period, the oxidation and

Anne Hahn; Gudrun Brandes; Philipp Wagener; Stephan Barcikowski

2011-01-01

180

Characterization of metal ion-nucleic acid interactions in solution.  

PubMed

Metal ions are inextricably involved with nucleic acids due to their polyanionic nature. In order to understand the structure and function of RNAs and DNAs, one needs to have detailed pictures on the structural, thermodynamic, and kinetic properties of metal ion interactions with these biomacromolecules. In this review we first compile the physicochemical properties of metal ions found and used in combination with nucleic acids in solution. The main part then describes the various methods developed over the past decades to investigate metal ion binding by nucleic acids in solution. This includes for example hydrolytic and radical cleavage experiments, mutational approaches, as well as kinetic isotope effects. In addition, spectroscopic techniques like EPR, lanthanide(III) luminescence, IR and Raman as well as various NMR methods are summarized. Aside from gaining knowledge about the thermodynamic properties on the metal ion-nucleic acid interactions, especially NMR can be used to extract information on the kinetics of ligand exchange rates of the metal ions applied. The final section deals with the influence of anions, buffers, and the solvent permittivity on the binding equilibria between metal ions and nucleic acids. Little is known on some of these aspects, but it is clear that these three factors have a large influence on the interaction between metal ions and nucleic acids. PMID:22210334

Pechlaner, Maria; Sigel, Roland K O

2012-01-01

181

Polyphosphazene membranes for metal ion separations  

SciTech Connect

The Idaho National Engineering Laboratory (INEL), under sponsorship by the Bureau of Mines, evaluated the use of polyphosphazene-based polymer membranes for chemical separations. Synthetic membranes based on phosphazene inorganic polymers offer the promise of new industrial chemical separation technologies that are more energy efficient and economical than traditional phase change separation processes and extraction techniques. The research focused on the separation of metal ions from aqueous solutions. The polyphosphazene membranes were also tested for gaseous separations, results of which are presented in a separate Report of Investigation. Historically, membranes used for chemical separation have been prepared from organic polymers. In general, these membranes are stable only at temperatures less than 100{degrees}C, within narrow pH ranges, and in a very limited number of organic media. As a result, many organic- based membranes are unsuitable for industrial applications, which often involve harsh environments. In recent years, membrane research has focused on ceramic and metal membranes for use in the adverse environments of separation applications. These membranes are suitable for gas and liquid sieve separation applications, where molecules may be separated based on their molecular size. These membranes are not effective where additional selectivity is needed. A membrane that separates on the basis of solubility and that can perform separations in adverse environments is needed, and this need motivated the investigation of polyphosphazene membranes.

Stone, M.L.

1996-05-01

182

The DOE`s radioactively contaminated metal recycling: The policy and its implementation  

Microsoft Academic Search

Millions of tons of potentially recoverable materials have accumulated over the years at U.S. DOE sites and facilities now undergrowing environmental restoration. These materials include thousands of tones of scrap metals, both radioactively contaminated and not. This article discusses the DOE`s policy on contaminated metal recycling and its implementation in the following topic areas: the recycling policy concept; an innovative

S. Warren; E. Rizkalla

1997-01-01

183

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

Microsoft Academic Search

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.

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

2006-01-01

184

Slow collisions of multicharged ions with metal surfaces  

SciTech Connect

Some recent experimental results in the area of multicharged ion-surface interactions are summarized. Discussed are measurements of projectile K-Auger electron emission during interactions of hydrogen-like multicharged ions with clean and cesiated metal surfaces, measurements of total electron yields for various multicharged ions incident on metal targets, and measurements of projectile angular scattering during grazing metal surface collisions. The various experimental results are presented to illustrate progress in the understanding of multicharged ion-surface interactions in the area of above- vs sub-surface neutralization and relaxation processes, as well as to identify certain aspects of such interactions where the picture is as yet still incomplete.

Meyer, F.W.

1993-12-31

185

Metal ion transport in eukaryotic microorganisms: insights from Saccharomyces cerevisiae.  

PubMed

Metal ions such as iron, copper, manganese, and zinc are essential nutrients for all eukaryotic microorganisms. Therefore, these organisms possess efficient uptake mechanisms to obtain these nutrients from their extracellular environment. Metal ions must also be transported into intracellular organelles where they function as catalytic and structural cofactors for compartmentalized enzymes. Thus, intracellular transport mechanisms are also present. When present in high levels, metal ions can also be toxic, so their uptake and intracellular transport is tightly regulated at both transcriptional and post-transcriptional levels to limit metal ion overaccumulation and facilitate storage and sequestration. Remarkable molecular insight into these processes has come from recent studies of the yeast Saccharomyces cerevisiae. This organism, which is the primary subject of this chapter, serves as a useful paradigm to understand metal ion metabolism in other eukaryotic microbes. PMID:10907553

Eide, D J

2000-01-01

186

Fulvic acid: modifier of metal-ion chemistry  

SciTech Connect

Fulvic acid, which is derived from the decay of plants and animals, is being studied for its role in the transport and toxicity of metal ions in soil and water. It is discussed in relation to the origin of humic substances and its interactions with metal ions. Techniques for investigating complexes of fulvic acid and metal ions are presented. They are separation and nonseparation analyses which are applied to speciation problems. The applicability, advantages, and disadvantages of both methods are presented. Separation of free and complexed metal ions can be done by chromatography, or with membranes that exclude the metal-ion complexes. Chromatographic techniques include liquid chromatography by size exclusion. Nonseparation techniques include voltametry and potentiometry, as well as fluorescence. A comparison of methods for calculation of the conditional stability constant K for complexes containing fulvic acid and copper (II) or cadmium (II) is presented.

Saar, R.A.; Weber, J.H.

1982-01-01

187

Multiply stripped ion generation in the metal vapor vacuum arc  

SciTech Connect

We consider the charge state distribution of ions produced in the metal vapor vacuum arc plasma discharge. A high current metal ion source, the MEVVA ion source, in which the ion beam is extracted from a metal vapor vacuum arc plasma, has been used to obtain the spectra of multiple charged ions produced within the cathode spots. A computer calculation of the charge state distribution that evolves within the spots via stepwide ionization of ions by electron impact provides a theoretical basis for comparison of the data. In this paper we report on the measured charge state distributions for a wide variety of metallic species and compare these results with the predictions of this theory. 55 refs.

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

1986-08-01

188

Breast milk metal ion levels in a young and active patient with a metal-on-metal hip prosthesis.  

PubMed

Metal-on-metal resurfacing arthroplasty of the hip has been used increasingly over the last 10 years in younger active patients. The dissolution of the metal wear particles results in measurable increases in cobalt and chromium ions in the serum and urine of patients with a metal-on-metal bearing. We measured the cobalt, chromium, and molybdenum ion levels in urine; serum; and breast milk in a young and active patient with a metal-on-metal hip prosthesis after a pathologic fracture of the femoral neck. Metal-on-metal hip prosthesis leads to increasing levels of molybdenum in breast milk in the short-term follow-up. There are no increasing levels of chromium and cobalt ions in breast milk. Besides the already known elevated concentrations in serum of chromium and cobalt after implantation of a metal-on-metal hip prosthesis, we found no increasing levels of chromium and cobalt in urine. PMID:22868068

Nelis, Raymond; de Waal Malefijt, Jan; Gosens, Taco

2013-01-01

189

Ion-beam-deposited ultrathin transparent metal contacts  

Microsoft Academic Search

Using ion-beam sputtering we have prepared ultrathin transparent metal contacts with large broad-band optical transmittance and low electrical sheet resistance. Metal films deposited by ion-beam sputtering have exceptionally small surface roughness, and films as thin as about 20 Å are continuous and conductive, and provide optical transmittance as large as 80%. Ultrathin transparent metal contacts provide a number of advantages

Hagen Klauk; Jiunn-Ru Huang; Jonathan A Nichols; Thomas N Jackson

2000-01-01

190

The NRAMP family of metal-ion transporters  

Microsoft Academic Search

The family of NRAMP metal ion transporters functions in diverse organisms from bacteria to human. NRAMP1 functions in metal transport across the phagosomal membrane of macrophages, and defective NRAMP1 causes sensitivity to several intracellular pathogens. DCT1 (NRAMP2) transport metal ions at the plasma membrane of cells of both the duodenum and in peripheral tissues, and defective DCT1 cause anemia. The

Yaniv Nevo; Nathan Nelson

2006-01-01

191

Mechanism of metal ion biosorption by fungal biomass  

Microsoft Academic Search

Alkali extracted mycelial biomass from Aspergillus niger, referred to as Biosorb, was found to sequester metal ions (Cd2+, Cu2+, Zn2+, Ni2+ and Co2+) efficiently both from dilute and concentrated solutions upto 10% of its weight (w\\/w). Sequestration of metal ions from a mixture was also efficient but with attendant antagonisms. The kinetics of metal binding by Biosorb indicated that it

K. Sivarama Sastry; P. Maruthi Mohan

1996-01-01

192

Aspects on metal ion distribution models in pulp washing simulation  

Microsoft Academic Search

The closure of the liquid system in a pulp mill has increased the concentration of metal ions in the process as compared to traditional plants. These ions commonly referred to as non-process elements, NPE, enter the pulp mill with the wood chips, the water supply and the pulping chemicals. The presence of these ions may lead to various problems, e.g.

Karin Mattsson; Gunnar Eriksson; Urban Grén; Krister Ström

2007-01-01

193

Gas-Phase Ion/Ion Reactions of Multiply Protonated Polypeptides with Metal Containing Anions  

PubMed Central

Gas-phase reactions of multiply protonated polypeptides and metal containing anions represent a new methodology for manipulating the cationizing agent composition of polypeptides. This approach affords greater flexibility in forming metal containing ions than commonly used methods, such as electrospray ionization of a metal salt/peptide mixture and matrix-assisted laser desorption. Here, the effects of properties of the polypeptide and anionic reactant on the nature of the reaction products are investigated. For a given metal, the identity of the ligand in the metal containing anion is the dominant factor in determining product distributions. For a given polypeptide ion, the difference between the metal ion affinity and the proton affinity of the negatively charged ligand in the anionic reactant is of predictive value in anticipating the relative contributions of proton transfer and metal ion transfer. Furthermore, the binding strength of the ligand anion to charge sites in the polypeptide correlates with the extent of observed cluster ion formation. Polypeptide composition, sequence, and charge state can also play a notable role in determining the distribution of products. In addition to their usefulness in gas-phase ion synthesis strategies, the reactions of protonated polypeptides and metal containing anions represent an example of a gas-phase ion/ion reaction that is sensitive to polypeptide structure. These observations are noteworthy in that they allude to the possibility of obtaining information, without requiring fragmentation of the peptide backbone, about ion structure as well as the relative ion affinities associated with the reactants.

Newton, Kelly A.; Amunugama, Ravi; McLuckey, Scott A.

2005-01-01

194

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

Microsoft Academic Search

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)

John T. McCloskey; Michael C. Newman; Sue B. Clark

1996-01-01

195

Ion exchange of some heavy metal ions from polar organicsolvents into zeolite  

Microsoft Academic Search

In the present study the possibility of ion exchange of heavy metal ions using polar organic solvents and naturalzeolite clinoptilolite is approached. The organic solvents used are nearly pure ethanol and acetone. These solventsare compared to deionized water. The heavy metal ions studied are Cu2+, Cr3+ and Fe3+. While ion exchange levelsin water are much greater for Fe3+ (53.1%) in

V. J. Inglezakis; M. D. Loizidou

2007-01-01

196

Ion efflux systems involved in bacterial metal resistances  

Microsoft Academic Search

Summary Studying metal ion resistances gives us important insights into environmental processes and provides an understanding of basic living processes. This review concentrates on bacterial efflux systems for inorganic metal cations and anions, which have generally been found as resistance systems from bacteria isolated from metal-polluted environments. The protein products of the genes involved are sometimes prototypes of new families

Dietrich H. Nies; Simon Silver

1995-01-01

197

A self-sputtering ion source: a new approach to quiescent metal ion beams.  

PubMed

A new metal ion source is presented based on sustained self-sputtering plasma in a magnetron discharge. Metals exhibiting high self-sputtering yield such as Cu, Ag, Zn, and Bi can be used in a high-power impulse magnetron sputtering discharge such that the plasma almost exclusively contains singly charged metal ions of the target material. The plasma and extracted ion beam are quiescent. The ion beams consist mostly of singly charged ions with a space-charge limited current density which reached about 10 mA/cm(2) at an extraction voltage of 45 kV and a first gap spacing of 12 mm. PMID:20192429

Oks, Efim; Anders, André

2010-02-01

198

Comparison of radioactive ion-beam intensities produced by means of thick targets bombarded with neutrons, protons and heavy ions  

Microsoft Academic Search

Target and ion-source techniques which allow rapid separation of thermalized radioactive nuclei from 1-500 g\\/cm2 thick irradiated target material and continuously convert them into a mono-isotopic ion beam have been proven to be a powerful method of radiochemical separation. These techniques combine nuclear reactions with high-temperature chemistry, metallurgy, solid-state diffusion, and ionization phenomena. Developed at the many mass separators on-line

H. L. Ravn; P G Bricault; G. Ciavola; P V Drumm; B. Fogelberg; E. Hagebø; M. Huyse; R. Kirchner; W. Mittig; A. Mueller; H. Nifenecker; E. Roeckl

1994-01-01

199

Radioactive Ion Beams at FAIR-NuSTAR  

SciTech Connect

The future FAIR facility will open up an unprecedented range of exotic nuclear beams in the energy interval between 0-1.5 GeV/u produced by the Super-FRS. The envisaged experimental programme with radioactive beams, being prepared within the NuSTAR collaboration, will cover most aspects of contemporary physics within nuclear structure, astrophysics and reactions.

Nilsson, Thomas [Fundamental Physics, Chalmers Tekniska Hogskola, Gothenburg (Sweden)

2009-06-03

200

The acceleration and storage of radioactive ions for a neutrino factory  

SciTech Connect

The term beta-beam has been coined for the production of a pure beam of electron neutrinos or their antiparticles through the decay of radioactive ions circulating in a storage ring. This concept requires radioactive ions to be accelerated to a Lorentz gamma of 150 for {sup 6}He and 60 for {sup 18}Ne. The neutrino source itself consists of a storage ring for this energy range, with long straight sections in line with the experiment(s). Such a decay ring does not exist at CERN today, nor does a high-intensity proton source for the production of the radioactive ions. Nevertheless, the existing CERN accelerator infrastructure could be used as this would still represent an important saving for a beta-beam facility. This paper outlines the first study, while some of the more speculative ideas will need further investigations.

B. Autin et al.

2003-12-23

201

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

SciTech Connect

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.

Nitschke, J.M. (ed.)

1984-04-01

202

Catalysis using hydrous metal oxide ion exchanges  

DOEpatents

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.

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

1985-01-01

203

A general two-metal-ion mechanism for catalytic RNA.  

PubMed Central

A mechanism is proposed for the RNA-catalyzed reactions involved in RNA splicing and RNase P hydrolysis of precursor tRNA. The mechanism postulates that chemical catalysis is facilitated by two divalent metal ions 3.9 A apart, as in phosphoryl transfer reactions catalyzed by protein enzymes, such as the 3',5'-exonuclease of Escherichia coli DNA polymerase I. One metal ion activates the attacking water or sugar hydroxyl, while the other coordinates and stabilizes the oxyanion leaving group. Both ions act as Lewis acids and stabilize the expected pentacovalent transition state. The symmetry of a two-metal-ion catalytic site fits well with the known reaction pathway of group I self-splicing introns and can also be reconciled with emerging data on group II self-splicing introns, the spliceosome, and RNase P. The role of the RNA is to position the two catalytic metal ions and properly orient the substrates via three specific binding sites.

Steitz, T A; Steitz, J A

1993-01-01

204

Cesium Ion Bombardment of Metal Surfaces  

NASA Astrophysics Data System (ADS)

The steady state cesium coverage due to cesium ion bombardment of molybdenum and tungsten has been studied for the incident energy range below 500 eV. When a sample is exposed to a positive cesium ion beam, the work function decreases until steady state is reached with a total dose of less than (DBLTURN)1*10('16) ions/cm('2), for both tungsten and molybdenum. A steady state minimum work function surface is produced at an incident energy of (DBLTURN)100 eV for molybdenum and at an incident energy of (DBLTURN)45 eV for tungsten. Increasing the incident energy results in an increase in the work function corresponding to a decrease in the surface coverage of cesium. At incident energies less than that giving the minimum work function, the work function approaches that of cesium metal. At a given bombarding energy the cesium coverage of tungsten is uniformly less than that of molybdenum. The effects of hydrogen gas coadsorption have also been examined. Hydrogen coadsorption does not have a large effect on the steady state work functions. The largest shifts in the work function due to the coadsorption of hydrogen occur on the samples when there is no cesium present. A theory describing the steady state coverage has been developed and is used to make predictions for other materials. A simple sticking and sputtering relationship, not including implantation, cannot account for the steady state coverage. At low concentrations, cesium coverage of a target is proportional to the ratio of (1-(beta))/(gamma) where (beta) is the reflection coefficient and (gamma) is the sputter yield. High coverages are produced on molybdenum due to implantation and low backscattering, because molybdenum is lighter than cesium. For tungsten the high backscattering and low implantation result in low coverages. The implications of these results for negative hydrogen surface conversion sources are clear, molybdenum is a better material than tungsten since a much lower work function surface is maintained on molybdenum at converter operating energies.

Tompa, Gary S.

205

Radioactive ion beams at the Bevalac: Greatly enhanced fragment separation for high energy beams  

SciTech Connect

Radioactive beams are routinely produced at the Bevalac by the fragmentation process. High energy beams (energies {approximately} 800 MeV/u) produce fragments with nearly the original beam momentum, forming a radioactive ion beam. A new beamline is being constructed which will provide resolution for ions approaching the mass 100 region, compared to the present mass 20 capability, by strongly increasing the dispersion and also increasing the beam size for easier tuning and more effective collimation. In addition, the angular acceptance has been more than doubled. Details of the design will be presented. 6 refs., 4 figs., 1 tab.

Feinberg, B.; Kalnins, J.G.; Krebs, G.F.

1990-09-01

206

Natural radioactivity and trace metals in crude oils: implication for health  

Microsoft Academic Search

Crude oil samples were collected from six different fields in the central Niger Delta in order to determine their natural\\u000a radioactivity and trace element contents, with the aim of assessing the radiological health implications and environmental\\u000a health hazard of the metals, and also to provide natural radioactivity baseline data that could be used for more comprehensive\\u000a future study in this

T. R. Ajayi; N. Torto; P. Tchokossa; A. Akinlua

2009-01-01

207

Analysis of disposition alternatives for radioactively contaminated scrap metal  

Microsoft Academic Search

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

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

1997-01-01

208

Analysis of disposition alternatives for radioactively contaminated scrap metal  

Microsoft Academic Search

Millions of tons 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 either to develop a regulatory process for decontamination and recycling

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

1998-01-01

209

Adhesive bonding of ion beam textured metals and fluoropolymers  

NASA Technical Reports Server (NTRS)

An electron bombardment argon ion source was used to ion etch various metals and fluoropolymers. The metal and fluoropolymers were exposed to (0.5 to 1.0) keV Ar ions at ion current densities of (0.2 to 1.5) mA/sq cm for various exposure times. The resulting surface texture is in the form of needles or spires whose vertical dimensions may range from tenths to hundreds of micrometers, depending on the selection of beam energy, ion current density, and etch time. The bonding of textured surfaces is accomplished by ion beam texturing mating pieces of either metals or fluoropolymers and applying a bonding agent which wets in and around the microscopic cone-like structures. After bonding, both tensile and shear strength measurements were made on the samples. Also tested, for comparison's sake, were untextured and chemically etched fluoropolymers. The results of these measurements are presented.

Mirtich, M. J.; Sovey, J. S.

1978-01-01

210

Adhesive bonding of ion beam textured metals and fluoropolymers  

NASA Technical Reports Server (NTRS)

An electron-bombardment argon ion source was used to ion-etch various metals and fluoropolymers. The metal and fluoropolymers were exposed to (0.5 to 1.0)-keV Ar ions at ion current densities of 0.2 to 1.5 mA/sq cm for various exposure times. The resulting surface texture is in the form of needles or spires whose vertical dimensions may range from tenths to hundreds of micrometers, depending on the selection of beam energy, ion current density, and etch time. The bonding of textured surfaces is accomplished by ion-beam texturing mating pieces of either metals or fluoropolymers and applying a bonding agent which wets in and around the microscopic conelike structures. After bonding, both tensile and shear strength measurements were made on the samples. Also tested, for comparison's sake, were untextured and chemically etched fluoropolymers. The results of these measurements are presented in this paper.

Mirtich, M. J.; Sovey, J. S.

1978-01-01

211

Applications of radioactive ion beams to solid-state physics  

Microsoft Academic Search

:   Radioactive atoms have been used in solid-state physics and in material science for many decades. Besides their classical\\u000a application as tracer for diffusion studies, nuclear techniques such as Mößbauer spectroscopy, perturbed angular correlation,\\u000a ?-NMR, and emission channeling have used nuclear properties (via hyperfine interactions or emitted ?- or ?-particles) to gain\\u000a microscopical information on the structural and dynamical properties

M. Deicher

2002-01-01

212

Progress in metal ion separation and preconcentration : an overview.  

SciTech Connect

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.

Bond, A. H.

1998-05-19

213

Metal ion levels decrease after revision for metallosis arising from large-diameter metal-on-metal hip arthroplasty.  

PubMed

Concerns have been renewed regarding the possible long-term effects of elevated circulating levels of cobalt and chromium as a direct result of implantation of large femoral head diameter metal-on-metal bearings. In order to establish whether metal ion levels remain persistently elevated, we compared metal ion levels before and after revision surgery in patients with large head diameter (greater than 38 mm) metal-on-metal total hip arthroplasty or hip resurfacing arthroplasty. At greater than one year post removal of a large-diameter metal-on-metal hip implant for the indication of symptomatic metallosis, metal ion levels were found to fall to almost normal levels. PMID:22308623

Ebreo, Darren; Khan, Abdul; El-Meligy, Mohammed; Armstrong, Catherine; Peter, Viju

2011-12-01

214

Influences of peptide side chains on the metal ion binding site in metal ion-cationized peptides: Participation of aromatic rings in metal chelation  

Microsoft Academic Search

Aromatic side chains on amino acids influence the fragmentations of cationic complexes of doubly charged metal ions and singly\\u000a deprotonated peptides. The metal ion interacts with an aromatic side chain and binds to adjacent amide nitrogens. When fragmentation\\u000a occurs, this bonding leads to the formation of abundant metal-containing a-type ions by reactions that occur at the sites\\u000a of amino acids

Peifeng Hu; Curt Sorensen; Michael L. Gross

1995-01-01

215

Potential radioactive scrap metal quantities from nuclear power plants worldwide  

Microsoft Academic Search

Approximately 12 million tons of scrap metals are likely to be generated worldwide during the next 50 years from decommissioning and dismantling nuclear power plants. A large portion of this material will be only slightly contaminated it at all, and, it it is releasable, it would have a scrap value of billions of dollars. Disposition of the metal is complicated

L. A. Nieves; R. W. Tilbrook

1996-01-01

216

Metal ion levels: how can they help us?  

PubMed

Ion levels have been shown to reliably predict abnormal function of the bearing surface with increased wear, but ion levels should not be used alone as a trigger for when to proceed with revision surgery with metal-metal articulations. Risk stratification strategies help determine which patients should be monitored more closely with serial ion levels, cross-sectional imaging with a MARS MRI, or proceed on to revision. Based on the current data available, an ion level greater than 4.5 ppb (Cr or Co) may serve as a threshold for when abnormal wear is occurring, and is suggested as a trigger for a MARS MRI scan. PMID:24655610

Griffin, William L

2014-04-01

217

Metal ion acquisition in Staphylococcus aureus: overcoming nutritional immunity  

PubMed Central

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.

Cassat, James E.

2013-01-01

218

Studies of sorbent\\/ion-exchange materials for the removal of radioactive strontium from liquid radioactive waste and high hardness groundwaters  

Microsoft Academic Search

Different sorbents were studied in terms of their full-scale applicability for radioactive strontium removal in low-level liquid radioactive waste (LLRW) management. The following types of sorbent\\/ion-exchange materials were investigated: natural zeolite–clinoptilolite, modified natural clinoptilolite, synthetic zeolites, new synthetic crystalline materials selective to strontium, ion-exchange resins, and modified fiber sorbents. Simulated solutions for experimental tests were prepared according to the composition

Dmitry V Marinin; Garrett N Brown

2000-01-01

219

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

SciTech Connect

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.

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

2008-08-26

220

Silica-polyamine composite materials for heavy metal ion removal, recovery, and recycling. 2. Metal ion separations from mine wastewater and soft metal ion extraction efficiency  

SciTech Connect

Silica-polyamine composites have been synthesized which have metal ion capacities as high as 0.84 mmol/g for copper ions removed from aqueous solutions. In previous reports it has been demonstrated that these materials survive more than 3,000 cycles of metal ion extraction, elution, and regeneration with almost no loss of capacity (less than 10%). This paper describes two modified silica-polyamine composite materials and reveals the results of tests designed to determine the effectiveness of these materials for extracting and separating metal ions from actual mining wastewater samples. Using these materials, the concentration of copper, aluminum, and zinc in Berkeley Pit mine wastewater is reduced to below allowable discharge limits. The recovered copper and zinc solutions were greater than 90% pure, and metal ion concentration factors of over 20 for copper were realized. Further, the ability of one of these materials to decrease low levels of the soft metals cadmium, mercury, and lead from National Sanitation Foundation recommended challenge levels to below Environmental Protection Agency allowable limits is also reported.

Fischer, R.J.; Pang, D.; Beatty, S.T.; Rosenberg, E.

1999-12-01

221

Amphipathic cyclooctapeptides: interactions with detergent micelles and metal ions  

NASA Astrophysics Data System (ADS)

In order to study the secondary structural preferences of amphipathic cyclopeptides in detergent assemblies and their interactions with metal ions, two basic amphiphatic cyclooctapeptides, c[(Lys- D-Lys) 2-Xaa- D-Leu-Leu- D-Leu], where Xaa is Leu ( P1) or Trp ( P2), were studied by circular dichroism (CD) spectroscopy. In water, P1 exhibited an unordered secondary structure whereas P2 adopted a partial ?-sheet structure. Temperature effect on the CD of these cyclopeptides showed small changes over the temperature range from 278 to 353 K. P1 showed low and non-specific binding affinity for metal ions (Ca 2+, Zn 2+, Na +, or Li +) in water whereas P2 did not exhibit any significant interaction with these ions. However, in the zwitterionic micellar detergent dodecylphosphocholine (DPC), P2 adopted a ?-sheet structure, which exhibited a greater propensity for metal ion interactions (K 1˜10 3 M -1 and K2˜10 2 M -1). Variable temperature CD studies on the peptide-metal ion complexes showed that these interactions are thermally reversible. Our results indicate that amphipathic cyclooctapeptides can co-assemble with micellar DPC and are capable of interacting with metal ions. This study will improve our ability to design a better metal ion sensing cyclopeptide in co-micellar assembles.

Gates, William Day; Rostas, Jack; Kakati, Bobby; Ngu-Schwemlein, Maria

2005-01-01

222

Metal ion removal from aqueous solution using physic seed hull.  

PubMed

The potential of physic seed hull (PSH), Jantropha curcas L. as an adsorbent for the removal of Cd(2+) and Zn(2+) metal ions from aqueous solution has been investigated. It has been found that the amount of adsorption for both Cd(2+) and Zn(2+) increased with the increase in initial metal ions concentration, contact time, temperature, adsorbent dosage and the solution pH (in acidic range), but decreased with the increase in the particle size of the adsorbent. The adsorption process for both metal ions on PSH consists of three stages-a rapid initial adsorption followed by a period of slower uptake of metal ions and virtually no uptake at the final stage. The kinetics of metal ions adsorption on PSH followed a pseudo-second-order model. The adsorption equilibrium data were fitted in the three adsorption isotherms-Freundlich, Langmuir and Dubinin-Radushkevich isotherms. The data best fit in the Langmuir isotherm indication monolayer chemisorption of the metal ions. The adsorption capacity of PSH for both Zn(2+) and Cd(2+) was found to be comparable with other available adsorbents. About 36-47% of the adsorbed metal could be leached out of the loaded PSH using 0.1M HCl as the eluting medium. PMID:20362390

Mohammad, Masita; Maitra, Saikat; Ahmad, Naveed; Bustam, Azmi; Sen, T K; Dutta, Binay K

2010-07-15

223

Natural radioactivity consideration for high-? dielectrics and metal gates choice in nanoelectronic devices  

NASA Astrophysics Data System (ADS)

In order to face downscaling, new chemical elements are used and suggested for the semiconductor industry. However, some of these elements have natural radioactive isotopes, which may cause reliability issues in nanoelectronic devices by triggering soft errors. In this paper, we focus on high-? dielectric materials and metal gates. We show that besides physical, chemical and mechanical properties of high-? dielectrics and metal gates, natural radioactivity is also a crucial property to be considered in order to select suitable materials. Using samarium in gate oxides and platinum in electrodes turns out to be a crucial issue for ground level applications.

Gedion, Michael; Wrobel, Frédéric; Saigné, Frédéric

2010-07-01

224

A thermodynamic "vocabulary" for metal ion interactions in biological systems.  

PubMed

This Account focuses on metal ion-ligand complexes of biological relevance and measurements of the bond dissociation energies (BDEs) of such species. These complexes yield thermochemistry that begins to provide a thermodynamic "vocabulary" for thinking quantitatively about the strength of interactions in biological systems. The method utilized is threshold collision-induced dissociation in a guided ion beam tandem mass spectrometer. Accurate determination of BDEs requires attention to many details of the experiments and data analysis, as outlined here. Trends in metal ion-ligand BDEs are examined as a function of the metal ion, ligand, and extent of ligation. We elucidate the importance of ion-dipole and ion-induced dipole interactions, chelation, conformation, tautomeric form, steric interactions, and electronic effects such as hybridization and promotion. Interactions of metal ions with nucleobases and amino acids are quantified and the effects of hydration on these values are explored for the amino acid systems. Although data limitations restrict the present discussion to monocations, the trends elucidated here should be relevant to multiply charged metal ions, for which data is forthcoming. PMID:15609991

Rodgers, M T; Armentrout, P B

2004-12-01

225

Femoral Head Size Does Not Affect Ion Values in Metal-on-Metal Total Hips  

Microsoft Academic Search

Background  Metal-on-metal articulations can release substantial amounts of particles containing cobalt and chromium into the surrounding\\u000a milieu, causing concern for cellular toxicity and adverse local soft tissue reactions. The diameter of the femoral head has\\u000a been one of the variables that inversely affects wear of metal-on-metal total hip arthroplasty (THA). The oxidative stress\\u000a of increased metal ions can be measured with

Mitchell Bernstein; Alan Walsh; Alain Petit; David J. Zukor; John Antoniou

2011-01-01

226

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

Microsoft Academic Search

Modern metal-on-metal hip resurfacing was introduced as a bone-preserving method of joint reconstruction for young and active\\u000a patients; however, the large diameter of the bearing surfaces is of concern for potential increased metal ion release. We\\u000a hypothesized there were no differences in serum concentrations of chromium, cobalt, and molybdenum between patients who had\\u000a metal-on-metal hip resurfacing (Group A; average head

Antonio Moroni; Lucia Savarino; Matteo Cadossi; Nicola Baldini; Sandro Giannini

2008-01-01

227

Application of ion beams in materials science of radioactive waste forms: focus on the performance of spent nuclear fuel  

Microsoft Academic Search

Ion beam techniques provide unique tools for the qualification of radioactive waste forms. They address three major issues: (i) the simulation by ion irradiation of the stability of a matrix submitted to radiative environment; (ii) the doping of a material with stable or radioactive elements which simulate the species to be confined; (iii) the characterisation of a material via nuclear

Frédérico Garrido; Lech Nowicki; Lionel Thomé

2005-01-01

228

Main Group Metal Ion Chemistry In Planetary Atmospheres  

NASA Astrophysics Data System (ADS)

Metal ions are a significant product of meteoric ablation within planetary atmospheres. The lifetimes and ultimate chemical processing of these metal ions depend crucially on their association chemistry with the dominant atmospheric constituents (variously N2, CO2, and H2 among the Solar System's representative planetary atmospheres), yet this association chemistry has received very little previous study. In this work we present, for the first time, calculated temperature-dependent termolecular association rate coefficients for the reactions of the dominant main-group metal ions Na+, Mg+, Al+, K+, and Ca+ with N2, CO2, and H2. These rate coefficients have been determined through the use of variational transition state theory, employing structural and thermochemical data obtained via ab initio quantum chemical calculations. Implications of the calculated kinetic data, for a few specific instances of meteoric metal-ion chemistry, are sketched out, and directions for future study are also outlined.

Petrie, Simon; Dunbar, Robert C.

2006-09-01

229

Extracting metal ions with diphosphonic acid, or derivative thereof  

SciTech Connect

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.

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

1994-01-01

230

An engineered palette of metal ion quenchable fluorescent proteins.  

PubMed

Many fluorescent proteins have been created to act as genetically encoded biosensors. With these sensors, changes in fluorescence report on chemical states in living cells. Transition metal ions such as copper, nickel, and zinc are crucial in many physiological and pathophysiological pathways. Here, we engineered a spectral series of optimized transition metal ion-binding fluorescent proteins that respond to metals with large changes in fluorescence intensity. These proteins can act as metal biosensors or imaging probes whose fluorescence can be tuned by metals. Each protein is uniquely modulated by four different metals (Cu2+, Ni2+, Co2+, and Zn2+). Crystallography revealed the geometry and location of metal binding to the engineered sites. When attached to the extracellular terminal of a membrane protein VAMP2, dimeric pairs of the sensors could be used in cells as ratiometric probes for transition metal ions. Thus, these engineered fluorescent proteins act as sensitive transition metal ion-responsive genetically encoded probes that span the visible spectrum. PMID:24752441

Yu, Xiaozhen; Strub, Marie-Paule; Barnard, Travis J; Noinaj, Nicholas; Piszczek, Grzegorz; Buchanan, Susan K; Taraska, Justin W

2014-01-01

231

An Engineered Palette of Metal Ion Quenchable Fluorescent Proteins  

PubMed Central

Many fluorescent proteins have been created to act as genetically encoded biosensors. With these sensors, changes in fluorescence report on chemical states in living cells. Transition metal ions such as copper, nickel, and zinc are crucial in many physiological and pathophysiological pathways. Here, we engineered a spectral series of optimized transition metal ion-binding fluorescent proteins that respond to metals with large changes in fluorescence intensity. These proteins can act as metal biosensors or imaging probes whose fluorescence can be tuned by metals. Each protein is uniquely modulated by four different metals (Cu2+, Ni2+, Co2+, and Zn2+). Crystallography revealed the geometry and location of metal binding to the engineered sites. When attached to the extracellular terminal of a membrane protein VAMP2, dimeric pairs of the sensors could be used in cells as ratiometric probes for transition metal ions. Thus, these engineered fluorescent proteins act as sensitive transition metal ion-responsive genetically encoded probes that span the visible spectrum.

Yu, Xiaozhen; Strub, Marie-Paule; Barnard, Travis J.; Noinaj, Nicholas; Piszczek, Grzegorz; Buchanan, Susan K.; Taraska, Justin W.

2014-01-01

232

Measuring Neutrino Mass with Radioactive Ions in a Storage Ring  

SciTech Connect

A method to measure the neutrino mass kinematically using beams of ions which undergo beta decay is proposed. The idea is to tune the ion beam momentum so that in most decays, the electron is forward moving with respect to the beam, and only in decays near the endpoint is the electron moving backwards. By counting the backward moving electrons one can observe the effect of neutrino mass on the beta spectrum close to the endpoint. In order to reach sensitivities for m{sub n}u<0.2 eV, it is necessary to control the ion momentum with a precision better than deltap/p<10{sup -5}, identify suitable nuclei with low Q-values (in the few to ten keV range), and one must be able to observe at least O(10{sup 18}) decays.

Lindroos, Mats [AB division, CERN, Geneva (Switzerland); McElrath, Bob [Theory division, CERN, Geneva (Switzerland); Orme, Christopher [IPPP, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Schwetz, Thomas [Max-Planck-Institute for Nuclear Physics, PO Box 103980, 69029 Heidelberg (Germany)

2010-03-30

233

Exploiting neutron-rich radioactive ion beams to constrain the symmetry energy  

NASA Astrophysics Data System (ADS)

The Modular Neutron Array (MoNA) and 4 Tm Sweeper magnet were used to measure the free neutrons and heavy charged particles from the radioactive ion beam induced 32Mg+9Be reaction. The fragmentation reaction was simulated with the constrained molecular dynamics model (CoMD), which demonstrated that the of the heavy fragments and free neutron multiplicities were observables sensitive to the density dependence of the symmetry energy at subsaturation densities. Through comparison of these simulations with the experimental data, constraints on the density dependence of the symmetry energy were extracted. The advantage of radioactive ion beams as a probe of the symmetry energy is demonstrated through examination of CoMD calculations for stable and radioactive-beam-induced reactions.

Kohley, Z.; Christian, G.; Baumann, T.; DeYoung, P. A.; Finck, J. E.; Frank, N.; Jones, M.; Smith, J. K.; Snyder, J.; Spyrou, A.; Thoennessen, M.

2013-10-01

234

Effusive-Flow of Pure Elemental Species in Tubular Transport Systems: Radioactive Ion Beam Applications  

SciTech Connect

Maximum practically achievable intensities are required for research with accelerated radioactive ion beams (RIBs). Time delays due to diffusion of radioactive species from solid or liquid target materials and their effusive-flow transport to the ion source can severely limit intensities of short-lived radioactive beams, and therefore, such delays must be minimized. An analytical formula has been developed that can be used to calculate characteristic effusive-flow times through tubular transport systems, independent of species, tube material, and operational temperature for ideal cases. Thus, the equation permits choice of materials of construction on a relative basis that minimize transport times of atoms or molecules moving through the system, independent of transport system geometry and size. In this report, we describe the formula and compare results derived by its use with those determined by use of Monte-Carlo techniques.

Bilheux, J.C.

2001-04-16

235

Metallic glass as a temperature sensor during ion plating  

NASA Technical Reports Server (NTRS)

The temperature of the interface and/or a superficial layer of a substrate during ion plating was investigated using a metallic glass of the composition Fe67Co18B14Si1 as the substrate and as the temperature sensor. Transmission electron microscopy and diffraction studies determined the microstructure of the ion-plated gold film and the substrate. Results indicate that crystallization occurs not only in the film, but also in the substrate. The grain size of crystals formed during ion plating was 6 to 60 nm in the gold film and 8 to 100 nm in the substrate at a depth of 10 to 15 micrometers from the ion-plated interface. The temperature rise of the substrate during ion plating was approximately 500 C. Discontinuous changes in metallurgical microstructure, and physical, chemical, and mechanical properties during the amorphous to crystalline transition in metallic glasses make metallic glasses extremely useful materials for temperature sensor applications in coating processes.

Miyoshi, K.; Spalvins, T.; Buckley, D. H.

1985-01-01

236

Element Synthesis Calculations for Stellar Explosions: Robust Uncertainties, Sensitivities, and Radioactive Ion Beam Measurements  

SciTech Connect

We utilize multiple-zone, post-processing element synthesis calculations to determine the impact of recent ORNL radioactive ion beam measurements on predictions of novae and X-ray burst simulations. We also assess the correlations between all relevant reaction rates and all synthesized isotopes, and translate nuclear reaction rate uncertainties into abundance prediction uncertainties, via a unique Monte Carlo technique.

Smith, Michael Scott [ORNL; Hix, William Raphael [ORNL; Parete-Koon, Suzanne T [ORNL; Dessieux Jr, Luc Lucius [ORNL; Ma, Zhanwen [ORNL; Starrfield, Sumner [Arizona State University; Bardayan, Daniel W [ORNL; Guidry, Mike W [ORNL; Smith, Donald L. [Argonne National Laboratory (ANL); Blackmon, Jeff C [ORNL; Mezzacappa, Anthony [ORNL

2004-12-01

237

Frictional and morphological characteristics of ion plated soft, metallic films  

NASA Technical Reports Server (NTRS)

Ion plated metallic films in contrast to films applied by other deposition techniques offer a lower friction coefficient, longer endurance lives and exhibit a gradual increase in friction coefficient after the film has been worn off. The friction coefficients of metallic films are affected by the degree of adherence, thickness and nucleation and growth characteristics during ion plating lead to a fine, continuous crystalline structure, which contributes to a lower friction coefficient.

Spalvins, T.; Buzek, B.

1981-01-01

238

Removal of toxic metal ions from wastewater by semiconductor photocatalysis  

Microsoft Academic Search

Semiconductor photocatalytic reduction is a relatively new technique for the removal of dissolved metal ions in wastewater. In this paper, physical adsorption and photocatalytic reduction of eight environmentally significant metal ions in TiO2 suspensions of Degussa P25 and Hombikat UV100 were investigated. Critical scrutiny of the potential versus pC and pH diagrams reveals that any particular oxidation or reduction reaction

Dingwang Chen; Ajay K. Ray

2001-01-01

239

Determination of noble metals in Savannah River Site high-level radioactive sludge  

SciTech Connect

High-level radioactive sludge at the Savannah River Site (SRS) will be processed at the Defense Waste Processing Facility (DWPF) into durable borosilicate glass wasteforms. The sludges are analyzed for elemental content before processing to ensure compatibility with the glass-making processes. Noble metal fission products in sludge, can under certain conditions, cause problems in the glass melter. Therefore, reliable noble metal determinations are important. The scheme used to measure noble metals in SRS sludges consists of dissolving sludge with hot aqua regia followed by determinations with inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and ICP-Mass Spectroscopy (ICP-MS) techniques. ICP-MS is the preferred method for measuring trace levels of noble metals in SRS radioactive waste because of superior sensitivity. Analytical results are presented for the two major types of SRS sludge.

Coleman, C.J.; Kinard, W.F.; Bibler, N.E.; Bickford, D.F.; Ramsey, W.G.

1990-12-31

240

Determination of noble metals in Savannah River Site high-level radioactive sludge  

SciTech Connect

High-level radioactive sludge at the Savannah River Site (SRS) will be processed at the Defense Waste Processing Facility (DWPF) into durable borosilicate glass wasteforms. The sludges are analyzed for elemental content before processing to ensure compatibility with the glass-making processes. Noble metal fission products in sludge, can under certain conditions, cause problems in the glass melter. Therefore, reliable noble metal determinations are important. The scheme used to measure noble metals in SRS sludges consists of dissolving sludge with hot aqua regia followed by determinations with inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and ICP-Mass Spectroscopy (ICP-MS) techniques. ICP-MS is the preferred method for measuring trace levels of noble metals in SRS radioactive waste because of superior sensitivity. Analytical results are presented for the two major types of SRS sludge.

Coleman, C.J.; Kinard, W.F.; Bibler, N.E.; Bickford, D.F.; Ramsey, W.G.

1990-01-01

241

Metal ion implantation for large scale surface modification  

SciTech Connect

Intense energetic beams of metal ions can be produced by using a metal vapor vacuum arc as the plasma discharge from which the ion beam is formed. We have developed a number of ion sources of this kind and have built a metal ion implantation facility which can produce repetitively pulsed ion beams with mean ion energy up to several hundred key, pulsed beam current of more than an ampere, and time averaged current of several tens of milliamperes delivered onto a downstream target. We've also done some preliminary work on scaling up this technology to very large size. For example, a 50-cm diameter (2000 cm[sup 2]) set of beam formation electrodes was used to produce a pulsed titanium beam with ion current over 7 amperes at a mean ion energy of 100 key. Separately, a dc embodiment has been used to produce a dc titanium ion beam with current over 600 mA, power supply limited in this work, and up to 6 amperes of dc plasma ion current was maintained for over an hour. In a related program we've developed a plasma immersion method for applying thin metallic and compound films in which the added species is atomically mixed to the substrate. By adding a gas flow to the process, well-bonded compound films can also be formed; metallic films and multilayers as well as oxides and nitrides with mixed transition zones some hundreds of angstroms thick have been synthesized. Here we outline these parallel metal-plasma-based research programs and describe the hardware that we've developed and some of the surface modification research that we've done with it.

Brown, I.G.

1992-10-01

242

Metal Ion release with large-diameter metal-on-metal hip arthroplasty.  

PubMed

Preoperative and postoperative ion concentrations were measured in 29 metal-on-metal, large-diameter head total hip arthroplasty (LDH-THA) patients. Mean chromium, cobalt (Co), and titanium levels from LDH-THA were 1.3, 2.2, and 2.7 ?g/L at 12 months. The open femoral head design showed significantly higher Co concentrations than the closed design (3.0 vs 1.8 ?g/L, P = .037). Compared with previously published ion levels from a hip resurfacing system presenting the same bearing characteristics, Co levels were significantly higher in LDH-THA (2.2 vs 0.7 ?g/L, P < .001). This study has demonstrated that the addition of a sleeve with modular junctions and an open femoral head design of LDH-THA causes more Co release than bearing surface wear (157% and 67%, respectively). Even if no pathologic metal ion threshold level has been determined, efforts should be made to minimize its release. We recommend modification or abandonment of the modular junction and femoral head open design for this specific LDH-THA system. PMID:20206466

Vendittoli, Pascal-André; Amzica, Traian; Roy, Alain G; Lusignan, Daniel; Girard, Julien; Lavigne, Martin

2011-02-01

243

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

SciTech Connect

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.

McCloskey, J.T.; Newman, M.C.; Clark, S.B. [Univ. of Georgia, Aiken, SC (United States). Savannah River Ecology Lab.

1996-10-01

244

Metal ion adsorption to complexes of humic acid and metal oxides: Deviations from the additivity rule  

SciTech Connect

The adsorption of cadmium ions to a mixture of Aldrich humic acid and hematite is investigated. The actual adsorption to the humic acid-hematite complex is compared with the sum of the cadmium ion adsorptivities to each of the isolated components. It is shown that the sum of the cadmium ion adsorptivities is not equal to the adsorption to the complex. In general, the adsorption of a specific metal ion to the complex can be understood and qualitatively predicted using the adsorptivities to each of the pure components and taking into account the effect of the pH on the interaction between humic acid and iron oxide on the metal ion adsorption. Due to the interaction between the negatively charged humic acid and the positively charged iron oxide, the adsorption of metal ions on the mineral oxide in the complex will increase as compared to that on the isolated oxide, whereas the adsorption to the humic acid will decrease as compared to that on the isolated humic acid. As a result, the overall adsorption of a specific metal ion to the complex will be smaller than predicted by the additivity rule when this metal ion has a more pronounced affinity for the humic acid than for the mineral oxide, whereas it will be larger than predicted by the additivity rule when the metal ion has a higher affinity for the oxide than for the humic acid.

Vermeer, A.W.P.; McCulloch, J.K.; Van Riemsdijk, W.H.; Koopal, L.K.

1999-11-01

245

Environmentally relevant metal and transition metal ions enhance Fc epsilon RI-mediated mast cell activation.  

PubMed Central

Upon contact with allergen, sensitized mast cells release highly active proinflammatory mediators. Allergen-mediated mast cell activation is an important mechanism in the pathogenesis of atopic asthma. Asthmatic patients are especially susceptible to air pollution. Epidemiologic studies found a positive correlation between severity of symptoms among asthmatic patients and the level of particulate matter (PM) in the air. Among the constituents of PM are metals and transition metals, which could mediate some of its adverse effects on human health. We sought to determine the effect of metal and transition metal ions on allergen-mediated mast cell activation. We observed that several metal and transition metal ions activated mast cells and enhanced allergen-mediated mast cell activation. Thus, Al(3+), Cd(2+), and Sr(2+) induced release of granule-associated N-acetyl-ss-d-hexosaminidase, and Al(3+) and Ni(2+) enhanced antigen-mediated release. Metal and transition metal ions also induced significant secretion of interleukin (IL)-4 and increased antigen-mediated IL-4 secretion in mast cells. These effects of metal and transition metal ions on mast cells were observed at concentrations that do not result in direct cytotoxicity and might be relevant for environmental exposure. Thus, metals and transition metals could increase the level of allergen-mediated mast cell activation, which might be one of the mechanisms mediating exacerbation of allergen-driven asthma symptoms by air pollution.

Walczak-Drzewiecka, Aurelia; Wyczolkowska, Janina; Dastych, Jaroslaw

2003-01-01

246

Comet Encke: Meteor Metallic Ion Identification by Mass Spectrometer  

Microsoft Academic Search

Metal ions including 23+ (Na+), 24+ (Mg+), 28+ (Si+), 39+ (K+), 40+ (Ca+), 45+ (Sc+), 52+ (Cr+), 56+ (Fe+), and 58+ (Ni+) have been detected in the upper atmosphere during the period of the Beta Taurids meteor shower. The abundances of these ions relative to Si+ show agreement in most instances with abundances in chondrites. A notable exception is 45+,

R. A. Goldberg; A. C. Aikin

1973-01-01

247

Ion Beam Mixing in Metallic Glasses at Low Temperatures.  

National Technical Information Service (NTIS)

Measurements of ion beam mixing of tracer impurities in metallic glasses and in the pure crystalline elements comprising the glasses were performed at approx.80 K. It was observed that the ion mixing efficiency of the tracer impurities was greater in the ...

H. Hahn T. D. de la Rubia R. S. Averback

1987-01-01

248

Heavy metal ion adsorption onto polypyrrole-impregnated porous carbon  

Microsoft Academic Search

Polypyrrole-impregnated porous carbon was readily synthesized using vapor infiltration polymerization of pyrrole monomers. The results show that the functionalized polymer layer was successfully coated onto the pore surface of carbon without collapse of mesoporous structure. The modified porous carbon exhibited an improved complexation affinity for heavy metal ions such as mercury, lead, and silver ions due to the amine group

Moonjung Choi; Jyongsik Jang

2008-01-01

249

Metal ion deposition from ionized mangetron sputtering discharge  

Microsoft Academic Search

A technique has been developed for highly efficient postionization of sputtered metal atoms from a magnetron cathode. The process is based on conventional magnetron sputtering with the addition of a high density, inductively coupled rf (RFI) plasma in the region between the sputtering cathode and the sample. Metal atoms sputtered from the cathode due to inert gas ion bombardment transit

S. M. Rossnagel; J. Hopwood

1994-01-01

250

Comparative study of metal and non-metal ion implantation in polymers: Optical and electrical properties  

NASA Astrophysics Data System (ADS)

The implantation of 1 MeV metal (63Cu+, 107Ag+, 197Au+) and non-metal (4He+, 12C+) ions in a polycarbonate (PC) matrix has been studied in order to evaluate the role of ion species in the modification of optical and electrical properties of the polymer. When the ion fluence is above ?1 × 1013 ions cm-2, the threshold for latent tracks overlapping is overcome and ?-bonded carbon clusters grow and aggregate forming a network of conjugated Cdbnd C bonds. For fluences around 1 × 1017 ions cm-2, the aggregation phenomena induce the formation of amorphous carbon and/or graphite like structures. At the same time, nucleation of metal nanoparticles (NPs) from implanted species can take place when the supersaturation threshold is overcome. The optical absorption of the samples increases in the visible range and the optical band gap redshifts from 3.40 eV up to 0.70 eV mostly due to the carbonization process and the formation of C0x clusters and cluster aggregates. Specific structures in the extinction spectra are observed when metal ions are selected in contrast to the non-metal ion implanted PC, thus revealing the possible presence of noble metal based NPs interstitial to the C0x cluster network. The corresponding electrical resistance decreases much more when metal ions are implanted with at least a factor of 2 orders of magnitude difference than the non-metal ions based samples. An absolute value of ?107 ?/sq has been measured for implantation with metals at doses higher than 5 × 1016 ions cm-2, being 1017 ?/sq the corresponding sheet resistance for pristine PC.

Resta, V.; Quarta, G.; Farella, I.; Maruccio, L.; Cola, A.; Calcagnile, L.

2014-07-01

251

In situ bioremediation of soils contaminated with radioactive elements and toxic heavy metals  

Microsoft Academic Search

Two experimental plots of an agricultural land contaminated with radioactive elements (uranium, radium thorium) and toxic heavy metals (copper, zinc, cadmium) were treated by two different biotechnological in situ methods. The soil in this land was characterized by a negative net neutralization potential, and the soil pH was in a slightly acidic pH range (from 4 to 5). The contaminants

S. N. Groudev; I. I. Spasova; P. S. Georgiev

2001-01-01

252

Fernald's dilemma: Recycle the radioactively contaminated scrap metal, or bury it?  

Microsoft Academic Search

During the past 5 years, a number of US 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 accelerator shielding blocks, to the construction of low level waste containers, technology has been applied to this fabrication process in a safe and stakeholder

Katherine L. Yuracko; Stanton W. Hadley; Robert D. Perlack; Rafael G. Rivera; T. Randall Curlee

1997-01-01

253

Health risk and impact evaluation for recycling of radioactive scrap metal  

Microsoft Academic Search

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

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

1994-01-01

254

Radioactive halos and ion microprobe measurement of Pb isotope ratios  

NASA Technical Reports Server (NTRS)

This investigation was to obtain, if possible, the Pb isotope ratios of both lunar and meteoritic troilite grains by utilizing ion microprobe techniques. Such direct in situ measurement of Pb isotope ratios would eliminate contamination problems inherent in wet chemistry separation procedures, and conceivably determine whether lunar troilite grains were of meteoritic origin. For comparison purposes two samples of meteoritic troilite were selected (one from Canyon Diablo) for analysis along with two very small lunar troilite grains (approximately 50-100 microns). It was concluded that the ion microprobe as presently operating, does not permit the in situ measurement of Pb isotope ratios in lunar or meteoritic troilite. On the basis of these experiments no conclusions could be drawn as to the origin of the lunar troilite grains.

Gentry, R. V.

1974-01-01

255

Precision mass measurements at TITAN with radioactive ions  

NASA Astrophysics Data System (ADS)

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.

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

256

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...

257

Removal of metal ions from aqueous solution  

DOEpatents

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.

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

258

Removal of metal ions from aqueous solution  

DOEpatents

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.

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

259

A specific monovalent metal ion integral to the AA platform of the RNA tetraloop receptor  

Microsoft Academic Search

Metal ions are essential for the folding and activity of large catalytic RNAs. While divalent metal ions have been directly implicated in RNA tertiary structure formation, the role of monovalent ions has been largely unexplored. Here we report the first specific monovalent metal ion binding site within a catalytic RNA. As seen crystallographically, a potassium ion is coordinated immediately below

Soumitra Basu; Robert P. Rambo; Juliane Strauss-Soukup; Jamie H. Cate; Adrian R. Ferré-D´Amaré; Scott A. Strobel; Jennifer A. Doudna

1998-01-01

260

2008 John Charnley Award: Metal Ion Levels After Metal-on-Metal Total Hip Arthroplasty: A Randomized Trial  

Microsoft Academic Search

Metal-on-metal bearing total hip arthroplasty is performed more commonly than in the past. There may be manufacturing differences\\u000a such as clearance, roughness, metallurgy, and head size that affect performance. In a prospective, randomized trial, we compared\\u000a 2-year postoperative ion levels for a 28-mm metal-on-polyethylene bearing with 28-mm and 36-mm metal-on-metal bearings. We\\u000a measured serum, erythrocyte, and urine ion levels. We

C. Anderson Engh Jr; Steven J. MacDonald; Supatra Sritulanondha; Abigail Thompson; Douglas Naudie; Charles A. Engh

2009-01-01

261

Plasma spectroscopy of metal ions for hyper-electron cyclotron resonance ion source.  

PubMed

In this research, the optical line spectra of metal ions from ECR plasma were observed using a grating monochromator with a photomultiplier. The light intensity of line spectrum from the ECR plasma had a strong correlation with ion beam intensity measured by a magnetic mass analyzer. This correlation is a significant information for the beam tuning process, because it allows to conduct the extraction of the desired metal ion species from the ECR plasma. Separation of ion species of the same charge to mass ratio with an electromagnetic mass analyzer is known to be an exceptionally complex process, but this research provides a new approach for its simplification. In this paper the grating monochromator method for metal ion beam tuning such as (40)Ca(12+), (56)Fe(15+), and (85)Rb(20+) of hyper-ECR ion source as an injector for RIKEN Azimuthal Varying Field cyclotron is described. PMID:24593484

Muto, Hideshi; Ohshiro, Yukimitsu; Yamaka, Shoichi; Watanabe, Shin-ichi; Oyaizu, Michihiro; Kubono, Shigeru; Yamaguchi, Hidetoshi; Kase, Masayuki; Hattori, Toshiyuki; Shimoura, Susumu

2014-02-01

262

Metallic dental material biocompatibility in osteoblastlike cells: correlation with metal ion release.  

PubMed

Ions released from metallic dental materials used in orthodontic appliances could induce undesirable effects on cells and tissues. This study evaluates the biocompatibility of two of the most labile components of metallic dental alloys on osteoblastlike cells. The influence of protein and ions on metal dissolution properties is also investigated using different electrolyte solutions. Morphological alterations, cell growth, and differentiation of osteoblasts were assessed after exposure to pure metals (Ag, Cu, Pd, Au) and Ni-Ti alloy and correlated with the kinetics of elements released into the culture media. Results showed that Cu and Ag were the most cytotoxic elements and the other metals were biocompatible with the osteoblasts. The parameters of biocompatibility were correlated with the levels of ions detected into the culture media. Metal ions induced cell death through early mitosis arrest, apoptotic phenomena, and necrotic processes. Voltammograms showed that anions and proteins interfered in the corrosion process. Fetal bovine serum (FBS) strongly affected the electrochemical process, decreasing the oxidation rate of the metals. In conclusion, copper and silver ions showed a time-dependent low biocompatibility, which correlated with the concentration of released ions. The dissolution of the metallic materials was dependent on the composition of the simulated biological media. PMID:15326364

Cortizo, María C; De Mele, Mónica Fernández L; Cortizo, Ana M

2004-08-01

263

Heavy metal ion adsorption onto polypyrrole-impregnated porous carbon.  

PubMed

Polypyrrole-impregnated porous carbon was readily synthesized using vapor infiltration polymerization of pyrrole monomers. The results show that the functionalized polymer layer was successfully coated onto the pore surface of carbon without collapse of mesoporous structure. The modified porous carbon exhibited an improved complexation affinity for heavy metal ions such as mercury, lead, and silver ions due to the amine group of polypyrrole. The introduced polypyrrole layer could provide the surface modification to be applied for heavy metal ion adsorbents. Especially, polymer-impregnated porous carbon has an enhanced heavy metal ion uptake, which is 20 times higher than that of adsorbents with amine functional groups. Furthermore, the relationship between the coated polymer amount and surface area was also investigated in regard to adsorption capacity. PMID:18602641

Choi, Moonjung; Jang, Jyongsik

2008-09-01

264

Multiply stripped ion generation in the metal vapor vacuum arc  

NASA Astrophysics Data System (ADS)

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 reported 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.

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

1987-09-01

265

Adsorption characteristics of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto chitosan/clinoptilolite sorbents.  

PubMed

Adsorption features of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto a novel chitosan/clinoptilolite (CS/CPL) composite as beads have been investigated compared with chitosan cross-linked with epichlorohydrin. The effects of contact time, the initial metal ion concentration, sorbent mass and temperature on the adsorption capacity of the CS-based sorbents were investigated. The adsorption kinetics was well described by the pseudo-second order equation, and the adsorption isotherms were better fitted by the Sips model. The maximum experimental adsorption capacities were 328.32 mg Th(4+)/g composite, and 408.62 mg UO(2)(2+)/g composite. The overall adsorption tendency of CS/CPL composite toward UO(2)(2+) and Th(4+) radiocations in the presence of Cu(2+), Fe(2+) and Al(3+), under competitive conditions, followed the order: Cu(2+)>UO(2)(2+)>Fe(2+)>Al(3+), and Cu(2+)>Th(4+)>Fe(2+)>Al(3+), respectively. The negative values of Gibbs free energy of adsorption indicated the spontaneity of the adsorption of radioactive ions on both the CS/CPL composite and the cross-linked CS. The desorption level of UO(2)(2+) from the composite CS/CPL, by using 0.1M Na(2)CO(3), was around 92%, and that of Th(4+) ions, performed by 0.1M HCl, was around 85%, both values being higher than the desorption level of radiocations from the cross-linked CS, which were 89% and 83%, respectively. PMID:20943312

Humelnicu, Doina; Dinu, Maria Valentina; Dr?gan, Ecaterina Stela

2011-01-15

266

Layered metal sulfides: Exceptionally selective agents for radioactive strontium removal  

PubMed Central

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.

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

2008-01-01

267

Fluorescence study of the interaction of Suwannee River fulvic acid with metal ions and Al3+-metal ion competition.  

PubMed

In this study emission and synchronous-scan fluorescence spectroscopy have been used to investigate the interaction of the class A (oxygen seeking 'hard acid') metal Al(3+), with Suwannee River fulvic acid (SRFA), as well as competition between Al(3+) and several other metal ions (Ca(2+), Mg(2+), Cu(2+), Pd(2+), La(3+), Tb(3+) and Fe(3+)) for binding sites on SRFA. Of the four metal ions possessing very similar (and relatively low) ionic indices (Ca(2+), Mg(2+), Cu(2+) and Pd(2+)) only the latter two paramagnetic ions significantly quenched SRFA fluorescence emission intensity. Of the four metal ions possessing very similar (and relatively low) covalent indices (Ca(2+), Mg(2+), La(3+) and Tb(3+)) only the last paramagnetic ion (Tb(3+)) significantly quenched SRFA fluorescence. None of these metals was able to significantly compete with SRFA-bound Al(3+).Fe(3+), which differs substantially from all of the other metals examined in this study in that it possesses a relatively high ionic index (but not as high as Al(3+)) and a relatively low covalent index (but not as low as Al(3+)), was able not only to quench SRFA fluorescence but also to compete (at least to some extent) with SRFA-bound Al(3+). Synchronous-scan fluorescence SRFA spectra taken in the absence and presence of Fe(3+) and/or Al(3+) support the view that these two metal ions can compete for sites on SRFA. The results of these fluorescence experiments further confirm the Al(3+), and metal ions that have electronic properties somewhat similar to Al(3+) (such as Fe(3+)) are somewhat unique in their ability to interact strongly with binding sites on fulvic acids. PMID:15621270

Zhao, Jingyan; Nelson, Donald J

2005-02-01

268

Stopping, Trapping and Cooling of Radioactive Fission Fragments in an Ion Catcher Device  

NASA Astrophysics Data System (ADS)

An ion catcher as presented in this contribution is able to create cooled and very clean singly-charged ion pulses out of a ‘hot’ beam within a very short period of time. Precision measurements on shortlived radioactive nuclides become possible. This contribution describes experiments with a 252Cf fission source at the ‘gas-cooler’ at ATLAS (Argonne Tandem Linac Accelerating System) at the Argonne National Laboratories (ANL), Argonne, USA[1]. The system consists of a gas-cell to stop and thermalize the ions, two extraction radio frequency quadrupole structures (RFQ) to separate the ions from the buffer gas and a buncher RFQ to cool and accumulate the ions. The system and its performance is investigated with two independent measurements. The transported activity was measured to determine the efficiency of the system and time of flight measurements (TOF) were performed to determine the transported masses with respect to the transported activity.

Maier, M.; Boudreau, C.; Buchinger, F.; Clark, J. A.; Crawford, J. E.; Dilling, J.; Fukutani, H.; Gulick, S.; Lee, J. K. P.; Moore, R. B.; Savard, G.; Schwartz, J.; Sharma, K. S.

2001-01-01

269

Ion source developments for the production of radioactive isotope beams at TRIUMF.  

PubMed

At the ISAC facility at TRIUMF radioactive ions are produced by bombarding solid targets with up to 100 ?A of 500 MeV protons. The reaction products have to diffuse out of the hot target into an ion source. Normally, singly charged ions are extracted. They can be transported either directly to experiments or via an ECR charge state breeder to a post accelerator. Several different types of ion sources have to be used in order to deliver a large variety of rare isotope beams. At ISAC those are surface ion sources, forced electron beam arc discharge (FEBIAD) ion sources and resonant laser ionization sources. Recent development activities concentrated on increasing the selectivity for the ionization to suppress isobaric contamination in the beam. Therefore, a surface ion rejecting resonant laser ionization source (SIRLIS) has been developed to suppress ions from surface ionization. For the FEBIAD ion source a cold transfer line has been introduced to prevent less volatile components from reaching the ion source. PMID:24593617

Ames, F; Bricault, P; Heggen, H; Kunz, P; Lassen, J; Mjøs, A; Raeder, S; Teigelhöfer, A

2014-02-01

270

Characterization of Chromized Metallic Surfaces by Means of Radioactive Cr  

Microsoft Academic Search

The spatial distribution of Cr deposited on metallic surfaces at concentrations of about 10 at\\/cm was examined by detecting the radiation components emitted in the Cr decay. The autoradiography revealed a non-homogeneous Cr covering. Combined Auger electron and X-ray spectroscopies yielded information on the Cr concentration, especially in the 2 nm thick surface layer. This concentration was found to depend

V. Rö?iger; A. Freyer; E. Hartmann; C. Treutler; V. Brabec; O. Dragoun; A. Kovalik

1986-01-01

271

Radioactive metals complexed with phosphonate derivatives of dicyclopentadienebis (methylamine)  

Microsoft Academic Search

Complexes of radionuclides with a compound of the formula (X-N(-Y)-CHââ,(A-N(-B)-CHââPerhydro-4,7-Methanoindene wherein substituents A, B, X and Y are each independently selected from radicals including hydrogen, hydroxyalkyl (wherein the alkyl group contains 2-6 carbon atoms) phosphonic, sulfonic, methylenephosphonic, methylene-, ethylene- and propylene-sulfonic, carboxylic acid radicals (having 2-4 carbon atoms) and the alkali or alkaline earth metal, ammonia and amine salts, thereof

J. Simon; W. Volkert; D. A. Wilson

1985-01-01

272

Radioactive ion beams for biomedical research and nuclear medical application  

NASA Astrophysics Data System (ADS)

In this article a review is given on the research strategies, on experimental work and application of ISOLDE produced radionuclides used in the field of biomedicine over a period of more than 2 decades. Special attention will be directed to the radio-lanthanides for several reasons: firstly, the radio-lanthanides are three-valent metallic radionuclides which show any radiation properties we wish (single photon emission suitable for SPECT, positron emission suitable for PET, ?-- and Auger electron emission suitable for therapy). Even the alpha decay mode (suitable for therapy in selected cases) is available in the lanthanide group. Secondly, the 15 lanthanides can be seen chemically as one single element for labelling of tracer molecules, providing the unique possibility to study systematically relationships between physico-chemical molecule parameter and a biological response without changes in the basic tracer molecule. Very recent developments in bioconjugation chemistry call for three-valent metallic radionuclides for all kinds of nuclear medical application: diagnosis, in vivo dosimetry and radionuclide therapy where the rare-earth elements will play an important role in future.

Beyer, G. J.

2000-12-01

273

Metal ion levels in total hip arthroplasty versus hip resurfacing.  

PubMed

Recent studies suggest that the tapered interface between stem and femoral head may be a substantial source of cobalt and chromium ion release after metal-on-metal (MOM) total hip arthroplasty (THA). This study compared patient ion levels after MOM hip resurfacing (HR) and MOM THA performed with identical acetabular components. 110 HRs were compared with 22 THAs. All had well-oriented components, unilateral implants, and serum ion studies beyond one year post-operatively. The HR group's median cobalt value was 1.11 ?g/L vs. 2.86 ?g/L for the THA patients. The HR group's median chromium value was 1.49 ?g/L vs. 2.94 ?g/L for THA. Significantly higher THA ion levels suggest a source of ions other than the MOM bearing itself. PMID:23618754

Johnson, Alicia J; Le Duff, Michel J; Yoon, James P; Al-Hamad, Mariam; Amstutz, Harlan C

2013-08-01

274

Does ion release differ between hip resurfacing and metal-on-metal THA?  

PubMed

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

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

2008-03-01

275

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

PubMed Central

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.

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

2008-01-01

276

Therapeutic redistribution of metal ions to treat Alzheimer's disease.  

PubMed

Currently, therapeutics that modify Alzheimer's disease (AD)are not available. Increasing age is the primary risk factor for AD and due to an aging global population the urgent need for effective therapeutics increases every year. This Account presents the development of an AD treatment strategy that incorporates diverse compounds with a common characteristic: the ability to redistribute metal ions within the brain. Central to cognitive decline in AD is the amyloid-? peptide (A?) that accumulates in the AD brain. A range of therapeutic strategies have been developed based on the premise that decreasing the brain A? burden will attenuate the severity of the disease symptoms. Unfortunately these treatments have failed to show any positive outcomes in large-scale clinical trials, raising many questions regarding whether therapeutics for AD can rely solely on decreasing A? levels. An alternate strategy is to target the interaction between A? and metal ions using compounds with the potential to redistribute metal ions within the brain. The original rationale for this strategy came from studies showing that metal ions promote A? toxicity and aggregation. In initial studies using the prototype metal-chelating compound clioquinol (CQ), CQ prevented A? toxicity in vitro, out-competed A? for metal ions without affecting the activity of metal-dependent enzymes, and attenuated the rate of cognitive decline in AD subjects in a small phase II clinical trial. All these outcomes were consistent with the original hypothesized mechanism of action for CQ where prevention or reversal of the extracellular A?-metal interactions could prevent A? toxicity. Soon after the completion of these studies, a new body of work began to suggest that this hypothesized mechanism of action for CQ was simplistic and that other factors were also important for the positive therapeutic outcomes. Perhaps most significantly, it was shown that after CQ sequesters metal ions the neutral CQ-metal complex crosses cell membranes to increase intracellular levels of the metals, thereby initiating protective cell signaling cascades. The activity of CQ therefore appeared to be two-fold: it prevented toxic interactions between A? and metal ions outside the cell, and it redistributed the metal ions into the cell to promote healthy cell function. To determine the significance of redistributing metal ions into the cell, glyoxalbis(N(4)-methylthiosemicarbazonato)Cu(II) [Cu(II)(gtsm)] was tested in models of AD. Cu(II)(gtsm) delivers Cu into cells, but, unlike CQ, it cannot out-compete A? for metal ions. When tested in AD model mice, the Cu(II)(gtsm) treatment restored cognitive function back to levels expected for cognitively healthy mice. The most advanced compound from this therapeutic strategy, PBT2, can sequester metal ions from A? and redistribute them into the cell like CQ. PBT2 improved cognition in a phase II clinical trial with AD patients, and further clinical testing is currently underway. PMID:22747493

Crouch, Peter J; Barnham, Kevin J

2012-09-18

277

Characterization of low temperature metallic magnetic calorimeters having gold absorbers with implanted 163Ho ions  

NASA Astrophysics Data System (ADS)

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 163Ho using MMCs having the radioactive 163Ho ions implanted in the absorber. The isotope 163Ho decays through electron capture to 163Dy and features the smallest known QEC value. This peculiarity makes 163Ho a very interesting candidate to investigate the value of the electron neutrino mass by the analysis of the energy spectrum. The implantation of 163Ho 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. Moreover the performance of the detector prototype having the 163Ho ions implanted in the absorber is already close to the requirements needed for an experiment with sub-eV sensitivity to the electron neutrino mass. Based on these results, an optimized detector design for future 163Ho experiments is presented.

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

2013-05-01

278

Batch sorption of divalent metal ions onto brown coal  

SciTech Connect

Brown coal, a relatively abundant and inexpensive material is currently being investigated as an adsorbent to remove some contaminants from aqueous solution. The adsorption of some heavy metals from aqueous solutions on the brown coals was studied as a function of pH, contact time, adsorbent dosage and concentration of metal solutions. A carboxyl, phenolic hydroxyl, and metoxyl functional group present on the coal surface was the adsorption site to remove metal ions from solution by means of ion exchange and hydrogen bonding. Effective removal of heavy metals was achieved at pH values of 4.0-5.0. The experimental data have been analyzed using the Langmuir isotherm models. Under optimized conditions, the percentage of metal removal by brown coal adsorption was over 80%.

Pehlivan, E.; Gode, F. [University of Selcuk, Konya (Turkey). Faculty of Engineering & Architecture

2006-12-15

279

Metal ion levels in patients with a lumbar metal-on-metal total disc replacement: should we be concerned?  

PubMed

The purpose of this study was to evaluate whether concerns about the release of metal ions in metal-on-metal total hip replacements (THR) should be extended to patients with metal-bearing total disc replacements (TDR). Cobalt and chromium levels in whole blood and serum were measured in ten patients with a single-level TDR after a mean follow-up of 34.5 months (13 to 61) using inductively-coupled plasma mass spectrometry. These metal ion levels were compared with pre-operative control levels in 81 patients and with metal ion levels 12 months after metal-on-metal THR (n = 21) and resurfacing hip replacement (n = 36). Flexion-extension radiographs were used to verify movement of the TDR. Cobalt levels in whole blood and serum were significantly lower in the TDR group than in either the THR (p = 0.007) or the resurfacing group (p < 0.001). Both chromium levels were also significantly lower after TDR versus hip resurfacing (p < 0.001), whereas compared with THR this difference was only significant for serum levels (p = 0.008). All metal ion levels in the THR and resurfacing groups were significantly higher than in the control group (p < 0.001). In the TDR group only cobalt in whole blood appeared to be significantly higher (p < 0.001). The median range of movement of the TDR was 15.5° (10° to 22°). These results suggest that there is minimal cause for concern about high metal ion concentrations after TDR, as the levels appear to be only moderately elevated. However, spinal surgeons using a metal-on-metal TDR should still be aware of concerns expressed in the hip replacement literature about toxicity from elevated metal ion levels, and inform their patients appropriately. PMID:21705569

Bisseling, P; Zeilstra, D J; Hol, A M; van Susante, J L C

2011-07-01

280

Metal Ion Complexation by Ionizable Crown Ethers.  

National Technical Information Service (NTIS)

Since the last report (Progress Report DOE/ER/10604-4) research has been focused upon the synthesis and characterization of novel ionizable multidentate ligands and their application in competitive solvent extraction of alkali metal cations and alkaline e...

R. A. Bartsch

1985-01-01

281

Process for modifying the metal ion sorption capacity of a medium  

DOEpatents

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.

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

2002-01-01

282

Existence of efficient divalent metal ion-catalyzed and inefficient divalent metal ion-independent channels in reactions catalyzed by a hammerhead ribozyme  

PubMed Central

The hammerhead ribozyme is generally accepted as a well characterized metalloenzyme. However, the precise nature of the interactions of the RNA with metal ions remains to be fully defined. Examination of metal ion-catalyzed hammerhead reactions at limited concentrations of metal ions is useful for evaluation of the role of metal ions, as demonstrated in this study. At concentrations of Mn2+ ions from 0.3 to 3 mM, addition of the ribozyme to the reaction mixture under single-turnover conditions enhances the reaction with the product reaching a fixed maximum level. Further addition of the ribozyme inhibits the reaction, demonstrating that a certain number of divalent metal ions is required for proper folding and also for catalysis. At extremely high concentrations, monovalent ions, such as Na+ ions, can also serve as cofactors in hammerhead ribozyme-catalyzed reactions. However, the catalytic efficiency of monovalent ions is extremely low and, thus, high concentrations are required. Furthermore, addition of monovalent ions to divalent metal ion-catalyzed hammerhead reactions inhibits the divalent metal ion-catalyzed reactions, suggesting that the more desirable divalent metal ion–ribozyme complexes are converted to less desirable monovalent metal ion–ribozyme complexes via removal of divalent metal ions, which serve as a structural support in the ribozyme complex. Even though two channels appear to exist, namely an efficient divalent metal ion-catalyzed channel and an inefficient monovalent metal ion-catalyzed channel, it is clear that, under physiological conditions, hammerhead ribozymes are metalloenzymes that act via the significantly more efficient divalent metal ion-dependent channel. Moreover, the observed kinetic data are consistent with Lilley’s and DeRose’s two-phase folding model that was based on ground state structure analyses.

Zhou, Jing-Min; Zhou, De-Min; Takagi, Yasuomi; Kasai, Yasuhiro; Inoue, Atsushi; Baba, Tadashi; Taira, Kazunari

2002-01-01

283

Emittance characterization of a hot-cavity laser ion source at Holifield Radioactive Ion Beam Facility  

SciTech Connect

The first investigation of the transverse emittance of a hot-cavity laser ion source based on all-solid-state Ti:sapphire lasers is presented. The emittances of {sup 63}Cu ion beams generated by three-photon resonant ionization are measured and compared with that of the {sup 69}Ga and {sup 39}K ion beams resulting from surface ionization in the same ion source. A self-consistent unbiased elliptical exclusion method is adapted for noise reduction and emittance analysis. Typical values of the rms and 90% fractional emittances of the Cu ion beams at 20 keV energy are found to be about 2 and 8 {pi} mm mrad, respectively, for the ion currents of 2-40 nA investigated. The emittances of the laser-produced Cu ion beams are smaller than those of the surface-ionized Ga and K ion beams.

Liu, Y.; Baktash, C.; Beene, J. R.; Havener, C. C.; Krause, H. F.; Schultz, D. R.; Stracener, D. W.; Vane, C. R. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Geppert, Ch.; Gottwald, T.; Kessler, T.; Wies, K.; Wendt, K. [Institut fuer Physik, Johannes Gutenberg-Universitaet Mainz, D-55099 Mainz (Germany)

2009-08-15

284

Use of ion characteristics to predict relative toxicity of mono-, di- and trivalent metal ions: Caenorhabditis elegans LC50  

Microsoft Academic Search

Predictive models for relative toxicity of divalent metal ions using ion characteristics have been produced with both Microtox®, a 15 min microbial bioassay, and the 24 h Caenorhabditis elegans bioassay. Relative toxicity of mono-, di- and trivalent metal ions has also been successfully modeled using ion characteristics with the Microtox® bioassay. This study extends this approach to include longer exposure

Christopher P. Tatara; Michael C. Newman; John T. McCloskey; Phillip L. Williams

1998-01-01

285

Photophysical properties of metal ion functionalized NaY zeolite.  

PubMed

A series of luminescent ion exchanged zeolite are synthesized by introducing various ions into NaY zeolite. Monometal ion (Eu(3+), Tb(3+), Ce(3+), Y(3+), Zn(2+), Cd(2+), Cu(2+)) exchanged zeolite, rare-earth ion (Eu(3+), Tb(3+), Ce(3+)) exchanged zeolite modified with Y(3+) and rare-earth ion (Eu(3+), Tb(3+), Ce(3+)) exchanged zeolite modified with Zn(2+) are discussed here. The resulting materials are characterized by Fourier transform infrared spectrum radiometer (FTIR), XRD, scanning electronic microscope (SEM), PLE, PL and luminescence lifetime measurements. The photoluminescence spectrum of NaY indicates that emission band of host matrix exhibits a blueshift of about 70 nm after monometal ion exchange process. The results show that transition metal ion exchanged zeolites possess a similar emission band due to dominant host luminescence. A variety of luminescence phenomenon of rare-earth ion broadens the application of zeolite as a luminescent host. The Eu(3+) ion exchanged zeolite shows white light luminescence with a great application value and Ce(3+) exchanged zeolite steadily exhibits its characteristic luminescence in ultraviolet region no matter in monometal ion exchanged zeolite or bimetal ions exchanged zeolite. PMID:24392790

Duan, Tian-Wei; Yan, Bing

2014-01-01

286

Preconcentration and selective metal ion separation using chelating micelles.  

PubMed

Chelating aggregates consisting of Triton X100 host micelles and hydrophobic derivatives of PAN have been examined as suitable candidates for preconcentration and selective separation of transition metal ions through micellar-enhanced ultrafiltration. The effective accumulation in the surfactant-rich retentate of nickel(II), copper(II), cobalt(II), manganese(II) and zinc(II), present at trace levels in aqueous samples, has been achieved by operating at pH ca. 6 with a ligand having a binding constant to the host micelles higher than 2000 l./mol. The efficient separation of micelle-bound metal chelates from unreactive ions has been assessed, together with the feasibility of selective enrichment and purification of the investigated metal ions present in mixtures through a multistage process. PMID:18966066

Pramauro, E; Prevot, A B; Zelano, V; Hinze, W L; Viscardi, G; Savarino, P

1994-08-01

287

Low coefficient of thermal expansion polyimides containing metal ion additives  

NASA Technical Reports Server (NTRS)

Polyimides have become widely used as high performance polymers as a result of their excellent thermal stability and toughness. However, lowering their coefficient of thermal expansion (CTE) would increase their usefulness for aerospace and electronic applications where dimensional stability is a requirement. The incorporation of metal ion-containing additives into polyimides, resulting in significantly lowered CTE's, has been studied. Various metal ion additives have been added to both polyamic acid resins and soluble polyimide solutions in the concentration range of 4-23 weight percent. The incorporation of these metal ions has resulted in reductions in the CTE's of the control polyimides of 12 percent to over 100 percent depending on the choice of additive and its concentration.

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

1992-01-01

288

Ion exchange properties of novel hydrous metal oxide materials  

SciTech Connect

Hydrous metal oxide (HMO) materials are inorganic ion exchangers which have many desirable characteristics for catalyst support applications, including high cation exchange capacity, anion exchange capability, high surface area, ease of adjustment of acidity and basicity, bulk or thin film preparation, and similar chemistry for preparation of various transition metal oxides. Cation exchange capacity is engineered into these materials through the uniform incorporation of alkali cations via manipulation of alkoxide chemistry. Specific examples of the effects of Na stoichiometry and the addition of SiO{sub 2} to hydrous titanium oxide (HTO) on ion exchange behavior will be given. Acid titration and cationic metal precursor complex exchange will be used to characterize the ion exchange behavior of these novel materials.

Gardner, T.J.; McLaughlin, L.I.

1996-12-31

289

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

PubMed

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

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

2014-01-01

290

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

Microsoft Academic Search

The ISOLDE isotope separator facility at CERN provides a variety of radioactive ion beams, currently more than 800 different isotopes from ?70 chemical elements. The radioisotopes are produced on-line by nuclear reactions from a 1.4GeV proton beam with various types of targets, outdiffusion of the reaction products and, if possible, chemically selective ionisation, followed by 60kV acceleration and mass separation.

U. Wahl

291

Metal ion levels not sufficient as a screening measure for adverse reactions in metal-on-metal hip arthroplasties.  

PubMed

This study aims to assess the accuracy of metal ion analysis in the diagnosis of adverse reaction to metal debris (ARMD) in patients with metal-on-metal hip arthroplasties by comparing the cobalt and chromium levels in 57 patients (62 hips) to findings on metal artifact reduction magnetic resonance imaging (MRI). An ARMD was detected using MRI in 18 (29%) of the hips. Forty patients had cobalt levels less than 7 ?g/L, and 33 had chromium levels less than 7 ?g/L, but 8 of these had an ARMD on MRI and only minimal symptoms (Oxford Hip Score ? 44/48). The incidence of ARMD was significantly higher when chromium concentration was above 7 ?g/L (P = .02), but normal metal ion levels can be misleading and metal artifact reduction MRI imaging is advised in all patients. PMID:22771092

Macnair, Rory D; Wynn-Jones, Henry; Wimhurst, James A; Toms, Andoni; Cahir, John

2013-01-01

292

TRPM7 Provides an Ion Channel Mechanism for Cellular Entry of Trace Metal Ions  

Microsoft Academic Search

Trace metal ions such as Zn 2 ? , Fe 2 ? , Cu 2 ? , Mn 2 ? , and Co 2 ? are required cofactors for many essential cellular enzymes, yet little is known about the mechanisms through which they enter into cells. We have shown previously that the widely expressed ion channel TRPM7 (LTRPC7, ChaK1, TRP-PLIK)

Mahealani K. Monteilh-Zoller; Meredith C. Hermosura; Monica J. S. Nadler; Andrew M. Scharenberg; Reinhold Penner; Andrea Fleig

2002-01-01

293

Complexation ion-exchange chromatography of some metal ions on papers impregnated with Ti(IV)-based inorganic ion exchangers.  

PubMed

The chromatographic behavior of 40 metal ions is studied on titanium (IV) arsenate, titanium (IV) phosphate-, titanium (IV) molybdate-, titanium(IV) tungstate-, and titanium(IV) selenite-impregnated papers in 0.1M oxalic, citric, and tartaric acid as mobile phases. Similar studies are carried out on Whatman No. 1 papers for comparison. The ion-exchange capacity of these papers is determined, and their selectivity for different cations is discussed. The mechanism of migration is explained in terms of ion-exchange, precipitation, and adsorption. The prediction of elution sequence from RF values is also checked. The average Ri is found to be almost linearly dependent on the charge of the metal ions. The effect of the pKa of complexing acids on average RF values of 3d series metal ions is explained. A number of binary and ternary separations are achieved. PMID:10677834

Sharma, S D; Gupta, R

2000-02-01

294

Metal-ion recycle technology for metal electroplating waste waters.  

National Technical Information Service (NTIS)

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 th...

N. N. Sauer B. F. Smith

1993-01-01

295

Metal-ion recycle technology for metal electroplating waste waters  

Microsoft Academic Search

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

N. N. Sauer; B. F. Smith

1993-01-01

296

Surface metal ion enhancement of thermally treated zeolites  

SciTech Connect

During the past several years the area of zeolite science has received increasingly intense attention owing to the preparation of new molecular sieves and the availability of modern spectroscopic methods for the study of these materials. The majority of spectroscopic studies of zeolites have focused on measurements of bulk magnetic, electronic, and structural properties, but few surface studies have been reported. Surface-inhomogeneous aluminum and silicon species have recently been reported by Barr and co-workers. In this study the authors have heated metal ion containing zeolites under controlled conditions in order to probe interactions between the zeolite and the metal ion. Here they present preliminary results for Ag/sup +//NaY and Cs/sup +//NaY zeolites studied by X-ray photoelectron spectroscopy (XPS), static secondary ion mass spectrometry (SSIMS), and ion scattering spectroscopy (ISS).

Willis, W.S.; Suib, S.L.

1986-09-03

297

Are metal ion levels a useful trigger for surgical intervention?  

PubMed

The purpose of this study was to determine if cobalt and chromium ion levels can predict soft tissue damage at total hip revision. This study included 90 metal-on-metal total hip patients with preoperative cobalt and chromium ion levels. Tissue damage noted at revision surgery was graded on a 4-point scale. Sensitivity, specificity, and predictive values were calculated for various threshold values. Receiver operating characteristic analysis was conducted. Using 7 ppb as a threshold, cobalt and chromium ion levels had poor sensitivity and specificity (Co, 65% and 56%; Cr, 29% and 75%). Positive predictive values for cobalt and chromium were only 48% and 26% respectively. The area under the curve was 0.37 for cobalt and 0.44 for chromium. The length of time to revision significantly correlated with tissue damage (P = .001). Ion levels are unreliable predictors of periarticular soft tissue damage and should not be used in isolation as surgical intervention triggers. PMID:22608683

Griffin, William L; Fehring, Thomas K; Kudrna, James C; Schmidt, Robert H; Christie, Michael J; Odum, Susan M; Dennos, Anne C

2012-09-01

298

Metal plasma immersion ion implantation and deposition: A review  

SciTech Connect

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.

Anders, A. [Lawrence Berkeley National Lab., CA (United States). Accelerator and Fusion Research Div.

1996-09-01

299

Adsorbent for metal ions and method of making and using  

DOEpatents

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.

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

2000-01-01

300

Adsorbent for metal ions and method of making and using  

DOEpatents

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.

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

1999-08-10

301

Adsorbent for metal ions and method of making and using  

DOEpatents

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.

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

1999-01-01

302

Development and investigation of a metal ion source for accelerators  

NASA Astrophysics Data System (ADS)

The design and operation of a new spray-type metal ion source are described. The source is built around a plasma emitter containing metal ions and using a two-step glow discharge with double plasma compression. The necessary temperature of electrons in a discharge chamber is reached by distributing the discharge power without heating. The design of the discharge chamber is optimized. The first set of experimental data for the mass-and-charge composition of a beam generated by this source is presented.

Litvinov, P. A.; Baturin, V. A.; Pustovoitov, S. A.

2014-04-01

303

Determination of metal ions in biological purification of waste waters  

SciTech Connect

Chromium, nickel, copper, zinc, and manganese were determined in active sludge extracted for utilization from sewage purification works in biological purification of waste waters. The measurements were carried out by the atomic absorption method and with Merck colorimetric kits for rapid determination of metal ions. The results obtained by the rapid colorimetric method agree fairly well with those obtained by the atomic absorption method, which makes it possible to recommend rapid colorimetric methods for routine analysis of biological objects for the content of ions of heavy metals.

Tikhomirova, L.N.; Spiridonova, N.N.; Mandzhgaladze, I.D. [Moscow State Correspondence Inst. of the Food Industry, Moscow (Russian Federation)] [and others

1994-12-01

304

Formation of gels in the presence of metal ions.  

PubMed

A small library of stereoisomeric pseudopeptides able to make gels in different solvents has been prepared and their attitude to make gels in the presence of several metal ions was evaluated. Four benzyl esters and four carboxylic acids, all containing a moiety of azelaic acid (a long chain dicarboxylic acid) coupled with four different pseudopeptide moieties sharing the same skeleton (a phenyl group one atom apart from the oxazolidin-2-one carboxylic group), were synthesized in solution, by standard coupling reaction. The tendency of these pseudopeptides to form gels was evaluated using the inversion test of 10 mM solutions of pure compounds and of stoichiometric mixtures of pseudopeptides and metal ions. To obtain additional information on the molecular association, the gel samples were left dry in the air to form xerogels that were further analyzed using SEM and XRD. The formation of gel containing Zn(II) or Cu(II) ions gave good results in term of incorporation of the metal ions, while the presence of Cu(I), Al(III) and Mg(II) gave less satisfactory results. This outcome is a first insight in the formation of stable LMWGs formed by stoichiometric mixtures of pseudopeptides and metal ions. Further studies will be carried out to develop similar compounds of pharmacological interest. PMID:21487726

Castellucci, Nicola; Falini, Giuseppe; Angelici, Gaetano; Tomasini, Claudia

2011-08-01

305

Comet Encke: Meteor metallic ion identification by mass spectrometer  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

306

Comet encke: meteor metallic ion identification by mass spectrometer.  

PubMed

Metal ions including 23(+) (Na(+)), 24(+) (Mg(+)) 28(+) (Si(+)), 39(+) (K(+)), 40(+) (Ca(+)), 45(+) (Sc(+)), 52(+) Cr(+)). 56(+) (Fe(+)), and 58(+) (Ni(+)) have been detected in the upper atmosphere during the period of the Beta Taurids meteor shower. The abundances of these ions relative to Si(+) show, agreement in most instances with abundances in chondrites. A notable exception is 45(+), which, if it is Sc(+), is 100 times more abundant than neutral scandium found in chondrites. PMID:17816288

Goldberg, R A; Aikin, A C

1973-04-20

307

Effect of mechanical surface pretreatment on metal ion release  

Microsoft Academic Search

The degree of metal ion dissolution from Ti–6Al–4V alloy hip replacement stems subjected to various mechanical and chemical surface pretreatments was analysed in vitro. High-dissolution rates were observed for nitric acid passivated samples that had been mechanically surface treated to increase the implant surface area. Significantly lower ion release levels were observed for mechanically treated samples which had been aged

M Browne; P. J Gregson

2000-01-01

308

Extraction of heavy metal ions sorbed on clays  

Microsoft Academic Search

The ability of seventeen different chemical solutions to displace heavy metal ions (Pb, Zn, Cu, Cd), pre-adsorbed on clay (kaolinite, illite and montmorillonite) at either pH 5 or 7, has been examined and the relative efficiency of each extractant ascertained. Of the reagents used, only EDTA (0.001 M, pH 7) quantitatively released all four ions from the three clays; oxalic

Helen Farrah; William F. Pickering

1978-01-01

309

Nuclear and Astro Physics at the Center of Excellence for Radioactive Ion Beam Studies for Stewardship Science  

SciTech Connect

Neutron transfer reactions with radioactive ion beams of atomic nuclei have been used to probe the shell structure of nuclei far from stability and provide information important to understanding the origin of the elements heavier than iron.

Cizewski, Jolie A. [Department of Physics and Astronomy, 136 Frelinghuysen Road, Piscataway, New Jersey 08854-8019 (United States)

2010-10-11

310

Metal-Ion Additives Reduce Thermal Expansion Of Polyimides  

NASA Technical Reports Server (NTRS)

Polyimides widely used as high-performance polymers because of their excellent thermal stability and toughness. However, their coefficients of thermal expansion (CTE's) greater than those of metals, ceramics, and glasses. Decreasing CTE's of polyimides increase usefulness for aerospace and electronics applications in which dimensional stability required. Additives containing metal ions reduce coefficients of thermal expansion of polyimides. Reductions range from 11 to over 100 percent.

Stoakley, Diane M.; St. Clair, Anne K.; Emerson, Burt R., Jr.; Willis, George L.

1994-01-01

311

In vivo liberation of silver ions from metallic silver surfaces  

Microsoft Academic Search

In vivo liberation of electrically charged silver atoms\\/silver ions from metallic silver pellets, silver grids and silver\\u000a threads placed in the brain, skin and abdominal cavity was proved by way of the histochemical technique autometallography\\u000a (AMG). A bio-film or “dissolution membrane” inserted between the metallic surface and macrophages was recognized on the surface\\u000a of the implanted silver after a short

Gorm Danscher; Linda Jansons Locht

2010-01-01

312

Reactions and Thermochemistry of Small Transition Metal Cluster Ions  

Microsoft Academic Search

This review discusses the reactivities and thermodynamics of small-size-specific transition metal clusters and focuses on thermodynamic information, which has not been comprehensively discussed before. Because of this focus, guided-ion-beam mass spectrometry was used to acquire much of the data. The details of this technique and the associated data analysis methods are provided. Results on the stabilities of bare transition metal

Pb Armentrout

2001-01-01

313

Rates and stoichiometries of metal ion probes of cysteine residues within ion channels.  

PubMed

Metal ion probes are used to assess the accessibility of cysteine side chains in polypeptides lining the conductive pathways of ion channels and thereby determine the conformations of channel states. Despite the widespread use of this approach, the chemistry of metal ion-thiol interactions has not been fully elucidated. Here, we investigate the modification of cysteine residues within a protein pore by the commonly used Ag(+) and Cd(2+) probes at the single-molecule level, and provide rates and stoichiometries that will be useful for the design and interpretation of accessibility experiments. PMID:23870257

Choi, Lai-Sheung; Mach, Tivadar; Bayley, Hagan

2013-07-16

314

Rates and Stoichiometries of Metal Ion Probes of Cysteine Residues within Ion Channels  

PubMed Central

Metal ion probes are used to assess the accessibility of cysteine side chains in polypeptides lining the conductive pathways of ion channels and thereby determine the conformations of channel states. Despite the widespread use of this approach, the chemistry of metal ion-thiol interactions has not been fully elucidated. Here, we investigate the modification of cysteine residues within a protein pore by the commonly used Ag+ and Cd2+ probes at the single-molecule level, and provide rates and stoichiometries that will be useful for the design and interpretation of accessibility experiments.

Choi, Lai-Sheung; Mach, Tivadar; Bayley, Hagan

2013-01-01

315

Smart responsive microcapsules capable of recognizing heavy metal ions.  

PubMed

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

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

2010-09-15

316

A life cycle decision methodology for recycle of radioactive scrap metal  

Microsoft Academic Search

During the past five years, a number of U.S. Department of Energy (DOE) funded efforts have demonstrated the technical efficacy\\u000a of converting various forms of radioactive scrap metal (RSM) into useable products. While health and safety and other technical\\u000a issues have been addressed, the question remains: do the benefits of fabricating products from RSM outweigh the costs? This\\u000a paper presents

Katherine L. Yuracko; Stanton W. Hadley; Robert D. Perlack; Rafael G. Rivera; T. Randall Curlee

1997-01-01

317

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

NASA Astrophysics Data System (ADS)

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.

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

318

Analysis of Th, U, Pu, and Am in radioactive metal waste using extraction chromatography  

Microsoft Academic Search

In order to analyze actinide elements in radioactive metal waste, the dissolution and chemical separation conditions were\\u000a optimized. The surfaces of a type 304 stainless steel plate and of pipe waste sampled from the prototype advanced thermal\\u000a reactor (Fugen) were dissolved in mixed acid solution (HNO3:HCl:H2O = 1:1:4). The resulting solution was evaporated to dryness and dissolved with 2 mol\\/dm3 of HNO3 to

Asako Shimada; Tomoko Haraga; Akiko Hoshi; Yutaka Kameo; Mikio Nakashima; Kuniaki Takahashi

2010-01-01

319

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

SciTech Connect

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.

Kessinger, G.F.

1993-10-01

320

Superconductivity in metal-mixed ion-implanted polymer films  

SciTech Connect

Ion implantation of normally insulating polymers offers an alternative to depositing conjugated organics onto plastic films to make electronic circuits. We used a 50 keV nitrogen ion beam to mix a thin 10 nm Sn/Sb alloy film into the subsurface of polyetheretherketone and report the low temperature properties of this material. We observed metallic behavior, and the onset of superconductivity below 3 K. There are strong indications that the superconductivity does not result from a residual thin film of alloy, but instead from a network of alloy grains coupled via a weakly conducting, ion-beam carbonized polymer matrix.

Micolich, A. P.; Tavenner, E.; Powell, B. J.; Hamilton, A. R.; Curry, M. T.; Giedd, R. E.; Meredith, P. [School of Physics, University of New South Wales, Sydney NSW 2052 (Australia); Physics Department, University of Queensland, Brisbane QLD 4072 (Australia); School of Physics, University of New South Wales, Sydney NSW 2052 (Australia); Center for Applied Science and Engineering, Missouri State University, Springfield, Missouri 65804 (United States); Physics Department, University of Queensland, Brisbane QLD 4072 (Australia)

2006-10-09

321

A concept for emittance reduction of DC radioactive heavy-ion beams  

NASA Astrophysics Data System (ADS)

Numerical simulations indicate that it should be possible to use an electron beam to strip 1+ DC radioactive ion beams to 2+ or higher charge states with on the order of 50% efficiency. The device, which the authors call an Electron-Beam Charge-State Amplifier, is similar to an Electron Beam Ion Source, except that it is not pulsed, the beams are continuous. The 2+ beams are obtained in a single pass through a magnetic solenoid while higher charge states may be reached via multiple passes. An unexpected result of the ion optics simulations is that the normalized transverse emittance of the ion beam is reduced in proportion to the charge-state gain. Ion beams with realistic emittances and zero angular momentum relative to the optic axis before entering the solenoid will travel though the solenoid on helical orbits which intercept the axis once per cycle. With an ion beam about 2 mm in diameter and an electron beam about 0.2 mm in diameter, the ion stripping only occurs very near the optic axis, resulting in the emittance reduction.

Nolen, J. A.; Dooling, J. C.

1995-05-01

322

Uptake of Metal Ions by Rhizopus arrhizus Biomass  

PubMed Central

Rhizopus arrhizus biomass was found to absorb a variety of different metal cations and anions but did not absorb alkali metal ions. The amount of uptake of the cations was directly related to ionic radii of La3+, Mn2+, Cu2+, Zn2+, Cd2+, Ba2+, Hg2+, Pb2+, UO22+, and Ag+. The uptake of all the cations is consistent with absorption of the metals by sites in the biomass containing phosphate, carboxylate, and other functional groups. The uptake of the molybdate and vanadate anions was strongly pH dependent, and it is proposed that the uptake mechanism involves electrostatic attraction to positively charged functional groups.

Tobin, J. M.; Cooper, D. G.; Neufeld, R. J.

1984-01-01

323

Effect of central metal ions on first hyperpolarizability of unsymmetrical metal porphyrins  

NASA Astrophysics Data System (ADS)

We present a quantum-chemical analysis of the central metal ions effect on first hyperpolarizabilities of a series of push-pull porphyrins whose synthesis and NLO properties has been reported earlier [T.G. Zhang, Y. Zhao, I. Asselberghs, A. Persoons, K. Clays, M.J. Therien, J. Am. Chem. Soc. 127 (2005) 9710]. The molecular geometries are obtained via B3LYP/6-31G (d, p) level optimization including SCRF/PCM approach, while the dynamic NLO properties are calculated with the ZINDO/CV method including solvent effects. It has been observed that the first hyperpolarizabilities can be greatly enhanced by changing the central metal ions. It is found that the CT transition between the metal ion's d orbital and the macrocycle ? orbital plays an important role on first hyperpolarizability of metal porphyrins. Our data suggest a new approach to enhance nonlinear optical properties of porphyrin materials.

Bonifassi, P.; Ray, Paresh C.; Leszczynski, J.

2006-11-01

324

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

SciTech Connect

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.

Zhao, W. J.; Mueller, M. W. O.; Janik, J.; Liu, K. X.; Ren, X. T. [Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China) and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, 100871 (China); GSI, D64291 Darmstadt (Germany) and Sentastr. 12, D68199, Mannheim (Germany); Institute of Microelectronics, Slovak Technical University, Bratislava, Llcovicova 3 (Slovakia); Institute of Heavy Ion Physics, Peking University, Beijing, 100871 (China) and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, 100871 (China)

2008-02-15

325

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

NASA Astrophysics Data System (ADS)

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.

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

2008-02-01

326

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

PubMed

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

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

2008-02-01

327

Metallic ions in cometary comae and plasma tails  

NASA Astrophysics Data System (ADS)

A surprising result of the International Cometary Explorer (ICE) observations of the comet Giacobini-Zinner was the detection of ions of mass 23-24 AMU with a relatively high abundance. According to the experiments, these ions may be either Na(+) or C2(+), if not both. It is suggested here that the detected ions may indeed be in part Na(+) and/or Mg(+), and that these and other metallic ions, especially Si(+) and Fe(+), may be an important component of the cometary ionosphere and central plasma tail. The reasons are similar in principle to those which account for the prevalence of such ions in sporadic E layers in the terrestrial ionosphere, notably the comparatively short timescales for ionization of their neutral parent atoms and the large difference between the rates of dissociative and radiative recombination.

Ip, W.-H.; Axford, W. I.

1986-06-01

328

Search for new physics with neutrinos at radioactive ion beam facilities  

NASA Astrophysics Data System (ADS)

We propose applications of radioactive ion beam facilities to investigate physics beyond the Standard Model. In particular, we focus upon the search for sterile neutrinos and the possible measurement of coherent neutrino-nucleus scattering, by means of a low-energy beta beam with a Lorentz boost factor ??1. In both cases, we consider Li8 and B8 ions as neutrino sources. In the considered setup, the collected radioactive ions are sent inside a 4? detector. For the first application, we provide the number of events associated with neutrino-nucleus coherent scattering, when the detector is filled with a noble liquid. For the sterile search, we consider that the spherical detector is filled with a liquid scintillator, and that the neutrino detection channel is inverse beta decay. We provide the exclusion curves for the sterile neutrino mixing parameters, based upon the 3+1 formalism, depending upon the achievable ion intensity. Our results are obtained both from total rates, and by including spectral information with binning in energy and in distance. The proposed experiment represents a possible alternative to clarify the current anomalies observed in neutrino experiments.

Espinoza, Catalina; Lazauskas, Rimantas; Volpe, Cristina

2012-12-01

329

Metal oxide hollow nanostructures for lithium-ion batteries.  

PubMed

Metal oxide hollow structures have received great attention because of their many promising applications in a wide range of fields. As electrode materials for lithium-ion batteries (LIBs), metal oxide hollow structures provide high specific capacity, superior rate capability, and improved cycling performance. In this Research News, we summarize the recent research activities in the synthesis of metal oxide hollow nanostructures with controlled shape, size,composition, and structural complexity, as well as their applications in LIBs. By focusing on hollow structures of some binary metal oxides (such as SnO 2 ,TiO 2 , Fe 2 O 3 , Co 3 O 4 ) and complex metal oxides, we seek to provide some rational understanding on the effect of nanostructure engineering on the electrochemical performance of the active materials. It is thus anticipated that this article will shed some light on the development of advanced electrode materials for next-generation LIBs. PMID:22574316

Wang, Zhiyu; Zhou, Liang; Lou, Xiong Wen David

2012-04-10

330

Molecular design of the microbial cell surface toward the recovery of metal ions.  

PubMed

The genetic engineering of microorganisms to adsorb metal ions is an attractive method to facilitate the environmental cleanup of metal pollution and to enrich the recovery of metal ions such as rare metal ions. For the recovery of metal ions by microorganisms, cell surface design is an effective strategy for the molecular breeding of bioadsorbents as an alternative to intracellular accumulation. The cell surface display of known metal-binding proteins/peptides and the molecular design of novel metal-binding proteins/peptides have been performed using a cell surface engineering approach. The adsorption of specific metal ions is the important challenge for the practical recovery of metal ions. In this paper, we discuss the recent progress in surface-engineered bioadsorbents for the recovery of metal ions. PMID:21247751

Kuroda, Kouichi; Ueda, Mitsuyoshi

2011-06-01

331

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

PubMed

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

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

2014-06-01

332

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

PubMed Central

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.

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

333

Infrared Photodissociation Spectroscopy of Metal Ion -WATER Complexes  

NASA Astrophysics Data System (ADS)

Metal ion-water complexes are produced in a supersonic expansion cluster source via laser vaporization technique. Infrared photodissociation spectroscopy has been performed in the O-H stretch region. DFT calculations have also been carried out to obtain the structures and vibrational frequencies. Infrared spectra show partially resolved rotational structures which will be analyzed.

Bandyopadhyay, B.; Carnegie, P. D.; Duncan, M. A.

2011-06-01

334

Accumulation of heavy-metal ions by Zoogloea ramigera  

Microsoft Academic Search

Biomass has been produced from glucose using the organism Zoogloea ramigera 115. This biomass has been used to remove copper, cadmium, and uranyl ions from water solutions. The metal uptake was studied with two different methods: either by spectrophotometric measurements on the solutions after flocculation or by potentiometric measurements with amalgam electrodes in order to follow the entire complex formation.

Anders B. Norberg; Hans Persson

1984-01-01

335

Guided ion beam studies of transition metal–ligand thermochemistry  

Microsoft Academic Search

Studies of organometallic chemistry in the gas phase can provide substantial quantitative information regarding the interactions of transition metals with a wide variety of covalently and noncovalently bound ligands. In this review, the technique of guided ion beam tandem mass spectrometry for the measurement of thermodynamic information is highlighted. Periodic trends in covalent bonds between first, second, and a few

P. B. Armentrout

2003-01-01

336

Impact of metal ions on netilmicin-melanin interaction.  

PubMed

Netilmicin, which is mainly used as the sulfate, is a semisynthetic, water soluble aminoglycoside antibiotic obtained by chemical modification of sisomicin. It is active against both Gram-positive and Gram-negative bacteria, including strains which are resistant to other aminoglycosides. Netilmicin form complexes with melanin. The aim of the presented work was to examine the effect of Cu2+, Zn2+, Ca2+ and Mg2+ on netilmicin binding to synthetic DOPA-melanin. It has been demonstrated that metal ions decrease the amount of antibiotic bound to melanin as compared with netilmicin-melanin complexes obtained in the absence of metals. It has been also shown that only one class of binding sites participates in netilmicin-[melanin-metal ion] complexes formation with the association constant K approximately 10(3) M(-1). The obtained results demonstrate that Cu2+, Zn2+, Ca2+ and Mg2+ ions modify the interaction between netilmicin and melanin biopolymer. The blocking of some active centers in melanin molecules by metal ions, which potentially exist in living systems, may influence the clinical therapeutic efficiency as well as the undesirable side effects of netilmicin. PMID:22574505

Wrze?niok, Dorota; Buszman, Ewa; Grzegorczyk, Magdalena; Grzegorczyk, Aneta; Hryniewicz, Tomasz

2012-01-01

337

Relaxation of slow highly charged ions hitting thin metallic foils  

Microsoft Academic Search

We developed a method to determine the relaxation time of the innermost vacancies for highly ionized heavy ions moving through the bulk. The method compares the intensities of photons emitted through the front and back sides of a thin metal foil. Using foils with known thickness and x-ray absorption cross sections, we directly obtained the mean x-ray emission depth, and

Z. D. Pesic; Gy. Vikor; S. Atanassova; J. Anton; S. Leontein; M. Björkhage; A. Paál; H. Hanafy; R. Schuch

2007-01-01

338

Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete  

DOEpatents

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.

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

1985-01-01

339

Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete  

DOEpatents

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.

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

1983-05-13

340

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

SciTech Connect

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.

Galle, P.

1982-01-01

341

Metal-on-metal bearings total hip arthroplasty: the cobalt and chromium ions release concern.  

PubMed

With certain concerns recently reported on metal-on-metal bearing couples in total hip arthroplasty, this study's objective is to review the current knowledge concerning release of metal ions and its potential consequences. Each metal-on-metal implant presents different tribological properties. The analytical techniques for metals are accurate and the Co ion rates seem acceptable up to 2 ?g/L. A delayed type IV hypersensitivity reaction (atypical lymphocytic vasculitis-associated lesion [ALVAL]) may be the source of arthroplasty failure. Idiosyncratic, it remains unpredictable even using cutaneous tests and apparently is rare (0.3%). Today, there are no scientific or epidemiologic data supporting a risk of carcinogenesis or teratogenesis related to the use of a metal-on-metal bearings couple. Solid pseudotumors nearly exclusively are observed with resurfacing procedures, carrying a high annual revision rate in women under 40 years of age, occurring particularly in cases of acetabular malposition and with use of cast molded Cr-Co alloys. Osteolysis manifests through complete and progressive radiolucent lines or through cavitary lesions stemming from ALVAL-type alterations or impingement problems or implant incompatibility. The formation of wear debris exceeding the biological tolerance is possible with implant malposition, subluxation, and jamming of the femoral head in cases of cup deformity. Moreover, each implant presents different metal ion production; assessment of their performance and safety is required before their clinical use. With the knowledge available today, metal-on-metal bearing couples are contraindicated in cases of metal allergies or end stage renal dysfunction and small size resurfacing should cautiously be used. PMID:20832379

Delaunay, C; Petit, I; Learmonth, I D; Oger, P; Vendittoli, P A

2010-12-01

342

Method for removing metal ions from solution with titanate sorbents  

DOEpatents

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.

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

1999-01-01

343

Isotopomer differentiation using metal ion chemical ionization reagents  

SciTech Connect

In this paper we demonstrate that transition metal ion chemical ionization used in conjunction with Fourier transform mass spectrometry holds promise as a simple, qualitative, and potentially quantitative method for determining isotopolog and isotopomer distributions in partially deuterated cyclic hydrocarbons. The isotopolog distribution is obtained by generating the pseudomolecular ions, ML[sup +] (M = transition metal; L = cyclic hydrocarbon). A particular isotopolog can then be isolated followed by collision-induced dissociation resulting in dehydrogenation. The dehydrogenation process is regio- and stereoselective, permitting information to be obtained on the isotopomer composition within the particular isotopolog. The samples analyzed are the end products from the metal-catalyzed hydrogenation of perdeuterated naphthalene and benzene. The isotope effects observed in the dehydrogenation reactions are studied. Compared to high-resolution NMR, this method requires far less sample, easily detects components of low concentration which might be obscured by the major species in NMR, and is far less difficult to interpret. 12 refs., 11 figs.

Huang, Y.; Profilet, R.D.; Ng, J.H.; Ranasinghe, Y.A.; Rothwell, I.P.; Freiser, B.S. (Purdue Univ., West Lafayette, IN (United States))

1994-04-01

344

Study on the THz spectra of metallic ion in soil  

NASA Astrophysics Data System (ADS)

In order to observe the spectroscopic characteristics of metallic ion in soil in terahertz region, terahertz time-domain spectroscopy (THz-TDS) was used to analyze the absorption coefficient and refractive index in the frequency range 0.2 ~1.6 THz at room temperature. In the present work, we designed several kinds of soil samples (i.e. different content copper sulphate and zinc sulphate in soil).The terahertz time-domain spectra of samples were measured. The experimental results indicate that the metallic ion in soil has many distinct characteristic spectra between 0.2 and 1.6THz. This study can not only assign the characteristic absorption of the sample, but also can provide the absorption frequencies in wider effective spectra range. The results show that the THz-TDS can be used to measure the metal residues in the soil.

Li, Jiu-Sheng; Zhao, Xiao-Li; Li, Jian-Rui

2009-07-01

345

Whole blood metal ion concentrations in correlation with activity level in three different metal-on-metal bearings.  

PubMed

Seventy consecutive osteoarthritis patients younger than 65 years undergoing a hip arthroplasty were included. Three different metal bearings were used (2 different resurfacing systems and one 28-mm metal bearing) and compared with a ceramic control group. Whole blood cobalt and chromium levels were analyzed preoperatively, at 3 months, 6 months, 1 year, and 2 years. Patients with steep cups (abduction >55°) were excluded. No significant differences in functional scores and activity level were found between either groups. Ion levels were significantly lower with one type of resurfacing. No correlation was found between ion and activity level. In conclusion, although the current second-generation metal bearings may show differences in ion release, more attention should be paid to the correlation between ion release and implant positioning. PMID:20171052

Pattyn, Christophe A; Lauwagie, Sofie N; Verdonk, René C

2011-01-01

346

Infrared absorbing croconaine dyes: synthesis and metal ion binding properties.  

PubMed

Quinaldine-based croconaine dyes synthesized by the condensation reaction between croconic acid and the respective quinaldinium salts are described. These dyes exhibit absorption maximum in the infrared region (840-870 nm) with high molar extinction coefficients (1-5 x 10(5) M(-1) cm(-1)) and have very low fluorescence quantum yields. Upon binding to divalent metal ions, these dyes were found to form complexes with a 2:1 stoichiometry having high association constants of the order of 10(11)-10(14) M(-2), while the monovalent metal ions showed negligible affinity. The binding of the croconaine dye 3d with divalent metal ions especially Zn(2+), Pb(2+), and Cd(2+) led to significant chelation-enhanced fluorescence emission. The broadening of the aromatic signals, vinylic and N-methyl protons and the negligible changes at the aliphatic region of the dye 3d in the (1)H NMR spectrum in the presence of Zn(2+), indicate that the binding occurs at the carbonyl groups of the croconyl ring. The shift in the croconyl carbonyl stretching frequency in the [3d-Zn(2+)] complex analyzed through FT-IR analysis further confirms the involvement of two electron-rich carbonyl groups of the croconyl moiety in the complexation. These results demonstrate that the binding of the divalent metal ions at the carbonyl oxygens of these infrared absorbing dyes can be favorably utilized for the development of potential sensors for the detection of metal ions and further can be exploited as sensitizers for photodynamic therapeutic applications. PMID:18069856

Avirah, Rekha R; Jyothish, Kuthanapillil; Ramaiah, Danaboyina

2008-01-01

347

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

SciTech Connect

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.

Nicholas B. Lentz

2007-12-01

348

Ion mobility studies of electronically excited states of atomic transition metal cations: Development of an ion mobility source for guided ion beam experiments  

Microsoft Academic Search

The design of an ion mobility source developed to couple to a guided ion beam tandem mass spectrometer is presented. In these\\u000a exploratory studies, metal ions are created continuously by electron ionization of the volatile hexacarbonyls of the three\\u000a group 6 transition metals. These ions are focused into a linear hexapole ion trap, which collects the ions and then creates

Christopher Iceman; Chad Rue; Robert M. Moision; Barun K. Chatterjee; P. B. Armentrout

2007-01-01

349

The reactivity of metallated nitrenium ions studied by FT-ICR  

NASA Astrophysics Data System (ADS)

The reactivity of two metallated nitrenium ions toward various substrates was examined in the gas phase. The nitrenium ions were generated by a reaction of benzoyl azide with laser-ablated Mg+ or Cu+ in a Fourier transform ion cyclotron resonance mass spectrometer. The two nitrenium ions show drastically different reactivity. While the Mg-nitrenium ion reacts by radical mechanisms (e.g., H atom abstraction), the Cu-nitrenium ion follows non-radical pathways (e.g., metal ion transfer).

Yurkovich, Michael J.; Duan, Penggao; Shea, Ryan C.; Watkins, Michael A.; Mandell, Sarah M.; Tippmann, Eric M.; Jason Li, Sen; Platz, Matthew S.; Kenttämaa, Hilkka I.

2009-10-01

350

Do Ion Levels In Hip Resurfacing Differ From Metal-on-metal THA at Midterm?  

Microsoft Academic Search

Background  Metal-on-metal Birmingham hip resurfacing (MOM-BHR) is an alternative to metal-on-metal total hip arthroplasty (MOM-THA),\\u000a especially for young and\\/or active patients. However, wear resulting in increased serum ion levels is a concern.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  We asked whether (1) serum chromium (Cr), cobalt (Co), and molybdenum (Mo) concentrations would differ between patients with\\u000a either MOM-BHR or MOM-THA at 5 years, (2) confounding factors such as

A. Moroni; L. Savarino; M. Hoque; M. Cadossi; N. Baldini

2011-01-01

351

Serum metal ion exposure after total knee arthroplasty.  

PubMed

All metal implants release metal ions because of corrosion. This has been studied and debated, especially in metal-on-metal total hip arthroplasties. Total knee arthroplasty implants have large metal surface areas and therefore substantial potential for corrosion. We determined changes in serum levels of metal ions in 41 patients after cemented unconstrained total knee arthroplasty without patellar resurfacing, 18 with unilateral total knee arthroplasty (median, 66 months after surgery) and 23 patients with bilateral total knee arthroplasties (75 and 50 months after first and second surgeries, respectively). Serum concentrations of chromium, cobalt, and molybdenum were analyzed and related to the number of total knee arthroplasties and compared with those of 130 control patients without implants. The median chromium, cobalt, and molybdenum concentrations were 0.92, 3.28, and 2.55 microg/L, respectively, in the unilateral total knee arthroplasty sample and 0.98, 4.28, and 2.40 microg/L, respectively, in the bilateral total knee arthroplasty sample. We observed no difference between the serum levels in patients with unilateral and bilateral arthroplasties, but the serum levels of chromium and cobalt of both study groups were greater than those of the control group (less than 0.25 microg/L). The patients who had total knee arthroplasty had molybdenum profiles that were similar to those of the control group (median, 2.11 microg/L). PMID:17438467

Luetzner, Joerg; Krummenauer, Frank; Lengel, Attila Michael; Ziegler, Joerg; Witzleb, Wolf-Christoph

2007-08-01

352

Interaction of metal ions with cadmium-induced cellular toxicity  

SciTech Connect

Interactions between Cd and other metal ions are important from both nutritional and toxicological aspects. As Cd is toxic to isolated hepatocytes, these cells can be used to investigate the effects of other metals on Cd-induced cellular injury. Isolated hepatocytes were incubated at 37/sup 0/C with vehicle (saline); Cd (200 or 400 ..mu..M); or Cd plus Cr, Mn, Zn, Ni, Pb, Se, or Fe (200 to 1000 ..mu..M). Evidence of cellular injury was assessed by loss of intracellular K/sup +/ and aspartate aminotransferase from the hepatocytes. Effects on lipid peroxidation, as measured by concentration of thiobarbituric acid reactants, were assessed. Uptake of /sup 109/Cd and interaction of the other metal ions with this accumulation were also quantitated. Cell injury due to Cd was consistently reduced by Cr, Mn, Zn, Pb, and Fe. Lipid peroxidation due to Cd was inhibited by Cr, Mn, and Zn. All the metals except Ni produced an increase in the amount of Cd accumulated by hepatocytes. There was no consistent relation between reduction of cellular toxicity and either inhibition of lipid peroxidation or uptake of Cd. These experiments show that (1) protective properties of some metals seen in vivo can be demonstrated at the cellular level and (2) protective effects of metals in general on Cd-induced cellular toxicity are not due to a decrease in either Cd uptake or lipid peroxidation.

Stacey, N.H.; Klaassen, C.D.

1981-01-01

353

Functionalized silica for heavy metal ions adsorption  

Microsoft Academic Search

Heavy metals adsorbents were prepared by co-condensation of tetraethoxysilane and functionalized trialkoxysilane RSi(OR?)3. Functionalized porous silicas with aminopropyl (H2N(CH2)3-), [amino-ethylamino]propyl- (H2N-(CH2)2-NH(CH2)3), (2-aminoethylamino)-ethylamino]propyl (H2N-(CH2)2-NH-(CH2)2-NH(CH2)3-), and mercaptopropyl (HS-(CH2)3-) groups were synthesized using dodecylamine as structure directing agent. These materials have been characterized by elemental analysis, powder X-ray diffraction, nitrogen gas sorption, Fourier transform infrared and Raman spectroscopies and thermogravimetric analysis. These organo-silicas

Laurence Bois; Anne Bonhommé; Annie Ribes; Bernadette Pais; Guy Raffin; Franck Tessier

2003-01-01

354

Analysis of radioactive waste samples by ion chromatography-ICP/MS  

SciTech Connect

A comprehensive ion chromatography (IC) with beta-counting (beta) and inductively coupled plasma mass spectrometry (ICP/MS) detection approach has been developed to separate and detect 20 radionuclides in a Hanford waste tank sample. The IC separation was performed using a multi-functional group (anion/cation) resin and eluents of oxalic acid, diglycolic acid, and hydrochloric acid. Shorter-lived radionuclides were detected by a solid-state beta scintillation counter on-line with the IC separation. Mass spectrometry detection using an efficient and robust plasma ionization source provides isotopic discernability for both stable isotopes and long-lived radioactive species. Effective separation of over 47 elements and 160 isotopes was obtained from a single-elution scheme lasting 70 min. Automated IC separations provide the potential for rapid isotopic and radionuclide analysis of complex radioactive waste, using minimal sample and reagent volumes and reducing personnel exposures.

Farmer, O.T. III; Reeves, J.H.; Wyse, E.J.; Clemeston, C.J.; Barinaga, C.J.; Smith, M.R.; Koppenaal, D.W.

1994-10-01

355

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

PubMed

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

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

356

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

DOEpatents

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.

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

357

The contribution of metal ions to the conformational stability of ribonuclease T1: crystal versus solution.  

PubMed

In the crystalline state, ribonuclease T1 binds calcium ions at different lattice-dependent positions. In solution, its conformational stability is also remarkably increased in the presence of divalent metal ions. Combining urea unfolding studies and X-ray crystallography, we compared the presence of several metal ions at specific sites in the protein to their contribution to the overall stabilizing effect in solution. We constructed thermodynamic cycles involving particular metal ions and specific carboxylate functions. The resulting coupling energies indicate that some (but not all) metal ions found at lattice contacts in crystal structures may indeed significantly contribute to stability enhancement in the presence of metal ions in solution. PMID:11453993

Deswarte, J; De Vos, S; Langhorst, U; Steyaert, J; Loris, R

2001-07-01

358

Treatment of pseudotumors after metal-on-metal hip resurfacing based on magnetic resonance imaging, metal ion levels and symptoms.  

PubMed

Peri-prosthetic pseudotumor formation can be a severe complication following Metal-on-Metal hip resurfacing arthroplasty (MoMHRA), with limited data on the optimal management of this complication. The aims of this study were (1) to evaluate the prevalence and severity of pseudotumors in a consecutive cohort of 248 MoMHRA (214 patients, mean follow-up 4.6 years, range: 1 - 8.2), and (2) to present a clinical guideline for their treatment based on severity grading with Metal Artefact Reduction Sequence Magnetic Resonance Imaging, metal ion levels and symptoms. Pseudotumor prevalence was 36.3%: 61 mild, 25 moderate and four were graded severe. Five revisions followed, all in symptomatic patients with elevated metal ion levels. Pseudotumor severity grading allowed us to be conservative with revision surgery for mild and moderate MoM disease. PMID:23871706

van der Weegen, Walter; Sijbesma, Thea; Hoekstra, Henk J; Brakel, Koen; Pilot, Peter; Nelissen, Rob G H H

2014-02-01

359

Near-barrier reactions with radioactive ion beams at the ReA3 facility  

NASA Astrophysics Data System (ADS)

The new ReA3 re-accelerated beam facility at the National Superconducting Cyclotron Laboratory (NSCL) will provide high quality radioactive ion beams (RIBs), produced from fast fragmentation reactions, at energies around the Coulomb barrier. These radioactive isotopes can have exotic properties such as neutron/proton skins, halos, or unexpected changes in their shell structure. ReA3 will allow us to explore how these exotic properties manifest themselves in low-energy reactions. In particular, heavy-ion fusion induced with medium mass RIBs remains almost completely unexplored as only three fusion reactions using RIBs, between fluorine (Z = 9) and tin (Z = 50), have ever been measured. A new research program focused on the study of heavy-ion fusion reactions is being developed to take advantage of the world-unique RIBs offered by the ReA3 facility. Along with an overview of the ReA3 facility, details about three devices being developed for exploration of fusion reactions induced by RIBs will be presented.

Kohley, Z.

2013-12-01

360

Removal of metal ions from aqueous solution by cellulose ion exchangers  

SciTech Connect

The sorption of metal ions [Cd(II), Cu(II), Pb(II), Zn(II), Cr(III), V(IV), V(V)] from aqueous solution by Whatman cellulose ion exchangers was investigated as a function of pH. Whatman P-11 (ammonium cellulose phosphate) exhibited better performance than a fibrous anion exchanger (Whatman Cellect-Ion Exchanger DT-1) with respect to their sorption capacities for Cd(II), Cu(II), Co(II), Pb(II), Zn(II), and Cr(III). The Cellect-Ion anion exchanger (DT-1) had a higher sorption for V(IV) and V(V). The ionic form of cellulose phosphate (P-11) influenced their metal sorption capacities.

Kabay, N.; Demircioglu, M.; Yayli, S.; Yuksel, M.; Saglam, M. [Ege Univ., Bornova (Turkey). Dept. of Chemical Engineering] [Ege Univ., Bornova (Turkey). Dept. of Chemical Engineering; Levison, P.R. [Whatman International Ltd., Maidstone (United Kingdom)] [Whatman International Ltd., Maidstone (United Kingdom)

1999-01-01

361

Multiply stripped ion generation in the metal vapor vacuum arc  

SciTech Connect

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.

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

1987-09-01

362

Application of ion implantation to ceramic/metal joining  

NASA Astrophysics Data System (ADS)

The joining of ceramics to metals is problematic primarily due to the vastly different atomic bonding in these materials. In an attempt to overcome this problem MEVVA ion implantation of titanium into alumina was performed to modify the atomic bonding in the near-surface region of the ceramic. The brazing of alumina to copper, before and after implantation, was performed using both reactive and non-reactive Cu?Ag eutectic brazes. It has been established, for the first time, that metallic implantation of ceramic enables joining to metal with non-reactive braze. Extensive characterisation of faying surfaces was carried out by Rutherford backscattering (RBS), glancing angle X-ray diffraction (GAXRD), four-point probe conductivity tests, and braze wettability tests. It has been demonstrated that implantation drastically changes the nature of bonding in alumina by forming metallic-like compounds such as TiO 2 thus enhancing the degree of wetting by braze compared to the unimplanted alumina.

Samandi, M.; Gudze, M.; Evans, P.

1997-05-01

363

Superaromatic terpyridines based on corannulene responsive to metal ions.  

PubMed

Two superaromatic terpyridine ligands (1 and 2) incorporating a corannulene unit at the 4'-position are reported. The optical and metal sensing properties of both ligands were investigated by the naked eye, and UV-vis and fluorescence spectroscopy in this work. In 1, the corannulene motif is directly connected to the 4'-phenylterpyridine domain, while in 2, the corannulene motif and the 4'-phenylterpyridine domain are separated by an acetylene linker. Both 1 and 2 can work as chemosensors for metal ions and display different optical responses to various metal ions. It is shown that both ligands exhibit a colorimetric sensing ability for Fe(2+) through an obvious color change from colorless to magenta, and this color change can be observed easily by the naked eye. The addition of Fe(2+) also leads to significant changes in the absorption spectra of the ligands. A characteristic red shift in the emission spectra is observed in the presence of Zn(2+), which facilitates the discrimination of Zn(2+) from other metal ions. In addition, density functional theory (DFT) and time-dependent-density functional theory (TD-DFT) calculations were performed and shown to be consistent with the observed experimental results. PMID:24233385

Wu, Difeng; Shao, Tao; Men, Jian; Chen, Xiaochuan; Gao, Guowei

2014-01-28

364

Cobalt and chromium ion release after large-diameter metal-on-metal total hip arthroplasty.  

PubMed

Seventy-five patients underwent unilateral metal-on-metal total hip arthroplasty using a large-diameter head. Serum levels of cobalt and chromium were determined. Significant increases in both cobalt and chromium were observed at 3 months (cobalt, 1.4 ?g/L; chromium, 1.4 ?g/L) compared with preoperative values (P < .001). At 1 year, the median cobalt and chromium levels were 2.3 and 2.1 ?g/L, respectively, and the levels had increased significantly compared with 3 months (P < .001). There were no significant differences between levels of either metal at 1 or 2 years (cobalt, 2.3 ?g/L; chromium, 1.6 ?g/L). Pseudotumor occurred in 2 hips. Patients with large-diameter metal-on-metal total hip arthroplasty had higher circulating metal ion levels at 3 months and 1 year, with no additional significant increases at 2 years. PMID:22325959

Hasegawa, Masahiro; Yoshida, Kakunoshin; Wakabayashi, Hiroki; Sudo, Akihiro

2012-06-01

365

Rhodobacter capsulatus porphobilinogen synthase, a high activity metal ion independent hexamer  

Microsoft Academic Search

BACKGROUND: The enzyme porphobilinogen synthase (PBGS), which is central to the biosynthesis of heme, chlorophyll and cobalamins, has long been known to use a variety of metal ions and has recently been shown able to exist in two very different quaternary forms that are related to metal ion usage. This paper reports new information on the metal ion independence and

David W. Bollivar; Cheryl Clauson; Rachel Lighthall; Siiri Forbes; Bashkim Kokona; Robert Fairman; Lenka Kundrat; Eileen K. Jaffe

2004-01-01

366

Effect of ion implantation on the tribology of metal-on-metal hip prostheses.  

PubMed

Nitrogen ion implantation (which considerably hardens the surface of the bearing) may represent one possible method of reducing the wear of metal-on-metal (MOM) hip bearings. Currently there are no ion-implanted MOM bearings used clinically. Therefore a physiological hip simulator test was undertaken using standard test conditions, and the results compared to previous studies using the same methods. N2-ion implantation of high carbon cast Co-Cr-Mo-on-Co-Cr-Mo hip prostheses increased wear by 2-fold during the aggressive running-in phase compared to untreated bearing surfaces, plus showing no wear reductions during steady-state conditions. Although 2 specimens were considered in the current study, it would appear that ion implantation has no clinical benefit for MOM. PMID:15578563

Bowsher, John G; Hussain, Azad; Williams, Paul; Nevelos, Jim; Shelton, Julia C

2004-12-01

367

Polymer filtration systems for dilute metal ion recovery  

SciTech Connect

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.

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

1998-12-01

368

Recycling radioactive scrap metal by producing concrete shielding with steel granules  

SciTech Connect

Siempelkamp foundry at Krefeld, Germany, developed a method for recycling radioactively contaminated steel from nuclear installations. The material is melted and used for producing shielding plates, containers, etc., on a cast-iron basis. Because the percentage of stainless steel has recently increased significantly, problems in the production of high-quality cast iron components have also grown. The metallurgy, the contents of nickel and chromium especially, does not allow for the recycling of stainless steel in a percentage to make this process economical. In Germany, the state of the art is to use shielded concrete containers for the transport of low active waste; this concrete is produced by using hematite as an additive for increasing shielding efficiency. The plan was to produce steel granules from radioactive scrap metal as a substitute for hematite in shielding concrete.

Sappok, M. [Siempelkamp Giesserei GmbH, Krefeld (Germany)

1996-12-31

369

The application of metal cutting technologies in tasks performed in radioactive environments  

SciTech Connect

The design and use of equipment to perform work in radioactive environments is uniquely challenging. Some tasks require that the equipment be operated by a person wearing a plastic suit or full face respirator and donning several pairs of rubber gloves. Other applications may require that the equipment be remotely controlled. Other important, design considerations include material compatibility, mixed waste issues, tolerance to ionizing radiation, size constraints and weight capacities. As always, there is the ``We need it ASAP`` design criteria. This paper describes four applications where different types of metal cutting technologies were used to successfully perform tasks in radioactive environments. The technologies include a plasma cutting torch, a grinder with an abrasive disk, a hydraulic shear, and a high pressure abrasive water jet cutter.

Fogle, R.F.; Younkins, R.M.

1997-05-01

370

Nuclear structure and astrophysics with accelerated beams of radioactive ions: A new multidisciplinary research tool  

SciTech Connect

After a brief discussion of the techniques for producing accelerated radioactive ion beams (RIBs), several recent scientific applications are mentioned. Three general nuclear structure topics, which can be addressed using RIBs, are discussed in some detail: possible modifications of the nuclear shell structure near the particle drip lines; various possibilities for decoupling the proton and neutron mass distributions for weakly bound nuclei; and tests of fundamental nuclear symmetries for self-conjugate and nearly self-conjugate nuclei. The use of RIBs to study r- and rp-process nucleosynthesis also is discussed.

Garrett, J.D.

1995-12-31

371

Reaction dynamics with light weakly bound Radioactive Ion Beams at near-barrier energies  

NASA Astrophysics Data System (ADS)

In the present contribution, we will briefly present an overview of the last experimental results obtained by the Italian EXOTIC collaboration on the study of the reaction mechanisms around the Coulomb barrier with light weakly bound Radioactive Ion Beams. Several experiments have been performed by our group in different laboratories: at ANL (USA) and, more recently, at LNL (Italy) to study the system 17F+208Pb and at RIKEN (Japan) for the system 11Be+209Bi. A comparative discussion with the results obtained for other reactions induced by light weakly- and tightly-bound projectiles will be finally given.

Mazzocco, M.; Glodariu, T.; Martin, B.; Pierroutsakou, D.; Signorini, C.; Bonetti, R.; de Rosa, A.; Farinon, F.; Guglielmetti, A.; Inglima, G.; La Commara, M.; Mazzocchi, C.; Romoli, M.; Sandoli, M.; Stroe, L.; Soramel, F.; Vardaci, E.

2008-05-01

372

Reaction dynamics with light weakly bound Radioactive Ion Beams at near-barrier energies  

SciTech Connect

In the present contribution, we will briefly present an overview of the last experimental results obtained by the Italian EXOTIC collaboration on the study of the reaction mechanisms around the Coulomb barrier with light weakly bound Radioactive Ion Beams. Several experiments have been performed by our group in different laboratories: at ANL (USA) and, more recently, at LNL (Italy) to study the system {sup 17}F+{sup 208}Pb and at RIKEN (Japan) for the system {sup 11}Be+{sup 209}Bi. A comparative discussion with the results obtained for other reactions induced by light weakly- and tightly-bound projectiles will be finally given.

Mazzocco, M.; Signorini, C. [Dipartimento di Fisica and INFN--Sezione di Padova, via Marzolo 8, I-35131 Padova (Italy); Glodariu, T.; Stroe, L. [NIPNE, 407 Atomistilor st., 077125, Magurele (Romania); Martin, B.; Pierroutsakou, D.; De Rosa, A.; Inglima, G.; La Commara, M.; Romoli, M.; Sandoli, M.; Vardaci, E. [Dipartimento di Scienze Fisiche and INFN--Sezione di Napoli, via Cinthia, I-80126 Napoli (Italy); Bonetti, R.; Guglielmetti, A. [Istituto di Fisica Generale ed Applicata and INFN--Sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Farinon, F. [GSI, Planckstrasse 1, D-64291 Darmstadt (Germany); Mazzocchi, C. [Istituto di Fisica Generale ed Applicata, via Celoria 16, I-20133 Milano (Italy); Soramel, F. [Dipartimento di Fisica and INFN--Sezione di Udine, via delle Scienze 208, I-33100 Padova (Italy)

2008-05-12

373

An overview on TRIUMF's developments on ion source for radioactive beams (invited)  

NASA Astrophysics Data System (ADS)

The ISAC facility at TRIUMF utilizes up to 100 ?A from the 500 MeV H- cyclotron to produce the radioactive ion beam (RIB) using the isotopic separation on line method. The ISAC-I facility comprised the RIB production target stations, the mass separator, and the beam delivery to low energy area and to a room temperature linear accelerator composed of a four-rod radio frequency quadrupole and an interdigital H-type structure drift tube LINAC. ISAC-I linear accelerator can provide beam from A=3 to 30 amu with an energy range from 0.15 to 1.5 A MeV. Since the beginning of operations target development program has been to increase proton beam currents on targets. Now we routinely operate our target at 50-85 ?A and recently we have operated our target at 100 ?A. Other developments are in place to add other ion sources, laser, force electron beam induced are discharge and electron cyclotron resonance ion source to the actual surface ion source. The last two five year plans were mainly devoted to the construction of a heavy ion superconducting LINAC (ISAC-II) that will upgrade the mass and the energy range from 30 to 150 and from 1.5 to 6.5 A MeV, respectively. The intermediate stage E<=4.2 A MeV is already completed and commissioned; three experiments using 11Li, 9Li, and 29Na have been completed this summer.

Bricault, Pierre; Ames, Friedhelm; Achtzehn, Tobias; Dombsky, Marik; Labrecque, Francis; Lassen, Jens; Lavoie, Jean-Phillipe; Lecesne, Nathalie

2008-02-01

374

Microbial metal-ion reduction and Mars: extraterrestrial expectations?  

PubMed

Dissimilatory metal-ion-reducing bacteria (DMRB) can couple the reduction of a variety of different metal ions to cellular respiration and growth. The excitement of this metabolic group lies not only in the elucidation of a new type of metabolism, but also in the potential use of these abilities for the removal of toxic organics, and in their ability to reduce (and thus, detoxify) other toxic metals, such as U(VI) and Cr(VI). This review focuses on recent advances in the study of DMRB, including the use of external electron shuttles to enhance rates of metal reduction; genome sequencing and consequent genomic and proteomic analyses; new imaging approaches for high resolution analysis of both cells and chemical components; the demonstration of fractionation of stable isotopes of iron during iron reduction; and the elucidation of the types and patterns of secondary mineral formation during metal reduction. One of the secondary minerals is magnetite, the subject of intense controversy regarding the possibility of evidence for life from the Martian meteorite ALH84001. This review thus ends with a short consideration of the evidence for magnetic 'proof' of the existence of past life on Mars. PMID:12057684

Nealson, Kenneth H; Cox, B Lea

2002-06-01

375

The Corrosion Protection of Metals by Ion Vapor Deposited Aluminum  

NASA Technical Reports Server (NTRS)

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.

Danford, M. D.

1993-01-01

376

The Belgian approach and status on the radiological surveillance of radioactive substances in metal scrap and non-radioactive waste and the financing of orphan sources  

SciTech Connect

Numerous facilities in the non-nuclear sector in Belgium (e.g. in the non-radioactive waste processing and management sector and in the metal recycling sector) have been equipped with measuring ports for detecting radioactive substances. These measuring ports prevent radioactive sources or radioactive contamination from ending up in the material fluxes treated by the sectors concerned. They thus play an important part in the protection of the workers and the people living in the neighbourhood of the facilities, as well as in the protection of the population and the environment in general. In 2006, Belgium's federal nuclear control agency (FANC/AFCN) drew up guidelines for the operators of non-nuclear facilities with a measuring port for detecting radioactive substances. These guidelines describe the steps to be followed by the operators when the port's alarm goes off. Following the publication of the European guideline 2003/122/EURATOM of 22 December 2003 on the control of high-activity sealed radioactive sources and orphan sources, a procedure has been drawn up by FANC/AFCN and ONDRAF/NIRAS, the Belgian National Agency for Radioactive Waste and Enriched Fissile Materials, to identify the responsible to cover the costs relating to the further management of detected sealed sources and if not found to declare the sealed source as an orphan source. In this latter case and from mid-2006 the insolvency fund managed by ONDRAF/NIRAS covers the cost of radioactive waste management. At the request of the Belgian government, a financing proposal for the management of unsealed orphan sources as radioactive waste was also established by FANC/AFCN and ONDRAF/NIRAS. This proposal applies the same approach as for sealed sources and thus the financing of unsealed orphan sources will also be covered by the insolvency fund. (authors)

Braeckeveldt, Marnix; Preter, Peter De [ONDRAF/NIRAS, Kunstlaan 14, B 1210 Brussels (Belgium); Michiels, Jan; Pepin, Stephane; Schrauben, Manfred; Wertelaers, An [FANC/AFCN, Ravensteinstraat 36 B 1000 Brussels (Belgium)

2007-07-01

377

UPTAKE OF METAL IONS BY A NEW CHELATING ION-EXCHANGE RESIN. PART 4 : KINETICS  

Microsoft Academic Search

The rate of uptake of several actinide ions [Am(III), U(VI), Th(IV), Np(IV) and Pu(IV)] and of some transition-metal ions [Co(II), Zn(II), Fe(III) and Cr(III)] at tracer concentration level, from solutions of various compositions, by the new chelating ion-exchange resin, Diphonix, has been investigated. Diphonix is a polyfunctional resin containing sulfonic and gem-diphosphonic acid groups chemically bonded in a styrene-divinylbenzene polymeric

R. Chiarizia; E. P. Horwitz; S. D. E. P. Alexandratos

1994-01-01

378

Production of intense beams of highly charged metallic ions from RIKEN 18 GHz electron cyclotron resonance ion source  

Microsoft Academic Search

We successfully produced intense beams of highly charged metallic ions from various kinds of organic metallic compounds by the metal ions from volatile compounds method and solid materials in RIKEN 18 GHz electron cyclotron resonance ion source (ECRIS) (e.g., 135 emuA of Fe11+, 80 emuA of Fe13+, 10 emuA of Os29+, and 1 emuA of Os37+). Using this ECRIS the

T. Nakagawa; J. Ärje; Y. Miyazawa; M. Hemmi; T. Chiba; N. Inabe; M. Kase; T. Kageyama; O. Kamigaito; M. Kidera; A. Goto; Y. Yano

1998-01-01

379

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

PubMed

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. PMID:24593450

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

2014-02-01

380

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

PubMed

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

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

2006-07-01

381

Sensing metal ions with ion selectivity of a crown ether and fluorescence resonance energy transfer between carbon dots and graphene.  

PubMed

Here we report a metal ion sensor with high potassium selectivity and tunable dynamic range by using an ion-selective crown ether and fluorescence resonance energy transfer from carbon dots to graphene. PMID:22179588

Wei, Weili; Xu, Can; Ren, Jinsong; Xu, Bailu; Qu, Xiaogang

2012-01-30

382

The Holifield Radioactive Ion Beams Facility (HRIBF) -- getting ready to do experiments  

SciTech Connect

The conversion of the HHIRF facility to a Radioactive Ion Beam facility started in 1994. In this ISOL type facility the Cyclotron has been re-fitted as a driver providing high intensity proton beams which react with the target from which the radioactive products are extracted and then accelerated in the Tandem Electrostatic Accelerator to the desired energy for nuclear science studies. Facilities for nuclear physics experiments are at different stages of development: A Recoil Mass Spectrometer (RMS) with a complement of detectors at the focal plane and around the target is used primarily for nuclear structure studies. A large recoil separator combining velocity and momentum selection, with its complement of focal plane detectors, will be dedicated to measurements relevant to nuclear astrophysics. The Enge Split Pole spectrograph is being re-fitted for operation in a gas filled mode, making it a more versatile tool for nuclear reaction studies. With the new experimental equipment being commissioned and the prospects of running experiments with low intensity radioactive beams a significant effort to develop equipment for beam diagnostics is underway. Some of the efforts and results in developing beam diagnostic tools will be described.

Shapira, D.; Lewis, T.A.

1998-02-26

383

Nanomagnetic chelators for removal of toxic metal ions  

NASA Astrophysics Data System (ADS)

Ethylenediamine trtraaceteic acid (EDTA) functionalized Fe3O4 nanomagnetic chelators (NMCs) were synthesized by co-precipitation method followed by in-situ grafting of EDTA. XRD and TEM analyses reveal the formation of highly crystalline single-phase Fe3O4 nanoparticles of size about 10 nm. Surface functionalization of Fe3O4 with EDTA was evident from FTIR spectroscopy, TGA analysis and zeta-potential measurement. These NMCs exhibit superparamagnetic behavior at room temperature with strong field dependent magnetic responsivity. It has been observed that NMCs have strong tendency for adsorption of various toxic metal ions (Ni2+, Cr3+, Cu2+, Cd2+, Co2+ and Pb2+) from waste-water. Furthermore, these magnetic chelators can be used as highly efficient separable and reusable material for removal of toxic metal ions.

Singh, Sarika; Barick, K. C.; Bahadur, D.

2013-02-01

384

Stabilization of Metal-Loaded Ion-Exchange Resin with a Porous Silica Supporter Through Thermal Treatment  

SciTech Connect

A new ion exchanger with porous silica as a supporting material and diphosphonic acid as a functional chelating group has been developed at ANL for the effective removal of transition metals and actinide ions from very acidic radioactive liquid wastes. The applicability of this resin for the treatment of low- and/or intermediate-level aqueous waste from nuclear power plants (NPP) has not been reported in scientific literature, but is under study now in Korea. The major radioisotopes in NPP radioactive liquid waste are Cs and Co in neutral pH ranges. This study on the thermal stabilization of metal-loaded waste resin has been carried out in parallel with the sorption experiment. Thermal treatment of metal (Co, Cs or U) loaded resin was accomplished to see the possibility of enhancing the safety and stability of the final product during transportation and disposal. In this paper, characteristics of the metal-loaded resins before and after heat treatment at three different thermal conditions were investigated and compared with each other to see the effectiveness of the thermal treatment method.

Kim, I-T. Park, H-S.; Yoo, J-H.; Kim, J-H.

2003-02-25

385

Metal/acid ion permeable membrane fuel cell  

SciTech Connect

A fuel cell is disclosed which comprises a metal anode immersed in a base electrolyte solution and connected with an electric circuit, a cathode comprising an acid solution, a carbon catalyst and electron distributor plate in that solution and connected with an electron supply and a wettable fluid impermeable membrane and disposed between the electrolyte and cathode solution and establishing an acid-base reactor interface where hydroxyl ions are generated for conduction through the electrolyte to the anode.

Struthers, R.C.

1982-10-05

386

Principles of Nucleic Acid Cleavage by Metal Ions  

Microsoft Academic Search

\\u000a Nucleic acids are responsible for the storage, transmission, and expression of genetic information in all living organisms.\\u000a These macromolecules tend to behave as salts in solution since the negative charges of the polynucleotide phosphodiester backbone\\u000a are usually neutralized by metal solute ions. Therefore, for practical purposes, it is difficult if not impossible to separate\\u000a the behavior of DNA and RNA

A. Dallas; A. V. Vlassov; S. A. Kazakov

387

Equilibrium sorption isotherm for metal ions on tree fern  

Microsoft Academic Search

A new sorbent system for removing heavy metal ions, such as Zn(II), Cu(II) and Pb(II), from aqueous solutions has been investigated. This new sorbent is tree fern, an agriculture product. Variables of the system include solution temperature and sorbent particle size. The experimental results were fitted to the Langmuir, Freundlich and Redlich–Peterson isotherms to obtain the characteristic parameters of each

Y. S. Ho; C. T. Huang; H. W. Huang

2002-01-01

388

Metal ion release from electric guitar strings in artificial sweat  

Microsoft Academic Search

The aim of this study was to monitor the dissolution of metal ions from electric guitar strings. For characterization of investigated strings, two independent methods of analysis were chosen: ICP-OES and AAS. Electric guitar strings consisted of two separate parts: Sn-plated steel core wire which was hexagonal in cross section and Ni-plated steel wrap which was round in cross section.

Iva Rezi?; Lidija ?urkovi?; Magdalena Ujevi?

2009-01-01

389

Metal ion accumulation by immobilised cells of Brevibacterium sp  

Microsoft Academic Search

  This paper explores the use of an experimental system based on polyacrylamide-entrapped cells of Brevibacterium sp strain PBZ for the removal of metal ions from solutions. Experiments were performed in columns filled with the immobilised\\u000a cells and challenged with influents containing 20?mg L?1 of lead and 10?mg L?1 of cadmium. The cells were able to accumulate lead (about 40?mg g?1

D Di Simine; C Finoli; A Vecchio; V Andreoni

1998-01-01

390

Health risk and impact evaluation for recycling of radioactive scrap metal  

SciTech Connect

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.

Nieves, L.A.; Chen, S.Y. [Argonne National Lab., IL (United States); Murphie, W.E.; Lilly, M.J. III [USDOE, Washington, DC (United States)

1994-03-01

391

Preliminary shielding estimates for the proposed National ISOL Radioactive Ion Beam (RIB) Facility at Oak Ridge  

SciTech Connect

ORNL built a first-generation Radioactive Ion Beam (RIB) facility for astrophysics and nuclear physics research; it was named Holifield Radioactive Ion Beam Facility (HRIBF) and is based on the Isotope Separator On Line (ISOL) technique. Planning is underway for a second- generation facility, the National ISOL RIB facility at Oak Ridge; it will build on the existing HRIBF and may utilize many existing components and shielded areas. Preliminary upgrade plan for the new facility includes: adding a superconducting booster for the tandem accelerator; replacing the 1960-vintage, 60-MeV proton, 50-microamp ORIC (Oak Ridge Isochronous Cyclotron) with a modern 200-MeV proton, 200-microamp cyclotron; and building a high-power {sup 238}U fission target to accept the 200-MeV proton beam. This report summarizes the results of a preliminary 1-D shielding analysis of the proposed upgrade, to determine the shielding requirements for a 0.25 mrem/h dose rate at the external surface of the exclusion area. Steel shielding weights ranging from 60 to 100 metric tons, were considered manageable; these could be reduced by a factor of 2 to 3 if the orientation of the proposed target station was changed.

Johnson, J.O.; Gabriel, T.A.; Lillie, R.A.

1996-10-01

392

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

SciTech Connect

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.

McClelland, J.B.; Vieira, D.J. (comps.)

1990-10-01

393

Production of metal cluster patterns using Focused Ion Beams (FIB)  

NASA Astrophysics Data System (ADS)

Nanometer sized pits on graphite (HOPG) substrates can be used as nucleation centers to produce clusters with a narrow size distribution. In previous experiments [1] nanometer sized pits were produced by sputtering and oxidizing the sample. As a result we get nanopits which are a few nanometers wide and only one monolayer deep, distributed at random locations on the surface. In the present study a focused beam of gallium ions is used to produce nanopits in a given pattern on the substrate. The FIB instrument (Raith ionLiNE) is capable of a resolution below 10 nm [2]. Using the nanopits as nucleation centers we are able to produce gold islands as well as silver clusters in a given pattern by depositing metal atoms. Furthermore the nanopit distribution on the surface in combination with Monte Carlo simulations helps investigating the ion beams, e.g. ion distribution, recoils as well as the penetration depth of the ions [3]. In this respect the oxidation of HOPG-samples provides a method to study the ion impact effects. [1] H. Hövel, Appl. Phys. A 72 (2001) 295; [2] J. Gierak et al., Appl. Phys. A 80 (2005) 187; [3] F. Ghaleh, R. Köster, H. Hövel, L. Bruchhaus, S. Bauerdick, J. Thiel, R. Jede, J. Appl. Phys. 101 (2007) 044301.

Ghaleh, Farhad; Grönhagen, Niklas; Hövel, Heinz; Bruchhaus, Lars; Bauerdick, Sven; Thiel, Jürgen; Jede, Ralf

2008-03-01

394

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

SciTech Connect

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.

Lima, L. H. de [Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas, 13083-859, Campinas, SP (Brazil)] [Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas, 13083-859, Campinas, SP (Brazil); Cun, H. Y.; Hemmi, A.; Kälin, T.; Greber, T. [Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich (Switzerland)] [Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich (Switzerland)

2013-12-15

395

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

396

Ion chromatographic determination of metals in biocompatibility testing.  

PubMed

The increasing numbers of materials used in surgical implants require a wide spectrum of tests to evaluate their biocompatibility. The release of metals is an important additional feature for determining the suitability for clinical applications of biomaterials such as ceramics and metals. Due to the difficulty of performing time-consuming experiments in vivo, one approach for rapidly determining the suitability of biomaterials and their interactions with the tissues with which they will come in contact is to perform in vitro tests, based on cell culture analysis, using solutions that reproduce the cleavage and binding capabilities of body fluids and tissues. The present work reports on the application of ion chromatography to the simultaneous determination of some metal ions in a few biologic media. Agar-Agar solution, "199 medium, " and betadine and Schiff's reagents were selected as some of the most representative biologic simulating solutions. A method is recommended for the pretreatment of the sample with minimal reagent addition since it is very rich in organic compounds and cannot be analyzed without pretreatment. The proposed procedure requires the sample to be subjected to oxidative UV photolysis for about 60 min in an UV digester at 85 degrees +/- 5 degrees C, followed by the ion chromatographic determination. Lead (II), cadmium (II), iron (III), copper (II), nickel (II), zinc (II), and cobalt (II) simultaneously were determined at microg/L levels. PMID:10679676

Buldini, P L; Mevoli, A; Sharma, J L

2000-05-01

397

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

PubMed

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

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

398

Development of a surface ionization source for the production of radioactive alkali ion beams in SPIRAL  

NASA Astrophysics Data System (ADS)

In the framework of the production of radioactive alkali ion beams by the isotope separation on-line (ISOL) method in SPIRAL I, a surface ionization source has been developed at GANIL to produce singly-charged ions of Li, Na and K. This new source has been designed to work in the hostile environment whilst having a long lifetime. This new system of production has two ohmic heating components: the first for the target oven and the second for the ionizer. The latter, being in carbon, offers high reliability and competitive ionization efficiency. This surface ionization source has been tested on-line using a 48Ca primary beam at 60.3 A MeV with an intensity of 0.14 pA. The ionization efficiencies obtained for Li, Na and K are significantly better than the theoretical values of the ionization probability per contact. The enhanced efficiency, due to the polarization of the ionizer, is shown to be very important also for short-lived isotopes. In the future, this source will be associated with the multicharged electron-cyclotron-resonance (ECR) ion source NANOGAN III for production of multicharged alkali ions in SPIRAL. The preliminary tests of the set up are also presented in this contribution.

Eléon, C.; Jardin, P.; Gaubert, G.; Saint-Laurent, M.-G.; Alcántara-Núñez, J.; Alvès Condé, R.; Barué, C.; Boilley, D.; Cornell, J.; Delahaye, P.; Dubois, M.; Jacquot, B.; Leherissier, P.; Leroy, R.; Lhersonneau, G.; Marie-Jeanne, M.; Maunoury, L.; Pacquet, J. Y.; Pellemoine, F.; Pierret, C.; Thomas, J. C.; Villari, A. C. C.

2008-10-01

399

Nanostructure operations by means of the liquid metal ion sources.  

PubMed

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

Gasanov, I S; Gurbanov, I I

2012-02-01

400

Surface modified, collapsible controlled pore glass materials for sequestration and immobilization of trivalent metal ions.  

SciTech Connect

We report a one-pot method for sequestration, containment, and immobilization of lanthanide (Ln) ions from dilute aqueous waste streams. The approach is based on the use of collapsible, surface modified controlled pore glass (CPG) nanomaterials. We present several approaches for a single-step chemical modification of 3-propylaminated CPGs that yield highly efficient Ln-extracting materials with distribution coefficients exceeding 10000 mL/g. The resulting Ln complexes were studied using X-ray absorption, magnetic resonance, and time-resolved luminescence spectroscopies. One of these CPG materials involving an imidodi(methanediphosphate) moiety demonstrated high extraction efficacy, significant ionic radius sensitivity, and exceptional tolerance to masking agents, which is conducive to its use for removal of traces of radionuclide ions from aqueous TALSPEAK raffinate (trivalent actinide-lanthanide separation by phosphorus reagent extraction from aqueous complexes process used in processing of spent nuclear fuel). The glass loaded with the extracted metal ions can be calcined and sintered at 1100 C, yielding fused material that buries Ln ions in the vitreous matrix. This processing temperature is significantly lower than 1700 C that is required for direct vitrification of lanthanide oxides in high-silica glass. X-ray absorption spectroscopy and acid leaching tests indicate that the immobilized ions are isolated and dispersed in the fused glass matrix. Thus, the method integrates Ln ions into the glass network. The resulting glass can be used for temporary storage or as the source of silica for production of borosilicate waste forms that are used for long-term disposal of high level radioactive waste.

Shkrob, I.; Tisch, A.; Marin, T.; Muntean, J.; Kaminski, M.; Kropf, A. (Chemical Sciences and Engineering Division); (Benedictine Univ.)

2011-04-20

401

Metal ion concentrations in the joint fluid immediately after total knee arthroplasty  

Microsoft Academic Search

Extensive research has demonstrated increased levels of blood metal ions caused by corrosion or wear of the metal after prosthetic\\u000a implantations. However, metal ion levels in the joint fluid immediately after prosthetic implantation have not been investigated.\\u000a We measured the concentrations of metal ions in the joint fluid immediately after total knee arthroplasty in seven patients.\\u000a Fluid specimens from the

Yasuo Niki; Hideo Matsumoto; Toshiro Otani; Yasunori Suda; Yoshiaki Toyama

2001-01-01

402

Fluorescence Spectroscopy of Polymer Systems Doped with Rare-Earth Metal Ions and Their Complexes  

Microsoft Academic Search

There has been an increased attention to explore the possibility of using polymer materials with rare-earth (RE) metal ions and their complexes as potential optical materials due to their capability of exhibiting novel and unusual properties. The fluorescence characteristics of polymer systems doped with RE metal ions and\\/or their complexes were analyzed and the effects of the doping metal ion\\/metal

K. S. V. Krishna Rao; Hong-Guo Liu; Yong-Ill Lee

2010-01-01

403

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

PubMed

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

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

2014-08-01

404

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

DOEpatents

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.

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

1997-01-21

405

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

DOEpatents

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.

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

1997-01-21

406

Capillary electrophoresis for trace metal ion analysis in environmental studies.  

PubMed

A new buffer system consisting of 30 mM hydroxylamine hydrochloride, 0.1 mM 1,10-phenanthroline, 1% methanol and pH 3.7 was optimized for simultaneous determination of water and acid leachable metals from respirable, fine and coarse air particulate matters. A reducing environment was used to resolve metal ions with variable oxidation states. A suitable counteranion was employed to enable acidic pH to be used and methanol was added to improve the resolution of the electropherograms and to achieve simultaneous determination of several metal ions. Compared to existing capillary electrophoresis (CE) buffers, the buffer developed, based on direct UV detection of ion-pair with weak interaction, gives improved resolution and sharper, more stable and well-resolved peaks. It detects total irons and solves interfering problems due to the variable oxidation states of iron in environmental samples. Compared to existing mostly alkaline CE buffers for metal analysis, the acidic nature of the buffer system developed makes the pretreatment step simpler and reduces the risk of reagent contamination. Satisfactory working ranges (15-5500 ppb) and detection limits (0.5-3 ppb) were obtained for leachable Zn, Cu, Co, Fe and Cd. The NIST 1648 urban particulate matters were found to leach out 2.53-42.8% water-extractable and 2.76-71.7% acid-extractable Zn, Cu, Fe and Cd. High iron contents, and lower copper and zinc concentrations were found in respirable suspended particulates (RSP) sampled in Hong Kong. PMID:10445323

Fung, Y S; Tung, H S

1999-07-01

407

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

SciTech Connect

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.

Bayrakal, S.

1993-09-30

408

Use of the Holifield Facility 25-MV tandem accelerator in the Oak Ridge Radioactive Ion Beam Project  

SciTech Connect

The absence of time structure and the excellent beam and beam transport properties of tandem electrostatic accelerators make them an attractive choice for the acceleration of a large class of radioactive ion species produced with the ISOL technique. In this paper, considerations on the use of the Holified facility 25-MV tandem accelerator in the ORNL Radioactive Ion Beam Facility now under construction will be presented. Preliminary beam parameter measurement which suggest that the 25-MV tandem accelerator can be used as an effective separator of isobaric contaminant beams will also be presented and discussed.

Jones, C.M.; Juras, R.C.; Meigs, M.J.; Olsen, D.K.

1993-10-01

409

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

SciTech Connect

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.

Greife, U. [Colorado School of Mines, Golden; Livesay, Jake [ORNL; Jewett, Cybele [ORNL; Chipps, K. [Colorado School of Mines, Golden; Sarazin, F. [Colorado School of Mines, Golden; Bardayan, Daniel W [ORNL; Blackmon, Jeff C [ORNL; Nesaraja, Caroline D [ORNL; Smith, Michael Scott [ORNL; Champagne, A. E. [University of North Carolina, Chapel Hill; Fitzgerald, R. P. [University of North Carolina, Chapel Hill; Jones, K. L. [University of Tennessee; Thomas, J. S. [Rutgers University; Kozub, R. L. [Tennessee Technological University

2007-03-01

410

Radiation damage from single heavy ion impacts on metal surfaces  

SciTech Connect

The effects of single ion impacts on the surfaces of films of Au, Ag, In and Pb have been studied using in-situ transmission electron microscopy. On all of these materials, individual ion impacts produce surface craters, in some cases, with associated expelled material. The cratering efficiency scales with the density of the irradiated metal. For very thin Au foils ({approx} 20--50 nm), in some cases individual ions are seen to punch small holes completely through the foil. Continued irradiation results in a thickening of the foil. The process giving rise to crater and hole formation and other changes observed in the thin foils has been found to be due to pulsed localized flow--i.e. melting and flow due to the thermal spikes arising from individual ion impacts. Experiments carried out on thin films of silver sandwiched between SiO{sub 2} layers have indicated that pulsed localized flow also occurs in this system and contributes to the formation of Ag nanoclusters in SiO{sub 2}--a system of interest for its non-linear optical properties. Calculation indicates that, when ion-induced, collision cascades occur near surfaces (within {approx} 5 nm) with energy densities sufficient to cause melting, craters are formed. Crater formation occurs as a result of the explosive outflow of material from the hot molten core of the cascade. Processes occurring in the sandwiched layer are less well understood.

Donnelly, S.E. [Univ. of Salford, Manchester (United Kingdom); Birtcher, R.C. [Argonne National Lab., IL (United States). Materials Science Div.

1998-06-01

411

Assessment of some trace heavy metals and radioactivity concentration in water of Bendimahi River Basin (Van, Turkey).  

PubMed

The levels of heavy metals were determined in the water of Bendimahi River Basin, statistically analysed and compared to natural gross radioactivity concentration. Fifteen samples of water were collected from Bendimahi River and Van Lake for two seasons in 2005. Water samples were analyzed for eight trace elements and concluded together with gross-alpha and gross-beta radioactivity concentrations. Atomic absorption spectrometry (AAS) was used to determine the concentrations of heavy metals in water samples collected from Bendimahi River basin. Correlation analysis was made for radioactivity and heavy metal concentrations and the Pearson correlation coefficients between gross-alpha and gross-beta radioactivity and heavy metal were determined. The concentrations of all metals were found to be higher than WHO, EC, EPA and TSE-266 guidelines for drinking water, except for Zn and Cu. Generally, the heavy metal concentrations in water samples obtained in May and in August were found to be in sequence of Fe>Zn>Pb>Cr>Cu>Mn>Co>Cd and Fe>Zn>Cu>Pb>Cr>Mn>Co>Cd, respectively. The gross-alpha and gross-beta activity concentration varies between 0.063 and 0.782, 0.021 and 0.816 Bq l(-1) in samples collected in May, and 0.009 and 0.037, 0.081 and 3.116 Bq l(-1) in samples collected in August. PMID:18085419

Zorer, Ozlem Selçuk; Ceylan, Hasan; Do?ru, Mahmut

2008-12-01

412

An overview on TRIUMF's developments on ion source for radioactive beams.  

PubMed

The ISAC facility at TRIUMF utilizes up to 100 microA from the 500 MeV H(-) cyclotron to produce the radioactive ion beam (RIB) using the isotopic separation on line method. The ISAC-I facility comprised the RIB production target stations, the mass separator, and the beam delivery to low energy area and to a room temperature linear accelerator composed of a four-rod radio frequency quadrupole and an interdigital H-type structure drift tube LINAC. ISAC-I linear accelerator can provide beam from A=3 to 30 amu with an energy range from 0.15 to 1.5 A MeV. Since the beginning of operations target development program has been to increase proton beam currents on targets. Now we routinely operate our target at 50-85 microA and recently we have operated our target at 100 microA. Other developments are in place to add other ion sources, laser, force electron beam induced are discharge and electron cyclotron resonance ion source to the actual surface ion source. The last two five year plans were mainly devoted to the construction of a heavy ion superconducting LINAC (ISAC-II) that will upgrade the mass and the energy range from 30 to 150 and from 1.5 to 6.5 A MeV, respectively. The intermediate stage E< or =4.2 A MeV is already completed and commissioned; three experiments using (11)Li, (9)Li, and (29)Na have been completed this summer. PMID:18315163

Bricault, Pierre; Ames, Friedhelm; Achtzehn, Tobias; Dombsky, Marik; Labrecque, Francis; Lassen, Jens; Lavoie, Jean-Phillipe; Lecesne, Nathalie

2008-02-01

413

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

PubMed

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

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

2014-06-10

414

Correlation between the limiting pH of metal ion solubility and total metal concentration  

SciTech Connect

As an alternative to species distribution diagrams (pM vs pH curves in aqueous solution) drawn for a fixed total metal concentration, this work has developed simple linear models for correlating the limiting pH of metal ion solubility -- in equilibrium with the least soluble amorphous metal hydroxide solid phase -- to the total metal concentration. Thus adsorptive metal removal processes in complex systems can be better designed once the limiting pH of heavy metal solubility (i.e., pH{sup *}) in such a complex environment can be envisaged by simple linear equations. pH{sup *} vs pM{sub t} (M{sub t} = total metal concentration that can exist in aqueous solution in equilibrium with M(OH){sub 2(s)}) linear curves for uranyl-hydroxide, uranyl-carbonate-hydroxide, and mercuric-chloride-hydroxide simple and mixed-ligand systems and cupric-carbonate-hydroxide complexes in equilibrium with mixed hydroxide solid phases may enable the experimental chemist to distinguish true adsorption (e.g., onto hydrous oxide sorbents) from bulk precipitation removal of the metal and to interpret some anomalous metal fixation data -- usually attributed to pure adsorption in the literature -- with precipitation if the pM{sub t} at the studied pH is lower than that tolerated by pH{sup *} vs pM{sub t} curves. This easily predictable pH{sup *} corresponding to a given pM{sub t} may aid the design of desorptive mobilization experiments for certain metals as well as their adsorptive removal with the purpose of simulating metal adsorption and desorption cycles in real complex environments with changing groundwater pH.

Apak, R.; Hizal, J.; Ustaer, C. [Istanbul Univ. (Turkey)] [Istanbul Univ. (Turkey)

1999-03-15

415

The Use of the Photofission of 238U for a Neutron-Rich Radioactive Ion Beams Generation  

NASA Astrophysics Data System (ADS)

The fission fragments yield for photofission of 238U, induced by bremsstrahlung photons with endpoint energies of 25 and 50MeV was evaluated to estimate the possibility of producing the neutron-rich nuclei. The systematics coming from A.C. Wahl's Zp model 1 for charge distribution of fission fragments were used. Results for xenon and krypton isotopes are compared with experimental data 2 obtained on the DRIBs 3 (Dubna Radioactive Ion Beams) facility for neutron-rich nuclei production in Flerov Laboratory. The fission rate and fission density in production target for metallic uranium and UCx compounds were simulated with Geant4 4 simulation toolkit to design the target geometry, The fission rate dependence on material of the electron stopping target was examined, At nominal beam values on microtron MT-25 (Ie = 20?A, Ee = 25MeV) up to 2.1011 fissions/s could be achieved. Then the production rate of neutron-rich isotopes reaching order of 109s-1. The induced activity in the production target depending on an irradiation time was calculated for radiation protection purposes and target safety estimation. The cumulation of actinide nuclei was also calculated.

Szöll?s, O.; Kliman, J.

2003-10-01

416

The kinetics of bivalent metal ion dissociation from myosin subfragments.  

PubMed Central

Bivalent metal ions have multiple roles in subunit association and ATPase regulation in scallop adductor-muscle myosin. To help elucidate these functions, the rates of Ca2+ and Mg2+ dissociation from the non-specific high-affinity sites on the regulatory light chains were measured and compared with those of rabbit skeletal-muscle myosin subfragments. Ca2+ dissociation had a rate constant of about 0.7 s-1 in both species, as measured by the time course of the pH change on EDTA addition. Mg2+ dissociation had a rate constant of 0.05 s-1, as monitored by its displacement with the paramagnetic Mn2+ ion. It is concluded that the exchange between Ca2+ and Mg2+ at the non-specific site, on excitation of both skeletal and adductor muscles, is too slow to contribute to the activation itself. The release of bivalent metal ions from the non-specific site is, however, the first step in release of the scallop regulatory light chain (Bennett & Bagshaw (1986) Biochem. J. 233, 179-186). In scallop myosin additional specific sites are present, which can bind Ca2+ rapidly, to effect activation of the ATPase. In the course of this work, Ca2+ dissociation from EGTA was studied as a model system. This gave rates of 1 s-1 and 0.3 s-1 at pH 7.0 and pH 8.0 respectively.

Bennett, A J; Bagshaw, C R

1986-01-01

417

Catalytic properties of ion-bombarded non-metals  

NASA Astrophysics Data System (ADS)

Sputtering, ion implantation and ion beam mixing are useful new techniques for producing catalysts consisting of an active metal introduced in a non-active substrate. We studied the performance of implanted and ion beam mixed electrocatalysts containing platinum as the active component in graphite or RuO 2 substrates. The specimens were used as electrodes in electrochemical cells and their activity was studied for the oxidation of formic acid and methanol, the reduction of oxygen and the evolution of hydrogen. All reactions are important for fuel cells and hydrogen production. The intermixing of a thin Pt layer with a RuO 2 substrate by means of 150 keV Kr + beams did not change the activity, normalized to a standard Pt surface concentration, for formic acid oxidation and oxygen reduction. The activity for methanol oxidation, however, decreased with increasing mixing dose and was nearly zero for implanted Pt in RuO 2. For Pt on graphite substrates the activity for all reactions increased with the mixing dose up to 10 16{Kr +}/{cm 2}, and decreased or saturated above this value. The observed dependency of the activity on the individual chemical reaction as well as on the type of substrate was explained provisionally by a cooperation of small particle effects and metal-substrate interactions.

Wolf, G. K.; Zucholl, K.; Folger, H.

1984-02-01

418

Amperometric microsensors for metal ion determination in single biological cells  

SciTech Connect

Amperometric microelectrode sensors were fabricated with the length and area of the electroactive surface tailored for the dimensions of the cells under investigation. A procedure for producing a sharpened carbon fiber sensor substrate was developed in order to avoid cell membrane rupture during single cell implantation. This carbon fiber sensor was then coated with a conductive polymeric porphyrin capable of the selective measurement of a specific metal ion. Differential pulse voltammetry was used for the determination of the concentration of the metal ions on the coated surface of the sensor. Tris(4-N-methylpyridyl)p-hydroxyphenylporphyrin was deposited on the surface of a carbon fiber ultramicroelectrode to measure Ca{sup 2+} concentration of 1 {times} 10{sup {minus}5} M in BHK-2/C-13 cells. Ni{sup 2+} at 1 {times} 10{sup {minus}6} M were measured in individual BC3H-T-myocytes, H4-IIC3 rat hepatoma or BHK-2/C-13 cells using ultramicroelectrodes coated with 3-methoxy-4-hydroxy-phenylporphyrin. In conclusion, these ultramicroelectrodes are capable of measuring the concentration of unbound Ni{sup 2+} and Ca{sup 2+} in the pathophysiologic range. The porphyrin ring may be modified by attaching different substituents with specificity for the coordination other metal cations.

Malinski, T.; Bailey, F.; Fish, J.R.; Kiechle, F. (Oakland Univ., Rochester, MI (United States) William Beaumont Hospital, Royal Oak, MI (United States))

1991-03-15

419

The release of metal ions from orthodontic appliances Animal tests.  

PubMed

ABSTRACT Objective: To investigate the release of metal ions from an orthodontic appliance in tests on animals (pigs). Materials and Methods: An animal test was conducted on 24 pigs divided equally into an experimental and a control group. In total, 12 sets of experimental orthodontic plates were surgically inserted into pig snouts in the experimental group for 6 months. Noninvasive matrices (hair [0, 3, and 6 months]) and invasive matrices (kidneys, liver, lungs, aorta, and oral mucosa) were collected for multi-elemental analysis (inductively coupled plasma optical emission spectrometry) from the experimental and control groups. Results: The greatest differences in the content of toxic metals were found in the aorta (Ni level was 4.8 times higher in experimental than in the control group), in the cheek (Ni 3.5 times higher), and in the hair sampled after 3 months (Cr 3.4 times higher). Conclusions: The obtained data indicate that the products of corrosion have passed into selected tissues of pigs; however, the doses of toxic metal ions released from the appliance did not reach toxic levels. PMID:24417497

Mikulewicz, Marcin; Wo?owiec, Paulina; Janeczek, Maciej; Gedrange, Thomas; Chojnacka, Katarzyna

2014-07-01

420

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

PubMed

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

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

2010-07-15

421

The kinetics of sorption of divalent metal ions onto sphagnum moss peat  

Microsoft Academic Search

A pseudo-second order rate equation describing the kinetics of sorption of divalent metal ions onto sphagnum moss peat at different initial metal ion concentrations and peat doses has been developed. The kinetics of sorption were followed based on the amounts of metal sorbed at various time intervals. Results show that sorption (chemical bonding) might be rate-limiting in the sorption of

Y. S. Ho; G. McKay

2000-01-01

422

The Role of Metal Ion Polymerization in Beer's Law Deviations Using Extractive-Colorimetric Procedures  

Microsoft Academic Search

In the solvent extraction of metal chelates, the presence of polymerized metal ion in either the aqueous or organic layer, can cause the efficiency of extraction to vary throughout a range of metal ion concentrations. Should an extractive-colorimetric determination be employed, a deviation from Beer's Law can result in addition to other intrinsic causes. In this study, the nature of

Selman A. Berger

1990-01-01

423

Atomic transport in metal\\/ceramic interfaces under heavy ion irradiation  

Microsoft Academic Search

Ion beam mixing is a useful tool to modify the physical properties of interfaces in different materials. Metal\\/metal systems were extensively studied in the last decade. In the last few years research has been focused on the technologically more important metal\\/ceramic systems. In these systems, however, there is only limited knowledge on stability and diffusion processes under heavy ion irradiation.

R. Nagel; A. G Balogh

1999-01-01

424

Spectroscopy and chemical dynamics of weakly bound alkaline-earth metal ion-H and alkaline-earth metal ion-hydrocarbon complexes 2  

Microsoft Academic Search

The activation of hydrocarbon bonds by metal atoms are among the most vital processes in chemistry. This review focuses on the spectroscopy and chemical dynamics of weakly bound alkaline-earth metal ion-H and alkaline-earth metal ion-hydrocarbon bimolecular complexes using mass-resolved photodissociation spectroscopy techniques. The photodissociation spectroscopy of isolated clusters, in concert with translationalenergy spectroscopy of the products, gives unique and detailed

Paul D. Kleiber Jing Chen

1998-01-01

425

Approaches to develop targets for production of intense radioactive ion beams  

SciTech Connect

Approaches to develop targets for production of intense radioactive ion beams (RIBs) have been evaluated over the past five years. It is acknowledged that many desired physics objectives using RIBs can be met only by using production beams of energetic protons with currents up to 100 {mu}A. Such beams can be made available at future spallation neutron facilities. The production targets will require active cooling to control operational temperatures due to internal heating caused by the production beam. A target concept has been selected, and calculational analyses of the target concept have been performed to guide the design of a prototype target for an in-beam test of the actual thermal behavior. For this test, a high-power test facility is needed; fortunately, the beam currents required exist at the TRIUMF accelerator facility. An experimental proposal has been approved for such a test.

Talbert, W. L.; Drake, D. M.; Wilson, M. T.; Walker, J. J. [Amparo Corporation, Santa Fe, New Mexico 87504 (United States); Lenz, J. W. [John. W. Lenz and Associates, Waxahachie, Texas 75165 (United States)

1999-06-10

426

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

SciTech Connect

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.

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

1999-06-13

427

Natural radioactivity and trace metals in crude oils: implication for health.  

PubMed

Crude oil samples were collected from six different fields in the central Niger Delta in order to determine their natural radioactivity and trace element contents, with the aim of assessing the radiological health implications and environmental health hazard of the metals, and also to provide natural radioactivity baseline data that could be used for more comprehensive future study in this respect. The activity concentrations of the radionuclides were measured using a well, accurately calibrated and shielded vertical cryostat, Canberra coaxial high-purity germanium (HPGe) detector system, and the derived doses were evaluated. The metal concentrations were determined by the graphite furnace atomic absorption spectroscopic (GFAAS) method. The radionuclides identified with reliable regularity belong to the decay series of naturally occurring radionuclides headed by (238)U and (232)Th along with the non-decay series radionuclide, (40)K. The averaged activity concentrations obtained were 10.52 +/- 0.03 Bq kg(-1), 0.80 +/- 0.37 Bq kg(-1) and 0.17 +/- 0.09 Bq kg(-1) for (40)K, (238)U and (232)Th, respectively. The equivalent doses were very low, ranging from 0.0028 to 0.012 mSv year(-1) with a mean value of 0.0070 mSv year(-1). The results obtained were low, and hence, the radioactivity content from the crude oils in the Niger delta oil province of Nigeria do not constitute any health hazard to occupationally exposed workers, the public and the end user. The concentrations of the elements (As, Cd, Co, Fe, Mn, Ni, Se and V) determined ranged from 0.73 to 202.90 ppb with an average of 74.35 ppb for the oil samples analysed. The pattern of occurrence of each element agreed with the earlier studies from other parts of the Niger Delta. It was obvious from this study and previous ones that the Niger Delta oils have low metal contents. However, despite the low concentrations, they could still pose an intrinsic health hazard considering their cumulative effects in the environment. Also, various studies on the impact of oil spillage and activities of oil exploration and production on organisms in the immediate environment suggest this. PMID:18320332

Ajayi, T R; Torto, N; Tchokossa, P; Akinlua, A

2009-02-01

428

High-resolution mass spectrometer for liquid metal ion sources  

SciTech Connect

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.

Wortmann, Martin; Ludwig, Arne; Reuter, Dirk; Wieck, Andreas D. [Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany)] [Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany); Meijer, Jan [Institut für Experimentelle Physik II, Universität Leipzig, Linnestr. 5, 04103 Leipzig (Germany)] [Institut für Experimentelle Physik II, Universität Leipzig, Linnestr. 5, 04103 Leipzig (Germany)

2013-09-15

429

Ion-induced spike effects on metal surfaces.  

SciTech Connect

The effects of single Xe ion impacts on the surfaces of Au, Ag, In and Pb have been studied using in-situ transmission electron microscopy. Individual ion impacts produce surface craters with associated expelled material. The cratering efficiency scales with the density of the irradiated metal. Calculation indicates that, when collision cascades occur near surfaces (within about 5 nm) with energy densities sufficient to cause local melting, craters will occur. Crater formation occurs as a result of the explosive outflow of material from the hot molten core of the cascade. This would appear to indicate that, although the number of atoms in a spike is small and its duration short, it is reasonable to use macroscopic concepts such as vibrational temperature, melting and flow to describe spike effects.

Donnelly, S. E.; Birtcher, R. C.; Materials Science Division; Univ. of Salford

1999-01-01

430

Metallic atoms and ions in comets: Comet Halley 1986 3  

NASA Technical Reports Server (NTRS)

The origin of metallic atoms and ions in the cometary comae is investigated theoretically. Two effects are revealed in the comas of bright comets: (1) the Na anomalous type effect is possible within the gas-dust jets of comet P/Halley 1986 3 due to cooling cometary dust by cryogenic gas flow from the nucleus; and (2) the production of ions of refractory elements (Fe(+), Si(+), etc.) at large heliocentric distances is possible in the comas of the Halley type dusty comets due to high-velocity impacts between cometary and zodiacal dust particles. Spectral observations of comets with high sensitivity and spatial resolution are important for studying both comets and interplanetary dust.

Ibadov, S.

1992-01-01

431

High-resolution mass spectrometer for liquid metal ion sources.  

PubMed

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(6)-10(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. PMID:24089821

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

2013-09-01

432

Another look at equatorial metallic ions in the F region  

NASA Technical Reports Server (NTRS)

An extensive survey is made of the equatorial occurrences of the Fe+ ion as detected by the ion mass spectrometer on the Atmospheric Explorer E. The longest time period (4 years) data base available for the study of the equatorial metallic ion distributions is considered, as well as Fe+ concentrations exceeding 10, 30, and 100 per cubic cm. The number of occurrences in the F region are most frequent at the dayside dip equator. Diurnally, the events are not appreciable in the F region until a few hours after dawn, reaching a maximum near noon followed by a secondary maximum in the afternoon. Near and after dusk the Fe+ ions extended on the average to higher altitudes than during the day and became less and less frequent from midnight to dawn. Seasonally, the distributions between 200 and 300 km are skewed away from the dip equator during the day with the maximum frequency of occurrence north (south) of the dip equator during a period centered on the December (June) solstice.

Grebowsky, J. M.; Reese, N.

1989-01-01

433