WorldWideScience

Sample records for europium sulfates

  1. Europium ion as a probe for binding sites to carrageenans

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Ana P.; Goncalves, Rogeria R.; Serra, Osvaldo A. [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo 14040-901 (Brazil); Zaniquelli, Maria Elisabete D. [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo 14040-901 (Brazil)], E-mail: medzaniquelli@ffclrp.usp.br; Wong, Kenneth [Laboratorio de Fisico-Quimica, Centro de Pesquisas de Paulinia, Rhodia Brasil, Paulinia, Sao Paulo (Brazil)

    2007-12-15

    Carrageenans, sulfated polysaccharides extracted from red algae, present a coil-helix transition and helix aggregation dependence on the type and concentration of counterions. In this study, we focus attention on a mixed valence counterion system: Eu{sup 3+}/Na{sup +} or K{sup +} with different gel-forming carrageenans: kappa, iota, and kappa-2. Results of stationary and time-dependent luminescence showed to be a suitable tool to probe ion binding to both the negatively charged sulfate group and the hydroxyl groups present in the biopolymer. For lower europium ion concentrations, a single longer decay emission lifetime was detected, which was attributed to the binding of europium ion to the carrageenan sulfate groups. An additional decay ascribed to europium binding to hydroxyl groups was observed above a threshold concentration, and this decay was dependent on the carrageenan charge density. Symmetry of the europium ion microenvironment was estimated by the ratio between the intensities of its emission bands, which has been shown to depend on the concentration of europium ions and on the specificity of the monovalent counterion bound to the carrageenan.

  2. Europium ion as a probe for binding sites to carrageenans

    International Nuclear Information System (INIS)

    Ramos, Ana P.; Goncalves, Rogeria R.; Serra, Osvaldo A.; Zaniquelli, Maria Elisabete D.; Wong, Kenneth

    2007-01-01

    Carrageenans, sulfated polysaccharides extracted from red algae, present a coil-helix transition and helix aggregation dependence on the type and concentration of counterions. In this study, we focus attention on a mixed valence counterion system: Eu 3+ /Na + or K + with different gel-forming carrageenans: kappa, iota, and kappa-2. Results of stationary and time-dependent luminescence showed to be a suitable tool to probe ion binding to both the negatively charged sulfate group and the hydroxyl groups present in the biopolymer. For lower europium ion concentrations, a single longer decay emission lifetime was detected, which was attributed to the binding of europium ion to the carrageenan sulfate groups. An additional decay ascribed to europium binding to hydroxyl groups was observed above a threshold concentration, and this decay was dependent on the carrageenan charge density. Symmetry of the europium ion microenvironment was estimated by the ratio between the intensities of its emission bands, which has been shown to depend on the concentration of europium ions and on the specificity of the monovalent counterion bound to the carrageenan

  3. Moessbauer studies of {sup 151}Eu in europium oxalate, europium bissalen ammonium and europium benzoate

    Energy Technology Data Exchange (ETDEWEB)

    Wynter, C. I., E-mail: wynterc@ncc.edu [Nassau Community College, Department of Chemistry (United States); Ryan, D. H. [McGill University, Centre for the Physics Materials, Department of Physics (Canada); Taneja, S. P. [Maharshi Dayanand University, Department of Physics (India); May, L. [Catholic University of America, Department of Chemistry (United States); Oliver, F. W. [Morgan State University, Department of Physics (United States); Brown, D. E. [Northern Illinois University, Department of Physics (United States); Iwunzie, M. [Morgan State University, Department of Chemistry (United States)

    2005-11-15

    Although a number of europium water insoluble chelates have been prepared for several decades, the covalent nature of these compounds has never been established in any quantitative fashion. Shifts in the I.R. bands and conductivity measurements of these salts were hitherto used to qualitatively compare their molecular nature. In this communique we have used temperature coefficients of {sup 151}Eu Moessbauer spectra to determine the Debye temperatures ({theta}{sub D}) of three europium chelates: namely europium oxalate, europium bissalen ammonium (recently reported) and europium benzoate and compared their {theta}{sub D} with the measured {theta}{sub D} of the known ionic EuF{sub 3}. Additionally, the mean square amplitude (europium bissalen ammonium (133 {+-} 5 K) and lastly the europium benzoate with a {theta}{sub D} of (105 {+-} 5 K).

  4. Magneto-optical studies of valence instability in europium and terbium phosphors

    Czech Academy of Sciences Publication Activity Database

    Rodrigues, L.C.v.; Hölsä, J.; Brito, H.F.; Maryško, Miroslav; Matos, J.R.; Paturi, P.; Rodrigues, R.V.; Lastusaari, M.

    2016-01-01

    Roč. 170, Feb (2016), 701-706 ISSN 0022-2313 Institutional support: RVO:68378271 Keywords : valence * europium * terbium * oxysulfide and -sulfate * phosphors * paramagnetic susceptibility Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.686, year: 2016

  5. Europium-155 in Debris from Nuclear Weapons

    DEFF Research Database (Denmark)

    Aarkrog, Asker; Lippert, Jørgen Emil

    1967-01-01

    The lithium-drifted germanium detector enables determination of europium-155 on a routine basis in environmental samples contaminated with debris from nuclear weapons. From measurements of europium-155, cesium-144, and strontium-90 in air filters collected between 1961 and 1966, the yield...

  6. Resonance ionization scheme development for europium

    Energy Technology Data Exchange (ETDEWEB)

    Chrysalidis, K., E-mail: katerina.chrysalidis@cern.ch; Goodacre, T. Day; Fedosseev, V. N.; Marsh, B. A. [CERN (Switzerland); Naubereit, P. [Johannes Gutenberg-Universität, Institiut für Physik (Germany); Rothe, S.; Seiffert, C. [CERN (Switzerland); Kron, T.; Wendt, K. [Johannes Gutenberg-Universität, Institiut für Physik (Germany)

    2017-11-15

    Odd-parity autoionizing states of europium have been investigated by resonance ionization spectroscopy via two-step, two-resonance excitations. The aim of this work was to establish ionization schemes specifically suited for europium ion beam production using the ISOLDE Resonance Ionization Laser Ion Source (RILIS). 13 new RILIS-compatible ionization schemes are proposed. The scheme development was the first application of the Photo Ionization Spectroscopy Apparatus (PISA) which has recently been integrated into the RILIS setup.

  7. Europium-151 Moessbauer spectroscopic and XANES investigation of europium-exchanged Y-zeolite

    International Nuclear Information System (INIS)

    Berry, F.J.; Marco, J.F.; Steel, A.T.

    1994-01-01

    Eu 3+ in ca. 10 wt% europium-exchanged Y-zeolite is partially reduced by treatment in hydrogen at 600 C to Eu 2+ . The reduction of Eu 3+ is more readily achieved in Y-zeolite than in europium(III) oxide. The discrepancy in the extent of reduction as revealed by 151 Eu Moessbauer spectroscopy and near edge X-ray absorption fine structure (XANES) is associated with any difference in the recoil free fractions of Eu 2+ and Eu 3+ which may exist at 298 K and the enhanced sensitivity of the XANES to changes in the europium oxidation state. (orig.)

  8. Synthesis of samarium, europium and ytterbium acetylenides

    International Nuclear Information System (INIS)

    Bochkarev, M.N.; Fedorova, E.A.; Glushkova, N.V.; Protchenko, A.V.; Druzhkov , O.N.; Khorshev, S.Ya.

    1995-01-01

    Ethynyl complexes of samarium, europium and ytterbium were prepared by interaction of naphthalinides of metals with acetylene in tetrahydrofuran. The compounds are isolated in the form of dark-coloured pyrophore powders. Data of magnetic measurements suggest that in the course of the reaction Sm(2) is oxidized completely to Sm(3), Yb(2) transforms into Yb(3) partially, whereas europium preserves its initial bivalent state. Hydrolysis of the compounds prepared provides acetylene, ethylene, ethane and hydrogen which indicates the presence of acethylenide Ln 2 C 2 and hydride LnH groupings (Ln = Sm, Eu, Yb). 9 refs., 2 tabs

  9. Organophosphate Nerve Agent Detection with Europium Complexes

    Directory of Open Access Journals (Sweden)

    Jake R. Schwierking

    2004-01-01

    Full Text Available We explore the detection of paraoxon, a model compound for nonvolatile organophosphate nerve agents such as VX. The detection utilizes europium complexes with 1,10 phenanthroline and thenoyltrifluoroacetone as sensitizing ligands. Both europium luminescence quenching and luminescence enhancement modalities are involved in the detection, which is simple, rapid, and sensitive. It is adaptable as well to the more volatile fluorophosphate nerve agents. It involves nothing more than visual luminescence observation under sample illumination by an ordinary hand-held ultraviolet lamp.

  10. Fermi Surface and Antiferromagnetism in Europium Metal

    DEFF Research Database (Denmark)

    Andersen, O. Krogh; Loucks, T. L.

    1968-01-01

    of the nearly cubical part of the hole surface at P, and we also discuss the effects of the electron surface at H. Since it is likely that barium and europium have similar Fermi surfaces, we have presented several extremal areas and the corresponding de Haas-van Alphen frequencies in the hope that experimental...

  11. Synthesis and spectral properties of europium phthalocyanine complexes

    International Nuclear Information System (INIS)

    Maksimova, K.N.; Bazyakina, N.L.; Kutyreva, V.V.; Suvorova, O.N.; Domrachev, G.A.

    2008-01-01

    Synthesis of europium monophthalocyanic complexes with thenoyltrifluroacetonate (tta) and ferrocenoyltrifluoroacetate (fta) ligands has been considered. Spectral characteristics of complexes PcEu(tta)(ttaH) and PcEu(fta)(ftaH) (Pc - phthalocyanine ligand) have been investigated. One of β-diketonate ligand is proposed to bind with europium ion covalently, and the second ligand saturates coordination sphere of europium due to donor-acceptor binding [ru

  12. Temperature effects in the valence fluctuation of europium intermetallic compounds

    International Nuclear Information System (INIS)

    Menezes, O.L.T. de; Troper, A.; Gomes, A.A.

    1978-03-01

    A previously reported model for valence fluctuations in europium compound in order to account for thermal occupation effect. Experimental results are critically discussed and new experiments are suggested

  13. Characteristics of transfer of europium ions from phosphoric acid solution into the CaSO4·O.5H2O solid phase

    International Nuclear Information System (INIS)

    Berdonosova, D.G.; Burlakova, E.V.; Yasenkova, M.A.; Ivanov, L.N.; Melikhov, I.V.

    1989-01-01

    The mechanism of formation of the precipitated CaSO 4 ·0.5H 2 O phase was studied in detail; the precipitation was performed at 80 degree, equimolar solutions of Ca(H 2 PO 4 ) 2 and H 2 SO 4 in phosphoric acid of 38% concentration being used. The availability of detailed information on the mechanism of formation of CaSO 4 ·0.5H 2 O precipitates determined the choice of conditions of study of capture of rare earths. In particular, H 3 PO 4 of 38% P 2 O 5 concentration was used as the medium of formation of the calcium sulfate precipitate. Europium was chosen as the rare earth. Its behavior in the liquid and solid phases was studied by radiometric and luminescence methods. The radionuclide 152 Eu is convenient as a radioactive tracer while luminescence of europium is structure-sensitive; therefore, europium is often used in physicochemical investigations as a luminescent probe. It follows from the data that most of the europium captured by the precipitate during coagulation of the ultramicrocrystals is retained firmly by the solid phase. Therefore, in order to diminish capture of europium (and other rare earths) by the precipitate coagulation of the latter should be prevented

  14. On the composition of nonstoichiometric europium monoxide

    International Nuclear Information System (INIS)

    Ignat'eva, N.I.

    1990-01-01

    Consideration is given to results of of investigation into chemical composition, homogeneity region, type of disordering of nonstoichiometric europium monoxide. Precision methods of X-ray diffraction, electron-microscopic, atomic-absorption chemical analysis were used. It is shown that lattice volume reduces with increase of oxygen content in the oxide. For monocrystal of EuO 1.01 composition a=5.146 A. All samples of europium monoxide are characterized by low conductivity. Conductivity value changes by two orders (from 10 -8 to 10 -6 Θ -1 ·cm -1 ) when passing from the sample of stoichiometric composition to maximally disordered one. The disordering is considered according to the type of charged cation vacancies, leading to occurrence of equivalent number of electron defects of positive holes. 4 refs.; 1 tab

  15. Formation of americium and europium humate complexes

    International Nuclear Information System (INIS)

    Minai, Y.; Tominaga, T.; Meguro, Y.

    1991-01-01

    Binding constants of americium and europium with a humic acid were determined to study if complex formation of trivalent actinide-humates affects dissolved species of the actinides in hydrosphere. The purified humic acid was characterized by means of UV-vis, IR, and pH titration, indicating high carboxylate capacity and low aromaticity. Binding constants of americium and europium humates were determined at pH 4.6 and 6.0 by solvent extraction using 241 Am or 152 Eu as a tracer. The binding constants for americium-humate obtained preliminarily suggest that complexes with humic acid are not negligible in speciation of trivalent actinides in hydrosphere. The obtained binding constants were nearly identical with those determined previously by the same procedures, but with humic acids of different origin and compositions. (author)

  16. APW research of europium monochalcogenides. 1

    International Nuclear Information System (INIS)

    Farberovich, O.V.; Vlasov, S.V.

    1981-01-01

    The augmented plane wave method (APW) is used for a theoretical study of the electron properties of europium monochalcogenides. Spin-polarized energy band calculations of the ferromagnetic EuO, EuS, and EuSe explain qualitatively the exchange interactions therein. Based on the APW data in the frame of perturbation theory the Coulomb electron-electron interaction at the 4f shell of europium is taken into account for EuO and EuS. The band structures and the multiplet terms of the f 6 d and 3d 9 4f 8 excited states gives a new interpretation of a known experimental spectra for these compounds. (author)

  17. The migrant 152Eu as europium humate

    International Nuclear Information System (INIS)

    Klotz, D.

    2001-01-01

    Europium was used as a representative of the lanthanide group in the migration experiments in underground water. These 14 elements, with the atomic numbers of 58 (cerium) through 71 (lutetium) are quite similar in their chemical characteristics, and all of them will form metal-humate complexes with humic acids via proton exchange groups. Apart from the concentration, chemical composition and structure, also the particle size of these metal humates will vary strongly as it is dependent on the geochemistry and geophysics of the underground systems [de

  18. Europium enabled luminescent nanoparticles for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Syamchand, S.S., E-mail: syamchand.ss@gmail.com; Sony, G., E-mail: emailtosony@gmail.com

    2015-09-15

    Lanthanide based nanoparticles are receiving great attention ought to their excellent luminescent and magnetic properties and find challenging biomedical applications. Among the luminescent lanthanide NPs, europium based NPs (Eu-NPs) are better candidates for immunoassay and imaging applications. The Eu-NPs have an edge over quantum dots (QDs) by means of their stable luminescence, long fluorescence lifetime, sharp emission peaks with narrow band width, lack of blinking and biocompatibility. This review surveys the synthesis and properties of a variety of Eu-NPs consolidated from different research articles, for their applications in medicine and biology. The exquisite luminescent properties of Eu-NPs are explored for developing biomedical applications such as immunoassay and bioimaging including multimodal imaging. The biomedical applications of Eu-NPs are mostly diagnostic in nature and mainly focus on various key analytes present in biological systems. The luminescent properties of europium enabled NPs are influenced by a number of factors such as the site symmetry, the metal nanoparticles, metal ions, quantum dots, surfactants, morphology of Eu-NPs, crystal defect, phenomena like antenna effect and physical parameters like temperature. Through this review we explore and assimilate all the factors which affect the luminescence in Eu-NPs and coil a new thread of parameters that control the luminescence in Eu-NPs, which would provide further insight in developing Eu-based nanoprobes for future biomedical prospects. - Highlights: • The review describes 14 major factors that influence the luminescence properties of europium enabled luminescent nanoparticles (Eu-NPs). • Surveys different types of europium containing nanoparticles that have been reported for their biomedical applications. • Eu-NPs are conveniently divided into four different categories, based on the type of the substrates involved. The four categories are (1) virgin Eu-substrate based NPs; (2

  19. Europium enabled luminescent nanoparticles for biomedical applications

    International Nuclear Information System (INIS)

    Syamchand, S.S.; Sony, G.

    2015-01-01

    Lanthanide based nanoparticles are receiving great attention ought to their excellent luminescent and magnetic properties and find challenging biomedical applications. Among the luminescent lanthanide NPs, europium based NPs (Eu-NPs) are better candidates for immunoassay and imaging applications. The Eu-NPs have an edge over quantum dots (QDs) by means of their stable luminescence, long fluorescence lifetime, sharp emission peaks with narrow band width, lack of blinking and biocompatibility. This review surveys the synthesis and properties of a variety of Eu-NPs consolidated from different research articles, for their applications in medicine and biology. The exquisite luminescent properties of Eu-NPs are explored for developing biomedical applications such as immunoassay and bioimaging including multimodal imaging. The biomedical applications of Eu-NPs are mostly diagnostic in nature and mainly focus on various key analytes present in biological systems. The luminescent properties of europium enabled NPs are influenced by a number of factors such as the site symmetry, the metal nanoparticles, metal ions, quantum dots, surfactants, morphology of Eu-NPs, crystal defect, phenomena like antenna effect and physical parameters like temperature. Through this review we explore and assimilate all the factors which affect the luminescence in Eu-NPs and coil a new thread of parameters that control the luminescence in Eu-NPs, which would provide further insight in developing Eu-based nanoprobes for future biomedical prospects. - Highlights: • The review describes 14 major factors that influence the luminescence properties of europium enabled luminescent nanoparticles (Eu-NPs). • Surveys different types of europium containing nanoparticles that have been reported for their biomedical applications. • Eu-NPs are conveniently divided into four different categories, based on the type of the substrates involved. The four categories are (1) virgin Eu-substrate based NPs; (2

  20. Study of the europium behavior in aqueous media

    International Nuclear Information System (INIS)

    Fernandez R, E.; Jimenez R, M.; Solache R, M.; Martinez M, V.

    1999-01-01

    Europium as waste can produce a pollution problem in water that is in contact with it, what would has a heavy environmental impacts, because of the possibilities of diffusion of these wastes from their place of confinement or storage until the geo and biosphere. The solution of such problem requires of a lot of knowledge over the behavior of several chemical elements such as europium in aqueous solutions. In this work it was used a low ion force (0.02 M). The data set will allow extrapolate the hydrolytic behavior of europium in too much minors ion force media, such as the ground waters, including in ion force zero

  1. Synthesis and characterization of europium aluminophosphate

    International Nuclear Information System (INIS)

    Araujo, A.S.; Diniz, J.C.; Silva, A.O.S.

    1998-01-01

    Full text: Aluminophosphate molecular sieves (ALPO) represents a class of materials formed by AlO 2+ and PO 2- tetrahedra linked together through b the oxygen atom. The incorporation of metal cations, specifically rare earths, in the ALPO matrix, gives rise to generation of new materials that can be used as acid catalysts in chemical processes. In this work, it was synthesized hydrothermally a molecular sieve type Eu-ALPO-11, starting from an hydrated alumina (pseudobohemite), phosphoric acid solution, europium chloride, water, and di-isopropylamine (DIPA) as organic template. The gel of synthesis presented the following composition: 1.0 DIPA: 0.05 Eu 2 O 3 :0.95 Al 2 O 3 : 1.0 P 2 O 5 : 80 H 2 O The hydrogel was autoclaved at 170 deg C for a period of 3 days. After that the obtained solid was filtered, washed, dried and calcined at 500 deg C to remove the template. The sample was characterized by several physico-chemical methods, such a atomic absorption, FT-IR spectroscopy, X-ray diffraction, thermal analysis, scanning electron microscopy. Its spectroscopic properties was investigated by europium luminescence. The physico-chemical characterization of the Eu-ALPO-11 showed very good crystallinity, with AEL structure, and orthorhombic symmetry. Also, the material presents excellent thermal stability, with no structural collapse until 950 deg C. Through the luminescence spectra in the visible region, it was observed that the emission of the Eu 3+ is strongly influenced by the increasing of the 5d0 7f0 transition (Electric Dipole), as compared to the 5d0 7f1 transition (Magnetic Dipole) between the levels of 4f configuration perturbed by the crystalline field. The ED/MD ratio to the as synthesized sample was ca. 2.1, against ca. 1.1 relative to the calcined sample. The FT-IR spectra presented well defined absorption bands relative to Al-O and P-O bonds, of the structural internal tetrahedra (IT) and external links (EL): 1250- 950 cm -1 , symmetric stretching due to

  2. Preparation and spectral properties of europium hydrogen squarate microcrystals

    Science.gov (United States)

    Kolev, T.; Danchova, N.; Shandurkov, D.; Gutzov, S.

    2018-04-01

    A simple scheme for preparation of europium hydrogen squarate octahydrate microcrystals, Eu(HSq)3·8H2O is demonstrated. The microcrystalline powders obtained have a potential application as non-centrosymmetric and UV radiation - protective hybrid optical material. The site-symmetry of the Eu - ion is C2V or lower, obtained from diffuse reflectance spectra. The formation of europium hydrogen squarate is supported by IR - spectroscopy, UV-vis spectroscopy, chemical analysis and X-ray diffraction. A detailed analysis of the UV-vis and IR spectra of the micropowders prepared is presented. The reaction between europium oxide and squaric acid leads to formation of microcrystalline plate-like crystals of europium hydrogen squarate Eu(HSq)3·8H2O, a non-centrosymmetric hybrid optical material with a potential application as UV radiation - protective coatings.

  3. Sorption of Europium in zirconium silicate

    International Nuclear Information System (INIS)

    Garcia R, G.

    2004-01-01

    Some minerals have the property of sipping radioactive metals in solution, that it takes advantage to manufacture contention barriers that are placed in the repositories of nuclear wastes. The more recent investigations are focused in the development of new technologies guided to the sorption of alpha emissors on minerals which avoid their dispersion in the environment. In an effort to contribute to the understanding of this type of properties, some studies of sorption of Europium III are presented like homologous of the americium, on the surface of zirconium silicate (ZrSiO 4 ). In this work the results of sorption experiences are presented as well as the interpretation of the phenomena of the formation of species in the surface of the zirconium silicate. (Author)

  4. Electronic structure and superconductivity of europium

    International Nuclear Information System (INIS)

    Nixon, Lane W.; Papaconstantopoulos, D.A.

    2010-01-01

    We have calculated the electronic structure of Eu for the bcc, hcp, and fcc crystal structures for volumes near equilibrium up to a calculated 90 GPa pressure using the augmented-plane-wave method in the local-density approximation. The frozen-core approximation was used with a semi-empirical shift of the f-states energies in the radial Schroedinger equation to move the occupied 4f valence states below the Γ 1 energy and into the core. This shift of the highly localized f-states yields the correct europium phase ordering with lattice parameters and bulk moduli in good agreement with experimental data. The calculated superconductivity properties under pressure for the bcc and hcp structures are also found to agree with and follow a T c trend similar to recent measurement by Debessai et al.

  5. Metal plasmon enhanced europium complex luminescence

    International Nuclear Information System (INIS)

    Liu Feng; Aldea, Gabriela; Nunzi, Jean-Michel

    2010-01-01

    The plasmon enhanced luminescence of a rare-earth complex Tris(6, 6, 7, 7, 8, 8, 8-heptafluoro-2, 2-dimethyl-3, 5-octanedionato) europium (Eu(fod) 3 ) was investigated. A polyvinyl alcohol (PVA) thin film was successfully adopted as a spacer to separate the Eu complex from the silver island film (SIF), and five-fold enhancement of the radiative decay rate of the Eu complex on SIF was demonstrated based on the luminescence intensity and lifetime measurement. Investigation of the distance dependent luminescence indicates that 7 nm is an optimal distance for SIF enhanced Eu luminescence. Plasmon enhanced rare-earth luminescence based on an organic film spacer would find potential applications in plasmon enhanced organic light emitting diode (OLED) devices.

  6. Europium polyoxometalates encapsulated in silica nanoparticles - characterization and photoluminescence studies

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Cristina S.; Granadeiro, Carlos M.; Cunha-Silva, Luis; Eaton, Peter; Balula, Salete S.; Pereira, Eulalia [REQUIMTE/Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto (Portugal); Ananias, Duarte [CICECO, Departamento de Quimica, Universidade de Aveiro (Portugal); Gago, Sandra [REQUIMTE, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica (Portugal); Feio, Gabriel [CENIMAT/I3N, Departamento de Ciencia dos Materiais, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica (Portugal); Carvalho, Patricia A. [ICEMS/Departamento de Bioengenharia, Instituto Superior Tecnico, Lisboa (Portugal)

    2013-06-15

    The incorporation of europium polyoxometalates into silica nanoparticles can lead to a biocompatible nanomaterial with luminescent properties suitable for applications in biosensors, biological probes, and imaging. Keggin-type europium polyoxometalates Eu(PW{sub 11}){sub x} (x = 1 and 2) with different europium coordination environments were prepared by using simple methodologies and no expensive reactants. These luminescent compounds were then encapsulated into silica nanoparticles for the first time through the water-in-oil microemulsion methodology with a nonionic surfactant. The europium polyoxometalates and the nanoparticles were characterized by using several techniques [FTIR, FT-Raman, {sup 31}P magic angle spinning (MAS) NMR, and TEM/energy-dispersive X-ray spectroscopy (TEM-EDS), AFM, dynamic light scattering (DLS), and inductively coupled plasma MS (ICP-MS) analysis]. The stability of the material and the integrity of the europium compounds incorporated were also examined. Furthermore, the photoluminescence properties of the Eu(PW{sub 11}){sub x} rate at SiO{sub 2} nanomaterials were evaluated and compared with those of the free europium polyoxometalates. The silica surface of the most stable nanoparticles was successfully functionalized with appropriate organosilanes to enable the covalent binding of oligonucleotides. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Recoverable immobilization of transuranic elements in sulfate ash

    Science.gov (United States)

    Greenhalgh, Wilbur O.

    1985-01-01

    Disclosed is a method of reversibly immobilizing sulfate ash at least about 20% of which is sulfates of transuranic elements. The ash is mixed with a metal which can be aluminum, cerium, samarium, europium, or a mixture thereof, in amounts sufficient to form an alloy with the transuranic elements, plus an additional amount to reduce the transuranic element sulfates to elemental form. Also added to the ash is a fluxing agent in an amount sufficient to lower the percentage of the transuranic element sulfates to about 1% to about 10%. The mixture of the ash, metal, and fluxing agent is heated to a temperature sufficient to melt the fluxing agent and the metal. The mixture is then cooled and the alloy is separated from the remainder of the mixture.

  8. Statistical optimization of synthesis procedure and characterization of europium (III) molybdate nano-plates

    Energy Technology Data Exchange (ETDEWEB)

    Pourmortazavi, Seied Mahdi [Malek Ashtar University of Technology, Faculty of Material and Manufacturing Technologies, P. O. Box 16765-3454, Tehran (Iran, Islamic Republic of); Rahimi-Nasrabadi, Mehdi [Imam Hossein University, Nano Science Center, Tehran (Iran, Islamic Republic of); Fazli, Yousef [Islamic Azad University, Department of Chemistry, Faculty of Science, Arak Branch, Arak (Iran, Islamic Republic of); Mohammad-Zadeh, Mohammad [Sabzevar University of Medical Sciences, Department of Physiology and Pharmacology, School of Medicine, Sabzevar (Iran, Islamic Republic of)

    2015-06-15

    Europium (III) molybdate nano-plates were synthesized in this work via chemical precipitation route involving adding of europium (III) ion solution to the aqueous solution of molybdate reagent. Effects of some reaction variables such as concentrations of europium and molybdate ions, flow rate of europium reagent, and reactor temperature on the diameter of the synthesized europium (III) molybdate nano-plates were experimentally investigated by orthogonal array design. The results showed that the size of europium (III) molybdate nano-plates can be optimized by adjusting the concentrations of europium (III) and molybdate ions, as well as the reactional temperature. Europium (III) molybdate nano-plates prepared under the optimum conditions were characterized by X-ray powder diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. (orig.)

  9. On the existence of europium aluminum oxynitrides with a magnetoplumbite or beta-alumina type structure

    NARCIS (Netherlands)

    Hintzen, H.T.J.M.; Hanssen, R.; Jansen, S.R.; Metselaar, R.

    1999-01-01

    In the literature confusion exists concerning the structure type, the valence of europium, and the amount of nitrogen incorporation of the compound europium aluminum oxynitride. By using X-ray diffraction and luminescence measurements, we show that europium aluminum oxynitride has the

  10. X-ray structural analysis of plasma sprayed europium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Gorshkov, B.N.; Loskutov, V.S.; Gavrish, A.A.; Shakh, G.E.

    1981-12-01

    An X-ray structure microanalysis is made for europium oxide powder produced by sintering and plasmic spheroidization for plasma spraying. The technique of concern is shown not to alter chemical composition of the powder. It is stated that a rise in the plasma jet enthalpy while spraying does not result in dissociation of europium oxide and its interaction with the plasma flux. The coating (to 15.2 kWxs/g) is found to have only a high-temperature (monoclinic) europium oxide phase and there appears a low-temperature (cubic) phase with a subsequent increase in the enthalpy. The plasma jet enthalpy increasing the grain size and the crystal lattice c parameter of the sprayed europium oxide are shown to decrease; the a parameter reduces with an enthalpy growth to 16.2 kW s/g and then smoothly increases with the enthalpy further growth. It is noticed that the europium oxide coating does not interact with an aluminium D16 alloy substrate.

  11. Chloride, bromide and iodide scintillators with europium

    Science.gov (United States)

    Zhuravleva, Mariya; Yang, Kan

    2016-09-27

    A halide scintillator material is disclosed where the halide may comprise chloride, bromide or iodide. The material is single-crystalline and has a composition of the general formula ABX.sub.3 where A is an alkali, B is an alkali earth and X is a halide which general composition was investigated. In particular, crystals of the formula ACa.sub.1-yEu.sub.yI.sub.3 where A=K, Rb and Cs were formed as well as crystals of the formula CsA.sub.1-yEu.sub.yX.sub.3 (where A=Ca, Sr, Ba, or a combination thereof and X=Cl, Br or I or a combination thereof) with divalent Europium doping where 0.ltoreq.y.ltoreq.1, and more particularly Eu doping has been studied at one to ten mol %. The disclosed scintillator materials are suitable for making scintillation detectors used in applications such as medical imaging and homeland security.

  12. A novel photoluminescent and photochromic europium complex

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A ternary europium complex of 4-aminobutyric acid (ABA) with 1,10-phenanthroline (phen) [Eu2(ABA)4 (phen)4](phen)4(ClO4)6 was synthesized and characterized by X-ray single crystal diffraction. The result shows that 4-aminobutyric acid exists in zwitterion form in the binuclear complex and that the carboxylates coordinate with Eu3+ ion in bidentate bridging and tridentate chelating-bridging modes. There are two types of phen molecules, one is coordinated and the other is uncoordinated. When excited by YAG: Nd laser with 355 nm light, the title complex can emit strong red fluorescence, and its high-resolution emission spectrum was recorded at 77 K. The Eu3+ ion site is in low symmetry, which is in agreement with the result of X-ray single crystal diffraction analysis. When irradiated with a mercury lamp, the aqueous solution of the title complex can perform photochromism with the color change from colorless to green and the green color can fade away in the dark. The photochromic response time is related to the concentration and pH of the solution, the temperature and the light intensity.

  13. First-Principles Investigations on Europium Monoxide

    KAUST Repository

    Wang, Hao

    2011-05-01

    Europium monoxide is both an insulator and a Heisenberg ferromagnet (Tc=69 K). In the present thesis, the author has investigated the electronic structure of different types of EuO by density functional theory. The on-site Coulomb interaction of the localized Eu 4f and 5d electrons, which is wrongly treated in the standard generalized gradient approximation method, is found to be crucial to obtain the correct insulating ground state as observed in experiments. Our results show that the ferromagnetism is stable under pressure, both hydrostatic and uniaxial. For both types of pressure an insulator-metal transition is demonstrated. Moreover, the experimentally observed insulator-metal transition in oxygen deficient and gadolinium-doped EuO is reproduced in our calculations for impurity concentrations of 6.25% and 25%. Furthermore, a 10- layer EuO thin film is theoretically predicted to be an insulator with a narrow band gap of around 0.08 eV, while the Si/EuO interface shows metallic properties with the Si and O 2p as well as Eu 5d bands crossing the Fermi level.

  14. Investigations of white light emitting europium doped zinc oxide nanoparticles

    International Nuclear Information System (INIS)

    Ashtaputre, S S; Nojima, A; Marathe, S K; Matsumura, D; Ohta, T; Tiwari, R; Dey, G K; Kulkarni, S K

    2008-01-01

    Europium doped zinc oxide nanoparticles have been synthesized using a chemical route. The amount of doped europium was varied which shows the changes in the photoluminescence (PL) intensity. The post synthesis annealing effect on the properties of ZnO nanoparticles has also been investigated. In general, PL is broad and a white light is emitted which originates from ZnO and the intra-4f transitions of Eu 3+ ions. The x-ray diffraction patterns do not show any Eu-related peaks for as-synthesized ZnO nanoparticles as well as for annealed samples. X-ray absorption spectroscopy reveals that europium ions are present on the surface of the core of ZnO and inside the shell of zinc hydroxide [Zn(OH 2 )] after annealing

  15. Barium Sulfate

    Science.gov (United States)

    ... uses a computer to put together x-ray images to create cross-sectional or three dimensional pictures of the inside of the body). Barium sulfate is in a class of medications called radiopaque contrast media. It works by coating the esophagus, stomach, or ...

  16. Excess europium content in Precambrian sedimentary rocks and continental evolution

    Science.gov (United States)

    Jakes, P.; Taylor, S. R.

    1974-01-01

    It is proposed that the europium excess in Precambrian sedimentary rocks, relative to those of younger age, is derived from volcanic rocks of ancient island arcs, which were the source materials for the sediments. Precambrian sedimentary rocks and present-day volcanic rocks of island arcs have similar REE patterns, total REE abundances, and excess Eu, relative to the North American shale composite. The present upper crustal REE pattern, as exemplified by that of sediments, is depleted in Eu, relative to chondrites. This depletion is considered to be a consequence of development of a granodioritic upper crust by partial melting in the lower crust, which selectively retains europium.

  17. Enantioselective cellular localisation of europium(iii) coordination complexes.

    Science.gov (United States)

    Frawley, Andrew T; Linford, Holly V; Starck, Matthieu; Pal, Robert; Parker, David

    2018-01-28

    The selective mitochondrial localisation of the Λ enantiomer of three different emissive europium(iii) complexes in NIH 3T3 and MCF7 cells contrasts with the behaviour of the Δ enantiomer, for which a predominant lysosomal localisation was observed by confocal microscopy. In each case, cell uptake occurs via macropinocytosis.

  18. Stability constants of the Europium complexes with the chloride ions

    International Nuclear Information System (INIS)

    Jimenez R, M.; Solache R, M.; Rojas H, A.

    2000-01-01

    The stability constants of lanthanides complexes with chloride ions which were determined at the same ionic force but in different media, are significantly different. It does not exist a systematic study over these stability constants. The purpose of this work is to determine the stability constants of the europium complexes with chloride ions at 303 K, by the solvents extraction method. (Author)

  19. White OLED with a single-component europium complex.

    Science.gov (United States)

    Law, Ga-Lai; Wong, Ka-Leung; Tam, Hoi-Lam; Cheah, Kok-Wai; Wong, Wing-Tak

    2009-11-16

    A new direction for white organic light-emitting devices is shown, fabricated from a novel europium complex; this single component contains a double emission center of bluish-green and red, combined to a give a pure white emission (CIE x = 0.34 and y = 0.35).

  20. Sorption of europium by Haro river sand in aqueous solution

    International Nuclear Information System (INIS)

    Syed Moosa Hasany; Syed Javaid Khurshid

    1997-01-01

    The sorption of Eu(III) on Haro river sand has been investigated. Influences include composition of the sorptive medium, the concentration of sorbent and sorbate, and shaking time. Haro river sand can be exploited for the preconcentration and removal of europium from very dilute solutions, for the decontamination and treatment of radioactive waste water and effluents from nuclear installations. (Author)

  1. SEPARATION OF EUROPIUM FROM OTHER LANTHANIDE RAE EARTHS BY SOLVENT EXTRACTION

    Science.gov (United States)

    Peppard, D.F.; Horwitz, E.P.; Mason, G.W.

    1963-02-12

    This patent deals with a process of separating europium from other lanthanides present in aqueous hydrochloric or sulfuric acid solutions. The europium is selectively reduced to the divalent state with a divalent chromium salt formed in situ from chromium(III) salt plus zinc amalgam. The other trivalent lanthanides are then extracted away from the divalent europium with a nitrogen-flushed phosphoric acid ester or a phosphonic acid ester. (AEC)

  2. Extraction of europium (3) ions with stearic acid

    International Nuclear Information System (INIS)

    Lobanov, F.I.; Gladyshchev, V.P.; Nurtaeva, A.K.; Andreeva, N.N.

    1981-01-01

    Extraction of europium (3) in nitric acid solutions with the melts of stearic acid and its mixtures with paraffin at (80+-1) deg C is studied. The constant of stearic acid dimerization in paraffin K 2 =9.6+-0.6 and the constant of stearic acid distribution in the paraffin-water system Ksub(D,HA)=(1.06+-0.07)x10sub(3) are determined. The diagram of europium ion extraction at initial concentrations of metal in the aqueous phase of 10 -4 -10 -3 mol/l is suggested. The compound extracted has the EuA 3 composition with extraction constant of lg Ksub(ex)=-7.58 [ru

  3. Bioenvironmental aspects of europium and rhodium: a selected bibliography

    International Nuclear Information System (INIS)

    Fore, C.S.; Carrier, R.F.; Talmage, S.S.; Fielden, J.M.; Daniel, E.W.

    1983-09-01

    This bibliography of 428 abstracted references represents a summary of the domestic and foreign literature relevant to the biological and environmental aspects of europium and rhodium. The collected data are organized by current NAEG interests - research highlighting inventory and distribution of the radionulcides, ecological studies covering terrestrial and aquatic systems, and biological studies in both man and animals. Studies that focus directly on research conducted at specific sites (e.g., the Nevada Test Site) are emphasized throughout the bibliography

  4. Synthesis and luminescence properties for europium oxide nanotubes

    International Nuclear Information System (INIS)

    Mo Zunli; Deng Zhepeng; Guo Ruibin; Fu Qiangang; Feng Chao; Liu Pengwei; Sun Yu

    2012-01-01

    Highlights: ► A novel high temperature sensitive fluorescent CNTs/Eu 2 O 3 nanocomposite was fabricated. ► The nanocomposite showed strong fluorescent emission peaks at around 540 and 580 nm after calcined beyond 620 °C for 4 h. ► The ultrahigh fluorescence intensity of the nanocomposites resulted from a synergetic effect of CNTs and europium oxide. ► We also discovered that CNTs had an effect of fluorescence quenching. - Abstract: A novel high temperature sensitive fluorescent nanocomposite has been successfully synthesized by an economic hydrothermal method using carbon nanotubes (CNTs), europium oxide, and sodium dodecyl benzene sulfonate (SDBS). To our great interest, the nanocomposites show high temperature sensitivity after calcinations at various temperatures, suggesting a synergetic effect of CNTs and europium oxide which leads to ultrahigh fluorescence intensity of europium oxide nanotubes. When the novel high temperature sensitive fluorescent nanocomposites were calcined beyond 620 °C for 4 h, the obtained nanocomposites have a strong emission peak at around 540 and 580 nm, due to the 5 D 0 → 7 F j (j = 0, 1) forced electric dipole transition of Eu 3+ ions. In turn, the emission spectra showed a slight blue shift. The intensity of this photoluminescence (PL) band is remarkably temperature-dependent and promotes strongly beyond 620 °C. This novel feature is attributed to the thermally activated carrier transfer process from nanocrystals and charged intrinsic defects states to Eu 3+ energy levels. The novel high temperature sensitive fluorescent nanocomposite has potential applications in high temperature warning materials, sensors and field emission displays. It is also interesting to discover that CNTs have the effect of fluorescence quenching.

  5. Luminescent micro- and nanofibers based on novel europium phthalate complex

    Energy Technology Data Exchange (ETDEWEB)

    Enculescu, M., E-mail: mdatcu@infim.ro [National Institute of Materials Physics, Multifunctional Materials and Structures, PO Box MG-7, 77125 Magurele-Bucharest (Romania); Preda, N.; Matei, E.; Enculescu, I. [National Institute of Materials Physics, Multifunctional Materials and Structures, PO Box MG-7, 77125 Magurele-Bucharest (Romania)

    2012-09-14

    We synthesized by wet chemical route a novel europium-potassium phthalate complex Eu{sup 3+}K{sup +}[(COO){sub 2}(C{sub 6}H{sub 4})]{sub 2}. The compound is a white powder insoluble in water. X-ray diffraction evaluation shows that we obtained a new crystalline compound with no traces of the starting materials (potassium hydrogen phthalate and europium chloride). Scanning electron microscopy reveals that the powder consists of fiber-shaped structures with sizes larger than 250 nm in diameter. Energy dispersive X-ray analysis proves that the compound has a 1:1 europium-potassium ratio. Fourier transform infrared spectroscopy confirms the presence of the phthalate in the new compound. Photoluminescence and cathodoluminescence measurements show that the fiber-shaped structures are intensely luminescent with emission bands corresponding to the {sup 5}D{sub 0} {yields} {sup 7}F{sub J} (J = 1-4) Eu (III) ion's transitions in the region between 580 nm and 700 nm, the most intense maximum being observed around 615 nm. Up-converted luminescence with a maximum at 315 nm was recorded. -- Highlights: Black-Right-Pointing-Pointer A new europium-potassium phthalate complex was synthesized by wet chemical route. Black-Right-Pointing-Pointer Fiber-shaped crystalline structures with sizes larger than 250 nm. Black-Right-Pointing-Pointer The most probable structure of the molecule is [C{sub 6}H{sub 4}(COO{sup -}){sub 2}]{sub 2} K{sup +}Eu{sup 3+}. Black-Right-Pointing-Pointer Intense luminescence due to Eu{sup 3+} ions {sup 5}D{sub 0} {yields} {sup 7}F{sub J} transitions. Black-Right-Pointing-Pointer Up-converted luminescence with a maximum at 315 nm was recorded.

  6. Optical and magnetization studies on europium based iron pnictides

    Energy Technology Data Exchange (ETDEWEB)

    Zapf, Sina Maria Ute

    2015-07-01

    The investigations carried out in the framework of this thesis mainly concentrate on europium based iron pnictides. These are a peculiar member of the 122 family as they develop at low temperatures (∝20K) an additional magnetic order of the local rare earth moments. Therefore, europium based iron pnictides provide a unique platform to study the interplay of structural, magnetic and electronic effects in high-temperature superconductors. For this challenging purpose, we have employed SQUID magnetometry and Fourier-transform infrared spectroscopy on EuFe{sub 2}(As{sub 1-x}P{sub x}){sub 2} single crystals. By systematic studies of the in- and out-of-plane magnetic properties of a series of single crystals, we derived the complex magnetic phase diagram of europium based iron pnictides, which contains an A-type antiferromagnetic and a re-entrant spin glass phase. Furthermore, we have investigated the magneto-optical properties of EuFe{sub 2}As{sub 2}, revealing a much more complex magnetic detwinning process than expected. These studies demonstrate a remarkable interdependence between magnetic, electronic and structural effects that might be very important to understand the unconventional superconductivity in these fascinating materials.

  7. Optical and magnetization studies on europium based iron pnictides

    International Nuclear Information System (INIS)

    Zapf, Sina Maria Ute

    2015-01-01

    The investigations carried out in the framework of this thesis mainly concentrate on europium based iron pnictides. These are a peculiar member of the 122 family as they develop at low temperatures (∝20K) an additional magnetic order of the local rare earth moments. Therefore, europium based iron pnictides provide a unique platform to study the interplay of structural, magnetic and electronic effects in high-temperature superconductors. For this challenging purpose, we have employed SQUID magnetometry and Fourier-transform infrared spectroscopy on EuFe 2 (As 1-x P x ) 2 single crystals. By systematic studies of the in- and out-of-plane magnetic properties of a series of single crystals, we derived the complex magnetic phase diagram of europium based iron pnictides, which contains an A-type antiferromagnetic and a re-entrant spin glass phase. Furthermore, we have investigated the magneto-optical properties of EuFe 2 As 2 , revealing a much more complex magnetic detwinning process than expected. These studies demonstrate a remarkable interdependence between magnetic, electronic and structural effects that might be very important to understand the unconventional superconductivity in these fascinating materials.

  8. Synthesis of xerogels with Europium impurities for dosimetric applications

    International Nuclear Information System (INIS)

    Rivera R, C.; Garcia R, F.J.; Yanez L, M. -

    2007-01-01

    The objective of this work is the obtaining xerogels in bundle of SiO 2 with europium impurities to low concentrations, with the objective of exploring their mechanical, optical and emission properties. The obtained xerogels was synthesized by means of the sol-gel technique, using water, TEOS and ethanol to a molar relationship 16:1:4 respectively, the europium was added by oxide via to the precursor solution and to catalyze the hydrolysis condensation reaction, its were added: nitric acid and hydrofluorhydric acid. Later on these mixtures were left to gel by 72 hours and under this same composition, but with different quantities of impurifying material (0.0, 0.01 and 0.05g of europium oxide), the materials were dried in a ramp of controlled temperature, from ambient temperature up to 120 C, some of these thermally tried materials were calcined at 500 and 800 C, being obtained in this way xerogels free of fractures, stable, porous and semi-transparent. The characterization of these materials includes: pH measurements and solutions viscosity during the gelation stage, as well as characterization of their optic properties by means of infrared spectroscopy, UV-vis and emission spectroscopy. The microhardness results show that these materials present smaller values to those corresponding of the corning glass, as well as a growing behavior with regard to the calcination temperatures of the material. (Author)

  9. Characterisation of kaolinite and adsorption of europium on kaolinite

    International Nuclear Information System (INIS)

    Olin, M.; Puhakka, E.; Lehikoinen, J.; Puukko, E.; Hakanen, M.; Lindberg, A.

    2007-10-01

    Kaolinite is a common fracture mineral in many crystalline rocks and, thus, a potential sorbent for groundwater solutes. The low cation-exchange capacity makes kaolinite a good mineral to study sorption by inner-sphere complexation of multivalent ions, such as trivalent actinides or their analogues, the trivalent lanthanides. The sorption of europium and americium on kaolinite has been studied previously by Puukko and Hakanen using a natural kaolinite, KGa-1b (from the Clay Minerals Society, USA). This work describes the determination of surface-charging mechanism and surface acidity constants for KGa-1b kaolinite, and adsorption of Eu(III) on both the natural (KGa-1b) and its acid-conditioned form (HKGa). The ionic strength of the background NaNO 3 electrolyte used in these titrations was 0.05 M, 0.1 M and 0.5 M. The surface acidity of kaolinite was explained using the FITEQL software by applying the 1-pK model. The optimized concentration of surface sites was close to a value previously reported for KGa-1b kaolinite. The adsorption modelling of europium was carried out by adopting one surfacecomplexation and one cation-exchange reaction. In the acidic pH range, sorption of europium decreased with increasing ionic strength of the NaNO 3 solution, which is an indication of the dominance of cation exchange or outer-sphere complexation. At the lowest ionic strength, the sorption was reversible. In the 0.1 M and 0.5 M NaNO 3 solutions, the sorption of europium in the basic pH range was only partly reversible, or desorption kinetically slow. The degree of irreversibility increased with increasing pH and ionic strength. A diffuse-layer model was readily fitted on the per-cents sorbed scale (default in FITEQL), but the results were not as good on a Kd scale, especially at circumneutral pH values. In the water analysis of the batch titration of KGa-1b kaolinite, the main observed elements were aluminium and zinc. The concentrations of Al and Zn decreased with p

  10. Enhancement in red emission at room temperature from europium doped ZnO nanowires by 1,10 phenanthroline-europium interface induced resonant excitations

    Directory of Open Access Journals (Sweden)

    Soumen Dhara

    2017-02-01

    Full Text Available We show that europium doped ZnO nanowires after surface modification with organic ligand, 1,10 phenanthroline (phen leads to strong red emission at 613 nm which is a characteristic emission from the atomic levels of Eu3+. Surface modification with phen leads to formation of phenanthroline-europium interface on the surface of the nanowires due to attachment of Eu3+ ions. After an optimized surface modification with phen, intensity of both the UV emission (band edge and red emission improved by two orders of magnitude at room temperature. We observed multiple energy transfer pathways to the energy levels of Eu3+ ions through the phenanthroline-europium interface, which found to be very effective to the significant enhancement of emission from the dopant Eu3+. This study shows a new insight in to the energy transfer process from phen to the europium doped ZnO system.

  11. Sulfate adsorption on goethite

    Energy Technology Data Exchange (ETDEWEB)

    Rietra, R P.J.J.; Hiemstra, T; Riemsdijk, W.H. van

    1999-10-15

    Recent spectroscopic work has suggested that only one surface species of sulfate is dominant on hematite. Sulfate is therefore a very suitable anion to test and develop adsorption models for variable charge minerals. The authors have studied sulfate adsorption on goethite covering a large range of sulfate concentrations, surface coverages, pH values, and electrolyte concentrations. Four different techniques were used to cover the entire range of conditions. For characterization at low sulfate concentrations, below the detection limit of sulfate with ICP-AES, the authors used proton-sulfate titrations at constant pH. Adsorption isotherms were studied for the intermediate sulfate concentration range. Acid-base titrations in sodium sulfate and electromobility were used for high sulfate concentrations. All the data can be modeled with one adsorbed species if it is assumed that the charge of adsorbed sulfate is spatially distributed in the interface. The charge distribution of sulfate follows directly from modeling the proton-sulfate adsorption stoichoimemtry sine this stoichiometry is independent of the intrinsic affinity constant of sulfate. The charge distribution can be related to the structure of the surface complex by use of the Pauling bond valence concept and is in accordance with the microscopic structure found by spectroscopy. The intrinsic affinity constant follows from the other measurements. Modeling of the proton-ion stoichoimetry with the commonly used 2-pK models, where adsorbed ions are treated as point charges, is possible only if at least two surface species for sulfate are used.

  12. Synthesis and characterization of highly triboluminescent doped europium tetrakis compounds

    International Nuclear Information System (INIS)

    Fontenot, Ross S.; Hollerman, William A.; Bhat, Kamala N.; Aggarwal, Mohan D.

    2012-01-01

    One of the most intriguing properties involving crystals is their ability to emit light when fractured. While this property was discovered over 200 years ago, no one has ever been able to come up with a complete theory that can predict the physical principles associated with triboluminescence. However, this has not stopped scientists from coming up with various uses for these materials. One such application is to use these materials as the active element for smart impact sensors that can warn of catastrophic impacts. If these sensors are to become a reality however, the material must emit a bright light when fractured. One of the brightest triboluminescent materials found thus far is europium dibenzoylmethide triethylammonium (EuD 4 TEA). This material was discovered by Hurt in 1966 and is bright enough to be seen in daylight. In 2011, the authors discovered that synthesizing EuD 4 TEA using europium nitrate instead of chloride significantly increased the triboluminescence yield and made the synthesis much easier and more consistent. However, to date, there are few investigations into the effects of dopants on the triboluminescence of EuD 4 TEA. This paper reports the investigation of the effects of various dopants on: (1) The triboluminescent light yield, (2) Crystal size and structure, (3) Synthesis time, and (4) Prompt decay time. Results show that inclusion of dopants during synthesis increases the triboluminescence emission of EuD 4 TEA by 55%, significantly reduces the synthesis time, and controls the decay time. All of these properties can be useful for constructing the first prototype of a customized impact sensor. - Highlights: ► Doped europium dibenzoylmethide triethylammonium (EuD 4 TEA) was synthesized. ► Effects of dopants was studied from EuD 4 TEA during low velocity (<10 m/s) impacts. ► The triboluminescent light yield, decay time, and synthesis time were measured. ► A specially-built drop tower was developed to measure triboluminescence

  13. Mass spectrometric investigation of fluorated europium. beta. -diketonates. [Electrons

    Energy Technology Data Exchange (ETDEWEB)

    Khomenko, V.S.; Lozinskij, M.O.; Fialkov, Yu.A.; Rasshinina, T.A.; Suboch, V.P. (AN Belorusskoj SSR, Minsk. Inst. Fiziki; AN Ukrainskoj SSR, Kiev. Inst. Organicheskoj Khimii)

    Ternary complexes of europium with two organic ligands - fluorated ..beta..-diketone and organic base - in the aqueous phase at electron shock are investigated; regroupings that take place in them are established. Mass-spectrometric investigation has shown that complexes with ..beta..-diketones, containing in oxygen atom in a fluorated radical, eliminate stable molecules of difluorophosgen, CoF/sub 2/. For the complexes studied under the above conditions the Co molecule elimination is also typical which is accompanied by the formation of ions with a metal-carbon bond.

  14. Mass spectrometric investigation of fluorated europium β-diketonates

    International Nuclear Information System (INIS)

    Khomenko, V.S.; Lozinskij, M.O.; Fialkov, Yu.A.; Rasshinina, T.A.; Suboch, V.P.; AN Ukrainskoj SSR, Kiev. Inst. Organicheskoj Khimii)

    1983-01-01

    Ternary complexes of europium with two organic lidands - fluorated β-diketone and organic base - in the aqueous phase at electron shock are investigated; regroupings that take place in them are established. Mass-spectrometric investigation has shown that complexes with β-diketones, containing in oxygen atom in a fluorated radical, eliminate stable molecules of difluorophosgen, CoF 2 . For the complexes studied under the above conditions the Co molecule elimination is also typical which is accompanied by the formation of ions with a metal-carbon bond

  15. Test of zircon materials for sorption of europium

    International Nuclear Information System (INIS)

    Ordonez R, E.; Fernandez V, S.M.; Garcia R, G.

    2003-01-01

    In previous works it has already been made notice that some phosphates have the property of sipping radioactive metals in solution, what takes advantage to fabricate reactive barriers that are placed in the repositories of nuclear wastes. In our laboratory it has been obtained to the zirconium silicate (ZrSiO 4 ) and the alpha zirconium hydrogen phosphate (Zr(HPO 4 ) 2H 2 0) starting from sea sand in an easy and economic way. With the interest of knowing if these compounds can be used in contention barriers the evaluation of their surface properties it is made and of europium sorption. (Author)

  16. In vivo toxicity studies of europium hydroxide nanorods in mice

    International Nuclear Information System (INIS)

    Patra, Chitta Ranjan; Abdel Moneim, Soha S.; Wang, Enfeng; Dutta, Shamit; Patra, Sujata; Eshed, Michal; Mukherjee, Priyabrata; Gedanken, Aharon; Shah, Vijay H.; Mukhopadhyay, Debabrata

    2009-01-01

    Lanthanide nanoparticles and nanorods have been widely used for diagnostic and therapeutic applications in biomedical nanotechnology due to their fluorescence and pro-angiogenic properties to endothelial cells, respectively. Recently, we have demonstrated that europium (III) hydroxide [Eu III (OH) 3 ] nanorods, synthesized by the microwave technique and characterized by several physico-chemical techniques, can be used as pro-angiogenic agents which introduce future therapeutic treatment strategies for severe ischemic heart/limb disease, and peripheral ischemic disease. The toxicity of these inorganic nanorods to endothelial cells was supported by several in vitro assays. To determine the in vivo toxicity, these nanorods were administered to mice through intraperitoneal injection (IP) everyday over a period of seven days in a dose dependent (1.25 to 125 mg kg -1 day -1 ) and time dependent manner (8-60 days). Bio-distribution of europium elements in different organs was analyzed by inductively coupled plasma mass spectrometry (ICPMS). Short-term (S-T) and long-term (L-T) toxicity studies (mice euthanized on days 8 and 60 for S-T and L-T, respectively) show normal blood hematology and serum clinical chemistry with the exception of a slight elevation of liver enzymes. Histological examination of nanorod-treated vital organs (liver, kidney, spleen and lungs) showed no or only mild histological changes that indicate mild toxicity at the higher dose of nanorods.

  17. Temperature dependences in electron-stimulated desorption of neutral europium

    CERN Document Server

    Ageev, V N; Madey, T E

    2003-01-01

    The electron-stimulated desorption (ESD) yield for neutral europium (Eu) atoms from Eu layers adsorbed on oxygen-covered tungsten surfaces has been measured as a function of electron energy, europium coverage and degree of oxidation of tungsten, with an emphasis on effects of substrate temperature. The measurements have been carried out using a time-of-flight method and surface ionization detector. We expand on an earlier report, and compare ESD of multivalent Eu with ESD of monovalent alkali atoms, studied previously. The Eu atom ESD is a complicated function of Eu coverage, electron energy and substrate temperature. In the coverage range 0.05-0.35 monolayer (ML), overlapping resonant-like Eu atom yield peaks are observed at electron energies E sub e of 36 and 41 eV that might be associated with Eu or W shallow core level excitations. Additional resonant-like peaks are seen at E sub e of 54 and 84 eV that are associated with W 5p and 5s level excitations. The Eu atom yield peaks at 36 and 41 eV are seen only...

  18. Trivalent europium speciation in a room-temperature ionic liquid

    International Nuclear Information System (INIS)

    Mekki, S.

    2006-10-01

    Since the nuclear industry is playing an important role in the power production field, a relevant number of problems have been revealed. Indeed, high-level radioactive long-lived nuclear wastes present a real difficulty for nuclear wastes management. Minor actinides, which compose most of these wastes, will be radioactive for several thousands of years. For eventual disposal deep underground, their reprocessing needs to be optimized. The extraction processes used industrially to separate actinides and lanthanides from other metal species characterizing the spent nuclear fuel produce, nevertheless, enormous quantities of contaminated liquid wastes directly issued from the liquid/liquid extraction step. During the last decade, some room-temperature ionic liquid have been studied and integrated into industrial processes. The interest on this class of solvent came out from their 'green' properties (non volatile, non flammable, recyclable, etc...), but also from the variability of their physico-chemical properties (stability, hydrophobicity, viscosity) as a function of the RTIL chemical composition. Indeed, it has been shown that classical chemical industrial processes could be transferred into those media, even more improved, while a certain number of difficulties arising from using traditional solvent can be avoided. In this respect, it could be promising to investigate the ability to use room-temperature ionic liquid into the spent nuclear fuel reprocessing field. The aim of this thesis is to test the ability of the specific ionic liquid bumimTf 2 N to allow trivalent europium extraction. The choice of this metal is based on the chemical analogy with trivalent minor actinides Curium and Americium which are contributing the greatest part of the long-lived high-level radioactive wastes. Handling these elements needs to be very cautious for the safety and radioprotection aspect. Moreover, europium is a very sensitive luminescent probe to its environment even at the

  19. Soluble dendrimers europium(III) β-diketonate complex for organic memory devices

    International Nuclear Information System (INIS)

    Wang Binbin; Fang Junfeng; Li Bin; You Han; Ma Dongge; Hong Ziruo; Li Wenlian; Su Zhongmin

    2008-01-01

    We report the synthesis of a soluble dendrimers europium(III) complex, tris(dibenzoylmethanato)(1,3,5-tris[2-(2'-pyridyl) benzimidazoly]methylbenzene)-europium(III), and its application in organic electrical bistable memory device. Excellent stability that ensured more than 10 6 write-read-erase-reread cycles has been performed in ambient conditions without current-induced degradation. High-density, low-cost memory, good film-firming property, fascinating thermal and morphological stability allow the application of the dendrimers europium(III) complex as an active medium in non-volatile memory devices

  20. Sorption of europium (3) by polymer sorbents with grafted heterocyclic nitrogen-containing groupings

    International Nuclear Information System (INIS)

    Bel'tyukova, S.V.; Kravchenko, T.B.; Balamtsarashvili, G.M.; Roska, A.S.

    1990-01-01

    On polymer sorbents (copolymer of styrene-divinylbenzene) with grafted heterocyclic nitrogen-containing functional groupings of tetrazole, triazole and imidazole (sorbents 1,2,3, respectively). It is stated that europium sorption takes place from neutral solutions in presence of organic solvents. Luminescent properties of europium on sorbent are used to develope methods of its determination in high purity lanthanide and yttrium oxides. Europium determination limits consist 7.5·10 -5 μg/ml on 1 and 3 sorbents and 1.5·10 -4 μg/ml on sorbent 2, S p value is 0.089 and 0.075, respectivaly

  1. Luminescent properties of europium different-ligand complexes with cyclic. beta. -diketones and diantipyrylalkanes

    Energy Technology Data Exchange (ETDEWEB)

    Ul' yanova, T M; Gerasimenko, G N; Tishchenko, M A; Vitkun, R A [AN Ukrainskoj SSR, Odessa. Fiziko-Khimicheskij Inst.

    1983-03-01

    Using luminescence method different-ligand complexing of europium ions with diantipyrylalkanes and cyclic ..beta..-diketones: 2-acetyl- and 2-benzoyl-1.3-indandions, has been studied. The optimum conditions of the formation of different-ligand complexes and the ratio of components in it are determined. Effect of alien lanthanides and diantipyrylmethane derivatives on the luminescence intensity of europium complexes is clarified. A correlation between the ratio of the luminescence intensity bands of europium complexes and the values of oscillator strengths of supersensitive transitions of neodymium and erbium absorption bands is established.

  2. Sorption of small amounts of europium(III) on iron(III) hydroxide and oxide

    International Nuclear Information System (INIS)

    Music, S.; Gessner, M.; Wolf, R.H.H.

    1979-01-01

    The sorption of small amounts of europium(III) on iron(III) hydroxide and oxide has been studied as a function of pH. The mechanism of sorption is discussed. Optimum conditions have been found for the preconcentration of small or trace amounts of europium(III) by iron(III) hydroxide and oxide. The influence of complexing agents (EDTA, oxalate, tartrate and 5-sulfosalicylic acid) on the sorption of small amounts of europium(III) on iron(III) oxide has also been studied. (author)

  3. Development of ultraviolet LED devices containing europium (III) complexes in fluorescence layer

    International Nuclear Information System (INIS)

    Iwanaga, Hiroki; Amano, Akio; Aiga, Fumihiko; Harada, Kohichi; Oguchi, Masayuki

    2006-01-01

    Relations between molecular structures of europium complexes and their luminescent properties were investigated. Europium complex with β-diketones and two different phosphine oxides 8 was highly soluble in fluorinated medium, and realized largest fluorescence intensities. The luminous intensity of ultraviolet light emitting diodes devices (LEDs) whose fluorescence layer consists of fluorinated polymer and 8 was over 200 mcd (20 mA). Fluorescence compounds of this type are promising for application in next-generation white LEDs. Moreover, we proposed a novel molecular design of europium complex with asymmetric diphosphine dioxide

  4. Synthesis and spectroscopic behavior of highly luminescent trinuclear europium complexes with tris-β-diketone ligand

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dunjia, E-mail: dunjiawang@163.com; Pi, Yan; Liu, Hua; Wei, Xianhong; Hu, Yanjun; Zheng, Jing

    2014-11-15

    Highlights: • Synthesis of the tris-β-diketone ligand and its trinuclear europium complexes. • Photoluminescence behavior of trinuclear europium complexes. • Analysis of the Judd–Ofelt intensity parameters (Ω{sub t}), lifetime (τ) and quantum yield (η). - Abstract: A new tris-β-diketone ligand, 2-[4,6-bis-(1-benzoyl-2-oxo-2-phenyl-ethyl)-[1,3,5]triazin-2-yl] -1,3-diphenyl-propane-1,3-dione (H{sub 3}L), and its trinuclear europium complexes, Eu{sub 3}(DBM){sub 6}L (C1), Eu{sub 3}(DBM){sub 6}(Bipy){sub 3}L (C2) and Eu{sub 3}(DBM){sub 6}(Phen){sub 3}L (C3) were synthesized and their spectroscopic behaviors were studied by FT-IR, {sup 1}H NMR, UV–vis and photoluminescence spectroscopic techniques. These europium complexes exhibited the characteristic emission bands that arise from the {sup 5}D{sub 0} → {sup 7}F{sub J} (J = 0–4) transitions of the europium ion in solid state. The Ω{sub 2} and Ω{sub 4} intensity parameters, lifetime (τ) and luminescence quantum yield (η) were calculated according to the emission spectra and luminescence decay curves in solid state. The results indicated that these trinuclear europium complexes displayed a longer lifetime (τ) and higher luminescence quantum efficiency (η), especially complexes C2 (τ = 0.820 ms, η = 46.5%) and C3 (τ = 0.804 ms, η = 47.4%), which due to the effect of two additional europium ion lumophors and the introduction of the third ligands, Bipy or Phen in trinuclear complexes. Their Ω{sub 2} values demonstrated that the europium ion in these complexes is in a highly polarizable chemical environment.

  5. Luminescent amine sensor based on europium(III) chelate.

    Science.gov (United States)

    Petrochenkova, Nataliya V; Mirochnik, Anatolii G; Emelina, Tatyana B; Sergeev, Alexander A; Leonov, Andrei A; Voznesenskii, Sergey S

    2018-07-05

    The effect of methylamine vapor on luminescence of Eu(III) tris-benzoylacetonate (I) immobilized in thin-layer chromatography plates has been investigated. It has been revealed that interaction of I with analyte vapor results in increase of the intensity of Eu(III) luminescence. The mechanism of the effect of methylamine vapors on intensification of the Eu(III) luminescence has been suggested using the data of IR spectroscopy and quantum chemistry calculations. The mechanism of luminescence sensitization consists in bonding of an analyte molecule with a water molecule into the coordination sphere of Eu(III). As a result, the bond of a water molecule with the luminescence centre weakens, rigid structural fragment including europium ion, water and methylamine molecules forms. The presence of such fragment must naturally promote decrease of influence of OH-vibrations on luminescence of the complex I. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Preparation of 1 Ci of europium 155 without carrier

    International Nuclear Information System (INIS)

    Falconi, N.; Radicella, R.

    1968-01-01

    High activity 'point' sources of 155 Eu are used for medical and industrial applications. For this purpose we have studied a method of obtaining I Ci of carrier free 155 Eu, with a solid residue smaller than 5 mg per Ci. In order to separate the 155 Eu from several grams of a 154 Sm enriched target we propose a procedure which is based on the work of Bouissieres and David, Onstott, and Takekoshi et al. The separation is carried out by electrolysis on a mercury cathode followed by purification on ion exchange resin. The yields of the europium separation and target recovery are 80 per cent and 90 per cent respectively. The time required for the procedure is three days. (authors) [fr

  7. Ferromagnetic semiconductor-metal transition in heterostructures of europium monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Stollenwerk, Tobias; Kroha, Johann [Physikalisches Institut der Universitaet Bonn (Germany)

    2012-07-01

    Experiments on thin films of electron doped europium monoxide show a simultaneous ferromagnetic semiconductor-metal transition which goes along with a huge drop in resistivity over several orders of magnitude. Therefore, this material is a very promising candidate for spintronics applications. We have developed a theory which correctly predicts the simultaneous phase transition in thin films of electron doped EuO and the increase of the Curie temperature T{sub C} with doping concentration. The origin of the increased T{sub C} lies in the enhanced RKKY interaction between the localized 4f moments of the Eu atoms. Therefore, the phase transition is controlled by the population of the conduction band. We investigate the influence of film thickness and interface effects on the population of the conduction band and on the magnetic and electronic properties of the EuO film.

  8. Magnetic and structural properties of yellow europium oxide compound and Eu(OH)3

    International Nuclear Information System (INIS)

    Lee, Dongwook; Seo, Jiwon; Valladares, Luis de los Santos; Avalos Quispe, O.; Barnes, Crispin H.W.

    2015-01-01

    A new material based on a yellow europium oxide compound was prepared from europium oxide in a high vacuum environment. The structural and magnetic properties of the material were investigated. Owing to the absence of a crystal structure, the material exhibited a disordered magnetic behavior. In a reaction with deionized (DI) water without applied heat, the compound assumed a white color as soon as the DI water reached the powder, and the structure became polycrystalline Eu(OH) 3 . The magnetic properties, such as the thermal hysteresis, disappeared after the reaction with DI water, and the magnetic susceptibility of the yellow oxide compound weakened. The magnetic properties of Eu(OH) 3 were also examined. Although Eu 3+ is present in Eu(OH) 3 , a high magnetic moment due to the crystal field effect was observed. - Graphical abstract: (top left) Optical image of the yellow europium oxide compound. (top right) Optical image of the product of DI water and yellow europium oxide. (bottom) Magnetization curves as a function of temperature measured in various magnetic field. - Highlights: • We prepared a new material based on a yellow europium oxide compound from europium oxide. • We characterized the magnetic properties of the material which exhibits a disordered magnetic behavior such as thermal hysteresis. • The compound turned white (Eu(OH) 3 ) as soon as the DI water reached the powder. • The thermal hysteresis disappeared after the reaction with DI water and the magnetic susceptibility of the yellow oxide compound weakened

  9. Purification and measurement of acid leachable europium in sands as an aid in the study of sediment transport

    International Nuclear Information System (INIS)

    Ditchburn, R.G.; McCabe, W.J.

    1982-05-01

    The use of europium labelled sand as an aid in the study of sediment transport has been suggested. A method for the purification of acid leachable europium is described. The final measurement is made by flame emission spectrometry using a nitrous oxide-acetylene flame. The usefulness of the method is limited by the natural levels of europium which, in the sand studied, was around 0.3 ppm

  10. Rare earth sulfates

    International Nuclear Information System (INIS)

    Komissarova, L.N.; Shatskij, V.M.; Pokrovskij, A.N.; Chizhov, S.M.; Bal'kina, T.I.; Suponitskij, Yu.L.

    1986-01-01

    Results of experimental works on the study of synthesis conditions, structure and physico-chemical properties of rare earth, scandium and yttrium sulfates, have been generalized. Phase diagrams of solubility and fusibility, thermodynamic and crystallochemical characteristics, thermal stability of hydrates and anhydrous sulfates of rare earths, including normal, double (with cations of alkali and alkaline-earth metals), ternary and anion-mixed sulfates of rare earths, as well as their adducts, are considered. The state of ions of rare earths, scandium and yttrium in aqueous sulfuric acid solutions is discussed. Data on the use of rare earth sulfates are given

  11. The ceric sulfate dosimeter

    DEFF Research Database (Denmark)

    Bjergbakke, Erling

    1970-01-01

    The process employed for the determination of absorbed dose is the reduction of ceric ions to cerous ions in a solution of ceric sulfate and cerous sulfate in 0.8N sulfuric acid: Ce4+→Ce 3+ The absorbed dose is derived from the difference in ceric ion concentration before and after irradiation...

  12. Europium-doped calcium titanate: Optical and structural evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Mazzo, Tatiana Martelli; Pinatti, Ivo Mateus [INCTMN, LIEC, Departamento de Química, Universidade Federal de São Carlos, P.O. Box 676, 13565-905 São Carlos, SP (Brazil); Macario, Leilane Roberta [INCTMN, LIEC, Instituto de Química, Universidade Estadual Paulista, P.O. Box 355, 14800-900 Araraquara, SP (Brazil); Avansi, Waldir [Centro de Ciências Exatas e de Tecnologia, Departamento de Física, Universidade Federal de São Carlos, Jardim Guanabara, 13565-905 São Carlos, SP (Brazil); Moreira, Mario Lucio [Instituto de Física e Matemática, Universidade Federal de Pelotas, P.O. Box 354, Campus do Capão do Leão, 96001-970 Pelotas, RS (Brazil); Rosa, Ieda Lucia Viana, E-mail: ilvrosa@ufscar.br [INCTMN, LIEC, Departamento de Química, Universidade Federal de São Carlos, P.O. Box 676, 13565-905 São Carlos, SP (Brazil); Mastelaro, Valmor Roberto [Instituto de Física de São Carlos, Departamento de Física e Ciência dos Materiais, Universidade de São Paulo, P.O. Box 369, Av Trabalhador São Carlense 400, 13560-970 São Carlos, SP (Brazil); Varela, José Arana; Longo, Elson [INCTMN, LIEC, Instituto de Química, Universidade Estadual Paulista, P.O. Box 355, 14800-900 Araraquara, SP (Brazil)

    2014-02-05

    Highlights: • CaTiO{sub 3}:Eu{sup 3+} were obtained using low temperatures and very short reactional times. • The Eu{sup 3+} changes the local order–disorder of the [TiO{sub 6}] and [CaO{sub 12}] clusters. • Lifetime decay curves reveal two sites of symmetry of the Eu{sup 3+} in the CT matrix. • CaTiO{sub 3}:Eu{sup 3+} exhibit the strongest luminescent intensity and pure red color. -- Abstract: Pure Calcium Titanate (CT-pure) and Europium doped Calcium Titanate Ca{sub 1−x}Eu{sub x}TiO{sub 3} (x = 0.5%, 1.0% and 2.0% molar ratio of Eu{sup 3+} ions) powders were synthesized by hydrothermal microwave method (HTMW) at 140 °C for 8 min. The HTMW method appears to be an efficient method to prepare the luminescence materials using low temperatures and very short reactional times. In addition it is possible to determine specific correlations imposed by TiCl{sub 4} replacement by titanium isopropoxide [Ti(OC{sub 3}H{sub 7}){sub 4}] changing the reaction character and resulting in two different options of europium doping CT syntesis. To evaluate the influence of the structural order–disorder among the reactions and different properties of these materials, the following techniques were used for characterization. XANES spectroscopy that revealed that the introduction of Eu{sup 3+} ions into the CT lattice induces to significant changes in the local order–disorder around both, [TiO{sub 6}] and [CaO{sub 12}], complex clusters. PL spectra show Eu{sup 3+} emission lines ascribed to the Eu{sup 3+} transitions from {sup 5}D{sub 0} excited states to {sup 7}F{sub J} (J = 0, 1–4) fundamental states in CT:Eu{sup 3+} powders excited at 350 and 394 nm.

  13. Heparan sulfate biosynthesis

    DEFF Research Database (Denmark)

    Multhaupt, Hinke A B; Couchman, John R

    2012-01-01

    Heparan sulfate is perhaps the most complex polysaccharide known from animals. The basic repeating disaccharide is extensively modified by sulfation and uronic acid epimerization. Despite this, the fine structure of heparan sulfate is remarkably consistent with a particular cell type. This suggests...... that the synthesis of heparan sulfate is tightly controlled. Although genomics has identified the enzymes involved in glycosaminoglycan synthesis in a number of vertebrates and invertebrates, the regulation of the process is not understood. Moreover, the localization of the various enzymes in the Golgi apparatus has......-quality resolution of the distribution of enzymes. The EXT2 protein, which when combined as heterodimers with EXT1 comprises the major polymerase in heparan sulfate synthesis, has been studied in depth. All the data are consistent with a cis-Golgi distribution and provide a starting point to establish whether all...

  14. Preparation of 1 Ci of europium 155 without carrier; Une methode de production d'europium 155 sans entraineur au niveau du curie

    Energy Technology Data Exchange (ETDEWEB)

    Falconi, N; Radicella, R [Commissariat a l' Energie Atomique, Dir. des Materiaux et Combustibles Nucleaires, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    High activity 'point' sources of {sup 155}Eu are used for medical and industrial applications. For this purpose we have studied a method of obtaining I Ci of carrier free {sup 155}Eu, with a solid residue smaller than 5 mg per Ci. In order to separate the {sup 155}Eu from several grams of a {sup 154}Sm enriched target we propose a procedure which is based on the work of Bouissieres and David, Onstott, and Takekoshi et al. The separation is carried out by electrolysis on a mercury cathode followed by purification on ion exchange resin. The yields of the europium separation and target recovery are 80 per cent and 90 per cent respectively. The time required for the procedure is three days. (authors) [French] L'obtention de sources ponctuelles de haute activite d'europium-l55 est interessante tant pour des usages medicaux qu'industriels. Nous avons cherche le moyen de preparer en une seule fois, une solution d'un curie d'europium-155 sans entraineur presentant un extrait sec inferieur a 5 mg par curie. En se basant sur des travaux de Bouissieres et Davis, d'Onstott, et de Takekoshi et coll., nous avons mis au point une methode permettant de separer l'europium-155 de sa cible de samarium enrichi en {sup 154}Sm par une electrolyse sur cathode de mercure suivie d'une purification sur resine echangeuse d'ions. Les rendements chimiques de separation de l'europium et de recuperation de la cible de samarium enrichi sont respectivement de 80 pour cent et 90 pour cent. La duree de l'operation est de 3 jours. (auteurs)

  15. Use of europium ions for SAD phasing of lysozyme at the Cu Kα wavelength

    International Nuclear Information System (INIS)

    Vijayakumar, Balakrishnan; Velmurugan, Devadasan

    2012-01-01

    Europium(III) ions bound to the surface of hen egg-white lysozyme were found to exhibit good anomalous signal facilitating SAD phasing using laboratory-source data and automated model building. The europium ion-binding sites were observed up to the 15σ level. Europium is shown to be a good anomalous scatterer in SAD phasing for solving the structure of biological macromolecules. The large value of the anomalous contribution of europium, f′′ = 11.17 e − , at the Cu Kα wavelength is an advantage in de novo phasing and automated model building. Tetragonal crystals of hen egg-white lysozyme (HEWL) incorporating europium(III) chloride (50 mM) were obtained which diffracted to a resolution of 2.3 Å at a wavelength of 1.54 Å (Cu Kα). The master data set (360° frames) was split and analyzed for anomalous signal-to-noise ratio, multiplicity, completeness, SAD phasing and automated building. The structure solution and model building of the split data sets were carried out using phenix.autosol and phenix.autobuild. The contributions of the Eu ions to SAD phasing using in-house data collection are discussed. This study revealed successful lysozyme phasing by SAD using laboratory-source data involving Eu ions, which are mainly coordinated by the side chains of Asn46, Asp52 and Asp101 together with some water molecules

  16. Sulfur, cobalt and europium activation from the A-bombs in Japan

    International Nuclear Information System (INIS)

    Gritzner, M.L.; Egbert, S.D.; Woolson, W.A.

    1987-01-01

    Comparisons are made between calculations and measurements of in-situ sulfur, cobalt, and europium activation by neutrons at Hiroshima and Nagasaki to check the validity of the neutron sources and transport air-over-ground used in the new Dosimetry System 1986 (DS86). Europium and cobalt are activated by epithermal/thermal neutrons. The sulfur activation has an effective threshold around 2 MeV. Comparisons of sulfur activation at Hiroshima, which necessitate considering the tilt and heading of the cylindrically shaped Little Boy bomb, confirm the high energy neutron portion of the source relevant to sulfur activation. The europium and cobalt activation calculations tend to be higher than the measurements for ground ranges within 300 m and lower than the measurements beyond 700 m. Thus, the cobalt and europium measurements do not validate the source or the transport, embodied in DS87, for those neutrons relevant to europium and cobalt activation. Presently, it is unresolved as to whether the discrepancy can be explained as a problem in the measurements, in their interpretation, or as a problem in the calculations due to the source neutrons and/or their transport from source to the sample site

  17. Highly sensitive sorption-luminescence determination of trace europium with preconcentration on silica chemically modified with iminodiacetic acid

    International Nuclear Information System (INIS)

    Voronina, R.D.; Zorov, N.B.

    2007-01-01

    Features of a sorption-luminescence method for the determination of trace europium were studied. The method includes the preliminary sorption of europium at pH 7.1 from solutions with silica chemically modified with iminodiacetic acid, the subsequent treatment of the sorbent with 2-thenoyltrifluoroacetone at pH 8.0, and the measurement of the intensity of luminescence of the surface three-component europium complex at 613 nm. The effect of moisture as the quencher of luminescence of the surface europium complex was studied, and techniques for its removal were proposed. Sorption in the static mode provides the detection limit of europium of 7 x 10 -5 g/ml. The calibration plot is linear in the range of two orders of magnitude of europium concentration in solutions. The relative standard deviation in the determination of 1.5 x 10 -2 μg/ml europium is 5%. In the dynamic mode of sorption from 1000 ml of an analyzed solution with the use of sorption-desorption, the detection limit of europium of 8 x 10 -7 μg/ml was attained [ru

  18. Synergistic extraction of europium(III) in ammonium ionic liquid

    International Nuclear Information System (INIS)

    Rout, Alok; Venkatesan, K.A.; Antony, M.P.

    2016-01-01

    Room temperature ionic liquids have been receiving increased attention for possible applications in the area of nuclear fuel reprocessing and waste management due to their fascinating properties such as good ionicity, high solvation capability, properties tunable etc. Most of the studies in the literature on the extraction of metal ions with molecular extractants dissolved in ionic liquid diluents are making use of the hydrophobic ionic liquids containing imidazolium cations such as the 1-alkyl-3-methylimidazolium ion. From an environmental point of view, such ionic liquids are not suitable as the primary mode of the metal extraction is by cation exchange mechanism wherein ionic liquid cation is lost to the aqueous phase leading to aqueous contamination and issue of recyclability of organic phase. However, there are some hydrophobic ionic liquids such as trioctylmethylammonium chloride ((N 1888 )(Cl)), and trihexyl(tetradecyl)phoshonium chloride (Cyphos IL 101) that exhibit no cation exchange in the aqueous phase during extraction. In this context, the extraction behavior of europium(III) using a neutral extractant, octyl, phenyl-N.N-diisobutylmethylcarbamoylphophinoxide (CMPO) and/or an acidic extractant bis(ethylhexyl)phosphoric acid (D2EHPA) dissolved in the ammonium ionic liquid diluent, trioctylmethylammonium bis(trifluoromethanesulfonyl)imide, (N 1888 )(NTf 2 ). The extraction behavior of CMPO (or D2EHPA)/(N 1888 )((Tf 2 ) system was investigated as a function of different extraction parameters such as feed acidity, extractant concentration, equilibration time etc.

  19. RBS and RNRA studies on sorption of europium by apatite

    Energy Technology Data Exchange (ETDEWEB)

    Ohnuki, Toshihiko; Kozai, Naofumi; Isobe, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Murakami, Takashi; Yamamoto, Shunya; Aoki, Yasushi; Naramoto, Hiroshi

    1997-03-01

    The sorption mechanism of europium, alternative of trivalent TRU has been studied based on the depth profiles of elements obtained by Rutherford Backscattering Spectroscopy (RBS) and Resonant Nuclear Reaction Analysis (RNRA). The positive peak for Eu and the negative peak for Ca were observed in the subtracted RBS spectra of the apatites on which Eu was sorbed from that of the fresh apatite. This indicates that Eu was sorbed on apatite, while a fraction of Ca was released from apatite. The peak height for Eu in the RBS spectrum of the apatite obtained at 75degC was higher than that of the apatite at 40degC. The depth profile of hydrogen of the apatite on which Eu was sorbed was similar to that of the fresh apatite. The concentration of Eu in the solution decreased with increasing temperature. On the contrary, the concentration of Ca increased with increasing temperature. Thus, it is concluded that a fraction of Eu is exchanged for Ca in the structure of apatite. (author)

  20. Europium-Doped Lanthanum Hafnate Nanoparticles: Structure, Photoluminescence, and Radioluminescence

    Science.gov (United States)

    Wahid, Kareem; Pokhrel, Madhab; Mao, Yuanbing

    Due to their novel physical properties, nanostructured phosphors are of interest for radiation-based imaging and therapeutics. Herein, the structural and luminescent properties of europium-doped lanthanum hafnate (La2Hf2O7:xmol%Eu3+, x = 0 - 35) nanoparticles are investigated for use as scintillators. X-ray diffraction, Raman spectroscopy, and scanning electron microscopy confirm samples prepared through a combined co-precipitation and low-temperature molten salt synthetic process homogenously form spherical nanocrystals of 36 nm in the ordered pyrochlore phase. Ultraviolet and X-ray excitation of these samples induce strong red emissions in the 580 - 590 and 612 - 630 nm range corresponding to the 5D0->7 F1 magnetic dipole and 5D0->7 F2 electric dipole transitions of Eu3+. Optical response and quantum yield are optimized at 5% Eu3+; a proposed trade-off between quenching mechanisms (defect-states/cross-relaxation) and dopant concentration is discussed. Owing to their high density, large effective atomic number, and bright luminescence, these La2Hf2O7:xmol%Eu3+ nanoparticles warrant further investigation for scintillator applications. The authors thank the support from the Defense Threat Reduction Agency of the U.S. Department of Defense (award #HDTRA1- 10-1-0114).

  1. Chloride, bromide and iodide scintillators with europium doping

    Science.gov (United States)

    Zhuravleva, Mariya; Yang, Kan

    2014-08-26

    A halide scintillator material is disclosed where the halide may comprise chloride, bromide or iodide. The material is single-crystalline and has a composition of the general formula ABX.sub.3 where A is an alkali, B is an alkali earth and X is a halide which general composition was investigated. In particular, crystals of the formula ACa.sub.1-yEu.sub.yI.sub.3 where A=K, Rb and Cs were formed as well as crystals of the formula CsA.sub.1-yEu.sub.yX.sub.3 (where A=Ca, Sr, Ba, or a combination thereof and X=Cl, Br or I or a combination thereof) with divalent Europium doping where 0.ltoreq.y.ltoreq.1, and more particularly Eu doping has been studied at one to ten mol %. The disclosed scintillator materials are suitable for making scintillation detectors used in applications such as medical imaging and homeland security.

  2. A Preliminary Study of Europium Uptake by Yeast Cells. The Case of Kluveromyces Marxianus

    International Nuclear Information System (INIS)

    Anagnostopoulos, V.; Symeopoulos, B.

    2008-01-01

    The objective of the present work is an exploration of a cost effective recovery of lanthanides, either for minimizing the industrial processes losses, or for reasons related to Radioactive Waste Management. Specifically, the uptake of europium from aqueous solutions by Kluveromyces marxianus cells was studied. Moreover, this biotechnological approach turns out to be environmental friendly, considering that cells of Kluveromyces marxianus are readily available as wastes from food fermentation industries. Europium [ 152 Eu+ 154 Eu]-labelled solutions were used providing better accuracy and reproducibility of measurements, mainly in low concentration range. The effect of pH, contact time and europium initial concentration were investigated. Adsorption data were fitted to Langmuir and Freundlich sorption models and Scatchard plots were used to reveal the existence of at least two types of binding sites

  3. Magnetic and structural properties of yellow europium oxide compound and Eu(OH){sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dongwook, E-mail: dongwookleedl324@gmail.com [Cavendish Laboratory, University of Cambridge, J. J Thomson Av., Cambridge CB3 0HE (United Kingdom); Seo, Jiwon, E-mail: jiwonseo@yonsei.ac.kr [Department of Physics and IPAP, Yonsei University, Seoul 120-749 (Korea, Republic of); Valladares, Luis de los Santos [Cavendish Laboratory, University of Cambridge, J. J Thomson Av., Cambridge CB3 0HE (United Kingdom); Avalos Quispe, O. [Laboratorio de Cerámicos y Nanomateriales, Facultad de Ciencias Físicas, Universidad Nacional Mayor de San Marcos, Ap. Postal 14-0149, Lima, Perú (Peru); Barnes, Crispin H.W. [Cavendish Laboratory, University of Cambridge, J. J Thomson Av., Cambridge CB3 0HE (United Kingdom)

    2015-08-15

    A new material based on a yellow europium oxide compound was prepared from europium oxide in a high vacuum environment. The structural and magnetic properties of the material were investigated. Owing to the absence of a crystal structure, the material exhibited a disordered magnetic behavior. In a reaction with deionized (DI) water without applied heat, the compound assumed a white color as soon as the DI water reached the powder, and the structure became polycrystalline Eu(OH){sub 3}. The magnetic properties, such as the thermal hysteresis, disappeared after the reaction with DI water, and the magnetic susceptibility of the yellow oxide compound weakened. The magnetic properties of Eu(OH){sub 3} were also examined. Although Eu{sup 3+} is present in Eu(OH){sub 3}, a high magnetic moment due to the crystal field effect was observed. - Graphical abstract: (top left) Optical image of the yellow europium oxide compound. (top right) Optical image of the product of DI water and yellow europium oxide. (bottom) Magnetization curves as a function of temperature measured in various magnetic field. - Highlights: • We prepared a new material based on a yellow europium oxide compound from europium oxide. • We characterized the magnetic properties of the material which exhibits a disordered magnetic behavior such as thermal hysteresis. • The compound turned white (Eu(OH){sub 3}) as soon as the DI water reached the powder. • The thermal hysteresis disappeared after the reaction with DI water and the magnetic susceptibility of the yellow oxide compound weakened.

  4. Ferrous Sulfate (Iron)

    Science.gov (United States)

    ... are allergic to ferrous sulfate, any other medications tartrazine (a yellow dye in some processed foods and ... in, tightly closed, and out of reach of children. Store it at room temperature and away from ...

  5. Holothurian Fucosylated Chondroitin Sulfate

    Directory of Open Access Journals (Sweden)

    Vitor H. Pomin

    2014-01-01

    Full Text Available Fucosylated chondroitin sulfate (FucCS is a structurally distinct glycosaminoglycan found in sea cucumber species. It has the same backbone composition of alternating 4-linked glucuronic acid and 3-linked N-acetyl galactosamine residues within disaccharide repeating units as regularly found in mammalian chondroitin sulfates. However, FucCS has also sulfated fucosyl branching units 3-O-linked to the acid residues. The sulfation patterns of these branches vary accordingly with holothurian species and account for different biological actions and responses. FucCSs may exhibit anticoagulant, antithrombotic, anti-inflammatory, anticancer, antiviral, and pro-angiogenic activities, besides its beneficial effects in hemodialysis, cellular growth modulation, fibrosis and hyperglycemia. Through an historical overview, this document covers most of the science regarding the holothurian FucCS. Both structural and medical properties of this unique GAG, investigated during the last 25 years, are systematically discussed herein.

  6. DHEA-sulfate test

    Science.gov (United States)

    ... DHEA sulfate may be due to: Adrenal gland disorders that produce lower than normal amounts of adrenal hormones, including adrenal insufficiency and Addison disease The pituitary gland not producing normal amounts of its hormones ( hypopituitarism ) ...

  7. Nuclear orientation experiments on the magnetic moments of europium and gadolinium nuclei

    International Nuclear Information System (INIS)

    Berg, F.G. van den.

    1984-01-01

    In this thesis, experimental results on the ground state nuclear magnetic moments of europium and gadolinium isotopes are presented. The nuclear orientation experiments were performed on europium and gadolinium nuclei embedded in several host lattices. Attention is paid to the hyperfine interactions of the ions. Nuclear moments are discussed in the context of nuclear shell model. The theoretical framework is described for nuclear structure and low temperature nuclear orientation. Furthermore, the experimental techniques, the technical arrangement of the orientation apparatus, the methods for radiative detection and the use of nuclear orientation thermometry are described. (Auth.)

  8. Carbamoyl methylphosphine oxide derivatives of adamantane as americium and europium extractants

    International Nuclear Information System (INIS)

    Babain, V.A.; Alyapyshev, M.Yu.; Novakov, I.A.; Orlinson, B.S.; Savel'ev, E.N.; Shokova, Eh.A.; Serebrayannikova, A.E.; Kovalev, V.V.

    2007-01-01

    Adamantane di-1,3-carbamoyl methylphosphine oxide (CMPO) derivatives, where CMPO-groups connect with 1,3-positions of rigid adamantane platform by methylene and ethylene bridges, are synthesized, and their efficiency as extractants of americium(III) and europium(III) from nitric acid solutions is demonstrated. Distribution function of Am 3+ and Eu + during extraction from 3M HNO 3 are measured in the investigation of extraction properties. It is noted that first synthesized adamantane CMPO derivatives are more effective for the extraction of americium(III) and europium(III) from 3MHNO 3 [ru

  9. The europium and praseodymium hydrolysis in a 2M NaCl environment

    International Nuclear Information System (INIS)

    Jimenez R, M.; Lopez G, H.; Solache R, M.; Rojas H, A.

    1998-01-01

    It was studied the europium and praseodymium hydrolysis in a 2M NaCl ion force environment at 303 K, through two methods: this one extraction with dissolvents (lanthanide-water-NaCl-dibenzoylmethane) in presence of a competitive ligand (diglycolic acid) and that one direct potentiometric titration, of soluble species, followed by a computer refining. The values of one or another techniques of the first hydrolysis constants obtained were similar, which demonstrates that the results are reliable. The set of data obtained on the stability constants of hydrolysis products allowed to draw up the distribution diagrams of chemical species, as europium as praseodymium in aqueous environment. (Author)

  10. Direct Sulfation of Limestone

    DEFF Research Database (Denmark)

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2007-01-01

    The direct sulfation of limestone was studied in a laboratory fixed-bed reactor. It is found that the direct sulfation of limestone involves nucleation and crystal grain growth of the solid product (anhydrite). At 823 K and at low-conversions (less than about 0.5 %), the influences of SO2, O-2...... and CO2 on the direct sulfation of limestone corresponds to apparent reaction orders of about 0.2, 0.2 and -0.5, respectively. Water is observed to promote the sulfation reaction and increase the apparent reaction orders of SO2 and O-2. The influence of O-2 at high O-2 concentrations (> about 15...... %) becomes negligible. In the temperature interval from 723 K to 973 K, an apparent activation energy of about 104 kJ/mol is observed for the direct sulfation of limestone. At low temperatures and low conversions, the sulfation process is most likely under mixed control by chemical reaction and solid...

  11. Europium(II)heptaphosphide EuP/sub 7/

    Energy Technology Data Exchange (ETDEWEB)

    von Schnering, H G; Wittmann, M

    1980-07-01

    The novel polyphosphide, EuP/sub 7/, was prepared under controlled conditions by reaction of the elements in salt melts at 750-800 K. EuP/sub 7/ forms black prismatic crystals not attacked by dilute mineral acids and bases. The thermal decomposition yields EuP/sub 3/ at 700 K and in further steps EuP/sub 2/, Eu/sub 3/P/sub 4/ and EuP, respectively. According to the crystal structure as well as the electrical, optical and magnetic properties, EuP/sub 7/ is a semiconductor (Esub(G) = 0.9 eV; Esub(G) (vert) = 1.1 eV) with divalent europium (..mu.. = 7.55 B.M.). The compound crystallizes in the monoclinic space group P 2/sub 1//n with a = 1148.8(7) pm, b = 570.0(3) pm, c = 1061.0(6) pm, and ..beta.. = 106.08/sup 0/(5); (X-ray diffraction data; 1479 hkl; R = 0.031). The P-atoms are connected ((P-P) = 218.0-223.5 pm) to a 2-dimensional infinite polyanionic structure 2sub(infinity)(P/sub 7//sup 2 -/) with homonuclear 3-bonded and 2-bonded P-atoms in the ratio 5 : 2. The polyanionic network contains P/sub 6/-rings (chair conformation) as well as P/sub 8/-rings and P/sub 10/-rings. The Eu-atoms are bonded to 9 P-atoms (1,4,4-polyhedra) with bond distances ranging from 306.6 to 326.6 pm. The Eu-atoms complete the tetrahedral environment of the P-atoms.

  12. Spectral characteristics of europium-doped lead iodide

    International Nuclear Information System (INIS)

    Novosad, I.S.; Novosad, S.S.

    2013-01-01

    Optical absorption and x-ray luminescence spectra and thermally stimulated luminescence curves of a PbI 2 :EuCl 3 crystal grown by the Stockbarger method were investigated in the temperature range 85-295 K. It was presumed based on results of EPR spectral studies that the europium ions in this material existed in the divalent state and replaced matrix cations. An intense broad non-elementary band at 780 nm in addition to a weak band with a maximum in the range 512-520 nm were observed in the PbI 2 :Eu 2+ x-ray luminescence spectrum at 85 K. The intensity of the long-wavelength emission increased slightly upon increasing the crystal temperature from 85 to 130 K and was quenched in several stages upon increasing the temperature further to 220 K. The maximum shifted to 740 nm. It was proposed based on an analysis of the obtained data and results of a study of the luminescence properties of PbI 2 and PbI 2 :Mn 2+ crystals that the non-elementary emission band of the PbI 2 :Eu 2+ crystal at 780 nm could be represented as a superposition of three individual Gaussian bands with maxima near 715, 740, and 800 nm that were due to centers characteristic of the matrix and additional centers that were formed by Eu ions through association with intrinsic and dopant oxygen-containing defects, respectively. Doping PbI 2 with Eu 2+ ions did not affect the spectrum of matrix trapping levels. The nature of emission and trapping centers and luminescence excitation mechanisms of PbI 2 :Eu 2+ were discussed. (authors)

  13. Molecular interactions of Leucoagaricus naucinus with uranium(VI) and europium(III)

    Energy Technology Data Exchange (ETDEWEB)

    Wollenberg, Anne; Raff, Johannes [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry; Guenther, A. [Helmholtz Institute Freiberg for Resource Technology, Freiberg (Germany)

    2017-06-01

    With regard to a molecular understanding of the interaction of fungal mycelium with radionuclides and its possible application for precautionary radiation protection and bio-remediation, the binding mechanism of the radionuclide uranium and the metal europium, as surrogate for trivalent actinides, where investigated with different starting conditions by the living fungal cells of Leucoagaricus naucinus.

  14. Molecular interactions of Leucoagaricus naucinus with uranium(VI) and europium(III)

    International Nuclear Information System (INIS)

    Wollenberg, Anne; Raff, Johannes

    2017-01-01

    With regard to a molecular understanding of the interaction of fungal mycelium with radionuclides and its possible application for precautionary radiation protection and bio-remediation, the binding mechanism of the radionuclide uranium and the metal europium, as surrogate for trivalent actinides, where investigated with different starting conditions by the living fungal cells of Leucoagaricus naucinus.

  15. Thermodynamic and structural description of europium complexation in 1-octanol - H2O solutions

    International Nuclear Information System (INIS)

    Vu, T.H.; Charbonnel, M.C.; Boubals, N.; Couston, L.; Arnaud, F.

    2008-01-01

    Polydentate N-bearing ligands such as bis-triazinyl-pyridines (BTPs) are interesting extractants for actinide(III)/lanthanide(III) separation. A description of europium complexation in 1-octanol solutions was undertaken to enhance the knowledge of the extraction mechanisms. The first solvation shell for europium(III) nitrate, chloride, and perchlorate with different amounts of water was determined by Time-Resolved Laser-Induced Fluorescence (TRLIF) spectroscopy. Europium nitrate complexation by iPr-BTP was then studied by TRLIF and micro-calorimetry; similar stability constants related to the formation of Eu(BTP) 2 3+ and Eu(BTP) 3 3+ were obtained by both techniques (log(β 2 ) = 9.0 ± 0.3 and log(β 3 ) = 13.8 ± 0.2). The presence of water in the octanol diluent has an influence on solvation of europium and also on the [Eu(BTP) 2 3+ ] / [Eu(BTP) 3 3+ ] ratio. (authors)

  16. Thermodynamic and structural description of europium complexation in 1-octanol - H{sub 2}O solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vu, T.H.; Charbonnel, M.C.; Boubals, N.; Couston, L. [CEA Marcoule, DEN/DRCP/SCPS/LCAM, BP 17171, 30207 Bagnols-sur-Ceze (France); Arnaud, F. [Laboratoire de Chimie Physique, IPHC, 25 rue Becquerel, 67087 Strasbourg (France)

    2008-07-01

    Polydentate N-bearing ligands such as bis-triazinyl-pyridines (BTPs) are interesting extractants for actinide(III)/lanthanide(III) separation. A description of europium complexation in 1-octanol solutions was undertaken to enhance the knowledge of the extraction mechanisms. The first solvation shell for europium(III) nitrate, chloride, and perchlorate with different amounts of water was determined by Time-Resolved Laser-Induced Fluorescence (TRLIF) spectroscopy. Europium nitrate complexation by iPr-BTP was then studied by TRLIF and micro-calorimetry; similar stability constants related to the formation of Eu(BTP){sub 2}{sup 3+} and Eu(BTP){sub 3}{sup 3+} were obtained by both techniques (log({beta}{sub 2}) = 9.0 {+-} 0.3 and log({beta}{sub 3}) = 13.8 {+-} 0.2). The presence of water in the octanol diluent has an influence on solvation of europium and also on the [Eu(BTP){sub 2}{sup 3+}] / [Eu(BTP){sub 3}{sup 3+}] ratio. (authors)

  17. ULTRAVIOLET TRANSITIONS IN EUROPIUM STUDIED WITH A FREQUENCY-DOUBLED CW RING DYE-LASER

    NARCIS (Netherlands)

    Eliel, E.R.; Hogervorst, W.; van Leeuwen, K.A.H.; Post, B.H.

    1981-01-01

    High resolution laser spectroscopy has been applied to the study of three ultraviolet transitions in Europium at λ = 294.8, 295.1 and 295.8 nm. The tunable narrowband UV has been generated by intracavity frequency doubling in a cw ring dye laser using a temperate tuned, Brewster angled ADA crystal.

  18. Detection of Molecular Chirality by Induced Resonance Raman Optical Activity in Europium Complexes

    Czech Academy of Sciences Publication Activity Database

    Yamamoto, Shigeki; Bouř, Petr

    2012-01-01

    Roč. 51, č. 44 (2012), s. 11058-11061 ISSN 1433-7851 R&D Projects: GA MŠk(CZ) LH11033; GA ČR GAP208/11/0105 Institutional support: RVO:61388963 Keywords : europium * complexes * raman optical activity * resonance Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 13.734, year: 2012

  19. Study of the europium behavior in aqueous media; Estudio sobre el comportamiento del europio en medios acuosos

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez R, E.; Jimenez R, M.; Solache R, M.; Martinez M, V. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

    2000-07-01

    Europium as waste can produce a pollution problem in water that is in contact with it, what would has a heavy environmental impacts, because of the possibilities of diffusion of these wastes from their place of confinement or storage until the geo and biosphere. The solution of such problem requires of a lot of knowledge over the behavior of several chemical elements such as europium in aqueous solutions. In this work it was used a low ion force (0.02 M). The data set will allow extrapolate the hydrolytic behavior of europium in too much minors ion force media, such as the ground waters, including in ion force zero.

  20. Atomic absorption spectrophotometry of europium using an enhancing effect of ammonium perchlorate

    International Nuclear Information System (INIS)

    Oguro, Hiroshi

    1976-01-01

    In the atomic absorption spectrophotometry of europium in air-acetylene flame, ammonium perchlorate (NH 4 ClO 4 ) increases the absorption of europium. In the case of 0.5 M NH 4 ClO 4 , the increase is by about 1.5 times. In this paper, a method for eliminating the interferences of many coexisting compounds using an enhancing effect and a method for determining Eu 2 O 3 in La 2 O 3 were investigated. The working conditions using Nippon Jarrell-Ash model AA-1 atomic absorption/flame emission spectrophotometer were as follows; wavelength 4594 A, lamp current 15 mA, burner height 10 mm, air flow-rate 6.51/min, acetylene flow-rate 1.81/min. Though the enhancing or depressing effects of HCl, HNO 3 , HBr and HClO 4 in concentrations below 0.1 M were eliminated by 0.5 M NH 4 ClO 4 , the remarkable depressing effects of H 2 SO 4 and H 3 PO 4 on europium could not be eliminated. The interferences of Na + , K + , Cs + and Al 3+ in the concentration of 200 ppm were not eliminated, but those of other cations including rare earth elements were completely eliminated. Lanthanum in the range of (2000--10000) ppm increased the absorption of europium by about 1.4 times. But the effect of lanthanum in the range of (0--9000) ppm was also eliminated by NH 4 ClO 4 . The calibration curve for europium in the presence of NH 4 ClO 4 was linear in the range of (0--400) ppm with a sensitivity larger by about 1.5 times than that for europium alone. The analytical procedure is as follows. A sample is dissolved in HCl and NH 4 ClO 4 is added. Europium in the sample solution is determined by atomic absorption method using air-acetylene flame. For practical samples, the values obtained were in fair agreement with those by the flame emission method using a nitrous oxide-acetylene flame. The coefficients of variation by the present method were (3.7--2.4)% (Eu 2 O 3 content (1--3)%). (auth.)

  1. Synthesis, characterization, and properties of reduced europium molybdates and tungstates

    Energy Technology Data Exchange (ETDEWEB)

    Abeysinghe, Dileka [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States); Gerke, Birgit [Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, Münster D-48149 (Germany); Morrison, Gregory; Hsieh, Chun H.; Smith, Mark D. [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States); Pöttgen, Rainer [Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, Münster D-48149 (Germany); Makris, Thomas M. [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States); Loye, Hans-Conrad zur, E-mail: zurloye@mailbox.sc.edu [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States)

    2015-09-15

    Single crystals of K{sub 0.094}Eu{sub 0.906}MoO{sub 4}, K{sub 0.097}Eu{sub 0.903}WO{sub 4}, EuWO{sub 4}, and EuMoO{sub 4} were grown from molten chloride fluxes contained in vacuum-sealed fused silica and structurally characterized via single crystal X-ray diffraction. The in situ reduction of Eu{sup 3+} to Eu{sup 2+} was carried out using Mo, W, and Zn as metal reducing agents. All four compounds crystallize in the tetragonal space group of I4{sub 1}/a and adopt the scheelite (CaWO{sub 4}) structure type. The magnetic susceptibility of the reported compounds shows paramagnetic behavior down to 2 K. {sup 151}Eu Mössbauer spectroscopy was used to analyze the relative Eu{sup 2+} and Eu{sup 3+} content of the samples. All the compounds were further characterized by EPR, and UV-vis spectroscopy. - Graphical abstract: TOC Caption Two new reduced europium containing quaternary oxides, K{sub 0.094}Eu{sub 0.906}MoO{sub 4} and K{sub 0.097}Eu{sub 0.903}WO{sub 4}, and two previously reported ternary reduced oxides, EuWO{sub 4} and EuMoO{sub 4}, were synthesized via an in situ reduction of Eu{sup 3+} to Eu{sup 2+} under flux method using Mo, W, and Zn as metal reducing agents. {sup 151}Eu Mössbauer spectroscopy was used to analyze the relative Eu{sup 2+} and Eu{sup 3+} content of the samples. - Highlights: • K{sub 0.094}Eu{sub 0.906}MoO{sub 4}, K{sub 0.097}Eu{sub 0.903}WO{sub 4}, EuWO{sub 4}, and EuMoO{sub 4} have been synthesized and characterized. • The in situ reduction of Eu{sup 3+} to Eu{sup 2+} was carried out using Mo, W, and Zn as metal reducing agents. • Magnetic susceptibility data were collected. • {sup 151}Eu Mössbauer spectroscopy was used to analyze Eu{sup 2+} and Eu{sup 3+} content.

  2. Silica- and silylated europium-based luminescent hybrids: new analysis tools for biological environments

    International Nuclear Information System (INIS)

    Pereira Duarte, Adriana

    2012-01-01

    The association of the very interesting luminescence properties of the lanthanide chelates with the physicochemical properties of inorganic matrix such as silica is a promising way to obtain new probes or luminescent markers for biology analyses. In this idea, this work focuses on the preparation of new hybrid materials based on the grafting of new europium(III) complexes on silica nanoparticles. These europium complexes were developed in our group using bifunctional ligands containing both complexing and grafting sites. Intrinsic characteristic of the ligands gives us the ability to make a covalent bond between the material surface and the complex. Two different methodologies were used; the first one is the direct grafting reaction involving the complex and silica nanoparticles (i.e. dense or meso-porous particles). The second one is the Stoeber reaction, where the SiO 2 nanoparticles were prepared in presence of the europium complex. The last methodology has an additional difficult, because of the presence of silylated europium complex, it needs a closer control of the physicochemical conditions. The new organic-inorganic hybrid materials, obtained in this work, present an interesting luminescence behavior and this one is depending on the localization of the europium complex, i.e. on the surface or within the nanoparticles. In addition, the obtained hybrids present the nano-metric dimension and the complex is not leachable. Analyses were realized to describe the luminescence properties, beyond surface and structural characteristics. Initial results show that the new hybrids are promising candidates for luminescent bio-markers, particularly for the time-resolved analysis. (author) [fr

  3. Sulfate metabolism. I. Sulfate uptake and redistribution of acid rain sulfate by edible plants

    International Nuclear Information System (INIS)

    Dallam, R.D.

    1987-01-01

    Sulfur is the major component of polluted air in industrialized societies. Atmospheric sulfur is converted to sulfuric acid through a series of chemical reactions which can eventually reenter many ecosystems. When edible plants are grown in soils containing varying amounts of sulfate, the roots take up and transport inorganic sulfate to the stems and leaves. The sulfate taken up by the roots and the amount transported to the stem and leaves was found to be a function of the concentration of sulfate in the soil. Inorganic sulfate taken up by a corn plant seedling can be rapidly converted to organic sulfate by the root system. Nine days after one of a pair of pea plants was inoculated with artificial acid rain sulfate (dilute H 2 35 SO 4 ) it was found that the sulfate was translocated not only in the inoculated plant, but also to the uninoculated pea plant in the same container. Also, when the leaves of a mature potato plant were inoculated with artificial acid rain sulfate it was found that the sulfate was translocated into the edible potatoes. Fractionation of the potatoes showed that most of the sulfate was water soluble of which 30% was inorganic sulfate and 70% was in the form of organic sulfur. One third of the non-water soluble translocated acid rain sulfate was equally divided between lipid and non-lipid organic sulfur of the potato. 9 references, 2 figures, 5 tables

  4. Luminescent properties of Europium(III) nitrate with 1,10-phenantroline and cinnamic acid in light - Transforming polymer materials

    Science.gov (United States)

    Kalinovskaya, I. V.; Zadorozhnaya, A. N.

    2018-04-01

    Influence of cinnamic acid on the luminescent properties of the europium(III) nitrate with 1,10-phenantroline in a polymer materials was studied. It was shown that combined use of these rare earth complexes leads to intense luminescence in the 400-700 nm region. Samples containing polymer europium nitrate with 1,10-phenantroline and cinnamic acid at a molar ratio of 1:2,0 had the maximum luminescence intensity and photostability.

  5. Europium determination in oxide and oxysulfide luminophors and their wastes by the method of direct and derivative spectrophotometry

    International Nuclear Information System (INIS)

    Mishchenko, V.T.; Aleksandrova, N.N.

    1989-01-01

    Spectrophotometric methods for europium determination in luminophors are proposed. Application of standard and derivative spectrophotometry allows one to determine europium in oxide and oxysulfide luminophors, their wastes and raffinates produced during waste reprocessing quite accurately and reliably. When determining Eu 2 O 3 (Eu 2 O 2 S) mass shares within 4-8 % limits absolute deviation from the mean result makes up to more than ± 0.2 %, relative standard deviation does not exceed 0.02

  6. Fluorimetric determination of samarium(III) and europium(III) in neodymium oxide by separation with a resin column

    Energy Technology Data Exchange (ETDEWEB)

    Shaorong Liu; Jian Meng (Beijing Research Institute of Chemical Engineering and Metallurgy (China)); Wenhua Liu (General Research Institute for Non-Ferrous Metals (China))

    1992-08-24

    When thenoyltrifluoroacetone-phenanthroline-Triton X-100 is used to determine samarium(III) and europium(III) fluorimetrically, only a limited amount of neodymium(III) can be tolerated. By using an on- line separation which can partially separate neodymium(III) from samarium(III), a practical and convenient method was developed to detect samarium(III) at concentrations >0.05% and europium(III) at concentrations >0.005% in neodymium oxide. (author). 7 refs.; 4 figs.; 3 tabs.

  7. Fluorimetric determination of samarium(III) and europium(III) in neodymium oxide by separation with a resin column

    International Nuclear Information System (INIS)

    Shaorong Liu; Jian Meng; Wenhua Liu

    1992-01-01

    When thenoyltrifluoroacetone-phenanthroline-Triton X-100 is used to determine samarium(III) and europium(III) fluorimetrically, only a limited amount of neodymium(III) can be tolerated. By using an on- line separation which can partially separate neodymium(III) from samarium(III), a practical and convenient method was developed to detect samarium(III) at concentrations >0.05% and europium(III) at concentrations >0.005% in neodymium oxide. (author). 7 refs.; 4 figs.; 3 tabs

  8. Lanthanum and yttrium oxysulfides activated by europium: (Ln1-x Eux)2 O2 S - Synthesis and characterization

    International Nuclear Information System (INIS)

    Luiz, J.M.

    1989-01-01

    The synthesis of lanthanum and yttrium oxysulfides activated by europium were obtained by thermal decomposition of lanthanum and yttrium oxalates doped with europium, under an argon and sulphur atmosphere. The thermal decomposition of these compounds is studied by differential thermal analysis (DTA). The characterization of these oxysulfides were made by chemical analyses, infrared spectroscopy, X-ray diffraction, scanning electron microscopy and emission spectroscopy. (M.V.M.)

  9. Spectroscopic studies of europium-tetracyclines complexes and their applications in detection of hydrogen peroxide and urea peroxide

    International Nuclear Information System (INIS)

    Grasso, Andrea Nastri

    2010-01-01

    In this work were studied the spectroscopic properties of trivalent europium ion complexed with components of tetracycline family, chlorotetracycline, oxytetracycline and metacycline, in the presence of hydrogen peroxide and urea peroxide. Optical parameters were obtained such as absorption, emission, lifetime and calibration curves were constructed for luminescence spectra. Experiments were carried out with both inorganic compounds and europium-tetracyclines complexes in order to verify possible interferences. Studies for glucose determination were also described using europium-tetracyclines complexes as biosensors. Results show that europium tetracyclines complexes emit a narrow band in the visible region and, in the presence of hydrogen peroxide or urea peroxide there is a greater enhancement in their luminescence and lifetime. Thus, europium-tetracyclines complexes studied can be used as biosensors for hydrogen and urea peroxides determination as a low cost and room temperature method. An indirect method for glucose determination was studied by adding glucose oxidase enzyme in europium-tetracyclines complex in the presence of glucose promoting as product hydrogen peroxide. (author)

  10. Influence of biofilms on migration of uranium, americium and europium in the environment; Einfluss von Biofilmen auf das Migrationsverhalten von Uran, Americium und Europium in der Umwelt

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Nils; Zirnstein, Isabel; Arnold, Thuro

    2015-07-01

    The report on the influence of biofilms on migration of uranium, americium and europium in the environment deals with the contamination problems of uranium mines such as SDAG WISMUT in Saxonia and Thuringia. In mine waters microorganisms form a complex microbiological biocoenosis in spite of low pH values and high heavy metal concentrations including high uranium concentrations. The analyses used microbiological methods like confocal laser scanning microscopy and molecular-biological techniques. The interactions of microorganism with fluorescent radioactive heavy metal ions were performed with TRLFS (time resolved laser-induced fluorescence spectroscopy).

  11. Dissolution of sulfate scales

    Energy Technology Data Exchange (ETDEWEB)

    Hen, J.

    1991-11-26

    This patent describes a composition for the removal of sulfate scale from surfaces. It comprises: an aqueous solution of about 0.1 to 1.0 molar concentration of an aminopolycarboxylic acid (APCA) containing 1 to 4 amino groups or a salt thereof, and about 0.1 to 1.0 molar concentration of a second component which is diethylenetriaminepenta (methylenephosphonic acid) (DTPMP) or a salt thereof, or aminotri (methylenephosphonic acid) (ATMP) or a salt thereof as an internal phase enveloped by a hydrocarbon membrane phase which is itself emulsified in an external aqueous phase, the hydrocarbon membrane phase continuing a complexing agent weaker for the cations of the sulfate scale than the APCA and DTPMP or ATMP, any complexing agent for the cations in the external aqueous phase being weaker than that in the hydrocarbon membrane phase.

  12. Radioimmunoassay of dehydroepiandrosterone sulfate

    International Nuclear Information System (INIS)

    Vieira, J.G.H.; Furlanetto, R.P.; Russo, E.M.K.; Noguti, K.O.; Chacra, A.R.

    1980-01-01

    The development of a radioimmunological method for the measurement of dehydroepiandrosterone sulfate in serum is described. For the immunization of rabbits, a DHA-3-hemissuccinate-bovine serum albumin conjugate was synthetized and a highly specific anti-serum was produced. The method developed requires only simple dilution prior to assay and the normal values for the different age groups were determined in 146 normal individuals. (Author) [pt

  13. Incorporation of europium III complex into nanoparticles and films obtained by the Sol-Gel methodology

    Directory of Open Access Journals (Sweden)

    Faley Jean de Sousa

    2010-03-01

    Full Text Available The sol-gel process is very effective for the preparation of new materials with potential applications in optics, sensors, catalyst supports, coatings, and specialty inorganic polymers that can be used as hosts for the accommodation of organic molecules. The low temperature employed in the process is the main advantage of this methodology. In this work, the europium (III complex with 1,10-phenantroline was prepared, and this luminescent complex was incorporated into silica nanoparticles and films by the sol-gel process. The nanoparticles were obtained by the modified Stöber methodology. The films were obtained by the dip-coating technique, at different deposition rates and numbers of layers. The nanoparticles and films were characterized by photoluminescence, thermal analysis, and Raman and infrared spectroscopies. Characterization revealed that the europium (III complex was not affected upon incorporation into the nanoparticles and films, opening a new field for the application of these materials.

  14. Synthesis, characterization and fluorescence studies of a novel europium complex based sensor

    International Nuclear Information System (INIS)

    Li Bin; Chen Qiuyun; Wang Yachen; Huang Jing; Li Yang

    2010-01-01

    A novel europium(III) complex was synthesized using TTA (α-thenoyltrifluoroacetone) as the first ligand and H 2 bpdc (2,2'-bipyridine-3,3'-dicarboxylate) as the second ligand. Elemental analysis, thermal analysis, IR and UV-vis spectrum and fluorescence spectrum of the europium(III) complex were carried out. A characteristic Eu 3+ fluorescence emission was observed in ethanol-water (1:1) solution, indicating that the complex is stable in solution and the emission of Eu(III) ions was not influenced by the water molecules. The fluorescence emission of the complex was quenched completely by the Co 2+ and Fe 3+ ions, but the quenched emission was recovered in the presence of glycine. Moreover, the Eu 3+ emission was very sensitive to pH, so the complex can be used as pH-dependent fluorescence probe or chemosensors.

  15. Characterization of photoluminescent europium doped yttrium oxide thin-films prepared by metallorganic chemical vapor deposition

    International Nuclear Information System (INIS)

    McKittrick, J.; Bacalski, C.F.; Hirata, G.A.; Hubbard, K.M.; Pattillo, S.G.; Salazar, K.V.; Trkula, M.

    1998-01-01

    Europium doped yttrium oxide, (Y 1-x Eu x ) 2 O 3 , thin-films were deposited on silicon and sapphire substrates by metallorganic chemical vapor deposition (MOCVD). The films were grown in a MOCVD chamber reacting yttrium and europium tris(2,2,6,6-tetramethyl-3,5,-heptanedionates) precursors in an oxygen atmosphere at low pressures (5 Torr) and low substrate temperatures (500--700 C). The films deposited at 500 C were flat and composed of nanocrystalline regions of cubic Y 2 O 3 , grown in a textured [100] or [110] orientation to the substrate surface. Films deposited at 600 C developed from the flat, nanocrystalline morphology into a plate-like growth morphology oriented in the [111] with increasing deposition time. Monoclinic Y 2 O 3 :Eu 3+ was observed in x-ray diffraction for deposition temperatures ≥600 C on both (111) Si and (001) sapphire substrates. This was also confirmed by the photoluminescent emission spectra

  16. Is the stoichiometry of the europium nitrate complexes with neutral organophosphorus extractants be anticipated?

    International Nuclear Information System (INIS)

    Beudaert, Ph.; Lamare, V.; Wipff, G.

    2001-01-01

    Molecular dynamics simulations have been performed in water on europium nitrate complexes with three neutral organophosphorus extractants (TBP, TPPO and CMPO) in order to determine on what criteria it is possible to obtain by simulations the experimental 1:3 stoichiometry in organic solution. This stoichiometry was investigated by progressive saturation of the cation coordination sphere. When the nitrate counter-ions are bidentate, the 1:3 stoichiometry corresponds to the degree of saturation where the interaction energy between europium and water becomes repulsive. Beyond this stoichiometry, complexes with TPPO and CMPO are unstable, although a 1:4 complex with TBP may exist but its formation appears to be energetically unfavored. (author)

  17. Study on Europium-Doped Hydroxyapatite Nanoparticles by Fourier Transform Infrared Spectroscopy and Their Antimicrobial Properties

    Directory of Open Access Journals (Sweden)

    Simona-Liliana Iconaru

    2013-01-01

    Full Text Available Fourier transform infrared spectroscopy (FT-IR analysis was conducted on europium-doped hydroxyapatite, Ca10-xEux(PO46(OH2 nanocrystalline powders (Eu:HAp with 0≤xEu≤0.2. Antimicrobial studies were also performed for the first time on Eu:HAp. The antimicrobial properties of Eu:HAp nanoparticles with 0≤xEu≤0.2 on Gram-negative (E. coli ATCC 25922, Pseudomonas aeruginosa 1397 and Gram-positive (Staphylococcus aureus 0364, Enterococcus faecalis ATCC 29212 bacteria systems and a species of fungus (Candida albicans ATCC 10231 were reported. Our study demonstrates that the antimicrobial activity of Eu:HAp nanoparticles is dependent on the europium concentration.

  18. The enthalpies of formation of neutral and charged components of saturated vapor over europium dichloride

    International Nuclear Information System (INIS)

    Pogrebnoj, A.M.; Kudin, L.S.

    2003-01-01

    Composition of saturated vapor over europium dichloride was studied by the method of high-temperature mass spectrometry in the temperature range of 1154 - 1267 K. For neutral components of the vapor, represented by monomer and dimer molecules, partial pressures were determined. Enthalpies of sublimation of europium dichloride Δ s H 0 (298 K) as monomers (338 ± 9) and dimers (407 ± 20 kJ/mol) were calculated. Equilibrium constants of ion-molecular and ion-ionic reactions were measured, their enthalpies being ascertained. Enthalpies of formation of molecules and ions Δ f H 0 (298 K) were calculated: -486 ± 11 (EuCl 2 ), -1242 ± 22 (Eu 2 Cl 4 ), 1 ± 12 (Eu 2 Cl 2 + ), -347 ± 20 (Eu 2 Cl 3 + ), -1111 ± 42 (Eu 3 Cl 5 + ), -975 ± 20 (EuCl 3 - ), -1309 ± 17(EuCl 4 - ), -1734 ± 20 (Eu 2 Cl 5 - ) kJ/mol [ru

  19. Luminescence properties of europium (III) cryptates trapped in sol-gel glass

    International Nuclear Information System (INIS)

    Zaitoun, M.A.; Kim, T.; Jaradat, Q.M.; Momani, K.; Qaseer, H.A.; El-Qisairi, A.K.; Qudah, A.; Radwan, N.E.

    2008-01-01

    The Lanthanide complexes Eu-2.2.1 and Eu-2.2.2 were synthesized and then incorporated into silica based transparent organic-inorganic hybrid material by the sol-gel method as an example of how doped xerogel materials are emerging as an important means of producing new materials. The produced gels were diagnosed to monitor emission spectra of the luminescent trivalent europium (Eu 3+ ) complexes; emissions were compared to those for gels containing uncomplexed Eu 3+ . Results of the experiments (emission and lifetimes) concerning the coordination sphere composition showed that a cryptand ligand with aromatic groups (short range effect) and the hydrophobic gel host (long range effect) settle efficient action in the antenna effect and isolate the central ion from efficient quenchers, as e.g. water molecules. Each ligand imposed a distinct splitting pattern on the europium emission bands that helps identify them

  20. Crystal agglomeration of europium oxalate in reaction crystallization using double-jet semi-batch reactor

    International Nuclear Information System (INIS)

    Kim, Woo-Sik; Kim, Woon-Soo; Kim, Kwang-Seok; Kim, Joon-Soo; Ward, Michael D.

    2004-01-01

    The particle agglomeration of europium oxalate was investigated in a double-jet semi-batch reactor over a wide range of operating variables, including the agitation speed, reactant feed rate, and reactant concentration. The size of the agglomerates was directly dictated by the particle collision and supersaturation promoting agglomeration and the fluid shear force inhibiting agglomeration. Thus, with a longer feeding time and higher feed concentration for the reaction crystallization, the mean particle size increased, while the corresponding total particle population decreased due to the enhanced chance of particle agglomeration, resulting from a longer residence time and higher supersaturation in the reactor. Agitation was found to exhibit a rather complicated influence on particle agglomeration. Although both particle collision and turbulent fluid shear were promoted by an increase in the mixing intensity, the crystal agglomeration of europium oxalate was maximized at around 500 rpm of agitation speed due to an optimized balance between particle aggregation and breakage

  1. Improved efficiency of organic light-emitting diodes based on a europium complex by fluorescent dye

    Energy Technology Data Exchange (ETDEWEB)

    You Han [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China); Fang Junfeng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China); Gao Jia [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China); Ma Dongge [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of Chinese Academy of Sciences, Changchun 130022 (China)]. E-mail: mdg1014@ciac.jl.cn

    2007-01-15

    Improved efficiency of organic light-emitting diodes (OLEDs) based on europium complexes have been realized by using a fluorescent dye 4-(dicyanomethylene)-2-t-butyl-6 (1,1,7,7-tetramethyljulolidyl-9-enyl))-4H-pyran (DCJTB) doping .The luminous efficiency of the devices with a fluorescent dye in the emissive layer was found to improve two times of that in devices without fluorescent dye. The devices showed pure red light, which is the characteristic emission of trivalent europium ion with a full-width at half-maximum of 3 nm.The maximum brightness and luminous efficiency reached 1200 cd/m{sup 2} at 23 V and 7.3 cd/A (2.0 lm/w), respectively, at a current density of 0.35 mA/cm{sup 2}.

  2. Determination of the first hydrolysis constant of Europium (III) in 3 M of ionic strength

    International Nuclear Information System (INIS)

    Ramirez B, M.E.

    1994-01-01

    The first hydrolysis constant of Eu 3+ has been determined at 303 K and 3 M (NaCl) ionic strength. A solvent extraction method was used, the extractant was dibenzoylmethane in benzene and di glycolate anion in the aqueous phase provided competitive complexation. The tracer solution was 152m1 Eu (III) in water. The radioactive solution of europium was obtained by neutron irradiation of europium nitrate solutions at pH 3.0, in a TRIGA Mark III nuclear reactor at a neutron flux of 1 x 10 13 cm -2 s -1 . The half life of the produced isotope, 152m1 Eu (9.3 h), was verified by means of a Ge H detector and no interfering radiations were observed in the spectra. (Author)

  3. Extraction of europium with thenoyltrifluoroacetone into alcohol, ketone and ester solvents

    International Nuclear Information System (INIS)

    Akiba, K.; Kanno, T.

    1980-01-01

    The effect of solvent has been studied on the extraction of tris-thenoyltrifluoroacetone (TTA) chelate of europium(III). Donor-active solvents (S) greatly promote the extraction owing to the formation of solvate species EuA 3 .mS (m = 1,2). Linear relations were established between the distribution of ratios of europium (Dsub(Eu)) and the partition constants of TTA (Psub(HA)); log Dsub(Eu) (at a definite pA) = a log Psub(HA) + b, where constants a and b were empirically determined for each series of solvents. The regularity is interpreted in terms of dual roles of solvent as donor and as medium. (author)

  4. Sulfation of chondroitin. Specificity, degree of sulfation, and detergent effects with 4-sulfating and 6-sulfating microsomal systems

    International Nuclear Information System (INIS)

    Sugumaran, G.; Silbert, J.E.

    1988-01-01

    Microsomal preparations from chondroitin 6-sulfate-producing chick embryo epiphyseal cartilage, and from chondroitin 4-sulfate-producing mouse mastocytoma cells, were incubated with UDP-[14C]glucuronic acid and UDP-N-acetylgalactosamine to form non-sulfated proteo[14C]chondroitin. Aliquots of the incubations were then incubated with 3'-phosphoadenylylphosphosulfate (PAPS) in the presence or absence of various detergents. In the absence of detergents, there was good sulfation of this endogenous proteo[14C]chondroitin by the original microsomes from both sources. Detergents, with the exception of Triton X-100, markedly inhibited sulfation in the mast cell system but not in the chick cartilage system. These results indicate that sulfation and polymerization are closely linked on cell membranes and that in some cases this organization can be disrupted by detergents. When aliquots of the original incubation were heat inactivated, and then reincubated with new microsomes from chick cartilage and/or mouse mastocytoma cells plus PAPS, there was no significant sulfation of this exogenous proteo[14C] chondroitin with either system unless Triton X-100 was added. Sulfation of exogenous chondroitin and chondroitin hexasaccharide was compared with sulfation of endogenous and exogenous proteo[14C]chondroitin. Sulfate incorporation into hexasaccharide and chondroitin decreased as their concentrations (based on uronic acid) approached that of the proteo[14C]chondroitin. At the same time, the degree of sulfation in percent of substituted hexosamine increased. However, the degree of sulfation did not reach that of the endogenous proteo[14C]chondroitin. Hexasaccharide and chondroitin sulfation were stimulated by the presence of Triton X-100. However, in contrast to the exogenous proteo[14C]chondroitin, there was some sulfation of hexasaccharide and chondroitin in the absence of this detergent

  5. Spectroscopic properties of trivalent Europium in various composites with an eulytin structure. Internship report

    International Nuclear Information System (INIS)

    Raynal, Francoise

    1975-01-01

    Eulytin is a bismuth orthosilicate and eulytin compounds revealed to be interesting matrix materials which can be used as medium gain laser materials. This research report is thus a contribution for a better knowledge of this material. Different eulytin compounds doped with lanthanide ions have been used to study the cationic polyhedron (by using structural probes such as the trivalent Europium in spectroscopy, or the trivalent gadolinium in electronic paramagnetic resonance) and the anionic polyhedron

  6. Systematic investigation and in vitro biocompatibility studies on mesoporous europium doped hydroxyapatite

    OpenAIRE

    Popa Cristina; Ciobanu Carmen; Iconaru Simona; Stan Miruna; Dinischiotu Anca; Negrila Constantin; Motelica-Heino Mikael; Guegan Regis; Predoi Daniela

    2014-01-01

    International audience; This paper reports a systematic investigation on europium doped hydroxyapatite (Eu:HAp). In this work, a set of complementary techniques Fourier Transform Infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and, Brunauer-Emmett-Teller (BET) technique was used to allowing a proper understanding of Eu:HAp. The XPS analysis confirmed the substitution of Ca ions by Eu ions in Eu:HAp samples. Eu:HAp and pure HAp show ...

  7. Effects of added uranium on the triboluminescent properties of europium dibenzoylmethide triethylammonium

    International Nuclear Information System (INIS)

    Fontenot, Ross S.; Hollerman, William A.; Bhat, Kamala N.; Aggarwal, Mohan D.

    2013-01-01

    The ability of a material to emit light upon fracture is known as triboluminescence. One of the few materials that emits triboluminescence in daylight is europium dibenzoylmethide triethylammonium (EuD 4 TEA). It has been shown that this material is 106% brighter than ZnS:Mn when excited by low speed impacts. In 2011, the authors of this paper found that replacing the traditional europium chloride with europium nitrate and changing the carrier solvent could both significantly affect the triboluminescent emission yield. While these changes provided a significant increase in yield, the emission was still not sufficient to be observed in bright daylight. In order to enhance the effect, a series of materials were added to the EuD 4 TEA to study the effects of “doping” on the triboluminescence yield. Results from this research showed that doping from a small number of materials, such as uranyl acetate, increased emission yield. This paper discusses the research that was completed on effects of the addition of uranyl acetate to EuD 4 TEA could increase the triboluminmescent emission yield. Results show that the added uranium does indeed increase emission yield when it is first synthesized. However, radiation emitted by the uranium also was found to damage the doped EuD 4 TEA, thus reducing the emitted triboluminescence over a period of time. - Highlights: ► Uranium doped europium dibenzoylmethide triethylammonium (EuD 4 TEA) was synthesized. ► Effects of uranium was studied for low velocity ( 4 TEA was determined.

  8. Determination of Europium by fluorescence using pyrrolidinium based task specific ionic liquid

    International Nuclear Information System (INIS)

    Kumar, Satendra; Gayan, Siuli Maji; Sankaran, K.

    2012-01-01

    Determination of lanthanides using fluorescence is a major challenge in aqueous medium due to their poor molar absorptivities and low quantum yield. To overcome these problems, ligand sensitized fluorescence has been widely used for trace level detection of lanthanides in solutions. Recently, ionic liquid a non aqueous medium has been used to observe the fluorescence of lanthanides. In this work we have used pyrrolidinium based ionic liquid for the study of europium fluorescence. The ionic liquid (bmpyr)(BA) was prepared using the metathesis reaction involving 1-butyl,1-methyl pyrrolidinium chloride (bmpyr)(CI). (bmpyr)(Cl) crystals and silver benzoate were added according to their mole equivalents in methanol and stirred for 4 hrs. The filtrate was concentrated using a rotary evaporator, dried for 10 h at room temperature, and then for 40 h at 105℃under reduced pressure. This results in a white crystalline hygroscopic solid which was characterized by FT-lR spectroscopy. The yield of the product was ∼ 95%. Butyl-1, methyl pyrrolidinium bis(trifluoromethanesulfonyl)amide (bmpyr)(TF 2 N) is used for dissolve and dilute (bmpyr)(BA) and fluorescence and life time of Eu 3+ were obtained. For the concentration of Eu 3+ used in this study (2x10 -7 M), the optimum concentration of the sensitizing ionic liquid was found to be 10 -4 M. An enhancement factor of about 32000 was found in this ionic liquid compare to aqueous medium. Fluorescence life time of europium in this ionic liquid is 1100 μs which is ten times more than the life time of europium in aqueous medium (110 μs), indicating a reduction in the rates of non-radiative processes which was provided by the ionic liquid. This study leads to detection of europium in ppb level. (author)

  9. Solubility and first hydrolysis constants of europium at different ionic strength and 303 K

    International Nuclear Information System (INIS)

    Ramirez-Garcia, J.J.; Jimenez-Reyes, M.; Lopez-Gonzalez, H.; Autonoma Metropolitana-Iztapalapa Univ., Mexico City; Solache-Rios, M.; Fernandez-Ramirez, E.; Centro Interamericano de Recursos del Agua, Toluca; Rojas-Hernandez, A.

    2003-01-01

    The solubility of europium at 0.02M, 0.1M and 0.7M NaClO 4 ionic strength solutions was determined by a radiometric method and pEu s -pC H diagrams were obtained. Hydrolysis constants were also determined at the same ionic strengths by pH titration and the values found were log *β 1 -7.68±0.11, -8.07±0.10 and -8.20±0.11. The log K sp values were -23.5±0.2, -22.7±0.2 and -21.9±0.2 for 0.02M, 0.1M and 0.7M NaClO 4 ionic strengths, respectively, at 303 K under CO 2 -free conditions and the extrapolated value at zero ionic strength was log K sp 0 = -24.15. The working pC H ranges for the calculation of the hydrolysis constants were selected from the pEu s -pC H diagrams in the region where precipitation of europium oxide or hydroxide was less than 20%. Europium removal from aqueous solutions with zeolites was explored. (author)

  10. Time-resolved laser fluorescence spectroscopy of organic ligands by europium: Fluorescence quenching and lifetime properties

    Science.gov (United States)

    Nouhi, A.; Hajjoul, H.; Redon, R.; Gagné, J. P.; Mounier, S.

    2018-03-01

    Time-resolved Laser Fluorescence Spectroscopy (TRLFS) has proved its usefulness in the fields of biophysics, life science and geochemistry to characterize the fluorescence probe molecule with its chemical environment. The purpose of this study is to demonstrate the applicability of this powerful technique combined with Steady-State (S-S) measurements. A multi-mode factor analysis, in particular CP/PARAFAC, was used to analyze the interaction between Europium (Eu) and Humic substances (HSs) extracted from Saint Lawrence Estuary in Canada. The Saint Lawrence system is a semi-enclosed water stream with connections to the Atlantic Ocean and is an excellent natural laboratory. CP/PARAFAC applied to fluorescence S-S data allows introspecting ligands-metal interactions and the one-site 1:1 modeling gives information about the stability constants. From the spectral signatures and decay lifetimes data given by TRLFS, one can deduce the fluorescence quenching which modifies the fluorescence and discuss its mechanisms. Results indicated a relatively strong binding ability between europium and humic substances samples (Log K value varies from 3.38 to 5.08 at pH 7.00). Using the Stern-Volmer plot, it has been concluded that static and dynamic quenching takes places in the case of salicylic acid and europium interaction while for HSs interaction only a static quenching is observed.

  11. Ferromagnetic semiconductor-metal transition in heterostructures of electron doped europium monoxide

    International Nuclear Information System (INIS)

    Stollenwerk, Tobias

    2013-09-01

    In the present work, we develop and solve a self-consistent theory for the description of the simultaneous ferromagnetic semiconductor-metal transition in electron doped Europium monoxide. We investigate two different types of electron doping, Gadolinium impurities and Oxygen vacancies. Besides the conduction band occupation, we can identify low lying spin fluctuations on magnetic impurities as the driving force behind the doping induced enhancement of the Curie temperature. Moreover, we predict the signatures of these magnetic impurities in the spectra of scanning tunneling microscope experiments. By extending the theory to allow for inhomogeneities in one spatial direction, we are able to investigate thin films and heterostructures of Gadolinium doped Europium monoxide. Here, we are able to reproduce the experimentally observed decrease of the Curie temperature with the film thickness. This behavior is attributed to missing coupling partners of the localized 4f moments as well as to an electron depletion at the surface which leads to a reduction of the number of itinerant electrons. By investigating the influence of a metallic substrate onto the phase transition in Gadolinium doped Europium monoxide, we find that the Curie temperature can be increased up to 20%. However, as we show, the underlying mechanism of metal-interface induced charge carrier accumulation is inextricably connected to a suppression of the semiconductor-metal transition.

  12. Ferromagnetic semiconductor-metal transition in heterostructures of electron doped europium monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Stollenwerk, Tobias

    2013-09-15

    In the present work, we develop and solve a self-consistent theory for the description of the simultaneous ferromagnetic semiconductor-metal transition in electron doped Europium monoxide. We investigate two different types of electron doping, Gadolinium impurities and Oxygen vacancies. Besides the conduction band occupation, we can identify low lying spin fluctuations on magnetic impurities as the driving force behind the doping induced enhancement of the Curie temperature. Moreover, we predict the signatures of these magnetic impurities in the spectra of scanning tunneling microscope experiments. By extending the theory to allow for inhomogeneities in one spatial direction, we are able to investigate thin films and heterostructures of Gadolinium doped Europium monoxide. Here, we are able to reproduce the experimentally observed decrease of the Curie temperature with the film thickness. This behavior is attributed to missing coupling partners of the localized 4f moments as well as to an electron depletion at the surface which leads to a reduction of the number of itinerant electrons. By investigating the influence of a metallic substrate onto the phase transition in Gadolinium doped Europium monoxide, we find that the Curie temperature can be increased up to 20%. However, as we show, the underlying mechanism of metal-interface induced charge carrier accumulation is inextricably connected to a suppression of the semiconductor-metal transition.

  13. Enthalpies of formation of europium alkoxides: What lessons can be drawn from them

    International Nuclear Information System (INIS)

    Branco, Joaquim B.; Carretas, José M.; Epple, Matthias; Cruz, Adelaide; Pires de Matos, A.; Leal, João Paulo

    2014-01-01

    Highlights: • First time measurement of europium(II) alkoxides enthalpy of formation. • Calculation of alkoxides thermochemical radii and M–O distances in this environment. • Comparison of experimental EXAFS distance with the calculated ones. • Hints on the type of bond existing in these compounds. • Correlation of bond type and possible use as catalysts. - Abstract: The synthesis and characterization of two europium alkoxides, Eu(OCH 3 ) 2 and Eu(OC 2 H 5 ) 2 , were described. For the first time the enthalpies of formation of divalent lanthanide alkoxides were determined by using reaction-solution calorimetry. The values obtained are Δ f H 0 [Eu(OCH 3 ) 2 ,cr] = −850.5 ± 5.0 kJ/mol and Δ f H 0 [Eu(OC 2 H 5 ) 2 ,cr] = −902.5 ± 5.5 kJ/mol, respectively. Since these compounds have a large use as catalysts or catalysts precursors, the first step of the reaction of them with CO 2 was addressed, which permits to have an idea of the kind of bond involved in those compounds. Moreover, insertion of CO 2 in the europium oxygen bond and formation of metal carboxylate complexes, is in both cases presumably bidentate

  14. Enhanced sulfate reduction with acidogenic sulfate-reducing bacteria

    International Nuclear Information System (INIS)

    Wang Aijie; Ren Nanqi; Wang Xu; Lee Duujong

    2008-01-01

    Sulfate reduction in a continuous flow, acidogenic reactor using molasses wastewater as the carbon source was studied at varying chemical oxygen demand/sulfate (COD/SO 4 2- ) ratios. At a critical COD/SO 4 2- ratio of 2.7, neither COD nor sulfate were in excess for extra production of ethanol or acetate in the reactor. An acetic-type microbial metabolism was established with sulfate-reducing bacteria (SRB) significantly consuming hydrogen and volatile fatty acids produced by acidogenic bacteria and hydrogen producing acetogens in degrading COD, thereby yielding sulfate removal rate >94.6%. A low critical COD/SO 4 2- ratio of 1.6 was also observed with the enriched ASRB population in reactor which overcomes the barrier to the treatment capability of sulfate-laden wastewater treatment with limited COD supply

  15. Syndecan heparan sulfate proteoglycans

    DEFF Research Database (Denmark)

    Gomes, Angélica Maciel; Sinkeviciute, Dovile; Multhaupt, Hinke A.B.

    2016-01-01

    discuss how, in partial catabolic processes, new roles for HSPGs emerge that affect cell behavior. Examples from tumor studies are emphasized, since HSPGs may be altered in composition and distribution and may also represent targets for the development of new therapeutics....... signaling can therefore be complex, but it is now known that syndecans are capable of independent signaling. This review is divided in two sections, and will first discuss how the assembly of heparan sulfate, the anabolic process, encodes information related to ligand binding and signaling. Second, we...

  16. 2-Amino-4-hydroxyethylaminoanisole sulfate

    DEFF Research Database (Denmark)

    Madsen, Jakob T; Andersen, Klaus E

    2016-01-01

    positive patch test reactions to the coupler 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. METHODS: Patch test results from the Allergen Bank database for eczema patients patch tested with 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014 were reviewed. RESULTS......: A total of 902 dermatitis patients (154 from the dermatology department and 748 from 65 practices) were patch tested with amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. Thirteen (1.4%) patients had a positive patch test reaction. Our results do not indicate irritant reactions....... CONCLUSIONS: 2-Amino-4-hydroxyethylaminoanisole sulfate is a new but rare contact allergen....

  17. The Preparation and Thermodynamics of Europium Dicarbide; Preparation et Thermodynamique du Bicarbure d'Europium; Poluchenie i termodinamicheskie svojstva dikarbida evropiya; Preparacion y Termodinamica del Dicarburo de Europio

    Energy Technology Data Exchange (ETDEWEB)

    Gebelt, R. E. [Oklahoma State University, Stillwater, OK (United States); Eick, H. A. [Michigan State University, East Lansing, MI (United States)

    1966-01-15

    Europium dicarbide has been prepared by the reaction of europium metal and graphite in a stainless steel bomb. Chemical analysis indicates an average composition of the product of EuC{sub 1.87{+-}0.07}. X-ray powder diffraction analysis shows the compound to be of body-centred tetragonal symmetry, space group D{sup 17}{sub 4}n-14/mm , with lattice parameters: a{sub 0} = 4.045 A; c{sub 0} = 6.645 A. Vapour phase chromatographic analysis indicates that 98% of the gaseous product of acid hydrolysis of europium dicarbide is the hydrocarbon acetylene. These analytical data, together with the lattice parameters, indicate that europium dicarbide resembles alkaline earth dicarbides more than it resembles the other lanthanon dicarbides. The vaporization of europium dicarbide over the temperature range 1130 to 1600 Degree-Sign K was investigated by the Knudsen effusion method. The effusate was either collected and analysed chemically or observed with a time-of-flight mass spectrometer. Thedata presented here are based predominantly on the massspectro- metric observations since they yielded more reproducible data than the collection technique. Gaseous europium dicarbide and europium, in concentrations of 1 and 99%respectively, were found in the effusate. Instrument limitations prevented determination of the concentration of the gaseous dicarbide as a function of temperature. Calibration of the mass spectrometer with silver permitted the calculation of the pressures corresponding to the observed ion intensities. An empirical equation was fitted to the data for europium by the method of least squares. From the second law of thermodynamics the following values were calculated for the reaction: EuC{sub 2} Rightwards-Harpoon-Over-Leftwards-Harpoon Eu(g) + 2C (graphite); {Delta}H{sup 0}{sub 298} = 51.09{+-}1.42kcal/mole; {Delta}H{sup 0}{sub 298} = 18.43 {+-} 1.75 e.u. Values of the free energy function for EuC{sub 2}(s) were estimated and combined with published data to yield for

  18. Morpholine-4-carboxamidinium sulfate

    Directory of Open Access Journals (Sweden)

    Ioannis Tiritiris

    2016-01-01

    Full Text Available The asymmetric unit of the title salt, 2C5H12N3O+·SO42−, comprises two cations and one sulfate ion. In both cations, the C, N and O atoms of the morpholine rings are disordered over two sets of sites, with refined occupancies of 0.849 (3:0.151 (3 for cation I and 0.684 (4:0.316 (4 for cation II. The C—N bond lengths in both central C3N units of the carboxamidinium ions range between 1.253 (12 and 1.362 (5 Å, indicating a degree of double-bond character. The central C atoms are bonded to the three N atoms in a nearly ideal trigonal–planar geometry and the positive charges are delocalized in both CN3 planes. The crystal structure is stabilized by a three-dimensional network of N—H...O hydrogen bonds between the cations and the sulfate ion. Scheme tiny font, charges and delocalized bonds almost invisible

  19. INTRACELLULAR SYNTHESIS OF CHONDROITIN SULFATE

    Science.gov (United States)

    Dziewiatkowski, Dominic D.

    1962-01-01

    In autoradiograms of slices of costal cartilage, incubated for 4 hours in a salt solution containing S35-sulfate and then washed extensively and dehydrated, about 85 per cent of the radioactivity was assignable to the chondrocytes. From alkaline extracts of similarly prepared slices of cartilage, 64 to 83 per cent of the total sulfur-35 in the slices was isolated as chondroitin sulfate by chromatography on an anion-exchange resin. In view of the estimate that only about 15 per cent of the radioactivity was in the matrix, the isolation of 64 to 83 per cent of the total sulfur-35 as chondroitin sulfate is a strong argument that the chondrocytes are the loci in which chondroitin sulfate(s) is synthesized. PMID:13888910

  20. Characterization of the europium tetracycline complex as a biomarker for atherosclerosis

    Science.gov (United States)

    Courrol, Lilia C.; da Silva, Mônica N.; Sicchieri, Leticia B.

    2016-04-01

    Atherosclerosis is a narrowing of the arteries caused by an increase of atheromatous plaque: material formed by macrophage cells containing cholesterol and fatty acids, calcium and a variable amount of fibrous connective tissue. The elation between vulnerable plaques and cardiovascular events can be determined using plaque biomarkers. In this work, atherosclerotic plaques stained with different molar ratios of europium, in a potential plaque biomarker, europium tetracycline complex, were studied by fluorescence microscopy. The tetracycline antibiotic used was chlortetracycline. The growth of atherosclerotic plaque was followed during 60 days in New Zealand rabbits divided in two groups: an experimental group (EG), with nine animals and a control group (CG) with three animals. The animals in the EG received a diet with 1% of cholesterol and the animals of GC received a normal diet. The aortic arch of the animals with 60 days were cut in the vertical plane in 6 μm thick slices, which were mounted on glass slides and stained with hematoxylin an eosin and europium chlortetracycline complex (EuCTc). The fluorescence images were obtained exciting the EuCTc absorption band with a filter cube D (BP 355 - 425) and the emission was collected with a LP 470 suppression filter. Light intensity, detector gain and acquisition time were fixed for comparisons. The 20× magnified images were collected with 12 bit (or 4096 gray tones) resolution. The mean value of gray scale for each molar ratio of EuCTc was different, indicating that the complex interacts with the components of atherosclerotic plaque and the best molar ratio was 1.5 EuCTc. These results indicate the potential use of the EuCTc biomarker for atherosclerotic plaque characterization.

  1. Europium sorption on zirconia at elevated temperatures: experimental study and modeling

    International Nuclear Information System (INIS)

    Eglizaud, N.; Catalette, H.

    2005-01-01

    Full text of publication follows: Direct disposal of spent nuclear fuel in deep underground repository is being considered by several countries. The waste package maintains an elevated temperature for thousands of years. As sorption is one of the main phenomenon limiting the dispersion of radionuclides in the environment, it has to be studied at elevated temperatures. Zirconia is an oxide produced by cladding oxidation which is suspected in the near field of a nuclear repository. It then could possibly be in contact with waste elements as Europium (III), the sorption of which is therefore studied on zirconia. Experiments were performed by the batch method at a solid/liquid ratio of 10 g.L-1. The sorption edges were recorded in the pH-range from 2 to 10 at 2.10 -5 mol.L -1 Eu(NO 3 ) 3 (I = 0.1 mol.L -1 KNO 3 ). An over-pressure device in an autoclave with an incorporated filtering system allowed the experiments, carbonate free, at 25 deg. C, 50 deg. C, 80 deg. C, 120 deg. C and 150 deg. C and in situ pH measurements. Filtrates were analyzed by the ICP-AES method. Sorption isotherms show an increase in the sorption phenomenon when the temperature raises. The half sorption pH decreases from 7 at 25 deg. C to 3,6 at 150 deg. C. The distribution coefficients that were obtained at elevated temperatures enriched the databases of integrated performance assessment codes. Raw data were modeled with the surface complexation theory using the double layer model (DLM). Several possible surface complexes were examined and discussed, taking into account aqueous hydrolyzed and precipitated species of Europium. A good agreement between experimental values and modeled isotherms was found at all studied temperatures. Results were consistent with a bidentate complex formed by Europium (III) on the zirconia surface. Associated formation constants were then determined with the geochemical computer code CHESS. (authors)

  2. Preparation and luminescence of silica aerogel composites containing an europium (III) phenanthroline nitrate complex

    Energy Technology Data Exchange (ETDEWEB)

    Gutzov, Stoyan, E-mail: sgutzov@chem.uni-sofia.bg [University of Sofia “St. Kliment Ohridski”, Department of Physical Chemistry, J. Bourchier Blvd. 1, 1164 Sofia (Bulgaria); Danchova, Nina; Kirilova, Rada; Petrov, Vesselin [University of Sofia “St. Kliment Ohridski”, Department of Physical Chemistry, J. Bourchier Blvd. 1, 1164 Sofia (Bulgaria); Yordanova, Stanislava [University of Sofia “St. Kliment Ohridski”, Department of Organic Chemistry, J. Bourchier Blvd. 1, 1164 Sofia (Bulgaria)

    2017-03-15

    A simple two step procedure for the functionalization of hydrophobic silica aerogel microgranules with europium ions and/or 1,10 - phenanthroline is demonstrated. The activation procedure is based on soaking aerogels in a europium nitrate solution, followed by functionalization with 1,10 – phenanthroline. The functionalized materials display strong red or blue emission at UV-excitation, coming from the formation of [Eu(phen){sub 2}](NO{sub 3}){sub 3} or Si(IV)– 1,10-phenathroline complexes in the porous system of the aerogels. The most probable site symmetry of the europium cation is C{sub 2v} confirmed by luminescence spectra analysis. Room temperature diffuse reflectance spectra and excitation/luminescence spectra are used to describe the optical properties of the hybrid composites. Excitation spectra prove an efficient energy transfer between 1,10 – phenanthroline and the Eu{sup 3+} ion. - Graphical abstract: An effective activation procedure for functionalization of silica aerogel granules with [Eu(phen){sub 2}](NO{sub 3}){sub 3} and/or 1,10 – phenanthroline /phen/ has been demonstrated in order to obtain red or blue emitting materials. Luminescence spectra (excitation at 355 nm) of functionalized aerogel granules: 1 – SiO{sub 2}:0.18phen; 2 – [Eu(phen){sub 2}](NO{sub 3}){sub 3}; 3– SiO{sub 2}:0.007Eu(phen){sub 2}(NO{sub 3}){sub 3}. The Eu{sup 3+} f-f {sup 5}D{sub 0} →{sup 7}F {sub 0,1,2,3,4} emission transitions are denoted as 0-0, 0-1, 0-2, 0-3, 0-4. The most probable site symmetry of Eu3{sup +} ion is C{sub 2v}.

  3. Electron-induced desorption of europium atoms from oxidized tungsten surface: concentration dependence of low-energy peak

    CERN Document Server

    Davydov, S Y

    2002-01-01

    One discusses nature of electron induced desorption of Eu sup 0 europium atoms under E sub e irradiating electron low-energies (approx 30 eV) and peculiarities of yield dependence of Eu sup 0 atoms on their concentration at oxidized tungsten surface. Primary act of vacancy origination in europium adatom inner 5p-shell turned to be the determining stage. Evaluations have shown that just the first of two possible scenarios of ionization (electron intra-atomic to Eu adatom external quasi-level or realise of knocked out electron into vacuum) leads to Eu sup 0 desorption. One determined concentration threshold for yield of Eu sup 0 atoms

  4. Highly specific ''sensing'' of tryptophan by a luminescent europium(III) complex

    Energy Technology Data Exchange (ETDEWEB)

    Stubenrauch, Jan A.; Mevissen, Christian; Schulte, Marie F.; Bochenek, Steffen; Albrecht, Markus [RWTH Univ. Aachen (Germany). Inst. fuer Organische Chemie; Subramanian, Palani S. [Central Salt and Marine Chemicals, Research Institute (CSRI), Gujarat (India)

    2016-07-01

    The europium(III) complex 1-Cl{sub 3} (S,S-2,2{sup '}-(((1,10-phenanthroline-2,9-diyl)bis(methanylylidene))bis (azanylyliden e))bis(3-methylbutanamide)europiumtrichloride) undergoes, only in the presence of the amino acid tryptophan, a change of emission at 615 nm. In the presence of few equivalents of tryptophan, emission of the europium complex is enhanced while it disappears upon addition of large amounts. This behavior can be assigned to displacement of the sensitizing phenanthroline ligand of 1-Cl{sub 2} x Trp in the latter case.

  5. Different-ligand coordination europium compounds with dibenzoylmethane, nitrate-group, and hexamethylphosphotriamide

    International Nuclear Information System (INIS)

    Karasev, V.E.; Botova, I.N.

    1988-01-01

    Some different-ligand europium complexes with dibenzoylmethane (DBM), hexamethylphosphotriamide (HMPA) and NO 3 -group of composition: Eu(NO 3 ) 3 x3HMPAx2H 2 O, Eu(NO 3 ) 2 xDBMx2HMPA, EuNO 3 x(DBM) 2 x2HMPA and Eu(DBM) 3 xHMPA are synthesized. Individuality of each complex is confirmed by methods of chemical, IR spectroscopic, luminescent, thermogravimetric analyses. Integral intensities of luminescence of synthesized complexes are measured, their excitation spectra in the crystal state at 77 K in the 200-600 nm range are studied

  6. Synthesis of mixed ligand europium complexes: Verification of predicted luminescence intensification

    International Nuclear Information System (INIS)

    Lima, Nathalia B.D.; Silva, Anderson I.S.; Gonçalves, Simone M.C.; Simas, Alfredo M.

    2016-01-01

    Mixed ligand europium complexes are predicted to be more luminescent than what would be expected from their corresponding repeating ligand compounds according to a conjecture recently advanced by our research group; a conjecture that has already been validated for strongly luminescent europium complexes. In this article, we seek to further verify the validity of this conjecture for complexes which are much more symmetric, and which thus display lower levels of luminescence. Accordingly, we synthesized complexes Eu(DBM) 3 (L) 2 , and all novel mixed ligand combinations Eu(DBM) 3 (L,L') with L and L' equal to DBSO, PTSO, and TPPO. The syntheses were carried out via displacement reactions from the starting complex Eu(DBM) 3 (H 2 O) 2 , passing through the intermediates Eu(DBM) 3 (L) 2 and finally, by displacement of L by L', arriving at Eu(DBM) 3 (L,L'). The ligands L obey the following order of displacement TPPO>PTSO>DBSO>H 2 O, which had been previously described by our group. In the present article, we further show that this displacement order could have been predicted by Sparkle/RM1 thermochemical calculations. Subsequently, we determined the radiative decay rates, A rad , for all six compounds by photophysical measurements. As expected, results show that the measured A rad values for all novel mixed ligand complexes are larger than the average of the A rad values for the corresponding repeating ligand coordination compounds. In conclusion, the present article does broaden the scope of our conjecture, which enunciates that an increase in the diversity of ligands around the europium ion tends to intensify the luminescence. - Highlights: • Mixed ligand europium complexes are predicted to be more luminescent than repeating ligand ones. • Radiative decay rates increase with structural coordination asymmetry. • The non-ionic ligands displacement order in substitution reactions is TPPO>PTSO>DBSO>H 2 O. • Sparkle/RM1 correctly predicts the

  7. Test of zircon materials for sorption of europium; Pruebas de materiales circoniferos para sorcion de europio

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E.; Fernandez V, S.M.; Garcia R, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-01

    In previous works it has already been made notice that some phosphates have the property of sipping radioactive metals in solution, what takes advantage to fabricate reactive barriers that are placed in the repositories of nuclear wastes. In our laboratory it has been obtained to the zirconium silicate (ZrSiO{sub 4}) and the alpha zirconium hydrogen phosphate (Zr(HPO{sub 4}) 2H{sub 2}0) starting from sea sand in an easy and economic way. With the interest of knowing if these compounds can be used in contention barriers the evaluation of their surface properties it is made and of europium sorption. (Author)

  8. Determination of micro amounts of samarium and europium by analogue derivative spectrophotometry

    International Nuclear Information System (INIS)

    Ishii, H.; Satoh, K.

    1982-01-01

    Derivative spectrophotometry using the analogue differentiation circuit was applied to the determination of samarium and europium at ppm levels. By measuring the second or the fourth derivative spectra of the characteristic absorption bands of both the rare earth ions around 400 nm, they can be determined directly and selectively in the presence of large amounts of most other rare earths without any prior separation. Further, aptly selecting conditions for the measurement of the derivative spectra, the simultaneous determination of both the rare earth elements was feasible. The principle and the characteristics of analogue derivative spectrophotometry are also described. (orig.) [de

  9. Spectroscopic studies of 2-thenoyltrifluoro acetonate of uranyl salts doped with europium

    International Nuclear Information System (INIS)

    Nakagawa, F.T.; Luiz, J.E.M. de Sa; Felinto, M.C.F.C.; Brito, H.F.; Teotonio, E.E.S.

    2006-01-01

    Uranyl compounds present a great potential as luminescence materials. Some examples of applications are: in laser technology, cathode ray tube, X-rays diagnostic. In this work it was studied the synthesis, characterization and spectroscopic properties study of uranyl 2-thenoyl trifluoroacetonate and uranyl 2- thenoyl trifluoroacetonate doped with europium. The compounds were synthesized and characterized by infrared absorption spectroscopy, thermal analysis, scanning electronic microscopy, and electronic spectroscopy of emission and excitation. The Eu 3+ ion acted as an effective luminescent probe, however the process of energy transfer from UO 2 2+ to Eu 3+ ion has not been efficient. (author)

  10. Positive parity states and some electromagnetic transition properties of even-odd europium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Yazar, Harun Resit, E-mail: yazar@nevsehir.edu.tr [Nevsehir University, Faculty of Art and Science (Turkey)

    2013-06-15

    The positive-parity low-spin states of even-odd Europium isotopes ({sup 151-155}Eu) were studied within the framework of the interacting boson-fermion model. The calculated positive low-spin state energy spectra of the odd Eu isotope were found to agree quite well with the experimental data. The B(E2) values were also calculated and it was found that the calculated positive-parity low-spin state energy spectra of the odd-A Eu isotopes agree quite well with the experimental data.

  11. Luminescent sensing of organophosphates using europium(III) containing imprinted polymers prepared by RAFT polymerization

    International Nuclear Information System (INIS)

    Southard, Glen E.; Van Houten, Kelly A.; Ott, Edward W.; Murray, George M.

    2007-01-01

    Molecularly imprinted polymers capable of sensing organophosphorous compounds by luminescence have been prepared by reversible addition fragmentation chain transfer (RAFT) polymerization. The polymer contained a dithiobenzoate substituted tris(β-diketonate) europium(III) complex which served as a polymerization substrate and as a luminescent binding site for pinacolyl methylphosphonate (PMP), the hydrolysis product of the nerve agent Soman. The resultant polymer allowed quantitation of PMP in the low ppb range with minimal interference from similar compounds. Polymers were characterized by luminescence spectroscopy and scanning electron microscopy

  12. Spectral-luminescent investigation of polymers doped with europium trisphenoyltrifluoroacetonate compound with 1,10-phenanthroline

    International Nuclear Information System (INIS)

    Karasev, V.E.; Mirochnik, A.G.; Shchelokov, R.N.

    1983-01-01

    Spectral-luminescent characteristics of europium tristhenoyltrifluoroacetonate with 1.10-phenanthpoline in polystyrepe and polyvinyl chloride are investigated. E 4 (TTA) 3 phen during introduction into polymers preserves its composition and structure. Weak temperature dependence of half-Width of luminescent lines qualitatively different from the case of crystal chelate is characteristic for polymers doped with E 4 (TTA) 3 xphen. Investigation into temperature dependence of E 4 3+ luminescent intensity in chelate doped polymers proves the conclusion on weakening processes of excitation energy relaxation by vibration constituents of close and far environment during chelate introduction into polymers

  13. A microemulsion preparation of nanoparticles of europium in silica with luminescence enhancement using silver

    International Nuclear Information System (INIS)

    Ma Zhiya; Dosev, Dosi; Kennedy, Ian M

    2009-01-01

    A facile one-pot microemulsion method has been developed for the synthesis of spherical silver core-silica shell (Ag-SiO 2 ) nanoparticles with europium chelates doped in the shell through a silane agent. The method is significantly more straightforward than other extant methods. Measurements of the luminescent emissions from the Ag-SiO 2 nanoparticles, in comparison with control silica nanoparticles without silver cores, showed that the presence of the silver cores can increase the fluorescence intensity approximately 24-fold and decrease the luminescence lifetime. This enhancement offers a potential increase in overall particle detectability with increased fluorophore photostability.

  14. The different-ligand complexing of europium with complexones and β-diketones in micellar solution

    International Nuclear Information System (INIS)

    Svetlova, I.E.; Dobrynina, N.A.; Smirnova, N.S.; Martynenko, L.I.; Evseev, A.M.; Savitskij, A.P.

    1989-01-01

    Method of pH-metric titration with mathematical simulation was used to study the effect of nonionic surfactant (polyoxyethyleneoctylphenyl este) on stability of europium complexes with cyclohexanediaminetetraacetic and ethylenediaminetetraacetic acids. Optimal conditions for ternary complex formation in the system Eu 3+ -complexone-β-diketone at pH 7.0-9.0 were found. Complex-compositions were determined and their stability constants were calculated. It is shown that complex stability decreases by several orders in micellar solutions, tecause β-diketone introduction to the solution decreases thermodynamic stability of complexes

  15. Trace electrochemical analysis of Europium, Ytterbium, and Cerium at their joint presence in solution

    Directory of Open Access Journals (Sweden)

    Rema Matakova

    2012-03-01

    Full Text Available In the course of several decades at the department of analytical chemistry and chemistry of rare elements there were studied the electrode processes with participation of rare-earth metals (REM in accordance with the long awaiting problem of the development of rare-metal and rare-earth branch of non-ferrous metallurgy of Kazakhstan. With the aim of express and highly sensitive analytical control of raw materials and final product of rare-earth industry there were developed the methods of inversion-voltamperometric determination of low concentrations of europium, ytterbium and cerium under the conditions of their individual and combined presence in the solution.

  16. Preparation and fluorescent recognition properties for fluoride of a nanostructured covalently bonded europium hybrid material

    Institute of Scientific and Technical Information of China (English)

    余旭东; 李景印; 李亚娟; 耿丽君; 甄小丽; 于涛

    2015-01-01

    A novel covalently bonded Eu3+-based silica hybrid material was designed and its spectrophotometric anion sensing prop-erty was studied. The fluorescent receptor (europium complex) was covalently grafted to the silica matrix via a sol-gel approach. FTIR, UV-vis spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and photoluminescent spectra were characterized, and the results revealed that the hybrid material with nanosphere structure displayed excellent photophysical property. In addition, the selective anion sensing property of the hybrid material was studied by UV-vis and fluorescence spectra. The results showed that the hybrid material exhibited a smart response with fluoride anions.

  17. The condition for electroplex emission from an europium complex doped poly( N-vinylcarbazole)

    Science.gov (United States)

    Zhang, T.; Xu, Z.; Qian, L.; Tao, D. L.; Teng, F.; Gao, X.; Xu, X. R.

    2005-10-01

    Spectral characteristics of photoluminescence (PL) and electroluminescence (EL) of poly( N-vinylcarbazole) (PVK) matrices doped with a novel europium complex Eu(aspirin) 3phen were investigated. A red-shift and broadening were observed in the EL spectra but not in the PL ones. However, neither red-shift nor broadening were observed in the EL spectra of PVK doped with a similar complex with the same ligand, terbium complex (Tb(aspirin) 3phen). This result suggests the formation of electroplexes in blend systems, which is likely due to inefficient energy transfer from host molecules to dopant molecules.

  18. Thermal expansion studies on europium titanate (Eu2TiO5)

    International Nuclear Information System (INIS)

    Panneerselvam, G.; Subramanian, G.G.S.; Antony, M.P.

    2008-01-01

    The lattice thermal expansion characteristics of europium titanate (Eu 2 TiO 5 ) have been studied by measuring the lattice parameter by high temperature X-ray diffraction technique (HT-XRD) in the temperature range 298-1573K. Percentage linear thermal expansion and mean linear thermal expansion coefficients were computed from the lattice parameter data. The percentage linear thermal expansion in the temperature range 298-1573 K along a, b and c axes are 1.05, 1.15 and 0.95 respectively. (author)

  19. Temperature dependence of the luminescence lifetime of a europium complex immobilized in different polymer matrices

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Bharathi Bai J. [Surface Engineering Division, National Aerospace Laboratories, Bangalore 560017 (India)], E-mail: bharathi@css.nal.res.in; Vasantharajan, N. [Surface Engineering Division, National Aerospace Laboratories, Bangalore 560017 (India)

    2008-10-15

    The temperature dependence of the luminescence lifetime of temperature sensor films based on europium (III) thenoyltrifluoroacetonate (EuTTA) as sensor dye in various polymer matrices such as polystyrene (PS), polymethylmethacrylate (PMMA), polyurethane (PU) and model airplane dope was studied and compared. The luminescence lifetime of EuTTA was found to depend on the polymer matrix. The temperature sensitivity of lifetime was maximum for EuTTA-PS coating in the temperature range of 10-60 deg. C. The effect of concentration of the sensor dye in the polymer on the lifetime and temperature sensitivity was also studied.

  20. Influence of biofilms on migration of uranium, americium and europium in the environment

    International Nuclear Information System (INIS)

    Baumann, Nils; Zirnstein, Isabel; Arnold, Thuro

    2015-01-01

    The report on the influence of biofilms on migration of uranium, americium and europium in the environment deals with the contamination problems of uranium mines such as SDAG WISMUT in Saxonia and Thuringia. In mine waters microorganisms form a complex microbiological biocoenosis in spite of low pH values and high heavy metal concentrations including high uranium concentrations. The analyses used microbiological methods like confocal laser scanning microscopy and molecular-biological techniques. The interactions of microorganism with fluorescent radioactive heavy metal ions were performed with TRLFS (time resolved laser-induced fluorescence spectroscopy).

  1. Heparan sulfate and cell division

    Directory of Open Access Journals (Sweden)

    Porcionatto M.A.

    1999-01-01

    Full Text Available Heparan sulfate is a component of vertebrate and invertebrate tissues which appears during the cytodifferentiation stage of embryonic development. Its structure varies according to the tissue and species of origin and is modified during neoplastic transformation. Several lines of experimental evidence suggest that heparan sulfate plays a role in cellular recognition, cellular adhesion and growth control. Heparan sulfate can participate in the process of cell division in two distinct ways, either as a positive or negative modulator of cellular proliferation, or as a response to a mitogenic stimulus.

  2. Final report on the safety assessment of sodium cetearyl sulfate and related alkyl sulfates as used in cosmetics.

    Science.gov (United States)

    Fiume, Monice; Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Alan Andersen, F

    2010-05-01

    Sodium cetearyl sulfate is the sodium salt of a mixture of cetyl and stearyl sulfate. The other ingredients in this safety assessment are also alkyl salts, including ammonium coco-sulfate, ammonium myristyl sulfate, magnesium coco-sulfate, sodium cetyl sulfate, sodium coco/hydrogenated tallow sulfate, sodium coco-sulfate, sodium decyl sulfate, sodium ethylhexyl sulfate, sodium myristyl sulfate, sodium oleyl sulfate, sodium stearyl sulfate, sodium tallow sulfate, sodium tridecyl sulfate, and zinc coco-sulfate. These ingredients are surfactants used at concentrations from 0.1% to 29%, primarily in soaps and shampoos. Many of these ingredients are not in current use. The Cosmetic Ingredient Review (CIR) Expert Panel previously completed a safety assessment of sodium and ammonium lauryl sulfate. The data available for sodium lauryl sulfate and ammonium lauryl sulfate provide sufficient basis for concluding that sodium cetearyl sulfate and related alkyl sulfates are safe in the practices of use and concentration described in the safety assessment.

  3. Synthesis and structural characterization of an unusual heterometallic europium(III) amidinate complex

    International Nuclear Information System (INIS)

    Sroor, Farid M.; Hrib, Cristian G.; Hilfert, Liane; Edelmann, Frank T.

    2015-01-01

    The reaction of EuI_2(THF)_2 with 3 equiv. of the recently discovered lithium-cyclopropylethinylamidinate Li[c-C_3H_5-C≡C-C(NCy)_2] (1) (Cy = cyclohexyl) unexpectedly afforded the heterometallic europium(III) amidinate complex [{c-C_3H_5-C≡C-C(NCy)_2}Li{c-C_3H_5-C≡C-C(NCy)_2}_2Eu(μ-I)_2Li(THF)_2] (2) in the form of bright yellow, air- and moisture-sensitive crystals. An X-ray diffraction study of 2 revealed several unusual structural features. It comprises a double ''ate'' complex of the tentative trivalent europium(III) bis(cyclopropylethinylamidinate) derivative [c-C_3H_5-C≡C-C(NCy)_2]_2Eu"I"I"II. ''Ate'' complex formation occurred not only through retention of one equiv. of lithium iodide but also through addition of one equiv. of Li[c-C_3H_5-C≡C-C(NCy)_2]. The Li atom in the iodo-bridged Eu(μ-I)_2Li(THF)_2 part of the molecule is tetrahedrally coordinated, whereas the second lithium atom is only tricoordinate through the presence of a rare monodentate (dangling) amidinate ligand. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Determination for Enterobacter cloacae based on a europium ternary complex labeled DNA probe

    Science.gov (United States)

    He, Hui; Niu, Cheng-Gang; Zeng, Guang-Ming; Ruan, Min; Qin, Pin-Zhu; Liu, Jing

    2011-11-01

    The fast detection and accurate diagnosis of the prevalent pathogenic bacteria is very important for the treatment of disease. Nowadays, fluorescence techniques are important tools for diagnosis. A two-probe tandem DNA hybridization assay was designed for the detection of Enterobacter cloacae based on time-resolved fluorescence. In this work, the authors synthesized a novel europium ternary complex Eu(TTA) 3(5-NH 2-phen) with intense luminescence, high fluorescence quantum yield and long lifetime before. We developed a method based on this europium complex for the specific detection of original extracted DNA from E. cloacae. In the hybridization assay format, the reporter probe was labeled with Eu(TTA) 3(5-NH 2-phen) on the 5'-terminus, and the capture probe capture probe was covalent immobilized on the surface of the glutaraldehyde treated glass slides. The original extracted DNA of samples was directly used without any DNA purification and amplification. The detection was conducted by monitoring the fluorescence intensity from the glass surface after DNA hybridization. The detection limit of the DNA was 5 × 10 -10 mol L -1. The results of the present work proved that this new approach was easy to operate with high sensitivity and specificity. It could be conducted as a powerful tool for the detection of pathogen microorganisms in the environment.

  5. Luminescence variations in europium-doped silicon-substituted hydroxyapatite nanobiophosphor via three different methods

    Energy Technology Data Exchange (ETDEWEB)

    Thang, Cao Xuan; Pham, Vuong-Hung, E-mail: vuong.phamhung@hust.edu.vn

    2015-07-15

    Highlights: • Europium doped silicon-substituted hydroxyapatite was synthesized by wet chemical synthesis method. • Morphology of nanoparticles depended on the synthesized method. • Photoluminescence intensity of the sample increases with the increasing of Si substitutions, Eu dopants and thermal annealing. - Abstract: This paper reports the first attempt for the synthesis of europium-doped Si-substituted hydroxyapatite (HA) nanostructure to achieve strong and stable luminescence of nanobiophosphor, particularly, by addition of different Eu dopants, Si substitutions, and application of optimum annealing temperatures of up to 1000 °C. The nanobiophosphor was synthesized by the coprecipitation, microwave, and hydrothermal methods. The nanoparticles demonstrated a nanowire to a spindle-like morphology, which was dependent on the method of synthesis. The photoluminescence (PL) intensity of the sample increases with the increase in Si substitutions and Eu dopants. The luminescent nanoparticles also showed the typical luminescence of Eu{sup 3+} centered at 610 nm, which was more efficient for the annealed Eu-doped Si-HA nanoparticles than for the as-synthesized nanoparticles. Among the different synthesis methods, the hydrothermal method reveals the best light emission represented by high PL intensity and narrow PL spectra. These results suggest the potential application of Eu-doped Si-HA in stable and biocompatible nanophosphors for light emission and nanomedicine.

  6. Red light emission from europium doped zinc sodium bismuth borate glasses

    Science.gov (United States)

    Hegde, Vinod; Viswanath, C. S. Dwaraka; Upadhyaya, Vyasa; Mahato, K. K.; Kamath, Sudha D.

    2017-12-01

    Zinc sodium bismuth borate (ZNBB) glasses doped with different concentrations of europium were prepared by conventional melt quenching method and characterized through the measurements of density, refractive index, X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectra, optical absorption, luminescence and radiative lifetimes. FTIR spectra showed seven characteristic peaks of bismuth and borate functional groups in the range of 400-1600 cm-1. The optical band gap and bonding parameters have been calculated from absorption spectra. Photoluminescence spectra recorded in the visible region with 394 nm excitation are used to calculate the Judd-Ofelt (JO) intensity parameters (Ω2 and Ω4). The JO intensity parameters have been used to calculate the radiative parameters such as branching ratio (β), stimulated emission cross-section (σse), transition probability (A) for the fluorescent level of 5D0→7F2. Decay rates through single exponential are used to calculate the lifetime (τm) of the meta-stable state 5D0 of (Eu3+ ion) these glasses. The radiative parameters measured for all these glasses show 0.7 mol% europium doped zinc sodium bismuth borate glass 5D0→7F2 transition has the potential for red laser applications. The quality of the colour emitted by the present glasses are estimated quantitatively by CIE chromaticity coordinates, which confirms the suitability of these glasses as a red emitting material for field emission technologies and LEDs.

  7. Theoretical spectroscopic study of the conjugate microcystin-LR-europium cryptate

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Julio G.; Dutra, Jose Diogo L.; Costa Junior, Nivan B. da; Freire, Ricardo O., E-mail: rfreire@ufs.br [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Departamento de Quimica; Alves Junior, Severino; Sa, Gilberto F. de [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Quimica Fundamental

    2013-02-15

    In this work, theoretical tools were used to study spectroscopic properties of the conjugate microcystin-LR-europium cryptate. The Sparkle/AM1 model was applied to predict the geometry of the system and the INDO/S-CIS model was used to calculate the excited state energies. Based on the Judd-Ofelt theory, the intensity parameters were predicted and a theoretical model based on the theory of the 4f-4f transitions was applied to calculate energy transfer and backtransfer rates, radiative and non-radiative decay rates, quantum efficiency and quantum yield. A detailed study of the luminescent properties of the conjugate Microcystin-LR-europium cryptate was carried out. The results show that the theoretical quantum yield of luminescence of 23% is in good agreement with the experimental value published. This fact suggests that this theoretical protocol can be used to design new systems in order to improve their luminescence properties. The results suggest that this luminescent system may be a good conjugate for using in assay ELISA for detection by luminescence of the Microcystin-LR in water. (author)

  8. Europium-doped amorphous calcium phosphate porous nanospheres: preparation and application as luminescent drug carriers

    Directory of Open Access Journals (Sweden)

    Zhang Kui-Hua

    2011-01-01

    Full Text Available Abstract Calcium phosphate is the most important inorganic constituent of biological tissues, and synthetic calcium phosphate has been widely used as biomaterials. In this study, a facile method has been developed for the fabrication of amorphous calcium phosphate (ACP/polylactide-block-monomethoxy(polyethyleneglycol hybrid nanoparticles and ACP porous nanospheres. Europium-doping is performed to enable photoluminescence (PL function of ACP porous nanospheres. A high specific surface area of the europium-doped ACP (Eu3+:ACP porous nanospheres is achieved (126.7 m2/g. PL properties of Eu3+:ACP porous nanospheres are investigated, and the most intense peak at 612 nm is observed at 5 mol% Eu3+ doping. In vitro cytotoxicity experiments indicate that the as-prepared Eu3+:ACP porous nanospheres are biocompatible. In vitro drug release experiments indicate that the ibuprofen-loaded Eu3+:ACP porous nanospheres show a slow and sustained drug release in simulated body fluid. We have found that the cumulative amount of released drug has a linear relationship with the natural logarithm of release time (ln(t. The Eu3+:ACP porous nanospheres are bioactive, and can transform to hydroxyapatite during drug release. The PL properties of drug-loaded nanocarriers before and after drug release are also investigated.

  9. Resonance ionization spectroscopy of Europium The first application of the PISA at ISOLDE-RILIS

    CERN Document Server

    AUTHOR|(CDS)2099873; Marsh, Bruce Alan

    The following work has been carried out at the radioactive ion beam facility ISOLDE at CERN. A compact atomic beam unit named PISA (Photo Ionization Spectroscopy Apparatus) has been implemented as a recent addition to the laboratory of the Resonance Ionization Laser Ion Source (RILIS). The scope of this thesis work was to demonstrate different applications of the PISA, using the existing and highly developed laser setup of the RILIS installation. In a demonstration of the suitability of PISA for ionization scheme development, a new ionization scheme for Europium has been developed. This resulted in the observation of several new autoionizing states and Rydberg series. Through the analysis of the observed Rydberg resonances a refined value of $45734.33(3)(3)$ cm$^{-1}$ for the ionization potential of the europium atom has been determined. In addition this thesis reports on the feasibility of the use of the PISA as a RILIS performance monitoring device during laser ion source operations. Finally the present wor...

  10. Study of Polymeric Luminescent Blend (PC/PMMA) Doped with Europium Complex under Gamma-Iradiation

    International Nuclear Information System (INIS)

    Parra, D. F.

    2006-01-01

    Spectroscopic properties of blends formed by bisphenol-A polycarbonate (PC) and poly(methyl methacrylate) (PMMA) doped with europium in organic complex were studied. Polymeric luminescent blends are potential materials for many applications; however, little information has been reported concerning the stability under thermal and radiation conditions. Luminescent films were synthesized from europium thenoyltrifluoroacetonate at different concentrations doped in PC/PMMA blends. Films produced of the luminescent polymer blend were irradiated in a 60 C o source. Their luminescent properties, in the solid state, as well as, the thermal oxidative resistance after gamma irradiation was investigated. These systems were characterized by elemental analysis, thermogravimetry (TGA), differential scanning calorimetry (DSC) and infrared spectroscopy (FTIR). Based on TGA data, the thermal stability of PC/PMMA:(tta)3 system is higher than the polymer blend. The DSC results indicated that those new systems are chemically stables. The emission spectra of the Eu 3 +-tta complex doped in the PC/PMMA recorded at 298 and 77 K exhibited the characteristic bands arising from the 5 D 0 →7 F J transitions (J = 0-6). The luminescence intensity decreases with increasing of precursor concentration in the doped polymer obtained by chemical reaction. This result is different from that of samples obtained by physical method in melting doping. The blend was irradiated under ionizing radiation of 60 C o source. After irradiation of the luminescent films the physical properties of luminescence, thermal and oxidative stability were evaluated.(Fapesp and Cnpq financial support)

  11. Rapid screening of oxytetracycline residue in catfish muscle by dispersive liquid-liquid microextraction and europium-sensitized luminescence

    Science.gov (United States)

    Oxytetracycline (OTC) residue in catfish muscle was screened by dispersive liquid-liquid microextraction (DLLME) and europium-sensitized luminescence (ESL). After extraction in EDTA, HCl, and acetonitrile, cleanup was carried out by DLLME, and ESL was measured at microgram = 385 nm and wavelength = ...

  12. Synthesis and luminescence properties of europium and terbium complexes with pyridine- or bipyridine-linked oligothiophene ligand

    International Nuclear Information System (INIS)

    Liu Ping; Huang Mingsheng; Pan Wanzhang; Zhang Yamin; Hu Jianhua; Deng Wenji

    2006-01-01

    With an aim to develop novel luminescence materials, europium and terbium complexes of 2,5-(2-thiophene)-pyridine (TPY) and 5,5'-bis(5-(2,2'-bithiophene))-2,2'-bipyridine (B2TBPY) were synthesized, and their luminescence properties studied. The complexes exhibit ligand-sensitized emission, which is typical of Eu(III) and Tb(III) ions

  13. Chondroitin sulfate/dermatan sulfate sulfatases from mammals and bacteria.

    Science.gov (United States)

    Wang, Shumin; Sugahara, Kazuyuki; Li, Fuchuan

    2016-12-01

    Sulfatases that specifically catalyze the hydrolysis of the sulfate groups on chondroitin sulfate (CS)/dermatan sulfate (DS) poly- and oligosaccharides belong to the formylglycine-dependent family of sulfatases and have been widely found in various mammalian and bacterial organisms. However, only a few types of CS/DS sulfatase have been identified so far. Recently, several novel CS/DS sulfatases have been cloned and characterized. Advanced studies have provided significant insight into the biological function and mechanism of action of CS/DS sulfatases. Moreover, further studies will provide powerful tools for structural and functional studies of CS/DS as well as related applications. This article reviews the recent progress in CS/DS sulfatase research and is expected to initiate further research in this field.

  14. Structural and luminescence properties of europium(III)-doped zirconium carbonates and silica-supported Eu3+-doped zirconium carbonate nanoparticles

    International Nuclear Information System (INIS)

    Sivestrini, S.; Riello, P.; Freris, I.; Cristofori, D.; Enrichi, F.; Benedetti, A.

    2010-01-01

    The synthesis, morphology and luminescence properties of europium(III)-doped zirconium carbonates prepared as bulk materials and as silica-supported nanoparticles with differing calcination treatments are reported. Transmission electron microscopy and X-ray diffraction analyses have, respectively, been used to study the morphology and to quantify the atomic amount of europium present in the optically active phases of the variously prepared nanomaterials. Rietveld analysis was used to quantify the constituting phases and to determinate the europium content. Silica particles with an approximate size of 30 nm were coated with 2 nm carbonate nanoparticles, prepared in situ on the surface of the silica core. Luminescence measurements revealed the role of different preparation methods and of europium-doping quantities on the optical properties observed.

  15. Determination of the hydrolysis constants of Europium (III), in ion strength media 4, 5 and 6 M NaClO4 at 303 K

    International Nuclear Information System (INIS)

    Alvarado B, A.; Jimenez R, M.; Solache R, M.

    1999-01-01

    This work was made with the purpose to complete information about the hydrolysis constants of Europium (III) in high ion strength media. So it was determined at a ion forces media 4, 5 and 6 M of sodium perchlorate at 303 K. The method used was the potentiometric with the aid of the Super quad computer program. In high ion strength media, the measurements of p H do not correspond directly to negative logarithm of the concentration of hydrogen ions, by this it is necessary to calibrate the electrode in these conditions. The Europium was hydrolized at pC H values greater 6 in all cases. The potentiometric method used under the described experimental conditions is adequate to determine the hydrolysis constants of Europium (III). According to the results and diagrams of chemical species of Europium obtained we can conclude that the hydrolysis constants, differ by its distribution but not in its identity. (Author)

  16. Semi-synthesis of chondroitin sulfate-E from chondroitin sulfate-A

    OpenAIRE

    Cai, Chao; Solakyildirim, Kemal; Yang, Bo; Beaudet, Julie M.; Weyer, Amanda; Linhardt, Robert J.; Zhang, Fuming

    2012-01-01

    Chondroitin sulfate-E (chondroitin-4, 6-disulfate) was prepared from chondroitin sulfate-A (chondroitin-4 - sulfate) by regioselective sulfonation, performed using trimethylamine sulfur trioxide in formamide under argon. The structure of semi-synthetic chondroitin sulfate-E was analyzed by PAGE, 1H NMR, 13C NMR, 2D NMR and disaccharide analysis and compared with natural chondroitin sulfate-E. Both semi-synthetic and natural chondroitin sulfate-E were each biotinylated and immobilized on BIAco...

  17. Chondroitin Sulfate Perlecan Enhances Collagen Fibril Formation

    DEFF Research Database (Denmark)

    Kvist, A. J.; Johnson, A. E.; Mörgelin, M.

    2006-01-01

    in collagen type II fibril assembly by perlecan-null chondrocytes. Cartilage perlecan is a heparin sulfate or a mixed heparan sulfate/chondroitin sulfate proteoglycan. The latter form binds collagen and accelerates fibril formation in vitro, with more defined fibril morphology and increased fibril diameters...... produced in the presence of perlecan. Interestingly, the enhancement of collagen fibril formation is independent on the core protein and is mimicked by chondroitin sulfate E but neither by chondroitin sulfate D nor dextran sulfate. Furthermore, perlecan chondroitin sulfate contains the 4,6-disulfated...... disaccharides typical for chondroitin sulfate E. Indeed, purified glycosaminoglycans from perlecan-enriched fractions of cartilage extracts contain elevated levels of 4,6-disulfated chondroitin sulfate disaccharides and enhance collagen fibril formation. The effect on collagen assembly is proportional...

  18. Study of relaxation processes and uniaxial anisotropy in the Europium Gallium Garnet epitaxial films

    International Nuclear Information System (INIS)

    Mukhopadhyay, P.

    1987-04-01

    We report here the magnetic properties of Europium-Gallium Garnet LPE films of the type Eu x Y 3-x Fe 5-y Ga y O 12 (where O< x<1.2 and 1< y<1.1). The mechanism by which the magnetic moments relax in Eu or Sm Garnets is still not fully understood. We have made studies on Eu-Ga garnet films and explain some of the results observed in these films. Pb and Pt ions are always found as impurities in our films. Pb ions contribute to the anisotropy in the film. Most of the experimental results can be explained with the three sub lattice model. The shape of the FMR line width shows strong sensitivity towards the surface impurities. (author). 18 refs, 6 figs, 1 tab

  19. First principles description of the insulator-metal transition in europium monoxide

    KAUST Repository

    Wang, Hao

    2012-02-01

    Europium monoxide, EuO, is a ferromagnetic insulator. Its electronic structure under pressure and doping is investigated by means of density functional theory. We employ spin polarized electronic structure calculations including onsite electron-electron interaction for the localized Eu 4f and 5d electrons. Our results show that under pressure the ferromagnetism is stable, both for hydrostatic and uniaxial pressure, while the compound undergoes an insulator-metal transition. The insulator-metal transition in O deficient and Gd doped EuO is reproduced for an impurity concentration of 6.25%. A 10 monolayer thick EuO(1 0 0) thin film is predicted to be an insulator with a narrow band gap of 0.08 eV. © 2011 Elsevier B.V. All rights reserved.

  20. Spectroscopic studies of an europium(III) tris-β-diketonate complex bearing a pyrazolylpyridine ligand

    International Nuclear Information System (INIS)

    Moreira dos Santos, Antonio; Coelho, Ana C.; Almeida Paz, Filipe A.; Rocha, Joao; Goncalves, Isabel S.; Carlos, Luis D.

    2008-01-01

    A new europium(III) complex, Eu(BTA) 3 (ethyl[3-(2-pyridyl)-1-pyrazolyl]acetate) (where BTA: 1-benzoyl-3,3,3-trifluoroacetonate), was synthesised by simple ligand exchange with the solvent adduct Eu(BTA) 3 (H 2 O) 2 . The compound was characterised by elemental analysis, thermogravimetry, FTIR, FT Raman and photoluminescence spectroscopies. A significant increase of the 5 D 0 lifetime of the complex, relative to the value found for the water-coordinated adduct (from 0.657 ± 0.001 to 0.835 ± 0.002 ms), and a larger contribution of the ligand levels to the excitation spectrum indicate a better photoluminescence performance for the former complex

  1. The mercury-richest europium amalgam Eu{sub 10}Hg{sub 55}

    Energy Technology Data Exchange (ETDEWEB)

    Tambornino, Frank; Hoch, Constantin [Department of Chemistry, Ludwig-Maximilians-Universitaet Muenchen (Germany)

    2015-03-15

    The mercury-richest europium amalgam Eu{sub 10}Hg{sub 55} was synthesized by isothermal electrocrystallization from a solution of EuI{sub 3}.8DMF in DMF on a reactive mercury cathode. The crystal structure shows remarkable complexity and polar metal-metal bonding. Closely related to the structures of mercury-rich amalgams A{sub 11-x}Hg{sub 55+x} (A = Na, Ca, Sr), it shows underoccupied Hg positions along [00z]. Eu{sub 10}Hg{sub 55} can be described as hettotype structure of the Gd{sub 14}Ag{sub 51} structure type. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Removal of cobalt and europium radioisotopes using activated carbon prepared from apricot stones

    International Nuclear Information System (INIS)

    Daifullah, A.A.M.; Moloukhia, H.

    2002-01-01

    the phenomena of cobalt and europium sorption by activated carbon from aqueous solution was studied. Activated carbon prepared from locally available agricultural wastes; apricot stones; was used. The prepared carbon was characterized using different techniques. The chemical nature of the surface of the activated carbon was also studied. Experimental studies were conducted to evaluate and optimize the various process variables i.e. equilibrium time, carbon dose, solution ph and the presence of competitive. Optimal conditions for the sorption of the radioisotopes have been identified. The sorption isotherm of Freundlich was the best fitting for the concentration range studied. Interference of oxalic acid, EDTA and phenol molecules were discussed. Percentages desorption of both acid, EDTA and phenol using bi-distilled water and IMHCI was determined. The data suggest the possible use of activated carbon of apricot stone (ACAS) for the concentration of these cations

  3. Characterization of an azo-calix[4]arene-based optical sensor for Europium (III) ions

    International Nuclear Information System (INIS)

    Echabaane, M.; Rouis, A.; Bonnamour, I.; Ouada, H. Ben

    2012-01-01

    Selective and sensitive optical sensor membranes (optodes) were elaborated to detect cations in aqueous solutions. The sensing films are based on chromogenic calix[4]arene derivatives. The optode membranes were studied using UV/Vis absorption spectroscopy measurements. The sensitivity of the optode has been tested for Pb 2+ , Cd 2+ , Mg 2+ and Eu 3+ ions at pH 6.8. The results showed a good selectivity response towards Eu 3+ . Low selectivity coefficients were observed for Cd 2+ and Mg 2+ where Pb 2+ can be considered as interfering ions. The characteristics of this optode such as response time, regeneration, reproducibility and lifetime are discussed. - Highlights: ► We report optical sensing studies of chromogenic calixarene derivatives. ► We investigate optical interaction between azo-calix[4]arene and Eu 3+ . ► We study sensitivity and selectivity of optode films. ► We describe characteristics of optode films for determination of europium traces.

  4. Quadrupole splitting and Eu partial lattice dynamics in europium orthophosphate EuPO {sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Klobes, B., E-mail: b.klobes@fz-juelich.de [JARA-FIT - Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science JCNS and Peter Grünberg Institute PGI (Germany); Arinicheva, Y., E-mail: y.arinicheva@fz-juelich.de; Neumeier, S., E-mail: s.neumeier@fz-juelich.de [Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research (IEK-6) Nuclear Waste Management and Reactor Safety (Germany); Simon, R. E., E-mail: r.simon@fz-juelich.de; Jafari, A., E-mail: a.jafari@fz-juelich.de [JARA-FIT - Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science JCNS and Peter Grünberg Institute PGI (Germany); Bosbach, D., E-mail: d.bosbach@fz-juelich.de [Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research (IEK-6) Nuclear Waste Management and Reactor Safety (Germany); Hermann, R. P., E-mail: hermannrp@ornl.gov [JARA-FIT - Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science JCNS and Peter Grünberg Institute PGI (Germany)

    2016-12-15

    Hyperfine interactions in europium orthophosphate EuPO{sub 4} were investigated using {sup 151}Eu Mössbauer spectroscopy from 6 to 300 K. The value of the quadrupole splitting and the asymmetry parameter were refined and further substantiated by nuclear forward scattering data obtained at room temperature. The temperature dependence of the relative absorption was modeled with an Eu specific Debye temperature of 221(1) K. Eu partial lattice dynamics were probed by means of nuclear inelastic scattering and the mean force constant, the Lamb-Mössbauer factor, the internal energy, the vibrational entropy, the average phonon group velocity were calculated using the extracted density of phonon states. In general, Eu specific vibrations are characterized by rather small phonon energies and contribute strongly to the total entropy of the system. Although there is no classical Debye like behavior at low vibrational energies, the average phonon group velocity can be reasonably approximated using a linear fit.

  5. Chemiluminescence determination of tetracyclines using Fenton system in the presence europium(III) ions

    International Nuclear Information System (INIS)

    Kaczmarek, Malgorzata; Lis, Stefan

    2009-01-01

    A new simple chemiluminescent method for the determination of chlortetracycline (Chlor-TC), oxytetracycline (Oxy-TC) and doxycycline (Doxy-TC) is described. This method is based on the europium(III) emission as a result of the energy transfer process from the excited product of the tetracyclines oxidation to the uncomplexed Eu(III). Under the optimum conditions, calibration graphs were obtained for 4 x 10 -7 to 2 x 10 -5 mol L -1 of Chlor-TC; 2 x 10 -7 to 2 x 10 -5 mol L -1 of Oxy-TC and 1 x 10 -7 to 3 x 10 -5 mol L -1 of Doxy-TC. The method was successfully applied to the determination of these drugs in pharmaceutical and veterinary formulation and honey.

  6. Chemiluminescence determination of tetracyclines using Fenton system in the presence europium(III) ions

    Energy Technology Data Exchange (ETDEWEB)

    Kaczmarek, Malgorzata [Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60 - 780 Poznan (Poland); Lis, Stefan [Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60 - 780 Poznan (Poland)

    2009-04-20

    A new simple chemiluminescent method for the determination of chlortetracycline (Chlor-TC), oxytetracycline (Oxy-TC) and doxycycline (Doxy-TC) is described. This method is based on the europium(III) emission as a result of the energy transfer process from the excited product of the tetracyclines oxidation to the uncomplexed Eu(III). Under the optimum conditions, calibration graphs were obtained for 4 x 10{sup -7} to 2 x 10{sup -5} mol L{sup -1} of Chlor-TC; 2 x 10{sup -7} to 2 x 10{sup -5} mol L{sup -1} of Oxy-TC and 1 x 10{sup -7} to 3 x 10{sup -5} mol L{sup -1} of Doxy-TC. The method was successfully applied to the determination of these drugs in pharmaceutical and veterinary formulation and honey.

  7. Sorption of Europium in zirconium silicate; Sorcion de Europio en silicato de circonio

    Energy Technology Data Exchange (ETDEWEB)

    Garcia R, G. [ININ, Carretera Mexico-Toluca Km. 36.5, 52045 Estado de Mexico (Mexico)

    2004-07-01

    Some minerals have the property of sipping radioactive metals in solution, that it takes advantage to manufacture contention barriers that are placed in the repositories of nuclear wastes. The more recent investigations are focused in the development of new technologies guided to the sorption of alpha emissors on minerals which avoid their dispersion in the environment. In an effort to contribute to the understanding of this type of properties, some studies of sorption of Europium III are presented like homologous of the americium, on the surface of zirconium silicate (ZrSiO{sub 4}). In this work the results of sorption experiences are presented as well as the interpretation of the phenomena of the formation of species in the surface of the zirconium silicate. (Author)

  8. Effect of the ion force on the hydrolysis constants and of the solubility product of Europium

    International Nuclear Information System (INIS)

    Jimenez R, M.; Ramirez G, J.J.; Solache R, M.; Rojas H, A.

    2003-01-01

    A study on the behavior of the first hydrolysis constant β Eu,H l-0 and the constant of the solubility product Kps of the europium in front of the changes of the ion force: 0. 02 M, 0.1 M, 0.7M, 2M, 3M and 4M of sodium perchlorate, at 303 K. Experimentally the potentiometry and also radioactivity measures its were used. The specific interaction of ions theory (SIT) of Bronsted-Guggenheim-Scatchard allows the extrapolation of the values to infinite dilution and the results were: log β Eu,H l-0 = -7 36 and log K sp l-0 = -24. 68. A discussion of the group of results with the data of the literature is presented. (Author)

  9. Use of dispersive liquid-liquid microextraction for simultaneous preconcentration of samarium, europium, gadolinium and dysprosium

    International Nuclear Information System (INIS)

    Mallah, M.H.; Atomic Energy Organization of Iran, Tehran; Shemirani, F.; Ghannadi Maragheh, M.

    2008-01-01

    A new preconcentration method of dispersive liquid-liquid microextraction (DLLME) was developed for simultaneous preconcentration of samarium, europium, gadolinium and dysprosium. DLLME technique was successfully used as a sample preparation method. In this preconcentration method, an appropriate mixture of extraction solvent, disperser solvent was injected rapidly into an aqueous solution containing Sm, Eu, Gd and Dy after complex formation using chelating reagent of the 1-(2-pyridylazo)-2-naphthol (PAN). After phase separation, 0.5 mL of the settled phase containing enriched analytes was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The main factors affected the preconcentration of Sm, Eu, Gd and Dy were extraction and dispersive solvent type and their volume, extraction time, volume of chelating agent (PAN), centrifuge speed and drying temperature of the samples. Under the best operating condition simultaneous preconcentration factors of 80, 100, 103 and 78 were obtained for Sm, Eu, Gd and Dy, respectively. (author)

  10. Synthesis, Structure, and Luminescent Properties of Europium-Doped Hydroxyapatite Nanocrystalline Powders

    International Nuclear Information System (INIS)

    Ciobanu, C.S.; Iconaru, S.L.; Predoi, D.; Massuyeau, F.; Constantin, L.V.; Costescu, A.

    2012-01-01

    The luminescent europium-doped hydroxyapatite (Eu:HAp, Ca 10-x Eu x (PO 4 ) 6 (OH) 2 ) with 0>x>0.2 nanocrystalline powders was synthesized by coprecipitation. The structural, morphological, and textural properties were well characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The vibrational studies were performed by Fourier transform infrared, Raman, and photoluminescence spectroscopies. The X-ray diffraction analysis revealed that hydroxyapatite is the unique crystalline constituent of all the samples, indicating that Eu has been successfully inserted into the HAp lattice. Eu doping inhibits HAp crystallization, leading to a decrease of the average crystallite size from around 20 nm in the undoped sample to around 7 nm in the sample with the highest Eu concentration. Furthermore, the samples show the characteristic 5 D 0 → 7 F 0 transition observed at 578 nm related to Eu 3+ ions distributed on Ca 2+ sites of the apatitic structure

  11. Europium and samarium doped calcium sulfide thin films grown by PLD

    International Nuclear Information System (INIS)

    Christoulakis, S.; Suchea, M; Katsarakis, N.; Koudoumas, E

    2007-01-01

    Europium and samarium doped calcium sulfide thin films (CaS:Eu,Sm) with different thickness were prepared by the pulsed laser deposition technique using sintered targets. A typical homemade deposition chamber and XeCl excimer laser (308 nm) were employed and the films were deposited in helium atmosphere onto silicon and corning glass substrates. Structural investigations carried out by X-ray diffraction and atomic force microscopy showed a strong influence of the deposition parameters on the film properties. The films grown had an amorphous or polycrystalline structure depending on growth temperature and the number of pulses used, the same parameters affecting the film roughness, the grain shape and dimensions, the film thickness and the optical transmittance. This work indicates that pulsed laser deposition can be a suitable technique for the preparation of CaS:Eu,Sm thin films, the film characteristics being controlled by the growth conditions

  12. Magnesium ionophore II as an extraction agent for trivalent europium and americium

    Energy Technology Data Exchange (ETDEWEB)

    Makrlik, Emanuel [Czech Univ. of Life Sciences, Prague (Czech Republic). Faculty of Environmental Sciences; Vanura, Petr [Univ. of Chemistry and Technology, Prague (Czech Republic). Dept. of Analytical Chemistry

    2016-11-01

    Solvent extraction of microamounts of trivalent europium and americium into nitrobenzene by using a mixture of hydrogen dicarbollylcobaltate (H{sup +}B{sup -}) and magnesium ionophore II (L) was studied. The equilibrium data were explained assuming that the species HL{sup +}, HL{sup +}{sub 2}, ML{sup 3+}{sub 2}, and ML{sup 3+}{sub 3} (M{sup 3+} = Eu{sup 3+}, Am{sup 3+}; L=magnesium, ionophore II) are extracted into the nitrobenzene phase. Extraction and stability constants of the cationic complex species in nitrobenzene saturated with water were determined and discussed. From the experimental results it is evident that this effective magnesium ionophore II receptor for the Eu{sup 3+} and Am{sup 3+} cations could be considered as a potential extraction agent for nuclear waste treatment.

  13. Ligand effect on the performance of organic light-emitting diodes based on europium complexes

    International Nuclear Information System (INIS)

    Fang Junfeng; You Han; Gao Jia; Lu Wu; Ma Dongge

    2007-01-01

    A series of europium complexes were synthesized and their electroluminescent (EL) characteristics were studied. It was found by comparison that the different substituted groups, such as methyl, chlorine, and nitryl, on ligand 1,10-phenanthroline affect significantly the EL performance of devices based on these complexes. The more methyl-substituted groups on ligand 1,10-phenanthroline led to higher device efficiency. A chlorine-substituted group showed the approximate EL performance as two methyl-substituted groups, whereas a nitryl substituent reduced significantly the EL luminous efficiency. However, β-diketonate ligand TTA and DBM exhibited similar EL performance. The improved EL luminous efficiency by proper substituted groups on the 1,10-phenanthroline was attributed to the reduction of the energy loss caused by light hydrogen atom vibration, as well as concentration quenching caused by intermolecular interaction, and the match of energy level between the ligand and Eu 3+

  14. Effects of added dibutyl phosphate on the luminescent properties of europium tetrakis dibenzoylmethide triethylammonium

    International Nuclear Information System (INIS)

    Fontenot, Ross S.; Bhat, Kamala N.; Owens, Constance A.; Hollerman, William A.; Aggarwal, Mohan D.

    2015-01-01

    Since 2003, the authors have been pushing the boundaries on a special type of functional material, i.e., a material that gives off light when it is stressed, strained, and/or fractured. This unique class of materials has been proposed for the active element of impact sensors, earthquake detectors, and stress sensors. However, in order for this concept to go from the lab to real world applications, the light emission from these functional materials must be bright such that inexpensive light detectors can be used. One of the brightest materials found thus far is europium tetrakis dibenzoylmethide triethylammonium (EuD 4 TEA). This material has an emission so bright that it can be observed in daylight. In 2013, the authors discovered that the addition of dimethyl methylphosphonate (DMMP) increased the light emission two fold. As a result, a search for similar compounds was conducted to determine if the emission can be increased further. This paper explores the effects of dibutyl phosphate (DBP) on EuD 4 TEA. The effects of DBP on the triboluminescence, photoluminescence, and crystal structure of EuD 4 TEA will be determined. This paper will show that DBP has an even greater effect on the properties of EuD 4 TEA than DMMP. - Highlights: • Synthesized europium tetrakis dibenzoylmethide triethylammonium. • Six fold increase in the light yield was detected. • Effects of dibutyl phosphate on the triboluminescence on EuD 4 TEA were determined. • Effects of dibutyl phosphate on the photoluminescence of EuD 4 TEA were determined

  15. Red polymer light-emitting devices based on an oxadiazole-functionalized europium(III) complex

    International Nuclear Information System (INIS)

    Liu, Yu; Wang, Yafei; Li, Chun; Huang, Ying; Dang, Dongfeng; Zhu, Meixiang; Zhu, Weiguo; Cao, Yong

    2014-01-01

    A novel tris(dibenzoylmethanato)[5-(2-(4-tert-butylbenzenyl)-5-benzenyl-1,3, 4-oxadiazole-4′)-1,10-phenanthroline]europium(III) [Eu(DBM) 3 (BuOXD-Phen)] containing an electron-transporting oxadiazole-functionalized phenanthroline ligand was synthesized and characterized. Its UV–vis absorption and photoluminescence (PL), as well as the electroluminescence (EL) in polymer light-emitting devices (PLEDs) were investigated. The double-layer PLEDs with a configuration of ITO/PEDOT:PSS (50 nm)/PVK (40 nm)/PFO:PBD (30%):Eu(DBM) 3 (BuOXD-Phen) (1–8 wt %) (80 nm)/Ba (4 nm)/Al (150 nm) were fabricated. Saturated red Eu 3+ ion emission, based on the 5 D 0 → 7 F 2 transition, is centered at a wavelength of 614 nm with a full width at half maximum (FWHM) of 10 nm. The highest external quantum efficiency (QE ext ) of 1.26% at current density of 1.65 mA cm −2 , with a maximum brightness of 568 cd m −2 at 137.8 mA cm −2 was achieved from the device at 1 wt % dopant concentration. - Highlights: • An oxadiazole-functionalized europium(III) complex of Eu(DBM) 3 (BuOXD-Phen) was presented. • The optophysical properties of Eu(DBM) 3 (BuOXD-Phen) were investigated. • Saturated red emission was observed in the PLEDs. • An external quantum efficiency of 1.26% was obtained in these devices

  16. Radiotracer study of sorption of europium on Gorleben sand from aqueous solutions containing humic substances

    International Nuclear Information System (INIS)

    Benes, P.; Stamberg, K.; Siroky, L.; Mizera, J.

    2002-01-01

    The sorption of trace europium, as a trivalent actinide homologue, was studied in the system Gorleben sand - aqueous solution with the aim to elucidate its mechanism. Radiotracer method ( 152/154 Eu) and batch experiments were used. Simultaneously, the distribution of humic substances present in, or added to the system was measured. The evaluation of the sorption was complicated by the adsorption of Eu on the walls of polyethylene vials used for the experiments, which was rather high and had to be taken into consideration. It has been found that Eu sorption on Gorleben sand increases from pH 2 to pH 5-7 and then it decreases. The decrease is due to the complexation of Eu with humic substances leached from Gorleben sand at pH>7. The position of the sorption maximum depends on the composition of the solution and on the liquid-to-solid ratio. It is shifted to lower pH values in the presence of added humic acid (HA), which enhances Eu sorption at low PH values and suppresses it at pH values higher than 5. The regions of the enhancing/suppressing effects coincidence with the high/low adsorption of HA on Gorleben sand, respectively. The increasing ionic strength (from 0.01 to 0.1) and europium concentration (3.4 x 10 -8 to 9.3 x 10 -7 mol/l) suppress the relative sorption (expressed in %) at low pH values and enhance it at pH>6-8. Addition of carbonates (5 x 10 -3 mol/l) supports Eu sorption at pH>7.5 so that no decrease with pH is observed till pH 9. Alkaline leaching of the sand significantly changes most of the effects found. These results were qualitatively interpreted and conclusions were drawn on the mechanism of the sorption. (author)

  17. Effects of added dibutyl phosphate on the luminescent properties of europium tetrakis dibenzoylmethide triethylammonium

    Energy Technology Data Exchange (ETDEWEB)

    Fontenot, Ross S., E-mail: rsfontenot@hotmail.com [Alabama A and M University, Department of Physics, Chemistry, and Mathematics, P.O. Box 1268, Normal, AL 35762 (United States); University of Louisiana at Lafayette, Department of Physics, P.O. Box 44210, Lafayette, LA 70504 (United States); Bhat, Kamala N.; Owens, Constance A. [Alabama A and M University, Department of Physics, Chemistry, and Mathematics, P.O. Box 1268, Normal, AL 35762 (United States); Hollerman, William A. [University of Louisiana at Lafayette, Department of Physics, P.O. Box 44210, Lafayette, LA 70504 (United States); Aggarwal, Mohan D. [Alabama A and M University, Department of Physics, Chemistry, and Mathematics, P.O. Box 1268, Normal, AL 35762 (United States)

    2015-02-15

    Since 2003, the authors have been pushing the boundaries on a special type of functional material, i.e., a material that gives off light when it is stressed, strained, and/or fractured. This unique class of materials has been proposed for the active element of impact sensors, earthquake detectors, and stress sensors. However, in order for this concept to go from the lab to real world applications, the light emission from these functional materials must be bright such that inexpensive light detectors can be used. One of the brightest materials found thus far is europium tetrakis dibenzoylmethide triethylammonium (EuD{sub 4}TEA). This material has an emission so bright that it can be observed in daylight. In 2013, the authors discovered that the addition of dimethyl methylphosphonate (DMMP) increased the light emission two fold. As a result, a search for similar compounds was conducted to determine if the emission can be increased further. This paper explores the effects of dibutyl phosphate (DBP) on EuD{sub 4}TEA. The effects of DBP on the triboluminescence, photoluminescence, and crystal structure of EuD{sub 4}TEA will be determined. This paper will show that DBP has an even greater effect on the properties of EuD{sub 4}TEA than DMMP. - Highlights: • Synthesized europium tetrakis dibenzoylmethide triethylammonium. • Six fold increase in the light yield was detected. • Effects of dibutyl phosphate on the triboluminescence on EuD{sub 4}TEA were determined. • Effects of dibutyl phosphate on the photoluminescence of EuD{sub 4}TEA were determined.

  18. Modified magnetic and optical properties of manganese nanoparticles incorporated europium doped magnesium borotellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Siti Maisarah; Sahar, M.R., E-mail: mrahim057@gmail.com; Ghoshal, S.K.

    2017-02-01

    This paper reports the modified optical and magnetic properties of europium (Eu{sup 3+}) ions doped and Manganese nanoparticles (NPs) embedded Magnesium Borotellurite glass synthesized via melt quenching method. The influence of varying Mn NPs concentrations on the magnetic, absorption and emission properties of such glass samples are determined. Stables, transparent and amorphous glasses are obtained. The observed modification of the electronic polarizability is interpreted in terms of the generation of non-bridging oxygen (NBO) and bridging oxygen (BO) in the amorphous network. TEM images manifested the growth of Mn NPs with average diameter 11±1 nm. High-resolution TEM reveals that the lattice spacing of manganese nanoparticles is 0.308 nm at (112) plane. The emission spectra revealed four prominent peaks centered at 587 nm, 610 nm, 651 nm and 700 nm assigned to the transition from {sup 5}D{sub 0} →{sup 7}F{sub J} (J=1, 2, 3, 4) states of Eu{sup 3+} ion. A significant drop in the luminescence intensity due to the incorporation of Mn NPs is ascribed to the enhanced energy transfer from the Eu{sup 3+} ion to NPs. Prepared glass systems exhibited paramagnetic behavior. - Highlights: • The europium doped magnesium borotellurite glasses embedded Mn NPs prepared using the conventional melt-quenching method. • The TEM result reveals the size of Mn NPs while its planar spacing has been determined by HRTEM. • The luminescence properties of TeO{sub 2}–B{sub 2}O{sub 3}–MgO–Eu{sub 2}O{sub 3}–Mn{sub 3}O{sub 4} glasses have been investigated as effect of Mn NPs content. • The magnetization measurement of glass sample is carried out using vibrating sample magnetometer (VSM)

  19. Crystal growth and characterization of europium doped lithium strontium iodide scintillator as an ionizing radiation detector

    Science.gov (United States)

    Uba, Samuel

    High performance detectors used in the detection of ionizing radiation is critical to nuclear nonproliferation applications and other radiation detectors applications. In this research we grew and tested Europium doped Lithium Strontium Iodide compound. A mixture of lithium iodide, strontium iodide and europium iodide was used as the starting materials for this research. Congruent melting and freezing temperature of the synthesized compound was determined by differential scanning calorimetry (DSC) using a Setaram Labsys Evo DSC-DTA instrument. The melting temperatures were recorded at 390.35°C, 407.59°C and freezing temperature was recorded at 322.84°C from a graph of heat flow plotted against temperature. The synthesized material was used as the charge for the vertical Bridgeman growth, and a 6.5 cm and 7.7cm length boule were grown in a multi-zone transparent Mullen furnace. A scintillating detector of thickness 2.53mm was fabricated by mechanical lapping in mineral oil, and scintillating response and timing were obtained to a cesium source using CS-137 isotope. An energy resolution (FWHM over peak position) of 12.1% was observed for the 662keV full absorption peak. Optical absorption in the UV-Vis wavelength range was recorded for the grown crystal using a U-2900 UV/VIS Spectrophotometer. Absorption peaks were recorded at 194nm, 273nm, and 344nm from the absorbance spectrum, various optical parameters such as absorption coefficient, extinction coefficient, refractive index, and optical loss were derived. The optical band gap energy was calculated using Tauc relation expression at 1.79eV.

  20. Spectroscopic investigation on europium doped heavy metal borate glasses for red luminescent application

    Energy Technology Data Exchange (ETDEWEB)

    Hegde, Vinod; Wagh, Akshatha; Kamath, Sudha D. [Manipal University, Department of Physics, Manipal Institute of Technology, Manipal (India); Hegde, Hemanth [Manipal University, Department of Chemistry, Manipal Institute of Technology, Manipal (India); Vishwanath, C.S.D. [Sri Venkateswara University, Department of Physics, Tirupati (India)

    2017-05-15

    The present study explores a new borate family glasses based on 10ZnO-5Na{sub 2}O-10Bi{sub 2}O{sub 3}-(75 - x) B{sub 2}O{sub 3}-xEu{sub 2}O{sub 3} (x = 0, 0.1, 0.5, 1, 1.5, 2, 3 mol%) composition, synthesized by rapid melt quench technique. Prepared glasses were subjected to the density and refractive index measurements and their values were used to calculate other physical properties of the glass matrix as a function of Eu{sup 3+} concentration. XRD confirmed amorphous nature of the glasses. FTIR spectra in the absorption mode were recorded in the 400-4000 cm{sup -1} region to identify different functional groups in the glass matrix. Deconvoluted FTIR spectra showed increase in BO{sub 4} units with rise in europium content which confirmed the 'network strengthener' role of europium ions by creating bridging oxygens (BOs). Optical properties were investigated for their luminescence behavior through various spectroscopic techniques such as UV-Vis-NIR absorption, excitation, emission, decay profiles, and color measurements at room temperature. Lasing properties of the glasses like total radiative life time, branching ratio, emission cross section, and optical gain were obtained from the calculated Judd-Ofelt (Ω{sub 2},Ω{sub 4}) intensity parameters. From the measured values of emission, cross sections, branching ratios, life times, strong photoluminescence features, and CIE chromaticity coordinates, 0.5 mol% of Eu{sup 3+} ions doped ZnNaBiB glasses showed optimum performance and are potential candidate for red light generation at 613 nm. (orig.)

  1. Tuning Eu"3"+ emission in europium sesquioxide films by changing the crystalline phase

    International Nuclear Information System (INIS)

    Mariscal, A.; Quesada, A.; Camps, I.; Palomares, F.J.; Fernández, J.F.; Serna, R.

    2016-01-01

    Highlights: • PLD production of high quality europium sesquioxide (Eu_2O_3) films. • The deposition of Al_2O_3 capping and/or buffer layers modifies the crystallization for Eu_2O_3 films upon annealing. • The formation of cubic or monoclinic phases can be favored. • Eu"3"+ emission tuning is achieved as a consequence of crystal field effects. - Abstract: We report the growth of europium sesquioxide (Eu_2O_3) thin films by pulsed laser deposition (PLD) in vacuum at room temperature from a pure Eu_2O_3 ceramic bulk target. The films were deposited in different configurations formed by adding capping and/or buffer layers of amorphous aluminum oxide (a-Al_2O_3). The optical properties, refractive index and extinction coefficient of the as deposited Eu_2O_3 layers were obtained. X-ray photoelectron spectroscopy (XPS) measurements were done to assess its chemical composition. Post-deposition annealing was performed at 500 °C and 850 °C in air in order to achieve the formation of crystalline films and to accomplish photoluminescence emission. According to the analysis of X-ray diffraction (XRD) spectra, cubic and monoclinic phases were formed. It is found that the relative amount of the phases is related to the different film configurations, showing that the control over the crystallization phase can be realized by adequately designing the structures. All the films showed photoluminescence emission peaks (under excitation at 355 nm) that are attributed to the intra 4f-transitions of Eu"3"+ ions. The emission spectral shape depends on the crystalline phase of the Eu_2O_3 layer. Specifically, changes in the hypersensitive "5D_0 → "7F_2 emission confirm the strong influence of the crystal field effect on the Eu"3"+ energy levels.

  2. Surface-imprinted nanofilaments for europium-amplified luminescent detection of fluoroquinolone antibiotics.

    Science.gov (United States)

    Zdunek, Jolanta; Benito-Peña, Elena; Linares, Ana; Falcimaigne-Cordin, Aude; Orellana, Guillermo; Haupt, Karsten; Moreno-Bondi, María C

    2013-07-29

    The development and characterization of novel, molecularly imprinted polymer nanofilament-based optical sensors for the analysis of enrofloxacin, an antibiotic widely used for human and veterinary applications, is reported. The polymers were prepared by nanomolding in porous alumina by using enrofloxacin as the template. The antibiotic was covalently immobilized on to the pore walls of the alumina by using different spacers, and the prepolymerization mixture was cast in the pores and the polymer synthesized anchored onto a glass support through UV polymerization. Various parameters affecting polymer selectivity were evaluated to achieve optimal recognition, namely, the spacer arm length and the binding solvent. The results of morphological characterization, binding kinetics, and selectivity of the optimized polymer material for ENR and its derivatives are reported. For sensing purposes, the nanofilaments were incubated in solutions of the target molecule in acetonitrile/HEPES buffer (100 mM, pH 7.5, 50:50, v/v) for 20 min followed by incubation in a 10 mM solution of europium(III) ions to generate a europium(III)-enrofloxacin complex on the polymer surface. The detection event was based on the luminescence of the rare-earth ion (λexc=340 nm; λem=612 nm) that results from energy transfer from the antibiotic excited state to the metal-ion emitting excited state. The limit of detection of the enrofloxacin antibiotic was found to be 0.58 μM. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Determination of europium content in Li_2SiO_3(Eu) by neutron activation analysis using Am-Be neutron source

    International Nuclear Information System (INIS)

    Naik, Yeshwant; Tapase, Anant Shamrao; Mhatre, Amol; Datrik, Chandrashekhar; Tawade, Nilesh; Kumar, Umesh; Naik, Haladhara

    2016-01-01

    Circulardiscs of Li_2SiO_3 doped with europium were prepared and a new activation procedure for the neutron dose estimation in a breeder blanket of fusion reactor is described. The amount of europium in the disc was determined by neutron activation analysis (NAA) using an isotopic neutron source. The average neutron absorption cross section for the reaction was calculated using neutron distribution of the Am-Be source and available neutron absorption cross section data for the "1"5"1Eu(n,γ)"1"5"2"mEu reaction, which was used for estimation of europium in the pallet. The cross section of the elements varies with neutron energy, and the flux of the neutrons in each energy range seen by the nuclei under investigation also varies. Neutron distribution spectrum of the Am-Be source was worked out prior to NAA and the effective fractional flux for the nuclear reaction considered for the flux estimation was also determined. - Highlights: • Lithium meta-silicate is breeder materials for a fusion reactor. • Europium is used for neutron dose estimation in a breeder blanket. • It is important to determine amount of europium in lithium meta-silicate. • Amount of europium in lithium meta-silicate was determined by neutron activation and off-line gamma spectrometry.

  4. Sulfate reduction in freshwater peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Oequist, M.

    1996-12-31

    This text consist of two parts: Part A is a literature review on microbial sulfate reduction with emphasis on freshwater peatlands, and part B presents the results from a study of the relative importance of sulfate reduction and methane formation for the anaerobic decomposition in a boreal peatland. The relative importance of sulfate reduction and methane production for the anaerobic decomposition was studied in a small raised bog situated in the boreal zone of southern Sweden. Depth distribution of sulfate reduction- and methane production rates were measured in peat sampled from three sites (A, B, and C) forming an minerotrophic-ombrotrophic gradient. SO{sub 4}{sup 2-} concentrations in the three profiles were of equal magnitude and ranged from 50 to 150 {mu}M. In contrast, rates of sulfate reduction were vastly different: Maximum rates in the three profiles were obtained at a depth of ca. 20 cm below the water table. In A it was 8 {mu}M h{sup -1} while in B and C they were 1 and 0.05 {mu}M h{sup -1}, respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 {mu}g d{sup -1} g{sup -1}) were found 10 cm below the water table, in B (ca. 1.0 {mu}g d{sup -1} g{sup -1}) in the vicinity of the water table, and in C (0.75 {mu}g d{sup -1} g{sup -1}) 20 cm below the water table. In all profiles both sulfate reduction and methane production rates were negligible above the water table. The areal estimates of methane production for the profiles were 22.4, 9.0 and 6.4 mmol m{sup -2} d{sup -1}, while the estimates for sulfate reduction were 26.4, 2.5, and 0.1 mmol m{sup -2} d{sup -1}, respectively. The calculated turnover times at the sites were 1.2, 14.2, and 198.7 days, respectively. The study shows that sulfate reducing bacteria are important for the anaerobic degradation in the studied peatland, especially in the minerotrophic sites, while methanogenic bacteria dominate in ombrotrophic sites Examination

  5. Sulfate reduction in freshwater peatlands

    International Nuclear Information System (INIS)

    Oequist, M.

    1996-01-01

    This text consist of two parts: Part A is a literature review on microbial sulfate reduction with emphasis on freshwater peatlands, and part B presents the results from a study of the relative importance of sulfate reduction and methane formation for the anaerobic decomposition in a boreal peatland. The relative importance of sulfate reduction and methane production for the anaerobic decomposition was studied in a small raised bog situated in the boreal zone of southern Sweden. Depth distribution of sulfate reduction- and methane production rates were measured in peat sampled from three sites (A, B, and C) forming an minerotrophic-ombrotrophic gradient. SO 4 2- concentrations in the three profiles were of equal magnitude and ranged from 50 to 150 μM. In contrast, rates of sulfate reduction were vastly different: Maximum rates in the three profiles were obtained at a depth of ca. 20 cm below the water table. In A it was 8 μM h -1 while in B and C they were 1 and 0.05 μM h -1 , respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 μg d -1 g -1 ) were found 10 cm below the water table, in B (ca. 1.0 μg d -1 g -1 ) in the vicinity of the water table, and in C (0.75 μg d -1 g -1 ) 20 cm below the water table. In all profiles both sulfate reduction and methane production rates were negligible above the water table. The areal estimates of methane production for the profiles were 22.4, 9.0 and 6.4 mmol m -2 d -1 , while the estimates for sulfate reduction were 26.4, 2.5, and 0.1 mmol m -2 d -1 , respectively. The calculated turnover times at the sites were 1.2, 14.2, and 198.7 days, respectively. The study shows that sulfate reducing bacteria are important for the anaerobic degradation in the studied peatland, especially in the minerotrophic sites, while methanogenic bacteria dominate in ombrotrophic sites Examination paper. 67 refs, 6 figs, 3 tabs

  6. Acid Sulfate Alteration on Mars

    Science.gov (United States)

    Ming, D. W.; Morris, R. V.

    2016-01-01

    A variety of mineralogical and geochemical indicators for aqueous alteration on Mars have been identified by a combination of surface and orbital robotic missions, telescopic observations, characterization of Martian meteorites, and laboratory and terrestrial analog studies. Acid sulfate alteration has been identified at all three landing sites visited by NASA rover missions (Spirit, Opportunity, and Curiosity). Spirit landed in Gusev crater in 2004 and discovered Fe-sulfates and materials that have been extensively leached by acid sulfate solutions. Opportunity landing on the plains of Meridiani Planum also in 2004 where the rover encountered large abundances of jarosite and hematite in sedimentary rocks. Curiosity landed in Gale crater in 2012 and has characterized fluvial, deltaic, and lacustrine sediments. Jarosite and hematite were discovered in some of the lacustrine sediments. The high elemental abundance of sulfur in surface materials is obvious evidence that sulfate has played a major role in aqueous processes at all landing sites on Mars. The sulfate-rich outcrop at Meridiani Planum has an SO3 content of up to 25 wt.%. The interiors of rocks and outcrops on the Columbia Hills within Gusev crater have up to 8 wt.% SO3. Soils at both sites generally have between 5 to 14 wt.% SO3, and several soils in Gusev crater contain around 30 wt.% SO3. After normalization of major element compositions to a SO3-free basis, the bulk compositions of these materials are basaltic, with a few exceptions in Gusev crater and in lacustrine mudstones in Gale crater. These observations suggest that materials encountered by the rovers were derived from basaltic precursors by acid sulfate alteration under nearly isochemical conditions (i.e., minimal leaching). There are several cases, however, where acid sulfate alteration minerals (jarosite and hematite) formed in open hydrologic systems, e.g., in Gale crater lacustrine mudstones. Several hypotheses have been suggested for the

  7. Sulfate Transporters in Dissimilatory Sulfate Reducing Microorganisms: A Comparative Genomics Analysis

    Directory of Open Access Journals (Sweden)

    Angeliki Marietou

    2018-03-01

    Full Text Available The first step in the sulfate reduction pathway is the transport of sulfate across the cell membrane. This uptake has a major effect on sulfate reduction rates. Much of the information available on sulfate transport was obtained by studies on assimilatory sulfate reduction, where sulfate transporters were identified among several types of protein families. Despite our growing knowledge on the physiology of dissimilatory sulfate-reducing microorganisms (SRM there are no studies identifying the proteins involved in sulfate uptake in members of this ecologically important group of anaerobes. We surveyed the complete genomes of 44 sulfate-reducing bacteria and archaea across six phyla and identified putative sulfate transporter encoding genes from four out of the five surveyed protein families based on homology. We did not find evidence that ABC-type transporters (SulT are involved in the uptake of sulfate in SRM. We speculate that members of the CysP sulfate transporters could play a key role in the uptake of sulfate in thermophilic SRM. Putative CysZ-type sulfate transporters were present in all genomes examined suggesting that this overlooked group of sulfate transporters might play a role in sulfate transport in dissimilatory sulfate reducers alongside SulP. Our in silico analysis highlights several targets for further molecular studies in order to understand this key step in the metabolism of SRMs.

  8. Sulfate transport in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Simonsen, K

    1988-01-01

    1. In short-circuited toad skin preparations exposed bilaterally to NaCl-Ringer's containing 1 mM SO2(-4), influx of sulfate was larger than efflux showing that the skin is capable of transporting sulfate actively in an inward direction. 2. This active transport was not abolished by substituting...... apical Na+ for K+. 3. Following voltage activation of the passive Cl- permeability of the mitochondria-rich (m.r.) cells sulfate flux-ratio increased to a value predicted from the Ussing flux-ratio equation for a monovalent anion. 4. In such skins, which were shown to exhibit vanishingly small leakage...... conductances, the variation of the rate coefficient for sulfate influx (y) was positively correlated with the rate coefficient for Cl- influx (x), y = 0.035 x - 0.0077 cm/sec (r = 0.9935, n = 15). 5. Addition of the phosphodiesterase inhibitor, 3-isobutyl-1-methyl-xanthine to the serosal bath of short...

  9. 21 CFR 184.1261 - Copper sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Copper sulfate. 184.1261 Section 184.1261 Food and... Substances Affirmed as GRAS § 184.1261 Copper sulfate. (a) Copper sulfate (cupric sulfate, CuSO4·5H2O, CAS... the reaction of sulfuric acid with cupric oxide or with copper metal. (b) The ingredient must be of a...

  10. Periodate Oxidation for Sulfated Glycosaminoglycans, with Special Reference to the Position of Extra Sulfate Groups in Chondroitin Polysulfates, Chondroitin Sulfate D and Chondroitin Sulfate K

    OpenAIRE

    Seno, Nobuko; Murakami, Keiko; Shibusawa, Haru

    1981-01-01

    The optimum conditions for periodate oxidation of sulfated disaccharides were investigated to determine the position of extra sulfate groups on the saturated disulfated disaccharides obtained from chondroitin polysulfates, chondroitin sulfates D and K. Under the conditions: 2mM saturated disulfated disaccharide with 20mM sodium periodate at 37°in the dark, the uronic acid residue in the disulfated disaccharide from chondroitin sulfate D was rapidly and completely destroyed, whereas that in th...

  11. Nature of the concentration thresholds of europium atom yield from the oxidized tungsten surface under electron stimulated desorption

    CERN Document Server

    Davydov, S Y

    2002-01-01

    The nature of the electron-stimulated desorption (ESD) of the europium atoms by the E sub e irradiating electrons energies, equal to 50 and 80 eV, as well as peculiarities of the Eu atoms yield dependence on their concentration on the oxidized tungsten surface are discussed. It is shown, that the ESD originates by the electron transition from the interval 5p- or 5s shell of the tungsten surface atom onto the oxygen external unfilled 2p-level

  12. New coordination compounds of europium (3) with fluorated β-diketones and their use as lanthanide shift reagents

    International Nuclear Information System (INIS)

    Goryushko, A.G.; Davidenko, N.K.; Kudryavtseva, L.S.; Lozinskij, M.O.; Lugina, L.N.; Fialkov, Yu.A.

    1980-01-01

    Altogether five coordination compounds of europium (3) of the composition EuL 3 , wherein HL is a fluorinated beta-diketone containing in its fluorinated linear or cyclic radical a heteroatom, such as oxygen, have been obtained. The hygroscopicity of the obtained tris-beta-ketones has been tested. Their activity as lanthanide shifting agents for NMR spectroscopy purposes has been analyzed and the stability constants of their monoadducts with ethyl acetate have been determined [ru

  13. Liquid crystal europium(III) β-diketonato complex with 5,5'-di(heptadecyl)-2,2'-bipyridine

    International Nuclear Information System (INIS)

    Knyazev, A.A.; Lobkov, V.S.; Galyametdinov, Yu.G.

    2004-01-01

    Liquid crystal europium(III) complex containing β-diketone and 5,5-di(heptadecyl)-2,2'-bipyridine as ligands was prepared in ethanol solution and was isolated as a yellow precipitate with 62% yield. The product was characterized by data of elementary analysis, thermography, IR spectroscopy and luminescence spectra. Temperatures of crystal-mesophase and mesophase-isotropic liquid phase transitions amount to 95 and 130 Deg C respectively [ru

  14. 21 CFR 582.5230 - Calcium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium sulfate. 582.5230 Section 582.5230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use. This substance...

  15. 21 CFR 184.1643 - Potassium sulfate.

    Science.gov (United States)

    2010-04-01

    ... hydroxide or potassium carbonate. (b) The ingredient meets the specifications of the “Food Chemicals Codex... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg...

  16. 21 CFR 184.1443 - Magnesium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium sulfate. 184.1443 Section 184.1443 Food... Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O, CAS... magnesium oxide, hydroxide, or carbonate with sulfuric acid and evaporating the solution to crystallization...

  17. EFFECT OF MAGNESIUM SULFATE (A LAXATIVE) ON ...

    African Journals Online (AJOL)

    use with little success . Magnesium sulfate also known as Epsom salt or bitter salt is a hydrate salt with a chemical name of magnesium sulfate heptahydrate . Chemical formula is MgSO. 7HO and trade name is. Andrews liver salt. Dried magnesium sulfate is an osmotic laxative or a saline laxative that acts by increasing the.

  18. 21 CFR 582.5443 - Magnesium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium sulfate. 582.5443 Section 582.5443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use. This...

  19. Modeling and minimization of barium sulfate scale

    Science.gov (United States)

    Alan W. Rudie; Peter W. Hart

    2006-01-01

    The majority of the barium present in the pulping process exits the digester as barium carbonate. Barium carbonate dissolves in the bleach plant when the pH drops below 7 and, if barium and sulfate concentrations are too high, begins to precipitate as barium sulfate. Barium is difficult to control because a mill cannot avoid this carbonate-to-sulfate transition using...

  20. 21 CFR 582.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  1. 21 CFR 182.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

  2. Effect of temperature on the extraction of europium (III) bymixtures of neutral phosphoro-organic extractants from nitrate solutions

    International Nuclear Information System (INIS)

    Milchlin, E.B.; Khmuran, M.A.; Mikhailichenko, A.I.

    1986-01-01

    A study has been made of the distribution of microquantities of europium (III) on extraction with neutral phosphoorganic compounds-tri-n-butyl phosphate (TBP), diisooctylmethyl phosphonate (DIOMP),trialkylphosphine oxide with dissimilar radicals (PODR), or mixtures thereof-from a solution of 2 mole/liter NH 4 NO 3 and 0.01 mole/liter HNO 3 , in the temperature range 20-60 0 C. A temperature rise results in a decrease of the distribution coefficients of the europium on extraction by all of the extractants tested and their mixtures, and also in a reduction of the synergistic effect in extraction by mixtures of the extractants. Based on an investigation of the temperature dependences of the distribution constants of europium nitrate upon extraction by TBP, DIOMP, PODR, or their mixtures, values have been determined for the enthalpy, free energy, and entropy of extraction. It is shown that the enthalpy (-ΔH) increases in the order TBP< DIOMP< PODR. In an extraction with mixed extractants, the enthalpy has a value intermediate between those with the individual extractants. The entropy of extraction (-ΔS) increases in the reverse order PODR< DIOMP< TBP

  3. Electroplex emission from a layer of a mixture of a europium complex and tris(8-quinolinolato) aluminum

    Science.gov (United States)

    Cao, Hong; Gao, Xicun; Huang, Chun-Hui

    2000-07-01

    With a europium complex, tris(α-thenoyltrifluoroacetonato) bis(triphenylphosphine oxide) europium (Eu(TTA) 3(TPPO) 2), as the light-emitting layer, N, N'-diphenyl- N, N'-di( m-tolyl)-benzidine (TPD) as the hole transport layer and tris(8-quinolinolato) aluminum (ALQ) as the electron transport layer, the triple-layer electroluminescent (EL) device emits red light characteristic of Eu 3+ emission. However, as the mixture of Eu(TTA) 3(TPPO) 2 and ALQ is co-evaporated as the light-emitting layer to form a bilayer EL device, a new wide-banded emission peaked at c. 640 nm was obtained. This emission is neither from ALQ nor from the europium complex. The photoluminescence (PL) of the thin film on quartz substrate evaporated from one mixed solid powder of Eu(TTA) 3(TPPO) 2 and ALQ is composed of distinct PL emissions of Eu(TTA) 3(TPPO) 2 and ALQ, denying an exciplex formation mechanism. It is impossible to form a host-guest system. We propose that the EL emission peaked at c. 640 nm is from an electroplex route: a transition between the lowest unoccupied molecular orbital (LUMO) of Eu(TTA) 3(TPPO) 2 and the highest occupied molecular orbital (HOMO) of ALQ.

  4. Regeneration of sulfated metal oxides and carbonates

    Science.gov (United States)

    Hubble, Bill R.; Siegel, Stanley; Cunningham, Paul T.

    1978-03-28

    Alkali metal or alkaline earth metal carbonates such as calcium carbonate and magnesium carbonate found in dolomite or limestone are employed for removal of sulfur dioxide from combustion exhaust gases. The sulfated carbonates are regenerated to oxides through use of a solid-solid reaction, particularly calcium sulfide with calcium sulfate to form calcium oxide and sulfur dioxide gas. The regeneration is performed by contacting the sulfated material with a reductant gas such as hydrogen within an inert diluent to produce calcium sulfide in mixture with the sulfate under process conditions selected to permit the sulfide-sulfate, solid-state reaction to occur.

  5. Application of a room temperature ionic liquid for nuclear spent fuel reprocessing: speciation of trivalent europium and solvatation effects

    International Nuclear Information System (INIS)

    Moutiers, G.; Mekki, S.; Billard, I.

    2007-01-01

    One of the solutions proposed for the optimization of the long term storage and conditioning of spent nuclear fuel is to separate actinide and lanthanide both from each other and from other less radioactive metallic species. The industrial proposed processes, based on liquid liquid extraction steps, involve solvents with non negligible vapour pressure and may generate contaminated liquid wastes that will have to be reprocessed. During the last decade, some room-temperature ionic liquids have been studied and integrated into industrial processes. The interest on this class of solvent came out from their 'green' properties (non volatile, non flammable, recyclable, etc...), but also from the variability of their physico-chemical properties (stability, hydrophobicity, viscosity) as a function of the RTIL chemical composition. Indeed, it has been shown that classical chemical industrial processes could be transferred into those media, even more improved, while a certain number of difficulties arising from using traditional solvent can be avoided. In this respect, it could be promising to investigate the ability to use room temperature ionic liquid into the spent nuclear fuel reprocessing field. The aim of this this study is to test the ability of the specific ionic liquid bumimTf 2 N to allow trivalent europium extraction. The choice of this metal is based on the chemical analogy with trivalent minor actinides Curium and Americium which are contributing the greatest part of the long-lived high level radioactive wastes. Handling these elements needs to be very cautious for the safety and radioprotection aspect. Moreover, europium is a very sensitive luminescent probe to its environment even at the microscopic scale. The report is structured with four parts. In a first chapter, we present the main physico-chemical properties of an imidazolium-based ionic liquid family, and then we choose the ionic liquid bumimTf 2 N for the whole thesis and start with the electrochemical

  6. Computational Investigation on the Spectroscopic Properties of Thiophene Based Europium β-Diketonate Complexes.

    Science.gov (United States)

    Greco, Claudio; Moro, Giorgio; Bertini, Luca; Biczysko, Malgorzata; Barone, Vincenzo; Cosentino, Ugo

    2014-02-11

    The adiabatic transition energies from the lowest triplet states of four Europium tris β-diketonate/phenantroline complexes have been determined in vacuo and in dicholomethane solution by the ΔSCF approach at the density functional theory level, using the PBE1PBE and the CAM-B3LYP hybrid functionals. The calculated adiabatic transition energies have been compared with the experimental 0-0 transitions of each complex determined from phosphorescence spectra of the corresponding Gd(3+) complexes and followed by direct comparison between simulated and experimental spectra line shapes. For compound 1, the Eu(TTA)3Phen system, triplet states other than the lowest one and conformational isomers other than the one present in the crystallographic structure have been considered. In the crystallographic structure, this compound presents three quasi-degenerate low energy triplet states, differing for the TTA ligand where the two unpaired electrons are localized and showing close adiabatic transition energies. For compound 1, the lowest triplet states of the four investigated conformational isomers show similar characteristics and close adiabatic transition energies. On the basis of these results, an investigation of compounds 2-4 (Eu(Br-TTA)3Phen, Eu(DTDK)3Phen, and Eu(MeT-TTA)3) has been performed by considering only the isomer present in the crystallographic structure and only the lowest triplet state of each compound. For compounds 1-3, the energies of the lowest triplet states calculated by both functionals in solution including zero-point energy corrections well reproduce the experimental trends as well as the values of the adiabatic transition energies: CAM-B3LYP, the best performing functional, provides energies of the lowest triplet state with deviations from experiments lower than 1200 cm(-1). Also, the calculated vibrationally resolved phosphorescence spectra and UV-vis absorptions well reproduce the main features of their experimental counterparts. Significant

  7. Synthesis and characterization of phosphors based on calcium and magnesium silicates doped with europium and dysprosium

    International Nuclear Information System (INIS)

    Misso, Agatha Matos

    2016-01-01

    Ca and Mg silicates based phosphors were prepared by sol-gel method combined with the molten salts process. The gel of silica was obtained from Na 2 SiO 3 solution by using europium, dysprosium, calcium and magnesium chloride solutions. Therefore, those chlorides were homogeneously dispersed into the gel. The obtained gel was dried and heat treated to 900° C for 1h to allow the fusion of the present salts. Then it was water washed until negative test for Cl - , and dried. The reduction of the europium to Eu 2+ was performed under atmosphere of 5% of H 2 and 95% of Ar to 900° C for 3h, to reach CaMgSi 2 O 6 :Eu 2+ and CaMgSi 2 O 6 :Eu 2+ :Dy 3+ phosphors. Diopside was identified as main crystalline phase and quartz, as secondary phase from XRD (X-ray diffraction) patterns. SEM (scanning electron microscopy) micrographs, of the samples showed needles, spheres, leaves and rods of particles and agglomerates. Thermal analysis (TGA-DTGA) curves revealed that the crystallization temperature of CaMgSi 2 O 6 :Eu 2+ lies around 765° C. Photoluminescence spectroscopy of the phosphors was studied based on interconfigurational 4f N → 4f N-1 5d transition of Eu 2+ ion. The spectra of excitation showed 4f N → 4f N-1 5d transition of Eu 2+ ion broad band, related to the ligand to metal charge transfer transition (LMCT) O 2- (2p) → Eu 3+ in the 250 nm region, when the emission is monitored at 583,5 nm. It also presents the 4f ↔ 4f transitions of Eu 3+ ion bands, showing the 7 F 0 → 5 L 6 transition at 393 nm. From emission spectra with excitation monitored at 393 nm, it can be observed fine peaks between 570 and 750 nm which are characteristics of 5 D 0 → 7 F J (J = 0 - 5) transition of Eu 3+ ion, indicating that the Eu 3+ ion occupies a site with center of inversion. Finally, the obtained results indicate that the developed method is suitable to synthesize CaMgSi 2 O 6 :Eu 2+ and CaMgSi 2 O 6 :Eu 2+ :Dy 3+ phosphors, as it has been proposed. (author)

  8. Fluorometric determination of samarium and europium in rare earth minerals with. beta. -diketoneternary complex

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H; Hiraki, K; Nishikawa, Y [Kinki Univ., Higashi-Osaka, Osaka (Japan). Faculty of Science and Technology

    1981-07-01

    This communication reported the optimum conditions for the fluorometric determination of these ions, and the method was adopted in the simultaneous determination of samarium and europium in xenotime and monazite minerals. From the experimental results on the effect of diverse ions and the extraction pH of the aqueous phase, it became clear that TTA-TOPO hexane method was the best system for the determination of samarium and europium because of the highest fluorescence sensitivity of the ternary complex, and also because the lower extraction pH eliminated the effect of diverse ions. Moreover, the very high detection limit (2 ppb) of Sm was achieved by the use of a red sensitive photomultiplier. Which was used at 644 nm, and that of Eu (0.02 ppb) at 614 nm. The procedure was established as follows: The rare earth minerals (xenotime, monazite) sample was treated with hot conc. H/sub 2/SO/sub 4/ and twice precipitated with 0.5 mol dm/sup -3/ oxalic acid (pH was adjusted to 2.0 -- 2.2). Then the precipitate was filtered and ignited to give the rare earth oxide. Fifty milligrams of the oxide was dissolved in HCl and diluted with water in order to obtain the solution containing 5 ..mu..g cm/sup -3/ rare earth oxide. An aliquot of the solution ((1.0 -- 3.0) cm/sup 3/) was adjusted to pH 5.5 with sodium acetate and shaken with 1 x 10/sup -4/ mol dm/sup -3/ TTA- 2 x 10/sup -2/ mol dm/sup -3/ TOPO hexane solution. Then the fluorescence intensity of the organic layer was measured at 644 nm for Sm and 614 nm for Eu. In this procedure, the recovery of Sm and Eu was found to be about 96%. Xenotime contained 0.70% of Sm and 0.004% of Eu, and monazite contained 1.84% of Sm and 0.003% of Eu.

  9. Fluorescence properties of europium and samarium. beta. -diketonates and their use in fluorometry

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H; Hiraki, K; Nishikawa, Y [Kinki Univ., Higashi-Osaka, Osaka (Japan). Faculty of Science and Technology

    1981-01-01

    Several europium and samarium ..beta..-diketonates (tta, ntfa, bfa) complexed with 1, 10-phenanthroline, or with trioctylphosphine oxide (topo) were synthesized. The fluorescence properties of these compounds in benzene or hexane have been studied. Absorption and fluorescence spectra, fluorescence quantum yield, fluorescence sensitivity index (F.S.I.), and fluorescence lifetime were measured. From the measurement of fluorescence lifetime of the ..beta..-diketonates, the velocity of radiative process (k sub(f)/phi sub(f)) has almost the same value for benzene and hexane solvent. The red fluorescence (Em. max. : 619 nm) of Eu(III) in these chelates is attributed to transitions from /sup 5/D/sub 0/ ..-->.. /sup 7/F/sub 2/ levels of this ion, and the three-band spectrum (Em. max. : 569 nm, 606 nm, 650 nm) indicates the transitions from the /sup 4/G sub(5/2) ..-->.. /sup 6/H sub(5/2), /sup 4/G sub(5/2) ..-->.. /sup 6/H sub(7/2), and /sup 4/G sub(5/2) ..-->.. /sup 6/H sub(9/2) levels of Sm(III), respectively. These spectra are not changed by any solvents and ligands. From the results, the fluorescence of the ..beta..-diketonates in organic solvent has been attributed to m* ..-->.. m luminescence transition. The complexes of Eu(III) and Sm(III) show radiative transition within orbitals, composed exclusively of 4f orbitals of rare earth ions (m* ..-->.. m radiative transition). Fluorinated ligands show better sensitivity than unfluorinated ligands, and the best sensitivity is obtained with TTA-phen system, and/or TTA-topo system for the spectrofluorometric determination of the two metals. In the case of Eu determination, 619 nm emission wavelength is used (the determinable range : 0.2 -- 10 ppb Eu), and in the case of Sm determination, 650 nm emission wavelength is adopted (the determinable range : 0.1 -- 1 ppm Sm), because of much higher sensitivity than the other two peaks (569, 606 nm) without interference from europium complex.

  10. Tuning Eu{sup 3+} emission in europium sesquioxide films by changing the crystalline phase

    Energy Technology Data Exchange (ETDEWEB)

    Mariscal, A., E-mail: antonio.mariscal@csic.es [Laser Processing Group, Instituto de Óptica, CSIC, C/ Serrano 121, 28006 Madrid (Spain); Quesada, A. [Ceramics for Smart Systems Group, Instituto de Cerámica y Vidrio, C/ Kelsen 5, 28049 Madrid (Spain); Camps, I. [Laser Processing Group, Instituto de Óptica, CSIC, C/ Serrano 121, 28006 Madrid (Spain); Palomares, F.J. [Instituto de Ciencia de Materiales de Madrid, C/ Sor Juana Inés de la Cruz 3, 28049 Madrid (Spain); Fernández, J.F. [Ceramics for Smart Systems Group, Instituto de Cerámica y Vidrio, C/ Kelsen 5, 28049 Madrid (Spain); Serna, R. [Laser Processing Group, Instituto de Óptica, CSIC, C/ Serrano 121, 28006 Madrid (Spain)

    2016-06-30

    Highlights: • PLD production of high quality europium sesquioxide (Eu{sub 2}O{sub 3}) films. • The deposition of Al{sub 2}O{sub 3} capping and/or buffer layers modifies the crystallization for Eu{sub 2}O{sub 3} films upon annealing. • The formation of cubic or monoclinic phases can be favored. • Eu{sup 3+} emission tuning is achieved as a consequence of crystal field effects. - Abstract: We report the growth of europium sesquioxide (Eu{sub 2}O{sub 3}) thin films by pulsed laser deposition (PLD) in vacuum at room temperature from a pure Eu{sub 2}O{sub 3} ceramic bulk target. The films were deposited in different configurations formed by adding capping and/or buffer layers of amorphous aluminum oxide (a-Al{sub 2}O{sub 3}). The optical properties, refractive index and extinction coefficient of the as deposited Eu{sub 2}O{sub 3} layers were obtained. X-ray photoelectron spectroscopy (XPS) measurements were done to assess its chemical composition. Post-deposition annealing was performed at 500 °C and 850 °C in air in order to achieve the formation of crystalline films and to accomplish photoluminescence emission. According to the analysis of X-ray diffraction (XRD) spectra, cubic and monoclinic phases were formed. It is found that the relative amount of the phases is related to the different film configurations, showing that the control over the crystallization phase can be realized by adequately designing the structures. All the films showed photoluminescence emission peaks (under excitation at 355 nm) that are attributed to the intra 4f-transitions of Eu{sup 3+} ions. The emission spectral shape depends on the crystalline phase of the Eu{sub 2}O{sub 3} layer. Specifically, changes in the hypersensitive {sup 5}D{sub 0} → {sup 7}F{sub 2} emission confirm the strong influence of the crystal field effect on the Eu{sup 3+} energy levels.

  11. Reduced sulfation of chondroitin sulfate but not heparan sulfate in kidneys of diabetic db/db mice.

    Science.gov (United States)

    Reine, Trine M; Grøndahl, Frøy; Jenssen, Trond G; Hadler-Olsen, Elin; Prydz, Kristian; Kolset, Svein O

    2013-08-01

    Heparan sulfate proteoglycans are hypothesized to contribute to the filtration barrier in kidney glomeruli and the glycocalyx of endothelial cells. To investigate potential changes in proteoglycans in diabetic kidney, we isolated glycosaminoglycans from kidney cortex from healthy db/+ and diabetic db/db mice. Disaccharide analysis of chondroitin sulfate revealed a significant decrease in the 4-O-sulfated disaccharides (D0a4) from 65% to 40%, whereas 6-O-sulfated disaccharides (D0a6) were reduced from 11% to 6%, with a corresponding increase in unsulfated disaccharides. In contrast, no structural differences were observed in heparan sulfate. Furthermore, no difference was found in the molar amount of glycosaminoglycans, or in the ratio of hyaluronan/heparan sulfate/chondroitin sulfate. Immunohistochemical staining for the heparan sulfate proteoglycan perlecan was similar in both types of material but reduced staining of 4-O-sulfated chondroitin and dermatan was observed in kidney sections from diabetic mice. In support of this, using qRT-PCR, a 53.5% decrease in the expression level of Chst-11 (chondroitin 4-O sulfotransferase) was demonstrated in diabetic kidney. These results suggest that changes in the sulfation of chondroitin need to be addressed in future studies on proteoglycans and kidney function in diabetes.

  12. Modeling of ferric sulfate decomposition and sulfation of potassium chloride during grate‐firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Jappe Frandsen, Flemming

    2013-01-01

    Ferric sulfate is used as an additive in biomass combustion to convert the released potassium chloride to the less harmful potassium sulfate. The decomposition of ferric sulfate is studied in a fast heating rate thermogravimetric analyzer and a volumetric reaction model is proposed to describe...... the process. The yields of sulfur oxides from ferric sulfate decomposition under boiler conditions are investigated experimentally, revealing a distribution of approximately 40% SO3 and 60% SO2. The ferric sulfate decomposition model is combined with a detailed kinetic model of gas‐phase KCl sulfation...... and a model of K2SO4 condensation to simulate the sulfation of KCl by ferric sulfate addition. The simulation results show good agreements with experiments conducted in a biomass grate‐firing reactor. The results indicate that the SO3 released from ferric sulfate decomposition is the main contributor to KCl...

  13. Damage recovery and optical activity in europium implanted wide gap oxides

    International Nuclear Information System (INIS)

    Alves, E.; Marques, C.; Franco, N.; Alves, L.C.; Peres, M.; Soares, M.J.; Monteiro, T.

    2010-01-01

    In this study we compare and discuss the defects and optical behaviour of sapphire and magnesium oxide single crystals implanted at room temperature with different fluences (1 x 10 15 -1 x 10 16 cm -2 ) of europium ions. Rutherford backscattering channelling shows that for fluences above 5 x 10 15 cm -2 the surface disorder level in the Al-sublattice reaches the random level. Implantation damage recovers fast for annealing in oxidizing atmosphere but even for the highest fluence we recover almost completely all the damage after annealing at 1300 o C, independently of the annealing environment (reducing or oxidizing). Annealing above 1000 o C promotes the formation of Eu 2 O 3 in the samples with higher concentration of Eu. The optical activation of the rare earth ions at room temperature was observed after annealing at 800 o C by photoluminescence and ionoluminescence. In Al 2 O 3 lattice the highest intensity line of the Eu 3+ ions corresponds to the forced electric dipole 5 D 0 → 7 F 2 transition that occurs ∼616 nm. For the MgO samples the Eu 3+ optical activation was also achieved after implantation with different fluences. Here, the lanthanide recombination is dominated by the magnetic dipole 5 D 0 → 7 F 1 transition near by 590 nm commonly observed for samples were Eu 3+ is placed in a high symmetry local site. The results clearly demonstrate the possibility to get Eu incorporated in optical active regular lattice sites in wide gap oxides.

  14. Synthesis and electroluminescence properties of europium (III) complexes with new second ligands

    International Nuclear Information System (INIS)

    Liu Ze; Wen Fushan; Li Wenlian

    2005-01-01

    Two novel second ligands, 9,9-Di-(4-methoxyphenyl)-9-H-4,5-' (OMe-Spiro-DF) and 9,9-Di-(2-(4-(4-butyloxy)phenyl)-5-phenyl-1,3,4-oxadiazolyl)-phenyl-9-H-4, 5-Diazafluorene (OXD-Spiro-DF), were successfully prepared. Europium complexes, Eu(DBM) 3 (OMe-Spiro-DF) and Eu(DBM) 3 (OXD-Spiro-DF) (DBM=dibenzolylmethane) based on the two ligands were designed and synthesized. For a double-layer device with configuration of indium tin oxide (ITO)/N, N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD)/Eu(DBM) 3 (OXD-Spiro-DF) or Eu(DBM) 3 (OMe-Spiro-DF)/Mg/Ag, compared with the device based on complex Eu(DBM) 3 (OMe-Spiro-DF), the brightness and electroluminescent (EL) efficiency of device based on complex Eu(DBM) 3 (OXD-Spiro-DF) with oxadiazole-functionalized ligand OXD-Spiro-DF are significantly improved due to the improvement of electron-transporting ability. A maximum brightness of 154 cd/m 2 was obtained at 17 V in the complex Eu(DBM) 3 (OXD-Spiro-DF), about four times brighter than the corresponding complex Eu(DBM) 3 (OMe-Spiro-DF)

  15. Photoluminescent behaviors of several kinds of europium ternary complexes doped in PMMA

    International Nuclear Information System (INIS)

    Liu, H.-G.; Lee, Yong-Ill; Park, Seongtae; Jang, Kiwan; Kim, Sang Su

    2004-01-01

    Four kinds of europium ternary complexes; Eu(DBM) 3 phen, Eu(DBM) 3 (DB-bpy), Eu(DBM) 3 (DN-bpy) and Eu(DBM) 3 biq (DBM, phen, DB-bpy, DN-bpy and biq refer to Dibenzoylmethane, 1,10-phenanthroline, 4,4'-Di-tert-butyl-2,2'-dipyridyl, 4,4'-Dinonyl-2,2'-dipyridyl and 2,2'-Biquinoline, respectively), were doped in poly(methyl methacrylate) (PMMA) matrix. The luminescence properties of the composites were investigated by emission spectroscopy and lifetime measurements. It was found that the composites formed by the three complexes, Eu(DBM) 3 phen, Eu(DBM) 3 (DB-bpy), and Eu(DBM) 3 (DN-bpy), exhibit strong luminescence and similar emission spectral characteristics to Eu(III). Whereas, Eu(DBM) 3 biq shows large differences in its luminescence spectrum compared to those of other complexes. The luminescence was very weak and broad. The emission spectral features of Eu(III) in the Eu(DBM) 3 biq/PMMA systems change with the molar ratios of the complex and PMMA. The lifetime of 5 D 0 level of Eu(III) in Eu(DBM) 3 biq/PMMA systems is shorter than those in the other systems. The luminescence intensity of Eu(III) in Eu(DBM) 3 biq/PMMA systems decreases gradually when exposed to UV-light while the broad emission band becomes stronger

  16. Complexation and molecular modeling studies of europium(III)-gallic acid-amino acid complexes.

    Science.gov (United States)

    Taha, Mohamed; Khan, Imran; Coutinho, João A P

    2016-04-01

    With many metal-based drugs extensively used today in the treatment of cancer, attention has focused on the development of new coordination compounds with antitumor activity with europium(III) complexes recently introduced as novel anticancer drugs. The aim of this work is to design new Eu(III) complexes with gallic acid, an antioxida'nt phenolic compound. Gallic acid was chosen because it shows anticancer activity without harming health cells. As antioxidant, it helps to protect human cells against oxidative damage that implicated in DNA damage, cancer, and accelerated cell aging. In this work, the formation of binary and ternary complexes of Eu(III) with gallic acid, primary ligand, and amino acids alanine, leucine, isoleucine, and tryptophan was studied by glass electrode potentiometry in aqueous solution containing 0.1M NaNO3 at (298.2 ± 0.1) K. Their overall stability constants were evaluated and the concentration distributions of the complex species in solution were calculated. The protonation constants of gallic acid and amino acids were also determined at our experimental conditions and compared with those predicted by using conductor-like screening model for realistic solvation (COSMO-RS) model. The geometries of Eu(III)-gallic acid complexes were characterized by the density functional theory (DFT). The spectroscopic UV-visible and photoluminescence measurements are carried out to confirm the formation of Eu(III)-gallic acid complexes in aqueous solutions. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Mean-field potential approach for thermodynamic properties of lanthanide: Europium as a prototype

    Science.gov (United States)

    Kumar, Priyank; Bhatt, N. K.; Vyas, P. R.; Gohel, V. B.

    2018-03-01

    In the present paper, a simple conjunction scheme [mean-field potential (MFP) + local pseudopotential] is used to study the thermodynamic properties of divalent lanthanide europium (Eu) at extreme environment. Present study has been carried out due to the fact that divalent nature of Eu arises because of stable half-filled 4f-shell at ambient condition, which has great influence on the thermodynamic properties at extreme environment. Due to such electronic structure, it is different from remaining lanthanides having incomplete 4f-shell. The presently computed results of thermodynamic properties of Eu are in good agreement with the experimental results. Looking to such success, it seems that the concept of MFP approach is successful to account contribution due to nuclear motion to the total Helmholtz free energy at finite temperatures and pressure-induced inter-band transfer of electrons for condensed state of matter. The local pseudopotential is used to evaluate cold energy and hence MFP accounts the s-p-d-f hybridization properly. Looking to the reliability and transferability along with its computational and conceptual simplicity, we would like to extend the present scheme for the study of thermodynamic properties of remaining lanthanides and actinides at extreme environment.

  18. EUROPIUM ION INFLUENCE ON THE FORMATION OF Ag-NANOPARTICLES IN FLUORINE PHOSPHATE GLASSES

    Directory of Open Access Journals (Sweden)

    R. O. Pysh'ev

    2015-05-01

    Full Text Available The paper deals with research of formation characteristics of silver nanoparticles in fluorophosphate glasses 0.25 Na2O - 0.5 P2O5 - 0.10 Ga2O3 - 0.075 AlF3 - 0.025 NaF - 0.05 ZnF2 doped with EuF3 (0.8 and 4 wt.% and without them. The synthesis was carried out in closed glassy carbon crucibles in argon atmosphere. Nanoparticles were formed after a low temperature process of Ag+ → Na+ ion-exchange (320 °C and subsequent heat treatment. It was shown that in the initial glasses doped with EuF3, rare earth ions exist in two valence forms (Eu2+ and Eu3+ in dynamic equilibrium and the concentration of Eu2+ increases proportionally to the total concentration of fluoride. It was shown that sizes of molecular clusters or metal nanoparticles depend on the concentration of europium fluoride and duration of ion exchange. The metallic Ag-nanoparticles sizes were defined for different times of heat treatment and ion exchange. The possibility of the stimulating growth of nanoparticles through the introduction of additional EuF3 in the glass was proved. The possibility of obtaining nanoparticles without the heat treatment in glasses with a high concentration of EuF3 was shown. Chemical mechanism for the formation of Ag-nanoparticles during the ion exchange was suggested.

  19. Determination of piroxicam in pharmaceutical formulations and urine samples using europium-sensitized luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Al-Kindy, Salma M.Z. [Department of Chemistry, College of Science, P.O. Box 36, Al-Khod 123, Sultan Qaboos University (Oman)], E-mail: alkindy@squ.edu.om; Suliman, Fakhr Eldin O.; Al-Wishahi, Aisha A.; Al-Lawati, Haidar A.J.; Aoudia, Muhammed [Department of Chemistry, College of Science, P.O. Box 36, Al-Khod 123, Sultan Qaboos University (Oman)

    2007-12-15

    A simple, selective and sensitive luminescence method for the assay of piroxicam (PX) in aqueous solution is developed. The method is based on the luminescence sensitization of europium (Eu{sup 3+}) by formation of ternary complex with PX in the presence of TOPO and Tween-80 as surfactant. The signal for Eu-PX-TOPO is monitored at {lambda}{sub ex}=359 nm and {lambda}{sub em}=615 nm. Optimum conditions for the formation of the complex in sequential injection analysis (SIA) were 0.01 M Tris buffer, pH 7.5, TOPO 5.0x10{sup -5} M, Tween-80 0.15% and 1.5 mM of Eu{sup 3+}, which allows the determination of 100-1000 ppb of PX with limit of detection (LOD) of 29 ppb. The relative standard deviations of the method range between 0.5% and 3.9% indicating excellent reproducibility of the method. The proposed method was successfully applied for the assay of PX in pharmaceutical formulations and in urine samples. Average recoveries of 100.8{+-}1.7% was obtained in tablet, whereas a recovery of 97.5{+-}2.0% was obtained for the total PX (PX+hydoxy-PX) in urine sample.

  20. Photoluminescent study of Polycarbonate (PC) and Poly(9-vinylcarbazole) (PVK) doped films with europium complex

    International Nuclear Information System (INIS)

    Forster, Pedro Lima

    2010-01-01

    Polymers doped with rare earth complexes are advantaged in film production for many applications in the luminescent field. In this study luminescent polymer obtained from polycarbonate (PC) and poly(9-vinylcarbazole) films doped with diaquatris(thenoyltrifluoroacetonate)europium(III) complex [Eu(tta) 3 (H 2 0) 2 ] were prepared and their calorimetric and luminescent properties in the solid state are reported. The thermal behavior was investigated by differential scanning calorimetry (OSC) and thermogravimetry analysis (TGA). Due of the addition of rare earth Eu(tta) 3 (H 2 0) 2 ] into PC and PVK matrices, changes were observed in the thermal behavior concerning the glass transition and thermal stability. Characteristic broadened narrow bands arising from the 5 D 0 -→ 7 F J transitions (J = 0-4) of Eu 3+ ion indicate the incorporation of the Eu 3+ ions into those polymers. The luminescent films show enhancement emission intensity with an increase in the rare earth concentration in polymeric matrix accompanied by decrease in thermal stability. (author)

  1. Determination of piroxicam in pharmaceutical formulations and urine samples using europium-sensitized luminescence

    International Nuclear Information System (INIS)

    Al-Kindy, Salma M.Z.; Suliman, Fakhr Eldin O.; Al-Wishahi, Aisha A.; Al-Lawati, Haidar A.J.; Aoudia, Muhammed

    2007-01-01

    A simple, selective and sensitive luminescence method for the assay of piroxicam (PX) in aqueous solution is developed. The method is based on the luminescence sensitization of europium (Eu 3+ ) by formation of ternary complex with PX in the presence of TOPO and Tween-80 as surfactant. The signal for Eu-PX-TOPO is monitored at λ ex =359 nm and λ em =615 nm. Optimum conditions for the formation of the complex in sequential injection analysis (SIA) were 0.01 M Tris buffer, pH 7.5, TOPO 5.0x10 -5 M, Tween-80 0.15% and 1.5 mM of Eu 3+ , which allows the determination of 100-1000 ppb of PX with limit of detection (LOD) of 29 ppb. The relative standard deviations of the method range between 0.5% and 3.9% indicating excellent reproducibility of the method. The proposed method was successfully applied for the assay of PX in pharmaceutical formulations and in urine samples. Average recoveries of 100.8±1.7% was obtained in tablet, whereas a recovery of 97.5±2.0% was obtained for the total PX (PX+hydoxy-PX) in urine sample

  2. Temperature effects on the interaction mechanisms between the europium (III) and uranyl ions and zirconium diphosphate

    International Nuclear Information System (INIS)

    Finck, N.

    2006-10-01

    Temperature should remain higher than 25 C in the near field environment of a nuclear waste repository for thousands years. In this context, the aim of this work is to study the temperature influence on the interaction mechanisms between europium (III) and uranyl ions and zirconium diphosphate, as well as the influence of a complexing medium (nitrate) on the sorption of the lanthanide. The experimental definition of the equilibria was achieved by combining a structural investigation with the macroscopic sorption data. Surface complexes were characterized at all temperatures (25 C to 90 C) by TRLFS experiments carried out on dry and in situ samples using an oven. This characterization was completed by XPS experiments carried out at 25 C on samples prepared at 25 C and 90 C. The reaction constants (surface hydration and cations sorption) were obtained by simulating the experimental data with the constant capacitance surface complexation model. The reaction constants temperature dependency allowed one to characterize thermodynamically the different reactions by application of the van't Hoff relation. The validity of this law was tested by performing microcalorimetric measurements of the sorption heat for both cations. (author)

  3. NMR and luminescence spectroscopy study of formation of mixed β-diketonate europium complexes

    International Nuclear Information System (INIS)

    Kavun, V.Ya.; Kalinovskaya, I.V.; Karasev, V.E.; Chernyshov, B.N.; Steblevskaya, N.I.

    1987-01-01

    Methods of NMR ('H, 19 F) and luminescent spectroscopy were applied to study ligand substitution in Eu(β-dik) 3 phen-CDCl 3 -(β-dik)' systems, where β-dik-acetylacetone (AA) and hexafluoroacetyl-acetone (HFAA), phen-1.10-phenathroline at different mole ratio (m) of competing ligands (m=AA/HFAA). Formation of mixed Eu(AA) 2 (HFAA)phen and Eu(AA)(HFAA) 2 phen complexes is proved; calculation of the stark structure of 5 D 0 - 7 F j (j=0,1,2) transitions in low-temperature luminescence spectra is conducted for these complexes. It is stated that at minimum HFAA concentration in the solution the latter replaces AA from europium coordination sphere. It is shown that depending on the value in substitution of acidoligands proceeds successfully by the equations Eu(AA) 3 phen+(NHFAA) n → Eu(AA) 3-n → (HFAA) n phen+(NAA) n ; (n=1,2,3)

  4. Doping β-Ga2O3 with europium: influence of the implantation and annealing temperature

    Science.gov (United States)

    Peres, M.; Lorenz, K.; Alves, E.; Nogales, E.; Méndez, B.; Biquard, X.; Daudin, B.; Víllora, E. G.; Shimamura, K.

    2017-08-01

    β-Ga2O3 bulk single crystals were doped by ion implantation at temperatures from room temperature to 1000 °C, using a 300 keV Europium beam with a fluence of 1  ×  1015 at cm-2. Rising the implantation temperature from room temperature to 400-600 °C resulted in a significant increase of the substitutional Eu fraction and of the number of Eu ions in the 3+  charge state as well as in a considerable decrease of implantation damage. Eu is found in both charge states 2+  and 3+  and their relative fractions are critically dependent on the implantation and annealing temperature, suggesting that defects play an important role in stabilizing one of the charge states. The damage recovery during post-implant annealing is a complex process and typically defect levels first increase for intermediate annealing temperatures and a significant recovery of the crystal only starts around 1000 °C. Cathodoluminescence spectra are dominated by the sharp Eu3+ related intra-ionic 4f transition lines in the red spectral region. They show a strong increase of the emission intensity with increasing annealing temperature, in particular for samples implanted at elevated temperature, indicating the optical activation of Eu3+ ions. However, no direct correlation of emission intensity and Eu3+ fraction was found, again pointing to the important role of defects on the physical properties of these luminescent materials.

  5. Influence of organic solvent treatment on elasticoluminescent property of europium-doped strontium aluminates

    International Nuclear Information System (INIS)

    Fujio, Yuki; Xu, Chao-Nan; Terasaki, Nao; Ueno, Naohiro

    2014-01-01

    The influence of an organic solvent treatment on elasticoluminescent (ELS) characteristics of mechanoluminescent (ML) sensor using the composite film consisting of an ELS material and epoxy resin was investigated. We used strontium aluminate doped with a small amount of europium (SrAl 2 O 4 :Eu, SAOE) as an ELS material in this study. After evaluating the ELS characteristics of the fabricated ML sensors using SAOE treated with/without various organic solvents, SAOE treated with methanol and ethanol showed lower ELS intensities than that of untreated SAOE. In contrast, the ELS response curves against strain for the ML sensors using SAOE treated with acetone and toluene, overlapped with that of untreated SAOE. From the characterization of SAOE treated with alcohols, such as methanol and ethanol, we can hypothesize that poor ELS characteristics is due to the degradation of the SAOE grain surfaces by the hydrolyze reaction of SAOE with hydroxyl group of alcohol. Thus, on the basis of the obtained results, we can conclude that the selection of organic solvent used in the preparation of SAOE film is of considerable importance in the development of ML sensor with a highly-reliable ELS characteristic. -- Highlights: • Influence of organic solution treatment on the sensing characteristics of a mechanoluminescent (ML) sensor using SrAl 2 O 4 :Eu has been investigated. • An alcohol treatment of SAOE powder has considerable effect on its ML characteristic. • There is almost no influence of acetone and toluene treatments on ML characteristics

  6. Effects of europium polyoxometalate encapsulated in silica nanoparticles (nanocarriers) in soil invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Bicho, Rita C., E-mail: ritabicho@ua.pt; Soares, Amadeu M.V.M. [Universidade de Aveiro, Departamento de Biologia & CESAM (Portugal); Nogueira, Helena I.S. [Universidade de Aveiro, Departamento de Química & CICECO (Portugal); Amorim, Mónica J.B. [Universidade de Aveiro, Departamento de Biologia & CESAM (Portugal)

    2016-12-15

    Polyoxometalates (POMs) are metal oxo clusters that have been investigated for several applications in material sciences, catalysis, and biomedicine; these gained increasing interest in the field of nanotechnology as nanocarriers for drug delivery. Associated to the increasing applications, there is the need for information regarding the effects on the environment of these compounds, which is completely absent in the literature. In the present study, the effects of europium polyoxometalates encapsulated into silica nanoparticles (Eu-POM/SiO{sub 2} NPs) were assessed on the soil representative Enchytraeus crypticus. The individual materials were also assessed (Eu-POMs and SiO{sub 2} NPs). Toxicity was evaluated in various test media with increasing complexity: water, soil/water extracts, and soil. Toxicity was only observed for Eu-POM/SiO{sub 2} NPs and in the presence of soil components. Despite the fact that effects were observed for concentrations higher than current predicted environmental concentration (PEC), attention should be given to the growing use of these compounds. The present study shows the importance of assessing the effects in soil media, also compared to water. Moreover, results of “no effect” are critically needed and often unpublished. The present study can contribute to the improvement of the OECD guidelines for safety of manufactured nanomaterials on environmental toxicity in the soil compartment providing an improved test alternative.

  7. Synthesis, Structure, and Luminescent Properties of Europium-Doped Hydroxyapatite Nanocrystalline Powders

    Directory of Open Access Journals (Sweden)

    Carmen Steluta Ciobanu

    2012-01-01

    Full Text Available The luminescent europium-doped hydroxyapatite (Eu:HAp, Ca10−xEux(PO46(OH2 with 0≤x≤0.2 nanocrystalline powders was synthesized by coprecipitation. The structural, morphological, and textural properties were well characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The vibrational studies were performed by Fourier transform infrared, Raman, and photoluminescence spectroscopies. The X-ray diffraction analysis revealed that hydroxyapatite is the unique crystalline constituent of all the samples, indicating that Eu has been successfully inserted into the HAp lattice. Eu doping inhibits HAp crystallization, leading to a decrease of the average crystallite size from around 20 nm in the undoped sample to around 7 nm in the sample with the highest Eu concentration. Furthermore, the samples show the characteristic 5D0→7F0 transition observed at 578 nm related to Eu3+ ions distributed on Ca2+ sites of the apatitic structure.

  8. Europium concentration effect on characteristics and luminescent properties of hydroxyapatite nanocrystalline powders

    Science.gov (United States)

    Nikolaev, Anton; Kolesnikov, Ilya; Frank-Kamenetskaya, Olga; Kuz'mina, Maria

    2017-12-01

    Series of Eu-apatites were synthesized by precipitation from aqueous solutions with the Eu/Ca atomic ratio from 0.5% to 5% at T = 90 °C. Resulting precipitates were studied using different experimental techniques including X-ray powder diffraction, infrared and raman spectroscopy, scanning elecrton microscopy, EDX and photoluminescent spectroscopy. Eu-doped Ca-deficit nanosized non-stoichiometric hydroxyapatite with high water content has been obtained throughout the experiment. Europium content in the synthesized apatites reaches 0.24 apfu (Eu/Ca = 2.5%). Relations between Eu content is the solution and precipitate have been established. It was shown that Eu-monacite starts to precipitate as secondary phase at Eu/Ca ratio in starting solution 1% or higher. Maximum luminescence is observed in apatite with ∼2% Eu/Ca ratio (which equals to ∼0.2 apfu and corresponds to 3% Eu/Ca ratio in the starting solution). As an important and brand-new result, apatite with 2% Eu/Ca ratio can be considered as the most appropriate material for the producing biolabels for luminescent research in medicine and biology.

  9. Reducing the photo-bleaching effect of a new europium complex embedded in styrene butadiene copolymer

    Science.gov (United States)

    Jiménez, G. Lesly; Reyes-Rodríguez, J. L.; Padilla, Isela; Alarcón-Flores, G.; Falcony, C.

    2018-02-01

    A highly luminescent europium complex obtained with two different ligands, succinimide (SI) and 2-thenoyltrifluoroacetone (TTA) , was synthetized with different TTA concentrations. The photoluminescence (PL) emission from these materials corresponds to the characteristic inter-electronic energy level transitions of the Eu3+ ions. However, the excitation spectrum is strongly dependent on the presence of TTA, having an optimum response when 0.75 mmol of this compound is added to the EuL3(H2O)3 complex. The quantum yield obtained by these powders were around 72 % ± 1.7 % indicating an optimum sensitization of these complex. The EuL3 TTA complex with the best PL properties was embedded in a styrene butadiene copolymer (SBC) film, produced by the drop casting method, obtaining similar PL behavior at different concentrations, the highest intensity was observed at 1.2% (w/v) of EuL3 TTA complex and the quantum yield of these composite films was 60.5 % ± 2 % . These films were exposed to continuous UV irradiation and after 141 h no photo-bleaching effect was observed in contrast with the EuL3 TTA complex that exhibited a noticeable photoluminescence intensity degradation at much shorter exposure times. Both the Eu-complexes and the composite films were characterized by FT-IR, XRD, SEM and fluorescence spectroscopy.

  10. Effects of europium polyoxometalate encapsulated in silica nanoparticles (nanocarriers) in soil invertebrates

    International Nuclear Information System (INIS)

    Bicho, Rita C.; Soares, Amadeu M.V.M.; Nogueira, Helena I.S.; Amorim, Mónica J.B.

    2016-01-01

    Polyoxometalates (POMs) are metal oxo clusters that have been investigated for several applications in material sciences, catalysis, and biomedicine; these gained increasing interest in the field of nanotechnology as nanocarriers for drug delivery. Associated to the increasing applications, there is the need for information regarding the effects on the environment of these compounds, which is completely absent in the literature. In the present study, the effects of europium polyoxometalates encapsulated into silica nanoparticles (Eu-POM/SiO 2 NPs) were assessed on the soil representative Enchytraeus crypticus. The individual materials were also assessed (Eu-POMs and SiO 2 NPs). Toxicity was evaluated in various test media with increasing complexity: water, soil/water extracts, and soil. Toxicity was only observed for Eu-POM/SiO 2 NPs and in the presence of soil components. Despite the fact that effects were observed for concentrations higher than current predicted environmental concentration (PEC), attention should be given to the growing use of these compounds. The present study shows the importance of assessing the effects in soil media, also compared to water. Moreover, results of “no effect” are critically needed and often unpublished. The present study can contribute to the improvement of the OECD guidelines for safety of manufactured nanomaterials on environmental toxicity in the soil compartment providing an improved test alternative.

  11. Inhibition of synthesis of heparan sulfate by selenate: Possible dependence on sulfation for chain polymerization

    International Nuclear Information System (INIS)

    Dietrich, C.P.; Nader, H.B.; Buonassisi, V.; Colburn, P.

    1988-01-01

    Selenate, a sulfation inhibitor, blocks the synthesis of heparan sulfate and chondroitin sulfate by cultured endothelial cells. In contrast, selenate does not affect the production of hyaluronic acid, a nonsulfated glycosaminoglycan. No differences in molecular weight, [ 3 H]glucosamine/[ 35 S]sulfuric acid ratios, or disaccharide composition were observed when the heparan sulfate synthesized by selenate-treated cells was compared with that of control cells. The absence of undersulfated chains in preparations from cultures exposed to selenate supports the concept that, in the intact cell, the polymerization of heparan sulfate might be dependent on the sulfation of the saccharide units added to the growing glycosaminoglycan chain

  12. Analysis of tyrosine-O-sulfation

    DEFF Research Database (Denmark)

    Bundgaard, J.R.; Sen, J.W.; Johnsen, A.H.

    2008-01-01

    Tyrosine O-sulfation was first described about 50 years ago as a post-translational modification of fibrinogen. In the following 30 years it was considered to be a rare modification affecting only a few proteins and peptides. However, in the beginning of the 1980s tyrosine (Tyr) sulfation was shown...... to be a common modification and since then an increasing number of proteins have been identified as sulfated. The target proteins belong to the classes of secretory, plasma membrane, and lysosomal proteins, which reflects the intracellular localization of the enzymes catalyzing Tyr sulfation, the tyrosylprotein...... sulfotransferases (TPSTs).Traditionally, Tyr sulfation has been analyzed by incorporation of radiolabeled sulfate into target cells followed by purification of the target protein. Subsequently, the protein is degraded enzymatically or by alkaline hydrolysis followed by thin-layer electrophoresis to demonstrate...

  13. Bactericide for sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Shklyar, T F; Anoshina, G M; Blokhin, V Ye; Kisarrev, Ye L; Novikovsa, G M

    1981-01-01

    The aim of the invention is to find a bactericide for sulfate-reducing bacteria of oil fields in Western Siberia in order to suppress the biocorrosive activity on oil industry equipment. This goal is achieved by using M-nitroacetanylide as the bactericide of sulfate-reducing bacteria. This agent suppresses the activity of a stored culture of sulfate-reducing bacteria that comes from industrial waste waters injection wells of the Smotlor oil field.

  14. Europium(III) chelate-dyed nanoparticles as donors in a homogeneous proximity-based immunoassay for estradiol

    International Nuclear Information System (INIS)

    Kokko, Leena; Sandberg, Kaisa; Loevgren, Timo; Soukka, Tero

    2004-01-01

    Nanoparticles containing thousands of fluorescent europium(III) chelates have a very high specific activity compared to traditional lanthanide chelate labels. It can be assumed that if these particles are used in a homogeneous assay as donors, multiple chelates can excite a single acceptor in turns and the energy transfer to the acceptor is increased. The principle was employed in an immunoassay using luminescent resonance energy transfer from a long lifetime europium(III) chelate-dyed nanoparticle to a short lifetime, near-infrared fluorescent molecule. Due to energy transfer fluorescence lifetime of the sensitised emission was prolonged and fluorescence could be measured using a time-resolved detection. A competitive homogeneous immunoassay for estradiol was created using 92 nm europium(III) chelate-dyed nanoparticle coated with 17β-estradiol specific recombinant antibody Fab fragments as a donor and estradiol conjugated with near-infrared dye AlexaFluor 680 as an acceptor. The density of Fab fragments on the surface of the particle influenced the sensitivity of the immunoassay. The optimal Fab density was reached when the entire surface of the particle participated in the energy transfer, but the areas where the energy was transferred to a single acceptor, did not overlap. We were able to detect estradiol concentrations down to 70 pmol l -1 (3xSD of a standard containing 0 nmol l -1 of E2) using a 96-well platform. In this study we demonstrated that nanoparticles containing lanthanide chelates could be used as efficient donors in homogeneous assays

  15. Comparison of infrared-excited up-converting phosphors and europium nanoparticles as labels in a two-site immunoassay

    International Nuclear Information System (INIS)

    Ukonaho, Telle; Rantanen, Terhi; Jaemsen, Laura; Kuningas, Katri; Paekkilae, Henna; Loevgren, Timo; Soukka, Tero

    2007-01-01

    Research in the field of immunoassays and labels used in the detection has been recently focused on particulate reporters, which possess very high specific activity that excludes the label as a sensitivity limiting factor. However, the large size and shape of the particulate labels may produce additional problems to immunoassay performance. The aim of this work was to study with two identical non-competitive two-site immunoassays whether up-converting phosphor (UCP) particles are comparable in performance with europium(III) chelate-dyed nanoparticles as particulate labels. In addition we strived to verify the common assumption of the photostability of up-converting phosphor particles supporting their potential applicability in imaging. Detection limits in two-site immunoassay for free prostate-specific antigen (free-PSA) were 0.53 ng L -1 and 1.3 ng L -1 using two different up-converting phosphors and 0.16 ng L -1 using europium(III) nanoparticle. Large size distribution and non-specific binding of up-converting phosphor particles caused assay variation in low analyte concentrations and limited the analytical detection limit. The non-specific binding was the major factor limiting the analytical sensitivity of the immunoassay. The results suggests the need for nanoscaled and uniformely sized UCP-particles to increace the sensitivity and applicability of up-converting phosphor particles. Anti-Stokes photoluminescence of up-converting phosphor particles did not photobleach when measured repeatedly, on the contrary, the time-resolved fluorescence of europium nanoparticles photobleached relatively rapidly

  16. Europium (III) PVC membrane sensor based on N-pyridine-2-carboxamido-8-aminoquinoline as a sensing material

    International Nuclear Information System (INIS)

    Zamani, Hassan Ali; Kamjoo, Rahman; Mohammadhosseini, Majid; Zaferoni, Mojdeh; Rafati, Zynab; Ganjali, Mohammad Reza; Faridbod, Farnoush; Meghdadi, Soraia

    2012-01-01

    Conductometric study in acetonitrile solution shows the selectivity of PCQ toward europium ion. Therefore, a new europium PVC membrane electrode was prepared based on N-pyridine-2-carboxamido-8-aminoquinoline (PCQ) as an ion carrier. The electrode has a wide concentration range from 1.0 × 10 −2 and 1.0 × 10 −6 mol L −1 , Nernstian slope of 19.8 ± 0.3 mV per decade and a detection limit of 6.4 × 10 −7 mol L −1 . The potentiometric response is pH independent in the range of 2.4–7.4. The proposed sensor has a relatively fast response time less than 10 s and it can be used for at least 2 months without any considerable divergence in its potentials. The proposed electrode revealed good selectivity toward europium ion in comparison with variety of other metal ions. The practical utility of the electrodes has been demonstrated by their use as indicator electrodes in the potentiometric titration of Eu 3+ ions with EDTA and for determination of Eu 3+ ion concentration in mixtures of two and three different ions. - Highlights: ► A new ion carrier is introduced to preparation of a selective sensor for Eu 3+ ions. ► This technique is very simple and it's not necessary to use sophisticated equipment. ► The novelty of this work is the high affinity of the ionophore toward the Eu 3+ ions. ► The sensor is superior to the formerly reported Eu 3+ sensors in terms of selectivity.

  17. Determination of the theoretical feasibility for the transmutation of europium isotopes from high flux isotope reactor control cylinders

    International Nuclear Information System (INIS)

    Elam, K.R.; Reich, W.J.

    1995-09-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) is a 100 MWth light-water research reactor designed and built in the 1960s primarily for the production of transuranic isotopes. The HFIR is equipped with two concentric cylindrical blade assemblies, known as control cylinders, that are used to control reactor power. These control cylinders, which become highly radioactive from neutron exposure, are periodically replaced as part of the normal operation of the reactor. The highly radioactive region of the control cylinders is composed of europium oxide in an aluminum matrix. The spent HFIR control cylinders have historically been emplaced in the ORNL Waste Area Grouping (WAG) 6. The control cylinders pose a potential radiological hazard due to the long lived radiotoxic europium isotopes 152 Eu, 154 Eu, and 155 Eu. In a 1991 health evaluation of WAG 6 (ERD 1991) it was shown that these cylinders were a major component of the total radioactivity in WAG 6 and posed a potential exposure hazard to the public in some of the postulated assessment scenarios. These health evaluations, though preliminary and conservative in nature, illustrate the incentive to investigate methods for permanent destruction of the europium radionuclides. When the cost of removing the control cylinders from WAG 6, performing chemical separations and irradiating the material in HFIR are factored in, the option of leaving the control cylinders in place for decay must be considered. Other options, such as construction of an engineered barrier around the disposal silos to reduce the chance of migration, should also be analyzed

  18. Europium (III) PVC membrane sensor based on N-pyridine-2-carboxamido-8-aminoquinoline as a sensing material

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Kamjoo, Rahman [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Mohammadhosseini, Majid [Department of Chemistry, Faculty of Basic Sciences, Shahrood Branch, Islamic Azad University, Shahrood (Iran, Islamic Republic of); Zaferoni, Mojdeh; Rafati, Zynab [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Faridbod, Farnoush [Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Meghdadi, Soraia [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2012-04-01

    Conductometric study in acetonitrile solution shows the selectivity of PCQ toward europium ion. Therefore, a new europium PVC membrane electrode was prepared based on N-pyridine-2-carboxamido-8-aminoquinoline (PCQ) as an ion carrier. The electrode has a wide concentration range from 1.0 Multiplication-Sign 10{sup -2} and 1.0 Multiplication-Sign 10{sup -6} mol L{sup -1}, Nernstian slope of 19.8 {+-} 0.3 mV per decade and a detection limit of 6.4 Multiplication-Sign 10{sup -7} mol L{sup -1}. The potentiometric response is pH independent in the range of 2.4-7.4. The proposed sensor has a relatively fast response time less than 10 s and it can be used for at least 2 months without any considerable divergence in its potentials. The proposed electrode revealed good selectivity toward europium ion in comparison with variety of other metal ions. The practical utility of the electrodes has been demonstrated by their use as indicator electrodes in the potentiometric titration of Eu{sup 3+} ions with EDTA and for determination of Eu{sup 3+} ion concentration in mixtures of two and three different ions. - Highlights: Black-Right-Pointing-Pointer A new ion carrier is introduced to preparation of a selective sensor for Eu{sup 3+} ions. Black-Right-Pointing-Pointer This technique is very simple and it's not necessary to use sophisticated equipment. Black-Right-Pointing-Pointer The novelty of this work is the high affinity of the ionophore toward the Eu{sup 3+} ions. Black-Right-Pointing-Pointer The sensor is superior to the formerly reported Eu{sup 3+} sensors in terms of selectivity.

  19. Internal-standard method for the determination of uranium, thorium, lanthanum and europium in carbonaceous shale and monazite by epithermal neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shuenn-Gang; Tsai, Hui-Tuh; Wu, Shaw-Chii [Institute of Nuclear Energy Research, Lung-Tan (Taiwan, Republic of China)

    1981-10-03

    An internal-standard method was applied for the determination of uranium, thorium, lanthanum and europium is carbonaceous shale samples and monazite sand by epithermal neutron activation analysis using gold as an internal standard element. The samples were irradiated in a zero-power reactor at the Institute of Nuclear Energy Research and measured with a high-resolution Ge(Li) detector. The detection limit is 0.1 ppm for uranium and europium, 1 ppm for thorium, 5 ppm for lanthanum, and the realative error of all elements is within +-2.6%.

  20. Significant role of organic sulfur in supporting sedimentary sulfate reduction in low-sulfate environments

    Science.gov (United States)

    Fakhraee, Mojtaba; Li, Jiying; Katsev, Sergei

    2017-09-01

    Dissimilatory sulfate reduction (DSR) is a major carbon mineralization pathway in aquatic sediments, soils, and groundwater, which regulates the production of hydrogen sulfide and the mobilization rates of biologically important elements such as phosphorus and mercury. It has been widely assumed that water-column sulfate is the main sulfur source to fuel this reaction in sediments. While this assumption may be justified in high-sulfate environments such as modern seawater, we argue that in low-sulfate environments mineralization of organic sulfur compounds can be an important source of sulfate. Using a reaction-transport model, we investigate the production of sulfate from sulfur-containing organic matter for a range of environments. The results show that in low sulfate environments (50%) of sulfate reduction. In well-oxygenated systems, porewater sulfate profiles often exhibit sub-interface peaks so that sulfate fluxes are directed out of the sediment. Our measurements in Lake Superior, the world's largest lake, corroborate this conclusion: offshore sediments act as sources rather than sinks of sulfate for the water column, and sediment DSR is supported entirely by the in-sediment production of sulfate. Sulfate reduction rates are correlated to the depth of oxygen penetration and strongly regulated by the supply of reactive organic matter; rate co-regulation by sulfate availability becomes appreciable below 500 μM level. The results indicate the need to consider the mineralization of organic sulfur in the biogeochemical cycling in low-sulfate environments, including several of the world's largest freshwater bodies, deep subsurface, and possibly the sulfate-poor oceans of the Early Earth.

  1. Structural and photocatalytic properties of iron- and europium-doped TiO2 nanoparticles obtained under hydrothermal conditions

    International Nuclear Information System (INIS)

    Diamandescu, L.; Vasiliu, F.; Tarabasanu-Mihaila, D.; Feder, M.; Vlaicu, A.M.; Teodorescu, C.M.; Macovei, D.; Enculescu, I.; Parvulescu, V.; Vasile, E.

    2008-01-01

    Iron- and europium-doped (≤1 at.%) TiO 2 nanoparticles powders have been synthesized by a hydrothermal route at 200 deg. C, starting with TiCl 4 , FeCl 3 .6H 2 O and EuCl 3 .6H 2 O. The structure, morphology and optical peculiarities were investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), extended X-ray absorption fine structure (EXAFS), Moessbauer spectroscopy and UV-vis measurements. The photocatalytic performance was analysed in the photodegradation reaction of phenol. Rietveld refinements of XRD patterns reveal that the as-prepared samples consist in iron- and europium-doped TiO 2 in the tetragonal anatase structural shape, with particle size as low as 15 nm. By means of Moessbauer spectroscopy on both 57 Fe and 151 Eu isotopes as well as by EXAFS analyses, the presence of Fe 3+ and/or Eu 3+ ions in the nanosized powders has been evidenced. It was found that iron and europium ions can substitute for titanium in the anatase structure. From the UV-vis reflection spectra, by using the transformed Kubelka-Munk functions, the band gap energy (E g ) of the hydrothermal samples has been determined in comparison with that of Degussa P-25 photocatalyst. A decrease of E g from 2.9 eV found for Degussa photocatalyst to 2.8 eV for the titania doped with 1 at.% Fe has been evidenced, indicating a valuable absorption shift (∼20 nm) towards visible light region. However, the best photocatalytic activity in the photodegradation reaction of phenol was evidenced for the hydrothermal sample, TiO 2 : 1 at.% Fe, 0.5 at.% Eu, in both UV and visible light regions. The photocatalytic activities of iron-doped and iron-europium-codoped samples are high and practically the same only in visible light. The photocatalytic properties in correlation with the structural and optical peculiarities of the hydrothermal samples are discussed

  2. The Magnetic Response of Europium Implanted in Cerium and in Platinum as Investigated by the PAC-Method

    International Nuclear Information System (INIS)

    Zeitz, W.-D.; Unterricker, S.; Schneider, F.; Samokhvalov, V.; Potzger, K.; Weber, A.; Dietrich, M.

    2004-01-01

    The magnetic response of europium in γ-cerium and in platinum was studied by applying the perturbed angular correlation spectroscopy. The probe nuclei were 147 Eu(11/2 - ) and 149 Eu(11/2 - ). The response in γ-Ce was determined by the electronic S = J = 7/2 ground state of divalent Eu. In Pt, on the other hand, Eu is trivalent (J = 0 ground state). Here the magnetic contributions originate from Van Vleck terms of the whole multiplet system.

  3. Solid-phase synthesis of compounds of europium and terbium with nitrogen-containing heterocyclic compounds under mechanical activation

    International Nuclear Information System (INIS)

    Kalinovskaya, I.V.; Karasev, V.E.

    2000-01-01

    Effect of solvents and parameters of mechanical treatment on basic regularities of synthesis of rare earth compounds with nitrogen-containing heterocyclic compounds is studied. It is shown that interaction on europium (3) and terbium (3) nitrates with nitrogen-containing heterocyclic compounds leads to formation of compounds of Ln(NO 3 )·2D composition, where Ln=Eu, Tb; D=2,2-dipyridyl, 1,10-phenanthroline, diphenylguanidine. Effect of conditions of mechanical treatment and different additions on process and yield of products is studied. Compounds prepared are characterized by the methods of chemical element analysis, IR spectroscopy and luminescent spectroscopy [ru

  4. Uncertainties in measuring trace amounts of cobalt and europium with low-flux neutron activation analysis

    Directory of Open Access Journals (Sweden)

    Burnham Steven

    2017-01-01

    Full Text Available Neutron activation analysis is widely used for identification of elements and their quantities even in trace amounts in the samples of almost any type. The challenges in detecting trace amounts of particular elements are often associated with the neutron flux produced at the research reactors. Low-flux neutron activation analysis usually presents the biggest challenge when analyzing trace quantities of elements with lower magnitude of radiative capture cross-sections. In this paper, we present the methodology and the quantified uncertainties associated with the detection of trace amounts of cobalt and europium, using as an example concrete aggregates. Recent growing interest is in improving structural concrete (increasing its strength but reducing its activation in nuclear power plant environments. Aside from buildings, structural concrete is also used as a biological shield in nuclear power plant that become radioactive after exposure to neutron flux. Due to radiative capture interactions, artificial radionuclides are generated to high enough concentrations that classify concrete as low-level radioactive waste at the time of the plant's decommissioning. Disposal of this concrete adds to the expense of nuclear power plant financing and its construction. Three radionuclides, 60Co, 152Eu, and 154Eu, account for 99 % of total residual radioactivity of nuclear power plant decommissioned concrete. IAEA document RS-G-1.7, Application of the Concepts of Exclusion, Exemption, and Clearance, specifies clearance levels of radionuclides specific activities: a specific activity lower than 0.1 Bqg-1 for 60Co and 152Eu, and 154Eu allows for a concrete to be recycled after decommissioning of the nuclear power plant. Therefore, low-flux neutron activation analysis is used to test the detection limits of trace elements in samples of cement, coarse, and fine concrete aggregates. These samples are irradiated at the University of Utah's 100 kW TRIGA Reactor at

  5. Discovery of a Heparan sulfate 3- o -sulfation specific peeling reaction

    NARCIS (Netherlands)

    Huang, Yu; Mao, Yang; Zong, Chengli; Lin, Cheng; Boons, Geert Jan|info:eu-repo/dai/nl/088245489; Zaia, Joseph

    2015-01-01

    Heparan sulfate (HS) 3-O-sulfation determines the binding specificity of HS/heparin for antithrombin III and plays a key role in herpes simplex virus (HSV) infection. However, the low natural abundance of HS 3-O-sulfation poses a serious challenge for functional studies other than the two cases

  6. 21 CFR 172.822 - Sodium lauryl sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium lauryl sulfate. 172.822 Section 172.822 Food... Multipurpose Additives § 172.822 Sodium lauryl sulfate. The food additive sodium lauryl sulfate may be safely... specifications: (1) It is a mixture of sodium alkyl sulfates consisting chiefly of sodium lauryl sulfate [CH2(CH2...

  7. Different photoluminescent properties of binary and ternary europium chelates doped in PMMA

    International Nuclear Information System (INIS)

    Liu Hongguo; Park, Seongtae; Jang, Kiwan; Zhang Wansong; Seo, Hyo-Jin; Lee, Yong-Ill

    2003-01-01

    Two kinds of europium-β-diketone chelates, binary Eu(DBM) 3 and ternary Eu(DBM) 3 phen were doped in poly(methyl methacrylate) (PMMA). These chelates show very different photoluminescent (PL) behaviors: the hypersensitive 5 D 0 → 7 F 2 emission bands of Eu(DBM) 3 phen change slightly with the molar ratios, while those of Eu(DBM) 3 change obviously and regularly with the molar ratios. The results of the luminescent lifetimes of 5 D 0 levels show that the binary chelate exists as two kinds of species in the doped systems, and the lifetimes and contents of each species change with the molar ratios, while the ternary chelate exists as one kind of species in the doped systems. X-ray diffraction (XRD) patterns of the binary chelate doped systems give some diffraction peaks that are different from those of pure chelate and change with the molar ratios, indicating new kinds of crystal structures formed, and consequently, the first coordination sphere of Eu 3+ ion changes; while those of the ternary chelate doped systems just show amorphous diffraction halos of the host, indicating that the ternary chelate exist in an amorphous state and disperse well in the host. The FTIR spectra of PMMA also change gradually with increasing the molar ratios of the doped two kinds of chelates, and the XRD patterns show that the amorphous halos of PMMA in the doped systems are different from those of pure PMMA and change with the molar ratios, too, suggesting the interaction between the guest and the host

  8. Thermoluminescence of europium-doped zinc oxide exposed to beta particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Iriqui R, J. L.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R. [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83000 Hermosillo, Sonora (Mexico); Castano, V. M., E-mail: jorgeiriqui@gimmunison.com [UNAM, Instituto de Fisica, Centro de Fisica Aplicada y Tecnologia Avanzada, Apdo. Postal 1-1010, 76000 Queretaro, Qro. (Mexico)

    2015-10-15

    Full text: Zn O is a promising material for a range of optoelectronics applications, due to its direct wide band gap (E{sub g} ∼3.3 eV at 300 K) and large exciton binding energy (60 MeV). Its applications include UV light emitters, varistors, surface acoustic wave devices, piezoelectric transducers, and chemical and gas sensing. Rare-earth activation of phosphors has long been seen as an effective process since coupling energy into the rare-earth-ion site, either by ionization, charge exchange or a resonance energy process, results in light production. It is reported that Europium modifies the response thermoluminescence (Tl) for pure zinc oxide, when is irradiated with X-ray, created a peak at 365 degrees C. In this work, Zn O:Eu phosphors were synthesized by a chemical method. Some samples were exposed to beta particle irradiation for doses ranging from 1 up to 100 Gy. Tl response as a function of dose is linear throughout the studied dose range. The glow curve exhibits three maxima, centered at 176, 279 and 340 degrees C. The reusability studies obtained after ten repeated cycles of annealing irradiation readout for the Zn O:Eu shows that the variation in the Tl response is ten percent and tends to stabilization. The results indicate that these new Zn O:Eu phosphors are promising detectors and dosimeters for beta radiation. The structural and morphological characterization was carried out by X-ray diffraction and scanning electron microscopy, respectively. (Author)

  9. Determination of the stability constants of lanthanum, praseodymium, europium, erbium and lutetium complexes with chloride ions

    International Nuclear Information System (INIS)

    Fernandez R, E.

    2008-01-01

    The stability constants of La 3+ , Pr 3+ , Eu 3+ , Er 3+ and Lu 3+ chloride complexes were determined in perchloric acid media using a liquid-liquid extraction method. The dinonyl napthalene sulfonic acid in n-heptane was used as extractant. The lanthanide (Ln) concentrations were measured by a radiochemical (Eu and Lu) and a spectrophotometric (La, Pr, and Er) methods. In the last method, xylenol orange was used for the determinations at ph 6. The stability constants of lanthanum, praseodymium, erbium and lutetium chloride complexes were determined in 2, 3 and 4 M ionic strength and europium in 1, 2 and 3 M, at 303 K. The fitting of experimental data to the equations for the calculation of the stability constants, was carry out considering both one chemical species (LnCl 2+ ) or two chemical species (LnCl 2+ and LnCl 2 + ). The Specific Ion Interaction Theory was applied to the values of log β I Ln , Cl and the first stability constants at zero ionic strength were calculated by extrapolation. The same theory could not be applied to the log β I Ln , 2Cl , due to its low abundance and the values determined for the stability constants were similar. The distribution diagrams of the chemical species were obtained using the program MEDUSA and considering log β I Ln , CI , log β I Ln , 2CI values obtained in this work and the hydrolysis constants taken from the literature. The lanthanide chloride complexes are present in solution at specific conditions of ionic strength, concentration and in the absence of hydrolysis. The log β I Ln , Cl data were related to the charge density and the corresponding equations were obtained. These equations could be used to determine the stability constants along the lanthanide series. (Author)

  10. Two-dimensional high spatial-resolution dosimeter using europium doped potassium chloride: a feasibility study

    International Nuclear Information System (INIS)

    Li, H Harold; Yang, Deshan; Xiao, Zhiyan; Driewer, Joseph P; Han, Zhaohui; Low, Daniel A

    2014-01-01

    Recent research has shown that KCl:Eu 2+  has great potential for use in megavoltage radiation therapy dosimetry because this material exhibits excellent storage performance and is reusable due to strong radiation hardness. This work reports the authors’ attempts to fabricate 2D KCl:Eu 2+  storage phosphor films (SPFs) using both a physical vapor deposition (PVD) method and a tape casting method. X-ray diffraction analysis showed that a 10 µm thick PVD sample was composed of highly crystalline KCl. No additional phases were observed, suggesting that the europium activator had been completely incorporated into the KCl matrix. Photostimulated luminescence and photoluminescence spectra suggested that F (Cl − ) centers were the electron storage centers post x-ray irradiation and that Eu 2+  cations acted as luminescence centers in the photostimulation process. The 150 µm thick casted KCl:Eu 2+  SPF showed sub-millimeter spatial-resolution. Monte Carlo simulations further demonstrated that the admixture of 20% KCl:Eu 2+  and 80% low Z polymer binder exhibited almost no energy-dependence in a 6 MV beam. KCl:Eu 2+  pellet samples showed a large dynamic range from 0.01 cGy to 60 Gy dose-to-water, and saturated at approximately 500 Gy as a result of KCl's intrinsic high radiation hardness. Taken together, this work provides strong evidence that KCl:Eu 2+ -based SPF with associated readout apparatus could result in a novel electronic film system that has all the desirable features associated with classic radiographic film and, importantly, water equivalence and the capability of permanent identification of each detector. (paper)

  11. Europium-labeled epidermal growth factor and neurotensin: novel probes for receptor-binding studies.

    Science.gov (United States)

    Mazor, Ohad; Hillairet de Boisferon, Marc; Lombet, Alain; Gruaz-Guyon, Anne; Gayer, Batya; Skrzydelsky, Delphine; Kohen, Fortune; Forgez, Patricia; Scherz, Avigdor; Rostene, William; Salomon, Yoram

    2002-02-01

    We investigated the possibility of labeling two biologically active peptides, epidermal growth factor (EGF) and neurotensin (NT), with europium (Eu)-diethylenetriaminepentaacetic acid. More specifically, we tested them as probes in studying receptor binding using time-resolved fluorescence of Eu3+. The relatively simple synthesis yields ligands with acceptable binding characteristics similar to isotopically labeled derivatives. The binding affinity (Kd) of labeled Eu-EGF to human A431 epidermal carcinoid cells was 3.6 +/- 1.2 nM, similar to the reported Kd values of EGF, whereas the Kd of Eu-NT to human HT29 colon cancer cells (7.4 +/- 0.5 nM) or to Chinese hamster ovary (CHO) cells transfected with the high-affinity NT receptor (CHO-NT1) were about 10-fold higher than the Kd values of NT. The bioactivity of the Eu-labeled EGF as determined by stimulation of cultured murine D1 hematopoietic cell proliferation was nearly the same as that obtained with native EGF. The maximal stimulation of Ca2+ influx with NT and Eu-NT in CHO-NT1 cells was similar, but the respective K0.5 values were 20 pM and 1 nM, corresponding to differences in the binding affinities previously described. The results of these studies indicate that Eu labeling of peptide hormones and growth factor molecules ranging from 10(3) to 10(5) Da can be conveniently accomplished. Importantly, the Eu-labeled products are stable for approximately 2 years and are completely safe for laboratory use compared to the biohazardous radioligands. Thus, Eu-labeled peptides present an attractive alternative for commonly used radiolabeled ligands in biological studies in general and in receptor assays in particular.

  12. Size-dependent cytotoxicity of europium doped NaYF4 nanoparticles in endothelial cells

    International Nuclear Information System (INIS)

    Chen, Shizhu; Zhang, Cuimiao; Jia, Guang; Duan, Jianlei; Wang, Shuxiang; Zhang, Jinchao

    2014-01-01

    Lanthanide-doped sodium yttrium fluoride (NaYF 4 ) nanoparticles exhibit novel optical properties which make them be widely used in various fields. The extensive applications increase the chance of human exposure to these nanoparticles and thus raise deep concerns regarding their riskiness. In the present study, we have synthesized europium doped NaYF 4 (NaYF 4 :Eu 3+ ) nanoparticles with three diameters and used endothelial cells (ECs) as a cell model to explore the potential toxic effect. The cell viability, cytomembrane integrity, cellular uptake, intracellular localization, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), apoptosis detection, caspase-3 activity and expression of inflammatory gene were studied. The results indicated that these nanoparticles could be uptaken into ECs and decrease the cell viability, induce the intracellular lactate dehydrogenase (LDH) release, increase the ROS level, and decrease the cell MMP in a size-dependent manner. Besides that, the cells were suffered to apoptosis with the caspase-3 activation, and the inflammation specific gene expressions (ICAM1 and VCAM1) were also increased. Our results suggest that the damage pathway may be related to the ROS generation and mitochondrial damage. The results provide novel evidence to elucidate their toxicity mechanisms and may be helpful for more rational applications of these compounds in the future. - Highlights: • NaYF 4 :Eu 3+ nanoparticles with three diameters have been synthesized. • NaYF 4 :Eu 3+ nanoparticles could be uptaken by endothelial cells (ECs). • NaYF 4 :Eu 3+ nanoparticles show a significant cytotoxicity on ECs. • The size of NaYF 4 :Eu 3+ nanoparticles may be important to their toxicology effect

  13. Sorption behavior of europium(III) and curium(III) on the cell surfaces of microorganisms

    International Nuclear Information System (INIS)

    Ozaki, T.; Kimura, T.; Ohnuki, T.; Yoshida, Z.; Gillow, J.B.; Francis, A.J.

    2004-01-01

    We investigated the association of europium(III) and curium(III) with the microorganisms Chlorella vulgaris, Bacillus subtilis, Pseudomonas fluorescens, Halomonas sp., Halobacterium salinarum, and Halobacterium halobium. We determined the kinetics and distribution coefficients (K d ) for Eu(III) and Cm(III) sorption at pH 3-5 by batch experiments, and evaluated the number of water molecules in the inner-sphere (N H 2 O ) and the degree of strength of ligand field (R E/M ) for Eu(III) by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Exudates from C. vulgaris, Halomonas sp., and H. halobium had an affinity for Eu(III) and Cm(III). The log K d of Eu(III) and Cm(III) showed that their sorption was not fully due to the exchange with three protons on the functional groups on cell surfaces. The halophilic microorganisms (Halomonas sp., Halobacterium salinarum, H. halobium) showed almost no pH dependence in log K d , indicating that an exchange with Na + on the functional groups was involved in their sorption. The ΔN H 2 O (= 9 - N H 2 O ) for Eu(III) on C. vulgaris was 1-3, while that for the other microorganisms was over 3, demonstrating that the coordination of Eu(III) with C. vulgaris was predominantly an outer-spherical process. The R E/M for Eu(III) on halophilic microorganisms was 2.5-5, while that for non-halophilic ones was 1-2.5. This finding suggests that the coordination environment of Eu(III) on the halophilic microorganisms is more complicated than that on the other three non-halophilic ones. (orig.)

  14. Sorption behavior of europium(III) and curium(III) on the cell surfaces of microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, T.; Kimura, T.; Ohnuki, T.; Yoshida, Z. [Advanced Science Research Center, Japan Atomic Energy Research Inst., Ibaraki (Japan); Gillow, J.B.; Francis, A.J. [Environmental Sciences Dept., Brookhaven National Lab., Upton, NY (United States)

    2004-07-01

    We investigated the association of europium(III) and curium(III) with the microorganisms Chlorella vulgaris, Bacillus subtilis, Pseudomonas fluorescens, Halomonas sp., Halobacterium salinarum, and Halobacterium halobium. We determined the kinetics and distribution coefficients (K{sub d}) for Eu(III) and Cm(III) sorption at pH 3-5 by batch experiments, and evaluated the number of water molecules in the inner-sphere (N{sub H{sub 2}O}) and the degree of strength of ligand field (R{sub E/M}) for Eu(III) by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Exudates from C. vulgaris, Halomonas sp., and H. halobium had an affinity for Eu(III) and Cm(III). The log K{sub d} of Eu(III) and Cm(III) showed that their sorption was not fully due to the exchange with three protons on the functional groups on cell surfaces. The halophilic microorganisms (Halomonas sp., Halobacterium salinarum, H. halobium) showed almost no pH dependence in log K{sub d}, indicating that an exchange with Na{sup +} on the functional groups was involved in their sorption. The {delta}N{sub H{sub 2}O} (= 9 - N{sub H{sub 2}O}) for Eu(III) on C. vulgaris was 1-3, while that for the other microorganisms was over 3, demonstrating that the coordination of Eu(III) with C. vulgaris was predominantly an outer-spherical process. The R{sub E/M} for Eu(III) on halophilic microorganisms was 2.5-5, while that for non-halophilic ones was 1-2.5. This finding suggests that the coordination environment of Eu(III) on the halophilic microorganisms is more complicated than that on the other three non-halophilic ones. (orig.)

  15. Influence of natural mobile organic matter on europium retention on Bure clay rock

    International Nuclear Information System (INIS)

    Vu-Do, Laurence

    2013-01-01

    Bure clay rock (CR) was chosen as host rock for the French high and intermediate level long lived radioactive waste repository. This choice is mostly explained by the retention ability of the Callovo-Oxfordian rock (COx). Bure clay rock contains natural organic matter (OM) that could have an influence on radionuclide retention. The aim of this work is to assess the influence of natural mobile OM on the retention of Eu on clay rock. Eu was chosen as a chemical model for trivalent actinides contained in vitrified waste. Three organic molecules were studied: suberic, sorbic and tiglic acids, small organic acids identified in COx pore water. All the experiments were carried out in an environment recreating COx water (pH=7.5; I=0.1 mol/L; PCO 2 =10 -2 bar).Clay rock sample characterization showed that the sample used in this work was similar to those previously extracted from the area of interest and that it was necessary to maintain pH at 7.5 to avoid altering the clay rock. The Eu-OM system study indicated that organic acids had no influence on Eu speciation in COx water. The Eu-CR system experimental study confirmed that retention implied sorption on CR (C(Eu)≤6.10 -6 mol/L) and precipitation in COx water (C(Eu)≥6.10 -6 mol/L). Distribution coefficient Rd (quantifying sorption) was estimated at 170 ± 30 L/g. This high value is consistent with literature values obtained on clay rocks. The ternary Eu-OM-CR system study showed a slight increase of sorption in the presence of organic matter. This synergistic effect is very satisfactory in terms of storage security: the presence of small organic acids in clay rock does not question retention properties with respect to europium and trivalent actinides. (author)

  16. Brittlestars contain highly sulfated chondroitin sulfates/dermatan sulfates that promote fibroblast growth factor 2-induced cell signaling.

    Science.gov (United States)

    Ramachandra, Rashmi; Namburi, Ramesh B; Ortega-Martinez, Olga; Shi, Xiaofeng; Zaia, Joseph; Dupont, Sam T; Thorndyke, Michael C; Lindahl, Ulf; Spillmann, Dorothe

    2014-02-01

    Glycosaminoglycans (GAGs) isolated from brittlestars, Echinodermata class Ophiuroidea, were characterized, as part of attempts to understand the evolutionary development of these polysaccharides. A population of chondroitin sulfate/dermatan sulfate (CS/DS) chains with a high overall degree of sulfation and hexuronate epimerization was the major GAG found, whereas heparan sulfate (HS) was below detection level. Enzymatic digestion with different chondroitin lyases revealed exceptionally high proportions of di- and trisulfated CS/DS disaccharides. The latter unit appears much more abundant in one of four individual species of brittlestars, Amphiura filiformis, than reported earlier in other marine invertebrates. The brittlestar CS/DS was further shown to bind to growth factors such as fibroblast growth factor 2 and to promote FGF-stimulated cell signaling in GAG-deficient cell lines in a manner similar to that of heparin. These findings point to a potential biological role for the highly sulfated invertebrate GAGs, similar to those ascribed to HS in vertebrates.

  17. The anaerobic treatment of sulfate containing wastewater

    NARCIS (Netherlands)

    Visser, A.

    1995-01-01


    In the anaerobic treatment of sulfate containing wastewater sulfate reducing bacteria (SRB) will compete with methanogenic- (MB) and acetogenic bacteria (AB) for the available substrates such as hydrogen, acetate, propionate and butyrate. The outcome of this competition will

  18. Influence of the organic coating and calcium ions on the sorption of europium on a silica gel

    International Nuclear Information System (INIS)

    Fleury, C.; Barbot, C.; Pieri, J.; Durand, J.P.; Goudard, F.

    1999-01-01

    Humic substances, ubiquitous polyelectrolyte and polydisperse macromolecules, have a great affinity towards heavy metals and radionuclides. It is important to understand the role of these substances in the migration of contaminants that could be accidentialy released from radioactive waste repositories. The migration of these radionuclides is also governed by different influent parameters like pH, flow rate, ionic strength and presence of competing cations. Lab experiments have been undertaken, they allowed us to confirm that the behaviour and dispersion of europium (used as analog of actinides) depends on the presence of humic acids. If the latter are bound to mineral surfaces, they immobilize the radionuclides. On the other hand, if they are in a suspended form, they are able to decrease the influence of some parameters (pH, flow rate or ionic strength) and stabilize europium onto the mineral surfaces. The presence of calcium cations tends to increase the migration of Eu at lower flow rates and at most alcaline pH. (orig.)

  19. A microwave-assisted solution combustion synthesis to produce europium-doped calcium phosphate nanowhiskers for bioimaging applications.

    Science.gov (United States)

    Wagner, Darcy E; Eisenmann, Kathryn M; Nestor-Kalinoski, Andrea L; Bhaduri, Sarit B

    2013-09-01

    Biocompatible nanoparticles possessing fluorescent properties offer attractive possibilities for multifunctional bioimaging and/or drug and gene delivery applications. Many of the limitations with current imaging systems center on the properties of the optical probes in relation to equipment technical capabilities. Here we introduce a novel high aspect ratio and highly crystalline europium-doped calcium phosphate nanowhisker produced using a simple microwave-assisted solution combustion synthesis method for use as a multifunctional bioimaging probe. X-ray diffraction confirmed the material phase as europium-doped hydroxyapatite. Fluorescence emission and excitation spectra and their corresponding peaks were identified using spectrofluorimetry and validated with fluorescence, confocal and multiphoton microscopy. The nanowhiskers were found to exhibit red and far red wavelength fluorescence under ultraviolet excitation with an optimal peak emission of 696 nm achieved with a 350 nm excitation. Relatively narrow emission bands were observed, which may permit their use in multicolor imaging applications. Confocal and multiphoton microscopy confirmed that the nanoparticles provide sufficient intensity to be utilized in imaging applications. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  20. Investigation of the influence of silver and tin on the luminescence of trivalent europium ions in glass

    International Nuclear Information System (INIS)

    Jimenez, J.A.; Lysenko, S.; Liu, H.; Fachini, E.; Cabrera, C.R.

    2010-01-01

    Europium-doped aluminophosphate glasses prepared by the melt-quenching technique have been studied by photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). The effects of silver and tin doping, and of further thermal processing on Eu 3+ ions luminescence have been assessed. For the glass system containing only europium, Eu 3+ PL observed under UV excitation is suggested to occur through energy transfer from the excited glass host. After silver and tin doping, an enhanced UV excited Eu 3+ PL has been indicated to occur essentially due to radiative energy transfer from isolated Ag + ions and/or two fold-coordinated Sn centers. Since thermal processing of the material leads to a quenching effect on Eu 3+ PL and Ag nanoparticles (NPs) formation due to reduction of silver ions by tin, XPS was employed in order to investigate the possibility for Eu 3+ →Eu 2+ reduction during HT as a potential source of the PL decrease. The data points towards Ag NPs as main responsible for the observed weakening of Eu 3+ PL.

  1. Simple preparation of fluorescent composite films based on cerium and europium doped LaF3 nanoparticles

    Science.gov (United States)

    Secco, Henrique de L.; Ferreira, Fabio F.; Péres, Laura O.

    2018-03-01

    The combination of materials to form hybrids with unique properties, different from those of the isolated components, is a strategy used to prepare functional materials with improved properties aiming to allow their application in specific fields. The doping of lanthanum fluoride with other rare earth elements is used to obtain luminescent particles, which may be useful to the manufacturing of electronic devices' displays and biological markers, for instance. The application of the powder of nanoparticles has limitations in some fields; to overcome this, the powder may be incorporated in a suitable polymeric matrix. In this work, lanthanum fluoride nanoparticles, undoped and doped with cerium and europium, were synthesized through the co-precipitation method in aqueous solution. Aiming the formation of solid state films, composites of nanoparticles in an elastomeric matrix, the nitrile rubber (NBR), were prepared. The flexibility and the transparency of the matrix in the regions of interest are advantages for the application of the luminescent composites. The composites were applied as films using the casting and the spin coating techniques and luminescent materials were obtained in the samples doped with europium and cerium. Scanning electron microscopy images showed an adequate dispersion of the particles in the matrix in both film formation techniques. Aggregates of the particles were detected in the samples which may affect the uniformity of the emission of the composites.

  2. Highly Sensitive Luminescence Assessment of Bile Acid Using a Balofloxacin-Europium(III) Probe in Micellar Medium

    International Nuclear Information System (INIS)

    Cai, Huan; Zhao, Fang; Si, Hailin; Zhang, Shuaishuai; Wang, Chunchun; Qi, Peirong

    2012-01-01

    A novel and simple method of luminescence enhancement effect for the determination of trace amounts of bile acid was proposed. The procedure was based on the luminescence intensity of the balofloxacin-europium(III) complex that could be strongly enhanced by bile acid in the presence of sodium dodecyl benzene sulfonate (SDBS). Under the optimum conditions, the enhanced luminescence intensity of the system exhibited a good linear relationship with the bile acid concentration in the range 5.0 Χ 10 -9 - 7.0 Χ 10 -7 mol L -1 with a detection limit of 1.3 Χ 10 -9 mol L.1 (3σ). The relative standard deviation (RSD) was 1.7% (n = 11) for 5.0 Χ 10 -8 mol L -1 bile acid. The applicability of the method to the determination of bile acid was demonstrated by investigating the effect of potential interferences and by analyzing human serum and urine samples. The possible enhancement mechanism of luminescence intensity in balofloxacin-europium(III)-bile acid-SDBS system was also discussed briefly

  3. Chemical states and electronic properties of the interface between aluminium and a photoluminescent conjugated copolymer containing europium complex

    International Nuclear Information System (INIS)

    Cai, Q.J.; Ling, Q.D.; Li, S.; Zhu, F.R.; Huang, Wei; Kang, E.T.; Neoh, K.G.

    2004-01-01

    The chemical states and electronic properties of the interface between thermally evaporated aluminium and a photoluminescent conjugated copolymer containing 9,9'-dihexylfluorene and europium complex-chelated benzoate units in the main chain (PF6-Eu(dbm) 2 phen) were studied in situ by X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). The changes in C 1s, Eu 3d, N 1s, and Al 2p core-level lineshapes with progressive deposition of aluminium atoms were carefully monitored. Aluminium was found to interact with the conjugated backbone of the copolymer to form the Al carbide, Al-O-C complex, and Al(III)-N chelate at the interface. In addition, the europium ions were reduced to the metallic state by the deposited aluminium atoms, which were oxidized and chelated by the 1,10-phenanthroline ligands (phen). The changes in chemical states at the interface suggest that the intramolecular energy transfer process in this copolymer had been affected. Moreover, aluminium also interacted with the bulk-adsorbed oxygen, which migrates to the surface in response to the deposition of aluminium atoms, to form a layer of metal oxides. On the other hand, the evolution of the UPS spectra suggests that the π-states of the conjugated system were affected and an unfavorable dipole layer was induced by the deposited aluminium atoms

  4. Metabolic Flexibility of Sulfate Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Caroline M. Plugge

    2011-05-01

    Full Text Available Dissimilatory sulfate-reducing prokaryotes (SRB are a very diverse group of anaerobic bacteria that are omnipresent in nature and play an imperative role in the global cycling of carbon and sulfur. In anoxic marine sediments sulfate reduction accounts for up to 50% of the entire organic mineralization in coastal and shelf ecosystems where sulfate diffuses several meters deep into the sediment. As a consequence, SRB would be expected in the sulfate-containing upper sediment layers, whereas methanogenic Archaea would be expected to succeed in the deeper sulfate-depleted layers of the sediment. Where sediments are high in organic matter, sulfate is depleted at shallow sediment depths, and biogenic methane production will occur. In the absence of sulfate, many SRB ferment organic acids and alcohols, producing hydrogen, acetate, and carbon dioxide, and may even rely on hydrogen- and acetate-scavenging methanogens to convert organic compounds to methane. SRB can establish two different life styles, and these can be termed as sulfidogenic and acetogenic, hydrogenogenic metabolism. The advantage of having different metabolic capabilities is that it raises the chance of survival in environments when electron acceptors become depleted. In marine sediments, SRB and methanogens do not compete but rather complement each other in the degradation of organic matter.Also in freshwater ecosystems with sulfate concentrations of only 10-200 μM, sulfate is consumed efficiently within the top several cm of the sediments. Here, many of the δ-Proteobacteria present have the genetic machinery to perform dissimilatory sulfate reduction, yet they have an acetogenic, hydrogenogenic way of life.In this review we evaluate the physiology and metabolic mode of SRB in relation with their environment.

  5. Synthesis and characterization of barium titanate, doped with europium and neodymium; Sintese e caracterizacao de titanato de bario, dopados com europio e neodimio

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Fernanda L.C.; Cabral, Alciney M.; Silva, Ademir O.; Oliveiro, Joao B.L., E-mail: nanda_louise@yahoo.com.br [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil). Instituto de Quimica

    2013-07-01

    This work aims at synthesize and characterize mixed oxides in Barium Titanium matrix in doping with Neodymium and Europium analyzing thermogravimetric curves, characteristic bands at infrared region of the polymer complex, which are intermediates to mixed oxides, and identify the formation thereof, and the crystallinity using XRD analysis.

  6. Stability constants of the Europium complexes with the chloride ions; Constantes de estabilidad de los complejos del europio con los iones cloruro

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez R, M.; Solache R, M.; Rojas H, A. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

    2000-07-01

    The stability constants of lanthanides complexes with chloride ions which were determined at the same ionic force but in different media, are significantly different. It does not exist a systematic study over these stability constants. The purpose of this work is to determine the stability constants of the europium complexes with chloride ions at 303 K, by the solvents extraction method. (Author)

  7. Structural, optical and electrical properties of europium picrate tetraethylene glycol complex as emissive material for OLED

    Energy Technology Data Exchange (ETDEWEB)

    Kusrini, Eny, E-mail: ekusrini@che.ui.ac.id [Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, 16424 Depok (Indonesia); Saleh, Muhammad I.; Adnan, Rohana [School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia); Yulizar, Yoki [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, 16424 Depok (Indonesia); Sha Shiong, Ng; Fun, H.K. [School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Adhha Abdullah, M.A.; Mamat, Mazidah [Department of Chemical Sciences, Faculty of Science and Technology, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu Darul Iman (Malaysia); Za' aba, N.K.; Abd. Majid, W.H. [Solid State Research Laboratory, Department of Physics, Universiti Malaya, 50603 Kuala Lumpur (Malaysia)

    2012-01-15

    A new europium complex [Eu(Pic){sub 2}(H{sub 2}O)(EO4)](Pic).0.75H{sub 2}O was synthesized and used as the emission material for the single layer device structure of ITO/EO4-Eu-Pic/Al, using a spin-coating technique. Study on the optical properties of the [Eu(Pic){sub 2}(H{sub 2}O)(EO4)](Pic).0.75H{sub 2}O complex where EO4=tetraethylene glycol and Pic=picrate anion, had to be undertaken before being applicable to the study of an organic light emitting diode (OLED). The electrical property of an OLED using current-voltage (I-V) measurement was also studied. In complex, the Eu(III) ion was coordinated with the EO4 ligand as a pentadentate mode, one water molecule, and with two Pic anions as bidentate and monodentate modes, forming a nine-coordination number. The photoluminescence (PL) spectra of the crystalline complex in the solid state and its thin film showed a hypersensitive peak at 613.5-614.9 nm that assigned to the {sup 5}D{sub 0}{yields}{sup 7}F{sub 2} transition. A narrow band emission from the thin film EO4-Eu-Pic was obtained. The typical semiconductor I-V curve of device ITO/EO4-Eu-Pic/Al showed the threshold and turn on voltages at 1.08 and 4.6 V, respectively. The energy transfer process from the ligand to the Eu(III) ion was discussed by investigating the excitation and PL characteristics. Effect of the picrate anion on the device performance was also studied. - Highlights: > The [Eu(Pic){sub 2}(H{sub 2}O)(EO4)](Pic).0.75(H{sub 2}O) is crystallized in triclinic with space group P-1. > The complex is applied as a emissive center in single layer device structure of ITO/EO4-Eu-Pic/Al. > The complex displays a red luminescence in both the crystalline complex and its thin film state. > The low turn on voltage of the device (4.6 V), indicating that this material is suitable for OLED. > The roughness and morphology of the thin film affects luminance and electrical properties of OLED.

  8. Studies on effect of europium concentration on the photoemission of laser ablated Y2O3:Eu based nano-phosphors

    International Nuclear Information System (INIS)

    Nissamudeen, K.M.; Krishnan, Renju R.; Rajan, Geo; Gopchandran, K.G.

    2007-01-01

    Full text: Phosphors are essential materials in display applications. Oxide-based phosphors are likely to emerge as the potential choice for the FED red phosphor. Among those oxide-based phosphors, there has been significant research interest in the development of Y 2 O 3 :Eu thin films as one of the most promising oxide based red phosphor systems. Yttrium oxide mixed with europium exhibit strong UV and cathode-ray-excited luminescence that are useful in lamp and display applications. Dielectric Y 2 O 3 film has recently attracted much attention for its potential application as an electric insulation layer in electroluminescent devices and high-density dynamic random access memory gate dielectrics because of its high band gap (5.8 eV) and large dielectric constant (14 to 18). Another important application of Y 2 O 3 has been in luminescent displays as a host material for rare-earth ions, specifically europium, in order to get emission of red light. In the present study thin films were deposited under a vacuum of 10 -6 mbar on fused amorphous quartz substrates using a Q-switched Nd: YAG laser, 532 nm, pulse width 9 n sec, and repetition frequency of 10 Hz, with sintered Y 2 O 3 pellets having different europium concentration as target material. Attempts were made to understand the effect of europium concentration and annealing process on the photoemission properties of the films. A europium concentration of 8 wt% and an annealing temperature of 1173 K were found to be optimum conditions for maximum photoemission. The dependence of structure and morphology of the films on the photoemission intensity are described with XRD patterns and images obtained from AFM and SEM studies

  9. Extraction of uranyl sulfate with primary amine

    International Nuclear Information System (INIS)

    Mrnka, M.; Bizek, V.; Nekovar, P.; Cizevska, S.; Schroetterova, D.

    1984-01-01

    PRIMENE JM-T was used for extraction. Its composition was found to approach the general formula C 21 H 43 NH 2 . It was found that the extraction of uranyl sulfate is lower in case of a higher steady-state concentration of sulfuric acid in the aqueous phase. Extraction is accompanied with coextraction of water. The results obtained showed that uranyl sulfate passes into the organic phase by two mechanisms: extraction with amine sulfate and extraction with free amine. A mathematical description of the process was made based on the obtained results. (E.S.)

  10. Chlorate: a reversible inhibitor of proteoglycan sulfation

    International Nuclear Information System (INIS)

    Humphries, D.E.; Silbert, J.E.

    1988-01-01

    Bovine aorta endothelial cells were cultured in medium containing [ 3 H]glucosamine, [ 35 S]sulfate, and various concentrations of chlorate. Cell growth was not affected by 10 mM chlorate, while 30 mM chlorate had a slight inhibitory effect. Chlorate concentrations greater than 10 mM resulted in significant undersulfation of chondroitin. With 30 mM chlorate, sulfation of chondroitin was reduced to 10% and heparan to 35% of controls, but [ 3 H]glucosamine incorporation on a per cell basis did not appear to be inhibited. Removal of chlorate from the culture medium of cells resulted in the rapid resumption of sulfation

  11. Polymorphism of nickel sulfate hexahydrate

    International Nuclear Information System (INIS)

    Angel, R.J.; Finger, L.W.

    1988-01-01

    NiSO 4 .6H 2 O, M r =262.85; data collections with Mo Kα radiation, λ=0.7093 A, room temperature. Monoclinic polymorph: C2/c, a=9.880(3), b=7.228(2), c=24.130(3) A, β=98.38(2) 0 , V=1704.7(6) A 3 , Z=8, D x =2.05 g cm -3 , μ=25.54 cm -1 , F(000)=1088, R=0.031 (wR=0.038) for 2176 observed reflections. Tetragonal polymorph: P4 1 2 1 2, a=6.780 (1), c=18.285 (2) A, V=840.5 (3) A 3 , Z=4, D x =2.07 g cm -3 , μ=25.81 cm -1 , F(000)=544, R=0.045 (wR=0.050) for 2102 observed reflections. The structure of the tetragonal polymorph originally determined (without H positions) by Beevers and Lipson and refined by O'Connor and Dale and Stadnicka, Glazer and Koralewski, is confirmed by refinement of X-ray diffraction data. The structure of the monoclinic polymorph is confirmed as being isostructural with NiSO 4 .6D 2 O, and a number of other hexahydrate sulfates, e.g. MgSO 4 .6H 2 O. Both structures contain isolated [Ni(H 2 O 6 ] octahedra and [SO 4 ] tetrahedra linked by hydrogen bonding. (orig.)

  12. Sulfate reduction and methanogenesis at a freshwater

    DEFF Research Database (Denmark)

    Iversen, Vibeke Margrethe Nyvang; Andersen, Martin Søgaard; Jakobsen, Rasmus

    The freshwater-seawater interface was studied in a ~9-m thick anaerobic aquifer located in marine sand and gravel with thin peat lenses. Very limited amounts of iron-oxides are present. Consequently, the dominating redox processes are sulfate reduction and methanogenesis, and the groundwater...... is enriched in dissolved sulfide, methane and bicarbonate. Under normal conditions the seawater-freshwater interface is found at a depth of 4 m at the coastline and reaches the bottom of the aquifer 40 m inland. However, occasional flooding of the area occurs, introducing sulfate to the aquifer. Groundwater...... chemistry was studied in a 120 m transect perpendicular to the coast. Cores were taken for radiotracer rate measurements of sulfate reduction and methanogenesis. In the saline part of the aquifer 35 m inland, sulfate reduction was the dominant process with rates of 0.1-10 mM/year. In the freshwater part 100...

  13. Lymphocyte mobilization by dextran sulfate in beagles

    International Nuclear Information System (INIS)

    Ragan, H.A.; Debban, K.H.

    1978-01-01

    Dogs manifesting 239 Pu-induced lymphopenia responded to the lymphocyte-mobilizing agent, dextran sulfate, to a degree similar to that observed in control dogs. No life-threatening increase in prothrombin times or hemorrhagic tendencies were observed

  14. Sulfated cellulose thin films with antithrombin affinity

    Directory of Open Access Journals (Sweden)

    2009-11-01

    Full Text Available Cellulose thin films were chemically modified by in situ sulfation to produce surfaces with anticoagulant characteristics. Two celluloses differing in their degree of polymerization (DP: CEL I (DP 215–240 and CEL II (DP 1300–1400 were tethered to maleic anhydride copolymer (MA layers and subsequently exposed to SO3•NMe3 solutions at elevated temperature. The impact of the resulting sulfation on the physicochemical properties of the cellulose films was investigated with respect to film thickness, atomic composition, wettability and roughness. The sulfation was optimized to gain a maximal surface concentration of sulfate groups. The scavenging of antithrombin (AT by the surfaces was determined to conclude on their potential anticoagulant properties.

  15. COMBINED ALUMINIUM SULFATE/HYDROXIDE PROCESS FOR ...

    African Journals Online (AJOL)

    sulfate, and used for fluoride removal from water by combining with Nalgonda Technique. ... effects on human health and could result in fluorosis. ... [23], nanoscale aluminium oxide hydroxide (AlOOH) [24] and natural zeolite [25], were among.

  16. ROE Wet Sulfate Deposition 2009-2011

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  17. Effect of metakaolin on external sulfate attack

    Energy Technology Data Exchange (ETDEWEB)

    Ramlochan, T.; Thomas, M. [Toronto Univ., Dept. of Civil Engineering, ON (Canada)

    2000-07-01

    The effect of high reactivity metakaolin (HRM) on the sulfate resistance of mortars was studied. Mortar bars with three cements of varying C{sub 3}A content were used for the experiment. After a six month exposure to a 5 per cent solution of sodium sulfate, mortar bars incorporating any level of HRM as a partial replacement for a high-C{sub 3}A was considered 'moderately sulfate resistant'; mortar bars with HRM and a moderate or low C{sub 3}A content as 'high sulfate resistant'. It was also determined that for long term sulfate resistance 15 per cent HRM or more may be required, depending on the C{sub 3}A content. The performance of HRM was found to be significantly influenced by the water-cementitious material ratio, and in turn, by permeability, suggesting that HRM might increase sulfate resistance more by lowering the permeability of the concrete than by any chemical action. 7 refs., 4 tabs., 7 figs.

  18. 340nm UV LED excitation in time-resolved fluorescence system for europium-based immunoassays detection

    DEFF Research Database (Denmark)

    Rodenko, Olga; Fodgaard, Henrik; Tidemand-Lichtenberg, Peter

    2017-01-01

    In immunoassay analyzers for in-vitro diagnostics, Xenon flash lamps have been widely used as excitation light sources. Recent advancements in UV LED technology and its advantages over the flash lamps such as smaller footprint, better wall-plug efficiency, narrow emission spectrum......, and no significant afterglow, have made them attractive light sources for gated detection systems. In this paper, we report on the implementation of a 340 nm UV LED based time-resolved fluorescence system based on europium chelate as a fluorescent marker. The system performance was tested with the immunoassay based...... on the cardiac marker, TnI. The same signal-to-noise ratio as for the flash lamp based system was obtained, operating the LED below specified maximum current. The background counts of the system and its main contributors were measured and analyzed. The background of the system of the LED based unit was improved...

  19. A search for long-lived radionuclides produced by fast-neutron irradiations of copper, silver, europium, terbium, and hafnium

    International Nuclear Information System (INIS)

    Meadows, J.W.; Smith, D.L.; Ikeda, Y.; Konno, C.

    1990-01-01

    Identical sample packets, each containing samples of elemental copper, silver, europium, terbium, and hafnium, as well as titanium, iron and nickel as dosimeters, have been irradiated in three distinct accelerator neutron fields (at Argonne National Laboratory and Los Alamos National Laboratory in the U.S.A., and Japan Atomic Energy Research Institute, Tokai, Japan) as part of an interlaboratory research collaboration to search for the production of long-lived radionuclides for fusion waste disposal applications. This paper is a progress report on this project. To date, we have detected the following activities, and have obtained preliminary experimental cross section values for several of these: Ag-106m,108m,110m; Eu-150m,152g,154; Tb-158,160; and Hf-175,178m2,179m2,181. (author). 11 refs, 1 fig., 4 tabs

  20. Luminescence behavior of the dibenzoyl methane europium(III) complexes in sol-gel derived host materials

    International Nuclear Information System (INIS)

    Wang Feng; Fan Xianping; Wang Minquan; Zhang Xianghua

    2005-01-01

    The luminescence behavior of the dibenzoyl methane europium(III) complexes (Eu(DBM) 3 ) in sol-gel derived host materials have been investigated. The steady-state excitation and emission spectra and the time-resolved spectra of the 1% EuCl 3 and 3% DBM co-doped gel indicated an efficient ligand-to-metal energy transfer. The Eu(DBM) 3 complexes in the gel showed longer 5 D 0 lifetimes in comparison with Eu(DBM) 3 .3H 2 O complexes. The luminescence intensity of the 1% EuCl 3 and 3% DBM co-doped gel decreased continuously with increasing temperature and time of heat treatment, which indicated the gradual decomposition of the Eu(DBM) 3 complexes in the gel during heat treatment

  1. Inorganic ion exchanger based on tin/titanium mixed oxide doped with europium to be used in radioactive waste

    International Nuclear Information System (INIS)

    Paganini, Paula P.; Felinto, Maria Claudia F.C.; Kodaira, Claudia A.; Brito, Hermi F.

    2009-01-01

    This work presents the results of synthesis and characterization of an inorganic ion exchanger based on tin/titanium mixed oxides doped with europium (SnO 2 /TiO 2 :Eu 3+ ) to be used in environmental field. The adsorption study of nickel was realized in this exchanger to recover the nickel metal which is in thorium-nickel alloys used as electrode of discharge lamps. The studied exchanger was synthesized by neutralization of tin chloride (IV) and titanium chloride (III) mixed solution and characterized by thermogravimetric measurement (TG), Differential Scanning Calorimetry (DSC), X-Ray Powder Diffraction (XRD), Infrared Spectroscopy (IR) and Scanning Electron Microscopy (SEM). The adsorption study showed that these inorganic ion exchangers are good materials to recovery nickel with high weight distribution ratios (Dw Ni 2+ ) and percent adsorption. (author)

  2. On the complexing of phosphoric acid vinyl esters with praseodymium (3) and europium (3) nitrates in acetonitrile

    International Nuclear Information System (INIS)

    Goryushko, A.G.; Gololobov, Yu.G.; Boldeskul, A.E.; Oganesyan, A.S.; Yartsev, V.G.

    1990-01-01

    By the methods of electron, IR and PMR spectroscopy interaction of vinyl esters of phosphoric acid with praseodymium (3) and europium (3) nitrates in acetonitrile solutions has been studied. It is shown that the character of metal-ligand interaction is determined by chemical nature of the ligands: for a compound of ionic structure partially covalent bond is formed, and for a compound of betaine structure the interaction has mainly dipole character. Addition of molecule with betaine structure to praseodymium nitrate causes a change in geometry of Pr 3+ close surrounding and increase in its coordination number. The possibility of formation of the complex with metal-ligand ratio equal to 1:3 is shown

  3. The effect of organics on the sorption of strontium, caesium, iodine, neptunium, uranium and europium by glacial sand

    International Nuclear Information System (INIS)

    Haigh, D.; Higgo, J.J.W.; Williams, G.M.; Hooker, P.J.; Ross, C.A.M.; Falck, W.E.; Allen, M.A.; Warwick, P.

    1991-01-01

    This study has been undertaken within the Commission of the European Communities MIRAGE II program on the determination of radionuclides in the geosphere. Preliminary batch sorption experiments have been carried out to study the behaviour of strontium, caesium, iodine, europium and uranium in a glacial sand-groundwater system. The effect of (i) the presence or absence of natural organic material and (ii) the addition of increasing quantities of EDTA or acetate on the distribution ratios was determined. In some cases speciation modelling was used as an aid to designing the experiments and interpreting the results. The aim of this work was to select suitable tracers for use in field experiments at Drigg. Cumbria and the results are intended to aid the design of future experiments rather than to provide a complete analysis of the radionuclide-organic interactions. 11 tabs., 49 refs

  4. Polymorphism of nickel sulfate hexahydrate

    Energy Technology Data Exchange (ETDEWEB)

    Angel, R.J.; Finger, L.W.

    1988-11-15

    NiSO/sub 4/.6H/sub 2/O, M/sub r/=262.85; data collections with Mo K..cap alpha.. radiation, lambda=0.7093 A, room temperature. Monoclinic polymorph: C2/c, a=9.880(3), b=7.228(2), c=24.130(3) A, ..beta..=98.38(2)/sup 0/, V=1704.7(6) A/sup 3/, Z=8, D/sub x/=2.05 g cm/sup -3/, ..mu..=25.54 cm/sup -1/, F(000)=1088, R=0.031 (wR=0.038) for 2176 observed reflections. Tetragonal polymorph: P4/sub 1/2/sub 1/2, a=6.780 (1), c=18.285 (2) A, V=840.5 (3) A/sup 3/, Z=4, D/sub x/=2.07 g cm/sup -3/, ..mu..=25.81 cm/sup -1/, F(000)=544, R=0.045 (wR=0.050) for 2102 observed reflections. The structure of the tetragonal polymorph originally determined (without H positions) by Beevers and Lipson and refined by O'Connor and Dale and Stadnicka, Glazer and Koralewski, is confirmed by refinement of X-ray diffraction data. The structure of the monoclinic polymorph is confirmed as being isostructural with NiSO/sub 4/.6D/sub 2/O, and a number of other hexahydrate sulfates, e.g. MgSO/sub 4/.6H/sub 2/O. Both structures contain isolated (Ni(H/sub 2/O/sub 6/) octahedra and (SO/sub 4/) tetrahedra linked by hydrogen bonding.

  5. Mitochondria Targetable Time-Gated Luminescence Probe for Singlet Oxygen Based on a β-Diketonate-Europium Complex.

    Science.gov (United States)

    Sun, Jingyan; Song, Bo; Ye, Zhiqiang; Yuan, Jingli

    2015-12-21

    Singlet oxygen ((1)O2) plays a key role in the photodynamic therapy (PDT) technique of neoplastic diseases. In this work, by using a 9,10-dimethyl-2-anthryl-containing β-diketone, 1,1,1,2,2-pentafluoro-5-(9',10'-dimethyl-2'-anthryl)-3,5-pentanedione (Hpfdap), as a (1)O2-recognition ligand, a novel β-diketonate-europium(III) complex that can act as a luminescence probe for (1)O2, [Eu(pfdap)3(tpy)] (tpy = 2,2',2″-terpyridine), has been designed and synthesized for the time-gated luminescence detection of (1)O2 in living cells. The complex is weakly luminescent due to the quenching effect of 9,10-dimethyl-2-anthryl groups. After reaction with (1)O2, accompanied by the formation of endoperoxides of 9,10-dimethyl-2-anthryl groups, the luminescence quenching disappears, so that the long-lived luminescence of the europium(III) complex is switched on. The complex showed highly selective luminescence response to (1)O2 with a remarkable luminescence enhancement. Combined with the time-gated luminescence imaging technique, the complex was successfully used as a luminescent probe for the monitoring of the time-dependent generation of (1)O2 in 5-aminolevulinic acid (a PDT drug) loaded HepG2 cells during the photodynamic process. In addition, by coloading the complex and a mitochondrial indicator, Mito-Tracker Green, into HepG2 cells, the specific localization of [Eu(pfdap)3(tpy)] molecules in mitochondria of HepG2 cells was demonstrated by confocal fluorescence imaging measurements.

  6. Efficient red organic electroluminescent devices based on trivalent europium complex obtained by designing the device structure with stepwise energy levels

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Liang; Jiang, Yunlong; Cui, Rongzhen; Li, Yanan; Zhao, Xuesen; Deng, Ruiping; Zhang, Hongjie, E-mail: hongjie@ciac.ac.cn

    2016-02-15

    In this study, we aim to further enhance the electroluminescence (EL) performances of trivalent europium complex Eu(TTA){sub 3}phen (TTA=thenoyltrifluoroacetone and phen=1,10-phenanthroline) by designing the device structure with stepwise energy levels. The widely used bipolar material 2,6-bis(3-(9H-carbazol-9-yl)phenyl)pyridine (26DCzPPy) was chosen as host material, while the doping concentration of Eu(TTA){sub 3}phen was optimized to be 4%. To facilitate the injection and transport of holes, MoO{sub 3} anode modification layer and 4,4′,4′′-Tris(carbazole-9-yl)triphenylamine (TcTa) hole transport layer were inserted in sequence. Efficient pure red emission with suppressed efficiency roll-off was obtained attributed to the reduction of accumulation holes, the broadening of recombination zone, and the improved balance of holes and electrons on Eu(TTA){sub 3}phen molecules. Finally, the device with 3 nm MoO{sub 3} and 5 nm TcTa obtained the highest brightness of 3278 cd/m{sup 2}, current efficiency of 12.45 cd/A, power efficiency of 11.50 lm/W, and external quantum efficiency of 6.60%. Such a device design strategy helps to improve the EL performances of emitters with low-lying energy levels and provides a chance to simplify device fabrication processes. - Highlights: • Electroluminescent performances of europium complex were further improved. • Device structure with stepwise energy levels was designed. • Better carriers' balance was realized by improving the injection and transport of holes. • The selection of bipolar host caused the broadening of recombination zone.

  7. Spectroscopic studies of europium-tetracyclines complexes and their applications in detection of hydrogen peroxide and urea peroxide; Estudos espectroscopicos dos complexos europio-tetraciclinas e suas aplicacoes na detecao de peroxido de hidrogenio e peroxido de ureia

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, Andrea Nastri

    2010-07-01

    In this work were studied the spectroscopic properties of trivalent europium ion complexed with components of tetracycline family, chlorotetracycline, oxytetracycline and metacycline, in the presence of hydrogen peroxide and urea peroxide. Optical parameters were obtained such as absorption, emission, lifetime and calibration curves were constructed for luminescence spectra. Experiments were carried out with both inorganic compounds and europium-tetracyclines complexes in order to verify possible interferences. Studies for glucose determination were also described using europium-tetracyclines complexes as biosensors. Results show that europium tetracyclines complexes emit a narrow band in the visible region and, in the presence of hydrogen peroxide or urea peroxide there is a greater enhancement in their luminescence and lifetime. Thus, europium-tetracyclines complexes studied can be used as biosensors for hydrogen and urea peroxides determination as a low cost and room temperature method. An indirect method for glucose determination was studied by adding glucose oxidase enzyme in europium-tetracyclines complex in the presence of glucose promoting as product hydrogen peroxide. (author)

  8. Oxygen isotopic fractionation during bacterial sulfate reduction

    Science.gov (United States)

    Balci, N.; Turchyn, A. V.; Lyons, T.; Bruchert, V.; Schrag, D. P.; Wall, J.

    2006-12-01

    Sulfur isotope fractionation during bacterial sulfate reduction (BSR) is understood to depend on a variety of environmental parameters, such as sulfate concentration, temperature, cell specific sulfate reduction rates, and the carbon substrate. What controls oxygen isotope fractionation during BSR is less well understood. Some studies have suggested that carbon substrate is important, whereas others concluded that there is a stoichiometric relationship between the fractionations of sulfur and oxygen during BSR. Studies of oxygen fractionation are complicated by isotopic equilibration between sulfur intermediates, particularly sulfite, and water. This process can modify the isotopic composition of the extracellular sulfate pool (δ18OSO4 ). Given this, the challenge is to distinguish between this isotopic equilibration and fractionations linked to the kinetic effects of the intercellular enzymes and the incorporation of sulfate into the bacterial cell. The δ18OSO4 , in concert with the sulfur isotope composition of sulfate (δ34SSO4), could be a powerful tool for understanding the pathways and environmental controls of BSR in natural systems. We will present δ18OSO4 data measured from batch culture growth of 14 different species of sulfate reducing bacteria for which sulfur isotope data were previously published. A general observation is that δ18OSO4 shows little isotopic change (kinetic effect during BSR and/or equilibration between sulfur intermediates and the isotopically light water (~-5‰) of the growth medium. Our present batch culture data do not allow us to convincingly isolate the magnitude and the controlling parameters of the kinetic isotope effect for oxygen. However, ongoing growth of mutant bacteria missing enzymes critical in the different steps of BSR may assist in this mission.

  9. Sulfation of corrosive alkali chlorides by ammonium sulfate in a biomass fired CFB boiler

    Energy Technology Data Exchange (ETDEWEB)

    Brostroem, Markus; Backman, Rainer; Nordin, Anders [Energy Technology and Thermal Process Chemistry, Umeaa University, SE-901 87 Umeaa (Sweden); Kassman, Haakan [Vattenfall Power Consultant AB, Box 1046, SE-611 29 Nykoeping (Sweden); Helgesson, Anna; Berg, Magnus; Andersson, Christer [Vattenfall Research and Development AB, SE-814 26 Aelvkarleby (Sweden)

    2007-12-15

    Biomass and waste derived fuels contain relatively high amounts of alkali and chlorine, but contain very little sulfur. Combustion of such fuels can result in increased deposit formation and superheater corrosion. These problems can be reduced by using a sulfur containing additive, such as ammonium sulfate, which reacts with the alkali chlorides and forms less corrosive sulfates. Ammonium sulfate injection together with a so-called in situ alkali chloride monitor (IACM) is patented and known as ''ChlorOut''. IACM measures the concentrations of alkali chlorides (mainly KCl in biomass combustion) at superheater temperatures. Tests with and without spraying ammonium sulfate into the flue gases have been performed in a 96MW{sub th}/25MW{sub e} circulating fluidized bed (CFB) boiler. The boiler was fired mainly with bark and a chlorine containing waste. KCl concentration was reduced from more than 15 ppm to approximately 2 ppm during injection of ammonium sulfate. Corrosion probe measurements indicated that both deposit formation and material loss due to corrosion were decreased using the additive. Analysis of the deposits showed significantly higher concentration of sulfur and almost no chlorine in the case with ammonium sulfate. Results from impactor measurements supported that KCl was sulfated to potassium sulfate by the additive. (author)

  10. 21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.

    Science.gov (United States)

    2010-04-01

    ... ophthalmic solution. 524.1484e Section 524.1484e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution. (a...

  11. Modeling of sulfation of potassium chloride by ferric sulfate addition during grate-firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Aho, Martti

    2013-01-01

    Potassium chloride, KCl, formed from critical ash-forming elements released during combustion may lead to severe ash deposition and corrosion problems in biomass-fired boilers. Ferric sulfate, Fe2(SO4)3 is an effective additive, which produces sulfur oxides (SO2 and SO3) to convert KCl to the less...... harmful K2SO4. In the present study the decomposition of ferric sulfate is studied in a fast-heating rate thermogravimetric analyzer (TGA), and a kinetic model is proposed to describe the decomposition process. The yields of SO2 and SO3 from ferric sulfate decomposition are investigated in a laboratory......-scale tube reactor. It is revealed that approximately 40% of the sulfur is released as SO3, the remaining fraction being released as SO2. The proposed decomposition model of ferric sulfate is combined with a detailed gas phase kinetic model of KCl sulfation, and a simplified model of K2SO4 condensation...

  12. The electrical and thermal properties of sodium sulfate mixed with lithium sulfate, yttrium sulfate, and silicon dioxide

    International Nuclear Information System (INIS)

    Imanaka, N.; Yamaguchi, Y.; Adachi, G.; Shiokawa, J.

    1986-01-01

    Sodium sulfate mixed with lithium sulfate, yttrium sulfate, and silicon dioxide was prepared. The thermal and electrical properties of its phases were investigated. The Na 2 SO 4 -Li 2 SO 4 -Y 2 (SO 4 ) 3 SiO 2 samples are similar to the Na 2 SO 4 -I phase (a high temperature phase), which is appreciably effective for Na + ionic conduction. Phase transformation was considerably suppressed by mixing. Electromotive force (EMF) was measured, using Na 2 SO 4 -Li 2 SO 4 -Y 2 (SO 4 ) 3 -SiO 2 as a solid electrolyte, by constructing an SO 2 gas concentration cell. The measured EMF's at 823 and 773 K were in fairly good accordance with the calculated EMF's for inlet SO 2 gas concentration between 30 ppm and 1%, and 500 ppm and 0.5% respectively

  13. Heparan sulfate-chondroitin sulfate hybrid proteoglycan of the cell surface and basement membrane of mouse mammary epithelial cells

    International Nuclear Information System (INIS)

    David, G.; Van den Berghe, H.

    1985-01-01

    Chondroitin sulfate represents approximately 15% of the 35 SO 4 -labeled glycosaminoglycans carried by the proteoglycans of the cell surface and of the basolateral secretions of normal mouse mammary epithelial cells in culture. Evidence is provided that these chondroitin sulfate-carrying proteoglycans are hybrid proteoglycans, carrying both chondroitin sulfate and heparan sulfate chains. Complete N-desulfation but limited O-desulfation, by treatment with dimethyl sulfoxide, of the proteoglycans decreased the anionic charge of the chondroitin sulfate-carrying proteoglycans to a greater extent than it decreased the charge of their constituent chondroitin sulfate chains. Partial depolymerization of the heparan sulfate residues of the proteoglycans with nitrous acid or with heparin lyase also reduced the effective molecular radius of the chondroitin sulfate-carrying proteoglycans. The effect of heparin lyase on the chondroitin sulfate-carrying proteoglycans was prevented by treating the proteoglycan fractions with dimethyl sulfoxide, while the effect of nitrous acid on the dimethyl sulfoxide-treated proteoglycans was prevented by acetylation. This occurrence of heparan sulfate-chondroitin sulfate hybrid proteoglycans suggests that the substitution of core proteins by heparan sulfate or chondroitin sulfate chains may not solely be determined by the specific routing of these proteins through distinct chondroitin sulfate and heparan sulfate synthesizing mechanisms. Moreover, regional and temporal changes in pericellular glycosaminoglycan compositions might be due to variable postsynthetic modification of a single gene product

  14. Co-existence of Methanogenesis and Sulfate Reduction with Common Substrates in Sulfate-Rich Estuarine Sediments

    Directory of Open Access Journals (Sweden)

    Michal Sela-Adler

    2017-05-01

    Full Text Available The competition between sulfate reducing bacteria and methanogens over common substrates has been proposed as a critical control for methane production. In this study, we examined the co-existence of methanogenesis and sulfate reduction with shared substrates over a large range of sulfate concentrations and rates of sulfate reduction in estuarine systems, where these processes are the key terminal sink for organic carbon. Incubation experiments were carried out with sediment samples from the sulfate-methane transition zone of the Yarqon (Israel estuary with different substrates and inhibitors along a sulfate concentrations gradient from 1 to 10 mM. The results show that methanogenesis and sulfate reduction can co-exist while the microbes share substrates over the tested range of sulfate concentrations and at sulfate reduction rates up to 680 μmol L-1 day-1. Rates of methanogenesis were two orders of magnitude lower than rates of sulfate reduction in incubations with acetate and lactate, suggesting a higher affinity of sulfate reducing bacteria for the available substrates. The co-existence of both processes was also confirmed by the isotopic signatures of δ34S in the residual sulfate and that of δ13C of methane and dissolved inorganic carbon. Copy numbers of dsrA and mcrA genes supported the dominance of sulfate reduction over methanogenesis, while showing also the ability of methanogens to grow under high sulfate concentration and in the presence of active sulfate reduction.

  15. A Smart Europium-Ruthenium Complex as Anticancer Prodrug: Controllable Drug Release and Real-Time Monitoring under Different Light Excitations.

    Science.gov (United States)

    Li, Hongguang; Xie, Chen; Lan, Rongfeng; Zha, Shuai; Chan, Chi-Fai; Wong, Wing-Yan; Ho, Ka-Lok; Chan, Brandon Dow; Luo, Yuxia; Zhang, Jing-Xiang; Law, Ga-Lai; Tai, William C S; Bünzli, Jean-Claude G; Wong, Ka-Leung

    2017-11-09

    A unique, dual-function, photoactivatable anticancer prodrug, RuEuL, has been tailored that features a ruthenium(II) complex linked to a cyclen-europium chelate via a π-conjugated bridge. Under irradiation at 488 nm, the dark-inactive prodrug undergoes photodissociation, releasing the DNA-damaging ruthenium species. Under evaluation-window irradiation (λ irr = one-photon 350 nm or two-photon 700 nm), the drug delivery process can be quantitatively monitored in real-time because of the long-lived red europium emission. Linear relationships between released drug concentration and ESI-MS or luminescence responses are established. Finally, the efficiency of the new prodrug is demonstrated both in vitro RuEuL anticancer prodrug over some existing ones and open the way for decisive improvements in multipurpose prodrugs.

  16. Gamma-induced radiation polymerization of kaolin composite for sorption of lanthanum, europium and uranium ions from low-grade monazite leachate

    International Nuclear Information System (INIS)

    Metwally, S.S.; Hassan, R.S.; El-Masry, E.H.; Borai, E.H.

    2018-01-01

    Gamma radiation polymerization method was used for the modification of kaolin to produce (poly acrylamide-acrylic acid)-Kaolin (PAM-AA-K). Monazite ore is one of the main resources of uranium and lanthanide elements, therefore, this work focused on sorption of uranium, lanthanum and europium ions from low grade monazite leachate. The removal percent for Eu 3+ , La 3+ and UO 2 2+ are 94.6, 91.6 and 73.4%, respectively. Monolayer capacity of Eu 3+ , La 3+ and UO 2 2+ were found to be 54.64, 45.87 and 37.59 mg/g, respectively. The sorption mechanism of lanthanum and europium ions on PAM-AA-K composite mainly takes place as Ln(OH) 2+ , and for uranium as uranyl ion, UO 2 2+ . (author)

  17. Sulfation in lead-acid batteries

    Science.gov (United States)

    Catherino, Henry A.; Feres, Fred F.; Trinidad, Francisco

    Virtually, all military land vehicle systems use a lead-acid battery to initiate an engine start. The maintainability of these batteries and as a consequence, system readiness, has suffered from a lack of understanding of the reasons for battery failure. Often, the term most commonly heard for explaining the performance degradation of lead-acid batteries is the word, sulfation. Sulfation is a residual term that came into existence during the early days of lead-acid battery development. The usage is part of the legend that persists as a means for interpreting and justifying the eventual performance deterioration and failure of lead-acid batteries. The usage of this term is confined to the greater user community and, over time, has encouraged a myriad of remedies for solving sulfation problems. One can avoid the connotations associated with the all-inclusive word, sulfation by visualizing the general "sulfation" effect in terms of specific mechanistic models. Also, the mechanistic models are essential for properly understanding the operation and making proper use this battery system. It is evident that the better the model, the better the level of understanding.

  18. Immunohistochemical localization of chondroitin sulfate, chondroitin sulfate proteoglycan, heparan sulfate proteoglycan, entactin, and laminin in basement membranes of postnatal developing and adult rat lungs

    DEFF Research Database (Denmark)

    Sannes, P L; Burch, K K; Khosla, J

    1993-01-01

    Histologic preparations of lungs from 1-, 5-, 10-, 18-, and 25-day-old postnatal and adult rats were examined immunohistochemically with antibodies specific against chondroitin sulfate (CS), basement membrane chondroitin sulfate proteoglycan (BM-CSPG), heparan sulfate proteoglycan (HSPG), entactin...

  19. Structural and optical analysis on europium doped AZrO{sub 3} (A=Ba, Ca, Sr) phosphor for display devices application

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Vikas, E-mail: jsvikasdubey@gmail.com [Department of Physics, Bhilai Institute of Technology Raipur, 493661 (India); Tiwari, Neha [Department of Physics, Govt. Model Science College, Jabalpur (India)

    2016-05-06

    Behavior displayed by europium doped AZrO{sub 3} phosphor which was synthesized by solid state reaction method. For synthesis of BaZrO{sub 3}, SrZrO{sub 3} and CaZrO{sub 3} phosphor with fixed concentration of europium ion was calcination at 1000°C and sintered at 1300°C following intermediate grinding. Synthesized sample was characterized by X-ray diffraction analysis and crystallite sized was calculated by Scherer’s formula. From PL spectra of prepared phosphors shows intense emission centred at 612nm (red emission) with high intensity for SrZrO{sub 3}:Eu{sup 3+}. For europium doped BaZrO{sub 3} and CaZrO{sub 3} (613nm) phosphor shows less intense PL spectra as compared to SrZrO{sub 3}:Eu{sup 3+}. The strong emission peak of AZrO{sub 3}:Eu{sup 3+} phosphor is due to forced electric dipole transition of {sup 5}D{sub 0} to {sup 7}F{sub 2} centered at 612 and 613nm. It is characteristic red emission for europium ion. The excitation spectra of AZrO{sub 3}:Eu{sup 3+} phosphor mainly consists of the charge transfer and (CTB) of Eu{sup 3+} located in 200–350 nm centred at 254nm. The present phosphors can act as single host for red light emission in display devices. The CIE coordinates were calculated by Spectrophotometric method using the spectral energy distribution of the AZrO{sub 3}:Eu{sup 3+} sample.

  20. Spectrochemical study of europium and neodymium complexes with 3-(3'-trifluoromethoxy-2',2',3',3'-tetrafluoropropionyl)camphor and bisheterocycles

    International Nuclear Information System (INIS)

    Khomenko, V.S.; Pavich, T.A.; Lozonskij, M.O.; Fialkov, Yu.A.; AN Ukrainskoj SSR, Kiev. Inst. Organicheskoj Khimii)

    1987-01-01

    Methods of mass-spectrometry, luminescent specroscopy and thermogravimetry are used to study decomposition ways, structure and volatility of mixed europium and neodymium complexes with fluorated organic ligands and bisheterocycles. It is shown that complexes containing an oxygen atom in a fluorated ligand elimination of difluorophosgene and tetrafluoroethylene molecules takes place. The addition of a bisheterocyclic ligand to a triligand complex makes the averaged bond in the complex more covalent and increase its volatility

  1. p-Cresyl sulfate and indoxyl sulfate in pediatric patients on chronic dialysis

    Directory of Open Access Journals (Sweden)

    Hye Sun Hyun

    2013-04-01

    Full Text Available &lt;b&gt;Purpose:&lt;/b&gt; Indoxyl sulfate and p- cresyl sulfate are important protein-bound uremic retention solutes whose levels can be partially reduced by renal replacement therapy. These solutes originate from intestinal bacterial protein fermentation and are associated with cardiovascular outcomes and chronic kidney disease progression. The aims of this study were to investigate the levels of indoxyl sulfate and p- cresyl sulfate as well as the effect of probiotics on reducing the levels of uremic toxins in pediatric patients on dialysis. &lt;b&gt;Methods:&lt;/b&gt; We enrolled 20 pediatric patients undergoing chronic dialysis; 16 patients completed the study. The patients underwent a 12-week regimen of VSL#3, a high-concentration probiotic preparation, and the serum levels of indoxyl sulfate and p- cresyl sulfate were measured before treatment and at 4, 8, and 12 weeks after the regimen by using fluorescence liquid chromatography. To assess the normal range of indoxyl sulfate and p- cresyl sulfate we enrolled the 16 children with normal glomerular filtration rate who had visited an outpatient clinic for asymptomatic microscopic hematuria that had been detected by a school screening in August 2011. &lt;b&gt;Results:&lt;/b&gt; The baseline serum levels of indoxyl sulfate and p- cresyl sulfate in the patients on chronic dialysis were significantly higher than those in the children with microscopic hematuria. The baseline serum levels of p- cresyl sulfate in the peritoneal dialysis group were significantly higher than those in the hemodialysis group. There were no significant changes in the levels of these uremic solutes after 12-week VSL#3 treatment in the patients on chronic dialysis. &lt;b&gt;Conclusion:&lt;/b&gt; The levels of the uremic toxins p- cresyl sulfate and indoxyl sulfate are highly elevated in pediatric patients on dialysis, but there was no significant effect by

  2. Sulfated glycopeptide nanostructures for multipotent protein activation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sungsoo S.; Fyrner, Timmy; Chen, Feng; Álvarez, Zaida; Sleep, Eduard; Chun, Danielle S.; Weiner, Joseph A.; Cook, Ralph W.; Freshman, Ryan D.; Schallmo, Michael S.; Katchko, Karina M.; Schneider, Andrew D.; Smith, Justin T.; Yun, Chawon; Singh, Gurmit; Hashmi, Sohaib Z.; McClendon, Mark T.; Yu, Zhilin; Stock, Stuart R.; Hsu, Wellington K.; Hsu, Erin L.; Stupp , Samuel I. (NWU)

    2017-06-19

    Biological systems have evolved to utilize numerous proteins with capacity to bind polysaccharides for the purpose of optimizing their function. A well-known subset of these proteins with binding domains for the highly diverse sulfated polysaccharides are important growth factors involved in biological development and tissue repair. We report here on supramolecular sulfated glycopeptide nanostructures, which display a trisulfated monosaccharide on their surfaces and bind five critical proteins with different polysaccharide-binding domains. Binding does not disrupt the filamentous shape of the nanostructures or their internal β-sheet backbone, but must involve accessible adaptive configurations to interact with such different proteins. The glycopeptide nanostructures amplified signalling of bone morphogenetic protein 2 significantly more than the natural sulfated polysaccharide heparin, and promoted regeneration of bone in the spine with a protein dose that is 100-fold lower than that required in the animal model. These highly bioactive nanostructures may enable many therapies in the future involving proteins.

  3. Formation of the natural sulfate aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Kerminen, V.M.; Hillamo, R.; Maekinen, M.; Virkkula, A.; Maekelae, T.; Pakkanen, T. [Helsinki Univ. (Finland). Dept. of Physics

    1996-12-31

    Anthropogenic sulfate aerosol, together with particles from biomass burning, may significantly reduce the climatic warming due to man-made greenhouse gases. The radiative forcing of aerosol particles is based on their ability to scatter and absorb solar radiation (direct effect), and on their influences on cloud albedos and lifetimes (indirect effect). The direct aerosol effect depends strongly on the size, number and chemical composition of particles, being greatest for particles of 0.1-1 {mu}m in diameter. The indirect aerosol effect is dictated by the number of particles being able to act as cloud condensation nuclei (CCN). For sulfate particles, the minimum CCN size in tropospheric clouds is of the order of 0.05-0.2 {mu}m. To improve aerosol parameterizations in future climate models, it is required that (1) both primary and secondary sources of various particle types will be characterized at a greater accuracy, and (2) the influences of various atmospheric processes on the spatial and temporal distribution of these particles and their physico-chemical properties are known much better than at the present. In estimating the climatic forcing due to the sulfate particles, one of the major problems is to distinguish between sulfur from anthropogenic sources and that of natural origin. Global emissions of biogenic and anthropogenic sulfate pre-cursors are comparable in magnitude, but over regional scales either of these two source types may dominate. The current presentation is devoted to discussing the natural sulfate aerosol, including the formation of sulfur-derived particles in the marine environment, and the use of particulate methanesulfonic acid (MSA) as a tracer for the natural sulfate

  4. Formation of the natural sulfate aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Kerminen, V M; Hillamo, R; Maekinen, M; Virkkula, A; Maekelae, T; Pakkanen, T [Helsinki Univ. (Finland). Dept. of Physics

    1997-12-31

    Anthropogenic sulfate aerosol, together with particles from biomass burning, may significantly reduce the climatic warming due to man-made greenhouse gases. The radiative forcing of aerosol particles is based on their ability to scatter and absorb solar radiation (direct effect), and on their influences on cloud albedos and lifetimes (indirect effect). The direct aerosol effect depends strongly on the size, number and chemical composition of particles, being greatest for particles of 0.1-1 {mu}m in diameter. The indirect aerosol effect is dictated by the number of particles being able to act as cloud condensation nuclei (CCN). For sulfate particles, the minimum CCN size in tropospheric clouds is of the order of 0.05-0.2 {mu}m. To improve aerosol parameterizations in future climate models, it is required that (1) both primary and secondary sources of various particle types will be characterized at a greater accuracy, and (2) the influences of various atmospheric processes on the spatial and temporal distribution of these particles and their physico-chemical properties are known much better than at the present. In estimating the climatic forcing due to the sulfate particles, one of the major problems is to distinguish between sulfur from anthropogenic sources and that of natural origin. Global emissions of biogenic and anthropogenic sulfate pre-cursors are comparable in magnitude, but over regional scales either of these two source types may dominate. The current presentation is devoted to discussing the natural sulfate aerosol, including the formation of sulfur-derived particles in the marine environment, and the use of particulate methanesulfonic acid (MSA) as a tracer for the natural sulfate

  5. Electron tunneling transport across heterojunctions between europium sulfide and indium arsenide

    Science.gov (United States)

    Kallaher, Raymond L.

    This dissertation presents research done on utilizing the ferromagnetic semiconductor europium sulfide (EuS) to inject spin polarized electrons into the non-magnetic semiconductor indium arsenide (InAs). There is great interest in expanding the functionality of modern day electronic circuits by creating devices that depend not only on the flow of charge in the device, but also on the transport of spin through the device. Within this mindset, there is a concerted effort to establish an efficient means of injecting and detecting spin polarized electrons in a two dimensional electron system (2DES) as the first step in developing a spin based field effect transistor. Thus, the research presented in this thesis has focused on the feasibility of using EuS, in direct electrical contact with InAs, as a spin injecting electrode into an InAs 2DES. Doped EuS is a concentrated ferromagnetic semiconductor, whose conduction band undergoes a giant Zeeman splitting when the material becomes ferromagnetic. The concomitant difference in energy between the spin-up and spin-down energy bands makes the itinerant electrons in EuS highly spin polarized. Thus, in principle, EuS is a good candidate to be used as an injector of spin polarized electrons into non-magnetic materials. In addition, the ability to adjust the conductivity of EuS by varying the doping level in the material makes EuS particularly suited for injecting spins into non-magnetic semiconductors and 2DES. For this research, thin films of EuS have been grown via e-beam evaporation of EuS powder. This growth technique produces EuS films that are sulfur deficient; these sulfur vacancies act as intrinsic electron donors and the resulting EuS films behave like heavily doped ferromagnetic semiconductors. The growth parameters and deposition procedures were varied and optimized in order to fabricate films that have minimal crystalline defects. Various properties and characteristics of these EuS films were measured and compared to

  6. Inhibition of sulfate reduction in paddy soils

    Energy Technology Data Exchange (ETDEWEB)

    Vamos, R

    1958-12-13

    The hydrogen sulfide formed in waterlogged soils is a serious problem in rice cultivation. It inhibits the uptake of water and nutrients and may even cause root-rot. Results can best be obtained by preventing the formation of hydrogen sulfide. It is formed mainly by reduction of sulfate for which the cellulose-butyric acid fermentation provides the hydrogen source. Addition of ammonium or potassium nitrate prevents the formation of H/sub 2/S. The hydrogen produced by butyric acid fermentation is used to reduce nitrate and consequently cannot be utilized by the sulfate-reducing bacteria as a source of energy. 6 references.

  7. Measurement of chemical leaching potential of sulfate from landfill disposed sulfate containing wastes.

    Science.gov (United States)

    Sun, Wenjie; Barlaz, Morton A

    2015-02-01

    A number of sulfate-containing wastes are disposed in municipal solid wastes (MSW) landfills including residues from coal, wood, and MSW combustion, and construction and demolition (C&D) waste. Under anaerobic conditions that dominate landfills, the sulfate can be reduced to hydrogen sulfide which is problematic for several reasons including its low odor threshold, toxicity, and corrosive nature. The overall objective of this study was to evaluate existing protocols for the quantification of total leachable sulfate from solid samples and to compare their effectiveness and efficiency with a new protocol described in this study. Methods compared include two existing acid extraction protocols commonly used in the U.S., a pH neutral protocol that requires multiple changes of the leaching solution, and a new acid extraction method. The new acid extraction method was shown to be simple and effective to measure the leaching potential of sulfate from a range of landfill disposed sulfate-containing wastes. However, the acid extraction methods do not distinguish between sulfate and other forms of sulfur and are thus most useful when sulfate is the only form of sulfur present. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Sulfates on Mars: A systematic Raman spectroscopic study of hydration states of magnesium sulfates

    Science.gov (United States)

    Wang, A.; Freeman, J.J.; Jolliff, B.L.; Chou, I.-Ming

    2006-01-01

    The martian orbital and landed surface missions, OMEGA on Mar Express and the two Mars Explorations Rovers, respectively, have yielded evidence pointing to the presence of magnesium sulfates on the martian surface. In situ identification of the hydration states of magnesium sulfates, as well as the hydration states of other Ca- and Fe- sulfates, will be crucial in future landed missions on Mars in order to advance our knowledge of the hydrologic history of Mars as well as the potential for hosting life on Mars. Raman spectroscopy is a technique well-suited for landed missions on the martian surface. In this paper, we report a systematic study of the Raman spectra of the hydrates of magnesium sulfate. Characteristic and distinct Raman spectral patterns were observed for each of the 11 distinct hydrates of magnesium sulfates, crystalline and non-crystalline. The unique Raman spectral features along with the general tendency of the shift of the position of the sulfate ??1 band towards higher wavenumbers with a decrease in the degree of hydration allow in situ identification of these hydrated magnesium sulfates from the raw Raman spectra of mixtures. Using these Raman spectral features, we have started the study of the stability field of hydrated magnesium sulfates and the pathways of their transformations at various temperature and relative humidity conditions. In particular we report on the Raman spectrum of an amorphous hydrate of magnesium sulfate (MgSO4??2H2O) that may have specific relevance for the martian surface. ?? 2006 Elsevier Inc. All rights reserved.

  9. Novel processes for anaerobic sulfate production from elemental sulfur by sulfate-reducing bacteria

    Science.gov (United States)

    Lovley, D.R.; Phillips, E.J.P.

    1994-01-01

    Sulfate reducers and related organisms which had previously been found to reduce Fe(III) with H2 or organic electron donors oxidized S0 to sulfate when Mn(IV) was provided as an electron acceptor. Organisms catalyzing this reaction in washed cell suspensions included Desulfovibrio desulfuricans, Desulfomicrobium baculatum. Desulfobacterium autotrophicum, Desulfuromonas acetoxidans, and Geobacter metallireducens. These organisms produced little or no sulfate from S0 with Fe(III) as a potential electron acceptor or in the absence of an electron acceptor. In detailed studies with Desulfovibrio desulfuricans, the stoichiometry of sulfate and Mn(II) production was consistent with the reaction S0 + 3 MnO2 + 4H+ ???SO42- + 3Mn(II) + 2H2O. None of the organisms evaluated could be grown with S0 as the sole electron donor and Mn(IV) as the electron acceptor. In contrast to the other sulfate reducers evaluated, Desulfobulbus propionicus produced sulfate from S0 in the absence of an electron acceptor and Fe(III) oxide stimulated sulfate production. Sulfide also accumulated in the absence of Mn(IV) or Fe(III). The stoichiometry of sulfate and sulfide production indicated that Desulfobulbus propionicus disproportionates S0 as follows: 4S0 + 4H2O???SO42- + 3HS- + 5 H+. Growth of Desulfobulbus propionicus with S0 as the electron donor and Fe(III) as a sulfide sink and/or electron acceptor was very slow. The S0 oxidation coupled to Mn(IV) reduction described here provides a potential explanation for the Mn(IV)-dependent sulfate production that previous studies have observed in anoxic marine sediments. Desulfobulbus propionicus is the first example of a pure culture known to disproportionate S0.

  10. Activation and transfer of sulfate in biological systems (1960); Activation biologique du sulfate et son transfert (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Chapeville, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    It examines in this review the successive stages of active sulfate formation and its role in biological synthesis of sulfuric esters. The possible role of active sulfate as intermediary in sulfate reduction is also discussed. (author) [French] On examine dans cette etude les stades successifs de la mise en evidence du sulfate actif, son role dans la formation des esters sulfuriques de natures diverses, ainsi que sa participation eventuelle comme intermediaire au cours de la reduction du sulfate. On decrit aussi un procede de preparation du systeme biologique, generateur du sulfate actif et une methode de synthese chimique. (auteur)

  11. Highly luminescent pure-red-emitting fluorinated β-diketonate europium(III) complex for full solution-processed OLEDs

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Joao P. [CEMDRX, Physics Department, Universidade de Coimbra, Rua Larga, Coimbra P-3004-516 (Portugal); Serviço de Medicina Nuclear, SESARAM E.P.E., Avenida Luís de Camões 57, Funchal 9004-514, Madeira (Portugal); Martín-Ramos, Pablo [CEMDRX, Physics Department, Universidade de Coimbra, Rua Larga, Coimbra P-3004-516 (Portugal); Higher Technical School of Telecommunications Engineering, Universidad de Valladolid, Campus Miguel Delibes, Paseo Belén 15, Valladolid 47011 (Spain); Coya, Carmen, E-mail: carmen.coya@urjc.es [Escuela Superior de Ciencias Experimentales y Tecnología (ESCET), Universidad Rey Juan Carlos, Madrid 28933 (Spain); Silva, Manuela Ramos [CEMDRX, Physics Department, Universidade de Coimbra, Rua Larga, Coimbra P-3004-516 (Portugal); Eusebio, M. Ermelinda S. [Chemistry Department, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, Coimbra P-3004-535 (Portugal); Andrés, Alicia de [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (CSIC), Cantoblanco, Madrid 28049 (Spain); Álvarez, Ángel L. [Escuela Superior de Ciencias Experimentales y Tecnología (ESCET), Universidad Rey Juan Carlos, Madrid 28933 (Spain); Martín-Gil, Jesús [Advanced Materials Laboratory, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 44, Palencia 34004 (Spain)

    2015-03-15

    Current manufacturing technologies for OLEDs involve the use of expensive high vacuum techniques and call for thermal stability requirements which are not fulfilled by many materials. These problems disappear when the OLED films are deposited directly from solution. In this study, we have designed, synthesized and characterized a novel octacoordinated complex, Tris(1-(4-chlorophenyl)-4,4,4-trifluoro-1, 3-butanedionate)mono(bathophenanthroline) europium(III), to be used as a “complex-only” emissive layer in wet-processed OLEDs. Upon excitation in the UV region, very efficient energy transfer from the ligands to Eu{sup 3+} takes place, giving rise to intense red emission with very high monochromaticity (R=19), both in powder and as a thin film. The decay times of 754 µs (powder) and 620 µs (thin film) are comparable to those of the most efficient Eu{sup 3+} β-diketonate complexes reported to date. The same energy transfer leading to saturated red and narrow emission is also observed in the OLED device (glass/ITO/PEDOT:PSS/[Eu(cbtfa){sub 3}(bath)]/Ca/Al) when biased at >5.2 V. Its high quantum efficiency (∼60%), good thermal stability up to 200 °C and adequate thin film forming properties make this material a promising chromophore for cost-effective OLEDs. - Highlights: • A highly fluorinated europium(III) octacoordinated complex, [Eu(cbtfa)3(bath)], has been synthesized and its structure elucidated by single crystal X-ray diffraction. • The chosen coordination environment is well-suited for sensitizing the luminescence of the Eu{sup 3+} ion, achieving very efficient energy transfer from the organic ligands (excited in the UV region) to the rare earth ion, leading to highly efficient (Q∼60% in crystalline powder and Q∼50% in thin film) and saturated red photoluminescence. • The material has also been integrated into a single active layer, full solution-processed OLED, with ITO/PEDOT:PSS/[Eu(cbtfa)3(bath)]/ Ca/Al structure.

  12. Simultaneous analysis of free and humic acid complexed europium and gadolinium species by CE-ICP-MS

    International Nuclear Information System (INIS)

    Kautenburger, R.; Nowotka, K.; Beck, H.P.

    2005-01-01

    Full text of publication follows: For the long-term safety assessment of waste repositories, detailed information about geo-chemical behaviour of radioactive and toxic metal ions under environmental conditions (geological matrix and aquifer systems) is necessary. It includes knowledge about the mechanism of relevant geochemical reactions, as well as thermodynamic and kinetic data. Several previous studies have shown that humic acid can play an important role in the immobilisation or mobilization of metal ions due to complexation and colloid formation. In this project we investigate the complexation behaviour of humic acid (purified Aldrich humic acid) and its influence on the migration of the lanthanides europium and gadolinium (homologues of the actinides americium and curium) in the the ternary system consisting of these heavy metals, humic acid and kaolinite (KGa-1b) as geological model system under conditions close to nature. Capillary electrophoresis (CE, Beckman Coulter P/ACE MDQ), with its excellent separation performance, was coupled to Inductively Coupled Plasma Mass Spectrometry (ICP-MS, VG Elemental Plasma Quad 3) to obtain a high sensitivity for the determination of the rare earth elements europium (Eu 3+ ) and gadolinium (Gd 3+ ) and their complexes with humic acid. Additionally, the used humic acid was halogenated with iodine as ICP-MS marker. A fused-silica capillary was flexibly fitted into a MicroMist 50 μl nebulizer with a Cinnabar cyclonic spray chamber. The chamber was chilled to a temperature of 4 deg. C for best sensitivity. 200 ppb of caesium were added to the CE separation buffer to observe the capillary flow. A make-up fluid including 4 ppb Ho as an internal standard was combined with the flow from the capillary within the interface to obtain a fluid throughput high enough to maintain a continuous nebulization. Very low detection limits were achieved, 100 ppt for 153 Eu and 125 ppt for 158 Gd. With this optimized CE-ICP-MS coupling

  13. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS ...

    African Journals Online (AJOL)

    Four strains of eri, Samia cynthia ricini Lepidoptera: Saturniidae that can be identified morphologically and maintained at North East Institute of Science and Technology, Jorhat were characterized based on their protein profile by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and DNA by random ...

  14. Determination of boron spectrophotometry in thorium sulfate

    International Nuclear Information System (INIS)

    Federgrun, L.; Abrao, A.

    1976-01-01

    A procedure for the determination of microquantities of boron in nuclear grade thorium sulfate is described. The method is based on the extraction of BF - 4 ion associated to monomethylthionine (MMT) in 1,2 - dichloroethane. The extraction of the colored BF - 4 -MMT complex does not allow the presence of sulfuric and phosphoric acids; other anions interfere seriously. This fact makes the dissolution of the thorium sulfate impracticable, since it is insoluble in both acids. On the other hand, the quantitative separation of thorium is mandatory, to avoid the precipitation of ThF 4 . To overcome this difficulty, the thorium sulfate is dissolved using a strong cationic ion exchanger, Th 4+ being totally retained into the resin. Boron is then analysed in the effluent. The procedure allows the determination of 0.2 to 10.0 microgramas of B, with a maximum error of 10%. Thorium sulfate samples with contents of 0.2 to 2.0μg B/gTh have being analysed [pt

  15. Sulfate reducing potential in an estuarine beach

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Chandramohan, D.

    Sulfate reducing bacteria (SRB) and their activity (SRA) together with total anaerobic and aerobic bacterial flora were estimated during July 1982-April 1983 and July-August 1984 from 1, 3 and 5 cm depths using core samples. The average number (no...

  16. Sulfate-reducing bacteria in anaerobic bioreactors

    NARCIS (Netherlands)

    Oude Elferink, S.J.W.H.

    1998-01-01

    The treatment of industrial wastewaters containing high amounts of easily degradable organic compounds in anaerobic bioreactors is a well-established process. Similarly, wastewaters which in addition to organic compounds also contain sulfate can be treated in this way. For a long time, the

  17. Mechanisms and Effectivity of Sulfate Reducing Bioreactors ...

    Science.gov (United States)

    Mining-influenced water (MIW) is the main environmental challenges associated with the mining industry. Passive MIW remediation can be achieved through microbial activity in sulfate-reducing bioreactors (SRBRs), but their actual removal rates depend on different factors, one of which is the substrate composition. Chitinous materials have demonstrated high metal removal rates, particularly for the two recalcitrant MIW contaminants Zn and Mn, but their removal mechanisms need further study. We studied Cd, Fe, Zn, and Mn removal in bioactive and abiotic SRBRs to elucidate the metal removal mechanisms and the differences in metal and sulfate removal rates using a chitinous material as substrate. We found that sulfate-reducing bacteria are effective in increasing metal and sulfate removal rates and duration of operation in SRBRs, and that the main mechanism involved was metal precipitation as sulfides. The solid residues provided evidence of the presence of sulfides in the bioactive column, more specifically ZnS, according to XPS analysis. The feasibility of passive treatments with a chitinous substrate could be an important option for MIW remediation. Mining influenced water (MIW) remediation is still one of the top priorities for the agency because it addresses the most important environmental problem associated with the mining industry and that affects thousands of communities in the U.S. and worldwide. In this paper, the MIW bioremediation mechanisms are studied

  18. Controlling sulfate attack in Mississippi Department of Transportation structures.

    Science.gov (United States)

    2010-08-01

    At some construction sites in Mississippi, deterioration of concrete in contact with the surrounding soil could be related to the high sulfate content of the adjacent soils. Studies dating to 1966 have documented sulfate attack associated with specif...

  19. Transmission spectra study of sulfate substituted potassium dihydrogen phosphate

    KAUST Repository

    LI, LIANG; Zhang, Jianqin; Sun, Xun; Zhang, Qiang; Zhao, Xian; Zhang, Xixiang

    2013-01-01

    Potassium dihydrogen phosphate (KDP) crystals with different amounts of sulfate concentration were grown and the transmittance spectrum was studied. A crystal with high sulfate replacement density exhibits heavy absorption property

  20. Controlling sulfate attack in Mississippi Department of Transportation structures

    Science.gov (United States)

    2010-08-01

    At some construction sites in Mississippi, deterioration of concrete in contact with the surrounding soil could be related to the high sulfate content of the adjacent soils. Studies dating to 1966 have documented sulfate attack associated with sp...

  1. Bone sialoprotein II synthesized by cultured osteoblasts contains tyrosine sulfate

    International Nuclear Information System (INIS)

    Ecarot-Charrier, B.; Bouchard, F.; Delloye, C.

    1989-01-01

    Isolated mouse osteoblasts that retain their osteogenic activity in culture were incubated with [35S] sulfate. Two radiolabeled proteins, in addition to proteoglycans, were extracted from the calcified matrix of osteoblast cultures. All the sulfate label in both proteins was in the form of tyrosine sulfate as assessed by amino acid analysis and thin layer chromatography following alkaline hydrolysis. The elution behavior on DEAE-Sephacel of the major sulfated protein and the apparent Mr on sodium dodecyl sulfate gels were characteristic of bone sialoprotein II extracted from rat. This protein was shown to cross-react with an antiserum raised against bovine bone sialoprotein II, indicating that bone sialoprotein II synthesized by cultured mouse osteoblasts is a tyrosine-sulfated protein. The minor sulfated protein was tentatively identified as bone sialoprotein I or osteopontin based on its elution properties on DEAE-Sephacel and anomalous behavior on sodium dodecyl sulfate gels similar to those reported for rat bone sialoprotein I

  2. Galactose 6-sulfate sulfatase activity in Morquio syndrome

    International Nuclear Information System (INIS)

    Yutaka, T.; Okada, S.; Kato, T.; Inui, K.; Yabuuhi, H.

    1982-01-01

    The authors have prepared a new substrate, o-β-D-sulfo-galactosyl-(1-4)-β-D-6-sulfo-2-acetamido-2-deoxyglucosyl-(1-4)-D-[1- 3 H]galactitol, from shark cartilage keratan sulfate, for the assay of galactose 6-sulfate sulfatase activity. Using this substrate, they found there was a striking deficiency of galactose 6-sulfate sulfatase activity, in addition to the known deficiency of N-acetylgalactosamine 6-sulfate sulfatase, in the cultured skin fibroblasts of patients with Morquio syndrome. Their results could be explained by the hypothesis that accumulation of keratan sulfate and chondroitin 6-sulfate in Morquio syndrome is due to a deficiency of galactose 6-sulfate sulfatase and N-acetylgalactosamine 6-sulfate sulfatase activity, which are necessary for the degradation of these two mucopolysaccharides. (Auth.)

  3. Galactose 6-sulfate sulfatase activity in Morquio syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yutaka, T.; Okada, S.; Kato, T.; Inui, K.; Yabuuhi, H. (Osaka Univ. (Japan). Faculty of Medicine)

    1982-07-01

    The authors have prepared a new substrate, o-..beta..-D-sulfo-galactosyl-(1-4)-..beta..-D-6-sulfo-2-acetamido-2-deoxyglucosyl-(1-4)-D-(1-/sup 3/H)galactitol, from shark cartilage keratan sulfate, for the assay of galactose 6-sulfate sulfatase activity. Using this substrate, they found there was a striking deficiency of galactose 6-sulfate sulfatase activity, in addition to the known deficiency of N-acetylgalactosamine 6-sulfate sulfatase, in the cultured skin fibroblasts of patients with Morquio syndrome. Their results could be explained by the hypothesis that accumulation of keratan sulfate and chondroitin 6-sulfate in Morquio syndrome is due to a deficiency of galactose 6-sulfate sulfatase and N-acetylgalactosamine 6-sulfate sulfatase activity, which are necessary for the degradation of these two mucopolysaccharides.

  4. Temperature effects on the interaction mechanisms between the europium (III) and uranyl ions and zirconium diphosphate; Effets de la temperature sur les mecanismes d'interaction entre les ions europium (3) et uranyle et le diphosphate de zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Finck, N

    2006-10-15

    Temperature should remain higher than 25 C in the near field environment of a nuclear waste repository for thousands years. In this context, the aim of this work is to study the temperature influence on the interaction mechanisms between europium (III) and uranyl ions and zirconium diphosphate, as well as the influence of a complexing medium (nitrate) on the sorption of the lanthanide. The experimental definition of the equilibria was achieved by combining a structural investigation with the macroscopic sorption data. Surface complexes were characterized at all temperatures (25 C to 90 C) by TRLFS experiments carried out on dry and in situ samples using an oven. This characterization was completed by XPS experiments carried out at 25 C on samples prepared at 25 C and 90 C. The reaction constants (surface hydration and cations sorption) were obtained by simulating the experimental data with the constant capacitance surface complexation model. The reaction constants temperature dependency allowed one to characterize thermodynamically the different reactions by application of the van't Hoff relation. The validity of this law was tested by performing microcalorimetric measurements of the sorption heat for both cations. (author)

  5. Isolation of a sulfate reducing bacterium and its application in sulfate ...

    African Journals Online (AJOL)

    The results show that the effect of C. freundii in removing sulfate was best when the temperature was 32°C, pH was 7.0, COD/SO42- was 5.0 and the initial SO42- concentration was 1500 mg/L. Also, the SRB was inoculated onto an up-flow anaerobic sludge bed (UASB) to remove sulfate in actual tannery wastewater.

  6. Comparison of magnesium sulfate and sodium sulfate for removal of water from pesticide extracts of foods.

    Science.gov (United States)

    Schenck, Frank J; Callery, Patrick; Gannett, Peter M; Daft, Jonathan R; Lehotay, Steven J

    2002-01-01

    Water-miscible solvents, such as acetone and acetonitrile, effectively extract both polar and nonpolar pesticide residues from nonfatty foods. The addition of sodium chloride to the resulting acetonitrile-water or acetone-water extract (salting out) results in the separation of the water from the organic solvent. However, the organic solvent layer (pesticide extract) still contains some residual water, which can adversely affect separation procedures that follow, such as solid-phase extraction and/or gas chromatography. Drying agents, such as sodium sulfate or magnesium sulfate, are used to remove the water from the organic extracts. In the present study, we used nuclear magnetic resonance spectroscopy to study the composition of the phases resulting from salting out and to compare the effectiveness of sodium sulfate and magnesium sulfate as drying agents. The study showed that considerable amounts of water remained in the organic phase after phase separation. Sodium sulfate was a relatively ineffective drying agent, removing little or no residual water from the organic solvent. Magnesium sulfate proved to be a much more effective drying agent.

  7. Effects of added dopants on various triboluminescent properties of europium dibenzoylmethide triethylammonium (EuD4TEA)

    Science.gov (United States)

    Owens, Constance; Fontenot, Ross S.; Bhat, Kamala N.; Aggarwal, Mohan D.

    2014-03-01

    A triboluminescent (TL) material is one that emits light upon pressure, impact, friction, or mechanical shock. TL materials are desirable for investigation because they have the potential to be used as the active element for smart impact sensors. While the material europium dibenzoylmethide triethylammonium (EuD4TEA) produces a TL emission yield that can be observed by the naked eye, it is still not sufficiently bright for use in smart sensor devices. Previous studies have shown that additional materials can be combined with EuD4TEA in order to improve the TL emission yield. In this paper, we discuss the effects of doping on EuD4TEA at different concentrations with a variety of materials on the TL emission yield and decay times. The dopants that were used in this study were nicotine, dibutyl phosphate (DBP), and magnesium. We also discuss both the effects of pH on EuD4TEA, and the doping effects on impact energy. For testing triboluminescent properties, we use a custom-built drop tower that generates triboluminescence by fracturing compounds through impact. Collected data is analyzed using specially written LabVIEW programs.

  8. 340nm UV LED excitation in time-resolved fluorescence system for europium-based immunoassays detection

    Science.gov (United States)

    Rodenko, Olga; Fodgaard, Henrik; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    2017-02-01

    In immunoassay analyzers for in-vitro diagnostics, Xenon flash lamps have been widely used as excitation light sources. Recent advancements in UV LED technology and its advantages over the flash lamps such as smaller footprint, better wall-plug efficiency, narrow emission spectrum, and no significant afterglow, have made them attractive light sources for gated detection systems. In this paper, we report on the implementation of a 340 nm UV LED based time-resolved fluorescence system based on europium chelate as a fluorescent marker. The system performance was tested with the immunoassay based on the cardiac marker, TnI. The same signal-to-noise ratio as for the flash lamp based system was obtained, operating the LED below specified maximum current. The background counts of the system and its main contributors were measured and analyzed. The background of the system of the LED based unit was improved by 39% compared to that of the Xenon flash lamp based unit, due to the LEDs narrower emission spectrum and longer pulse width. Key parameters of the LED system are discussed to further optimize the signal-to-noise ratio and signal-to-background, and hence the sensitivity of the instrument.

  9. Influence of ligands on the photoluminescent properties of Eu3+ in europium β-diketonate/PMMA-doped systems

    International Nuclear Information System (INIS)

    Liu, H.-G.; Park, Seongtae; Jang, Kiwan; Feng, X.-S.; Kim, Changdae; Seo, H.-J.; Lee, Y.-I.

    2004-01-01

    Three kinds of europium β-diketonates Eu(DBM) 3 , Eu(BA) 3 and Eu(TTA) 3 (DBM: Dibenzoylmethane; BA: 1-Benzoylacetone; TTA: Thenoyltrifluoroacetone) were doped in poly(methyl methacrylate) (PMMA) matrix. The doped systems were studied by using photoluminescent (PL) spectroscopy, emission decay experiments and X-ray diffractometry. Eu(III) ions in the doped Eu(DBM) 3 /PMMA systems have two distinct symmetric sites and the emission band changes greatly with the compositions. Eu(III) in the Eu(BA) 3 /PMMA systems gives only one symmetric site in the doped systems and the emission band changes slightly with the compositions. Although two distinct symmetric sites of Eu(III) can be distinguished in the doped systems of Eu(TTA) 3 /PMMA, the two sites have similar 5 D 0 lifetimes and the luminescent spectra almost do not change with the compositions. XRD reveals that crystallites were formed in the doped Eu(DBM) 3 /PMMA systems that have different crystalline structure from that of the chelate, and Eu(BA) 3 and Eu(TTA) 3 exist in amorphous state in the doped systems. The difference between the PL properties and structures of the doped systems for the three kinds of chelates should be attributed to different interactions between the chelate molecules and between the chelate and PMMA

  10. Synthesis of red fluorescent graphene quantum dot-europium complex composites as a viable bio imaging platform

    International Nuclear Information System (INIS)

    Liu, Yanting; Fan, Louzhen; Zhou, Shixin; Fan, Hong

    2016-01-01

    We have prepared graphene quantum dot-europium(III) complex composites by noncovalently connecting chelating ligands dibenzoylmethane (DBM) and 1,10-phenanthroline (Phen) with graphene quantum dots (GQDs) first, followed by coordination to Eu(III). The resulting composites are well water-soluble and display red fluorescence of high color purity. The composites were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. Aqueous solutions of the composites under 365 nm excitation display fluorescence with a peak at 613 nm and a quantum yield as high as 15.5 %. The good water solubility and stable photoluminescence make the composites very different from other Eu(III)-based coordination complexes. The composites are cell viable and can be used to label both the cell membrane and the cytoplasm of MCF-7 cells. They are also shown to act as bioprobes for in-vivo localization of tumorous tissue. In our perception, such composites are expected to possess wide scope because of the many functionalizations that are possible with GQDs. (author)

  11. Interaction of europium and nickel with calcite studied by Rutherford Backscattering Spectrometry and Time-Resolved Laser Fluorescence Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, A. [Agence Nationale pour la gestion des Déchets RAdioactifs, 1-7 rue J. Monnet, Parc de la Croix Blanche, 92298 Châtenay-Malabry Cedex (France); Université de Nice Sophia Antipolis, Ecosystèmes Côtiers Marins et Réponses aux Stress (ECOMERS), 28 avenue Valrose, 06108 Nice Cedex 2 (France); Pipon, Y., E-mail: pipon@ipnl.in2p3.fr [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Institut Universitaire de Technologie (IUT) Lyon-1, Université Claude Bernard Lyon 1, 69 622 Villeurbanne Cedex (France); Toulhoat, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); CEA/DEN, Saclay, 91191 Gif sur Yvette (France); Lomenech, C. [Université de Nice Sophia Antipolis, Ecosystèmes Côtiers Marins et Réponses aux Stress (ECOMERS), 28 avenue Valrose, 06108 Nice Cedex 2 (France); Jordan, N. [Helmholtz Zentrum Dresden Rossendorf (HZDR), Institute of Resource Ecology (IRE) (Germany); Moncoffre, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Barkleit, A. [Helmholtz Zentrum Dresden Rossendorf (HZDR), Institute of Resource Ecology (IRE) (Germany); and others

    2014-08-01

    This study aims at elucidating the mechanisms regulating the interaction of Eu and Ni with calcite (CaCO{sub 3}). Calcite powders or single crystals (some mm sized) were put into contact with Eu or Ni solutions at concentrations ranging from 10{sup −3} to 10{sup −5} mol L{sup −1} for Eu and 10{sup −3} mol L{sup −1} for Ni. The sorption durations ranged from 1 week to 1 month. Rutherford Backscattering Spectrometry (RBS) well adapted to discriminate incorporation processes such as: (i) adsorption or co precipitation at the mineral surfaces or, (ii) incorporation into the mineral structure (through diffusion for instance), has been carried out. Moreover, using the fluorescence properties of europium, the results have been compared to those obtained by Time-Resolved Laser Fluorescence Spectroscopy (TRLFS) on calcite powders. For the single crystals, complementary SEM observations of the mineral surfaces at low voltage were also performed. Results showed that Ni accumulates at the calcite surface whereas Eu is also incorporated at a greater depth. Eu seems therefore to be incorporated into two different states in calcite: (i) heterogeneous surface accumulation and (ii) incorporation at depth greater than 160 nm after 1 month of sorption. Ni was found to accumulate at the surface of calcite without incorporation.

  12. Fluorimetric study of the interaction between nicotinamide adenine dinucleotide phosphate and tetracycline-europium complex and its application

    International Nuclear Information System (INIS)

    Peng Qian; Hou Faju; Ge Xiaoxia; Jiang Chongqiu; Gong Shubo

    2005-01-01

    A new spectrofluorimetric method was developed for the determination of trace amount of nicotinamide adenine dinucleotide phosphate (NADP). Using europium (Eu 3+ )-tetracycline (TC) complex as a fluorescent probe, in the buffer solution of pH 7.60. NADP can remarkably enhance the fluorescence intensity of the Eu 3+ -TC complex at λ = 612 nm and the enhanced fluorescence intensity of Eu 3+ ion is in proportion to the concentration of NADP. Optimum conditions for the determination of NADP were also investigated. The dynamic range for the determination of NADP is 4.4 x 10 -7 to 2.2 x 10 -6 mol l -1 with detection limit of 6.9 x 10 -8 mol l -1 . This method is simple, practical and relatively free interference from coexisting substances and can be successfully applied to determination of NADP in synthetic water samples and in serum samples. Moreover, the enhancement mechanisms of the fluorescence intensity in the Eu 3+ -TC system and the Eu 3+ -TC-NADP system have been also discussed

  13. Sparkle/PM3 for the modeling of europium(III), gadolinium(III), and terbium(III) complexes

    International Nuclear Information System (INIS)

    Freire, Ricardo O.; Rocha, Gerd B.; Simas, Alfredo M.

    2009-01-01

    The Sparkle/PM3 model is extended to europium(III), gadolinium(III), and terbium(III) complexes. The validation procedure was carried out using only high quality crystallographic structures, for a total of ninety-six Eu(III) complexes, seventy Gd(III) complexes, and forty-two Tb(III) complexes. The Sparkle/PM3 unsigned mean error, for all interatomic distances between the trivalent lanthanide ion and the ligand atoms of the first sphere of coordination, is: 0.080 A for Eu(III); 0.063 A for Gd(III); and 0.070 A for Tb(III). These figures are similar to the Sparkle/AM1 ones of 0.082 A, 0.061 A, and 0.068 A respectively, indicating they are all comparable parameterizations. Moreover, their accuracy is similar to what can be obtained by present-day ab initio effective core potential full geometry optimization calculations on such lanthanide complexes. Finally, we report a preliminary attempt to show that Sparkle/PM3 geometry predictions are reliable. For one of the Eu(III) complexes, BAFZEO, we created hundreds of different input geometries by randomly varying the distances and angles of the ligands to the central Eu(III) ion, which were all subsequently fully optimized. A significant trend was unveiled, indicating that more accurate local minima geometries cluster at lower total energies, thus reinforcing the validity of sparkle model calculations. (author)

  14. Photovoltaic Performance Enhancement of Silicon Solar Cells Based on Combined Ratios of Three Species of Europium-Doped Phosphors

    Directory of Open Access Journals (Sweden)

    Wen-Jeng Ho

    2018-05-01

    Full Text Available This paper presents a scheme for the enhancement of silicon solar cells in terms of luminescent emission band and photovoltaic performance. The proposed devices are coated with an luminescent down-shifting (LDS layer comprising three species of europium (Eu-doped phosphors mixed within a silicate film (SiO2 using a spin-on film deposition. The three species of phosphor were mixed at ratios of 0.5:1:1.5, 1:1:1, or 1.5:1:0.5 in weight percentage (wt %. The total quantity of Eu-doped phosphors in the silicate solution was fixed at 3 wt %. The emission wavelengths of the Eu-doped phosphors were as follows: 518 nm (specie-A, 551 nm (specie-B, and 609 nm (specie-C. We examined the extended luminescent emission bands via photoluminescence measurements at room temperature. Closely matching the luminescent emission band to the high responsivity band of the silicon semiconductor resulted in good photovoltaic performance. Impressive improvements in efficiency were observed in all three samples: 0.5:1:1.5 (20.43%, 1:1:1 (19.67%, 1.5:1:0.5 (16.81%, compared to the control with a layer of pure SiO2 (13.80%.

  15. Quantum dot based on tin/titanium mixed oxide doped with europium synthesized by protein sol-gel method

    International Nuclear Information System (INIS)

    Paganini, Paula P.; Felinto, Maria Claudia F.C.; Brito, Hermi F.

    2011-01-01

    Special luminescence biomarkers have been developed to find more sensitive fluoroimmunoassay methods. A new generation of these biomarkers is the semiconductors nanocrystals, known as quantum dots, doped with lanthanides. The use of lanthanides ions as luminescent markers has many advantages, for example a security method, low cost, high specificity and also the luminescence can be promptly measured with high sensibility and accuracy. The protein sol-gel is a modification of conventional method, in which the coconut water replacing the alkoxides normally used. The advantage is that, the proteins present in coconut water bind chemically with metal salts forming a polymer chain. This work presents nanoparticles based on tin/titanium mixed oxide doped with 3% of europium synthesized by protein sol-gel method. The nanoparticles were burned at 300 deg C, 500 deg C, 800 deg C and 1100 deg C. The samples were analyzed and characterized by thermal analysis, X-ray powder diffraction (XRD), infrared spectroscopy (IR) and scanning electron microscopy (SEM). The synthesis was effective and the nanoparticles showed nanometric size and structural differences with the annealing. To be used in the fluoroimmunoassays tests, these particles need to be functionalized before be connect with biological molecules and after this process, these nanoparticles going to be submitted at gamma radiation for sterilization. (author)

  16. Quantum dot based on tin/titanium mixed oxide doped with europium synthesized by protein sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Paganini, Paula P.; Felinto, Maria Claudia F.C., E-mail: paulapaganini@usp.b, E-mail: mfelinto@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Brito, Hermi F., E-mail: hefbrito@iq.usp.b [Universidade de Sao Paulo (IQ/USP), Sao Paulo, SP (Brazil). Inst. de Quimica. Lab. de Elementos do Bloco f

    2011-07-01

    Special luminescence biomarkers have been developed to find more sensitive fluoroimmunoassay methods. A new generation of these biomarkers is the semiconductors nanocrystals, known as quantum dots, doped with lanthanides. The use of lanthanides ions as luminescent markers has many advantages, for example a security method, low cost, high specificity and also the luminescence can be promptly measured with high sensibility and accuracy. The protein sol-gel is a modification of conventional method, in which the coconut water replacing the alkoxides normally used. The advantage is that, the proteins present in coconut water bind chemically with metal salts forming a polymer chain. This work presents nanoparticles based on tin/titanium mixed oxide doped with 3% of europium synthesized by protein sol-gel method. The nanoparticles were burned at 300 deg C, 500 deg C, 800 deg C and 1100 deg C. The samples were analyzed and characterized by thermal analysis, X-ray powder diffraction (XRD), infrared spectroscopy (IR) and scanning electron microscopy (SEM). The synthesis was effective and the nanoparticles showed nanometric size and structural differences with the annealing. To be used in the fluoroimmunoassays tests, these particles need to be functionalized before be connect with biological molecules and after this process, these nanoparticles going to be submitted at gamma radiation for sterilization. (author)

  17. Photovoltaic Performance Enhancement of Silicon Solar Cells Based on Combined Ratios of Three Species of Europium-Doped Phosphors.

    Science.gov (United States)

    Ho, Wen-Jeng; You, Bang-Jin; Liu, Jheng-Jie; Bai, Wen-Bin; Syu, Hong-Jhang; Lin, Ching-Fuh

    2018-05-18

    This paper presents a scheme for the enhancement of silicon solar cells in terms of luminescent emission band and photovoltaic performance. The proposed devices are coated with an luminescent down-shifting (LDS) layer comprising three species of europium (Eu)-doped phosphors mixed within a silicate film (SiO₂) using a spin-on film deposition. The three species of phosphor were mixed at ratios of 0.5:1:1.5, 1:1:1, or 1.5:1:0.5 in weight percentage (wt %). The total quantity of Eu-doped phosphors in the silicate solution was fixed at 3 wt %. The emission wavelengths of the Eu-doped phosphors were as follows: 518 nm (specie-A), 551 nm (specie-B), and 609 nm (specie-C). We examined the extended luminescent emission bands via photoluminescence measurements at room temperature. Closely matching the luminescent emission band to the high responsivity band of the silicon semiconductor resulted in good photovoltaic performance. Impressive improvements in efficiency were observed in all three samples: 0.5:1:1.5 (20.43%), 1:1:1 (19.67%), 1.5:1:0.5 (16.81%), compared to the control with a layer of pure SiO₂ (13.80%).

  18. Photo/electroluminescence properties of an europium (III) complex doped in 4,4'-N,N'-dicarbazole-biphenyl matrix

    International Nuclear Information System (INIS)

    Zhou Yonghui; Zhou Liang; Wu, Jing; Li, Hong-Yan; Zheng Youxuan; You Xiaozeng; Zhang Hongjie

    2010-01-01

    The photoluminescence properties of one europium complex Eu(TFNB) 3 Phen (TFNB = 4,4,4-trifluoro-1-(naphthyl)-1,3-butanedione, Phen = 1,10-phenanthroline) doped in a hole-transporting material CBP (4,4'-N,N'-dicarbazole-biphenyl) films were studied. A series of organic light-emitting devices (OLEDs) using Eu(TFNB) 3 Phen as the emitter were fabricated with a multilayer structure of indium tin oxide, 250 Ω/square)/TPD (N,N'-diphenyl-N,N'-bis(3-methyllphenyl)-(1,1'-biphenyl)-4,4'-diamine, 50 nm)/Eu(TFNB) 3 phen (x): CBP (4,4'-N,N'-dicarbazole-biphenyl, 45 nm)/BCP (2,9-dimethyl-4,7-diphenyl-l,10 phenanthroline, 20 nm)/AlQ (tris(8-hydroxy-quinoline) aluminium, 30 nm)/LiF (1 nm)/Al (100 nm), where x is the weight percentage of Eu(TFNB) 3 phen doped in the CBP matrix (1-6%). A red emission at 612 nm with a half bandwidth of 3 nm, characteristic of Eu(III) ion, was observed with all devices. The device with a 3% dopant concentration shows the maximum luminance up to 1169 cd/m 2 (18 V) and the device with a 5% dopant concentration exhibits a current efficiency of 4.46 cd/A and power efficiency of 2.03 lm/W. The mechanism of the electroluminescence was also discussed.

  19. Acid Sulfate Alteration in Gusev Crater, Mars

    Science.gov (United States)

    Morris, R. V.; Ming, D. W.; Catalano, J. G.

    2016-01-01

    The Mars Exploration Rover (MER) Spirit landed on the Gusev Crater plains west of the Columbia Hills in January, 2004, during the Martian summer (sol 0; sol = 1 Martian day = 24 hr 40 min). Spirit explored the Columbia Hills of Gusev Crater in the vicinity of Home Plate at the onset on its second winter (sol approximately 900) until the onset of its fourth winter (sol approximately 2170). At that time, Spirit became mired in a deposit of fined-grained and sulfate-rich soil with dust-covered solar panels and unfavorable pointing of the solar arrays toward the sun. Spirit has not communicated with the Earth since sol 2210 (January, 2011). Like its twin rover Opportunity, which landed on the opposite side of Mars at Meridiani Planum, Spirit has an Alpha Particle X-Ray Spectrometer (APXS) instrument for chemical analyses and a Moessbauer spectrometer (MB) for measurement of iron redox state, mineralogical speciation, and quantitative distribution among oxidation (Fe(3+)/sigma Fe) and coordination (octahedral versus tetrahedral) states and mineralogical speciation (e.g., olivine, pyroxene, ilmenite, carbonate, and sulfate). The concentration of SO3 in Gusev rocks and soils varies from approximately 1 to approximately 34 wt%. Because the APXS instrument does not detect low atomic number elements (e.g., H and C), major-element oxide concentrations are normalized to sum to 100 wt%, i.e., contributions of H2O, CO2, NO2, etc. to the bulk composition care not considered. The majority of Gusev samples have approximately 6 plus or minus 5 wt% SO3, but there is a group of samples with high SO3 concentrations (approximately 30 wt%) and high total iron concentrations (approximately 20 wt%). There is also a group with low total Fe and SO3 concentrations that is also characterized by high SiO2 concentrations (greater than 70 wt%). The trend labeled "Basaltic Soil" is interpreted as mixtures in variable proportions between unaltered igneous material and oxidized and SO3-rich basaltic

  20. Constraining Δ33S signatures of Archean seawater sulfate with carbonate-associated sulfate

    Science.gov (United States)

    Peng, Y.; Bao, H.; Bekker, A.; Hofmann, A.

    2017-12-01

    Non-mass dependent sulfur isotope deviation of S-bearing phases in Archean sedimentary strata, and expressed as Δ33S, has a consistent pattern, i.e., sulfide (pyrite) predominantly bear positive Δ33S values, while Paleoarchean sulfate (barite) has negative Δ33S values. This pattern was later corroborated by observations of negative Δ33S values in Archean volcanogenic massive sulfide deposits and negative Δ33S values in early diagenetic nodular pyrite with a wide range of δ34S values, which is thought to be due to microbial sulfate reduction. These signatures have provided a set of initial conditions for a mechanistic interpretation at physical chemistry level. Unlike the younger geological times when large bodies of seawater evaporite deposits are common, to expand seawater sulfate records, carbonate-associated sulfate (CAS) was utilized as a proxy for ancient seawater sulfate. CAS extracted from the Archean carbonates carries positive Δ33S values. However, CAS could be derived from pyrite oxidation following exposure to modern oxidizing conditions and/or during laboratory extraction procedures. It is, therefore, important for us understanding context of the overall early earth atmospheric condition to empirically confirm whether Archean seawater sulfate was generally characterized by negative Δ33S signatures. Combined δ18O, Δ17O, δ34S, and Δ33S analyses of sequentially extracted water-leachable sulfate (WLS) and acid-leachable sulfate (ALS = CAS) and δ34S and Δ33S analyses of pyrite can help to identify the source of extracted sulfate. We studied drill-core samples of Archean carbonates from the 2.55 Ga Malmani and Campell Rand supgroups, South Africa. Our preliminary results show that 1) neither WLS nor ALS were extracted from samples with extremely low pyrite contents (less than 0.05 wt.%); 2) extractable WLS and ALS is present in samples with relatively high pyrite contents (more than 1 wt.%), and that δ34S and Δ33S values of WLS, ALS, and

  1. High rates of sulfate reduction in a low-sulfate hot spring microbial mat are driven by a low level of diversity of sulfate-respiring microorganisms

    DEFF Research Database (Denmark)

    Dillon, Jesse G; Fishbain, Susan; Miller, Scott R

    2007-01-01

    The importance of sulfate respiration in the microbial mat found in the low-sulfate thermal outflow of Mushroom Spring in Yellowstone National Park was evaluated using a combination of molecular, microelectrode, and radiotracer studies. Despite very low sulfate concentrations, this mat community...... was shown to sustain a highly active sulfur cycle. The highest rates of sulfate respiration were measured close to the surface of the mat late in the day when photosynthetic oxygen production ceased and were associated with a Thermodesulfovibrio-like population. Reduced activity at greater depths...... was correlated with novel populations of sulfate-reducing microorganisms, unrelated to characterized species, and most likely due to both sulfate and carbon limitation....

  2. Magneto-optical studies of valence instability in europium and terbium phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Lucas C.V. [Department of Chemistry, University of Turku, FI-20014 Turku (Finland); Instituto de Química, Universidade de São Paulo, São Paulo, -SP (Brazil); Hölsä, Jorma [Department of Chemistry, University of Turku, FI-20014 Turku (Finland); Instituto de Química, Universidade de São Paulo, São Paulo, -SP (Brazil); Turku University Centre for Materials and Surfaces (MatSurf) (Finland); University of the Free State, Department of Physics, Bloemfontein (South Africa); Brito, Hermi F. [Instituto de Química, Universidade de São Paulo, São Paulo, -SP (Brazil); Maryško, Miroslav [Institute of Physics, The Academy of Sciences of the Czech Republic, Cukrovarnická 10, CZ-162 53 Praha 6 (Czech Republic); Matos, Jivaldo R. [Instituto de Química, Universidade de São Paulo, São Paulo, -SP (Brazil); Paturi, Petriina [Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Rodrigues, Rodrigo V. [Instituto de Química, Universidade de São Paulo, São Paulo, -SP (Brazil); Lastusaari, Mika, E-mail: miklas@utu.fi [Department of Chemistry, University of Turku, FI-20014 Turku (Finland); Turku University Centre for Materials and Surfaces (MatSurf) (Finland)

    2016-02-15

    The impurities and dopants' inappropriate valences may deteriorate the performance of luminescent materials, cause waste of the precious rare earth (R) material and thus incur financial losses. The usual methods to detect the valence of rare earths; XPS, Mössbauer and XANES spectroscopies, are not sensitive enough for low concentrations and the EPR methods are not very suitable for powders. In this work, the comparison between the theoretical and experimental temperature-dependent paramagnetic susceptibilities was used to obtain quantitatively the concentrations of the impurity valence in Eu{sub 2}O{sub 2}S and Tb{sub 2}O{sub 2}SO{sub 4}, both containing nominally only R{sup 3+}. Minute (ppm level) Eu{sup 2+} impurities could be analyzed because of the huge difference in the paramagnetic susceptibility between Eu{sup 2+} and Eu{sup 3+} at low temperatures. However, temperatures below 50 K are then needed whilst the Tb{sup IV} impurity in a Tb{sup 3+} matrix can be observed already at higher temperatures. The latter method based on comparing the slopes of the Tb{sup 3+}/Tb{sup IV} paramagnetic susceptibility vs temperature curves for the Tb{sup 3+}/Tb{sup IV} couple is less sensitive than for the Eu{sup 2+}/Eu{sup 3+} one. Finally, the host independent temperature evolution of the paramagnetic susceptibility was calculated for Gd{sup 3+} (or Eu{sup 2+} or Tb{sup IV}) to yield a simple analytical expression to be used universally. - Highlights: • Wave functions for Eu{sup 3+}/Tb{sup 3+} with crystal field effect calculated for oxysulfide/sulfate. • Paramagnetic susceptibility between 4 and 300 K simulated for 4f{sup 6/7/8} configurations. • Amount of valence impurities (Eu{sup 2+} and Tb{sup IV}) evaluated from susceptibility data. • Waste of raw materials and loss of luminescence intensity of phosphors can be avoided.

  3. Effects of sulfate chitosan derivatives on nonalcoholic fatty liver disease

    Science.gov (United States)

    Yu, Mingming; Wang, Yuanhong; Jiang, Tingfu; Lv, Zhihua

    2014-06-01

    Sulfate chitosan derivatives have good solubility and therapeutic effect on the cell model of NAFLD. The aim of this study was to examine the therapeutic effect of sulfate chitosan derivatives on NAFLD. The male Wistar rats were orally fed high fat emulsion and received sulfate chitosan derivatives for 5 weeks to determine the pre-treatment effect of sulfate chitosan derivatives on NAFLD. To evaluate the therapeutic effect of sulfate chitosan derivatives on NAFLD, the rats were orally fed with high concentration emulsion for 5 weeks, followed by sulfate chitosan derivatives for 3 weeks. Histological analysis and biomedical assays showed that sulfate chitosan derivatives can dramatically prevent the development of hepatic steatosis in hepatocyte cells. In animal studies, pre-treatment and treatment with sulfate chitosan derivatives significantly protected against hepatic steatohepatitis induced by high fat diet according to histological analysis. Furthermore, increased TC, ALT, MDA, and LEP in NAFLD were significantly ameliorated by pre-treatment and treatment with sulfate chitosan derivatives. Furthermore, increased TG, AST, and TNF-α in NAFLD were significantly ameliorated by treatment with sulfate chitosan derivatives. Sulfate chitosan derivatives have good pre-treatment and therapeutic effect on NAFLD.

  4. Chinese hamster ovary cell mutants defective in heparan sulfate biosynthesis

    International Nuclear Information System (INIS)

    Bame, K.J.; Kiser, C.S.; Esko, J.D.

    1987-01-01

    The authors have isolated Chinese hamster ovary cell mutants defective in proteoglycan synthesis by radiographic screening for cells unable to incorporate 35 SO 4 into acid-precipitable material. Some mutants did not incorporate 35 SO 4 into acid-precipitable material, whereas others incorporated about 3-fold less radioactivity. HPLC anion exchange chromatographic analysis of radiolabelled glycosaminoglycans isolated from these mutants revealed many are defective in heparan sulfate biosynthesis. Mutants 803 and 677 do not synthesize heparan sulfate, although they produce chondroitin sulfate: strain 803 makes chondroitin sulfate normally, whereas 677 overaccumulates chondroitin sulfate by a factor of three. These mutants fall into the same complementation group, suggesting that the mutations are allelic. A second group of heparan sulfate biosynthetic mutants, consisting of cell lines 625, 668 and 679, produce undersulfated heparan sulfate and normal chondroitin sulfate. Treatment of the chains with nitrous acid should determine the position of the sulfate groups along the chain. These mutants may define a complementation group that is defective in the enzymes which modify the heparan sulfate chain. To increase the authors repertoire of heparan sulfate mutants, they are presently developing an in situ enzyme assay to screen colonies replica plated on filter discs for sulfotransferase defects

  5. Thermophilic Sulfate-Reducing Bacteria in Cold Marine Sediment

    DEFF Research Database (Denmark)

    ISAKSEN, MF; BAK, F.; JØRGENSEN, BB

    1994-01-01

    sulfate-reducing bacteria was detected. Time course experiments showed constant sulfate reduction rates at 4 degrees C and 30 degrees C, whereas the activity at 60 degrees C increased exponentially after a lag period of one day. Thermophilic, endospore-forming sulfate-reducing bacteria, designated strain...... C to search for presence of psychrophilic, mesophilic and thermophilic sulfate-reducing bacteria. Detectable activity was initially only in the mesophilic range, but after a lag phase sulfate reduction by thermophilic sulfate-reducing bacteria were observed. No distinct activity of psychrophilic...... P60, were isolated and characterized as Desulfotomaculum kuznetsovii. The temperature response of growth and respiration of strain P60 agreed well with the measured sulfate reduction at 50 degrees-70 degrees C. Bacteria similar to strain P60 could thus be responsible for the measured thermophilic...

  6. DEPENDENCY OF SULFATE SOLUBILITY ON MELT COMPOSITION AND MELT POLYMERIZATION

    International Nuclear Information System (INIS)

    JANTZEN, CAROL M.

    2004-01-01

    Sulfate and sulfate salts are not very soluble in borosilicate waste glass. When sulfate is present in excess it can form water soluble secondary phases and/or a molten salt layer (gall) on the melt pool surface which is purported to cause steam explosions in slurry fed melters. Therefore, sulfate can impact glass durability while formation of a molten salt layer on the melt pool can impact processing. Sulfate solubility has been shown to be compositionally dependent in various studies, (e.g. , B2O3, Li2O, CaO, MgO, Na2O, and Fe2O3 were shown to increase sulfate solubility while Al2O3 and SiO2 decreased sulfate solubility). This compositional dependency is shown to be related to the calculated melt viscosity at various temperatures and hence the melt polymerization

  7. Chondroitin-4-sulfation negatively regulates axonal guidance and growth

    Science.gov (United States)

    Wang, Hang; Katagiri, Yasuhiro; McCann, Thomas E.; Unsworth, Edward; Goldsmith, Paul; Yu, Zu-Xi; Tan, Fei; Santiago, Lizzie; Mills, Edward M.; Wang, Yu; Symes, Aviva J.; Geller, Herbert M.

    2008-01-01

    Summary Glycosaminoglycan (GAG) side chains endow extracellular matrix proteoglycans with diversity and complexity based upon the length, composition, and charge distribution of the polysaccharide chain. Using cultured primary neurons, we show that specific sulfation in the GAG chains of chondroitin sulfate (CS) mediates neuronal guidance cues and axonal growth inhibition. Chondroitin-4-sulfate (CS-A), but not chondroitin-6-sulfate (CS-C), exhibits a strong negative guidance cue to mouse cerebellar granule neurons. Enzymatic and gene-based manipulations of 4-sulfation in the GAG side chains alter their ability to direct growing axons. Furthermore, 4-sulfated CS GAG chains are rapidly and significantly increased in regions that do not support axonal regeneration proximal to spinal cord lesions in mice. Thus, our findings provide the evidence showing that specific sulfation along the carbohydrate backbone carries instructions to regulate neuronal function. PMID:18768934

  8. Thermophilic Sulfate-Reducing Bacteria in Cold Marine Sediment

    DEFF Research Database (Denmark)

    ISAKSEN, MF; BAK, F.; JØRGENSEN, BB

    1994-01-01

    C to search for presence of psychrophilic, mesophilic and thermophilic sulfate-reducing bacteria. Detectable activity was initially only in the mesophilic range, but after a lag phase sulfate reduction by thermophilic sulfate-reducing bacteria were observed. No distinct activity of psychrophilic...... sulfate-reducing bacteria was detected. Time course experiments showed constant sulfate reduction rates at 4 degrees C and 30 degrees C, whereas the activity at 60 degrees C increased exponentially after a lag period of one day. Thermophilic, endospore-forming sulfate-reducing bacteria, designated strain...... P60, were isolated and characterized as Desulfotomaculum kuznetsovii. The temperature response of growth and respiration of strain P60 agreed well with the measured sulfate reduction at 50 degrees-70 degrees C. Bacteria similar to strain P60 could thus be responsible for the measured thermophilic...

  9. Sulfate and acid resistant concrete and mortar

    Science.gov (United States)

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1998-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction and other applications, which hardenable mixtures demonstrate significant levels of acid and sulfate resistance while maintaining acceptable compressive strength properties. The acid and sulfate hardenable mixtures of the invention containing fly ash comprise cementitious materials and a fine aggregate. The cementitous materials may comprise fly ash as well as cement. The fine aggregate may comprise fly ash as well as sand. The total amount of fly ash in the hardenable mixture ranges from about 60% to about 120% of the total amount of cement, by weight, whether the fly ash is included as a cementious material, fine aggregate, or an additive, or any combination of the foregoing. In specific examples, mortar containing 50% fly ash and 50% cement in cementitious materials demonstrated superior properties of corrosion resistance.

  10. Biosynthesis and function of chondroitin sulfate.

    Science.gov (United States)

    Mikami, Tadahisa; Kitagawa, Hiroshi

    2013-10-01

    Chondroitin sulfate proteoglycans (CSPGs) are principal pericellular and extracellular components that form regulatory milieu involving numerous biological and pathophysiological phenomena. Diverse functions of CSPGs can be mainly attributed to structural variability of their polysaccharide moieties, chondroitin sulfate glycosaminoglycans (CS-GAG). Comprehensive understanding of the regulatory mechanisms for CS biosynthesis and its catabolic processes is required in order to understand those functions. Here, we focus on recent advances in the study of enzymatic regulatory pathways for CS biosynthesis including successive modification/degradation, distinct CS functions, and disease phenotypes that have been revealed by perturbation of the respective enzymes in vitro and in vivo. Fine-tuned machineries for CS production/degradation are crucial for the functional expression of CS chains in developmental and pathophysiological processes. Control of enzymes responsible for CS biosynthesis/catabolism is a potential target for therapeutic intervention for the CS-associated disorders. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Regional transport model of atmospheric sulfates

    International Nuclear Information System (INIS)

    Rao, K.S.; Thomson, I.; Egan, B.A.

    1977-01-01

    As part of the Sulfate Regional Experiment (SURE) Design Project, a regional transport model of atmospheric sulfates has been developed. This quasi-Lagrangian three-dimensional grid numerical model uses a detailed SO 2 emission inventory of major anthropogenic sources in the Eastern U.S. region, and observed meteorological data during an episode as inputs. The model accounts for advective transport and turbulent diffusion of the pollutants. The chemical transformation of SO 2 and SO 4 /sup =/ and the deposition of the species at the earth's surface are assumed to be linear processes at specified constant rates. The numerical model can predict the daily average concentrations of SO 2 and SO 4 /sup =/ at all receptor locations in the grid region during the episode. Because of the spatial resolution of the grid, this model is particularly suited to investigate the effect of tall stacks in reducing the ambient concentration levels of sulfur pollutants. This paper presents the formulations and assumptions of the regional sulfate transport model. The model inputs and results are discussed. Isopleths of predicted SO 2 and SO 4 /sup =/ concentrations are compared with the observed ground level values. The bulk of the information in this paper is directed to air pollution meteorologists and environmental engineers interested in the atmospheric transport modeling studies of sulfur oxide pollutants

  12. Sulfation and cation effects on the conformational properties of the glycan backbone of chondroitin sulfate disaccharides.

    Science.gov (United States)

    Faller, Christina E; Guvench, Olgun

    2015-05-21

    Chondroitin sulfate (CS) is one of several glycosaminoglycans that are major components of proteoglycans. A linear polymer consisting of repeats of the disaccharide -4GlcAβ1-3GalNAcβ1-, CS undergoes differential sulfation resulting in five unique sulfation patterns. Because of the dimer repeat, the CS glycosidic "backbone" has two distinct sets of conformational degrees of freedom defined by pairs of dihedral angles: (ϕ1, ψ1) about the β1-3 glycosidic linkage and (ϕ2, ψ2) about the β1-4 glycosidic linkage. Differential sulfation and the possibility of cation binding, combined with the conformational flexibility and biological diversity of CS, complicate experimental efforts to understand CS three-dimensional structures at atomic resolution. Therefore, all-atom explicit-solvent molecular dynamics simulations with Adaptive Biasing Force sampling of the CS backbone were applied to obtain high-resolution, high-precision free energies of CS disaccharides as a function of all possible backbone geometries. All 10 disaccharides (β1-3 vs β1-4 linkage × five different sulfation patterns) were studied; additionally, ion effects were investigated by considering each disaccharide in the presence of either neutralizing sodium or calcium cations. GlcAβ1-3GalNAc disaccharides have a single, broad, thermodynamically important free-energy minimum, whereas GalNAcβ1-4GlcA disaccharides have two such minima. Calcium cations but not sodium cations bind to the disaccharides, and binding is primarily to the GlcA -COO(-) moiety as opposed to sulfate groups. This binding alters the glycan backbone thermodynamics in instances where a calcium cation bound to -COO(-) can act to bridge and stabilize an interaction with an adjacent sulfate group, whereas, in the absence of this cation, the proximity of a sulfate group to -COO(-) results in two like charges being both desolvated and placed adjacent to each other and is found to be destabilizing. In addition to providing information

  13. Study of the influence of humic acids (in solution or bound to a silica gel) on the migration of europium in a porous medium. Comparison with inorganic colloids

    International Nuclear Information System (INIS)

    Fleury, Ch.

    1998-01-01

    After having been reprocessed, radioactive wastes are stored in conditions which depend on the toxicity of the radioelements. In particular, for the actinides, the packaging has to be sure for several thousands years. In the case of a defective storage, phenomena which favour or diminish the migration of radioelements in the environment have to be identified. In water, organic or inorganic colloids able to bind radioelements can migrate. Among these colloids, are found the humic acids (HA), macromolecules (poly-electrolytes and poly-dispersed) known for their affinity towards some radioelements. These HA are either present on a soluble state or bound to mineral supports. Humic acids have then been studied in these two states and their influence on the europium migration in dynamical system have been observed (ion exchange and affinity chromatography). When HA are bound by covalent bonds to silica gel, they strongly retain the radioelement, whatever be the conditions of pH, flow rate or ionic strength, and either if phosphate ions are present. The study of HA in solution has shown that, on the one hand the formation of a Eu-HA complex alters the adsorption of the radioelement on sand and that the influence of the humic acids on the europium retention is superior to those of the inorganic colloids (silicon oxide, bentonite). On the other hand, the study has revealed that a solution containing HA desorbs almost entirely the europium beforehand bound to the sand. This desorption depends on the pH and on the flow rate but not on the presence of competitive ions as for instance phosphate ions. (O.M.)

  14. Isotopic exchange between 232Th and 234Th using ion exchange resins and its application for the radiochemical separation of thorium and europium

    International Nuclear Information System (INIS)

    Sepulveda Munita, C.J.A.; Atalla, L.T.

    1980-01-01

    The determination of thorium via the measurement of 233 Th activity (obtained by irradiating natural thorium with neutrons) may suffer the interference of various radioisotopes which may be also formed during irradiation, if their parent isotopes are present in the sample. Taking into account this possibility, another technique was chosen for the determination of thorium, based on isotopic exchange associated with ionic exchange. Conditions for the isotopic exchange between 234 Th in solution and 232 Th in the resin were optimized. It was verified that the behaviour of 233 Th and 234 Th is the same regarding isotopic exchange with 232 Th. 234 Th was chosen for the experiments since it has a longer half-life (24.1 days) than 233 Th (22.3 min), thus facilitating the performance of the work. As the major objective of this work is to separate thorium and europium isotopes, the behaviour of 152-154 Eu was studied in the same system used for thorium, envisaging a minimum retention of these radioisotopes in the resin. In order to establish the best conditions for separating 234-Th and 152/154-Eu, the following parameters were considered: the thorium concentration in the solution; the hydrochloric acid concentration in solution; the concentration of other elements in solution; the degree of cross-linking of the resin; the flow rate of the solution through the column. The other elements added to the elutant solution were: uranium, molybdenum, lanthanum, europium, ytterbium, bromine, cobalt, barium, manganese, indium, cesium and selenium. Europium was added so to dilute the 152/154-Eu tracer and avoid the retention of the latter in the resin. The other elements were added because they give rise to radioisotopes which interfere in the activation analysis of thorium when 233-Th activity is used and, the separation of these elements from thorium will also be subsequently studied by the method used in the present work. (C.L.B.) [pt

  15. Purification and sequence characterization of chondroitin sulfate and dermatan sulfate from fishes.

    Science.gov (United States)

    Lin, Na; Mo, Xiaoli; Yang, Yang; Zhang, Hong

    2017-04-01

    Chondroitin sulfate (CS) and dermatan sulfate (DS) were extracted and purified from skins or bones of salmon (Salmo salar), snakehead (Channa argus), monkfish (Lophius litulon) and skipjack tuna (Katsuwonus pelamis). Size, structural sequences and sulfate groups of oligosaccharides in the purified CS and DS could be characterized and identified using high performance liquid chromatography (HPLC) combined with Orbitrap mass spectrometry. CS and DS chain structure varies depending on origin, but motif structure appears consistent. Structures of CS and DS oligosaccharides with different size and sulfate groups were compared between fishes and other animals, and results showed that some minor differences of special structures could be identified by hydrophilic interaction chromatography-liquid chromatography-fourier transform-mass/mass spectrometry (HILIC-LC-FT-MS/MS). For example, data showed that salmon and skipjack CS had a higher percentage content of high-level sulfated oligosaccharides than that porcine CS. In addition, structural information of different origins of CS and DS was analyzed by principal component analysis (PCA) and results showed that CS and DS samples could be differentiated according to their molecular conformation and oligosaccharide fragments information. Understanding CS and DS structure derived from different origins may lead to the production of CS or DS with unique disaccharides or oligosaccharides sequence composition and biological functions.

  16. The europium and praseodymium hydrolysis in a 2M NaCl environment; La hidrolisis del europio y del praseodimio en un medio 2M de NaCl

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez R, M.; Lopez G, H.; Solache R, M.; Rojas H, A. [Instituto Nacional de Investigaciones Nucleares, Departamento de quimica, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1998-07-01

    It was studied the europium and praseodymium hydrolysis in a 2M NaCl ion force environment at 303 K, through two methods: this one extraction with dissolvents (lanthanide-water-NaCl-dibenzoylmethane) in presence of a competitive ligand (diglycolic acid) and that one direct potentiometric titration, of soluble species, followed by a computer refining. The values of one or another techniques of the first hydrolysis constants obtained were similar, which demonstrates that the results are reliable. The set of data obtained on the stability constants of hydrolysis products allowed to draw up the distribution diagrams of chemical species, as europium as praseodymium in aqueous environment. (Author)

  17. Europium-activated phosphors containing oxides of rare-earth and group-IIIB metals and method of making the same

    Science.gov (United States)

    Comanzo, Holly Ann; Setlur, Anant Achyut; Srivastava, Alok Mani; Manivannan, Venkatesan

    2004-07-13

    Europium-activated phosphors comprise oxides of at least a rare-earth metal selected from the group consisting of gadolinium, yttrium, lanthanum, and combinations thereof and at least a Group-IIIB metal selected from the group consisting of aluminum, gallium, indium, and combinations thereof. A method for making such phosphors comprises adding at least a halide of at least one of the selected Group-IIIB metals in a starting mixture. The method further comprises firing the starting mixture in an oxygen-containing atmosphere. The phosphors produced by such a method exhibit improved absorption in the UV wavelength range and improved quantum efficiency.

  18. Heritability and clinical determinants of serum indoxyl sulfate and p-cresyl sulfate, candidate biomarkers of the human microbiome enterotype.

    Directory of Open Access Journals (Sweden)

    Liesbeth Viaene

    Full Text Available BACKGROUND: Indoxyl sulfate and p-cresyl sulfate are unique microbial co-metabolites. Both co-metabolites have been involved in the pathogenesis of accelerated cardiovascular disease and renal disease progression. Available evidence suggests that indoxyl sulfate and p-cresyl sulfate may be considered candidate biomarkers of the human enterotype and may help to explain the link between diet and cardiovascular disease burden. OBJECTIVE AND DESIGN: Information on clinical determinants and heritability of indoxyl sulfate and p-cresyl sulfate serum is non-existing. To clarify this issue, the authors determined serum levels of indoxyl sulfate and p-cresyl sulfate in 773 individuals, recruited in the frame of the Flemish Study on Environment, Genes and Health Outcomes (FLEMENGHO study. RESULTS: Serum levels of indoxyl sulfate and p-cresyl sulfate amounted to 3.1 (2.4-4.3 and 13.0 (7.4-21.5 μM, respectively. Regression analysis identified renal function, age and sex as independent determinants of both co-metabolites. Both serum indoxyl sulfate (h2 = 0.17 and p-cresyl sulfate (h2 = 0.18 concentrations showed moderate but significant heritability after adjustment for covariables, with significant genetic and environmental correlations for both co-metabolites. LIMITATIONS: Family studies cannot provide conclusive evidence for a genetic contribution, as confounding by shared environmental effects can never be excluded. CONCLUSIONS: The heritability of indoxyl sulfate and p-cresyl sulfate is moderate. Besides genetic host factors and environmental factors, also renal function, sex and age influence the serum levels of these co-metabolites.

  19. Measurements of europium-152 depth profile of stone embankments exposed the Nagasaki atomic bomb for neutron spectrum analysis

    International Nuclear Information System (INIS)

    Tatsumi-Miyajima, Junko; Shimasaki, Tatsuya; Okajima, Shunzo; Takada, Jitsuya; Yoshida, Masahiro; Takao, Hideaki; Okumura, Yutaka; Nakazawa, Masaharu.

    1990-01-01

    Quantitative measurement of neutron-induced radionuclide of 152 Eu in rocks near the hypocenter (ground center of the atomic bomb explosion) in Nagasaki was performed to obtain the depth profiles and calculate the neutron energy spectrum. Core samples were drilled and taken from the stone embankments on both sides of river within a radius of 500 m from the hypocenter. After cutting each core into about 27 mm-thick sections, each section was measured its gamma-ray spectrum with a pure germanium semiconductor detector and analyzed a content of natural europium by the activation method. The highest value 8.0 x 10 -2 Bq/μg of 152 Eu at the time of the blast was obtained from the surface plates of rock cores collected near the hypocenter. The surface activity of cores was reduced with increasing the slant distances from the hypocenter. The slopes of the depth profiles were similar among samples taken from the same location. In order to analyze the depth profile of 152 Eu activity in rock andesite, experiments using a fast neutron reactor and thermal neutron reactor were carried out. Comparing the measurements on the A-bomb exposure rock with the simulated results at the reactors, among the experiments, the depth profile using the neutron moderator of 10 mm polyethylene was closed to that obtained from the A-bomb exposed samples. The experiment of thermal neutron incidence only could not reproduce the profiles from the A-bomb exposed samples. This fact indicates that the depth profiles of 152 Eu in rock exposed to the A-bomb include valuable information concerning the neutron spectrum and intensity. (author)

  20. Distribution of Europium between poly-maleic acid in solution or adsorbed onto alumina and Bacillus subtilis

    International Nuclear Information System (INIS)

    Markai, S.

    2002-07-01

    In order to understand the interactions of radionuclides under natural water conditions, the interactions were studied in a quaternary system composed of well characterized reference substances: europium as a heavy metal, poly-maleic acid (PMA) as model of humic substances, alumina as mineral phase and Bacillus subtilis representing biomass. The work was performed at pH=5 in 0,1 mol/L of NaClO 4 . The fundamental question addressed was to know if parameters deduced from the quantitative study of the reference systems Eu/PMA, Eu/PMA-Al 2 O 3 and Eu/Bacillus subtilis, could be used to quantify the distribution of Eu in the multi-substrate systems Eu/PMA/Bacillus subtilis and Eu/PMA-Al 2 O 3 /Bacillus subtilis. The experimental interaction data were described by a Langmuir-type model or by a surface complexation model, with surface speciation assessment by time resolved laser induced fluorescence spectroscopy. The study of the Eu/PMA system showed similarities with the Eu/ humic substances system as far as interaction strength and the nature of Eu environment were concerned. When PMA was adsorbed onto Al 2 O 3 , its complexation properties towards Eu were different. For high concentrations of Eu, a ternary complex was formed in which Eu was bound to a carboxylic function of PMA and to an aluminol function of Al 2 O 3 . For the Eu/B.subtilis system, Eu was bound to a carboxylic function and to a phosphate function. For the PMA/Eu/bacteria system, the reference systems were reversible and the parameters deduced from sub-systems allowed to quantify the distribution of Eu in the global system. In the PMA A l 2 O 3 /Eu/bacteria system, the equilibrium Eu/PMA-Al 2 O 3 was not reversible due to a diffusion of Eu in the adsorbed layer of PMA, reducing its bio-availability. (author)

  1. Raman, photoluminescence and EPR spectroscopic characterization of europium(III) oxide–lead dioxide–tellurite glassy network

    Energy Technology Data Exchange (ETDEWEB)

    Dehelean, A. [National Research and Development Institute for Isotopic and Molecular Technologies, Cluj-Napoca (Romania); Rada, S. [Technical University of Cluj-Napoca (Romania); Popa, A.; Suciu, R.C. [National Research and Development Institute for Isotopic and Molecular Technologies, Cluj-Napoca (Romania); Culea, E., E-mail: eugen.culea@phys.utcluj.ro [Technical University of Cluj-Napoca (Romania)

    2016-09-15

    Raman, photoluminescence and EPR spectroscopies were used to characterize some xEu{sub 2}O{sub 3}·(100−x)[4TeO{sub 2}·PbO{sub 2}] glasses with x=0–50 mol% obtained by melt quenching technique. Raman spectra of these glasses were interpreted in terms of vibration modes of deformed Te–O–Te linkages due to the intercalation of [PbO{sub n}] and [EuO{sub n}] entities produced by addition of Eu{sub 2}O{sub 3} to the host lead–tellurite glass. Photoluminescence spectra of xEu{sub 2}O{sub 3}·(100−x)[4TeO{sub 2}·PbO{sub 2}] glasses reveal the presence of Pb{sup 2+}, Eu{sup 2+} and Eu{sup 3+} ions. EPR data confirm the presence of Eu{sup 2+} ions in the europium–lead–tellurite glassy network and offer information about the compositional evolution of the Eu{sup 2+} ions local environment and Eu{sup 3+}↔Eu{sup 2+} redox process. PL and EPR data show that the decrease of the Eu{sup 2+} ions luminescence intensity for the x≥40 mol% Eu{sub 2}O{sub 3} region is not due to the clusterization of europium ions but is due the decrease of the amount of Eu{sup 2+} ions as result of changes in the Eu{sup 3+}→Eu{sup 2+} redox equilibrium.

  2. Migration of strontium, cesium, and europium from poly(butyl acrylate)/phosphate/composites prepared using gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Alhassanieh, O., E-mail: cscientific@aec.org.s [Nuclear and Radiochemistry Division, Chemistry Department, Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic); Ajji, Z. [Polymer Technology Division, Radiation Technology Department, Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic); Alkourdi, H.; Haloum, D. [Nuclear and Radiochemistry Division, Chemistry Department, Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic)

    2011-02-15

    Composites based on natural phosphate powder and the monomer N-butyl acrylate have been prepared by means of gamma irradiation. The conversion of polymerization was followed up with respect to the irradiation dose using thermogravimetric analyzer (TGA). A total polymerization conversion was achieved by exposure of the samples to a dose of 10 kGy. A thermomechanical analyzer (TMA) was used to locate the region of the glass transition temperatures (T{sub g}) using the mode with alternative variable force; the mode with constant force was used to determine the T{sub g} of the pure polymer and the composite prepared at the same irradiation dose. The T{sub g} of the pure poly(butyl acrylate) is -51.41 {sup o}C, and the T{sub g} of poly(butyl acrylate)/phosphate/composites is -46.54 {sup o}C. The distribution of {sup 137}Cs, {sup 152}Eu, and {sup 85}Sr in a solid-aqueous system, a composite of phosphate-polybutyl acrylate in contact with groundwater, was investigated using {gamma}-spectrometry. The effect of contact time, pH, and the concentration of concurrent elements (Na, Ca, and La) were studied. The results were compared with earlier results with phosphate alone in the solid phase. The ability of the produced composites to keep the studied radioisotopes in the solid phase is much higher than mineral phosphate. This improvement is more remarkable by strontium and cesium than europium, due to its high element ratio in the solid phase in phosphate experiments.

  3. Photophysical studies of highly luminescent europium(III) and terbium(III) complexes functionalized with amino and mercapto groups

    Energy Technology Data Exchange (ETDEWEB)

    Souza, E.R.; Monteiro, J.H.S.K.; Mazali, I.O.; Sigoli, F.A., E-mail: fsigoli@iqm.unicam.br

    2016-02-15

    This work proposes the replacement of coordinated-water molecules from the precursor complexes [Ln(aba){sub 3}(H{sub 2}O)] and [Ln(tta){sub 3}(H{sub 2}O){sub 2}], (Ln=Eu{sup 3+}, Gd{sup 3+} or Tb{sup 3+}, aba{sup −}=aminobenzoate, tta{sup −}=thenoyltrifluoroacetonate) by the ligands mercaptobenzoate (mba{sup −}), mercaptopropionate (mpa{sup −}), phenanthroline (phen), dimethylformamide (dmf) and acetoacetanilide (aaa{sup −}), leading to anionic or neutral amino (–NH{sub 2}) or mercapto (–SH) functionalized-lantanides (III) complexes with reasonable emission quantum yields for potential application on fluorescence microscopy of biological moieties. The complexes photophysical properties were studied using luminescence spectroscopy and theoretical models to determine the transfer and back energy transfer rates and quantum yields, that were compared with experimental ones. The anionic complexes [Eu(tta){sub 3}(L)]{sup −} showed high quantum yield values and their sensitization efficiency are in the range of 39–81%. The overlay of the ground state geometries, obtained from the Sparkle/PM3 model, of the complexes [Eu(tta){sub 3}(aba)]{sup −}, [Eu(tta){sub 3}(mba)]{sup −} and [Eu(tta){sub 3}(mpa)]{sup −}, suggest similar coordination polyhedrons occupied by the europium(III). The highest transfer rates T→{sup 5}D{sub 1,0} were obtained for the anionic complexes [Eu(tta){sub 3}(L)]{sup −} which might be a result of the low triplet level energies and R{sub L} values. - Highlights: • Lanthanides functionalized-complexes. • Free mercapto and amino groups. • Covalence degree of Eu-ligands. • Energy transfer rates. • Intrinsic and absolute quantum yields and sensitization.

  4. Carbon footprint assessment of recycling technologies for rare earth elements: A case study of recycling yttrium and europium from phosphor.

    Science.gov (United States)

    Hu, Allen H; Kuo, Chien-Hung; Huang, Lance H; Su, Chao-Chin

    2017-02-01

    Rare earth elements are key raw materials in high-technology industries. Mining activities and manufacturing processes of such industries have caused considerable environmental impacts, such as soil erosion, vegetation destruction, and various forms of pollution. Sustaining the long-term supply of rare earth elements is difficult because of the global shortage of rare earth resources. The diminishing supply of rare earth elements has attracted considerable concern because many industrialized countries regarded such elements as important strategic resources for economic growth. This study aims to explore the carbon footprints of yttrium and europium recovery techniques from phosphor. Two extraction recovery methods, namely, acid extraction and solvent extraction, were selected for the analysis and comparison of carbon footprints. The two following functional units were used: (1) the same phosphor amounts for specific Y and Eu recovery concentrations, and (2) the same phosphor amounts for extraction. For acid extraction method, two acidic solutions (H 2 SO 4 and HCl) were used at two different temperatures (60 and 90°C). For solvent extraction method, acid leaching was performed followed by ionic liquid extraction. Carbon footprints from acid and solvent extraction methods were estimated to be 10.1 and 10.6kgCO 2 eq, respectively. Comparison of the carbon emissions of the two extraction methods shows that the solvent extraction method has significantly higher extraction efficiency, even though acid extraction method has a lower carbon footprint. These results may be used to develop strategies for life cycle management of rare earth resources to realize sustainable usage. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Study of the spectroscopy properties of uranium matrix doped with europium. Energy transfer between UO22+ and Eu3+

    International Nuclear Information System (INIS)

    Luiz, Jose Eduardo Monteiro de Sa

    2007-01-01

    Uranyl compounds (UO 2 2+ ) present a great potential as luminescent materials, for instance, applied in technology laser, luminescent probes, cells for conversion of energy, etc. In this work it is studied the efficiency of energy transfer in the compound Eu 3+ doped in UO 2 (MS) 2 .(H 2 O)n matrix and UO 2 2+ in Eu(MS) 3 (H 2 O)n for to be used as efficient Light Conversion Molecular Devices (LCMD) and/or in solar cells for energy conversion. It is also described the synthesis, characterization and spectroscopic study of the matrix Eu(MS) 3 .(H 2 O)n.(x%mol) UO 2 2+ and UO 2 (MS) 2 .(H 2 O)n.(x%mol) Eu 3+ (where x= 1, 3, 5 and 10). The compounds obtained was characterized by elementary analyses for determine the U 6+ concentration, infrared spectra, thermal analyses and luminescence spectra. The IR data suggest that the MS ligand acts as bidentate one. The emission spectra of Eu 3+ doped in UO 2 (MS) 2 .(H 2 O) 2 matrix showed characteristic fluorescence bands of the uranyl ion, attributed to the transition of 3 Π u -> 1 Σ g + of the uranium matrix. For the UO 2 2+ in Eu(MS) 3 (H 2 O) 6 the transitions of D o -> 7 F J (J=0 ->4 ) are predominant in the spectra. The intense europium luminescence associated with uranyl sensitising is registered in emission spectra of Eu 3+ ions in the range of 420-720 nm. The quenching rate constant of UO 2 2+ fluorescence with Eu 3+ is also determined. (author)

  6. Sulfation pattern of fucose branches affects the anti-hyperlipidemic activities of fucosylated chondroitin sulfate.

    Science.gov (United States)

    Wu, Nian; Zhang, Yu; Ye, Xingqian; Hu, Yaqin; Ding, Tian; Chen, Shiguo

    2016-08-20

    Fucosylated chondroitin sulfates (fCSs) are glycosaminoglycans extracted from sea cucumbers, consisting of chondroitin sulfate E (CSE) backbones and sulfated fucose branches. The biological properties of fCSs could be affected by the sulfation pattern of their fucose branches. In the present study, two fCSs were isolated from sea cucumbers Isostichopus badionotus (fCS-Ib) and Pearsonothuria graeffei (fCS-Pg). Their monosaccharide compositions of glucuronic acid (GlcA), N-acetylgalactosamine (GalNAc), fucose (Fuc) and sulfate were at similar molar ratio with 1.0/0.7/0.9/3.1 for fCS-Ib and 1.0/0.8/1.5/2.6 for fCS-Pg. The two fCSs have different sulfation patterns on their fucose branches, fCS-Pg with 3,4-O-disulfation while fCS-Ib with 2,4-O-disulfation. Their antihyperlipidemic effects were compared using a high-fat high-fructose diet (HFFD)-fed C57BL/6J mice model. Both fCS-Ib and fCS-Pg had significant effects on lipid profile improvement, liver protection, blood glucose diminution and hepatic glycogen synthesis. Specifically, fCS-Pg with 3,4-O-disulfation fucose branches was more effective in reduction of blood cholesterol (TC), low density lipoprotein (LDL) and atherogenic index (AI). Our results indicate that both fCSs, especially fCS-Pg, could be used as a potential anti-hyperlipidemic drug. Copyright © 2016. Published by Elsevier Ltd.

  7. A potential role for chondroitin sulfate/dermatan sulfate in arm regeneration in Amphiura filiformis.

    Science.gov (United States)

    Ramachandra, Rashmi; Namburi, Ramesh B; Dupont, Sam T; Ortega-Martinez, Olga; van Kuppevelt, Toin H; Lindahl, Ulf; Spillmann, Dorothe

    2017-05-01

    Glycosaminoglycans (GAGs), such as chondroitin sulfate (CS) and dermatan sulfate (DS) from various vertebrate and invertebrate sources are known to be involved in diverse cellular mechanisms during repair and regenerative processes. Recently, we have identified CS/DS as the major GAG in the brittlestar Amphiura filiformis, with high proportions of di- and tri-O-sulfated disaccharide units. As this echinoderm is known for its exceptional regeneration capacity, we aimed to explore the role of these GAG chains during A. filiformis arm regeneration. Analysis of CS/DS chains during the regeneration process revealed an increase in the proportion of the tri-O-sulfated disaccharides. Conversely, treatment of A. filiformis with sodium chlorate, a potent inhibitor of sulfation reactions in GAG biosynthesis, resulted in a significant reduction in arm growth rates with total inhibition at concentrations higher than 5 mM. Differentiation was less impacted by sodium chlorate exposure or even slightly increased at 1-2 mM. Based on the structural changes observed during arm regeneration we identified chondroitin synthase, chondroitin-4-O-sulfotransferase 2 and dermatan-4-O-sulfotransferase as candidate genes and sought to correlate their expression with the expression of the A. filiformis orthologue of bone morphogenetic factors, AfBMP2/4. Quantitative amplification by real-time PCR indicated increased expression of chondroitin synthase and chondroitin-4-O-sulfotransferase 2, with a corresponding increase in AfBMP2/4 during regeneration relative to nonregenerating controls. Our findings suggest that proper sulfation of GAGs is important for A. filiformis arm regeneration and that these molecules may participate in mechanisms controlling cell proliferation. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. On the roles and regulation of chondroitin sulfate and heparan sulfate in zebrafish pharyngeal cartilage morphogenesis

    DEFF Research Database (Denmark)

    Holmborn, Katarina; Habicher, Judith; Kasza, Zsolt

    2012-01-01

    The present study addresses the roles of heparan sulfate (HS) proteoglycans and chondroitin sulfate (CS) proteoglycans in the development of zebrafish pharyngeal cartilage structures. uxs1 and b3gat3 mutants, predicted to have impaired biosynthesis of both HS and CS because of defective formation...... levels of CS than control larvae, whereas morpholino-mediated suppression of csgalnact1/csgalnact2 resulted in increased HS biosynthesis. Thus, the balance of the Extl3 and Csgalnact1/Csgalnact2 proteins influences the HS/CS ratio. A characterization of the pharyngeal cartilage element morphologies...

  9. Effects of sulfate deprivation on the production of chondroitin/dermatan sulfate by cultures of skin fibroblasts from normal and diabetic individuals

    International Nuclear Information System (INIS)

    Silbert, C.K.; Humphries, D.E.; Palmer, M.E.; Silbert, J.E.

    1991-01-01

    Human skin fibroblast monolayer cultures from two normal men, three Type I diabetic men, and one Type I diabetic woman were incubated with [3H]glucosamine in the presence of diminished concentrations of sulfate. Although total synthesis of [3H]chondroitin/dermatan glycosaminoglycans varied somewhat between cell lines, glycosaminoglycan production was not affected within any line when sulfate levels were decreased from 0.3 mM to 0.06 mM to 0.01 mM to 0 added sulfate. Lowering of sulfate concentrations resulted in diminished sulfation of chondroitin/dermatan in a progressive manner, so that overall sulfation dropped to as low as 19% for one of the lines. Sulfation of chondroitin to form chondroitin 4-sulfate and chondroitin 6-sulfate was progressively and equally affected by decreasing the sulfate concentration in the culture medium. However, sulfation to form dermatan sulfate was preserved to a greater degree, so that the relative proportion of dermatan sulfate to chondroitin sulfate increased. Essentially all the nonsulfated residues were susceptible to chondroitin AC lyase, indicating that little epimerization of glucuronic acid residues to iduronic acid had occurred in the absence of sulfation. These results confirm the previously described dependency of glucuronic/iduronic epimerization on sulfation, and indicate that sulfation of the iduronic acid-containing disaccharide residues of dermatan can take place with sulfate concentrations lower than those needed for 6-sulfation and 4-sulfation of the glucuronic acid-containing disaccharide residues of chondroitin. There were considerable differences among the six fibroblast lines in susceptibility to low sulfate medium and in the proportion of chondroitin 6-sulfate, chondroitin 4-sulfate, and dermatan sulfate. However, there was no pattern of differences between normals and diabetics

  10. Global source attribution of sulfate aerosol and its radiative forcing

    Science.gov (United States)

    Yang, Y.; Wang, H.; Smith, S.; Easter, R. C.; Ma, P. L.; Qian, Y.; Li, C.; Yu, H.; Rasch, P. J.

    2017-12-01

    Sulfate is an important aerosol that poses health risks and influences climate. Due to long-range atmospheric transport, local sulfate pollution could result from intercontinental influences, making domestic efforts of improving air quality inefficient. Accurate understanding of source attribution of sulfate and its radiative forcing is important for both regional air quality improvement and global climate mitigation. In this study, for the first time, a sulfur source-tagging capability is implemented in the Community Atmosphere Model (CAM5) to quantify the global source-receptor relationships of sulfate and its direct and indirect radiative forcing (DRF and IRF). Near-surface sulfate concentrations are mostly contributed by local emissions in regions with high emissions, while over regions with relatively low SO2 emissions, the near-surface sulfate is primarily attributed to non-local sources from long-range transport. The export of SO2 and sulfate from Europe contributes 20% of sulfate concentrations over North Africa, Russia and Central Asia. Sources from the Middle East account for 20% of sulfate over North Africa, Southern Africa and Central Asia in winter and autumn, and 20% over South Asia in spring. East Asia accounts for about 50% of sulfate over Southeast Asia in winter and autumn, 15% over Russia in summer, and 10% over North America in spring. South Asia contributes to 25% of sulfate over Southeast Asia in spring. Lifetime of aerosols, together with regional export, is found to determine regional air quality. The simulated global total sulfate DRF is -0.42 W m-2, with 75% contributed by anthropogenic sulfate and 25% contributed by natural sulfate. In the Southern Hemisphere tropics, dimethyl sulfide (DMS) contributes the most to the total DRF. East Asia has the largest contribution of 20-30% over the Northern Hemisphere mid- and high-latitudes. A 20% perturbation of sulfate and its precursor emissions gives a sulfate IRF of -0.44 W m-2. DMS has the

  11. Removal of Sulfate Ion From AN-107 by Evaporation

    International Nuclear Information System (INIS)

    GJ Lumetta; GS Klinger; DE Kurath; RL Sell; LP Darnell; LR Greenwood; CZ Soderquist; MJ Steele; MW Urie; JJ Wagner

    2000-01-01

    Hanford low-activity waste solutions contain sulfate, which can cause accelerated corrosion of the vitrification melter and unacceptable operating conditions. A method is needed to selectively separate sulfate from the waste. An experiment was conducted to evaluate evaporation for removing sulfate ion from Tank AN-107 low-activity waste. Two evaporation steps were performed. In the first step, the volume was reduced by 55% while in the second step, the liquid volume was reduced another 22%. Analysis of the solids precipitated during these evaporations revealed that large amounts of sodium nitrate and nitrite co-precipitated with sodium sulfate. Many other waste components precipitated as well. It can be concluded that sulfate removal by precipitation is not selective, and thus, evaporation is not a viable option for removing sulfate from the AN-107 liquid

  12. Metabolic interactions in methanogenic and sulfate-reducing bioreactors.

    Science.gov (United States)

    Stams, A J M; Plugge, C M; de Bok, F A M; van Houten, B H G W; Lens, P; Dijkman, H; Weijma, J

    2005-01-01

    In environments where the amount of electron acceptors is insufficient for complete breakdown of organic matter, methane is formed as the major reduced end product. In such methanogenic environments organic acids are degraded by syntrophic consortia of acetogenic bacteria and methanogenic archaea. Hydrogen consumption by methanogens is essential for acetogenic bacteria to convert organic acids to acetate and hydrogen. Several syntrophic cocultures growing on propionate and butyrate have been described. These syntrophic fatty acid-degrading consortia are affected by the presence of sulfate. When sulfate is present sulfate-reducing bacteria compete with methanogenic archaea for hydrogen and acetate, and with acetogenic bacteria for propionate and butyrate. Sulfate-reducing bacteria easily outcompete methanogens for hydrogen, but the presence of acetate as carbon source may influence the outcome of the competition. By contrast, acetoclastic methanogens can compete reasonably well with acetate-degrading sulfate reducers. Sulfate-reducing bacteria grow much faster on propionate and butyrate than syntrophic consortia.

  13. Process for removing sulfate anions from waste water

    Science.gov (United States)

    Nilsen, David N.; Galvan, Gloria J.; Hundley, Gary L.; Wright, John B.

    1997-01-01

    A liquid emulsion membrane process for removing sulfate anions from waste water is disclosed. The liquid emulsion membrane process includes the steps of: (a) providing a liquid emulsion formed from an aqueous strip solution and an organic phase that contains an extractant capable of removing sulfate anions from waste water; (b) dispersing the liquid emulsion in globule form into a quantity of waste water containing sulfate anions to allow the organic phase in each globule of the emulsion to extract and absorb sulfate anions from the waste water and (c) separating the emulsion including its organic phase and absorbed sulfate anions from the waste water to provide waste water containing substantially no sulfate anions.

  14. Immobilization of calcium sulfate contained in demolition waste

    International Nuclear Information System (INIS)

    Ambroise, J.; Pera, J.

    2008-01-01

    This paper presents the results of a laboratory study undertaken to examine the treatment of demolition waste containing calcium sulfate by means of calcium sulfoaluminate clinker (CSA). The quantity of CSA necessary to entirely consume calcium sulfate was determined. Using infrared spectrometry analysis and X-ray diffraction, it was shown that calcium sulfate was entirely consumed when the ratio between CSA and calcium sulfate was 4. Standard sand was polluted by 4% calcium sulfate. Two solutions were investigated: ·either global treatment of sand by CSA, ·or immobilization of calcium sulfate by CSA, followed by the introduction of this milled mixture in standard sand. Regardless of the type of treatment, swelling was almost stabilized after 28 days of immersion in water

  15. A radioimmunoassay for measurement of thyroxine sulfate

    International Nuclear Information System (INIS)

    Chopra, I.J.; Santini, F.; Hurd, R.E.; Chua Teco, G.N.

    1993-01-01

    A highly sensitive, specific, and reproducible RIA has been developed to measure T 4 sulfate (T 4 S) in ethanol extracts of serum. rT 3 sulfate (rT 3 S) cross-reacted 7.1%, and T 3 S cross-reacted 0.59% in the RIA; T 4 , T 3 , rT 3 and 3,3'-diiodothyronine cross-reacted 0.004% or less. The recovery of nonradioactive T 4 S added to serum averaged 95%. The detection threshold of the RIA was 18 pmol/L. The coefficient of variation averaged 6.9% within an assay and 12% between assays. T 4 S was bound by T 4 -binding globulin and albumin in serum. The free fraction of T 4 S in four normal sera averaged 0.06% compared to a value of 0.03% for T 4 (P 4 S was (mean ± SE) 19 ± 1.2 pmol/L in normal subjects, 33 ± 10 in hyperthyroid patients with Graves disease, 42 ± 15 in hypothyroid patients, 34 ± 6.9 in patients with systematic nonthyroidal illnesses, 21 ± 4.3 in pregnant women at 15-40 weeks gestation, and 245 ± 26 in cord blood sera of newborns; the value in the newborn was significantly different from normal (P 4 S. The T 4 S content of the thyroid gland was less than 1/4000th that of T 4 . We conclude that (1) T 4 S is a normal component of human serum, and its levels are markedly increased in newborn serum and amniotic fluid; and (2) the sulfation pathway plays an important role in the metabolism of T 4 in man. 28 refs., 4 figs., 2 tabs

  16. Sequence determination of synthesized chondroitin sulfate dodecasaccharides.

    Science.gov (United States)

    Shioiri, Tatsumasa; Tsuchimoto, Jun; Watanabe, Hideto; Sugiura, Nobuo

    2016-06-01

    Chondroitin sulfate (CS) is a linear acidic polysaccharide composed of repeating disaccharide units of glucuronic acid and N-acetyl-d-galactosamine. The polysaccharide is modified with sulfate groups at different positions by a variety of sulfotransferases. CS chains exhibit various biological and pathological functions by interacting with cytokines and growth factors and regulating their signal transduction. The fine structure of the CS chain defines its specific biological roles. However, structural analysis of CS has been restricted to disaccharide analysis, hampering the understanding of the structure-function relationship of CS chains. Here, we chemo-enzymatically synthesized CS dodecasaccharides having various sulfate modifications using a bioreactor system of bacterial chondroitin polymerase mutants and various CS sulfotransferases. We developed a sequencing method for CS chains using the CS dodecasaccharides. The method consists of (i) labeling a reducing end with 2-aminopyridine (PA), (ii) partial digestion of CS with testicular hyaluronidase, followed by separation of PA-conjugated oligosaccharides with different chain lengths, (iii) limited digestion of these oligosaccharides with chondroitin lyase AC II into disaccharides, followed by labeling with 2-aminobenzamide, (iv) CS disaccharide analysis using a dual-fluorescence HPLC system (reversed-phase ion-pair and ion-exchange chromatography), and (v) estimation of the composition by calculating individual disaccharide ratios. This CS chain sequencing allows characterization of CS-modifying enzymes and provides a useful tool toward understanding the structure-function relationship of CS chains. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. A case study of energy transfer mechanism from uranium to europium in ZnAl2O4 spinel host by photoluminescence spectroscopy

    Science.gov (United States)

    Kumar, Mithlesh; Mohapatra, M.

    2016-04-01

    Zinc aluminate (ZAO), a member of spinel class of inorganic compounds has been of much interest of late due to its wide range of use in catalysis, optical, electronic and ceramic industries. When doped with several lanthanides, this material has proved to be a potential host matrix for phosphors. As lanthanides suffer from poor (direct) excitation and emission cross sections, the use of a co-dopant ion can help to circumvent this and extract better emission from a lanthanide doped ZAO system. In this connection, energy transfer mechanism from uranium to europium in the ZAO host was investigated by photoluminescence spectroscopic technique. It was seen that uranium gets stabilized in the hexavalent state as UO66 - (octahedral uranate) where as the lanthanide ion, Eu is stabilized in its trivalent state in the ZAO host. In the co-doped system, an efficient energy transfer pathway from the uranate to europium ion was observed. Based upon emission and life time data a suitable mechanism was proposed for the energy transfer (quenching) process. It was proposed that after excitation by photons, the uranate ions transfer their energy to nearby 5D1 level of Eu3 + ions which non-radiatively de-excites to the corresponding lower levels of 5D0. Further this 5D0 level decays in a radiative mode to the 7F manifold giving the characteristic emission profile of trivalent Eu. It was proposed that both static and dynamic types of energy transfer mechanism were responsible for this process.

  18. Exploration of spectroscopic properties of solvated tris(thenoyltrifluoroacetonate)(2,2′-bipyridine)europium(III)red hybrid organic complex for solution processed OLEDs and displays

    Energy Technology Data Exchange (ETDEWEB)

    Chitnis, Dipti [Department of Physics, RTM Nagpur University, Nagpur 440033 (India); Thejokalyani, N., E-mail: thejokalyani@rediffmail.com [Department of Applied Physics, Laxminarayan Institute of Technology, Nagpur 440033 (India); Dhoble, S.J. [Department of Physics, RTM Nagpur University, Nagpur 440033 (India)

    2017-05-15

    In order to explore the spectroscopic properties of a novel europium activated hybrid organic tris(thenoyltrifluoroacetonate)(2,2′-bipyridine)europium(III), Eu(TTA){sub 3}bipy phosphor in various solvents at different pH and molar concentrations, UV–vis optical absorption and photoluminescence spectra were carried out. With a variation in the solvent from basic (chloroform, toluene, tetrahydrofuran) to acidic (acetic acid, formic acid) media, staggering differences in optical absorptions and optical densities were noticed with hypsochromic shift in the absorption peaks. The optical density was found to be maximum for the complex with pH= 7.0 and the intensity as well as optical density gradually decreased when pH is lowered to 6.0 or raised to 8.0 (at an interval of 0.5), proving that the complex is pH sensitive. It's optical energy gap and stokes shift values in various organic solvents were also calculated on the basis of Lippert-Mataga plot. The exploration of spectroscopic properties of solvated Eu(TTA){sub 3}bipy complex demonstrates its prospective for solution processed OLEDs and display devices. - Graphical abstract: Pictorial depiction of photoluminescence in solvated Eu(TTA){sub 3}bipy complex under UV light.

  19. Efficacy of the semiempirical sparkle model as compared to ECP ab-initio calculations for the prediction of ligand field parameters of europium (III) complexes

    International Nuclear Information System (INIS)

    Freire, Ricardo O.; Rocha, Gerd B.; Albuquerque, Rodrigo Q.; Simas, Alfredo M.

    2005-01-01

    The second version of the sparkle model for the calculation of lanthanide complexes (SMLC II) as well as ab-initio calculations (HF/STO-3G and HF/3-21G) have been used to calculate the geometries of a series of europium (III) complexes with different coordination numbers (CN=7, 8 and 9), ligating atoms (O and N) and ligands (mono, bi and polydentate). The so-called ligand field parameters, Bqk's, have been calculated from both SMLC II and ab-initio optimized structures and compared to the ones calculated from crystallographic data. The results show that the SMLC II model represents a significant improvement over the previous version (SMLC) and has given good results when compared to ab-initio methods, which demand a much higher computational effort. Indeed, ab-initio methods take around a hundred times more computing time than SMLC. As such, our results indicate that our sparkle model can be a very useful and a fast tool when applied to the prediction of both ground state geometries and ligand field parameters of europium (III) complexes

  20. Novel europium (III)-gatifloxacin complex structure with dual functionality for pH sensing and metal recognition in aqueous environment

    Science.gov (United States)

    Chen, Muhua; Zheng, Yuhui; Gao, Jinwei; Wang, Qianming

    2016-10-01

    A new type of Eu(III)-gatifloxacin complex with characteristic red luminescence has been prepared. Due to the presence of ionization effect linked to the organic chromophore, the molecular fluorescent sensor demonstrated variable pH-sensitive absorption and emission curves. The red emission derived from europium ions was strong during pH range 8-10. Between pH = 7 and 4, the europium emission remained relatively stable and fluorescence signals of gatifloxacin has been improved substantially. Under acidic conditions (pH = 1 to 3), the dramatic changes in the emission colors (from red, yellow to green) were clearly observed. Moreover, the excitation wavelength can be extended into the visible light range (Ex = 411 nm) by using the concentration effect experiment. Importantly, it gave turn-off emissions in the presence of Cu2+ or Fe3+ and the detection limits were determined to be 6.5 μM for Cu2+ and 6.2 μM for Fe3+ respectively.

  1. Emission tunability and local environment in europium-doped OH{sup −}-free calcium aluminosilicate glasses for artificial lighting applications

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Aline M.; Sandrini, Marcelo; Viana, José Renato M.; Baesso, Mauro L.; Bento, Antônio C.; Rohling, Jurandir H. [Departamento de Física, Universidade Estadual de Maringá, Av Colombo, 5790, 87020-900, Maringá, PR (Brazil); Guyot, Yannick [Laboratoire de Physico–Chimie des Matériaux Luminescents, Université de Lyon, Université Claude Bernard Lyon 1, Villeurbanne, UMR 5620 CNRS 69622 (France); De Ligny, Dominique [Department of Materials Science and Engineering, University of Erlangen Nürnberg, Martens str. 5, 91058, Erlangen (Germany); Nunes, Luiz Antônio O. [Instituto de Física de São Carlos, Universidade de São Paulo, Av. Trabalhador São-Carlense400, 13566-590, São Carlos, SP (Brazil); Gandra, Flávio G. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, 13083-859, Campinas, SP (Brazil); Sampaio, Juraci A. [Lab Ciências Físicas, Universidade Estadual Norte Fluminense, 28013-602, Campos Dos Goytacazes, RJ (Brazil); Lima, Sandro M.; Andrade, Luis Humberto C. [Grupo de Espectroscopia Óptica e Fototérmica, Universidade Estadual de Mato Grosso do Sul-UEMS, Dourados, MS, C. P. 351, CEP 79804-970 (Brazil); and others

    2015-04-15

    The relationship between emission tunability and the local environment of europium ions in OH{sup −}-free calcium aluminosilicate glasses was investigated, focusing on the development of devices for artificial lighting. Significant conversion of Eu{sup 3+} to Eu{sup 2+} was obtained by means of melting the glasses under a vacuum atmosphere and controlling the silica content, resulting in broad, intense, and tunable luminescence ranging from blue to red. Electron spin resonance and X-ray absorption near edge structure measurements enabled correlation of the luminescence behavior of the material with the Eu{sup 2+}/Eu{sup 3+} concentration ratio and changes in the surrounding ions' crystal field. The coordinates of the CIE 1931 chromaticity diagram were calculated from the spectra, and the contour maps showed that the light emitted from Eu{sup 2+} presented broad bands and enhanced color tuning, ranging from reddish-orange to blue. The results showed that these Eu doped glasses can be used for tunable white lighting by combining matrix composition and the adjustment of the pumping wavelength. - Highlights: • Eu{sup 2+}-doped OH{sup −} free calcium aluminosilicate glass as a new source for white lighting. • Correlation between emission tunability and local environment of europium ions. • Significant reduction of Eu{sup 3+} to Eu{sup 2+} by melting the glasses under vacuum atmosphere. • Broad, intense and tunable luminescence ranging from blue to red.

  2. Exploration of spectroscopic properties of solvated tris(thenoyltrifluoroacetonate)(2,2′-bipyridine)europium(III)red hybrid organic complex for solution processed OLEDs and displays

    International Nuclear Information System (INIS)

    Chitnis, Dipti; Thejokalyani, N.; Dhoble, S.J.

    2017-01-01

    In order to explore the spectroscopic properties of a novel europium activated hybrid organic tris(thenoyltrifluoroacetonate)(2,2′-bipyridine)europium(III), Eu(TTA) 3 bipy phosphor in various solvents at different pH and molar concentrations, UV–vis optical absorption and photoluminescence spectra were carried out. With a variation in the solvent from basic (chloroform, toluene, tetrahydrofuran) to acidic (acetic acid, formic acid) media, staggering differences in optical absorptions and optical densities were noticed with hypsochromic shift in the absorption peaks. The optical density was found to be maximum for the complex with pH= 7.0 and the intensity as well as optical density gradually decreased when pH is lowered to 6.0 or raised to 8.0 (at an interval of 0.5), proving that the complex is pH sensitive. It's optical energy gap and stokes shift values in various organic solvents were also calculated on the basis of Lippert-Mataga plot. The exploration of spectroscopic properties of solvated Eu(TTA) 3 bipy complex demonstrates its prospective for solution processed OLEDs and display devices. - Graphical abstract: Pictorial depiction of photoluminescence in solvated Eu(TTA) 3 bipy complex under UV light.

  3. Sulfated oligosaccharide structures, as determined by NMR techniques

    International Nuclear Information System (INIS)

    Noseda, M.D.; Duarte, M.E.R.; Tischer, C.A.; Gorin, P.A.J.; Cerezo, A.S.

    1997-01-01

    Carrageenans are sulfated polysaccharides, produced by red seaweeds (Rhodophyta), that have important biological and physico-chemical properties. Using partial autohydrolysis, we obtained sulfated oligosaccharides from a λ-carrageenan (Noseda and Cerezo, 1993). These oligosaccharides are valuable not only for the study of the structures of the parent carrageenans but also for their possible biological activities. In this work we determined the chemical structure of one of the sulfated oligosaccharides using 1D and 2D NMR techniques. (author)

  4. Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

    Science.gov (United States)

    Zaromb, Solomon; Lawson, Daniel B.

    1994-01-01

    A process for recovering zinc/rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10.degree. C., separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream.

  5. Purification, structural characterization and antiproliferative properties of chondroitin sulfate/dermatan sulfate from tunisian fish skins.

    Science.gov (United States)

    Krichen, Fatma; Volpi, Nicola; Sila, Assaâd; Maccari, Francesca; Mantovani, Veronica; Galeotti, Fabio; Ellouz-Chaabouni, Semia; Bougatef, Ali

    2017-02-01

    Chondroitin sulfate/dermatan sulfate GAGs were extracted and purified from the skins of grey triggerfish (GTSG) and smooth hound (SHSG). The disaccharide composition produced by chondroitinase ABC treatment showed the presence of nonsulfated disaccharide, monosulfated disaccharides ΔDi6S and ΔDi4S, and disulfated disaccharides in different percentages. In particular, the nonsulfated disaccharide ΔDi0S of GTSG and SHSG were 3.5% and 5.5%, respectively, while monosulfated disaccharides ΔDi6S and ΔDi4S were evaluated to be 18.2%, 59% and 14.6%, 47.0%, respectively. Capillary elecrophoresis analysis of GTSG and SHSG contained 99.2% and 95.4% of chondroitin sulfate/dermatan sulfate, respectively. PAGE analysis showed a GTSG and SHSG having molecular masses with average values of 41.72KDa and 23.8KDa, respectively. HCT116 cell proliferation was inhibited (p<0.05) by 70.6% and 72.65% at 200μg/mL of GTSG and SHSG respectively. Both GTSG and SHSG demonstrated promising antiproliferative potential, which may be used as a novel, effective agent. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Inter vs. intraglycosidic acetal linkages control sulfation pattern in semi-synthetic chondroitin sulfate.

    Science.gov (United States)

    Laezza, Antonio; De Castro, Cristina; Parrilli, Michelangelo; Bedini, Emiliano

    2014-11-04

    Microbial-sourced unsulfated chondroitin could be converted into chondroitin sulfate (CS) polysaccharide by a multi-step strategy relying upon benzylidenation and acetylation reactions as key-steps for its regioselective protection. By conducting the two reactions one- or two-pots, CSs with different sulfation patterns could be obtained at the end of the semi-synthesis. In particular, a CS polysaccharide possessing sulfate groups randomly distributed between positions 4 and 6 of N-acetyl-galactosamine (GalNAc) units could be obtained through the two-pots route, whereas the one-pot pathway allowed an additional sulfation at position 3 of some glucuronic acid (GlcA) units. This difference was ascribed to the stabilization of a labile interglycosidic benzylidene acetal involving positions O-3 and O-6 of some GlcA and GalNAc, respectively, when the benzylidene-acetylation reactions were conducted in a one-pot fashion. Isolation and characterization of a polysaccharide intermediate showing interglycosidic acetal moieties was accomplished. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Sulfate Formation on Mars by Volcanic Aerosols: A New Look

    Science.gov (United States)

    Blaney, D. L.

    1996-03-01

    Sulfur was measured at both Viking Lander sites in abundances of 5-9 wt % SO3. Because the sulfur was more concentrated in clumps which disintegrated and the general oxidized nature of the Martian soil, these measurements led to the assumption that a sulfate duricrust existed. Two types of models for sulfate formation have been proposed. One is a formation by upwardly migrating ground water. The other is the formation of sulfates by the precipitation of volcanic aerosols. Most investigators have tended to favor the ground water origin of sulfates on Mars. However, evidence assemble since Viking may point to a volcanic aerosol origin.

  8. Bicarbonate sulfate exchange in canalicular rat liver plasma membrane vesicles

    International Nuclear Information System (INIS)

    Meier, P.J.; Valantinas, J.; Hugentobler, G.; Rahm, I.

    1987-01-01

    The mechanism(s) and driving forces for biliary excretion of sulfate were investigated in canalicular rat liver plasma membrane vesicles (cLPM). Incubation of cLPM vesicles in the presence of an inside-to-outside (in, out) bicarbonate gradient but not pH or out-to-in sodium gradients, stimulated sulfate uptake 10-fold compared with the absence of bicarbonate and approximately 2-fold above sulfate equilibrium (overshoot). Initial rates of this bicarbonate gradient-driven [ 35 S]-sulfate uptake were saturable with increasing concentrations of sulfate and could be inhibited by probenecid, N-(4-azido-2-nitrophenyl)-2-aminoethylsulfonate, acetazolamide, furosemide, 4-acetamideo-4'-isothiocyanostilbene-2,2'-disulfonic acid, and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (IC 50 , ∼40 μM). Cisinhibition of initial bicarbonate gradient-stimulated sulfate uptake and transstimulation of sulfate uptake in the absence of bicarbonate were observed with sulfate, thiosulfate, and oxalate but not with chloride, nitrate, phosphate, acetate, lactate, glutamate, aspartate, cholate, taurocholate, dehydrocholate, taurodehydrocholate, and reduced or oxidized glutathione. These findings indicate the presence of a sulfate (oxalate)-bicarbonate anion exchange system in canalicular rat liver plasma membranes. These findings support the concept that bicarbonate-sensitive transport system might play an important role in bile acid-independent canalicular bile formation

  9. Mencegah Pembentukan Kalsium Sulfat pada Desalinasi Air Laut

    Directory of Open Access Journals (Sweden)

    Mirna Rahmah Lubis

    2007-06-01

    Full Text Available Resin penukar-anion, Relite MG 1/P, dapat digunakan untuk memisahkan sulfat dalam air laut guna mencegah pembentukan kerak kalsium sulfat pada heat exchanger. Resin tersebut menunjukkan selektivitas sulfat yang tinggi dalam air laut sintetis. Resin yang telah dipakai dapat diregenerasi menggunakan air asin yang dipekatkan dengan asam hingga mencapai pH 4. Untuk waktu pemakaian dan regenerasi yang sama, faktor konsentrasi desalinasi (misalnya 2 hingga 4 menaikkan konsentrasi klorida dalam air asin yang diblowdown. Dengan faktor konsentrasi yang tetap, kenaikan laju alir (pengurangan waktu pemakaian dan regenerasi memperendah efisiensi regenerasi dan menaikkan pemisahan sulfat. Akibat kelarutan kalsium sulfat yang bersifat terbalik tersebut, temperatur air asin yang tinggi memerlukan pemisahan sulfat yang lebih banyak, yang dapat dicapai dengan mengurangi laju alir air laut. Pengurangan laju alir tersebut membutuhkan peralatan yang lebih besar dan resin yang lebih banyak, sehingga biaya modal bertambah. Untuk pabrik desalinasi dengan kapasitas produksi 1 juta gallon per hari dan faktor konsentrasi sebesar 2, biaya pemisahan sulfat meliputi biaya resin dan biaya peralatan. Biaya tersebut bervariasi dari $0.246 hingga $0.356/kgalon (per ribu galon air yang diproduksi karena temperatur maksimum air asin berubah dari 140°C menjadi 180°C. Keywords: desalinasi air laut, ion exchange, kalsium sulfat, kerak; mechanical vapor compression (MVC, pemisahan sulfat, resin penukar-anion basa lemah

  10. Chemical species of europium (III) in ionic force media 0.02M, 0.1M, and 0.7M NaClO4 at 298 K

    International Nuclear Information System (INIS)

    Fernandez R, E.; Jimenez R, M.; Solache R, M.

    2000-01-01

    In order to know the effects of the controlled or accidental liberation of the europium in the environment, it is necessary to know its chemical behavior in found conditions in oceans, ground and surface water. The behavior of this element in these environments can be controlled mainly by the hydrolysis and its interaction with inorganic and organic ions. (Author)

  11. Divergent Synthesis of Chondroitin Sulfate Disaccharides and Identification of Sulfate Motifs that Inhibit Triple Negative Breast Cancer

    Science.gov (United States)

    Wei Poh, Zhong; Heng Gan, Chin; Lee, Eric J.; Guo, Suxian; Yip, George W.; Lam, Yulin

    2015-09-01

    Glycosaminoglycans (GAGs) regulate many important physiological processes. A pertinent issue to address is whether GAGs encode important functional information via introduction of position specific sulfate groups in the GAG structure. However, procurement of pure, homogenous GAG motifs to probe the “sulfation code” is a challenging task due to isolation difficulty and structural complexity. To this end, we devised a versatile synthetic strategy to obtain all the 16 theoretically possible sulfation patterns in the chondroitin sulfate (CS) repeating unit; these include rare but potentially important sulfated motifs which have not been isolated earlier. Biological evaluation indicated that CS sulfation patterns had differing effects for different breast cancer cell types, and the greatest inhibitory effect was observed for the most aggressive, triple negative breast cancer cell line MDA-MB-231.

  12. Acute Exacerbations of COPD Are Associated With Increased Expression of Heparan Sulfate and Chondroitin Sulfate in BAL.

    Science.gov (United States)

    Papakonstantinou, Eleni; Klagas, Ioannis; Roth, Michael; Tamm, Michael; Stolz, Daiana

    2016-03-01

    Acute exacerbations of COPD (AECOPDs) are associated with accelerated aggravation of clinical symptoms and deterioration of pulmonary function. The mechanisms by which exacerbations may contribute to airway remodeling and declined lung function are poorly understood. We investigated whether AECOPDs are associated with differential expression of glycosaminoglycans in BAL in a cohort of 97 patients with COPD. Patients with COPD with either stable disease (n = 53) or AECOPD (n = 44) and undergoing diagnostic bronchoscopy were matched for demographics and lung function parameters. Levels of heparan sulfate, chondroitin sulfate, dermatan sulfate, and matrix metalloproteinases (MMPs) in BAL were measured by enzyme-linked immunosorbent assay. Heparan sulfate and chondroitin sulfate were significantly increased in BAL of patients during exacerbations. Levels of heparan sulfate were higher in the BAL of patients with microbial infections. Chondroitin sulfate was negatively correlated with FEV1 % predicted but not with diffusing capacity of lung for carbon monoxide % predicted, indicating that chondroitin sulfate is associated with airway remodeling, leading to obstruction rather than to emphysema. Furthermore, heparan sulfate and chondroitin sulfate were significantly correlated with MMP-9, MMP-2, and MMP-12 in BAL, indicating that they were cleaved from their respective proteoglycans by MMPs and subsequently washed out in BAL. During AECOPD, there is increased expression of heparan sulfate and chondroitin sulfate in BAL. These molecules are significantly correlated with MMPs in BAL, indicating that they may be associated with airway remodeling and may lead to lung function decline during exacerbations of COPD. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  13. Medical Gains of Chondroitin Sulfate Upon Fucosylation.

    Science.gov (United States)

    Pomin, Vitor H

    2015-01-01

    Chondroitin sulfate (CS) is a glycosaminoglycan (GAG) composed of alternating N-acetyl galactosamine and glucuronic acid units within disaccharide building blocks. CS is a key functional component in proteoglycans of cartilaginous tissues. Owing to its numerous biological roles, CS is widely explored in the pharmaceutical market as nutraceutical ingredient commonly utilized against arthritis, osteoarthrosis, and sometimes osteoporosis. Tissues like shark cartilage and bovine trachea are common sources of CS. Nonetheless, a new CS type has been introduced and investigated in the last few decades in what regards its medical potentials. It is named fucosylated chondroitin sulfate (FucCS). This less common CS type is isolated exclusively from the body wall of sea cucumbers. The presence of fucosyl branching units in the holothurian FucCS gives to this unique GAG, therapeutic properties in various pathophysiological systems which are inexistent in the common CS explored in the market. Examples of these systems are coagulation, thrombosis, hemodialysis, atherosclerosis, cellular growth, angiogenesis, fibrosis, tumor growth, inflammation, viral and protozoan infections, hyperglycemia, diabetes-related pathological events and tissue damage. This report aims at describing the medical benefits gained upon fucosylation of CS. Clinical prospects of these medical benefits are also discussed herein.

  14. Optimizing substrate for sulfate-reducing bacteria

    International Nuclear Information System (INIS)

    Chang, L.K.; Updegraff, D.M.; Wildeman, T.R.

    1991-01-01

    Microbial sulfate reduction followed by sulfide precipitation effectively removes heavy metals from wastewaters. The substrate in the anaerobic zone in a constructed wetland can be designed to emphasize this removal process. This group of bacteria requires CH 2 O, P, N, and SO 4 =, reducing conditions, and pH range of 5-9 (pH=7 is optimum). The objective of this study was to find an inexpensive source of nutrients that would give the best initial production of sulfide and make a good wetland substrate. All tested materials contain sufficient P and N; mine drainage provides sulfate. Thus, tests focused on finding organic material that provides the proper nutrients and does not cause the culture to fall below pH of 5. Among chemical nutrients, sodium lactate combined with (NH 4 ) 2 HPO 4 were the only compounds that produced sulfide after 11 days. Among complex nutrients, only cow manure produced sulfide after 26 days. Among complex carbohydrates, cracked corn and raw rice produced sulfide after 10 days. Most substrates failed to produce sulfide because anaerobic fermentation reduced the pH below 5. Presently, cracked corn is the best candidate for a substrate. Five grams of cow manure produced 0.14 millimole of sulfide whereas 0.1 g of cracked corn produced 0.22 millimole

  15. Growth and sedimentation of fine particles produced in aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Hatada, Motoyoshi; Jonah, C.D.

    1994-10-01

    It is known that palladium and palladium-silver fine particles were formed from deaerated aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation. Changes in particle size and with amount of particles in the solution with time during and after irradiation were studied using dynamic light scattering technique and UV spectrophotometer. The particles formed from palladium sulfate solution are found to be water-filled bulky particles of diameter of 200 nm, which grow by mutual coagulation even after irradiation was terminated. Average density depends on concentration of palladium ion in the solution and dose, and the lowest density was about 2 g/cm 3 for particles of 200 nm obtained from 0.06 mM solution by 2.4 kGy irradiation. The average density of the particles obtained from palladium sulfate-silver sulfate solutions was smaller than those obtained for the corresponding palladium sulfate solutions. Supersonic agitation destroyed coagulated precipitates to form fine particles, but did not form clusters of a few atoms. (author)

  16. The Level of Europium-154 Contaminating Samarium-153-EDTMP Activates the Radiation Alarm System at the US Homeland Security Checkpoints

    Directory of Open Access Journals (Sweden)

    Mohammed Najeeb Al Hallak

    2009-08-01

    Full Text Available 153Sm-EDTMP is a radiopharmaceutical composed of EDTMP (ethylenediamine-tetramethylenephosphonate and Samarium-153 [1]. 153Sm-EDTMP has an affinity for skeletal tissue and concentrates in areas with increased bone turnover; thus, it is successfully used in relieving pain related to diffuse bone metastases [1]. The manufacturing process of 153Sm-EDTMP leads to contamination with 154Eu (Europium-154 [2]. A previous study only alluded to the retention of 154Eu in the bones after receiving treatment with 153Sm-EDTMP [2]. Activation of the alarm at security checkpoints after 153Sm-EDTMP therapy has not been previously reported. Two out of 15 patients who received 153Sm-EDTMP at Roger Maris Cancer Center (Fargo, N. Dak., USA activated the radiation activity sensors while passing through checkpoints; one at a US airport and the other while crossing theAmerican-Canadian border. We assume that the 154Eu which remained in the patients’ bones activated the sensors. Methods: In order to investigate this hypothesis, we obtained the consent from 3 of our 15 patients who received 153Sm-EDTMP within the previous 4 months to 2 years, including the patient who had activated the radiation alarm at the airport. The patients were scanned with a handheld detector and a gamma camera for energies from 511 keV to 1.3 MeV. Results: All three patients exhibited identical spectral images, and further analysis showed that the observed spectra are the result of 154Eu emissions. Conclusion: Depending on the detection thresholds and windows used by local and federal authorities, the remaining activity of 154Eu retained in patients who received 153Sm-EDTMP could be sufficient enough to increase the count rates above background levels and activate the sensors. At Roger Maris Cancer Center, patients are now informed of the potential consequences of 153Sm-EDTMP therapy prior to initiating treatment. In addition, patients treated with 153Sm-EDTMP at Roger Maris Cancer Center

  17. TH-C-19A-12: Two-Dimensional High Spatial-Resolution Dosimeter Using Europium Doped Potassium Chloride

    International Nuclear Information System (INIS)

    Li, H; Yang, D; Xiao, Z; Driewer, J; Han, Z; Low, D

    2014-01-01

    Purpose: Recent research has shown that KCl:Eu2+ has great potential for use in megavoltage radiation therapy dosimetry because this material exhibits excellent storage performance and is reusable due to strong radiation hardness. This work reports our attempts to fabricate 2D KCl:Eu2+ storage phosphor films (SPFs) using both a physical vapor deposition (PVD) method and a tape casting method. Methods: A thin layer of KCl:Eu2+ was deposited on a substrate of borosilicate glass (e.g., laboratory slides) with a PVD system. For tape casting, a homogenous suspension containing storage phosphor particles, liquid vehicle and polymer binder was formed and subsequently cast by doctor-blade onto a polyethylene terephthalate substrate to form a 150 μm thick SPF. Results: X ray diffraction analysis showed that a 10 μm thick PVD sample was composed of highly crystalline KCl. No additional phases were observed, suggesting that the europium activator had completed been incorporated into the KCl matrix. Photostimulated luminescence and photoluminescence spectra suggested that F (Cl−) centers were the electron storage centers post x ray irradiation and that Eu2+ cations acted as luminescence centers in the photostimulation process. The 150 μm thick casted KCl:Eu2+ SPF showed sub-millimeter spatial resolution. Monte Carlo simulations further demonstrated that the admixture of 20% KCl:Eu2+ and 80% low Z polymer binder exhibited almost no energy dependence in a 6 MV beam. KCl:Eu2+ pellet samples showed a large dynamic range from 0.01 cGy to 60 Gy dose-to-water, and saturated at approximately 500 Gy as a Result of its intrinsic high radiation hardness. Conclusions: This discovery research provides strong evidence that KCl:Eu2+ based SPF with associated readout apparatus could Result in a novel electronic film system that has all the desirable features associated with classic radiographic film and, importantly, water equivalence and the capability of permanent identification of

  18. TH-C-19A-12: Two-Dimensional High Spatial-Resolution Dosimeter Using Europium Doped Potassium Chloride

    Energy Technology Data Exchange (ETDEWEB)

    Li, H; Yang, D; Xiao, Z [Washington University School of Medicine, St. Louis, MO (United States); Driewer, J [University of Nebraska Medical Center, Omaha, NE (United States); Han, Z [Brigham and Womens Hospital and Harvard Medical School, Boston, MA (United States); Low, D [UCLA, Los Angeles, CA (United States)

    2014-06-15

    Purpose: Recent research has shown that KCl:Eu2+ has great potential for use in megavoltage radiation therapy dosimetry because this material exhibits excellent storage performance and is reusable due to strong radiation hardness. This work reports our attempts to fabricate 2D KCl:Eu2+ storage phosphor films (SPFs) using both a physical vapor deposition (PVD) method and a tape casting method. Methods: A thin layer of KCl:Eu2+ was deposited on a substrate of borosilicate glass (e.g., laboratory slides) with a PVD system. For tape casting, a homogenous suspension containing storage phosphor particles, liquid vehicle and polymer binder was formed and subsequently cast by doctor-blade onto a polyethylene terephthalate substrate to form a 150 μm thick SPF. Results: X ray diffraction analysis showed that a 10 μm thick PVD sample was composed of highly crystalline KCl. No additional phases were observed, suggesting that the europium activator had completed been incorporated into the KCl matrix. Photostimulated luminescence and photoluminescence spectra suggested that F (Cl−) centers were the electron storage centers post x ray irradiation and that Eu2+ cations acted as luminescence centers in the photostimulation process. The 150 μm thick casted KCl:Eu2+ SPF showed sub-millimeter spatial resolution. Monte Carlo simulations further demonstrated that the admixture of 20% KCl:Eu2+ and 80% low Z polymer binder exhibited almost no energy dependence in a 6 MV beam. KCl:Eu2+ pellet samples showed a large dynamic range from 0.01 cGy to 60 Gy dose-to-water, and saturated at approximately 500 Gy as a Result of its intrinsic high radiation hardness. Conclusions: This discovery research provides strong evidence that KCl:Eu2+ based SPF with associated readout apparatus could Result in a novel electronic film system that has all the desirable features associated with classic radiographic film and, importantly, water equivalence and the capability of permanent identification of

  19. The confused world of sulfate attack on concrete

    International Nuclear Information System (INIS)

    Neville, Adam

    2004-01-01

    External sulfate attack is not completely understood. Part I identifies the issues involved, pointing out disagreements, and distinguishes between the mere occurrence of chemical reactions of sulfates with hydrated cement paste and the damage or deterioration of concrete; only the latter are taken to represent sulfate attack. Furthermore, sulfate attack is defined as deleterious action involving sulfate ions; if the reaction is physical, then, it is physical sulfate attack that takes place. The discussion of the two forms of sulfate attack leads to a recommendation for distinct nomenclature. Sulfate attack on concrete structures in service is not widespread, and the amount of laboratory-based research seems to be disproportionately large. The mechanisms of attack by different sulfates--sodium, calcium, and magnesium--are discussed, including the issue of topochemical and through-solution reactions. The specific aspects of the action of magnesium sulfate are discussed, and the differences between laboratory conditions and field exposure are pointed out. Part II discusses the progress of sulfate attack and its manifestations. This is followed by a discussion of making sulfate-resisting concrete. One of the measures is to use Type V cement, and this topic is extensively discussed. Likewise, the influence of w/c on sulfate resistance is considered. The two parameters are not independent of one another. Moreover, the cation in the sulfate salt has a strong bearing on the efficiency of the Type V cement. Recent interpretations of the Bureau of Reclamation tests, both long term and accelerated, are evaluated, and it appears that they need reworking. Part III reviews the standards and guides for the classification of the severity of exposure of structures to sulfates and points out the lack of calibration of the various classes of exposure. A particular problem is the classification of soils because much depends on the extraction ratio of sulfate in the soil: there is a

  20. A radioimmunoassay for measurement of thyroxine sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, I.J.; Santini, F.; Hurd, R.E.; Chua Teco, G.N. (Univ. of California Center for the Health Sciences, Los Angeles (United States))

    1993-01-01

    A highly sensitive, specific, and reproducible RIA has been developed to measure T[sub 4] sulfate (T[sub 4]S) in ethanol extracts of serum. rT[sub 3] sulfate (rT[sub 3]S) cross-reacted 7.1%, and T[sub 3]S cross-reacted 0.59% in the RIA; T[sub 4], T[sub 3], rT[sub 3] and 3,3[prime]-diiodothyronine cross-reacted 0.004% or less. The recovery of nonradioactive T[sub 4]S added to serum averaged 95%. The detection threshold of the RIA was 18 pmol/L. The coefficient of variation averaged 6.9% within an assay and 12% between assays. T[sub 4]S was bound by T[sub 4]-binding globulin and albumin in serum. The free fraction of T[sub 4]S in four normal sera averaged 0.06% compared to a value of 0.03% for T[sub 4] (P < 0.001). The serum concentration of T[sub 4]S was (mean [+-] SE) 19 [+-] 1.2 pmol/L in normal subjects, 33 [+-] 10 in hyperthyroid patients with Graves disease, 42 [+-] 15 in hypothyroid patients, 34 [+-] 6.9 in patients with systematic nonthyroidal illnesses, 21 [+-] 4.3 in pregnant women at 15-40 weeks gestation, and 245 [+-] 26 in cord blood sera of newborns; the value in the newborn was significantly different from normal (P < 0.001). Administration of sodium ipodate (Oragrafin; 3 g, orally) to hyperthyroid patients was associated with a transient increase in serum T[sub 4]S. The T[sub 4]S content of the thyroid gland was less than 1/4000th that of T[sub 4]. We conclude that (1) T[sub 4]S is a normal component of human serum, and its levels are markedly increased in newborn serum and amniotic fluid; and (2) the sulfation pathway plays an important role in the metabolism of T[sub 4] in man. 28 refs., 4 figs., 2 tabs.

  1. Biological processes for the production of aryl sulfates

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention generally relates to the field of biotechnology as it applies to the production of aryl sulfates using polypeptides or recombinant cells comprising said polypeptides. More particularly, the present invention pertains to polypeptides having aryl sulfotransferase activity......, recombinant host cells expressing same and processes for the production of aryl sulfates employing these polypeptides or recombinant host cells....

  2. Dietary reference intakes for water, potassium, sodium, chloride, and sulfate

    National Research Council Canada - National Science Library

    Institute of Medicine (U.S.). Panel on Dietary Reference Intakes for Electrolytes and Water

    2005-01-01

    ... intake to the risk of high blood pressure and hypertension as well as other diseases and the amounts of water from beverages and foods needed to maintain hydration. In addition, since requirements for sulfur can be met by inorganic sulfate in the diets of animals, a review of the role in inorganic sulfur in the form of sulfate is included. The gro...

  3. Effects of magnesium sulfate on the acquisition and reinstatement of ...

    African Journals Online (AJOL)

    In the current study, the effects of magnesium sulfate on the acquisition and reinstatement of morphine-induced conditioned place preference (CPP) in an animal model were investigated. The acquisition and extinction and reinstatement phases induced using morphine 40 and 10mg/kg. Magnesium sulfate 300 and 600 ...

  4. Sulfur accumulation and atmospherically deposited sulfate in the Lake States.

    Science.gov (United States)

    Mark B. David; George Z. Gernter; David F. Grigal; Lewis F. Ohmann

    1989-01-01

    Characterizes the mass of soil sulfur (adjusted for nitrogen), and atmospherically deposited sulfate along an acid precipitation gradient from Minnesota to Michigan. The relationship of these variables, presented graphically through contour mapping, suggests that patterns of atmospheric wet sulfate deposition are reflected in soil sulfur pools.

  5. Sulfated zirconia modified SBA-15 catalysts for cellobiose hydrolysis

    NARCIS (Netherlands)

    Degirmenci, V.; Uner, D.; Cinlar, B.; Shanks, B.H.; Yilmaz, A.; Santen, van R.A.; Hensen, E.J.M.

    2011-01-01

    Zirconia modified SBA-15 becomes a very active catalyst for the selective hydrolysis of cellobiose to glucose after sulfation. Spectroscopic investigations indicate the presence of Brønsted acid sites with similar properties to those present in conventional sulfated zirconia. Indications are found

  6. Reductive and sorptive properties of sulfate green rust (GRSO4)

    DEFF Research Database (Denmark)

    Nedel, Sorin

    The Fe(II), Fe(III) hydroxide containing sulfate in its structure, called sulfate green rust (GRSO4), can effectively reduce and convert contaminants to less mobile and less toxic forms. However, the ability of GRSO4 to remove positively charged species from solution, via sorption, is very limited...

  7. Sulfate was a trace constituent of Archean seawater

    DEFF Research Database (Denmark)

    Crowe, Sean Andrew; Paris, Guillaume; Katsev, Sergei

    2014-01-01

    In the low-oxygen Archean world (>2400 million years ago), seawater sulfate concentrations were much lower than today, yet open questions frustrate the translation of modern measurements of sulfur isotope fractionations into estimates of Archean seawater sulfate concentrations. In the water column...

  8. Extraction and determination of chondroitin sulfate from fish processing byproducts

    Science.gov (United States)

    Chondroitin sulfate (CS) refers to a group of sulfated glycosaminoglycan containing a chain of alternating N-acetylgalactosamine and glucuronic acid sugars. It is a major component of the extracellular matrix of cartilage and attached to proteins. CS is usually an over the counter dietary supplement...

  9. Annual sulfate budgets for Dutch lowland peat polders

    NARCIS (Netherlands)

    Vermaat, Jan E.; Harmsen, Joop; Hellmann, Fritz A.; Geest, van der Harm G.; Klein, de Jeroen J.M.; Kosten, Sarian; Smolders, Alfons J.P.; Verhoeven, Jos T.A.; Mes, Ron G.; Ouboter, Maarten

    2016-01-01

    Annual sulfate mass balances have been constructed for four low-lying peat polders in the Netherlands, to resolve the origin of high sulfate concentrations in surface water, which is considered a water quality problem, as indicated amongst others by the absence of sensitive water plant species.

  10. Transmission spectra study of sulfate substituted potassium dihydrogen phosphate

    KAUST Repository

    LI, LIANG

    2013-04-18

    Potassium dihydrogen phosphate (KDP) crystals with different amounts of sulfate concentration were grown and the transmittance spectrum was studied. A crystal with high sulfate replacement density exhibits heavy absorption property in the ultraviolet region which confirms and agrees well with former results. © 2013 Astro Ltd.

  11. Preparation and characterization of a chemically sulfated cashew gum polysaccharide

    Energy Technology Data Exchange (ETDEWEB)

    Moura Neto, Erico de; Maciel, Jeanny da S.; Cunha, Pablyana L. R.; Paula, Regina Celia M. de; Feitosa, Judith P.A., E-mail: judith@dqoi.ufc.br [Departamento de Quimica Organica e Inorganica, Universidade Federal do Ceara, Fortaleza (Brazil)

    2011-09-15

    Cashew gum (CG) was sulfated in pyridine:formamide using chlorosulfonic acid as the reagent. Confirmation of sulfation was obtained by Fourier transform infrared (FTIR) spectroscopy through the presence of an asymmetrical S=O stretching vibration at 1259 cm{sup -1}. The degrees of substitution were 0.02, 0.24 and 0.88 determined from the sulfur percentage. 1D and 2D nuclear magnetic resonance (NMR) data showed that the sulfation occurred at primary carbons. An increase of at least 4% of the solution viscosity was observed due to sulfation. The thermal gravimetric curves (TGA) indicate that the derivatives are stable up to ca. 200 deg C. The sulfated CG is compared to carboxymethylated CG in order to verify the possibility of the use of the former in the preparation of polyelectrolyte complexes; the latter is already being used for this application. (author)

  12. Sulfate reduction in an entrained-flow black liquor gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Kymaelaeinen, M.; Janka, K. [Tampella Power, Tampere (Finland); Frederick, W.J.; Littau, M.; Sricharoenchaikul, V.; Jivakanun, N.; Waag, K. [Oregon State Univ., Corvallis, OR (United States). Dept. of Chemical Engineering

    1995-12-31

    Sulfate reduction and carbon conversion during pyrolysis and gasification of black liquor particles were experimentally studied in a laminar entrained-flow reactor. A model was also developed to simulate an entrained-flow black liquor gasifier. Experimental results were then compared to model calculations. Results indicated that carbon must be present to get a high degree of sulfate reduction during gasification. It is therefore important to balance the rates of carbon conversion and sulfate reduction. High local temperatures in the reactor should be avoided so that carbon does not convert too rapidly, but temperatures of nearly 1000 degrees C are required to achieve good sulfate reduction. It was suggested that a new equation was needed to adequately predict sulfate reduction in an entrained-flow black liquor gasifier. 12 refs., 8 figs., 5 tabs.

  13. Extraction of beryllium sulfate by a long chain amine

    International Nuclear Information System (INIS)

    Etaix, E.S.

    1968-01-01

    The extraction of sulfuric acid in aqueous solution by a primary amine in benzene solution, 3-9 (diethyl) - 6-amino tri-decane (D.E.T. ) - i.e., with American nomenclature 1-3 (ethyl-pentyl) - 4-ethyl-octyl amine (E.P.O.) - has made it possible to calculate the formation constants of alkyl-ammonium sulfate and acid sulfate. The formula of the beryllium and alkyl-ammonium sulfate complex formed in benzene has next been determined, for various initial acidity of the aqueous solution. Lastly, evidence has been given of negatively charged complexes of beryllium and sulfate in aqueous solution, through the dependence of the aqueous sulfate ions concentration upon beryllium extraction. The formation constant of these anionic complexes has been evaluated. (author) [fr

  14. Dendritic Polyglycerol Sulfate for Therapy and Diagnostics

    Directory of Open Access Journals (Sweden)

    Nadine Rades

    2018-05-01

    Full Text Available Dendritic polyglycerol sulfate (dPGS has originally been investigated as an anticoagulant to potentially substitute for the natural glycosaminoglycan heparin. Compared to unfractionated heparin, dPGS possesses lower anticoagulant activity but a much higher anticomplementary effect. Since coagulation, complement activation, and inflammation are often present in the pathophysiology of numerous diseases, dPGS polymers with both anticoagulant and anticomplementary activities represent promising candidates for the development of polymeric drugs of nanosized architecture. In this review, we describe the nanomedical applications of dPGS based on its anti-inflammatory activity. Furthermore, the application of dPGS as a carrier molecule for diagnostic molecules and therapeutic drugs is reviewed, based on the ability to target tumors and localize in tumor cells. Finally, the application of dPGS for inhibition of virus infections is described.

  15. Moessbauer study of hydrated iron sulfates

    International Nuclear Information System (INIS)

    Araujo, S.I.; Danon, J.; Iannarella, L.

    1991-01-01

    The hydrated iron sulfates amarantite Fe(SO sub(4))(OH).3H sub(2)O, copiapite (Mg,Al)Fe sup(3+) sub(4)(SO sub(4)) sub(6)(OH) sub(2).20H sub(2)O and ungemachite K sub(3)Na sub(9)Fe(SO sub(4)) sub(6)(OH) sub(3).9H sub(2)O were studied by Moessbauer Spectroscopy (MS) in connection with Differential Scanning Calorimetry (DSC). The effect of the dehydration on the hyperfine parameters at the Fe sites was investigated. For amarantite, the Moessbauer spectrum remained practically unchanged, while the Fe sup(3+) quadrupole splittings for copiapite and ungemachite increased. The Fe sup(2+) quadrupole splitting of ungemachite was also unchanged. We have found out the anisotropy of the recoiless absorption probability for the sup(57)Fe Moessbauer gamma ray in amarantite. The three minerals were found to be highly hygroscopic after the dehydration consequent of the DSC measurements. (author)

  16. Europium resonance parameters from neutron capture and transmission measurements in the energy range 0.01–200 eV

    International Nuclear Information System (INIS)

    Leinweber, G.; Barry, D.P.; Burke, J.A.; Rapp, M.J.; Block, R.C.; Danon, Y.; Geuther, J.A.; Saglime III, F.J.

    2014-01-01

    Highlights: • Metal samples were sealed and imaged with X-rays to determine sample uniformity. • Eleven new resonances were identified below 100 eV. • The resonance regions of 151 Eu and 153 Eu have been extended from 100 to 200 eV. • The thermal total cross section for 151 Eu was measured, up (9 ± 3)% from ENDF/B-VII.1. • Radiation widths were assigned for all resonances from experimental data. - Abstract: Europium is a good absorber of neutrons suitable for use as a nuclear reactor control material. It is also a fission product in the low-yield tail at the high end of the fission fragment mass distribution. Measurements have been made of the stable isotopes with natural and enriched samples. The linear electron accelerator center (LINAC) at the Rensselaer Polytechnic Institute (RPI) was used to explore neutron interactions with europium in the energy region from 0.01 to 200 eV. Neutron capture and transmission measurements were performed by the time-of-flight technique. Two transmission measurements were performed at flight paths of 15 and 25 m with 6 Li glass scintillation detectors. The neutron capture measurements were performed at a flight path of 25 m with a 16-segment sodium iodide multiplicity detector. Resonance parameters were extracted from the data using the multilevel R-matrix Bayesian code SAMMY. A table of resonance parameters and their uncertainties is presented. To prevent air oxidation metal samples were sealed in airtight aluminum cans in an inert environment. Metal samples of natural europium, 47.8 atom% 151 Eu, 52.2 atom% 153 Eu, as well as metal samples enriched to 98.77 atom% 153 Eu were measured. The measured neutron capture resonance integral for 153 Eu is (9.9 ± 0.4)% larger than ENDF/B-VII.1. The capture resonance integral for 151 Eu is (7 ± 1)% larger than ENDF/B-VII.1. Another significant finding from these measurements was a significant increase in thermal total cross section for 151 Eu, up (9 ± 3)% from ENDF/B-VII.1

  17. Neutron cross section evaluations of europium isotopes in 1 keV - 30 MeV energy range. Format - validation - comparison; Evaluation de sections efficaces pour des neutrons incidents sur des isotopes d'europium aux energies 1 keV - 30 MeV. Format - validation - comparaison

    Energy Technology Data Exchange (ETDEWEB)

    Dossantos-Uzarralde, P.; Le Luel, C.; Bauge, E. [CEA Bruyeres le Chatel, 91 (France). Dept. de Physique Theorique et Appliquee

    2004-07-01

    This paper presents neutron cross section evaluations of Europium isotopes. The cross sections are evaluated in 1 keV - 30 MeV energy range for the isotopes {sup 146}Eu, {sup 147}Eu, {sup 148}Eu, {sup 149}Eu, {sup 150}Eu, {sup 151}Eu, {sup 152}Eu, {sup 153}Eu, {sup 154}Eu in their ground state. This evaluation includes cross section productions of the long life isomeric states. Special attention is put on the options used for the description of the files written in ENDF-6 format. The final issue is a proposal of a new breed of ENDF-6 formatted neutron activation file. (authors)

  18. Biological sulfate removal from gypsum contaminated construction and demolition debris.

    Science.gov (United States)

    Kijjanapanich, Pimluck; Annachhatre, Ajit P; Esposito, Giovanni; van Hullebusch, Eric D; Lens, Piet N L

    2013-12-15

    Construction and demolition debris (CDD) contains high levels of sulfate that can cause detrimental environmental impacts when disposed without adequate treatment. In landfills, sulfate can be converted to hydrogen sulfide under anaerobic conditions. CDD can thus cause health impacts or odor problems to landfill employees and surrounding residents. Reduction of the sulfate content of CDD is an option to overcome these problems. This study aimed at developing a biological sulfate removal system to reduce the sulfate content of gypsum contaminated CDD in order to decrease the amount of solid waste, to improve the quality of CDD waste for recycling purposes and to recover sulfur from CDD. The treatment leached out the gypsum contained in CDD by water in a leaching column. The sulfate loaded leachate was then treated in a biological sulfate reducing Upflow Anaerobic Sludge Blanket (UASB) reactor to convert the sulfate to sulfide. The UASB reactor was operated at 23 ± 3 °C with a hydraulic retention time and upflow velocity of 15.5 h and 0.1 m h(-1), respectively while ethanol was added as electron donor at a final organic loading rate of 3.46 g COD L(-1) reactor d(-1). The CDD leachate had a pH of 8-9 and sulfate dissolution rates of 526.4 and 609.8 mg L(-1) d(-1) were achieved in CDD gypsum and CDD sand, respectively. Besides, it was observed that the gypsum dissolution was the rate limiting step for the biological treatment of CDD. The sulfate removal efficiency of the system stabilized at around 85%, enabling the reuse of the UASB effluent for the leaching step, proving the versatility of the bioreactor for practical applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Chondroitin / dermatan sulfate modification enzymes in zebrafish development.

    Directory of Open Access Journals (Sweden)

    Judith Habicher

    Full Text Available Chondroitin/dermatan sulfate (CS/DS proteoglycans consist of unbranched sulfated polysaccharide chains of repeating GalNAc-GlcA/IdoA disaccharide units, attached to serine residues on specific proteins. The CS/DS proteoglycans are abundant in the extracellular matrix where they have essential functions in tissue development and homeostasis. In this report a phylogenetic analysis of vertebrate genes coding for the enzymes that modify CS/DS is presented. We identify single orthologous genes in the zebrafish genome for the sulfotransferases chst7, chst11, chst13, chst14, chst15 and ust and the epimerase dse. In contrast, two copies were found for mammalian sulfotransferases CHST3 and CHST12 and the epimerase DSEL, named chst3a and chst3b, chst12a and chst12b, dsela and dselb, respectively. Expression of CS/DS modification enzymes is spatially and temporally regulated with a large variation between different genes. We found that CS/DS 4-O-sulfotransferases and 6-O-sulfotransferases as well as CS/DS epimerases show a strong and partly overlapping expression, whereas the expression is restricted for enzymes with ability to synthesize di-sulfated disaccharides. A structural analysis further showed that CS/DS sulfation increases during embryonic development mainly due to synthesis of 4-O-sulfated GalNAc while the proportion of 6-O-sulfated GalNAc increases in later developmental stages. Di-sulfated GalNAc synthesized by Chst15 and 2-O-sulfated GlcA/IdoA synthesized by Ust are rare, in accordance with the restricted expression of these enzymes. We also compared CS/DS composition with that of heparan sulfate (HS. Notably, CS/DS biosynthesis in early zebrafish development is more dynamic than HS biosynthesis. Furthermore, HS contains disaccharides with more than one sulfate group, which are virtually absent in CS/DS.

  20. Role of protein sulfation in vasodilation induced by minoxidil sulfate, a K+ channel opener

    International Nuclear Information System (INIS)

    Meisheri, K.D.; Oleynek, J.J.; Puddington, L.

    1991-01-01

    Evidence from contractile, radioisotope ion flux and electrophysiological studies suggest that minoxidil sulfate (MNXS) acts as a K+ channel opener in vascular smooth muscle. This study was designed to examine possible biochemical mechanisms by which MNXS exerts such an effect. Experiments performed in the isolated rabbit mesenteric artery (RMA) showed that MNXS, 5 microM, but not the parent compound minoxidil, was a potent vasodilator. Whereas the relaxant effects of an another K+ channel opener vasodilator, BRL-34915 (cromakalim), were removed by washing with physiological saline solution, the effects of MNXS persisted after repeated washout attempts. Furthermore, after an initial exposure of segments of intact RMA to [35S] MNXS, greater than 30% of the radiolabel was retained 2 hr after removal of the drug. In contrast, retention of radiolabel was not detected with either [3H]MNXS (label on the piperidine ring of MNXS) or [3H]minoxidil (each less than 3% after a 2-hr washout). These data suggested that the sulfate moiety from MNXS was closely associated with the vascular tissue. To determine if proteins were the acceptors of sulfate from MNXS, intact RMAs were incubated with [35S]MNXS, and then 35S-labeled proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analyzed by fluorography. Preferential labeling of a 116 kD protein was detected by 2 and 5 min of treatment. A 43 kD protein (resembling actin) also showed significant labeling. A similar profile of 35S-labeled proteins was observed in [35S] MNXS-treated A7r5 rat aortic smooth muscle cells, suggesting that the majority of proteins labeled by [35S]MNXS in intact RMA were components of smooth muscle cells

  1. Heparan Sulfate and Chondroitin Sulfate Glycosaminoglycans Are Targeted by Bleomycin in Cancer Cells.

    Science.gov (United States)

    Li, Xiulian; Lan, Ying; He, Yanli; Liu, Yong; Luo, Heng; Yu, Haibo; Song, Ni; Ren, Sumei; Liu, Tianwei; Hao, Cui; Guo, Yunliang; Zhang, Lijuan

    2017-01-01

    Bleomycin is a clinically used anti-cancer drug that produces DNA breaks once inside of cells. However, bleomycin is a positively charged molecule and cannot get inside of cells by free diffusion. We previously reported that the cell surface negatively charged glycosaminoglycans (GAGs) may be involved in the cellular uptake of bleomycin. We also observed that a class of positively charged small molecules has Golgi localization once inside of the cells. We therefore hypothesized that bleomycin might perturb Golgi-operated GAG biosynthesis. We used stable isotope labeling coupled with LC/MS analysis of GAG disaccharides simultaneously from bleomycin-treated and non-treated cancer cells. To further understand the cytotoxicity of bleomycin and its relationship to GAGs, we used sodium chlorate to inhibit GAG sulfation and commercially available GAGs to compete for cell surface GAG/bleomycin interactions in seven cell lines including CHO745 defective in both heparan sulfate and chondroitin sulfate biosynthesis. we discovered that heparan sulfate GAG was significantly undersulfated and the quantity and disaccharide compositions of GAGs were changed in bleomycin-treated cells in a concentration- and time-dependent manner. We revealed that bleomycin-induced cytotoxicity was directly related to cell surface GAGs. GAGs were targeted by bleomycin both at cell surface and at Golgi. Thus, GAGs might be the biological relevant molecules that might be related to the bleomycin-induced fibrosis in certain cancer patients, a severe side effect with largely unknown molecular mechanism. © 2017 The Author(s). Published by S. Karger AG, Basel.

  2. Determination of the hydrolysis constants of Europium (III), in ion strength media 4, 5 and 6 M NaClO{sub 4} at 303 K; Determinacion de las constantes de hidrolisis del Europio (III), en medios de fuerza ionica 4, 5 y 6 M de NaClO{sub 4} a 303 K

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado B, A.; Jimenez R, M.; Solache R, M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    This work was made with the purpose to complete information about the hydrolysis constants of Europium (III) in high ion strength media. So it was determined at a ion forces media 4, 5 and 6 M of sodium perchlorate at 303 K. The method used was the potentiometric with the aid of the Super quad computer program. In high ion strength media, the measurements of p H do not correspond directly to negative logarithm of the concentration of hydrogen ions, by this it is necessary to calibrate the electrode in these conditions. The Europium was hydrolized at pC{sub H} values greater 6 in all cases. The potentiometric method used under the described experimental conditions is adequate to determine the hydrolysis constants of Europium (III). According to the results and diagrams of chemical species of Europium obtained we can conclude that the hydrolysis constants, differ by its distribution but not in its identity. (Author)

  3. N-sulfation of heparan sulfate is critical for syndecan-4-mediated podocyte cell-matrix interactions

    NARCIS (Netherlands)

    Sugar, T.; Wassenhove-McCarthy, D.J.; Orr, A.W.; Green, J.; Kuppevelt, T.H. van; McCarthy, K.J.

    2016-01-01

    Previous research has shown that podocytes unable to assemble heparan sulfate on cell surface proteoglycan core proteins have compromised cell-matrix interactions. This report further explores the role of N-sulfation of intact heparan chains in podocyte-matrix interactions. For the purposes of this

  4. Low levels of H2S may replace sulfate as sulfur source in sulfate-deprived onion

    NARCIS (Netherlands)

    Durenkamp, Mark; De Kok, LJ

    2005-01-01

    Onion (Allium cepa L.) was exposed to low levels of H2S in order to investigate to what extent H2S could be used as a sulfur source for growth under sulfate-deprived conditions. Sulfate deprivation for a two-week period resulted in a decreased biomass production of the shoot, a subsequently

  5. Estrogenicity and androgenicity screening of PCB sulfate monoesters in human breast cancer MCF-7 cells

    OpenAIRE

    Flor, Susanne; He, Xianran; Lehmler, Hans-Joachim; Ludewig, Gabriele

    2015-01-01

    Recent studies identified PCB sulfate esters as a major product of PCB metabolism. Since hydroxy-PCBs (HO-PCBs), the immediate precursors of PCB sulfates and important contributors to PCB toxicity, were shown to have estrogenic activity, we investigated the estrogenicity/androgenicty of a series of PCB sulfate metabolites. We synthesized the five possible structural sulfate monoester metabolites of PCB 3, a congener shown to be biotransformed to sulfates, a sulfate ester of the paint-specific...

  6. Development of affinity-based delivery of NGF from a chondroitin sulfate biomaterial

    OpenAIRE

    Butterfield, Karen Chao; Conovaloff, Aaron W.; Panitch, Alyssa

    2011-01-01

    Chondroitin sulfate is a major component of the extracellular matrix in both the central and peripheral nervous systems. Chondroitin sulfate is upregulated at injury, thus methods to promote neurite extension through chondroitin sulfate-rich matrices and synthetic scaffolds are needed. We describe the use of both chondroitin sulfate and a novel chondroitin sulfate-binding peptide to control the release of nerve growth factor. Interestingly, the novel chondroitin sulfate-binding peptide enhanc...

  7. Potential for beneficial application of sulfate reducing bacteria in sulfate containing domestic wastewater treatment.

    Science.gov (United States)

    van den Brand, T P H; Roest, K; Chen, G H; Brdjanovic, D; van Loosdrecht, M C M

    2015-11-01

    The activity of sulfate reducing bacteria (SRB) in domestic wastewater treatment plants (WWTP) is often considered as a problem due to H2S formation and potential related odour and corrosion of materials. However, when controlled well, these bacteria can be effectively used in a positive manner for the treatment of wastewater. The main advantages of using SRB in wastewater treatment are: (1) minimal sludge production, (2) reduction of potential pathogens presence, (3) removal of heavy metals and (4) as pre-treatment of anaerobic digestion. These advantages are accessory to efficient and stable COD removal by SRB. Though only a few studies have been conducted on SRB treatment of domestic wastewater, the many studies performed on industrial wastewater provide information on the potential of SRB in domestic wastewater treatment. A key-parameter analyses literature study comprising pH, organic substrates, sulfate, salt, temperature and oxygen revealed that the conditions are well suited for the application of SRB in domestic wastewater treatment. Since the application of SRB in WWTP has environmental benefits its application is worth considering for wastewater treatment, when sulfate is present in the influent.

  8. Acidity-Reactivity Relationships in Catalytic Esterification over Ammonium Sulfate-Derived Sulfated Zirconia

    Directory of Open Access Journals (Sweden)

    Abdallah I. M. Rabee

    2017-07-01

    Full Text Available New insight was gained into the acidity-reactivity relationships of sulfated zirconia (SZ catalysts prepared via (NH42SO4 impregnation of Zr(OH4 for propanoic acid esterification with methanol. A family of systematically related SZs was characterized by bulk and surface analyses including XRD, XPS, TGA-MS, N2 porosimetry, temperature-programmed propylamine decomposition, and FTIR of adsorbed pyridine, as well as methylbutynol (MBOH as a reactive probe molecule. Increasing surface sulfation induces a transition from amphoteric character for the parent zirconia and low S loadings <1.7 wt %, evidenced by MBOH conversion to 3-hydroxy-3-methyl-2-butanone, methylbutyne and acetone, with higher S loadings resulting in strong Brønsted-Lewis acid pairs upon completion of the sulfate monolayer, which favored MBOH conversion to prenal. Catalytic activity for propanoic acid esterification directly correlated with acid strength determined from propylamine decomposition, coincident with the formation of Brønsted-Lewis acid pairs identified by MBOH reactive titration. Monodispersed bisulfate species are likely responsible for superacidity at intermediate sulfur loadings.

  9. Opiate-like excitatory effects of steroid sulfates and calcium-complexing agents given cerebroventricularly.

    Science.gov (United States)

    LaBella, F S; Havlicek, V; Pinsky, C

    1979-01-12

    Intracerebroventricular administration of 10--20 microgram of steroid-O-sulfates induced hypermotility, agitation, salivation, EEG abnormalities, stereotypies, wet dog shakes and seizures. Equivalent effects resulted from 30--200 microgram morphine sulfate (H2SO4 salt), 50 microgram EGTA or 300--400 microgram of sodium sulfate or phosphate, but not chloride, nitrate or acetate. Non-steroid sulfates, steroid glucuronides and steroid phosphates were inactive. Naloxone, previously found to antagonize the excitatory effects of androsterone sulfate, failed to antagonize those of cortisol sulfate, sodium sulfate or EGTA. These findings suggest a role for extracellular calcium ions and for sulfate derived from circulating steroids in central responses to opiates.

  10. Sulfates on Mars: TES Observations and Thermal Inertia Data

    Science.gov (United States)

    Cooper, C. D.; Mustard, J. F.

    2001-05-01

    The high resolution thermal emission spectra returned by the TES spectrometer on the MGS spacecraft have allowed the mapping of a variety of minerals and rock types by different sets of researchers. Recently, we have used a linear deconvolution approach to compare sulfate-palagonite soil mixtures created in the laboratory with Martian surface spectra. This approach showed that a number of areas on Mars have spectral properties that match those of sulfate-cemented soils (but neither loose powder mixtures of sulfates and soils nor sand-sized grains of disaggregated crusted soils). These features do not appear to be caused by atmospheric or instrumental effects and are thus believed to be related to surface composition and texture. The distribution and physical state of sulfate are important pieces of information for interpreting surface processes on Mars. A number of different mechanisms could have deposited sulfate in surface layers. Some of these include evaporation of standing bodies of water, aerosol deposition of volcanic gases, hydrothermal alteration from groundwater, and in situ interaction between the atmosphere and soil. The areas on Mars with cemented sulfate signatures are spread across a wide range of elevations and are generally large in spatial scale. Some of the areas are associated with volcanic regions, but many are in dark red plains that have previously been interpreted as duricrust deposits. Our current work compares the distribution of sulfate-cemented soils as mapped by the spectral deconvolution approach with thermal inertia maps produced from both Viking and MGS-TES. Duricrust regions, interpreted from intermediate thermal inertia values, are large regions thought to be sulfate-cemented soils similar to coherent, sulfate-rich materials seen at the Viking lander sites. Our observations of apparent regions of cemented sulfate are also large in spatial extent. This scale information is important for evaluating formation mechanisms for the

  11. Ferric sulfates on Mars: Surface Explorations and Laboratory Experiments

    Science.gov (United States)

    Wang, A.; Ling, Z.; Freeman, J. J.

    2008-12-01

    Recent results from missions to Mars have reinforced the importance of sulfates for Mars science. They are the hosts of water, the sinks of acidity, and maybe the most active species in the past and current surface/near-surface processes on Mars. Fe-sulfate was found frequently by Spirit and Opportunity rovers: jarosite in Meridiani Planum outcrops and a less specific "ferric sulfate" in the salty soils excavated by Spirit at Gusev Crater. Pancam spectral analysis suggests a variety of ferric sulfates in these soils, i.e. ferricopiapite, jarosite, fibroferrite, and rhomboclase. A change in the Pancam spectral features occurred in Tyrone soils after ~ 190 sols of exposure to surface conditions. Dehydration of ferric sulfate is a possible cause. We synthesized eight ferric sulfates and conducted a series of hydration/dehydration experiments. Our goal was to establish the stability fields and phase transition pathways of these ferric sulfates. In our experiments, water activity, temperature, and starting structure are the variables. No redox state change was observed. Acidic, neutral, and basic salts were used. Ferric sulfate sample containers were placed into relative humidity buffer solutions that maintain static relative humidity levels at three temperatures. The five starting phases were ferricopiapite (Fe4.67(SO4)6(OH)2.20H2O), kornelite (Fe2(SO4)3.7H2O), rhomboclase (FeH(SO4)2.4H2O), pentahydrite (Fe2(SO4)3.5H2O), and an amorphous phase (Fe2(SO4)3.5H2O). A total of one hundred fifty experiments have been running for nearly ten months. Thousands of coupled Raman and gravimetric measurements were made at intermediate steps to monitor the phase transitions. The first order discovery from these experiments is the extremely large stability field of ferricopiapite. Ferricopiapite is the major ferric sulfate to precipitate from a Fe3+-S-rich aqueous solution at mid-low temperature, and it has the highest H2O/Fe ratio (~ 4.3). However, unlike the Mg-sulfate with highest

  12. Setting constraints on the nature and origin of the two major hydrous sulfates on Mars: Monohydrated and polyhydrated sulfates

    Science.gov (United States)

    Wang, Alian; Jolliff, Bradley L.; Liu, Yang; Connor, Kathryn

    2016-04-01

    Monohydrated Mg sulfate (MgSO4·H2O) and polyhydrated sulfate are the most common and abundant hydrous sulfates observed thus far on Mars. They are widely distributed and coexist in many locations. On the basis of results from two new sets of experiments, in combination with past experimental studies and the subsurface salt mineralogy observed at a saline playa (Dalangtan, DLT) in a terrestrial analogue hyperarid region on the Tibet Plateau, we can now set new constraints on the nature and origin of these two major Martian sulfates. Starkeyite (MgSO4·4H2O) is the best candidate for polyhydrated sulfate. MgSO4·H2O in the form of "LH-1w," generated from dehydration of Mg sulfates with high degrees of hydration, is the most likely mineral form for the majority of Martian monohydrated Mg sulfate. Two critical properties of Mg sulfates are responsible for the coexistence of these two phases that have very different degrees of hydration: (1) the metastability of a substructural unit in starkeyite at relatively low temperatures, and (2) catalytic effects attributed to coprecipitated species (sulfates, chlorides, oxides, and hydroxides) from chemically complex brines that help overcome the metastability of starkeyite. The combination of these two properties controls the coexistence of the LH-1w layer and starkeyite layers at many locations on Mars, which sometimes occur in an interbedded stratigraphy. The structural H2O held by these two broadly distributed sulfates represents a large H2O reservoir at the surface and in the shallow subsurface on current Mars.

  13. Europium(III) complex-functionalized magnetic nanoparticle as a chemosensor for ultrasensitive detection and removal of copper(II) from aqueous solution.

    Science.gov (United States)

    Liu, Jing; Zuo, Wei; Zhang, Wei; Liu, Jian; Wang, Zhiyi; Yang, Zhengyin; Wang, Baodui

    2014-10-07

    Ultrasensitive, accurate detection and separation of heavy metal ions is very important in environmental monitoring and biological detection. In this paper, a highly sensitive and specific detection method for Cu(2+) based on the fluorescence quenching of a europium(III) hybrid magnetic nanoprobe is presented. This nanoprobe can detect Cu(2+) over a wide pH range (5.0-10.0) with a detection limit as low as 0.1 nM and it can be used for detecting Cu(2+) in living cells. After the magnetic separation, the Cu(2+) concentration decreased to 1.18 ppm, which is less than the US EPA drinking water standard (1.3 ppm), and more than 70% Cu(2+) could be removed when the amount of nanocomposite 1 reached 1 mg.

  14. Study for the determination of samarium, europium,terbium, dysprosium and yttrium in gadolinium oxide matrix by means of atomic absorption spectrophotometry using a graphite furnace

    International Nuclear Information System (INIS)

    Caires, A.C.F.

    1985-01-01

    A study for determination of samarium, europium, terbium, dysprosium and yttrium in a gadolinium oxide matrix by atomic absorption spectrophotometry using a graphite furnace is presented. The best charrring and atomization conditions were estabilished for each element, the most convenient ressonance lines being selected as well. The study was carried out for the mentioned lanthanides both when pure and when in binary mixtures with gadolinium, besides those where all for them were together with gadolinium. The determination limits for pure lanthanides were found to be between 1.3 and 9.6 ng assuming a 20% relative standard deviation as acceptable. The detection limits were in the range 0.51 and 7.5 ng, assuming as positive any answer higher than twofold the standard deviation. (author) [pt

  15. Sol-gel approach to the novel organic-inorganic hybrid composite films with ternary europium complex covalently bonded with silica matrix

    International Nuclear Information System (INIS)

    Dong Dewen; Yang Yongsheng; Jiang Bingzheng

    2006-01-01

    Novel organic-inorganic hybrid composite films with ternary lanthanide complex covalently bonded with silica matrix were prepared in situ via co-ordination of N-(3-propyltriethoxysilane)-4-carboxyphthalimide (TAT) and 1,10-phenanthroline (Phen) with europium ion (Eu 3+ ) during a sol-gel approach and characterized by the means of spectrofluorimeter, phosphorimeter and infrared spectrophotometer (FTIR). The resulting transparent films showed improved photophysical properties, i.e. increased luminescence intensity and longer luminescence lifetime, compared with the corresponding binary composite films without Phen. All the results revealed that the intense luminescence of the composite film was attributed to the efficient energy transfer from ligands, especially Phen, to chelated Eu 3+ and the reduced non-radiation through the rigid silica matrix and 'site isolation'

  16. Synthesis and luminescence properties of two novel europium (III) perchlorate complexes with bis(benzylsulfinyl)methane and 1,10-phenanthroline

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wen-Xian, E-mail: nmglwx@163.com [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Guo, Feng [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Zheng, Yu-Shan [Inner Mongolia Autonomous Region Product Quality Inspection Institute, Hohhot 010010 (China); Cao, Xiao-Fang; Feng, Shu-Yan; Bai, Juan; Xin, Xiao-Dong [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China)

    2014-09-15

    Two novel binary and ternary Europium (III) perchlorate complexes were synthesized. The binary complex was prepared with bis(benzylsulfinyl)methane as ligand, and the ternary complex was with bis(benzylsulfinyl)methane as first ligand and 1,10-Phenanthroline as second ligand. They were characterized by element analysis, molar conductivity, coordination titration analysis, IR, TG-DSC, {sup 1}HNMR and UV spectra. The results indicated that the composition of binary and ternary complexes was EuL{sub 2.5}·(ClO{sub 4}){sub 3}·3H{sub 2}O and Eu{sub 2}L{sub 4}·phen·(ClO{sub 4}){sub 6}·12H{sub 2}O (L=C{sub 6}H{sub 5}CH{sub 2}SOCH{sub 2}SOCH{sub 2}C{sub 6}H{sub 5}), respectively. The fluorescent spectra illustrated that the complexes displayed characteristic Europium (III) ion fluorescence in solid state, indicating the ligands favored energy transfer to the excitation state energy level of it. The strongest characteristic fluorescence emission intensity of the ternary system was 1.87 times as strong as that of the binary system. The fluorescent quantum yields of the Eu (III) ternary and binary complexes were also calculated. Additionally, the phosphorescence spectra and the luminescence mechanisms of the complexes were studied and explained. - Highlights: • Two rare earth complexes are new. And they are stabilized. • The intensities of the two rare earth complexes were all stronger and the lifetimes were longer. • The introduction of the second organic ligand1,10-Phenanthroline enhanced the fluorescence intensity. • The fluorescent quantum yields of two complexes being calculated are both very high.

  17. Extraction of uranium(6), transuranium elements and europium by bidentate neutral phosphorus- and phosphorus-nitrogen-containing reagents with substituent in methylene bridge

    International Nuclear Information System (INIS)

    Kochetkova, N.E.; Kojro, O.Eh.; Nesterova, N.P.; Medved', T.Ya.; Chmutova, M.K.; Myasoedov, B.F.; Kabachnik, M.I.

    1986-01-01

    The influence of substituents in methylene bridge on solubility, extractivity and selectivity of bidentate neutral phosphorus- and phosphorus-nitrogen-containing reagents in the process of U(6), TUE, Eu extraction has been studied. It is ascertained that hydrogen substitution in the bridge of tetraphenylmethylenediphosphine dioxide (1) causes a decrease in the extractivity of reagent as to TPE, uranium (6) and europium. There is no visible regular relation between basicity and extractivity of substituted reagents. Hydrogen substitution in the bridge of diphenyl[diethylcarbamoylmethyl]phosphine oxide (2) causes a decrease in extractivity of the reagent as to TPE, uranium (6) and europium. In contrast to monodentate neutral reagents, when bidentate neutral reagents are used, sometimes no increase in the reagent extractivity with an increase in its basicity is observed. When fragments restricting the conformation mobility of bidentate reagent molecule are introduced in it (here substituents in methylene bridge), it may result in the violation of the regularity, since of all the factors affecting the reagent extractivity the spatial factor may become the prevailing one. On hydrogen substitution in the bridge of 1 separation factors of practically all (with few exceptions) studied pairs of elements increase. Hydrogen substitution in the bridge of 2 causes an increase in separation factor of U (6) /Am pair and it does not affect the separation factor of Am/Eu pair. Hydrogen substitution in the bridge of 1 and 2 does not result in the preparation of more efficient and considerably more selective reagents for extractive isolation and separation of the elements, but some of the substituted reagents (Cl-substituted 1, for instance) may turn out useful for the element separation

  18. A facile one-pot hydrothermal method to prepare europium-doped titania hollow phosphors and their sensitized luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Feng Xuan; Yang Ling; Zhang Nianchun [Department of Chemistry and Institute of Nanochemistry, Jinan University, 601 Western Huangpu Road, Guangzhou 510632 (China); Liu Yingliang, E-mail: tliuyl@jnu.edu.c [Department of Chemistry and Institute of Nanochemistry, Jinan University, 601 Western Huangpu Road, Guangzhou 510632 (China)

    2010-09-17

    Research highlights: {yields} The strongest emission intensity was observed with TiO{sub 2}:Eu{sub 0.2} hollow spheres and TiO{sub 2}:Eu{sub 0.2} hollow spheres calcining at 550 {sup o}C. Moreover, the strongest excitation of TiO{sub 2}:Eu{sub 0.2} hollow spheres transferred from 400 to 500 {sup o}C and the effective nonradiative energy transfer from the TiO{sub 2} hollow spheres host matrix to Eu{sup 3+} ions crystal field states was realized due to changes of crystalline field in the environment around Eu{sup 3+} ions occupying Ti{sup 4+} sites. The proposed energy transfer mechanism was that UV light is absorbed in the band of TiO{sub 2} hollow spheres crystal and then the energy is relaxed to the defect states of TiO{sub 2} host. The energy can transfer to the crystal states of Eu{sup 3+} ions ({sup 7}F{sub j}, j = 0, 1, 2, 3 and 4), which results in efficient photoluminescence. The fluorescent intensity of TiO{sub 2}:Eu{sub 0.2} hollow spheres was 2.2 times as strong as that of TiO{sub 2}:Eu{sub 0.2} bulk material. - Abstract: Monodisperse europium-activated titania hollow phosphors had been synthesized by a facile one-pot hydrothermal method using carbon spheres as hard templates. Samples were characterized by X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive spectrometer and photoluminescence spectrum. The strongest emission intensity was observed with TiO{sub 2}:Eu{sub 0.2} hollow spheres and TiO{sub 2}:Eu{sub 0.2} hollow spheres calcining at 550 {sup o}C. Moreover, the strongest excitation of TiO{sub 2}:Eu{sub 0.2} hollow spheres transferred from 400 to 500 {sup o}C and the effective nonradiative energy transfer from the TiO{sub 2} hollow spheres host matrix to Eu{sup 3+} ions crystal field states was realized due to changes of crystalline field in the environment around Eu{sup 3+} ions occupying Ti{sup 4+} sites. The proposed energy transfer mechanism was that UV light is absorbed in the band

  19. Biological functions of iduronic acid in chondroitin/dermatan sulfate.

    Science.gov (United States)

    Thelin, Martin A; Bartolini, Barbara; Axelsson, Jakob; Gustafsson, Renata; Tykesson, Emil; Pera, Edgar; Oldberg, Åke; Maccarana, Marco; Malmstrom, Anders

    2013-05-01

    The presence of iduronic acid in chondroitin/dermatan sulfate changes the properties of the polysaccharides because it generates a more flexible chain with increased binding potentials. Iduronic acid in chondroitin/dermatan sulfate influences multiple cellular properties, such as migration, proliferation, differentiation, angiogenesis and the regulation of cytokine/growth factor activities. Under pathological conditions such as wound healing, inflammation and cancer, iduronic acid has diverse regulatory functions. Iduronic acid is formed by two epimerases (i.e. dermatan sulfate epimerase 1 and 2) that have different tissue distribution and properties. The role of iduronic acid in chondroitin/dermatan sulfate is highlighted by the vast changes in connective tissue features in patients with a new type of Ehler-Danlos syndrome: adducted thumb-clubfoot syndrome. Future research aims to understand the roles of the two epimerases and their interplay with the sulfotransferases involved in chondroitin sulfate/dermatan sulfate biosynthesis. Furthermore, a better definition of chondroitin/dermatan sulfate functions using different knockout models is needed. In this review, we focus on the two enzymes responsible for iduronic acid formation, as well as the role of iduronic acid in health and disease. © 2013 The Authors Journal compilation © 2013 FEBS.

  20. Interpreting isotopic analyses of microbial sulfate reduction in oil reservoirs

    Science.gov (United States)

    Hubbard, C. G.; Engelbrektson, A. L.; Druhan, J. L.; Cheng, Y.; Li, L.; Ajo Franklin, J. B.; Coates, J. D.; Conrad, M. E.

    2013-12-01

    Microbial sulfate reduction in oil reservoirs is often associated with secondary production of oil where seawater (28 mM sulfate) is commonly injected to maintain reservoir pressure and displace oil. The hydrogen sulfide produced can cause a suite of operating problems including corrosion of infrastructure, health exposure risks and additional processing costs. We propose that monitoring of the sulfur and oxygen isotopes of sulfate can be used as early indicators that microbial sulfate reduction is occurring, as this process is well known to cause substantial isotopic fractionation. This approach relies on the idea that reactions with reservoir (iron) minerals can remove dissolved sulfide, thereby delaying the transport of the sulfide through the reservoir relative to the sulfate in the injected water. Changes in the sulfate isotopes due to microbial sulfate reduction may therefore be measurable in the produced water before sulfide is detected. However, turning this approach into a predictive tool requires (i) an understanding of appropriate fractionation factors for oil reservoirs, (ii) incorporation of isotopic data into reservoir flow and reactive transport models. We present here the results of preliminary batch experiments aimed at determining fractionation factors using relevant electron donors (e.g. crude oil and volatile fatty acids), reservoir microbial communities and reservoir environmental conditions (pressure, temperature). We further explore modeling options for integrating isotope data and discuss whether single fractionation factors are appropriate to model complex environments with dynamic hydrology, geochemistry, temperature and microbiology gradients.

  1. Sulfate Reduction Remediation of a Metals Plume Through Organic Injection

    International Nuclear Information System (INIS)

    Phifer, M.A.

    2003-01-01

    Laboratory testing and a field-scale demonstration for the sulfate reduction remediation of an acidic/metals/sulfate groundwater plume at the Savannah River Site has been conducted. The laboratory testing consisted of the use of anaerobic microcosms to test the viability of three organic substrates to promote microbially mediated sulfate reduction. Based upon the laboratory testing, soybean oil and sodium lactate were selected for injection during the subsequent field-scale demonstration. The field-scale demonstration is currently ongoing. Approximately 825 gallons (3,123 L) of soybean oil and 225 gallons (852 L) of 60 percent sodium lactate have been injected into an existing well system within the plume. Since the injections, sulfate concentrations in the injection zone have significantly decreased, sulfate-reducing bacteria concentrations have significantly increased, the pH has increased, the Eh has decreased, and the concentrations of many metals have decreased. Microbially mediated sulfate reduction has been successfully promoted for the remediation of the acidic/metals/sulfate plume by the injection of soybean oil and sodium lactate within the plume

  2. Sulfate Aerosol in the Arctic: Source Attribution and Radiative Forcing

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Wang, Hailong [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Smith, Steven J. [Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park MD USA; Easter, Richard C. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Rasch, Philip J. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA

    2018-02-08

    Source attributions of Arctic sulfate and its direct radiative effect for 2010–2014 are quantified in this study using the Community Earth System Model (CESM) equipped with an explicit sulfur source-tagging technique. Regions that have high emissions and/or are near/within the Arctic present relatively large contributions to Arctic sulfate burden, with the largest contribution from sources in East Asia (27%). East Asia and South Asia together have the largest contributions to Arctic sulfate concentrations at 9–12 km, whereas sources within or near the Arctic account largely below 2 km. For remote sources with strong emissions, their contributions to Arctic sulfate burden are primarily driven by meteorology, while contributions of sources within or near the Arctic are dominated by their emission strength. The sulfate direct radiative effect (DRE) is –0.080 W m-2 at the Arctic surface, offsetting the net warming effect from the combination of in-snow heating and DRE cooling from black carbon. East Asia, Arctic local and Russia/Belarus/Ukraine sources contribute –0.017, –0.016 and –0.014 W m-2, respectively, to Arctic sulfate DRE. A 20% reduction in anthropogenic SO2 emissions leads to a net increase of +0.013 W m-2 forcing at the Arctic surface. These results indicate that a joint reduction in BC emissions could prevent possible Arctic warming from future reductions in SO2 emissions. Sulfate DRE efficiency calculations suggest that short transport pathways together with meteorology favoring long sulfate lifetimes make certain sources more efficient in influencing the Arctic sulfate DRE.

  3. Localized sulfate-reducing zones in a coastal plain aquifer

    Science.gov (United States)

    Brown, C.J.; Coates, J.D.; Schoonen, M.A.A.

    1999-01-01

    High concentrations of dissolved iron in ground water of coastal plain or alluvial aquifers contribute to the biofouling of public supply wells for which treatment and remediation is costly. Many of these aquifers, however, contain zones in which microbial sulfate reduction and the associated precipitation of iron-sulfide minerals decreases iron mobility. The principal water-bearing aquifer (Magothy Aquifer of Cretaceous age) in Suffolk County, New York, contains localized sulfate-reducing zones in and near lignite deposits, which generally are associated with clay lenses. Microbial analyses of core samples amended with [14C]-acetate indicate that microbial sulfate reduction is the predominant terminal-electron-accepting process (TEAP) in poorly permeable, lignite-rich sediments at shallow depths and near the ground water divide. The sulfate-reducing zones are characterized by abundant lignite and iron-sulfide minerals, low concentrations of Fe(III) oxyhydroxides, and by proximity to clay lenses that contain pore water with relatively high concentrations of sulfate and dissolved organic carbon. The low permeability of these zones and, hence, the long residence time of ground water within them, permit the preservation and (or) allow the formation of iron-sulfide minerals, including pyrite and marcasite. Both sulfate-reducing bacteria (SRB) and iron-reducing bacteria (IRB) are present beneath and beyond the shallow sulfate-reducing zones. A unique Fe(III)-reducing organism, MD-612, was found in core sediments from a depth of 187 m near the southern shore of Long Island. The distribution of poorly permeable, lignite-rich, sulfate-reducing zones with decreased iron concentration is varied within the principal aquifer and accounts for the observed distribution of dissolved sulfate, iron, and iron sulfides in the aquifer. Locating such zones for the placement of production wells would be difficult, however, because these zones are of limited aerial extent.

  4. Evolutionary relationships and functional diversity of plant sulfate transporters

    Directory of Open Access Journals (Sweden)

    Hideki eTakahashi

    2012-01-01

    Full Text Available Sulfate is an essential nutrient cycled in nature. Ion transporters that specifically facilitate the transport of sulfate across the membranes are found ubiquitously in living organisms. The phylogenetic analysis of known sulfate transporters and their homologous proteins from eukaryotic organisms indicate two evolutionarily distinct groups of sulfate transport systems. One major group named Tribe 1 represents yeast and fungal SUL, plant SULTR and animal SLC26 families. The evolutionary origin of SULTR family members in land plants and green algae is suggested to be common with yeast and fungal sulfate transporters (SUL and animal anion exchangers (SLC26. The lineage of plant SULTR family is expanded into four subfamilies (SULTR1 to SULTR4 in land plant species. By contrast, the putative SULTR homologues from Chlorophyte green algae are in two separate lineages; one with the subfamily of plant tonoplast-localized sulfate transporters (SULTR4, and the other diverged before the appearance of lineages for SUL, SULTR and SLC26. There also was a group of yet undefined members of putative sulfate transporters in yeast and fungi divergent from these major lineages in Tribe 1. The other distinct group is Tribe 2, primarily composed of animal sodium-dependent sulfate/carboxylate transporters (SLC13 and plant tonoplast-localized dicarboxylate transporters (TDT. The putative sulfur-sensing protein (SAC1 and SAC1-like transporters (SLT of Chlorophyte green algae, bryophyte and lycophyte show low degrees of sequence similarities with SLC13 and TDT. However, the phylogenetic relationship between SAC1/SLT and the other two families, SLC13 and TDT in Tribe 2, is not clearly supported. In addition, the SAC1/SLT family is completely absent in the angiosperm species analyzed. The present study suggests distinct evolutionary trajectories of sulfate transport systems for land plants and green algae.

  5. Development of affinity-based delivery of NGF from a chondroitin sulfate biomaterial.

    Science.gov (United States)

    Butterfield, Karen Chao; Conovaloff, Aaron W; Panitch, Alyssa

    2011-01-01

    Chondroitin sulfate is a major component of the extracellular matrix in both the central and peripheral nervous systems. Chondroitin sulfate is upregulated at injury, thus methods to promote neurite extension through chondroitin sulfate-rich matrices and synthetic scaffolds are needed. We describe the use of both chondroitin sulfate and a novel chondroitin sulfate-binding peptide to control the release of nerve growth factor. Interestingly, the novel chondroitin sulfate-binding peptide enhances the controlled release properties of the chondroitin sulfate gels. While introduction of chondroitin sulfate into a scaffold inhibits primary cortical outgrowth, the combination of chondroitin sulfate, chondroitin sulfate-binding peptide and nerve growth factor promotes primary cortical neurite outgrowth in chondroitin sulfate gels.

  6. Incorporation of Monovalent Cations in Sulfate Green Rust

    DEFF Research Database (Denmark)

    Christiansen, B. C.; Dideriksen, K.; Katz, A.

    2014-01-01

    Green rust is a naturally occurring layered mixed-valent ferrous-ferric hydroxide, which can react with a range of redox-active compounds. Sulfate-bearing green rust is generally thought to have interlayers composed of sulfate and water. Here, we provide evidence that the interlayers also contain...... with water showed that Na+ and K+ were structurally fixed in the interlayer, whereas Rb+ and Cs+ could be removed, resulting in a decrease in the basal layer spacing. The incorporation of cations in the interlayer opens up new possibilities for the use of sulfate green rust for exchange reactions with both...

  7. Improved biological processes for the production of aryl sulfates

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention generally relates to the field of biotechnology as it applies to the production of aryl sulfates using recombinant host cells. More particularly, the present invention pertains to recombinant host cells comprising (e.g., expressing) a polypeptide having aryl sulfotransferase...... activity, wherein said recombinant host cells have been modified to have an increased uptake of sulfate compared to identical host cells that does not carry said modification. Further provided are processes for the production of aryl sulfates, such as zosteric acid, employing such recombinant host cells....

  8. Studies on sulfate attack: Mechanisms, test methods, and modeling

    Science.gov (United States)

    Santhanam, Manu

    The objective of this research study was to investigate various issues pertaining to the mechanism, testing methods, and modeling of sulfate attack in concrete. The study was divided into the following segments: (1) effect of gypsum formation on the expansion of mortars, (2) attack by the magnesium ion, (3) sulfate attack in the presence of chloride ions---differentiating seawater and groundwater attack, (4) use of admixtures to mitigate sulfate attack---entrained air, sodium citrate, silica fume, and metakaolin, (5) effects of temperature and concentration of the attack solution, (6) development of new test methods using concrete specimens, and (7) modeling of the sulfate attack phenomenon. Mortar specimens using portland cement (PC) and tricalcium silicate (C 3S), with or without mineral admixtures, were prepared and immersed in different sulfate solutions. In addition to this, portland cement concrete specimens were also prepared and subjected to complete and partial immersion in sulfate solutions. Physical measurements, chemical analyses and microstructural studies were performed periodically on the specimens. Gypsum formation was seen to cause expansion of the C3S mortar specimens. Statistical analyses of the data also indicated that the quantity of gypsum was the most significant factor controlling the expansion of mortar bars. The attack by magnesium ion was found to drive the reaction towards the formation of brucite. Decalcification of the C-S-H and its subsequent conversion to the non-cementitious M-S-H was identified as the mechanism of destruction in magnesium sulfate attack. Mineral admixtures were beneficial in combating sodium sulfate attack, while reducing the resistance to magnesium sulfate attack. Air entrainment did not change the measured physical properties, but reduced the visible distress of the mortars. Sodium citrate caused a substantial reduction in the rate of damage of the mortars due to its retarding effect. Temperature and

  9. Damage modelling in concrete subject to sulfate attack

    Directory of Open Access Journals (Sweden)

    N. Cefis

    2014-07-01

    Full Text Available In this paper, we consider the mechanical effect of the sulfate attack on concrete. The durability analysis of concrete structures in contact to external sulfate solutions requires the definition of a proper diffusion-reaction model, for the computation of the varying sulfate concentration and of the consequent ettringite formation, coupled to a mechanical model for the prediction of swelling and material degradation. In this work, we make use of a two-ions formulation of the reactive-diffusion problem and we propose a bi-phase chemo-elastic damage model aimed to simulate the mechanical response of concrete and apt to be used in structural analyses.

  10. Micro-SHINE Uranyl Sulfate Irradiations at the Linac

    Energy Technology Data Exchange (ETDEWEB)

    Youker, Amanda J. [Argonne National Lab. (ANL), Argonne, IL (United States); Kalensky, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Schneider, John [Argonne National Lab. (ANL), Argonne, IL (United States); Byrnes, James [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-08-01

    Peroxide formation due to water radiolysis in a uranyl sulfate solution is a concern for the SHINE Medical Technologies process in which Mo-99 is generated from the fission of dissolved low enriched uranium. To investigate the effects of power density and fission on peroxide formation and uranyl-peroxide precipitation, uranyl sulfate solutions were irradiated using a 50-MeV electron linac as part of the micro-SHINE experimental setup. Results are given for uranyl sulfate solutions with both high and low enriched uranium irradiated at different linac powers.

  11. Sulfated oligosaccharide structures, as determined by NMR techniques

    Energy Technology Data Exchange (ETDEWEB)

    Noseda, M.D.; Duarte, M.E.R.; Tischer, C.A.; Gorin, P.A.J. [Parana Univ., Curitiba, PR (Brazil). Dept. De Bioquimica; Cerezo, A.S. [Buenos Aires Univ. Nacional (Argentina). Dept. de Quimica Organica

    1997-12-31

    Carrageenans are sulfated polysaccharides, produced by red seaweeds (Rhodophyta), that have important biological and physico-chemical properties. Using partial autohydrolysis, we obtained sulfated oligosaccharides from a {lambda}-carrageenan (Noseda and Cerezo, 1993). These oligosaccharides are valuable not only for the study of the structures of the parent carrageenans but also for their possible biological activities. In this work we determined the chemical structure of one of the sulfated oligosaccharides using 1D and 2D NMR techniques. (author) 4 refs., 8 figs., 1 tabs.

  12. Chemical Structures and Bioactivities of Sulfated Polysaccharides from Marine Algae

    Directory of Open Access Journals (Sweden)

    H. Stephen Ewart

    2011-02-01

    Full Text Available Sulfated polysaccharides and their lower molecular weight oligosaccharide derivatives from marine macroalgae have been shown to possess a variety of biological activities. The present paper will review the recent progress in research on the structural chemistry and the bioactivities of these marine algal biomaterials. In particular, it will provide an update on the structural chemistry of the major sulfated polysaccharides synthesized by seaweeds including the galactans (e.g., agarans and carrageenans, ulvans, and fucans. It will then review the recent findings on the anticoagulant/antithrombotic, antiviral, immuno-inflammatory, antilipidemic and antioxidant activities of sulfated polysaccharides and their potential for therapeutic application.

  13. The europium(II) oxide halides Eu{sub 2}OBr{sub 2} and Eu{sub 2}OI{sub 2}; Die Europium(II)-Oxidhalogenide Eu{sub 2}OBr{sub 2} und Eu{sub 2}OI{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Rudolph, Daniel; Schleid, Thomas [Stuttgart Univ. (Germany). Inst. fuer Anorganische Chemie

    2017-07-01

    The syntheses and crystal structures of the two isotypic europium(II) oxide halides Eu{sub 2}OBr{sub 2} and Eu{sub 2}OI{sub 2} are reported. They crystallize orthorhombically in the space group Ibam (Z=4; Eu{sub 2}OBr{sub 2}: a=709.86(5), b=1200.34(9), c=628.71(4) pm; Eu{sub 2}OI{sub 2}: a=739.78(5), b=1295.13(9), c=644.82(4) pm). The unit cell parameters presented here, and thus the interatomic distances of Eu{sub 2}OI{sub 2}, are significantly smaller than the ones reported in the literature, which is explained by the substitution of europium with larger barium cations due to the synthesis route described in the early study. Central building blocks of both crystal structures are trans-edge-connected [OEu{sub 4}]{sup 6+} tetrahedra forming straight {sup 1}{sub ∞}{[OEu"e_4_/_2]"2"+} chains running parallel to the [001] direction. Bundled like a hexagonal rod packing, their interaction is achieved by Br{sup -} or I{sup -} anions for charge compensation.

  14. Application of a room temperature ionic liquid for nuclear spent fuel reprocessing: speciation of trivalent europium and solvatation effects; Application d'un liquide ionique basse temperature pour les procedes de separation: speciation de l'europium trivalent et effets solvatation

    Energy Technology Data Exchange (ETDEWEB)

    Moutiers, G.; Mekki, S. [CEA Saclay, Dept. de Physico-Chimie, Service de Chimie Physique, 91 - Gif sur Yvette (France); Billard, I. [IN2P3/CNRS, 69 - Villeurbanne (France)

    2007-07-01

    One of the solutions proposed for the optimization of the long term storage and conditioning of spent nuclear fuel is to separate actinide and lanthanide both from each other and from other less radioactive metallic species. The industrial proposed processes, based on liquid liquid extraction steps, involve solvents with non negligible vapour pressure and may generate contaminated liquid wastes that will have to be reprocessed. During the last decade, some room-temperature ionic liquids have been studied and integrated into industrial processes. The interest on this class of solvent came out from their 'green' properties (non volatile, non flammable, recyclable, etc...), but also from the variability of their physico-chemical properties (stability, hydrophobicity, viscosity) as a function of the RTIL chemical composition. Indeed, it has been shown that classical chemical industrial processes could be transferred into those media, even more improved, while a certain number of difficulties arising from using traditional solvent can be avoided. In this respect, it could be promising to investigate the ability to use room temperature ionic liquid into the spent nuclear fuel reprocessing field. The aim of this this study is to test the ability of the specific ionic liquid bumimTf{sub 2}N to allow trivalent europium extraction. The choice of this metal is based on the chemical analogy with trivalent minor actinides Curium and Americium which are contributing the greatest part of the long-lived high level radioactive wastes. Handling these elements needs to be very cautious for the safety and radioprotection aspect. Moreover, europium is a very sensitive luminescent probe to its environment even at the microscopic scale. The report is structured with four parts. In a first chapter, we present the main physico-chemical properties of an imidazolium-based ionic liquid family, and then we choose the ionic liquid bumimTf{sub 2}N for the whole thesis and start with

  15. Extraction of beryllium sulfate by a long chain amine; Extraction du sulfate de beryllium par une amine a longue chaine

    Energy Technology Data Exchange (ETDEWEB)

    Etaix, E S [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

    1968-06-01

    The extraction of sulfuric acid in aqueous solution by a primary amine in benzene solution, 3-9 (diethyl) - 6-amino tri-decane (D.E.T. ) - i.e., with American nomenclature 1-3 (ethyl-pentyl) - 4-ethyl-octyl amine (E.P.O.) - has made it possible to calculate the formation constants of alkyl-ammonium sulfate and acid sulfate. The formula of the beryllium and alkyl-ammonium sulfate complex formed in benzene has next been determined, for various initial acidity of the aqueous solution. Lastly, evidence has been given of negatively charged complexes of beryllium and sulfate in aqueous solution, through the dependence of the aqueous sulfate ions concentration upon beryllium extraction. The formation constant of these anionic complexes has been evaluated. (author) [French] L'etude de l'extraction de l'acide sulfurique en solution aqueuse par une amine primaire en solution dans le benzene, le diethyl-3,9 amino-6 tridecane (D.E.T.) - autre nom americain 1-3 (ethylpentyl) - 4-ethyloctylamine (E.P.O.) a permis de calculer les constantes de formation du sulfate et de l'hydrogenosulfate d'alkyl-ammonium. La formule du complexe de sulfate de beryllium et d'alkyl-ammonium forme en solution benzenique a ete ensuite determinee pour diverses acidites initiales de la solution aqueuse. Enfin, l'influence de la concentration des ions sulfate de la phase aqueuse sur l'extraction du beryllium a mis en evidence la formation en solution aqueuse de complexes anioniques de sulfate et de beryllium dont la constante de formation a ete evaluee. (auteur)

  16. Extraction of beryllium sulfate by a long chain amine; Extraction du sulfate de beryllium par une amine a longue chaine

    Energy Technology Data Exchange (ETDEWEB)

    Etaix, E.S. [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

    1968-06-01

    The extraction of sulfuric acid in aqueous solution by a primary amine in benzene solution, 3-9 (diethyl) - 6-amino tri-decane (D.E.T. ) - i.e., with American nomenclature 1-3 (ethyl-pentyl) - 4-ethyl-octyl amine (E.P.O.) - has made it possible to calculate the formation constants of alkyl-ammonium sulfate and acid sulfate. The formula of the beryllium and alkyl-ammonium sulfate complex formed in benzene has next been determined, for various initial acidity of the aqueous solution. Lastly, evidence has been given of negatively charged complexes of beryllium and sulfate in aqueous solution, through the dependence of the aqueous sulfate ions concentration upon beryllium extraction. The formation constant of these anionic complexes has been evaluated. (author) [French] L'etude de l'extraction de l'acide sulfurique en solution aqueuse par une amine primaire en solution dans le benzene, le diethyl-3,9 amino-6 tridecane (D.E.T.) - autre nom americain 1-3 (ethylpentyl) - 4-ethyloctylamine (E.P.O.) a permis de calculer les constantes de formation du sulfate et de l'hydrogenosulfate d'alkyl-ammonium. La formule du complexe de sulfate de beryllium et d'alkyl-ammonium forme en solution benzenique a ete ensuite determinee pour diverses acidites initiales de la solution aqueuse. Enfin, l'influence de la concentration des ions sulfate de la phase aqueuse sur l'extraction du beryllium a mis en evidence la formation en solution aqueuse de complexes anioniques de sulfate et de beryllium dont la constante de formation a ete evaluee. (auteur)

  17. Correction: Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfateβ-1→3GalNAc(4-Sulfateβ-1→] motifs in dermatan sulfate on heparin cofactor II activity

    Directory of Open Access Journals (Sweden)

    Sugahara Kazuyuki

    2011-07-01

    Full Text Available Abstract After the publication of the work entitled "Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfateβ-1→3GalNAc(4-Sulfateβ-1→] motifs in dermatan sulfate on heparin cofactor II activity", by Kozlowski et al., BMC Biochemistry 2011, 12:29, we found that the legends to Figures 2 to 5 contain serious mistakes that compromise the comprehension of the work. This correction article contains the correct text of the legends to Figures 2 to 5.

  18. Effects of sodium dodecyl sulfate of polyphenoloxidase

    International Nuclear Information System (INIS)

    Moore, B.M.; Flurkey, W.H.

    1989-01-01

    The effects of sodium dodecyl sulfate (SDS) on the enzymatic and physical characteristics of purified broad bean polyphenoloxidase (PPO) were examined. A sigmoidal increase in PPO activation was observed with increasing SDS concentrations. Half maximal activation occurred at .9 mM SDS well below the CMC of 3.5 mM. No apparent changes in the Km for catechol, pH optimum, of I 50 for tropolone were observed in the presence vs absence of SDS. Thermal inactivation and binding of 14 C dopa increased in the presence of SDS. Analytical ultracentrifugation and HPLC-SEC indicated that SDS did not change the apparent size of the PPO under nondenaturing conditions. Scanning fluorescence spectroscopy showed an increase in intrinsic trp/tyr fluorescence at approximately the same concentration in which SDS activation began. Further addition of SDS caused a large increase in intrinsic fluorescence. These results suggest the SDS causes an apparent conformational change induced by SDS binding which leads to enzyme activation

  19. Monitoring sulfide and sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, R.S.

    1995-12-31

    Simple yet precise and accurate methods for monitoring sulfate-reducing bacteria (SRB) and sulfide remain useful for the study of bacterial souring and corrosion. Test kits are available to measure sulfide in field samples. A more precise methylene blue sulfide assay for both field and laboratory studies is described here. Improved media, compared to that in API RP-38, for enumeration of SRB have been formulated. One of these, API-RST, contained cysteine (1.1 mM) as a reducing agent, which may be a confounding source of sulfide. While cysteine was required for rapid enumeration of SRB from environmental samples, the concentration of cysteine in medium could be reduced to 0.4 mM. It was also determined that elevated levels of yeast extract (>1 g/liter) could interfere with enumeration of SRB from environmental samples. The API-RST medium was modified to a RST-11 medium. Other changes in medium composition, in addition to reduction of cysteine, included reduction of the concentration of phosphate from 3.4 mM to 2.2 mM, reduction of the concentration of ferrous iron from 0.8 mM to 0.5 mM and preparation of a stock mineral solution to ease medium preparation. SRB from environmental samples could be enumerated in a week in this medium.

  20. Quantitative analysis of glycosaminoglycans, chondroitin/dermatan sulfate, hyaluronic acid, heparan sulfate, and keratan sulfate by liquid chromatography-electrospray ionization-tandem mass spectrometry.

    Science.gov (United States)

    Osago, Harumi; Shibata, Tomoko; Hara, Nobumasa; Kuwata, Suguru; Kono, Michihaya; Uchio, Yuji; Tsuchiya, Mikako

    2014-12-15

    We developed a method using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) with a selected reaction monitoring (SRM) mode for simultaneous quantitative analysis of glycosaminoglycans (GAGs). Using one-shot analysis with our MS/MS method, we demonstrated the simultaneous quantification of a total of 23 variously sulfated disaccharides of four GAG classes (8 chondroitin/dermatan sulfates, 1 hyaluronic acid, 12 heparan sulfates, and 2 keratan sulfates) with a sensitivity of less than 0.5 pmol within 20 min. We showed the differences in the composition of GAG classes and the sulfation patterns between porcine articular cartilage and yellow ligament. In addition to the internal disaccharides described above, some saccharides derived from the nonreducing terminal were detected simultaneously. The simultaneous quantification of both internal and nonreducing terminal saccharides could be useful to estimate the chain length of GAGs. This method would help to establish comprehensive "GAGomic" analysis of biological tissues. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Expanding the role of 3-O sulfated heparan sulfate in herpes simplex virus type-1 entry

    International Nuclear Information System (INIS)

    O'Donnell, Christopher D.; Kovacs, Maria; Akhtar, Jihan; Valyi-Nagy, Tibor; Shukla, Deepak

    2010-01-01

    Heparan sulfate (HS) proteoglycans are commonly exploited by multiple viruses for initial attachment to host cells. Herpes simplex virus-1 (HSV-1) is unique because it can use HS for both attachment and penetration, provided specific binding sites for HSV-1 envelope glycoprotein gD are present. The interaction with gD is mediated by specific HS moieties or 3-O sulfated HS (3-OS HS), which are generated by all but one of the seven isoforms of 3-O sulfotransferases (3-OSTs). Here we demonstrate that several common experimental cell lines express unique sets of 3-OST isoforms. While the isoforms 3-OST-3, -5 and -6 were most commonly expressed, isoforms 3-OST-2 and -4 were undetectable in the cell lines examined. Since most cell lines expressed multiple 3-OST isoforms, we addressed the significance of 3-OS HS in HSV-1 entry by down-regulating 2-O-sulfation, a prerequisite for 3-OS HS formation, by knocking down 2-OST expression by RNA interference (RNAi). 2-OST knockdown was verified by reverse-transcriptase PCR and Western blot analysis, while 3-OS HS knockdown was verified by immunofluorescence. Cells showed a significant decrease in viral entry, suggesting an important role for 3-OS HS. Implicating 3-OS HS further, cells knocked down for 2-OST expression also demonstrated decreased cell-cell fusion when cocultivated with effector cells transfected with HSV-1 glycoproteins. Our findings suggest that 3-OS HS may play an important role in HSV-1 entry into many different cell lines.

  2. Wound healing and antibacterial activities of chondroitin sulfate- and acharan sulfate-reduced silver nanoparticles

    International Nuclear Information System (INIS)

    Im, A-Rang; Kim, Jee Young; Kim, Yeong Shik; Kim, Hyun-Seok; Cho, Seonho; Park, Youmie

    2013-01-01

    For topical applications in wound healing, silver nanoparticles (AgNPs) have attracted much attention as antibacterial agents. Herein, we describe a green-synthetic route for the production of biocompatible and crystalline AgNPs using two glycosaminoglycans, chondroitin sulfate (CS) and acharan sulfate (AS), as reducing agents. The synthetic approach avoids the use of toxic chemicals, and the yield of AgNPs formation is found to be 98.1% and 91.1% for the chondroitin sulfate-reduced silver nanoparticles (CS-AgNPs) and the acharan sulfate-reduced silver nanoparticles (AS-AgNPs), respectively. Nanoparticles with mostly spherical and amorphous shapes were observed, with an average diameter of 6.16 ± 2.26 nm for CS-AgNPs and 5.79 ± 3.10 nm for AS-AgNPs. Images of the CS-AgNPs obtained from atomic force microscopy revealed the self-assembled structure of CS was similar to a densely packed woven mat with AgNPs sprinkled on the CS. These nanoparticles were stable under cell culture conditions without any noticeable aggregation. An approximately 128-fold enhancement of the antibacterial activities of the AgNPs was observed against Enterobacter cloacae and Escherichia coli when compared to CS and AS alone. In addition, an in vivo animal model of wound healing activity was tested using mice that were subjected to deep incision wounds. In comparison to the controls, the ointments containing CS-AgNPs and AS-AgNPs stimulated wound closure under histological examination and accelerated the deposition of granulation tissue and collagen in the wound area. The wound healing activity of the ointments containing CS-AgNPs and AS-AgNPs are comparable to that of a commercial formulation of silver sulfadiazine even though the newly prepared ointments contain a lower silver concentration. Therefore, the newly prepared AgNPs demonstrate potential for use as an attractive biocompatible nanocomposite for topical applications in the treatment of wounds. (paper)

  3. Wound healing and antibacterial activities of chondroitin sulfate- and acharan sulfate-reduced silver nanoparticles

    Science.gov (United States)

    Im, A.-Rang; Kim, Jee Young; Kim, Hyun-Seok; Cho, Seonho; Park, Youmie; Kim, Yeong Shik

    2013-10-01

    For topical applications in wound healing, silver nanoparticles (AgNPs) have attracted much attention as antibacterial agents. Herein, we describe a green-synthetic route for the production of biocompatible and crystalline AgNPs using two glycosaminoglycans, chondroitin sulfate (CS) and acharan sulfate (AS), as reducing agents. The synthetic approach avoids the use of toxic chemicals, and the yield of AgNPs formation is found to be 98.1% and 91.1% for the chondroitin sulfate-reduced silver nanoparticles (CS-AgNPs) and the acharan sulfate-reduced silver nanoparticles (AS-AgNPs), respectively. Nanoparticles with mostly spherical and amorphous shapes were observed, with an average diameter of 6.16 ± 2.26 nm for CS-AgNPs and 5.79 ± 3.10 nm for AS-AgNPs. Images of the CS-AgNPs obtained from atomic force microscopy revealed the self-assembled structure of CS was similar to a densely packed woven mat with AgNPs sprinkled on the CS. These nanoparticles were stable under cell culture conditions without any noticeable aggregation. An approximately 128-fold enhancement of the antibacterial activities of the AgNPs was observed against Enterobacter cloacae and Escherichia coli when compared to CS and AS alone. In addition, an in vivo animal model of wound healing activity was tested using mice that were subjected to deep incision wounds. In comparison to the controls, the ointments containing CS-AgNPs and AS-AgNPs stimulated wound closure under histological examination and accelerated the deposition of granulation tissue and collagen in the wound area. The wound healing activity of the ointments containing CS-AgNPs and AS-AgNPs are comparable to that of a commercial formulation of silver sulfadiazine even though the newly prepared ointments contain a lower silver concentration. Therefore, the newly prepared AgNPs demonstrate potential for use as an attractive biocompatible nanocomposite for topical applications in the treatment of wounds.

  4. Predictive mapping of the acidifying potential for acid sulfate soils

    DEFF Research Database (Denmark)

    Boman, A; Beucher, Amélie; Mattbäck, S

    Developing methods for the predictive mapping of the potential environmental impact from acid sulfate soils is important because recent studies (e.g. Mattbäck et al., under revision) have shown that the environmental hazards (e.g. leaching of acidity) related to acid sulfate soils vary depending...... on their texture (clay, silt, sand etc.). Moreover, acidity correlates, not only with the sulfur content, but also with the electrical conductivity (EC) measured after incubation. Electromagnetic induction (EMI) data collected from an EM38 proximal sensor also enabled the detailed mapping of acid sulfate soils...... over a field (Huang et al., 2014).This study aims at assessing the use of EMI data for the predictive mapping of the acidifying potential in an acid sulfate soil area in western Finland. Different supervised classification modelling techniques, such as Artificial Neural Networks (Beucher et al., 2015...

  5. Diversity of sulfur isotope fractionations by sulfate-reducing prokaryotes

    DEFF Research Database (Denmark)

    Detmers, Jan; Brüchert, Volker; Habicht, K S

    2001-01-01

    Batch culture experiments were performed with 32 different sulfate-reducing prokaryotes to explore the diversity in sulfur isotope fractionation during dissimilatory sulfate reduction by pure cultures. The selected strains reflect the phylogenetic and physiologic diversity of presently known...... sulfate reducers and cover a broad range of natural marine and freshwater habitats. Experimental conditions were designed to achieve optimum growth conditions with respect to electron donors, salinity, temperature, and pH. Under these optimized conditions, experimental fractionation factors ranged from 2.......0 to 42.0 per thousand. Salinity, incubation temperature, pH, and phylogeny had no systematic effect on the sulfur isotope fractionation. There was no correlation between isotope fractionation and sulfate reduction rate. The type of dissimilatory bisulfite reductase also had no effect on fractionation...

  6. Initial kinetics of the direct sulfation of limestone

    DEFF Research Database (Denmark)

    Hu, Guilin; Shang, Lei; Dam-Johansen, Kim

    2008-01-01

    The initial kinetics of direct sulfation of Faxe Bryozo, a porous bryozoan limestone was studied in the temperature interval from 873 to 973 K in a pilot entrained flow reactor with very short reaction times (between 0.1 and 0.6 s). The initial conversion rate of the limestone - for conversions...... less than 0.3% - was observed to be significantly promoted by higher SO2 concentrations and lower CO2 concentrations, whereas 02 showed negligible influence. A mathematical model for the sulfation of limestone involving chemical reaction at calcite grain surfaces and solid-state diffusion of carbonate...... ions in calcite grains is established. The validity of the model is limited to the initial sulfation period, in which nucleation of the solid product calcium sulphate is not started. This theoretical reaction-diffusion model gives a good simulation of the initial kinetics of the direct sulfation...

  7. SULFATE RADICAL-BASED ADVANCED OXIDATION PROCESSES- ACS MEETING

    Science.gov (United States)

    This paper will present an overview of sulfate radical-based advanced oxidation technologies for the destruction of environmentally toxic chemicals in wastewater, industrial water, groundwater and sources of water supply. The paper will include fundamental aspects of the generati...

  8. Antenatal Magnesium Sulfate and Neurologic Outcome in Preterm Infants

    NARCIS (Netherlands)

    Doyle, Lex W.; Crowther, Caroline A.; Middleton, Philippa; Marret, Stephane

    OBJECTIVE: To systematically review rates of neurologic outcomes reported in childhood for the preterm fetus exposed to antenatal magnesium sulfate. DATA SOURCES: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register, CENTRAL (The Cochrane Library 2008, Issue 3), relevant

  9. Chondroitin sulfate effects on neural stem cell differentiation.

    Science.gov (United States)

    Canning, David R; Brelsford, Natalie R; Lovett, Neil W

    2016-01-01

    We have investigated the role chondroitin sulfate has on cell interactions during neural plate formation in the early chick embryo. Using tissue culture isolates from the prospective neural plate, we have measured neural gene expression profiles associated with neural stem cell differentiation. Removal of chondroitin sulfate from stage 4 neural plate tissue leads to altered associations of N-cadherin-positive neural progenitors and causes changes in the normal sequence of neural marker gene expression. Absence of chondroitin sulfate in the neural plate leads to reduced Sox2 expression and is accompanied by an increase in the expression of anterior markers of neural regionalization. Results obtained in this study suggest that the presence of chondroitin sulfate in the anterior chick embryo is instrumental in maintaining cells in the neural precursor state.

  10. Inhibitory effect of chondroitin sulfate oligosaccharides on bovine testicular hyaluronidase.

    Science.gov (United States)

    Kakizaki, Ikuko; Koizumi, Hideyo; Chen, Fengchao; Endo, Masahiko

    2015-05-05

    Hyaluronan and chondroitin sulfates are prominent components of the extracellular matrices of animal tissues; however, their functions in relation to their oligosaccharide structures have not yet been fully elucidated. The oligosaccharides of hyaluronan and chondroitin sulfate were prepared and used to investigate their effects on the hydrolysis and transglycosylation reactions of bovine testicular hyaluronidase when hyaluronan was used as a substrate. Hydrolysis and transglycosylation activities were assessed in independent reaction systems by analyzing the products by HPLC. The hydrolysis and transglycosylation reactions of bovine testicular hyaluronidase were dose-dependently inhibited by chondroitin sulfate oligosaccharides, but not by hyaluronan or chondroitin oligosaccharides. A kinetic analysis of the hydrolysis reaction using hyaluronan octasaccharide revealed that the inhibition mode by chondroitin sulfate oligosaccharides was competitive. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Acidity characterization of a titanium and sulfate modified vermiculite

    International Nuclear Information System (INIS)

    Hernandez, W.Y.; Centeno, M.A.; Odriozola, J.A.; Moreno, S.; Molina, R.

    2008-01-01

    A natural vermiculite has been modified with titanium and sulfated by the intercalation and impregnation method in order to optimize the acidity of the clay mineral, and characterization of samples were analyzed by X-ray fluorescence (XRF), X-ray diffraction (XRD), nitrogen adsorption isotherms, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature programmed desorption with ammonia (TPD-NH 3 ). All the modified solids have a significantly higher number of acidic sites with respect to the parent material and in all of these, Broensted as well as Lewis acidity are identified. The presence of sulfate appears not to increase the number of acidic centers in the modified clay. For the materials sulfated with the intercalation method, it is observed that the strength of the acidic sites found in the material increases with the nominal sulfate/metal ratio. Nevertheless, when elevated quantities of sulfur are deposited, diffusion problems in the heptane reaction appear

  12. Relationship between microbial sulfate reduction rates and sulfur isotopic fractionation

    Science.gov (United States)

    Matsu'Ura, F.

    2009-12-01

    Sulfate reduction is one of the common processes to obtain energy for certain types of microorganisms.They use hydrogen gas or organic substrates as electron donor and sulfates as electron acceptor, and reduce sulfates to sulfides. Sulfate reducing microbes extend across domains Archea and Bacteria, and are believed to be one of the earliest forms of terrestrial life (Shen 2004). The origin of 34S-depleted (light) sulfide sulfur, especially δ34S vials, which contain 40ml of liquid culture media slightly modified from DSMZ #63 medium.Excess amount of Fe (II) is added to the DSMZ#63 medium to precipitate sulfide as iron sulfide. The vials were incubated at 25°C, 30°C, and 37°C, respectively. 21 vials were used for one temperature and sulfide and sulfate was collected from each three glass vials at every 12 hours from 72 hours to 144 hours after start of incubation. The sulfide was precipitated as iron sulfide and the sulfate was precipitated as barite. Sulfur isotope compositions of sulfate and sulfide were measured by standard method using Delta Plus mass-spectrometer. [Results and Discussion] The fractionation between sulfide and sulfate ranged from 2.7 to 11.0. The fractionation values varied among the different incubation temperature and growth phase of D. desulfuricans. The maximum fractionation values of three incubation temperatures were 9.9, 11.0, and 9.7, for 25 °C, 30°C, and 37°C, respectively. These results were different from standard model and Canfield et al. (2006). I could not find the clear correlation between ∂34S values and incubation temperatures in this experiment. The measured fractionation values during the incubation varied with incubation stage. The fractionation values clearly increased with incubation time at every temperature, and at 25°C ∂34S value was 3.6 at the 72h and it increased to 7.9 at 144 hours. This indicated the difference of sulfate reduction rate due to the growth phase of SRB. In the early logarithmic growth phase

  13. Biological functions of iduronic acid in chondroitin/dermatan sulfate

    OpenAIRE

    Thelin, Martin A; Bartolini, Barbara; Axelsson, Jakob; Gustafsson, Renata; Tykesson, Emil; Pera, Edgar; Oldberg, ?ke; Maccarana, Marco; Malmstrom, Anders

    2013-01-01

    The presence of iduronic acid in chondroitin/dermatan sulfate changes the properties of the polysaccharides because it generates a more flexible chain with increased binding potentials. Iduronic acid in chondroitin/dermatan sulfate influences multiple cellular properties, such as migration, proliferation, differentiation, angiogenesis and the regulation of cytokine/growth factor activities. Under pathological conditions such as wound healing, inflammation and cancer, iduronic acid has diverse...

  14. Reduction of sulfate to sulfite by the tobacco leaf

    International Nuclear Information System (INIS)

    Fromageot, P.; Perez-Milan, H.

    1959-01-01

    It is shown that whole tobacco leaf reduces [ 35 SI] sulfate to [ 35 SI] sulfite. The amount and the specific radioactivity of the labelled sulfite recovered indicate that daylight plays an essential part in this process, which is a rapid one. Its quantitative analysis is, however, rendered difficult by oxidation of sulfite to sulfate, which is catalysed by the tissues utilised. Reprint of a paper published in Biochimica et Biophysica Acta, vol. 32, 1959, p. 457-464 [fr

  15. A New Ursane type Sulfated Saponin from Zygophyllum fabago Linn.

    Directory of Open Access Journals (Sweden)

    Saleha Suleman Khan

    2014-07-01

    Full Text Available One new sulfated saponin 3β,23,30-trihydroxyurs-20-en-28-al-23-sulfate 3-O-β- D -xylopyranoside (Zygofaboside C; 1 was purified from the water soluble fraction of ethanolic extract of the aerial parts of Zygophyllum fabago Linn. The structure of the compound was elucidated through spectral studies, especially 1D- and 2D-NMR, HR-FAB mass spectrometry, and comparison with literature data.

  16. Alkylation of isobutane by butenes on zirconium sulfate catalysts

    International Nuclear Information System (INIS)

    Lavrenov, A.V.; Perelevskij, E.V.; Finevich, V.P.; Zajkovskij, V.I.; Paukshtis, E.A.; Duplyakiv, V.K.; Bal'zhinimaev, B.S.

    2003-01-01

    Preparation of applied zirconium sulfate catalysts obtained by the method of impregnation is investigated. Results of comparative study of structural, acid-base and catalytic properties of sulfated zirconium dioxide applied on silica gel and aluminium oxide are represented. Intervals of values of synthesis basic parameters and characteristics of catalysts properties providing achievement of high activity and selectivity in isobutane alkylation by butenes in liquid phase are determined [ru

  17. A novel chondroitin sulfate hydrogel for nerve repair

    Science.gov (United States)

    Conovaloff, Aaron William

    Brachial plexus injuries affect numerous patients every year, with very debilitating results. The majority of these cases are very severe, and involve damage to the nerve roots. To date, repair strategies for these injuries address only gross tissue damage, but do not supply cells with adequate regeneration signals. As a result, functional recovery is often severely lacking. Therefore, a chondroitin sulfate hydrogel that delivers neurotrophic signals to damaged neurons is proposed as a scaffold to support nerve root regeneration. Capillary electrophoresis studies revealed that chondroitin sulfate can physically bind with a variety of neurotrophic factors, and cultures of chick dorsal root ganglia demonstrated robust neurite outgrowth in chondroitin sulfate hydrogels. Outgrowth in chondroitin sulfate gels was greater than that observed in control gels of hyaluronic acid. Furthermore, the chondroitin sulfate hydrogel's binding activity with nerve growth factor could be enhanced by incorporation of a synthetic bioactive peptide, as revealed by fluorescence recovery after photobleaching. This enhanced binding was observed only in chondroitin sulfate gels, and not in hyaluronic acid control gels. This enhanced binding activity resulted in enhanced dorsal root ganglion neurite outgrowth in chondroitin sulfate gels. Finally, the growth of regenerating dorsal root ganglia in these gels was imaged using label-free coherent anti-Stokes scattering microscopy. This technique generated detailed, high-quality images of live dorsal root ganglion neurites, which were comparable to fixed, F-actin-stained samples. Taken together, these results demonstrate the viability of this chondroitin sulfate hydrogel to serve as an effective implantable scaffold to aid in nerve root regeneration.

  18. Controlling Sulfate Attack in Mississippi Department of Transportation Structures

    Science.gov (United States)

    2010-08-01

    such as calcium aluminates and calcium hydroxide , can influence the degree of damage observed. In all cases, the deterioration observed appears to be...high levels of sulfate showed mineralogical evidence that calcium alumino-sulfate minerals such as ettringite were present in significant quantities...investigation, the Caltrans test was modified to adapt it to the available equipment. A description of the modified test procedure is given in Appendix B. A

  19. Evolutionary relationships and functional diversity of plant sulfate transporters.

    Science.gov (United States)

    Takahashi, Hideki; Buchner, Peter; Yoshimoto, Naoko; Hawkesford, Malcolm J; Shiu, Shin-Han

    2011-01-01

    Sulfate is an essential nutrient cycled in nature. Ion transporters that specifically facilitate the transport of sulfate across the membranes are found ubiquitously in living organisms. The phylogenetic analysis of known sulfate transporters and their homologous proteins from eukaryotic organisms indicate two evolutionarily distinct groups of sulfate transport systems. One major group named Tribe 1 represents yeast and fungal SUL, plant SULTR, and animal SLC26 families. The evolutionary origin of SULTR family members in land plants and green algae is suggested to be common with yeast and fungal SUL and animal anion exchangers (SLC26). The lineage of plant SULTR family is expanded into four subfamilies (SULTR1-SULTR4) in land plant species. By contrast, the putative SULTR homologs from Chlorophyte green algae are in two separate lineages; one with the subfamily of plant tonoplast-localized sulfate transporters (SULTR4), and the other diverged before the appearance of lineages for SUL, SULTR, and SLC26. There also was a group of yet undefined members of putative sulfate transporters in yeast and fungi divergent from these major lineages in Tribe 1. The other distinct group is Tribe 2, primarily composed of animal sodium-dependent sulfate/carboxylate transporters (SLC13) and plant tonoplast-localized dicarboxylate transporters (TDT). The putative sulfur-sensing protein (SAC1) and SAC1-like transporters (SLT) of Chlorophyte green algae, bryophyte, and lycophyte show low degrees of sequence similarities with SLC13 and TDT. However, the phylogenetic relationship between SAC1/SLT and the other two families, SLC13 and TDT in Tribe 2, is not clearly supported. In addition, the SAC1/SLT family is absent in the angiosperm species analyzed. The present study suggests distinct evolutionary trajectories of sulfate transport systems for land plants and green algae.

  20. 75 FR 37790 - Lauryl Sulfate Salts; Antimicrobial Registration Review Final Work Plan and Proposed Registration...

    Science.gov (United States)

    2010-06-30

    ..., and opens a 60-day public comment period on the proposed decision. Sodium lauryl sulfate (PC Code...% sodium lauryl sulfate and is registered by Kimberly-Clark Global Sales, LLC (EPA Reg. No. 9402-10). The... sulfate as an active ingredient were first registered in 1948 and sodium lauryl sulfate is widely used as...