WorldWideScience

Sample records for cobalt 59 target

  1. Structural variation study of cobalt nanoparticles synthesized by co-precipitation method using 59Co NMR

    Science.gov (United States)

    Manjunatha, M.; Kumar, Rajeev; B. M., Siddesh; Sahoo, Balaram; Damle, R.; Ramesh, K. P.

    2018-04-01

    We have synthesized cobalt nanoparticles using co-precipitation method. Further, the two phases of the cobalt is monitored by varying the synthesis parameters. 59Co NMR and XRD are used as characterization tools to study the phase variation in the cobalt samples. XRD and NMR results show a remarkable correlation in the two samples (Co-1 and Co-2). Co-2 has predominant fcc and hcp phases, whereas, Co-1 has fcc phase with lower amount of hcp. Both the samples show same saturation magnetization (Ms) but there is a remarkable difference in the phase composition. Thus, 59Co NMR appears to be a good tool to identify the phase purity of the ferromagnetic cobalt samples.

  2. Measurement for cobalt target activity and its axial distribution

    International Nuclear Information System (INIS)

    Li Xingyuan; Chen Zigen.

    1985-01-01

    Cobalt target activity and its axial distribution are measured in process of producing radioactive isotopes 60 Co by irradiation in HFETR. Cobalt target activity is obtained with measured data at 3.60 m and 4.60 m, relative axial distribution of cobalt target activity is obtained with one at 30 cm, and axial distribution of cobalt target activity(or specific activity) is obtained with both of data. The difference between this specific activity and measured result for 60 Co teletherapy sources in the end is less than +- 5%

  3. Cobalt

    International Nuclear Information System (INIS)

    Stolyarova, I.A.; Bunakova, N.Yu.

    1983-01-01

    The neutron-activation method for determining cobalt in rocks, polymetallic and iron ores and rockforming minerals at 2x10 -6 -5x10 -3 % content is developed. Cobalt determination is based on the formation under the effect of thermal neutrons of nuclear reactor of the 60 Co radioactive isotope by the 59 Co (n, γ) 60 Co reaction with radiation energy of the most intensive line of 1333 keV. Cobalt can be determined by the scheme of the multicomponent analysis from the sample with other elements. Co is determined in the solution after separation of all determinable by the scheme elements. The 60 Co intensity is measured by the mUltichannel gamma-spectrometer with Ge(Li)-detector

  4. A monocrystal of 59Co as a nuclear orientation thermometer in neutron experiments with oriented targets

    International Nuclear Information System (INIS)

    Fasoli, U.; Galeazzi, G.; Pavan, P.; Toniolo, D.; Zago, G.; Zannoni, R.

    1980-01-01

    An apparatus for measuring temperatures in the millikelvin region is described based on the 'deformation effect' on fast neutron transmission through an aligned 59 Co monocrystal, employing a 252 Cf pill as the neutron source. A statistical accuracy of a few percent in a few minutes is obtainable with a heat input of some tens of pW. The apparatus is suitable in neutron experiments with oriented targets when the gamma-ray background hinders the use of gamma-ray anisotropy thermometers. In these and similar cases, in which the temperature must be held constant for long periods, the large heat capacity of the cobalt sample is not a drawback. (orig.)

  5. Ligand field effects in the nuclear magnetic shielding of nitrogen-15 and cobalt-59 in bent nitrosyl complexes of cobalt(III)

    International Nuclear Information System (INIS)

    Duffin, P.A.; Larkworthy, L.F.; Mason, J.; Stephens, A.N.; Thompson, R.M.

    1987-01-01

    A range of square-pyramidal complexes of cobalt(III) with a bent apical nitrosyl ligand has been prepared and examined by 15 N and 59 Co NMR spectroscopy, in a study of nephelauxetic and spectrochemical effects at the metal and nitrogen nuclei in the bent Co-NO chromophore. The basal ligands in this comparison include dithiocarbamate, quadridentate Schiff base or porphine, and bis-chelating diamine or oximate, so as to give S 4 , S 2 N 2 , N 4 , OONN, or ONON coordination in the plane and a range of substituents in the chelate and phenylene rings. The shielding of both cobalt and nitrogen tends to decrease with decrease in the M(d) → π*(NO) back-bonding, as indicated by the MN and NO bond distances, the MNO angle and the NO stretching frequency. The shieldings decrease from sulfur to nitrogen to oxygen coligators and also with electron withdrawal by ring substituents (and vice versa), i.e. with decrease in the ligand field splitting and in the nephelauxetism of the coligands. These parallelisms of the cobalt and nitrogen shielding accord with the orbital theory that was developed to explain the bending of the MNO ligand and influences of the metal and coligands. Significant interdependence of spectrochemical and nephelauxetic effects at cobalt and nitrogen arises from the degree of overlap and similarity in energies of the frontier orbitals for the paramagnetic circulation at nitrogen [n(N) → π* (NO)] and at cobalt (d-d). 43 references, 5 figures, 2 tables

  6. Cobalt

    Science.gov (United States)

    Slack, John F.; Kimball, Bryn E.; Shedd, Kim B.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    Cobalt is a silvery gray metal that has diverse uses based on certain key properties, including ferromagnetism, hardness and wear-resistance when alloyed with other metals, low thermal and electrical conductivity, high melting point, multiple valences, and production of intense blue colors when combined with silica. Cobalt is used mostly in cathodes in rechargeable batteries and in superalloys for turbine engines in jet aircraft. Annual global cobalt consumption was approximately 75,000 metric tons in 2011; China, Japan, and the United States (in order of consumption amount) were the top three cobalt-consuming countries. In 2011, approximately 109,000 metric tons of recoverable cobalt was produced in ores, concentrates, and intermediate products from cobalt, copper, nickel, platinum-group-element (PGE), and zinc operations. The Democratic Republic of the Congo (Congo [Kinshasa]) was the principal source of mined cobalt globally (55 percent). The United States produced a negligible amount of byproduct cobalt as an intermediate product from a PGE mining and refining operation in southeastern Montana; no U.S. production was from mines in which cobalt was the principal commodity. China was the leading refiner of cobalt, and much of its production came from cobalt ores, concentrates, and partially refined materials imported from Congo (Kinshasa).The mineralogy of cobalt deposits is diverse and includes both primary (hypogene) and secondary (supergene) phases. Principal terrestrial (land-based) deposit types, which represent most of world’s cobalt mine production, include primary magmatic Ni-Cu(-Co-PGE) sulfides, primary and secondary stratiform sediment-hosted Cu-Co sulfides and oxides, and secondary Ni-Co laterites. Seven additional terrestrial deposit types are described in this chapter. The total terrestrial cobalt resource (reserves plus other resources) plus past production, where available, is calculated to be 25.5 million metric tons. Additional resources of

  7. Separation of iron and cobalt using 59Fe and 60Co by dialysis of polyvinylpyrrolidone-metal complexes: A greener approach

    International Nuclear Information System (INIS)

    Lahiri, Susanta; Sarkar, Soumi

    2007-01-01

    An environmentally benign method to separate iron and cobalt has been developed using a safe chemical, polyvinylpyrrolidone (PVP). The method involves dialysis of PVP-Fe and PVP-Co complexes against triple-distilled water. 59 Fe and 60 Co were used as radioactive tracers of iron and cobalt throughout the experiment. No other chemicals are required for clean separation of cobalt from iron. The optimum condition for separation has been obtained at pH 5 using 10% aqueous solution of PVP. The method is applicable from trace scale to macro-scale. Very high separation factors have been obtained

  8. Advantageous use of metallic cobalt in the target for pulsed laser deposition of cobalt-doped ZnO films

    Energy Technology Data Exchange (ETDEWEB)

    Ying, Minju, E-mail: mjying@bnu.edu.cn, E-mail: g.gehring@sheffield.ac.uk [Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH (United Kingdom); Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Blythe, Harry J.; Gerriu, Fatma M.; Fox, A. Mark; Gehring, Gillian A., E-mail: mjying@bnu.edu.cn, E-mail: g.gehring@sheffield.ac.uk [Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH (United Kingdom); Dizayee, Wala [Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH (United Kingdom); Department of Science, Salahaddin University, Erbil (Iraq); Heald, Steve M. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2016-08-15

    We investigate the magnetic properties of ZnCoO thin films grown by pulsed laser deposition (PLD) from targets made containing metallic Co or CoO precursors instead of the usual Co{sub 3}O{sub 4}. We find that the films grown from metallic Co precursors in an oxygen rich environment contain negligible amounts of Co metal and have a large magnetization at room temperature. Structural analysis by X-ray diffraction and magneto-optical measurements indicate that the enhanced magnetism is due, in part, from Zn vacancies that partially compensate the naturally occurring n-type defects. We conclude that strongly magnetic films of Zn{sub 0.95}Co{sub 0.05}O that do not contain metallic cobalt can be grown by PLD from Co-metal-precursor targets if the films are grown in an oxygen atmosphere.

  9. Cobalt-60 production in CANDU power reactors

    International Nuclear Information System (INIS)

    Slack, J.; Norton, J.L.; Malkoske, G.R.

    2003-01-01

    MDS Nordion has been supplying cobalt-60 sources to industry for industrial and medical purposes since 1946. These cobalt-60 sources are used in many market and product segments. The major application is in the health care industry where irradiators are used to sterilize single use medical products. These irradiators are designed and built by MDS Nordion and are used by manufacturers of surgical kits, gloves, gowns, drapes and other medical products. The irradiator is a large shielded room with a storage pool for the cobalt-60 sources. The medical products are circulated through the shielded room and exposed to the cobalt-60 sources. This treatment sterilizes the medical products which can then be shipped to hospitals for immediate use. Other applications for this irradiation technology include sanitisation of cosmetics, microbial reduction of pharmaceutical raw materials and food irradiation. The cobalt-60 sources are manufactured by MDS Nordion in their Cobalt Operations Facility in Kanata. More than 75,000 cobalt-60 sources for use in irradiators have been manufactured by MDS Nordion. The cobalt-60 sources are double encapsulated in stainless steel capsules, seal welded and helium leak tested. Each source may contain up to 14,000 curies. These sources are shipped to over 170 industrial irradiators around the world. This paper will focus on the MDS Nordion proprietary technology used to produce the cobalt-60 isotope in CANDU reactors. Almost 55 years ago MDS Nordion and Atomic Energy of Canada developed the process for manufacturing cobalt-60 at the Chalk River Labs, in Ontario, Canada. A cobalt-59 target was introduced into a research reactor where the cobalt-59 atom absorbed one neutron to become cobalt-60. Once the cobalt-60 material was removed from the research reactor it was encapsulated in stainless steel and seal welded using a Tungsten Inert Gas weld. The first cobalt-60 sources manufactured using material from the Chalk River Labs were used in cancer

  10. Transport of cobalt-60 industrial radiation sources

    Science.gov (United States)

    Kunstadt, Peter; Gibson, Wayne

    This paper will deal with safety aspects of the handling of Cobalt-60, the most widely used industrial radio-isotope. Cobalt-60 is a man-made radioisotope of Cobalt-59, a naturally occurring non radioactive element, that is made to order for radiation therapy and a wide range of industrial processing applications including sterilization of medical disposables, food irradiation, etc.

  11. The Targeted Antitumor Effects of C- PC/CMC-CD59sp Nanoparticles on HeLa Cells in Vitro and in Vivo.

    Science.gov (United States)

    Wang, Yujuan; Jiang, Liangqian; Yin, Qifeng; Liu, Huihui; Liu, Guoxiang; Zhu, Guoteng; Li, Bing

    2017-01-01

    The novel C-PC/CMC-CD59sp-NPs were made by carbocymethyl chitosan (CMC) loading C-phycocyanin (C-PC) with the lead of CD59 specific ligand peptide (CD59sp) for targeting, and the characteristics and targeted anti-tumor mechanism were explored in order to realize the targeted therapy of C-PC on the growth of HeLa cells both in vitro and vivo . The targeting nanoparticles were synthesized by ionic-gelation method, and the optimal condition was selected out by orthogonal analysis. The properties of nanoparticles were observed by laser particle analyzer and dynamic light scattering (DLS) and Fourier Transform Infrared Spectrometer (FTIR). The effects of nanoparticles on the proliferation of HeLa cells in vitro were assessed by MTT assay. The mice model with tumor was constructed by subcutaneous injection of HeLa cells into the left axilla of NU/NU mice. The weight of tumor and the spleen were tested. The expression quantities of cleaved caspase-3, Bcl-2 were determined by western blot and immunofluorescent staining. Results showed the morphology of the finally prepared nanoparticles was well distributed with a diameter distribution of 200±11.3 nm and zeta potential of -19.5±4.12mV. Under the guidance of CD59sp, the targeting nanoparticles could targetedly and efficiently arrive at the surface of HeLa cells, and had obvious inhibitory effect on HeLa cells proliferation both in vitro and vivo. Moreover, the nanoparticles could induce cell apoptosis by up-regulation of cleaved caspase-3 proteins expression, but down-regulation of Bcl-2 and cyclinD1 proteins. Our study provided a new idea for the research and development of marine drugs, and supplied a theoretical support for the target therapy of anticancer drug.

  12. Cobalt production in RAPS-1

    International Nuclear Information System (INIS)

    Krishnan, P.D.; Purandare, H.D.

    1978-01-01

    At present in RAPS-1 radioisotope Co 60 is produced by irradiating Co 59 in the adjusters which perform the function of regulation of reactivity, power and xenon override. But the manrem expenditure of the crew handling the charge and discharge of the adjusters is going to be prohibitively high. It is therefore proposed to irradiate Co 59 in the fuel channel positions. The physics optimisation study for such irradiation is presented. The burnup penalty and loss of power are estimated to produce the required quantity of Co 60 after optimising the number of cobalt pencils in a bundle and the positions of the cobalt producing channels in the reactor core. (author)

  13. Salicylic Acid Suppresses Jasmonic Acid Signaling Downstream of SCFCOI1-JAZ by Targeting GCC Promoter Motifs via Transcription Factor ORA59[C][W][OA

    Science.gov (United States)

    Van der Does, Dieuwertje; Leon-Reyes, Antonio; Koornneef, Annemart; Van Verk, Marcel C.; Rodenburg, Nicole; Pauwels, Laurens; Goossens, Alain; Körbes, Ana P.; Memelink, Johan; Ritsema, Tita; Van Wees, Saskia C.M.; Pieterse, Corné M.J.

    2013-01-01

    Antagonism between the defense hormones salicylic acid (SA) and jasmonic acid (JA) plays a central role in the modulation of the plant immune signaling network, but the molecular mechanisms underlying this phenomenon are largely unknown. Here, we demonstrate that suppression of the JA pathway by SA functions downstream of the E3 ubiquitin-ligase Skip-Cullin-F-box complex SCFCOI1, which targets JASMONATE ZIM-domain transcriptional repressor proteins (JAZs) for proteasome-mediated degradation. In addition, neither the stability nor the JA-induced degradation of JAZs was affected by SA. In silico promoter analysis of the SA/JA crosstalk transcriptome revealed that the 1-kb promoter regions of JA-responsive genes that are suppressed by SA are significantly enriched in the JA-responsive GCC-box motifs. Using GCC:GUS lines carrying four copies of the GCC-box fused to the β-glucuronidase reporter gene, we showed that the GCC-box motif is sufficient for SA-mediated suppression of JA-responsive gene expression. Using plants overexpressing the GCC-box binding APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) transcription factors ERF1 or ORA59, we found that SA strongly reduces the accumulation of ORA59 but not that of ERF1. Collectively, these data indicate that the SA pathway inhibits JA signaling downstream of the SCFCOI1-JAZ complex by targeting GCC-box motifs in JA-responsive promoters via a negative effect on the transcriptional activator ORA59. PMID:23435661

  14. Salicylic acid suppresses jasmonic acid signaling downstream of SCFCOI1-JAZ by targeting GCC promoter motifs via transcription factor ORA59.

    Science.gov (United States)

    Van der Does, Dieuwertje; Leon-Reyes, Antonio; Koornneef, Annemart; Van Verk, Marcel C; Rodenburg, Nicole; Pauwels, Laurens; Goossens, Alain; Körbes, Ana P; Memelink, Johan; Ritsema, Tita; Van Wees, Saskia C M; Pieterse, Corné M J

    2013-02-01

    Antagonism between the defense hormones salicylic acid (SA) and jasmonic acid (JA) plays a central role in the modulation of the plant immune signaling network, but the molecular mechanisms underlying this phenomenon are largely unknown. Here, we demonstrate that suppression of the JA pathway by SA functions downstream of the E3 ubiquitin-ligase Skip-Cullin-F-box complex SCF(COI1), which targets JASMONATE ZIM-domain transcriptional repressor proteins (JAZs) for proteasome-mediated degradation. In addition, neither the stability nor the JA-induced degradation of JAZs was affected by SA. In silico promoter analysis of the SA/JA crosstalk transcriptome revealed that the 1-kb promoter regions of JA-responsive genes that are suppressed by SA are significantly enriched in the JA-responsive GCC-box motifs. Using GCC:GUS lines carrying four copies of the GCC-box fused to the β-glucuronidase reporter gene, we showed that the GCC-box motif is sufficient for SA-mediated suppression of JA-responsive gene expression. Using plants overexpressing the GCC-box binding APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) transcription factors ERF1 or ORA59, we found that SA strongly reduces the accumulation of ORA59 but not that of ERF1. Collectively, these data indicate that the SA pathway inhibits JA signaling downstream of the SCF(COI1)-JAZ complex by targeting GCC-box motifs in JA-responsive promoters via a negative effect on the transcriptional activator ORA59.

  15. Cobalt-60 control in Ontario Hydro reactors

    International Nuclear Information System (INIS)

    Lacy, C.S.

    1988-01-01

    This paper discusses the impact of specifying reduced Cobalt-59 in the primary heat transport circuit materials of construction on the radiation fields developed around the primary circuit. An eight-fold reduction in steam generator radiation fields due to Cobalt-60 has been observed for two identical sets of reactors, one with and one without Cobalt-59 control. The comparison is between eight reactors at the Pickering Nuclear Generating Station (PNGS). Units 5 to 8 (PNGS-B) are identical to Units 1 to 4 (PNGS-A) except that PNGS-B has reduced impurity Cobalt-59 in the alloys of construction and a reduced use of stellite. The effects of chemistry control are also discussed

  16. Global gene expression profiling in human lung cells exposed to cobalt

    Energy Technology Data Exchange (ETDEWEB)

    Malard, V.; Berenguer, F.; Prat, O.; Ruat, S.; Steinmetz, G.; Quemeneur, E. [CEA VALRHO, Serv Biochim and Toxicol Nucl, DSV, iBEB, F-30207 Bagnols Sur Ceze (France)

    2007-06-06

    It has been estimated that more than 1 million workers in the United States are exposed to cobalt. Occupational exposure to {sup 59}Co occurs mainly via inhalation and leads to various lung diseases. Cobalt is classified by the IARC as a possible human carcinogen (group 2B). Although there is evidence for in vivo and in vitro toxicity, the mechanisms of cobalt-induced lung toxicity are not fully known. The purpose of this work was to identify potential signatures of acute cobalt exposure using a toxico-genomic approach. Data analysis focused on some cellular processes and protein targets that are thought to be relevant for carcinogenesis, transport and bio-marker research. Results: A time course transcriptome analysis was performed on A549 human pulmonary cells, leading to the identification of 85 genes which are repressed or induced in response to soluble 59 Co. A group of 29 of these genes, representing the main biological functions, was assessed by quantitative RT-PCR. The expression profiles of six of them were then tested by quantitative RT-PCR in a time-dependent manner and three modulations were confirmed by Western blotting. The 85 modulated genes include potential cobalt carriers (FBXL2, ZNT1, SLC12A5), tumor suppressors or transcription factors (MAZ, DLG1, MYC, AXL) and genes linked to the stress response (UBC, HSPCB, BN1P3L). We also identified nine genes coding for secreted proteins as candidates for bio-marker research. Of those, T1MP2 was found to be down-regulated and this modulation was confirmed, in a dose-dependent manner, at protein level in the supernatant of exposed cells. Conclusion: Most of these genes have never been described as related to cobalt stress and provide original hypotheses for further study of the effects of this metal ion on human lung epithelial cells. A putative bio-marker of cobalt toxicity was identified. (authors)

  17. Cobalt-60 production in CANDU reactors

    International Nuclear Information System (INIS)

    Ross, Michel; Lemire, Christian

    2002-01-01

    CANDU reactors can produce cobalt-60 very efficiently and with an interesting return on investment. This paper discusses what is needed to convert a CANDU reactor into a cobalt-60 producer: what are the different phases, the safety studies required, the physical modifications needed, and what is the minimum involvement of the utility owning the plant. The past ten years of experience of Hydro-Quebec as a cobalt-60 producer will be reviewed, including the management of the risk of both incident and electricity generation loss, and including the benefits for the utility and its personnel. Originally a simple metal used for centuries as a pigment, cobalt-59 today is transformed into cobalt-60, a radioactive element of unprecedented value. Well known in medicine for cancer treatment, cobalt-60 is also used to sterilize a wide range of disposable medical products used in hospitals and to sanitize pharmaceutical and cosmetic products. Cobalt-60 is proving to be a new and effective solution, in the food sector, for preserving harvests and controlling food-borne diseases, or to advantageously replace certain gases and chemical products which are suspected of being harmful or carcinogenic. There are also other applications, such as: hardening of some plastics, treatment of sewage sludge and elimination of harmful insect populations. With a half-life of 5,3 years, cobalt-60 is a metal not found in nature. It is a radioactive isotope produced by exposing stable nuclei of cobalt-59 to neutrons. One of the best places to find such an important neutron source is a nuclear reactor. High energy gamma rays are then emitted during the process of radioactive decay, where cobalt-60 seeks again its stable state

  18. The cytotoxicity and genotoxicity of soluble and particulate cobalt in human lung fibroblast cells

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Leah J.; Holmes, Amie L. [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Maine Center for Environmental Toxicology and Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Kandpal, Sanjeev Kumar; Mason, Michael D. [Department of Chemical and Biological Engineering, University of Maine, Orono, ME (United States); Zheng, Tongzhang [Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT (United States); Wise, John Pierce, E-mail: John.Wise@usm.maine.edu [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Maine Center for Environmental Toxicology and Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States)

    2014-08-01

    Cobalt exposure is increasing as cobalt demand rises worldwide due to its use in enhancing rechargeable battery efficiency, super-alloys, and magnetic products. Cobalt is considered a possible human carcinogen with the lung being a primary target. However, few studies have considered cobalt-induced toxicity in human lung cells. Therefore, in this study, we sought to determine the cytotoxicity and genotoxicity of particulate and soluble cobalt in human lung cells. Cobalt oxide and cobalt chloride were used as representative particulate and soluble cobalt compounds, respectively. Exposure to both particulate and soluble cobalt induced a concentration-dependent increase in cytotoxicity, genotoxicity, and intracellular cobalt ion levels. Based on intracellular cobalt ion levels, we found that soluble cobalt was more cytotoxic than particulate cobalt while particulate and soluble cobalt induced similar levels of genotoxicity. However, soluble cobalt induced cell cycle arrest indicated by the lack of metaphases at much lower intracellular cobalt concentrations compared to cobalt oxide. Accordingly, we investigated the role of particle internalization in cobalt oxide-induced toxicity and found that particle-cell contact was necessary to induce cytotoxicity and genotoxicity after cobalt exposure. These data indicate that cobalt compounds are cytotoxic and genotoxic to human lung fibroblasts, and solubility plays a key role in cobalt-induced lung toxicity. - Highlights: • Particulate and soluble cobalt are cytotoxic and genotoxic to human lung cells. • Soluble cobalt induces more cytotoxicity compared to particulate cobalt. • Soluble and particulate cobalt induce similar levels of genotoxicity. • Particle-cell contact is required for particulate cobalt-induced toxicity.

  19. Feasibility Study for Cobalt Bundle Loading to CANDU Reactor Core

    International Nuclear Information System (INIS)

    Park, Donghwan; Kim, Youngae; Kim, Sungmin

    2016-01-01

    CANDU units are generally used to produce cobalt-60 at Bruce and Point Lepreau in Canada and Embalse in Argentina. China has started production of cobalt-60 using its CANDU 6 Qinshan Phase III nuclear power plant in 2009. For cobalt-60 production, the reactor’s full complement of stainless steel adjusters is replaced with neutronically equivalent cobalt-59 adjusters, which are essentially invisible to reactor operation. With its very high neutron flux and optimized fuel burn-up, the CANDU has a very high cobalt-60 production rate in a relatively short time. This makes CANDU an excellent vehicle for bulk cobalt-60 production. Several studies have been performed to produce cobalt-60 using adjuster rod at Wolsong nuclear power plant. This study proposed new concept for producing cobalt-60 and performed the feasibility study. Bundle typed cobalt loading concept is proposed and evaluated the feasibility to fuel management without physics and system design change. The requirement to load cobalt bundle to the core was considered and several channels are nominated. The production of cobalt-60 source is very depend on the flux level and burnup directly. But the neutron absorption characteristic of cobalt bundle is too high, so optimizing design study is needed in the future

  20. Feasibility Study for Cobalt Bundle Loading to CANDU Reactor Core

    Energy Technology Data Exchange (ETDEWEB)

    Park, Donghwan; Kim, Youngae; Kim, Sungmin [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    CANDU units are generally used to produce cobalt-60 at Bruce and Point Lepreau in Canada and Embalse in Argentina. China has started production of cobalt-60 using its CANDU 6 Qinshan Phase III nuclear power plant in 2009. For cobalt-60 production, the reactor’s full complement of stainless steel adjusters is replaced with neutronically equivalent cobalt-59 adjusters, which are essentially invisible to reactor operation. With its very high neutron flux and optimized fuel burn-up, the CANDU has a very high cobalt-60 production rate in a relatively short time. This makes CANDU an excellent vehicle for bulk cobalt-60 production. Several studies have been performed to produce cobalt-60 using adjuster rod at Wolsong nuclear power plant. This study proposed new concept for producing cobalt-60 and performed the feasibility study. Bundle typed cobalt loading concept is proposed and evaluated the feasibility to fuel management without physics and system design change. The requirement to load cobalt bundle to the core was considered and several channels are nominated. The production of cobalt-60 source is very depend on the flux level and burnup directly. But the neutron absorption characteristic of cobalt bundle is too high, so optimizing design study is needed in the future.

  1. Cobalt reduction of NSSS valve hardfacings for ALARA

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joo Hak; Lee, Sang Sub [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-07-01

    This report informs NSSS designer that replacement of materials is one of the major means of ALARA implementation, and describes that NSSS valves with high-cobalt hardfacing are significant contributors to post-shutdown radiation fields caused by activation of cobalt-59 to cobalt-60. Generic procedures for implementing cobalt reduction programs for valves are presented. Discussions are presented of the general and specific design requirements for valve hardfacing in nuclear service. The nuclear safety issues involved with changing valve hardfacing materials are discussed. The common methods used to deposit hardfacing materials are described together with an explanation of the wear measurements. Wear resistance, corrosion resistance, friction coefficient, and mechanical properties of candidate hardfacing alloys are given. World-wide nuclear utility experience with cobalt-free hardfacing alloys is described. The use of low-cobalt or cobalt-free alloys in other nuclear plant components is described. 17 figs., 38 tabs., 18 refs. (Author).

  2. Cobalt reduction of NSSS valve hardfacings for ALARA

    International Nuclear Information System (INIS)

    Kim, Joo Hak; Lee, Sang Sub

    1994-07-01

    This report informs NSSS designer that replacement of materials is one of the major means of ALARA implementation, and describes that NSSS valves with high-cobalt hardfacing are significant contributors to post-shutdown radiation fields caused by activation of cobalt-59 to cobalt-60. Generic procedures for implementing cobalt reduction programs for valves are presented. Discussions are presented of the general and specific design requirements for valve hardfacing in nuclear service. The nuclear safety issues involved with changing valve hardfacing materials are discussed. The common methods used to deposit hardfacing materials are described together with an explanation of the wear measurements. Wear resistance, corrosion resistance, friction coefficient, and mechanical properties of candidate hardfacing alloys are given. World-wide nuclear utility experience with cobalt-free hardfacing alloys is described. The use of low-cobalt or cobalt-free alloys in other nuclear plant components is described. 17 figs., 38 tabs., 18 refs. (Author)

  3. Cobalt-60 production in CANDU power reactors

    International Nuclear Information System (INIS)

    Malkoske, G.R.; Norton, J.L.; Slack, J.

    2002-01-01

    elements in the core. For cobalt-60 production, the reactor's full complement of stainless steel adjusters is replaced with neutronically equivalent cobalt-59 adjusters, which are essentially invisible to reactor operation. With its very high neutron flux and optimized fuel bum-up, the CANDU has a very high cobalt-60 production rate in a relatively short time. This makes CANDU an excellent vehicle for bulk cobalt-60 production. (author)

  4. Cobalt release from inexpensive jewellery

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Jellesen, Morten Stendahl; Menné, Torkil

    2010-01-01

    . Conclusions: This study showed that only a minority of inexpensive jewellery purchased in Denmark released cobalt when analysed with the cobalt spot test. As fashion trends fluctuate and we found cobalt release from dark appearing jewellery, cobalt release from consumer items should be monitored in the future......Objectives: The aim was to study 354 consumer items using the cobalt spot test. Cobalt release was assessed to obtain a risk estimate of cobalt allergy and dermatitis in consumers who would wear the jewellery. Methods: The cobalt spot test was used to assess cobalt release from all items...

  5. Cobalt sensitization and dermatitis

    DEFF Research Database (Denmark)

    Thyssen, Jacob P

    2012-01-01

    : This clinical review article presents clinical and scientific data on cobalt sensitization and dermatitis. It is concluded that cobalt despite being a strong sensitizer and a prevalent contact allergen to come up on patch testing should be regarded as a very complex metal to test with. Exposure...

  6. Elicitation threshold of cobalt chloride

    DEFF Research Database (Denmark)

    Fischer, Louise A; Johansen, Jeanne D; Voelund, Aage

    2016-01-01

    : On the basis of five included studies, the ED10 values of aqueous cobalt chloride ranged between 0.0663 and 1.95 µg cobalt/cm(2), corresponding to 30.8-259 ppm. CONCLUSIONS: Our analysis provides an overview of the doses of cobalt that are required to elicit allergic cobalt contactdermatitis in sensitized...

  7. Detection of {sup 59}Ni by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Per; Erlandsson, Bengt; Freimann, K.; Hellborg, R.; Stenstroem, K. [Lund Univ. (Sweden). Dept. of Nuclear Physics; Larsson, Ragnar [Lund Univ. (Sweden). Chemical Engineering II; Skog, G. [Lund Univ. (Sweden). Dept. of Quaternary Geology

    1999-02-01

    The aims of this project were to develop a method to measure the amount of {sup 59}Ni in stainless steel and to determine the detection limit for this method. {sup 59}Ni is produced by neutron activation in the construction material close to the core in a nuclear reactor and it is important to know the amount of {sup 59}Ni present as it governs the classification of the waste. If the amount of {sup 59}Ni is known at different locations in relation to the core, it is also possible to refine the calculation models of the neutron flux in the reactor. Accelerator mass spectrometry, an ultra-sensitive method for measuring small concentrations of radionuclides as well as stable nuclides, has been used in this investigation to determine the concentration of {sup 59}Ni (and thereby the activity) in stainless steel. As the cobalt content in stainless steel is the main contributor to the background in a measurement of {sup 59}Ni, a method for the chemical extraction of nickel from stainless steel, including a purification step to reduce the cobalt content in the sample, has been developed. The detection limit for {sup 59}Ni has been determined to 100{+-}30 Bq per gram nickel (100{+-}30 Bq/g) with the present status of the system 14 refs, 6 figs, 3 tabs

  8. Detection of 59Ni by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Persson, Per; Erlandsson, Bengt; Freimann, K.; Hellborg, R.; Stenstroem, K.; Larsson, Ragnar; Skog, G.

    1999-02-01

    The aims of this project were to develop a method to measure the amount of 59 Ni in stainless steel and to determine the detection limit for this method. 59 Ni is produced by neutron activation in the construction material close to the core in a nuclear reactor and it is important to know the amount of 59 Ni present as it governs the classification of the waste. If the amount of 59 Ni is known at different locations in relation to the core, it is also possible to refine the calculation models of the neutron flux in the reactor. Accelerator mass spectrometry, an ultra-sensitive method for measuring small concentrations of radionuclides as well as stable nuclides, has been used in this investigation to determine the concentration of 59 Ni (and thereby the activity) in stainless steel. As the cobalt content in stainless steel is the main contributor to the background in a measurement of 59 Ni, a method for the chemical extraction of nickel from stainless steel, including a purification step to reduce the cobalt content in the sample, has been developed. The detection limit for 59 Ni has been determined to 100±30 Bq per gram nickel (100±30 Bq/g) with the present status of the system

  9. Systematic continuum-discretized coupled-channels calculations of total fusion for 6Li with targets 28Si, 59Co, 96Zr, 198Pt, and 209Bi: Effect of resonance states

    Science.gov (United States)

    Gómez Camacho, A.; Wang, Bing; Zhang, H. Q.

    2018-05-01

    Continuum discretized coupled-channel (CDCC) calculations of total fusion cross sections for reactions induced by the weakly bound nucleus 6Li with targets 28Si, 59Co, 96Zr, 198Pt, and 209Bi at energies around the Coulomb barrier are presented. In the cluster structure frame of 6Li→α +d , short-range absorption potentials are considered for the interactions between the α and d fragments with the targets. The effect of resonance (l =2 , Jπ=3+,2+,1+ ) and nonresonance states of 6Li on fusion is studied by using two approaches: (1) by omitting the resonance states from the full discretized CDCC breakup space and (2) by considering only the resonance subspace. A systematic analysis of the effect on fusion from resonance breakup couplings is carried out from light to heavy mass targets. Among other things, it is found that resonance breakup states produce strong repulsive polarization potentials that lead to fusion suppression. Couplings from nonresonance states give place to weak repulsive potentials at high energies; however, these become attractive for the heavier targets at low energies.

  10. Green methods for the radiochemical separations of no-carrier-added 61Cu, 62Zn from 7Li irradiated cobalt target

    International Nuclear Information System (INIS)

    Moumita Maiti; Kaustab Ghosh; Susanta Lahiri

    2015-01-01

    A nat Co target was irradiated with 47 MeV 7 Li beam to produce no-carrier-added 61 Cu, 62 Zn in the target matrix. Two new green radiochemical methods were developed for separation of 61 Cu and 62 Zn from the target matrix, (i) liquid-liquid extraction (LLX) technique using room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium hexafluorophosphate ([C 4 mim][PF 6 ]) and ammonium pyrrolidinedithiocarbamate (APDC) (ii) adsorption on calcium alginate beads. (author)

  11. A novel method to synthesize cobalt oxide (Co3O4) nanowires from cobalt (Co) nanobowls

    DEFF Research Database (Denmark)

    Srivastava, Akhilesh Kumar; Madhavi, S.; Ramanujan, R.V.

    2010-01-01

    A novel method suitable for the synthesis of the cobalt oxide (Co3O4) nanowires at targeted regions is presented in this report. Cobalt (Co) nanobowls synthesized by colloidal crystal directed assembly were transformed into Co3O4 nanowires by a simple heat treatment process. Co nanobowls exhibited...... a two phase (h.c.p. + f.c.c.) microstructure while single phase microstructure was observed for Co3O4 nanowires. Ferromagnetic Co nanobowls showed a dependence of coercivity on bowl size while Co3O4 exhibited weak ferromagnetic behavior....

  12. cobalt (ii), nickel (ii)

    African Journals Online (AJOL)

    DR. AMINU

    Department of Chemistry Bayero University, P. M. B. 3011, Kano, Nigeria. E-mail: hnuhu2000@yahoo.com. ABSTRACT. The manganese (II), cobalt (II), nickel (II) and .... water and common organic solvents, but are readily soluble in acetone. The molar conductance measurement [Table 3] of the complex compounds in.

  13. Sputtering on cobalt with noble gas ions

    International Nuclear Information System (INIS)

    Sarholt-Kristensen, L.; Johansen, A.; Johnson, E.

    1983-01-01

    Single crystals of cobalt have been bombarded with 80 keV Ar + ions and with 80 keV and 200 keV Xe + ions in the [0001] direction of the hcp phase and the [111] direction of the fcc phase. The sputtering yield has been measured as function of target temperature (20 0 C-500 0 C), showing a reduction in sputtering yield for 80 keV Ar + ions and 200 keV Xe + ions, when the crystal structure changes from hcp to fcc. In contrast to this, bombardment with 80 keV Xe + ions results in an increase in sputtering yield as the phase transition is passed. Sputtering yields for [111] nickel are in agreement with the sputtering yields for fcc cobalt indicating normal behaviour of the fcc cobalt phase. The higher sputtering yield of [0001] cobalt for certain combinations of ion mass and energy may then be ascribed to disorder induced partly by martensitic phase transformation, partly by radiation damage. (orig.)

  14. Calculation support for industrial production of cobalt-60 at Leningrad NPP

    International Nuclear Information System (INIS)

    Artemov, Vladimir; Elshin, Alexander; Ivanov, Alexander; Gorbunov, Evgeny; Ikonnikov, Roman; Pimenov, Alexander

    2008-01-01

    Cobalt-60 is industrially produced at the Leningrad NPP by irradiation of cobalt-59 in special-purpose facilities loaded into the RBMK reactor core (all 4 units). The paper describes calculation methods used to determine the current activity of cobalt in irradiation assemblies for their timely unloading. The described peculiarities of core calculation model account for continuous refueling, overloading of irradiation assemblies and individual thermohydraulics in each channel under variation of reactor power. Fuel burnup in the core is calculated with a time step of about 24 hours. The resulting values for cobalt activity and uncertainties are presented in the paper as well. Deviation of calculated cobalt activity from measured activity is within the experimental accuracy of 10% (at confidence probability of 0.95). (authors)

  15. Analysis of radioactive cobalt

    International Nuclear Information System (INIS)

    1977-01-01

    This is a manual published by Science and Technology Agency, Japan, which prescribes on the analysis method for radioactive cobalt which is a typical indexing nuclide among the radioactive nuclides released from nuclear facilities. Since the released cobalt is mainly discharged to coastal region together with waste water, this manual is written for samples of sea water, sea bottom sediments and marine organisms. Radioactive cobalt includes the nuclides of 57 co, 58 Co, 60 Co, etc., the manual deals with them as a whole as 60 Co of long half life. Though 60 Co analysis has become feasible comparatively simply due to scintillation or semi-conductor spectrometry, trace 60 Co analysis is performed quantitatively by co-precipitation or collection into alumina and scintillation spectrometry. However, specific collecting operation and γ-γ coincidence measurement have been required so far. This manual employs 60 Co collection by means of ion-exchange method and measurement with low background GM counting system, to analyze quantitatively and rapidly low level 60 Co. It is primarily established as the standard analyzing method for the survey by local autonomous bodies. It is divided into 4 chapters including introduction sea water, marine organisms, and sea bottom sediments. List of required reagents is added in appendix. (Wakatsuki, Y.)

  16. Deformation effect in the fast neutron total cross section of aligned /sup 59/Co

    Energy Technology Data Exchange (ETDEWEB)

    Fasoli, U.; Pavan, P.; Toniolo, D.; Zago, G.; Zannoni, R.; Galeazzi, G.

    1982-07-19

    The variation of the total neutron cross section, ..delta.. sigma/sub align/, on /sup 59/Co due to nuclear alignment of the target in the beam direction, has been measured over the energy range from 0.8 to 20 MeV, employing a cobalt single-crystal with a 34% nuclear alignment degree. The results show that ..delta.. sigma/sub align/ oscillates from a minimum of -5% at about 2.5 MeV to a maximum of +1% at about 10 MeV. The data were successfully fitted by optical model coupled-channel calculations. The coupling terms were deduced from a model representing the /sup 59/Co nucleus as a virbrational /sup 60/Ni core coupled to a proton-hole in a (lf 7/2) shell, without free parameters. The optical model parameters were determined by fitting the total cross-section independently measured. The theoretical calculations show that, at lower energies, ..delta.. sigma/sub align/ depends appreciably on the coupling with the low-lying levels.

  17. Deformation effect in the fast neutron total cross section of alligned 59Co

    International Nuclear Information System (INIS)

    Fasoli, U.; Pavan, P.; Toniolo, D.; Zago, G.; Zannoni, R.; Galeazzi, G.

    1982-01-01

    The variation of the total neutron cross section, DELTAsigmasub(align), on 59 Co due to nuclear alignement of the target in the beam direction, has been measured over the energy range from 0.8 to 20 MeV, emploing a cobalt single-crystal with a 34% nuclear alignment degree. The results show that DELTAsigmasub(align) oscillates from a minimum of -5% at about 2.5 MeV to a maximum of +1% at about 10 MeV. The data were succesfully fitted by optical model coupled-channel calculations. The coupling terms were deduced from a model representing the 59 Co nucleus as a vibrational 60 Ni core coupled to a proton hole in a (lf7/2) shell, without free parameters. The optical model parameters were determined by fitting the total cross section independently measured. The theoretical calculations show that, at lower energies, DELTAsigmasub(align) depends appreciably on the coupling with the low-liyng levels

  18. Deformation effect in the fast neutron total cross section of aligned 59Co

    International Nuclear Information System (INIS)

    Fasoli, U.; Pavan, P.; Toniolo, D.; Zago, G.; Zannoni, R.; Galeazzi, G.

    1983-01-01

    The variation of the total neutron cross section, Δsigma/sub align/, on 59 Co due to nuclear alignment of the target has been measured over the energy range from 0.8 to 20 MeV employing a cobalt single crystal with a 34% nuclear alignment. The results show that Δsigma/sub align/ oscillates from a minimum of -5% at about 2.5 MeV to a maximum of +1% at about 10 MeV. The data were successfully fitted by optical model coupled-channel calculations. The coupling terms were deduced from a model representing the 59 Co nucleus as a vibrational 60 Ni core coupled to a proton hole in a (1f/sub 7/2/) shell, without free parameters. The optical model parameters were determined by fitting the total cross section, which was independently measured. The theoretical calculations show that, at lower energies, Δsigma/sub align/ depends appreciably on the coupling with the low-lying levels

  19. Heating analysis of cobalt adjusters in reactor core

    International Nuclear Information System (INIS)

    Mei Qiliang; Li Kang; Fu Yaru

    2011-01-01

    In order to produce 60 Co source for industry and medicine applications in CANDU-6 reactor, the stainless steel adjusters were replaced with the cobalt adjusters. The cobalt rod will generate the heat when it is irradiated by neutron and γ ray. In addition, 59 Co will be activated and become 60 Co, the ray released due to 60 Co decay will be absorbed by adjusters, and then the adjusters will also generate the heat. So the heating rate of adjusters to be changed during normal operation must be studied, which will be provided as the input data for analyzing the temperature field of cobalt adjusters and the relative heat load of moderator. MCNP code was used to simulate whole core geometric configuration in detail, including reactor fuel, control rod, adjuster, coolant and moderator, and to analyze the heating rate of the stainless steel adjusters and the cobalt adjusters. The maximum heating rate of different cobalt adjuster based on above results will be provided for the steady thermal hydraulic and accident analysis, and make sure that the reactor is safe on the thermal hydraulic. (authors)

  20. Blood doping by cobalt. Should we measure cobalt in athletes?

    Directory of Open Access Journals (Sweden)

    Guidi Gian

    2006-07-01

    Full Text Available Abstract Background Blood doping is commonplace in competitive athletes who seek to enhance their aerobic performances through illicit techniques. Presentation of the hypothesis Cobalt, a naturally-occurring element with properties similar to those of iron and nickel, induces a marked and stable polycythemic response through a more efficient transcription of the erythropoietin gene. Testing the hypothesis Although little information is available so far on cobalt metabolism, reference value ranges or supplementation in athletes, there is emerging evidence that cobalt is used as a supplement and increased serum concentrations are occasionally observed in athletes. Therefore, given the athlete's connatural inclination to experiment with innovative, unfair and potentially unhealthy doping techniques, cobalt administration might soon become the most suited complement or surrogate for erythropoiesis-stimulating substances. Nevertheless, cobalt administration is not free from unsafe consequences, which involve toxic effects on heart, liver, kidney, thyroid and cancer promotion. Implications of the hypothesis Cobalt is easily purchasable, inexpensive and not currently comprehended within the World Anti-Doping Agency prohibited list. Moreover, available techniques for measuring whole blood, serum, plasma or urinary cobalt involve analytic approaches which are currently not practical for antidoping laboratories. Thus more research on cobalt metabolism in athletes is compelling, along with implementation of effective strategies to unmask this potentially deleterious doping practice

  1. Nickel, cobalt, and their alloys

    CERN Document Server

    2000-01-01

    This book is a comprehensive guide to the compositions, properties, processing, performance, and applications of nickel, cobalt, and their alloys. It includes all of the essential information contained in the ASM Handbook series, as well as new or updated coverage in many areas in the nickel, cobalt, and related industries.

  2. Cobalt source calibration

    International Nuclear Information System (INIS)

    Rizvi, H.M.

    1999-01-01

    The data obtained from these tests determine the dose rate of the two cobalt sources in SRTC. Building 774-A houses one of these sources while the other resides in room C-067 of Building 773-A. The data from this experiment shows the following: (1) The dose rate of the No.2 cobalt source in Building 774-A measured 1.073 x 10 5 rad/h (June 17, 1999). The dose rate of the Shepherd Model 109 Gamma cobalt source in Building 773-A measured 9.27 x 10 5 rad/h (June 25, 1999). These rates come from placing the graduated cylinder containing the dosimeter solution in the center of the irradiation chamber. (2) Two calibration tests in the 774-A source placed the graduated cylinder with the dosimeter solution approximately 1.5 inches off center in the axial direction. This movement of the sample reduced the measured dose rate 0.92% from 1.083 x 10 5 rad/h to 1.073 x 10 5 rad/h. and (3) A similar test in the cobalt source in 773-A placed the graduated cylinder approximately 2.0 inches off center in the axial direction. This change in position reduced the measured dose rate by 10.34% from 1.036 x 10 6 to 9.27 x 10 5 . This testing used chemical dosimetry to measure the dose rate of a radioactive source. In this method, one determines the dose by the chemical change that takes place in the dosimeter. For this calibration experiment, the author used a Fricke (ferrous ammonium sulfate) dosimeter. This solution works well for dose rates to 10 7 rad/h. During irradiation of the Fricke dosimeter solution the Fe 2+ ions ionize to Fe 3+ . When this occurs, the solution acquires a slightly darker tint (not visible to the human eye). To determine the magnitude of the change in Fe ions, one places the solution in an UV-VIS Spectrophotometer. The UV-VIS Spectrophotometer measures the absorbency of the solution. Dividing the absorbency by the total time (in minutes) of exposure yields the dose rate

  3. Unithiol - a cobalt antidote

    International Nuclear Information System (INIS)

    Cherkes, A.I.; Braver-Chernobul'skaya, B.S.

    1977-06-01

    The blockade of the sulfhydryl groups of the proteins leads to a disturbance of the normal activity of many enzymes and thus of the functioning of the organs and tissue. The search for antidotes against these substances which inactivate the enzymes led to the synthesis of a large group of thiols in the Ukrainian Scientific Research Sanitary Chemical Institute. The most active is sodium dithiol-2,3-dimercaptonpropansulphonate CH 2 SH-CHSH-CH 2 SO 3 Na x H 2 O, named unithiol. Its antidote activity is discussed in detail, especially concerning cobalt intoxication. (HK) [de

  4. An analysis of cobalt irradiation in CANDU 6 reactor core

    International Nuclear Information System (INIS)

    Gugiu, E.D.; Dumitrache, I.

    2003-01-01

    In CANDU reactors, one has the ability to replace the stainless steel adjuster rods with neutronically equivalent Co assemblies with a minimum impact on the power plant safety and efficiency. The 60 Co produced by 59 Co irradiation is used extensively in medicine and industry. The paper mainly describes some of the reactor physics and safety requirements that must be carried into practice for the Co adjuster rods. The computations related to the neutronically equivalence of the stainless steel adjusters with the Co adjuster assemblies, as well as the estimations of the activity and the heating of the irradiated cobalt rods are performed using the Monte Carlo codes MCNP5 and MONTEBURNS2.1. The 60 Co activity and heating evaluations are closely related to the neutronics computations and to the density evolution of cobalt isotopes during assumed in-core irradiation period. Unfortunately, the activities of these isotopes could not be evaluated directly using the burn-up capabilities of the MONTEBURNS code because of the lack of their neutron cross-section from the MCNP5 code library. Additional MCNP5 runs for all the cobalt assemblies have been done in order to compute the flux-spectrum, the 59 Co and the 60 Co radiative capture reaction rates in the adjusters. The 60m Co cross-section was estimated using the flux-spectrum and the ORIGEN2.1 code capabilities THERM and RES. These computational steps allowed the evaluation of the one-group cross-section for the radiative capture reactions of cobalt isotopes. The values obtained replaced the corresponding ones from the ORIGEN library, which have been estimated using the flux-spectrum specific to the fuel. The activity values are used to evaluate the dose at the surface of the device designed to transport the cobalt adjusters. (authors)

  5. Investigations on the formation of cobalt thiomolybdates

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, S [Paraiba Univ., Joao Pessoa (Brazil). Dept. de Engenharia Quimica

    1984-06-01

    The reactions between Co/sup 2 +/ and different thiomolybdate anions (MoS/sup 2 -//sub 4/, Mo/sub 4/S/sup 6 -//sub 15/, Mo/sub 2/S/sup 2 -//sub 7/ and Mo/sub 4/S/sup 2 -//sub 13/) have been investigated by means of glass electrode and conductometric titrations between the reactants at several concentrations. The results provide definite evidence for the formation of CoS.MoS/sub 3/ and 3CoS.4MoS/sub 3/ around pH 7.1 and 5.9, respectively. The titrations of cobalt chloride with Na/sub 2/S.2MoS/sub 3/ and Na/sub 2/S.4MoS/sub 3/ failed to provide any dependable results for the formation of the corresponding cobalt thiomolybdates. The accuracy and reproducibility of these titrations are of high order. Analytical investigations of these compounds have also been carried out and substantiate the results of the pH and conductometric measurements.

  6. Radio cobalt in French rivers

    International Nuclear Information System (INIS)

    Lambrechts, A.; Baudin-Jaulent, Y.

    1996-01-01

    The isotopes 58 and 60 of cobalt present in liquid wastes from nuclear plants or from fuel reprocessing plant of Marcoule are fixed in the different compartments of French rivers. The activity levels of radio-cobalt vary according to the sampled compartments nature (bryophyta > immersed plants > sediment > fish). Elsewhere, laboratory experimentations show that the contamination of fish occurs essentially from the water way rather than from food. Cobalt is mainly fixed by kidneys; muscles is no more than 30 % of the total fish activity. (author)

  7. Optical Coherence Tomography Substudy of A Prospective Multicenter Randomized Post-Market Trial to Assess the Safety and Effectiveness of the Firehawk™ Rapamycin Target Eluting Cobalt Chromium Coronary Stent System for the Treatment of Atherosclerotic Lesions: TARGET All Comers.

    Science.gov (United States)

    Baumbach, Andreas; Lansky, Alexandra J; Onuma, Yoshi; Asano, Taku; Johnson, Thomas; Anderson, Richard; Kiemeneij, Ferdinand; Zheng, Ming; Van Royen, Niels; Slagboom, Ton; Vlachojannis, Georg; Xu, Bo; Serruys, Patrick; Wijns, William

    2018-06-12

    Durable polymer drug-eluting stents (DP DES) may contribute to persistent inflammation, delayed endothelial healing and subsequent late DES thrombosis. The aim of this Optical Coherence Tomography (OCT) sub-study was to compare healing and neointimal coverage of a novel bioabsorbable polymer sirolimus-eluting stent (FIREHAWK®) (BP DES) versus the DP DES (XIENCE) at 90 days in an all comers patient population. The TARGET All Comers study is a prospective multicenter randomised post-market trial of 1656 patients randomised 1:1 to FIREHAWK or XIENCE at 21 centers in 10 European countries. The TARGET OCT sub-study enrolled 36 consecutive patients with 52 lesions at 6 centers proficient in OCT. Follow-up OCT was performed at 3 months or prior to revascularisation when occurring before the 3-month window. The substudy was designed for non-inferiority of the primary endpoint of neointimal thickness. At follow-up, the mean neointimal thickness by OCT (52 lesions, Firehawk, n=24; Xience, n=28), was not significantly different between groups (Firehawk 75.5μm vs Xience V 82.3 μm) meeting the primary endpoint of non-inferiority (Pnoninferiority<0.001). The percentage of stent strut coverage was high in both groups (strut level: 99.9% ± 0.3 vs 100% ± 0.1, p=0.26), and the proportion of malapposed struts (1.0±1.6% vs. 1.2±2.0%, p=0.51) was low in both groups. Based on OCT, the FIREHAWK BP DES has a similar healing response 3 months after implantation compared to the DP DES, with near complete strut coverage, moderate neointima formation and minimal strut malapposition.

  8. Investigation of the production of cobalt-60 via particle accelerator

    Directory of Open Access Journals (Sweden)

    Artun Ozan

    2017-01-01

    Full Text Available The production process of cobalt-60 was simulated by a particle accelerator in the energy range of 5 to 100 MeV, particle beam current of 1 mA, and irradiation time of 1 hour to perform yield, activity of reaction, and integral yield for charged particle-induced reactions. Based on nuclear reaction processes, the obtained results in the production process of cobalt-60 were also discussed in detail to determine appropriate target material, optimum energy ranges, and suitable reactions.

  9. Cobalt: for strength and color

    Science.gov (United States)

    Boland, Maeve A.; Kropschot, S.J.

    2011-01-01

    Cobalt is a shiny, gray, brittle metal that is best known for creating an intense blue color in glass and paints. It is frequently used in the manufacture of rechargeable batteries and to create alloys that maintain their strength at high temperatures. It is also one of the essential trace elements (or "micronutrients") that humans and many other living creatures require for good health. Cobalt is an important component in many aerospace, defense, and medical applications and is a key element in many clean energy technologies. The name cobalt comes from the German word kobold, meaning goblin. It was given this name by medieval miners who believed that troublesome goblins replaced the valuable metals in their ore with a substance that emitted poisonous fumes when smelted. The Swedish chemist Georg Brandt isolated metallic cobalt-the first new metal to be discovered since ancient times-in about 1735 and identified some of its valuable properties.

  10. Cobalt release from implants and consumer items and characteristics of cobalt sensitized patients with dermatitis

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Menne, Torkil; Liden, Carola

    2012-01-01

    -containing dental alloys and revised hip implant components.Results. Six of eight dental alloys and 10 of 98 revised hip implant components released cobalt in the cobalt spot test, whereas none of 50 mobile phones gave positive reactions. The clinical relevance of positive cobalt test reactions was difficult......-tested dermatitis patients in an attempt to better understand cobalt allergy.Materials and methods. 19 780 dermatitis patients aged 4-99 years were patch tested with nickel, chromium or cobalt between 1985 and 2010. The cobalt spot test was used to test for cobalt ion release from mobile phones as well as cobalt...

  11. Model for cobalt 60/58 deposition on primary coolant piping in a boiling water reactor

    International Nuclear Information System (INIS)

    Dehollander, W.R.

    1979-01-01

    A first principles model for deposition of radioactive metals into the corrosion films of primary coolant piping is proposed. It is shown that the predominant mechanism is the inclusion of the radioactive species such as Cobalt 60 into the spinel structure of the corrosion film during the act of active corrosion. This deposition can occupy only a defined fraction of the available plus 2 valence sites of the spinel. For cobalt ions, this ratio is roughly 4.6 x 10 -3 of the total iron sites. Since no distinction is made between Cobalt 60, Cobalt 58, and Cobalt 59 in this process, the radioactivity associated with this inclusion is a function of the ratio of the radioactive species to the nonradioactive species in the water causing the corrosion of the pipe metal. The other controlling parameter is the corrosion rate of the pipe material. This can be a function of time, for example, and it shown that freshly descaled metal when exposed to the cobalt containing water can incorporate as much as 10 x 10 -3 cobalt ions per iron atom in the initial corrosion period. This has implications for the problem of decontaminating nuclear reactor piping. Equations and selected observations are presented without reference to any specifically identified reactor or utility, so as to protect any proprietary interest

  12. Electroplated zinc-cobalt alloy

    International Nuclear Information System (INIS)

    Carpenter, D.E.O.S.; Farr, J.P.G.

    2005-01-01

    Recent work on the deposition and use of ectrodeposited zinc-cobalt alloys is surveyed. Alloys containing lower of Nuclear quantities of cobalt are potentially more useful. The structures of the deposits is related to their chemical and mechanical properties. The inclusion of oxide and its role in the deposition mechanism may be significant. Chemical and engineering properties relate to the metallurgical structure of the alloys, which derives from the mechanism of deposition. The inclusion of oxides and hydroxides in the electroplate may provide evidence for this mechanism. Electrochemical impedance measurements have been made at significant deposition potentials, in alkaline electrolytes. These reveal a complex electrode behaviour which depends not only on the electrode potential but on the Co content of the electrolyte. For the relevant range of cathodic potential zinc-cobalt alloy electrodeposition occurs through a stratified interface. The formation of an absorbed layer ZnOH/sup +/ is the initial step, this inhibits the deposition of cobalt at low cathodic potentials, so explaining its 'anomalous deposition'. A porous layer of zinc forms on the adsorbed ZnOH/sup +/ at underpotential. As the potential becomes more cathodic, cobalt co- deposits from its electrolytic complex forming a metallic solid solution of Co in Zn. In electrolytes containing a high concentration of cobalt a mixed entity (ZnCo)/sub +/ is assumed to adsorb at the cathode from which a CoZn intermetallic deposits. (author)

  13. COBALT SALTS PRODUCTION BY USING SOLVENT EXTRACTION

    Directory of Open Access Journals (Sweden)

    Liudmila V. Dyakova

    2010-06-01

    Full Text Available The paper deals with the extracting cobalt salts by using mixtures on the basis of tertiary amine from multicomponent solutions from the process of hydrochloride leaching of cobalt concentrate. The optimal composition for the extraction mixture, the relationship between the cobalt distribution coefficients and modifier’s nature and concentration, and the saltingout agent type have been determined. A hydrochloride extraction technology of cobalt concentrate yielding a purified concentrated cobalt solution for the production of pure cobalt salts has been developed and introduced at Severonikel combine.

  14. 59 Cyg and OT Gem

    Indian Academy of Sciences (India)

    2009-07-23

    Jul 23, 2009 ... of the circumstellar disk using the Hα line and also ... the time interval 1978–1987 and saw the V /R variabil- ..... Time series of 59 Cyg Hα line observed in July 2009; (Spectra are offset and labelled with the observation date,.

  15. Phosphorus introduction mechanism in electrodeposited cobalt films

    International Nuclear Information System (INIS)

    Kravtchenko, Jean-Francois

    1973-01-01

    The cathodic reduction of hypophosphite, phosphite and phosphate ions was studied using chrono-potentiometry and voltammetry. Then cobalt was deposited at constant current from a bath containing one of these three compounds. The current, while giving an electrodeposition of cobalt, also enhances at the same time a chemical deposition of cobalt. It is shown that high coercive forces in cobalt films are much more related to this chemical deposition than to the simple fact that the films contain some phosphorus. (author) [fr

  16. 59 eyes with endogenous endophthalmitis

    DEFF Research Database (Denmark)

    Bjerrum, Søren Solborg; la Cour, Morten

    2017-01-01

    BACKGROUND: To study the epidemiology of patients with endogenous endophthalmitis in Denmark. MATERIAL AND METHODS: Retrospective and prospective case series of 59 eyes in patients with endogenous endophthalmitis in Denmark between 2000 and 2016. RESULTS: The age of the patients ranged from 28 to......, the visual outcome and the mortality of the patients. The epidemiology of the disease is very different in Scandinavia compared to Asia. The visual prognosis remains grave and the majority of the eyes lose useful vision....

  17. Eco-friendly microbial route to synthesize cobalt nanoparticles using Bacillus thuringiensis against malaria and dengue vectors.

    Science.gov (United States)

    Marimuthu, Sampath; Rahuman, Abdul Abdul; Kirthi, Arivarasan Vishnu; Santhoshkumar, Thirunavukkarasu; Jayaseelan, Chidambaram; Rajakumar, Govindasamy

    2013-12-01

    The developments of resistance and persistence to chemical insecticides and concerns about the non-target effects have prompted the development of eco-friendly mosquito control agents. The aim of this study was to investigate the larvicidal activities of synthesized cobalt nanoparticles (Co NPs) using bio control agent, Bacillus thuringiensis against malaria vector, Anopheles subpictus and dengue vector, Aedes aegypti (Diptera: Culicidae). The synthesized Co NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy, and Transmission electron microscopy (TEM). XRD analysis showed three distinct diffraction peaks at 27.03°, 31.00°, and 45.58° indexed to the planes 102, 122, and 024, respectively on the face-centered cubic cobalt acetate with an average size of 85.3 nm. FTIR spectra implicated role of the peak at 3,436 cm(-1) for O-H hydroxyl group, 2924 cm(-1) for methylene C-H stretch in the formation of Co NPs. FESEM analysis showed the topological and morphological appearance of NPs which were found to be spherical and oval in shape. TEM analysis showed polydispersed and clustered NPs with an average size of 84.81 nm. The maximum larvicidal mortality was observed in the cobalt acetate solution, B. thuringiensis formulation, and synthesized Co NPs against fourth instar larvae of A. subpictus and A. aegypti with LC50 values of 29.16, 8.12, 3.59 mg/L; 34.61, 6.94, and 2.87 mg/L; r (2) values of 0.986, 0.933, 0.942; 0.962, 0.957, and 0.922, respectively.

  18. Molecular mechanics calculations on cobalt phthalocyanine dimers

    NARCIS (Netherlands)

    Heuts, J.P.A.; Schipper, E.T.W.M.; Piet, P.; German, A.L.

    1995-01-01

    In order to obtain insight into the structure of cobalt phthalocyanine dimers, molecular mechanics calculations were performed on dimeric cobalt phthalocyanine species. Molecular mechanics calculations are first presented on monomeric cobalt(II) phthalocyanine. Using the Tripos force field for the

  19. Accumulation of cobalt by cephalopods

    International Nuclear Information System (INIS)

    Nakahara, Motokazu

    1981-01-01

    Accumulation of cobalt by cephalopod mollusca was investigated by radiotracer experiments and elemental analysis. In the radiotracer experiments, Octopus vulgaris took up cobalt-60 from seawater fairly well and the concentration of the nuclide in whole body attained about 150 times the level of seawater at 25th day at 20 0 C. Among the tissues and organs measured, branchial heart which is the specific organ of cephalopods showed the highest affinity for the nuclide. The organ accumulated about 50% of the radioactivity in whole body in spite of its little mass as 0.2% of total body weight. On the other hand, more than 90% of the radioactivity taken up from food (soft parts of Gomphina melanaegis labelled with cobalt-60 previously in an aquarium) was accumulated in liver at 3rd day after the single administration and then the radioactivity in the liver seemed to be distributed to other organs and tissues. The characteristic elution profiles of cobalt-60 was observed for each of the organs and tissues in Sephadex gel-filtration experiment. It was confirmed by the gel-filtration that most of cobalt-60 in the branchial heart was combined with the constituents of low molecular weights. The average concentration of stable cobalt in muscle of several species of cephalopods was 5.3 +- 3.0 μg/kg wet and it was almost comparable to the fish muscle. On the basis of soft parts, concentration of the nuclide closed association among bivalve, gastropod and cephalopod except squid that gave lower values than the others. (author)

  20. Cobalt(II) and Cobalt(III) Coordination Compounds.

    Science.gov (United States)

    Thomas, Nicholas C.; And Others

    1989-01-01

    Presents a laboratory experiment which illustrates the formation of tris(phenanthroline)cobalt complexes in the 2+ and 3+ oxidation states, the effect of coordination on reactions of the ligand, and the use of a ligand displacement reaction in recovering the transformed ligand. Uses IR, UV-VIS, conductivity, and NMR. (MVL)

  1. Hydrogen evolution catalyzed by cobalt diimine-dioxime complexes.

    Science.gov (United States)

    Kaeffer, Nicolas; Chavarot-Kerlidou, Murielle; Artero, Vincent

    2015-05-19

    Mimicking photosynthesis and producing solar fuels is an appealing way to store the huge amount of renewable energy from the sun in a durable and sustainable way. Hydrogen production through water splitting has been set as a first-ranking target for artificial photosynthesis. Pursuing that goal requires the development of efficient and stable catalytic systems, only based on earth abundant elements, for the reduction of protons from water to molecular hydrogen. Cobalt complexes based on glyoxime ligands, called cobaloximes, emerged 10 years ago as a first generation of such catalysts. They are now widely utilized for the construction of photocatalytic systems for hydrogen evolution. In this Account, we describe our contribution to the development of a second generation of catalysts, cobalt diimine-dioxime complexes. While displaying similar catalytic activities as cobaloximes, these catalysts prove more stable against hydrolysis under strongly acidic conditions thanks to the tetradentate nature of the diimine-dioxime ligand. Importantly, H2 evolution proceeds via proton-coupled electron transfer steps involving the oxime bridge as a protonation site, reproducing the mechanism at play in the active sites of hydrogenase enzymes. This feature allows H2 to be evolved at modest overpotentials, that is, close to the thermodynamic equilibrium over a wide range of acid-base conditions in nonaqueous solutions. Derivatization of the diimine-dioxime ligand at the hydrocarbon chain linking the two imine functions enables the covalent grafting of the complex onto electrode surfaces in a more convenient manner than for the parent bis-bidentate cobaloximes. Accordingly, we attached diimine-dioxime cobalt catalysts onto carbon nanotubes and demonstrated the catalytic activity of the resulting molecular-based electrode for hydrogen evolution from aqueous acetate buffer. The stability of immobilized catalysts was found to be orders of magnitude higher than that of catalysts in the

  2. Improved detection limit for {sup 59}Ni using the technique of accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Per; Erlandsson, Bengt; Hellborg, Ragnar; Kiisk, Madis; Larsson, Ragnar; Skog, Goeran; Stenstroem, Kristina [Lund Univ. (Sweden). Dept. of Nuclear Physics

    2002-11-01

    59 Ni is produced by neutron activation in the stainless steel close to the core of a nuclear reactor. To be able to classify the different parts of the reactor with respect to their content of long-lived radionuclides before final storage it is important to measure the 59 Ni level. Accelerator mass spectrometry is an ultra-sensitive method for counting atoms, suitable for 59 Ni measurements. Improvements in the reduction of the background and in the chemical reduction of cobalt, the interfering isobar, have been made. This chemical purification is essential when using small tandem accelerators, <3 MV, combined with the detection of characteristic projectile X-rays. These improvements have lowered the detection limit for 59 Ni by a factor of twenty compared with the first value reported for the Lund AMS facility. Material from the Swedish nuclear industry has been analysed and examples of the results are presented.

  3. The cobalt-60 container scanner

    International Nuclear Information System (INIS)

    Jigang, A.; Liye, Z.; Yisi, L.; Haifeng, W.; Zhifang, W.; Liqiang, W.; Yuanshi, Z.; Xincheng, X.; Furong, L.; Baozeng, G.; Chunfa, S.

    1997-01-01

    The Institute of Nuclear Energy Technology (INET) has successfully designed and constructed a container (cargo) scanner, which uses cobalt-60 of 100-300 Ci as radiation source. The following performances of the Cobalt-60 container scanner have been achieved at INET: a) IQI (Image Quality Indicator) - 2.5% behind 100 mm of steel; b) CI (Contrast Indicator) - 0.7% behind 100 mm of steel; c) SP (Steel Penetration) - 240 mm of steel; d) Maximum Dose per Scanning - 0.02mGy; e) Throughput - twenty 40-foot containers per hour. These performances are equal or similar to those of the accelerator scanners. Besides these nice enough inspection properties, the Cobalt-60 scanner possesses many other special features which are better than accelerator scanners: a) cheap price - it will be only or two tenths of the accelerator scanner's; b) low radiation intensity - the radiation protection problem is much easier to solve and a lot of money can be saved on the radiation shielding building; c) much smaller area for installation and operation; d) simple operation and convenient maintenance; e) high reliability and stability. The Cobalt-60 container (or cargo) scanner is satisfied for boundary customs, seaports, airports and railway stations etc. Because of the nice special features said above, it is more suitable to be applied widely. Its high properties and low price will make it have much better application prospects

  4. Cobalt 60 commercial irradiation facilities

    International Nuclear Information System (INIS)

    West, G.

    1985-01-01

    The advantage of using cobalt 60 for ionizing treatment is that it has excellent penetration. Gamma plants are also very efficient, in as much as there is very little mechanical or electrical equipment in a gamma irradiation facility. The average efficiency of a gamma plant is usually around 95% of all available processing time

  5. Cobalt (III) complexes as novel matrix metalloproteinase-9 inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jiyoun [Sungshin Women' s Univ., Seoul (Korea, Republic of)

    2012-04-15

    We have synthesized a series of novel MMP-9 inhibitors containing cobalt(III) complexes. The synthesized cobalt(III) complexes are effective as enzyme inhibitors and the attachment of a biphenyl group enhanced the efficiency of enzyme inhibition up to 6-fold. When compared to the reported non-hydroxamate MMP inhibitors, the synthesized complexes showed comparable in vitro potency. The enzyme assay showed that the cobalt(III) complex can disrupt the zinc binding active site of MMP-9 and is proposed to work via a ligand exchange mechanism. Since histidine residues are essential for the catalytic activity of a large percentage of enzymes and zinc finger proteins, these cobalt(III) complexes can serve as a prototype inhibitor towards various zinc containing enzymes and proteins. Matrix metalloproteinases (MMPs) are a family of zinc binding endopeptidases that play crucial roles in various physiological processes and diseases such as embryogenic growth, angiogenesis, arthritis, skin ulceration, liver fibrosis and tumor metastasis. Because of their implications in a wide range of diseases, MMPs are considered as intriguing drug targets. The majority of MMP inhibitors are organic small molecules containing a hydroxamate functionality for the zinc binding group. This hydroxamate group binds to a zinc(II) center in a bidentate fashion and creates a distorted trigonal bipyramidal geometry.

  6. Cobalt (III) complexes as novel matrix metalloproteinase-9 inhibitors

    International Nuclear Information System (INIS)

    Lee, Jiyoun

    2012-01-01

    We have synthesized a series of novel MMP-9 inhibitors containing cobalt(III) complexes. The synthesized cobalt(III) complexes are effective as enzyme inhibitors and the attachment of a biphenyl group enhanced the efficiency of enzyme inhibition up to 6-fold. When compared to the reported non-hydroxamate MMP inhibitors, the synthesized complexes showed comparable in vitro potency. The enzyme assay showed that the cobalt(III) complex can disrupt the zinc binding active site of MMP-9 and is proposed to work via a ligand exchange mechanism. Since histidine residues are essential for the catalytic activity of a large percentage of enzymes and zinc finger proteins, these cobalt(III) complexes can serve as a prototype inhibitor towards various zinc containing enzymes and proteins. Matrix metalloproteinases (MMPs) are a family of zinc binding endopeptidases that play crucial roles in various physiological processes and diseases such as embryogenic growth, angiogenesis, arthritis, skin ulceration, liver fibrosis and tumor metastasis. Because of their implications in a wide range of diseases, MMPs are considered as intriguing drug targets. The majority of MMP inhibitors are organic small molecules containing a hydroxamate functionality for the zinc binding group. This hydroxamate group binds to a zinc(II) center in a bidentate fashion and creates a distorted trigonal bipyramidal geometry

  7. Magnetic Moment of $^{59}$Cu

    CERN Multimedia

    2002-01-01

    Experiment IS358 uses the intense and pure beams of copper isotopes provided by the ISOLDE RILIS (resonance ionization laser ion source). The isotopes are implanted and oriented in the low temperature nuclear orientation set-up NICOLE. Magnetic moments are measured by $\\beta$-NMR. Copper (Z=29), with a single proton above the proton-magic nickel isotopes provides an ideal testground for precise shell model calculations of magnetic moments and their experimental verification. In the course of our experiments we already determined the magnetic moments of $^{67}$Ni, $^{67}$Cu, $^{68g}$Cu, $^{69}$Cu and $^{71}$Cu which provide important information on the magicity of the N=40 subshell closure. In 2001 we plan to conclude our systematic investigations by measuring the magnetic moment of the neutron-deficient isotope $^{59}$Cu. This will pave the way for a subsequent study of the magnetic moment of $^{57}$Cu with a complementary method.

  8. Cobalt release from inexpensive jewellery: has the use of cobalt replaced nickel following regulatory intervention?

    Science.gov (United States)

    Thyssen, Jacob Pontoppidan; Jellesen, Morten S; Menné, Torkil; Lidén, Carola; Julander, Anneli; Møller, Per; Johansen, Jeanne Duus

    2010-08-01

    Before the introduction of the EU Nickel Directive, concern was raised that manufacturers of jewellery might turn from the use of nickel to cobalt following the regulatory intervention on nickel exposure. The aim was to study 354 consumer items using the cobalt spot test. Cobalt release was assessed to obtain a risk estimate of cobalt allergy and dermatitis in consumers who would wear the jewellery. The cobalt spot test was used to assess cobalt release from all items. Microstructural characterization was made using scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS). Cobalt release was found in 4 (1.1%) of 354 items. All these had a dark appearance. SEM/EDS was performed on the four dark appearing items which showed tin-cobalt plating on these. This study showed that only a minority of inexpensive jewellery purchased in Denmark released cobalt when analysed with the cobalt spot test. As fashion trends fluctuate and we found cobalt release from dark appearing jewellery, cobalt release from consumer items should be monitored in the future. Industries may not be fully aware of the potential cobalt allergy problem.

  9. Polytypic transformations during the thermal decomposition of cobalt hydroxide and cobalt hydroxynitrate

    International Nuclear Information System (INIS)

    Ramesh, Thimmasandra Narayan

    2010-01-01

    The isothermal decomposition of cobalt hydroxide and cobalt hydroxynitrate at different intervals of temperature leads to the formation of Co 3 O 4 . The phase evolution during the decomposition process was monitored using powder X-ray diffraction. The transformation of cobalt hydroxide to cobalt oxide occurs via three phase mixture while cobalt hydroxynitrate to cobalt oxide occurs through a two phase mixture. The nature of the sample and its preparation method controls the decomposition mechanism. The comparison of topotactical relationship between the precursors to the decomposed product has been reported in relation to polytypism. - Graphical abstract: Isothermal thermal decomposition studies of cobalt hydroxide and cobalt hydroxynitrate at different intervals of temperature show the metastable phase formed prior to Co 3 O 4 phase.

  10. Theoretical study of cross sections of proton-induced reactions on cobalt

    Directory of Open Access Journals (Sweden)

    Mustafa Yiğit

    2018-04-01

    Full Text Available Nuclear fusion may be among the strongest sustainable ways to replace fossil fuels because it does not contribute to acid rain or global warming. In this context, activated cobalt materials in corrosion products for fusion energy are significant in determination of dose levels during maintenance after a coolant leak in a nuclear fusion reactor. Therefore, cross-section studies on cobalt material are very important for fusion reactor design. In this article, the excitation functions of some nuclear reaction channels induced by proton particles on 59Co structural material were predicted using different models. The nuclear level densities were calculated using different choices of available level density models in ALICE/ASH code. Finally, the newly calculated cross sections for the investigated nuclear reactions are compared with the experimental values and TENDL data based on TALYS nuclear code. Keywords: Cobalt, Nuclear Structural Materials, Reaction Cross Section, TENDL Database

  11. Recovery of Cobalt as Cobalt Oxalate from Cobalt Tailings Using Moderately Thermophilic Bioleaching Technology and Selective Sequential Extraction

    Directory of Open Access Journals (Sweden)

    Guobao Chen

    2016-07-01

    Full Text Available Cobalt is a very important metal which is widely applied in various critical areas, however, it is difficult to recover cobalt from minerals since there is a lack of independent cobalt deposits in nature. This work is to provide a complete process to recover cobalt from cobalt tailings using the moderately thermophilic bioleaching technology and selective sequential extraction. It is found that 96.51% Co and 26.32% Cu were extracted after bioleaching for four days at 10% pulp density. The mean compositions of the leach solutions contain 0.98 g·L−1 of Co, 6.52 g·L−1 of Cu, and 24.57 g·L−1 of Fe (III. The copper ion was then recovered by a solvent extraction process and the ferric ions were selectively removed by applying a goethite deironization process. The technological conditions of the above purification procedures were deliberately discussed. Over 98.6% of copper and 99.9% of ferric ions were eliminated from the leaching liquor. Cobalt was finally produced as cobalt oxalate and its overall recovery during the whole process was greater than 95%. The present bioleaching process of cobalt is worth using for reference to deal with low-grade cobalt ores.

  12. Derivative spectrophotometry of cobalt alloys

    International Nuclear Information System (INIS)

    Spitsyn, P.K.

    1985-01-01

    The method of derivative spectrophotometry is briefly described, and derivative absorption spectra are presented for samarium, cobalt, and commercial Sm-Co alloys. It is shown that the use of derivative spectrophotometry not only improves the accuracy and selectivity of element determinations but also simplifies the analysis of alloys. Results of a statistical evaluation of the metrological characteristics of the analytical procedure described here are presented. 8 references

  13. EFTF cobalt test assembly results

    International Nuclear Information System (INIS)

    Rawlins, J.A.; Wootan, D.W.; Carter, L.L.; Brager, H.R.; Schenter, R.E.

    1988-01-01

    A cobalt test assembly containing yttrium hydride pins for neutron moderation was irradiated in the Fast Flux Test Facility during Cycle 9A for 137.7 equivalent full power days at a power level fo 291 MW. The 36 test pins consisted of a batch of 32 pins containing cobalt metal to produce Co-60, and a set of 4 pins with europium oxide to produce Gd-153, a radioisotope used in detection of the bone disease Osteoporosis. Post-irradiation examination of the cobalt pins determined the Co-60 produced with an accuracy of about 5 %. The measured Co-60 spatially distributed concentrations were within 20 % of the calculated concentrations. The assembly average Co-60 measured activity was 4 % less than the calculated value. The europium oxide pins were gamma scanned for the europium isotopes Eu-152 and Eu-154 to an absolute accuracy of about 10 %. The measured europium radioisotpe anc Gd-153 concentrations were within 20 % of calculated values. In conclusion, the hydride assembly performed well and is an excellent vehicle for many Fast Flux Test Facility isotope production applications. The results also demonstrate that the calculational methods developed by the Westinghouse Hanford Company are very accurate. (author)

  14. National Low-Level Waste Management Program Radionuclide Report Series: Volume 12, Cobalt-60

    Energy Technology Data Exchange (ETDEWEB)

    Adams, J.P.

    1995-06-01

    This report outlines the basic radiological and chemical characteristics of cobalt-60 ({sup 60}Co) and examines how these characteristics affect the behavior of {sup 60}Co in various environmental media, such as soils, groundwater, plants, animals, the atmosphere, and the human body. Discussions also include methods of {sup 60}Co production, waste types, and waste forms that contain {sup 60}Co. All cobalt atoms contain 27 protons (Z = 27) and various numbers of neutrons (typically N = 27 to 37 neutrons) within the atom`s nucleus. There is only one stable isotope of cobalt, namely {sup 59}Co. All other cobalt isotopes, including {sup 60}Co, are radioactive. The radioactive isotopes of cobalt have half-lives ranging from less than a second ({sup 54}Co-0.19 s) to 5.2 years ({sup 60}Co). The radioactive isotopes of cobalt are not a normal constituent of the natural environment and are generated as a result of human activities. The primary source of {sup 60}Co in the environment has been low-level radioactive waste material generated as a result of neutron activation of stable {sup 59}Co that is present in the structural components of nuclear reactor vessels. This isotope is also intentionally produced, usually in reactors but also to some degree in accelerators for industrial and medical uses, such as for radiation sources for cancer treatment and nondestructive testing of metals and welds. {sup 60}Co may enter the environment as a result of the activities associated with nuclear reactor operations and decommissioning and when industrial and medical sources are being used, manufactured, or disposed.

  15. National Low-Level Waste Management Program Radionuclide Report Series: Volume 12, Cobalt-60

    International Nuclear Information System (INIS)

    Adams, J.P.

    1995-06-01

    This report outlines the basic radiological and chemical characteristics of cobalt-60 ( 60 Co) and examines how these characteristics affect the behavior of 60 Co in various environmental media, such as soils, groundwater, plants, animals, the atmosphere, and the human body. Discussions also include methods of 60 Co production, waste types, and waste forms that contain 60 Co. All cobalt atoms contain 27 protons (Z = 27) and various numbers of neutrons (typically N = 27 to 37 neutrons) within the atom's nucleus. There is only one stable isotope of cobalt, namely 59 Co. All other cobalt isotopes, including 60 Co, are radioactive. The radioactive isotopes of cobalt have half-lives ranging from less than a second ( 54 Co-0.19 s) to 5.2 years ( 60 Co). The radioactive isotopes of cobalt are not a normal constituent of the natural environment and are generated as a result of human activities. The primary source of 60 Co in the environment has been low-level radioactive waste material generated as a result of neutron activation of stable 59 Co that is present in the structural components of nuclear reactor vessels. This isotope is also intentionally produced, usually in reactors but also to some degree in accelerators for industrial and medical uses, such as for radiation sources for cancer treatment and nondestructive testing of metals and welds. 60 Co may enter the environment as a result of the activities associated with nuclear reactor operations and decommissioning and when industrial and medical sources are being used, manufactured, or disposed

  16. Cobalt accumulation and circulation by blackgum trees

    International Nuclear Information System (INIS)

    Thomas, W.A.

    1975-01-01

    Blackgum (Nyssa sylvatica Marsh.) trees accumulate far greater concentrations of cobalt in mature foliage than do other species on the same site (363 ppM in ash of blackgum, compared with about 3 ppM by mockernut hickory and about 1 ppM by red maple, tulip tree, and white oak). Cobalt concentrations in dormant woody tissues of blackgum also significantly exceed those in the other four species. Inoculation of six blackgums with 60 Co revealed that cobalt remains mobile in the trees for at least 3 years. Foliar concentrations of stable cobalt increase uniformly until senescence. In late August, foliage accounts for only 9 percent of total tree weight but 57 percent of total tree cobalt. Losses of cobalt from trees occur almost entirely by leaf abscission, and the loss rates of weight and cobalt from decomposing litter are similar. Retention of cobalt in the biologically active soil layers perpetuates zones of cobalt concentration created by this species in woodlands

  17. A59 waste repackaging database (AWARD)

    International Nuclear Information System (INIS)

    Keel, A.

    1993-06-01

    This document describes the data structures to be implemented to provide the A59 Waste Repackaging Database (AWARD); a Computer System for the in-cave Bertha waste sorting and LLW repackaging operations in A59. (Author)

  18. Ultrasonography-guided cobalt-60 brachytherapy for malignant glioma

    International Nuclear Information System (INIS)

    Sakai, Noboru; Takenaka, Katsunobu; Ueda, Tatsuya

    1989-01-01

    Brachytherapy with cobalt-60 source is reported. In this method it is characterized that the source is inserted interstitially with remote control system by after-loading method via outer catheter (using tandem tube), which was established in the center of residual tumor, using ultrasonography guide with trepanation, or intraoperatively put within the dead space after tumor resection. Six cases of deep-seated and recurrent malignant glioma, were treated with this method. A total dose of 20 to 45 Gy (10 to 15 Gy/day for 2 to 3 days) was delivered to the target. Additionally conventional external irradiation was followed. The effect of cobalt-60 brachytherapy on such tumors were favorable especially for well-circumscribed glioma less than 3 cm on CT scan. (author)

  19. 33 CFR 401.59 - Pollution.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pollution. 401.59 Section 401.59 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.59 Pollution. (a) No vessel shall: (1...

  20. 28 CFR 59.1 - Introduction.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Introduction. 59.1 Section 59.1 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) GUIDELINES ON METHODS OF OBTAINING DOCUMENTARY MATERIALS HELD BY THIRD PARTIES § 59.1 Introduction. (a) A search for documentary materials necessarily involves...

  1. 40 CFR 59.514 - Circumvention.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Circumvention. 59.514 Section 59.514 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Compound Emission Standards for Aerosol Coatings § 59.514 Circumvention. Each manufacturer, distributor...

  2. 40 CFR 59.109 - Circumvention.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Circumvention. 59.109 Section 59.109 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Compound Emission Standards for Automobile Refinish Coatings § 59.109 Circumvention. Each manufacturer and...

  3. 40 CFR 59.411 - Circumvention.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Circumvention. 59.411 Section 59.411 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Compound Emission Standards for Architectural Coatings § 59.411 Circumvention. Each manufacturer and...

  4. 40 CFR 59.212 - Circumvention.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Circumvention. 59.212 Section 59.212 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Compound Emission Standards for Consumer Products § 59.212 Circumvention. No regulated entity subject to...

  5. 42 CFR 59.212 - Grantee accountability.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Grantee accountability. 59.212 Section 59.212 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS GRANTS FOR FAMILY PLANNING SERVICES Grants for Family Planning Service Training § 59.212 Grantee accountability. (a...

  6. 49 CFR 801.59 - Geological records.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Geological records. 801.59 Section 801.59... PUBLIC AVAILABILITY OF INFORMATION Exemption From Public Disclosure § 801.59 Geological records. Pursuant to 5 U.S.C. 552(b)(9), records concerning geological wells are exempt from public disclosure. ...

  7. 45 CFR 86.59 - Advertising.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Advertising. 86.59 Section 86.59 Public Welfare... in Employment in Education Programs or Activities Prohibited § 86.59 Advertising. A recipient shall not in any advertising related to employment indicate preference, limitation, specification, or...

  8. 7 CFR 15a.59 - Advertising.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Advertising. 15a.59 Section 15a.59 Agriculture Office of the Secretary of Agriculture EDUCATION PROGRAMS OR ACTIVITIES RECEIVING OR BENEFITTING FROM... Activities Prohibited § 15a.59 Advertising. A recipient shall not in any advertising related to employment...

  9. 40 CFR 59.207 - Test methods.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test methods. 59.207 Section 59.207 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Compound Emission Standards for Consumer Products § 59.207 Test methods. Each manufacturer or importer...

  10. Effect of excess supply of heavy metals on the absorption and translocation of iron (/sup 59/Fe) in barley

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, C P; Bisht, S S; Agarwala, S C [Lucknow Univ. (India). Dept. of Botany

    1978-03-01

    The effects of an excess supply of manganese, copper, zinc, cobalt, and nickel on the absorption and translocation of iron tagged with /sup 59/Fe were xamined in 15 days old barley seedlings raised in solution culture. Excess heavy metal treatments and /sup 59/Fe were administered in three different ways: (i) both excess heavy metals and iron supplied through roots- Series A; (ii) excess heavy metal supplied as foliar spray and iron through roots- Series B; and (iii) excess heavy metal supplied through roots and iron as foliar spray-Series C. Results obtained revealed that excess concentrations of manganese, zinc, cobalt, and a to a lesser extent copper interfered with the absorption of iron from the rooting medium, but excess nickel enhanced the absorption and translocation of iron. Thus, unlike other metals, a toxic supply of nickel does not induce iron deficiency.

  11. Cobalt 60 availability for radiation processing

    International Nuclear Information System (INIS)

    Fraser, F.M.

    1986-01-01

    In the last 20 years, the steady and significant growth in the application of radiation processing to industrial sterilization has been seen. The principal application of this technology is the sterilization of disposable medical products, food irradiation, the irradiation of personal care goods and so on. At present, more than 70 million curies of cobalt-60 supplied by Atomic Energy of Canada Ltd. have been used for gamma processing in these applications. This is estimated to be more than 80 % of the total cobalt-60 in service in the world. Commercial food irradiation has an exciting future, and as to the impact of food irradiation on the availability of cobalt-60 over the next ten years, two principal factors must be examined, namely, the anticipated demand for cobalt-60 in all radiation processing applications, and the supply of cobalt-60 to reliably meet the expected demand. As for the cobalt-60 in service today, 90 % is used for the sterilization of disposable medical products, 5 % for food irradiation, and 5 % for other application. The demand for up to 30 million curies of cobalt-60 is expected over the next 10 years. Today, it is estimated that over 150,000 tons of spices, fruit and fish are irradiated. The potential cobalt-60 production could exceed 110 million curies per year. Gamma processing application will demand nearly 50 million curies in 1990. (Kako, I.)

  12. Cobalt allergy in hard metal workers

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, T; Rystedt, I

    1983-03-01

    Hard metal contains about 10% cobalt. 853 hard metal workers were examined and patch tested with substances from their environment. Initial patch tests with 1% cobalt chloride showed 62 positive reactions. By means of secondary serial dilution tests, allergic reactions to cobalt were reproduced in 9 men and 30 women. Weak reactions could not normally be reproduced. A history of hand eczema was found in 36 of the 39 individuals with reproducible positive test reactions to cobalt, while 21 of 23 with a positive initial patch test but negative serial dilution test had never had any skin problems. Hand etching and hand grinding, mainly female activities and traumatic to the hands, were found to involve the greatest risk of cobalt sensitization. 24 individuals had an isolated cobalt allergy. They had probably been sensitized by hard metal work, while the individuals, all women, who had simultaneous nickel allergy had probably been sensitized to nickel before their employment and then became sensitized to cobalt by hard metal work. A traumatic occupation, which causes irritant contact dermatitis and/or a previous contact allergy or atopy is probably a prerequisite for the development of cobalt allergy.

  13. Cobalt sorption onto Savannah River Plant soils

    International Nuclear Information System (INIS)

    Hoeffner, S.L.

    1985-06-01

    A laboratory study of cobalt-60 sorption was conducted using Savannah River Plant soil and groundwater from the low-level waste burial ground. Systematic variation of soil and water composition indicates that cobalt sorption is most strongly a function of pH. Over a pH range of 2 to 9, the distribution coefficient ranged from 2 to more than 10,000 mL/g. Changes in clay content and in K + , Ca 2+ , or Mg 2+ concentrations influence cobalt sorption indirectly through the slight pH changes which result. The ions Na + , Cl - , and NO 3 - have no effect on cobalt sorption. Ferrous ion, added to groundwater to simulate the condition of water at the bottom of the waste trenches, accounts for part of the decrease in cobalt sorption observed with trench waters. 17 refs., 3 figs., 4 tabs

  14. 42 CFR 59.209 - Civil rights.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Civil rights. 59.209 Section 59.209 Public Health... Grants for Family Planning Service Training § 59.209 Civil rights. Attention is called to the requirements of Title VI of the Civil Rights Act of 1964 (78 Stat. 252, 42 U.S.C. 2000d et seq.) and in...

  15. Nickel acts as an adjuvant during cobalt sensitization

    DEFF Research Database (Denmark)

    Bonefeld, Charlotte Menne; Nielsen, Morten Milek; Vennegaard, Marie T.

    2015-01-01

    Metal allergy is the most frequent form of contact allergy with nickel and cobalt being the main culprits. Typically, exposure comes from metal-alloys where nickel and cobalt co-exist. Importantly, very little is known about how co-exposure to nickel and cobalt affects the immune system. We...... investigated these effects by using a recently developed mouse model. Mice were epicutaneously sensitized with i) nickel alone, ii) nickel in the presence of cobalt, iii) cobalt alone, or iv) cobalt in the presence of nickel, and then followed by challenge with either nickel or cobalt alone. We found...... that sensitization with nickel alone induced more local inflammation than cobalt alone as measured by increased ear-swelling. Furthermore, the presence of nickel during sensitization to cobalt led to a stronger challenge response to cobalt as seen by increased ear-swelling and increased B and T cell responses...

  16. 16 CFR 5.59 - Presiding official.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Presiding official. 5.59 Section 5.59 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE STANDARDS OF... Chief Administrative Law Judge, who shall appoint an Administrative Law Judge to preside over the...

  17. 28 CFR 91.59 - OJP's responsibilities.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false OJP's responsibilities. 91.59 Section 91.59 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) GRANTS FOR CORRECTIONAL FACILITIES... be required. (b) Specific duties. As part of its role in the NEPA process, OJP shall: (1) Issue...

  18. 40 CFR 59.105 - Reporting requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Reporting requirements. 59.105 Section... Volatile Organic Compound Emission Standards for Automobile Refinish Coatings § 59.105 Reporting requirements. (a) Each regulated entity must submit an initial report no later than January 11, 1999 or within...

  19. 34 CFR 106.59 - Advertising.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Advertising. 106.59 Section 106.59 Education Regulations of the Offices of the Department of Education OFFICE FOR CIVIL RIGHTS, DEPARTMENT OF EDUCATION... Advertising. A recipient shall not in any advertising related to employment indicate preference, limitation...

  20. 28 CFR 51.59 - Redistrictings.

    Science.gov (United States)

    2010-07-01

    ... extent to which the plan departs from objective redistricting criteria set by the submitting jurisdiction... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Redistrictings. 51.59 Section 51.59 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) PROCEDURES FOR THE ADMINISTRATION OF SECTION 5 OF...

  1. C59N Peapods Sensing the Temperature

    Directory of Open Access Journals (Sweden)

    Toshiro Kaneko

    2013-01-01

    Full Text Available We report the novel photoresponse of nanodevices made from azafullerene (C59N-encapsulated single-walled carbon nanotubes (C59N@SWNTs, so called peapods. The photoconducting properties of a C59N@SWNT are measured over a temperature range of 10 to 300 K under a field-effect transistor configuration. It is found that the photosensitivity of C59N@SWNTs depends very sensitively on the temperature, making them an attractive candidate as a component of nanothermometers covering a wide temperature range. Our results indicate that it is possible to read the temperature by monitoring the optoelectronics signal of C59N@SWNTs. In particular, sensing low temperatures would become more convenient and easy by giving a simple light pulse.

  2. Physical aspects of quality assurance in cobalt teletherapy units

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Kwan Hong [Malaya Univ., Kuala Lumpur (Malaysia)

    1989-06-01

    ICRU Report No. 24 states that +- 5% is a reasonable degree of accuracy to strive for in the delivery of absorbed doses to target volumes in radiotherapy. To achieve this quality assurance level, a comprehensive programme comprising both physical and clinical components is needed. The purpose of this paper is to present the rationale and guidelines for implementing a recommended quality assurance programme. It will emphasize the physical aspects pertaining to acceptance and constancy tests using Cobalt-60 teletherapy units. It will also outline a suggested schedule of quality assurance testings including radiation dosimetry, geometry and electrochemical safety. (author).

  3. Nickel and cobalt base alloys

    International Nuclear Information System (INIS)

    Houlle, P.

    1994-01-01

    Nickel base alloys have a good resistance to pitting, cavernous or cracks corrosion. Nevertheless, all the nickel base alloys are not equivalent. Some differences exit between all the families (Ni, Ni-Cu, Ni-Cr-Fe, Ni-Cr-Fe-Mo/W-Cu, Ni-Cr-Mo/W, Ni-Mo). Cobalt base alloys in corrosive conditions are generally used for its wear and cracks resistance, with a compromise to its localised corrosion resistance properties. The choice must be done from the perfect knowledge of the corrosive medium and of the alloys characteristics (chemical, metallurgical). A synthesis of the corrosion resistance in three medium (6% FeCl 3 , 4% NaCl + 1% HCl + 0.1% Fe 2 (SO 4 ) 3 , 11.5% H 2 SO 4 + 1.2% HCl + 1% Fe 2 (SO 4 ) 3 + 1% CuCl 2 ) is presented. (A.B.). 11 refs., 1 fig., 12 tabs

  4. Preparation of high purity cobalt

    International Nuclear Information System (INIS)

    Isshiki, M.; Fukuda, Y.; Igaki, K.

    1985-01-01

    A combination of anion exchange separation, electrolytic extraction, floating zone refining and dry hydrogen treatment was used to purify cobalt. The effectiveness of each purification process was confirmed by measurements of the residual resistivity ratio (RRR) and activation analyses. Proton activation analysis revealed that all the main metallic impurities except iron were effectively removed by a combination of these processes. The effective removal of oxygen, nitrogen and carbon by dry hydrogen treatment was confirmed by activation analyses using 3 He ion beams, proton beams and γ rays. It was found that the rate-controlling step in the decarburization process was a surface reaction. The maximum RRR obtained for the purified specimen was 334, which is higher than previously reported values. (Auth.)

  5. Nano cobalt oxides for photocatalytic hydrogen production

    KAUST Repository

    Mangrulkar, Priti A.; Joshi, Meenal M.; Tijare, Saumitra N.; Polshettiwar, Vivek; Labhsetwar, Nitin K.; Rayalu, Sadhana Suresh

    2012-01-01

    of various operating parameters in hydrogen generation by nano cobalt oxide was then studied in detail. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  6. An elevator for cobalt-60 source

    International Nuclear Information System (INIS)

    Tang Zaimin; Liang Donghu

    1990-07-01

    The elevator used for cobalt-60 source is a key device in the irradiation industry. It plays an important role in the safety and control of irradiation operation as well as the utilization rate of radiation source. From 1983 to 1986, Beijing Institute of Nuclear Engineering undertook designing of various size irradiation projects for different uses. Since then a kind of cobalt-60 source elevator suited for the irradiator of wet-source-storage has been chosen. It is reliable in the operation and complete in the function. An automatic control circuit brings the systems of cobalt-60 source elevator into an interlock system which ensures the irradiation operation safety. Besides introducing the structural features and performance of this elevator, the conditions of safety interlocking in raising or lowering the cobalt-60 source is also discussed. The discussion is from the safety viewpoint of operating an irradiator and irradiation technology

  7. Transport properties of cobalt at low temperatures

    DEFF Research Database (Denmark)

    Radharkishna, P.; Nielsen, Mourits

    1965-01-01

    Measurements are made of electrical resistivity, absolute thermoelectric power, and thermal conductivity of polycrystalline cobalt between 1.2 and 6 K; results are discussed on basis of inter-electronic scattering.......Measurements are made of electrical resistivity, absolute thermoelectric power, and thermal conductivity of polycrystalline cobalt between 1.2 and 6 K; results are discussed on basis of inter-electronic scattering....

  8. Cobalt chloride administration in athletes: a new perspective in blood doping?

    Science.gov (United States)

    Lippi, G; Franchini, M; Guidi, G C

    2005-11-01

    Blood doping is an illegal and unfair way of enhancing athletic performance by increasing the oxygen carrying capacity of the blood. Currently used methods usually involve stimulation of erythropoiesis. Gene therapy targeting the hypoxia inducible factor pathway may be an attractive alternative to traditional blood doping techniques. Hypoxia activates a large number of genes with essential roles in cell and tissue adaptation to low oxygen. Cobalt chloride is a well established chemical inducer of hypoxia-like responses such as erythropoiesis. Cobalt supplementation is not banned and therefore would not be detected by current anti-doping testing. Although there is as yet no direct or anecdotal evidence of cobalt chloride administration to athletes, its use should be warned against as being not only unfair but potentially dangerous.

  9. Electrocatalytic miRNA Detection Using Cobalt Porphyrin-Modified Reduced Graphene Oxide

    Directory of Open Access Journals (Sweden)

    Camille De Souza

    2014-06-01

    Full Text Available Metalated porphyrins have been described to bind nucleic acids. Additionally, cobalt porphyrins present catalytic properties towards oxygen reduction. In this work, a carboxylic acid-functionalized cobalt porphyrin was physisorbed on reduced graphene oxide, then immobilized on glassy carbon electrodes. The carboxylic groups were used to covalently graft amino-terminated oligonucleotide probes which are complementary to a short microRNA target. It was shown that the catalytic oxygen electroreduction on cobalt porphyrin increases upon hybridization of miRNA strand (“signal-on” response. Current changes are amplified compared to non-catalytic amperometric system. Apart from oxygen, no added reagent is necessary. A limit of detection in the sub-nanomolar range was reached. This approach has never been described in the literature.

  10. X-ray tube targets

    International Nuclear Information System (INIS)

    Hirsch, H.H.

    1980-01-01

    In rotary targets for X-ray tubes warping is a problem which causes X-ray deficiency. A rotary target is described in which warping is reduced by using alloys of molybdenum with 0.05 to 10% iron, silicon, cobalt, tantalum, niobium, hafnium, stable metal oxide or mixture thereof. Suitable mixtures are 0.5 to 10% of tantalum, niobium or hafnium with from 0.5 to 5% yttrium oxide, or 0.05 to 0.3% of cobalt or silicon. Optionally 0.1 to 5% by weight of additional material may be alloyed with the molybdenum, such as tantalum or hafnium carbides. (author)

  11. Anion-Regulated Selective Generation of Cobalt Sites in Carbon: Toward Superior Bifunctional Electrocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Gang [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road Shanghai 200050 P. R. China; University of Chinese Academy of Sciences, Beijing 100049 P. R. China; Yang, Ce [Chemical Science and Engineering Division, Argonne National Laboratory, 9700 Cass Avenue Lemont IL 60439 USA; Zhao, Wanpeng [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road Shanghai 200050 P. R. China; University of Chinese Academy of Sciences, Beijing 100049 P. R. China; Li, Qianru [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road Shanghai 200050 P. R. China; University of Chinese Academy of Sciences, Beijing 100049 P. R. China; Wang, Ning [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road Shanghai 200050 P. R. China; University of Chinese Academy of Sciences, Beijing 100049 P. R. China; Li, Tao [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, 9700 Cass Avenue Lemont IL 60439 USA; Zhou, Hua [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, 9700 Cass Avenue Lemont IL 60439 USA; Chen, Hangrong [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road Shanghai 200050 P. R. China; Shi, Jianlin [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road Shanghai 200050 P. R. China

    2017-11-06

    The introduction of active transition metal sites (TMSs) in carbon enables the synthesis of noble-metal-free electrocatalysts for clean energy conversion applications, however, there are often multiple existing forms of TMSs, which are of different natures and catalytic models. Regulating the evolution of distinctive TMSs is highly desirable but remains challenging to date. Anions, as essential elements involved in the synthesis, have been totally neglected previously in the construction of TMSs. Herein, the effects of anions on the creation of different types of TMSs is investigated for the first time. It is found that the active cobalt-nitrogen sites tend to be selectively constructed on the surface of N-doped carbon by using chloride, while metallic cobalt nanoparticles encased in protective graphite layers are the dominant forms of cobalt species with nitrate ions. The obtained catalysts demonstrate cobalt-sites-dependent activity for ORR and HER in acidic media. And the remarkably enhanced catalytic activities approaching that of benchmark Pt/C in acidic medium has been obtained on the catalyst dominated with cobalt-nitrogen sites, confirmed by the advanced spectroscopic . Our finding demonstrates a general paradigm of anion-regulated evolution of distinctive TMSs, providing a new pathway for enhancing performances of various targeted reactions related with TMSs.

  12. COBALT COMPOUNDS AS ANTIDOTES FOR HYDROCYANIC ACID.

    Science.gov (United States)

    EVANS, C L

    1964-12-01

    The antidotal potency of a cobalt salt (acetate), of dicobalt edetate, of hydroxocobalamin and of cobinamide against hydrocyanic acid was examined mainly on mice and rabbits. All the compounds were active antidotes for up to twice the LD50; under some conditions for larger doses. The most successful was cobalt acetate for rabbits (5xLD50), which was effective at a molar cyanide/cobalt (CN/Co) ratio of 5, but had as a side-effect intense purgation. Hydroxocobalamin was irregular in action, but on the whole was most effective for mice (4.5xLD50 at a molar ratio of 1), and had no apparent side effects. Dicobalt edetate, at molar ratios of up to 2, was more effective for rabbits (3xLD50) than for mice (2xLD50), but had fewer side effects than cobalt acetate. The effect of thiosulphate was to augment the efficacy of dicobalt edetate and, in mice, that of hydroxocobalamin; but, apparently, in rabbits, to reduce that of hydroxocobalamin. Cobinamide, at a molar ratio of 1, was slightly more effective than hydroxocobalamin on rabbits and also less irregular in its action. Cobalt acetate by mouth was effective against orally administered hydrocyanic acid. The oxygen uptake of the body, reduced by cyanide, is rapidly reinstated when one of the cobalt antidotes has been successfully administered.

  13. Monte Carlo estimation of the dose and heating of cobalt adjuster rods irradiated in the CANDU 6 reactor core

    International Nuclear Information System (INIS)

    Gugiu, D.; Dumitrache, I.

    2005-01-01

    The present work is a part of a more complex project related to the replacement of the original stainless steel adjuster rods with cobalt assemblies in the CANDU 6 reactor core. The 60 Co produced by 59 Co irradiation could be used extensively in medicine and industry. The paper will mainly describe some of the reactor physics and safety requirements that must be carried into practice for the Co adjuster rods. The computations related to the neutronic equivalence of the stainless steel adjusters with the Co adjuster assemblies, as well as the estimations of the activity and heating of the irradiated cobalt rods, are performed using the Monte Carlo codes MCNP5 and MONTEBURNS 2.1. The activity values are used to evaluate the dose at the surface of the device designed to transport the cobalt adjusters. (authors)

  14. Complex magnetic differentiation of cobalts in Na x CoO2 with 22 K Néel temperature

    Science.gov (United States)

    Mukhamedshin, I. R.; Gilmutdinov, I. F.; Salosin, M. A.; Alloul, H.

    2014-06-01

    Single crystals of sodium cobaltates Na x CoO2 with x ≈ 0.8 were grown by the floating zone technique. Using electrochemical Na de-intercalation method we reduced the sodium content in the as-grown crystals down to pure phase with 22 K Néel temperature and x ≈ 0.77. The 59Co NMR study in the paramagnetic state of the T N = 22 K phase permitted us to evidence that at least 6 Co sites are differentiated. They could be separated by their magnetic behavior into three types: a single site with cobalt close to non-magnetic Co3+, two sites with the most magnetic cobalts in the system, and the remaining three sites displaying an intermediate behavior. This unusual magnetic differentiation calls for more detailed NMR experiments on our well characterized samples.

  15. A59 waste repackaging database (AWARD)

    International Nuclear Information System (INIS)

    Keel, A.

    1993-06-01

    This paper sets out the requirements for AWARD (the A59 Waste Repackaging Database); a computer-based system to record LLW sorting and repacking information from the North Cave Line in A59. A solution will be developed on the basis of this document. AWARD will record and store details entered from waste sorting and LLW repackaging operations. This document will be used as the basis of the development of the host computer system. (Author)

  16. Cobalt release from inexpensive jewellery: has the use of cobalt replaced nickel following regulatory intervention?

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Jellesen, Morten S; Menné, Torkil

    2010-01-01

    Before the introduction of the EU Nickel Directive, concern was raised that manufacturers of jewellery might turn from the use of nickel to cobalt following the regulatory intervention on nickel exposure.......Before the introduction of the EU Nickel Directive, concern was raised that manufacturers of jewellery might turn from the use of nickel to cobalt following the regulatory intervention on nickel exposure....

  17. Synthesis of new cobalt aluminophosphate framework by opening a cobalt methylphosphonate layered material

    Czech Academy of Sciences Publication Activity Database

    Zaarour, M.; Pérez, O.; Boullay, P.; Martens, J.; Mihailova, B.; Karaghiosoff, K.; Palatinus, Lukáš; Mintova, S.

    2017-01-01

    Roč. 19, č. 34 (2017), s. 5100-5105 ISSN 1466-8033 Institutional support: RVO:68378271 Keywords : cobalt aluminophosphate * cobalt methylphosphonate * layered materials * crystallic structure * X-ray diffraction Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.474, year: 2016

  18. AN ELECTROPLATING METHOD OF FORMING PLATINGS OF NICKEL, COBALT, NICKEL ALLOYS OR COBALT ALLOYS

    DEFF Research Database (Denmark)

    1997-01-01

    An electroplating method of forming platings of nickel, cobalt, nickel alloys or cobalt alloys with reduced stresses in an electrodepositing bath of the type: Watt's bath, chloride bath or a combination thereof, by employing pulse plating with periodic reverse pulse and a sulfonated naphthalene...

  19. Control of carbon nanotube growth using cobalt nanoparticles as catalyst

    International Nuclear Information System (INIS)

    Huh, Yoon; Green, Malcolm L.H.; Kim, Young Heon; Lee, Jeong Yong; Lee, Cheol Jin

    2005-01-01

    We have controllably grown carbon nanotubes using uniformly distributed cobalt nanoparticles as catalyst. Cobalt nanoparticles with a uniform size were synthesized by chemical reaction and colloidal solutions including the cobalt nanoparticles were prepared. The cobalt nanoparticles were uniformly distributed on silicon substrates by a spin-coating method. Carbon nanotubes with a uniform diameter were synthesized on the cobalt nanoparticles by thermal chemical vapor deposition of acetylene gas. The density and vertical alignment of carbon nanotubes could be controlled by adjusting the density of cobalt (Co) nanoparticles

  20. Calcium-assisted reduction of cobalt ferrite nanoparticles for nanostructured iron cobalt with enhanced magnetic performance

    International Nuclear Information System (INIS)

    Qi, B.; Andrew, J. S.; Arnold, D. P.

    2017-01-01

    This paper demonstrates the potential of a calcium-assisted reduction process for synthesizing fine-grain (~100 nm) metal alloys from metal oxide nanoparticles. To demonstrate the process, an iron cobalt alloy (Fe_6_6Co_3_4) is obtained by hydrogen annealing 7-nm cobalt ferrite (CoFe_2O_4) nanoparticles in the presence of calcium granules. The calcium serves as a strong reducing agent, promoting the phase transition from cobalt ferrite to a metallic iron cobalt alloy, while maintaining high crystallinity. Magnetic measurements demonstrate the annealing temperature is the dominant factor of tuning the grain size and magnetic properties. Annealing at 700 °C for 1 h maximizes the magnetic saturation, up to 2.4 T (235 emu/g), which matches that of bulk iron cobalt.

  1. Calcium-assisted reduction of cobalt ferrite nanoparticles for nanostructured iron cobalt with enhanced magnetic performance

    Energy Technology Data Exchange (ETDEWEB)

    Qi, B. [University of Florida, Interdisciplinary Microsystems Group, Department of Electrical and Computer Engineering (United States); Andrew, J. S. [University of Florida, Department of Materials Science and Engineering (United States); Arnold, D. P., E-mail: darnold@ufl.edu [University of Florida, Interdisciplinary Microsystems Group, Department of Electrical and Computer Engineering (United States)

    2017-03-15

    This paper demonstrates the potential of a calcium-assisted reduction process for synthesizing fine-grain (~100 nm) metal alloys from metal oxide nanoparticles. To demonstrate the process, an iron cobalt alloy (Fe{sub 66}Co{sub 34}) is obtained by hydrogen annealing 7-nm cobalt ferrite (CoFe{sub 2}O{sub 4}) nanoparticles in the presence of calcium granules. The calcium serves as a strong reducing agent, promoting the phase transition from cobalt ferrite to a metallic iron cobalt alloy, while maintaining high crystallinity. Magnetic measurements demonstrate the annealing temperature is the dominant factor of tuning the grain size and magnetic properties. Annealing at 700 °C for 1 h maximizes the magnetic saturation, up to 2.4 T (235 emu/g), which matches that of bulk iron cobalt.

  2. Synthesis of Samarium Cobalt Nanoblades

    Energy Technology Data Exchange (ETDEWEB)

    Darren M. Steele

    2010-08-25

    As new portable particle acceleration technologies become feasible the need for small high performance permanent magnets becomes critical. With particle accelerating cavities of a few microns, the photonic crystal fiber (PCF) candidate demands magnets of comparable size. To address this need, samarium cobalt (SmCo) nanoblades were attempted to be synthesized using the polyol process. Since it is preferable to have blades of 1-2 {micro}m in length, key parameters affecting size and morphology including method of stirring, reaction temperature, reaction time and addition of hydroxide were examined. Nanoparticles consisting of 70-200 nm spherical clusters with a 3-5 nm polyvinylpyrrolidone (PVP) coating were synthesized at 285 C and found to be ferromagnetic. Nanoblades of 25nm in length were observed at the surface of the nanoclusters and appeared to suggest agglomeration was occurring even with PVP employed. Morphology and size were characterized using a transmission electron microscope (TEM). Powder X-Ray Diffraction (XRD) analysis was conducted to determine composition but no supportive evidence for any particular SmCo phase has yet been observed.

  3. BARNARD 59: NO EVIDENCE FOR FURTHER FRAGMENTATION

    Energy Technology Data Exchange (ETDEWEB)

    Roman-Zuniga, C. G. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Km 103 Carr. Tijuana-Ensenada, Ensenada BC 22860 (Mexico); Frau, P.; Girart, J. M. [Institut de Ciencies de l' Espai (CSIC-IEEC), Campus UAB, Facultat de Ciencies, Torre C-5p, 08193 Bellaterra, Catalunya (Spain); Alves, Joao F., E-mail: croman@astrosen.unam.mx [Institute of Astronomy, University of Vienna, Tuerkenschanzstr. 17, 1180 Vienna (Austria)

    2012-03-10

    The dense molecular clump at the center of the Barnard 59 (B59) complex is the only region in the Pipe Nebula that has formed a small, stellar cluster. The previous analysis of a high-resolution near-IR dust extinction map revealed that the nuclear region in B59 is a massive, mostly quiescent clump of 18.9 M{sub Sun }. The clump shows a monolithic profile, possibly indicating that the clump is on the way to collapse, with no evident fragmentation that could lead to another group of star systems. In this paper, we present new analysis that compares the dust extinction map with a new dust emission radio-continuum map of higher spatial resolution. We confirm that the clump does not show any significant evidence for prestellar fragmentation at scales smaller than those probed previously.

  4. BARNARD 59: NO EVIDENCE FOR FURTHER FRAGMENTATION

    International Nuclear Information System (INIS)

    Román-Zúñiga, C. G.; Frau, P.; Girart, J. M.; Alves, João F.

    2012-01-01

    The dense molecular clump at the center of the Barnard 59 (B59) complex is the only region in the Pipe Nebula that has formed a small, stellar cluster. The previous analysis of a high-resolution near-IR dust extinction map revealed that the nuclear region in B59 is a massive, mostly quiescent clump of 18.9 M ☉ . The clump shows a monolithic profile, possibly indicating that the clump is on the way to collapse, with no evident fragmentation that could lead to another group of star systems. In this paper, we present new analysis that compares the dust extinction map with a new dust emission radio-continuum map of higher spatial resolution. We confirm that the clump does not show any significant evidence for prestellar fragmentation at scales smaller than those probed previously.

  5. The trigger and DAQ systems of the NA59 experiment

    CERN Document Server

    Ünel, Gokhan; Ballestrero, Sergio

    2004-01-01

    The NA59 experiment on the CERN SPS-H2 beam-line took data during the summers of 1999 and 2000 to perform intercalibration studies of polarization measurement and to test the use of an aligned crystal as a quarter-wave plate. The analysis revealed a proof of concept for the birefringence property of aligned crystals for photons in the 30-170 GeV energy range. The 90-m-long detector for this fixed target experiment had two independent readout schemes: one for more than 120 time-to-digital and analog-to-digital converter channels to obtain tracking and energy information; and another for the readout of the silicon strip detectors to improve vertex resolution. The readout electronics of the Na59 experiment was based on VMEbus and CAMAC systems. Novel data acquisition and online monitoring software were written to work on the commodity hardware (PCs) running mainly the Linux operating system. 21 Refs.

  6. Cobalt: A vital element in the aircraft engine industry

    Science.gov (United States)

    Stephens, J. R.

    1981-01-01

    Recent trends in the United States consumption of cobalt indicate that superalloys for aircraft engine manufacture require increasing amounts of this strategic element. Superalloys consume a lion's share of total U.S. cobalt usage which was about 16 million pounds in 1980. In excess of 90 percent of the cobalt used in this country was imported, principally from the African countries of Zaire and Zambia. Early studies on the roles of cobalt as an alloying element in high temperature alloys concentrated on the simple Ni-Cr and Nimonic alloy series. The role of cobalt in current complex nickel base superalloys is not well defined and indeed, the need for the high concentration of cobalt in widely used nickel base superalloys is not firmly established. The current cobalt situation is reviewed as it applies to superalloys and the opportunities for research to reduce the consumption of cobalt in the aircraft engine industry are described.

  7. Assessment of cobalt levels in wastewater, soil and vegetable ...

    African Journals Online (AJOL)

    User

    Key words: Cobalt level, Kubanni River, soil, vegetable, wastewater. INTRODUCTION. Cobalt is ... metals released into the environment from a variety of anthropogenic activities ..... Heavy Metal Stress in Plants, 2nd Edition,. Springer,. United.

  8. Synthesis and phosphatase activity of a Cobalt(II) phenanthroline ...

    Indian Academy of Sciences (India)

    MAMONI GARAI

    2017-09-19

    Sep 19, 2017 ... Synthesis and phosphatase activity of a Cobalt(II) phenanthroline complex. MAMONI GARAIa ... tion, cobalt complexes have gained importance because of their application as ... 2.3 Physical measurements. Infrared spectrum ...

  9. STAR FORMATION NEAR BERKELEY 59: EMBEDDED PROTOSTARS

    Energy Technology Data Exchange (ETDEWEB)

    Rosvick, J. M. [Department of Physical Sciences, Thompson Rivers University, 900 McGill Road, Kamloops, BC V2C 0C8 (Canada); Majaess, D. [Department of Astronomy and Physics, Saint Mary' s University, Halifax, NS B3H 3C3 (Canada)

    2013-12-01

    A group of suspected protostars in a dark cloud northwest of the young (∼2 Myr) cluster Berkeley 59 and two sources in a pillar south of the cluster have been studied in order to determine their evolutionary stages and ascertain whether their formation was triggered by Berkeley 59. Narrowband near-infrared observations from the Observatoire du Mont Mégantic, {sup 12}CO (J = 3-2) and SCUBA-2 (450 and 850 μm) observations from the JCMT, 2MASS, and WISE images, and data extracted from the IPHAS survey catalog were used. Of 12 sources studied, two are Class I objects, while three others are flat/Class II, one of which is a T Tauri candidate. A weak CO outflow and two potential starless cores are present in the cloud, while the pillar possesses substructure at different velocities, with no outflows present. The CO spectra of both regions show peaks in the range v {sub LSR} = –15 to –17 km s{sup –1}, which agrees with the velocity adopted for Berkeley 59 (–15.7 km s{sup –1}), while spectral energy distribution models yield an average interstellar extinction A{sub V} and distance of 15 ± 2 mag and 830 ± 120 pc, respectively, for the cloud, and 6.9 mag and 912 pc for the pillar, indicating that the regions are in the same vicinity as Berkeley 59. The formation of the pillar source appears to have been triggered by Berkeley 59. It is unclear whether Berkeley 59 triggered the association's formation.

  10. The physiological effect of cobalt on watermelon cultivation

    International Nuclear Information System (INIS)

    Yao Naihua; Jin Yafang; Sun Yaochen; Huang Yiming

    1993-01-01

    Cobalt has essential physiological action on both animals and plants. For the latter it can raise plant's nitrogen-fixing ability and saccharine content. Spray of cobalt mixed with other nutritive elements can improve the germinatit of seeds and the yield of fruit. For specifying the nutritive function of cobalt upon watermelon, isotope 60 Co was mixed into a complex leaf nutritive aqua and the regularity of transferring and absorbing cobalt in the watermelon's body was investigated

  11. Relaxation resistance of heat resisting alloys with cobalt

    International Nuclear Information System (INIS)

    Borzdyka, A.M.

    1977-01-01

    Relaxation resistance of refractory nickel-chromium alloys containing 5 to 14 % cobalt is under study. The tests involve the use of circular samples at 800 deg to 850 deg C. It is shown that an alloy containing 14% cobalt possesses the best relaxation resistance exceeding that of nickel-chromium alloys without any cobalt by a factor of 1.5 to 2. The relaxation resistance of an alloy with 5% cobalt can be increased by hardening at repeated loading

  12. Manipulating radicals: Using cobalt to steer radical reactions

    OpenAIRE

    Chirilă, A.

    2017-01-01

    This thesis describes research aimed at understanding and exploiting metallo-radical reactivity and explores reactions mediated by square planar, low-spin cobalt(II) complexes. A primary goal was to uncover novel reactivity of discrete cobalt(III)-bound carbene radicals generated upon reaction of the cobalt(II) catalysts with carbene precursors. Another important goal was to replace cobalt(II)-porphyrin catalysts with cheaper and easier to prepare metallo-radical analogues. Therefore the cata...

  13. Recovery of lithium and cobalt from waste lithium ion batteries of mobile phone

    Energy Technology Data Exchange (ETDEWEB)

    Jha, Manis Kumar, E-mail: mkjha@nmlindia.org; Kumari, Anjan; Jha, Amrita Kumari; Kumar, Vinay; Hait, Jhumki; Pandey, Banshi Dhar

    2013-09-15

    Graphical abstract: Recovery of valuable metals from scrap batteries of mobile phone. - Highlights: • Recovery of Co and Li from spent LIBs was performed by hydrometallurgical route. • Under the optimum condition, 99.1% of lithium and 70.0% of cobalt were leached. • The mechanism of the dissolution of lithium and cobalt was studied. • Activation energy for lithium and cobalt were found to be 32.4 kJ/mol and 59.81 kJ/mol, respectively. • After metal recovery, residue was washed before disposal to the environment. - Abstract: In view of the stringent environmental regulations, availability of limited natural resources and ever increasing need of alternative energy critical elements, an environmental eco-friendly leaching process is reported for the recovery of lithium and cobalt from the cathode active materials of spent lithium-ion batteries of mobile phones. The experiments were carried out to optimize the process parameters for the recovery of lithium and cobalt by varying the concentration of leachant, pulp density, reductant volume and temperature. Leaching with 2 M sulfuric acid with the addition of 5% H{sub 2}O{sub 2} (v/v) at a pulp density of 100 g/L and 75 °C resulted in the recovery of 99.1% lithium and 70.0% cobalt in 60 min. H{sub 2}O{sub 2} in sulfuric acid solution acts as an effective reducing agent, which enhance the percentage leaching of metals. Leaching kinetics of lithium in sulfuric acid fitted well to the chemical controlled reaction model i.e. 1 − (1 − X){sup 1/3} = k{sub c}t. Leaching kinetics of cobalt fitted well to the model ‘ash diffusion control dense constant sizes spherical particles’ i.e. 1 − 3(1 − X){sup 2/3} + 2(1 − X) = k{sub c}t. Metals could subsequently be separated selectively from the leach liquor by solvent extraction process to produce their salts by crystallization process from the purified solution.

  14. Perfluorinated cobalt phthalocyanine effectively catalyzes water electrooxidation

    KAUST Repository

    Morlanes, Natalia Sanchez

    2014-12-08

    Efficient electrocatalysis of water oxidation under mild conditions at neutral pH was achieved by a fluorinated cobalt phthalocyanine immobilized on fluorine-doped tin oxide (FTO) surfaces with an onset potential at 1.7 V vs. RHE. Spectroscopic, electrochemical, and inhibition studies indicate that phthalocyanine molecular species are the operational active sites. Neither free cobalt ions nor heterogeneous cobalt oxide particles or films were observed. During long-term controlled-potential electrolysis at 2 V vs. RHE (phosphate buffer, pH 7), electrocatalytic water oxidation was sustained for at least 8 h (TON ≈ 1.0 × 105), producing about 4 μmol O2 h-1 cm-2 with a turnover frequency (TOF) of about 3.6 s-1 and no measurable catalyst degradation.

  15. Characterization of a Cobalt-Tungsten Interconnect

    DEFF Research Database (Denmark)

    Harthøj, Anders; Holt, Tobias; Caspersen, Michael

    2012-01-01

    is to act both as a diffusion barrier for chromium and provide better protection against high temperature oxidation than a pure cobalt coating. This work presents a characterization of a cobalt-tungsten alloy coating electrodeposited on the ferritic steel Crofer 22 H which subsequently was oxidized in air......A ferritic steel interconnect for a solid oxide fuel cell must be coated in order to prevent chromium evaporation from the steel substrate. The Technical University of Denmark and Topsoe Fuel Cell have developed an interconnect coating based on a cobalt-tungsten alloy. The purpose of the coating...... for 300 h at 800 °C. The coating was characterized with Glow Discharge Optical Spectroscopy (GDOES), Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The oxidation properties were evaluated by measuring weight change of coated samples of Crofer 22 H and Crofer 22 APU as a function...

  16. Solubility of cobalt in primary circuit solutions

    International Nuclear Information System (INIS)

    Lambert, I.; Joyer, F.

    1992-01-01

    The solubility of cobalt ferrite (CoFe 2 O 4 ) was measured in PWR primary circuit conditions, in the temperature range 250-350 deg C, and the results were compared with the ones obtained on magnetite and nickel ferrite. As in the former cases, it was found that, in the prevailing primary circuit conditions, the solubility of the cobalt ferrite was minimum at temperatures around 300 deg C, for cobalt as well as for iron. The equilibrium iron concentration is significantly lower than in the case of magnetite. The results are discussed in relation with the POTHY code, based only on thermodynamic laws and data, used for the prediction of the primary circuit chemistry

  17. Total quality management of cobalt-60 sources

    International Nuclear Information System (INIS)

    Malkoske, G.R.

    1999-01-01

    Total Quality Management of Cobalt-60 sources by a supplier requires a life cycle approach to source management. This covers various aspects, including design, manufacturing, installation, field inspection, source surveillance and return of cobalt-60 sources at the end of their useful life. The Total Quality Management approach demonstrates a strong industry commitment to the beneficial use of gamma technology for industrial irradiation applications in both developed nations and in those nations who are developing their infrastructure and techniques for the beneficial use of this technology. MDS Nordion continues to demonstrate its support and commitment to the industry by developing and implementing state-of-the-art standards for the safe use of cobalt-60 sources

  18. Preliminary studies of cobalt complexation in groundwater

    International Nuclear Information System (INIS)

    Warwick, P.; Shaw, P.; Williams, G.M.; Hooker, P.J.

    1988-01-01

    A relatively non-invasive method has been used to separate complexed from free cobalt-60 in groundwater, using the weak cationic adsorption properties of Sephadex gels, and a mobile phase of natural groundwater. Results show the kinetics of Co complex formation in groundwater to be slow, and that the equilibrium position is affected by temperature, cobalt concentration and the ionic/organic strength of the groundwater. The addition of DAEA cellulose to the groundwater to remove humic material, also removed the majority of organic species which absorb UV at 254 nm, but 45% of the original total organic carbon remained, and the amount of complexed cobalt left in solution was only reduced to 76% of its former concentration. This suggests that the completed Co species separated by the method described in this paper are a mixture of inorganic and organic compounds, and studies are therefore continuing to establish their exact nature. (author)

  19. Preliminary studies of cobalt complexation in groundwater

    International Nuclear Information System (INIS)

    Warwick, P.; Shaw, P.; Williams, G.M.; Hooker, P.J.

    1988-01-01

    A relatively non-invasive method has been used to separate complexed from free cobalt-60 in groundwater, using the weak cationic adsorption properties of Sephadex gels, and a mobile phase of natural groundwater. Results show the kinetics of Co complex formation in groundwater to be slow, and that the equilibrium position is affected by temperature, cobalt concentration and the ionic/organic strength of the groundwater. The addition of DEAE cellulose to the groundwater to remove humic material, also removed the majority of organic species with absorb UV at 254 nm, but 45% of the original total organic carbon remained, and the amount of complexed cobalt left in solution was only reduced to 76% of its former concentration. This suggests that the complexed Co species separated by the method described in this paper are a mixture of inorganic and organic compounds, and studies are therefore continuing to establish their exact nature. (orig.)

  20. Palladium-cobalt particles as oxygen-reduction electrocatalysts

    Science.gov (United States)

    Adzic, Radoslav [East Setauket, NY; Huang, Tao [Manorville, NY

    2009-12-15

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

  1. 21 CFR 73.1015 - Chromium-cobalt-aluminum oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Chromium-cobalt-aluminum oxide. 73.1015 Section 73... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1015 Chromium-cobalt-aluminum oxide. (a) Identity. The color additive chromium-cobalt-aluminum oxide is a blue-green pigment obtained by calcining a...

  2. Paediatric liver transplantation in Johannesburg revisited: 59 ...

    African Journals Online (AJOL)

    Of the 57 patients, 45 are alive and well with actuarial 1-year patient and graft survival of 85% and 84% and 5-year patient and graft survival of 78% and 74%, respectively. Sixteen (25.42%) biliary complications occurred in 15 of our 59 transplants. Seven patients developed significant vascular complications. Comparing ...

  3. A59 waste repackaging database (AWARD)

    International Nuclear Information System (INIS)

    Keel, A.

    1993-06-01

    This document describes the software modules to be implemented to provide the user interface for the A59 Waste Repackaging Database (AWARD). The modules will consist of a front end menu with options giving access to the various screen forms and printed reports. (Author)

  4. 7 CFR 319.59-1 - Definitions.

    Science.gov (United States)

    2010-01-01

    ..., DEPARTMENT OF AGRICULTURE FOREIGN QUARANTINE NOTICES Wheat Diseases § 319.59-1 Definitions. Administrator... disease caused by the fungus Tilletia indica (Mitra) Mundkur. Plant. Any plant (including any plant part) for or capable of propagation, including a tree, a tissue culture, a plantlet culture, pollen, a shrub...

  5. 49 CFR 192.59 - Plastic pipe.

    Science.gov (United States)

    2010-10-01

    ... Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe...

  6. 33 CFR 151.59 - Placards.

    Science.gov (United States)

    2010-07-01

    ... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS... Pertains to Pollution from Ships Garbage Pollution and Sewage § 151.59 Placards. (a) This section applies... following: (1) The discharge of plastic or garbage mixed with plastic into any waters is prohibited. (2) The...

  7. Cobalt-free nickel-base superalloys

    International Nuclear Information System (INIS)

    Koizumi, Yutaka; Yamazaki, Michio; Harada, Hiroshi

    1979-01-01

    Cobalt-free nickel-base cast superalloys have been developed. Cobalt is considered to be a beneficial element to strengthen the alloys but should be eliminated in alloys to be used for direct cycle helium turbine driven by helium gas from HTGR (high temp. gas reactor). The elimination of cobalt is required to avoid the formation of radioactive 60 Co from the debris or scales of the alloys. Cobalt-free alloys are also desirable from another viewpoint, i.e. recently the shortage of the element has become a serious problem in industry. Cobalt-free Mar-M200 type alloys modified by the additions of 0.15 - 0.2 wt% B and 1 - 1.5 wt% Hf were found to have a creep rupture strength superior or comparable to that of the original Mar-M200 alloy bearing cobalt. The ductility in tensile test at 800 0 C, as cast or after prolonged heating at 900 0 C (the tensile test was done without removing the surface layer affected by the heating), was also improved by the additions of 0.15 - 0.2% B and 1 - 1.5% Hf. The morphology of grain boundaries became intricated by the additions of 0.15 - 0.2% B and 1 - 1.5% Hf, to such a degree that one can hardly distinguish grain boundaries by microscopes. The change in the grain boundary morphology was considered, as suggested previously by one of the authors (M.Y.), to be the reason for the improvements in the creep rupture strength and tensile ductility. (author)

  8. Radiation induced ligand loss from cobalt complexes

    International Nuclear Information System (INIS)

    Funston, A. M.; McFadyen, W.D.; Tregloan, P.A.

    2000-01-01

    Full text: Due to the rapid nature of ligand dissociation from cobalt(II) complexes the study of the rate of ligand dissociation necessitates the use of a technique such as pulse radiolysis. This allows the rapid reduction of the corresponding cobalt(III) complex by a reducing radical, such as the aquated electron, to form the cobalt(II) complex. However, to date, no systematic study of either the mechanism of reduction or the influence of the electronic structure on the rate of ligand dissociation has been carried out. In order to understand these processes more fully the mechanism of reduction of a range of related cobalt(III) complexes by the aquated electron and the subsequent rate of ligand dissociation from the resulting cobalt(II) complexes is being investigated. It has been found that a number of processes are observed following the initial rapid reaction of the cobalt(III) complex with the aquated electron. Ultimately ligand loss is observed. Depending upon the complex, the initial processes observed may include the formation of coordinated radicals and electron transfer within the complex. For complexes containing aromatic ligands such as 2,2'-bipyridine, 1,10-phenanthroline and dipyrido[3,2-a:2',3'-c]phenazine the formation of a coordinated radical is observed as the initial reduction step. The kinetics of ligand dissociation of these complexes has been determined. The loss of monodentate ligands is fast and has been indistinguishable from the reduction processes when aromatic ligands are also present in the complex. However, for diamine chelates and diimine chelates spectra of the transient species can be resolved

  9. Cation distributions on rapidly solidified cobalt ferrite

    Science.gov (United States)

    De Guire, Mark R.; Kalonji, Gretchen; O'Handley, Robert C.

    1990-01-01

    The cation distributions in two rapidly solidified cobalt ferrites have been determined using Moessbauer spectroscopy at 4.2 K in an 8-T magnetic field. The samples were obtained by gas atomization of a Co0-Fe2O3-P2O5 melt. The degree of cation disorder in both cases was greater than is obtainable by cooling unmelted cobalt ferrite. The more rapidly cooled sample exhibited a smaller departure from the equilibrium cation distribution than did the more slowly cooled sample. This result is explained on the basis of two competing effects of rapid solidification: high cooling rate of the solid, and large undercooling.

  10. Separation and purification of carrier-free cobalt-58 from neutron irradiated nickel foil for electrochemical studies

    International Nuclear Information System (INIS)

    Egamediev, S.; Nurbaeva, D.; Rakhmanov, A.

    2004-01-01

    Full text: Cobalt-58 will be used for tracer studies of the behaviour of cobalt radionuclides in no- carrier-added form during electrochemical deposition on metal backing. The 58 Co can be produced by using 58 Ni(n,p) 58 Co nuclear reaction in nuclear reactor. 58 Co (T 1/2 =71 days) decays by positron emitting (15%) and electron capture (85%) with simultaneous γ -irradiation. In this study, we have developed the simple method for separation and purification of 58 Co in no- carrier-added form from neutron irradiated nickel foil. Previously, we have studied the dissolution of nickel foil in various media to find best conditions for rapid dissolution of nickel target. It was found that nickel foil dissolved completely without heating in 6.3 M hydrobromic acid with addition a few drops of hydrogen peroxide. After dissolution of the target material, the cobalt-58 is separated from nickel, copper, iron and other elements by extraction chromatography. The solution in 6.3 M hydrobromic acid is passed through a column containing suspension of polytetrafluoroethylene powder with 0.5 M trioctylamine in xylene, equilibrated with the same acid. Nickel is not extracted and passed through column. Cobalt is retained and finally eluted with 3 M HBr in the one free column volume. The cobalt fraction is percolated through a column filled with suspension of pure polytetrafluoroethylene powder to purify from the admixture of extractant. The obtained solution is evaporated to dryness and the dry residue is treated by evaporation with aqua regia. After treatment the damp residue is dissolved in electrolyte and the obtained solution is used to study of 58 Co electrochemical deposition procedure. The yield of cobalt-58 was higher than 93% and the radiochemical purity was more than 99%. This method will be used for separation and purification of cobalt-57 to make of sealed sources for X-ray fluorescence analysis

  11. EXAFS Determination of the Structure of Cobalt in Carbon-Supported Cobalt and Cobalt-Molybdenum Sulfide Hydrodesulfurization Catalysts.

    NARCIS (Netherlands)

    Koningsberger, D.C.; Bouwens, S.M.A.M.; Veen, J.A.R. van; Beer, V.H.J. de; Prins, R.

    1991-01-01

    The structure of the cobalt present in carbon-supported Co and Co-Mo sulfide catalysts was studied by means of X-ray absorption spectroscopy at the Co K-edge and by X-ray photoelectron spectroscopy (XPS). Thiophene hydrodesulfurization activities were used to measure the catalytic properties of

  12. X-ray target with substrate of molybdenum alloy

    International Nuclear Information System (INIS)

    Hirsch, H.H.

    1980-01-01

    Rotary targets for x-ray tubes are provided comprising a molybdenum base body alloyed with a stabilizing proportion of iron, silicon, cobalt, tantalum, niobium, hafnium, stable metal oxide, or a mixture of the preceding

  13. TMEM59 potentiates Wnt signaling by promoting signalosome formation.

    Science.gov (United States)

    Gerlach, Jan P; Jordens, Ingrid; Tauriello, Daniele V F; van 't Land-Kuper, Ineke; Bugter, Jeroen M; Noordstra, Ivar; van der Kooij, Johanneke; Low, Teck Y; Pimentel-Muiños, Felipe X; Xanthakis, Despina; Fenderico, Nicola; Rabouille, Catherine; Heck, Albert J R; Egan, David A; Maurice, Madelon M

    2018-04-09

    Wnt/β-catenin signaling controls development and adult tissue homeostasis by regulating cell proliferation and cell fate decisions. Wnt binding to its receptors Frizzled (FZD) and low-density lipoprotein-related 6 (LRP6) at the cell surface initiates a signaling cascade that leads to the transcription of Wnt target genes. Upon Wnt binding, the receptors assemble into large complexes called signalosomes that provide a platform for interactions with downstream effector proteins. The molecular basis of signalosome formation and regulation remains elusive, largely due to the lack of tools to analyze its endogenous components. Here, we use internally tagged Wnt3a proteins to isolate and characterize activated, endogenous Wnt receptor complexes by mass spectrometry-based proteomics. We identify the single-span membrane protein TMEM59 as an interactor of FZD and LRP6 and a positive regulator of Wnt signaling. Mechanistically, TMEM59 promotes the formation of multimeric Wnt-FZD assemblies via intramembrane interactions. Subsequently, these Wnt-FZD-TMEM59 clusters merge with LRP6 to form mature Wnt signalosomes. We conclude that the assembly of multiprotein Wnt signalosomes proceeds along well-ordered steps that involve regulated intramembrane interactions. Copyright © 2018 the Author(s). Published by PNAS.

  14. Passivation and corrosion behaviours of cobalt and cobalt-chromium-molybdenum alloy

    International Nuclear Information System (INIS)

    Metikos-Hukovic, M.; Babic, R.

    2007-01-01

    Passivation and corrosion behaviour of the cobalt and cobalt-base alloy Co30Cr6Mo was studied in a simulated physiological solution containing chloride and bicarbonate ions and with pH of 6.8. The oxido-reduction processes included solid state transformations occurring at the cobalt/electrolyte interface are interpreted using theories of surface electrochemistry. The dissolution of cobalt is significantly suppressed by alloying it with chromium and molybdenum, since the alloy exhibited 'chromium like' passivity. The structural and protective properties of passive oxide films formed spontaneously at the open circuit potential or during the anodic polarization were studied using electrochemical impedance spectroscopy in the wide frequency range

  15. The determination of iron-59 in water

    International Nuclear Information System (INIS)

    Zhao Min; Ban Ying

    1993-06-01

    A method to analyse iron-59 in water is introduced. The procedure of this method includes concentration by co-precipitation with hydroxides purification by anion exchange, electrodeposition in NH 4 H 2 PO 4 -(NH 4 ) 2 CO 3 system and final measurements of beta activity with a background beta-counter. The effect of iron carrier amount and pH value of water sample on the carrying Fe-59, and the effect of concentration hydrochloric acid, flowrate of adsorption and elutriation with 6 mol/L HCl-1% H 2 O 2 solution on the adsorption efficiency have been studied. The experimental results indicate that for 101 water sample, both the chemical and radiochemical yields are greater than 90%. For 51 Cr, 60 Co, 65 Zn, 95 Zr- 95 Nb and 137 Cs the decontamination factor is greater than 10 3 . The minimum detectable limit of this method is 3.8 x 10 -3 Bq/L

  16. 10CFR50.59 safety evaluations

    International Nuclear Information System (INIS)

    Grime, L.; Page, E.

    1987-01-01

    As a plant changes from the design phase to the operational phase, new regulations and standards apply. One such regulation is 10CFR50.59 on safety evaluations. Once an operating license is issued, it is mandatory to submit all applicable changes, tests, and experiments to the safety evaluation process. As preparation for this transition, Detroit Edison had procedures in place and conducted personnel training. Reviews of the safety engineering were conducted by the on-site review board. The off-site board delegated detailed reviews of most safety evaluations to the independent safety evaluation group (ISEG). The on-site group review included presentation of complete design packages by engineers. The ISEG and off-site review group's activity focused on safety evaluation. This paper addresses industry trends that were studied, Detroit Edison's recent actions, and industry issues related to 10CFR50.59 safety evaluations

  17. Determination of 59Ni in radioactive waste

    International Nuclear Information System (INIS)

    Fisera, O.; Sebesta, F.

    2010-01-01

    Composite material PAN-DMG, containing chelating agent dimethylglyoxime (DMG) immobilized in porous matrix of binding polymer polyacrylonitrile (PAN), was used for nickel separation and concentration. Method for preparation of 59 Ni source for low energy photon spectrometry was developed using homogeneous precipitation of nickel with DMG. The proposed method was tested with two types of real radioactive waste (boric acid concentrate from nuclear power plant (NPP) evaporator and spent ion exchanger from NPP). (author)

  18. 59 MDW/Science and Technology Poster

    Science.gov (United States)

    2017-04-28

    the Air Force, and Science and Engineering community Employ innov1tlve technologies ind lj)prOIChH to sustain health, performance ind revolutionize...Medics Through Patient.Centered Care Our Goals Provide technic1I expertise and resources, project management assistance, direction, ind...SGYU SUBJECT: Professional Presentation Approval • ’ ...... -""""’ ~ 18 APR 20 17 1. Your paper, entitled 59 MDW/ Science & Technology Poster

  19. Water splitting: Taking cobalt in isolation

    Science.gov (United States)

    Wang, Aiqin; Zhang, Tao

    2016-01-01

    The sustainable production of hydrogen is key to the delivery of clean energy in a hydrogen economy; however, lower-cost alternatives to platinum electrocatalysts are needed. Now, isolated, earth-abundant cobalt atoms dispersed over nitrogen-doped graphene are shown to efficiently electrolyse water to generate hydrogen.

  20. Synthesis and Characterization of Cobalt Ferrite Nanoparticles ...

    African Journals Online (AJOL)

    prepared material. It was observed that surface modification such as with silica coating on the cobalt ferrite will have significant effect on the structural and magnetic properties. It is also observed that, silica coated nanoparticles could be used in biomedical applications (Hong et al., 2013). In this work we have chosen sol-gel ...

  1. Nano cobalt oxides for photocatalytic hydrogen production

    KAUST Repository

    Mangrulkar, Priti A.

    2012-07-01

    Nano structured metal oxides including TiO 2, Co 3O 4 and Fe 3O 4 have been synthesized and evaluated for their photocatalytic activity for hydrogen generation. The photocatalytic activity of nano cobalt oxide was then compared with two other nano structured metal oxides namely TiO 2 and Fe 3O 4. The synthesized nano cobalt oxide was characterized thoroughly with respect to EDX and TEM. The yield of hydrogen was observed to be 900, 2000 and 8275 mmol h -1 g -1 of photocatalyst for TiO 2, Co 3O 4 and Fe 3O 4 respectively under visible light. It was observed that the hydrogen yield in case of nano cobalt oxide was more than twice to that of TiO 2 and the hydrogen yield of nano Fe 3O 4 was nearly four times as compared to nano Co 3O 4. The influence of various operating parameters in hydrogen generation by nano cobalt oxide was then studied in detail. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  2. Research advances in adsorption treatment of cesium and cobalt in waste liquid of nuclear power plants by ion exchange resin

    International Nuclear Information System (INIS)

    Liu Dan; Wang Xin; Liu Jiean; Zhu Laiye; Chen Bin; Weng Minghui

    2014-01-01

    Liquid radwaste is unavoidably produced during the operation of nuclear power plants (NPP). With the development of China's nuclear power, much more attention will be paid to the impact of NPP construction on water environment. Radionuclides are the main targets for adsorption treatment of NPP liquid radwaste. Thereinto, cesium and cobalt are typical cationic ones. Currently, ion exchange process is widely used in liquid radwaste treatment system (WLS) of NPP, wherein resin plays a key role. The paper reviewed the research progress on adsorption of cesium and cobalt existed in NPP liquid radwaste using ion exchange resin. (authors)

  3. Exposure to cobalt causes transcriptomic and proteomic changes in two rat liver derived cell lines.

    Directory of Open Access Journals (Sweden)

    Matthew G Permenter

    Full Text Available Cobalt is a transition group metal present in trace amounts in the human diet, but in larger doses it can be acutely toxic or cause adverse health effects in chronic exposures. Its use in many industrial processes and alloys worldwide presents opportunities for occupational exposures, including military personnel. While the toxic effects of cobalt have been widely studied, the exact mechanisms of toxicity remain unclear. In order to further elucidate these mechanisms and identify potential biomarkers of exposure or effect, we exposed two rat liver-derived cell lines, H4-II-E-C3 and MH1C1, to two concentrations of cobalt chloride. We examined changes in gene expression using DNA microarrays in both cell lines and examined changes in cytoplasmic protein abundance in MH1C1 cells using mass spectrometry. We chose to closely examine differentially expressed genes and proteins changing in abundance in both cell lines in order to remove cell line specific effects. We identified enriched pathways, networks, and biological functions using commercial bioinformatic tools and manual annotation. Many of the genes, proteins, and pathways modulated by exposure to cobalt appear to be due to an induction of a hypoxic-like response and oxidative stress. Genes that may be differentially expressed due to a hypoxic-like response are involved in Hif-1α signaling, glycolysis, gluconeogenesis, and other energy metabolism related processes. Gene expression changes linked to oxidative stress are also known to be involved in the NRF2-mediated response, protein degradation, and glutathione production. Using microarray and mass spectrometry analysis, we were able to identify modulated genes and proteins, further elucidate the mechanisms of toxicity of cobalt, and identify biomarkers of exposure and effect in vitro, thus providing targets for focused in vivo studies.

  4. Satelite structure in 59Co NMR spectrum of magnetically ordered Dysub(1-x)Ysub(x)Co2 intermetallic compound

    International Nuclear Information System (INIS)

    Yoshimura, Kazuyoshi; Hirosawa, Satoshi; Nakamura, Yoji

    1984-01-01

    The magnetic environment effect of cobalt in Dysub(1-x)Ysub(x)Co 2 has been studied by means of bulk magnetization and 59 Co spin-echo NMR measurements at 4.2K. Clearly resolved satellite structures of the NMR spectra have been observed. The hyperfine field distributions of 59 Co are decomposed into contributions of Co atoms in various nearest neighbor configurations of rare earth atoms. In this analysis the dipole field due to nearest neighbor rare earth moments plays an important role. The result indicates that the magnetic moment of Co in the RCo 2 cubic Laves phase pseudobinary compounds is quite sensitive to the nearest neighbor rare earth environment. (author)

  5. Cobalt Fischer-Tropsch catalysts: influence of cobalt dispersion and titanium oxides promotion

    Energy Technology Data Exchange (ETDEWEB)

    Azib, H

    1996-04-10

    The aim of this work is to study the effect of Sol-Gel preparation parameters which occur in silica supported cobalt catalysts synthesis. These catalysts are particularly used for the waxes production in natural gas processing. The solids have been characterized by several techniques: transmission electron microscopy (TEM), X-ray absorption near edge spectroscopy (XANES), programmed temperature reduction (TPR), infrared spectroscopy (IR), ultraviolet spectroscopy (UV), Magnetism, thermodesorption of H{sub 2} (TPD). The results indicate that the control of the cobalt dispersion and oxide phases nature is possible by modifying Sol-Gel parameters. The catalytic tests in Fischer-Tropsch synthesis were conducted on a pilot unit under pressure (20 atm) and suggested that turnover rates were independent of Co crystallite size, Co phases in the solids (Co deg., cobalt silicate) and titanium oxide promotion. On the other methane, the C{sub 3}{sup +} hydrocarbon selectivity is increased with increasing crystallite size. Inversely, the methane production is favoured by very small crystallites, cobalt silicate increase and titanium addition. However, the latter, used as a cobalt promoter, has a benefic effect on the active phase stability during the synthesis. (author). 149 refs., 102 figs., 71 tabs.

  6. Electrocatalytic performance evaluation of cobalt hydroxide and cobalt oxide thin films for oxygen evolution reaction

    Science.gov (United States)

    Babar, P. T.; Lokhande, A. C.; Pawar, B. S.; Gang, M. G.; Jo, Eunjin; Go, Changsik; Suryawanshi, M. P.; Pawar, S. M.; Kim, Jin Hyeok

    2018-01-01

    The development of an inexpensive, stable, and highly active electrocatalyst for oxygen evolution reaction (OER) is essential for the practical application of water splitting. Herein, we have synthesized an electrodeposited cobalt hydroxide on nickel foam and subsequently annealed in an air atmosphere at 400 °C for 2 h. In-depth characterization of all the films using X-ray diffraction (XRD), X-ray photoelectron emission spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV) techniques, which reveals major changes for their structural, morphological, compositional and electrochemical properties, respectively. The cobalt hydroxide nanosheet film shows high catalytic activity with 290 mV overpotential at 10 mA cm-2 and 91 mV dec-1 Tafel slope and robust stability (24 h) for OER in 1 M KOH electrolyte compared to cobalt oxide (340 mV). The better OER activity of cobalt hydroxide in comparison to cobalt oxide originated from high active sites, enhanced surface, and charge transport capability.

  7. A computer controlled tele-cobalt unit

    International Nuclear Information System (INIS)

    Brace, J.A.

    1982-01-01

    A computer controlled cobalt treatment unit was commissioned for treating patients in January 1980. Initially the controlling computer was a minicomputer, but now the control of the therapy unit is by a microcomputer. The treatment files, which specify the movement and configurations necessary to deliver the prescribed dose, are produced on the minicomputer and then transferred to the microcomputer using minitape cartridges. The actual treatment unit is based on a standard cobalt unit with a few additional features e.g. the drive motors can be controlled either by the computer or manually. Since the treatment unit is used for both manual and automatic treatments, the operational procedure under computer control is made to closely follow the manual procedure for a single field treatment. The necessary safety features which protect against human, hardware and software errors as well as the advantages and disadvantages of computer controlled radiotherapy are discussed

  8. Creep-fatigue of low cobalt superalloys

    Science.gov (United States)

    Halford, G. R.

    1982-01-01

    Testing for the low cycle fatigue and creep fatigue resistance of superalloys containing reduced amounts of cobalt is described. The test matrix employed involves a single high temperature appropriate for each alloy. A single total strain range, again appropriate to each alloy, is used in conducting strain controlled, low cycle, creep fatigue tests. The total strain range is based upon the level of straining that results in about 10,000 cycles to failure in a high frequency (0.5 Hz) continuous strain-cycling fatigue test. No creep is expected to occur in such a test. To bracket the influence of creep on the cyclic strain resistance, strain hold time tests with ore minute hold periods are introduced. One test per composition is conducted with the hold period in tension only, one in compression only, and one in both tension and compression. The test temperatures, alloys, and their cobalt compositions that are under study are given.

  9. Process for obtaining cobalt and lanthanum nickelate

    International Nuclear Information System (INIS)

    Tapcov, V.; Samusi, N.; Gulea, A.; Horosun, I.; Stasiuc, V.; Petrenco, P.

    1999-01-01

    The invention relates to the process for obtaining polycrystalline ceramics of cobalt and lanthanum nickelate with the perovskite structure from coordinative hetero metallic compounds. The obtained products can be utilized in the industry in the capacity of catalysts. Summary of the invention consists in obtaining polycrystalline ceramics LaCoO 3 and LaNiO 3 with the perovskite structure by pyrolysis of the parent compounds, namely, the coordinative hetero metallic compounds of the lanthanum cobalt or lanthanum nickel. The pyrolysis of the parent compound runs during one hour at 800 C. The technical result of the invention consists in lowering the temperature of the parent compound pyrolysis containing the precise ratio of metals necessary for ceramics obtaining

  10. Cobalt oxides from crystal chemistry to physics

    CERN Document Server

    Raveau, Bernard

    2012-01-01

    Unparalleled in the breadth and depth of its coverage of all important aspects, this book systematically treats the electronic and magnetic properties of stoichiometric and non-stoichiometric cobaltites in both ordered and disordered phases. Authored by a pioneer and a rising star in the field, the monograph summarizes, organizes and streamlines the otherwise difficult-to-obtain information on this topic. An introductory chapter sets forth the crystal chemistry of cobalt oxides to lay the groundwork for an understanding of the complex phenomena observed in this materials class. Special emphasis is placed on a comprehensive discussion of cobaltite physical properties in different structural families. Providing a thorough introduction to cobalt oxides from a chemical and physical viewpoint as a basis for understanding their intricacies, this is a must-have for both experienced researchers as well as entrants to the field.

  11. Photoionization of cobalt impuritiesin zinc oxide

    Czech Academy of Sciences Publication Activity Database

    Ivanov, V.; Godlewski, M.; Dejneka, Alexandr

    2015-01-01

    Roč. 252, č. 9 (2015), s. 1988-1992 ISSN 0370-1972 R&D Projects: GA MŠk(CZ) LM2011029; GA ČR GAP108/12/1941 Grant - others:SAFMAT(XE) CZ.2.16/3.1.00/22132 Institutional support: RVO:68378271 Keywords : absorption band * cobalt * photoionization * electron spin resonance * pulsed mode * ZnO Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.522, year: 2015

  12. Speciation studies of cobalt in sea water

    International Nuclear Information System (INIS)

    Toteja, R.S.D.; Sudersanan, M.; Iyer, R.K.

    1995-01-01

    Recent results on the speciation of cobalt in simulated and actual sea water is reported using ion exchangers. The influence of magnesium ions in affecting the composition of ion exchangers and subsequent interpretation of the results is discussed. The results indicated that Co +2 may predominate in both the simulated and actual sea water and the presence of other constituents in sea water does not affect the nature of complex species present. (author). 2 refs., 3 tabs., 1 fig

  13. Literature study on the physiology of cobalt

    International Nuclear Information System (INIS)

    Erzberger, A.

    1986-12-01

    This literature study analyses the metabolism of cobalt in the human body, focussing on its resorption and the influence of various parameters like its chemical form, antagonisms, etc. on the level of resorption rate. The value currently recommended by ICRP for resorption rates (f 1 factor) of 0,3 or 0,05 for man is examined for its confirmation or non-confirmation in literature. (orig./MG) [de

  14. Enhanced magnetocrystalline anisotropy in deposited cobalt clusters

    Energy Technology Data Exchange (ETDEWEB)

    Eastham, D.A.; Denby, P.M.; Kirkman, I.W. [Daresbury Laboratory, Daresbury, Warrington (United Kingdom); Harrison, A.; Whittaker, A.G. [Department of Chemistry, University of Edinburgh, Edinburgh (United Kingdom)

    2002-01-28

    The magnetic properties of nanomaterials made by embedding cobalt nanocrystals in a copper matrix have been studied using a SQUID magnetometer. The remanent magnetization at temperatures down to 1.8 K and the RT (room temperature) field-dependent magnetization of 1000- and 8000-atom (average-size) cobalt cluster samples have been measured. In all cases it has been possible to relate the morphology of the material to the magnetic properties. However, it is found that the deposited cluster samples contain a majority of sintered clusters even at cobalt concentrations as low as 5% by volume. The remanent magnetization of the 8000-atom samples was found to be bimodal, consisting of one contribution from spherical particles and one from touching (sintered) clusters. Using a Monte Carlo calculation to simulate the sintering it has been possible to calculate a size distribution which fits the RT superparamagnetic behaviour of the 1000-atom samples. The remanent magnetization for this average size of clusters could then be fitted to a simple model assuming that all the nanoparticles are spherical and have a size distribution which fits the superparamagnetic behaviour. This gives a value for the potential energy barrier height (for reversing the spin direction) of 2.0 {mu}eV/atom which is almost four times the accepted value for face-centred-cubic bulk cobalt. The remanent magnetization for the spherical component of the large-cluster sample could not be fitted with a single barrier height and it is conjectured that this is because the barriers change as a function of cluster size. The average value is 1.5 {mu}eV/atom but presumably this value tends toward the bulk value (0.5 {mu}eV/atom) for the largest clusters in this sample. (author)

  15. Cobalt metabolism and toxicology-A brief update

    Energy Technology Data Exchange (ETDEWEB)

    Simonsen, Lars Ole, E-mail: LOSimonsen@dadlnet.dk; Harbak, Henrik; Bennekou, Poul

    2012-08-15

    Cobalt metabolism and toxicology are summarized. The biological functions of cobalt are updated in the light of recent understanding of cobalt interference with the sensing in almost all animal cells of oxygen deficiency (hypoxia). Cobalt (Co{sup 2+}) stabilizes the transcriptional activator hypoxia-inducible factor (HIF) and thus mimics hypoxia and stimulates erythropoietin (Epo) production, but probably also by the same mechanism induces a coordinated up-regulation of a number of adaptive responses to hypoxia, many with potential carcinogenic effects. This means on the other hand that cobalt (Co{sup 2+}) also may have beneficial effects under conditions of tissue hypoxia, and possibly can represent an alternative to hypoxic preconditioning. Cobalt is acutely toxic in larger doses, and in mammalian in vitro test systems cobalt ions and cobalt metal are cytotoxic and induce apoptosis and at higher concentrations necrosis with inflammatory response. Cobalt metal and salts are also genotoxic, mainly caused by oxidative DNA damage by reactive oxygen species, perhaps combined with inhibition of DNA repair. Of note, the evidence for carcinogenicity of cobalt metal and cobalt sulfate is considered sufficient in experimental animals, but is as yet considered inadequate in humans. Interestingly, some of the toxic effects of cobalt (Co{sup 2+}) have recently been proposed to be due to putative inhibition of Ca{sup 2+} entry and Ca{sup 2+}-signaling and competition with Ca{sup 2+} for intracellular Ca{sup 2+}-binding proteins. The tissue partitioning of cobalt (Co{sup 2+}) and its time-dependence after administration of a single dose have been studied in man, but mainly in laboratory animals. Cobalt is accumulated primarily in liver, kidney, pancreas, and heart, with the relative content in skeleton and skeletal muscle increasing with time after cobalt administration. In man the renal excretion is initially rapid but decreasing over the first days, followed by a second, slow

  16. Uptake of radionuclides caesium and cobalt

    International Nuclear Information System (INIS)

    Lukac, P.; Foldesova, M.

    1995-01-01

    By means of chemical treatment ammonium, potassium, sodium and H-form of zeolite were prepared. The chemical modifications of zeolite were carried out with: 2M solution of NaNO 3 , NH 4 NO 3 , KNO 3 ; 0,1M solution of HCl; NaOH solution of different concentration. The method of model radioactive solution was used to find the sorption ability for cesium and cobalt every modified zeolite. The model solution were 0.05M solution of cobalt labelled by 60 Co or cesium labelled by 137 Cs. The highest sorption ability was observed for zeolite modified by NaOH. The influence of pH on uptake of cesium and cobalt by modified zeolite was searched as well. The experimental data (leaching tests, compressive strength measurement and porosity) were measured for the case the Cs and Cs from model water solution and radioactive waste water were up taken on chemically modified zeolite and were subsequently incorporated into cement casts on blast furnace cement slags basis. The leachability was tested in water, in basis solution and in acid solution. The leachability in water and basic solution was negligible, in acid solution it was less than 4% which is inside of value of applied measure method. The compressive strength, porosity and leaching experiment are hopefully and show good mechanical stability and good retention of observed radionuclides in samples exposed in leaching solutions. (J.K.)

  17. Uptake of radionuclides caesium and cobalt

    Energy Technology Data Exchange (ETDEWEB)

    Lukac, P; Foldesova, M [Slovak Technical Univ., Bratislava (Slovakia)

    1996-12-31

    By means of chemical treatment ammonium, potassium, sodium and H-form of zeolite were prepared. The chemical modifications of zeolite were carried out with: 2M solution of NaNO{sub 3}, NH{sub 4}NO{sub 3}, KNO{sub 3}; 0,1M solution of HCl; NaOH solution of different concentration. The method of model radioactive solution was used to find the sorption ability for cesium and cobalt every modified zeolite. The model solution were 0.05M solution of cobalt labelled by {sup 60}Co or cesium labelled by {sup 137}Cs. The highest sorption ability was observed for zeolite modified by NaOH. The influence of pH on uptake of cesium and cobalt by modified zeolite was searched as well. The experimental data (leaching tests, compressive strength measurement and porosity) were measured for the case the Cs and Cs from model water solution and radioactive waste water were up taken on chemically modified zeolite and were subsequently incorporated into cement casts on blast furnace cement slags basis. The leachability was tested in water, in basis solution and in acid solution. The leachability in water and basic solution was negligible, in acid solution it was less than 4% which is inside of value of applied measure method. The compressive strength, porosity and leaching experiment are hopefully and show good mechanical stability and good retention of observed radionuclides in samples exposed in leaching solutions. (J.K.).

  18. Plasma sprayed samarium--cobalt permanent magnets

    International Nuclear Information System (INIS)

    Willson, M.C.; Janowiecki, R.J.

    1975-01-01

    Samarium--cobalt permanent magnets were fabricated by arc plasma spraying. This process involves the injection of relatively coarse powder particles into a high-temperature gas for melting and spraying onto a substrate. The technique is being investigated as an economical method for fabricating cobalt--rare earth magnets for advanced traveling wave tubes and cross-field amplifiers. Plasma spraying permits deposition of material at high rates over large areas with optional direct bonding to the substrate, and offers the ability to fabricate magnets in a variety of shapes and sizes. Isotropic magnets were produced with high coercivity and good reproducibility in magnetic properties. Post-spray thermal treatments were used to enhance the magnetic properties of sprayed deposits. Samarium--cobalt magnets, sprayed from samarium-rich powder and subjected to post-spray heat treatment, displayed energy products in excess of 9 million gauss-oersteds and coercive forces of approximately 6000 oersteds. Bar magnet arrays were constructed by depositing magnets on ceramic substrates. (auth)

  19. Sintered cobalt-rare earth intermetallic product

    International Nuclear Information System (INIS)

    Benz, M.C.

    1975-01-01

    A process is described for preparing novel sintered cobalt--rare earth intermetallic products which can be magnetized to form permanent magnets having stable improved magnetic properties. A cobalt--rare earth metal alloy is formed having a composition which at sintering temperature falls outside the composition covered by the single Co 5 R intermetallic phase on the rare earth richer side. The alloy contains a major amount of the Co 5 R intermetallic phase and a second solid CoR phase which is richer in rare earth metal content than the Co 5 R phase. The specific cobalt and rare earth metal content of the alloy is substantially the same as that desired in the sintered product. The alloy, in particulate form, is pressed into compacts and sintered to the desired density. The sintered product is comprised of a major amount of the Co 5 R solid intermetallic phase and up to about 35 percent of the product of the second solid CoR intermetallic phase which is richer in rare earth metal content than the Co 5 R phase

  20. The cobalt radioactive isotopes in environment

    International Nuclear Information System (INIS)

    2007-01-01

    For the year 1993 the total activity released in cobalt is 69 GBq for the whole of nuclear power plants. The part of activity in cobalt for La Hague in 1993 is 8 GBq of 58 Co and 2 GBq of 60 Co. The radioactive isotopes released by nuclear power plants or the reprocessing plant of La Hague under liquid effluents are shared by half between 58 Co and 60 Co. The exposure to sealed sources is the most important risk for the cobalt. The risk of acute exposure can associate a local irradiation of several decades of grays inducing a radiological burns, deep burn to treat in surgery by resection or graft even amputation. A global irradiation of organism for several grays induces an acute irradiation syndrome, often serious. At long term the stochastic effects are represented by leukemia and radio-induced cancers. The increase of probability of their occurrence is 1% by sievert. We must remind that the natural spontaneous probability is 25%. (N.C.)

  1. Hot corrosion of low cobalt alloys

    Science.gov (United States)

    Stearns, C. A.

    1982-01-01

    The hot corrosion attack susceptibility of various alloys as a function of strategic materials content are investigated. Preliminary results were obtained for two commercial alloys, UDIMET 700 and Mar-M 247, that were modified by varying the cobalt content. For both alloys the cobalt content was reduced in steps to zero. Nickel content was increased accordingly to make up for the reduced cobalt but all other constituents were held constant. Wedge bar test samples were produced by casting. The hot corrosion test consisted of cyclically exposing samples to the high velocity flow of combustion products from an air-fuel burner fueled with jet A-1 and seeded with a sodium chloride aqueous solution. The flow velocity was Mach 0.5 and the sodium level was maintained at 0.5 ppm in terms of fuel plus air. The test cycle consisted of holding the test samples at 900 C for 1 hour followed by 3 minutes in which the sample could cool to room temperature in an ambient temperature air stream.

  2. Cobalt metabolism and toxicology—A brief update

    International Nuclear Information System (INIS)

    Simonsen, Lars Ole; Harbak, Henrik; Bennekou, Poul

    2012-01-01

    Cobalt metabolism and toxicology are summarized. The biological functions of cobalt are updated in the light of recent understanding of cobalt interference with the sensing in almost all animal cells of oxygen deficiency (hypoxia). Cobalt (Co 2+ ) stabilizes the transcriptional activator hypoxia-inducible factor (HIF) and thus mimics hypoxia and stimulates erythropoietin (Epo) production, but probably also by the same mechanism induces a coordinated up-regulation of a number of adaptive responses to hypoxia, many with potential carcinogenic effects. This means on the other hand that cobalt (Co 2+ ) also may have beneficial effects under conditions of tissue hypoxia, and possibly can represent an alternative to hypoxic preconditioning. Cobalt is acutely toxic in larger doses, and in mammalian in vitro test systems cobalt ions and cobalt metal are cytotoxic and induce apoptosis and at higher concentrations necrosis with inflammatory response. Cobalt metal and salts are also genotoxic, mainly caused by oxidative DNA damage by reactive oxygen species, perhaps combined with inhibition of DNA repair. Of note, the evidence for carcinogenicity of cobalt metal and cobalt sulfate is considered sufficient in experimental animals, but is as yet considered inadequate in humans. Interestingly, some of the toxic effects of cobalt (Co 2+ ) have recently been proposed to be due to putative inhibition of Ca 2+ entry and Ca 2+ -signaling and competition with Ca 2+ for intracellular Ca 2+ -binding proteins. The tissue partitioning of cobalt (Co 2+ ) and its time-dependence after administration of a single dose have been studied in man, but mainly in laboratory animals. Cobalt is accumulated primarily in liver, kidney, pancreas, and heart, with the relative content in skeleton and skeletal muscle increasing with time after cobalt administration. In man the renal excretion is initially rapid but decreasing over the first days, followed by a second, slow phase lasting several weeks, and

  3. Pharmacokinetics of inorganic cobalt and a vitamin B12 supplement in the Thoroughbred horse: Differentiating cobalt abuse from supplementation.

    Science.gov (United States)

    Hillyer, L L; Ridd, Z; Fenwick, S; Hincks, P; Paine, S W

    2018-05-01

    While cobalt is an essential micronutrient for vitamin B 12 synthesis in the horse, at supraphysiological concentrations, it has been shown to enhance performance in human subjects and rats, and there is evidence that its administration in high doses to horses poses a welfare threat. Animal sport regulators currently control cobalt abuse via international race day thresholds, but this work was initiated to explore means of potentially adding to application of those thresholds since cobalt may be present in physiological concentrations. To devise a scientific basis for differentiation between presence of cobalt from bona fide supplementation and cobalt doping through the use of ratios. Six Thoroughbred horses were given 10 mL vitamin B 12 /cobalt supplement (Hemo-15 ® ; Vetoquinol, Buckingham, Buckinghamshire, UK., 1.5 mg B 12 , 7 mg cobalt gluconate = 983 μg total Co) as an i.v. bolus then an i.v. infusion (15 min) of 100 mg cobalt chloride (45.39 mg Co) 6 weeks later. Pre-and post-administration plasma and urine samples were analysed for cobalt and vitamin B 12 . Urine and plasma samples were analysed for vitamin B 12 using an immunoassay and cobalt concentrations were measured via ICP-MS. Baseline concentrations of cobalt in urine and plasma for each horse were subtracted from their cobalt concentrations post-administration for the PK analysis. Compartmental analysis was used for the determination of plasma PK parameters for cobalt using commercially available software. On administration of a vitamin B 12 /cobalt supplement, the ratio of cobalt to vitamin B 12 in plasma rapidly increased to approximately 3 and then rapidly declined below a ratio of 1 and then back to near baseline over the next week. On administration of 100 mg cobalt chloride, the ratio initially exceeded 10 in plasma and then declined with the lower 95% confidence interval remaining above a ratio of 1 for 7 days. For two horses with extended sampling, the plasma ratio remained above one for

  4. Conceptual design of a conveyor system for the Philippine multipurpose cobalt-60 gamma irradiation facility

    International Nuclear Information System (INIS)

    Borras, A.M.

    1992-01-01

    The Multipurpose Cobalt-60 Gamma Irradiation Facility at the PNRI presently utilizes the batch irradiation method using turntables to rotate the product boxes. The target materials or products are being carried manually or with the use of pushcart through the personnel maze. This paper presents a conceptual design for the best suitable product-handling or conveyor system for the Philippine Multipurpose Cobalt-60 Gamma Irradiation Facility. The main irradiation conveyor line shall be a 55 cm x 200 cm slat-type conveyor made of SUS 304 material that could be operated in a semi-batch continuous flow and/or shuffle-dwell method with a tact-time range of 10 min to 7 h. The products can be irradiated in a single direction, two-pass, two-sided method. (auth.). 11 refs.; 4 figs.; 2 tabs

  5. Study of complex formation of cobalt (II) and cobalt (III) in acrylamide aqueous solutions and in the phase of acrylamide hydrogel

    International Nuclear Information System (INIS)

    Ismailova, M.M.; Egorova, L.A.; Khamidov, B.O.

    1993-01-01

    Present article is devoted to study of complex formation of cobalt (II) and cobalt (III) in acrylamide aqueous solutions and in the phase of acrylamide hydrogel. The condition of cobalt in various rate of oxidation in acrylamide aqueous solutions was studied. The concentration conditions of stability of system Co(II)-Co(III) were defined. The composition of coordination compounds of cobalt (II) and cobalt (III) in acrylamide aqueous solutions and in the phase of acrylamide hydrogel was determined.

  6. COBALT: A GN&C Payload for Testing ALHAT Capabilities in Closed-Loop Terrestrial Rocket Flights

    Science.gov (United States)

    Carson, John M., III; Amzajerdian, Farzin; Hines, Glenn D.; O'Neal, Travis V.; Robertson, Edward A.; Seubert, Carl; Trawny, Nikolas

    2016-01-01

    The COBALT (CoOperative Blending of Autonomous Landing Technology) payload is being developed within NASA as a risk reduction activity to mature, integrate and test ALHAT (Autonomous precision Landing and Hazard Avoidance Technology) systems targeted for infusion into near-term robotic and future human space flight missions. The initial COBALT payload instantiation is integrating the third-generation ALHAT Navigation Doppler Lidar (NDL) sensor, for ultra high-precision velocity plus range measurements, with the passive-optical Lander Vision System (LVS) that provides Terrain Relative Navigation (TRN) global-position estimates. The COBALT payload will be integrated onboard a rocket-propulsive terrestrial testbed and will provide precise navigation estimates and guidance planning during two flight test campaigns in 2017 (one open-loop and closed- loop). The NDL is targeting performance capabilities desired for future Mars and Moon Entry, Descent and Landing (EDL). The LVS is already baselined for TRN on the Mars 2020 robotic lander mission. The COBALT platform will provide NASA with a new risk-reduction capability to test integrated EDL Guidance, Navigation and Control (GN&C) components in closed-loop flight demonstrations prior to the actual mission EDL.

  7. Dosing of anaerobic granular sludge bioreactors with cobalt: Impact of cobalt retention on methanogenic activity

    KAUST Repository

    Fermoso, Fernando G.

    2010-12-01

    The effect of dosing a metal limited anaerobic sludge blanket (UASB) reactor with a metal pulse on the methanogenic activity of granular sludge has thus far not been successfully modeled. The prediction of this effect is crucial in order to optimize the strategy for metal dosage and to prevent unnecessary losses of resources. This paper describes the relation between the initial immobilization of cobalt in anaerobic granular sludge cobalt dosage into the reactor and the evolution of methanogenic activity during the subsequent weeks. An operationally defined parameter (A0· B0) was found to combine the amount of cobalt immobilized instantaneously upon the pulse (B0) and the amount of cobalt immobilized within the subsequent 24. h (A0). In contrast with the individual parameters A0 and B0, the parameter A0· B0 correlated significantly with the methanogenic activity of the sludge during the subsequent 16 or 35. days. This correlation between metal retention and activity evolution is a useful tool to implement trace metal dosing strategies for biofilm-based biotechnological processes. © 2010.

  8. Cobalt(I) and Cobalt(III) Cyclopentadienyl Complexes with New Silicon-branched Fluorous Tags

    Czech Academy of Sciences Publication Activity Database

    Strašák, Tomáš; Čermák, Jan; Červenková Šťastná, Lucie; Sýkora, Jan; Fajgar, Radek

    2014-01-01

    Roč. 159, MAR 2014 (2014), s. 15-20 ISSN 0022-1139 R&D Projects: GA ČR(CZ) GAP106/12/1372 Institutional support: RVO:67985858 Keywords : fluorous tag * cobalt complex * cyclopentadienyl complex Subject RIV: CC - Organic Chemistry Impact factor: 1.948, year: 2014

  9. Weight of Polyethylene Wear Particles is Similar in TKAs with Oxidized Zirconium and Cobalt-chrome Prostheses

    Science.gov (United States)

    Kim, Jun-Shik; Huh, Wansoo; Lee, Kwang-Hoon

    2009-01-01

    Background The greater lubricity and resistance to scratching of oxidized zirconium femoral components are expected to result in less polyethylene wear than cobalt-chrome femoral components. Questions/purposes We examined polyethylene wear particles in synovial fluid and compared the weight, size (equivalent circle diameter), and shape (aspect ratio) of polyethylene wear particles in knees with an oxidized zirconium femoral component with those in knees with a cobalt-chrome femoral component. Patients and Methods One hundred patients received an oxidized zirconium femoral component in one knee and a cobalt-chrome femoral component in the other. There were 73 women and 27 men with a mean age of 55.6 years (range, 44–60 years). The minimum followup was 5 years (mean, 5.5 years; range, 5–6 years). Polyethylene wear particles were analyzed using thermogravimetric methods and scanning electron microscopy. Results The weight of polyethylene wear particles produced at the bearing surface was 0.0223 ± 0.0054 g in 1 g synovial fluid in patients with an oxidized zirconium femoral component and 0.0228 ± 0.0062 g in patients with a cobalt-chrome femoral component. Size and shape of polyethylene wear particles were 0.59 ± 0.05 μm and 1.21 ± 0.24, respectively, in the patients with an oxidized zirconium femoral component and 0.52 ± 0.03 μm and 1.27 ± 0.31, respectively, in the patients with a cobalt-chrome femoral component. Knee Society knee and function scores, radiographic results, and complication rate were similar between the knees with an oxidized zirconium and cobalt-chrome femoral component. Conclusions The weight, size, and shape of polyethylene wear particles were similar in the knees with an oxidized zirconium and a cobalt-chrome femoral component. We found the theoretical advantages of this surface did not provide the actual advantage. Level of Evidence Level I, therapeutic study. See the guidelines for Authors for a complete

  10. 21 CFR 189.120 - Cobaltous salts and its derivatives.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cobaltous salts and its derivatives. 189.120 Section 189.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... malt beverages as a foam stabilizer and to prevent “gushing.” (b) Food containing any added cobaltous...

  11. Study to use graded cobalt adjuster in 540 MWe PHWR

    International Nuclear Information System (INIS)

    Raj, Manish; Fernando, M.P.S.; Pradhan, A.S.; Kumar, A.N.

    2007-01-01

    Full text: There are 17 adjusters in 540 MWe PHWR, which are essentially provided for xenon override function. They also provide flux flattening being in the central region of the reactor core. The present design of adjusters consists of stainless steel tube. The adjuster rods are grouped into 8 banks for movement. Since adjusters are normally fully inserted during reactor operation, they are best suited for production of cobalt 60. The nickel-plated cobalt in the form of either slugs or pellet are used for the design of cobalt pencils. The number of pencils can be varied to optimize the reactivity load and cobalt 60 production requirement. The worth and activity of cobalt adjusters have been worked out considering different pin configuration for the adjuster assembly. To start with we have assumed all adjusters throughout its length are of the same configuration. The flux depression factors within the cobalt pencils have been considered in the estimations of the specific and total cobalt 60 activities. The option of using graded cobalt adjusters, where different pin configuration along the length is considered for better flux flattening

  12. Removal of Cobalt Ions by Precipitate Foam Flotation

    Energy Technology Data Exchange (ETDEWEB)

    Jung, In Ha; Lee, Jung Won [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-09-30

    Simulated waste liquid containing 50 ppm cobalt ion was tested by precipitate flotation using a sodium lauryl sulfate as a collector. The effects of initial cobalt ion concentration, pH, surfactant concentration, flotation time, gas flow rate and foreign ions on removal efficiency of cobalt ion were studied. Pretreatment of the waste liquid with 35% H{sub 2}O{sub 2} prior to precipitate flotation made shift of optimal flotation pH from the strong alkalinity to weak alkaline range and made a favorable flotation of cobalt ion in wide range of pH. For the result of this experiment, 99.8% removal efficiency was obtained on the conditions of initial cobalt ion concentration 50 ppm, pH 9.5, gas flow rate 70 ml/min, flotation time 30 min. The simulate ion was formed to be the most harmful ion against removal of cobalt by precipitate flotation of the species which were tested. The presence of 0.1 M of SO{sub 4}{sup 2-} ion decreased removal efficiency of cobalt to 90% while the cobalt were almost entirely removed in the absence of sulfate ion. (author). 11 refs., 8 figs.

  13. Adsorption Study of Cobalt on Treated Granular Activated Carbon

    OpenAIRE

    Y. V. Hete; S. B. Gholase; R. U. Khope

    2012-01-01

    This study is carried out for the removal of cobalt from aqueous solution using granular activated carbon in combination with p-nitro benzoic acid at temperature 25±1 °C. The adsorption isotherm of cobalt on granular activated carbon has been determined and the data fitted reasonably well to the Langmuir and Freundlich isotherm for activated carbon.

  14. Adsorption Study of Cobalt on Treated Granular Activated Carbon

    Directory of Open Access Journals (Sweden)

    Y. V. Hete

    2012-01-01

    Full Text Available This study is carried out for the removal of cobalt from aqueous solution using granular activated carbon in combination with p-nitro benzoic acid at temperature 25±1 °C. The adsorption isotherm of cobalt on granular activated carbon has been determined and the data fitted reasonably well to the Langmuir and Freundlich isotherm for activated carbon.

  15. Microwave Mapping Demonstration Using the Thermochromic Cobalt Chloride Equilibrium

    Science.gov (United States)

    Nguyen, Vu D.; Birdwhistell, Kurt R.

    2014-01-01

    An update to the thermochromic cobalt(II) chloride equilibrium demonstration is described. Filter paper that has been saturated with aqueous cobalt(II) chloride is heated for seconds in a microwave oven, producing a color change. The resulting pink and blue map is used to colorfully demonstrate Le Châtelier's principle and to illuminate the…

  16. The role of cobalt on the creep of Waspaloy

    Science.gov (United States)

    Jarrett, R. N.; Chin, L.; Tien, J. K.

    1984-01-01

    Cobalt was systematically replaced with nickel in Waspaloy (which normally contains 13% Co) to determine the effects of cobalt on the creep behavior of this alloy. Effects of cobalt were found to be minimal on tensile strengths and microstructure. The creep resistance and the stress rupture resistance determined in the range from 704 to 760 C (1300 to 1400 C) were found to decrease as cobalt was removed from the standard alloy at all stresses and temperatures. Roughly a ten-fold drop in rupture life and a corresponding increase in minimum creep rate were found under all test conditions. Both the apparent creep activation energy and the matrix contribution to creep resistance were found to increase with cobalt. These creep effects are attributed to cobalt lowering the stacking fault energy of the alloy matrix. The creep resistance loss due to the removal of cobalt is shown to be restored by slightly increasing the gamma' volume fraction. Results are compared to a previous study on Udimet 700, a higher strength, higher gamma' volume fraction alloy with similar phase chemistry, in which cobalt did not affect creep resistance. An explanation for this difference in behavior based on interparticle spacing and cross-slip is presented.

  17. Potential for cobalt recovery from lateritic ores in Europe

    Science.gov (United States)

    Herrington, R.

    2012-04-01

    Cobalt is one of the 'critical metals' identified under the EU Raw Materials Initiative. Annually the global mine production of cobalt is around 55,000 tonnes,with Europe's industries consuming around 30% of that figure. Currently Europe produces around 27 tonnes of cobalt from mines in Finland although new capacity is planned. Co-bearing nickel laterite ores being mined in Greece, Macedonia and Kosovo where the cobalt is currently not being recovered (ores have typical analyses of 0.055% Co and >1% Ni,). These ores are currently treated directly in pyrometallurgical plants to recover the contained nickel and this process means there is no separate cobalt product produced. Hydrometallurgical treatment of mineralogically suitable laterite ores can recover the cobalt; for example Cuba recovers 3,500 tonnes of cobalt from its laterite mining operations, which are of a similar scale to the current European operations. Implementation of hydrometallurgical techniques is in its infancy in Europe with one deposit in Turkey planning to use atmospheric heap leaching to recover nickel and copper from oxide-dominated ores. More widespread implementation of these methods to mineralogically suitable ore types could unlock the highly significant undeveloped resources (with metal contents >0.04% Co and >1% Ni), which have been defined throughout the Balkans eastwards into Turkey. At a conservative estimate, this region has the potential to supply up to 30% of the EU cobalt requirements.

  18. Highly selective cobalt-catalyzed hydrovinylation of styrene

    NARCIS (Netherlands)

    Grutters, M.M.P.; Müller, C.; Vogt, D.

    2006-01-01

    The hydrovinylation reaction is a codimerization of a 1,3-diene or vinyl arene and ethene with great potential for fine chemicals and pharmaceuticals. For the first time, enantioselective cobalt-catalyzed hydrovinylations of styrene were achieved with a cobalt-based system bearing a chiral

  19. Cobalt ferrite nanoparticles under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Saccone, F. D.; Ferrari, S.; Grinblat, F.; Bilovol, V. [Instituto de Tecnologías y Ciencias de la Ingeniería, “Ing. H. Fernández Long,” Av. Paseo Colón 850 (1063), Buenos Aires (Argentina); Errandonea, D., E-mail: daniel.errandonea@uv.es [Departamento de Fisica Aplicada, Institut Universitari de Ciència dels Materials, Universitat de Valencia, c/ Doctor Moliner 50, E-46100 Burjassot, Valencia (Spain); Agouram, S. [Departamento de Física Aplicada y Electromagnetismo, Universitat de València, 46100 Burjassot, Valencia (Spain)

    2015-08-21

    We report by the first time a high pressure X-ray diffraction and Raman spectroscopy study of cobalt ferrite (CoFe{sub 2}O{sub 4}) nanoparticles carried out at room temperature up to 17 GPa. In contrast with previous studies of nanoparticles, which proposed the transition pressure to be reduced from 20–27 GPa to 7.5–12.5 GPa (depending on particle size), we found that cobalt ferrite nanoparticles remain in the spinel structure up to the highest pressure covered by our experiments. In addition, we report the pressure dependence of the unit-cell parameter and Raman modes of the studied sample. We found that under quasi-hydrostatic conditions, the bulk modulus of the nanoparticles (B{sub 0} = 204 GPa) is considerably larger than the value previously reported for bulk CoFe{sub 2}O{sub 4} (B{sub 0} = 172 GPa). In addition, when the pressure medium becomes non-hydrostatic and deviatoric stresses affect the experiments, there is a noticeable decrease of the compressibility of the studied sample (B{sub 0} = 284 GPa). After decompression, the cobalt ferrite lattice parameter does not revert to its initial value, evidencing a unit cell contraction after pressure was removed. Finally, Raman spectroscopy provides information on the pressure dependence of all Raman-active modes and evidences that cation inversion is enhanced by pressure under non-hydrostatic conditions, being this effect not fully reversible.

  20. Cobalt60 plaques in recurrent retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Fass, D.; McCormick, B.; Abramson, D.; Ellsworth, R. (Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, NY, NY (USA))

    1991-08-01

    Cobalt60 plaque irradiation is one treatment option for patients with recurrent retinoblastoma following conventional external beam irradiation (ERT). Tumorocidal doses can be delivered without excessive risk of normal tissue injury. In patients not considered candidates for xenon arc or cryotherapy, 60Co is an alternative to enucleation. Between 1968 and 1987, 85 patients were treated with 60Co plaques, 72 of whom had failed prior ERT. Age at diagnosis ranged from 1 week to 4 years. There are 37 males and 35 females. Seventy-one patients had bilateral disease and one had unilateral. Three patients had both eyes plaqued. Prior ERT ranged from 30 to 70 Gy (mean 4200 Gy). Time from initial therapy to failure ranged from 13 to 60 months. Cobalt plaques of 10 mm, 15 mm, or 10 {times} 15 mm were used depending on tumor size and location. Dose prescribed to the apex of the tumor ranged from 30 to 50 Gy (median 40 Gy) given over 3 to 8 days. Twelve patients had two plaque applications; three patients had three plaque applications. All patients were followed with routine ophthalmoscopic examinations. Follow-up ranged from 2 to 22 years (mean 8.7). Seven patients died of metastatic disease; 10 patients developed non-ocular second tumors. Thirty patients required enucleation. Twenty-two patients had clear tumor progression, two patients had radiation complications, and six patients had a combination of tumor growth and complications. Cobalt60 can salvage eyes in retinoblastoma patients failing ERT. Currently, the authors are using I125 in an attempt to spare normal ocular tissue and reduce subsequent complications.

  1. Cobalt60 plaques in recurrent retinoblastoma

    International Nuclear Information System (INIS)

    Fass, D.; McCormick, B.; Abramson, D.; Ellsworth, R.

    1991-01-01

    Cobalt60 plaque irradiation is one treatment option for patients with recurrent retinoblastoma following conventional external beam irradiation (ERT). Tumorocidal doses can be delivered without excessive risk of normal tissue injury. In patients not considered candidates for xenon arc or cryotherapy, 60Co is an alternative to enucleation. Between 1968 and 1987, 85 patients were treated with 60Co plaques, 72 of whom had failed prior ERT. Age at diagnosis ranged from 1 week to 4 years. There are 37 males and 35 females. Seventy-one patients had bilateral disease and one had unilateral. Three patients had both eyes plaqued. Prior ERT ranged from 30 to 70 Gy (mean 4200 Gy). Time from initial therapy to failure ranged from 13 to 60 months. Cobalt plaques of 10 mm, 15 mm, or 10 x 15 mm were used depending on tumor size and location. Dose prescribed to the apex of the tumor ranged from 30 to 50 Gy (median 40 Gy) given over 3 to 8 days. Twelve patients had two plaque applications; three patients had three plaque applications. All patients were followed with routine ophthalmoscopic examinations. Follow-up ranged from 2 to 22 years (mean 8.7). Seven patients died of metastatic disease; 10 patients developed non-ocular second tumors. Thirty patients required enucleation. Twenty-two patients had clear tumor progression, two patients had radiation complications, and six patients had a combination of tumor growth and complications. Cobalt60 can salvage eyes in retinoblastoma patients failing ERT. Currently, the authors are using I125 in an attempt to spare normal ocular tissue and reduce subsequent complications

  2. Hot Corrosion of Cobalt-Base Alloys

    Science.gov (United States)

    1975-06-01

    Alloys 20. ABSTRACT (Continue on revet -se tside lf necessary and identify by block number) ~ lThe sodium sulfate-induced hot corrosion of cobalt and...Figures 12 and 13. The Na2 SO 4 was observed to form puddles on the oxide-covered specimen surface. An oxide slag was usually suspended in the... slag (black arrows) were suspended (30 sees at 1000°C in air). b) After washing the Na2SO 4 from the specimen, the exposed oxide surface was highly

  3. Future of U.S. cobalt irradiation

    International Nuclear Information System (INIS)

    Clouser, J.F.

    1995-01-01

    An examination of future cobalt needs requires us to review our base business, customer trends, technology trends, and people, the human aspect of our business. I am approaching this discussion from the perspective of a contract supplier of gamma irradiation services in the United States. The base business is comprised primarily of the sterilization of medical devices followed by containers, labware, food products, and other items. Since the core business is serving the medical industry, trends observed within medical device manufacturers can impact our growth and the type of services needed to support that industry. (author)

  4. HYDROCARBON FORMATION ON POLYMER-SUPPORTED COBALT

    Energy Technology Data Exchange (ETDEWEB)

    Benner, Linda S.; Perkins, Patrick; Vollhardt, K.Peter C.

    1980-10-01

    In this report we detail the synthesis catalytic chemistry of polystyrene supported {eta}{sup 5} ~cyclopentadienyl- dicarbonyl cobalt, CpCo(CO){sub 2}. This material is active in the hydrogenation of CO to saturated linear hydrocarbons and appears to retain its "homogeneous", mononuclear character during the course of its catalysis, During ·the course of our work 18% and 20% crosslinked analogs of polystyrene supported CpCo(CO){sub 2} were shown to exhibit limited catalytic activity and no CO activation.

  5. Bifunctional cobalt F-T catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.G.; Coughlin, P.K.; Yang, C.L.; Rabo, J.A.

    1986-03-01

    Results on the catalytic screening of Fischer-Tropsch catalysts containing shape selective components are reported. Catalysts consist of promoted cobalt intimately contacted with Union Carbide molecular sieves and were tested using a Berty type internally recycled reactor. Methods of preparation, promoters and shape selective components were varied and aimed at improving catalyst performance. Catalysts were developed demonstrating high C/sub 5/ + yields with high olefin content and low methane production while maintaining stability under both low and high H/sub 2/:CO ratio conditions.

  6. Nitrogen oxides storage catalysts containing cobalt

    Science.gov (United States)

    Lauterbach, Jochen; Snively, Christopher M.; Vijay, Rohit; Hendershot, Reed; Feist, Ben

    2010-10-12

    Nitrogen oxides (NO.sub.x) storage catalysts comprising cobalt and barium with a lean NO.sub.x storage ratio of 1.3 or greater. The NO.sub.x storage catalysts can be used to reduce NO.sub.x emissions from diesel or gas combustion engines by contacting the catalysts with the exhaust gas from the engines. The NO.sub.x storage catalysts can be one of the active components of a catalytic converter, which is used to treat exhaust gas from such engines.

  7. Study of Malayaite and Malayaite Cobalt Pigment

    International Nuclear Information System (INIS)

    Pina, C.; Arriola, H.; Nava, N.

    2005-01-01

    Calcium tin silicate, CaSnSiO 5 , called Malayaite is synthesized with equimolecular quantities of calcium oxide, silica and stannic oxide followed by a thermic process. In this work, the synthesis of Malayaite and the structure of a Malayaite-based pigment, Sn/Co pink, is investigated by X-ray diffraction and Mossbauer spectroscopy. The results indicate Malayaite and Cassiterite formation, but the ion cobalt incorporated in the Malayaite structure, diminishes the Cassiterite proportion and causes larger asymmetry in the environment of the tin atom.

  8. Low-Cobalt Powder-Metallurgy Superalloy

    Science.gov (United States)

    Harf, F. H.

    1986-01-01

    Highly-stressed jet-engine parts made with less cobalt. Udimet 700* (or equivalent) is common nickel-based superalloy used in hot sections of jet engines for many years. This alloy, while normally used in wrought condition, also gas-atomized into prealloyed powder-metallurgy (PM) product. Product can be consolidated by hot isostatically pressing (HIPPM condition) and formed into parts such as turbine disk. Such jet-engine disks "see" both high stresses and temperatures to 1,400 degrees F (760 degrees C).

  9. Association between cobalt allergy and dermatitis caused by leather articles

    DEFF Research Database (Denmark)

    Bregnbak, David; Thyssen, Jacob P; Zachariae, Claus

    2015-01-01

    BACKGROUND: Cobalt is a strong skin sensitizer and a prevalent contact allergen. Recent studies have recognized exposure to leather articles as a potential cause of cobalt allergy. OBJECTIVES: To examine the association between contact allergy to cobalt and a history of dermatitis resulting from...... exposure to leather. METHODS: A questionnaire case-control study was performed: the case group consisted of 183 dermatitis patients with a positive patch test reaction to cobalt chloride and a negative patch test reaction to potassium dichromate; the control group consisted of 621 dermatitis patients who...... did not react to either cobalt or chromium in patch testing. Comparisons were made by use of a χ(2) -test, Fisher's exact, and the Mann-Whitney test. Logistic regression analyses were used to test for associations while taking confounding factors into consideration. RESULTS: Leather was observed...

  10. Total body irradiation with a reconditioned cobalt teletherapy unit.

    Science.gov (United States)

    Evans, Michael D C; Larouche, Renée-Xavière; Olivares, Marina; Léger, Pierre; Larkin, Joe; Freeman, Carolyn R; Podgorsak, Ervin B

    2006-01-01

    While the current trend in radiotherapy is to replace cobalt teletherapy units with more versatile and technologically advanced linear accelerators, there remain some useful applications for older cobalt units. The expansion of our radiotherapy department involved the decommissioning of an isocentric cobalt teletherapy unit and the replacement of a column-mounted 4-MV LINAC that has been used for total body irradiation (TBI). To continue offering TBI treatments, we converted the decommissioned cobalt unit into a dedicated fixed-field total body irradiator and installed it in an existing medium-energy LINAC bunker. This article describes the logistical and dosimetric aspects of bringing a reconditioned cobalt teletherapy unit into clinical service as a total body irradiator.

  11. 46 CFR 59.10-30 - Seal welding.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Seal welding. 59.10-30 Section 59.10-30 Shipping COAST... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-30 Seal welding. Where leaks occur in riveted joints or connections, they shall be carefully investigated to...

  12. 20 CFR 617.59 - Agreements with State agencies.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Agreements with State agencies. 617.59 Section 617.59 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TRADE... § 617.59 Agreements with State agencies. (a) Authority. Before performing any function or exercising any...

  13. 25 CFR 141.59 - Customer complaint procedures.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Customer complaint procedures. 141.59 Section 141.59... THE NAVAJO, HOPI AND ZUNI RESERVATIONS Enforcement Powers, Procedures and Remedies § 141.59 Customer complaint procedures. (a) Any customer of a licensee may file a complaint with the Commissioner alleging...

  14. 32 CFR 1605.59 - Signing official papers.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Signing official papers. 1605.59 Section 1605.59 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM SELECTIVE SERVICE SYSTEM ORGANIZATION Local Boards § 1605.59 Signing official papers. Official papers issued by a local...

  15. 7 CFR 59.301 - Mandatory Daily Reporting for Lambs.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Mandatory Daily Reporting for Lambs. 59.301 Section 59... (CONTINUED) LIVESTOCK MANDATORY REPORTING Lamb Reporting § 59.301 Mandatory Daily Reporting for Lambs. (a) In... prices for lambs (per hundredweight) established on that day as F.O.B. feedlot or delivered at the plant...

  16. 14 CFR 1260.59 - Choice of law.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Choice of law. 1260.59 Section 1260.59... Special Conditions § 1260.59 Choice of law. Choice of Law October 2000 The rights and obligations of the parties to the grant (or cooperative agreement) shall be ascertainable by recourse to the laws of the...

  17. 40 CFR 205.59 - Recall of noncomplying vehicles.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Recall of noncomplying vehicles. 205.59 Section 205.59 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Medium and Heavy Trucks § 205.59 Recall...

  18. Polarized neutron capture in polarized 59Co and 165Ho nuclei

    International Nuclear Information System (INIS)

    Bosman, J.J.

    1976-01-01

    Gamma spectroscopy on the reactions 59 Co(n,γ) 60 Co and 165 Ho(n,γ) 166 Ho with polarized neutrons and polarized targets enabled the assignment of spins to 36 levels in 60 Co and 15 levels in 166 Ho. Several of them had not been reported earlier. The techniques used to polarize neutron beams and targets and the gamma-spectroscopy are extensively discussed

  19. Experimental evidence for cobalt(III)-carbene radicals: key intermediates in cobalt(II)-based metalloradical cyclopropanation

    NARCIS (Netherlands)

    Lu, H.; Dzik, W.I.; Xu, X.; Wojtas, L.; de Bruin, B.; Zhang, X.P.

    2011-01-01

    New and conclusive evidence has been obtained for the existence of cobalt(III)-carbene radicals that have been previously proposed as the key intermediates in the underlying mechanism of metalloradical cyclopropanation by cobalt(II) complexes of porphyrins. In the absence of olefin substrates,

  20. Preparation and characterization of electrodeposited cobalt nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Irshad, M. I., E-mail: imrancssp@gmail.com; Mohamed, N. M., E-mail: noranimuti-mohamed@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 31750 PERAK (Malaysia); Ahmad, F., E-mail: faizahmad@petronas.com.my; Abdullah, M. Z., E-mail: zaki-abdullah@petronas.com.my [Department of Mechanical Engineering, Universiti Teknologi PETRONAS, 31750 PERAK (Malaysia)

    2014-10-24

    Electrochemical deposition technique has been used to deposit cobalt nanowires into the nano sized channels of Anodized Aluminium Oxide (AAO) templates. CoCl{sub 2}Ðœ‡6H2O salt solution was used, which was buffered with H{sub 3}BO{sub 3} and acidified by dilute H{sub 2}SO{sub 4} to increase the plating life and control pH of the solution. Thin film of copper around 150 nm thick on one side of AAO template coated by e-beam evaporation system served as cathode to create electrical contact. FESEM analysis shows that the as-deposited nanowires are highly aligned, parallel to one another and have high aspect ratio with a reasonably high pore-filing factor. The TEM results show that electrodeposited cobalt nanowires are crystalline in nature. The Hysteresis loop shows the magnetization properties for in and out of plane configuration. The in plane saturation magnetization (Ms) is lower than out of plane configuration because of the easy axis of magnetization is perpendicular to nanowire axis. These magnetic nanowires could be utilized for applications such as spintronic devices, high density magnetic storage, and magnetic sensor applications.

  1. Preparation and characterization of electrodeposited cobalt nanowires

    International Nuclear Information System (INIS)

    Irshad, M. I.; Mohamed, N. M.; Ahmad, F.; Abdullah, M. Z.

    2014-01-01

    Electrochemical deposition technique has been used to deposit cobalt nanowires into the nano sized channels of Anodized Aluminium Oxide (AAO) templates. CoCl 2 Ðœ‡6H2O salt solution was used, which was buffered with H 3 BO 3 and acidified by dilute H 2 SO 4 to increase the plating life and control pH of the solution. Thin film of copper around 150 nm thick on one side of AAO template coated by e-beam evaporation system served as cathode to create electrical contact. FESEM analysis shows that the as-deposited nanowires are highly aligned, parallel to one another and have high aspect ratio with a reasonably high pore-filing factor. The TEM results show that electrodeposited cobalt nanowires are crystalline in nature. The Hysteresis loop shows the magnetization properties for in and out of plane configuration. The in plane saturation magnetization (Ms) is lower than out of plane configuration because of the easy axis of magnetization is perpendicular to nanowire axis. These magnetic nanowires could be utilized for applications such as spintronic devices, high density magnetic storage, and magnetic sensor applications

  2. Spin-dependent transport in cobalt nanocontacts

    Energy Technology Data Exchange (ETDEWEB)

    Sarau, G.

    2007-04-16

    The magnetoresistance response of cobalt nanocontacts with varying geometries formed between two extended electrodes has been experimentally investigated and linked to micromagnetic simulations. The contribution of the nanoconstriction to the measured magnetoresistance signal has been separated from that of the electrode bulk. The different nanocontact geometries exhibit different shape anisotropies resulting in a characteristic behavior of the magnetization at each nanocontact. The magnetization reversal processes are explained on the basis of the anisotropic magnetoresistance and domain wall scattering effects. The domain wall resistance takes positive values, which is in agreement with models based on the spin mistracking inside the domain wall. The 4 K MR measurements are found to be influenced by the exchange bias effect between the ferromagnetic cobalt electrodes and the antiferromagnetic oxidized Co surface. When cooling down in an applied magnetic field, the uniform biased Co layer behaves as if it possesses a unidirectional anisotropy axis along the field cooling direction. In the zero field cooling case, the exchange bias varies locally throughout the sample giving rise to non-reproducible successive MR traces. (orig.)

  3. A spot test for detection of cobalt release – early experience and findings

    DEFF Research Database (Denmark)

    Thyssen, Jacob P.; Menné, Torkil; Johansen, Jeanne D.

    2010-01-01

    Background: It is often difficult to establish clinical relevance of metal exposure in cobalt-allergic patients. Dermatologists and patients may incorrectly assume that many metallic items release cobalt at levels that may cause cobalt dermatitis. Cobalt-allergic patients may be unaware that they...

  4. A spot test for detection of cobalt release - early experience and findings

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Menné, Torkil; Johansen, Jeanne D

    2010-01-01

    It is often difficult to establish clinical relevance of metal exposure in cobalt-allergic patients. Dermatologists and patients may incorrectly assume that many metallic items release cobalt at levels that may cause cobalt dermatitis. Cobalt-allergic patients may be unaware that they are exposed...

  5. Synthesis of cobalt boride nanoparticles using radio frequency thermal plasma

    International Nuclear Information System (INIS)

    Lapitan, Jr. Lorico DS.; Ying Ying Chen; Seesoek Choe; Watanabe, Takayuki

    2012-01-01

    Nano size cobalt boride particles were synthesized from vapor phase using a 30 kw-4 MHz radio frequency (RF) thermal plasma. Cobalt and boron powder mixtures used as precursors in different composition and feed rate were evaporated immediately in the high temperature plasma and cobalt boride nanoparticles were produced through the quenching process. The x-ray diffractometry (XRD) patterns of cobalt boride nanoparticles prepared from the feed powder ratio of 1:2 and 1:3 for Co: B showed peaks that are associated with the Co 2 B and CoB crystal phases of cobalt boride. The XRD analysis revealed that increasing the powder feed rate results in a higher mass fraction and a larger crystalline diameter of cobalt boride nanoparticles. The images obtained by field emission scanning electron microscopy (FE-SEM) revealed that cobalt boride nanoparticles have a spherical morphology. The crystallite size of the particles estimated with XRD was found to be 18-22 nm. (author)

  6. Nickel-cobalt hydroxide nanosheets: Synthesis, morphology and electrochemical properties.

    Science.gov (United States)

    Schneiderová, Barbora; Demel, Jan; Zhigunov, Alexander; Bohuslav, Jan; Tarábková, Hana; Janda, Pavel; Lang, Kamil

    2017-08-01

    This paper reports the synthesis, characterization, and electrochemical performance of nickel-cobalt hydroxide nanosheets. The hydroxide nanosheets of approximately 0.7nm thickness were prepared by delamination of layered nickel-cobalt hydroxide lactate in water and formed transparent colloids that were stable for months. The nanosheets were deposited on highly oriented pyrolytic graphite by spin coating, and their electrochemical behavior was investigated by cyclic voltammetry in potassium hydroxide electrolyte. Our method of electrode preparation allows for studying the electrochemistry of nanosheets where the majority of the active centers can participate in the charge transfer reaction. The observed electrochemical response was ascribed to mutual compensation of the cobalt and nickel response via electron sharing between these metals in the hydroxide nanosheets, a process that differentiates the behavior of nickel-cobalt hydroxide nanosheets from single nickel hydroxide or cobalt hydroxide nanosheets or their physical mixture. The presence of cobalt in the nickel-cobalt hydroxide nanosheets apparently decreases the time of electrochemical activation of the nanosheet layer, which for the nickel hydroxide nanosheets alone requires more potential sweeps. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Concentration of radioactive cobalt by seaweeds in the food chain

    International Nuclear Information System (INIS)

    Nakahara, Motokazu; Koyanagi, Taku; Saiki, Masamichi

    1976-01-01

    On the pathway of radioactive substances in marine environments, seaweeds play an important role because of their higher concentration factors for many radionuclides and because they constitute a link of food chain in the sea. In the present work, uptake, distribution and excretion of radioactive cobalt were studied on several kinds of seaweeds by radioisotope tracer experiments under laboratory conditions and concentration factors were calculated. The concentration factors were also estimated from the results of stable cobalt determination by activation analysis or atomic absorption spectrometry on seaweeds and seawater, and compared with the results of tracer expts. The seaweeds showed the species specificity for the concentration of stable and radioactive cobalt with diverse values of concentration factors and biological half-lives. The transfer of radioactive cobalt in the food chain from contaminated seaweeds to mollusca was examined by feeding abalones, Haliotis discus, with four kinds of seaweed labelled with 60 Co and observing retention. Absorption rate for radioactive cobalt by abalones calculated at two days after feeding showed diverse values depending upon the species of seaweed, as follows: 47% through Laminaria japonica and Ulva pertusa, 31% through Undaria pinnatifida and 26 through Eisenia bicyclis, respectively. From the results, it was assumed that the accumulation of radioactive cobalt by mollusca is affected by the species of seaweeds as food. A very high concentration of ingested radioactive cobalt in the midgut gland was seen on the autoradiograph of abalone samples. (auth.)

  8. Concentration of radioactive cobalt by seaweeds in the food chain

    International Nuclear Information System (INIS)

    Nakahara, M.; Koyanagi, T.; Saiki, M.

    1975-01-01

    On the pathway of radioactive substances in marine environments, seaweeds play an important role because of their higher concentration factors for many radionuclides and because they constitute a link in the food chain. In the present work, uptake, distribution and excretion of radioactive cobalt were studied on several kinds of seaweeds by radioisotope tracer experiments under laboratory conditions and concentration factors were calculated. The concentration factors were also estimated from the results of stable cobalt determination by activation analysis or atomic absorption spectrometry on seaweeds and seawater, and compared with the results of tracer experiments. The seaweeds showed the species specificity for the concentration of stable and radioactive cobalt with diverse values of concentration factors and biological half-lives. The transfer of radioactive cobalt in the food chain from contaminated seaweeds to mollusca was examined by feeding abalones, Haliotis discus, with four kinds of seaweed labelled with 60 Co and observing retention. Absorption rate for radioactive cobalt by abalones calculated at two days after feeding showed diverse values depending upon the species of seaweed, as follows: 47% through Laminaria japonica and Ulva pertusa, 31% through Undaria pinnatifida and 26% through Eisenia bicyclis, respectively. From the results, it was assumed that the accumulation of radioactive cobalt by mollusca is affected by the species of seaweeds as food. A very high concentration of ingested radioactive cobalt in the midgut gland was seen on the autoradiograph of abalone samples. (author)

  9. Forward-planned intensity modulated radiation therapy using a cobalt source: A dosimetric study in breast cancer

    Directory of Open Access Journals (Sweden)

    Savino Cilla

    2013-01-01

    Full Text Available This analysis evaluates the feasibility and dosimetric results of a simplified intensity-modulated radiotherapy (IMRT treatment using a cobalt-therapy unit for post-operative breast cancer. Fourteen patients were included. Three plans per patient were produced by a cobalt-60 source: A standard plan with two wedged tangential beams, a standard tangential plan optimized without the use of wedges and a plan based on the forward-planned "field-in-field" IMRT technique (Co-FinF where the dose on each of the two tangential beams was split into two different segments and the two segments weight was determined with an iterative process. For comparison purposes, a 6-MV photon standard wedged tangential treatment plan was generated. D mean , D 98% , D 2% , V 95% , V 107%, homogeneity, and conformity indices were chosen as parameters for comparison. Co-FinF technique improved the planning target volume dose homogeneity compared to other cobalt-based techniques and reduced maximum doses (D 2% and high-dose volume (V 110% . Moreover, it showed a better lung and heart dose sparing with respect to the standard approach. The higher dose homogeneity may encourage the adoption of accelerated-hypofractionated treatments also with the cobalt sources. This approach can promote the spread of breast conservative treatment in developing countries.

  10. Smoothing an isolated interface of cobalt-copper under irradiation by low-energy argon ions

    International Nuclear Information System (INIS)

    Stognij, A.I.; Novitskij, N.N.; Stukalov, O.M.

    2003-01-01

    Multilayer film structures, i.e. gold layer-copper-cobalt, are considered. It is shown that the structure, where cobalt surface prior to copper layer deposition was subjected to additional irradiation by a flow of argon ions, features the smoothest surface. The conclusion is made about smoothing out of cobalt-copper interface as a result of multiple collisions of argon slow ions and cobalt atoms during braking within two or three upper atomic rows of the cobalt layer [ru

  11. Incentives and opportunities for reducing the cobalt content in reactor core components

    International Nuclear Information System (INIS)

    Ocken, H.

    1985-01-01

    Cobalt in core components contributes to radiation field buildup on out-of-core surfaces. Core components containing cobalt-base alloys and cobalt as an impurity are identified. The use of cobalt-free wear-resistant alloys and construction materials with lower impurity levels of cobalt is disused. It is argued that such measures are cost effective. Lower radiation fields and disposal costs will offset higher raw material costs. Component performance will not be affected. (author)

  12. The structural evolution and diffusion during the chemical transformation from cobalt to cobalt phosphide nanoparticles

    KAUST Repository

    Ha, Don-Hyung

    2011-01-01

    We report the structural evolution and the diffusion processes which occur during the phase transformation of nanoparticles (NPs), ε-Co to Co 2P to CoP, from a reaction with tri-n-octylphosphine (TOP). Extended X-ray absorption fine structure (EXAFS) investigations were used to elucidate the changes in the local structure of cobalt atoms which occur as the chemical transformation progresses. The lack of long-range order, spread in interatomic distances, and overall increase in mean-square disorder compared with bulk structure reveal the decrease in the NP\\'s structural order compared with bulk structure, which contributes to their deviation from bulk-like behavior. Results from EXAFS show both the Co2P and CoP phases contain excess Co. Results from EXAFS, transmission electron microscopy, X-ray diffraction, and density functional theory calculations reveal that the inward diffusion of phosphorus is more favorable at the beginning of the transformation from ε-Co to Co2P by forming an amorphous Co-P shell, while retaining a crystalline cobalt core. When the major phase of the sample turns to Co 2P, the diffusion processes reverse and cobalt atom out-diffusion is favored, leaving a hollow void, characteristic of the nanoscale Kirkendall effect. For the transformation from Co2P to CoP theory predicts an outward diffusion of cobalt while the anion lattice remains intact. In real samples, however, the Co-rich nanoparticles continue Kirkendall hollowing. Knowledge about the transformation method and structural properties provides a means to tailor the synthesis and composition of the NPs to facilitate their use in applications. © 2011 The Royal Society of Chemistry.

  13. Electrochemical performance of cobalt hydroxide nanosheets formed by the delamination of layered cobalt hydroxide in water

    Czech Academy of Sciences Publication Activity Database

    Schneiderová, Barbora; Demel, Jan; Pleštil, Josef; Tarábková, Hana; Bohuslav, Jan; Lang, Kamil

    2014-01-01

    Roč. 43, č. 27 (2014), s. 10484-10491 ISSN 1477-9226 R&D Projects: GA ČR GP13-09462P Institutional support: RVO:61388980 ; RVO:61388955 ; RVO:61389013 Keywords : Ray-absorption spectroscopy * Alpha-cobalt * Solvothermal decomposition * Nickel * Nanocomposites Subject RIV: CA - Inorganic Chemistry; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 4.197, year: 2014

  14. Activation of cobalt 60 in the LVR-15 reactor core

    International Nuclear Information System (INIS)

    Melichar, F.

    1995-12-01

    Cobalt disks were irradiated in the LVR-15 reactor and the relevant cobalt-60 production parameters, particularly the formation rate, were measured. The data were compared with those from previous work by other authors and some discrepancies were found. It is concluded that additional experiments have to be performed in order to obtain reliable data, usable in economic balance assessment with respect to the use of hot chambers for the production of sealed cobalt-60 sources. (P.A.). 4 tabs., 3 refs., 10 annexes

  15. The effect of gaseous ammonia on cobalt perrhenate

    International Nuclear Information System (INIS)

    Maslov, L.P.; Men'shikov, O.D.; Borisov, V.V.; Sorokin, S.I.; Krutovertsev, S.A.; Kharkevich, S.I.; Ivanova, O.M.

    1994-01-01

    The influence of humid air ammonia mixture on crystal pentahydrate of cobalt(2) perrhenate has been studied by the methods of PES, IR spectroscopy thermal analysis and electrophysical measurements. It is shown that with an increase in ammonia content in gaseous phase cobalt perrhenate successively transforms into diaquodiammine-, tetrammine- and μ-dioxo-bis-(tetrammine) derivatives of cobalt. Reversibility of dioxocomplex formation and a correlation between the change in electrophysical properties of crystal sample and change in ammonia content in gaseous phase are pointed out. 16 refs.; 4 figs.; 1 tab

  16. Multiwalled Carbon Nanotubes Decorated with Cobalt Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    D. G. Larrude

    2012-01-01

    Full Text Available Multiwalled carbon nanotubes (MWCNTs synthesized by spray pyrolysis were decorated with cobalt oxide nanoparticles using a simple synthesis route. This wet chemistry method yielded nanoparticles randomly anchored to the surface of the nanotubes by decomposition of cobalt nitrate hexahydrate diluted in acetone. Electron microscopy analysis indicated that dispersed particles were formed on the MWCNTs walls. The average size increased with the increasing concentration of cobalt nitrate in acetone in the precursor mixture. TEM images indicated that nanoparticles were strongly attached to the tube walls. The Raman spectroscopy results suggested that the MWCNT structure was slightly damaged after the nanoparticle growth.

  17. Measurement of soluble CD59 in CSF in demyelinating disease: Evidence for an intrathecal source of soluble CD59.

    Science.gov (United States)

    Zelek, Wioleta M; Watkins, Lewis M; Howell, Owain W; Evans, Rhian; Loveless, Sam; Robertson, Neil P; Beenes, Marijke; Willems, Loek; Brandwijk, Ricardo; Morgan, B Paul

    2018-02-01

    CD59, a broadly expressed glycosylphosphatidylinositol-anchored protein, is the principal cell inhibitor of complement membrane attack on cells. In the demyelinating disorders, multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD), elevated complement protein levels, including soluble CD59 (sCD59), were reported in cerebrospinal fluid (CSF). We compared sCD59 levels in CSF and matched plasma in controls and patients with MS, NMOSD and clinically isolated syndrome (CIS) and investigated the source of CSF sCD59 and whether it was microparticle associated. sCD59 was quantified using enzyme-linked immunosorbent assay (ELISA; Hycult; HK374-02). Patient and control CSF was subjected to western blotting to characterise anti-CD59-reactive materials. CD59 was localised by immunostaining and in situ hybridisation. CSF sCD59 levels were double those in plasma (CSF, 30.2 ng/mL; plasma, 16.3 ng/mL). Plasma but not CSF sCD59 levels differentiated MS from NMOSD, MS from CIS and NMOSD/CIS from controls. Elimination of microparticles confirmed that CSF sCD59 was not membrane anchored. CSF levels of sCD59 are not a biomarker of demyelinating diseases. High levels of sCD59 in CSF relative to plasma suggest an intrathecal source; CD59 expression in brain parenchyma was low, but expression was strong on choroid plexus (CP) epithelium, immediately adjacent the CSF, suggesting that this is the likely source.

  18. The cobalt radioactive isotopes in environment; Les isotopes radioactifs du cobalt dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    For the year 1993 the total activity released in cobalt is 69 GBq for the whole of nuclear power plants. The part of activity in cobalt for La Hague in 1993 is 8 GBq of {sup 58}Co and 2 GBq of {sup 60}Co. The radioactive isotopes released by nuclear power plants or the reprocessing plant of La Hague under liquid effluents are shared by half between {sup 58}Co and {sup 60}Co. The exposure to sealed sources is the most important risk for the cobalt. The risk of acute exposure can associate a local irradiation of several decades of grays inducing a radiological burns, deep burn to treat in surgery by resection or graft even amputation. A global irradiation of organism for several grays induces an acute irradiation syndrome, often serious. At long term the stochastic effects are represented by leukemia and radio-induced cancers. The increase of probability of their occurrence is 1% by sievert. We must remind that the natural spontaneous probability is 25%. (N.C.)

  19. Characterization of a Porous Carbon Material Functionalized with Cobalt-Oxide/Cobalt Core-Shell Nanoparticles for Lithium Ion Battery Electrodes

    KAUST Repository

    Anjum, Dalaver H.; Rasul, Shahid; Roldan-Gutierrez, Manuel A.; Da Costa, Pedro M. F. J.

    2016-01-01

    A nanoporous carbon (C) material, functionalized with Cobalt-Oxide/Cobalt (CoO/Co) core-shell nanoparticles (NPs), was structurally and chemically characterized with transmission electron microcopy (TEM) while its electrochemical response

  20. Sintered cobalt-rare earth intermetallic product

    International Nuclear Information System (INIS)

    Benz, M.G.

    1975-01-01

    This patent describes a sintered product having substantially stable permanent magnet properties in air at room temperature. It comprises compacted particulate cobalt--rare earth alloy consisting essentially of a Co 5 R intermetallic phase and a CoR intermetallic phase which is richer in rare earth metal content than the Co 5 R phase, where R is a rare earth metal. The Co 5 R intermetallic phase is present in an amount of at least 65 percent by weight of the sintered product and the CoR intermetallic phase which is richer in rare earth metal content than the Co 5 R phase is present in a positive amount having a value ranging up to about 35 percent by weight of the product. The sintered product has a density of at least 87 percent and has pores which are substantially noninterconnecting and wherein the component grains have an average size less than 30 microns

  1. Impurity diffusion of cobalt in plutonium

    International Nuclear Information System (INIS)

    Charissoux, Christian; Calais, Daniel.

    1975-01-01

    The sectioning method for investigation of the impurity diffusion of 60 Co in the fcc and bcc phases of plutonium gives the following results: 344-426 deg C: D=1.2x10 -2 exp(-12700/RT)cm 2 /s in delta Pu(fcc); 484-621 deg C: D=1.4x10 -3 exp(-9900/RT)cm 2 /s in epsilon Pu(bcc). Cobalt is a fast diffuser in plutonium; the diffusion coefficient being unaffected by phase changes delta'→delta; delta'→epsilon, the diffusion mechanism is probably dissociative in both phases, the solute becoming interstitial by: solute (substitution) reversible solute (interstitial) + vacancy [fr

  2. The role of cobalt ferrite magnetic nanoparticles in medical science

    International Nuclear Information System (INIS)

    Amiri, S.; Shokrollahi, H.

    2013-01-01

    The nanotechnology industry is rapidly growing and promises that the substantial changes that will have significant economic and scientific impacts be applicable to a wide range of areas, such as aerospace engineering, nano-electronics, environmental remediation and medical healthcare. In this area, cobalt ferrite nanoparticles have been regarded as one of the competitive candidates because of their suitable physical, chemical and magnetic properties like the high anisotropy constant, high coercivity and high Curie temperature, moderate saturation magnetization and ease of synthesis. This paper introduces the magnetic properties, synthesis methods and some medical applications, including the hyperthermia, magnetic resonance imaging (MRI), magnetic separation and drug delivery of cobalt ferrite nanoparticles. Highlights: ► Cobalt ferrite nanoparticles are one of the most important materials for nanomedicine. ► They have high coercivity and moderate saturation magnetization. ► Cobalt ferrite nanoparticles are synthesized easily. ► They are a good candidate for hyperthermia and magnetic resonance imaging.

  3. Assessment of cobalt levels in wastewater, soil and vegetable ...

    African Journals Online (AJOL)

    carrot, lettuce, onion, spinach, cabbage, tomato and okra) samples collected on seasonal basis from January, 2013 to September 2014 along Kubanni stream channels in Zaria. The results show cobalt levels in wastewater were in the range of ...

  4. Making a robust carbon-cobalt(III) bond

    DEFF Research Database (Denmark)

    Larsen, Erik; Madsen, Anders Østergaard; Kofod, Pauli

    2009-01-01

    The coordination ion with a well-characterized carbon-cobalt(III) bond, the (1,4,7-triazacyclononane)(1,6-diamino-3-thia-4-hexanido)cobalt(III) dication, [Co(tacn)(C-aeaps)](2+) (aeaps, for aminoethylaminopropylsulfide), has been reacted with iodomethane, and the S-methyl thionium derivative has...... been isolated. The crystal structure of the resulting [Co(tacn)(C-aeaps-SCH(3))]Br(3) x 3 H(2)O at 122 K has been determined by X-ray diffraction techniques to verify the structure. The crystal structure determination shows that the carbon-cobalt bond length is even shorter (2.001(4) A) than in [Co......(tacn)(C-aeaps)](2+) participates in bonding to cobalt(III), having implications for the transformation between the carbon- and sulfur-bound forms of the aeaps ligand....

  5. 46 SPIDER WEBS AS INDICATORS OF COBALT AND LEAD ...

    African Journals Online (AJOL)

    Spider webs were collected from the indoor and outdoor of 120 sampling sites of 10 zones of Kano ... diet, cobalt containing ceramic is administered into ... significant human and environmental health risk. ..... Evaluation of Health Workers.

  6. Ammonia induced precipitation of cobalt hydroxide: observation of turbostratic disorder

    Science.gov (United States)

    Ramesh, T. N.; Rajamathi, Michael; Kamath, P. Vishnu

    2003-05-01

    Cobalt hydroxide freshly precipitated from aqueous solutions of Co salts using ammonia, is a layered phase having a 9.17 Å interlayer spacing. DIFFaX simulations of the PXRD pattern reveal that it is turbostratically disordered.

  7. A review of cobalt adsorption on transition metal oxides

    International Nuclear Information System (INIS)

    Walker, S.M.

    1987-04-01

    This report reviews studies of cobalt adsorption on transition metal oxides, in the context of corrosion product and radioactivity transport in PWR primary circuits. In general, uptake of cobalt increases with pH, with temperature and with decreasing ionic strength. Very little data are available under PWR primary circuit conditions, but the limited data available suggest that cobalt uptake by the zirconium oxide corrosion product layer on fuel pins may be significant compared to that deposited on fuel crud. If fuel crud levels can be reduced in future by coolant chemistry control then uptake by the zirconia will assume a greater relative role. It is planned to use an autoclave to study uptake of cobalt on oxidised Zircaloy surfaces at temperatures up to 593K under PWR primary circuit chemistry conditions. (author)

  8. Valence control of cobalt oxide thin films by annealing atmosphere

    International Nuclear Information System (INIS)

    Wang Shijing; Zhang Boping; Zhao Cuihua; Li Songjie; Zhang Meixia; Yan Liping

    2011-01-01

    The cobalt oxide (CoO and Co 3 O 4 ) thin films were successfully prepared using a spin-coating technique by a chemical solution method with CH 3 OCH 2 CH 2 OH and Co(NO 3 ) 2 .6H 2 O as starting materials. The grayish cobalt oxide films had uniform crystalline grains with less than 50 nm in diameter. The phase structure is able to tailor by controlling the annealing atmosphere and temperature, in which Co 3 O 4 thin film was obtained by annealing in air at 300-600, and N 2 at 300, and transferred to CoO thin film by raising annealing temperature in N 2 . The fitted X-ray photoelectron spectroscopy (XPS) spectra of the Co2p electrons are distinguishable from different valence states of cobalt oxide especially for their satellite structure. The valence control of cobalt oxide thin films by annealing atmosphere contributes to the tailored optical absorption property.

  9. Synthesis and characterization of iron cobalt (FECO) nanorods ...

    African Journals Online (AJOL)

    Synthesis and characterization of iron cobalt (FECO) nanorods prepared by simple ... shaped by increasing annealing temperature from room temperature to 800 ... Keywords: FeCo nanoparticles, sodium borohydrid, CTAB, chemical synthesis ...

  10. Ion exchange of Cobalt and Cadmium in Zeolite X

    International Nuclear Information System (INIS)

    Nava M, I.

    1994-01-01

    The growing development in the industry has an important contribution to the environmental damage, where the natural effluents are each day more contaminated by toxic elements, such as: mercury, chromium, lead and cadmium. So as to separate such elements it has sorbent must have enough stability, and have a sharp capacity of sorption. In this work it was studied the sorption behavior of cobalt and on the other hand, cadmium in aqueous solutions, which along with sodic form of the Zeolite X, undergoes a phenomenon of ionic interchange. Such interchange was verify to different concentration of cadmium, cobalt and hydronium ion. The content of cobalt and sodium in the interchanged samples was detected through the neutronic activation analysis. The results disclose a higher selectivity for cadmium than cobalt. (Author)

  11. Topotactic Synthesis of Porous Cobalt Ferrite Platelets from a Layered Double Hydroxide Precursor and Their Application in Oxidation Catalysis.

    Science.gov (United States)

    Ortega, Klaus Friedel; Anke, Sven; Salamon, Soma; Özcan, Fatih; Heese, Justus; Andronescu, Corina; Landers, Joachim; Wende, Heiko; Schuhmann, Wolfgang; Muhler, Martin; Lunkenbein, Thomas; Behrens, Malte

    2017-09-12

    Monocrystalline, yet porous mosaic platelets of cobalt ferrite, CoFe 2 O 4 , can be synthesized from a layered double hydroxide (LDH) precursor by thermal decomposition. Using an equimolar mixture of Fe 2+ , Co 2+ , and Fe 3+ during co-precipitation, a mixture of LDH, (Fe II Co II ) 2/3 Fe III 1/3 (OH) 2 (CO 3 ) 1/6 ⋅m H 2 O, and the target spinel CoFe 2 O 4 can be obtained in the precursor. During calcination, the remaining Fe II fraction of the LDH is oxidized to Fe III leading to an overall Co 2+ :Fe 3+ ratio of 1:2 as required for spinel crystallization. This pre-adjustment of the spinel composition in the LDH precursor suggests a topotactic crystallization of cobalt ferrite and yields phase pure spinel in unusual anisotropic platelet morphology. The preferred topotactic relationship in most particles is [111] Spinel ∥[001] LDH . Due to the anion decomposition, holes are formed throughout the quasi monocrystalline platelets. This synthesis approach can be used for different ferrites and the unique microstructure leads to unusual chemical properties as shown by the application of the ex-LDH cobalt ferrite as catalyst in the selective oxidation of 2-propanol. Compared to commercial cobalt ferrite, which mainly catalyzes the oxidative dehydrogenation to acetone, the main reaction over the novel ex-LDH cobalt is dehydration to propene. Moreover, the oxygen evolution reaction (OER) activity of the ex-LDH catalyst was markedly higher compared to the commercial material. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. A Methods and procedures to apply probabilistic safety Assessment (PSA) techniques to the cobalt-therapy process. Cuban experience

    International Nuclear Information System (INIS)

    Vilaragut Llanes, J.J.; Ferro Fernandez, R.; Lozano Lima, B; De la Fuente Puch, A.; Dumenigo Gonzalez, C.; Troncoso Fleitas, M.; Perez Reyes, Y.

    2003-01-01

    This paper presents the results of the Probabilistic Safety Analysis (PSA) to the Cobalt Therapy Process, which was performed as part of the International Atomic Energy Agency's Coordinated Research Project (CRP) to Investigate Appropriate Methods and Procedures to Apply Probabilistic Safety Assessment (PSA) Techniques to Large Radiation Sources. The primary methodological tools used in the analysis were Failure Modes and Effects Analysis (FMEA), Event Trees and Fault Trees. These tools were used to evaluate occupational, public and medical exposures during cobalt therapy treatment. The emphasis of the study was on the radiological protection of patients. During the course of the PSA, several findings were analysed concerning the cobalt treatment process. In relation with the Undesired Events Probabilities, the lowest exposures probabilities correspond to the public exposures during the treatment process (Z21); around 10-10 per year, being the workers exposures (Z11); around 10-4 per year. Regarding to the patient, the Z33 probabilities prevail (not desired dose to normal tissue) and Z34 (not irradiated portion to target volume). Patient accidental exposures are also classified in terms of the extent to which the error is likely to affect individual treatments, individual patients, or all the patients treated on a specific unit. Sensitivity analyses were realised to determine the influence of certain tasks or critical stages on the results. As a conclusion the study establishes that the PSA techniques may effectively and reasonably determine the risk associated to the cobalt-therapy treatment process, though there are some weaknesses in its methodological application for this kind of study requiring further research. These weaknesses are due to the fact that the traditional PSA has been mainly applied to complex hardware systems designed to operate with a high automation level, whilst the cobalt therapy treatment is a relatively simple hardware system with a

  13. Sorption of cobalt and zinc from fresh water and seawater

    International Nuclear Information System (INIS)

    Arnoldus, R.; Weijden, C.H. van der; Das, H.A.

    1977-01-01

    The adsorption of Cosup(II) and Znsup(II) from artificial fresh and sea water on to clay minerals is studied. The adsorption isotherms are measured at pH-values of 7 and 8. The specific adsorption of zinc is higher than that of cobalt. This is compatible with the higher average residence time of cobalt than that of zinc in the oceans

  14. Recovery of cobalt and lithium fromspent Li-ion batteries

    OpenAIRE

    Busnardo, Natália Giovanini; Paulino, Jéssica Frontino; Afonso, Julio Carlos

    2007-01-01

    The "active mass" (cathode + anode + electrolyte) of spent Li-ion batteries was submitted to one of the following procedures: (a) it was calcined (500 ºC) and submitted to extraction with water to recover lithium salts. The residual solid was treated with sulfuric acid containing hydrogen peroxide. Cobalt was recovered as sulfate; (b) the "active mass" was treated with potassium hydrogen sulfate (500 ºC) and dissolved in water. Cobalt was precipitated together with copper after addition of so...

  15. Bioactivity and mechanical behaviour of cobalt oxide-doped ...

    Indian Academy of Sciences (India)

    tive base glass and cobalt oxide-doped glass were prepared by the addition of cobalt oxide (0, ... and 1 N HCl at 37. ◦. C as compared with the ... SO2−. 4. Cl. −. Simulated body fluid. 142.0. 5.0. 1.5. 2.5. 4.2. 1.0. 0.5. 147.8. Human blood plasma ...

  16. Synthesis and structural characterization of polyaniline/cobalt chloride composites

    Energy Technology Data Exchange (ETDEWEB)

    Asha, E-mail: arana5752@gmail.com [Department of Basic and Applied Sciences, Bhagat Phool Singh Mahilla Vishwavidyalaya, Khanpur Kalan, Sonipat-131305 (India); Goyal, Sneh Lata; Kishore, Nawal [Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar-125001 (India)

    2016-05-23

    Polyaniline (PANI) and PANI /cobalt chloride composites were synthesized by in situ chemical oxidative polymerization of aniline with CoCl{sub 2}.6H{sub 2}O using ammonium peroxidisulphate as an oxidant. These composites were characterized by X-ray diffraction (XRD) and Scanning electron microscopy (SEM). The XRD study reveals that both PANI and composites are amorphous. The XRD and SEM results confirm the presence of cobalt chloride in the composites.

  17. Mechanizm of propylene oxidation on modified cobalt-molybdenum catalysts

    International Nuclear Information System (INIS)

    Kutyrev, M.Yu.; Rozentuller, B.V.; Isaev, O.V.; Margolis, L.Ya.; Krylov, O.V.

    1977-01-01

    Effect is studied of additions of iron, copper, nickel, and vanadium oxides, introduced into cobalt, molybdate, on oxidation reactions of propylene to acrolein and acrylicacid. The principal parameters determining the activity and selectivity of oxidation of propylene and acrolein on modified cobalt molibdate are the structure, the type of Mo-O bond, and the nature of the electron transitions in the solid under the effect of adsorption of the reaction components

  18. Enhancement of electrical conductivity in gamma irradiated cobalt ferrite nanoparticles

    International Nuclear Information System (INIS)

    Nawpute, Asha A.; Raut, A.V.; Babrekar, M.K.; Kale, C.M.; Jadhav, K.M.; Shinde, A.B.

    2014-01-01

    The cobalt ferrite nanoparticles were synthesized by sol-gel auto- combustion method, in which L-ascorbic acid was used as a fuel. The effect of gamma irradiation on the electrical resistivity of cobalt ferrite nanoparticles has been studied. The ferrite powder annealed at 550℃ was irradiated by gamma source 137 Cs. The synthesized nanoparticles were characterized by X-ray diffraction and DC resistivity. (author)

  19. Geologic report and recommendations for the cobalt mission to Morocco sponsored by The Trade and Development Program of the International Development Cooperation Agency

    Science.gov (United States)

    Foose, M.P.; Rossman, D.L.

    1982-01-01

    A mission sponsored by the Trade and Development Program (TDP) of the International Development Cooperation Agency (IDCA) went to Morocco to evaluate the possibility of finding additional sources of cobalt in that country, as well as other types of mineralization. Information obtained during this trip shows Morocco to be a country for which much geologic information is available and in which there are many favorable target areas for future exploration. Work in the Bou Azzer district (Morocco's principal cobalt district) shows that much excellent geologic work has been done in searching for additional deposits. However, a number of useful approaches to locate cobalt have not been tried, and their use might be successful. The potential for undiscovered deposits in the Bou Azzer region seems very high. The cobalt mineralization in the Siroua uplift is different from that in the Bou Azzer district. However, geologic similarities between the two areas suggest that a genetic link may exist between the two types of mineralization. This further indicates that cobalt deposits of the Bou Azzer types might be present in the Siroua region. Examination of the Bleida copper mine shows it to be a well-exposed volcanic hosted stratabound copper deposit. Large unexplored areas containing similar rocks occur near this deposit and may contain as yet undiscovered copper mineralization.

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

    Science.gov (United States)

    Zelenay, Piotr; Wu, Gang

    2014-04-29

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

  1. Effects of cobalt in nickel-base superalloys

    Science.gov (United States)

    Tien, J. K.; Jarrett, R. N.

    1983-01-01

    The role of cobalt in a representative wrought nickel-base superalloy was determined. The results show cobalt affecting the solubility of elements in the gamma matrix, resulting in enhanced gamma' volume fraction, in the stabilization of MC-type carbides, and in the stabilization of sigma phase. In the particular alloy studied, these microstructural and microchemistry changes are insufficient in extent to impact on tensile strength, yield strength, and in the ductilities. Depending on the heat treatment, creep and stress rupture resistance can be cobalt sensitive. In the coarse grain, fully solutioned and aged condition, all of the alloy's 17% cobalt can be replaced by nickel without deleteriously affecting this resistance. In the fine grain, partially solutioned and aged condition, this resistance is deleteriously affected only when one-half or more of the initial cobalt content is removed. The structure and property results are discussed with respect to existing theories and with respect to other recent and earlier findings on the impact of cobalt, if any, on the performance of nickel-base superalloys.

  2. Temperature dependent viscosity of cobalt ferrite / ethylene glycol ferrofluids

    Science.gov (United States)

    Kharat, Prashant B.; Somvanshi, Sandeep B.; Kounsalye, Jitendra S.; Deshmukh, Suraj S.; Khirade, Pankaj P.; Jadhav, K. M.

    2018-04-01

    In the present work, cobalt ferrite / ethylene glycol ferrofluid is prepared in 0 to 1 (in the step of 0.2) volume fraction of cobalt ferrite nanoparticles synthesized by co-precipitation method. The XRD results confirmed the formation of single phase spinel structure. The Raman spectra have been deconvoluted into individual Lorentzian peaks. Cobalt ferrite has cubic spinel structure with Fd3m space group. FT-IR spectra consist of two major absorption bands, first at about 586 cm-1 (υ1) and second at about 392 cm-1 (υ2). These absorption bands confirm the formation of spinel-structured cobalt ferrite. Brookfield DV-III viscometer and programmable temperature-controlled bath was used to study the relationship between viscosity and temperature. Viscosity behavior with respect to temperature has been studied and it is revealed that the viscosity of cobalt ferrite / ethylene glycol ferrofluids increases with an increase in volume fraction of cobalt ferrite. The viscosity of the present ferrofluid was found to decrease with increase in temperature.

  3. Cobalt Blues The Story of Leonard Grimmett, the Man Behind the First Cobalt-60 Unit in the United States

    CERN Document Server

    Almond, Peter R

    2013-01-01

    For the latter half of the 20th century, cobalt-60 units were the mainstay of radiation treatments for cancer. Cobalt Blues describes the development of the first cobalt-60 unit in the United States and the man behind it, Leonard Grimmett. Conceptually conceived before World War II, it only became possible because of the development of nuclear reactors during the war. Although Grimmett conceived of and published his ideas first, the Canadians built the first units because of the capability of their reactor to produce more suitable cobalt-60 sources. This book tells the story of how Grimmett and others came together at the time that the U S Atomic Energy Agency was pushing the use of radioactivity in medicine. Due to his sudden death, very little information about Grimmett was known until recently, when various documents have come to light, allowing the full story to be told.

  4. 29 CFR 531.59 - The tip wage credit.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false The tip wage credit. 531.59 Section 531.59 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR REGULATIONS WAGE PAYMENTS UNDER THE FAIR LABOR STANDARDS ACT OF 1938 Interpretations Payment of Wages to Tipped Employees...

  5. 34 CFR 200.59 - Duties of paraprofessionals.

    Science.gov (United States)

    2010-07-01

    ...) Conducting parent involvement activities. (5) Providing instructional support in a library or media center... 34 Education 1 2010-07-01 2010-07-01 false Duties of paraprofessionals. 200.59 Section 200.59 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY...

  6. 46 CFR 188.10-59 - Recognized classification society.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Recognized classification society. 188.10-59 Section 188... VESSELS GENERAL PROVISIONS Definition of Terms Used in This Subchapter § 188.10-59 Recognized classification society. This term means the American Bureau of Shipping or other classification society...

  7. 28 CFR 345.59 - Inmate performance pay.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Inmate performance pay. 345.59 Section... INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.59 Inmate performance pay. Inmate workers for FPI may also receive Inmate Performance Pay for participation in programs where this award is made...

  8. 47 CFR 80.59 - Compulsory ship inspections.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Compulsory ship inspections. 80.59 Section 80... STATIONS IN THE MARITIME SERVICES Applications and Licenses § 80.59 Compulsory ship inspections. (a) Inspection of ships subject to the Communications Act or the Safety Convention. (1) The FCC will not normally...

  9. 14 CFR 63.59 - Retesting after failure.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Retesting after failure. 63.59 Section 63.59 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... failure. (a) An applicant for a flight navigator certificate who fails a written or practical test for...

  10. 10 CFR 74.59 - Quality assurance and accounting requirements.

    Science.gov (United States)

    2010-01-01

    ... measurement system in question must not be used for material control and accounting purposes until it has been... 10 Energy 2 2010-01-01 2010-01-01 false Quality assurance and accounting requirements. 74.59 Section 74.59 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) MATERIAL CONTROL AND ACCOUNTING OF SPECIAL...

  11. 7 CFR 59.302 - Mandatory weekly reporting for lambs.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Mandatory weekly reporting for lambs. 59.302 Section... (CONTINUED) LIVESTOCK MANDATORY REPORTING Lamb Reporting § 59.302 Mandatory weekly reporting for lambs. (a... domestic from imported market purchases: (1) The quantity of lambs purchased through a negotiated purchase...

  12. 36 CFR 902.59 - Geological and geophysical information.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Geological and geophysical information. 902.59 Section 902.59 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT... Geological and geophysical information. Any geological or geophysical information and data (including maps...

  13. 40 CFR 279.59 - Management of residues.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Management of residues. 279.59 Section 279.59 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED... Management of residues. Owners and operators who generate residues from the storage, processing, or re...

  14. 45 CFR 1180.59 - Records related to grant funds.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Records related to grant funds. 1180.59 Section 1180.59 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE...; and (e) Other records necessary to facilitate an effective audit. [71 FR 6372, Feb. 8, 2006] ...

  15. 38 CFR 59.124 - Inspections, audits, and reports.

    Science.gov (United States)

    2010-07-01

    ... reports. (a) A State will allow VA inspectors and auditors to conduct inspections and audits as necessary... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Inspections, audits, and reports. 59.124 Section 59.124 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS...

  16. 40 CFR 59.103 - Container labeling requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Container labeling requirements. 59.103... National Volatile Organic Compound Emission Standards for Automobile Refinish Coatings § 59.103 Container... automobile refinish coating or coating component container or package, the day, month, and year on which the...

  17. 40 CFR 59.405 - Container labeling requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Container labeling requirements. 59.405... National Volatile Organic Compound Emission Standards for Architectural Coatings § 59.405 Container... section on the coating container in which the coating is sold or distributed. (1) The date the coating was...

  18. Cobalt mineral exploration and supply from 1995 through 2013

    Science.gov (United States)

    Wilburn, David R.

    2011-01-01

    The global mining industry has invested a large amount of capital in mineral exploration and development over the past 15 years in an effort to ensure that sufficient resources are available to meet future increases in demand for minerals. Exploration data have been used to identify specific sites where this investment has led to a significant contribution in global mineral supply of cobalt or where a significant increase in cobalt production capacity is anticipated in the next 5 years. This report provides an overview of the cobalt industry, factors affecting mineral supply, and circumstances surrounding the development, or lack thereof, of key mineral properties with the potential to affect mineral supply. Of the 48 sites with an effective production capacity of at least 1,000 metric tons per year of cobalt considered for this study, 3 producing sites underwent significant expansion during the study period, 10 exploration sites commenced production from 1995 through 2008, and 16 sites were expected to begin production by 2013 if planned development schedules are met. Cobalt supply is influenced by economic, environmental, political, and technological factors affecting exploration for and production of copper, nickel, and other metals as well as factors affecting the cobalt industry. Cobalt-rich nickel laterite deposits were discovered and developed in Australia and the South Pacific and improvements in laterite processing technology took place during the 1990s and early in the first decade of the 21st century when mining of copper-cobalt deposits in Congo (Kinshasa) was restricted because of regional conflict and lack of investment in that country's mining sector. There was also increased exploration for and greater importance placed on cobalt as a byproduct of nickel mining in Australia and Canada. The emergence of China as a major refined cobalt producer and consumer since 2007 has changed the pattern of demand for cobalt, particularly from Africa and

  19. Gold-supported two-dimensional cobalt oxyhydroxide (CoOOH) and multilayer cobalt oxide islands

    DEFF Research Database (Denmark)

    Fester, Jakob; Walton, Alexander; Li, Zheshen

    2017-01-01

    In the present study, we investigate the facile conversion of Co-O bilayer islands on a Au(111) surface into preferentially O-Co-O trilayers in an oxygen atmosphere and O-Co-O-Co-O multilayers at elevated temperature. We characterize and compare the island morphologies with scanning tunneling...... microscopy, X-ray photoemission spectroscopy (XPS) and valence band spectroscopy, and show that the cobalt oxidation state changes from Co2+ in bilayers to purely Co3+ in trilayers and a mixture of Co2+ and Co3+ in the multilayer morphology. In contrast to bilayers and multilayers, the trilayer structure...

  20. Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched Polyester Polyol Matrix

    Directory of Open Access Journals (Sweden)

    O. I. Medvedeva

    2017-01-01

    Full Text Available A series of cobalt (Co and its oxides based nanoparticles were synthesized by using hyperbranched polyester polyol Boltorn H20 as a platform and sodium borohydride as a reducing agent. UV, FT-IR, XRD, NTA, and TEM methods were employed to obtain physicochemical characteristics of the products. The average diameter of Co nanoparticles was approximately 8.2±3.4 nm. Their magnetic properties, including hysteresis loop, field-cooled, and zero field-cooled curves were investigated. The nanoparticles exhibit superparamagnetism at room temperature, accompanied by magnetic hysteresis below the blocking temperature.

  1. Photosensitized oxygenation of alkenes in the presence of bisazafullerene (C59N)2 and hydroazafullerene C59HN

    International Nuclear Information System (INIS)

    Tagmatarchis, Nikos; Shinohara, Hisanori

    2001-01-01

    Bisazafullerene (C 59 N) 2 and hydroazafullerene C 59 HN photosensitize the reaction of alkenes with oxygen. 2-methyl 2-butene and α-terpinene undergo ene and Diels-Alder photooxygenation reactions, respectively, in the presence of minute amounts of azafullerenes to produce the corresponding peroxides

  2. DETECTION AND ISOLATION OF CD59 FROM HUMAN SEMINAL PLASMA

    Directory of Open Access Journals (Sweden)

    A REZAIE

    2002-06-01

    Full Text Available Introduction. CD59 is one of the complement regulatory proteins (CRPs which exert inhibitory function by blocking the formation of C5b-9 complex or Membrane Attacks complex (MAC. Regarding the therapeutic role of CD59 in treatment of pathological effects in uncontrolled activation of complements system and its efficiency to overcome the hyper-acute rejection, CD59 was suggested for maintenance of transplanted organ. In this study We determined and isolated CD59 from seminal plasma. Methods. Six normospermic sample according to WHO standards were chosen. Plasma of samples was separated and to remove the postasomes, the seminal plama was ultra centrifuged. CD59 was detected by Dot-Blot using CD59 mAb (MEM43. The molecular weight and purity of protein was detected by SOS-PAGE method follwed by Westerm Blot. Results. Protein was present in the 6.5 ml and 15ml of gel fitration fractions. Molecular weight based on marker size in these two fractions was 65 and 21KD respectively. Discussion. CD59 had previously beem purified by lysis of erythrocyte cell membrane. Because of use of detergent and preservative agents, this method decreased physiologic effects of the protein. In this study the isolation was performed from prostasome granules" without using of any detergent and preservative agents.

  3. Cobalt 60 cation exchange with mexican clays

    International Nuclear Information System (INIS)

    Nava Galve, R.G.

    1993-01-01

    Mexican clays can be used to remove radioactive elements from contaminated aqueous solutions. Cation exchange experiments were performed with 60 Co radioactive solution. In the present work the effect of contact time on the sorption of Co 2+ was studied. The contact time in hydrated montmorillonite was from 5 to 120 minutes and in dehydrated montmorillonite 5 to 1400 minutes. The Co 2+ uptake value was, in hydrated montmorillonite, between 0.3 to 0.85 m eq/g and in dehydrated montmorillonite, between 0.6 to 1.40 m eq/g. The experiments were done in a pH 5.1 to 5.7 and normal conditions. XRD patterns were used to characterize the samples. The crystallinity was determined by X-ray Diffraction and it was maintained before and after the cation exchange. DTA thermo grams showed the temperatures of the lost humidity and crystallization water. Finally, was observed that dehydrated montmorillonite adsorb more cobalt than hydrated montmorillonite. (Author)

  4. Cobalt teletherapy of urinary bladder tumors

    International Nuclear Information System (INIS)

    Kamprad, F.; Pfeiffer, J.; Oelssner, W.

    1978-01-01

    Based on results obtained from patients with urinary bladder carcinomas who were subjected to cobalt teletherapy at the Radiological Clinic of the Karl Marx University from 1969 to 1971, the influence of total dumor dose, of single tumor dose, and of nominal standard dose (NSD) on the frequency of radiation-induced vesicorectal changes as well as on the frequency of local recurrences was investigated in a catamnestic study. Under the conditions of a small volume pendulum irradiation there is a considerable increase in the rate of late effects above a total dose of 6,000 rad, with single doses of more than 180 rad per day and with a NSD of more than 1,750 ret. These dose limits should not be exceeded because a further dose increase does not essentially decrease the number of local recurrences. Higher tumor doese, for instance in stationary therapy, result in radiation-induced late effects even after low dosage. Therefore, the limiting values have to be lowered for this type of irradiation. (author)

  5. Cobalt-60 gamma irradiation of shrimp

    International Nuclear Information System (INIS)

    Sullivan, N.L.B.

    1993-01-01

    Meta- and ortho-tyrosine were measured using high performance liquid chromatography (HPLC) in conjunction with electrochemical detection in shrimp irradiated using cobalt-60 gamma radiation in the absorbed dose range 0.8 to 6.0 kGy, in nonirradiated shrimp, and in bovine serum albumin (BSA) irradiated in dilute aqueous solution at 25.0 kGy. Ortho-tyrosine was measured in nonirradiated BSA. Para-, meta-, and ortho-tyrosine was measured using HPLC in conjunction with uv-absorption detection in dilute aqueous solutions of phenylalanine irradiated in the absorbed dose range 16.0 to 195.0 kGy. The measured yields of tyrosine isomers were approximately linear as a function of absorbed dose in shrimp, and in irradiated solutions of phenylalanine up to 37.0 kGy. The occurrence of meta- and ortho-tyrosine, which had formerly been considered unique radiolytic products, has not previously been reported in nonirradiated shrimp or BSA. The conventional hydrolyzation and analytical techniques used in the present study to measure meta- and ortho-tyrosine may provide the basis for a method to detect and determine the dose used in food irradiation

  6. Practical and clinical considerations in Cobalt-60 tomotherapy

    Directory of Open Access Journals (Sweden)

    Joshi Chandra

    2009-01-01

    Full Text Available Cobalt-60 (Co-60 based radiation therapy continues to play a significant role in not only developing countries, where access to radiation therapy is extremely limited, but also in industrialized countries. Howver, technology has to be developed to accommodate modern techniques, in-clud-ing image guided and adaptive radiation therapy (IGART. In this paper we describe some of the practical and clinical considerations for Co-60 based tomotherapy by comparing Co-60 and 6 MV linac-based tomotherapy plans for a head and neck (HandN cancer and a prostate cancer case. The tomotherapy IMRT plans were obtained by modeling a MIMiC binary multi-leaf collimator attached to a Theratron-780c Co-60 unit and a 6 MV linear accelerator (CL2100EX. The EGSnrc/BEAMnrc Monte Carlo (MC code was used for the modeling of the treatment units with the MIMiC collimator and EGSnrc/DOSXYZnrc code was used for beamlet dose data. An in-house inverse treatment planning program was then used to generate optimized tomotherapy dose distributions for the H and N and prostate cases. The dose distributions, cumulative dose area histograms (DAHs and dose difference maps were used to evaluate and compare Co-60 and 6 MV based tomotherapy plans. A quantitative analysis of the dose distributions and dose-volume histograms shows that both Co-60 and 6 MV plans achieve the plan objectives for the targets (CTV and nodes and OARs (spinal cord in HandN case, and rectum in prostate case.

  7. 49 CFR 570.59 - Service brake system.

    Science.gov (United States)

    2010-10-01

    ... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any one of the following performance criteria will satisfy the requirements of this section. Verify that tire...

  8. Adsorption, Bioaccumulation and Kinetics Parameters of the Phytoremediation of Cobalt from Wastewater Using Elodea canadensis.

    Science.gov (United States)

    Mosoarca, Giannin; Vancea, Cosmin; Popa, Simona; Boran, Sorina

    2018-05-01

    Present paper investigates the phytoremediation of cobalt from wastewaters using Elodea canadensis. Bioaccumulation tests were conducted at various concentrations of cobalt ranging from 1 to 15 mg/L. Final concentrations of cobalt in wastewaters, after phytoremediation, were less than 1 mg/L. E. canadensis' hyperaccumulator character with regard to cobalt is emphasised by the amount of cobalt retained: 0.39% ± 0.02% of dry mass at an initial concentration in wastewater of 15 mg/L. After 14 days of exposure to contaminant, the biomass as well as the relative growth rate has increased with the amount of cobalt in wastewaters, the plant manifesting an excellent tolerance to cobalt exposure. Adsorption of cobalt ions by E. canadensis can be well described by the Langmuir adsorption isotherm and the pseudo-second-order model equation.

  9. Solvent extractions applications to hydrometallurgy. Pt.III: Nickel, cobalt, manganese and ocean nodules

    International Nuclear Information System (INIS)

    Amer, S.

    1981-01-01

    The main applications of solvent extraction to the hydrometallurgy of nickel, cobalt, manganese and manganese rich ocean nodules, which also contain nickel, cooper and cobalt, are exposed. A short description of the processes with commercial applications is made. (author)

  10. Monsoon induced cobalt enrichment in Porites (coral) from the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.A.S.; Nath, B.N.

    Cobalt concentrations in growth bands of a reef building coral (Porites sp.) collected from Kalpeni Atoll of the Lakshadweep group of islands (Arabian Sea), rvealed that cobalt concentrations and Co/Ca ratios exhibit similar trend. Study indicates...

  11. Cobalt doped proangiogenic hydroxyapatite for bone tissue engineering application

    International Nuclear Information System (INIS)

    Kulanthaivel, Senthilguru; Roy, Bibhas; Agarwal, Tarun; Giri, Supratim; Pramanik, Krishna; Pal, Kunal; Ray, Sirsendu S.; Maiti, Tapas K.; Banerjee, Indranil

    2016-01-01

    ABSTRACT: The present study delineates the synthesis and characterization of cobalt doped proangiogenic–osteogenic hydroxyapatite. Hydroxyapatite samples, doped with varying concentrations of bivalent cobalt (Co"2"+) were prepared by the ammoniacal precipitation method and the extent of doping was measured by ICP–OES. The crystalline structure of the doped hydroxyapatite samples was confirmed by XRD and FTIR studies. Analysis pertaining to the effect of doped hydroxyapatite on cell cycle progression and proliferation of MG-63 cells revealed that the doping of cobalt supported the cell viability and proliferation up to a threshold limit. Furthermore, such level of doping also induced differentiation of the bone cells, which was evident from the higher expression of differentiation markers (Runx2 and Osterix) and better nodule formation (SEM study). Western blot analysis in conjugation with ELISA study confirmed that the doped HAp samples significantly increased the expression of HIF-1α and VEGF in MG-63 cells. The analysis described here confirms the proangiogenic–osteogenic properties of the cobalt doped hydroxyapatite and indicates its potential application in bone tissue engineering. - Highlights: • Cobalt (Co"+"2) doped hydroxyapatite (Co-HAp) can be prepared by the wet chemical method. • The concentration of Co"+"2 influences the physico-chemical properties of HAp. • Co-HAp was found to be biocompatible and osteogenic. • Co-HAp enhanced cellular VEGF secretion through HIF-1α stabilization. • The optimum biological performance of Co-HAp was achieved for 0.33% (w/w) Co"+"2 doping.

  12. Investigations on bioaccumulation of cobalt by fish eggs

    International Nuclear Information System (INIS)

    Harms, U.; Behringer, H.; Kunze, J.

    1978-01-01

    In ionized form cobalt is taken up by fish eggs directly from the water. Accumulation takes place on the chorion where the metal ions are reversibly bound to functional groups of the protein of the envelope of the egg or of the mycosa. To a small extent there occurs a transport of metal ions into the interior of the egg. It could not be clarified within the scope of the studies performed if this process is to be attributed to diffusion. Binding of the cobalt ions to the chorion leads, within hours, to a nearly uncharged final state, an apparent equilibrium, whose position is determined by the cobalt ion concentration of the breeding medium. Foreign ions (electrolytes like Ca 2+ ) lead to reduced uptake of cobalt ions, because they compete with the latter for binding places in the egg's envelope. Complex-forming substances (cysteine) result in lower absorption rates, too, the concentration of available cobalt ions in the water being reduced. (orig.) [de

  13. Relationship between nickel and cobalt sensitization in hard metal workers

    Energy Technology Data Exchange (ETDEWEB)

    Rystedt, I; Fischer, T

    1983-05-01

    Eight hundred fifty-three hard metal workers were examined and patch tested with 20 substances from their environment, including nickel and cobalt. Nickel sensitivity was found in 2 men and 38 women. 88% of the nickel-sensitive individuals had developed a jewelry dermatitis prior to employment in the hard metal industry or before the appearance of hand eczema. 29% of the hard metal workers gave a history of slight irritant dermatitis. In the nickel sensitized group, 40% had had severe hand eczema which generally appeared 6-12 months after starting employment. In 25% of the cases, nickel sensitive individuals developed cobalt allergy, compared with 5% in the total population investigated. Most facts indicate that nickel sensitivity and irritant hand eczema precede cobalt sensitization. Hard metal workers with simultaneous nickel and cobalt sensitivity had a more severe hand eczema than those with isolated cobalt or nickel sensitivity or only irritant dermatitis. 64% of the female population had pierced ear lobes. Among the nickel allergic women, 95% had pierced ear lobes. The use of earrings containing nickel after piercing is strongly suspected of being the major cause of nickel sensitivity. Piercing at an early age seems to increase the risk of incurring nickel sensitivity.

  14. Contact dermatitis to cobalt chloride with an unusual mechanism.

    Science.gov (United States)

    Arslan, Sevket; Aksan, Serkan; Ucar, Ramazan; Caliskaner, Ahmet Zafer

    2015-10-01

    Contact dermatitis is a frequent inflammatory skin disease. A suspected diagnosis is based on clinical symptoms, a plausible contact to allergens and a suitable history of dermatitis. Therefore, careful diagnosis by patch testing is of great importance because the patch testing is important to find out which allergen/material causes the complaints. Metallic allergens such as cobalt are among the most common causes of allergic contact dermatitis, but frequencies of contact dermatitis to these allergens may vary in different skin areas. Here, we report an unusual case of cobalt allergy on the skin contact with the prosthetic leg of a 30-year-old female patient. The patient developed maculopapular and vesicular lesions on her contact region of residual limb to prosthetic leg. She underwent standard patch testing, which resulted in a strong positive reaction to cobalt chloride. This case report may serve to remind doctors to be aware of potential allergic reactions to prostheses and to enable them to recognize a metal allergy if it appears. Prosthetists should also be reminded of potential allergic reactions. Cobalt can be used as an accelerator in making a prosthetic socket. Several cases have been reported concerning allergies to components of the prosthetic socket. This is the first report of sensitization to cobalt which is used in making a prosthetic leg. © The International Society for Prosthetics and Orthotics 2014.

  15. Effect of Cobalt Supplementation on Performance of growing Calves

    Directory of Open Access Journals (Sweden)

    V.Nagabhushana

    Full Text Available The experiment was conducted to study the effect of critical supplementation of wheat straw with cobalt on fibre utilization and nutrient utilization in growing cross-bred male calves. Twenty-one crossbred (HF X Local male growing calves of 3-4 months age were fed with wheat straw based diet consisting without (Co0 and with 1 (Co1 and 6 (Co6 ppm cobalt as cobaltous chloride. There was no significant difference in intake of wheat straw, concentrate and DMI between the three groups and the ratio between concentrate and wheat straw was maintained at 40:60 irrespective of dietary level of cobalt. Similarly, average cumulative body weight, net gain in body weight or feed efficiency did not differ significantly between treatments. No significant effect was observed on the digestibility of dry matter, organic matter, crude protein, ether extract and fibre constituents like NDF, ADF, hemicellulose or cellulose by supplementation of 1 and 6 ppm Co to the diet of growing calves. Balance of nutrients such as Nitrogen, Calcium and Phosphorus was similar and positive in all the treatment groups. TDN and DCP values of the experimental diets remained almost similar irrespective of dietary level of cobalt. [Veterinary World 2008; 1(10.000: 299-302

  16. Effect of rare earth substitution in cobalt ferrite bulk materials

    International Nuclear Information System (INIS)

    Bulai, G.; Diamandescu, L.; Dumitru, I.; Gurlui, S.; Feder, M.; Caltun, O.F.

    2015-01-01

    The study was focused on the influence of small amounts of rare earth (RE=La, Ce, Sm, Gd, Dy, Ho, Er, Yb) addition on the microstructure, phase content and magnetic properties of cobalt ferrite bulk materials. The X-Ray diffraction measurements confirmed the formation of the spinel structure but also the presence of secondary phases of RE oxides or orthoferrite in small percentages (up to 3%). Density measurements obtained by Archimedes method revealed a ~1 g cm −3 decrease for the RE doped cobalt ferrite samples compared with stoichiometric one. Both the Mössbauer and Fourier Transform Infrared Spectrocopy analysis results confirmed the formation of the spinel phase. The saturation magnetization and coercive field values of the doped samples obtained by Vibrating Sample Magnetometry were close to those of the pure cobalt ferrite. For magnetostrictive property studies the samples were analyzed using the strain gauge method. Higher maximum magnetostriction coefficients were found for the Ho, Ce, Sm and Yb doped cobalt ferrite bulk materials as related to the stoichiometric CoFe 2 O 4 sample. Moreover, improved strain derivative was observed for these samples but at higher magnetic fields due to the low increase of the coercive field values for doped samples. - Highlights: • Substitution by a large number of rare earth elements was investigated. • First reported results on magnetostriction measurements of RE doped cobalt ferrite. • The doped samples presented an increased porosity and a decreased grain size. • Increased magnetostrctive response was observed for several doped samples

  17. 59 MDW/ST OVERVIEW BRIEFING 15 JUNE 2017

    Science.gov (United States)

    2017-06-15

    Animal Welfare Act of 1966, as amended." 59 MOW FORM 3039, 20160628 PrP~l".rihRrl hv !’i9 MDWI 41-108 PREVIOUS EDITIONS ARE OBSOLETE Page 1 of 3 Pages...and strengthen human capital , to build and maintain a strong R&A program to optimize our ability to fly, fight and win . -=~~.:~~- • 59 MOW Mission

  18. 59th Medical Wing Protection of Vulnerable Populations: Ombudsman Program

    Science.gov (United States)

    2018-04-20

    REPORT TYPE 20/04/2018 poster 4. TITLE AND SUBTITLE 59th Medical Wing Protection of Vulnerable Populations: Ombudsman Program 6. AUTHOR(S...13. SUPPLEMENTARY NOTES 2018 Annual AAHRPP Conference April 20-22, 2018 Denver, CO 14. ABSTRACT 1S. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF...59th Medical Wing Protection of Vulnerable Populations: Ombudsman Program Wayne DeutschDDS1, MPH, Michele Tavish LYN, PMP, CCRC 1 Brenda

  19. Inhibition of the radiolytic hydrogen production in the nuclear waste of 'bitumen coated' type: study of the interaction between hydrogen and cobalt hydroxo-sulphide

    International Nuclear Information System (INIS)

    Pichon, C.

    2006-11-01

    In the nuclear field in France, the bitumen is mainly used for the conditioning of the radioactive muds generated by the fuel reprocessing. However, the self-irradiation of the bitumen induces a production of hydrogen which generates safety problems. The comparison of various storage sites showed that the presence of cobalt hydroxo sulphide limited such a production. Consequently, this compound was regarded as an 'inhibitor of radiolytic hydrogen production'. However, the origin of this phenomenon was not clearly identified. In order to propose an explanation to this inhibition phenomenon, model organic molecules were used to represent the components of the bitumen. Irradiations were carried out by protons to simulate the alpha radiolysis. The organic molecules irradiations by a proton beam showed that cobalt hydroxo sulphide CoSOH, does not act as a hydrogenation catalyst of unsaturated hydrocarbons, nor as a radicals scavenger, but consists of a trap of hydrogen. Experiments of hydrogen trapping at ambient temperature were carried out according to two techniques: gravimetry and manometry. The solid was characterized before and after interaction with hydrogen (infrared and Raman spectroscopies, X-ray diffraction). The initial solid was composed of amorphous cobalt hydroxo sulphide and a minor phase of cobalt hydroxide. The gravimetry and manometry experiments showed that the maximum of hydrogen trapping capacity is equal to 0.59 ± 0.18 mole of hydrogen per mole of cobalt. After interaction with hydrogen, the Co(OH) 2 phase disappeared and a new solid phase appeared corresponding to Co 9 S 8 . These observations, as well as the analysis of the gas phase, made it possible to conclude with the following reaction (1): 9 CoSOH + 11/2 H 2 = Co 9 S 8 + 9 H 2 O + H 2 S (1). Gravimetry experiments at temperatures between 50 and 210 C revealed the desorption of water but not of hydrogen sulphide. The absence of hydrogen sulphide in gaseous phase and the Co(OH) 2 phase

  20. Hard hardfacing by welding in the manufacture of valves; Problem Cobalt, alternatives, advantages, disadvantages

    International Nuclear Information System (INIS)

    Piquer Caballero, J.

    2014-01-01

    Alloys of recharge usually used in the field of the valves are base alloys cobalt (stellite), but in the field of nuclear power plants, due to radioactive activation of the cobalt, there is a growing trend to replace these alloys with other calls cobalt free . In this paper we will explore the most frequent and will be deducted the relevant advantages and disadvantages of these, in comparison with base alloys cobalt. (Author)

  1. Importance of cobalt for individual trophic groups in an anaerobic methanol-degrading consortium.

    OpenAIRE

    Florencio, L; Field, J A; Lettinga, G

    1994-01-01

    Methanol is an important anaerobic substrate in industrial wastewater treatment and the natural environment. Previous studies indicate that cobalt greatly stimulates methane formation during anaerobic treatment of methanolic wastewaters. To evaluate the effect of cobalt in a mixed culture, a sludge with low background levels of cobalt was cultivated in an upflow anaerobic sludge blanket reactor. Specific inhibitors in batch assays were then utilized to study the effect of cobalt on the growth...

  2. Thermal transport in cuprates, cobaltates, and manganites

    International Nuclear Information System (INIS)

    Berggold, K.

    2006-09-01

    The subject of this thesis is the investigation of the thermal transport properties of three classes of transition-metal oxides: Cuprates, cobaltates, and manganites. The layered cuprates R 2 CuO 4 with R=La, Pr, Nd, Sm, Eu, and Gd show an anomalous thermal conductivity κ. Two maxima of κ are observed as a function of temperature for a heat current within the CuO 2 planes, whereas for a heat current perpendicular to the CuO 2 planes only a conventional phononic low-temperature maximum of κ is present. Evidence is provided that the high-temperature maximum is caused by heat-carrying excitations on the CuO 2 square lattice. Moreover, it is shown that the complex low-temperature and magnetic-field behavior of κ in Nd 2 CuO 4 is most likely caused by additional phonon scattering rather than by heat-carrying Nd magnons, as it was proposed in the literature. In the cobaltates RCoO 3 with R=La, Pr, Nd, and Eu, a temperature-induced spin-state transition of the Co 3+ ions occurs. It is shown that the additional lattice disorder caused by the random distribution of populated higher spin states causes a large suppression of the thermal conductivity of LaCoO 3 for T>25 K. The effect is much weaker in PrCoO 3 and NdCoO 3 due to the increased spin gap. A quantitative analysis of the responsible mechanisms based on EuCoO 3 as a reference compound is provided. A main result is that the static disorder is sufficient to explain the suppression of κ. No dynamical Jahn-Teller distortion, as proposed in the literature, is necessary to enhance the scattering strength. Below 25 K, k is mainly determined by resonant phonon scattering on paramagnetic impurity levels, e.g. caused by oxygen non-stoichiometry. Such a suppression of the thermal conductivity by resonant scattering processes is e.g. known from Holmium ethylsulfate. This effect is most pronounced in LaCoO 3 , presumably due to magnetic polaron formation. In the doped compounds La 1-x Sr x CoO 3 with 0≤x≤0.25, a large

  3. Study of obliquely deposited thin cobalt films

    International Nuclear Information System (INIS)

    Szmaja, W.; Kozlowski, W.; Balcerski, J.; Kowalczyk, P.J.; Grobelny, J.; Cichomski, M.

    2010-01-01

    Research highlights: → The paper reports simultaneously on the magnetic domain structure of obliquely deposited thin cobalt films (40 nm and 100 nm thick) and their morphological structure. Such studies are in fact rare (Refs. cited in the paper). → Moreover, to our knowledge, observations of the morphological structure of these films have not yet been carried out simultaneously by transmission electron microscopy (TEM) and atomic force microscopy (AFM). → The films of both thicknesses were found to have uniaxial in-plane magnetic anisotropy. → The magnetic microstructure of the films 40 nm thick was composed of domains running and magnetized predominantly in the direction perpendicular to the incidence plane of the vapor beam. → As the film thickness was changed from 40 nm to 100 nm, the magnetic anisotropy was observed to change from the direction perpendicular to parallel with respect to the incidence plane. → Thanks to the application of TEM and AFM, complementary information on the morphological structure of the films could be obtained. → In comparison with TEM images, AFM images revealed grains larger in size and slightly elongated in the direction perpendicular rather than parallel to the incidence plane. → These experimental findings clearly show that surface diffusion plays an important role in the process of film growth. → For the films 40 nm thick, the alignment of columnar grains in the direction perpendicular to the incidence plane was observed. → This correlates well with the magnetic domain structure of these films. → For the films 100 nm thick, the perpendicular alignment of columnar grains could also be found, although in fact with larger difficulty. → TEM studies showed that the films consisted mainly of the hexagonal close-packed (HCP) crystalline structure, but no preferred crystallographic orientation of the grains could be detected for the films of both thicknesses. → For the films 100 nm thick, the alignment of

  4. Thermal transport in cuprates, cobaltates, and manganites

    Energy Technology Data Exchange (ETDEWEB)

    Berggold, K.

    2006-09-15

    The subject of this thesis is the investigation of the thermal transport properties of three classes of transition-metal oxides: Cuprates, cobaltates, and manganites. The layered cuprates R{sub 2}CuO{sub 4} with R=La, Pr, Nd, Sm, Eu, and Gd show an anomalous thermal conductivity {kappa}. Two maxima of {kappa} are observed as a function of temperature for a heat current within the CuO{sub 2} planes, whereas for a heat current perpendicular to the CuO{sub 2} planes only a conventional phononic low-temperature maximum of {kappa} is present. Evidence is provided that the high-temperature maximum is caused by heat-carrying excitations on the CuO{sub 2} square lattice. Moreover, it is shown that the complex low-temperature and magnetic-field behavior of {kappa} in Nd{sub 2}CuO{sub 4} is most likely caused by additional phonon scattering rather than by heat-carrying Nd magnons, as it was proposed in the literature. In the cobaltates RCoO{sub 3} with R=La, Pr, Nd, and Eu, a temperature-induced spin-state transition of the Co{sup 3+} ions occurs. It is shown that the additional lattice disorder caused by the random distribution of populated higher spin states causes a large suppression of the thermal conductivity of LaCoO{sub 3} for T>25 K. The effect is much weaker in PrCoO{sub 3} and NdCoO{sub 3} due to the increased spin gap. A quantitative analysis of the responsible mechanisms based on EuCoO{sub 3} as a reference compound is provided. A main result is that the static disorder is sufficient to explain the suppression of {kappa}. No dynamical Jahn-Teller distortion, as proposed in the literature, is necessary to enhance the scattering strength. Below 25 K, k is mainly determined by resonant phonon scattering on paramagnetic impurity levels, e.g. caused by oxygen non-stoichiometry. Such a suppression of the thermal conductivity by resonant scattering processes is e.g. known from Holmium ethylsulfate. This effect is most pronounced in LaCoO{sub 3}, presumably due to

  5. Effects of bathing on skin exposed to Cobalt-60 teletherapy

    International Nuclear Information System (INIS)

    Bohannan, P.A.

    1982-01-01

    The problem of this study was to determine the effects of bathing or not bathing on the degree of skin reaction occurring in patients receiving Cobalt-60 radiation therapy to the chest, back, or head and neck. A quasi experimental study was done using a 2 x 7 repeated measures design. Sixty-seven subjects receiving Cobalt-60 radiation therapy at the Moncrief Radiation Center in Fort Worth, Texas, were randomly assigned to an experimental group who did not bathe during therapy and a control group who did bathe with water during therapy. Observations were made after each 1000 rads of therapy and two weeks after the final treatment. Erythema and pigmentation measurements were taken using the Photovolt 670 and rates were assigned using the Baker-Leith Rating Scale. Findings from the study suggest that bathing the portal of entry with water during the treatment period does not influence the degree of skin response that occurs from Cobalt-60 teletherapy

  6. C-188 cobalt-60 sealed source integrity: source monitoring

    International Nuclear Information System (INIS)

    Defalco, G.M.; Shah, V.

    1995-01-01

    The integrity of C-188 cobalt-60 sealed sources used for radiation processing will be a key factor in the continued industrial acceptance and growth of gamma irradiation technology. Given the public's relatively poor understanding of most nuclear topics and the news media's tendency to sensationalize events, it is appropriate for suppliers and users of gamma technology to be vigilant and conservative regarding the application of cobalt-60 sources to industrial purposes. Nordion's recent decision to extend the optional warranty on its C-188 cobalt-60 sealed source from 15 years to 20 years is based on over 30 years of data generated from its on-going SOURCE SURVEILLANCE PROGRAM. This paper presents an overview of the C-188 SOURCE SURVEILLANCE PROGRAM. (author)

  7. Cobalt 60 gamma irradiation current status, trends and insights

    International Nuclear Information System (INIS)

    Corley, John T.

    1998-01-01

    This paper discusses the current status, trends and insights into the continued, safe use of cobalt 60 gamma irradiation. Also presented are some of the many initiatives undertaken at MDS Nordion. Topics covered include our investment for the future supply of raw materials and the latest news from source production. Briefly presented are the tasks associated with the safe transport of cobalt 60 around the world. Discussed is cobalt 60 usage at the customer site; more specifically maintaining source integrity, source utilization and irradiator design trends. Highlighted are industry trends for North America, Europe and the rest of the world. Finally presented are the challenges and opportunities for the industry. Stressed in the paper is the need to work together

  8. Tungsen--nickel--cobalt alloy and method of producing same

    International Nuclear Information System (INIS)

    Dickinson, J.M.; Riley, R.E.

    1977-01-01

    An improved tungsten alloy having a tungsten content of approximately 95 weight percent, a nickel content of about 3 weight percent, and the balance being cobalt of about 2 weight percent is described. A method for producing this tungsten--nickel--cobalt alloy is further described and comprises coating the tungsten particles with a nickel--cobalt alloy, pressing the coated particles into a compact shape, heating the compact in hydrogen to a temperature in the range of 1400 0 C and holding at this elevated temperature for a period of about 2 hours, increasing this elevated temperature to about 1500 0 C and holding for 1 hour at this temperature, cooling to about 1200 0 C and replacing the hydrogen atmosphere with an inert argon atmosphere while maintaining this elevated temperature for a period of about 1 / 2 hour, and cooling the resulting alloy to room temperature in this argon atmosphere

  9. Magnetic and resonance properties of ferrihydrite nanoparticles doped with cobalt

    Science.gov (United States)

    Stolyar, S. V.; Yaroslavtsev, R. N.; Iskhakov, R. S.; Bayukov, O. A.; Balaev, D. A.; Dubrovskii, A. A.; Krasikov, A. A.; Ladygina, V. P.; Vorotynov, A. M.; Volochaev, M. N.

    2017-03-01

    Powders of undoped ferrihydrite nanoparticles and ferrihydrite nanoparticles doped with cobalt in the ratio of 5: 1 have been prepared by hydrolysis of 3 d-metal salts. It has been shown using Mössbauer spectroscopy that cobalt is uniformly distributed over characteristic crystal-chemical positions of iron ions. The blocking temperatures of ferrihydrite nanoparticles have been determined. The nanoparticle sizes, magnetizations, surface anisotropy constants, and bulk anisotropy constants have been estimated. The doping of ferrihydrite nanoparticles with cobalt leads to a significant increase in the anisotropy constant of a nanoparticle and to the formation of surface rotational anisotropy with the surface anisotropy constant K u = 1.6 × 10-3 erg/cm2.

  10. Absolute measurement of the critical scattering cross section in cobalt

    International Nuclear Information System (INIS)

    Glinka, C.J.; Minkiewicz, V.J.; Passell, L.

    1975-01-01

    Small-angle neutron scattering techniques have been used to study the angular distribution of the critical scattering from cobalt above T/sub c/. These measurements have been put on an absolute scale by calibrating the critical scattering directly against the nuclear incoherent scattering from cobalt. In this way the interaction range r 1 , which appears in the classical and modified Ornstein--Zernike expressions for the asymptotic form of the spin pair correlation function and is related to the strength of the spin correlations, has been determined. We obtain r 1 /a = 0.46 +- 0.03 for the ratio of the interaction range to the nearest-neighbor distance in cobalt. This result is in good agreement with theoretical predictions. Lack of agreement among previous determinations of the ratio r 1 /a made in iron failed to provide a definitive comparison with theory

  11. Activation of cobalt by neutrons from the Hiroshima bomb

    International Nuclear Information System (INIS)

    Kerr, G.D.; Dyer, F.F.; Emery, J.F.; Pace, J.V. III; Brodzinski, R.L.; Marcum, J.

    1990-02-01

    A study has been completed of cobalt activation in samples from two new locations in Hiroshima. The samples consisted of a piece of steel from a bridge located at a distance of about 1300 m from the hypocenter and pieces of both steel and concrete from a building located at approximately 700 m. The concrete was analyzed to obtain information needed to calculate the cobalt activation in the two steel samples. Close agreement was found between calculated and measured values for cobalt activation of the steel sample from the building at 700 m. It was found, however, that the measured values for the bridge sample at 1300 m were approximately twice the calculated values. Thus, the new results confirm the existence of a systematic error in the transport calculations for neutrons from the Hiroshima bomb. 52 refs., 32 figs., 16 tabs

  12. New avenues in cobalt-60 production at Ontario Hydro

    International Nuclear Information System (INIS)

    Mylvaganam, C.K.; Ronchka, R.A.

    1990-01-01

    Ontario Hydro produces cobalt-60 in the control rods of twelve power reactors. These reactors have a typical flux of 2 x 10 14 neutrons/cm 2 /s, making them efficient producers of cobalt-60. Current annual production is 45 million curies. Since the primary function of these reactors is the production of electricity, their flexibility to meet the needs of commercial cobalt production by the control rod route is limited. Ontario Hydro is therefore developing innovative production techniques, making use of the CANDU reactor's unique ability to be fuelled on-power. These techniques will enable production to better respond to the market's requirements for quantity and specific activity. As it is supplementary to control rod production, annual supply could potentially reach 165 million curies. (author)

  13. Hepatic lipidosis associated with cobalt deficiency in Omani goats.

    Science.gov (United States)

    Johnson, E H; Muirhead, D E; Annamalai, K; King, G J; Al-Busaidy, R; Hameed, M S

    1999-06-01

    Livers from 36 of 684 (5.3%) apparently healthy goats examined at an abattoir in the greater Muscat area of Oman exhibited gross pathological findings characterized by extremely pale, friable, fatty livers encompassing the entire organ. Histopathologically, diffuse hepatic lipidosis and occasional bile duct proliferation were observed. Periodic acid Schiff-positive, diastase-resistant pigment was observed in the macrophages lining the sinusoids. These histopathological lesions were consistent with those characteristic of ovine white liver disease. Cobalt analysis revealed that normal livers had six times more cobalt and a 3-fold less fat content than those measured in the fatty livers. This is the first report of an association between cobalt deficiency and hepatic lipidosis in Omani goats.

  14. Temperature and fluence effects in lead implanted cobalt single crystals

    International Nuclear Information System (INIS)

    Johansen, A.; Sarholt-Kristensen, L.; Johnson, E.; Steenstrup, S.; Chernysh, V.S.

    1988-01-01

    The channeled sputtering yields of the hcp and fcc phases of cobalt depend on the crystal structure and the radiation induced damage. Earlier irradiations of cobalt with argon ions channeled in the hcp direction give sputtering yields higher than expected in the temperature range 100-350deg C. This effect was attributed to a combination of radiation induced damage and a possible implantation induced hcp --> fcc phase transition. Sputtering yields for cobalt single crystals irradiated with 150 keV Pb + ions along the direction of the hcp phase and the direction of the fcc phase have been measured using the weightloss method. The radiation damage and the amount of lead retained in the implanted surface has been investigated by 'in situ' RBS/channeling analysis. Measured partial sputtering yields of lead ≅ 1 atom/ion indicate preferential sputtering of lead atoms. (orig.)

  15. Tribological research of cobalt alloys used as biomaterials

    Directory of Open Access Journals (Sweden)

    Robert Karpiński

    2015-12-01

    Full Text Available This study provides information about the cobalt alloys used in dentistry and medicine. The work includes a review of the literature describing the general properties of cobalt alloys. In addition it describes the impact of the manufacturing conditions and alloy additives used , on the structure and mechanical properties of these alloys. The research methodology and the results obtained has been presented in the study. Two cobalt-based alloys Co-CrMo-W and Co-Cr-Ni-Mo were selected for the tests. The first one was prepared with the use of casting technique whereas the second was obtained due to plastic forming. An analysis of the chemical composition and in vitro tribological tests with the use of tribotester of "ball-on-disc" type was conducted. Comparative tribological characteristics of these alloys has been presented.

  16. 21 CFR 73.3110a - Chromium-cobalt-aluminum oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Chromium-cobalt-aluminum oxide. 73.3110a Section... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3110a Chromium-cobalt-aluminum oxide. (a) Identity. The color additive chromium-cobalt-aluminum oxide (Pigment Blue 36) (CAS Reg. No...

  17. Removal of Cobalt Ion by Adsorbing Colloidal Flotation

    Energy Technology Data Exchange (ETDEWEB)

    Jung, In Ha; Lee, Jung Won [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-09-30

    Simulated waste liquid containing 50 ppm cobalt ion was treated by adsorbing colloidal flotation using Fe(III) or Al(III) as flocculant and a sodium lauryl sulfate as a collector. Parameters such as pH, surfactant concentration, Fe(III) or Al(III) concentration, gas flow rate, etc., were considered. The flotation with Fe(III) showed 99.8% removal efficiency of cobalt on the conditions of initial cobalt ion concentration 50 ppm, pH 9.5, gas flow rate 70 ml/min, and flotation time 30 min. When the waste solution was treated with 35% H{sub 2}O{sub 2} prior to adsorbing colloidal flotation, the optimal pH for removing cobalt shifted to weak alkaline range and flotation could be applied in wider range of pH as compared to non-use of H{sub 2}O{sub 2}. Additional use of 20 ppm Al(III) after precipitation of 50 ppm Co(II) with 50 ppm Fe(III) made the optimal pH range for preferable flotation wider. Foreign ions such as, NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, Na{sup +}, Ca{sup 2+} were adopted and their effects were observed, Of which sulfate ion was found to be detrimental to removal of cobalt ion by flotation. Coprecipitation of Co ion with Fe(III) and Al(III) resulted in better removal efficiency of cobalt ion in the presence of sulfate ion. (author). 14 refs., 13 figs.

  18. Cobalt Ferrite Nanocrystallites for Sustainable Hydrogen Production Application

    Directory of Open Access Journals (Sweden)

    Rajendra S. Gaikwad

    2011-01-01

    Full Text Available Cobalt ferrite, CoFe2O4, nanocrystalline films were deposited using electrostatic spray method and explored in sustainable hydrogen production application. Reflection planes in X-ray diffraction pattern confirm CoFe2O4 phase. The surface scanning microscopy photoimages reveal an agglomeration of closely-packed CoFe2O4 nanoflakes. Concentrated solar-panel, a two-step water splitting process, measurement technique was preferred for measuring the hydrogen generation rate. For about 5 hr sustainable, 440 mL/hr, hydrogen production activity was achieved, confirming the efficient use of cobalt ferrite nanocrystallites film in hydrogen production application.

  19. Nanofibre growth from cobalt carbide produced by mechanosynthesis

    International Nuclear Information System (INIS)

    Diaz Barriga-Arceo, L; Orozco, E; Garibay-Febles, V; Bucio-Galindo, L; Mendoza Leon, H; Castillo-Ocampo, P; Montoya, A

    2004-01-01

    Mechanical alloying was used to prepare cobalt carbide. Microstructural characterization of samples was performed by x-ray diffraction, differential scanning calorimetry and transmission electron microscopy methods. In order to produce carbon nanotubes, the cobalt carbide was precipitated after heating at 800 and 1000 deg. C for 10 min. Nanofibres of about 10-50 nm in diameter, 0.04-0.1 μm in length and 20-200 nm in diameter and 0.6-1.2 μm in length were obtained after heating at 800 and 1000 deg. C, respectively, by means of this process

  20. Characterization of Cobalt F-75 powder for biomedical application

    International Nuclear Information System (INIS)

    Zuraidawani, C.D.; Shamsul, J.B.; Fazlul, B.; Nur Hidayah, A.Z.

    2007-01-01

    Cobalt F-75 alloys is commonly used for surgical implants because of their strength, corrosion resistance, non-magnetic behaviour and biocompatibility. In this paper, gas atomized of Cobalt F-75 powders were selected for evaluation. These powders supplied by Sandvik Osprey Ltd. The characteristics of these powders were investigated by using particle size analysis, X-ray Diffraction (XRD), X-ray Fluorescence (XRF) and Scanning Electron Microscope (SEM). Two different powder sizes (8.8 μm and 11.5 μm) have showed spherical morphology and the value of densities are 7.9 and 7.6 g/cm 3 respectively. (author)

  1. Nanofibre growth from cobalt carbide produced by mechanosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Barriga-Arceo, L [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas 152, Colonia San Bartolo Atepehuacan, Mexico DF, 07730 (Mexico); Orozco, E [Instituto de Fisica UNAM, Apartado Postal 20-364 CP 01000, DF (Mexico); Garibay-Febles, V [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas 152, Colonia San Bartolo Atepehuacan, Mexico DF, 07730 (Mexico); Bucio-Galindo, L [Instituto de Fisica UNAM, Apartado Postal 20-364 CP 01000, DF (Mexico); Mendoza Leon, H [FM-UPALM, IPN, Apartado Postal 75-395 CP 07300, DF (Mexico); Castillo-Ocampo, P [UAM-Iztapalapa, Apartado Postal 55-334 CP 09340, DF (Mexico); Montoya, A [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas 152, Colonia San Bartolo Atepehuacan, Mexico DF, 07730 (Mexico)

    2004-06-09

    Mechanical alloying was used to prepare cobalt carbide. Microstructural characterization of samples was performed by x-ray diffraction, differential scanning calorimetry and transmission electron microscopy methods. In order to produce carbon nanotubes, the cobalt carbide was precipitated after heating at 800 and 1000 deg. C for 10 min. Nanofibres of about 10-50 nm in diameter, 0.04-0.1 {mu}m in length and 20-200 nm in diameter and 0.6-1.2 {mu}m in length were obtained after heating at 800 and 1000 deg. C, respectively, by means of this process.

  2. Transport of Cobalt 60 from the Argentine Nuclear Power Plant in Embalse

    International Nuclear Information System (INIS)

    Lopez Vietri, J.R.

    2011-01-01

    Full text: The purpose of this presentation is to point out some relevant issues related to the transport of cobalt 60 for domestic uses and export from the Argentine Nuclear Power Plant located in Embalse (ENPP). It is remarked that in last 22 years, ENPP produced about 2600 PBq (70 MCi) of Co-60, and that Argentina is the third Co-60 producer, after Canada and Russia. It is mentioned that in Argentina there are facilities which manufacture Zircaloy seamless tubes and reactivity control bars containing cobalt 59 to be used in ENPP, the operation of Candu reactor at ENPP including cobalt-related activities, and the manufacture and commercialization of Co-60 sealed sources. The Argentine Nuclear Regulatory Authority verifies the compliance of nuclear activities with regulatory standards, including those related to the transport of radioactive material. Then, it is described the process for obtaining Co-60 at ENPP with an activity concentration to allow its use in medicine and industry. After that, is considered in detail the type of package used for the transport of Co-60 from ENPP: it is to say, Type B(U) package designs that must be approved by the Competent Authority origin of the design, and they are able to withstand routine, normal and accident conditions of transport, including severe impacts, fires and immersion in water. The overall dimensions of packages are about 1.0 m to 1.5 m diameter by 1.2 m to 1.8 m high, as well as the gross mass could vary from 6500 kg to 9500 kg. Radioactive contents consist of Co-60 sealed sources (called pencils), with an activity range from 8 PBq to 16 PBq. Then, it is considered activities prior to dispatch of Type B(U) packages at ENPP, including the preparation of radioactive contents, packaging and package (labelling and marking) as well as necessary tests and documentation for transport in order to fulfil pertinent requirements of package design operation manual of the package and related standards. Finally, it is pointed

  3. Iron-59 absorption from soy hulls: intrinsic vs extrinsic labeling

    International Nuclear Information System (INIS)

    Lykken, G.I.; Mahalko, J.R.; Nielsen, E.J.; Dintzis, F.R.

    1986-01-01

    As part of an evaluation of the validity of the extrinsic labeling technique for measuring iron absorption, absorption from soy hulls extrinsically labeled ( 59 Fe added to bread dough) was compared with that from soy hulls intrinsically labeled ( 59 Fe incorporated into the soy plant during growth). Century soybeans were grown in a greenhouse. After pods had formed and were filling, each plant was stem injected twice, at 3 day intervals, with 22 μCi 59 Fe as FeCl 2 in 25 μl of 0.5 M HCl solution. After the plants had senesced, the soybeans were harvested, dried, shelled and the hulls removed. Standard meals containing 3.5 mg Fe/meal and up to 0.06 μCi 59 Fe in a soy hull bun were fed on 2 consecutive days to free-living volunteers in a crossover design. Absorption of 59 Fe was greater from intrinsically labeled soy hulls than from extrinsically labeled soy hulls, 20 +/- 20% vs 15 +/- 11% (n=14, p > 0.05 by paired t-test). Apparent absorption ranged from 1.3% to 77% from intrinsically labeled soy hulls and .5% to 29% from extrinsically labeled soy hulls with the highest absorption occurring in persons with low serum ferritin (S.F. < 8 ng/ml). These findings provide additional evidence that the extrinsic labeling method is a valid measure of iron bioavailability to humans

  4. Radiological safety aspects during handling of adjuster rod (cobalt-60) samples at Cirus

    International Nuclear Information System (INIS)

    Yadav, R.K.B.; Prasad, S.K.; Khuspe, R.R.; Babu, K.S.; Kamble, M.K.; Deshpande, S.B.; Srivastava, Alok; Ramesh, N.; Sharma, R.C.

    2008-01-01

    Cobalt -60 produced from the irradiation of the 59 Co capsules in adjuster rod of Cirus is used in many medical and industrial applications such as radiation therapy, sterilization of agricultural products, sterilization of medical equipment, industrial gamma exposure devices, nucleonic gauging sources etc. Two adjuster rods used for adjusting small reactivity loads (3.5 mk at 40 MW) in reactor contain thirty 59 Co slugs each. The 59 Co slugs are in the form of small capsules. These slugs were irradiated for nearly 3 years of full power operation. Since the amount of activity handled in the adjuster rod is very high (35 - 40 kCi), adequate radiological safety coverage is to be provided during the transfer of adjuster rod from the reactor pile to Tray Rod Facility (TRF) and during remote handling and loading of adjuster rod samples in shipping flask at TRF. Radiation fields observed are 0.4 - 3.0 Gy/h. In Cirus, falling of Adjuster rod from vertical flask at top of pile could result in declaration of evacuation emergency due to potential hazards associated with the high radiation field (∼26 Gy/h at 1m) of 60 Co slugs. Entire process of remote handling is viewed through lead glass and movement of samples is carried out with the help of a pair of master slave manipulator (MSM) arms. TRF with full samples give a radiation background of 0.2 - 20 mGy/h, requiring control of movement of personnel in the area. This paper explains in detail about the health physics aspects during handling of adjuster rod from reactor pile to TRF and back to pile, unloading and loading of radioisotope samples, operational radiation protection experience gained and collective dose consumed for the above transfer and loading job. The collective dose consumed in the handling of two adjuster rods is 8.7 per-mSv. (author)

  5. Distribution measurement of 60Co target radioactive specific activity

    International Nuclear Information System (INIS)

    Li Xingyan; Chen Zigen; Ren Min

    1994-01-01

    Radioactive specific activity distribution of cobalt 60 target by irradiation in HFETR is a key parameter. With the collimate principle, the under water measurement device and conversion coefficient which is get by experiments, and the radioactive specific activity distribution is obtained. The uncertainty of measurement is less than 10%

  6. New and superior adrenal scanning agent, NP-59

    International Nuclear Information System (INIS)

    Sarkar, S.D.; Beierwaltes, W.H.; Ice, R.D.; Basmadjian, G.P.; Hertzel, K.R.; Kennedy, W.P.; Mason, M.M.

    1975-01-01

    The first synthesis of 131 I-19-iodocholesterol had a 10 to 25 percent radiochemical impurity that was not iodide ion. This impurity has been identified as 6β- 131 I-iodomethyl-19-nor cholest-5(10)-en-3β-ol (NP-59) and has been synthesized. Tissue distribution studies with 131 I-NP-59 in rats and dogs revealed a higher adrenal uptake and adrenal-to-tissue ratios compared to 131 I 19-iodocholesterol, probably less in vivo deiodination, and superior adrenal images. A high uptake was seen in the adrenal medulla in addition to that in the cortex. Iodine-131-NP-59 is being evaluated for the early detection of adrenal--cortical disorders and as a potential scanning agent for detecting structural abnormalities of the adrenal medulla

  7. Cobalt coatings: deposition on a nickel substrate and electrocatalytic activity for alkaline water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Brossard, L. (Inst. de Recherche d' Hydro-Quebec (IREQ), Varennes, Quebec (Canada))

    1992-02-01

    The deposition of cobalt on a nickel substrate in 30 wt% KOH aqueous solution containing dissolved cobalt was investigated. The effect of the applied cathodic current density (i{sub a}) and the dissolved-cobalt concentration in the electrolyte on the deposition rate suggests that the rate-determining step is the diffusion of the dissolved cobalt in the solution. The faradic efficiency of the cobalt deposition reaction and the coating morphology are linked to i{sub a}, while the evolution rate of both oxygen and hydrogen in 30 wt% KOH at 70degC is dependent on the coating morphology. (orig.).

  8. Neodymium cobalt oxide as a chemical sensor

    Science.gov (United States)

    Abdel-Latif, I. A.; Rahman, Mohammed M.; Khan, Sher Bahadar

    2018-03-01

    Chemical sensing and electrical transport properties of neodymium coblate, NdCoO3, was investigated in this work. It was prepared by using co-precipitation method. Pure neodymium chloride and cobalt chloride were mixing in the presence of sodium hydroxide and the obtained co-precipitated powder was calcined at 850 and 1000 °C. The synthesized composites, as-grown (NdCoO3-I), calcined at 850 °C (NdCoO3-II), and calcined at 1000 °C (NdCoO3-III) were studied in details in terms of their morphological and structural properties. The X-ray analysis confirmed that the synthesized products are well crystalline possessing single phase orthorhombic crystal system of space group Pbnm(62). The crystallite size of NdCoO3-I, NdCoO3-II, and NdCoO3-III is 22, 111, and 338 nm, respectively which reflect that crystallite size is increasing with increase in firing temperature. The DC resistivity was measured as a function of temperature in the temperature range from room temperature up to 200 °C. All NdCoO3 are semiconductor in this range of temperature but showed different activation energy which strongly depends on the crystallite size of the products. The activation energy decreased with increase in crystallite size, 0.798, 0.414 and 0.371 eV for NdCoO3-I, NdCoO3-II, and NdCoO3-III, respectively. Thus resistivity increases with increase in crystallite size of NdCoO3. All NdCoO3 products were tested as chemical sensor for acetone by electrochemical approaches and showed excellent sensitivity. Among the NdCoO3 samples, NdCoO3-III showed the highest sensitivity (3.4722 μAcm-2 mM-1) compared to other compositions and gradually decreased to 3.2407 μAcm-2 mM-1 with decreasing the crystallite size of NdCoO3-II. It is also observed that the sensitivity drastically decreased to 0.76253 μAcm-2 mM-1 in the case of NdCoO3-I. It is introduced an efficient route for the detection of environmental unsafe chemicals by electrochemical approach for the safety of healthcare and environmental

  9. The Role of External Inputs and Internal Cycling in Shaping the Global Ocean Cobalt Distribution: Insights From the First Cobalt Biogeochemical Model

    Science.gov (United States)

    Tagliabue, Alessandro; Hawco, Nicholas J.; Bundy, Randelle M.; Landing, William M.; Milne, Angela; Morton, Peter L.; Saito, Mak A.

    2018-04-01

    Cobalt is an important micronutrient for ocean microbes as it is present in vitamin B12 and is a co-factor in various metalloenzymes that catalyze cellular processes. Moreover, when seawater availability of cobalt is compared to biological demands, cobalt emerges as being depleted in seawater, pointing to a potentially important limiting role. To properly account for the potential biological role for cobalt, there is therefore a need to understand the processes driving the biogeochemical cycling of cobalt and, in particular, the balance between external inputs and internal cycling. To do so, we developed the first cobalt model within a state-of-the-art three-dimensional global ocean biogeochemical model. Overall, our model does a good job in reproducing measurements with a correlation coefficient of >0.7 in the surface and >0.5 at depth. We find that continental margins are the dominant source of cobalt, with a crucial role played by supply under low bottom-water oxygen conditions. The basin-scale distribution of cobalt supplied from margins is facilitated by the activity of manganese-oxidizing bacteria being suppressed under low oxygen and low temperatures, which extends the residence time of cobalt. Overall, we find a residence time of 7 and 250 years in the upper 250 m and global ocean, respectively. Importantly, we find that the dominant internal resupply process switches from regeneration and recycling of particulate cobalt to dissolution of scavenged cobalt between the upper ocean and the ocean interior. Our model highlights key regions of the ocean where biological activity may be most sensitive to cobalt availability.

  10. Adrenal scintiscanning with NP-59: a new radioiodinated cholesterol agent

    International Nuclear Information System (INIS)

    Miles, J.M.; Wahner, H.W.; Carpenter, P.C.; Salassa, R.M.; Northcutt, R.C.

    1979-01-01

    Adrenal imaging in the past has been limited in its clinical application by the long interval between administration of dose and visualization of adrenal glands. We review our experience with the use of a newer labeling agent, NP-59, in 29 patients with various adrenal disorders and in 4 normal subjects. With this agent, identification of adrenal lesions is possible with a high degree of accuracy, and diagnostic information is usually available within 48 hrs. NP-59 is particularly useful in evaluating primary aldosteronism and selected cases of Cushing's syndrome

  11. Heating-induced inner-sphere substitution and reduction-oxidation reactions of the solid phenanthroline containing cobalt (2) and cobalt (3) complexes

    International Nuclear Information System (INIS)

    Palade, D.M.

    1996-01-01

    The results of the differential thermal and thermogravimetric analyses of solid phenanthroline-containing complexes of cobalt (2) and cobalt (3) in the atmosphere of the air have been analyzed. Mechanism of redox reactions occurring when cobalt (3) complexes are heated has been discussed. It is shown that some of gaseous products of the redox processes appear as a result of secondary reactions and not the processes of the ligands oxidation by Co 3+ . The influence of certain inner-sphere and coordinated anions (of I, inclusively) on cobalt (3) complexes behaviour during heating has been considered

  12. Characterization and Catalytic Activity of Montmorillonite K10-Supported Cobalt Catalysts

    International Nuclear Information System (INIS)

    Gobara, H.M.; Ghattas, M.S.; Henien, S.A.

    2010-01-01

    Montmorillonite K10-supported cobalt catalysts were prepared by wet impregnation method. The samples were analyzed by XRD, TPR, FTTR and BET characterization techniques. [Three phases of cobalt species were identified namely, cobalt oxide (Co 3 O 4 ), cobalt silicate (Co 2 S 1 O 4 ) and cobalt aluminate (CoAl 2 O 4 ). These species were most probably existing within the inter lamellar spaces of the meso porous montmorillonite K10 support]. The two bands observed at 1385 and 760 cm 1 were characteristic of metal species rather than the support, being mostly of Co - O bond vibration. The hysteresis loop, pore size distribution, pore volume and BET surface area were greatly affected by cobalt loading. The catalyst containing 18 wt% cobalt was the most selective sample for ethylene production from ethanol dehydration.

  13. Development of hierarchically porous cobalt oxide for enhanced photo-oxidation of indoor pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, J. P., E-mail: chengjp@zju.edu.cn [Zhejiang University, State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering (China); Shereef, Anas; Gray, Kimberly A., E-mail: k-gray@northwestern.edu [Northwestern University, Center for Catalysis and Surface Science (United States); Wu, Jinsong [Northwestern University, Department of Materials Science and Engineering (United States)

    2015-03-15

    Porous cobalt oxide was successfully prepared by precipitation of cobalt hydroxide followed by low temperature thermal decomposition. The morphologies of the resultant oxides remained as the corresponding hydroxides, although the morphology of cobalt hydroxides was greatly influenced by the precursor salts. The cobalt oxides with average crystal size less than 20 nm were characterized by X-ray diffraction, scanning electron microscope, BET surface area, and XPS analysis. The photocatalytic activities of the various cobalt oxides morphologies were investigated by comparing the photo-degradation of acetaldehyde under simulated solar illumination. Relative to their low order structures and reference titania samples, the hierarchical nanostructures of cobalt oxide showed excellent abilities to rapidly degrade acetaldehyde, a model air pollutant. This was attributed to the unique nature of these hierarchical cobalt oxide nanoassemblies, which contained many catalytically active reaction sites and open pores.

  14. Cobalt doped proangiogenic hydroxyapatite for bone tissue engineering application.

    Science.gov (United States)

    Kulanthaivel, Senthilguru; Roy, Bibhas; Agarwal, Tarun; Giri, Supratim; Pramanik, Krishna; Pal, Kunal; Ray, Sirsendu S; Maiti, Tapas K; Banerjee, Indranil

    2016-01-01

    The present study delineates the synthesis and characterization of cobalt doped proangiogenic-osteogenic hydroxyapatite. Hydroxyapatite samples, doped with varying concentrations of bivalent cobalt (Co(2+)) were prepared by the ammoniacal precipitation method and the extent of doping was measured by ICP-OES. The crystalline structure of the doped hydroxyapatite samples was confirmed by XRD and FTIR studies. Analysis pertaining to the effect of doped hydroxyapatite on cell cycle progression and proliferation of MG-63 cells revealed that the doping of cobalt supported the cell viability and proliferation up to a threshold limit. Furthermore, such level of doping also induced differentiation of the bone cells, which was evident from the higher expression of differentiation markers (Runx2 and Osterix) and better nodule formation (SEM study). Western blot analysis in conjugation with ELISA study confirmed that the doped HAp samples significantly increased the expression of HIF-1α and VEGF in MG-63 cells. The analysis described here confirms the proangiogenic-osteogenic properties of the cobalt doped hydroxyapatite and indicates its potential application in bone tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. The role of cobalt ferrite magnetic nanoparticles in medical science

    Energy Technology Data Exchange (ETDEWEB)

    Amiri, S.; Shokrollahi, H., E-mail: Shokrollahi@sutech.ac.ir

    2013-01-01

    The nanotechnology industry is rapidly growing and promises that the substantial changes that will have significant economic and scientific impacts be applicable to a wide range of areas, such as aerospace engineering, nano-electronics, environmental remediation and medical healthcare. In this area, cobalt ferrite nanoparticles have been regarded as one of the competitive candidates because of their suitable physical, chemical and magnetic properties like the high anisotropy constant, high coercivity and high Curie temperature, moderate saturation magnetization and ease of synthesis. This paper introduces the magnetic properties, synthesis methods and some medical applications, including the hyperthermia, magnetic resonance imaging (MRI), magnetic separation and drug delivery of cobalt ferrite nanoparticles. Highlights: Black-Right-Pointing-Pointer Cobalt ferrite nanoparticles are one of the most important materials for nanomedicine. Black-Right-Pointing-Pointer They have high coercivity and moderate saturation magnetization. Black-Right-Pointing-Pointer Cobalt ferrite nanoparticles are synthesized easily. Black-Right-Pointing-Pointer They are a good candidate for hyperthermia and magnetic resonance imaging.

  16. Consumer leather exposure: an unrecognized cause of cobalt sensitization

    DEFF Research Database (Denmark)

    Thyssen, J.P.; Johansen, Jeanne D.; Jellesen, Morten Stendahl

    2013-01-01

    BACKGROUND: A patient who had suffered from persistent generalized dermatitis for 7 years was diagnosed with cobalt sensitization, and his leather couch was suspected as the culprit, owing to the clinical presentation mimicking allergic chromium dermatitis resulting from leather furniture exposur...

  17. Cobalt-60 production in the BN-350 fast power reactor

    International Nuclear Information System (INIS)

    Zvonarev, A.V.; Korobejnikov, V.V.; Matveenko, I.P.

    1994-01-01

    A possibility of Co-60 isotope production in the BN-350 fast reactor was considered. A special irradiating device, which is an assembly with a central hole, where a container containing cobalt and zirconium hydride is placed. The irradiating device tested permits generating 60 Co with specific activity of 100 Ci/g

  18. Cobalt-55 positron emission tomography in recurrent ischaemic stroke

    NARCIS (Netherlands)

    De Reuck, J; Santens, P; Keppens, J; De Bleecker, J; Strijckmans, K; Goethals, P; Lemahieu, [No Value; Korf, J

    The present study investigates if Cobalt-55 (Co-55) positron emission tomography (PET) allows us to distinguish and detect recent, recurrent strokes in patients who had already suffered a previous infarct in the same vascular territory. Fourteen patients with recurrent strokes underwent a Co-55 PET

  19. Brightness coatings of zinc-cobalt alloys by electrolytic way

    International Nuclear Information System (INIS)

    Julve, E.

    1993-01-01

    Zinc-cobalt alloys provide corrosion resistance for the ferrous based metals. An acidic electrolyte for zinc-cobalt electrodeposition is examined in the present work. The effects of variations in electrolyte composition, in electrolyte temperature, pH and agitation on electrodeposit composition have been studied, as well as the current density influence. It was found that the following electrolyte gave the optimum results: 79 g.1''-1 ZnCl 2 , 15.3 g.1''-1 CoCl 2 .6H 2 O, 160 g.1''-1 KCl, 25 g.1''-1 H 3 BO 3 and 5-10 cm''3.1''-1 of an organic additive (caffeine, coumarin and sodium lauryl-sulphonate). The operating conditions were: pH=5,6 temperature: 30 degree centigree, current density: 0,025-0,035 A. cm''2, anode: pure zinc, agitation: slowly with air and filtration: continuous. The throwing power and cathode current efficiency of the electrolyte were also studied. This electrolyte yielded zinc-cobalt alloys white and lustrous and had a cobalt content of 0,5-0,8% (Author) 3 refs. 5 fig

  20. Synthesis and characterization of cobalt-manganese oxides

    Energy Technology Data Exchange (ETDEWEB)

    Valencia, J. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Department of Aerospace Engineering and Mechanics, University of Minnesota, Minneapolis 55455-0153 (United States); Arias, N.P. [Laboratorio de Materiales Nanoestructurados y Funcionales, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Departamento de Ingenieria Electrica, Electronica y Computacion, Facultad de Ingenieria y Arquitectura, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Giraldo, O. [Laboratorio de Materiales Nanoestructurados y Funcionales, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Rosales-Rivera, A., E-mail: arosalesr@unal.edu.co [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia)

    2012-08-15

    Cobalt doped/un-doped manganese oxides materials were synthesized at various doping rates by soft chemical reactions, oxidation-reduction method, which allows generating a metal-mixed oxide. The synthesized materials were characterized using several techniques including chemical analysis, X-rays diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The chemical analysis confirmed the presence of cobalt in the samples. XRD patterns reveal mainly a spinel-like structure and SEM micrographs exhibited morphology with fine aggregate of particles. TGA profiles showed weight loss due to loss of water in a first step, followed by a loss of oxygen from the lattice associated with partial reduction of Mn{sup 4+} to Mn{sup 3+}. VSM was used to measure the magnetization as a function of the applied magnetic field at temperatures T=50 and 300 K. Different magnetic behaviors were observed when cobalt percentage changed in the samples. These behaviors are considered to be related to the size of the particles and composition of the materials. Higher coercive field and lesser magnetization were observed for the sample with higher cobalt content.

  1. Cobalt uptake and binding in human red blood cells

    DEFF Research Database (Denmark)

    Simonsen, Lars Ole; Brown, Anthony M; Harbak, Henrik

    2011-01-01

    of cobalt, and also from the initial slope of the cobalt buffering curve. The cobalt accumulation is similar in fed and ATP-depleted cells. The buffering curve for [Co(T)](c) can be fitted by a Michaelis type function with B(max)=24 mmol (l cells)(-1) and half-saturation at 240 µM [Co(2+)](c). The tracer...... reversibly bound, being releasable by excess extracellular EGTA in the presence of A23187, and partly tightly bound, remaining in the cells even at high ionophore concentrations. The tightly bound fraction builds up over time, and is larger and develops earlier in fed cells compared to ATP-depleted cells......-migrate with hemoglobin in Sephadex column chromatography of a lysate of (57)Co-loaded cells. (57)Co also co-migrates with hemoglobin when added to a lysate of unlabeled cells or to a solution of purified hemoglobin, in both cases with a time-dependent development of tight binding. Cobalt is known to bind to the globin...

  2. Electrical and Magnetic Properties of Polyvinyl Alcohol-Cobalt ...

    Indian Academy of Sciences (India)

    7

    synthesis methods of shape, size, magnetic properties of cobalt ferrite ... substance was then ground into a fine powder and calcined at 600oC for 10 hours and .... From the particles distribution pattern of CFO nanoparticles in Figure 2(a), it is.

  3. Cobalt nanoparticles as reusable catalysts for reduction of 4 ...

    Indian Academy of Sciences (India)

    33

    active and ordered structures of cobalt nanoparticles. The air stable ... same surfactant was found to reduce p-nitrophenol but lose their catalytic efficiency after recovery. Based on chemical and ... industrial sources.11-13 The US Environmental Protection Agency has reported nitrophenols as one of the most hazardous and ...

  4. Tailoring the magnetic properties of cobalt-ferrite nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Vega, A. Estrada de la; Garza-Navarro, M. A., E-mail: marco.garzanr@uanl.edu.mx; Durán-Guerrero, J. G.; Moreno Cortez, I. E.; Lucio-Porto, R.; González-González, V. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica (Mexico)

    2016-01-15

    In this contribution, we report on the tuning of magnetic properties of cobalt-ferrite nanoclusters. The cobalt-ferrite nanoclusters were synthesized from a two-step approach that consists of the synthesis of cobalt-ferrite nanoparticles in organic media, followed by their dispersion into aqueous dissolution to form an oil-in-water emulsion. These emulsions were prepared at three different concentrations of the cationic surfactant cetyltrimethylammonium bromide (CTAB), in order to control the size and clustering density of the nanoparticles in the nanoclusters. The synthesized samples were characterized by transmission electron microscopy and their related techniques, such as bright-field and Z-contrast imaging, electron diffraction and energy-dispersive X-ray spectrometry; as well as static magnetic measures. The experimental evidence indicates that the size, morphology, and nanoparticles clustering density in the nanoclusters is highly dependent of the cobalt-ferrite:CTAB molar ratio that is used in their synthesis. In addition, due to the clustering of the nanoparticles into the nanoclusters, their magnetic moments are blocked to relax cooperatively. Hence, the magnetic response of the nanoclusters can be tailored by controlling the size and nanoparticles clustering density.

  5. Cobalt Cardiomyopathy Secondary to Hip Arthroplasty: An Increasingly Prevalent Problem

    Directory of Open Access Journals (Sweden)

    Russel Tilney

    2017-01-01

    Full Text Available A forty-year-old man experienced worsening heart failure four years following bilateral complicated total hip replacement. His condition was extensively worked up but no underlying pathology was immediately evident. Given the cobalt-chromium alloy component present in the hip arthroplasties, the raised cobalt blood levels, and a fitting clinical picture coupled with radiological findings, the patient underwent right hip revision. Evidence of biotribocorrosion was present on direct visualisation intraoperatively. The patient subsequently experienced symptomatic improvement (NYHA class III to class I and echocardiography showed recovery of ejection fraction. Cobalt exists as a bivalent and trivalent molecule in circulation and produces a cytotoxicity profile similar to nanoparticles, causing neurological, thyroid, and cardiological pathology. Blood levels are not entirely useful as there is no identifiable conversion factor for levels in whole blood, serum, and erythrocytes which seem to act independently of each other. Interestingly cobalt cardiomyopathy is frequently compounded by other possible causes of cardiomyopathy such as alcohol and a link has been postulated. Definitive treatment is revision of the arthroplasty as other treatments are unproven.

  6. Molecular dynamics simulation of thermophysical properties of undercooled liquid cobalt

    International Nuclear Information System (INIS)

    Han, X J; Wang, J Z; Chen, M; Guo, Z Y

    2004-01-01

    Molecular dynamics simulations with two different embedded-atom-method (EAM) potentials are applied to calculate the density, specific heat and self-diffusion coefficient of liquid cobalt at temperatures above and below the melting temperature. Simulation shows that Pasianot's EAM model of cobalt constructed on the basis of a hcp structure is more successful than Stoop's EAM model in the framework of a fcc structure in predicting the thermophysical properties of liquid cobalt. Simulations with Pasianot's EAM model indicate that the density fits into ρ = 7.49-9.17 x 10 -4 (T- T m ) g cm -3 , and the self-diffusion coefficient is given by D = 1.291 x 10 -7 exp(-48 795.71/RT) m 2 s -1 . Dissimilar to the linear dependence of the density and the Arrhenius dependence of the self-diffusion coefficient on temperature, the specific heat shows almost a constant value of 38.595 ± 0.084 J mol -1 K -1 within the temperature range of simulation. The simulated properties of liquid cobalt are compared with experimental data available. Comparisons show reasonable agreements between the simulated results from Pasianot's EAM model and experimental data

  7. Comparative effects of cobalt, nickel and copper on plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Brenchley, W E

    1938-11-01

    An account is given of the present position of our knowledge with regard to the distribution and the physiological importance of nickel and cobalt, in relation to plants and animals. Experiments on barley and broad beans were carried out in water cultures with the sulfates and chlorides of cobalt, nickel and copper. In every case a range of low concentrations did little or no damage, but toxic action occurred abruptly above a concentration which varied with the species and with the compound. With barley, copper was the most poisonous element in either compound, but the differences were not striking. Low concentrations of the sulfate were innocuous, but parallel low strengths of the chloride caused a slight, significant depression in growth. With broad beans, cobalt was much more poisonous than either nickel or copper, particularly with the sulfate. No slight depression with low concentrations of the chloride was noticeable with this species. The morphological response to toxicity varied with the element concerned. Copper, in poisonous strengths, caused shortening and bunching of barley roots, whereas nickel and cobalt permitted the growth of elongated roots of a very attenuated nature. The individuality of plant response to poison was frequently shown by the great variation in growth in the borderline concentrations just below those which caused marked depression of growth.

  8. Complications of cobalt plaque therapy of choroidal malanomas

    International Nuclear Information System (INIS)

    Char, D.H.; Lonn, L.I.; Margolis, L.W.

    1977-01-01

    We treated a small series of patients with choroidal melanomas with radioactive cobalt plaques. To assess the effectiveness of radiation, we performed radioactive phosphorus ( 32 P) uptake determinations before and after treatment. The 32 P results did not tumor destruction. In five of seven patients with posterior pole melanomas, radiation retinopathy developed after treatment with resultant decrease in vision

  9. and cobalt(III) octahedral monomer complexes: Synthesis and ...

    Indian Academy of Sciences (India)

    In compound 2 the central cobalt is in +3 oxidation state while `in' compound 2, the nickel ion is in +2 oxidation state. The two complexes are isostructural with octahedral coordination environment exhibiting helical twist topology. They also display strong H-bonding as well as CH- interactions to generate 1D chain.

  10. Cobalt-55 positron emission tomography in ischemic stroke

    NARCIS (Netherlands)

    Jansen, HML; Paans, AMJ; Vliet, AMV; VeenmavanderDuin, L; BolwijnMeijer, CJW; Pruim, J; Willemsen, ATM; Franssen, EJF; Minderhoud, JM; Korf, J

    After acute cerebral stroke, the (peri-) infarct tissue is characterized by calcium (Ca)-mediated neuronal damage and inflammatory processes. Monitoring Ca-mediated damage using the isotope cobalt-55 (Go) as a Ga-tracer may enable PET-imaging of this tissue. Since the fate of (peri-) infarct tissue

  11. IN SITU AND POST REACTION COBALT-INCORPORATION INTO ...

    African Journals Online (AJOL)

    Thermogravimetric analysis and Raman spectroscopy show that the surfactant is removed by solvent extraction. Cobalt ion incorporation is confirmed by Raman spectroscopy and UV-vis diffuse reflectance spectroscopy. KEY WORDS: Bifunctional periodic mesoporous organosilica, 1,2-bistrimethoxysilylethane, ...

  12. Hydrothermal synthesis, characterization, and magneticproperties of cobalt chromite nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Zákutná, Dominika; Repko, A.; Matulková, I.; Nižňanský, Daniel; Ardu, A.; Cannas, C.; Mantlíková, Alice; Vejpravová, Jana

    2014-01-01

    Roč. 16, č. 2 (2014), 1-14 ISSN 1388-0764 R&D Projects: GA ČR GAP108/10/1250 Institutional support: RVO:68378271 ; RVO:61388980 Keywords : cobalt chromite * hydrothermal method * nanoparticles * size effect * multiferroic materials Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.184, year: 2014

  13. Ternary complexes of cobalt cysteinylglycine with histidylserine and ...

    Indian Academy of Sciences (India)

    WINTEC

    Cobalt(II); dipeptides; 1H and C13 NMR; DNA binding; DNA hydrolytic cleavage; kinetics. 1. Introduction. Nucleic acids are also chemically altered through strand scission of their polymeric backbones. This form of nucleic acid modification, which is funda- mental to genetic engineering and biotechnology; can occur through ...

  14. Valence control of cobalt oxide thin films by annealing atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Wang Shijing [School of Materials Science and Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Beijing 100083 (China); Zhang Boping, E-mail: bpzhang@ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Beijing 100083 (China); Zhao Cuihua; Li Songjie; Zhang Meixia; Yan Liping [School of Materials Science and Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Beijing 100083 (China)

    2011-02-01

    The cobalt oxide (CoO and Co{sub 3}O{sub 4}) thin films were successfully prepared using a spin-coating technique by a chemical solution method with CH{sub 3}OCH{sub 2}CH{sub 2}OH and Co(NO{sub 3}){sub 2}.6H{sub 2}O as starting materials. The grayish cobalt oxide films had uniform crystalline grains with less than 50 nm in diameter. The phase structure is able to tailor by controlling the annealing atmosphere and temperature, in which Co{sub 3}O{sub 4} thin film was obtained by annealing in air at 300-600, and N{sub 2} at 300, and transferred to CoO thin film by raising annealing temperature in N{sub 2}. The fitted X-ray photoelectron spectroscopy (XPS) spectra of the Co2p electrons are distinguishable from different valence states of cobalt oxide especially for their satellite structure. The valence control of cobalt oxide thin films by annealing atmosphere contributes to the tailored optical absorption property.

  15. Sorghum cobalt analysis on not determined wave length with atomic ...

    African Journals Online (AJOL)

    This study was to know the better wave length on measuring cobalt content in forage sorghum hybrid (Sorghum bicolor) with an atomic absorption spectrophotometer. The analysis was on background correction mode with three wave lengths; 240.8, 240.7 (determined wave length or recommended wave length) and 240.6 ...

  16. Weak ferromagnetism and exchange biasing in cobalt oxide nanoparticle systems

    NARCIS (Netherlands)

    Tomou, A; Gournis, D; Panagiotopoulos, [No Value; Huang, Y; Hadjipanayis, GC; Kooi, BJ; Panagiotopoulos, I.

    2006-01-01

    Cobalt oxide nanoparticle systems have been prepared by wet chemical processing involving the encapsulation of the nanoparticles by an organic ligand shell (oleic acid and oleylamine). CoO nanoparticles were easily prepared by this method, while the synthesis of the CoPt/CoO nanocomposites was

  17. Comparative study on calcium, magnesium and cobalt in diabetic ...

    African Journals Online (AJOL)

    Comparative study on calcium, magnesium and cobalt in diabetic and non diabetic patients (males) in Punjab, Pakistan. A Anjum, M Yousaf, M Zuber, HB Ahmad, AF Zahoor, ZI Khan, K Ahmad, S Naheed, KG Ali, A Jabbar, TH Bukhari, S Hina, S Ahmad, MK Mukhtar, M Arshad, A Hussain ...

  18. Synthesis and characterization of cobalt-manganese oxides

    International Nuclear Information System (INIS)

    Valencia, J.; Arias, N.P.; Giraldo, O.; Rosales-Rivera, A.

    2012-01-01

    Cobalt doped/un-doped manganese oxides materials were synthesized at various doping rates by soft chemical reactions, oxidation-reduction method, which allows generating a metal-mixed oxide. The synthesized materials were characterized using several techniques including chemical analysis, X-rays diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The chemical analysis confirmed the presence of cobalt in the samples. XRD patterns reveal mainly a spinel-like structure and SEM micrographs exhibited morphology with fine aggregate of particles. TGA profiles showed weight loss due to loss of water in a first step, followed by a loss of oxygen from the lattice associated with partial reduction of Mn 4+ to Mn 3+ . VSM was used to measure the magnetization as a function of the applied magnetic field at temperatures T=50 and 300 K. Different magnetic behaviors were observed when cobalt percentage changed in the samples. These behaviors are considered to be related to the size of the particles and composition of the materials. Higher coercive field and lesser magnetization were observed for the sample with higher cobalt content.

  19. Carbon-encapsulated nickel-cobalt alloys nanoparticles fabricated via new post-treatment strategy for hydrogen evolution in alkaline media

    Science.gov (United States)

    Guo, Hailing; Youliwasi, Nuerguli; Zhao, Lei; Chai, Yongming; Liu, Chenguang

    2018-03-01

    This paper addresses a new post-treatment strategy for the formation of carbon-encapsulated nickel-cobalt alloys nanoparticles, which is easily controlled the performance of target products via changing precursor composition, calcination conditions (e.g., temperature and atmosphere) and post-treatment condition. Glassy carbon electrode (GCE) modified by the as-obtained carbon-encapsulated mono- and bi-transition metal nanoparticles exhibit excellent electro-catalytic activity for hydrogen production in alkaline water electrolysis. Especially, Ni0.4Co0.6@N-Cs800-b catalyst prepared at 800 °C under an argon flow exhibited the best electrocatalytic performance towards HER. The high HER activity of the Ni0.4Co0.6@N-Cs800-b modified electrode is related to the appropriate nickel-cobalt metal ratio with high crystallinity, complete and homogeneous carbon layers outside of the nickel-cobalt with high conductivity and the synergistic effect of nickel-cobalt alloys that also accelerate electron transfer process.

  20. Effects of cobalt-chromium everolimus eluting stents or bare metal stent on fatal and non-fatal cardiovascular events: patient level meta-analysis.

    Science.gov (United States)

    Valgimigli, Marco; Sabaté, Manel; Kaiser, Christoph; Brugaletta, Salvatore; de la Torre Hernandez, Jose Maria; Galatius, Soeren; Cequier, Angel; Eberli, Franz; de Belder, Adam; Serruys, Patrick W; Ferrante, Giuseppe

    2014-11-04

    To examine the safety and effectiveness of cobalt-chromium everolimus eluting stents compared with bare metal stents. Individual patient data meta-analysis of randomised controlled trials. Cox proportional regression models stratified by trial, containing random effects, were used to assess the impact of stent type on outcomes. Hazard ratios with 95% confidence interval for outcomes were reported. Medline, Embase, the Cochrane Central Register of Controlled Trials. Randomised controlled trials that compared cobalt-chromium everolimus eluting stents with bare metal stents were selected. The principal investigators whose trials met the inclusion criteria provided data for individual patients. The primary outcome was cardiac mortality. Secondary endpoints were myocardial infarction, definite stent thrombosis, definite or probable stent thrombosis, target vessel revascularisation, and all cause death. The search yielded five randomised controlled trials, comprising 4896 participants. Compared with patients receiving bare metal stents, participants receiving cobalt-chromium everolimus eluting stents had a significant reduction of cardiac mortality (hazard ratio 0.67, 95% confidence interval 0.49 to 0.91; P=0.01), myocardial infarction (0.71, 0.55 to 0.92; P=0.01), definite stent thrombosis (0.41, 0.22 to 0.76; P=0.005), definite or probable stent thrombosis (0.48, 0.31 to 0.73; Pstents the use of cobalt-chromium everolimus eluting stents improves global cardiovascular outcomes including cardiac survival, myocardial infarction, and overall stent thrombosis. © Valgimigli et al 2014.

  1. 42 CFR 410.59 - Outpatient occupational therapy services: Conditions.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Outpatient occupational therapy services... Other Health Services § 410.59 Outpatient occupational therapy services: Conditions. (a) Basic rule... occupational therapy services only if they are furnished by an individual meeting the qualifications in part...

  2. 42 CFR 59a.7 - Other HHS regulations that apply.

    Science.gov (United States)

    2010-10-01

    ... assistance through the Department of Health and Human Services—effectuation of title VI of the Civil Rights....7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL LIBRARY OF MEDICINE GRANTS Grants for Establishing, Expanding, and Improving Basic Resources § 59a.7 Other...

  3. Sample Set (SE): SE59 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available idopsis thaliana (Arabidopsis). However, the behavior of flavonoids during drough...t stress is still not well documented. Herein we investigated the time-series alternation of flavonoids in t...vonoids, a class of specialized metabolites, including flavonols and anthocyanins w...SE59 Alternation of flavonoid accumulation under drought stress in Arabidopsis thaliana We reported that fla

  4. 32 CFR 516.59 - Duties and procedures.

    Science.gov (United States)

    2010-07-01

    ... PUBLIC RELATIONS LITIGATION Remedies in Procurement Fraud and Corruption § 516.59 Duties and procedures... agencies; contracting officers; inspectors general of the executive branch; correspondence from the public... indications of fraud or corruption relating to Army contracts or Army administered contracts are reported...

  5. 49 CFR 213.59 - Elevation of curved track; runoff.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Elevation of curved track; runoff. 213.59 Section... track; runoff. (a) If a curve is elevated, the full elevation shall be provided throughout the curve, unless physical conditions do not permit. If elevation runoff occurs in a curve, the actual minimum...

  6. 42 CFR 59.206 - Evaluation and grant award.

    Science.gov (United States)

    2010-10-01

    ...) Development of a capability within family planning service projects to provide pre- and in-service training to... and health services personnel; (iii) Improvement in the utilization and career development of... PLANNING SERVICES Grants for Family Planning Service Training § 59.206 Evaluation and grant award. (a...

  7. 34 CFR 674.59 - Cancellation for military service.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Cancellation for military service. 674.59 Section 674... Cancellation for military service. (a) Cancellation on a Defense loan. (1) An institution must cancel up to 50... cancellation rate is 121/2 percent of the original loan principal, plus the interest on the unpaid balance...

  8. 40 CFR 59.412 - Incorporations by reference.

    Science.gov (United States)

    2010-07-01

    ... Test Method for Chemical Resistance of Coatings Used in Light-Water Nuclear Power Plants, incorporation by reference approved for § 59.401, Nuclear coating. (5) ASTM Method D 4082-89, Standard Test Method for Effects of Gamma Radiation on Coatings for Use in Light-Water Nuclear Power Plants, incorporation...

  9. 21 CFR 7.59 - General industry guidance.

    Science.gov (United States)

    2010-04-01

    ... Responsibilities § 7.59 General industry guidance. A recall can be disruptive of a firm's operation and business... and maintain a current written contingency plan for use in initiating and effecting a recall in... such product distribution records as are necessary to facilitate location of products that are being...

  10. 17 CFR 201.59 - Payment of award.

    Science.gov (United States)

    2010-04-01

    ... as authorized by law, unless judicial review of the award has been sought by the applicant. [54 FR... Regulations Pertaining to the Equal Access to Justice Act § 201.59 Payment of award. An applicant seeking... decision granting the award, accompanied by a sworn statement that the applicant will not seek review of...

  11. 38 CFR 59.100 - Payment of grant award.

    Science.gov (United States)

    2010-07-01

    ... instrumentality. Such amount shall be paid by way of reimbursement, and in such installments consistent with the... State representative, and must submit to VA a completed VA Form 10-0388-13 (this form is available on the internet Web site provided in § 59.170). The equipment list and the completed VA Form 10-0388-13...

  12. Surface-oxidized cobalt phosphide used as high efficient electrocatalyst in activated carbon air-cathode microbial fuel cell

    Science.gov (United States)

    Yang, Tingting; Wang, Zhong; Li, Kexun; Liu, Yi; Liu, Di; Wang, Junjie

    2017-09-01

    Herein, we report a simplistic method to fabricate the surface-oxidized cobalt phosphide (CoP) nanocrystals (NCs), which is used as electrocatalyst for oxygen reduction reaction (ORR) in microbial fuel cell (MFC) for the first time. The corallite-like CoP NCs are successfully prepared by a hydrothermal reaction following a phosphating treatment in N2 atmosphere. When used as an ORR catalyst, cobalt phosphide shows comparable onset potential, inferior resistance, as well as a small Tafel slope with long-term stability in neutral media. The maximum power density of MFC embellished with 10% CoP reached 1914.4 ± 59.7 mW m-2, which is 108.5% higher than the control. The four-electron pathway, observed by the RDE, plays a crucial role in electrochemical catalytic activity. In addition, material characterizations indicate that the surface oxide layer (CoOx) around the metallic CoP core is important and beneficial for ORR. Accordingly, it can be expected that the as-synthesized CoP will be a promising candidate of the non-precious metal ORR electrocatalysts for electrochemical energy applications.

  13. Aluminium - Cobalt-Pillared Clay for Dye Filtration Membrane

    Science.gov (United States)

    Darmawan, A.; Widiarsih

    2018-04-01

    The manufacture of membrane support from cobalt aluminium pillared clay has been conducted. This research was conducted by mixing a clay suspension with pillared solution prepared from the mixture of Co(NO3)2.6H2O and AlCl3.6H2O. The molar ratio between Al and Co was 75:25 and the ratio of [OH-]/[metal] was 2. The clay suspension was stirred for 24 hours at room temperature, filtered and dried. The dried clay was then calcined at 200°C, 300°C and 400°C with a ramp rate of 2°C/min. Aluminium-cobalt-pillared clay was then characterized by XRD and GSA and moulded become a membrane support for subsequent tests on dye filtration. The XRD analysis showed that basal spacing (d 001) value of aluminium cobalt was 19.49 Å, which was higher than the natural clay of 15.08Å however, the basal spacing decreased with increasing calcination temperature. The result of the GSA analysis showed that the pore diameter of the aluminium cobalt pillared clay membrane was almost the same as that of natural clay that were 34.5Å and 34.2Å, respectively. Nevertheless, the pillared clay has a more uniform pore size distribution. The results of methylene blue filtration measurements demonstrated that the membrane filter support could well which shown by a clear filtrate at all concentrations tested. The value of rejection and flux decreased with the increasing concentration of methylene blue. The values of dye rejection and water flux reached 99.89% and 5. 80 x 10-6 kg min-1, respectively but they decreased with increasing concentration of methylene blue. The results of this study indicates that the aluminium-pillared clay cobalt could be used as membrane materials especially for ultrafiltration.

  14. Distribution of cobalt in soil from Kavadarci and the environs

    International Nuclear Information System (INIS)

    Stafilov, Trajche; Shajn, Robert; Boev, Blazho; Cvetkovich, Julujana; Mukaetov, Dushko; Andreevski, Marjan; Lepitkova, Sonja

    2009-01-01

    The results of the study of spatial distribution of cobalt in surface soil and subsoil over of the Kavadarci region, Republic of Macedonia, are reported. From the investigated region (360 km 2 ) in total 344 soil samples from 172 locations were collected. At each sampling point soil samples were collected at two depths, topsoil (0-5 cm) and subsoil soil (20-30 cm). Inductively coupled plasma - mass spectrometry (ICP-MS) was applied for the determination of cobalt. Data analysis and construction of the map were performed using the Paradox (ver. 9), Statistica (ver. 6.1), AutoDesk Map (ver. 2008) and Surfer (ver. 8.09) software. It was found that for both topsoil and subsoil the median and average values are 15 mg/kg, ranges between 6.7 and 58 mg/kg. The highest content of cobalt is present in the soil from the area of Paleozoic and Mesozoic rocks (Pz-Mz) on the western part of the investigated area and Flysch (E) - Eocene upper flysch zone (on the northern part) and the lowest in the soils from the Holocene alluvium of the rivers Crna Reka and Vardar. There are no significant differences between the surface and subsoil in terms of its average quantities. It was found that the critically high contents are related primarily to high contents of cobalt in the sampling points from the western part of the investigated region. The contents of cobalt are higher in subsoil than in topsoil from which it can be concluded that the occurrence is natural.

  15. Cobalt doped proangiogenic hydroxyapatite for bone tissue engineering application

    Energy Technology Data Exchange (ETDEWEB)

    Kulanthaivel, Senthilguru [Department of Biotechnology and Medical Engineering, National Institute of Technology, Rourkela, Odisha 769008 (India); Roy, Bibhas [Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 (India); Agarwal, Tarun [Department of Biotechnology and Medical Engineering, National Institute of Technology, Rourkela, Odisha 769008 (India); Giri, Supratim [Department of Chemistry, National Institute of Technology, Rourkela, Odisha 769008 (India); Pramanik, Krishna; Pal, Kunal; Ray, Sirsendu S. [Department of Biotechnology and Medical Engineering, National Institute of Technology, Rourkela, Odisha 769008 (India); Maiti, Tapas K. [Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 (India); Banerjee, Indranil, E-mail: indraniliit@gmail.com [Department of Biotechnology and Medical Engineering, National Institute of Technology, Rourkela, Odisha 769008 (India)

    2016-01-01

    ABSTRACT: The present study delineates the synthesis and characterization of cobalt doped proangiogenic–osteogenic hydroxyapatite. Hydroxyapatite samples, doped with varying concentrations of bivalent cobalt (Co{sup 2+}) were prepared by the ammoniacal precipitation method and the extent of doping was measured by ICP–OES. The crystalline structure of the doped hydroxyapatite samples was confirmed by XRD and FTIR studies. Analysis pertaining to the effect of doped hydroxyapatite on cell cycle progression and proliferation of MG-63 cells revealed that the doping of cobalt supported the cell viability and proliferation up to a threshold limit. Furthermore, such level of doping also induced differentiation of the bone cells, which was evident from the higher expression of differentiation markers (Runx2 and Osterix) and better nodule formation (SEM study). Western blot analysis in conjugation with ELISA study confirmed that the doped HAp samples significantly increased the expression of HIF-1α and VEGF in MG-63 cells. The analysis described here confirms the proangiogenic–osteogenic properties of the cobalt doped hydroxyapatite and indicates its potential application in bone tissue engineering. - Highlights: • Cobalt (Co{sup +2}) doped hydroxyapatite (Co-HAp) can be prepared by the wet chemical method. • The concentration of Co{sup +2} influences the physico-chemical properties of HAp. • Co-HAp was found to be biocompatible and osteogenic. • Co-HAp enhanced cellular VEGF secretion through HIF-1α stabilization. • The optimum biological performance of Co-HAp was achieved for 0.33% (w/w) Co{sup +2} doping.

  16. Phosphorylation of SAF-A/hnRNP-U Serine 59 by Polo-Like Kinase 1 Is Required for Mitosis.

    Science.gov (United States)

    Douglas, Pauline; Ye, Ruiqiong; Morrice, Nicholas; Britton, Sébastien; Trinkle-Mulcahy, Laura; Lees-Miller, Susan P

    2015-08-01

    Scaffold attachment factor A (SAF-A), also called heterogenous nuclear ribonuclear protein U (hnRNP-U), is phosphorylated on serine 59 by the DNA-dependent protein kinase (DNA-PK) in response to DNA damage. Since SAF-A, DNA-PK catalytic subunit (DNA-PKcs), and protein phosphatase 6 (PP6), which interacts with DNA-PKcs, have all been shown to have roles in mitosis, we asked whether DNA-PKcs phosphorylates SAF-A in mitosis. We show that SAF-A is phosphorylated on serine 59 in mitosis, that phosphorylation requires polo-like kinase 1 (PLK1) rather than DNA-PKcs, that SAF-A interacts with PLK1 in nocodazole-treated cells, and that serine 59 is dephosphorylated by protein phosphatase 2A (PP2A) in mitosis. Moreover, cells expressing SAF-A in which serine 59 is mutated to alanine have multiple characteristics of aberrant mitoses, including misaligned chromosomes, lagging chromosomes, polylobed nuclei, and delayed passage through mitosis. Our findings identify serine 59 of SAF-A as a new target of both PLK1 and PP2A in mitosis and reveal that both phosphorylation and dephosphorylation of SAF-A serine 59 by PLK1 and PP2A, respectively, are required for accurate and timely exit from mitosis. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  17. Extension of the analysis of the three lowest configurations in the third spectrum of cobalt (Co III)

    International Nuclear Information System (INIS)

    Raassen, A.J.J.; Orti Ortin, S.

    1984-01-01

    The emission spectrum of cobalt has been observed in the wavelength region 450-3100 A using a hollow cathode as well as a sliding spark lightsource. In this region 680 lines belonging to transitions from the 3d 6 4p configuration to the 3d 7 configuration and 630 lines belonging to transitions from 3d 6 4p to 3d 6 4s are now classified. All 19 levels of the 3d 7 configuration have been established while in 3d 6 4s and 3d 6 4p 59(64) and 178(180) levels have been determined respectively. The numbers in parentheses give the total number of theoretically possible levels in the two configurations. Parametric fits to the levels of the three configurations as well as eigenvector compositions of the levels are presented. The parameter values are compared to Hartree-Fock predictions. (orig.)

  18. Investigation of non-corrin cobalt(II)-containing sites in protein structures of the Protein Data Bank.

    Science.gov (United States)

    Abriata, Luciano Andres

    2013-04-01

    Protein X-ray structures with non-corrin cobalt(II)-containing sites, either natural or substituting another native ion, were downloaded from the Protein Data Bank and explored to (i) describe which amino acids are involved in their first ligand shells and (ii) analyze cobalt(II)-donor bond lengths in comparison with previously reported target distances, CSD data and EXAFS data. The set of amino acids involved in Co(II) binding is similar to that observed for catalytic Zn(II) sites, i.e. with a large fraction of carboxylate O atoms from aspartate and glutamate and aromatic N atoms from histidine. The computed Co(II)-donor bond lengths were found to depend strongly on structure resolution, an artifact previously detected for other metal-donor distances. Small corrections are suggested for the target bond lengths to the aromatic N atoms of histidines and the O atoms of water and hydroxide. The available target distance for cysteine (Scys) is confirmed; those for backbone O and other donors remain uncertain and should be handled with caution in refinement and modeling protocols. Finally, a relationship between both Co(II)-O bond lengths in bidentate carboxylates is quantified.

  19. ORA59 and EIN3 interaction couples jasmonate-ethylene synergistic action to antagonistic salicylic acid regulation of PDF expression.

    Science.gov (United States)

    He, Xiang; Jiang, Jishan; Wang, Chang-Quan; Dehesh, Katayoon

    2017-04-01

    Hormonal crosstalk is central for tailoring plant responses to the nature of challenges encountered. The role of antagonism between the two major defense hormones, salicylic acid (SA) and jasmonic acid (JA), and modulation of this interplay by ethylene (ET) in favor of JA signaling pathway in plant stress responses is well recognized, but the underlying mechanism is not fully understood. Here, we show the opposing function of two transcription factors, ethylene insensitive3 (EIN3) and EIN3-Like1 (EIL1), in SA-mediated suppression and JA-mediated activation of PLANT DEFENSIN1.2 (PDF1.2). This functional duality is mediated via their effect on protein, not transcript levels of the PDF1.2 transcriptional activator octadecanoid-responsive Arabidopsis59 (ORA59). Specifically, JA induces ORA59 protein levels independently of EIN3/EIL1, whereas SA reduces the protein levels dependently of EIN3/EIL1. Co-infiltration assays revealed nuclear co-localization of ORA59 and EIN3, and split-luciferase together with yeast-two-hybrid assays established their physical interaction. The functional ramification of the physical interaction is EIN3-dependent degradation of ORA59 by the 26S proteasome. These findings allude to SA-responsive reduction of ORA59 levels mediated by EIN3 binding to and targeting of ORA59 for degradation, thus nominating ORA59 pool as a coordination node for the antagonistic function of ET/JA and SA. © 2017 Institute of Botany, Chinese Academy of Sciences.

  20. Cobalt toxicity: Chemical and radiological combined effects on HaCaT keratinocyte cell line

    International Nuclear Information System (INIS)

    Sandre, C.; Moulin, C.; Bresson, C.; Gault, N.; Poncy, J. L.; Lefaix, J. L.

    2010-01-01

    Cobalt (Co) is an essential trace element well known as a constituent of vitamin B 12 , but different compounds of Co are also described as highly toxic and/or radio-toxic for individuals or the environment. In nuclear power plants, 58 Co and 60 Co are radioactive isotopes of cobalt present as activation products of stable Co and Ni used in alloys. Skin exposure is a current occupational risk in the hard metal and nuclear industries. As biochemical and molecular cobalt-induced toxicological mechanisms are not fully identified, we investigated cobalt toxicity in a model human keratinocyte cell line, HaCaT. In this study, we propose a model to determine the in vitro chemical impact on cell viability of a soluble form of cobalt (CoCl 2 ) with or without gamma-ray doses to mimic contamination by 60 Co, to elucidate the mechanisms of cobalt intracellular chemical and radiological toxicity. Intracellular cobalt concentration was determined after HaCaT cell contamination and chemical toxicity was evaluated in terms of cellular viability and clonogenic survival. We investigated damage to DNA in HaCaT cells by combined treatment with chemical cobalt and a moderate gamma-ray dose. Additive effects of cobalt and irradiation were demonstrated. The underlying mechanism of cobalt toxicity is not clearly established, but our results seem to indicate that the toxicity of Co(II) and of irradiation arises from production of reactive oxygen species. (authors)

  1. Cobalt toxicity: Chemical and radiological combined effects on HaCaT keratinocyte cell line

    Energy Technology Data Exchange (ETDEWEB)

    Gault, N. [CEA Fontenay aux Roses, DSV/IRCM/SCSR/LRTS, 92265 Fontenay aux Rose (France); Sandre, C.; Moulin, B.; Bresson, C. [CEA, DEN, SECR, Laboratoire de Speciation des Radionucleides et des Molecules, F-91191 Gif-sur-Yvette (France); Poncy, J.L. [CEA Bruyeres Le Chatel, DSV/IRCM/SREIT/LRT, 91680 Bruyeres Le Chatel (France); Lefaix, J.L. [CEA Caen, DSV/IRCM/SRO/LARIA, 14070 Caen (France)

    2010-07-01

    Cobalt (Co) is an essential trace element well known as a constituent of vitamin B12, but different compounds of Co are also described as highly toxic and/or radio-toxic for individuals or the environment. In nuclear power plants, {sup 58}Co and {sup 60}Co are radioactive isotopes of cobalt present as activation products of stable Co and Ni used in alloys. Skin exposure is a current occupational risk in the hard metal and nuclear industries. As biochemical and molecular cobalt-induced toxicological mechanisms are not fully identified, we investigated cobalt toxicity in a model human keratinocyte cell line, HaCaT. In this study, we propose a model to determine the in vitro chemical impact on cell viability of a soluble form of cobalt (CoCl{sub 2}) with or without {gamma}-ray doses to mimic contamination by {sup 60}Co, to elucidate the mechanisms of cobalt intracellular chemical and radiological toxicity. Intracellular cobalt concentration was determined after HaCaT cell contamination and chemical toxicity was evaluated in terms of cellular viability and clonogenic survival. We investigated damage to DNA in HaCaT cells by combined treatment with chemical cobalt and a moderate {gamma}-ray dose. Additive effects of cobalt and irradiation were demonstrated. The underlying mechanism of cobalt toxicity is not clearly established, but our results seem to indicate that the toxicity of Co(II) and of irradiation arises from production of reactive oxygen species. (authors)

  2. Cobalt toxicity: Chemical and radiological combined effects on HaCaT keratinocyte cell line

    Energy Technology Data Exchange (ETDEWEB)

    Sandre, C.; Moulin, C.; Bresson, C. [CEA Saclay, DEN, SECR, Lab Speciat Radionucleides and Mol, F-91191 Gif Sur Yvette (France); Gault, N. [CEA Fontenay Roses, DSV IRCM SCSR LRTS, F-92265 Fontenay Aux Roses (France); Poncy, J. L. [CEA Bruyeres Le Chatel, DSV IRCM SREIT LRT, F-91680 Bruyeres Le Chatel (France); Lefaix, J. L. [CEA Caen, DSV IRCM SRO LARIA, F-14070 Caen (France)

    2010-07-01

    Cobalt (Co) is an essential trace element well known as a constituent of vitamin B{sub 12}, but different compounds of Co are also described as highly toxic and/or radio-toxic for individuals or the environment. In nuclear power plants, {sup 58}Co and {sup 60}Co are radioactive isotopes of cobalt present as activation products of stable Co and Ni used in alloys. Skin exposure is a current occupational risk in the hard metal and nuclear industries. As biochemical and molecular cobalt-induced toxicological mechanisms are not fully identified, we investigated cobalt toxicity in a model human keratinocyte cell line, HaCaT. In this study, we propose a model to determine the in vitro chemical impact on cell viability of a soluble form of cobalt (CoCl{sub 2}) with or without gamma-ray doses to mimic contamination by {sup 60}Co, to elucidate the mechanisms of cobalt intracellular chemical and radiological toxicity. Intracellular cobalt concentration was determined after HaCaT cell contamination and chemical toxicity was evaluated in terms of cellular viability and clonogenic survival. We investigated damage to DNA in HaCaT cells by combined treatment with chemical cobalt and a moderate gamma-ray dose. Additive effects of cobalt and irradiation were demonstrated. The underlying mechanism of cobalt toxicity is not clearly established, but our results seem to indicate that the toxicity of Co(II) and of irradiation arises from production of reactive oxygen species. (authors)

  3. Separation of cobalt from synthetic intermediate and decontamination radioactive wastes using polyurethane foam

    International Nuclear Information System (INIS)

    Rao, S.V.S.; Lal, K.B.; Narasimhan, S.V.; Ahmed, J.

    1997-01-01

    Studies have been carried out on the removal of radioactive cobalt ( 60 Co) from synthetic intermediate level waste (ILW) and decontamination waste using neat polyurethane (PU) foam as well as n-tributyl phosphate-polyurethane (TBP-PU) foam. The radioactive cobalt has been extracted on the PU foam as cobalt thiocyanate from the ILW. Maximum removal of cobalt has been observed when the concentration of thiocyanate in the solution is about 0.4 M. Cobalt can be separated from decontamination waste containing ethylenediaminetetraacetic acid (EDTA) and iron(II). The extent of extraction of cobalt is slow and the separation of iron and cobalt is better with the neat PU foam compared to the TBP-PU foam. The presence of iron in the decontamination waste facilitates the extraction of cobalt thiocyanate on the PU foam. Column studies have been carried out in order to extend these studies to the plant scale. The capacities of the PU foams for cobalt have been determined. The effect of density and the surface area of PU foam have been investigated. Fourier Transform Infrared (FT-IR) spectral studies have been conducted to find out the interaction between PU foam and cobalt thiocyanate species

  4. Alleviating effects of calcium on cobalt toxicity in two barley genotypes differing in cobalt tolerance.

    Science.gov (United States)

    Lwalaba, Jonas Lwalaba Wa; Zvobgo, Gerald; Fu, Liangbo; Zhang, Xuelei; Mwamba, Theodore Mulembo; Muhammad, Noor; Mundende, Robert Prince Mukobo; Zhang, Guoping

    2017-05-01

    Cobalt (Co) contamination in soils is becoming a severe issue in environment safety and crop production. Calcium (Ca) , as a macro-nutrient element, shows the antagonism with many divalent heavy metals and the capacity of alleviating oxidative stress in plants. In this study, the protective role of Ca in alleviating Co stress was hydroponically investigated using two barley genotypes differing in Co toxicity tolerance. Barley seedlings exposed to 100µM Co showed the significant reduction in growth and photosynthetic rate, and the dramatic increase in the contents of reactive oxygen species (ROS), malondialdehyde (MDA), reduced glutathione (GSH) and oxidized glutathione (GSSG), and the activities of anti-oxidative enzymes, with Ea52 (Co-sensitive) being much more affected than Yan66 (Co-tolerant). Addition of Ca in growth medium alleviated Co toxicity by reducing Co uptake and enhancing the antioxidant capacity. The effect of Ca in alleviating Co toxicity was much greater in Yan66 than in Ea52. The results indicate that the alleviation of Co toxicity in barley plants by Ca is attributed to the reduced Co uptake and enhanced antioxidant capacity. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. STS-59 crewmembers in training for onboard Earth observations

    Science.gov (United States)

    1993-01-01

    The six astronauts in training for the STS-59 mission are shown onboard Earth observations tips by Justin Wilkinson (standing, foreground) of the Space Shuttle Earth Observations Project (SSEOP) group. Astronaut Sidney M. Gutierrez, mission commander, is at center on the left side of the table. Others, left to right, are Astronauts Kevin P. Chilton, pilot; Jerome (Jay) Apt and Michael R.U. (Rich) Clifford, both mission specialists; Linda M. Godwin, payload commander; and Thomas D. Jones, mission specialist.

  6. SQUARE WAVE CATHODIC STRIPPING VOLTAMMETRY ADSORPTIVE FOR NICKEL AND COBALT ANALYSIS

    Directory of Open Access Journals (Sweden)

    Saryati Saryati

    2010-06-01

    Full Text Available The adsorptive stripping voltammetric determination of Ni and Co based on adsorption of the Ni/Co and dimethylglioxime (DMG complex on a hanging mercury drop electrode is studied. The reduction current of the adsorbed DMG complex is measured by square wave cathodic stripping voltammetry method. The effect of various parameters such as ligand concentration, pH of supporting electrolytic, adsorption potential and adsorption time on the current peak of Ni and Co voltammogram were studied. Optimum condition of this method are supporting electrolyte pH 9, DMG concentration 5×10 -4 M, adsorption potential -0.7 V vs Ag/AgCl and adsorption time 180 second. A linier relationship between the current peak and Ni or Co concentration was obtained in the range 5 - 30 ng/mL and the detection limit 0.6 ng/ml for both Ni and Co. The recovery of Ni and Co were 98.11-104.17% using standard biological materials with RSD 2.59 - 10.37%. Based on ";t"; test can be conclude that the result are nearly equal to the standard reference material.   Keywords: adsorptive stripping voltammetric, dimethylglioxime complex, nickel, cobalt

  7. Electrocatalytic activity of cobalt phosphide-modified graphite felt toward VO2+/VO2+ redox reaction

    Science.gov (United States)

    Ge, Zhijun; Wang, Ling; He, Zhangxing; Li, Yuehua; Jiang, Yingqiao; Meng, Wei; Dai, Lei

    2018-04-01

    A novel strategy for improving the electro-catalytic properties of graphite felt (GF) electrode in vanadium redox flow battery (VRFB) is designed by depositing cobalt phosphide (CoP) onto GF surface. The CoP powder is synthesized by direct carbonization of Co-based zeolitic imidazolate framework (ZIF-67) followed by phosphidation. Cyclic voltammetry results confirm that the CoP-modified graphite felt (GF-CoP) electrode has excellent reversibility and electro-catalytic activity to the VO2+/VO2+ cathodic reaction compared with the pristine GF electrode. The cell using GF-CoP electrode shows apparently higher discharge capacity over that based on GF electrode. The cell using GF-CoP electrode has the capacity of 67.2 mA h at 100 mA cm-2, 32.7 mA h larger than that using GF electrode. Compared with cell using GF electrode, the voltage efficiency of the cell based on GF-CoP electrode increases by 5.9% and energy efficiency by 5.4% at a current density of 100 mA cm-2. The cell using GF-CoP electrode can reach 94.31% capacity retention after 50 cycles at a current density of 30 mA cm-2. The results show that the CoP can effectively promote the VO2+/VO2+ redox reaction, implying that metal phosphides are a new kind of potential catalytic materials for VRFB.

  8. A spin-frustrated cobalt(II) carbonate pyrochlore network.

    Science.gov (United States)

    Zheng, Yanzhen; Ellern, Arkady; Kögerler, Paul

    2011-11-01

    The crystal structure of the cobalt(II) carbonate-based compound cobalt(II) dicarbonate trisodium chloride, Co(CO(3))(2)Na(3)Cl, grown from a water-ethanol mixture, exhibits a three-dimensional network of corner-sharing {Co(4)(μ(3)-CO(3))(4)} tetrahedral building blocks, in which the Co(II) centres define a pyrochlore lattice and reside in a slightly distorted octahedral Co(O-CO(2))(6) environment. The space outside the hexagonal framework defined by these interlinked groups is occupied by Na(+) and Cl(-) ions. Antiferromagnetic coupling between adjacent Co(II) centres, mediated by carbonate bridges, results in geometric spin frustration which is typical for pyrochlore networks. The Co and Cl atoms reside on the special position 3, one Na atom on position 2 and a carbonate C atom on position 3.

  9. Radiation dose distributions due to sudden ejection of cobalt device.

    Science.gov (United States)

    Abdelhady, Amr

    2016-09-01

    The evaluation of the radiation dose during accident in a nuclear reactor is of great concern from the viewpoint of safety. One of important accident must be analyzed and may be occurred in open pool type reactor is the rejection of cobalt device. The study is evaluating the dose rate levels resulting from upset withdrawal of co device especially the radiation dose received by the operator in the control room. Study of indirect radiation exposure to the environment due to skyshine effect is also taken into consideration in order to evaluate the radiation dose levels around the reactor during the ejection trip. Microshield, SHLDUTIL, and MCSky codes were used in this study to calculate the radiation dose profiles during cobalt device ejection trip inside and outside the reactor building. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Iron, lead, and cobalt absorption: similarities and dissimilarities

    International Nuclear Information System (INIS)

    Barton, J.C.; Conrad, M.E.; Holland, R.

    1981-01-01

    Using isolated intestinal segments in rats, the absorption of iron, lead, and cobalt was increased in iron deficiency and decreased in iron loading. Similarly, the absorption of these metals was decreased in transfusional erythocytosis, after intravenous iron injection and after parenteral endotoxin injection. Acute bleeding or abbreviated intervals of dietary iron deprivation resulted in increased iron absorption from isolated intestinal segments and in intact animals, while the absorption of lead and cobalt was unaffected. These results suggest that the specificity of the mucosal metal absorptive mechanism is either selectively enhanced for iron absorption by phlebotomy or brief periods of dietary iron deprivation, or that two or more mucosal pathways for iron absorption may exist

  11. Preparation and characterization of ABS/anhydrous cobalt chloride composites

    Science.gov (United States)

    Shao, Chengli; Shang, Peng; Mao, Yapeng; Li, Qiuying; Wu, Chifei

    2018-01-01

    Anhydrous cobalt chloride (CoCl2) particles filled acrylonitrile-butadiene-styrene (ABS) composites were successfully prepared and investigated. A strong interfacial interaction between CoCl2 particles and ABS matrix was generated by heat pressing at 190 °C for 15 min. SEM results demonstrated that the particles were dispersed uniformly in the matrix. Fourier transform infrared, x-ray photoelectron spectroscopy and electron spin resonance were used for the investigation of the coordination reaction. The interfacial interaction resulted from a solid-state coordination reaction between nitrile groups (-CN) and cobalt ions (Co2+), leading to an increase in mechanical properties and glass transition temperature. Moreover, heat deflection temperatures were measured and proved to achieve an improvement of 30.6 °C when the CoCl2 content was 7 wt%.

  12. COBALT CoOperative Blending of Autonomous Landing Technology

    Science.gov (United States)

    Carson, John M. III; Restrepo, Carolina I.; Robertson, Edward A.; Seubert, Carl R.; Amzajerdian, Farzin

    2016-01-01

    COBALT is a terrestrial test platform for development and maturation of GN&C (Guidance, Navigation and Control) technologies for PL&HA (Precision Landing and Hazard Avoidance). The project is developing a third generation, Langley Navigation Doppler Lidar (NDL) for ultra-precise velocity and range measurements, which will be integrated and tested with the JPL Lander Vision System (LVS) for Terrain Relative Navigation (TRN) position estimates. These technologies together provide navigation that enables controlled precision landing. The COBALT hardware will be integrated in 2017 into the GN&C subsystem of the Xodiac rocket-propulsive Vertical Test Bed (VTB) developed by Masten Space Systems (MSS), and two terrestrial flight campaigns will be conducted: one open-loop (i.e., passive) and one closed-loop (i.e., active).

  13. Antifungal activity of nicotine and its cobalt complex

    International Nuclear Information System (INIS)

    Zaidi, M.I.; Gul, A.

    2005-01-01

    Nicotine and its metal complex; Co(II)-nicotine were isolated from leaves of Nicotiana tabacum using various metal ions by the reported techniques and studied for their antifungal activity against fourteen different species of fungi. For comparative study, pure sample of nicotine and metal salt used for complexation; cobalt(II) chloride was also subjected to antifungal tests with the same species of fungus under similar conditions. Results indicated that nicotine had antifungal activity against all species of fungi studied except Candida albicans, Microsporum canis, Epidermophyton floccosum, Candida tropicalis, and Alternaria infectoria. Cobalt(II) nicotine was found to be effective against all selected species of fungi but ineffective against Candida solani, Penicillium notalum, Microsporum canis, Fusarium solani and Fusarium moniliforme. (author)

  14. Radiation regression patterns after cobalt plaque insertion for retinoblastoma

    International Nuclear Information System (INIS)

    Buys, R.J.; Abramson, D.H.; Ellsworth, R.M.; Haik, B.

    1983-01-01

    An analysis of 31 eyes of 30 patients who had been treated with cobalt plaques for retinoblastoma disclosed that a type I radiation regression pattern developed in 15 patients; type II, in one patient, and type III, in five patients. Nine patients had a regression pattern characterized by complete destruction of the tumor, the surrounding choroid, and all of the vessels in the area into which the plaque was inserted. This resulting white scar, corresponding to the sclerae only, was classified as a type IV radiation regression pattern. There was no evidence of tumor recurrence in patients with type IV regression patterns, with an average follow-up of 6.5 years, after receiving cobalt plaque therapy. Twenty-nine of these 30 patients had been unsuccessfully treated with at least one other modality (ie, light coagulation, cryotherapy, external beam radiation, or chemotherapy)

  15. Radiation regression patterns after cobalt plaque insertion for retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Buys, R.J.; Abramson, D.H.; Ellsworth, R.M.; Haik, B.

    1983-08-01

    An analysis of 31 eyes of 30 patients who had been treated with cobalt plaques for retinoblastoma disclosed that a type I radiation regression pattern developed in 15 patients; type II, in one patient, and type III, in five patients. Nine patients had a regression pattern characterized by complete destruction of the tumor, the surrounding choroid, and all of the vessels in the area into which the plaque was inserted. This resulting white scar, corresponding to the sclerae only, was classified as a type IV radiation regression pattern. There was no evidence of tumor recurrence in patients with type IV regression patterns, with an average follow-up of 6.5 years, after receiving cobalt plaque therapy. Twenty-nine of these 30 patients had been unsuccessfully treated with at least one other modality (ie, light coagulation, cryotherapy, external beam radiation, or chemotherapy).

  16. Optimization of the behavior of CTAB coated cobalt ferrite nanoparticles

    Science.gov (United States)

    Kumari, Mukesh; Bhatnagar, Mukesh Chander

    2018-05-01

    In this work, we have synthesized cetyltrimethyl ammonium bromide (CTAB) mixed cobalt ferrite (CoFe2O4) nanoparticles (NPs) using sol-gel auto-combustion method taking a different weight percent ratio of CTAB i.e., 0%, 1%, 2%, 3% and 4% with respect to metal nitrates. The morphological, structural and magnetic properties of these NPs are characterized by high resolution transmitted electron microscopy (HRTEM), X-ray diffraction (XRD), Raman spectrometer and physical property measurement system (PPMS). It has been found that saturation magnetization of cobalt ferrite increases with increase in crystalline size of the NPs. Saturation magnetization and crystallite size both were found to be lowest in the case of sample containing 2% CTAB.

  17. Structural and magnetic study of dysprosium substituted cobalt ferrite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Hemaunt, E-mail: hvatsal@gmail.com [Department of Physics, Govind Ballabh Pant University of Agr. & Technology, Pantnagar, Uttarakhand 263145 (India); Srivastava, R.C. [Department of Physics, Govind Ballabh Pant University of Agr. & Technology, Pantnagar, Uttarakhand 263145 (India); Pal Singh, Jitendra [Advanced Analysis Centre, Korea Institute of Science and Technology, Seoul 02792 (Korea, Republic of); Negi, P. [Department of Physics, Govind Ballabh Pant University of Agr. & Technology, Pantnagar, Uttarakhand 263145 (India); Agrawal, H.M. [Advanced Analysis Centre, Korea Institute of Science and Technology, Seoul 02792 (Korea, Republic of); Das, D. [UGC-DAE CSR Kolkata Centre, Kolkata 700098 (India); Hwa Chae, Keun [Advanced Analysis Centre, Korea Institute of Science and Technology, Seoul 02792 (Korea, Republic of)

    2016-03-01

    The present work investigates the magnetic behavior of Dy{sup 3+} substituted cobalt ferrite nanoparticles. X-ray diffraction studies reveal presence of cubic spinel phases in these nanoparticles. Raman spectra of these nanoparticles show change in intensity of Raman bands, which reflects cation redistribution in cubic spinel lattice. Saturation magnetization and coercivity decrease with increase of Dy{sup 3+}concentration in these nanoparticles. Room temperature Mössbauer measurements show the cation redistribution in these nanoparticles and corroborates the results obtained from Raman Spectroscopic measurements. Decrease in magnetization of Dy{sup 3+} substituted cobalt ferrite is attributed to the reduction in the magnetic interaction and cation redistribution. - Highlights: • Slight decrease in crystallite size after Dy{sup 3+} doping. • Saturation magnetization and coercivity decrease after Dy{sup 3+} doping. • Mössbauer measurements show the cation redistribution in the samples.

  18. World production and possible recovery of cobalt from the Kupferschiefer stratiform copper ore

    Directory of Open Access Journals (Sweden)

    Pazik Paulina M.

    2016-01-01

    Full Text Available Cobalt is recognized as a strategic metal and also E-tech element, which is crucial for worlds development. An increasing demand for cobalt forces for searching of new resources that could be explored in European countries. There are many examples of cobalt recoveries, mostly from laterite and sulphide deposits. However, the accurate choice of the technology depends on many factors. The Kupferschiefer stratiform copper ore located in Poland is the biggest deposit of cobalt in Europe. Although KGHM Polska Miedz S.A. recovers many precious metals from this ore, cobalt is not recovered yet. This metal occurs as an accompanying element, mostly in the form of cobaltite (CaAsS, with the average content of 50–80 g/Mg. In this paper a possible recovery of cobalt from the Kupferschiefer ore, with the use of hydrometallurgical methods, was investigated.

  19. Estimation of cobalt release from feed water heater tubes of BWRs

    International Nuclear Information System (INIS)

    Uchida, S.; Kitamura, M.; Ozawa, Y.

    1983-01-01

    To evaluate the release source of cobalt from heater tubes of the feed water line, release rate measurements were carried out by detecting 60 Co released from irradiated stainless steel in contact with neutral water at an oxygen concentration of 20 ppb. The dependences of cobalt release rate on temperature, flow velocity and exposure time were studied after 670 hours of release experiments, and an empirical equation (which is presented) was obtained in the temperature range from 150 to 240 deg C. A decrease in the cobalt release rate above 250 deg C was considered due to the formation of a protective oxide layer. From these data, the amount of cobalt released from individual feed water heaters was evaluated. It was demonstrated that low cobalt containing stainless steel was economically applied only in the higher temperature region of the heater (20% of the total surface) to reduce cobalt feed rate into the reactor (to approx. 1/2). (author)

  20. Effects of cobalt on structure, microchemistry and properties of a wrought nickel-base superalloy

    Science.gov (United States)

    Jarrett, R. N.; Tien, J. K.

    1982-01-01

    The effect of cobalt on the basic mechanical properties and microstructure of wrought nickel-base superalloys has been investigated experimentally by systematically replacing cobalt by nickel in Udimet 700 (17 wt% Co) commonly used in gas turbine (jet engine) applications. It is shown that the room temperature tensile yield strength and tensile strength only slightly decrease in fine-grained (disk) alloys and are basically unaffected in coarse-grained (blading) alloys as cobalt is removed. Creep and stress rupture resistances at 760 C are found to be unaffected by cobalt level in the blading alloys and decrease sharply only when the cobalt level is reduced below 8 vol% in the disk alloys. The effect of cobalt is explained in terms of gamma prime strengthening kinetics.

  1. DDT performance of energetic cobalt coordination compounds. [Dozen of compounds similar to 2-(5-cyanotetrazolato)pentaaminecobalt perchlorate, trinitrotriamine cobalt, dinitrobis(ethylenediamine) cobalt perchlorate

    Energy Technology Data Exchange (ETDEWEB)

    Lieberman, M.L.; Fleming, W.

    1986-01-01

    The compound 2-(5-cyanotetrazolato)pentaamminecobalt(III) perchlorate (CP) has been utilized in low-voltage detonators because it reliably undergoes deflagration-to-detonation transition (DDT). In the present investigation, we have compared the performance of over a dozen similar compounds. These compounds all have cobalt as the coordinating metal, most are ammine complexes, and all except one incorporate the perchlorate anion as an oxidizer. Chemical factors such as fuel-to-oxidizer ratio, trigger group, and organic content have been varied. 18 refs., 7 figs., 2 tabs.

  2. Ferric and cobaltous hydroacid complexes for forward osmosis (FO) processes

    KAUST Repository

    Ge, Qingchun; Fu, Fengjiang; Chung, Neal Tai-Shung

    2014-01-01

    Cupric and ferric hydroacid complexes have proven their advantages as draw solutes in forward osmosis in terms of high water fluxes, negligible reverse solute fluxes and easy recovery (Ge and Chung, 2013. Hydroacid complexes: A new class of draw solutes to promote forward osmosis (FO) processes. Chemical Communications 49, 8471-8473.). In this study, cobaltous hydroacid complexes were explored as draw solutes and compared with the ferric hydroacid complex to study the factors influencing their FO performance. The solutions of the cobaltous complexes produce high osmotic pressures due to the presence of abundant hydrophilic groups. These solutes are able to dissociate and form a multi-charged anion and Na+ cations in water. In addition, these complexes have expanded structures which lead to negligible reverse solute fluxes and provide relatively easy approaches in regeneration. These characteristics make the newly synthesized cobaltous complexes appropriate as draw solutes. The FO performance of the cobaltous and ferric-citric acid (Fe-CA) complexes were evaluated respectively through cellulose acetate membranes, thin-film composite membranes fabricated on polyethersulfone supports (referred as TFC-PES), and polybenzimidazole and PES dual-layer (referred as PBI/PES) hollow fiber membranes. Under the conditions of DI water as the feed and facing the support layer of TFC-PES FO membranes (PRO mode), draw solutions at 2.0M produced relatively high water fluxes of 39-48 LMH (Lm-2hr-1) with negligible reverse solute fluxes. A water flux of 17.4 LMH was achieved when model seawater of 3.5wt.% NaCl replaced DI water as the feed and 2.0M Fe-CA as the draw solution under the same conditions. The performance of these hydroacid complexes surpasses those of the synthetic draw solutes developed in recent years. This observation, along with the relatively easy regeneration, makes these complexes very promising as a novel class of draw solutes. © 2014 Elsevier Ltd.

  3. Consumer products polluted by cobalt-60 on the Dutch market

    International Nuclear Information System (INIS)

    Bothof, J.

    2002-01-01

    In several previous articles of this magazine attention has been paid to reporting of radioactive materials in scrap metals and incidents with radioactive materials, which were dealt with by the VROM-Inspectie Regio Zuid-West (Inspection for the Region South-West in the Netherlands). In this article attention is paid to a special incident with new stainless steel flanges, polluted by cobalt 60 [nl

  4. Nickel-cobalt hydroxide nanosheets: Synthesis, morphology and electrochemical properties

    Czech Academy of Sciences Publication Activity Database

    Schneiderová, Barbora; Demel, Jan; Zhigunov, Alexander; Bohuslav, Jan; Tarábková, Hana; Janda, Pavel; Lang, Kamil

    2017-01-01

    Roč. 499, AUG (2017), s. 138-144 ISSN 0021-9797 Institutional support: RVO:61388980 ; RVO:61389013 ; RVO:61388955 Keywords : Hydroxide nanosheets * Delamination * Exfoliation * Layered nickel hydroxide * Layered cobalt hydroxide * Electrode material Subject RIV: CA - Inorganic Chemistry; CF - Physical ; Theoretical Chemistry (UFCH-W); CD - Macromolecular Chemistry (UMCH-V) OBOR OECD: Inorganic and nuclear chemistry; Physical chemistry (UFCH-W); Polymer science (UMCH-V) Impact factor: 4.233, year: 2016

  5. Ferric and cobaltous hydroacid complexes for forward osmosis (FO) processes

    KAUST Repository

    Ge, Qingchun

    2014-07-01

    Cupric and ferric hydroacid complexes have proven their advantages as draw solutes in forward osmosis in terms of high water fluxes, negligible reverse solute fluxes and easy recovery (Ge and Chung, 2013. Hydroacid complexes: A new class of draw solutes to promote forward osmosis (FO) processes. Chemical Communications 49, 8471-8473.). In this study, cobaltous hydroacid complexes were explored as draw solutes and compared with the ferric hydroacid complex to study the factors influencing their FO performance. The solutions of the cobaltous complexes produce high osmotic pressures due to the presence of abundant hydrophilic groups. These solutes are able to dissociate and form a multi-charged anion and Na+ cations in water. In addition, these complexes have expanded structures which lead to negligible reverse solute fluxes and provide relatively easy approaches in regeneration. These characteristics make the newly synthesized cobaltous complexes appropriate as draw solutes. The FO performance of the cobaltous and ferric-citric acid (Fe-CA) complexes were evaluated respectively through cellulose acetate membranes, thin-film composite membranes fabricated on polyethersulfone supports (referred as TFC-PES), and polybenzimidazole and PES dual-layer (referred as PBI/PES) hollow fiber membranes. Under the conditions of DI water as the feed and facing the support layer of TFC-PES FO membranes (PRO mode), draw solutions at 2.0M produced relatively high water fluxes of 39-48 LMH (Lm-2hr-1) with negligible reverse solute fluxes. A water flux of 17.4 LMH was achieved when model seawater of 3.5wt.% NaCl replaced DI water as the feed and 2.0M Fe-CA as the draw solution under the same conditions. The performance of these hydroacid complexes surpasses those of the synthetic draw solutes developed in recent years. This observation, along with the relatively easy regeneration, makes these complexes very promising as a novel class of draw solutes. © 2014 Elsevier Ltd.

  6. Cobalt oxide nanoparticle-modified carbon nanotubes as an ...

    Indian Academy of Sciences (India)

    of 60 mV were observed at. 100 mV s. −1 for CoOx−MWNT/GCE. An anodic peak at. 100 mV attributed to Co(II)/Co(III) redox transition associated with the electrode surface. The cathodic peak at 20 mV corre- spond to the reduction of various cobalt oxide species formed during the anodic sweep. The stability of the modified ...

  7. Cobalt alloy ion sources for focused ion beam implantation

    Energy Technology Data Exchange (ETDEWEB)

    Muehle, R.; Doebeli, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Zimmermann, P. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Cobalt alloy ion sources have been developed for silicide formation by focused ion beam implantation. Four eutectic alloys AuCo, CoGe, CoY and AuCoGe were produced by electron beam welding. The AuCo liquid alloy ion source was investigated in detail. We have measured the emission current stability, the current-voltage characteristics, and the mass spectrum as a function of the mission current. (author) 1 fig., 2 refs.

  8. Cobalt-60 in the treatment of cancer-future scenario

    International Nuclear Information System (INIS)

    Sastri, K.V.S.; Patil, B.N.; Kohli, A.K.

    2009-01-01

    Treatment of cancer using radiation is established method. Cobalt-60 is the workhorse of cancer treatment from the beginning. Later linear accelerators with more accessories were developed and are now used for the advanced treatments like IMRT, IGRT etc. Gammaknife, Gyroknife and supergamma machines using 60 Co have also taken roots for the treatment of cancer. The use of 60 Co in the treatment of cancer is expected to continue for some more time to come. (author)

  9. Thermal Effect on Structure Organizations in Cobalt-Fullerene Nanocomposition

    Czech Academy of Sciences Publication Activity Database

    Lavrentiev, Vasyl; Vacík, Jiří; Naramoto, H.; Sakai, S.

    2010-01-01

    Roč. 10, č. 4 (2010), s. 2624-2629 ISSN 1533-4880 R&D Projects: GA AV ČR(CZ) KAN400480701; GA AV ČR IAA200480702; GA MŠk(CZ) LC06041 Institutional research plan: CEZ:AV0Z10480505 Keywords : cobalt * fullerene * simultaneous deposition Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.351, year: 2010

  10. CARDIOPROTECTIVE EFFECT OF NATIVE ANTIHYPOXANTS IN EXPERIMENTAL COBALT CARDIOMYOPATHY

    Directory of Open Access Journals (Sweden)

    I. V. Zadnipryany

    2016-01-01

    Full Text Available The aim of research – the study of cardioprotective properties of antioxidants in terms of histotoxic hypoxia under experimental conditions.Materials and methods. The study was conducted on 20 adult male Wistar rats divided into 3 experimental groups, which for 7 days were intraperitoneally injected aqueous CoCl2 solution at a dose of 60 mg/kg. Rats of the first experimental group (n = 6 had no administered drug correction, a the second group of animals (n = 7 after the cobalt chloride daily injections was administered intragastrically Enoant Premium aqueous solution at a dose of 2.5 ml / kg, along with 0.05 ml of water, the rats the third test group (n = 7 after the administration of cobalt chloride were exposed to cytoflavin correction concentrate and grape polyphenols administered simultaneously. Studies of myocardium were conducted using light and electron microscopy.Results of the research. The result of the cobalt toxic effect on the heart of animals in experiments lead to the development of cardiomyopathy, which required timely cardioprotection. Morphological changes in the second group of rats, despite a slight improvement compared with the group without correction,were characterized, above all, by uneven from mild to severe edema of the myocardium. Structure of myocardium observed in the third group of male rats after cobalt intoxication, generally reflected a tendency to minimization of the extent of the damage, which was manifested in the form of normalization of cell structures and muscle fibers.Conclusion. The administration of succinic acid derivatives combined with the grape polyphenols demonstrated vivid cytoprotective properties evidenced by mostly preserved myocardium structure in rats exposed to histotoxic hypoxia in comparison to only administration of plant polyphenols group. 

  11. Nanocrystalline Iron-Cobalt Alloys for High Saturation Indutance

    Science.gov (United States)

    2016-02-24

    film deposited just like the pick-up of a turn-table music player. The contact pads provide the electrical contacts to the starting and end point of...anisotropy using the geometry of the thin toroid. We have shown experimentally that the thin film toroid calculations may be applicable to up to millimeter...thin film as well as bulk devices. 15. SUBJECT TERMS Micromagnetic Calculations, Nanocrystalline cobalt-iron, Thin Film Toroids 16. SECURITY

  12. Cobalt-based orthopaedic alloys: Relationship between forming route, microstructure and tribological performance

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Bhairav [Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom); Favaro, Gregory [CSM Instruments SA, Rue de la Gare 4, Galileo Center, CH-2034 Peseux (Switzerland); Inam, Fawad [Advanced Composite Training and Development Centre and School of Mechanical and Aeronautical Engineering, Glyndwr University, Mold Road, Wrexham LL11 2AW (United Kingdom); School of Engineering and Materials Science and Nanoforce Technology Ltd, Queen Mary University of London, London E1 4NS (United Kingdom); Reece, Michael J. [School of Engineering and Materials Science and Nanoforce Technology Ltd, Queen Mary University of London, London E1 4NS (United Kingdom); Angadji, Arash [Orthopaedic Research UK, Furlong House, 10a Chandos Street, London W1G 9DQ (United Kingdom); Bonfield, William [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Huang, Jie [Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom); Edirisinghe, Mohan, E-mail: m.edirisinghe@ucl.ac.uk [Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)

    2012-07-01

    The average longevity of hip replacement devices is approximately 10-15 years, which generally depends on many factors. But for younger generation patients this would mean that revisions may be required at some stage in order to maintain functional activity. Therefore, research is required to increase the longevity to around 25-30 years; a target that was initially set by John Charnley. The main issues related to metal-on-metal (MoM) hip replacement devices are the high wear rates when malpositioned and the release of metallic ions into the blood stream and surrounding tissues. Work is required to reduce the wear rates and limit the amount of metallic ions being leached out of the current MoM materials, to be able to produce an ideal hip replacement material. The most commonly used MoM material is the cobalt-based alloys, more specifically ASTM F75, due to their excellent wear and corrosion resistance. They are either fabricated using the cast or wrought method, however powder processing of these alloys has been shown to improve the properties. One powder processing technique used is spark plasma sintering, which utilises electric current Joule heating to produce high heating rates to sinter powders to form an alloy. Two conventionally manufactured alloys (ASTM F75 and ASTM F1537) and a spark plasma sintered (SPS) alloy were evaluated for their microstructure, hardness, tribological performance and the release of metallic content. The SPS alloy with oxides and not carbides in its microstructure had the higher hardness, which resulted in the lowest wear and friction coefficient, with lower amounts of chromium and molybdenum detected from the wear debris compared to the ASTM F75 and ASTM F1537. In addition the wear debris size and size distribution of the SPS alloy generated were considerably small, indicating a material that exhibits excellent performance and more favourable compared to the current conventional cobalt based alloys used in orthopaedics. - Highlights

  13. Nationwide survey of cobalt-60 teletherapy. Final report

    International Nuclear Information System (INIS)

    Thompson, D.L.; Kearly, F.E.; Wyckoff, H.O.; Gitlin, J.N.; Reffit, E.B.; Shangold, E.J.

    1980-08-01

    The Bureau of Radiological Health and the National Bureau of Standards conducted a nationwide survey of cobalt-60 teletherapy facilities to determine their accuracy in delivery of a prescribed dose to a phantom. Participation was obtained from 684 respondents or 75 percent of US facilities. For each cobalt-60 unit the average dose recorded on five dosimeters was within 5 percent of the prescribed value for 83 percent of the respondents and only exceeded a 10 percent difference for 3 percent of the respondents. Sufficient information for reconstruction of dose calculations was available for 87 percent of the participating facilities. Of these reconstructed calculations, 56 percent were within 1 percent of the prescribed dose of 300 rads. The analysis of data from the survey showed that better performance were related to a number of factors. Among these were expressing the machine calibration in terms of dose rate, performing the machine calibration on an annual basis, and correcting for source decay on a monthly basis. Larger facilities achieved better results than smaller facilities when calculating the absorbed dose rate. Also, each 4 machine characteristics (isocentric mounting, short exposure time, high normalized output, and long treatment distance) were related to better performance with regard to both dosimeter readings and calculated doses. Larger facilities were more likely to be using a cobalt-60 unit having those characteristics

  14. Radiation dose distributions due to sudden ejection of cobalt device

    International Nuclear Information System (INIS)

    Abdelhady, Amr

    2016-01-01

    The evaluation of the radiation dose during accident in a nuclear reactor is of great concern from the viewpoint of safety. One of important accident must be analyzed and may be occurred in open pool type reactor is the rejection of cobalt device. The study is evaluating the dose rate levels resulting from upset withdrawal of co device especially the radiation dose received by the operator in the control room. Study of indirect radiation exposure to the environment due to skyshine effect is also taken into consideration in order to evaluate the radiation dose levels around the reactor during the ejection trip. Microshield, SHLDUTIL, and MCSky codes were used in this study to calculate the radiation dose profiles during cobalt device ejection trip inside and outside the reactor building. - Highlights: • This study aims to calculate the dose rate profiles after cobalt device ejection from open-pool-type reactor core. • MicroShield code was used to evaluate the dose rates inside the reactor control room. • McSKY code was used to evaluate the dose rates outside the reactor building. • The calculated dose rates for workers are higher than the permissible limits after 18 s from device ejection.

  15. Removal of Cobalt ion by Foam Flotation(I)

    Energy Technology Data Exchange (ETDEWEB)

    Jung, I.H.; Park, H.S.; Moon, J.S.; Yim, S.P.; Bae, K.K. [Korea Atomic Energy Research Institute (Korea)

    1999-02-01

    Simulated liquid waste containing 50 ppm cobalt ion was treated by precipitate flotation using the surfactant of sodium lauryl sulfate. The effects of initial cobalt ion concentration, pH, surfactant concentration, removal time, gas flow rate and foreign ions were estimated on removal efficiency. 35% H{sub 2}O{sub 2} was added for pre-treatment stage before precipitate flotation. As the result of pre-treatment, optimum removal pH and the pH of treated water being discharged were lowed and optimum removal pH range was broadened. For the result of this experiment, 99.8% removal efficiency was obtained at the condition of 50ppm of initial cobalt ion concentration, pH 9.5, 70 mL/min of gas flow rate, and 30 min of removal time. Attraction between precipitate and surfactant was supposed to be influenced by solubility and chemical affinity among species in solution as well as zeta potential. The influence of foreign ions such as, NO{sub 3}{sup -}, SO{sub 4}{sup -2}, Na{sup +}, Ca{sup +2} on the removal efficiency was also observed. Removal efficiency by precipitate flotation containing o.1 M of SO4{sup -}2 ion decreased to 90% due to the decrease of zeta potential and interruption of precipitation. 12 refs., 8 figs.

  16. Synthesis and characterization of cobalt sulfide nanoparticles by sonochemical method

    Science.gov (United States)

    Muradov, Mustafa B.; Balayeva, Ofeliya O.; Azizov, Abdulsaid A.; Maharramov, Abel M.; Qahramanli, Lala R.; Eyvazova, Goncha M.; Aghamaliyev, Zohrab A.

    2018-03-01

    Convenient and environmentally friendly synthesis of Co9S8/PVA, CoxSy/EG and CoxSy/3-MPA nanocomposites were carried out in the presence of ultrasonic irradiation by the liquid phase synthesis of the sonochemical method. For the synthesis, cobalt acetate tetrahydrate [Co(CH3COO)2·4H2O] and sodium sulfide (Na2S·9H2O) were used as a cobalt and sulfur precursor, respectively. Polyvinyl alcohol (PVA), ethylene glycol (EG) and 3-mercaptopropionic acid (3-MPA) were used as a capping agent and surfactant. The structural, optical properties and morphology of nanocomposites were characterized using X-ray diffractometer (XRD), Ultraviolet/Visible Spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The optical band gap of Co9S8/PVA is 1.81 eV and for CoxSy/EG is 2.42 eV, where the direct band gap of bulk cobalt sulfide is (0.78-0.9 eV). The wide band gap indicates that synthesised nanocomposites can be used in the fabrication of optical and photonic devices. The growth mechanisms of the Co9S8, CoS2 and Co3S4 nanoparticles were discussed by the reactions. The effects of sonication time and annealing temperature on the properties of the nanoparticles have been studied in detail.

  17. Recovery of molybdenum and cobalt powders from spent hydrogenation catalyst

    International Nuclear Information System (INIS)

    Rabah, M.A.; Hewaidy, I.F.; Farghaly, F.E.

    1996-01-01

    Free powders as well as compact shapes of molybdenum and cobalt have been successfully recovered from spent hydrogenation and desulphurization catalysts. A process flow sheet was followed involving crushing, milling, particle sizing, hydrometallurgical acid leaching roasting of the obtained salts in an atmospheric oxygen to obtain the respective oxides. These were reduced by hydrogen gas at 110 degree C and 900 degree C respectively. Parameters affecting the properties of the products and the recovery efficiency value such as acid concentration, particle diameter of the solid catalyst, temperature time under a constant mass flow rate the hydrogen gas, have been investigated. A mixture of concentration.sulphuric and nitric acids (3:1 by volume) achieved adequate recovery of both metals. The latter increased with the increase in acid concentration, time up 10 3 hours and temperature: 100 degree C and with the decrease in particle diameter of the spent catalyst. The PH of the obtained filtrate was adjusted to 2 with ammonia to precipitate insoluble ammonium molybdate and a solution of cobalt sulphate. Cobalt hydroxide can be precipitate from the latter solution at a PH = 7.6 using excess ammonium hydroxide solution. The obtained results showed that the metallic products are technically pure meeting the standard specifications. Compact shapes of molybdenum acquire density values increasing with the increase of the pressing load whereby a maximum density value of 2280 kg/m 3 is attained at 0.75 MPa. Maximum recovery efficiency amounts to 96%. 10 figs., 3 tabs

  18. Improvement of the oxidation stability of cobalt nanoparticles

    Directory of Open Access Journals (Sweden)

    Celin Dobbrow

    2012-01-01

    Full Text Available In order to enhance the resistance of cobalt nanoparticles to oxidation in air, the impact of different stabilization strategies on the isothermal oxidation of particle dispersions and powders was kinetically investigated and compared to as-prepared particle preparations. A post-synthesis treatment with different alcohols was employed, and we also investigate the influence of two different polymer shells on the oxidation process. We found a parabolic decrease of the magnetization for all particle charges, indicating that the process is dominated by a diffusion of oxygen to the cobalt core and a radial growth of the oxide layer from the particle surface to the core. A significant deceleration of the oxidation process was observed for all alcohol-passivated particle preparations, and this resulted finally in a stagnation effect. The stabilizing effect increases in the sequence Co@OA/MeOH < Co@OA/EtOH < Co@OA/iPrOH. For polymer-coated particle preparations Co@PCL and Co@PS, the deceleration was even more pronounced. The results demonstrate that cobalt nanoparticles can effectively be protected against oxidation in order to improve their mid- to longterm stability.

  19. Assessment of polyphase sintered iron-cobalt-iron boride cermets

    International Nuclear Information System (INIS)

    Nowacki, J.; Pieczonka, T.

    2004-01-01

    Sintering of iron, cobalt and boron powders has been analysed. As a result iron-iron boride, Fe-Fe 2 B and iron/cobalt boride with a slight admixture of molybdenum, Fe - Co - (FeMoCo) 2 B cermets have been produced. Iron was introduced to the mixture as the Astalloy Mo Hoeganaes grade powder. Elemental amorphous boron powder was used, and formation of borides occurred both during heating and isothermal sintering periods causing dimensional changes of the sintered body. Dilatometry was chosen to control basic phenomena taking place during multiphase sintering of investigated systems. The microstructure and phase constituents of sintered compacts were controlled as well. The cermets produced were substituted to: metallographic tests, X-ray analysis, measurements of hardness and of microhardness, and of wear in the process of sliding dry friction. Cermets are made up of two phases; hard grains of iron - cobalt boride, (FeCo) 2 B (1800 HV) constituting the reinforcement and a relatively soft and plastic eutectic mixture Fe 2 B - Co (400-500 HV) constituting the matrix. (author)

  20. Self-powered in-core detectors of cobalt type

    International Nuclear Information System (INIS)

    Jonsson, Georg

    1975-01-01

    Testing and development of self-powered neutron detectors with a cobalt emitter is described. Long term irradiation at 400 deg C is expected to indicate insulation quality, change in calibration and 60 Co build-up. Dynamic tests to investigate possible transient effects due to temperature changes are being performed on a number of detectors up to about 600 deg C. A long term irradiation at low temperature has been terminated after 4.5 years. On completion, neutron dose was estimated to be 5.6 x 10 21 nvt and the 60 Co background was 9.3 % of the full flux signal. A recently introduced long term test is expected to provide data on instability effects due to 61 Co. For a BWR in-core detector installation, the main advantage of cobalt detectors, apart from the small size, appears to be long life. Development work is being done on detectors with vanadium-cobalt emitters, electronic separation of fast and delayed signals and reduction of gamma sensitivity. (O.T.)

  1. Cobalt chloride speciation, mechanisms of cytotoxicity on human pulmonary cells, and synergistic toxicity with zinc

    International Nuclear Information System (INIS)

    Bresson, Carole; Darolles, Carine; Sage, Nicole; Malard, Veronique; Carmona, Asuncion; Roudeau, Stephane; Ortega, Richard; Gautier, Celine; Ansoborlo, Eric

    2013-01-01

    Cobalt is used in numerous industrial sectors, leading to occupational diseases, particularly by inhalation. Cobalt-associated mechanisms of toxicity are far from being understood and information that could improve knowledge in this area is required. We investigated the impact of a soluble cobalt compound, CoCl 2 .6H 2 O, on the BEAS-2B lung epithelial cell line, as well as its impact on metal homeostasis. Cobalt speciation in different culture media, in particular soluble and precipitated cobalt species, was investigated via theoretical and analytical approaches. The cytotoxic effects of cobalt on the cells were assessed. Upon exposure of BEAS-2B cells to cobalt, intracellular accumulation of cobalt and zinc was demonstrated using direct in situ microchemical analysis based on ion micro-beam techniques and analysis after cell lysis by inductively coupled plasma mass spectrometry (ICP-MS). Microchemical imaging revealed that cobalt was rather homogeneously distributed in the nucleus and in the cytoplasm whereas zinc was more abundant in the nucleus. The modulation of zinc homeostasis led to the evaluation of the effect of combined cobalt and zinc exposure. In this case, a clear synergistic increase in toxicity was observed as well as a substantial increase in zinc content within cells. Western blots performed under the same co-exposure conditions revealed a decrease in ZnT1 expression, suggesting that cobalt could inhibit zinc release through the modulation of ZnT1. Overall, this study highlights the potential hazard to lung function, of combined exposure to cobalt and zinc. (authors)

  2. Cobalt chloride speciation, mechanisms of cytotoxicity on human pulmonary cells, and synergistic toxicity with zinc

    International Nuclear Information System (INIS)

    Bresson, Carole; Darolles, Carine; Sage, Nicole; Malard, Veronique; Carmona, Asuncion; Roudeau, Stephane; Ortega, Richard; Gautier, Celine; Ansoborlo, Eric

    2013-01-01

    Complete text of publication follows: Cobalt is used in numerous industrial sectors, leading to occupational diseases, particularly by inhalation. Cobalt-associated mechanisms of toxicity are far from being understood and information that could improve knowledge in this area is required. We investigated the impact of a soluble cobalt compound, CoCl 2 , on the BEAS-2B lung epithelial cell line, as well as its impact on metal homeostasis. Cobalt speciation in different culture media, in particular soluble and precipitated cobalt species, was investigated via theoretical and analytical approaches. The cytotoxic effects of cobalt on the cells were assessed. Upon exposure of BEAS-2B cells to cobalt, intracellular accumulation of cobalt and zinc was demonstrated using direct in situ microchemical analysis based on ion micro-beam techniques and analysis after cell lysis by inductively coupled plasma mass spectrometry (ICP-MS). Microchemical imaging revealed that cobalt was rather homogeneously distributed in the nucleus and in the cytoplasm whereas zinc was more abundant in the nucleus. The modulation of zinc homeostasis led to the evaluation of the effect of combined cobalt and zinc exposure. In this case, a clear synergistic increase in toxicity was observed as well as a substantial increase in zinc content within cells. Western blots performed under the same co-exposure conditions revealed a decrease in ZnT1 expression, suggesting that cobalt could inhibit zinc release through the modulation of ZnT1. Overall, this study highlights the potential hazard to lung function, of combined exposure to cobalt and zinc

  3. Manganese substituted cobalt ferrite magnetostrictive materials for magnetic stress sensor applications

    OpenAIRE

    Paulsen, J. A.; Ring, A. P.; Lo, C. C. H.; Snyder, John Evan; Jiles, David

    2005-01-01

    Metal bonded cobalt ferrite composites have been shown to be promising candidate materials for use in magnetoelastic stress sensors, due to their large magnetostriction and high sensitivity of magnetization to stress. However previous results have shown that below 60 °C the cobalt ferrite material exhibits substantial magnetomechanical hysteresis. In the current study, measurements indicate that substituting Mn for some of the Fe in the cobalt ferrite can lower the Curie temperature of the ma...

  4. A laboratory and field evaluation of the mobility of cobalt-60/EDTA

    International Nuclear Information System (INIS)

    Jones, T.L.; Gee, G.W.; Kirkham, R.R.; Swanson, J.L.

    1983-01-01

    We have observed a time and soil type dependence in the ability of the organic complexant EDTA to keep cobalt-60 in solution. Test results indicate that short-term adsorption tests lasting 5 days or less can be misleading. In short-term tests using cobalt-60/EDTA and soil from the Hanford site, low sorption in batch tests and high mobility in column tests were observed. During long-term batch test using cobalt-60/EDTA, the percentage of cobalt remaining in solution decreased from 90% after 7 days to less than 10% after 500 days. In laboratory and field column tests where low water flow rates allowed long contact time, virtually no cobalt movement was observed even though in the field test tritium was transported over 4 meters. Long-term batch tests using cobalt-60/EDTA and soil from Savannah River burial grounds showed that cobalt remainin in solution dropped to 30% of the total cobalt added after 5 days and to less than 1% after 15 days. Batch tests using soil from Oak Ridge burial grounds were less dramatic showing cobalt in solution decreasing from 90% after 5 days to 70% after 35 days. The cobalt-60/EDTA complex appears to be dissociating and leaving uncomplexed cobalt which is readily sorbed. The dissociation seems to be rather complete in Hanford and Savannah River soil but limited in the Oak Ridge soil. The implication to waste management is that the potential for transport of cobalt by EDTA may not be as serious at all burial sites as once thought

  5. An Economic Analysis of Electron Accelerators and Cobalt-60 for Irradiating Food

    OpenAIRE

    Morrison, Rosanna Mentzer

    1989-01-01

    Average costs per pound of irradiating food are similar for the electron accelerator and cobalt-60 irradiators analyzed in this study, but initial investment costs can vary by $1 million. Irradiation costs range from 0.5 to 7 cents per pound and decrease as annual volumes treated increase. Cobalt-60 is less expensive than electron beams for annual volumes below 50 million pounds. For radiation source requirements above the equivalent of 1 million curies of cobalt-60, electron beams are more e...

  6. Neutron diffraction studies on cobalt substituted BiFeO3

    Science.gov (United States)

    Ray, J.; Biswal, A. K.; Acharya, S.; Babu, P. D.; Siruguri, V.; Vishwakarma, P. N.

    2013-02-01

    A dilute concentration of single phase Cobalt substituted Bismuth ferrite, BiFe1-XCoXO3; (x=0, 0.02) is prepared by sol-gel auto combustion method. Room temperature neutron diffraction patterns show no change in the crystal and magnetic structure upon cobalt doping. The calculation of magnetic moments shows 3.848 μB for Fe+ and 2.85 μB for Co3+. The cobalt is found to be in intermediate spin state.

  7. Effect of Pressing Parameters on the Structure of Porous Materials Based on Cobalt and Nickel Powders

    Science.gov (United States)

    Shustov, V. S.; Rubtsov, N. M.; Alymov, M. I.; Ankudinov, A. B.; Evstratov, E. V.; Zelensky, V. A.

    2018-03-01

    Porous materials with a bulk porosity of more than 68% were synthesized by powder metallurgy methods from a cobalt-nickel mixture. The effect of the ratio of nickel and cobalt powders used in the synthesis of this porous material (including cases when either nickel or cobalt alone was applied) and the conditions of their compaction on structural parameters, such as open and closed porosities and pose size, was established.

  8. Cobalt dinitrosoalkane complexes in the C-H functionalization of olefins.

    Science.gov (United States)

    Schomaker, Jennifer M; Boyd, W Christopher; Stewart, Ian C; Toste, F Dean; Bergman, Robert G

    2008-03-26

    The use of cobalt dinitrosoalkane complexes in the C-H functionalization of alkenes has been demonstrated. Reaction of a series of alkenes with Me4CpCo(CO)2 in the presence of NO generates intermediate cobalt dinitrosoalkane complexes that can be deprotonated alpha to the nitrosyl group and added to various Michael acceptors. The resultant products can then undergo retrocycloaddition reactions in the presence of the original alkene to regenerate the starting cobalt dinitrosoalkane complex and release the functionalized alkene.

  9. Influence of Reduction Promoters on Stability of Cobalt/g-Alumina Fischer-Tropsch Synthesis Catalysts

    OpenAIRE

    Gary Jacobs; Wenping Ma; Burtron H. Davis

    2014-01-01

    This focused review article underscores how metal reduction promoters can impact deactivation phenomena associated with cobalt Fischer-Tropsch synthesis catalysts. Promoters can exacerbate sintering if the additional cobalt metal clusters, formed as a result of the promoting effect, are in close proximity at the nanoscale to other cobalt particles on the surface. Recent efforts have shown that when promoters are used to facilitate the reduction of small crystallites with the aim of increasing...

  10. Carbon-Based Oxamate Cobalt(III) Complexes as Bioenzyme Mimics for Contaminant Elimination in High Backgrounds of Complicated Constituents.

    Science.gov (United States)

    Li, Nan; Zheng, Yun; Jiang, Xuemei; Zhang, Ran; Pei, Kemei; Chen, Wenxing

    2017-10-12

    Complex wastewater with massive components is now a serious environmental issue facing humanity. Selective removal of low-concentration contaminants in mixed constituents holds great promise for increasing water supplies. Bioenzymes like horseradish peroxidase exhibit oxidizing power and selectivity. Here, we manufactured its mimic through immobilizing non-heme oxamate anionic cobalt(III) complex ([Co III (opba)] - , opba = o-phenylenebis(oxamate)) onto pyridine (Py) modified multiwalled carbon nanotubes ([Co III (opba)] - -Py-MWCNTs, MWCNTs = multiwalled carbon nanotubes), where MWCNTs captured substrates and Py functioned as the fifth ligand. We chose typical azo dye (C.I. Acid Red 1) and antibiotic (ciprofloxacin) as model substrates. Without •OH, this catalyst could detoxify target micropollutants efficiently at pH from 8 to 11. It also remained efficient in repetitive tests, and the final products were non-poisonous OH-containing acids. Combined with radical scavenger tests and electron paramagnetic resonance result, we speculated that high-valent cobalt-oxo active species and oxygen atom transfer reaction dominated in the reaction pathway. According to density functional theory calculations, the electron spin density distribution order showed that electron-withdrawing ligand was beneficial for inward pulling the excess electron and lowering the corresponding energy levels, achieving an electrophilic-attack enhancement of the catalyst. With target removal property and recyclability, this catalyst is prospective in water detoxication.

  11. Erythrokinetics examination using 59Fe and 51Cr isotopes

    International Nuclear Information System (INIS)

    Mistrik, M.; Klinda, F.; Geso, L.; Lipsic, T.

    1987-01-01

    The results are discussed of 55 case studies of various hematological diseases in which 59 Fe was used as a tracer in studying iron kinetics, simultaneously with 51 Cr as a tracer in studying erythrocyte survival and the localization of erythrocyte destruction. The values of iron metabolism are graphically presented, while erythropoiesis data is tabulated. The method was especially beneficial in conditions that could not easily be diagnosed using laboratory techniques. They included osteomyelofibrosis, polycythemia vera, aplastic anemia, and the myelodysplastic syndrome. The method allows quantitative assessment of erythropoiesis, thus facilitating differential diagnosis in clinical practice. (L.O.). 3 figs., 1 tab., 22 refs

  12. Testing of cobalt-free alloys for valve applications using a special test loop

    International Nuclear Information System (INIS)

    Benhamou, C.

    1992-01-01

    Considering that use of cobalt alloys should be avoided as far as possible in PWR components, a programme aimed at establishing the performance of cobalt-free alloys has been performed for valve applications, where cobalt alloys are mainly used. Referring to past work, two types of cobalt-free alloys were selected: Ni-Cr-B-Si and Ni-Cr-Fe alloys. Cobalt-free valves' behaviour has been evaluated comparatively with cobalt valves by implementation of a programme in a special PWR test loop. At the issue of the loop test programme, which included endurance, thermal shock and erosion tests, cobalt-free alloys candidate to replace cobalt alloys are proposed in relation with valve type (globe valve and swing check valve). The following was established: (i) Colmonoy 4-26 (Ni-Cr-B-Si alloy) and Cenium Z20 (Ni-Cr-Fe alloy) deposited by plasma arc process were found suitable for use in 3inch swing check valves; (ii) for integral parts acting as guide rings, Nitronic 60 and Cesium Z20/698 were tested successfully; (iii) for small-bore components such as 2inch globe valves, no solution can yet be proposed; introduction of cobalt-free alloys is dependent on the development of automatic advanced arc surfacing techniques applied to small-bore components

  13. PENYERAPAN COBALT-60 DARI AIR OLEH TANAMAN KIAPU (Pistia stratiotes L.)

    OpenAIRE

    Lailatul Nuzzulul Safitri; Poppy Intan Tjahaja; Ida Bagus Made Suryatika

    2015-01-01

    Has conducted research Cobalt-60 radionuclide uptake by plants kiapu (Pistia stratiotes L.) found in many waters. The purpose of the study was to determine the value of the transfer factor on plant kiapu to Cobalt-60 in water. The study was conducted by growing plants on media kiapu gutter water in pots with the height 35 cm and diameter 11,5 cm containing Cobalt-60. The amount of Cobalt - 60 is absorbed and accumulated by the plant parts, i.e. roots and leaves, was observed by measuring the ...

  14. Research about combination of Gamma Knife and cobalt-60 radiation therapy to treat hypophysoma

    International Nuclear Information System (INIS)

    Xing Yueming; Zhao Xinping; Song Xiang; Wu Wei; Huang Bai

    2003-01-01

    Objective: To probe the therapeutic effectiveness of combination of Gamma Knife and cobalt-60 radiotherapy. Methods: 80 Hypophysoma patients who have been randomly grouped into two groups. Combination of Gamma Knife and cobalt-60 radiotherapy group and single Gamma knife group. Results: The therapeutic effectiveness of combination of Gamma Knife and cobalt-60 radiation therapy group was higher than that of single Gamma Knife group. Conclusion: The hospital that treat Hypophysoma with single Gamma Knife should add cobalt-60 radiotherapy in order to increase the local Hypophysoma dose

  15. Competitive Adsorption-Assisted Formation of One-Dimensional Cobalt Nanochains with High CO Hydrogenation Activity

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Xin [State; Ren, Zhibo [State; Institute; Zhu, Xiaolin [State; Zhang, Qinwei [State; Mei, Donghai [Institute; Chen, Biaohua [State

    2017-10-31

    In the present work, cobalt nanochains have been successfully synthesized by a novel co assisted self-assembling formation strategy. A dramatic morphology transformation from cobalt nanoparticles to nanochains are observed when co molecules were introduced into the synthetic system. DFT calculations further confirm that competitive co-adsorbed co and oleylamine over the cobalt nanoparticles facilitates the formation of cobalt nanochains, which show higher co hydrogenation performance. The present work provides a new strategic and promising method for controllable synthesis of catalyst nanomaterials with the preferred surface structure and morphology.

  16. HLA -A, -B, -C and -DR antigens in individuals with sensitivity to cobalt

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, T; Rystedt, I; Saefwenberg, J; Egle, I

    1984-01-01

    In a skin investigation of 853 individuals working with hard metal manufacturing 39 cases of cobalt allergy were found. Thirty-five of the individuals with cobalt sensitivity and 102 matched controls were HLA-A, -B, -C and -DR typed. No significantly deviating HLA antigen frequencies were observed when the two groups were compared. Thus, there are no signs that a certain HLA antigen would dispose to cobalt allergy. In the cobalt sensitive group the B7 positive individuals showed particularly often simultaneous reactions to other contact allergens. The B12 positive individuals had low reactivity while the A28 positive showed high reactivity.

  17. Migratory Insertion of Hydrogen Isocyanide in the Pentacyano(methyl)cobaltate(III) Anion

    DEFF Research Database (Denmark)

    Kofod, Pauli; Harris, Pernille Hanne; Larsen, Sine

    2003-01-01

    The preparation of the pentacyano(iminiumacetyl)cobaltate(III) anion and its N-methyl and N,N-dimethyl derivatives is reported. The iminiumacetyl group is formed by migratory insertion of cis hydrogen isocyanide in the pentacyano(methyl)cobaltate(III) anion. The new compounds have been spectrosco......The preparation of the pentacyano(iminiumacetyl)cobaltate(III) anion and its N-methyl and N,N-dimethyl derivatives is reported. The iminiumacetyl group is formed by migratory insertion of cis hydrogen isocyanide in the pentacyano(methyl)cobaltate(III) anion. The new compounds have been...

  18. Fracture and Residual Characterization of Tungsten Carbide Cobalt Coatings on High Strength Steel

    National Research Council Canada - National Science Library

    Parker, Donald S

    2003-01-01

    Tungsten carbide cobalt coatings applied via high velocity oxygen fuel thermal spray deposition are essentially anisotropic composite structures with aggregates of tungsten carbide particles bonded...

  19. Nitrogen induced ferromagnetism in Cobalt doped BaTiO3

    Directory of Open Access Journals (Sweden)

    Chandrima Mitra

    2012-09-01

    Full Text Available The electronic structure and magnetism of Cobalt doped BaTiO3 (BaTi1−xCoxO3 is investigated. Substitutional Nitrogen on an Oxygen site is found to play an important role in inducing net magnetic moments in the system. The presence of a Nitrogen atom as nearest neighbour to a Cobalt atom is crucial in producing spin splitting of both the Nitrogen and Cobalt states thereby introducing a net local magnetic moment. The introduction of Nitrogen is further found to enhance ferromagnetic interactions between Cobalt atoms.

  20. Electron transfer reactions of macrocyclic compounds of cobalt

    Energy Technology Data Exchange (ETDEWEB)

    Heckman, R.A.

    1978-08-01

    The kinetics and mechanisms of reduction of H/sub 2/O/sub 2/, Br/sub 2/, and I/sub 2/ by various macrocyclic tetraaza complexes of cobalt(II), including Vitamin B/sub 12r/, were studied. The synthetic macrocycles studied were all 14-membered rings which varied in the degree of unsaturation,substitution of methyl groups on the periphery of the ring, and substitution within the ring itself. Scavenging experiments demonstrated that the reductions of H/sub 2/O/sub 2/ produce free hydroxyl radicals only in the case of Co((14)ane)/sup 2 +/ but with none of the others. In the latter instances apparently H/sub 2/O/sub 2/ simultaneously oxidizes the metal center and the ligand. The reductions of Br/sub 2/ and I/sub 2/ produce an aquohalocobalt(III) product for all reductants (except B/sub 12r/ + Br/sub 2/, which was complicated by bromination of the corrin ring). The mechanism of halogen reduction was found to involve rate-limiting inner-sphere electron transfer from cobalt to halogen to produce a dihalide anion coordinated to the cobalt center. This intermediate subsequently decomposes in rapid reactions to halocobalt(III) and halogen atom species or reacts with another cobalt(II) center to give two molecules of halocobalt(III). The reductions of halomethylcobaloximes and related compounds and diamminecobaloxime by Cr/sup 2 +/ were also studied. The reaction was found to be biphasic in all cases with the reaction products being halomethane (for the halomethylcobaloximes), Co/sup 2 +/ (in less than 100 percent yield), a Cr(III)-dimethylglyoxime species, a small amount of free dmgH/sub 2/, and a highly-charged species containing both cobalt and chromium. The first-stage reaction occurs with a stoichiometry of 1:1 producing an intermediate with an absorption maximum at 460 nm for all starting reagents. The results were interpreted in terms of inner-sphere coordination of the cobaloxime to the Cr(II) and electron transfer through the oxime N-O bond.

  1. Black and green pigments based on chromium-cobalt spinels

    Energy Technology Data Exchange (ETDEWEB)

    Eliziario, Sayonara A., E-mail: sayonaraea@iq.unesp.br [Departamento de Fisico-Quimica, Instituto de Quimica, UNESP - Univ Estadual Paulista, Araraquara, SP (Brazil); Departamento de Quimica, CCEN, Universidade Federal da Paraiba, Campus I, Joao Pessoa, PB (Brazil); Andrade, Jeferson M. de [Departamento de Quimica, CCEN, Universidade Federal da Paraiba, Campus I, Joao Pessoa, PB (Brazil); Lima, Severino J.G. [Departamento de Engenharia Mecanica, CT, Universidade Federal da Paraiba, Campus I, Joao Pessoa, PB (Brazil); Paskocimas, Carlos A. [Universidade Federal do Rio Grande do Norte, CT, Natal, RN (Brazil); Soledade, Luiz E.B. [Departamento de Quimica, CCEN, Universidade Federal da Paraiba, Campus I, Joao Pessoa, PB (Brazil); Hammer, P.; Longo, E. [Departamento de Fisico-Quimica, Instituto de Quimica, UNESP - Univ Estadual Paulista, Araraquara, SP (Brazil); Souza, Antonio G.; Santos, Ieda M.G. [Departamento de Quimica, CCEN, Universidade Federal da Paraiba, Campus I, Joao Pessoa, PB (Brazil)

    2011-09-15

    Highlights: {yields} Co(Co{sub 2-x}Cr{sub x})O{sub 4} powders with different chromium concentrations (x = 0, 0.25 and 1) were prepared by the polymeric precursor method. {yields} Co(CoCr)O{sub 4} and Co(Co{sub 1.75}Cr{sub 0.25})O{sub 4} displayed a dark color and CoCr{sub 2}O{sub 4} was green. {yields} The colors were related to the different oxidation states of Cr and Co. {yields} Cobalt enrichment result in an increasing presence of Co(III) and a decrease amount of Cr(VI). - Abstract: Chromium and cobalt oxides are widely used in the manufacture of industrial pigments. In this work, the Co(Co{sub 2-x}Cr{sub x})O{sub 4} powders with different chromium concentrations (x = 0, 0.25 and 1) were synthesized by the polymeric precursor method, heat treatment between 600 and 1000 deg. C. These powders were characterized by X-ray diffraction, infrared spectroscopy, colorimetry, UV-vis absorption and X-ray photoelectron spectroscopies. Even with the addition of chromium, the XRD patterns revealed that all powders crystallize in a single spinel cubic structure. The spinels with higher cobalt amount, Co(CoCr)O{sub 4} and Co(Co{sub 1.75}Cr{sub 0.25})O{sub 4}, displayed a dark color, without the Co{sup 3+} reduction observed in Co{sub 3}O{sub 4} between 900 and 950 deg. C. The spinel with higher chromium amount, CoCr{sub 2}O{sub 4}, was green. The colors were directly related to the occupation of tetrahedral and octahedral sites by the chromophores, as well as to the different oxidation states of chromium and cobalt. The different optical band gap values estimated from UV-vis spectra suggested the existence of intermediary energy levels within the band gap. X-ray photoelectron spectroscopy confirmed an increasing presence of Co(III) and a decreasing amount of Cr(VI) with cobalt enrichment.

  2. Structural modifications under reactive atmosphere of cobalt catalysts; Modifications structurales sous atmospheres reactionnelles de catalyseurs a base de cobalt

    Energy Technology Data Exchange (ETDEWEB)

    Ducreux, O.

    1999-11-23

    The purpose of this work was to develop in situ methods under reactive dynamic conditions (XRD and Fourier transform infrared spectroscopy) to describe the active phase structure in order to understand Fischer-Tropsch catalyst behaviour and improve the natural gas conversion process performance. Experiments were designed to correlate structural modifications with catalytic results. The effect of ruthenium used as a promoter has also been studied. The impregnation process increases cobalt-support interaction. The presence of ruthenium promoter reduces this effect. Interactions between Co{sub 3}O{sub 4} oxide and support play an important role in the reducibility of cobalt and in the resulting metal structure. This in turn strongly influences the catalytic behaviour. Our results show a close correlation between structure modification and reactivity in the systems studied. Cobalt metal and CO can react to form a carbide Co{sub 2}C under conditions close to those of the Fischer-Tropsch synthesis. This carbide formation seems to be related to a deactivation process. The presence of interstitial carbon formed by dissociation of CO is proposed as a key to understanding the mechanism of the Fischer-Tropsch reaction. A specific catalyst activation treatment was developed to increase the catalytic activity. This work permits correlation of materials structure with their chemical properties and demonstrates the contribution of in situ physico-chemical characterisation methods to describe solids under reactive atmosphere. (author)

  3. Nanotoxicity of cobalt induced by oxidant generation and glutathione depletion in MCF-7 cells.

    Science.gov (United States)

    Akhtar, Mohd Javed; Ahamed, Maqusood; Alhadlaq, Hisham A; Alshamsan, Aws

    2017-04-01

    There are very few studies regarding the biological activity of cobalt-based nanoparticles (NPs) and, therefore, the possible mechanism behind the biological response of cobalt NPs has not been fully explored. The present study was designed to explore the potential mechanisms of the cytotoxicity of cobalt NPs in human breast cancer (MCF-7) cells. The shape and size of cobalt NPs were characterized by scanning and transmission electron microscopy (SEM and TEM). The crystallinity of NPs was determined by X-ray diffraction (XRD). The dissolution of NPs was measured in phosphate-buffered saline (PBS) and culture media by atomic absorption spectroscopy (AAS). Cytotoxicity parameters, such as [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT), neutral red uptake (NRU), and lactate dehydrogenase (LDH) release suggested that cobalt NPs were toxic to MCF-7 cells in a dose-dependent manner (50-200μg/ml). Cobalt NPs also significantly induced reactive oxygen species (ROS) generation, lipid peroxidation (LPO), mitochondrial outer membrane potential loss (MOMP), and activity of caspase-3 enzymes in MCF-7 cells. Moreover, cobalt NPs decreased intracellular antioxidant glutathione (GSH) molecules. The exogenous supply of antioxidant N-acetyl cysteine in cobalt NP-treated cells restored the cellular GSH level and prevented cytotoxicity that was also confirmed by microscopy. Similarly, the addition of buthionine-[S, R]-sulfoximine, which interferes with GSH biosynthesis, potentiated cobalt NP-mediated toxicity. Our data suggested that low solubility cobalt NPs could exert toxicity in MCF-7 cells mainly through cobalt NP dissolution to Co 2+ . Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Cobalt deficiency effects on trace elements, hormones and enzymes involved in energy metabolism of cattle.

    Science.gov (United States)

    Stangl, G I; Schwarz, F J; Kirchgessner, M

    1999-03-01

    This study was conducted to investigate the physiological consequences of long-term moderate cobalt deficiency in beef cattle, which have not hitherto been studied in detail. Cobalt deficiency was induced in cattle by feeding two groups of animals either a basal corn silage-based diet that was moderately low in cobalt (83 micrograms Co/kg), or the same diet supplemented with cobalt to a total of 200 micrograms per kg, for 43 weeks. Cobalt deficiency was induced, as judged by inappetance, diminished growth gain and a markedly reduced vitamin B12 status in serum and liver. The long-term cobalt deprivation which was primarily a combination of reduced feed intake and a tissue vitamin B12 deficiency did not show evidence of a significant dysfunction of energy metabolism. The activities of glucose-6-phosphate dehydrogenase and cytochrome oxidase in liver remained unaffected by cobalt deficiency, nor was there a significant change in serum glucose level of cattle on the cobalt-deprived diet. However, analysis of thyroid hormone status indicated a slight reduction of type I thyroxine monodeiodinase activity in liver accompanied by a significant reduction of the triiodothyronine level in serum. The diminished liver vitamin B12 level resulted in significantly reduced folate level in this tissue, reduced concentrations of heme-depending blood parameters. Moreover cobalt deficiency or rather vitamin B12 deficiency was accompanied by a dramatic accumulation of the trace elements iron and nickel in liver. These results indicate that long-term moderate cobalt deficiency may induce a number of physiological changes in cattle, but a follow-up study, which excluded different feed levels by including a pair-fed control group, will be necessary to actually obtain the single effect of cobalt deficiency in cattle.

  5. Multilevel resonance analysis of sup 59 Co neutron transmission measurements

    Energy Technology Data Exchange (ETDEWEB)

    De Saussure, G.; Larson, N.M.; Harvey, J.A.; Hill, N.W. (Oak Ridge National Lab., TN (United States))

    1992-07-01

    Large discrepancies exist between the recent high-resolution neutron transmission data of {sup 59}Co measured at the Oak Ridge Electron Linear Accelerator (ORELA) and transmissions computed from the resolved resonance parameters of the nuclear data collection ENDF/B-VI. In order to provide new resonance parameters consistent with these data, the transmission measurements have been analyzed with the computer code SAMMY in the energy range 200 eV to 100 keV. The resonance parameters reported in this paper provide an accurate total cross section from 10{sup -5} eV to 100 keV and correctly reproduce the thermal capture cross section. Thermal cross-section values and related quantities are also reviewed here. (author).

  6. Young Cluster Berkeley 59: Properties, Evolution, and Star Formation

    Science.gov (United States)

    Panwar, Neelam; Pandey, A. K.; Samal, Manash R.; Battinelli, Paolo; Ogura, K.; Ojha, D. K.; Chen, W. P.; Singh, H. P.

    2018-01-01

    Berkeley 59 is a nearby (∼1 kpc) young cluster associated with the Sh2-171 H II region. We present deep optical observations of the central ∼2.5 × 2.5 pc2 area of the cluster, obtained with the 3.58 m Telescopio Nazionale Galileo. The V/(V–I) color–magnitude diagram manifests a clear pre-main-sequence (PMS) population down to ∼0.2 M ⊙. Using the near-infrared and optical colors of the low-mass PMS members, we derive a global extinction of A V = 4 mag and a mean age of ∼1.8 Myr, respectively, for the cluster. We constructed the initial mass function and found that its global slopes in the mass ranges of 0.2–28 M ⊙ and 0.2–1.5 M ⊙ are ‑1.33 and ‑1.23, respectively, in good agreement with the Salpeter value in the solar neighborhood. We looked for the radial variation of the mass function and found that the slope is flatter in the inner region than in the outer region, indicating mass segregation. The dynamical status of the cluster suggests that the mass segregation is likely primordial. The age distribution of the PMS sources reveals that the younger sources appear to concentrate close to the inner region compared to the outer region of the cluster, a phenomenon possibly linked to the time evolution of star-forming clouds. Within the observed area, we derive a total mass of ∼103 M ⊙ for the cluster. Comparing the properties of Berkeley 59 with other young clusters, we suggest it resembles more closely the Trapezium cluster.

  7. The cobalt spot test - further insights into its performance and use

    DEFF Research Database (Denmark)

    Midander, Klara; Julander, Anneli; Skare, Lizbet

    2013-01-01

    A spot test was recently developed for easy and rapid testing to detect whether cobalt is available on surfaces in contact with skin.......A spot test was recently developed for easy and rapid testing to detect whether cobalt is available on surfaces in contact with skin....

  8. Computer simulation of the vertical growth of subsurface cobalt nanoclusters in gold

    NARCIS (Netherlands)

    Kulikov, D.V.; Kurnosikov, O.; Sicot, M.V.; Trushin, Yu.V.

    2009-01-01

    The vertical growth of nanodimensional cobalt clusters buried under the surface of a gold substrate has been studied using computer simulation methods with allowance for the interdiffusion of Au and Co atoms and the fields of elastic stresses generated by cobalt clusters in the gold matrix. The

  9. Design electronic of manual control for cobalt unit Alcyon II of the National Center of Radiotherapy

    International Nuclear Information System (INIS)

    Morraz V, E.; Campos, X.

    2002-01-01

    A manual control for the cobalt unit, of French production, it was designed by the team of electronic of the national center of radiotherapy with materials found in the national trade. The control has the same characteristics that the original one and it is also adapted a switch from which you can control the lights of the room of the cobalt

  10. Effect of Cobalt Source on the Catalyst Reducibility and Activity of ...

    African Journals Online (AJOL)

    The effect of cobalt precursor (nitrate, acetate and chloride salts) on the catalyst reducibility and dispersion, ... balt catalysts (>5.0 wt%) prepared using ammonium cobalt ... heated from 323 K to 1073 K using a heating ramp of 10 K min–1.

  11. Enhanced activity of gold-supported cobalt oxide for the electrochemical evolution of oxygen.

    Science.gov (United States)

    Yeo, Boon Siang; Bell, Alexis T

    2011-04-13

    Scanning electron microscopy, linear sweep voltammetry, chronoamperometry, and in situ surface-enhanced Raman spectroscopy were used to investigate the electrochemical oxygen evolution reaction (OER) occurring on cobalt oxide films deposited on Au and other metal substrates. All experiments were carried out in 0.1 M KOH. A remarkable finding is that the turnover frequency for the OER exhibited by ∼0.4 ML of cobalt oxide deposited on Au is 40 times higher than that of bulk cobalt oxide. The activity of small amounts of cobalt oxide deposited on Pt, Pd, Cu, and Co decreased monotonically in the order Au > Pt > Pd > Cu > Co, paralleling the decreasing electronegativity of the substrate metal. Another notable finding is that the OER turnover frequency for ∼0.4 ML of cobalt oxide deposited on Au is nearly three times higher than that for bulk Ir. Raman spectroscopy revealed that the as-deposited cobalt oxide is present as Co(3)O(4) but undergoes progressive oxidation to CoO(OH) with increasing anodic potential. The higher OER activity of cobalt oxide deposited on Au is attributed to an increase in fraction of the Co sites present as Co(IV) cations, a state of cobalt believed to be essential for OER to occur. A hypothesis for how Co(IV) cations contribute to OER is proposed and discussed. © 2011 American Chemical Society

  12. Speciation analysis of cobalt in foods by high-performance liquid chromatography and neutron activation analysis

    International Nuclear Information System (INIS)

    Muto, Toshio; Koyama, Motoko

    1994-01-01

    A combined method by coupling high-performance liquid chromatography (HPLC, as a separation method) with neutron activation analysis (as a detection method) have been applied to the speciation analysis of cobalt in daily foods (e.g. egg, fish and milk). Cobalt species including free cobalt, vitamin B 12 and protein-bound cobalt were separated with a preparative HPLC and a centrifuge. Subsequently, the determination of cobalt in the separated species was made by neutron activation analysis. The results showed that the content of the total cobalt in the foods was found to lie in the range 0.4-11ng/g(0.4-11ppb) based on wet weight. The compositions of free cobalt, vitamin B 12 and protein-bound cobalt were ranged 16-43%, 55-73%, 2.3-17%, respectively. These experimental evidences suggest that the combination of HPLC and neutron activation analysis is expected to be a useful tool for speciation analysis of trace elements in biological as well as environmental materials. (author)

  13. New efficient catalyst for ammonia synthesis: barium-promoted cobalt on carbon

    DEFF Research Database (Denmark)

    Hagen, Stefan; Barfod, Rasmus; Fehrmann, Rasmus

    2002-01-01

    Barium-promoted cobalt catalysts supported on carbon exhibit higher ammonia activities at synthesis temperatures than the commercial, multipromoted iron catalyst and also a lower ammonia......Barium-promoted cobalt catalysts supported on carbon exhibit higher ammonia activities at synthesis temperatures than the commercial, multipromoted iron catalyst and also a lower ammonia...

  14. Self-subunit swapping occurs in another gene type of cobalt nitrile hydratase.

    Directory of Open Access Journals (Sweden)

    Yi Liu

    Full Text Available Self-subunit swapping is one of the post-translational maturation of the cobalt-containing nitrile hydratase (Co-NHase family of enzymes. All of these NHases possess a gene organization of , which allows the activator protein to easily form a mediatory complex with the α-subunit of the NHase after translation. Here, we discovered that the incorporation of cobalt into another type of Co-NHase, with a gene organization of , was also dependent on self-subunit swapping. We successfully isolated a recombinant NHase activator protein (P14K of Pseudomonas putida NRRL-18668 by adding a Strep-tag N-terminal to the P14K gene. P14K was found to form a complex [α(StrepP14K(2] with the α-subunit of the NHase. The incorporation of cobalt into the NHase of P. putida was confirmed to be dependent on the α-subunit substitution between the cobalt-containing α(StrepP14K(2 and the cobalt-free NHase. Cobalt was inserted into cobalt-free α(StrepP14K(2 but not into cobalt-free NHase, suggesting that P14K functions not only as a self-subunit swapping chaperone but also as a metallochaperone. In addition, NHase from P. putida was also expressed by a mutant gene that was designed with a order. Our findings expand the general features of self-subunit swapping maturation.

  15. Interface Controlled Oxidation States in Layered Cobalt Oxide Nanoislands on Gold

    DEFF Research Database (Denmark)

    Walton, Alexander; Fester, Jakob; Bajdich, Michal

    2015-01-01

    Layered cobalt oxides have been shown to be highly active catalysts for the oxygen evolution reaction (OER; half of the catalytic “water splitting” reaction), particularly when promoted with gold. However, the surface chemistry of cobalt oxides and in particular the nature of the synergistic effect...

  16. NMR spectroscopic determination of an equilibrium isotope effect on the hydration of cobalt(II)

    International Nuclear Information System (INIS)

    Evilia, R.F.; Saunders, M.

    1985-01-01

    A recently reported NMR method for the measurement of deuterium equilibrium isotope effects is applied to the hydration of the paramagnetic cobalt(II) ion. An isotope effect of about 1.3% is measured. A substantial difference between the intrinsic shift of H 2 O and D 2 O when coordinated to cobalt is also measured

  17. A Rapid Synthetic Method for the Preparation of Two Tris-Cobalt(III) Compounds.

    Science.gov (United States)

    Jackman, Donald C.; Rillema, D. Paul

    1989-01-01

    Reports a method of preparation for tris(ethylenediamine)cobalt(III) and tris(2,2'-bipyridine)cobalt(III) that will shorten the preparation time by approximately 3 hours. Notes the time for synthesis and isolation of compound one was 1 hour (yield 38 percent) while compound two took 50 minutes (yield 71%). (MVL)

  18. Cobalt supported on carbon nanofibers as catalysts for the Fischer-Tropsch synthesis

    NARCIS (Netherlands)

    Bezemer, G.L.

    2006-01-01

    The Fischer-Tropsch (FT) process converts synthesis gas (H2/CO) over a heterogeneous catalyst into hydrocarbons. Generally, cobalt catalysts supported on oxidic carriers are used for the FT process, however it appears to be difficult to obtain and maintain fully reduced cobalt particles. To overcome

  19. The Application of Moessbauer Emission Spectroscopy to Industrial Cobalt Based Fischer-Tropsch Catalysts

    International Nuclear Information System (INIS)

    Loosdrecht, J. van de; Berge, P. J. van; Craje, M. W. J.; Kraan, A. M. van der

    2002-01-01

    The application of Moessbauer emission spectroscopy to study cobalt based Fischer-Tropsch catalysts for the gas-to-liquids process was investigated. It was shown that Moessbauer emission spectroscopy could be used to study the oxidation of cobalt as a deactivation mechanism of high loading cobalt based Fischer-Tropsch catalysts. Oxidation was observed under conditions that are in contradiction with the bulk cobalt phase thermodynamics. This can be explained by oxidation of small cobalt crystallites or by surface oxidation. The formation of re-reducible Co 3+ species was observed as well as the formation of irreducible Co 3+ and Co 2+ species that interact strongly with the alumina support. The formation of the different cobalt species depends on the oxidation conditions. Iron was used as a probe nuclide to investigate the cobalt catalyst preparation procedure. A high-pressure Moessbauer emission spectroscopy cell was designed and constructed, which creates the opportunity to study cobalt based Fischer-Tropsch catalysts under realistic synthesis conditions.

  20. Sorption of cobalt and nickel on anaerobic granular sludges: isotherms and sequential extraction

    NARCIS (Netherlands)

    Hullebusch, van E.D.; Peerbolte, A.; Zandvoort, M.H.; Lens, P.N.L.

    2005-01-01

    The objective of this study was to investigate the sorption capacity and the fractionation of sorbed nickel and cobalt onto anaerobic granular sludges. Two different anaerobic granular sludges (non-fed, pH = 7) were loaded with nickel and cobalt in. adsorption experiments (monometal and competitive

  1. Correlation between thermal expansion and Seebeck coefficient in polycrystalline cobalt oxide (Co3O4)

    NARCIS (Netherlands)

    Broemme, A.D.D.

    1991-01-01

    Characteristics of the cobalt-oxide spinel Co3O4 are described. Spinel is the name for a certain crystal structure that is built up out of three sublattices; one sublattice contains, in this case, only oxygen ions, and the other two sublattices, tetrahedral and octahedral, contain the metal cobalt

  2. The effect of cobalt substitution on magnetic hardening of magnetite

    Energy Technology Data Exchange (ETDEWEB)

    Mozaffari, M., E-mail: mozafari@sci.ui.ac.ir [Department of Physics, Faculty of Science, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Hadadian, Y. [Physics Department, Razi University, Taghebostan, Kermanshah (Iran, Islamic Republic of); Aftabi, A. [Department of Physics, University of Kurdistan, Sanandaj 66177-15175 (Iran, Islamic Republic of); Oveisy Moakhar, M. [Physics Department, Razi University, Taghebostan, Kermanshah (Iran, Islamic Republic of)

    2014-03-15

    In this work cobalt-substituted magnetite (Co{sub x}Fe{sub 1−x}Fe{sub 2}O{sub 4}, x=0, 0.25, 0.50 and 0.75) nanoparticles were synthesized by coprecipitation method and their structural and magnetic properties were investigated. X-ray diffraction was carried out and the results show that all of the samples have single phase spinel structure. Microstructure of the samples was studied using a field emission scanning electron microscope and the results show that particle sizes of the prepared nanoparticles were uniform and in the 50–55 nm range. Room temperature magnetic properties of the nanoparticles were measured by an alternating gradient force magnetometer and the results revealed that substituting cobalt for iron in magnetite structure, changes the magnetite from a soft magnetic material to a hard one. So that coercivity changes from 0 (a superparamagnetic state) to 337 Oe (a hard magnetic material), which is a remarkable change. Curie temperatures of the samples were determined by recording their susceptibility-temperature (χ–T) curves and the results show that by increasing cobalt content, Curie temperature of the samples also increases. Also χ–T curves of the samples were recorded from above Curie temperature to room temperature (first cooling), while the curves in the second heating and second cooling have the same behaviour as the first cooling curve. The results depict that all samples have different behaviour in the first cooling and in the first heating processes. This shows remarkable changes of the cation distribution in the course of first heating. - Highlights: • It is possible to get Co substituted magnetite nanoparticles by coprecipitation method. • Prepared nanoparticles have different cation distribution in comparison with that of bulk counterparts. • Co substitution increases coercivity of the magnetite.

  3. Nanotoxicity of gold and gold-cobalt nanoalloy.

    Science.gov (United States)

    Girgis, E; Khalil, W K B; Emam, A N; Mohamed, M B; Rao, K V

    2012-05-21

    Nanotoxicology test of gold nanoparticles (Au NPs) and gold-cobalt (Au-Co) nanoalloy is an important step in their safety evaluation for biomedical applications. The Au and Au-Co NPs were prepared by reducing the metal ions using sodium borohydride (NaBH(4)) in the presence of polyvinyl pyrrolidone (PVP) as a capping material. The average size and shape of the nanoparticles (NPs) were characterized using high resolution transmission electron microscopy (HRTEM). Cobalt presence in the nanoalloy was confirmed by energy dispersive X-ray spectroscopy (EDX) analysis, and the magnetic properties of these particles were determined using a vibrating sample magnetometer (VSM). The Gold and gold-cobalt NPs of average size 15 ± 1.5 nm were administered orally to mice with a dose of 80, 160, and 320 mg/kg per body weight (bw) using gavages. Samples were collected after 7 and 14 days of the treatment. The results indicated that the Au-Co NPs were able to induce significant alteration in the tumor-initiating genes associated with an increase of micronuclei (MNs) formation and generation of DNA adduct (8-hydroxy-2-deoxyguanosine, 8-OHdG) as well as a reduction in the glutathione peroxidase activity. This action of Au-Co NPs was observed using 160 and 320 mg/kg bw at both time intervals. However, Au NPs had much lower effects than Au-Co NPs on alteration in the tumor-initiating genes, frequency of MNs, and generation of 8-OHdG as well as glutathione peroxidase activity except with the highest dose of Au NPs. This study suggests that the potential to cause in vivo genetic and antioxidant enzyme alterations due to the treatment by Au-Co nanoalloy may be attributed to the increase in oxidative stress in mice.

  4. Measurement with self-powered cobalt and cadmium detectors

    International Nuclear Information System (INIS)

    Azzoni, A.

    The principle of function is described and the characteristics are given of self-powered cobalt and cadmium neutron detectors. Requirements are summed up for the material used for these detectors, and the specific properties of used detectors are given. The calibration of developed self-powered detectors was carried out using the L 54 CESNEF reactor channels with a maximum output of 40 kW and a neutron flux of 10 10 to 10 12 n.cm -2 s -1 . The absolute measurement of neutron flux and gamma radiation doses in the channel were carried out at an output of 10 kW. The objective of calibration measurements with cadmium and cobalt detectors was to ascertain the promptness of detector response, to determine their sensitivity to neutrons and to gamma radiation, the effects of radiation on the material of the detectors and the contribution thereof on the resulting signal. Inside the CART irradiation channel of the ESSOR reactor three such detectors were used for the measurement of neutron flux and its fluctuations effected by coolant density fluctuations. The behaviour of the detectors was studied in a high neutron flux (10 14 n.cm -2 s -1 ) and at long-term irradiation. It was found that cobalt detectors may be used to advantage for measuring the neutron flux if prompt response is required. The high sensitivity to gamma radiation does, however, limit their uses. Cadmium detectors are sensitive to the neutron flux (currents of several mA with a neutron flux of approximately 10 14 n.cm -2 s -1 ) while response to gamma radiation is considerably limited. These detectors are advantageous for short-term use, such as neutron flux mapping and measuring fluctuations. (B.S.)

  5. Computational, electrochemical, and spectroscopic studies of two mononuclear cobaloximes: the influence of an axial pyridine and solvent on the redox behaviour and evidence for pyridine coordination to cobalt(I) and cobalt(II) metal centres†

    Science.gov (United States)

    Lawrence, Mark A. W.; Celestine, Michael J.; Artis, Edward T.; Joseph, Lorne S.; Esquivel, Deisy L.; Ledbetter, Abram J.; Cropek, Donald M.; Jarrett, William L.; Bayse, Craig A.; Brewer, Matthew I.; Holder, Alvin A.

    2018-01-01

    [Co(dmgBF2)2(H2O)2] 1 (where dmgBF2 = difluoroboryldimethylglyoximato) was used to synthesize [Co(dmgBF2)2(H2O)(py)]·0.5(CH3)2CO 2 (where py = pyridine) in acetone. The formulation of complex 2 was confirmed by elemental analysis, high resolution MS, and various spectroscopic techniques. The complex [Co(dmgBF2)2(solv)(py)] (where solv = solvent) was readily formed in situ upon the addition of pyridine to complex 1. A spectrophotometric titration involving complex 1 and pyridine proved the formation of such a species, with formation constants, log K = 5.5, 5.1, 5.0, 4.4, and 3.1 in 2-butanone, dichloromethane, acetone, 1,2-difluorobenzene/acetone (4 : 1, v/v), and acetonitrile, respectively, at 20 °C. In strongly coordinating solvents, such as acetonitrile, the lower magnitude of K along with cyclic voltammetry, NMR, and UV-visible spectroscopic measurements indicated extensive dissociation of the axial pyridine. In strongly coordinating solvents, [Co(dmgBF2)2(solv)(py)] can only be distinguished from [Co(dmgBF2)2(solv)2] upon addition of an excess of pyridine, however, in weakly coordinating solvents the distinctions were apparent without the need for excess pyridine. The coordination of pyridine to the cobalt(II) centre diminished the peak current at the Epc value of the CoI/0 redox couple, which was indicative of the relative position of the reaction equilibrium. Herein we report the first experimental and theoretical 59Co NMR spectroscopic data for the formation of Co(I) species of reduced cobaloximes in the presence and absence of py (and its derivatives) in CD3CN. From spectroelectrochemical studies, it was found that pyridine coordination to a cobalt(I) metal centre is more favourable than coordination to a cobalt(II) metal centre as evident by the larger formation constant, log K = 4.6 versus 3.1, respectively, in acetonitrile at 20 °C. The electrosynthesis of hydrogen by complexes 1 and 2 in various solvents demonstrated the dramatic effects of the axial

  6. Morphological and magnetic properties of cobalt nanoclusters electrodeposited onto HOPG

    International Nuclear Information System (INIS)

    Rivera, M.; Rios-Reyes, C.H.; Mendoza-Huizar, L.H.

    2008-01-01

    In this work, the morphological and magnetic properties of cobalt nanoclusters obtained from two different sulphate electrolyte solutions were studied. The aggregates were electrodeposited onto highly oriented pyrolytic graphite electrodes in overpotential conditions, in order to investigate the cationic influence on the final properties of the aggregates. In both cases, scanning electron microscopy and atomic force microscopy showed random isolated clusters on the electrode surface, where size variations were determined by the electrolyte solution. By using magnetic force microscopy, the distribution of the electrodeposited magnetic material was more clearly observed which gave some insights on the growth mechanism of these aggregates.

  7. Thermal Plasma Decomposition Of Nickel And Cobalt Compounds

    Directory of Open Access Journals (Sweden)

    Woch M.

    2015-06-01

    Full Text Available The paper presents the study on manufacturing of nickel and cobalt powders by thermal plasma decomposition of the carbonates of these metals. It was shown the dependence of process parameters and grain size of initial powder on the composition of final product which was ether metal powder, collected in the container as well as the nanopowder with crystallite size of 70 - 90 nm, collected on the inner wall of the reaction chamber. The occurrence of metal oxides in the final products was confirmed and discussed.

  8. Remanence properties of Co-precipitated cobalt ferrite

    International Nuclear Information System (INIS)

    Bueno-Baques, D.; Medina-Boudri, Angela; Matutes-Aquino, J.

    2001-01-01

    Isothermal remanent magnetization (IRM) and DC demagnetization (DCD) curves of a co-precipitated cobalt ferrite sample were obtained. From the IRM and DCD data, the Henkel plot was obtained and analyzed in the Preisach model framework. The Henkel plot data are below the Wohlfarth line that indicates a dominant local disorder (demagnetizing-like effect). Forward and reverse switching field distribution curves were obtained from differentiation of the IRM and DCD curves. The peak values of these switching field distributions differ by a factor of about 2.7

  9. Comparative metallurgical study of thick hard coatings without cobalt

    International Nuclear Information System (INIS)

    Clemendot, F.; Van Duysen, J.C.; Champredonde, J.

    1992-07-01

    Wear and corrosion of stellite type hard coatings for valves of the PWR primary system raise important problems of contamination. Substitution of these alloys by cobalt-free hard coatings (Colmonoy 4 and 4.26, Cenium 36) should allow to reduce this contamination. A comparative study (chemical, mechanical, thermal, metallurgical), as well as a corrosion study of these coatings were carried out. The results of this characterization show that none of the studied products has globally characteristics as good as those of grade 6 Stellite currently in service

  10. Absolute exposure determination of cobalt-60 gamma radiation

    International Nuclear Information System (INIS)

    Ahmad, S.S.; Ali, A.; Orfi, S.D.

    1986-02-01

    The report describes the procedure for the determination of absolute exposure for Cobalt-60 gamma radiation. A graphite cavity chamber, nominal volume of 1 cm 3 , manufactured by Austrian Research Centre Seibersdorf has been used. The exposure rate at reference distance determined with the graphite chamber was compared with mean exposure rate measured with NPL-Therapy level X-ray exposure meter normalized to same date. An agreement of 0.39% was found between the two measuring systems, which seems to be very encouraging and quite satisfactory. (authors)

  11. Coordination compounds of cobalt and cadmium with isobutyric acid amide

    International Nuclear Information System (INIS)

    Tsivadze, A.Yu.; Ivanova, I.S.; Solovkina, O.A.

    1983-01-01

    Coordination compounds of cobalt and cadmium with isobutyric acid amide (IBAA) of Co(NCS) 2 x(IBAA) 2 (H 2 O) 2 , CoCl 2 (IBAA) 4 , CoI 2 (IBAA) 8 (H 2 O) 2 , CdI 2 (IBAA) 2 composition have been synthesized and characterized. Their infrared absorption spectra (200-400 cm -1 ), electron reflection spectra (200-750 nm) were studied. It is shown that in all compounds there are IBAA molecUles coordinated through an oxygen atom. Thiocyanogroups are coordinated throUgh nitrogen atoms

  12. Economics of gamma processing in cobalt-60 irradiation facilities

    International Nuclear Information System (INIS)

    Gay, H. G.; Kotler, J. G.

    1985-01-01

    Gamma processing by cobalt-60 is well established. However, since irradiation of food is relatively new from the commercial point of view, it is important to assess costs of gamma irradiation in the context of food processing. Five different types of AECL-RCC irradiation equipment are examined in terms of their throughputs, and capital and operating costs. Using these figures, costs of irradiation of nine types of food products are presented. In general, these represent about 2-10% of the wholesale cost of these products

  13. Preliminary results about Electrodeposition of Cobalt at laboratory level

    International Nuclear Information System (INIS)

    Cornejo, N.

    1992-01-01

    As of an organic compound, an extraction and Cobalt electrodeposition method had been developed as a part of fabrication aim of a sealed radioactive source with objective to the construction of density meter prototype. It was performed preliminary test of electrodeposition in the laboratory level in a simple cell. The used electrolyte had been a sulphate solution obtained by extraction of an organic solution. It is obtained a Co film by electrodeposition at 55 o C temperature and with an approximately Co concentration in 70 g/lt. (Author) 3 refs., 1 fig., 1 tab

  14. Synthesis and properties of nickel cobalt boron nanoparticles

    Science.gov (United States)

    Patel, J.; Pankhurst, Q. A.; Parkin, I. P.

    2005-01-01

    Amorphous cobalt nickel boride nanoparticles were synthesised by chemical reduction synthesis in aqueous solution. Careful control of synthesis conditions and post reaction oxidation enabled the nanoparticles to be converted into a core-shell structure comprising of an amorphous Co-Ni-B core and an outer metal oxide sheet. These particles had interesting magnetic properties including saturation magnetisations and coercivities of the order of 80 emu/g and 170 Oe respectively, making them suitable for a potential use as an exchange-pinned magnetic material.

  15. TECHNOLOGY DEVELOPMENT FOR IRON AND COBALT FISCHER-TROPSCH CATALYSTS

    Energy Technology Data Exchange (ETDEWEB)

    Burtron H. Davis

    1999-01-30

    The effects of copper on Fischer-Tropsch activity, selectivity and water-gas shift activity were studied over a wide range of syngas conversion. Three catalyst compositions were prepared for this study: (a) 100Fe/4.6Si/1.4K, (b) 100Fe/4.6Si/0.10Cu/1.4K and (c) 100Fe/4.6Si/2.0Cu/1.4K. The results are reported in Task 2. The literature review for cobalt catalysts is approximately 90% complete. Due to the size of the document, it has been submitted as a separate report labeled Task 6.

  16. Synthesis and characterization of cobalt/gold bimetallic nanoparticles

    International Nuclear Information System (INIS)

    Cheng, Guangjun; Hight Walker, Angela R.

    2007-01-01

    Cobalt/gold (Co/Au) bimetallic nanoparticles are prepared by chemically reducing gold (III) chloride to gold in the presence of pre-synthesized Co nanoparticles. Transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption spectrometry, and a superconducting quantum interference device (SQUID) magnetometer have been used to characterize as-prepared bimetallic nanoparticles. Our findings demonstrate Au not only grows onto Co nanoparticles, forming a surface coating, but also diffuses into Co nanoparticles. The introduction of Au alters the crystalline structure of Co nanoparticles and changes their magnetic properties. Dodecanethiols induce a reorganization of as-prepared Co/Au bimetallic nanoparticles

  17. The development of cobalt-base alloy ball bearing

    International Nuclear Information System (INIS)

    Yu Xinshui; Chen Jianting; Wang Zaishu; Wang Ximei; Huang Chongming.

    1986-01-01

    The main technologies and experiences in developing a Cobalt-base alloy ball bearing are described. In the hardfacing of bearing races, a lower-hardness alloy of type St-6 is used rather than an alloy with hardness similar to that of the ball and finally the hardness of race is increased to match that of the ball by heat treatment. This improvement has certain advantages. The experience of whole developing technology indicates that strict control of the technology in the bearing-race hardfacing is the key problem in the quality assurance of bearings

  18. Electrochemical Cobalt-Catalyzed C-H Activation.

    Science.gov (United States)

    Sauermann, Nicolas; Meyer, Tjark H; Ackermann, Lutz

    2018-06-19

    Carbon-heteroatom bonds represent omnipresent structural motifs of the vast majority of functionalized materials and bioactive compounds. C-H activation has emerged as arguably the most efficient strategy to construct C-Het bonds. Despite of major advances, these C-H transformations were largely dominated by precious transition metal catalysts, in combination with stoichiometric, toxic metal oxidants. Herein, we discuss the recent evolution of cobalt-catalyzed C-H activations that enable C-Het formations with electricity as the sole sustainable oxidant until May 2018. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Substitution of cobalt alloying in PWR primary circuit gate valves

    International Nuclear Information System (INIS)

    Cachon, L.; Sudreau, F.; Brunel, L.

    1995-01-01

    The object of this study is qualify cobalt-free alternative alloys for valve applications. This paper focus on tribological characterization of numerous coatings is done by using the first one, of a classical type. Then tests are performed with the second one which simulates solicitations supported by gate valves in primary circuit of PWR. 35% Ni-Cr - 65% Cr 3 C 2 coating, deposited by detonation gun technology, gives us hope to find a substitute of Stelite 6. (author). 5 refs., 16 figs., 2 tabs

  20. Fabrication and analysis of ordered magnetic cobalt nanoparticles; Herstellung und Untersuchung geordneter magnetischer Kobaltnanoteilchen

    Energy Technology Data Exchange (ETDEWEB)

    Zuern, Klaus P.

    2009-12-17

    In the dissertation on hand monodisperse, wellordered magnetic cobalt and cobalt hydride nanoparticles have been produced and investigated magnetically. The preparation was achieved by diblock-copolymer-micelles filled with cobalt salt, from which nanoparticles of elementary cobalt respectively cobalt hydride were generated in different steps of the procedure. It was evident that the cobalthydride generated by the hydrogen plasma was surprisingly stable. It could even be taken into consideration as a hydrogen storage device for fuel cell. The magnetic properties of the particles has been investigated by x-ray magnetic circular dichroism (XMCD). In addition it was evident, that it was principally impossible to investigate a film layered on a substrate with a SQUID-magnetometer, if this film produces only a small signal as well absolutely as relatively to the magnetically measured total moment of the sample. (orig.)

  1. Facile fabrication of cobalt oxalate nanostructures with superior specific capacitance and super-long cycling stability

    Science.gov (United States)

    Cheng, Guanhua; Si, Conghui; Zhang, Jie; Wang, Ying; Yang, Wanfeng; Dong, Chaoqun; Zhang, Zhonghua

    2016-04-01

    Transition metal oxalate materials have shown huge competitive advantages for applications in supercapacitors. Herein, nanostructured cobalt oxalate supported on cobalt foils has been facilely fabricated by anodization, and could directly serve as additive/binder-free electrodes for supercapacitors. The as-prepared cobalt oxalate electrodes present superior specific capacitance of 1269 F g-1 at the current density of 6 A g-1 in the galvanostatic charge/discharge test. Moreover, the retained capacitance is as high as 87.2% as the current density increases from 6 A g-1 to 30 A g-1. More importantly, the specific capacitance of cobalt oxalate retains 91.9% even after super-long cycling of 100,000 cycles. In addition, an asymmetric supercapacitor assembled with cobalt oxalate (positive electrode) and activated carbon (negative electrode) demonstrates excellent capacitive performance with high energy density and power density.

  2. All projects related to | Page 59 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... AFRICA SOUTH OF SAHARA, BUSINESS ORGANIZATION, RURAL AREAS, ... This project aims to alleviate food insecurity and malnutrition in Colombia. ... for Therapeutic and Complementary Foods for Children in Vietnam (CIFSRF Phase 2) ... using large-scale fermentation technologies to target urban consumers.

  3. CERN: Fixed target targets

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-03-15

    Full text: While the immediate priority of CERN's research programme is to exploit to the full the world's largest accelerator, the LEP electron-positron collider and its concomitant LEP200 energy upgrade (January, page 1), CERN is also mindful of its long tradition of diversified research. Away from LEP and preparations for the LHC proton-proton collider to be built above LEP in the same 27-kilometre tunnel, CERN is also preparing for a new generation of heavy ion experiments using a new source, providing heavier ions (April 1992, page 8), with first physics expected next year. CERN's smallest accelerator, the LEAR Low Energy Antiproton Ring continues to cover a wide range of research topics, and saw a record number of hours of operation in 1992. The new ISOLDE on-line isotope separator was inaugurated last year (July, page 5) and physics is already underway. The remaining effort concentrates around fixed target experiments at the SPS synchrotron, which formed the main thrust of CERN's research during the late 1970s. With the SPS and LEAR now approaching middle age, their research future was extensively studied last year. Broadly, a vigorous SPS programme looks assured until at least the end of 1995. Decisions for the longer term future of the West Experimental Area of the SPS will have to take into account the heavy demand for test beams from work towards experiments at big colliders, both at CERN and elsewhere. The North Experimental Area is the scene of larger experiments with longer lead times. Several more years of LEAR exploitation are already in the pipeline, but for the longer term, the ambitious Superlear project for a superconducting ring (January 1992, page 7) did not catch on. Neutrino physics has a long tradition at CERN, and this continues with the preparations for two major projects, the Chorus and Nomad experiments (November 1991, page 7), to start next year in the West Area. Delicate neutrino oscillation effects could become visible for the first

  4. The efficacy of radiotherapy for 59 patients with vertebral hemangioma

    International Nuclear Information System (INIS)

    Qian Liting; Liu Xinfan; Li Yexiong; Yu Zihao; Yin Weibo

    2004-01-01

    Objective: To investigate the indication, total dose and efficacy of radiotherapy for vertebral hemangiomas. Methods: Between 1967 and 2000, 59 patients (36 female, 23 male) with vertebral hemangioma were treated with deep X-ray, electron beam, 60 Co or 6-8MV X-ray with a total dose ranging from 28 to 90 Gy and a median of 40 Gy. Results: Of the 54 evaluable cases, the overall response rate was 87.0%. The response rates were 90.2% and 83.3%, respectively, for patients treated with 34-40 Gy and more than 40 Gy (χ 2 =0.41, P=0.608). Among the 9 patients with paraplegic patients, 4 achieved complete response, 4 partial response, and only one showed no response to the treatment. Conclusions: Radiotherapy is effective and safe for symptomatic vertebral hemangioma, on condition of a suitable total dose range of 30 to 40 Gy. Patients with asymptomatic or minor symptomatic lesion should be watched and followed rather than giving immediate treatment. Radiation therapy shows slow and delayed improvement in vertebral hemangioma and the symptoms are gradually relieved or disappear in three months to seven years with a median interval of 1.5 years, even though diagnostic images show no or only minor changes after treatment

  5. CERN: Fixed target targets

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Full text: While the immediate priority of CERN's research programme is to exploit to the full the world's largest accelerator, the LEP electron-positron collider and its concomitant LEP200 energy upgrade (January, page 1), CERN is also mindful of its long tradition of diversified research. Away from LEP and preparations for the LHC proton-proton collider to be built above LEP in the same 27-kilometre tunnel, CERN is also preparing for a new generation of heavy ion experiments using a new source, providing heavier ions (April 1992, page 8), with first physics expected next year. CERN's smallest accelerator, the LEAR Low Energy Antiproton Ring continues to cover a wide range of research topics, and saw a record number of hours of operation in 1992. The new ISOLDE on-line isotope separator was inaugurated last year (July, page 5) and physics is already underway. The remaining effort concentrates around fixed target experiments at the SPS synchrotron, which formed the main thrust of CERN's research during the late 1970s. With the SPS and LEAR now approaching middle age, their research future was extensively studied last year. Broadly, a vigorous SPS programme looks assured until at least the end of 1995. Decisions for the longer term future of the West Experimental Area of the SPS will have to take into account the heavy demand for test beams from work towards experiments at big colliders, both at CERN and elsewhere. The North Experimental Area is the scene of larger experiments with longer lead times. Several more years of LEAR exploitation are already in the pipeline, but for the longer term, the ambitious Superlear project for a superconducting ring (January 1992, page 7) did not catch on. Neutrino physics has a long tradition at CERN, and this continues with the preparations for two major projects, the Chorus and Nomad experiments (November 1991, page 7), to start next year in the West Area. Delicate neutrino oscillation effects could become

  6. Electron capture Auger aftereffect of ammine cobalt complex

    International Nuclear Information System (INIS)

    Harada, Masayuki; Sano, Hirotoshi

    1976-01-01

    The study of ammine cobalt complex by luminescent Moessbauer spectrometry method was performed. The method was compared with hot atom chemistry method. The electron states in atoms are changed by the aftereffect on Auger emission following the electron capture process. The state of oxidation of disintegration products is usually higher than that of parent nuclei. However, sometimes, lower oxidation is seen in Fe-57, the daughter nuclei of Co-57. This phenomenon may be due to radiation chemistry process, and this effect can be observed by the luminescent Moessbauer spectrometry method. However, the range of the effect can not be seen by the Moessbauer method. Estimation showed that the Auger electrons stay within the surrounding area of the disintegration atom, and the effect does not reach to distant places. The yield of Fe-57 in the electron capture process of Co-57 in cobalt complex, the G-value, and the hot atom chemical yield were obtained. It is concluded that the aftereffect of the Auger process is the localized radiation chemistry effect. Good correlation was seen between the present method and the hot atom chemistry method. (Kato, T.)

  7. Magnetic and Structural Investigations of Nanocrystalline Cobalt-Ferrite

    Directory of Open Access Journals (Sweden)

    I. Sharifi

    2012-10-01

    Full Text Available Cobalt ferrite is an important magnetic material due to their large magneto-crystalline anisotropy, high cohercivity, moderate saturation magnetization and chemical stability.In this study, cobalt ferrites Nanoparticles have been synthesized by the co-precipitation method and a new microemulsion route. We examined the cation occupancy in the spinel structure based on the “Rietveld with energies” method. The Xray measurements revealed the production of a broad single ferrite cubic phase with the average particle sizes of about 12 nm and 7nm, for co-precipitation and micro-emulsion methods, respectively. The FTIR measurements between 400 and 4000 cm-1 confirmed the intrinsic cation vibrations of the spinelstructure for the two methods. Furthermore, the Vibrating Sample Magnetometer (VSM was carried out at room temperature to study the structural and magnetic properties. The results revealed that by changing the method from co-precipitation to the reverse micelle the material exhibits a softer magnetic behavior in such a way that both saturation magnetization and coercivity decrease from 58 to 29 emu/g and from 286 to 25 Oe, respectively.

  8. Self-biased cobalt ferrite nanocomposites for microwave applications

    Energy Technology Data Exchange (ETDEWEB)

    Hannour, Abdelkrim, E-mail: abdelkrim.hannour@hotmail.com [LT2C Laboratory, Jean-Monnet University, 25 rue Dr. Rémy Annino, F-42000, Saint-Etienne (France); Vincent, Didier; Kahlouche, Faouzi; Tchangoulian, Ardaches [LT2C Laboratory, Jean-Monnet University, 25 rue Dr. Rémy Annino, F-42000, Saint-Etienne (France); Neveu, Sophie; Dupuis, Vincent [UPMC Univ Paris 06, UMR 7195, PECSA, F-75005, Paris (France)

    2014-03-15

    Oriented CoFe{sub 2}O{sub 4} nanoparticles, dispersed in polymethyl methacrylate (PMMA) matrix, were fabricated by magnetophoretic deposition of functionalized nanocolloidal cobalt ferrite particles into porous alumina membrane. Their magnetic behavior exhibits an out-of-plane easy axis with a large remanent magnetization and coercitivity. This orientation allows high effective internal magnetic anisotropy that contributes to the permanent bias along the wire axis. The microwave studies reveal a ferromagnetic resonance at 46.5 and 49.5 GHz, depending on the filling ratio of the membrane. Ansoft High Frequency Structure Simulator (Ansoft HFSS) simulations are in good agreement with experimental results. Such nanocomposite is presented as one of the promising candidates for microwave devices (circulators, isolators, noise suppressors etc.). - Highlights: • Oriented magnetic CoFe{sub 2}O{sub 4} nanoparticles were fabricated by magnetophoretic deposition of functionalized cobalt ferrite particles into porous alumina membrane. • The nanocomposite obtained presents an out-of-plane easy axis with a large remanent magnetization and coercitivity. • The high effective internal magnetic anisotropy contributes to the permanent bias along the wire axis. • The frequency ferromagnetic resonance ranges from 46.5 to 49.5 GHz, depending on the filling ratio of the membrane. • We have obtained a good agreement between Ansoft High Frequency Structure Simulator simulations and experimental results.

  9. Self-biased cobalt ferrite nanocomposites for microwave applications

    International Nuclear Information System (INIS)

    Hannour, Abdelkrim; Vincent, Didier; Kahlouche, Faouzi; Tchangoulian, Ardaches; Neveu, Sophie; Dupuis, Vincent

    2014-01-01

    Oriented CoFe 2 O 4 nanoparticles, dispersed in polymethyl methacrylate (PMMA) matrix, were fabricated by magnetophoretic deposition of functionalized nanocolloidal cobalt ferrite particles into porous alumina membrane. Their magnetic behavior exhibits an out-of-plane easy axis with a large remanent magnetization and coercitivity. This orientation allows high effective internal magnetic anisotropy that contributes to the permanent bias along the wire axis. The microwave studies reveal a ferromagnetic resonance at 46.5 and 49.5 GHz, depending on the filling ratio of the membrane. Ansoft High Frequency Structure Simulator (Ansoft HFSS) simulations are in good agreement with experimental results. Such nanocomposite is presented as one of the promising candidates for microwave devices (circulators, isolators, noise suppressors etc.). - Highlights: • Oriented magnetic CoFe 2 O 4 nanoparticles were fabricated by magnetophoretic deposition of functionalized cobalt ferrite particles into porous alumina membrane. • The nanocomposite obtained presents an out-of-plane easy axis with a large remanent magnetization and coercitivity. • The high effective internal magnetic anisotropy contributes to the permanent bias along the wire axis. • The frequency ferromagnetic resonance ranges from 46.5 to 49.5 GHz, depending on the filling ratio of the membrane. • We have obtained a good agreement between Ansoft High Frequency Structure Simulator simulations and experimental results

  10. Development and production of cobalt-60 sources for metallurgical application

    International Nuclear Information System (INIS)

    Oliveira, Paulo Fernando; Valente, Eduardo Sarmento; Maretti Junior, Fausto

    2002-01-01

    The CDTN has developed and produced 60 Co sources to be used in level controllers on continuous ingot casting. The sources used in these systems are sealed with a stainless steel revetment and have an useful life equivalent to one half life of the 60 Co (5.272 years). Each system of continuous ingot casting uses a source with one specified activity and different activation section. The sources have been imported with a very high cost due the special shields used to keep and transport them safety. One of its sources, with initial activity of 148 MBq, after being used for more than 5 years in one factory, was given to CDTN to carry out an activation section studies. After these studies be concluded CDTN/CNEN began the procedures to produce a new source in the IPR-R1 TRIGA Reactor, with an irradiation of one cobalt wire in the maximum flux region of the core. The same metallic cobalt wire was irradiated (10% of total activity), to determinate the necessary irradiation time to obtain the final activation. The CDTN developed too a stainless steel recipient with a aluminum nucleus, to seal and to guarantee the integrity of the source. (author)

  11. Anionic carbonato and oxalato cobalt(III) nitrogen mustard complexes.

    Science.gov (United States)

    Craig, Peter R; Brothers, Penelope J; Clark, George R; Wilson, William R; Denny, William A; Ware, David C

    2004-02-21

    Synthetic approaches to cobalt(III) complexes [Co(L)(L')2] containing the bidentate dialkylating nitrogen mustard N,N-bis(2-chloroethyl)-1,2-ethanediamine (L = dce) together with anionic ancilliary ligands (L') which are either carbonato (CO3(2-)), oxalato (ox2-), bis(2-hydroxyethyl)dithiocarbamato (bhedtc-), 2-pyridine carboxylato (pico-) or 2-pyrazine carboxylato (pyzc-) were investigated. Synthetic routes were developed using the related amines N,N-diethyl-1,2-ethanediamine (dee) and 1,2-ethanediamine (en). The complexes [Co(CO3)2(L)]- (L = dee 1, dce 2), [Co(ox)2(L)]- (L = dee 3, dce 4), [Co(bhedtc)2(dee)]+ 5, [Co(bhedtc)2(en)]+ 6, mer-[Co(pico)3], mer-[Co(pyzc)]3 7 and [Co(pico)2(dee)]+ 8 were prepared and were characterised by IR, UV-Vis, 1H and 13C[1H] NMR spectroscopy, mass spectrometry and cyclic voltammetry. [Co(bhedtc)2(en)]BPh4 6b and trans(O)-[Co(pico)2(dee)]ClO4 8 were characterised by X-ray crystallography. In vitro biological tests were carried out on complexes 1-4 in order to assess the degree to which coordination of the mustard to cobalt attenuated its cytotoxicity, and the differential toxicity in air vs. nitrogen.

  12. Cobalt-doped nanohydroxyapatite: synthesis, characterization, antimicrobial and hemolytic studies

    Energy Technology Data Exchange (ETDEWEB)

    Tank, Kashmira P., E-mail: kashmira_physics@yahoo.co.in [Saurashtra University, Crystal Growth Laboratory, Physics Department (India); Chudasama, Kiran S.; Thaker, Vrinda S. [Saurashtra University, Bioscience Department (India); Joshi, Mihir J., E-mail: mshilp24@rediffmail.com [Saurashtra University, Crystal Growth Laboratory, Physics Department (India)

    2013-05-15

    Hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}; HAP) is a major mineral component of the calcified tissues, and it has various applications in medicine and dentistry. In the present investigation, cobalt-doped hydroxyapatite (Co-HAP) nanoparticles were synthesized by surfactant-mediated approach and characterized by different techniques. The EDAX was carried out to estimate the amount of doping in Co-HAP. The transmission electron microscopy result suggested the transformation of morphology from needle shaped to spherical type on increasing the doping concentration. The powder XRD study indicated the formation of a new phase of brushite for higher concentration of cobalt. The average particle size and strain were calculated using Williamson-Hall analysis. The average particle size was found to be 30-60 nm. The FTIR study confirmed the presence of various functional groups in the samples. The antimicrobial activity was evaluated against four organisms Pseudomonas aeruginosa and Shigella flexneri as Gram negative as well as Micrococcus luteus and Staphylococcus aureus as Gram positive. The hemolytic test result suggested that all samples were non-hemolytic. The photoluminescence study was carried out to identify its possible applicability as a fluorescent probe.

  13. Cobalt-doped nanohydroxyapatite: synthesis, characterization, antimicrobial and hemolytic studies

    International Nuclear Information System (INIS)

    Tank, Kashmira P.; Chudasama, Kiran S.; Thaker, Vrinda S.; Joshi, Mihir J.

    2013-01-01

    Hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ; HAP) is a major mineral component of the calcified tissues, and it has various applications in medicine and dentistry. In the present investigation, cobalt-doped hydroxyapatite (Co-HAP) nanoparticles were synthesized by surfactant-mediated approach and characterized by different techniques. The EDAX was carried out to estimate the amount of doping in Co-HAP. The transmission electron microscopy result suggested the transformation of morphology from needle shaped to spherical type on increasing the doping concentration. The powder XRD study indicated the formation of a new phase of brushite for higher concentration of cobalt. The average particle size and strain were calculated using Williamson–Hall analysis. The average particle size was found to be 30–60 nm. The FTIR study confirmed the presence of various functional groups in the samples. The antimicrobial activity was evaluated against four organisms Pseudomonas aeruginosa and Shigella flexneri as Gram negative as well as Micrococcus luteus and Staphylococcus aureus as Gram positive. The hemolytic test result suggested that all samples were non-hemolytic. The photoluminescence study was carried out to identify its possible applicability as a fluorescent probe.

  14. Cobalt Xanthate Thin Film with Chemical Bath Deposition

    Directory of Open Access Journals (Sweden)

    İ. A. Kariper

    2013-01-01

    Full Text Available Cobalt xanthate thin films (CXTFs were successfully deposited by chemical bath deposition, onto amorphous glass substrates, as well as on p- and n-silicon, indium tin oxide, and poly(methyl methacrylate. The structure of the films was analyzed by far-infrared spectrum (FIR, mid-infrared (MIR spectrum, nuclear magnetic resonance (NMR, and scanning electron microscopy (SEM. These films were investigated from their structural, optical, and electrical properties point of view. Electrical properties were measured using four-point method, whereas optical properties were investigated via UV-VIS spectroscopic technique. Uniform distribution of grains was clearly observed from the photographs taken by scanning electron microscope (SEM. The transmittance was about 70–80% (4 hours, 50°C. The optical band gap of the CXTF was graphically estimated to be 3.99–4.02 eV. The resistivity of the films was calculated as 22.47–75.91 Ω·cm on commercial glass depending on film thickness and 44.90–73.10 Ω ·cm on the other substrates. It has been observed that the relative resistivity changed with film thickness. The MIR and FIR spectra of the films were in agreement with the literature analogues. The expected peaks of cobalt xanthate were observed in NMR analysis on glass. The films were dipped in chloroform as organic solvent and were analyzed by NMR.

  15. Nickel, copper and cobalt coalescence in copper cliff converter slag

    Directory of Open Access Journals (Sweden)

    Wolf A.

    2016-01-01

    Full Text Available The aim of this investigation is to assess the effect of various additives on coalescence of nickel, copper and cobalt from slags generated during nickel extraction. The analyzed fluxes were silica and lime while examined reductants were pig iron, ferrosilicon and copper-silicon compound. Slag was settled at the different holding temperatures for various times in conditions that simulated the industrial environment. The newly formed matte and slag were characterized by their chemical composition and morphology. Silica flux generated higher partition coefficients for nickel and copper than the addition of lime. Additives used as reducing agents had higher valuable metal recovery rates and corresponding partition coefficients than fluxes. Microstructural studies showed that slag formed after adding reductants consisted of primarily fayalite, with some minute traces of magnetite as the secondary phase. Addition of 5 wt% of pig iron, ferrosilicon and copper-silicon alloys favored the formation of a metallized matte which increased Cu, Ni and Co recoveries. Addition of copper-silicon alloys with low silicon content was efficient in copper recovery but coalescence of the other metals was low. Slag treated with the ferrosilicon facilitated the highest cobalt recovery while copper-silicon alloys with silicon content above 10 wt% resulted in high coalescence of nickel and copper, 87 % and 72 % respectively.

  16. Braze welding of cobalt with a silver–copper filler

    Directory of Open Access Journals (Sweden)

    Everett M. Criss

    2015-01-01

    Full Text Available A new method of joining cobalt by braze-welding it with a silver–copper filler was developed in order to better understand the residual stresses in beryllium–aluminum/silicon weldments which are problematic to investigate because of the high toxicity of Be. The base and filler metals of this new welding system were selected to replicate the physical properties, crystal structures, and chemical behavior of the Be–AlSi welds. Welding parameters of this surrogate Co–AgCu system were determined by experimentation combining 4-point bending tests and microscopy. Final welds are 5 pass manual TIG (tungsten inert gas, with He top gas and Ar back gas. Control of the welding process produces welds with full penetration melting of the cobalt base. Microscopy indicates that cracking is minimal, and not through thickness, whereas 4-point bending shows failure is not by base-filler delamination. These welds improve upon the original Be–AlSi welds, which do not possess full penetration, and have considerable porosity. We propose that utilization of our welding methods will increase the strength of the Be–AlSi weldments. The specialized welding techniques developed for this study may be applicable not only for the parent Be–AlSi welds, but to braze welds and welds utilizing brittle materials in general. This concept of surrogacy may prove useful in the study of many different types of exotic welds.

  17. Chitosan doped with nanoparticles of copper, nickel and cobalt.

    Science.gov (United States)

    Cárdenas-Triviño, Galo; Elgueta, Carolina; Vergara, Luis; Ojeda, Javier; Valenzuela, Ariel; Cruzat, Christian

    2017-11-01

    Metal colloids in 2 propanol using nanoparticles (NPs) of copper, nickel and cobalt were prepared by Chemical Liquid Deposition (CLD) method. The resulting colloidal dispersions were characterized by Transmission Electron Microscopy (TEM). The colloids were supported in chitosan. Then, microbiological assays were performed using E. coli and S. aureus in order to determine the bactericide/bacteriostatic activity of nanoparticles (NPs) trapped or chelated with chitosan. Finally, the toxicity of the metal colloids Cu, Ni and Co was tested. Bio-assays were conducted in three different animal species. First of all on earth warms (Eisenia foetida) to evaluate the toxicity and the biocompatibility of chitosan in lactic acid (1% and 0.5%). Secondly bio-assay done in fishes (rainbow trout), the liver toxicity of NPs in vivo was evaluated. Finally, a bio-assay was conducted in Sprange-Dawley rats of 100g weight, which were injected intraperitoneally with different solutions of chitosan metal colloids. Then, the minimum and maximum concentration were determined for copper, nickel and cobalt. The purpose of the use of chitosan was acting as a carrier for some magnetic NPs, which toxicity would allow to obtain new polymeric materials with potential applications as magnet future drugs carrier. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. The Neuron-Specific Protein TMEM59L Mediates Oxidative Stress-Induced Cell Death.

    Science.gov (United States)

    Zheng, Qiuyang; Zheng, Xiaoyuan; Zhang, Lishan; Luo, Hong; Qian, Lingzhi; Fu, Xing; Liu, Yiqian; Gao, Yuehong; Niu, Mengxi; Meng, Jian; Zhang, Muxian; Bu, Guojun; Xu, Huaxi; Zhang, Yun-Wu

    2017-08-01

    TMEM59L is a newly identified brain-specific membrane-anchored protein with unknown functions. Herein we found that both TMEM59L and its homolog, TMEM59, are localized in Golgi and endosomes. However, in contrast to a ubiquitous and relatively stable temporal expression of TMEM59, TMEM59L expression was limited in neurons and increased during development. We also found that both TMEM59L and TMEM59 interacted with ATG5 and ATG16L1, and that overexpression of them triggered cell autophagy. However, overexpression of TMEM59L induced intrinsic caspase-dependent apoptosis more dramatically than TMEM59. In addition, downregulation of TMEM59L prevented neuronal cell death and caspase-3 activation caused by hydrogen peroxide insults and reduced the lipidation of LC3B. Finally, we found that AAV-mediated knockdown of TMEM59L in mice significantly ameliorated caspase-3 activation, increased mouse duration in the open arm during elevated plus maze test, reduced mouse immobility time during forced swim test, and enhanced mouse memory during Y-maze and Morris water maze tests. Together, our study indicates that TMEM59L is a pro-apoptotic neuronal protein involved in animal behaviors such as anxiety, depression, and memory, and that TMEM59L downregulation protects neurons against oxidative stress.

  19. Construction of an apparatus for nuclear orientation measurements at low temperatures. Application to neodymium-cobalt alloy

    International Nuclear Information System (INIS)

    Mayer, E.

    1965-10-01

    We describe experiments along which has been studied the anisotropy of γ radiations emitted by oriented nuclei. We have used the great hyperfine fields acting on nuclei in ferromagnetic metals so as to produce alignment at low temperature. By irradiation we obtained a few cobalt 60 nuclei in our samples which were then cooled down to 0,01 K. The anisotropic rate of the 1,33 MeV γ radiation was measured in function of the sample temperature, using as thermometer the anisotropy of γ radiation emitted by cobalt 60 nuclei in a cobalt single crystal. Cobalt 60 was lined up in a cobalt nickel alloy (40% Ni). The hyperfine field at the cobalt was measured compared to the effective field in metallic cobalt: Heff(Co Ni)/Heff(Co metal) = 0.71 ± 0.12. These results are in good agreement with specific heat measurements made previously. Cobalt 60 has been polarised in a neodymium-cobalt alloy (NdCo 5 ). The field at the cobalt in NdCo 5 has been measured compared to the field in metallic cobalt and taking the non-saturation into account we found 165000 oersteds 5 ) [fr

  20. Variations in absorbed doses from 59Fe in different diseases

    International Nuclear Information System (INIS)

    Roth, P.; Werner, E.; Henrichs, K.; Elsasser, U.; Kaul, A.

    1986-01-01

    The biokinetics of radiopharmaceuticals administered in vivo may vary considerably with changes in organ functions. They studied the variations in absorbed doses from 59 Fe in 207 patients with different diseases, in whom ferrokinetic investigations were performed for diagnostic purposes. Radiation doses to the bone marrow were highest in patients with deserythropoietic anemias (mean 38 nSv/Bq, range 19 - 57 nSv/Bq) and in hemolytic anemias (mean 21 nSv/Bq, range 7 - 35 nSv/Bq), whereas lower and rather constant values were found in other diseases (mean values between 9 and 13 nSv/Bq). The highest organ doses, the greatest differences with respect to diagnosis and also the largest variations within each group of patients were found for liver and spleen (e. g. in aplastic anemia; liver: 66 nSv/Bq, range 29 - 104 nSv/Bq; spleen: 57 nSv/Bq, range 34 - 98 nSv/Bq. In iron deficiency; liver: 13 nSv/Bq range 12 - 14 nSv/q; spleen: 19 nSv/Bq, range 18 - 20 nSv/Bq). Lower organ doses and smaller variations within and between the groups of patients were found for the gonads (means 3 - 7 nSv/Bq), the kidneys (means 10 - 13 nSv/Bq), the bone (means 4 - 7 nSv/Bq), the lung (means 8 - 12 nSv/Bq), and the total body (means 6 - 8 nSv/Bq). In patients with chronic bleeding absorbed doses decrease concomitantly to the extent of blood loss. The D/sub E/ is not markedly affected by the variations in organ doses but is fairly constant for different diseases. 16 references, 1 figure, 3 tables