WorldWideScience

Sample records for barium iodides

  1. Europium-doped barium bromide iodide

    Energy Technology Data Exchange (ETDEWEB)

    Gundiah, Gautam; Hanrahan, Stephen M.; Hollander, Fredrick J.; Bourret-Courchesne, Edith D.

    2009-10-21

    Single crystals of Ba0.96Eu0.04BrI (barium europium bromide iodide) were grown by the Bridgman technique. The title compound adopts the ordered PbCl2 structure [Braekken (1932). Z. Kristallogr. 83, 222-282]. All atoms occupy the fourfold special positions (4c, site symmetry m) of the space group Pnma with a statistical distribution of Ba and Eu. They lie on the mirror planes, perpendicular to the b axis at y = +-0.25. Each cation is coordinated by nine anions in a tricapped trigonal prismatic arrangement.

  2. Potassium Iodide

    Science.gov (United States)

    Potassium iodide is used to protect the thyroid gland from taking in radioactive iodine that may be ... damage the thyroid gland. You should only take potassium iodide if there is a nuclear radiation emergency ...

  3. Barium Sulfate

    Science.gov (United States)

    Barium sulfate is used to help doctors examine the esophagus (tube that connects the mouth and stomach), stomach, and ... pictures of the inside of the body). Barium sulfate is in a class of medications called radiopaque ...

  4. Radioisotope analyzer of barium

    International Nuclear Information System (INIS)

    Principle of operation and construction of radioisotope barium sulphate analyzer type MZB-2 for fast determination of barium sulphate content in barite ores and enrichment products are described. The gauge equipped with Am-241 and a scintillation detector enables measurement of barium sulphate content in prepared samples of barite ores in the range 60% - 100% with the accuracy of 1%. The gauge is used in laboratories of barite mine and ore processing plant. 2 refs., 2 figs., 1 tab. (author)

  5. Barium iodide and strontium iodide crystals and scintillators implementing the same

    Energy Technology Data Exchange (ETDEWEB)

    Payne, Stephen A.; Cherepy, Nerine; Pedrini, Christian; Burger, Arnold

    2016-09-13

    In one embodiment, a crystal includes at least one metal halide; and an activator dopant comprising ytterbium. In another general embodiment, a scintillator optic includes: at least one metal halide doped with a plurality of activators, the plurality of activators comprising: a first activator comprising europium, and a second activator comprising ytterbium. In yet another general embodiment, a method for manufacturing a crystal suitable for use in a scintillator includes mixing one or more salts with a source of at least one dopant activator comprising ytterbium; heating the mixture above a melting point of the salt(s); and cooling the heated mixture to a temperature below the melting point of the salts. Additional materials, systems, and methods are presented.

  6. Lower GI Series (Barium Enema)

    Science.gov (United States)

    ... barium into a bedpan or nearby toilet. A health care professional may give you an enema to flush out the rest of the barium. An x-ray technician and a radiologist perform a lower gastrointestinal (GI) series at a ...

  7. New barium tantalum sulphides

    International Nuclear Information System (INIS)

    The authors discuss a new barium tantalum sulphide, Ba3Ta2S8, prepared by sulphurization of a mixture of BaCO3 and Ta2O5. The electron and powder X-ray diffraction patterns of the compound are indexed on the basis of a monoclinic cell with lattice constants. A structure model is proposed. The refinement based on the powder X-ray diffraction intensities is performed

  8. Synthesis of mercuric iodide and bismuth tri-iodide nanoparticles for heavy metal iodide films nucleation

    Energy Technology Data Exchange (ETDEWEB)

    Fornaro, L.; Pereira, H.Bentos [Compound Semiconductors Group, CURE, Universidad de la Republica, Rocha (Uruguay); Aguiar, I.; Perez Barthaburu, M. [Compound Semiconductors Group, Facultad de Quimica, Univ. de la Republica, Montevideo (Uruguay)

    2011-12-15

    We synthesized mercuric iodide and bismuth tri-iodide nanoparticles by suspension in octadecene, from Hg(NO{sub 3}){sub 2}.H{sub 2}O and I{sub 2}, and from Bi(NO{sub 3}){sub 3}.5H{sub 2}O and I{sub 2}, respectively. The best synthesis conditions were 2 h at 70-80 C, followed by 10 min at 110 C for mercuric iodide nanoparticles, and 4 h at 80-110 C, followed by 10 min at 180-210 C for bismuth tri-iodide ones. Nanoparticles were then washed and centrifuged with ether repeatedly. Compounds identity was confirmed by X-ray diffraction (XRD) and energy dispersive spectrometry (EDS). We found shifts of the X-ray diffraction maxima for nanoparticles of both compounds. We characterized the nanoparticles by transmission (TEM) and scanning (SEM) electron microscopy. We obtained disk-like and squared mercuric iodide nanostructures, 80-140 nm and 100-125 nm in size respectively. We also obtained rounded and rod-like bismuth tri-iodide nanoparticles, 30-500 nm in size. Acetonitrile and isopropanol suspensions of mercuric iodide nanoparticles, and acetonitrile suspension of bismuth tri-iodide nanoparticles exhibited peak maxima shifts in their UV-Vis spectra. We synthesized for the first time mercuric iodide and bismuth tri-iodide nanoparticles by the suspension method, although we have not yet obtained uniform shape and size distributions. They offer interesting perspectives for crystalline film nucleation and for improving current applications of these materials, as well as for opening new ones. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. 21 CFR 172.375 - Potassium iodide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium iodide. 172.375 Section 172.375 Food and... Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be safely used in accordance with the following prescribed conditions: (a) Potassium iodide may be...

  10. Mercuric iodide sensor technology

    International Nuclear Information System (INIS)

    This report describes the improvement in the performance and the manufacturing yield of mercuric iodide detectors achieved by identifying the dominant impurities, carrier traps, and processing steps limiting device performance. Theoretical studies of electron and hole transport in this material set fundamental limits on detector performance and provided a standard against which to compare experimental results. Spectroscopy techniques including low temperature photoluminescence and thermally stimulated current spectroscopy were applied to characterize the deep level traps in this material. Traps and defects that can be introduced into the detector during growth, from the contact, and during the various steps in detector fabrication were identified. Trap energy levels and their relative abundances were determined. Variations in material quality and detector performance at the micron scale were investigated to understand the distribution in electric field in large volume detectors suitable for gamma-ray spectroscopy. Surface aging and contact degradation was studied extensively by techniques including atomic force microscopy, transmission electron microscopy, and variable angle spectroscopic ellipsometry. Preferred handling and processing procedures for maximizing detector performance and yield were established. The manufacturing yield of high resolution gamma-ray detectors was improved from a few percent to more than 30%

  11. On Barium Oxide Solubility in Barium-Containing Chloride Melts

    Science.gov (United States)

    Nikolaeva, Elena V.; Zakiryanova, Irina D.; Bovet, Andrey L.; Korzun, Iraida V.

    2016-08-01

    Oxide solubility in chloride melts depends on temperature and composition of molten solvent. The solubility of barium oxide in the solvents with barium chloride content is essentially higher than that in molten alkali chlorides. Spectral data demonstrate the existence of oxychloride ionic groupings in such melts. This work presents the results of the BaO solubility in two molten BaCl2-NaCl systems with different barium chloride content. The received data together with earlier published results revealed the main regularities of BaO solubility in molten BaO-BaCl2-MCl systems.

  12. MR Colonography with fecal tagging: Barium vs. barium ferumoxsil

    DEFF Research Database (Denmark)

    Achiam, M.P.; Chabanova, E.; Logager, V.B.;

    2008-01-01

    and Methods. Twenty patients referred to CC underwent dark lumen MRC prior to the colonoscopy. Two groups of patients received two different oral contrast agents (barium sulfate and barium sulfate/ferumoxsil) as a laxative-free fecal tagging prior to the MRC. After MRC, the contrast agent was rated...... qualitatively (with the standard method using contrast-to-wall ratio) and subjectively (using a visual analog scale [VAS]) by three different blinded observers. Results. Evaluated both qualitatively and subjectively, the tagging efficiency of barium sulfate/ferumoxsil was significantly better (P ... barium sulfate alone. The VAS method for evaluating the tagging efficiency of contrast agents showed a high correlation (observer 11, r = 0.91) to the standard method using contrast-to-wall ratio and also a high interclass correlation (observer 11 and III = 0.89/0.85). MRC found I of 22 (5%) polyps

  13. Doped barium titanate nanoparticles

    Indian Academy of Sciences (India)

    T K Kundu; A Jana; P Barik

    2008-06-01

    We have synthesized nickel (Ni) and iron (Fe) ion doped BaTiO3 nanoparticles through a chemical route using polyvinyl alcohol (PVA). The concentration of dopant varies from 0 to 2 mole% in the specimens. The results from X-ray diffractograms and transmission electron micrographs show that the particle diameters in the specimen lie in the range 24–40 nm. It is seen that the dielectric permittivity in doped specimens is enhanced by an order of magnitude compared to undoped barium titanate ceramics. The dielectric permittivity shows maxima at 0.3 mole% doping of Fe ion and 0.6 mole% of Ni ion. The unusual dielectric behaviour of the specimens is explained in terms of the change in crystalline structure of the specimens.

  14. New barium tantalum sulphides

    International Nuclear Information System (INIS)

    A new barium tantalum sulphide has been synthesized by the reaction of CS2 with a mixture of BaCO3 and Ta2O5. The chemical analysis of the compound was performed for 3 components (Ba, Ta and S), and the chemical composition was found to be BaTa2S5. The powder X-ray diffraction peaks were indexable on the basis of a hexagonal cell with lattices constants of a=3.32A, c=25.13A. However, the electron diffraction measurements show that the structure is more complex than that observed by powder X-ray diffraction. The compound indicates metallic behavior and Pauli paramagnetism

  15. Abundance analysis of barium and mild barium stars

    CERN Document Server

    Smiljanic, R; Silva, L

    2007-01-01

    High signal to noise, high resolution spectra were obtained for a sample of normal, mild barium, and barium giants. Atmospheric parameters were determined from the FeI and FeII lines. Abundances for Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, and Gd, were determined from equivalent widths and model atmospheres in a differential analysis, with the red giant Eps Vir as the standard star. The different levels of s-process overabundances of barium and mild barium stars were earlier suggested to be related to the stellar metallicity. Contrary to this suggestion, we found in this work no evidence for barium and mild barium to have a different range in metallicity. However, comparing the ratio of abundances of heavy to light s-process elements, we found some evidence that they do not share the same neutron exposure parameter. The exact mechanism controlling this difference is still not clear. As a by-product of this analysis we identify two normal red giants misclass...

  16. Discovery of the Barium Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Thirty-eight barium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  17. Barium light source method and apparatus

    Science.gov (United States)

    Curry, John J. (Inventor); MacDonagh-Dumler, Jeffrey (Inventor); Anderson, Heidi M. (Inventor); Lawler, James E. (Inventor)

    2002-01-01

    Visible light emission is obtained from a plasma containing elemental barium including neutral barium atoms and barium ion species. Neutral barium provides a strong green light emission in the center of the visible spectrum with a highly efficient conversion of electrical energy into visible light. By the selective excitation of barium ionic species, emission of visible light at longer and shorter wavelengths can be obtained simultaneously with the green emission from neutral barium, effectively providing light that is visually perceived as white. A discharge vessel contains the elemental barium and a buffer gas fill therein, and a discharge inducer is utilized to induce a desired discharge temperature and barium vapor pressure therein to produce from the barium vapor a visible light emission. The discharge can be induced utilizing a glow discharge between electrodes in the discharge vessel as well as by inductively or capacitively coupling RF energy into the plasma within the discharge vessel.

  18. 21 CFR 184.1634 - Potassium iodide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium iodide. 184.1634 Section 184.1634 Food... Specific Substances Affirmed as GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium salt of hydriodic acid. It occurs naturally in sea water and in...

  19. 21 CFR 582.5634 - Potassium iodide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium iodide. 582.5634 Section 582.5634 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent....

  20. Uptake of iodide in the marine haptophyte Isochrysis sp. (T.ISO) driven by iodide oxidation.

    Science.gov (United States)

    van Bergeijk, Stef A; Hernández Javier, Laura; Heyland, Andreas; Manchado, Manuel; Pedro Cañavate, José

    2013-08-01

    Uptake of iodide was studied in the marine microalga Isochrysis sp. (isol. Haines, T.ISO) during short-term incubations with radioactive iodide ((125) I(-) ). Typical inhibitors of the sodium/iodide symporter (NIS) did not inhibit iodide uptake, suggesting that iodide is not taken up through this transport protein, as is the case in most vertebrate animals. Oxidation of iodide was found to be an essential step for its uptake by T.ISO and it seemed likely that hypoiodous acid (HOI) was the form of iodine taken up. Uptake of iodide was inhibited by the addition of thiourea and of other reducing agents, like L-ascorbic acid, L-glutathione and L-cysteine and increased after the addition of oxidized forms of the transition metals Fe and Mn. The simultaneous addition of both hydrogen peroxide (H2 O2 ) and a known iodide-oxidizing myeloperoxidase (MPO) significantly increased iodine uptake, but the addition of H2 O2 or MPO separately, had no effect on uptake. This confirms the observation that iodide is oxidized prior to uptake, but it puts into doubt the involvement of H2 O2 excretion and membrane-bound or extracellular haloperoxidase activity of T.ISO. The increase of iodide uptake by T.ISO upon Fe(III) addition suggests the nonenzymatic oxidation of iodide by Fe(III) in a redox reaction and subsequent influx of HOI. This is the first report on the mechanism of iodide uptake in a marine microalga.

  1. Neutron Detection with Mercuric Iodide

    CERN Document Server

    Bell, Z A

    2003-01-01

    Mercuric iodide is a high-density, high-Z semiconducting material useful for gamma ray detection. This makes it convertible to a thermal neutron detector by covering it with a boron rich material and detecting the 478 keV gamma rays resulting from the sup 1 sup 0 B(n, alpha) sup 7 Li* reaction. However, the 374 barn thermal capture cross section of sup n sup a sup t Hg, makes the detector itself an attractive absorber, and this has been exploited previously. Since previous work indicates that there are no low-energy gamma rays emitted in coincidence with the 368 keV capture gamma from the dominant sup 1 sup 9 sup 9 Hg(n, gamma) sup 2 sup 0 sup 0 Hg reaction, only the 368 keV capture gamma is seen with any efficiency a relatively thin (few mm) detector. In this paper we report preliminary measurements of neutrons via capture reactions in a bare mercuric iodide crystal and a crystal covered in sup 1 sup 0 B-loaded epoxy. The covered detector is an improvement over the bare detector because the presence of both ...

  2. Neutron Detection with Mercuric Iodide

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Z.A.

    2003-06-17

    Mercuric iodide is a high-density, high-Z semiconducting material useful for gamma ray detection. This makes it convertible to a thermal neutron detector by covering it with a boron rich material and detecting the 478 keV gamma rays resulting from the {sup 10}B(n, {alpha}){sup 7}Li* reaction. However, the 374 barn thermal capture cross section of {sup nat}Hg, makes the detector itself an attractive absorber, and this has been exploited previously. Since previous work indicates that there are no low-energy gamma rays emitted in coincidence with the 368 keV capture gamma from the dominant {sup 199}Hg(n, {gamma}){sup 200}Hg reaction, only the 368 keV capture gamma is seen with any efficiency a relatively thin (few mm) detector. In this paper we report preliminary measurements of neutrons via capture reactions in a bare mercuric iodide crystal and a crystal covered in {sup 10}B-loaded epoxy. The covered detector is an improvement over the bare detector because the presence of both the 478 and 368 keV gamma rays removes the ambiguity associated with the observation of only one of them. Pulse height spectra, obtained with and without lead and cadmium absorbers, showed the expected gamma rays and demonstrated that they were caused by neutrons.

  3. Radioisotope barium sulphate gauge MZB-2

    International Nuclear Information System (INIS)

    A method and the gauge for measuring content of barium sulphate are described. The gauge is intended for fast determination of barium sulphate in barite ore and in output products of the enrichment process. The measuring range 60-100% of BaSO4, accuracy ±1% and measuring time 60 s were reached. The barium sulphate gauge is used in barite mine ''Boguszow'' in Poland. (author)

  4. The problem of the barium stars

    Science.gov (United States)

    Bohm-Vitense, E.; Nemec, J.; Proffitt, C.

    1984-01-01

    Ultraviolet observations of barium stars and other cool stars with peculiar element abundances are reported. Those observations attempted to find hot white dwarf companions. Among six real barium stars studied, only Zeta Cap was found to have a white dwarf companion. Among seven mild, or marginal, barium stars studied, at least three were found to have hot subluminous companions. It is likely that all of them have white dwarf companions.

  5. Barium aspiration and alveolarisation of barium in an infant: A case report and review of management

    Directory of Open Access Journals (Sweden)

    Alan F. Isles

    2014-05-01

    Full Text Available We describe a case of bilateral inhalation and alveolarisation of barium in an infant following a barium swallow for investigation of dusky spells associated with feeds. A bronchoscopy subsequently revealed the presence of a mid-tracheal tracheo-oesophageal cleft. We review the literature on barium aspiration, its consequences and make recommendations for management.

  6. ONE CASE REPORT OF ACUTE POISONING BY BARIUM CARBONATE

    Institute of Scientific and Technical Information of China (English)

    GE Qin-min; BIAN Fan; WANG Shu-yun; SHEN Sheng-hui

    2009-01-01

    @@ Most barium poisoning cases were caused by oral intake by mistake. Recent years, barium carbonate poisoning has been rare to be reported. Here we reported a case of acute barium carbonate toxication taken orally on purpose.

  7. Rare, severe hypersensitivity reaction to potassium iodide

    DEFF Research Database (Denmark)

    Nielsen, Anne Sofie Korsholm; Ebbehøj, Eva; Richelsen, Bjørn

    2014-01-01

    The literature reports a large variety of adverse reactions to potassium iodide. A severe hypersensitivity reaction to potassium iodide in a 51-year-old woman with Graves' thyrotoxicosis is described. Following administration the patient developed sialadenitis, conjunctivitis, stomatitis and acne...

  8. Predissociation dynamics of lithium iodide

    CERN Document Server

    Schmidt, H; Stienkemeier, F; Bogomolov, A S; Baklanov, A V; Reich, D M; Skomorowski, W; Koch, C P; Mudrich, M

    2015-01-01

    The predissociation dynamics of lithium iodide (LiI) in the first excited A-state is investigated for molecules in the gas phase and embedded in helium nanodroplets, using femtosecond pump-probe photoionization spectroscopy. In the gas phase, the transient Li+ and LiI+ ion signals feature damped oscillations due to the excitation and decay of a vibrational wave packet. Based on high-level ab initio calculations of the electronic structure of LiI and simulations of the wave packet dynamics, the exponential signal decay is found to result from predissociation predominantly at the lowest avoided X-A potential curve crossing, for which we infer a coupling constant V=650(20) reciprocal cm. The lack of a pump-probe delay dependence for the case of LiI embedded in helium nanodroplets indicates fast droplet-induced relaxation of the vibrational excitation.

  9. Predissociation dynamics of lithium iodide

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, H.; Vangerow, J. von; Stienkemeier, F.; Mudrich, M., E-mail: mudrich@physik.uni-freiburg.de [Physikalisches Institut, Universität Freiburg, 79104 Freiburg (Germany); Bogomolov, A. S. [Institute of Chemical Kinetics and Combustion, Novosibirsk 630090 (Russian Federation); Baklanov, A. V. [Institute of Chemical Kinetics and Combustion, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Reich, D. M.; Skomorowski, W.; Koch, C. P. [Theoretische Physik, Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel (Germany)

    2015-01-28

    The predissociation dynamics of lithium iodide (LiI) in the first excited A-state is investigated for molecules in the gas phase and embedded in helium nanodroplets, using femtosecond pump-probe photoionization spectroscopy. In the gas phase, the transient Li{sup +} and LiI{sup +} ion signals feature damped oscillations due to the excitation and decay of a vibrational wave packet. Based on high-level ab initio calculations of the electronic structure of LiI and simulations of the wave packet dynamics, the exponential signal decay is found to result from predissociation predominantly at the lowest avoided X-A potential curve crossing, for which we infer a coupling constant V{sub XA} = 650(20) cm{sup −1}. The lack of a pump-probe delay dependence for the case of LiI embedded in helium nanodroplets indicates fast droplet-induced relaxation of the vibrational excitation.

  10. Processing science of barium titanate

    Science.gov (United States)

    Aygun, Seymen Murat

    Barium titanate and barium strontium titanate thin films were deposited on base metal foils via chemical solution deposition and radio frequency magnetron sputtering. The films were processed at elevated temperatures for densification and crystallization. Two unifying research goals underpin all experiments: (1) To improve our fundamental understanding of complex oxide processing science, and (2) to translate those improvements into materials with superior structural and electrical properties. The relationships linking dielectric response, grain size, and thermal budget for sputtered barium strontium titanate were illustrated. (Ba 0.6Sr0.4)TiO3 films were sputtered on nickel foils at temperatures ranging between 100-400°C. After the top electrode deposition, the films were co-fired at 900°C for densification and crystallization. The dielectric properties were observed to improve with increasing sputter temperature reaching a permittivity of 1800, a tunability of 10:1, and a loss tangent of less than 0.015 for the sample sputtered at 400°C. The data can be understood using a brick wall model incorporating a high permittivity grain interior with low permittivity grain boundary. However, this high permittivity value was achieved at a grain size of 80 nm, which is typically associated with strong suppression of the dielectric response. These results clearly show that conventional models that parameterize permittivity with crystal diameter or film thickness alone are insufficiently sophisticated. Better models are needed that incorporate the influence of microstructure and crystal structure. This thesis next explores the ability to tune microstructure and properties of chemically solution deposited BaTiO3 thin films by modulation of heat treatment thermal profiles and firing atmosphere composition. Barium titanate films were deposited on copper foils using hybrid-chelate chemistries. An in-situ gas analysis process was developed to probe the organic removal and the

  11. Laser cooling and trapping of barium

    NARCIS (Netherlands)

    De, Subhadeep

    2008-01-01

    Laser cooling and trapping of heavy alkaline-earth element barium have been demonstrated for the first time ever. For any possible cycling transition in barium that could provide strong cooling forces, the excited state has a very large branching probability to metastable states. Additional lasers a

  12. Synthesis of barium titanium oxide from barium sulphate and anatase. Study of equimolar mixtures under different atmospheres

    International Nuclear Information System (INIS)

    To enable the ceramization of a barium sulphate-rich radioactive waste the synthesis of barium titanium oxide is studied by using anatase and barium sulphate. As a function of the calcination atmosphere, helium (or air) and Ar/H2, two reactions are studied. A mechanism of barium titanium oxide synthesis in helium (or in air) is proposed

  13. Double contrast barium meal and acetylcysteine

    International Nuclear Information System (INIS)

    In a prospective double blind study, acetylcysteine, a local and systemic respiratory tract mucolytic agent, or a placebo, were given to 100 patients prior to a double contrast barium meal to decrease the gastric mucus viscosity and to make the mucus layer thinner, in order to permit barium to outline the furrows surrounding the areae gastricae instead of the overlying thick mucus. However, acetylcysteine failed to improve either visualization of the areae gastricae or the general quality of the double contrast barium meal. (orig.)

  14. Plasma etching of cesium iodide

    International Nuclear Information System (INIS)

    Thick films of cesium iodide (CsI) are often used to convert x-ray images into visible light. Spreading of the visible light within CsI, however, reduces the resolution of the resulting image. Anisotropic etching of the CsI film into an array of micropixels can improve the image resolution by confining light within each pixel. The etching process uses a high-density inductively coupled plasma to pattern CsI samples held by a heated, rf-biased chuck. Fluorine-containing gases such as CF4 are found to enhance the etch rate by an order of magnitude compared to Ar+ sputtering alone. Without inert-gas ion bombardment, however, the CF4 etch becomes self-limited within a few microns of depth due to the blanket deposition of a passivation layer. Using CF4+Ar continuously removes this layer from the lateral surfaces, but the formation of a thick passivation layer on the unbombarded sidewalls of etched features is observed by scanning electron microscopy. At a substrate temperature of 220 deg. C, the minimum ion-bombardment energy for etching is Ei∼50 eV, and the rate depends on Ei1/2 above 65 eV. In dilute mixtures of CF4 and Ar, the etch rate is proportional to the gas-phase density of atomic fluorine. Above 50% CF4, however, the rate decreases, indicating the onset of net surface polymer deposition. These observations suggest that anisotropy is obtained through the ion-enhanced inhibitor etching mechanism. Etching exhibits an Arrhenius-type behavior in which the etch rate increases from ∼40 nm/min at 40 deg. C to 380 nm/min at 330 deg. C. The temperature dependence corresponds to an activation energy of 0.13±0.01 eV. This activation energy is consistent with the electronic sputtering mechanism for alkali halides

  15. Neutral Barium Cloud Evolution at Different Altitudes

    Institute of Scientific and Technical Information of China (English)

    李磊; 徐荣栏

    2002-01-01

    Considering the joint effects of diffusion, collision, oxidation and photoionization, we study the evolution of the barium cloud at different altitudes in the space plasma active experiment. The results present the variation of the loss rate, number density distribution and brightness of the barium cloud over the range from 120 to 260km.This can be divided into oxidation, oxidation plus photoionization and photoionization regions.

  16. Small barium rail gun for plasma injection.

    Science.gov (United States)

    Kiwamoto, Y

    1980-03-01

    A small rail gun with a barium electrode can be operated at higher than one shot per second to produce more than 2x10(16) barium ions with energy 10-20 eV. The operation of the gun takes advantage of the external magnetic field for cross-field plasma injection into a trap. Up to 7 kG of the magnetic field examined, the gun performance improves with the increased magnetic field strength.

  17. Bacterial Reduction Of Barium Sulphate By Sulphate-Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Luptáková Alena

    2015-12-01

    Full Text Available Acid mine drainage (AMD is a worldwide problem leading to contamination of water sources. AMD are characterized by low pH and high content of heavy metals and sulphates. The barium salts application presents one of the methods for the sulphates removing from AMD. Barium chloride, barium hydroxide and barium sulphide are used for the sulphates precipitation in the form of barium sulphate. Because of high investment costs of barium salts, barium sulphide is recycled from barium sulphate precipitates. It can be recycled by thermic or bacterial reduction of barium sulphate. The aim of our study was to verify experimentally the possibility of the bacterial transformation of BaSO4 to BaS by sulphate-reducing bacteria. Applied BaSO4 came from experiments of sulphates removal from Smolnik AMD using BaCl2.

  18. Venous barium embolization, a rare, potentially fatal complication of barium enema: 2 case reports

    International Nuclear Information System (INIS)

    Venous embolization of barium has been recognized for 4 decades as one of the most dreaded complications of barium enema. Fortunately, the condition is extremely rare. In this report, the radiographic findings in 2 cases of venous embolization (one involving the portal vein and one systematic) are described, and ways to decrease the risk of this complication are discussed. (author)

  19. Thermochemical hydrogen production via a cycle using barium and sulfur - Reaction between barium sulfide and water

    Science.gov (United States)

    Ota, K.; Conger, W. L.

    1977-01-01

    The reaction between barium sulfide and water, a reaction found in several sulfur based thermochemical cycles, was investigated kinetically at 653-866 C. Gaseous products were hydrogen and hydrogen sulfide. The rate determining step for hydrogen formation was a surface reaction between barium sulfide and water. An expression was derived for the rate of hydrogen formation.

  20. Synthesis of barium mercaptides and application of antimony/barium mercaptides

    Institute of Scientific and Technical Information of China (English)

    瞿龙; 张露露; 舒万艮

    2001-01-01

    Mercaptoacetic acid, isooctyl thioglycolate and barium hydroxide used as start materials, barium bis (2-ethylhexyl thioglycolate) (Ba(2EHTG)2), barium thioglycolate (Ba(TG)) and barium bisthioglycolate (Ba(TG)2) were synthesized. Their optimum synthetic techniques were discussed, and some physicochemical data were reported. Infrared spectroscopy and elemental analysis methods were used to identify the structures. They were put into PVC plastic products together with antimony tris (2-ethylhexyl thioglycolate) (Sb(2EHTG)3) under the suitable compounding, and their heat stability to PVC was studied. It is shown that these barium mercaptides have remarkable synergisms with antimony mercaptides and the long-term stabilizing effect of organoantimony stabilizer can be effectively improved, reducing the amount of antimony compounds so as to avoid the decrease of its stabilizing effect.

  1. The partitioning of iodides into steam

    International Nuclear Information System (INIS)

    In order to estimate the likely releases of radioactive iodine during steam generator tube rupture (SGTR) faults, it is necessary to know the relevant partition coefficients as a function of temperature and solution composition. It has been suggested previously that, under SGTR fault conditions, partitioning of free or ion-paired I- into the steam may be more extensive than that for molecular HI. This report uses available information on the partitioning of iodides and other salts to provide a means of estimating the partition coefficient of the iodide ion as a function of boric acid concentration and temperature. (author)

  2. Adsorption of radioactive iodide by natural zeolites

    International Nuclear Information System (INIS)

    Two natural zeolites from Iranian deposits (clinoptilolite and natrolite) were characterized and their ability for adsorption of iodide from nuclear wastewaters was evaluated. The adsorption behavior was studied on natural and modified zeolites by γ-spectrometry using 131I as radiotracer. Adsorption isotherms and distribution coefficient (Kd) were measured. The results showed that clinoptilolite is a more promising zeolite for removal of iodide compared to natrolite. Furthermore, the adsorption was higher in silver, lead and thallium forms, whereas the lowest desorption was observed in lead modified zeolite. (author)

  3. Chemical abundances and kinematics of barium stars

    Science.gov (United States)

    de Castro, D. B.; Pereira, C. B.; Roig, F.; Jilinski, E.; Drake, N. A.; Chavero, C.; Sales Silva, J. V.

    2016-07-01

    In this paper, we present an homogeneous analysis of photospheric abundances based on high-resolution spectroscopy of a sample of 182 barium stars and candidates. We determined atmospheric parameters, spectroscopic distances, stellar masses, ages, luminosities and scaleheight, radial velocities, abundances of the Na, Al, α-elements, iron-peak elements, and s-process elements Y, Zr, La, Ce, and Nd. We employed the local thermodynamic equilibrium model atmospheres of Kurucz and the spectral analysis code MOOG. We found that the metallicities, the temperatures and the surface gravities for barium stars cannot be represented by a single Gaussian distribution. The abundances of α-elements and iron peak elements are similar to those of field giants with the same metallicity. Sodium presents some degree of enrichment in more evolved stars that could be attributed to the NeNa cycle. As expected, the barium stars show overabundance of the elements created by the s-process. By measuring the mean heavy-element abundance pattern as given by the ratio [s/Fe], we found that the barium stars present several degrees of enrichment. We also obtained the [hs/ls] ratio by measuring the photospheric abundances of the Ba-peak and the Zr-peak elements. Our results indicated that the [s/Fe] and the [hs/ls] ratios are strongly anticorrelated with the metallicity. Our kinematical analysis showed that 90 per cent of the barium stars belong to the thin disc population. Based on their luminosities, none of the barium stars are luminous enough to be an asymptotic giant branch star, nor to become self-enriched in the s-process elements. Finally, we determined that the barium stars also follow an age-metallicity relation.

  4. Electrochemical reaction rates in a dye sentisised solar cell - the iodide/tri-iodide redox system

    DEFF Research Database (Denmark)

    Bay, Lasse; West, Keld; Winter-Jensen, Bjørn;

    2006-01-01

    The electrochemical reaction rate of the redox couple iodide / tri-iodide in acetonitrile is characterised by impedance spectroscopy. Different electrode materials relevant for the function of dye-sensitised solar cells (DSSC) are investigated. Preferably, the reaction with the iodide / tri......), and polyaniline (PANI) - all deposited onto fluorine doped tin oxide (FTO) glass. Both Pt and PEDOT are found to have sufficiently high catalytic activities for practical use as counter electrode in DSSC. The reaction resistance on FTO and anatase confirmed the beneficial effect of a compact anatase layer on top...

  5. 21 CFR 184.1265 - Cuprous iodide.

    Science.gov (United States)

    2010-04-01

    ... the following specific limitations: Category of food Maximum treatment level in food Functional use... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cuprous iodide. 184.1265 Section 184.1265 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  6. Electronic and optical properties of lead iodide

    DEFF Research Database (Denmark)

    Ahuja, R.; Arwin, H.; Ferreira da Silva, A.;

    2002-01-01

    The electronic properties and the optical absorption of lead iodide (PbI2) have been investigated experimentally by means of optical absorption and spectroscopic ellipsometry, and theoretically by a full-potential linear muffin-tin-orbital method. PbI2 has been recognized as a very promising...

  7. Cu-catalyzed trifluoromethylation of aryl iodides with trifluoromethylzinc reagent prepared in situ from trifluoromethyl iodide

    OpenAIRE

    Yuzo Nakamura; Motohiro Fujiu; Tatsuya Murase; Yoshimitsu Itoh; Hiroki Serizawa; Kohsuke Aikawa; Koichi Mikami

    2013-01-01

    The trifluoromethylation of aryl iodides catalyzed by copper(I) salt with trifluoromethylzinc reagent prepared in situ from trifluoromethyl iodide and Zn dust was accomplished. The catalytic reactions proceeded under mild reaction conditions, providing the corresponding aromatic trifluoromethylated products in moderate to high yields. The advantage of this method is that additives such as metal fluoride (MF), which are indispensable to activate silyl groups for transmetallation in the corresp...

  8. Coherent Dark Resonances in Atomic Barium

    CERN Document Server

    Dammalapati, U; Jungmann, K; Willmann, L

    2007-01-01

    The observation of dark-resonances in the two-electron atom barium and their influence on optical cooling is reported. In heavy alkali earth atoms, i.e. barium or radium, optical cooling can be achieved using n^1S_0-n^1P_1 transitions and optical repumping from the low lying n^1D_2 and n^3D_{1,2} states to which the atoms decay with a high branching ratio. The cooling and repumping transition have a common upper state. This leads to dark resonances and hence make optical cooling less inefficient. The experimental observations can be accurately modelled by the optical Bloch equations. Comparison with experimental results allows us to extract relevant parameters for effective laser cooling of barium.

  9. Refractory oxides containing aluminium and barium

    OpenAIRE

    Davies T.J.; Biedermann M.; Q-G. Chen; Emblem H. G.; Al-Douri W. A.

    1998-01-01

    Oxides containing aluminium and barium, optionally with chromium, are refractory with several possible industrial uses. A gel precursor of an oxide having the formula BaO.n(Al2xCr2yO3), where 1barium salt with a solution of an aluminium salt or a solution of an aluminium salt and a chromium III salt, then forming a gel which was fired to obtain the desired oxide. Filaments may be drawn as the gel is forming or extr...

  10. Electronic structure of nanograin barium titanate ceramics

    Institute of Scientific and Technical Information of China (English)

    DENG Xiangyun; WANG Xiaohui; LI Dejun; LI Longtu

    2007-01-01

    The density of states and band structure of 20 nm barium titanate(BaTiO3,BT)ceramics are investigated by first-principles calculation.The full potential linearized augmented plane wave(FLAPW)method is used and the exchange correlation effects are treated by the generalized gradient approximation(GGA).The results show that there is substantial hybridization between the Ti 3d and O 2p states in 20 nm BT ceramics and the interaction between barium and oxygen is typically ionic.

  11. Printed Barium Strontium Titanate capacitors on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Sette, Daniele [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Luxembourg Institute of Science and Technology LIST, Materials Research and Technology Department, L-4422 Belvaux (Luxembourg); Kovacova, Veronika [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Defay, Emmanuel, E-mail: emmanuel.defay@list.lu [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Luxembourg Institute of Science and Technology LIST, Materials Research and Technology Department, L-4422 Belvaux (Luxembourg)

    2015-08-31

    In this paper, we show that Barium Strontium Titanate (BST) films can be prepared by inkjet printing of sol–gel precursors on platinized silicon substrate. Moreover, a functional variable capacitor working in the GHz range has been made without any lithography or etching steps. Finally, this technology requires 40 times less precursors than the standard sol–gel spin-coating technique. - Highlights: • Inkjet printing of Barium Strontium Titanate films • Deposition on silicon substrate • Inkjet printed silver top electrode • First ever BST films thinner than 1 μm RF functional variable capacitor that has required no lithography.

  12. Thermal decomposition of barium valerate in argon

    DEFF Research Database (Denmark)

    Torres, P.; Norby, Poul; Grivel, Jean-Claude

    2015-01-01

    The thermal decomposition of barium valerate (Ba(C4H9CO2)(2)/Ba-pentanoate) was studied in argon by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction and hot-stage optical microscopy. Melting takes place in two different steps, at 200 degrees C and 280...

  13. 75 FR 19657 - Barium Chloride From China

    Science.gov (United States)

    2010-04-15

    ... Commission found that the domestic interested party group response to its notice of institution (74 FR 31757... COMMISSION Barium Chloride From China AGENCY: United States International Trade Commission. ACTION: Notice of... chloride from China. SUMMARY: The Commission hereby gives notice that it will proceed with a full...

  14. 75 FR 20625 - Barium Chloride From China

    Science.gov (United States)

    2010-04-20

    ... established a schedule for the conduct of this review (74 FR 62587, November 30, 2010). Subsequently, counsel... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Barium Chloride From China AGENCY: United States International Trade Commission. ACTION:...

  15. Electrochemical reaction rates in a dye-sensitised solar cell - the iodide/tri-iodide redox system

    DEFF Research Database (Denmark)

    Bay, L.; West, K.; Winther-Jensen, B.;

    2006-01-01

    The electrochemical reaction rate of the redox couple iodide/tri-iodide in acetonitrile is characterised by impedance spectroscopy. Different electrode materials relevant for the function of dye-sensitised solar cells (DSSC) are investigated. Preferably, the reaction with the iodide/tri-iodide co......The electrochemical reaction rate of the redox couple iodide/tri-iodide in acetonitrile is characterised by impedance spectroscopy. Different electrode materials relevant for the function of dye-sensitised solar cells (DSSC) are investigated. Preferably, the reaction with the iodide......), and polyaniline (PANI)-all deposited onto fluorine-doped tin oxide (FTO) glass. Both Pt and PEDOT are found to have sufficiently high catalytic activities for practical use as counter electrodes in DSSC. The reaction resistance on FTO and anatase confirmed the beneficial effect of a compact anatase layer on top...

  16. Composition and properties of thallium mercury iodide

    Science.gov (United States)

    Kennedy, John H.; Schaupp, Christopher; Yang, Yuan; Zhang, Zhengming; Novinson, Thomas; Hoffard, Theresa

    1990-10-01

    Conflicting reports exist in the literature concerning the composition of thallium mercury iodide. Solid state synthesis with HgI 2 and TlI has been reported to give Tl 4HgI 6 while synthesis from solution has been reported to give Tl 2HgI 4. In this report we show that the "orange compound" precipitating from solution is actually a 1:1 mole ratio mixture of Tl 4HgI 6 and HgI 2. Pure Tl 4HgI 6, which is yellow, can be produced by heating the mixture at 100°C for several days to volatilize HgI 2 or more simply, by adding Tl(I) to a solution containing 2:1 KI:K 2HgI 4 to provide the additional iodide ions needed for Tl 4HgI 6. Tl 4HgI 6, unlike Ag 2HgI 4 and Cu 2HgI 4, has no sharp thermochromic changes and has no measurable ionic conductivity. This provides another example of the significant role the metal ion plans in determining structure and properties of metal mercury iodide compounds.

  17. Formation of cyanogen iodide by lactoperoxidase.

    Science.gov (United States)

    Schlorke, Denise; Flemmig, Jörg; Birkemeyer, Claudia; Arnhold, Jürgen

    2016-01-01

    The haem protein lactoperoxidase (LPO) is an important component of the anti-microbial immune defence in external secretions and is also applied as preservative in food, oral care and cosmetic products. Upon oxidation of SCN(-) and I(-) by the LPO-hydrogen peroxide system, oxidised species are formed with bacteriostatic and/or bactericidal activity. Here we describe the formation of the inter(pseudo)halogen cyanogen iodide (ICN) by LPO. This product is formed when both, thiocyanate and iodide, are present together in the reaction mixture. Using (13)C nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry we could identify this inter(pseudo)halogen after applying iodide in slight excess over thiocyanate. The formation of ICN is based on the reaction of oxidised iodine species with thiocyanate. Further, we could demonstrate that ICN is also formed by the related haem enzyme myeloperoxidase and, in lower amounts, in the enzyme-free system. As I(-) is not competitive for SCN(-) under physiologically relevant conditions, the formation of ICN is not expected in secretions but may be relevant for LPO-containing products.

  18. Barium carbonate as an agent to improve the electrical properties of neodymium-barium-copper system at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, J.P. [Post-Graduate Program in Chemical Engineering, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, 88040-900 (Brazil); Duarte, G.W. [Post-Graduate Program in Chemical Engineering, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, 88040-900 (Brazil); Research Group in Technology and Information, Centro Universitário Barriga Verde (UNIBAVE), Santa Catarina, SC (Brazil); Caldart, C. [Post-Graduate Program in Science and Materials Engineering, Universidade do Extremo Sul Catarinense (UNESC), Criciúma, SC, 88806-000 (Brazil); Kniess, C.T. [Post-Graduate Program in Professional Master in Management, Universidade Nove de Julho, São Paulo, SP (Brazil); Montedo, O.R.K.; Rocha, M.R. [Post-Graduate Program in Science and Materials Engineering, Universidade do Extremo Sul Catarinense (UNESC), Criciúma, SC, 88806-000 (Brazil); Riella, H.G. [Post-Graduate Program in Chemical Engineering, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, 88040-900 (Brazil); Fiori, M.A., E-mail: fiori@unochapeco.edu.br [Post-Graduate Program in Environmental Science, Universidade Comunitária da Região de Chapecó (UNOCHAPECÓ), Chapecó, SC, 89809-000 (Brazil); Post-Graduate Program in Technology and Management of the Innovation, Universidade Comunitária da Região de Chapecó (UNOCHAPECÓ), Chapecó, SC, 89809-000 (Brazil)

    2015-11-15

    Specialized ceramics are manufactured under special conditions and contain specific elements. They possess unique electrical and thermal properties and are frequently used by the electronics industry. Ceramics containing neodymium-barium-copper (NBC) exhibit high conductivities at low temperatures. NBC-based ceramics are typically combined with oxides, i.e., NBCo produced from neodymium oxide, barium oxide and copper oxide. This study presents NBC ceramics that were produced with barium carbonate, copper oxide and neodymium oxide (NBCa) as starting materials. These ceramics have good electrical conductivities at room temperature. Their conductivities are temperature dependent and related to the starting amount of barium carbonate (w%). - Highlights: • The new crystalline structure were obtained due presence of the barium carbonate. • The NBCa compound has excellent electrical conductivity at room temperature. • The grain crystalline morphology was modified by presence of the barium carbonate. • New Phases α and β were introduced by carbonate barium in the NBC compound.

  19. Effect of nitrogen and oxygen on radiolysis of iodide solution

    Energy Technology Data Exchange (ETDEWEB)

    Karasawa, H.; Endo, M. [Hitachi Ltd., Power and Industrial System R+D Divisions, Ibaraki (Japan)

    1996-12-01

    The effect of nitrogen and oxygen on radiolysis of iodide solution was examined. Direct decomposition of nitrogen by {gamma}-radiation produced nitric acid to decrease a water pH. This resulted in the iodine formation in the radiolysis of iodide solution. Hydrogen peroxide was produced by the radiolysis of water containing oxygen. This worked a reducing agent to suppress the formation of iodine in the radiolysis of iodide solution. In the analytical model, fourteen iodine species were considered and reaction scheme consisted in 124 reactions. The analytical model could estimate the oxidation state of iodide ions. (author) 4 figs., 4 refs.

  20. Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We utilize a new detector material, polycrystalline mercuric iodide, for background suppression by active anticoincidence shielding in gamma-ray spectrometers. Two...

  1. Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to utilize a new detector material, polycrystalline mercuric iodide, for background suppression by active anticoincidence shielding in gamma-ray...

  2. Radioactive Barium Ion Trap Based on Metal-Organic Framework for Efficient and Irreversible Removal of Barium from Nuclear Wastewater.

    Science.gov (United States)

    Peng, Yaguang; Huang, Hongliang; Liu, Dahuan; Zhong, Chongli

    2016-04-01

    Highly efficient and irreversible capture of radioactive barium from aqueous media remains a serious task for nuclear waste disposal and environmental protection. To address this task, here we propose a concept of barium ion trap based on metal-organic framework (MOF) with a strong barium-chelating group (sulfate and sulfonic acid group) in the pore structures of MOFs. The functionalized MOF-based ion traps can remove >90% of the barium within the first 5 min, and the removal efficiency reaches 99% after equilibrium. Remarkably, the sulfate-group-functionalized ion trap demonstrates a high barium uptake capacity of 131.1 mg g(-1), which surpasses most of the reported sorbents and can selectively capture barium from nuclear wastewater, whereas the sulfonic-acid-group-functionalized ion trap exhibits ultrafast kinetics with a kinetic rate constant k2 of 27.77 g mg(-1) min(-1), which is 1-3 orders of magnitude higher than existing sorbents. Both of the two MOF-based ion traps can capture barium irreversibly. Our work proposes a new strategy to design barium adsorbent materials and provides a new perspective for removing radioactive barium and other radionuclides from nuclear wastewater for environment remediation. Besides, the concrete mechanisms of barium-sorbent interactions are also demonstrated in this contribution.

  3. Production of translationally cold barium monohalide ions

    OpenAIRE

    DePalatis, M. V.; Chapman, M.S.

    2013-01-01

    We have produced sympathetically cooled barium monohalide ions BaX$^+$ (X = F, Cl, Br) by reacting trapped, laser cooled Ba$^+$ ions with room temperature gas phase neutral halogen-containing molecules. Reaction rates for two of these (SF$_6$ and CH$_3$Cl) have been measured and are in agreement with classical models. BaX$^+$ ions are promising candidates for cooling to the rovibrational ground state, and our method presents a straightforward way to produce these polar molecular ions.

  4. Novel mercuric iodide polycrystalline nuclear particles counters

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, M. [Hebrew Univ. of Jerusalem (Israel)]|[Sandia National Lab., Livermore, CA (United States); Zuck, A.; Braiman, M.; Nissenbaum, J. [Hebrew Univ. of Jerusalem (Israel)] [and others

    1996-12-31

    Polycrystalline mercuric iodide nuclear radiation detectors having areas between 0.01 to 100 cm{sup 2} and thicknesses 30 to 600 microns, have been fabricated with single, linear strip and square pixel contact. The large area detectors 10 to 600 cm{sup 2} were produced by industrial ceramic equipment while the smaller ones, about 1 cm{sup 2} area, were produced in the laboratory. The large detectors still had large leakage currents and the production process is being revised. The smaller detectors were tested and their response to lower and higher gamma energy, beta and even 100 GeV muons at CERN will be reported.

  5. Large-area mercuric iodide photodetectors

    International Nuclear Information System (INIS)

    This article discusses the limits of the active area of mercuric iodide photodetectors imposed by the size of available crystals, electronic noise, and the uniformity of charge carrier collection. Theoretical calculations of the photodetector electronic noise are compared with the experimental results. Different entrance contacts were studied including semitransparent palladium films and conductive liquids. HgI2 photodetectors with active area up to 4 sq cm are matched with NaI(Tl) and CsI(Tl) scintillation crystals and are evaluated as gamma radiation spectrometers

  6. Transfer of the human sodium/iodide symporter gene enhances iodide uptake in melanoma cells

    International Nuclear Information System (INIS)

    Objective: To obtain human sodium/iodide symporter (hNIS) cDNA and to study its biological property and potential use as a therapeutic radioiodide for melanoma. Methods: hNIS gene cDNA was amplified with total RNA from human thyroid tissue by RT-PCR. The hNIS cDNA was inserted into cloning vector pUCm-T and subcloned into eukaryotic expression vector pcDNA3. The recombinant plasmid pcDNA3-hNIS was introduced into B16 cells using the electroporation technique. The uptake and efflux of iodide was examined in vitro. Results: The cloned hNIS cDNA sequence was identical to the published sequence. Two novel cell lines named B16-A containing hNIS and B16-B containing pcDNA3 only were established. The resultant cell line B16-A accumulated 17 and 19 times more radioiodide in vitro than B16 and B16-B did, respectively. However the efflux of iodide from B16-A was also rapid ( T1/2=10 min). Conclusions: Our preliminary data indicate that the transduction of the hNIS gene per se is sufficient to induce iodide transport in melanoma cells in vitro, but its T1/2 is short. With regard to therapeutic application, however, further investigation is necessary so as to develop a method of maintaining more radioiodide in the cells for long enough to produce greater therapeutic effects

  7. Chemical abundances and kinematics of barium stars

    CERN Document Server

    de Castro, D B; Roig, F; Jilinski, E; Drake, N A; Chavero, C; Silva, J V Sales

    2016-01-01

    In this paper we present an homogeneous analysis of photospheric abundances based on high-resolution spectroscopy of a sample of 182 barium stars and candidates. We determined atmospheric parameters, spectroscopic distances, stellar masses, ages, luminosities and scale height, radial velocities, abundances of the Na, Al, $alpha$-elements, iron-peak elements, and s-process elements Y, Zr, La, Ce, and Nd. We employed the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code {\\sc moog}. We found that the metallicities, the temperatures and the surface gravities for barium stars can not be represented by a single gaussian distribution. The abundances of $alpha$-elements and iron peak elements are similar to those of field giants with the same metallicity. Sodium presents some degree of enrichment in more evolved stars that could be attributed to the NeNa cycle. As expected, the barium stars show overabundance of the elements created by the s-process. By measuring the mean heav...

  8. Production of Molecular Iodine and Tri-iodide in the Frozen Solution of Iodide: Implication for Polar Atmosphere.

    Science.gov (United States)

    Kim, Kitae; Yabushita, Akihiro; Okumura, Masanori; Saiz-Lopez, Alfonso; Cuevas, Carlos A; Blaszczak-Boxe, Christopher S; Min, Dae Wi; Yoon, Ho-Il; Choi, Wonyong

    2016-02-01

    The chemistry of reactive halogens in the polar atmosphere plays important roles in ozone and mercury depletion events, oxidizing capacity, and dimethylsulfide oxidation to form cloud-condensation nuclei. Among halogen species, the sources and emission mechanisms of inorganic iodine compounds in the polar boundary layer remain unknown. Here, we demonstrate that the production of tri-iodide (I3(-)) via iodide oxidation, which is negligible in aqueous solution, is significantly accelerated in frozen solution, both in the presence and the absence of solar irradiation. Field experiments carried out in the Antarctic region (King George Island, 62°13'S, 58°47'W) also showed that the generation of tri-iodide via solar photo-oxidation was enhanced when iodide was added to various ice media. The emission of gaseous I2 from the irradiated frozen solution of iodide to the gas phase was detected by using cavity ring-down spectroscopy, which was observed both in the frozen state at 253 K and after thawing the ice at 298 K. The accelerated (photo-)oxidation of iodide and the subsequent formation of tri-iodide and I2 in ice appear to be related with the freeze concentration of iodide and dissolved O2 trapped in the ice crystal grain boundaries. We propose that an accelerated abiotic transformation of iodide to gaseous I2 in ice media provides a previously unrecognized formation pathway of active iodine species in the polar atmosphere.

  9. Phase 2 Methyl Iodide Deep-Bed Adsorption Tests

    Energy Technology Data Exchange (ETDEWEB)

    Soelberg, Nick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    Nuclear fission produces fission products (FPs) and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Research, demonstrations, and some reprocessing plant experience have indicated that diatomic iodine can be captured with efficiencies high enough to meet regulatory requirements. Research on the capture of organic iodides has also been performed, but to a lesser extent. Several questions remain open regarding the capture of iodine bound in organic compounds. Deep-bed methyl iodide adsorption testing has progressed according to a multi-laboratory methyl iodide adsorption test plan. This report summarizes the second phase of methyl iodide adsorption work performed according to this test plan using the deep-bed iodine adsorption test system at the Idaho National Laboratory (INL), performed during the second half of Fiscal Year (FY) 2014. Test results continue to show that methyl iodide adsorption using AgZ can achieve total iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) above 1,000, until breakthrough occurred. However, mass transfer zone depths are deeper for methyl iodide adsorption compared to diatomic iodine (I2) adsorption. Methyl iodide DFs for the Ag Aerogel test adsorption efficiencies were less than 1,000, and the methyl iodide mass transfer zone depth exceeded 8 inches. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption under various conditions specified in the methyl iodide test plan, and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

  10. Lanthanide doped strontium-barium cesium halide scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Bizarri, Gregory; Bourret-Courchesne, Edith; Derenzo, Stephen E.; Borade, Ramesh B.; Gundiah, Gautam; Yan, Zewu; Hanrahan, Stephen M.; Chaudhry, Anurag; Canning, Andrew

    2015-06-09

    The present invention provides for a composition comprising an inorganic scintillator comprising an optionally lanthanide-doped strontium-barium, optionally cesium, halide, useful for detecting nuclear material.

  11. Dissolution of gaseous methyl iodide into aqueous sodium hydroxide solutions

    International Nuclear Information System (INIS)

    Absorption process of gaseous methyl iodide by water or sodium hydroxide solutions was investigated using a semi-flow type experimental apparatus by measuring the concentration of all measurable chemical species in both the gas and the liquid phase. The experimental temperature ranged from 288 to 311 K and the gaseous methyl iodide and aqueous sodium hydroxide concentrations were approximately 0.6 x 10-3 to 7 x 10-3 and 0 to 0.2 mol/dm3, respectively. It is estimated that the dissolution of methyl iodide into the sodium hydroxide solution proceeds according to the following steps. Step (1) Methyl iodide in air dissolves physically into the aqueous phase. Physical dissolution process obeys Henry's law. Step (2) Methyl iodide dissolved into the aqueous phase is decomposed by a base catalytic hydrolysis and produces methyl alcohol and iodide ion. The equilibrium constants of physical dissolution were obtained from the steady concentration in both the gas and the liquid phases in the semi-flow type experiment because the hydrolysis reaction rate of methyl iodide is very slow in comparison with the physical dissolution in this experimental conditions. The obtained value of the standard heat of solution of methyl iodide into water was 7.2 kcal/mol. Salting-out effect was observed when the concentration of sodium hydroxide in the absorbent was over 0.01 mol/dm3. (auth.)

  12. Novel mercuric iodide polycrystalline nuclear particle counters

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, M. [Hebrew Univ. of Jerusalem (Israel)]|[Sandia National Labs., Livermore, CA (United States); Zuck, A.; Braiman, M.; Nissenbaum, J. [Hebrew Univ. of Jerusalem (Israel); Turchetta, R.; Dulinski, W.; Husson, D.; Riester, J.L. [LEPSI, Strasbourg (France)

    1997-12-01

    Polycrystalline mercuric iodide nuclear radiation detectors have been produced in a novel technology. Unlike the normal single-crystal technology, there is no intrinsic limit to the surface on which these detectors can be produced. Detectors with areas up to about 1.5 cm{sup 2}, thicknesses from 30 to 600 {micro}m, and with single electrodes as well as microstrip and pixel contacts have been fabricated and successfully tested with photons in the range of 40--660 keV, {beta} particle`s emitted from a Sr-Y source, and high energy (100 GeV) muons. Results on both charge collection and counting efficiency are reported as well as some very preliminary imaging results. The experimental results on charge collection have been compared with simulation, and a combined {mu}{tau} product 10{sup {minus}7} cm{sup 2}/V for electrons has been estimated.

  13. Ferroelastic Fingerprints in Methylammonium Lead Iodide Perovskite

    KAUST Repository

    Hermes, Ilka M.

    2016-02-12

    Methylammonium lead iodide (MAPbI3) perovskite materials show an outstanding performance in photovoltaic devices. However, certain material properties, especially the possible ferroic behavior, remain unclear. We observed distinct nanoscale periodic domains in the piezoresponse of MAPbI3(Cl) grains. The structure and the orientation of these striped domains indicate ferroelasticity as their origin. By correlating vertical and lateral piezoresponse force microscopy experiments performed at different sample orientations with x-ray diffraction, the preferred domain orientation was suggested to be the a1-a2-phase. The observation of these ferroelastic fingerprints appears to strongly depend on the film texture and thus the preparation route. The formation of the ferroelastic twin domains could be induced by internal strain during the cubic-tetragonal phase transition.

  14. Barium dithionate as an EPR dosemeter.

    Science.gov (United States)

    Baran, M P; Bugay, O A; Kolesnik, S P; Maksimenko, V M; Teslenko, V V; Petrenko, T L; Desrosiers, M F

    2006-01-01

    Electron paramagnetic resonance (EPR) dosimetry is growing in popularity and this success has encouraged the search for other dosimetric materials. Previous studies of gamma-irradiated barium dithionate (BaS(2)O(6) x 2H(2)O) have shown promise for its use as a radiation dosemeter. This work studies in greater detail several essential attributes of the system. Special attention has been directed to the study of EPR response dependences on microwave power, irradiation temperature, minimum detectable dose and post-irradiation stability. PMID:16565205

  15. Scattering lengths of calcium and barium isotopes

    OpenAIRE

    Dammalapati, U.; Willmann, L.; Knoop, S.

    2011-01-01

    We have calculated the s-wave scattering length of all the even isotopes of calcium (Ca) and barium (Ba), in order to investigate the prospect of Bose-Einstein condensation (BEC). For Ca we have used an accurate molecular potential based on detailed spectroscopic data. Our calculations show that Ca does not provide other isotopes alternative to the recently Bose condensed 40Ca that suffers strong losses because of a very large scattering length. For Ba we show by using a model potential that ...

  16. Barium enema findings of milk allergy in infants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gyoung Ju; Kim, Mi Jeong; Lee, Hee Jung [Keimyung University School of Medicine, Daegu (Korea, Republic of)

    2006-09-15

    We wanted to evaluate the barium enema findings of milk allergy in infants. Retrospective evaluation of the plain abdominal radiography and barium enema findings was performed in fifteen young infants suffering with milk allergy. The presence of gaseous distension, rectal gas, paralytic ileus and mechanical obstruction was evaluated on the plain radiography. The presence of spasm, a transitional zone, a reversed rectosigmoid index and mucosal irregularity was analyzed on the barium enema; the presence of barium retention was also evaluated on 24-hour-delayed plain radiography. Paralytic ileus was the most common finding on the plain radiography (93%). On the barium enema, continuous spasm of the colon, ranging from the rectum to the descending colon, was revealed in ten infants (67%). A transitional zone was observed in one infant and a reversed rectosigmoid index was revealed in four. Mucosal irregularity was observed in two infants. Barium retention was demonstrated in 11 of fifteen cases: throughout the entire colon (n = 3), from the rectum to the descending colon (n = 7), and up to the transverse colon (n = 1). The most common barium enema finding of milk allergy in infants was spasm of the distal colon. The other findings were a transitional zone, a reversed rectosigmoid index, mucosal irregularity and barium retention.

  17. Conserved charged amino acid residues in the extracellular region of sodium/iodide symporter are critical for iodide transport activity

    Directory of Open Access Journals (Sweden)

    Liang Ji-An

    2010-11-01

    Full Text Available Abstract Background Sodium/iodide symporter (NIS mediates the active transport and accumulation of iodide from the blood into the thyroid gland. His-226 located in the extracellular region of NIS has been demonstrated to be critical for iodide transport in our previous study. The conserved charged amino acid residues in the extracellular region of NIS were therefore characterized in this study. Methods Fourteen charged residues (Arg-9, Glu-79, Arg-82, Lys-86, Asp-163, His-226, Arg-228, Asp-233, Asp-237, Arg-239, Arg-241, Asp-311, Asp-322, and Asp-331 were replaced by alanine. Iodide uptake abilities of mutants were evaluated by steady-state and kinetic analysis. The three-dimensional comparative protein structure of NIS was further modeled using sodium/glucose transporter as the reference protein. Results All the NIS mutants were expressed normally in the cells and targeted correctly to the plasma membrane. However, these mutants, except R9A, displayed severe defects on the iodide uptake. Further kinetic analysis revealed that mutations at conserved positively charged amino acid residues in the extracellular region of NIS led to decrease NIS-mediated iodide uptake activity by reducing the maximal rate of iodide transport, while mutations at conserved negatively charged residues led to decrease iodide transport by increasing dissociation between NIS mutants and iodide. Conclusions This is the first report characterizing thoroughly the functional significance of conserved charged amino acid residues in the extracellular region of NIS. Our data suggested that conserved charged amino acid residues, except Arg-9, in the extracellular region of NIS were critical for iodide transport.

  18. Barium and radium migration in unconsolidated Canadian geological materials

    International Nuclear Information System (INIS)

    This report describes the results of laboratory studies on the distribution coefficients of radium and barium in samples of unconsolidated geologic materials. Graphs of Ksub(d) versus solution concentration for the respective elements showed constant Ksub(d) values in the low concentration range suggesting that, at low concentrations, a distribution coefficient is a valid means of representing the geochemical reactions of both barium and radium. The Ksub(d) values for barium range between 60 and 3500 ml/g. The values appear to be influenced by the amount of barium occurring naturally in the soil materials and thus there is little possiblility of using barium as an analog of radium in laboratory experiments. The Ksub(d) values of radium vary from 50 to 1000 ml/g indicating that a wide range of geological materials have a substantial capacity to retard the migration of radium

  19. Barium appendicitis: A single institution review in Japan

    Science.gov (United States)

    Katagiri, Hideki; Lefor, Alan Kawarai; Kubota, Tadao; Mizokami, Ken

    2016-01-01

    AIM To review clinical experience with barium appendicitis at a single institution. METHODS A retrospective review of patients admitted with a diagnosis of acute appendicitis, from January 1, 2013 to December 31, 2015 was performed. Age, gender, computed tomography (CT) scan findings if available, past history of barium studies, pathology, and the presence of perforation or the development of complications were reviewed. If the CT scan revealed high density material in the appendix, the maximum CT scan radiodensity of the material is measured in Hounsfield units (HU). Barium appendicitis is defined as: (1) patients diagnosed with acute appendicitis; (2) the patient has a history of a prior barium study; and (3) the CT scan shows high density material in the appendix. Patients who meet all three criteria are considered to have barium appendicitis. RESULTS In total, 396 patients were admitted with the diagnosis of acute appendicitis in the study period. Of these, 12 patients (3.0%) met the definition of barium appendicitis. Of these 12 patients, the median CT scan radiodensity of material in the appendix was 10000.8 HU, ranging from 3066 to 23423 HU (± 6288.2). In contrast, the median CT scan radiodensity of fecaliths in the appendix, excluding patients with barium appendicitis, was 393.1 HU, ranging from 98 to 2151 HU (± 382.0). The CT scan radiodensity of material in the appendices of patients with barium appendicitis was significantly higher than in patients with nonbarium fecaliths (P < 0.01). CONCLUSION Barium appendicitis is not rare in Japan. Measurement of the CT scan radiodensity of material in the appendix may differentiate barium appendicitis from routine appendicitis.

  20. High resolution studies of barium Rydberg states

    International Nuclear Information System (INIS)

    The subtle structure of Rydberg states of barium with orbital angular momentum 0, 1, 2 and 3 is investigated. Some aspects of atomic theory for a configuration with two valence electrons are reviewed. The Multi Channel Quantum Defect Theory (MQDT) is concisely introduced as a convenient way to describe interactions between Rydberg series. Three high-resolution UV studies are presented. The first two, presenting results on a transition in indium and europium serve as an illustration of the frequency doubling technique. The third study is of hyperfine structure and isotope shifts in low-lying p states in Sr and Ba. An extensive study of the 6snp and 6snf Rydberg states of barium is presented with particular emphasis on the 6snf states. It is shown that the level structure cannot be fully explained with the model introduced earlier. Rather an effective two-body spin-orbit interaction has to be introduced to account for the observed splittings, illustrating that high resolution studies on Rydberg states offer an unique opportunity to determine the importance of such effects. Finally, the 6sns and 6snd series are considered. The hyperfine induced isotope shift in the simple excitation spectra to 6sns 1S0 is discussed and attention is paid to series perturbers. It is shown that level mixing parameters can easily be extracted from the experimental data. (Auth.)

  1. NANOSCALE BARIUM HYDROSILICATES: CHOOSING THE SYNTHESIS TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    GRISHINA Anna Nikolaevna

    2013-08-01

    Full Text Available Cement concretes are the most used materials in modern civil engineering. Due to that such materials draw great attention both in the Russian Federation and abroad. The possibility to enhance the manufacturability and operational properties of concretes results in significant reduction of overall operating costs. Many enhancement methods have been elaborated. Among them there is one based on introduction of calcium hydrosilicates into construction composition. The authors set up a hypothesis that similarity between properties and structures of different hydrosilicates (for example, alkaline earth metals and metals of the second group will provide similar increased operational characteristics. The specialists of Research and Educational Center «Nanotechnology» are developing cement composites nanomodification methods which include introduction of nanodimensional barium hydrosilicates particles. The synthesis of barium hydrosilicates particles can be done with the use of many technologies, different by energy consumption or performing complexity. Taking into account both these factors, one can assume that low-temperature sol-gel synthesis from diluted water solutions is the proper technology. The present paper shows that this assumption is correct. The selection of certain technology is made by the means of multiobjective optimization, which is in turn is performed by the means of linear scalarization. This method, while not always giving the Pareto optimal solutions, can be easily implemented. The particle size distribution is taken into consideration during selection of objectives and weights. It is shown that selected technology allows manufacturing nanoparticles with median size about 30 nm.

  2. The Novel Formation of Barium Titanate Nanodendrites

    Directory of Open Access Journals (Sweden)

    Chien-Jung Huang

    2014-01-01

    Full Text Available The barium titanate (BaTiO3 nanoparticles with novel dendrite-like structures have been successfully fabricated via a simple coprecipitation method, the so-called BaTiO3 nanodendrites (BTNDs. This method was remarkable, fast, simple, and scalable. The growth solution is prepared by barium chloride (BaCl2, titanium tetrachloride (TiCl4, and oxalic acid. The shape and size of BaTiO3 depend on the amount of added BaCl2 solvent. To investigate the influence of amount of BaCl2 on BTNDs, the amount of BaCl2 was varied in the range from 3 to 6 mL. The role of BaCl2 is found to have remarkable influence on the morphology, crystallite size, and formation of dendrite-like structures. The thickness and length of the central stem of BTND were ~300 nm and ~20 μm, respectively. The branchings were found to occur at irregular intervals along the main stem. Besides, the formation mechanism of BTND is proposed and discussed.

  3. Coprecipitation of europium with barium sulphate

    International Nuclear Information System (INIS)

    The distribution behaviour of the trivalent europium ion at a micro-component scale, between barium sulphate and aqueous solution, was studied at ambient temperature. Experiments were carried out using radioactive tracers. Results indicate an enrichment of the micro component in the solid phase relative to the solution. The effects of the concentrations of the micro and macro-elements on the coprecipitation have been examined. Europium distribution coefficient DEu increases from 1.1 ± 0.2 to 3.2 ± 0.4 when initial europium concentration decreases from more than 17 x 10-5 to 1.4 x 10-5 M, in sulphuric media with SO42- in excess or CBa2+/CSO42- Eu. The coprecipitation of europium with barium sulphate as a heterovalent solid-solution is described by heterogeneous model obeying the Doerner and Hoskins logarithmic partition law. The weaker partition coefficients lower than unity (λ = 0.25 when CEu(III) ∼ 1.4 x 10-5 M and λ = 0.13 when CBa2+/CSO42- -5 ≤ CEu(III) = 153.5 x 10-5 M) lead to crystals increasingly enriched in the trace element. (orig.)

  4. The Effect on Sodium/Iodide Symporter and Pendrin in Thyroid Colloid Retention Developed by Excess Iodide Intake.

    Science.gov (United States)

    Chen, Xiao-Yi; Lin, Chu-Hui; Yang, Li-Hua; Li, Wang-Gen; Zhang, Jin-Wei; Zheng, Wen-Wei; Wang, Xiang; Qian, Jiang; Huang, Jia-Luan; Lei, Yi-Xiong

    2016-07-01

    It is well known that excess iodide can lead to thyroid colloid retention, a classic characteristic of iodide-induced goiter. However, the mechanism has not been fully unrevealed. Iodide plays an important role in thyroid function at multiple steps of thyroid colloid synthesis and transport among which sodium/iodide symporter (NIS) and pendrin are essential. In our study, we fed female BALB/c mice with different concentrations of high-iodine water including group A (control group, 0 μg/L), group B (1500 μg/L), group C (3000 μg/L), group D (6000 μg/L), and group E (12,000 μg/L). After 7 months of feeding, we found that excess iodide could lead to different degrees of thyroid colloid retention. Besides, NIS and pendrin expression were downregulated in the highest dose group. The thyroid iodide intake function detected by urine iodine assay and thyroidal (125)I experiments showed that the urine level of iodine increased, while the iodine intake rate decreased when the concentration of iodide used in feeding water increased (all p control group). In addition, transmission electron microscopy (TEM) indicated a reduction in the number of intracellular mitochondria of thyroid cells. Based on these findings, we concluded that the occurrence of thyroid colloid retention exacerbated by excess iodide was associated with the suppression of NIS and pendrin expression, providing an additional insight of the potential mechanism of action of excess iodide on thyroid gland. PMID:26660892

  5. Expression of the human sodium/iodide symporter (hNIS) in xenotransplanted human thyroid carcinoma

    NARCIS (Netherlands)

    Smit, J.W.A.; Schröder - van der Elst, J.P.; Karperien, M.; Que, I.; Romijn, J.A.; Heide, van der D.

    2001-01-01

    The uptake of iodide in thyroid epithelial cells is mediated by the sodium/iodide symporter (NIS). The uptake of iodide is of vital importance for thyroid physiology and is a prerequisite for radioiodine therapy in thyroid cancer. Loss of iodide uptake due to diminished expression of the human NIS (

  6. Strengthening mechanism of steels treated by barium-bearing alloys

    Institute of Scientific and Technical Information of China (English)

    Zhouhua Jiang; Yang Liu

    2008-01-01

    The deoxidation, desulfurization, dephosphorization, microstructure, and mechanical properties of steels treated by barium-bearing alloys were investigated in laboratory and by industrial tests. The results show that barium takes part in the deoxidation reaction at the beginning of the experiments, generating oxide and sulfide compound inclusions, which easily float up from the molten steel, leading to the rapid reduction of total oxygen content to a very low level. The desulfurization and dephosphorization capabilities of calcium-bearing alloys increase with the addition of barium. The results of OM and SEM observations and mechanical property tests show that the structure of the steel treated by barium-bearing alloys is refined remarkably, the iamellar thickness of pearlitic structure decreases, and the pearlitic morphology shows clustering distribution. Less barium exists in steel substrate and the enrichment of barium-bearing precipitated phase mostly occurs in grain boundary and phase boundary, which can prevent the movement of grain boundary and dislocation during the heat treatment and the deformation processes. Therefore, the strength and toughness of barium-treated steels are improved by the effect of grain-boundary strengthening and nail-prick dislocation.

  7. Improved Stability of Mercuric Iodide Detectors for Anticoincidence Shields Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to utilize guard ring electrode structures and a new film growth technique to create improved polycrystalline mercuric iodide detectors for background...

  8. Designed microstructures in textured barium hexaferrite

    Science.gov (United States)

    Hovis, David Brian

    It is a fundamental principle of materials science that the microstructure of a material defines its properties and ultimately its performance for a given application. A prime example of this can be found in the large conch shell Strombus gigas, which has an intricate microstructure extending across five distinct length scales. This microstructure gives extraordinary damage tolerance to the shell. The structure of Strombus gigas cannot be replicated in a modern engineering ceramic with any existing processing technique, so new processing techniques must be developed to apply this structure to a model material. Barium hexaferrite was chosen as a model material to create microstructures reminiscent of Strombus gigas and evaluate its structure-property relations. This work describes novel processing methods to produce textured barium hexaferrite with no coupling between the sample geometry and the texture direction. This technique, combining magnetic field-assisted gelcasting with templated grain growth, also allows multilayer samples to be fabricated with different texture directions in adjacent layers. The effects of adding either B2O3 or excess BaCO 3 on the densification and grain growth of barium hexaferrite was studied. The texture produced using this technique was assessed using orientation imaging microscopy (OIM) at Oak Ridge National Laboratory. These measurements showed peak textures as high as 60 MRD and sharp interfaces between layers cast with different texture directions. The effect of oxygen on the quality of gelcasting is also discussed, and it is shown that with proper mold design, it is possible to gelcast multiple layers with differing texture directions without delamination. Monolithic and multilayer samples were produced and tested in four point bending to measure the strength and work of fracture. Modulus measurements, made with the ultrasonic pulse-echo technique, show clear signs of microcracking in both the isotropic and textured samples

  9. Prevention of organic iodide formation in BWR`s

    Energy Technology Data Exchange (ETDEWEB)

    Karjunen, T. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland); Laitinen, T.; Piippo, J.; Sirkiae, P. [VTT Manufacturing Technology (Finland)

    1996-12-01

    During an accident, many different forms of iodine may emerge. Organic iodides, such as methyl iodide and ethyl iodide, are relatively volatile, and thus their appearance leads to increased concentration of gaseous iodine. Since organic iodides are also relatively immune to most accident mitigation measures, such as sprays and filters, they can affect the accident source term significantly even when only a small portion of iodine is in organic form. Formation of organic iodides may not be limited by the amount of organic substances available. Excessive amounts of methane can be produced, for example, during oxidation of boron carbide, which is used in BWR`s as a neutron absorber material. Another important source is cable insulation. In a BWR, a large quantity of cables is placed below the pressure vessel. Thus a large quantity of pyrolyse gases will be produced, should the vessel fail. Organic iodides can be formed as a result of many different reactions, but at least in certain conditions the main reaction takes place between an organic radical produced by radiolysis and elemental iodine. A necessary requirement for prevention of organic iodide production is therefore that the pH in the containment water pools is kept high enough to eliminate formation of elemental iodine. In a typical BWR the suppression pool water is usually unbuffered. As a result, the pH may be dominated by chemicals introduced during an accident. If no system for adding basic chemicals is operable, the main factor affecting pool water pH may be hydrochloric acid released during cable degradation. Should this occur, the conditions could be very favorable for production of elemental iodine and, consequently, formation of organic iodides. Although high pH is necessary for iodine retention, it could have also adverse effects. High pH may, for example, accelerate corrosion of containment materials and alter the characteristics of the solid corrosion products. (author) 6 figs., 1 tab., 13 refs.

  10. A review of polytypism in lead iodide

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, P.A. [Department of Physics, Bryn Mawr College, Bryn Mawr, Pennsylvania (United States)

    2010-05-15

    Lead Iodide (PbI{sub 2}) is an important inorganic solid for both basic scientific research and possible technological applications and in this brief review we discuss the structure of PbI{sub 2}. Although the basic structure is a simple I-Pb-I layered structure with a[PbI{sub 6}]{sup 4-} near-octahedron being the basic building block, there are many ways of stacking the layers which results in many polytypes. We present 20 of the 23 entries for the structure of PbI{sub 2} from the Inorganic Structural Database and order them by polytype. This represents more than 80 years of crystallographic research in the structure of this compound. We present a simple way to view the 2H, 4H, 6H, and 6R polytypes and extend the procedure to higher-order polytypes. We note a relationship, not generally appreciated, between the distortion of the near [PbI{sub 6}]{sup 4-} octahedrons and the polytype. We suggest that the significance of vacancies has only recently been appreciated. We suggest that small discrepancies in structure determination are probably due to different distributions of vacancies and that there are, in practice, very many structures for macroscopic or even mesoscopic samples of a given polytype when vacancies are considered. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Chloride, bromide and iodide scintillators with europium

    Energy Technology Data Exchange (ETDEWEB)

    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. Chemical composition of Eu2+ luminescence in the barium hexaaluminates

    International Nuclear Information System (INIS)

    This paper consists of two parts. In the first part the chemical composition of two kinds of barium hexaaluminate (one poor and one rich in barium) is explained using the local electroneutrality concept. In the second part a reinvestigation of the Eu2+ luminescence in these compounds is reported. The emission spectrum of each of the two compounds shows a blue and a green emission bank. The blue emission bank is ascribed to Eu2+ ions at barium sites, whereas the green emission band is identified with Eu2+ ions incorporated at aluminum sites within spinel blocks of the structure

  13. Barium concentration in grain of Aegilops and Triticum species

    Directory of Open Access Journals (Sweden)

    Denčić Srbislav S.

    2015-01-01

    Full Text Available The aim of this study was to evaluate the concentration of barium in grain of various Aegilops and Triticum species with different genomes. The studied species differed significantly with respect to the concentration of barium. The grain of wild diploid Aegilops speltoides, the donor of B genome, contained significantly higher Ba concentration than all other analyzed genotypes. Wild and cultivated tetraploid wheats (Triticum diciccoides, Triticum dicoccon, Triticum turgidum and Triticum durum had the lowest Ba concentration in grain. The modern cultivated hexaploid varieties presented substantial variation in grain concentration of barium. The highest Ba concentration (3.42 mg/kg occurred in Serbian winter wheat variety Panonnia.

  14. Structure of barium sodium trimetaphosphate trihydrate

    Energy Technology Data Exchange (ETDEWEB)

    Averbuch-Pouchot, M.T.; Durif, A.

    1987-03-15

    BaNaP/sub 3/O/sub 9/ . 3H/sub 2/O, M/sub r/=451.29, triclinic, Panti 1, a=7.067(3), b=9.071(3), c=9.906(4) A, ..cap alpha..=116.46(5), ..beta..=95.97(5), ..gamma..=74.03(5)/sup 0/, V=546.4 A/sup 3/, Z=2, D/sub m/ not measured, D/sub x/=2.743 Mg m/sup -3/, lambda(Mo K..cap alpha..)=0.7107 A, ..mu..=4.28 mm/sup -1/, F(000)=428, T=293 K, R=0.028 for 3775 independent reflexions. The P/sub 3/O/sub 9/ ring anions and the water molecules build up a three-dimensional network through hydrogen bonds. Inside this network barium and sodium have respectively nine- and sevenfold coordinations.

  15. Analysis of europium doped luminescent barium thioaluminate

    Institute of Scientific and Technical Information of China (English)

    张东璞; 喻志农; 薛唯; 章婷; 丁瞾; 王武育

    2010-01-01

    Europium-doped barium thioaluminate sputtering target was synthesized by powder sintering method and thin film was deposited by radio frequency(RF) sputtering.X-ray diffractometer(XRD) pattern indicated that the main compound of the target was BaAl4S7.Oxygen was the main impurity which led to the formation of BaAl2O4.It was shown that both BaAl4S7 and BaAl2S4 were contained in the as-grown thin films and a 471.7 nm emission peak in the PL spectra appeared due to a combination of BaAl4S7:Eu2+ and BaAl2S4:Eu2...

  16. Chemical abundance analysis of 19 barium stars

    CERN Document Server

    Yang, G C; Spite, M; Chen, Y Q; Zhao, G; Zhang, B; Liu, G Q; Liu, Y J; Liu, N; Deng, L C; Spite, F; Hill, V; Zhang, C X

    2016-01-01

    We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium (Ba) stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences. The chemical abundances of the sample stars were obtained from an LTE, plane-parallel and line-blanketed atmospheric model by inputting the atmospheric parameters (effective temperatures, surface gravities, metallicity and microturbulent velocity) and equivalent widths of stellar absorption lines. These samples of Ba stars are giants indicated by atmospheric parameters, metallicities and kinematic analysis about UVW velocity. Chemical abundances of 17 elements were obtained for these Ba stars. Their light elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn and Ni) are similar to the solar abundances. Our samples of Ba stars show obvious overabundances of neutron-capture (n-ca...

  17. A novel barium polymeric membrane sensor for selective determination of barium and sulphate ions based on the complex ion associate barium(II)-Rose Bengal as neutral ionophore

    Energy Technology Data Exchange (ETDEWEB)

    Othman, A.M. [Genetic Engineering and Biotechnology Research Institute (GEBRI), Minufiya University, Sadat City (Egypt); El-Shahawi, M.S. [Chemistry Department, Faculty of Science at Damiatta, Mansoura University, Damiatta, Dumyat 34517 (Egypt)]. E-mail: mohammad_el_shahawi@yahoo.co.uk; Abdel-Azeem, M. [Chemistry Department, Faculty of Science at Damiatta, Mansoura University, Damiatta, Dumyat 34517 (Egypt)

    2006-01-12

    A simple, long life, rapid response and sensitive barium(II)-PVC membrane sensor that typically follows Nernstian behavior has been developed for the assay of barium(II) ions. The developed sensor has been made by incorporating the complex ion associate of barium(II)-Rose Bengal (Ba-RB) as an ionophore into a plasticized PVC matrix. The sensor is stable and exhibited fast potential response of 20 s and gave a good linear response with a Nernstian slope of 28.5 {+-} 0.4 mV/decade of activity within the concentration range 5 x 10{sup -5} to 10{sup -1} M over a wide range of pH 4.5-10.0 for barium(II) ions. The developed sensor showed comparatively good selectivity for barium(II) ions with respect to other alkali, alkaline earth, transition and heavy metal ions. The plasticizer o-nitrophenyloctyl ether controlled significantly the calibration slope and the lifetime of the fabricated sensor. The proposed sensor was used successfully for the analysis of barium(II) ions in wastewater samples and in lithophone pigment with excellent recovery percentages in the range 98.9-99.8 {+-} 1.6%. The determination of sulphate in fresh and potable water samples with the developed sensor has been also achieved successfully. The described sensor provides a reliable means with good correlation with the data obtained by atomic absorption spectrometry (AAS) and other spectrophotometric methods for the analysis of trace amounts of barium(II) and/or sulphate ions in different matrices.

  18. A novel barium polymeric membrane sensor for selective determination of barium and sulphate ions based on the complex ion associate barium(II)-Rose Bengal as neutral ionophore

    International Nuclear Information System (INIS)

    A simple, long life, rapid response and sensitive barium(II)-PVC membrane sensor that typically follows Nernstian behavior has been developed for the assay of barium(II) ions. The developed sensor has been made by incorporating the complex ion associate of barium(II)-Rose Bengal (Ba-RB) as an ionophore into a plasticized PVC matrix. The sensor is stable and exhibited fast potential response of 20 s and gave a good linear response with a Nernstian slope of 28.5 ± 0.4 mV/decade of activity within the concentration range 5 x 10-5 to 10-1 M over a wide range of pH 4.5-10.0 for barium(II) ions. The developed sensor showed comparatively good selectivity for barium(II) ions with respect to other alkali, alkaline earth, transition and heavy metal ions. The plasticizer o-nitrophenyloctyl ether controlled significantly the calibration slope and the lifetime of the fabricated sensor. The proposed sensor was used successfully for the analysis of barium(II) ions in wastewater samples and in lithophone pigment with excellent recovery percentages in the range 98.9-99.8 ± 1.6%. The determination of sulphate in fresh and potable water samples with the developed sensor has been also achieved successfully. The described sensor provides a reliable means with good correlation with the data obtained by atomic absorption spectrometry (AAS) and other spectrophotometric methods for the analysis of trace amounts of barium(II) and/or sulphate ions in different matrices

  19. The Karlsruhe 4π barium fluoride detector

    International Nuclear Information System (INIS)

    A new experimental approach has been implemented for accurate measurements of neutron capture cross sections in the energy range from 5 to 200 keV. The Karlsruhe 4π Barium Fluoride Detector consists of 42 crystals shaped as hexagonal and pentagonal truncated pyramids forming a spherical shell with 10 cm inner radius and 15 cm thickness. All crystals are supplied with reflector and photomultiplier, thus representing independent gamma-ray detectors. Each detector module covers the same solid angle with respect to a gamma-ray source located in the centre. The energy resolution of the 4π detector is 14% at 662 keV and 7% at 2.5 MeV gamma-ray energy, the overall time reslution is 500 ps and the peak efficiency 90% at 1 MeV. The detector allows to register capture cascades with 95% probability above a threshold energy of 2.5 MeV in the sum energy spectrum. Neutrons are produced via the 7Li(p,n)7Be reaction using the pulsed proton beam of a Van de Graaff accelerator. The neutron spectrum can be taylored according to the experimental requirements in an energy range from 5 to 200 keV by choosing appropriate proton energies. A collimated neutron beam is passing through the detector and hits the sample in the centre. The energy of captured neutrons is determined via time of flight, the primary flight path being 77 cm. The combination of short primary flight path, a 10 cm inner radius of the spherical BaF2 shell, and the low capture cross section of barium allows to discriminate background due to capture of sample scattered neutrons in the scintillator by time of flight, leaving part of the neutron energy range completely undisturbed. (orig./HSI)

  20. A NOVEL HYDROTHERMAL SYNTHESIS METHOD FOR BARIUM FERRITE

    Institute of Scientific and Technical Information of China (English)

    Kang Li; Hongchen Gu; Qun Wei

    2004-01-01

    In the present work, fine barium ferrite powder has been synthesized through a one-step hydrothermal process in an autoclave at [OH-]/[Cl-] ratio of 2:1 in the temperature range from 180 to 260 ℃ using barium chloride (BaCl2), ferrous chloride (FeCl2) and potassium nitrate (KNO3) as the starting materials. Both particle size and saturation magnetization (Ms) increase with increasing hydrothermal reaction temperature, while the intrinsic coercivity (iHc) peaks at 685 Oe at 230 ℃. Morphology progress from the barium ferrite precursor particles to the barium hexaferrite particles has been monitored with increasing hydrothermal reaction time at 230 ℃ in the autoclave.

  1. Upper gastrointestinal barium evaluation of duodenal pathology: A pictorial review

    Institute of Scientific and Technical Information of China (English)

    Pankaj; Gupta; Uma; Debi; Saroj; Kant; Sinha; Kaushal; Kishor

    2014-01-01

    Like other parts of the gastrointestinal tract(GIT), duodenum is subject to a variety of lesions both congenital and acquired. However, unlike other parts of the GIT viz. esophagus, rest of the small intestine and large intestine, barium evaluation of duodenal lesions is technically more challenging and hence not frequently reported. With significant advances in computed tomography technology, a thorough evaluation including intraluminal, mural and extramural is feasible in a single non-invasive examination. Notwithstanding, barium evaluation still remains the initial and sometimes the only imaging study in several parts of the world. Hence,a thorough acquaintance with the morphology of various duodenal lesions on upper gastrointestinal barium examination is essential in guiding further evaluation. We reviewed our experience with various common and uncommon barium findings in duodenal abnormalities.

  2. Liquid-phase-deposited barium titanate thin films on silicon

    International Nuclear Information System (INIS)

    Using a mixture of hexafluorotitanic acid, barium nitrate and boric acid, high refractive index (1.54) barium titanate films can be deposited on silicon substrates. The deposited barium titanate films have featureless surfaces. The deposition temperature is near room temperature (800C). However, there are many fluorine and silicon incorporations in the films. The refractive index of the as-deposited film is 1.54. By current-voltage measurement, the leakage current of the as-deposited film with a thickness of 1000 A is about 9.48x10-7 A cm-2 at the electrical field intensity of 0.3 MV cm-1. By capacitance-voltage measurement, the effective oxide charge of the liquid-phase-deposited barium titanate film is 3.06x1011 cm-2 and the static dielectric constant is about 22. (author)

  3. Peritonite por bário Barium peritonitis

    Directory of Open Access Journals (Sweden)

    Gerson Alves Pereira Júnior

    1999-10-01

    Full Text Available We report a case of a 49 years-old man who underwent a barium meal examination for an epigastric pain. A perforated gastric ulcer with barium extravasation into peritoneal cavity was seen on X-rays. During an emergency laparotomy, a perforated pyloric ulcer was noted, along with barium contamination in the peritoneal cavity. The ulcer was closed with an omental patch and an extensive peritoneal lavage with saline was performed. During the postoperative period, the patient developed signs of peritonitis and underwent a new laparotomy was at the 9th day showing a subfrenic abscess with a large barium contamination. The patient presented septic shock and multiple organ failure. dying on the 21th day.

  4. Iodide kinetics and experimental I-131 therapy in a xenotransplanted human sodium-iodide symporter-transfected human follicular thyroid carcinoma cell line

    NARCIS (Netherlands)

    Smit, J.W.A.; Elst, van der J.P.; Karperien, M.; Que, I.; Stokkel, M.; Heide, van der D.; Romijn, J.A.

    2002-01-01

    Uptake of iodide is a prerequisite for radioiodide therapy in thyroid cancer. However, loss of iodide uptake is frequently observed in metastasized thyroid cancer, which may be explained by diminished expression of the human sodium-iodide symporter (hNIS). We studied whether transfection of hNIS int

  5. Evaluation of mercuric iodide ceramic semiconductor detectors

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, M.; Zuck, A.; Braiman, M.; Nissenbaum, J. [Hebrew Univ., Jerusalem (Israel); Turchetta, R.; Dulinski, W.; Husson, D.; Riester, J.L. [LEPSI (ULP/IN2P3), Strasbourg (France)

    1998-02-01

    Mercuric iodide ceramic radiation detectors, which can act as nuclear particle counters, have been fabricated with single continuos electrical contacts and with linear strip contacts. They have been tested with different kinds of {gamma} and {beta} sources as well as in a high energy beam at CERN. The detectors were also successfully tested for radiation hardness with irradiation of 5*10{sup 14} neutrons/cm{sup 2}. The ratio of detected photons over the number of absorbed photons has been measured with {gamma} sources of different energies, and it ranges from 20% at 44 keV up to about 30% at 660 keV. An absolute efficiency of 70% has been measured for a 350 {mu}m thick detector for {beta} particles emitted by a {sup 90}Sr source. Charge collection efficiency, defined as the amount of charge induced on the electrodes by a mminimum ionizing particle (MIP) traversing the detector, has been measured in two samples. The average collected charge fits well with a linear curve with slope of 35 electrons/(kV/cm) per 100 {mu}m. This result is well described by a dynamic device simulation, where the free carrier mean lifetime is used as a free parameter, adjusted to a value of 1.5 ns, i.e. about 1/100 of the corresponding lifetime in single crystal HgI{sub 2} detectors. The response to MIP has also been studied with a high energy (100 GeV) muon beam in CERN. A preliminary beam profile is presented while a more detailed analysis is still in progress and will be presented elsewhere. These results together with the low cost of the material make ceramic HgI{sub 2} detectors excellent candidates for large area particle tracking and imaging applications, even in a radiation harsh environment. (orig.). 14 refs.

  6. Methyl Iodide Formation Under Postulated Nuclear Reactor Accident Conditions

    International Nuclear Information System (INIS)

    The formation of methyl iodide under conditions of postulated nuclear reactor accidents is discussed. Although thermodynamic calculations indicate the equilibrium methyl iodide concentrations would be quite low, calculations based on a simple kinetic scheme involving reaction between small hydrocarbon species and iodine indicate that concentrations higher than equilibrium can occur during the course of the reaction. Such calculations were performed over a wide range of initial species concentrations and a range of temperatures representative of some reactor accident situations. These calculations suggest that little methyl iodide would be expected within the core volume where temperatures are maximum. As the gas leaves the core volume and expands into the plenum region, it cools and the concentration of methyl iodide increases. At the intermediate temperatures which might characterize this region, the formation of methyl iodide from thermally induced reactions could reach its maximum rate. The gas continues to cool, however, and it is probable that by the time it leaves the plenum region it has cooled to the point where thermally induced reactions may be of little importance. Although the thermally induced reactions will become slower as the gas expands and cools, the radiation-induced reactions will not be slowed to the same extent. The gases leaving the core carry fission products and hence a radiation source is available to initiate reaction by a temperature-independent process. An investigation of the radiation chemical formation and decomposition of methyl iodide in the presence of steam suggests that radiation-induced methyl iodide formation will generally be rapid under the postulated accident situations. Thus, in the plenum region where thermal reactions have become slow, the radiation-induced reaction can still proceed and may well become the dominant factor. The same situation probably pertains as well to the containment region. (author)

  7. Electrorheological behavior of rare earth-doped barium titanate suspensions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Doping Y, La, Ce into barium titanate is found to be able to improve its electrorheological (ER) effect in DC electrical field. The yield stress of a typical doped barium titanate/silicone oil suspension is approximately 3.2 -*7〗kPa at 3.5 -*7〗kV/mm, which is 10 times larger than that of pure barium titanate/silicone oil suspensions. The ER effect increases with the decrease of ionic radius of rare earth (RE) dopant when RE concentration remains constant, and the suspensions exhibit a relatively high shear stress when Y, La, Ce mole fractions are 15%, 10%~15%, and 5%, respectively. Dielectric measurements show that the suitable doping with RE element increases dielectric loss of barium titanate and causes very marked dielectric relaxation at low frequency. By measuring X-ray diffraction patterns of doped barium titanate, it is considered that the occurrence of lattice distortion or defects may be responsible for the change of dielectric properties which results in the improvement of ER effect of barium titanate in DC electrical field.

  8. Lifetime Measurement for 6snp Rydberg States of Barium

    Institute of Scientific and Technical Information of China (English)

    SHEN Li; WANG Lei; YANG Hai-Feng; LIU Xiao-Jun; LIU Hong-Ping

    2011-01-01

    @@ We present a simple and efficient method for measuring the atomic lifetimes in order of tens of microseconds and demonstrate it in the lifetime determination of barium Rydberg states.This method extracts the lifetime information from the time-of-flight spectrum directly, which is much more efficient than other methods such as the time-delayed field ionization and the traditional laser induced fluorescence.The lifetimes determined with our method for barium Rydberg 6snp(n=37-59)series are well coincident with the values deduced from the absolute oscillator strengths of barium which were given in the literature [J.Phys.B 14(1981)4489, 29(1996)655]on experiments.%We present a simple and efficient method for measuring the atomic lifetimes in order of tens of microseconds and demonstrate it in the lifetime determination of barium Rydberg states. This method extracts the lifetime information from the time-of-flight spectrum directly, which is much more efficient than other methods such as the time-delayed field ionization and the traditional laser induced fluorescence. The lifetimes determined with our method for barium Rydberg 6snp (n=37-59) series are well coincident with the values deduced from the absolute oscillator strengths of barium which were given in the literature [J. Phys. B 14 (1981) 4489, 29 (1996) 655] onexperiments.

  9. Bismuth tri-iodide radiation detector development

    Science.gov (United States)

    Gokhale, Sasmit S.

    Bismuth tri-iodide is an attractive material for room temperature radiation detection. BiI3 demonstrates a number of properties that are apt for semiconductor radiation detection, especially gamma ray spectroscopy. The high atomic number (ZBi = 83 and ZI = 53) and the relatively high density (5.78 g/cm3) cause the material to have good photon stopping power, while the large band-gap (1.67 eV ) allows it to function as a room temperature radiation detector without any cooling mechanism. This work presents the fabrication and characterization of BiI3 radiation detectors. For the purpose of this research detectors were fabricated by cutting BiI3 crystal boules, followed by mechanical and chemical surface treatments. Detectors with various electrode geometries enabling single polarity charge sensing were fabricated. The electrical characteristics and the radiation response of the detectors were measured. The radiation response measurement was performed at room temperature using a 241Am alpha particle source and a 241Am sealed gamma-ray source. The spectral resolutions of the detectors varied from 2.09% - 6.1% for 59.5 keV gamma-rays and between 26% - 40% for 5.48 MeV alpha particles. Charge carrier properties such as the electron and hole mobility and lifetime were also estimated. The electron mobility for an ultrapure BiI 3 detector was estimated to be approximately 433 cm 2/Vs while that for antimony doped BiI3 was estimated to be around 956 cm2/Vs and the mobility-lifetime product for electrons was estimated to be around 5.44 x 10-4 cm 2/V. Detector simulation was performed using the Monte Carlo simulation code MCNP5. A Matlab script which incorporates charge carrier trapping and statistical variation was written to generate a gamma-ray spectrum from the simulated energy deposition spectra. Measured and simulated spectra were compared to extract the charge carrier mobility-lifetime products, which for electrons and holes were estimated to be 5 x 10-3 cm2/V and 1.3 x

  10. Macrosegregation during Plane Front Solidification of Cesium Iodide wt Percent Thallium Iodide Alloy

    Science.gov (United States)

    Sidawi, Ibrahim M. S.

    Macrosegregation produced during directional solidification of CsI-1 wt% TlI by vertical Bridgman technique has been examined in crucibles of varying diameter, from 0.5 to 2.0 cm. Phase diagram and temperature dependence of the thermal conductivity have been determined. The experimentally observed liquid-solid interface shape and the fluid flow behavior have been compared with that computed from the commercially available code FIDAP. Thallium iodide content of the alloy was observed to increase along the length of the directionally solidified specimens, resulting in continuously decreasing light output. The experimentally observed solutal distribution agrees with predictions from the boundary layer model of Favier. The observed macrosegregation behavior suggests that there is a significant convection in the melt even in the smallest crucible diameter of 0.5 cm.

  11. Leachability of barium-radium sulphate sludges

    International Nuclear Information System (INIS)

    This paper presents results from the first phase of a research program designed to examine the leachability of radium-226 from barium-radium sulphate sludges. Batch leaching tests were performed. Results showed that liquid:solid contact time was relatively unimportant; radium in the sludge was stable in the presence of deionized water with a slight increase in the amount leached per gram of sludge occurring at higher liquid:solid ratios. Not unexpectedly, low and high values of leachant pH increased radium leaching. Both monovalent and divalent salt solutions also increased leaching; however, dissolved radium-226 activity levels in the leachate decreased as leachant molarity increased. For divalent salts this can be explained by the common ion effect; for monovalent salts it is opposite to results expected from solubility considerations. The interpretation of all results is complicated by the fact that in most tests, the amount of radium-226 present in the leachate was lower than the calculated contribution from the mother liquour present with the sludge. This apparent ability of the sludge to absorb radium from solution may be related to dissolution and reprecipitation of the sludge during the leaching tests

  12. Phase 1 Methyl Iodide Deep-Bed Adsorption Tests

    Energy Technology Data Exchange (ETDEWEB)

    Nick Soelberg; Tony Watson

    2014-08-01

    Nuclear fission results in the production of fission products (FPs) and activation products including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Research, demonstrations, and some reprocessing plant experience have indicated that diatomic iodine can be captured with efficiencies high enough to meet regulatory requirements. Research on the capture of organic iodides has also been performed, but to a lesser extent [Jubin 2012b]. Several questions remain open regarding the capture of iodine bound in organic compounds. Deep-bed methyl iodide adsorption testing has progressed according to a multi-laboratory methyl iodide adsorption test plan. This report summarizes the first phase of methyl iodide adsorption work performed according to this test plan using the deep-bed iodine adsorption test system at the Idaho National Laboratory (INL), performed during Fiscal Year (FY) 2013 and early FY-2014. Testing has been performed to address questions posed in the test plan, and followed the testing outline in the test plan. Tests established detection limits, developed procedures for sample analysis with minimal analytical interferences, and confirmed earlier results that show that the methyl iodide reacts when in contact with the AgZ sorbent, and not significantly in the gas flow upstream of the sorbent. The reaction(s) enable separation of the iodine from the organic moiety, so that the iodine can chemisorb onto the sorbent. The organic moiety can form other compounds, some of which are organic compounds that are detected and can be tentatively identified using GC-FID and GCMS. Test results also show that other gas constituents (NOx and/or H2O) can affect the methyl iodide reactions. With NOx and H2O present in the gas stream, the majority of uncaptured iodine exiting iodine-laden sorbent beds is in the form of I2 or HI, species that

  13. Standard free energy of formation of iron iodide

    Science.gov (United States)

    Khandkar, A.; Tare, V. B.; Wagner, J. B., Jr.

    1983-01-01

    An experiment is reported where silver iodide is used to determine the standard free energy of formation of iron iodide. By using silver iodide as a solid electrolyte, a galvanic cell, Ag/AgI/Fe-FeI2, is formulated. The standard free energy of formation of AgI is known, and hence it is possible to estimate the standard free energy of formation of FeI2 by measuring the open-circuit emf of the above cell as a function of temperature. The free standard energy of formation of FeI2 determined by this method is -38784 + 24.165T cal/mol. It is estimated that the maximum error associated with this method is plus or minus 2500 cal/mol.

  14. The diagnostic value of barium enema in acute appendicitis

    International Nuclear Information System (INIS)

    Acute appendicitis is the most common acute surgical condition of the abdomen. When the clinical presentation is atypical, barium enema has proven to be safe and useful in confirming the diagnosis and reducing the negative surgical exploration. However, the performance of barium enema in acute appendicitis has known contraindication primarily because of fear of leakage by perforation of the inflamed appendix. This study using barium enema as a diagnostic aid in acute appendicitis with atypical clinical presentation was performed to further support the previously noted efficacy and safety of this procedure. The results were as followings: 1. In case of acute appendicitis with atypical clinical presentation, the use of barium enema as a diagnostic aid increased the accuracy of diagnosis and decreased the negative surgical exploration. In women between 11 to 50 years old age, especially, it played important role differentiating appendicitis from nonsurgical acute abdomen. 2. The results of the study were 92.31% in sensitivity, 7.69% in false positive, 6.9% in false negative, and 10.26% in negative appendectomy. 3. None of case of leakage of barium by perforation of the inflamed appendix was noted, therefore, barium enema was thought to be safe as a diagnostic aid in acute appendicitis. 4. A simple partial or non filling of appendix without other associated positive finding could not exclude appendicitis, therefore, close clinical observation was necessary. 5. The positive findings of barium enema and their sensitivity were as followings: 1. Non filling of appendix: 90% 2. Partial filling of appendix: 91.7% 3. Displacement or a local impression on terminal ileum: 100%

  15. A novel peculiar mutation in the sodium/iodide symporter gene in spanish siblings with iodide transport defect.

    Science.gov (United States)

    Kosugi, Shinji; Okamoto, Hiroomi; Tamada, Aiko; Sanchez-Franco, F

    2002-08-01

    Previously, we reported two Spanish siblings with congenital hypothyroidism due to total failure of iodide transport. These were the only cases reported to date who received long-term iodide treatment over 10 yr. We examined the sodium/iodide symporter (NIS) gene of these patients. A large deletion was observed by long and accurate PCR using primers derived from introns 2 and 7 of the NIS gene. PCR-direct sequencing revealed a deletion of 6192 bases spanning from exon 3 to intron 7 and an inverted insertion of a 431-base fragment spanning from exon 5 to intron 5 of the NIS gene. The patients were homozygous for the mutation, and their mother was heterozygous. In the mutant, deletion of exons 3-7 was suggested by analysis using programs to predict exon/intron organization, resulting in an in-frame 182-amino acid deletion from Met(142) in the fourth transmembrane domain to Gln(323) in the fourth exoplasmic loop. The mutant showed no iodide uptake activity when transfected into COS-7 cells, confirming that the mutation was the direct cause of the iodide transport defect in these patients. Further, the mutant NIS protein was synthesized, but not properly expressed, on the cell surface, but was mostly accumulated in the cytoplasm, suggesting impaired targeting to the plasma membrane. PMID:12161518

  16. Enhanced Olefin Cross Metathesis Reactions: The Copper Iodide Effect

    Science.gov (United States)

    Voigtritter, Karl; Ghorai, Subir

    2011-01-01

    Copper iodide has been shown to be an effective co-catalyst for the olefin cross metathesis reaction. In particular, it has both a catalyst stabilizing effect due to iodide ion, as well as copper(I)-based phosphine-scavenging properties that apply to use of the Grubbs-2 catalyst. A variety of Michael acceptors and olefinic partners can be cross-coupled under mild conditions in refluxing diethyl ether that avoid chlorinated solvents. This effect has also been applied to chemistry in water at room temperature using the new surfactant TPGS-750-M. PMID:21528868

  17. Mercuric iodide dosimeter response to high energy electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Loewinger, E.; Nissenbaum, J.; Schieber, M.M.

    1988-01-01

    Mercuric iodide solid state dosimeter response to high energy electron beams of up to 35 MeV is reported. High sensitivity of up to 1.5 V/cGy was observed with a 200 V external bias, as well as several mV/cGy, with no external bias for small volume (approx. 10 mm/sup 3/) detectors. The physical characteristics of the detector response are discussed, showing the feasibility of mercuric iodide as a reliable dosimeter for high energy electron beams.

  18. Uptake of Iodide From Water in Atlantic Halibut Larvae (Hippoglossus Hippoglossus L.)

    DEFF Research Database (Denmark)

    Moren, Mari; Sloth, Jens Jørgen; Hamre, Kristin

    2008-01-01

    relative low levels of iodide (0-22 nM) and except for samples from one site; the levels of iodide and iodate were in agreement with previously published data. The uptake of iodide from seawater was measured by incubating Atlantic halibut larvae in water with a constant level of radioactive iodide (I-125...... is whether Atlantic halibut larvae are capable of absorbing iodide from the water and if so, can the seawater sustain the iodine requirement during larval development and metamorphosis. Levels of iodide and iodate in seawater samples from four different rearing facilities were analysed. All samples contained...... concentration of iodide in the water. The highest level of iodide used was 2000 nM,100 times higher than what was measured in the seawater samples. The uptake curves did not seem to reach equilibrium. This may be due to a constant nonspecific uptake or that the equilibrium level is higher than 2000 n...

  19. Occupational doses in pediatric barium meal procedures

    International Nuclear Information System (INIS)

    Ionizing radiation has become an indispensable tool when it comes to diagnosis and therapy. However, its use should happen in a rational manner, taking into account the risks to which the staff is being exposed. Barium meal (BM), or upper gastrointestinal (GI) studies, using fluoroscopy, are widely used for gastroesophageal reflux disease diagnostic in children and professionals are required to stay inside the examination room to position and immobilize pediatric patients during the procedure. Therefore, it is very important that proffessionals strictly follow the technical standards of radiation protection. According to the ICRP and the NCRP recommendations, the annual limit equivalent doses for eyes, thyroid and hands are, espectively, 20 mSv, 150 mSv and 500 mSv. Based on those data, the aim of the current study is to estimate the annual equivalent dose for eyes, thyroid and hands of professionals who perform BM procedures in children. This was done using properly package LiF:Mg,Cu,P thermoluminescent dosimeters in 37 procedures; 2 pairs were positioned near each staff´s eye, 2 pairs on each professional´s neck (on and under the lead protector) and 2 pairs on both staff´s hands. The range of the estimative annual equivalent doses, for eyes, thyroid and hands, are, respectively: 14 – 36 mSv, 7 – 22 mSv and 14 – 58 mSv. Only the closest staff to the patient exceeded the annual equivalent doses in the eyes (around 80% higher than the limit set by ICRP). However, the results from this study, for hands and thyroid, compared to similar studies, show higher values. Therefore, the optimization implementation is necessary, so that the radiation levels can be reduced. (authors)

  20. Barium titanate thick films prepared by screen printing technique

    Directory of Open Access Journals (Sweden)

    Mirjana M. Vijatović

    2010-06-01

    Full Text Available The barium titanate (BaTiO3 thick films were prepared by screen printing technique using powders obtained by soft chemical route, modified Pechini process. Three different barium titanate powders were prepared: i pure, ii doped with lanthanum and iii doped with antimony. Pastes for screen printing were prepared using previously obtained powders. The thick films were deposited onto Al2O3 substrates and fired at 850°C together with electrode material (silver/palladium in the moving belt furnace in the air atmosphere. Measurements of thickness and roughness of barium titanate thick films were performed. The electrical properties of thick films such as dielectric constant, dielectric losses, Curie temperature, hysteresis loop were reported. The influence of different factors on electrical properties values was analyzed.

  1. Deoxidation Behavior of Alloys Bearing Barium in Molten Steel

    Institute of Scientific and Technical Information of China (English)

    LI Yang; JIANG Zhou-hua; JIANG Mao-fa; WANG Jun-wen; GU Wen-bing

    2003-01-01

    The deoxidation behaviors of alloys bearing barium in pipe steel were researched with MgO crucible under argon atmosphere in MoSi2 furnace at 1 873 K. The total oxygen contents of molten steel, the distribution, size and morphology of deoxidation products in the steel were surveyed. The metamorphic mechanism for deoxidation products of alloy bearing barium was also discussed. The results show that applying alloy bearing barium to the pipe steel, very low total oxygen contents can be obtained, and deoxidation products, which easily float up from molten steel, can be changed into globular shape and uniformly distributed in steel. The equilibrium time of total oxygen is about 25 min, and the terminal total oxygen contents range from 0.002 0 % to 0.002 2 % after treating with SiCa wire. The best deoxidizers are SiAlBaCa and SiAlBaCaSr.

  2. Economically dissolving barium sulfate scale with a chelating agent

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, E.A.; Scheuerman, R.E.

    1977-06-21

    A composition is described for dissolving a barium sulfate scale from a subterranean or other relatively remote location into which fluid can be flowed. Fluid is flow-flowed into the remote location so that a stream of fluid contacts and flows along the surface of the scale. The composition and flow rate of the fluid are adjusted so that (1) the scale is contacted by a stream of aqueous solution in which each portion contains enough dissolved aminopolyacetic acid salt chelating agent to dissolve barium sulfate, and (2) substantially all upstream portions of the scale are contacted by a succession of portions of the aqueous liquid which are substantially unsaturated with respect to dissolved barium-chelant complex. (5 claims)

  3. The electrosorption of tetraalkylammonium ions on silver iodide

    NARCIS (Netherlands)

    Keizer, de A.

    1981-01-01

    The object of the present investigations was to study the ef fect of the adsorption of charged organic ions on electrically charged, solid-liquid interfaces. To that end, symmetrical quater nary ammonium ions were adsorbed on a silver iodide-electrolyte interface at various surface charges. The elec

  4. Radiation-hard polycrystalline mercuric iodide semiconductor particle counters

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, M. [Hebrew Univ., Jerusalem (Israel)]|[Sandia National Laboratories, Livermore Ca 94556 (United States); Zuck, A.; Melekhov, L.; Nissenbaum, J. [Hebrew Univ., Jerusalem (Israel); Turchetta, R.; Dulinski, W.; Husson, D.; Riester, J.L. [LEPSI (ULP/IN2P3), Strasbourg (France)

    1998-06-01

    Mercuric iodide polycrystalline radiation detectors, which can act as nuclear particle counters and for large area imaging devices, have been fabricated using three different methods. Response to X- and gamma rays, beta particles and to 100GeV muons, as well as radiation hardness results are briefly described. (orig.) 8 refs.

  5. Iodide volatility under condition relevant to PWR steam generator faults

    International Nuclear Information System (INIS)

    The evaluation of iodine volatility during steam generator tube rupture (SGTR) is hampered by three factors: (i) lack of suitable plant data under fault conditions, (ii) lack of experimental data (mainly due to the difficulty of performing experiments under the conditions required) and (iii) uncertainty in theoretical methods to extrapolate experimental data to the required conditions. This report summarises methods of estimating the volatility of hydrogen iodide and iodide salts at the required conditions of temperature and pressure. A thermodynamic method has been used to estimate HI volatility and the density correlation method for iodide salt volatility. It is assumed throughout that it is more conservative to predict higher volatility. Consideration is given to two explanations of experiments carried out at Oak Ridge National Laboratory (ORNL) on the influence of boric acid concentration and pH on the volatility of radioiodine ostensibly under SGTR conditions: (i) the results have been interpreted in terms of reactions involving volatility of iodide salt/ion-pairs and complexation by boric acid in the gas phase and (ii) the possibility is explored that the observed results are due to the influence of oxidation leading to the formation of much more volatile iodine species. (author)

  6. Radiation dose in mass screening for gastric cancer with high-concentration barium sulphate compared with moderate-concentration barium sulphate

    International Nuclear Information System (INIS)

    Full text: Recently, high-concentration barium sulfate has been developed and is used in many medical facilities. This study compared radiation dose using high-concentration and moderate-concentration barium sulfate. The dose was evaluated with an experimental method using a gastric phantom and with a clinical examination. In the former, the dose and X-ray tube load were measured on the phantom with two concentrations of barium sulfate. In the latter, the fluoroscopic dose-area product (DAP), the radiographic DAP and their sum, the total DAP, were investigated in 150 subjects (112 males, 38 females) treated with both concentrations of barium sulfate. The effective dose was calculated by the software of PCXMC in every case. The results of the experimental evaluation indicated that the effective dose and X-ray tube load were greater with high-concentration barium sulfate than with moderate-concentration barium sulfate (p < 0.05). The results of the clinical evaluation indicated that the fluoroscopic DAP was greater with moderate-concentration barium sulfate than with high-concentration barium sulfate (p < 0.05), but the radiographic DAP was quite the reverse, so the total DAP and effective dose were almost same with both concentrations of barium sulfate. We conclude that high-concentration barium sulfate does not increase radiation dose in mass screening for gastric cancer.

  7. Compact pulse forming line using barium titanate ceramic material.

    Science.gov (United States)

    Kumar Sharma, Surender; Deb, P; Shukla, R; Prabaharan, T; Shyam, A

    2011-11-01

    Ceramic material has very high relative permittivity, so compact pulse forming line can be made using these materials. Barium titanate (BaTiO(3)) has a relative permittivity of 1200 so it is used for making compact pulse forming line (PFL). Barium titanate also has piezoelectric effects so it cracks during high voltages discharges due to stresses developed in it. Barium titanate is mixed with rubber which absorbs the piezoelectric stresses when the PFL is charged and regain its original shape after the discharge. A composite mixture of barium titanate with the neoprene rubber is prepared. The relative permittivity of the composite mixture is measured to be 85. A coaxial pulse forming line of inner diameter 120 mm, outer diameter 240 mm, and length 350 mm is made and the composite mixture of barium titanate and neoprene rubber is filled between the inner and outer cylinders. The PFL is charged up to 120 kV and discharged into 5 Ω load. The voltage pulse of 70 kV, 21 ns is measured across the load. The conventional PFL is made up of oil or plastics dielectrics with the relative permittivity of 2-10 [D. R. Linde, CRC Handbook of Chemistry and Physics, 90th ed. (CRC, 2009); Xia et al., Rev. Sci. Instrum. 79, 086113 (2008); Yang et al., Rev. Sci. Instrum. 81, 43303 (2010)], which increases the length of PFL. We have reported the compactness in length achieved due to increase in relative permittivity of composite mixture by adding barium titanate in neoprene rubber. PMID:22129008

  8. 75 FR 36629 - Barium Chloride From the People's Republic of China: Continuation of Antidumping Duty Order

    Science.gov (United States)

    2010-06-28

    ... International Trade Administration Barium Chloride From the People's Republic of China: Continuation of... China: Final Results of Expedited Third Sunset Review of Antidumping Duty Order, 74 FR 55814 (October 29... Barium Chloride From China, 75 FR 33824 (June 15, 2010), and Barium Chloride from China (Inv. No....

  9. The adhesiometer: a simple device to measure adherence of barium sulfate to intestinal mucosa.

    Science.gov (United States)

    Salomonowitz, E; Frick, M P; Cragg, A H; Lund, G

    1984-04-01

    A simple, inexpensive device assessing barium sulfate adherence to alimentary tract mucosa was tested in an animal study using pigs and dogs. Interaction of gastric, intestinal, and colonic mucosal lining with three different barium preparations was studied. In both pigs and dogs, barium adherence to gastric mucosa was significantly stronger when compared with colonic mucosa. PMID:6608230

  10. Photoionization and Photoelectric Loading of Barium Ion Traps

    OpenAIRE

    Steele, A. V.; Churchill, L. R.; Griffin, P. F.; Chapman, M. S.

    2007-01-01

    Simple and effective techniques for loading barium ions into linear Paul traps are demonstrated. Two-step photoionization of neutral barium is achieved using a weak intercombination line (6s2 1S0 6s6p 3P1, 791 nm) followed by excitation above the ionization threshold using a nitrogen gas laser (337 nm). Isotopic selectivity is achieved by using a near Doppler-free geometry for excitation of the triplet 6s6p 3P1 state. Additionally, we report a particularly simple and efficient trap loading t...

  11. Equations of state for barium in high-pressure phases

    International Nuclear Information System (INIS)

    The universal equation of state with an arbitrary reference point presented by the author (Fang Zheng-Hua 1998 Phys. Rev. B 50 16 238) is applied successfully to the analysis of the experimental compression data of barium in different structural phases (I, II, and V). The comparison given in this paper shows that this equation suits for the isothermal compression behaviour of barium in the high-pressure phases (II and V) better than the Birch-Murnaghan equation. The applicability of equations of state for solids in high-pressure phases is also discussed. (author)

  12. Kinetics of thermal decomposition of barium zirconyl oxalate

    International Nuclear Information System (INIS)

    Kinetics of the thermal decomposition of anhydrous barium zirconyl oxalate and a carbonate intermediate have been studied. Decomposition of the anhydrous oxalate, though it could be explained based on a contracting-cube model, is quite complex. Kinetics of decomposition of the intermediate carbonate Ba2Zr2O5CO3 is greatly influenced by thermal effects during its formation. (α-t) curves are sigmoidal and obey a power law equation followed by first order decay. Presence of carbon in the vacuum-prepared carbonate has a strong deactivating effect. Decomposition of the carbonate is accompanied by growth in particle size of the product barium zirconate. (Author)

  13. Photoionization and Photoelectric Loading of Barium Ion Traps

    CERN Document Server

    Steele, A V; Churchill, L R; Griffin, P F

    2007-01-01

    Simple and effective techniques for loading barium ions into linear Paul traps are demonstrated. Two-step photoionization of neutral barium is achieved using a weak intercombination line (6s2 1S0 6s6p 3P1, 791 nm) followed by excitation above the ionization threshold using a nitrogen gas laser (337 nm). Isotopic selectivity is achieved by using a near Doppler-free geometry for excitation of the triplet 6s6p 3P1 state. Additionally, we report a particularly simple and efficient trap loading technique that employs an in-expensive UV epoxy curing lamp to generate photoelectrons.

  14. Esophageal intramural pseudodiverticulosis characterized by barium esophagography: a case report

    LENUS (Irish Health Repository)

    O'Connor, Owen J

    2010-05-21

    Abstract Introduction Esophageal intramural pseudodiverticulosis is a rare condition characterized by the dilatation of the submucosal glands. Case presentation We present a case of esophageal intramural pseudodiverticulosis in a 72-year-old Caucasian man who presented with dysphagia and with a background history of alcohol abuse. An upper gastrointestinal endoscopy of our patient showed an esophageal stricture with abnormal mucosal appearances, but no malignant cells were seen at biopsy. Appearances on a barium esophagram were pathognomonic for esophageal intramural pseudodiverticulosis. Conclusion We demonstrate the enduring usefulness of barium esophagography in the characterization of abnormal mucosal appearances at endoscopy.

  15. FY-2015 Methyl Iodide Deep-Bed Adsorption Test Report

    Energy Technology Data Exchange (ETDEWEB)

    Soelberg, Nicholas Ray [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony Leroy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-30

    Nuclear fission produces fission and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2015 according to a multi-laboratory methyl iodide adsorption test plan. Updates to the deep-bed test system have also been performed to enable the inclusion of evaporated HNO3 and increased NO2 concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reduced silver zeolite (AgZ) resulted in initial iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) under 1,000 for the conditions of the long-duration test performed this year (45 ppm CH3I, 1,000 ppm each NO and NO2, very low H2O levels [3 ppm] in balance air). The mass transfer zone depth exceeded the cumulative 5-inch depth of 4 bed segments, which is deeper than the 2-4 inch depth estimated for the mass transfer zone for adsorbing I2 using AgZ in prior deep-bed tests. The maximum iodine adsorption capacity for the AgZ under the conditions of this test was 6.2% (6.2 g adsorbed I per 100 g sorbent). The maximum Ag utilization was 51%. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

  16. FY-2015 Methyl Iodide Deep-Bed Adsorption Test Report

    International Nuclear Information System (INIS)

    Nuclear fission produces fission and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2015 according to a multi-laboratory methyl iodide adsorption test plan. Updates to the deep-bed test system have also been performed to enable the inclusion of evaporated HNO3 and increased NO2 concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reduced silver zeolite (AgZ) resulted in initial iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) under 1,000 for the conditions of the long-duration test performed this year (45 ppm CH3I, 1,000 ppm each NO and NO2, very low H2O levels [3 ppm] in balance air). The mass transfer zone depth exceeded the cumulative 5-inch depth of 4 bed segments, which is deeper than the 2-4 inch depth estimated for the mass transfer zone for adsorbing I2 using AgZ in prior deep-bed tests. The maximum iodine adsorption capacity for the AgZ under the conditions of this test was 6.2% (6.2 g adsorbed I per 100 g sorbent). The maximum Ag utilization was 51%. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

  17. Chemical abundance analysis of 19 barium stars

    Science.gov (United States)

    Yang, Guo-Chao; Liang, Yan-Chun; Spite, Monique; Chen, Yu-Qin; Zhao, Gang; Zhang, Bo; Liu, Guo-Qing; Liu, Yu-Juan; Liu, Nian; Deng, Li-Cai; Spite, Francois; Hill, Vanessa; Zhang, Cai-Xia

    2016-01-01

    We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium (Ba) stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences. The chemical abundances of the sample stars were obtained from an LTE, plane-parallel and line-blanketed atmospheric model by inputting the atmospheric parameters (effective temperatures Teff, surface gravities log g, metallicity [Fe/H] and microturbulence velocity ξt) and equivalent widths of stellar absorption lines. These samples of Ba stars are giants as indicated by atmospheric parameters, metallicities and kinematic analysis about UVW velocity. Chemical abundances of 17 elements were obtained for these Ba stars. Their Na, Al, α- and iron-peak elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Ni) are similar to the solar abundances. Our samples of Ba stars show obvious overabundances of neutron-capture (n-capture) process elements relative to the Sun. Their median abundances of [Ba/Fe], [La/Fe] and [Eu/Fe] are 0.54, 0.65 and 0.40, respectively. The Y I and Zr I abundances are lower than Ba, La and Eu, but higher than the α- and iron-peak elements for the strong Ba stars and similar to the iron-peak elements for the mild stars. There exists a positive correlation between Ba intensity and [Ba/Fe]. For the n-capture elements (Y, Zr, Ba, La), there is an anti-correlation between their [X/Fe] and [Fe/H]. We identify nine of our sample stars as strong Ba stars with [Ba/Fe] >0.6 where seven of them have Ba intensity Ba=2-5, one has Ba=1.5 and another one has Ba=1.0. The remaining ten stars are classified as mild Ba stars with 0.17<[Ba/Fe] <0.54.

  18. Thermodynamic analysis of production of high purity titanium by thermal decomposition of titanium iodide

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-hu; WANG Hua; LIU Yi-min; FANG Min

    2009-01-01

    High purity titanium was prepared by thermal decomposition of titanium iodide. The feasible synthetic route and optimum decompositon temperaure were obtained by thermodynamic analysis in the process of thermal decomposition of titanium iodide and nucleation growth theory. The temperature for the formation of titanium iodide is in the range of 800-900 K, at which a large amount of titanium iodide vapour can be obtained. The decomposition temperature of titanium iodide is in the range of 1 300-1 500 K, at which a favourable decomposition rate can be achieved. The experiment results show that the purity of the produced titanium is more than 99.995%.

  19. A novel mutation in the sodium/iodide symporter gene in the largest family with iodide transport defect.

    Science.gov (United States)

    Kosugi, S; Bhayana, S; Dean, H J

    1999-09-01

    We previously reported nine children with an autosomally recessive form of congenital hypothyroidism due to an iodide transport defect in a large Hutterite family with extensive consanguinity living in central Canada. Since the original report, we have diagnosed congenital hypothyroidism by newborn TSH screening in 9 additional children from the family. We performed direct sequencing of the PCR products of each NIS (sodium/iodide symporter) gene exon with flanking introns amplified from genomic DNA extracted from peripheral blood cells of the patients. We identified a novel NIS gene mutation, G395R (Gly395-->Arg; GGA-->AGA), in 10 patients examined in the present study. All of the parents tested were heterozygous for the mutation, suggesting that the patients were homozygous. The mutation was located in the 10th transmembrane helix. Expression experiments by transfection of the mutant NIS complimentary DNA into COS-7 cells showed no perchlorate-sensitive iodide uptake, confirming that the mutation is the direct cause of the iodide transport defect in these patients. A patient who showed an intermediate saliva/serum technetium ratio (14.0; normal, > or = 20) and was considered to have a partial or less severe defect in the previous report (IX-24) did not have a NIS gene mutation. It is now possible to use gene diagnostics of this unique NIS mutation to identify patients with congenital hypothyroidism due to an iodide transport defect in this family and to determine the carrier state of potential parents for genetic counseling and arranging rapid and early diagnosis of their infants. PMID:10487695

  20. Defective organification of iodide causing congenital goitrous hypothyroidism.

    Science.gov (United States)

    Ishikawa, N; Eguchi, K; Ohmori, T; Momotani, N; Nagayama, Y; Hosoya, T; Oguchi, H; Mimura, T; Kimura, S; Nagataki, S; Ito, K

    1996-01-01

    A 26-yr-old Japanese woman with congenital goitrous hypo-thyroidism and sensorineural deafness underwent a thyroidectomy. Examination of the thyroid gland revealed characteristic features of multinodular goiter. The T3 and T4 content in thyroglobulin (Tg) were 0.03 and 0.02 mol/mol Tg, respectively. Iodide incorporation into Tg, using slices of the thyroid tissue, revealed that iodide organification of thyroid tissue from our patient was markedly lower than that of normal controls. Then, guaiacol and iodide oxidation activities of thyroid peroxidase (TPO) in our patient's thyroid tissue were lower than those of normal controls (guaiacol assay: 1.92 vs. 30.0 +/- 5.7 mGU/mg protein; iodide assay: 1.1 vs. 6.6 +/- 2.8 mIU/mg protein). Lineweaver-Burk plot analysis of the oxidation rates of guaiacol and iodide indicated that this patient's TPO had a defect in the binding of guaiacol and iodide, but the coupling activity of the patient's TPO was not decreased compared with those of two normal thyroids. In this case and in control subjects, Nothern gel analysis of TPO messenger RNA from unstimulated and TSH-stimulated thyroid cells revealed a 3.2 kilobase species in the former and four distinct messenger RNA species of 4.0, 3.2, 2.1, and 1.7 kilobases in the latter. Western blot analysis of TPOs obtained from this patient and from control subjects identified the same 107 kDa protein, using antimicrosomal antibody-positive serum. We analyzed the coding sequence in the patient's TPO gene by using polymerase chain reaction technique. A single point mutation of G-->C at 1265 base pair was detected only in the TPO gene, but this point mutation does not alter the amino acid residue. It is possible that posttranslational modification such as abnormal glycosylation may occur in the TPO molecules. Furthermore, it is possible that there are differences in the tertiary structures of the TPO molecules between our patient and normal subjects. The above abnormalities of TPO molecules

  1. Synthesis of Nanocrystalline Barium Ferrite in Ethanol/Water Media

    Institute of Scientific and Technical Information of China (English)

    M.Montazeri-Pour; A.Ataie

    2009-01-01

    Nanocrystalline particles of barium ferrite magnetic material have been prepared by co-precipitation route using aqueous and non-aqueous solutions of iron and barium chlorides with a Fe/Ba molar ratio of 11 and subsequent drying-annealing treatment. Water and ethanol/water mixture with volume ratio of 3:1 were used as solvents in the process. Coprecipitated powders were annealed at various temperatures for 1 h. FTIR (Fourier transform infrared spectroscopy), XRD (X-ray diffraction), DTA/TGA (differential thermal analy-sis/thermogravimetric analysis) and SEM (scanning electron microscopy) techniques were used to evaluate powder particle characteristics. DTA/TGA results confirmed by those obtained from XRD indicated that the formation of barium ferrite occurs in sample synthesized in ethanol/water solution at a relatively low temperature of 631℃. Nano-size particles of barium ferrite with mean particle size of almost 75 and 100 nm were observed in the SEM micrographs of the samples synthesized in ethanol/water solution after annealing at 700 and 800℃ for 1 h, respectively.

  2. CNO and F abundances in the barium star HD 123396

    CERN Document Server

    Alves-Brito, Alan; Yong, David; Meléndez, Jorge; Vásquez, Sergio

    2011-01-01

    [Abridged] Barium stars are moderately rare chemically peculiar objects which are believed to be the result of the pollution of an otherwise normal star by material from an evolved companion on the asymptotic giant branch (AGB). We aim to derive carbon, nitrogen, oxygen, and fluorine abundances for the first time from infrared spectra of the barium red giant star HD 123396 to quantitatively test AGB nucleosynthesis models for producing barium stars via mass accretion. High-resolution and high S/N infrared spectra were obtained using the Phoenix spectrograph mounted at the Gemini South telescope. The abundances were obtained through spectrum synthesis of individual atomic and molecular lines, using the MOOG stellar line analysis program together with Kurucz's stellar atmosphere models. The analysis was classical, using 1D stellar models and spectral synthesis under the assumption of local thermodynamic equilibrium. We confirm that HD 123396 is a metal-deficient barium star ([Fe/H] = -1.05), with A(C) = 7.88, A...

  3. Removal of barium and radium from groundwater. Environmental research brief

    International Nuclear Information System (INIS)

    A research project was undertaken to investigate processes for removing barium and radium from drinking water. Special emphasis was placed on ion exchange processes that can be used without adding large concentrations of sodium to the water. The wastes from radium and barium removal processes were also characterized, and processes suitable for treatment of ion-exchange brines were evaluated. The report discusses two ion-exchange processes that can be used for barium and radium removal accompanied by either partial or no hardness removal. The calcium-form, strong-acid ion-exchange resin can be used for barium and radium removal without significant change in hardness or the concentration of other salts. This resin can be regenerated with CaC12 brine. The radium-selective complexer (RSC) will remove radium without altering hardness or other salt concentration. The capacity of this resin for waters with low total dissolved solids (TDS) (<1000 to 2000 mg/L TDS) is in excess of 30,000 pCi/dry g; however, if the TDS is increased to about 40,000 mg/L, the capacity drops to 200 to 300 pCi/dry g. Thus using this resin to remove radium from spent brine does not appear feasible

  4. Synthesis and Structure of Bis(4-nitrobenzaldehyde thiosemicarbazone) Cadmium Iodide

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The title complex, bis(4-nitrobenzaldehyde thiosemicarbazone) cadmium iodide (C16H16CdI2N8O4S2) crystallizes in the triclinic system, space group P1 with a=9.632(2), b=11.227(2), c=14.031(3), α= 67.50(3), β= 86.99(3), γ= 66.64(3)°, V=1278.13, Z = 2, Dc = 2.117gcm-3, F(000) = 772, μ =3.472mm-1 MoKα radiation (λ=0.71073), R = 0.0443, wR= 0.1425 for 4529 observed reflections [I>2σ(I)] of 4731 independent reflections. The result shows that the structure contains CdL2I2 (where L = 4-nitrobenzaldehyde thiosemicarbazone) distorted tetrahedral units in which the two ligands are S-bonded as monodentate to cadmium ion; the two iodide ions are also coordinated to Cd(II).

  5. (1,2-Dicarba-closo-dodecaboranyltrimethylmethanaminium iodide

    Directory of Open Access Journals (Sweden)

    Jong-Dae Lee

    2011-08-01

    Full Text Available The title compound, [1-(CH33NCH2-1,2-C2B10H11]+·I− or C6H22B10N+·I−, was obtained by the reaction of (1,2-dicarba-closo-dodecaboranyldimethylmethanamine with methyl iodide. The asymmetric unit contains two iodide anions and two (o-carboranyltetramethylammonium cations. The bond lengths and angles in the carborane cage are within normal ranges, but the N—Cmethylene—Ccage angle is very large [120.2 (2°] because of repulsion between the carborane and tetramethylammonium units. In the crystal, ions are linked through C—H...I hydrogen bonds.

  6. Methyl iodide production in the ocean: Implications for climate change

    Science.gov (United States)

    Smythe-Wright, Denise; Boswell, Stephen M.; Breithaupt, Petra; Davidson, Russell D.; Dimmer, Claudia H.; Eiras Diaz, Ledicia B.

    2006-09-01

    Methyl iodide concentrations of up to 45 pmol L-1, which flux into the marine boundary layer, have been found in low latitude waters of the Atlantic and Indian oceans. These high concentrations correlate well with the abundance of Prochlorococcus, and we have confirmed the release of methyl iodide by this species in laboratory culture experiments. Extrapolating, we estimate the global ocean flux of iodine to the marine boundary layer from this single source to be 5.3 × 1011 g I yr-1, which is a large fraction of the previously estimated total global flux and the implications are far reaching. Climate prediction models suggest increases in sea surface temperature and changes in biogeographical provenances in response to global warming. Such changes are likely to increase the abundance of Prochlorococcus, and we estimate a concomitant ˜15% increase in the release of iodine species to the atmosphere. Potentially, this could help mitigate global warming.

  7. New applications for the zinc iodide-osmium tetroxide technique.

    OpenAIRE

    Dağdeviren, A; ALP, H.; Ors, U

    1994-01-01

    The zinc iodide-osmium tetroxide (ZIO) fixation/staining method was applied for neurocytological studies and also to examine several other tissue samples including epidermal Langerhans cells, blood and bone marrow cells and lymphoid tissue. Although precise specificity cannot be attributed to the staining reaction, interesting staining patterns for different cell types were observed by using one of the ZIO staining solutions. The significance of ZIO positivity is briefly discussed.

  8. Heterogeneous ice nucleation on silver-iodide-like surfaces

    OpenAIRE

    Fraux, Guillaume; Doye, Jonathan P. K.

    2014-01-01

    We attempt to simulate the heterogeneous nucleation of ice at model silver-iodide surfaces and find relatively facile ice nucleation and growth at the Ag+ termi nated basal face, but never see nucleation at the I- terminated basal face or the prism and normal faces. Water molecules strongly adsorb onto the Ag+ terminate d face to give a well-ordered hexagonal ice-like bilayer that then acts as a template for further ice growth.

  9. Lead iodide perovskite light-emitting field-effect transistor

    OpenAIRE

    Chin, Xin Yu; Cortecchia, Daniele; Yin, Jun; Bruno, Annalisa; Soci, Cesare

    2015-01-01

    Despite the widespread use of solution-processable hybrid organic–inorganic perovskites in photovoltaic and light-emitting applications, determination of their intrinsic charge transport parameters has been elusive due to the variability of film preparation and history-dependent device performance. Here we show that screening effects associated to ionic transport can be effectively eliminated by lowering the operating temperature of methylammonium lead iodide perovskite (CH3NH3PbI3) field-eff...

  10. Radiative efficiency of lead iodide based perovskite solar cells

    OpenAIRE

    Kristofer Tvingstedt; Olga Malinkiewicz; Andreas Baumann; Carsten Deibel; Snaith, Henry J.; Vladimir Dyakonov; Bolink, Henk J.

    2015-01-01

    The maximum efficiency of any solar cell can be evaluated in terms of its corresponding ability to emit light. We herein determine the important figure of merit of radiative efficiency for Methylammonium Lead Iodide perovskite solar cells and, to put in context, relate it to an organic photovoltaic (OPV) model device. We evaluate the reciprocity relation between electroluminescence and photovoltaic quantum efficiency and conclude that the emission from the perovskite devices is dominated by a...

  11. Ionic transport in hybrid lead iodide perovskite solar cells

    OpenAIRE

    Eames, Christopher; Frost, Jarvist Moore; Piers R. F. Barnes; O'Regan, Brian C.; Walsh, Aron; Islam, M. Saiful

    2015-01-01

    Solar cells based on organic–inorganic halide perovskites have recently shown rapidly rising power conversion efficiencies, but exhibit unusual behaviour such as current–voltage hysteresis and a low-frequency giant dielectric response. Ionic transport has been suggested to be an important factor contributing to these effects; however, the chemical origin of this transport and the mobile species are unclear. Here, the activation energies for ionic migration in methylammonium lead iodide (CH3NH...

  12. The sodium iodide symporter: its implications for imaging and therapy

    International Nuclear Information System (INIS)

    The sodium iodide symporter (NIS) is an intrinsic plasma membrane glycoprotein that mediates the active transport of iodide in the thyroid gland and a number of extrathyroidal tissues, in particular lactating mammary gland. In addition to its key function in thyroid physiology, NIS-mediated iodide accumulation allows diagnostic thyroid scintigraphy as well as therapeutic radioiodine application in benign and malignant thyroid disease. NIS therefore represents one of the oldest targets for molecular imaging and therapy. Based on the effective administration of radioiodine that has been used for over 60 years in the management of follicular cell-derived thyroid cancer, cloning and characterization of the NIS gene has paved the way for the development of a novel cytoreductive gene therapy strategy based on targeted NIS expression in thyroidal and nonthyroidal cancer cells followed by therapeutic application of 131I or alternative radionuclides, including 188Re and 211At. In addition, the possibility of direct and non-invasive imaging of functional NIS expression by 123I- and 99mTc-scintigraphy or 124I-PET-imaging allows the application of NIS as a novel reporter gene. In conclusion, the dual role of NIS as diagnostic and therapeutic gene and the detection of extra-thyroidal endogenous NIS expression in breast cancer open promising perspectives in nuclear medicine and molecular oncology for diagnostic and therapeutic application of NIS outside the thyroid gland. (orig.)

  13. Synthesis and evaluation of iodide uptake inhibitors in thyroid gland

    International Nuclear Information System (INIS)

    This work was intended to discover small organic molecules acting as iodide uptake inhibitors in thyroid cells. These compounds can indeed be derivatized into biochemical probes for further characterization of proteins involved in iodide transport mechanisms. On the long term, these inhibitors also appear as attractive drug candidates for treatment of thyroid pathologies or radioprotection against iodine isotopes. A similar strategy was adopted for both of the two inhibitor families. First, we synthesized a chemical library of around 100 analogues; we measured their IC50 against iodide uptake in FRTL-5 cells to get structure-activity relationships. Absolute configuration of stereo-genic centers was also investigated, and a preferential stereochemistry was found to be responsible for activity. From this basis, around twenty 'second-generation' analogues were synthesized by combining fragments contributing to biological activity. Biological evaluation indicated that nine were very potent inhibitors, with IC50 ≤ 6 nM and satisfying physicochemical properties required for drug candidates. Finally, one photoactivatable biotinylated probe was developed in each family and used for photoaffinity labeling. Several specifically labeled proteins are still under identification and constitute new potential therapeutic targets. (author)

  14. Gold nanoelectrode ensembles for direct trace electroanalysis of iodide.

    Science.gov (United States)

    Pereira, Francisco C; Moretto, Ligia M; De Leo, Manuela; Zanoni, Maria V Boldrin; Ugo, Paolo

    2006-08-01

    A procedure for the standardization of ensembles of gold nanodisk electrodes (NEE) of 30 nm diameter is presented, which is based on the analytical comparison between experimental cyclic voltammograms (CV) obtained at the NEEs in diluted solutions of redox probes and CV patterns obtained by digital simulation. Possible origins of defects sometimes found in NEEs are discussed. Selected NEEs are then employed for the study of the electrochemical oxidation of iodide in acidic solutions. CV patterns display typical quasi-reversible behavior which involves associated chemical reactions between adsorbed and solution species. The main CV characteristics at the NEE compare with those observed at millimeter sized gold disk electrodes (Au-macro), apart a slight shift in E1/2 values and slightly higher peak to peak separation at the NEE. The detection limit (DL) at NEEs is 0.3 microM, which is more than one order of magnitude lower than DL at the Au-macro (4 microM). The mechanism of the electrochemical oxidation of iodide at NEEs is discussed. Finally, NEEs are applied to the direct determination of iodide at micromolar concentration levels in real samples, namely in some ophthalmic drugs and iodized table salt.

  15. Enhanced iodide sequestration by 3-biphenyl-5,6-dihydroimidazo 2,1-b thiazole in sodium/iodide sym-porter (NIS)-expressing cells

    International Nuclear Information System (INIS)

    The ability of the sodium/iodide sym-porter (NIS) to take up iodide has long provided the basis for cyto-reductive gene therapy and cancer treatment with radio-iodide. One of the major limitations of this approach is that radio-iodide retention in NIS-expressing cells is not sufficient for their destruction. We identified and characterized a small organic molecule capable of increasing iodide retention in HEK293 cells permanently transfected with human NIS cDNA (hNIS-HEK293) and in the rat thyroid-derived cell line FRTL-5. In the presence of 3-biphenyl-4'-yl-5,6-dihydroimidazo[2,1-b)thiazole (ISA1), the transmembrane iodide concentration gradient was increased up to 4.5-fold. Our experiments indicate that the imidazo-thiazole derivative acts either by inhibiting anion efflux mechanisms, or by promoting the relocation of iodide into subcellular compartments. This new compound is not only an attractive chemical tool to investigate the mechanisms of iodide flux at the cellular level, but also opens promising perspectives in the treatment of cancer after NIS gene transfer. (authors)

  16. Enhanced iodide sequestration by 3-biphenyl-5,6-dihydroimidazo 2,1-b thiazole in sodium/iodide sym-porter (NIS)-expressing cells

    Energy Technology Data Exchange (ETDEWEB)

    Lecat-Guillet, N.; Ambroise, Y. [CEA, DSV, Dept Bioorgan Chem andt IsotopLabelling, Inst Biol and Technol, iBiTecS, F-91191 Gif Sur Yvette (France)

    2008-07-01

    The ability of the sodium/iodide sym-porter (NIS) to take up iodide has long provided the basis for cyto-reductive gene therapy and cancer treatment with radio-iodide. One of the major limitations of this approach is that radio-iodide retention in NIS-expressing cells is not sufficient for their destruction. We identified and characterized a small organic molecule capable of increasing iodide retention in HEK293 cells permanently transfected with human NIS cDNA (hNIS-HEK293) and in the rat thyroid-derived cell line FRTL-5. In the presence of 3-biphenyl-4'-yl-5,6-dihydroimidazo[2,1-b)thiazole (ISA1), the transmembrane iodide concentration gradient was increased up to 4.5-fold. Our experiments indicate that the imidazo-thiazole derivative acts either by inhibiting anion efflux mechanisms, or by promoting the relocation of iodide into subcellular compartments. This new compound is not only an attractive chemical tool to investigate the mechanisms of iodide flux at the cellular level, but also opens promising perspectives in the treatment of cancer after NIS gene transfer. (authors)

  17. Electrochemistry of silver iodide the capacity of the double layer at the silver iodide-water interface

    NARCIS (Netherlands)

    Lyklema, J.; Overbeek, J.Th.G.

    1961-01-01

    A method is described for obtaining differential double layer capacities on silver iodide. Especially the influence of the nature and concentration of indifferent electrolytes was investigated, viz., the nitrates of Li·, K·, Rb·, NH4·, H·, Tl·, Mg··, Ba··, Co··, Cd··, Pb··, La···, Th····, the fluori

  18. Design, testing, fabrication and launch support of a liquid chemical barium release payload (utilizing the liquid fluorine-barium salt/hydrazine system)

    Science.gov (United States)

    Stokes, C. S.; Smith, E. W.; Murphy, W. J.

    1972-01-01

    A payload was designed which included a cryogenic oxidizer tank, a fuel tank, and burner section. Release of 30 lb of chemicals was planned to occur in 2 seconds at the optimum oxidizer to fuel ratio. The chemicals consisted of 17 lb of liquid fluorine oxidizer and 13 lb of hydrazine-barium salt fuel mixture. The fuel mixture was 17% barium chloride, 16% barium nitrate, and 67% hydrazine, and contained 2.6 lb of available barium. Two significant problem areas were resolved during the program: explosive valve development and burner operation. The release payload was flight tested, from Wallops Island, Virginia. The release took place at an altitude of approximately 260 km. The release produced a luminous cloud which expanded very rapidly, disappearing to the human eye in about 20 seconds. Barium ion concentration slowly increased over a wide area of sky until measurements were discontinued at sunrise (about 30 minutes).

  19. HYBRID AND CHARACTERISTIC OF POLYANILINE- BARIUM TITANATE NANOCOMPOSITE PARTICLES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Polyaniline-barium titanate (PAn-BaTiO3) ultrafine composite particles were prepared by the oxidative polymerization of aniline with H2O2 while barium titanate nanoparticles were synthesized with a sol-gel method. The infrared spectrogram shows that the polymerization of PAn in the hybrid process of PAn-BaTiO3 is similar with the polymeric process of pure aniline, and there is interaction of PAn and BaTiO3 in the PAn-BaTiO3. SEM and TEM results show that the average diameter of the composite particles is 1.50 μm and the diameters of BaTiO3 nanoparticles are 5-15 nm in the composite particle. The electrical conductivity of the ultrafine composite particles is transformable from 100 to 10-11S/cm by equilibrium doping or dedoping method using various concentration of HCl or NaOH solutions.

  20. The crystal growth of barium flouride in aqueous solution

    Science.gov (United States)

    Barone, J. P.; Svrjcek, D.; Nancollas, G. H.

    1983-06-01

    The kinetics of growth of barium flouride seed crystals were investigated in aqueous solution at 25°C using a constant composition method, in which the supersaturation and ionic strength were maintained constant by the addition of titrants consisting of barium nitrate and potassium flouride solutions. The rates of reaction, studied over a range of supersaturation (σ ≈ 0.4 to 1.0), were interpreted in terms of crystal growth models. A spiral growth mechanism best describes the data, and scanning electron microscopy indicates a three-dimensional growth. In the presence of inorganic additives such as phosphate, however, induction periods precede a morphological two-dimensional crystallization. Coulter Counter results show little crystal agglomeration.

  1. Electromagnetic properties of photodefinable barium ferrite polymer composites

    Directory of Open Access Journals (Sweden)

    Olusegun Sholiyi

    2014-07-01

    Full Text Available This article reports the magnetic and microwave properties of a Barium ferrite powder suspended in a polymer matrix. The sizes for Barium hexaferrite powder are 3–6 μm for coarse and 0.8–1.0 μm for the fine powder. Ratios 1:1 and 3:1 (by mass of ferrite to SU8 samples were characterized and analyzed for predicting the necessary combinations of these powders with SU8 2000 Negative photoresist. The magnetization properties of these materials were equally determined and were analyzed using Vibrating Sample Magnetometer (VSM. The Thru, Reflect, Line (TRL calibration technique was employed in determining complex relative permittivity and permeability of the powders and composites with SU8 between 26.5 and 40 GHz.

  2. Barium titanate nanoparticles: promising multitasking vectors in nanomedicine

    Science.gov (United States)

    Graziana Genchi, Giada; Marino, Attilio; Rocca, Antonella; Mattoli, Virgilio; Ciofani, Gianni

    2016-06-01

    Ceramic materials based on perovskite-like oxides have traditionally been the object of intense interest for their applicability in electrical and electronic devices. Due to its high dielectric constant and piezoelectric features, barium titanate (BaTiO3) is probably one of the most studied compounds of this family. Recently, an increasing number of studies have been focused on the exploitation of barium titanate nanoparticles (BTNPs) in the biomedical field, owing to the high biocompatibility of BTNPs and their peculiar non-linear optical properties that have encouraged their use as nanocarriers for drug delivery and as label-free imaging probes. In this review, we summarize all the recent findings about these ‘smart’ nanoparticles, including the latest, most promising potential as nanotransducers for cell stimulation.

  3. Electromagnetic properties of carbon black and barium titanate composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang Guiqin [School of Material Science and Engineering, Dalian University of Technology, Dalian 116023 (China)], E-mail: c2b2chen@163.com; Chen Xiaodong; Duan Yuping; Liu Shunhua [School of Material Science and Engineering, Dalian University of Technology, Dalian 116023 (China)

    2008-04-24

    Nanocrystalline carbon black/barium titanate compound particle (CP) was synthesized by sol-gel method. The phase structure and morphology of compound particle were investigated by X-ray diffraction (XRD), transmission electron microscope (TEM) and Raman spectrum measurements, the electroconductivity was test by trielectrode arrangement and the precursor powder was followed by differential scanning calorimetric measurements (DSC) and thermal gravimetric analysis (TGA). In addition, the complex relative permittivity and permeability of compound particle were investigated by reflection method. The compound particle/epoxide resin composite (CP/EP) with different contents of CP were measured. The results show barium titanate crystal is tetragonal phase and its grain is oval shape with 80-100 nm which was coated by carbon black film. As electromagnetic (EM) complex permittivity, permeability and reflection loss (RL) shown that the compound particle is mainly a kind of electric and dielectric lossy materials and exhibits excellent microwave absorption performance in the X- and Ku-bands.

  4. Thermophysical properties of americium-containing barium plutonate

    International Nuclear Information System (INIS)

    Polycrystalline specimens of americium-containing barium plutonate have been prepared by mixing the appropriate amounts of (Pu0.91Am0.09)O2 and BaCO3 powders followed by reacting and sintering at 1600 K under the flowing gas atmosphere of dry-air. The sintered specimens had a single phase of orthorhombic perovskite structure and were crack-free. Elastic moduli were determined from longitudinal and shear sound velocities. Debye temperature was also determined from sound velocities and lattice parameter measurements. Thermal conductivity was calculated from measured density at room temperature, literature values of heat capacity and thermal diffusivity measured by laser flash method in vacuum. Thermal conductivity of americium-containing barium plutonate was roughly independent of temperature and registered almost the same magnitude as that of BaPuO3 and BaUO3. (author)

  5. Abiotic formation of methyl iodide on synthetic birnessite: A mechanistic study

    Energy Technology Data Exchange (ETDEWEB)

    Allard, Sébastien, E-mail: s.allard@curtin.edu.au; Gallard, Hervé

    2013-10-01

    Methyl iodide is a well-known volatile halogenated organic compound that contributes to the iodine content in the troposphere, potentially resulting in damage to the ozone layer. Most methyl iodide sources derive from biological activity in oceans and soils with very few abiotic mechanisms proposed in the literature. In this study we report that synthetic manganese oxide (birnessite δ-MnO{sub 2}) can catalyze the formation of methyl iodide in the presence of natural organic matter (NOM) and iodide. Methyl iodide formation was only observed at acidic pH (4–5) where iodide is oxidized to iodine and NOM is adsorbed on δ-MnO{sub 2}. The effect of δ-MnO{sub 2}, iodide and NOM concentrations, nature of NOM and ionic strength was investigated. High concentrations of methyl iodide were formed in experiments conducted with the model compound pyruvate. The Lewis acid property of δ-MnO{sub 2} leads to a polarization of the iodine molecule, and catalyzes the reaction with natural organic matter. As manganese oxides are strong oxidants and are ubiquitous in the environment, this mechanism could significantly contribute to the global atmospheric input of iodine. Highlights: • Methyl iodide is formed when iodide, natural organic matter and MnO{sub 2} are in contact. • Iodide is oxidized to iodine by MnO{sub 2} which reacts with NOM already adsorbed on MnO{sub 2}. • High formation of methyl iodide was observed with pyruvate. • This abiotic mechanism could contribute to the input of iodine in the atmosphere. • This abiotic mechanism could impact the ozone layer in the troposphere.

  6. Abiotic formation of methyl iodide on synthetic birnessite: A mechanistic study

    International Nuclear Information System (INIS)

    Methyl iodide is a well-known volatile halogenated organic compound that contributes to the iodine content in the troposphere, potentially resulting in damage to the ozone layer. Most methyl iodide sources derive from biological activity in oceans and soils with very few abiotic mechanisms proposed in the literature. In this study we report that synthetic manganese oxide (birnessite δ-MnO2) can catalyze the formation of methyl iodide in the presence of natural organic matter (NOM) and iodide. Methyl iodide formation was only observed at acidic pH (4–5) where iodide is oxidized to iodine and NOM is adsorbed on δ-MnO2. The effect of δ-MnO2, iodide and NOM concentrations, nature of NOM and ionic strength was investigated. High concentrations of methyl iodide were formed in experiments conducted with the model compound pyruvate. The Lewis acid property of δ-MnO2 leads to a polarization of the iodine molecule, and catalyzes the reaction with natural organic matter. As manganese oxides are strong oxidants and are ubiquitous in the environment, this mechanism could significantly contribute to the global atmospheric input of iodine. Highlights: • Methyl iodide is formed when iodide, natural organic matter and MnO2 are in contact. • Iodide is oxidized to iodine by MnO2 which reacts with NOM already adsorbed on MnO2. • High formation of methyl iodide was observed with pyruvate. • This abiotic mechanism could contribute to the input of iodine in the atmosphere. • This abiotic mechanism could impact the ozone layer in the troposphere

  7. Thermoelectric power of barium up to 8 GPa

    Energy Technology Data Exchange (ETDEWEB)

    Ramani, G.; Divakar, C.; Singh, A.K.

    1987-01-15

    The present measurements indicate that the thermoelectric power (TEP) of barium at room temperature and pressure is 15 ..mu..V K/sup -1/, and decreases with increasing pressure, reaching about 4 ..mu..V K/sup -1/ just before the bcc..-->..hcp transition. The TEP shows a discontinuous increase at the bcc..-->..hcp transition beyond which it continues to decrease with increasing pressure.

  8. Acute barium intoxication following ingestion of soap water solution

    Directory of Open Access Journals (Sweden)

    Nandita Joshi

    2012-01-01

    Full Text Available We present a rare case in which a young girl ingested a solution of a hair-removing soap. The ingestion resulted in profound hypokalemia and severe acidosis leading to flaccid paralysis, respiratory arrest and ventricular arrhythmias. Ultimately the patient made complete recovery. The soapwas found to contain barium sulfide. The degree of paralysis and acidosis appeared to be directly related to serum potassium levels.

  9. Barium ferrite powders prepared by milling and annealing

    Directory of Open Access Journals (Sweden)

    R. Nowosielski

    2007-05-01

    Full Text Available Purpose: Microstructure and magnetic properties analysis of barium ferrite powder obtained by milling and heat treatment.Design/methodology/approach: The milling process was carried out in a vibratory mill, which generated vibrations of the balls and milled material inside the container during which their collisions occur. After milling process the powders were annealed in electric chamber furnace. The X-ray diffraction methods were used for qualitative phase analysis of studied powder samples. The distribution of powder particles was determined by a laser particle analyzer. The magnetic hysteresis loops of examined powder material were measured by resonance vibrating sample magnetometer (R-VSM.Findings: The milling process of iron oxide and barium carbonate mixture causes decrease of the crystallite size of involved phases. The X-ray investigations of tested mixture milled for 30 hours and annealed at 950 °C enabled the identification of hard magnetic BaFe12O19 phase and also the presence of Fe2O3 phase in examined material. The Fe2O3 phase is a rest of BaCO3 dissociation in the presence of Fe2O3, which forms a compound of BaFe12O19. The best coercive force (HC for mixture of powders annealed at 950 °C for 10, 20 and 30 hours is 349 kA/m, 366 kA/m and 364 kA/m, respectively. The arithmetic mean of diameter of Fe2O3 and BaCO3 mixture powders after 30 hours of milling is about 6.0 μm.Practical implications: The barium ferrite powder obtained by milling and annealing can be suitable components to produce sintered and elastic magnets with polymer matrix.Originality/value: The results of tested barium ferrite investigations by different methods confirm their utility in the microstructure and magnetic properties analysis of powder materials.

  10. Role of hexadecapole interaction in proton rich barium isotopes

    International Nuclear Information System (INIS)

    From the systematic analysis of the experimental data on proton rich barium isotopes, it is observed that nuclei in the region z ≥ 50 and N≤82 are the transitional nuclei as they show a shape transition from spherical to deformed shape. An interesting feature of the observed yrast spectra in barium isotopic mass chain is the systematic variation of E2+, E4+ and E6+ excitation energy states from 120Ba to 136Ba. It is observed that these states follow a systematic decreasing trend as move away from 136Ba towards 120Ba. The isotopes 120-128Ba can be taken to be quasi-deformed nuclei having E4+/E2+ ratio larger than 2.7. Based on the systematics of low-lying states and the experimental data of quadrupole moments and B(E2) transition probabilities, the stable barium isotopes range from the approximately spherical 138Ba to l30Ba which is close to the deformed 120-128Ba isotopes. The purpose of the paper is to determine the importance of octupole-octupole and hexadecapole- hexadecapole parts of the two body interaction in reproducing the observed nuclear structure properties of 120-136Ba isotopes

  11. Microwave-hydrothermal synthesis of barium strontium titanate nanoparticles

    International Nuclear Information System (INIS)

    Research highlights: → Barium strontium titanate nanoparticles were obtained by the Hydrothemal microwave technique (HTMW) → This is a genuine technique to obtain nanoparticles at low temperature and short times → Barium strontium titanate free of carbonates with tetragonal structure was grown at 130 oC. - Abstract: Hydrothermal-microwave method (HTMW) was used to synthesize crystalline barium strontium titanate (Ba0.8Sr0.2TiO3) nanoparticles (BST) in the temperature range of 100-130 oC. The crystallization of BST with tetragonal structure was reached at all the synthesis temperatures along with the formation of BaCO3 as a minor impurity at lower syntheses temperatures. Typical FT-IR spectra for tetragonal (BST) nanoparticles presented well defined bands, indicating a substantial short-range order in the system. TG-DTA analyses confirmed the presence of lattice OH- groups, commonly found in materials obtained by HTMW process. FE/SEM revealed that lower syntheses temperatures led to a morphology that consisted of uniform grains while higher syntheses temperature consisted of big grains isolated and embedded in a matrix of small grains. TEM has shown BST nanoparticles with diameters between 40 and 80 nm. These results show that the HTMW synthesis route is rapid, cost effective, and could serve as an alternative to obtain BST nanoparticles.

  12. Preparation of Nanoparticles of Barium Ferrite from Precipitation in Microemulsions

    International Nuclear Information System (INIS)

    Magnetic nanoparticles of barium ferrite (BaFe12O19) have been synthesized using a microemulsion mediated process. The aqueous cores of water-in-oil microemulsions were used as constrained microreactors for the precipitation of precursor carbonate and hydroxide particles. These precursors were then calcined at 925 deg. C for 12 h, during which time they were transformed to the hexagonal ferrite. The pH of reaction was varied between 5 and 12, and it was found that the fraction of non-magnetic hematite (α-Fe2O3) in the particles varied with the pH of reaction, thus affecting the magnetic properties of the particles. The same precursor particles were also prepared by bulk co-precipitation reaction for comparison. It was found that the microemulsion derived nanoparticles of barium ferrite had both higher intrinsic coercivity (Hc) and saturation magnetization (σs) than the particles derived from bulk co-precipitation. Particles were analyzed by electron microscopy, X-ray diffraction, differential thermal analysis (DTA), thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM). The best barium ferrite particles produced by the microemulsion synthesis method yielded an intrinsic coercivity of 4310 Oe and a saturation magnetization of 60.48 emu/g

  13. Expression of sodium-iodide symporter in thyroid gland tumors: immunohistochemical study

    Directory of Open Access Journals (Sweden)

    Bondarenko O.O.

    2009-01-01

    Full Text Available One of the key moments of radioiodine therapy, and also radioisotope diagnostics of cancers of a thyroid gland is ability of their cells to accumulate iodide. This ability is provided with activity of the specific transporter – sodium-iodide symporter. Our research has shown disorders of sodium-iodide symporter immunoexpression in all tumors of thyroid gland: from overexpression and absence of plasma membrane expression in differentiated carcinomas, up to weak or actually absent in low differentiated cancers and Hurtle-cells tumors. Thus, there is a prospect of application of the sodium-iodide symporter, as the prognostic marker of thyroid cancers.

  14. Simplified assessment of segmental gastrointestinal transit time with orally small amount of barium

    International Nuclear Information System (INIS)

    Objective: To determine the effectiveness and advantage of small amount of barium in the measurement of gastrointestinal transmission function in comparison with radio-opaque pallets. Methods: Protocal 1: 8 healthy volunteers (male 6, female 2) with average age 40 ± 6.1 were subjected to the examination of radio-opaque pellets and small amount of barium with the interval of 1 week. Protocol 2: 30 healthy volunteers in group 1 (male 8, female 22) with average age 42.5 ± 8.1 and 50 patients with chronic functional constipation in group 2 (male 11, female 39) with average age 45.7 ± 7.8 were subjected to the small amount of barium examination. The small amount of barium was made by 30 g barium dissolved in 200 ml breakfast. After taking breakfast which contains barium, objectives were followed with abdominal X-ray at 4, 8, 12, 24, 48, 72, 96 h until the barium was evacuated totally. Results: Small amount of barium presented actual chyme or stool transit. The transit time of radio-opaque pallets through the whole gastrointestinal tract was significantly shorter than that of barium (37 ± 8 h vs. 47 ± 10 h, P < 0.05) in healthy people. The transit times of barium in constipation patients were markedly prolonged in colon (61.1 ± 22 vs. 37.3 ± 11, P < 0.01) and rectum (10.8 ± 3.7 vs. 2.3 ± 0.8 h, P < 0.01) compared with unconstipated volunteers. Transit times in individual gastrointestinal segments were also recorded by using small amount of barium, which allowed identifying the subtypes of constipation. Conclusion: The small amount barium examination is a convenient and low cost method to provide the most useful and reliable information on the transmission function of different gastrointestinal segments and able to classify the subtypes of slow transit constipation

  15. Temperature dependent energy levels of methylammonium lead iodide perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Foley, Benjamin J.; Marlowe, Daniel L.; Choi, Joshua J., E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Sun, Keye; Gupta, Mool C., E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Saidi, Wissam A. [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States); Scudiero, Louis, E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Chemistry Department and Materials Science and Engineering Program, Washington State University, Pullman, Washington 99164 (United States)

    2015-06-15

    Temperature dependent energy levels of methylammonium lead iodide are investigated using a combination of ultraviolet photoemission spectroscopy and optical spectroscopy. Our results show that the valence band maximum and conduction band minimum shift down in energy by 110 meV and 77 meV as temperature increases from 28 °C to 85 °C. Density functional theory calculations using slab structures show that the decreased orbital splitting due to thermal expansion is a major contribution to the experimentally observed shift in energy levels. Our results have implications for solar cell performance under operating conditions with continued sunlight exposure and increased temperature.

  16. Mechanochromic and thermochromic luminescence of a copper iodide cluster.

    Science.gov (United States)

    Perruchas, Sandrine; Le Goff, Xavier F; Maron, Sébastien; Maurin, Isabelle; Guillen, François; Garcia, Alain; Gacoin, Thierry; Boilot, Jean-Pierre

    2010-08-18

    The mechanochromic and thermochromic luminescence properties of a molecular copper(I) iodide cluster formulated [Cu(4)I(4)(PPh(2)(CH(2)CH=CH(2)))(4)] are reported. Upon mechanical grinding in a mortar, its solid-state emission properties are drastically modified as well as its thermochromic behavior. This reversible phenomenon has been attributed to distortions in the crystal packing leading to modifications of the intermolecular interactions and thus of the [Cu(4)I(4)] cluster core geometry. Notably, modification of the Cu-Cu interactions seems to be involved in this phenomenon directly affecting the emissive properties of the cluster. PMID:20698644

  17. Persistent photovoltage in methylammonium lead iodide perovskite solar cells

    OpenAIRE

    Baumann, A.; Tvingstedt, K.; Heiber, M. C.; Väth, S.; C. Momblona; H. J. Bolink; Dyakonov, V.

    2014-01-01

    We herein perform open circuit voltage decay (OCVD) measurements on methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells to increase the understanding of the charge carrier recombination dynamics in this emerging technology. Optically pulsed OCVD measurements are conducted on CH3NH3PbI3 solar cells and compared to results from another type of thin-film photovoltaics, namely, the two reference polymer–fullerene bulk heterojunction solar cell devices based on P3HT:PC60BM and PTB7:PC70...

  18. Temperature dependent energy levels of methylammonium lead iodide perovskite

    International Nuclear Information System (INIS)

    Temperature dependent energy levels of methylammonium lead iodide are investigated using a combination of ultraviolet photoemission spectroscopy and optical spectroscopy. Our results show that the valence band maximum and conduction band minimum shift down in energy by 110 meV and 77 meV as temperature increases from 28 °C to 85 °C. Density functional theory calculations using slab structures show that the decreased orbital splitting due to thermal expansion is a major contribution to the experimentally observed shift in energy levels. Our results have implications for solar cell performance under operating conditions with continued sunlight exposure and increased temperature

  19. Measuring Cell Death by Propidium Iodide Uptake and Flow Cytometry.

    Science.gov (United States)

    Crowley, Lisa C; Scott, Adrian P; Marfell, Brooke J; Boughaba, Jeanne A; Chojnowski, Grace; Waterhouse, Nigel J

    2016-01-01

    Propidium iodide (PI) is a small fluorescent molecule that binds to DNA but cannot passively traverse into cells that possess an intact plasma membrane. PI uptake versus exclusion can be used to discriminate dead cells, in which plasma membranes become permeable regardless of the mechanism of death, from live cells with intact membranes. PI is excited by wavelengths between 400 and 600 nm and emits light between 600 and 700 nm, and is therefore compatible with lasers and photodetectors commonly available in flow cytometers. This protocol for PI staining can be used to quantitate cell death in most modern research facilities and universities. PMID:27371595

  20. Polarized spectral complexes of optical functions of monovalent mercury iodide

    Science.gov (United States)

    Sobolev, V. V.; Sobolev, V. Val.; Anisimov, D. V.

    2015-12-01

    Spectral complexes of optical functions of monovalent mercury iodide Hg2I2 were determined for E ⊥ c and E || c polarizations in the range from 2 to 5.5 eV at 4.2 K. The permittivity and characteristic electron energy loss spectra were expanded in simple components with the determination of their main parameters, including the energy of the maximum and the oscillator strength. The calculations were performed based on known reflectance spectra. Computer programs based on Kramers-Kronig relations and the improved parameter-free method of Argand diagrams were used.

  1. Electronic properties and Compton profiles of silver iodide

    Indian Academy of Sciences (India)

    Alpa Dashora; Ambica Marwal; K R Soni; B L Ahuja

    2010-06-01

    We have carried out an extensive study of electronic properties of silver iodide in - and -phases. The theoretical Compton profiles, energy bands, density of states and anisotropies in momentum densities are computed using density functional theories. We have also employed full-potential linearized augmented plane-wave method to derive the energy bands and the density of states. To compare our theoretical data, isotropic Compton profile measurement on -AgI using 137Cs Compton spectrometer at an intermediate resolution of 0.38 a.u. has been undertaken. The theoretical anisotropies are also interpreted on the basis of energy bands.

  2. Barium and Tc-poor S stars: Binary masqueraders among carbon stars

    OpenAIRE

    Jorissen, A; Van Eck, S.

    1997-01-01

    The current understanding of the origin of barium and S stars is reviewed, based on new orbital elements and binary frequencies. The following questions are addressed: (i) Is binarity a necessary condition to produce a barium star? (ii) What is the mass transfer mode (wind accretion or RLOF?) responsible for their formation? (iii) Do barium stars form as dwarfs or as giants? (iv) Do barium stars evolve into Tc-poor S stars? (v) What is the relative frequency of Tc-rich and Tc-poor S stars?

  3. High Resolution Computed Tomography Appearences of late sequelae of Barium Aspiration in an asymptomatic young child

    International Nuclear Information System (INIS)

    Barium aspiration is a well-known complication of upper gastro-intestinal studies. Consequences of aspiration are generally insignificant and leave no permanent changes in the lung parenchyma. However, large quantities of high density barium, if aspirated, lead to silent interstitial changes and fibrosis. High-resolution computed tomography HRCT appearances of lung changes have been demonstrated in adults; few such reports are available in the pediatric literature. We report a case of a child who aspirated barium 3 months before this presentation. The HRCT appearances of barium aspiration are presented with a review of the literature. (author)

  4. Effects of powdered versus liquid barium on the viscosity of fluids used in modified swallow studies

    Energy Technology Data Exchange (ETDEWEB)

    Baron, J.; Alexander, T. [Univ. of Alberta, Dept. of Radiology, Edmonton, Alberta (Canada)

    2003-06-01

    To determine if the viscosity of thickened juice mixtures used in modified barium swallow studies significantly changes with the addition of powdered barium. We also describe a test formulation created using liquid barium, which has a negligible effect on juice viscosity. The viscosities of water and standardized honey- and nectar-consistency juices mixed with different amounts of powdered barium were measured by timing the laminar flow of a given initial hydrostatic head of fluid under gravity though an orifice of fixed diameter. Standardized juices were then mixed with a liquid formulation of barium and with measured quantities of water to produce viscosities that more closely equated with those of the standardized juices. With the addition of powdered barium, viscosity increased in all fluids, most markedly with the nectar-consistency juice. Liquid barium formulations maintained the viscosities of the original thickened juices. Rendering juices radio-opaque with barium powder results in dramatic increases in the viscosity of the resulting mixture and compromises diagnostic accuracy. Liquid barium preparations have the advantage that they can be rapidly and accurately dispensed by syringe, and their use does not significantly increase the viscosity of the preparation. (author)

  5. BARIUM SULPHATE ABSORPTION AND THE SERUM DIAGNOSIS OF SYPHILIS.

    Science.gov (United States)

    Noguchi, H; Bronfenbrenner, J

    1911-02-01

    The so-called syphilitic antibodies can be removed from a serum by means of absorption with barium sulphate. The removal is due either to an adsorption or a mechanical absorption. The activity of the syphilitic antibodies is thereby unimpaired. The readiness with which the absorption is accomplished with barium sulphate varies considerably with different syphilitic sera. That barium sulphate exerts the same absorbing effect upon non-syphilitic serum components is made evident by the interfering property which the latter manifest in the absorption experiment of the syphilitic antibodies. The selective removal of the serum components, other than the syphilitic antibodies, by means of barium sulphate absorption is, therefore, impossible. On the other hand, a partial removal of these components, with but little removal of the syphilitic antibodies, may be effected when the content of a given serum is poor in syphilitic antibodies and comparatively rich in the indifferent serum components. But this is impossible if the conditions are reversed. The main reasons why some negative syphilitic sera may be so modified by the barium sulphate treatment as to give positive reactions, are explained below, but these apply only to those methods in which inactivated serum is employed. The inactivation reduces the antibody content to about one-fourth to one-fifth of the original. When the serum is very rich in antibodies, this does not affect the result of the fixation test. But when the amount of the antibodies is small, the process of inactivation creates conditions quite unexpected. It may produce such a condition that a given amount of the serum contains, after inactivation, only one or two antibody units, while the other serum components remain undiminished. Here one must not lose sight of the vital fact that these apparently indifferent serum constituents are not at all indifferent in the fixation processes. They may possess affinities which are similar to those of complement

  6. 铝酸钡与氢氧化钡脱硫过程比较%Comparison of Barium Aluminate and Barium Hydroxide Desulfurization Process

    Institute of Scientific and Technical Information of China (English)

    张念炳; 黎志英; 丁彤

    2012-01-01

    The seed precipitation liquor was desulfurized with barium aluminate and barium hydroxide respectively. The desulfurization slag was characterized by XRD analysis, and the desulfurization process was compared. The results show that barium hydroxide exceeds barium aluminate with better desulfurization in terms of effect, speed and duration. In the desulfurization process with barium aluminate, 2BaO · Al2O3 · 5H2O is firstly produced in the reaction of barium aluminate with alkali, and then it reacts with sodium sulfate and sodium carbonate. To compare, Ba(OH)2 · 8H2O directly reacts with sodium sulfate and sodium carbonate in the desulfurization process with barium hydroxide. Both of desulfurization reaction processes can be described with "shrinking core model".%用铝酸钡和氢氧化钡对种分母液进行脱硫试验,对脱硫渣进行XRD分析,并比较脱硫过程.结果表明,氢氧化钡的脱硫效果更好,脱硫完成时间更短,速率更快;铝酸钡先与碱液反应生成2BaO·Al2O3·5H2O,再与硫碱和碳碱反应,而氢氧化钡直接与硫碱和碳碱反应,脱硫过程均可用未反应核模型描述.

  7. Progress in tumor therapy with human sodium iodide symporter

    International Nuclear Information System (INIS)

    The sodium iodide symporter (NIS) is an intrinsic plasma membrane protein that mediates active iodide transport into the thyroid gland and several extrathyroidal tissues, in particular the lactation mammary gland. Because of the cloning characterization of NIS, its key role in thyroid pathology and physiology could be investigated. The progress would be significant if the mechanisms of NIS expression in lactating mammary gland and breast cancer are elucidated, in which more than 80% of cases express endogenous NIS. In the future, two approaches could extend the use of radioiodide treatment to thyroid cancer and nonthyroidal cancer. One is by using the main mechanisms involving tumorous transformation to treat the tumor, based on the reinducing NIS expression in thyroid and cancer. The other is based on the application of NIS as a novel cytoreductive gene therapy strategy. NIS offers the unique advantage that it can be used both as a reporter and as a therapeutic gene, so that it is possible to image, monitor, and treat the tumor with radioiodide, just as in differentiated thyroid cancer. (authors)

  8. Polymorphic copper iodide clusters: insights into the mechanochromic luminescence properties.

    Science.gov (United States)

    Benito, Quentin; Le Goff, Xavier F; Maron, Sébastien; Fargues, Alexandre; Garcia, Alain; Martineau, Charlotte; Taulelle, Francis; Kahlal, Samia; Gacoin, Thierry; Boilot, Jean-Pierre; Perruchas, Sandrine

    2014-08-13

    An in-depth study of mechanochromic and thermochromic luminescent copper iodide clusters exhibiting structural polymorphism is reported and gives new insights into the origin of the mechanochromic luminescence properties. The two different crystalline polymorphs exhibit distinct luminescence properties with one being green emissive and the other one being yellow emissive. Upon mechanical grinding, only one of the polymorphs exhibits great modification of its emission from green to yellow. Interestingly, the photophysical properties of the resulting partially amorphous crushed compound are closed to those of the other yellow polymorph. Comparative structural and optical analyses of the different phases including a solution of clusters permit us to establish a correlation between the Cu-Cu bond distances and the luminescence properties. In addition, the local structure of the [Cu4I4P4] cluster cores has been probed by (31)P and (65)Cu solid-state NMR analysis, which readily indicates that the grinding process modifies the phosphorus and copper atoms environments. The mechanochromic phenomenon is thus explained by the disruption of the crystal packing within intermolecular interactions inducing shortening of the Cu-Cu bond distances in the [Cu4I4] cluster core and eventually modification of the emissive state. These results definitely establish the role of cuprophilic interactions in the mechanochromism of copper iodide clusters. More generally, this study constitutes a step further into the understanding of the mechanism involved in the mechanochromic luminescent properties of metal-based compounds. PMID:25076411

  9. Nuclear detonation, thyroid cancer and potassium iodide prophylaxis

    Directory of Open Access Journals (Sweden)

    Viroj Wiwanitkit

    2011-01-01

    Full Text Available The recent nuclear disaster at Japan has raised global concerns about effects of radioactive leakage in the environment, associated hazards, and how they can be prevented. In this article, we have tried to explain about the guidelines laid down by World Health Organization for a potassium iodide prophylaxis following a nuclear disaster, and its mechanism of action in preventing thyroid cancer. Data was collected mainly from the studies carried out during the Chernobyl disaster of Russia in 1986 and the hazardous effects especially on the thyroid gland were studied. It was seen that radioactive iodine leakage from the nuclear plants mainly affected the thyroid gland, and especially children were at a higher risk at developing the cancers. Potassium Iodide prophylaxis can be administered in order to prevent an increase in the incidence of thyroid cancers in the population of an area affected by a nuclear disaster. However, one has to be cautious while giving it, as using it without indication has its own risks.

  10. Nonradiometric and radiometric testing of radioiodine sorbents using methyl iodide

    International Nuclear Information System (INIS)

    A nonradiometric test of adsorbents and adsorbers with normal methyl iodide (CH3127I) is desirable. Use of methyl radioiodide (CH3131I) requires special precautions and facilities and results in bed contamination. However, first it must be established to what extent the removal of CH3127I by adsorbents is indicative of the removal of CH3131I. An experimental apparatus was built and used to simultaneously measure the penetrations of CH3I molecules and the radioisotope in CH3131I through charcoal absorbent beds. Gas chromatography with electron capture detection was used to measure CH3I. Radioiodine was measured using charcoal traps within NaI scintillation well crystals. Real time (5-min interval) radioiodine measurement provided immediate penetration results directly comparable to the real time penetrations of methyl iodide. These penetrations were compared for typical charcoal adsorbents with these impregnants: (a) 5% KI3, (b) 5% KI3 + 2% TEDA, (c) 5% TEDA, and (d) metal salts (Whetlerite). Differences between CH3I and CH3131I penetrations observed for the two iodized charcoals were attributed to isotope exchange reactions. Equivalent penetrations were observed for non-iodized adsorbents and for iodized ones at initial time. First order rates were confirmed for reactions with TEDA and for isotope exchange. This was one more confirmation of the lack of a challenge concentration effect on efficiencies at low test bed loadings. In addition to other removal mechanisms, reversible physical adsorption was observed with all charcoals

  11. Numerical modelling of methyl iodide in the eastern tropical Atlantic

    Directory of Open Access Journals (Sweden)

    I. Stemmler

    2013-06-01

    Full Text Available Methyl iodide (CH3I is a volatile organic halogen compound that contributes significantly to the transport of iodine from the ocean to the atmosphere, where it plays an important role in tropospheric chemistry. CH3I is naturally produced and occurs in the global ocean. The processes involved in the formation of CH3I, however, are not fully understood. In fact, there is an ongoing debate whether production by phytoplankton or photochemical degradation of organic matter is the main source term. Here, both the biological and photochemical production mechanisms are considered in a biogeochemical module that is coupled to a one-dimensional water column model for the eastern tropical Atlantic. The model is able to reproduce observed subsurface maxima of CH3I concentrations. But, the dominating source process cannot be clearly identified as subsurface maxima can occur due to both direct biological and photochemical production. However, good agreement between the observed and simulated difference between surface and subsurface methyl iodide concentrations is achieved only when direct biological production is taken into account. Production rates for the biological CH3I source that were derived from published laboratory studies are shown to be inappropriate for explaining CH3I concentrations in the eastern tropical Atlantic.

  12. Tungsten and barium transport in the internal plasma of hollow cathodes

    Science.gov (United States)

    Polk, James E.; Mikellides, Ioannis G.; Katz, Ira; Capece, Angela M.

    2009-06-01

    The effect of tungsten erosion, transport, and redeposition on the operation of dispenser hollow cathodes was investigated in detailed examinations of the discharge cathode inserts from 8200 h and 30 352 h ion engine wear tests. Erosion and subsequent redeposition of tungsten in the electron emission zone at the downstream end of the insert reduce the porosity of the tungsten matrix, preventing the flow of barium from the interior. This inhibits the interfacial reactions of the barium-calcium-aluminate impregnant with the tungsten in the pores. A numerical model of barium transport in the internal xenon discharge plasma shows that the barium required to reduce the work function in the emission zone can be supplied from upstream through the gas phase. Barium that flows out of the pores of the tungsten insert is rapidly ionized in the xenon discharge and pushed back to the emitter surface by the electric field and drag from the xenon ion flow. This barium ion flux is sufficient to maintain a barium surface coverage at the downstream end greater than 0.6, even if local barium production at that point is inhibited by tungsten deposits. The model also shows that the neutral barium pressure exceeds the equilibrium vapor pressure of the impregnant decomposition reaction over much of the insert length, so the reactions are suppressed. Only a small region upstream of the zone blocked by tungsten deposits is active and supplies the required barium. These results indicate that hollow cathode failure models based on barium depletion rates in vacuum dispenser cathodes are very conservative.

  13. CuI-catalyzed Synthesis of Aryl Thiocyanates from Aryl Iodides

    Institute of Scientific and Technical Information of China (English)

    Ye Feng WANG; Yuan ZHOU; Jia Rui WANG; Lei LIU; Qing Xiang GUO

    2006-01-01

    An operationally simple and inexpensive catalyst system was developed for the cross coupling of potassium thiocyanate with aryl iodides by using CuI as catalyst, 1, 10-phenanthroline as ligand, and tetraethylammonium iodide as activator. The procedure is applicable for the synthesis of diverse aryl thiocyanates without any exotic, poisonous reagents.

  14. Bibenzimidazole containing mixed ligand cobalt(III) complex as a selective receptor for iodide

    Digital Repository Service at National Institute of Oceanography (India)

    Indumathy, R.; Parameswarana, P.S.; Aiswarya, C.V.; Nair, B.U.

    -, OH- and OAc- do not bring about any dramatic visual colorimetric changes. However, metallo-receptor 2 brings about vivid color change with iodide anion visually and this could be due to charge transfer transition via ion pair formation with iodide ion...

  15. Synthesis, growth, structural, thermal, optical properties of new metal-organic crystals: Methyltriphenylphosphonium iodide thiourea and methyltriphenylphosphonium iodide chloroform hemisolvate

    Science.gov (United States)

    Shivachev, Boris L.; Kossev, Krassimir; Dimowa, Louiza T.; Yankov, Georgi; Petrov, Todor; Nikolova, Rositsa P.; Petrova, Nadia

    2013-08-01

    Crystals of methyltriphenylphosphonium iodide thiourea (1) and methyltriphenylphosphonium iodide chloroform hemisolvate (2) were obtained for the first time. Fourier transform infrared (FTIR) spectral studies have been performed to identify the functional groups. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were used to study their thermal properties. The optical transmittance window and the lower cutoff wavelength have been identified by UV-vis studies. Crystals of the title compounds suitable for single crystal X-ray analyses were successfully grown by slow evaporation and diffraction data were collected to elucidate the molecular structure and interactions. The proton donors (phosphonium) and proton acceptor (iodine) in the structure of 1 provide infrastructure to introduce charge asymmetry while in 2 chloroform molecule is not involved in the charge transfer. An optical quality crystal of 1 (5×4×2 mm3) was obtained by macroseeding. The crystal has developed facets with major ones (001) and (00¯1). A crystal of 1 was tested with 1060 nm laser radiation and showed second harmonic generation (SHG).

  16. Fabrication of Efficient Low-Bandgap Perovskite Solar Cells by Combining Formamidinium Tin Iodide with Methylammonium Lead Iodide

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Weiqiang; Zhao, Dewei; Yu, Yue; Shrestha, Niraj; Ghimire, Kiran; Grice, Corey R.; Wang, Changlei; Xiao, Yuqing; Cimaroli, Alexander J.; Ellingson, Randy J.; Podraza, Nikolas J.; Zhu, Kai; Xiong, Ren-Gen; Yan, Yanfa

    2016-09-28

    Mixed tin (Sn)-lead (Pb) perovskites with high Sn content exhibit low bandgaps suitable for fabricating the bottom cell of perovskite-based tandem solar cells. In this work, we report on the fabrication of efficient mixed Sn-Pb perovskite solar cells using precursors combining formamidinium tin iodide (FASnI3) and methylammonium lead iodide (MAPbI3). The best-performing cell fabricated using a (FASnI3)0.6(MAPbI3)0.4 absorber with an absorption edge of ~1.2 eV achieved a power conversion efficiency (PCE) of 15.08 (15.00)% with an open-circuit voltage of 0.795 (0.799) V, a short-circuit current density of 26.86(26.82) mA/cm2, and a fill factor of 70.6(70.0)% when measured under forward (reverse) voltage scan. The average PCE of 50 cells we have fabricated is 14.39 +/- 0.33%, indicating good reproducibility.

  17. Anion and cation diffusion in barium titanate and strontium titanate

    International Nuclear Information System (INIS)

    Perovskite oxides show various interesting properties providing several technical applications. In many cases the defect chemistry is the key to understand and influence the material's properties. In this work the defect chemistry of barium titanate and strontium titanate is analysed by anion and cation diffusion experiments and subsequent time-of-flight secondary ion mass spectrometry (ToF-SIMS). The reoxidation equation for barium titanate used in multi-layer ceramic capacitors (MLCCs) is found out by a combination of different isotope exchange experiments and the analysis of the resulting tracer diffusion profiles. It is shown that the incorporation of oxygen from water vapour is faster by orders of magnitude than from molecular oxygen. Chemical analysis shows the samples contain various dopants leading to a complex defect chemistry. Dysprosium is the most important dopant, acting partially as a donor and partially as an acceptor in this effectively acceptor-doped material. TEM and EELS analysis show the inhomogeneous distribution of Dy in a core-shell microstructure. The oxygen partial pressure and temperature dependence of the oxygen tracer diffusion coefficients is analysed and explained by the complex defect chemistry of Dy-doped barium titanate. Additional fast diffusion profiles are attributed to fast diffusion along grain boundaries. In addition to the barium titanate ceramics from an important technical application, oxygen diffusion in cubic, nominally undoped BaTiO3 single crystals has been studied by means of 18O2/16O2 isotope exchange annealing and subsequent determination of the isotope profiles in the solid by ToF-SIMS. It is shown that a correct description of the diffusion profiles requires the analysis of the diffusion through the surface space-charge into the material's bulk. Surface exchange coefficients, space-charge potentials and bulk diffusion coefficients are analysed as a function of oxygen partial pressure and temperature. The data

  18. Colorimetric sensing of iodide based on triazole-acetamide functionalized gold nanoparticles

    International Nuclear Information System (INIS)

    We have modified gold nanoparticles (AuNPs) with triazole acetamide to obtain a material for the sensitive and selective colorimetric determination of iodide. The functionalized AuNPs were prepared by a reductive single chemical step using a Cu(I)-catalyzed click reaction. The presence of iodide ions induces the aggregation of these AuNPs and results in a color change from wine-red to purple. The iodide-induced aggregation can be detected visually with bare eyes, but also by photometry. The detection limit is as low as 15 nM. The method displays excellent selectivity for iodide over other anions due to the selective interaction with the amido groups of the triazole. The method was applied to the determination of iodide in spiked lake waters. (author)

  19. Microstructure of polymer composite with barium ferrite powder

    Directory of Open Access Journals (Sweden)

    R. Nowosielski

    2008-12-01

    Full Text Available Purpose: The aim of the paper is the microstructure characterization of commercial BaFe12O19 powder and its composite material in polymer matrix; XRD (X-Ray Diffraction and SEM (Scanning Electron Microscopy methods were applied.Design/methodology/approach: The Rietveld method appeared to be very useful in the verification of the qualitative phase composition and in the determination of phase abundance. Hill and Howard procedure was applied for quantitative phase analysis. The parameters of the individual diffraction line profiles were determined by PRO-FIT Toraya procedure. The morphology of barium ferrite powders and a fracture surface of the examined composite material was analyzed using the scanning electron microscope.Findings: The X-ray diffraction analysis enabled the identification of BaFe12O19 and Fe2O3 phases in examined material. Basing on Rietveld and Toraya methods the determination of lattice parameters, crystallite size and the lattice distortion was performed. Distribution of powders of barium ferrite in polymer matrix is irregular and powder particles are of irregular shapes and different sizes.Research limitations/implications: Maked researches are limited only to characterization the microstructure of commercial material, because obtained results will be helpful to prepare barium ferrite powders by mechanical alloying and subsequent annealing in the future. As prepared BaFe12O19 powders will be used as the starting material for magnets bonded with polymer material.Originality/value: The obtained results of investigations by different methods of structure analysis confirm their useful in the microstructure analysis of powder materials.

  20. Barium Swallow Findings in the Evaluation of Patients with Dysphagia

    Directory of Open Access Journals (Sweden)

    Amirhosein Hashemi Attar

    2011-05-01

    Full Text Available Background/Objective: Dysphagia is a subjective"nsensation of difficulty in swallowing that has a wide"nrange of etiologies from psychosomatic disorders"nto high grade neoplasms. In this study we evaluated"nbarium swallow findings of patients with dysphagia."nPatients and Methods: We evaluated 200 patients"n(117 men, 83 women; mean age, 49.6 years with"ncomplaint of dysphagia. Fluoroscopic barium"nswallow was done for all the patients and they were"nreviewed for primary peristalsis (presence or absence,"nAbstracts"nS62 Iran J Radiol 2011, 8 (Supp.1"nAbstracts"nimpaired lower esophageal sphincter, esophageal dilatation, delayed emptying of barium, nonperistaltic contractions, stricture and filling defects. Clinical and in some cases endoscopic or manometric follow up was done for all patients."nResults: We had 134 (67% normal barium swallow"nexams with uncomplicated clinical courses. Sixty"nsix patients (33% had abnormal imaging findings"nincluding stricture in 24 patients (12%, filling defect"nin 12 patients (6% and mucosal abnormality in 14"n(7% patients (six cases of mucosal irregularity, three"ncases of mucosal ulceration and five cases of mucosal"nherniation, Bird's beak sign in three patients (1.5%,"ntertiary spasm in six patients (3% and hiatal hernia in"nseven patients (3.5%."nConclusion: In the majority of patients with dysphagia,"nbarium swallow is the only paraclinical study needed"nto plan proper treatment. If radiographic findings are"nequivocal, endoscopy or manometry may be required"nfor more certain diagnosis.

  1. Barium strontium titanate powders prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Ultasonic spray pyrolysis (SP) has been investigated for the production of the barium strontium titanate (BST) powders from the polymeric precursors. The processing parameters, such as flux of aerosol and temperature profile inside the furnace, were optimized to obtain single phase BST. The powders were characterized by the methods of X-ray diffraction analysis, SEM, EDS and TEM. The obtained powders were submicronic, consisting of spherical, polycrystalline particles, with internal nanocrystalline structure. Crystallite size of 10 nm, calculated using Rietveld refinement, is in a good agreement with results of HRTEM

  2. A barium-rich binary central star in Abell 70

    CERN Document Server

    Boffin, Henri M J; Frew, D J; Acker, A; Köppen, J; Moffat, A F J; Parker, Q A

    2011-01-01

    We have found the central star of Abell 70 (PN G038.1-25.4, hereafter A 70) to be a binary consisting of a G8 IV-V secondary and a hot white dwarf. The secondary shows enhanced Ba II and Sr II features, firmly classifying it as a barium star. The nebula is found to have Type-I chemical abundances with helium and nitrogen enrichment, which combined with future abundance studies of the central star, will establish A 70 as a unique laboratory for studying s-process AGB nucleosynthesis.

  3. Strain engineered barium strontium titanate for tunable thin film resonators

    Energy Technology Data Exchange (ETDEWEB)

    Khassaf, H.; Khakpash, N. [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Sun, F. [Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States); Sbrockey, N. M.; Tompa, G. S. [Structured Materials Industries, Inc., Piscataway, New Jersey 08854 (United States); Kalkur, T. S. [Department of Electrical and Computer Engineering, University of Colorado at Colorado Springs, Colorado Springs, Colorado 80918 (United States); Alpay, S. P., E-mail: p.alpay@ims.uconn.edu [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

    2014-05-19

    Piezoelectric properties of epitaxial (001) barium strontium titanate (BST) films are computed as functions of composition, misfit strain, and temperature using a non-linear thermodynamic model. Results show that through adjusting in-plane strains, a highly adaptive rhombohedral ferroelectric phase can be stabilized at room temperature with outstanding piezoelectric response exceeding those of lead based piezoceramics. Furthermore, by adjusting the composition and the in-plane misfit, an electrically tunable piezoelectric response can be obtained in the paraelectric state. These findings indicate that strain engineered BST films can be utilized in the development of electrically tunable and switchable surface and bulk acoustic wave resonators.

  4. K-shell fluorescence yields of barium and lanthanum

    International Nuclear Information System (INIS)

    K-shell fluorescence yields for barium and lanthanum have been measured adopting simple 2π geometrical configuration and employing a weak 57Co radioactive source. A scintillation spectrometer with an NaI(Tl) detector of dimensions 44.5 mm diameterx50 mm thickness was employed for the detection and measurement of radiation. The results obtained are in good agreement with the best-fitted values of and also with the other experimental values, indicating that our simple method can be extended to determine fluorescence parameters of high Z materials.

  5. The Kerr nonlinearity of the beta-barium borate crystal

    DEFF Research Database (Denmark)

    Bache, Morten; Guo, Hairun; Zhou, Binbin;

    2013-01-01

    A popular crystal for ultrafast cascading experiments is beta-barium-borate (β-BaB2O4, BBO). It has a decent quadratic nonlinear coefficient, and because the crystal is anisotropie it can be birefringence phase-matched for type I (oo → e) second-harmonic generation (SHG). For femtosecond...... experiments BBO is popular because of low dispersion and a high damage threshold. The main attractive property of ultrafast cascading is that the induced cascading nonlinearity nI 2, casc can be negative, i.e. generate a self-defocusing Kerr-like nonlinearity. However, the material Kerr nonlinearity nI 2...

  6. The Kerr nonlinearity of the beta-barium borate crystal

    OpenAIRE

    Bache, Morten; Guo, Hairun; Zhou, Binbin; Zeng, Xianglong

    2013-01-01

    A popular crystal for ultrafast cascading experiments is beta-barium-borate (β-BaB2O4, BBO). It has a decent quadratic nonlinear coefficient, and because the crystal is anisotropie it can be birefringence phase-matched for type I (oo → e) second-harmonic generation (SHG). For femtosecond experiments BBO is popular because of low dispersion and a high damage threshold. The main attractive property of ultrafast cascading is that the induced cascading nonlinearity nI 2, casc can be negative, i.e...

  7. Control on Crystal Forms of Ultrafine Barium Carbonate Particles and Study on its Mechanism

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Barium carbonate particles were prepared by using homogeneous precipitation method and co-precipitation method respectively. Through adding different crystalline controlling modifiers, Barium carbonate particles in five different shapes including linear, needle-like, pillarlike, sphere-like and dumbbell-like were synthesized. These particles were characterized by SEM and XRD, and their synthetic mechanism was discussed in this paper.

  8. Investigation on the effects of milling atmosphere on synthesis of barium ferrite/magnetite nanocomposite

    NARCIS (Netherlands)

    Molaei, M.J.; Ataie, A.; Raygan, S.; Picken,n S.J.

    2011-01-01

    In this research, barium ferrite /magnetite nanocomposites synthesized via a mechano-chemical route. Graphite was used in order to reduce hematite content of barium ferrite to magnetite to produce a magnetic nanocomposite. The effects of processing conditions on the powder characteristics were inves

  9. Acute respiratory failure caused by aspiration of high density barium: A case report

    International Nuclear Information System (INIS)

    Accidental aspiration of barium contrast medium during the upper gastrointestinal study can occur in patients with swallowing disorder, especially in the elderly patients. We experienced a case of respiratory failure followed by death within a few hours in 85 year-old patient after barium aspiration

  10. New efficient catalyst for ammonia synthesis: barium-promoted cobalt on carbon

    DEFF Research Database (Denmark)

    Hagen, Stefan; Barfod, Rasmus; Fehrmann, Rasmus;

    2002-01-01

    Barium-promoted cobalt catalysts supported on carbon exhibit higher ammonia activities at synthesis temperatures than the commercial, multipromoted iron catalyst and also a lower ammonia......Barium-promoted cobalt catalysts supported on carbon exhibit higher ammonia activities at synthesis temperatures than the commercial, multipromoted iron catalyst and also a lower ammonia...

  11. Horizontal Ampoule Growth and Characterization of Mercuric Iodide at Controlled Gas Pressures for X-Ray and Gamma Ray Spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas S. [Kansas State Univ., Manhattan, KS (United States). Semiconductor Materials and Radiological Technologies Lab., Dept. of Nuclear and Mechanical Engineering; Ariesanti, Elsa [Kansas State Univ., Manhattan, KS (United States). Semiconductor Materials and Radiological Technologies Lab., Dept. of Nuclear and Mechanical Engineering; Corcoran, Bridget [Kansas State Univ., Manhattan, KS (United States). Semiconductor Materials and Radiological Technologies Lab., Dept. of Nuclear and Mechanical Engineering

    2004-04-30

    The project developed a new method for producing high quality mercuric iodide crystals of x-ray and gamma spectrometers. Included are characterization of mercuric iodide crystal properties as a function of growth environment and fabrication and demonstration of room-temperature-operated high-resolution mercuric iodide spectrometers.

  12. Anion and cation diffusion in barium titanate and strontium titanate; Anionen- und Kationendiffusion in Barium- und Strontiumtitanat

    Energy Technology Data Exchange (ETDEWEB)

    Kessel, Markus Franz

    2012-12-19

    Perovskite oxides show various interesting properties providing several technical applications. In many cases the defect chemistry is the key to understand and influence the material's properties. In this work the defect chemistry of barium titanate and strontium titanate is analysed by anion and cation diffusion experiments and subsequent time-of-flight secondary ion mass spectrometry (ToF-SIMS). The reoxidation equation for barium titanate used in multi-layer ceramic capacitors (MLCCs) is found out by a combination of different isotope exchange experiments and the analysis of the resulting tracer diffusion profiles. It is shown that the incorporation of oxygen from water vapour is faster by orders of magnitude than from molecular oxygen. Chemical analysis shows the samples contain various dopants leading to a complex defect chemistry. Dysprosium is the most important dopant, acting partially as a donor and partially as an acceptor in this effectively acceptor-doped material. TEM and EELS analysis show the inhomogeneous distribution of Dy in a core-shell microstructure. The oxygen partial pressure and temperature dependence of the oxygen tracer diffusion coefficients is analysed and explained by the complex defect chemistry of Dy-doped barium titanate. Additional fast diffusion profiles are attributed to fast diffusion along grain boundaries. In addition to the barium titanate ceramics from an important technical application, oxygen diffusion in cubic, nominally undoped BaTiO{sub 3} single crystals has been studied by means of {sup 18}O{sub 2}/{sup 16}O{sub 2} isotope exchange annealing and subsequent determination of the isotope profiles in the solid by ToF-SIMS. It is shown that a correct description of the diffusion profiles requires the analysis of the diffusion through the surface space-charge into the material's bulk. Surface exchange coefficients, space-charge potentials and bulk diffusion coefficients are analysed as a function of oxygen partial

  13. Strawberry growers wavered over methyl iodide, feared public backlash

    Directory of Open Access Journals (Sweden)

    Julie Guthman

    2016-08-01

    Full Text Available Methyl iodide, once promoted as a suitable alternative to methyl bromide for soil fumigation in strawberry systems, was withdrawn from the market in 2012 after a contentious regulatory battle that revolved around its high toxicity. At the time of its withdrawal, Arysta LifeScience, the maker of the chemical, claimed that it was no longer economically viable. In this study, I investigated what made the chemical nonviable, with a specific focus on growers' nonadoption of it. Interviews with strawberry growers in the four top California strawberry-growing counties revealed that growers' decisions not to use it were primarily related to public disapproval, although the continued availability of methyl bromide and other fumigants played a contributing role by making adoption less urgent. The study results suggest that policies in place during the methyl bromide phaseout did not strongly encourage the development and extension of less toxic alternatives, which undermined the strawberry industry's position.

  14. Betaine potassium iodide dihydrate: a new compound of betaine

    International Nuclear Information System (INIS)

    Betaine potassium iodide dihydrate, [(CH3)3N+CH2COO-]2.KI.2H2O, BKI for short, is a new compound of the aminoacid betaine with a triclinic symmetry and the space group P1-bar at room temperature. The study of dielectric properties provided evidence for the existence of a structural phase transition occurring around 100 K. The spontaneous electric polarization is zero in both phases. A study of dielectric dispersion disclosed two relaxational modes with different relevance in the high and in the low temperature phases. The main features observed in BKI are consistently described by the Landau theory, by assuming a quadratic coupling between the primary order parameter and the electric polarization. (author). Letter-to-the-editor

  15. Mercuric iodide crystals obtained by solvent evaporation using ethanol

    International Nuclear Information System (INIS)

    Millimeter-sized mercuric iodide crystals were fabricated by the solvent evaporation technique using pure ethanol as a solvent. Three different conditions for solution evaporation were tested: (i) in the dark at room temperature; (ii) in the presence of light at room temperature and (iii) in an oven at 40 deg. C. Morphology, structure, optical and electrical properties were investigated using several techniques. Crystals fabricated in the dark show better properties and stability than others, possibly because the larger the energy of the system, the larger the number of induced growth defects. The crystals fabricated in the dark have adequate structure for higher resistivity and activation energy close to half the optical band-gap, as desired. With proper encapsulation these crystals might be good candidates for the development of ionizing radiation sensors.

  16. Photon recycling in lead iodide perovskite solar cells

    Science.gov (United States)

    Pazos-Outón, Luis M.; Szumilo, Monika; Lamboll, Robin; Richter, Johannes M.; Crespo-Quesada, Micaela; Abdi-Jalebi, Mojtaba; Beeson, Harry J.; Vrućinić, Milan; Alsari, Mejd; Snaith, Henry J.; Ehrler, Bruno; Friend, Richard H.; Deschler, Felix

    2016-03-01

    Lead-halide perovskites have emerged as high-performance photovoltaic materials. We mapped the propagation of photogenerated luminescence and charges from a local photoexcitation spot in thin films of lead tri-iodide perovskites. We observed light emission at distances of ≥50 micrometers and found that the peak of the internal photon spectrum red-shifts from 765 to ≥800 nanometers. We used a lateral-contact solar cell with selective electron- and hole-collecting contacts and observed that charge extraction for photoexcitation >50 micrometers away from the contacts arose from repeated recycling between photons and electron-hole pairs. Thus, energy transport is not limited by diffusive charge transport but can occur over long distances through multiple absorption-diffusion-emission events. This process creates high excitation densities within the perovskite layer and allows high open-circuit voltages.

  17. Investigation of sodium iodide hydration and dehydration in moist atmosphere

    International Nuclear Information System (INIS)

    Effect of different factors on NaI hydration and dehydration kinetics under nonequilibrium conditions is studied. NaIx2H2O solid or homogeneous solution is established to be formed at sodium iodide interaction with water vapour depending on air humidity. At low humidity water absorption is not observed. Effect of water vapour pressure, the NaI particle size, the air flux rate over a salt on the absorption rate is studied. The latter points to process rate limitation by diffusion in a gaseous phase. The NaI solution decomposition at light with iodine formation is marked. The character of NaIx2H2O dehydration depends on water vapour removing from the over-salt space. Total water removing before and after crystal hydrate thermal degradation when aqueous solution evaporation occurs, is possible. At 143 deg C the water vapour pressure over solution equals the atmospheric one

  18. Development of mercuric iodide detectors for XAS and XRD measurements

    International Nuclear Information System (INIS)

    A prototype element for an energy dispersive detector (EDD) array was constructed using a Mercuric Iodide detector. Both detector and front end FET could be thermoelectrically cooled. Tested at SSRL, the detector had 250 eV electronic noise and 315 eV resolution at 5.9 keV. K line fluorescence spectra were collected for selected elements between Cl (2622 eV) and Zn (8638 eV). Count rate capability to 60,000 cps was demonstrated. Several detector parameters were measured, including energy linearity, resolution vs. shaping time, and detector dead time. An EXAFS (extended x-ray absorption fine structure) spectrum was recorded and compared to simultaneously collected transmission data

  19. Ruthenium and hafnium abundances in giant and dwarf barium stars

    CERN Document Server

    Allen, D M

    2007-01-01

    We present abundances for Ru and Hf, compare them to abundances of other heavy elements, and discuss the problems found in determining Ru and Hf abundances with laboratory gf-values in the spectra of barium stars. We determined Ru and Hf abundances in a sample of giant and dwarf barium stars, by the spectral synthesis of two RuI (4080.574A and 4757.856A) and two HfII (4080.437A and 4093.155A) transitions. The stellar spectra were observed with FEROS/ESO, and the stellar atmospheric parameters lie in the range 4300 < Teff/K < 6500, -1.2 < [Fe/H] <= 0 and 1.4 <= log g < 4.6. The HfII 4080A and the RuI 4758A observed transitions result in a unreasonably high solar abundance, given certain known uncertainties, when fitted with laboratory gf-values. For these two transitions we determined empirical gf-values by fitting the observed line profiles of the spectra of the Sun and Arcturus. For the sample stars, this procedure resulted in a good agreement of Ru and Hf abundances given by the two availa...

  20. Study of barium bismuth titanate prepared by mechanochemical synthesis

    Directory of Open Access Journals (Sweden)

    Lazarević Z.Ž.

    2009-01-01

    Full Text Available Barium-bismuth titanate, BaBi4Ti4O15 (BBT, a member of Aurivillius bismuth-based layer-structure perovskites, was prepared from stoichiometric amounts of barium titanate and bismuth titanate obtained via mechanochemical synthesis. Mechanochemical synthesis was performed in air atmosphere in a planetary ball mill. The reaction mechanism of BaBi4Ti4O15 and the preparation and characteristics of BBT ceramic powders were studied using XRD, Raman spectroscopy, particle analysis and SEM. The Bi-layered perovskite structure of BaBi4Ti4O15 ceramic forms at 1100 °C for 4 h without a pre-calcination step. The microstructure of BaBi4Ti4O15 exhibits plate-like grains typical for the Bi-layered structured material and spherical and polygonal grains. The Ba2+ addition leads to changes in the microstructure development, particularly in the change of the average grain size.

  1. Materials Synthesis Of Barium Hexa ferrite Used Local Natural Resources

    International Nuclear Information System (INIS)

    The magnetic materials of barium hexa ferrites, Ba O.6Fe2O3 successfully synthesized by powder metallurgy method used local natural resources from materials waste of steel fabrication (HSM, CRM), waste of polymer fabrication (LK) as well as iron sands (PBA). These waste as well as iron sands were the main resources of iron oxide, Fe2O3. The barium oxide used in this experiments are from BaCO3 product of Merck, and BaCO4 which is commercially available in the market as barite. Phase identification by x-ray diffraction technique show the synthesized magnetic materials are agreed with the available commercial product, (SUMI). The energy product maximum (BH)max measured by vibrating sample magnetometer (VSM) for the samples used HSM-, CRM- and BaCO3 as basic materials are 1.141 MGOe and 1.136 MGOe while SUMI is 1.142 MGOe. However for the samples made from LK-, PBA- used of BaCO3 or CRM- with barite, the energy product maximum (BH)max are relatively lower than commercial product

  2. Microstructure of composite material with powders of barium ferrite

    Directory of Open Access Journals (Sweden)

    R. Nowosielski

    2006-04-01

    Full Text Available Purpose: The aim of the present work is the microstructure characterization of commercial powder BaFe12O19 (as-prepared and composite material with BaFe12O19 powders and polymer matrix, using XRD (X-Ray Diffraction and SEM (Scanning Electron Microscopy methods.Design/methodology/approach: The morphology of barium ferrite powders and a fracture surface of the examined composite material was realized by using the scanning electron microscope. The methods of X-ray diffraction were used for the qualitative phase analysis. The parameters of diffraction line profiles were determined by PRO-FIT Toraya procedure.Findings: The X-ray diffraction analysis permitted on identification the BaFe12O19 and Fe2O3 phases in an examined material. Basing on Toraya method is determination of: lattice parameters, crystallite size (D and the lattice distortion (. Distribution of powders of barium ferrite in polymer matrix is irregular and powder particles have irregular shapes and dimensions.Research limitations/implications: For future research the X-ray analysis should be performed by the Rietveld method, which allows to characterization the microstructure of tested material and verification of its qualitative phase composition.Originality/value: The applied Toraya method of structure analysis appeared to be very useful in the microstructure analysis.

  3. Redox processes in highly yttrium-doped barium titanate

    International Nuclear Information System (INIS)

    The changes of microstructure occurring during oxidation of the reduced form of yttrium-doped barium titanate (Ba1-xYx?Ti1-x4+Tix3+O3) have been studied. Samples were sintered under reduction conditions at PO2=10-4Pa and oxidized by annealing at high temperatures (1150 and 1350 deg. C) in air. Depending on yttrium concentration, the oxidation of the reduced form of the yttrium-doped BaTiO3 caused precipitation of the phase Ba6Ti17O40 or the phases Ba6Ti17O40 and Y2Ti2O7. The precipitates had well-defined orientational relationships with the perovskite matrix. Oxidation of the reduced form of doped barium titanate results in formation of the phase Ba1-xYx?Ti1-x/44+(VTi-bar )x/4O3 responsible for increase in the resistance of outer grain layers, which lie between grain boundaries and grain

  4. Thermal expansion behaviour of barium and strontium zirconium phosphates

    Indian Academy of Sciences (India)

    P Srikari Tantri; K Geetha; A M Umarji; Sheela K Ramasesha

    2000-12-01

    Ba1.5–SrZr4P5SiO24 compounds with = 0, 0.25, 0.5, 0.75, 1.0, 1.25 and 1.5, belonging to the low thermal expansion NZP family were synthesized by the solid state reaction method. The XRD pattern could be completely indexed with respect to R$\\bar{3}$ space group indicating the ordering of vacancy at the divalent cation octahedral sites. The microstructure and bulk thermal expansion coefficient from room temperature to 800°C of the sintered samples have been studied. All the samples show very low coefficient of thermal expansion (CTE), with = 0 samples showing negative expansion. A small substitution of strontium in the pure barium compound changes the sign of CTE. Similarly, = 1.5 sample (pure strontium) shows a positive CTE and a small substitution of barium changes its sign. = 1.0 and 1.25 samples have almost constant CTE over the entire temperature range. The low thermal expansion of these samples can be attributed to the ordering of the ions in the crystal structure of these materials.

  5. Evaluation of quaternary ammonium halides for removal of methyl iodide from flowing air streams

    International Nuclear Information System (INIS)

    The quaternary ammonium halides of several tertiary amines were used as impregnants on activated carbon and were tested for methyl iodide penetration in accordance with test Method A, ASTM D3803, 1979, ''Standard Test Methods for Radio-iodine Testing of Nuclear Grade Gas Phase Adsorbents''. The results suggest that the primary removal mechanism for methyl iodide-131 is isotopic exchange with the quaternary ammonium halide. For example, a 5 wt% impregnation of each of the tetramethyl, tetraethyl, tetrapropyl and tetrabutyl ammonium iodides on activated carbon yielded percent penetrations of 0.47, 0.53, 0.78, and 0.08 respectively when tested according to Method A of ASTM D3803. A sample impregnated with 5% tetramethyl ammonium hydroxide gave a methyl iodide penetration of 64.87%, thus supporting the isotopic exchange mechanism for removal. It has been a generally held belief that the success of tertiary amines as impregnants for radioiodine removal is a result of their ability to complex with the methyl iodide. The results of the work indicates that the superiority of the tertiary amines similar to triethylene diamine and quinuclidine, when compared to their straight chain analogs, is a result of their ease in reacting with methyl iodide-127 to form the quaternary ammonium iodide followed by isotopic exchange

  6. Bio-based barium alginate film: Preparation, flame retardancy and thermal degradation behavior.

    Science.gov (United States)

    Liu, Yun; Zhang, Chuan-Jie; Zhao, Jin-Chao; Guo, Yi; Zhu, Ping; Wang, De-Yi

    2016-03-30

    A bio-based barium alginate film was prepared via a facile ionic exchange and casting approach. Its flammability, thermal degradation and pyrolysis behaviors, thermal degradation mechanism were studied systemically by limiting oxygen index (LOI), vertical burning (UL-94), microscale combustion calorimetry (MCC), thermogravimetric analysis (TGA) coupled with Fourier transform infrared analysis (FTIR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). It showed that barium alginate film had much higher LOI value (52.0%) than that of sodium alginate film (24.5%). Moreover, barium alginate film passed the UL-94 V-0 rating, while the sodium alginate film showed no classification. Importantly, peak of heat release rate (PHRR) of barium alginate film in MCC test was much lower than that of sodium alginate film, suggested that introduction of barium ion into alginate film significantly decreased release of combustible gases. TG-FTIR and Py-GC-MS results indicated that barium alginate produced much less flammable products than that of sodium alginate in whole thermal degradation procedure. Finally, a possible degradation mechanism of barium alginate had been proposed. PMID:26794953

  7. Preparation of Barium Titanate Nanopowder through Thermal Decomposition of Peroxide Precursor and Its Formation Mechanism

    Institute of Scientific and Technical Information of China (English)

    PENG, Yangxi; CHEN, Qiyuan; LIU, Shijun

    2009-01-01

    H_2TiO_3 was dissolved in the mixture of hydrogen formed peroxide and ammonia under the pH range of 8-10 with a transparent yellow solution formed. When an equivalent mole of Ba~(2+) solution was added into the yellow solution, the precipitate produced was the peroxide precursor of barium titanate. The cubic nanopowder of barium titanate was obtained when the precipitate was washed, stoved, and then calcined at 600 ℃ for 1 h. The peroxide precursor of barium titanate and barium titanate nanopowder prepared were characterized to be BaTi(H_2O_2)_2O_3 by TGA-DTA, XRD, TEM, SEM, and XREDS. The peroxide precursor of barium titanate was determined to be BaTi(H_2O_2)_2O_3. The particle size of the barium titanate nanopowder, the calcined product of BaTi(H_2O_2)_2O_3, was in the range of 20-40 nm. A formation mechanism of the barium titanate nanopowder through thermal decomposition of its peroxide precursor was proposed and then validated.

  8. Preparation and properties of yttria doped tetragonal zirconia polycrystal/Sr-doped barium hexaferrite ceramic composites

    International Nuclear Information System (INIS)

    Highlights: • The 3Y-TZP/Sr-doped barium ferrite composites were prepared. • The saturation magnetization was improved by 15% with Sr-doping. • The dispersion coefficient p could reflect the microscopic lattice variation. • The composite with x = 0.5 had the maximum fracture toughness of 8.3 MPa m1/2. - Abstract: The effects of substitution of Ba2+ by Sr2+ on the magnetic property of barium ferrite and addition barium ferrite secondary phase to the 3 mol% yttria-doped tetragonal zirconia polycrystal (3Y-TZP) matrix on the mechanical property of composites were investigated. The Sr-doped barium ferrite (Ba1−xSrxFe12O19, x = 0, 0.25, 0.50 and 0.75) was synthesized by solid-state reaction in advance. Then 3Y-TZP/20 wt% Sr-doped barium ferrite composites were prepared by means of conventional ceramic method. It was found that a moderate amount of Sr added to barium ferrite could boost the saturation magnetization by 15% compared with the composites without Sr-doping. Besides, the composite with x = 0.50 possessed the best mechanical properties, such as 11.5 GPa for Vickers hardness and 8.3 MPa m1/2 for fracture toughness, respectively. It was demonstrated that magnetic and mechanical properties of the composites could be harmonized by the incorporation of barium ferrite secondary phase

  9. Bio-based barium alginate film: Preparation, flame retardancy and thermal degradation behavior.

    Science.gov (United States)

    Liu, Yun; Zhang, Chuan-Jie; Zhao, Jin-Chao; Guo, Yi; Zhu, Ping; Wang, De-Yi

    2016-03-30

    A bio-based barium alginate film was prepared via a facile ionic exchange and casting approach. Its flammability, thermal degradation and pyrolysis behaviors, thermal degradation mechanism were studied systemically by limiting oxygen index (LOI), vertical burning (UL-94), microscale combustion calorimetry (MCC), thermogravimetric analysis (TGA) coupled with Fourier transform infrared analysis (FTIR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). It showed that barium alginate film had much higher LOI value (52.0%) than that of sodium alginate film (24.5%). Moreover, barium alginate film passed the UL-94 V-0 rating, while the sodium alginate film showed no classification. Importantly, peak of heat release rate (PHRR) of barium alginate film in MCC test was much lower than that of sodium alginate film, suggested that introduction of barium ion into alginate film significantly decreased release of combustible gases. TG-FTIR and Py-GC-MS results indicated that barium alginate produced much less flammable products than that of sodium alginate in whole thermal degradation procedure. Finally, a possible degradation mechanism of barium alginate had been proposed.

  10. Wideband and enhanced microwave absorption performance of doped barium ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Pingyuan; Xiong, Kun [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Ju, Kui [Guizhou Institute of Metallurgy and Chemical Engineering, Guiyang 550002 (China); Li, Shengnan [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Xu, Guangliang, E-mail: xuguangliang@swust.edu.cn [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China)

    2015-07-01

    To achieve stronger microwave attenuation and larger bandwidth in electromagnetic absorber, the nickel ions (Ni{sup 2+}) and manganese ions (Mn{sup 2+}) were employed to partially replace the cobalt ions (Co{sup 2+}) in BaCoTiFe{sub 10}O{sub 19}, and the doped barium hexaferrite (Ba(MnNi){sub 0.2}Co{sub 0.6}TiFe{sub 10}O{sub 19} and Ba(MnNi){sub 0.25}Co{sub 0.5}TiFe{sub 10}O{sub 19}) powders were synthesized via the sol–gel combustion method. Subsequently, the microwave absorbing composites were prepared by mixing the ferrite powders with the paraffin. The X-ray diffraction (XRD) patterns of the doped ferrites confirmed the formation of the M-type barium ferrite, and no other types of barium ferrite could be found. Based on the electromagnetic parameters measured by the vector net-analyzer, it was found that the composite (Ba(MnNi){sub 0.2}Co{sub 0.6}TiFe{sub 10}O{sub 19}) possessed a minimum reflection loss of −52.8 dB at 13.4 GHz with a matching thickness of 1.8 mm and the bandwidth below −15 dB was 5.8 GHz. Moreover, the maximum attenuation of Ba(MnNi){sub 0.25}Co{sub 0.5}TiFe{sub 10}O{sub 19} could reach −69 dB when its thickness was 1.8 mm, and also the bandwidth less than −20 dB was ranging from 13.2 GHz to 18 GHz. Thus, Ba(MnNi){sub 0.2}Co{sub 0.6}TiFe{sub 10}O{sub 19} and Ba(MnNi){sub 0.25}Co{sub 0.5}TiFe{sub 10}O{sub 19} could be the good microwave absorbers, which have great potentials to be applied in the high frequency fields of the microwave absorbing materials. - Highlights: • The Co was first time substituted by Mn–Ni in ferrites. • The substituted ferrites had good microwave absorption. • The doped ferrites had broad bandwidth and low reflection loss.

  11. Barium titanate core – gold shell nanoparticles for hyperthermia treatments

    Directory of Open Access Journals (Sweden)

    FarrokhTakin E

    2013-06-01

    Full Text Available Elmira FarrokhTakin,1,2 Gianni Ciofani,1 Gian Luigi Puleo,1 Giuseppe de Vito,3,4 Carlo Filippeschi,1 Barbara Mazzolai,1 Vincenzo Piazza,3 Virgilio Mattoli1 1Center for Micro-BioRobotics @SSSA, Fondazione Istituto Italiano di Tecnologia, Pontedera, Pisa, Italy; 2The Biorobotics Institute, Scuola Superiore Sant'Anna, Pontedera, Pisa, Italy; 3Center for Nanotechnology Innovation @NEST, Fondazione Istituto Italiano di Tecnologia, Pisa, Italy; 4NEST, Scuola Normale Superiore, Pisa, Italy Abstract: The development of new tools and devices to aid in treating cancer is a hot topic in biomedical research. The practice of using heat (hyperthermia to treat cancerous lesions has a long history dating back to ancient Greece. With deeper knowledge of the factors that cause cancer and the transmissive window of cells and tissues in the near-infrared region of the electromagnetic spectrum, hyperthermia applications have been able to incorporate the use of lasers. Photothermal therapy has been introduced as a selective and noninvasive treatment for cancer, in which exogenous photothermal agents are exploited to achieve the selective destruction of cancer cells. In this manuscript, we propose applications of barium titanate core–gold shell nanoparticles for hyperthermia treatment against cancer cells. We explored the effect of increasing concentrations of these nanoshells (0–100 µg/mL on human neuroblastoma SH-SY5Y cells, testing the internalization and intrinsic toxicity and validating the hyperthermic functionality of the particles through near infrared (NIR laser-induced thermoablation experiments. No significant changes were observed in cell viability up to nanoparticle concentrations of 50 µg/mL. Experiments upon stimulation with an NIR laser revealed the ability of the nanoshells to destroy human neuroblastoma cells. On the basis of these findings, barium titanate core–gold shell nanoparticles resulted in being suitable for hyperthermia treatment

  12. A Comparative Study on Magnetostructural Properties of Barium Hexaferrite Powders Prepared by Polyethylene Glycol

    Directory of Open Access Journals (Sweden)

    Zehra Durmus

    2014-01-01

    Full Text Available Nanocrystalline particles of barium hexaferrite were synthesized by a sol-gel combustion route using nitrate-citrate gels prepared from metal nitrates and citric acid solutions with Fe/Ba molar ratio 12. The present paper aims to study the effect of addition of polyethylene glycol (PEG solutions with different molecular weights (MW: 400, 2000, and 10.000 g/mol on magnetostructural properties of barium hexaferrite. The formation of the barium hexaferrite was inspected using X-ray diffraction (XRD analysis, Fourier transform infrared (FT-IR analysis, thermogravimetric (TGA analysis, scanning electron microscopy (SEM analysis and vibrating sample magnetometer (VSM analysis for magnetic measurements.

  13. Microscopic insight into nuclear structure properties of proton-rich barium isotopes

    International Nuclear Information System (INIS)

    Variation after projection (VAP) calculations with Hartree-Bogoliubov (HB) Ansatz have been carried out for A=120-136 barium isotopes. In this framework, the yrast spectra with Jmaxπ=10+, B(E2) transition probabilities, quadrupole (β2) and hexadecapole (β4) deformation parameters for even-even barium isotopes have been obtained. The results of the calculation give an indication that it is important to include the hexadecapole-hexadecapole component of the two-body interaction for obtaining various nuclear structure quantities in these barium isotopes. (author)

  14. Application of barium fluoride for sulfur selective extraction at X-ray spectroscopic analysis of steel

    International Nuclear Information System (INIS)

    In order to increase the sensitivity of X-ray spectroscopic identification of sulphur in steels the application of barium fluoride for selective extraction of sulphate ions was proposed by authors of present work. The influence of concentration of sulphate ions, iron, nickel, chromium and titanium cations as well as acidity of solutions on the coefficient of distribution of sulphate ions in the system barium fluoride-water was studied. The distribution coefficients were calculated, the completeness of extraction was calculated as well. It is defined that sulphate ions from solutions containing cations of heavy metals and other anions can be extracted by means of barium fluoride.

  15. Barium ferrite nanoparticles prepared by self-propagating low-temperature combustion method and its characterization

    Indian Academy of Sciences (India)

    P M Prithviraj Swamy; S Basavaraja; Vijayanand Havanoor; N V Srinivas Rao; R Nijagunappa; A Venkataraman

    2011-12-01

    The barium ferrite particles were prepared using a self-propagating low-temperature combustion method using polyethylene glycol (PEG) as a fuel. The process was investigated with simultaneous thermogravimetric-differential thermal analysis (TG–DTA). The crystalline structure, morphology and the magnetic properties of the barium ferrite particles were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and SQUID susceptometer. The results show that the ignition temperature of PEG is lower compared with other combustion methods and gives nanocrystalline barium ferrite.

  16. Preparation and Characterization of Nano-particle Substituted Barium Hexaferrite

    CERN Document Server

    Atassi, Yomen; Tally, Mohammad

    2014-01-01

    High density magnetic recording requires high coercivity magnetic media and small particle size. Barium hexaferrite has been considered as a leading candidate material because of its chemical stability, fairly large crystal anisotropy and suitable magnetic characteristics. In this work, we present the preparation of the hexagonal ferrite BaFe12O19 and one of its derivative; the Zn-Sn substituted hexaferrite by the chemical co-precipitation method. The main advantage of this method on the conventional glass-ceramic one, resides in providing a small enough particle size for magnetic recording. We demonstrate using the X-ray diffraction patterns that the particle size decreases when substituting the hexaferrite by the Zn-Sn combination. This may improve the magnetic properties of the hexaferrite as a medium for HD magnetic recording

  17. Stark effect in Rydberg states of helium and barium

    International Nuclear Information System (INIS)

    This thesis, which deals with the effect of an electric field up to moderate field strengths on atoms with two valence electrons outside closed shells, in casu helium and barium, contains chapter in which the linear Stark effect in the 1 snp 1,3p Rydberg states of helium (n around 40) has been studied in a CW laser-atomic beam experiment. The evolution of the angular momentum manifolds into the n-mixing regime was followed and avoided level crossings were observed. Stark manifolds were also calculated by diagonalization of the complete energy matrix in the presence of an electric field. It turned out to be necessary to include up to five n-values in the calculations already at moderate values of the field to reproduce the data within the experimental accuracy (a few MHz), especially in the regime of the avoided crossings. (author). 147 refs.; 30 figs.; 8 tabs

  18. Effect of Nb on barium titanate prepared from citrate solutions

    Directory of Open Access Journals (Sweden)

    Stojanović Biljana D.

    2002-01-01

    Full Text Available The influence of the addition of dopants on the microstructure development and electrical properties of BaTiO3 doped with 0.2, 0.4, 0.6, 0.8 mol% of Nb and 0.01 mol% of Mn based compounds was studied. Doped barium titanate was prepared using the polymeric precursor method from citrate solutions. The powders calcined at 700°C for 4 hours were analysed by infrared (IR spectroscopy to verify the presence of carbonates, and by X-ray diffraction (XRD for phase formation. The phase composition, microstructure and dielectric properties show a strong dependence on the amount of added niobium.

  19. A buffer gas cooled beam of barium monohydride

    Science.gov (United States)

    Iwata, Geoffrey; Tarallo, Marco; Zelevinsky, Tanya

    2016-05-01

    Significant advances in direct laser cooling of diatomic molecules have opened up a wide array of molecular species to precision studies spanning many-body physics, quantum collisions and ultracold dissociation. We present a cryogenic beam source of barium monohydride (BaH), and study laser ablation of solid precursor targets as well as helium buffer gas cooling dynamics. Additionally, we cover progress towards a molecular magneto-optical trap, with spectroscopic studies of relevant cooling transitions in the B2 Σ <--X2 Σ manifold in laser ablated molecules, including resolution of hyperfine structure and precision measurements of the vibrational Frank-Condon factors. Finally, we examine the feasibility of photo dissociation of trapped BaH molecules to yield optically accessible samples of ultracold hydrogen.

  20. Optical-induced absorption tunability of Barium Strontium Titanate film

    Science.gov (United States)

    Luo, Chunya; Ji, Jie; Yue, Jin; Rao, Yunkun; Yao, Gang; Li, Dan; Zeng, Ying; Li, Renkui; Xiao, Longsheng; Liu, Xinxing; Yao, Jianquan; Ling, Furi

    2016-10-01

    The absorption tunability of 100 nm thickness of ferroelectric Barium Strontium Titanate (Ba0.5Sr0.5TiO3) thin films with different densities of pumped optical field is measured by terahertz time-domain spectroscopy in the range of 0.2 THz - 1.2 THz at 19 °C. Experimental results show that the absorption coefficient of BST film is approximately at 5000 cm-1-20000 cm-1 in the range of 0.2 THz - 1.2 THz and the absorption coefficient reached up to 16% when we applied the optical field up to 600 mW. The theoretical calculations reveal that increasing photoexcitation fluences is responsible for the increasing of transmission change in the conduction current density cause the absorption coefficient varied.

  1. Infrared Spectroscopic Characterization of Calcium and Barium Hydrazone Complexes

    Directory of Open Access Journals (Sweden)

    *A. Adeniyi

    2013-06-01

    Full Text Available Hydrazones have attracted considerable interest on account of their biological activities. Introduction of calcium and barium metal ions into m- and p-nitrobenzoic hydrazones is expected to modify these biological properties for enhanced activity and versatility. The ligands were synthesized from the parent acids. The complexes have been characterized using C, H and N microanalyses and IR spectrometry. The IR spectral data of the ligands and complexes revealed bonding via the C=O and C=N groups. The suggested metal to ligand stoichiometries are: [M (m-NBHx]Cl2.yH2O, x, y = 1 and 4 for M = Ca; x, y = 2 and 3 for M = Ba respectively. [M(p-NBHx]Cl2.yH2O, x, y = 1 and 12 for M = Ca; x, y = 1 and 3 for M = Ba respectively. The structural deductions are tentative pending future X-ray structural studies.

  2. Nonlinear optical properties of calcium barium niobate epitaxial thin films.

    Science.gov (United States)

    Bancelin, Stéphane; Vigne, Sébastien; Hossain, Nadir; Chaker, Mohammed; Légaré, François

    2016-07-25

    We investigate the potential of epitaxial calcium barium niobate (CBN) thin film grown by pulsed laser deposition for optical frequency conversion. Using second harmonic generation (SHG), we analyze the polarization response of the generated signal to determine the ratios d15 / d32 and d33 / d32 of the three independent components of the second-order nonlinear susceptibility tensor in CBN thin film. In addition, a detailed comparison to the signal intensity obtained in a y-cut quartz allows us to measure the absolute value of these components in CBN thin film: d15 = 5 ± 2 pm / V, d32 = 3.1 ± 0.6 pm / V and d33 = 9 ± 2 pm / V. PMID:27464195

  3. Pulsating aurora induced by upper atmospheric barium releases

    Science.gov (United States)

    Deehr, C.; Romick, G.

    1977-01-01

    The paper reports the apparent generation of pulsating aurora by explosive releases of barium vapor near 250 km altitude. This effect occurred only when the explosions were in the path of precipitating electrons associated with the visible aurora. Each explosive charge was a standard 1.5 kg thermite mixture of Ba and CuO with an excess of Ba metal which was vaporized and dispersed by the thermite explosion. Traces of Sr, Na, and Li were added to some of the charges, and monitoring was achieved by ground-based spectrophotometric observations. On March 28, 1976, an increase in emission at 5577 A and at 4278 A was observed in association with the first two bursts, these emissions pulsating with roughly a 10 sec period for approximately 60 to 100 sec after the burst.

  4. Bronchography in dogs. Comparative study with two barium sulphate solutions

    International Nuclear Information System (INIS)

    Two solutions of barium sulphate, 60 and 30% w/v, were compared with the ''overflow'' Bronchographic method. Two groups of eight healthy adult does of both sexes, weighing 7 to 18 kg were used for the study. The dogs were anaesthetised with thiopentone sodium 2% (20 mg/kg iv). After intubation, each dog received contrast medium by a catheter connected to a syringe, in a 9 mi dose. Two series of two x-rays plates were taken in left lateral recumbent, 3 and 6 min after administering the contrast medium and in ventrodorsal projection, 30 sec. later. The x-ray plates obtained were analysed and compared intra and inter group considering the advance speed of the contrast medium, the radiographic density and outlines. Adverse reactions were controlled

  5. Structural and functional characterization of barium zirconium titanate / epoxy composites

    Directory of Open Access Journals (Sweden)

    Filiberto González Garcia

    2011-12-01

    Full Text Available The dielectric behavior of composite materials (barium zirconium titanate / epoxy system was analyzed as a function of ceramic concentration. Structure and morphologic behavior of the composites was investigated by X-ray Diffraction (XRD, Fourier transformed infrared spectroscopy (FT-IR, Raman spectroscopy, field emission scanning electron microscopy (FE-SEM and transmission electron microscopy (TEM analyses. Composites were prepared by mixing the components and pouring them into suitable moulds. It was demonstrated that the amount of inorganic phase affects the morphology of the presented composites. XRD revealed the presence of a single phase while Raman scattering confirmed structural transitions as a function of ceramic concentration. Changes in the ceramic concentration affected Raman modes and the distribution of particles along into in epoxy matrix. Dielectric permittivity and dielectric losses were influenced by filler concentration.

  6. Synthesis and optical study of barium magnesium aluminate blue phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Jeet, Suninder, E-mail: suninder.jeet@thapar.edu; Pandey, O. P., E-mail: oppandey@thapar.edu [School of Physics and Materials Science, Thapar University, Patiala (147003), Punjab (India); Sharma, Manoj, E-mail: manojnarad@sggswu.org [Department of Nanotechnology, Sri Guru Granth Sahib World University, Fatehgarh Sahib(146406), Punjab (India)

    2015-05-15

    Europium doped barium magnesium aluminate (BaMgAl{sub 10}O{sub 17}:Eu{sup 2+}) phosphor was prepared via solution combustion method at 550°C using urea as a fuel. Morphological and optical properties of the prepared sample was studied by X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Photoluminescence spectroscopy (PL). XRD result showed the formation of pure phase BaMgAl{sub 10}O{sub 17}(JCPDS 26-0163) along with an additional phase BaAl{sub 2}O{sub 4}(JCPDS 01-082-1350). TEM image indicated the formation of faceted particles with average particle size 40 nm. From PL spectra, a broad emission band obtained at about 450 nm attributes to 4f{sup 6} 5d → 4f{sup 7} transition of Eu{sup 2+} which lies in the blue region of the visible spectrum.

  7. Study on a flexoelectric microphone using barium strontium titanate

    Science.gov (United States)

    Kwon, S. R.; Huang, W. B.; Zhang, S. J.; Yuan, F. G.; Jiang, X. N.

    2016-04-01

    In this study, a flexoelectric microphone was, for the first time, designed and fabricated in a bridge structure using barium strontium titanate (Ba0.65Sr0.35TiO3) ceramic and tested afterwards. The prototyped flexoelectric microphone consists of a 1.5 mm  ×  768 μm  ×  50 μm BST bridge structure and a silicon substrate with a cavity. The sensitivity and resonance frequency were designed to be 0.92 pC/Pa and 98.67 kHz, respectively. The signal to noise ratio was measured to be 74 dB. The results demonstrate that the flexoelectric microphone possesses high sensitivity and a wide working frequency range simultaneously, suggesting that flexoelectricity could be an excellent alternative sensing mechanism for microphone applications.

  8. Removal efficiency of radioactive methyl iodide on TEDA-impregnated activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Garcia, C.M.; Gonzalez, J.F.; Roman, S. [Extremadura Univ., Badajoz (Spain). Dept. de Fisica Aplicada

    2011-02-15

    Activated carbons were prepared by different series of carbon dioxide and steam activation from walnut shells for their optimal use as radioactive methyl iodide adsorbents in Nuclear Plants. The knowledge of the most favourable textural characteristics of the activated carbons was possible by the previous study of the commercial activated carbon currently used for this purpose. In order to increase their methyl iodide affinity, the effect of triethylenediamine impregnation was studied at 5 and 10 wt.%. The results obtained indicated that in both cases the adsorption efficiency is markedly improved by the addition of impregnant, which allows the adsorbate uptake to occur not only by physical adsorption, via non-specific interactions (as in non-impregnated carbons) but also by the specific interaction of triethylenediamine with radioactive methyl iodide. Methyl iodide retention efficiencies up to 98.1% were achieved. (author)

  9. Kinetics and mechanism of the mercury(II)-assisted hydrolysis of methyl iodide.

    Science.gov (United States)

    Celo, Valbona; Scott, Susannah L

    2005-04-01

    The kinetics and mechanism of the reaction of aqueous Hg(II) with methyl iodide have been investigated. The overall reaction is best described as Hg(II)-assisted hydrolysis, resulting in quantitative formation of methanol and, in the presence of excess methyl iodide, ultimately, HgI2 via the intermediate HgI+. The kinetics are biexponential when methyl iodide is in excess. At 25 degrees C, the acceleration provided by Hg2+ is 7.5 times greater than that caused by HgI+, while assistance of hydrolysis was not observed for HgI2. Thus, the reactions are not catalytic in Hg(II). The kinetics are consistent with an SN2-M+ mechanism involving electrophilic attack at iodide. As expected, methylation of mercury is not a reaction pathway; traces of methylmercury(II) are artifacts of the extraction/preconcentration procedure used for methylmercury analysis.

  10. Fluorescence characteristics of 5-amino salicylic acid: An iodide recognition study

    Science.gov (United States)

    Arora, Priyanka; Suyal, Kanchan; Joshi, Neeraj K.; Joshi, Hem Chandra; Pant, Sanjay

    In this paper we report the effect of iodide on the fluorescence of 5-amino salicylic acid (5-ASA). In the absence of iodide, prominent blue green (BG) emission band at ˜465 nm (broad) is observed in aprotic solvents whereas violet (V) emission at ˜408 nm, blue green (BG) at ˜480 nm and green (G) at ˜500 nm are observed in case of protic solvents. On the addition of iodide ion (I-), the intensity of BG fluorescence is enhanced in case of aprotic solvents. On the other hand the G band is enhanced in protic solvents and decrease in the intensity of the V band is observed. The effect of hydrogen bonding as well as the interplay of neutral and ionic species is invoked to explain the observed results. The study projects the application of this system in iodide recognition in protic/aprotic environments.

  11. A Direct Transformation of Aryl Aldehydes to Benzyl Iodides Via Reductive Iodination

    Energy Technology Data Exchange (ETDEWEB)

    Ruso, Jayaraman Sembian; Rajendiran, Nagappan; Kumaran, Rajendran Senthil [Univ. of Madras, Chennai (India)

    2014-02-15

    A facile transformation of aryl aldehydes to benzyl iodides through one-pot reductive iodination is reported. This protocol displays remarkable functional group tolerance and the title compound was obtained in good to excellent yield.

  12. Barium and carbon fluxes in the Canadian Arctic Archipelago

    Science.gov (United States)

    Thomas, Helmuth; Shadwick, Elizabeth; Dehairs, Frank; Lansard, Bruno; Mucci, Alfonso; Navez, Jacques; Gratton, Yves; Prowe, Friederike; Chierici, Melissa; Fransson, Agneta; Papakyriakou, Tim N.; Sternberg, Erika; Miller, Lisa A.; Tremblay, Jean-ÉRic; Monnin, Christophe

    2011-09-01

    The seasonal and spatial variability of dissolved Barium (Ba) in the Amundsen Gulf, southeastern Beaufort Sea, was monitored over a full year from September 2007 to September 2008. Dissolved Ba displays a nutrient-type behavior: the maximum water column concentration is located below the surface layer. The highest Ba concentrations are typically observed at river mouths, the lowest concentrations are found in water masses of Atlantic origin. Barium concentrations decrease eastward through the Canadian Arctic Archipelago. Barite (BaSO4) saturation is reached at the maximum dissolved Ba concentrations in the subsurface layer, whereas the rest of the water column is undersaturated. A three end-member mixing model comprising freshwater from sea-ice melt and rivers, as well as upper halocline water, is used to establish their relative contributions to the Ba concentrations in the upper water column of the Amundsen Gulf. Based on water column and riverine Ba contributions, we assess the depletion of dissolved Ba by formation and sinking of biologically bound Ba (bio-Ba), from which we derive an estimate of the carbon export production. In the upper 50 m of the water column of the Amundsen Gulf, riverine Ba accounts for up to 15% of the available dissolved Ba inventory, of which up to 20% is depleted by bio-Ba formation and export. Since riverine inputs and Ba export occur concurrently, the seasonal variability of dissolved Ba in the upper water column is moderate. Assuming a fixed organic carbon to bio-Ba flux ratio, carbon export out of the surface layer is estimated at 1.8 ± 0.45 mol C m-2 yr-1. Finally, we propose a climatological carbon budget for the Amundsen Gulf based on recent literature data and our findings, the latter bridging the surface and subsurface water carbon cycles.

  13. Brillouin function characteristics for La-Co substituted barium hexaferrites

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chuanjian, E-mail: wcjuestc2005@gmail.com, E-mail: ksun@uestc.edu.cn; Yu, Zhong; Sun, Ke, E-mail: wcjuestc2005@gmail.com, E-mail: ksun@uestc.edu.cn; Guo, Rongdi; Jiang, Xiaona; Lan, Zhongwen [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Yang, Yan [Department of Communication and Engineering, Chengdu Technological University, Chengdu 611730 (China)

    2015-09-14

    La-Co substituted barium hexaferrites with the chemical formula of Ba{sub 1−x}La{sub x}Fe{sub 12−x}Co{sub x}O{sub 19} (x = 0.0, 0.1, 0.3, and 0.5), prepared by a conventional ceramic method, were systematically investigated by Raman spectra, X-ray photoelectron spectroscopy, Rietveld refinement of X-ray diffraction patterns, and vibrating sample magnetometer. The result manifests that all the compounds are crystallized in magnetoplumbite hexagonal structure. Trivalent cobalt ions prevailingly occupy the 2a, 4f{sub 1}, and 12k sites. According to Néel model of collinear-spin ferrimagnetism, the molecular-field coefficients ω{sub bf2}, ω{sub kf1}, ω{sub af1}, ω{sub kf2}, and ω{sub bk} of La-Co substituted barium hexaferrites have been calculated using the nonlinear fitting method, and the magnetic moment of five sublattices (2a, 2b, 4f{sub 1}, 4f{sub 2}, and 12k) versus temperature T has been also investigated. The fitting results are coincided well with the experimental data. Moreover, with the increase of La-Co substitution amount x, the molecular-field coefficients ω{sub bf2} and ω{sub af1} decrease constantly, while the molecular-field coefficients ω{sub kf1}, ω{sub kf2}, and ω{sub bk} show a slight change.

  14. Horseradish Peroxidase-Mediated, Iodide-Catalyzed Cascade Reaction for Plasmonic Immunoassays.

    Science.gov (United States)

    Xianyu, Yunlei; Chen, Yiping; Jiang, Xingyu

    2015-11-01

    This report outlines an enzymatic cascade reaction for signal transduction and amplification for plasmonic immunoassays by using horseradish peroxidase (HRP)-mediated aggregation of gold nanoparticles (AuNPs). HRP-catalyzed oxidation of iodide and iodide-catalyzed oxidation of cysteine is employed to modulate the plasmonic signals of AuNPs. It agrees well with the current immunoassay platforms and allows naked-eye readout with enhanced sensitivity, which holds great promise for applications in resource-constrained settings.

  15. Polarization Effects in Methylammonium Lead Iodide Electronic Devices

    Science.gov (United States)

    Labram, John; Fabini, Douglas; Perry, Erin; Lehner, Anna; Wang, Hengbin; Glaudell, Anne; Wu, Guang; Evans, Hayden; Buck, David; Cotta, Robert; Echegoyen, Luis; Wudl, Fred; Seshadri, Ram; Chabinyc, Michael

    The immense success of group IV and III-V semiconductors has resulted in disruptive new photovoltaic (PV) cell technologies emerging extremely infrequently. For this reason, the recent progress in Methylammonium Lead Iodide (MAPbI3) solar cells can be viewed as a highly significant historic event. Despite the staggering recent progress made in reported power conversion efficiency (PCE), debate remains intense on the nature of the various instabilities synonymous with these devices. Using various electronic device measurements, we here present a body of experimental evidence consistent with the existence of a mobile ionic species within the MAPbI3 perovskite. Temperature-dependent transistor measurements reveal operating FET devices only below approximately 210K. This is attributed to ionic screening of the (otherwise charge-neutral) semiconductor-dielectric interface. Temperature-dependent pulsed-gate and impedance spectroscopy experiments also reveal behavior consistent with this interpretation. MAPbI3 PV cells were found to possess a PCE which decreases significantly below 210K. Combined, these set of measurements provide an interesting and consistent description of the internal processes at play within the MAPbI3 perovskite structure.

  16. Thermopower and activation energy of silver iodide based superionic materials

    International Nuclear Information System (INIS)

    Silver iodide based glasses, 60Agl-20Ag sub 2 O-20B sub 2O sub 3, 6 Agl-20Ag sub 2 O-20 MoO sub 3 and 60Agl-20Ag sub 2O-20WO sub 3, all in the mol % ratio, were prepared by rapidly quenching the melts of the chemicals in a stainless steel container; kept in a liquid nitrogen bath. The glassy nature of the as-quenched materials was confirmed by X-ray diffraction (XRD). The electrical conductivity of the glasses was measured at various temperatures ranging from 30 to 70 degree C using an impedance bridge operating in the frequency range between 40 Hz to 100 kHz. The plot of In σT versus 1000/T for each glassy material obeys Arrhenius law and the activation energy obtained is between 0.2 to 0.3 eV. Thermopower measurement was also carried out in the same temperature range as the conductivity measurement to obtain the heat of transport

  17. 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.

  18. Digermylene Oxide Stabilized Group 11 Metal Iodide Complexes.

    Science.gov (United States)

    Yadav, Dhirendra; Siwatch, Rahul Kumar; Sinhababu, Soumen; Karwasara, Surendar; Singh, Dharmendra; Rajaraman, Gopalan; Nagendran, Selvarajan

    2015-12-01

    Use of a substituted digermylene oxide as a ligand has been demonstrated through the isolation of a series of group 11 metal(I) iodide complexes. Accordingly, the reactions of digermylene oxide [{(i-Bu)2ATIGe}2O] (ATI = aminotroponiminate) (1) with CuI under different conditions afforded [({(i-Bu)2ATIGe}2O)2(Cu4I4)] (2) with a Cu4I4 octahedral core, [({(i-Bu)2ATIGe}2O)2(Cu3I3)] (3) with a Cu3I3 core, and [{(i-Bu)2ATIGe}2O(Cu2I2)(C5H5N)2] (4) with a butterfly-type Cu2I2 core. The reactions of compound 1 with AgI and AuI produced [({(i-Bu)2ATIGe}2O)2(Ag4I4)] (5) with a Ag4I4 octahedral core and [{(i-Bu)2ATIGe}2O(Au2I2)] (6) with a Au2I2 core, respectively. The presence of metallophilic interactions in these compounds is shown through the single-crystal X-ray diffraction and atom-in-molecule (AIM) studies. Preliminary photophysical studies on compound 6 are also carried out. PMID:26558406

  19. Persistent photovoltage in methylammonium lead iodide perovskite solar cells

    Directory of Open Access Journals (Sweden)

    A. Baumann

    2014-08-01

    Full Text Available We herein perform open circuit voltage decay (OCVD measurements on methylammonium lead iodide (CH3NH3PbI3 perovskite solar cells to increase the understanding of the charge carrier recombination dynamics in this emerging technology. Optically pulsed OCVD measurements are conducted on CH3NH3PbI3 solar cells and compared to results from another type of thin-film photovoltaics, namely, the two reference polymer–fullerene bulk heterojunction solar cell devices based on P3HT:PC60BM and PTB7:PC70BM blends. We observe two very different time domains of the voltage transient in the perovskite solar cell with a first drop on a short time scale that is similar to the decay in the studied organic solar cells. However, 65%–70% of the maximum photovoltage persists on much longer timescales in the perovskite solar cell than in the organic devices. In addition, we find that the recombination dynamics in all time regimes are dependent on the starting illumination intensity, which is also not observed in the organic devices. We then discuss the potential origins of these unique behaviors.

  20. Lead iodide X-ray and gamma-ray spectrometers for room and high temperature operation

    Energy Technology Data Exchange (ETDEWEB)

    Hermon, H.; James, R.B.; Cross, E. [and others

    1997-02-01

    In this study, we report on the results of the investigation of lead iodide material properties. The effectiveness of zone refining purification methods on the material purity is determined by ICP-MS and ICP-OES and correlated to the electrical and physical material properties. We show that this zone refining method is very efficient in removing impurities from lead iodide and we also determine the segregation coefficient for some of these impurities. Triple axis x- ray diffraction (TAD) analysis has been used to determine the crystalline perfection of the lead iodide after applying various cutting, etching, and fabrication methods. The soft lead iodide crystal was found to be damaged when cleaved by a razor blade, but by using a diamond wheel saw, followed by etching, the crystallinity of the material was improved, as observed by TAD. Low temperature photoluminescence also indicates an improvement in the material properties of the purified lead iodide. Electrical properties of lead iodide such as carrier mobility, were calculated based on carrier- phonon scattering. The results for the electrical properties were in good agreement with the experimental data.

  1. Critical Evaluation of Acetylthiocholine Iodide and Acetylthiocholine Chloride as Substrates for Amperometric Biosensors Based on Acetylcholinesterase

    Directory of Open Access Journals (Sweden)

    Gabriel-Lucian Radu

    2013-01-01

    Full Text Available Numerous amperometric biosensors have been developed for the fast analysis of neurotoxic insecticides based on inhibition of cholinesterase (AChE. The analytical signal is quantified by the oxidation of the thiocholine that is produced enzymatically by the hydrolysis of the acetylthiocholine pseudosubstrate. The pseudosubstrate is a cation and it is associated with chloride or iodide as corresponding anion to form a salt. The iodide salt is cheaper, but it is electrochemically active and consequently more difficult to use in electrochemical analytical devices. We investigate the possibility of using acetylthiocholine iodide as pseudosubstrate for amperometric detection. Our investigation demonstrates that operational conditions for any amperometric biosensor that use acetylthiocholine iodide must be thoroughly optimized to avoid false analytical signals or a reduced sensitivity. The working overpotential determined for different screen-printed electrodes was: carbon-nanotubes (360 mV, platinum (560 mV, gold (370 mV, based on a catalytic effect of iodide or cobalt phthalocyanine (110 mV, but with a significant reduced sensitivity in the presence of iodide anions.

  2. Experimental study of retinoic acid on improving iodide uptake in MCF-7 breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    FU Hong-Liang; WU Jing-Chuan; DU Xue-Liang; LI Jia-Ning; WU Zhen; ZOU Ren-Jian

    2005-01-01

    The study aims to investigate the effect of retinoic acid on the iodide uptake of MCF-7 cells and its mechanism. The iodide uptake and expression of hNIS(human sodium/iodide symporter)mRNA in the breast cancer MCF-7 cells were compared individually before and after the intervention of all-trans retinoic acid (ATRA) with the iodide uptake assay and RT-PCR. The following results are obtained: (1) when treated with all-trans retinoic acid in the concentration of 1.0 μmol/L, the capacity of iodide uptake of MCF-7 cells reached about 1.5 times of the basal state; (2) 12 h after the intervention of 1.0 μmol/L ATRA, the hNISmRNA expression of the MCF-7 cells reached maximum. The study shows that all-trans retinoic acid has the effect to improve the iodide uptake of the MCF-7 cells and this effect may result from its up-regulation of the hNISmRNA expression.

  3. Modelling iodide – iodate speciation in atmospheric aerosol: Contributions of inorganic and organic iodine chemistry

    Directory of Open Access Journals (Sweden)

    S. Pechtl

    2007-01-01

    Full Text Available The speciation of iodine in atmospheric aerosol is currently poorly understood. Models predict negligible iodide concentrations but accumulation of iodate in aerosol, both of which is not confirmed by recent measurements. We present an updated aqueous phase iodine chemistry scheme for use in atmospheric chemistry models and discuss sensitivity studies with the marine boundary layer model MISTRA. These studies show that iodate can be reduced in acidic aerosol by inorganic reactions, i.e., iodate does not necessarily accumulate in particles. Furthermore, the transformation of particulate iodide to volatile iodine species likely has been overestimated in previous model studies due to negligence of collision-induced upper limits for the reaction rates. However, inorganic reaction cycles still do not seem to be sufficient to reproduce the observed range of iodide – iodate speciation in atmospheric aerosol. Therefore, we also investigate the effects of the recently suggested reaction of HOI with dissolved organic matter to produce iodide. If this reaction is fast enough to compete with the inorganic mechanism, it would not only directly lead to enhanced iodide concentrations but, indirectly via speed-up of the inorganic iodate reduction cycles, also to a decrease in iodate concentrations. Hence, according to our model studies, organic iodine chemistry, combined with inorganic reaction cycles, is able to reproduce observations. The presented chemistry cycles are highly dependent on pH and thus offer an explanation for the large observed variability of the iodide – iodate speciation in atmospheric aerosol.

  4. A selective iodide ion sensor electrode based on functionalized ZnO nanotubes.

    Science.gov (United States)

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

    2013-01-01

    In this research work, ZnO nanotubes were fabricated on a gold coated glass substrate through chemical etching by the aqueous chemical growth method. For the first time a nanostructure-based iodide ion selective electrode was developed. The ZnO nanotubes were functionalized with miconazole ion exchanger and the electromotive force (EMF) was measured by the potentiometric method. The iodide ion sensor exhibited a linear response over a wide range of concentrations (1 × 10-6 to 1 × 10-1 M) and excellent sensitivity of -62 ± 1 mV/decade. The detection limit of the proposed sensor was found to be 5 × 10-7 M. The effects of pH, temperature, additive, plasticizer and stabilizer on the potential response of iodide ion selective electrode were also studied. The proposed iodide ion sensor demonstrated a fast response time of less than 5 s and high selectivity against common organic and the inorganic anions. All the obtained results revealed that the iodide ion sensor based on functionalized ZnO nanotubes may be used for the detection of iodide ion in environmental water samples, pharmaceutical products and other real samples. PMID:23385412

  5. A Selective Iodide Ion Sensor Electrode Based on Functionalized ZnO Nanotubes

    Directory of Open Access Journals (Sweden)

    Magnus Willander

    2013-02-01

    Full Text Available In this research work, ZnO nanotubes were fabricated on a gold coated glass substrate through chemical etching by the aqueous chemical growth method. For the first time a nanostructure-based iodide ion selective electrode was developed. The ZnO nanotubes were functionalized with miconazole ion exchanger and the electromotive force (EMF was measured by the potentiometric method. The iodide ion sensor exhibited a linear response over a wide range of concentrations (1 × 10−6 to 1 × 10−1 M and excellent sensitivity of –62 ± 1 mV/decade. The detection limit of the proposed sensor was found to be 5 × 10−7 M. The effects of pH, temperature, additive, plasticizer and stabilizer on the potential response of iodide ion selective electrode were also studied. The proposed iodide ion sensor demonstrated a fast response time of less than 5 s and high selectivity against common organic and the inorganic anions. All the obtained results revealed that the iodide ion sensor based on functionalized ZnO nanotubes may be used for the detection of iodide ion in environmental water samples, pharmaceutical products and other real samples.

  6. The effect of elemental and hydrocarbon impurities on mercuric iodide gamma ray detector performance

    Science.gov (United States)

    Cross, Eilene S.; Buffleben, George; Soria, Ed; James, Ralph; Schieber, Michael; Natarajan, Raj; Gerrish, Vern

    Mercuric iodide is a room temperature semiconductor material that is used for gamma ray and x-ray radiation detection. Mercuric iodide is synthesized from mercuric chloride and potassium iodide and is then purified by a series of melts and sublimation steps and by zone refining. The mercuric iodide is grown into crystals and platelets and then fabricated into detectors. Elemental contamination may be a determining factor in the performance of these detectors. These contaminates may be present in the starting material or may be introduced during, or be unaffected by, the purification, growth or fabrication steps. Methods have been developed for the analysis of trace levels of elemental contamination. Inductively Coupled Plasma/Mass Spectroscopy (ICP/MS), Inductively Coupled Plasma/Optical Emission Spectroscopy (ICP/OES) and Gas Chromatography/Mass Spectroscopy (GC/MS) are used to determine sub ppm levels of many trace elemental impurities. Trace levels of many elemental impurities in the raw mercuric iodide are significantly reduced during the purification and zone refining processes. Though the levels of impurities are reduced, poor performing mercuric iodide detectors have contamination levels remaining or reintroduced which are higher for Ag, Al, Ca, Cu, Mg, Mn, Na, Pb and Zn than detectors with good gamma ray response. This paper will discuss the analytical methodology, the effects of purification on impurity levels, and the correlation between detector performance and impurity levels.

  7. Characterization and growth dynamics of barium titanate crystallite on nanometer scale

    Institute of Scientific and Technical Information of China (English)

    Sen Wang; Yue Zhang; Zhen Ji; Yousong Gu; Yunhua Huang; Cheng Zhou

    2005-01-01

    Barium titanate powder on nanometer scale was synthesized by means of co-precipitation. The thermal mass loss, crystal grain growth and phase transition of the barium titanate nanometer powder were investigated by TG (Thermogravimetric)-DTA (Differential scanning calorimetric) and XRD (X-ray powder diffractometer) at different heat treatment temperatures. The results show that amorphous barium titanate powder can transfer into tetragonal symmetry structure after heat treatment. When the heat treatment temperature is below 900℃, the grains grow rapidly because the activation energy at low temperature is greatly less than that at high temperature. By controlling theheat treatment temperature, the optimization of the barium titanate crystallite size and formation of tetragonal phase can be realized.

  8. A study of magneto-crystalline alignment in sintered barium hexaferrite fabricated by powder injection molding

    Energy Technology Data Exchange (ETDEWEB)

    Zlatkov, B.S. [FOTEC Forschungs- und Technologietransfer GmbH, Viktor Kaplan-Strasse 2, 2700 Wiener Neustadt (Austria); Nikolic, M.V. [Institute for Multidisciplinary Research, Kneza Viseslava 1, 11000 Beograd (Serbia)], E-mail: mariavesna@cms.bg.ac.yu; Aleksic, O. [Institute for Multidisciplinary Research, Kneza Viseslava 1, 11000 Beograd (Serbia); Danninger, H.; Halwax, E. [Institute of Chemical Technologies and Analytics, Getreidemarkt 9/164, 1060 Wien (Austria)

    2009-02-15

    Barium hexaferrite permanent magnets were produced by powder injection molding. Starting barium hexaferrite powder was prepared from a Fe{sub 2}O{sub 3} and BaCO{sub 3} powder mixture by calcination followed by milling. The feedstock for powder injection molding was prepared by mixing barium hexaferrite powder with a low viscosity binder. Magnetic alignment was achieved by applying a high intensity magnetic field to the melted feedstock during the injection process. Green samples (with and without magnetic alignment) were subjected to solvent debinding and subsequent thermal debinding followed by sintering. Sintering conditions were optimized in order to achieve a maximum energy product value. Magneto-crystalline aligning in barium hexaferrite was studied on both green and sintered samples using X-ray diffraction, scanning electron microscope (SEM) and magnetic measurements (hysteresisgraphs). All measurements were made both in a parallel and perpendicular direction to the aligning magnetic field. The obtained results confirmed magneto-crystalline alignment.

  9. Study of the immunoisolating effects of barium-alginate microencapsulation on rat islets allograft survival

    Institute of Scientific and Technical Information of China (English)

    Mei Zhang; Chao Liu; Cuiping Liu; Youwen Qin; Zhaosun Zhen

    2005-01-01

    Objective: To evaluate the immunoisolating effects of barium-alginate microencapsulation on islets allograft survival. Methods: The nonmicroencapsulated and microencapsulated islets were transplanted under the kidney capsule or intraperitoneally into Wistar rat with STZ-induced diabetes. The blood glucose and insulin secretion of grafts were observed. Graft function was tested by oral rats was associated with normal glucose and insulin profiles in response to OGTT. Conclusion: Microencapsulation with barium-alginate membrane can prolong islet survival and protect islets against allorejection.

  10. Kinetics of barium sulphate reaction crystallization in crystallizers with internal circulation

    OpenAIRE

    Koralewska, J.; Piotrowski, K; B. Wierzbowska; A. Matynia

    2008-01-01

    Kinetic calculation results describing the observed nucleation and growth rates of barium sulphate crystals precipitated in an integrated reaction-crystallization process in a barium sulphate-ammonium chloride-water system are presented and analyzed. The scope of experiments included two continuous model DTM-type crystallizers (Draft Tube Magma) with internal circulation of the suspension forced by a liquid jet-pump device responsible for stable and intensive enough ascending/descending flow ...

  11. Impact of Biofield Treatment on Atomic and Structural Characteristics of Barium Titanate Powder

    OpenAIRE

    Trivedi, Mahendra; Nayak, Gopal

    2015-01-01

    Barium titanate, perovskite structure is known for its high dielectric constant and piezoelectric properties, which makes it interesting material for fabricating capacitors, transducer, actuator, and sensors. The perovskite crystal structure and lattice vibrations play a crucial role in its piezoelectric and ferroelectric behavior. In the present study, the barium titanate powder was subjected to biofield treatment. Further, the control and treated samples were characterized using X-ray diffr...

  12. Synthesis of nonstoichiometric M-type barium ferrite nanobelt by spark plasma sintering method

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wenyu; ZHANG Qingjie; TANG Xinfeng; CHENG Haibin

    2005-01-01

    This study investigated the feasibility of ultrafast crystallization of M-type barium ferrite when the coprecipitation precursors in stoichiometric proportions as BaFe12O19, Fe(OH)3 and BaCO3 nanoparticles, had been heated by spark plasma sintering (SPS) process. The results show that SPS method may realize the ultrafast crystallization of M-type barium ferrite, absolutely prevent the crystallization of intermediate phase α-Fe2O3, and significantly decrease the crystallization temperature of M-type barium ferrite. The sintered samples obtained at 800℃ by sintering the precursors for 10 minutes are a kind of multiphase ferrites composed of major phase M-type barium ferrite and trace amount of BaFe0.24Fe0.76O2.88. It is discovered that M-type barium ferrites in the holes of the sintered samples are in nanobelt microstructure about 100-300 nm in width and several micrometers in length. These M-type barium ferrite nanobelts are non-stoichiometric and may be expressed as BaFe12+Xo19+1.5x (-4.77≤x≤6.50). Their composistions suggest completely random Fe-rich or Ba-rich domains.

  13. Barium swallow study in routine clinical practice: a prospective study in patients with chronic cough

    Directory of Open Access Journals (Sweden)

    Carlos Shuler Nin

    2013-12-01

    Full Text Available OBJECTIVE: To assess the routine use of barium swallow study in patients with chronic cough.METHODS: Between October of 2011 and March of 2012, 95 consecutive patients submitted to chest X-ray due to chronic cough (duration > 8 weeks were included in the study. For study purposes, additional images were obtained immediately after the oral administration of 5 mL of a 5% barium sulfate suspension. Two radiologists systematically evaluated all of the images in order to identify any pathological changes. Fisher's exact test and the chi-square test for categorical data were used in the comparisons.RESULTS: The images taken immediately after barium swallow revealed significant pathological conditions that were potentially related to chronic cough in 12 (12.6% of the 95 patients. These conditions, which included diaphragmatic hiatal hernia, esophageal neoplasm, achalasia, esophageal diverticulum, and abnormal esophageal dilatation, were not detected on the images taken without contrast. After appropriate treatment, the symptoms disappeared in 11 (91.6% of the patients, whereas the treatment was ineffective in 1 (8.4%. We observed no complications related to barium swallow, such as contrast aspiration.CONCLUSIONS: Barium swallow improved the detection of significant radiographic findings related to chronic cough in 11.5% of patients. These initial findings suggest that the routine use of barium swallow can significantly increase the sensitivity of chest X-rays in the detection of chronic cough-related etiologies.

  14. A glucose bio-battery prototype based on a GDH/poly(methylene blue) bioanode and a graphite cathode with an iodide/tri-iodide redox couple.

    Science.gov (United States)

    Wang, Jen-Yuan; Nien, Po-Chin; Chen, Chien-Hsiao; Chen, Lin-Chi; Ho, Kuo-Chuan

    2012-07-01

    A glucose bio-battery prototype independent of oxygen is proposed based on a glucose dehydrogenase (GDH) bioanode and a graphite cathode with an iodide/tri-iodide redox couple. At the bioanode, a NADH electrocatalyst, poly(methylene blue) (PMB), which can be easily grown on the electrode (screen-printed carbon paste electrode, SPCE) by electrodeposition, is harnessed and engineered. We find that carboxylated multi-walled carbon nanotubes (MWCNTs) are capable of significantly increasing the deposition amount of PMB and thus enhancing the PMB's electrocatalysis of NADH oxidation and the glucose bio-battery's performance. The choice of the iodide/tri-iodide redox couple eliminates the dependence of oxygen for this bio-battery, thus enabling the bio-battery with a constant current-output feature similar to that of the solar cells. The present glucose bio-battery prototype can attain a maximum power density of 2.4 μW/cm(2) at 25 °C. PMID:22541949

  15. Characterization of strontium iodide scintillators with silicon photomultipliers

    Science.gov (United States)

    Mitchell, Lee J.; Phlips, Bernard

    2016-06-01

    This work characterizes a commercially available europium-doped strontium iodide detector recently developed by Radiation Monitoring Devices (RMD). The detector has been chosen for a space-based mission scheduled to launch in early 2017. The primary goal of this work was to characterize the detector's response over the expected operational range of -10 °C to 30 °C as well as the expected operational voltage range of +26.5-+28.5 V and identify background interferences that may develop due to neutron activation produced by cosmic-ray interactions. The 8 mm×8 mm×20 mm detectors use KETEK silicon photomultipliers (SiPM), with an active area of 6 mmx6 mm (KETEK PM6660). Our results show substantial integral nonlinearity due to the SiPM ranging from 0% to 25% at room temperature over the energy range of 80-2614 keV. The nonlinearity, a function of temperature and overvoltage, leads to an underestimate of the full width at half max (FWHM), which is 2.6% uncorrected at 662 keV and 3.8% corrected at 662 keV. The temperature dependence of the detector results in a noise threshold that increases substantially above 30 °C due to the SiPM dark rate. In an effort to simulate the harsh environment of space, neutron activation of the detector was also explored. Gamma-ray lines at 127 keV and 164 keV were observed in the detector along with Kα x-rays associated with europium. Beta decay from europium- and iodine-activation products were also observed within the detector.

  16. THERAPY OF GRAVES’ DISEASE WITH SODIUM IODIDE-131

    Directory of Open Access Journals (Sweden)

    I Wayan Hartadi Noor

    2013-11-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Graves’ disease is the most common form of thyrotoxicosis, with a peak incidence in the 20-40 year of age group. Females are involved about five times more commonly than male. The easiest sign to recognize patients with Graves’ disease is the present of Graves’ ophthalmopathy. The diagnosis of Graves’ disease may sometimes base only on a physical examination and a medical history. Diffuse thyroid enlargement and sign of thyrotoxicosis, mainly ophthalmopathy and to lesser extent dermopathy, usually adequate for diagnosis. TSH test combined with FT4 test is usually the first laboratory test performs in these patients. The patients suffered Graves’ disease can be treated with antithyroid drug therapy or undergo subtotal Thyroidectomy. Another therapy is by using sodium iodide-131, where this therapy has advantages including easy administration, effectiveness, low expense, and absence of pain. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  17. Imaging with polycrystalline mercuric iodide detectors using VLSI readout

    Energy Technology Data Exchange (ETDEWEB)

    Turchetta, R.; Dulinski, W.; Husson, D.; Riester, J.L.; Schieber, M.; Zuck, A.; Melekhov, L.; Saado, Y.; Hermon, H.; Nissenbaum, J

    1999-06-01

    Potentially low cost and large area polycrystalline mercuric iodide room-temperature radiation detectors, with thickness of 100-600 {mu}m have been successfully tested with dedicated low-noise, low-power mixed signal VLSI electronics which can be used for compact, imaging solutions. The detectors are fabricated by depositing HgI{sub 2} directly on an insulating substrate having electrodes in the form of microstrips and pixels with an upper continuous electrode. The deposition is made either by direct evaporation or by screen printing HgI{sub 2} mixed with glue such as Poly-Vinyl-Butiral. The properties of these first-generation detectors are quite uniform from one detector to another. Also for each single detector the response is quite uniform and no charge loss in the inter-electrode space have been detected. Because of the low cost and of the polycrystallinity, detectors can be potentially fabricated in any size and shape, using standard ceramic technology equipment, which is an attractive feature where low cost and large area applications are needed. The detectors which act as radiation counters have been tested with a beta source as well as in a high-energy beam of 100 GeV muons at CERN, connected to VLSI, low noise electronics. Charge collection efficiency and uniformity have been studied. The charge is efficiently collected even in the space between strips indicating that fill factors of 100% could be reached in imaging applications with direct detection of radiation. Single photon counting capability is reached with VLSI electronics. These results show the potential of this material for applications demanding position sensitive, radiation resistant, room-temperature operating radiation detectors, where position resolution is essential, as it can be found in some applications in high-energy physics, nuclear medicine and astrophysics.

  18. Excess Barium as a Paleoproductivity Proxy: A Reevaluation

    Science.gov (United States)

    Eagle, M.; Paytan, A.

    2001-12-01

    Marine barite may serve as a proxy to reconstruct past export production (Dymond, 1992). In most studies sedimentary barite accumulation is not measured directly, instead a parameter termed excess barium (Baexs), also referred to as biogenic barium, is used to estimate the barite content. Baexs is defined as the total Ba concentration in the sediment minus the Ba associated with terrigenous material. Baexs is calculated by normalization to a constant Ba/Al ratio, typically the average shale ratio. This application assumes that (1) all the Ba besides the fraction associated with terrigenous Al is in the form of barite (the phase related to productivity) (2) the Ba/Alshale is constant in space and time (3) all of the Al is associated with terrigenous matter. If these assumptions are invalidated however, this approach lead to significant errors in calculating export production rates. To test the validity of the use of Baexs as a proxy for barite we compared the Baexs in a wide range of core top sediments from different oceanic settings to the barite content in the same cores. We found that Baexs frequently overestimated the Ba fraction associated with barite and in several cases significant Baexs was measured in the cores where no barite was observed. We have also used a sequential leaching protocol (Collier and Edmond 1984) to determine Ba association with organic matter, carbonates, Fe-Mn hydroxides and silicates. While terrigenous Ba remains an important fraction, in our samples 25-95% of non-barite Ba was derived from other fractions, with Fe-Mn oxides contributing the most Ba. In addition we found that the Ba/Al ratio in the silicate fraction of our samples varied considerably from site to site. The above results suggest that at least two of the underlying assumptions for employing Baexs to reconstruct paleoproductivity are not always valid and previously published data from (Murray and Leinen 1993) indicate that the third assumption may also not hold in every

  19. Enthalpy of formation of (In, Gd)-doped barium cerate

    Energy Technology Data Exchange (ETDEWEB)

    Matskevich, N.I., E-mail: nata.matskevich@yandex.ru [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk (Russian Federation); Karlsruhe Institute of Technology, Institute of Solid State Physics, D-76334 Karlsruhe (Germany); Wolf, Th. [Karlsruhe Institute of Technology, Institute of Solid State Physics, D-76334 Karlsruhe (Germany); Adelmann, P.; Semerikova, A.N.; Anyfrieva, O.I. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk (Russian Federation)

    2015-09-10

    Highlights: • BaCe{sub 0.7}Gd{sub 0.2}In{sub 0.1}O{sub 2.85} was prepared by solid-state reaction. • The standard formation enthalpy was determined. • The stabilization energy (Δ{sub st}H°) was calculated. • Δ{sub st}H° of BaCe{sub 0.7}Gd{sub 0.2}In{sub 0.1}O{sub 2.85} is higher than BaCe{sub 0.7}Nd{sub 0.2}In{sub 0.1}O{sub 2.85} and BaCeO{sub 3}. - Abstract: Solution enthalpies of barium cerate doped by gadolinium and indium and a mixture of BaCl{sub 2} + 0.7CeCl{sub 3} + 2GdCl{sub 3} + 0.1InCl{sub 3} have been measured in 1 mol dm{sup −3} HCl with 0.1 mol dm{sup −3} KI. For the first time the standard molar formation enthalpy of BaCe{sub 0.7}Gd{sub 0.2}In{sub 0.1}O{sub 2.85} has been determined by solution calorimetry as follows: Δ{sub f}H° (298.15 K) = −1615.84 ± 9.01 kJ mol{sup −1}. The stabilization energy for above-mentioned compound has been calculated as well. It has been shown that barium cerate doped gadolinium and indium has higher stabilization energy than BaCe{sub 0.7}Nd{sub 0.2}In{sub 0.1}O{sub 2.85} and BaCeO{sub 3}. The reaction enthalpy with CO{sub 2} interaction has been calculated for BaCe{sub 0.7}Gd{sub 0.2}In{sub 0.1}O{sub 2.85}.

  20. Retinoic acid induces sodium/iodide symporter gene expression and radioiodide uptake in the MCF-7 breast cancer cell line

    OpenAIRE

    Kogai, Takahiko; Schultz, James J.; Johnson, Laura S.; Huang, Min; Brent, Gregory A.

    2000-01-01

    The sodium/iodide symporter (NIS) stimulates iodide uptake in normal lactating breast, but is not known to be active in nonlactating breast or breast cancer. We studied NIS gene regulation and iodide uptake in MCF-7 cells, an estrogen receptor (ER)-positive human breast cancer cell line. All-trans retinoic acid (tRA) treatment stimulated iodide uptake in a time- and dose-dependent fashion up to ≈9.4-fold above baseline. Stimulation with selective retinoid compounds indicated that the inductio...

  1. Mechanism of Phase Transformation and Formation of Barium Hexaferrite Doped with Rare-Earths in Sol-Gel Process

    Institute of Scientific and Technical Information of China (English)

    甘树才; 洪广言; 张军; 车平; 唐娟

    2003-01-01

    The phase-transformation in sol-gel preparation of barium hexaferrite and the formation of barium hexaferrite doped with La3+ were studied by chemical phase analysis, X-ray diffraction and infrared spectrometry analysis. The experimental results show that phase transformation reactions of FeCO3, Fe2O3 and BaFe2O4, barium hexaferrite and γ-Fe2O3 take place in the heat treatment of gel. While the doping lanthanide ion replace barium ion, an equivalent quantity of Fe3+ are reduced to Fe2+ to maintain the charge equilibrium.

  2. Trapping radiodine, in the form of methyl iodide, on nuclear carbon

    Energy Technology Data Exchange (ETDEWEB)

    Nacapricha, D. [Mahidol Univ., Bangkok (Thailand); Taylor, C. [John Moores Univ., Liverpool (United Kingdom)

    1996-12-31

    Studies have been performed on potassium-iodide-impregnated charcoals of the type used in the nuclear industry for trapping radioiodine released during nuclear fission. The effects of various parameters on the trapping efficiency of methyl iodide have been investigated. A variation in particle size within a bulk charcoal caused poor precision in K value measurements because of differences in surface area, pore volume, and bed density, leading to differences in the deposition of the impregnant. Precision is improved by sieving the charcoal to a narrower size because smaller particles have a higher porosity. This finding is supported by surface area and pore measurements. Two methods of impregnation are compared by measuring K values and the deposition of potassium iodide. Charcoal impregnated by rotary evaporation exhibits both higher K values and higher potassium iodide contents than sprayed charcoal. Two designs of spraying drum are compared: a drum with helical vanes allows more efficient deposition and more uniform distribution of impregnant than a drum with axial vanes. A decrease in the K value with increasing humidity correlates with the available surface area. A similar correlation exists between water content and available pore volume. Aging of potassium-iodide-impregnated charcoal, caused by the formation of oxygen complexes on the surface, is associated with significant falls in K value. K values of charcoals also can be restored to at least their original values by heat treatment in the absence of air. 12 refs., 6 figs., 1 tab.

  3. Processes of adsorption/desorption of iodides and cadmium cations onto/from Ag(111

    Directory of Open Access Journals (Sweden)

    VLADIMIR D. JOVIĆ

    2011-02-01

    Full Text Available In this work, the adsorption/desorption processes of iodides and cadmium cations in the presence of iodides onto/from Ag(111 were investigated. It was shown that both processes were complex, characterized by several peaks on the cyclic voltammograms (CVs. By PeakFit analysis of the recorded CVs and subsequent fitting of the obtained peaks by the Frumkin adsorption isotherm, the interaction parameter (f and the Gibbs energy of adsorption (DGads for each adsorbed phase were determined. In the case of iodide adsorption, four peaks were characterized by negative values of f, indicating attractive lateral interaction between the adsorbed anions, while two of them possessed value of f < –4, indicating phase transition processes. The adsorption/desorption processes of cadmium cations (underpotential deposition – UPD of cadmium in the presence of iodide anions was characterized by two main peaks, each of them being composed of two or three peaks with negative values of f. By the analysis of charge vs. potential dependences obtained either from the CVs or current transients on potentiostatic pulses, it was concluded that adsorbed iodides did not undergo desorption during the process of Cd UPD, but became replaced by Cd ad-atoms and remained adsorbed on top of a Cd layer and/or in between Cd the ad-atoms.

  4. [Determination of iodide, thiocyanate and perchlorate ions in environmental water by two-dimensional ion chromatography].

    Science.gov (United States)

    Lin, Li; Wang, Haibo; Shi, Yali

    2013-03-01

    A procedure for the determination of iodide, thiocyanate and perchlorate ions in environmental water by two-dimensional ion chromatography has been developed. At first the iodide, thiocyanate and perchlorate ions were separated from interfering ions by a column (IonPac AS16, 250 mm x 4 mm). The iodide ion, thiocyanate and perchlorate ions were then enriched with an enrichment column (MAC-200, 80 mm x 0.75 mm). In the 2nd-dimensional chromatography, iodide thiocyanate and perchlorate ions were separated and quantified by a capillary column (IonPac AS20 Capillary, 250 mm x 0.4 mm). The linear ranges were 0.05 -100 pg/L with correlation coefficients of 0. 999 9, and the detection limits were 0. 02 - 0.05 micro gg/L. The spiked recoveries of iodide, thiocyanate and perchlorate ions were in the range of 85.1% to 100.1%. The relative standard deviations of the recoveries were 1.7% to 4.9%.

  5. Proton and iodine-127 nuclear magnetic resonance studies on the binding of iodide by lactoperoxidase

    Energy Technology Data Exchange (ETDEWEB)

    Sakurada, J.; Takahashi, S.; Shimizu, T.; Hatano, M.; Nakamura, S.; Hosoya, T.

    1987-10-06

    Interaction of an iodide ion with lactoperoxidase was studied by the use of /sup 1/H NMR, /sup 127/I NMR, and optical difference spectrum techniques. /sup 1/H NMR spectra demonstrated that a major broad hyperfine-shifted signal at about 60 ppm, which is ascribed to the heme peripheral methyl protons, was shifted toward high field by adding KI, indicating the binding of iodide to the active site of the enzyme; the dissociation constant was estimated to be 38 mM at pH 6.1. The binding was further detected by /sup 127/I NMR, showing no competition with cyanide. Both /sup 1/H NMR and /sup 127/I NMR revealed that the binding of iodide to the enzyme is facilitated by the protonation of an ionizable group with a pK/sup a/ value of 6.0-6.8, which is presumably the distal histidyl residue. Optical difference spectra showed that the binding of an aromatic donor molecule to the enzyme is slightly but distinctly affected by adding KI. On the basis of these results, it was suggested that an iodide ion binds to lactoperoxidase outside the heme crevice but at the position close enough to interact with the distal histidyl residue which possibly mediates electron transport in the iodide oxidation reaction.

  6. Alpha-lipoic acid induces sodium iodide symporter expression in TPC-1 thyroid cancer cell line

    International Nuclear Information System (INIS)

    Introduction: Patients with metastatic thyroid cancers that do not uptake iodine need effective therapeutic option. Differentiation-inducing agents have been tried to restore functional expression of sodium iodide symporter (NIS) without success. Our objective was to assess the effect of alpha-lipoic acid (ALA), known as potential antioxidant, on expression of sodium iodide symporter in thyroid cancer cells. Methods: Human thyroid cancer-derived cell lines, TPC-1, were treated with ALA, and changes in NIS mRNA and protein expression were measured. ALA's effect on NIS gene promoter was evaluated, and functional NIS expression was assessed by iodide uptake assay. Results: Treatment with ALA increased NIS mRNA expression up to ten folds of control dose-dependently after 24 h of exposure. ALA increased NIS promoter activity, and increased iodide uptake by 1.6 fold. ALA induced expression of NIS protein, but had no significant effect on the plasma membrane trafficking. ALA increased phosphorylation of CREB and nuclear translocation of pCREB, and co-treatment of ALA and trichostatin A increased iodide uptake by three folds in TPC-1 cells. Conclusions: ALA is a potential agent to increase NIS transcription in TPC-1. It could be used as an adjunctive agent to increase efficacy of radioiodine therapy if combined with a strategy to increase NIS protein trafficking to cell membrane.

  7. Barium oxide, calcium oxide, magnesia, and alkali oxide free glass

    Science.gov (United States)

    Lu, Peizhen Kathy; Mahapatra, Manoj Kumar

    2013-09-24

    A glass composition consisting essentially of about 10-45 mole percent of SrO; about 35-75 mole percent SiO.sub.2; one or more compounds from the group of compounds consisting of La.sub.2O.sub.3, Al.sub.2O.sub.3, B.sub.2O.sub.3, and Ni; the La.sub.2O.sub.3 less than about 20 mole percent; the Al.sub.2O.sub.3 less than about 25 mole percent; the B.sub.2O.sub.3 less than about 15 mole percent; and the Ni less than about 5 mole percent. Preferably, the glass is substantially free of barium oxide, calcium oxide, magnesia, and alkali oxide. Preferably, the glass is used as a seal in a solid oxide fuel/electrolyzer cell (SOFC) stack. The SOFC stack comprises a plurality of SOFCs connected by one or more interconnect and manifold materials and sealed by the glass. Preferably, each SOFC comprises an anode, a cathode, and a solid electrolyte.

  8. Removal of uranyl ions from aqueous solutions using barium titanate

    International Nuclear Information System (INIS)

    Remediation of water sources contaminated with radioactive waste products is a major environmental issue that demands new and more efficient technologies. For this purpose, we report a highly efficient ion-exchange material for the removal of radioactive nuclides from aqueous solutions. The kinetic characteristics of adsorption of uranyl ions on the surface of barium titanate were investigated using a spectrophotometric method under a wide range of conditions. By controlling the pH it was possible to exert fine control over the speciation of uranium, and by optimizing the temperature and grain size of the exchanger, almost total removal was achieved in a matter of just hours. The highest efficiency (>90 % removal) was realized at high temperature (80 deg C). Moreover, the effect of competitive ion adsorption from a range of different cations and anions was quantified. Adsorption was found to follow first-order kinetics and both Freundlich and Langmuir isotherms could be applied to this system. The results of a mathematical treatment of the kinetic data combined with the observation that adsorption was independent of stirring speed and dependent on the ion-exchanger grain size, indicate that the dominant mechanism influencing adsorption is particle spreading. The adsorption behavior was not influenced by exposure to high-intensity gamma radiation, indicating potential for use of this ion-exchanger in systems containing radioactive material. These results will be of use in the development of uranium extraction systems for contaminated water sources. (author)

  9. Colonic diverticulosis: evaluation with double contrast barium enema

    International Nuclear Information System (INIS)

    To evaluate the pattern of colonic diverticulosis according to age and sex, and recent trend. The authors retrospectively reviewed 120 cases of colonic diverticulosis in 1,020 patients who had undergone a double contrast barium enema examination between January 1st, 1993, and December 31st, 1995, and analyzed the frequency, size, multiplicity and anatomical site, according to age and sex. Diverticulum size was classified into one of three groups : less than 5mm, 5-10mm, over 10mm in diameter. The overall incidence of colonic diverticulosis was 120 cases among 1,020 patients(11.8%) with an incidence 5.3 times higher in males than in females. Peak incidence was in the fifth decade, with 19 cases (15.8%) among males, and after the sixth decade, with four cases(3.3%) among females. Mean age was 57.7 years. Diverticulum size of 5-10mm in diameter was predominant (2% of cases); average diameter was 5-6mm. The incidence of colonic diverticulosis was 5.1 times more frequent in the right colon (101 cases) than in the left (20 cases). The overall incidence of colonic diverticulosis has continually increased; in addition it has also recently increased slightly in left-sided colon. This is thought to be due to various factors, both congenital and acquired, including longer life with good health care, constipation, irritable bowel syndrome, stress and the tendency of eating patterns to more closely resemble those of the west

  10. Abundance analysis of s-process enhanced barium stars

    Science.gov (United States)

    Mahanta, Upakul; Karinkuzhi, Drisya; Goswami, Aruna; Duorah, Kalpana

    2016-08-01

    Detailed chemical composition studies of stars with enhanced abundances of neutron-capture elements can provide observational constraints for neutron-capture nucleosynthesis studies and clues for understanding their contribution to the Galactic chemical enrichment. We present abundance results from high-resolution spectral analyses of a sample of four chemically peculiar stars characterized by s-process enhancement. High-Resolution spectra (R ˜42000) of these objects spanning a wavelength range from 4000 to 6800 Å, are taken from the ELODIE archive. We have estimated the stellar atmospheric parameters, the effective temperature Teff, the surface gravity log g, and metallicity [Fe/H] from local thermodynamic equilibrium analysis using model atmospheres. We report estimates of elemental abundances for several neutron-capture elements, Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy. While HD 49641 and HD 58368 show [Ba/Fe] ≥ 1.16 the other two objects HD 119650 and HD 191010 are found to be mild barium stars with [Ba/Fe] ˜ 0.4. The derived abundances of the elements are interpreted on the basis of existing theories for understanding their origin and evolution.

  11. Structural and magnetic properties of barium-gadolinium hexaferrites

    Energy Technology Data Exchange (ETDEWEB)

    Litsardakis, G. [Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)]. E-mail: Lits@eng.auth.gr; Manolakis, I. [Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Serletis, C. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Efthimiadis, K.G. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)

    2007-03-15

    A series of Gd-substituted M-type barium hexaferrites has been prepared by the ceramic route, according to the formula (Ba{sub 1-x}Gd{sub x})O.5.25Fe{sub 2}O{sub 3} (x=0-0.30). XRD analysis revealed that all the samples present primarily an M-type structure. Samples x=0 and x=0.05 are single-phase. Hematite (Fe{sub 2}O{sub 3}) and GdFeO{sub 3} were detected in the remaining samples. Coercivity (H{sub c}) shows remarkably high values, {approx}293kA/m for x=0.20 and 0.30 with a maximum of 322kA/m for x=0.25. Specific saturation magnetization ({sigma}{sub sat}) of the samples presents a small increase up to x=0.10. The microstructure examination indicates that Gd may act as a grain growth inhibitor.

  12. Nanoscale inhomogeneities in yttrium-barium-copper-oxide (YBCO) superconductors

    Science.gov (United States)

    Islam, Zahirul; Sinha, S. K.; Lang, J. C.; Liu, X.; Haskel, D.; Moss, S. C.; Srajer, G.; Veal, B. W.; Wermeille, D.; Lee, D. R.; Haeffner, D. R.; Welp, U.; Wochner, P.

    2004-03-01

    X-ray diffraction studies at the Advanced Photon Source reveal that nanoscale inhomogeneities, electronic or structural in origin, form in yttrium-barium-copper-oxide (YBa_2Cu_3O_6+x) superconductors and coexist with the superconducting (SC) state. Diffuse scattering from these inhomogeneous superstructures is due to atomic displacements with respect to equilibrium lattice sites (Z. Islam et al. Phys. Rev. B 66, 92501 (2002)), that are characterized by a wavevector of the form q=(q_x,0,0), where qx varies with hole doping from 2 unit cells (along shorter Cu-O-Cu direction) for very low doping to 4 unit cells at optimal doping. Interestingly, while these superstructures are 3-dimensionally ordered when the SC state is weakened (e.g., at x=0.4), as the doping increases, they become quasi 1D with correlation lengths comparable to SC coherence lengths in these cuprates. Recent first-principles calculations (D. de Fontaine et al., to be published) for the x=0.63 compound show that atomic displacements consistent with experimental data can be the result of ordering of O vacancies in YBCO. Models for various superstructures and their role in the phase diagram will be discussed.

  13. Properties of barium strontium titanate at millimeter wave frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Osman, Nurul [Department of Physics, Universiti Putra Malaysia (Malaysia); Free, Charles [Department of Engineering and Design, University of Sussex (United Kingdom)

    2015-04-24

    The trend towards using higher millimetre-wave frequencies for communication systems has created a need for accurate characterization of materials to be used at these frequencies. Barium Strontium Titanate (BST) is a ferroelectric material whose permittivity is known to change as a function of applied electric field and have found varieties of application in electronic and communication field. In this work, new data on the properties of BST characterize using the free space technique at frequencies between 145 GHz and 155 GHz for both thick film and bulk samples are presented. The measurement data provided useful information on effective permittivity and loss tangent for all the BST samples. Data on the material transmission, reflection properties as well as loss will also be presented. The outcome of the work shows through practical measurement, that BST has a high permittivity with moderate losses and the results also shows that BST has suitable properties to be used as RAM for high frequency application.

  14. Properties of barium strontium titanate at millimeter wave frequencies

    International Nuclear Information System (INIS)

    The trend towards using higher millimetre-wave frequencies for communication systems has created a need for accurate characterization of materials to be used at these frequencies. Barium Strontium Titanate (BST) is a ferroelectric material whose permittivity is known to change as a function of applied electric field and have found varieties of application in electronic and communication field. In this work, new data on the properties of BST characterize using the free space technique at frequencies between 145 GHz and 155 GHz for both thick film and bulk samples are presented. The measurement data provided useful information on effective permittivity and loss tangent for all the BST samples. Data on the material transmission, reflection properties as well as loss will also be presented. The outcome of the work shows through practical measurement, that BST has a high permittivity with moderate losses and the results also shows that BST has suitable properties to be used as RAM for high frequency application

  15. Combustion synthesis, characterization and luminescence properties of barium aluminate phosphor

    Institute of Scientific and Technical Information of China (English)

    AH Wako; FB Dejene; HC Swart

    2014-01-01

    The blue-green emitting Eu2+and Nd3+ doped polycrystalline barium aluminate (BaAl2O4:Eu2+,Nd3+) phosphor, was pre-pared by a solution-combustion method at 500 ºC without a post-annealing process. The characteristic variation in the structural and luminescence properties of the as-prepared samples was evaluated with regards to a change in the Ba/Al molar ratio from 0.1:1 to 1.4:1. The morphologies and the phase structures of the products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), while the optical properties were investigated using ultra-violet (UV) and photoluminescence (PL) spectroscopy, respectively. The XRD and TEM results revealed that the average crystallite size of the BaAl2O4:Eu2+,Nd3+ phosphor was about 70 nm. The broad-band UV-excited luminescence of the phosphors was observed atλmax=500 nm due to transitions from the 4f65d1 to the 4f7 configuration of the Eu2+ ion. The PL results indi-cated that the main peaks in the emission and excitation spectrum of phosphor particles slightly shifted to the short wavelength due to the changes in the crystal field due to the structure changes caused by the variation in the quantity of the Ba ions in the host lattice.

  16. Colonic diverticulosis: evaluation with double contrast barium enema

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Jae Kook; Lee, Jong Koo; Yun, Eun Joo; Moon, Hee Jung; Shin, Hyun Ja [Korea Veterans Hospital, Seoul (Korea, Republic of)

    1997-02-01

    To evaluate the pattern of colonic diverticulosis according to age and sex, and recent trend. The authors retrospectively reviewed 120 cases of colonic diverticulosis in 1,020 patients who had undergone a double contrast barium enema examination between January 1st, 1993, and December 31st, 1995, and analyzed the frequency, size, multiplicity and anatomical site, according to age and sex. Diverticulum size was classified into one of three groups : less than 5mm, 5-10mm, over 10mm in diameter. The overall incidence of colonic diverticulosis was 120 cases among 1,020 patients(11.8%) with an incidence 5.3 times higher in males than in females. Peak incidence was in the fifth decade, with 19 cases (15.8%) among males, and after the sixth decade, with four cases(3.3%) among females. Mean age was 57.7 years. Diverticulum size of 5-10mm in diameter was predominant (2% of cases); average diameter was 5-6mm. The incidence of colonic diverticulosis was 5.1 times more frequent in the right colon (101 cases) than in the left (20 cases). The overall incidence of colonic diverticulosis has continually increased; in addition it has also recently increased slightly in left-sided colon. This is thought to be due to various factors, both congenital and acquired, including longer life with good health care, constipation, irritable bowel syndrome, stress and the tendency of eating patterns to more closely resemble those of the west.

  17. Barium in landscape components of the western Transbaikal region

    Science.gov (United States)

    Kashin, V. K.

    2015-10-01

    Barium concentrations in parent materials, soils, and plants of the forest-steppe, steppe, and dry steppe landscapes of the Transbaikal region have been studied. The average concentration of this element in rocks and soils of this region exceeds its clarke by 1.8-2.1 times. A positive correlation between the contents of Ba in soils, soil-forming rocks, and plants has been found. The concentration of Ba in soils does not correlate with the soil pH and humus content. Distribution patterns of Ba in the soil profiles have been characterized. With respect to the coefficient of the biological uptake by plants, Ba is assigned to the group of low accumulation (0.55-0.65) for mineral soils and of strong accumulation (6.0) for alluvial bog soils. Average concentrations of Ba in the steppe, meadow, and cultivated vegetation of the region are 1.9-2.3 times higher in comparison with the average concentration of this element in plants of the continents. The biological migration of Ba is most active in meadow landscapes, whereas steppe landscapes are characterized by the least active biological migration of this element.

  18. Abundance analysis of s-process enhanced barium stars

    CERN Document Server

    Mahanta, Upakul; Goswami, Aruna; Duorah, Kalpana

    2016-01-01

    Detailed chemical composition studies of stars with enhanced abundances of neutron-capture elements can provide observational constraints for neutron-capture nucleosynthesis studies and clues for understanding their contribution to the Galactic chemical enrichment. We present abundance results from high-resolution spectral analyses of a sample of four chemically peculiar stars characterized by s-process enhancement. High-Resolution spectra (R ~ 42000) of these objects spanning a wavelength range from 4000 to 6800 A, are taken from the ELODIE archive. We have estimated the stellar atmospheric parameters, the effective temperature T_eff, the surface gravity log g, and metallicity [Fe/H] from local thermodynamic equilibrium analysis using model atmospheres. We report estimates of elemental abundances for several neutron-capture elements, Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy. While HD 49641 and HD 58368 show [Ba/Fe] > 1.16 the other two objects HD 119650 and HD 191010 are found to be mild barium stars wit...

  19. Gastrointestinal tract labeling for MDCT of abdomen: Comparison of low density barium and low density barium in combination with water

    Energy Technology Data Exchange (ETDEWEB)

    Gulati, Kavita; Shah, Zarine K.; Sainani, Nisha; Uppot, Raul; Sahani, Dushyant V. [Massachusetts General Hospital and Harvard Medical School, Department of Abdominal Imaging and Intervention, Boston, MA (United States)

    2008-05-15

    The purpose of the study was to compare the quality of stomach and small bowel marking/labeling using 1,350 ml of low-density barium alone (Volumen) with 900 ml of low-density barium and 450 ml of water for 16-MDCT scans of the abdomen and pelvis and assess cost benefits with the two protocols. In this IRB approved study, 80 consecutive patients scheduled for routine CECT (contrast-enhanced CT) of the abdomen-pelvis were studied. Patients were randomized into two groups and were administered either 1,350 ml of VoLumen (two bottles at 20-min intervals, one half bottle at 50 min and the last half on the table) or 900 ml of Volumen (two bottles at 20-min intervals and 450 ml water on the table). Portal venous phase scanning (detector collimation = 0.625 mm, speed = 18.75 mm, thickness = 5 mm) was subsequently performed. Images were reconstructed in axial and coronal plane at the CT console. Two blinded readers used a pre-designed template to assess distension and wall characteristics of the stomach and small bowel on a 5-point scale. Median scores with the two protocols were compared using the Wilcoxon rank sum test. The stomach and small bowel labeling was rated fair to optimal in all patients and did not differ significantly in the two protocols. The mean scores for distension of the small bowel and stomach were comparable. Inter-observer agreement for bowel labeling was found to be excellent (k 0.81). With the use of coronal images there was increased reader confidence in tracing the small bowel with both protocols. Acceptance for two bottles of Volumen and water was greater among patients as compared to three bottles of VoLumen. Use of two bottles of Volumen and water combination cost less than three bottles of Volumen. Stomach and small bowel labeling with administration of 900 ml of Volumen followed by 450 ml of water is cost effective and compares well to 1,350 ml of Volumen alone. (orig.)

  20. Skylab-barium alpha and beta L = 6 field-line tracing experiments

    International Nuclear Information System (INIS)

    Events SKYLAB-BARIUM ALPHA (27 November 1973) and BETA (4 December 1973) were shaped-charge barium field-line tracing experiments near L approximately equal to 6, conducted jointly by the Los Alamos Scientific Laboratory and the University of Alaska Geophysical Institute. Image-orthicon and pulsed intensified auroral cameras provided data for triangulating the fast ion streaks. Using the POGO 10-68, epoch 1965.0, field-line model with Mead-Fairfield corrections for the outer field, the triangulated positions of the fast ion streak were projected down to the 100 km altitude northern conjugate surface. The projected positions moved toward magnetic east with a velocity of 725 m/sec for both SKYLAB-BARIUM ALPHA and BETA. Assuming only an E x B/B2 force, this drift velocity is consistent with an electric field toward magnetic south of 39 mV/m. Radiometric analysis of the filtered, intensified auroral camera records gave observed peak radiance values of about 2 x 10-11 watts/cm2-Sr in the 455.4 nm line of Ba+. The barium in the portion of the ion streak for which radiometric data were obtained had initial injection velocities of 9.5 to 13.5 km/sec in both events. This portion of the ion streak for both SKYLAB-BARIUM ALPHA and BETA contained approximately 4 x 1023 ions compared to the 6.4 x 1024 atoms contained in the barium liner. Ion inventory estimates are based on a solution of the statistical equilibrium equations. Corrections have been made in the ion inventory calculations for Doppler shifts of the solar spectrum as received in the rest frame of the high-velocity barium ions

  1. Accelerating the transit time of barium sulphate suspensions in small bowel examinations

    International Nuclear Information System (INIS)

    Purpose: To determine whether hyperosmolar and effervescent agents proven individually to accelerate transit time in the barium small bowel examination have an additive effect when combined, surpassing that of either agent alone. Materials and methods: One hundred and forty-nine patients were randomised to four groups. Three hundred milliliters of barium sulphate alone was given to the first group. Fifteen milliliters of iodinated hyperosmolar contrast agent (Gastrografin, meglumine/sodium diatrizoate, Schering) was given in addition to barium sulphate to the second group while six packets of effervescent granules (Carbex, Ferring) were added for the third group. The final group was given a combination of both additives and barium sulphate. The time taken following ingestion for the contrast column to reach the caecum, as assessed by frequent interval fluoroscopy, was recorded. A subgroup of 32 patients were selected randomly from the four groups, 8 from each and assessed for quality of examination. Statistical assessments were made using Kruskal-Wallis and Mann-Whitney tests. Results: One hundred and nineteen patients were analysed after exclusions. The addition of accelerant to barium sulphate, both individually and in combination significantly reduced the small bowel transit time (p < 0.001). No significant difference existed between the additives when used with barium alone. The combined group had significantly faster transit times compared to the hyperosmolar group (p = 0.02). Differences between combined and effervescent groups tended towards significance (p = 0.09). No significant difference existed between groups when examination quality was assessed. Conclusion: These results suggest that the addition of combined effervescent and hyperosmolar agents to the barium suspension may significantly shorten the small bowel transit time without adversely affecting examination quality. This has implications for patient acceptability of the examination as well as

  2. An 8-year review of barium studies in the diagnosis of gastroparesis

    Energy Technology Data Exchange (ETDEWEB)

    Levin, A.A. [Department of Radiology, Hospital of University of Pennsylvania, Philadelphia, PA (United States); Levine, M.S. [Department of Radiology, Hospital of University of Pennsylvania, Philadelphia, PA (United States)], E-mail: marc.levine@uphs.upenn.edu; Rubesin, S.E.; Laufer, I. [Department of Radiology, Hospital of University of Pennsylvania, Philadelphia, PA (United States)

    2008-04-15

    Aim: To determine the utility of barium studies for diagnosing gastroparesis in patients with nausea, vomiting, or other related symptoms. Materials and methods: Radiology files revealed gastroparesis without gastric outlet obstruction on upper gastrointestinal tract barium studies in 50 patients with nausea, vomiting, and other related symptoms. Original reports and images were reviewed to determine whether gastric peristalsis was decreased/absent and to investigate gastric dilatation, fluid or debris, and delayed emptying of barium. Twenty patients (40%) had nuclear gastric emptying studies. Medical records were reviewed to determine the presentation, treatment, and course. The diagnosis of gastroparesis was considered accurate if patients with gastroparesis on barium studies responded to treatment. Results: Forty-six patients (92%) had predisposing factors for gastroparesis, including narcotics and diabetes. Forty-five patients (90%) presented with nausea or vomiting, and 40 patients (80%) had one or more other symptoms, including bloating, early satiety, postprandial fullness, and abdominal pain. Barium studies revealed decreased gastric peristalsis in 46 (92%) of the 50 patients and absent peristalsis in four (8%); 46 patients (92%) had additional findings, including gastric dilatation in 30 (60%), delayed emptying of barium in 27 (54%), debris in 28 (56%; bezoars in three), and retained fluid in 13 (26%). Thirteen (65%) of 20 patients with nuclear gastric emptying studies had delayed emptying of solids and seven (35%) had normal emptying. Thirty-five (83%) of 42 patients treated for gastroparesis had symptomatic improvement versus two (25%) of eight patients not treated. Conclusion: Patients with nausea, vomiting, or other related symptoms who have gastroparesis without gastric outlet obstruction on barium studies can be treated for this condition on the basis of the clinical and radiographic findings.

  3. Preparation and properties of yttria doped tetragonal zirconia polycrystal/Sr-doped barium hexaferrite ceramic composites

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shanshan; Zhang, Chao; Guo, Ruisong, E-mail: rsguo@tju.edu.cn; Liu, Lan; Yang, Yuexia; Li, Kehang

    2015-03-15

    Highlights: • The 3Y-TZP/Sr-doped barium ferrite composites were prepared. • The saturation magnetization was improved by 15% with Sr-doping. • The dispersion coefficient p could reflect the microscopic lattice variation. • The composite with x = 0.5 had the maximum fracture toughness of 8.3 MPa m{sup 1/2}. - Abstract: The effects of substitution of Ba{sup 2+} by Sr{sup 2+} on the magnetic property of barium ferrite and addition barium ferrite secondary phase to the 3 mol% yttria-doped tetragonal zirconia polycrystal (3Y-TZP) matrix on the mechanical property of composites were investigated. The Sr-doped barium ferrite (Ba{sub 1−x}Sr{sub x}Fe{sub 12}O{sub 19}, x = 0, 0.25, 0.50 and 0.75) was synthesized by solid-state reaction in advance. Then 3Y-TZP/20 wt% Sr-doped barium ferrite composites were prepared by means of conventional ceramic method. It was found that a moderate amount of Sr added to barium ferrite could boost the saturation magnetization by 15% compared with the composites without Sr-doping. Besides, the composite with x = 0.50 possessed the best mechanical properties, such as 11.5 GPa for Vickers hardness and 8.3 MPa m{sup 1/2} for fracture toughness, respectively. It was demonstrated that magnetic and mechanical properties of the composites could be harmonized by the incorporation of barium ferrite secondary phase.

  4. Obtaining of a barium compound by combustion chemistry and their evaluation as Co adsorbent

    International Nuclear Information System (INIS)

    In this work, barium carbonate synthesized by chemical combustion method using a chemical precursor prepared by the combination of barium nitrate and urea as a fuel, with a 1:1 molar ratio in aqueous solution, the chemical precursor was heated to evaporate excess water, producing a homogeneous viscous liquid, that when heated to 900 centi grades for 5 minutes an exothermic reaction was produced very quickly and abruptly, forming a white powder final product, fine porous, little spongy, dry and crystalline ready to be used as material adsorbent. Additionally, the effect of water on the synthesis by chemical combustion was studied. Simultaneously, and with the purpose of comparing the advantages and disadvantages of the method by chemical combustion, barium carbonate was synthesized by precipitation method using barium nitrate salts and sodium carbonate. Synthesized barium carbonate, was characterized by X-ray diffraction, thermal gravimetric analysis, infrared spectrometry and scanning electron microscopy. We studied the adsorption capacity of Co present in aqueous solution by static tests on materials synthesized at room temperature using the neutron activation analysis. It was found that the synthesis by chemical combustion provides an interesting alternative compared to the synthesis by precipitation because it offers simplicity of synthesis and speed to have a good adsorbent material. It was found that the barium carbonate synthesized by the chemical combustion method using in their synthesis 1.0 ml of water, was the one who achieved the maximum adsorption capacity of 95.6% compared with the barium carbonate prepared by precipitation, which reached a capacity adsorption of 51.48%. (Author)

  5. X-ray imaging performance of structured cesium iodide scintillators.

    Science.gov (United States)

    Zhao, Wei; Ristic, Goran; Rowlands, J A

    2004-09-01

    Columnar structured cesium iodide (CsI) scintillators doped with Thallium (Tl) have been used extensively for indirect x-ray imaging detectors. The purpose of this paper is to develop a methodology for systematic investigation of the inherent imaging performance of CsI as a function of thickness and design type. The results will facilitate the optimization of CsI layer design for different x-ray imaging applications, and allow validation of physical models developed for the light channeling process in columnar CsI layers. CsI samples of different types and thicknesses were obtained from the same manufacturer. They were optimized either for light output (HL) or image resolution (HR), and the thickness ranged between 150 and 600 microns. During experimental measurements, the CsI samples were placed in direct contact with a high resolution CMOS optical sensor with a pixel pitch of 48 microns. The modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) of the detector with different CsI configurations were measured experimentally. The aperture function of the CMOS sensor was determined separately in order to estimate the MTF of CsI alone. We also measured the pulse height distribution of the light output from both the HL and HR CsI at different x-ray energies, from which the x-ray quantum efficiency, Swank factor and x-ray conversion gain were determined. Our results showed that the MTF at 5 cycles/mm for the HR type was 50% higher than for the HL. However, the HR layer produces approximately 36% less light output. The Swank factor below K-edge was 0.91 and 0.93 for the HR and HL types, respectively, thus their DQE(0) were essentially identical. The presampling MTF decreased as a function of thickness L. The universal MTF, i.e., MTF plotted as a function of the product of spatial frequency f and CsI thickness L, increased as a function of L. This indicates that the light channeling process in CsI improved the MTF of

  6. 氯化钡除杂制取高纯氢氧化钡%Preparation of high purity barium hydroxide by impurity - removed barium chloride

    Institute of Scientific and Technical Information of China (English)

    翁贤芬; 毛逢银; 何琳; 李莉

    2009-01-01

    Removal technology of strontium and iron from crude barium chloride raw material were studied.Optimization of process conditions of strontium and iron removal were discussed.When crude barium chloride stiring and dissolving the mixture at 60 ℃ for 40 min,impurities of stromtium and calcuim can be removed and mass fraction of strontium in the obatined solid barium chloride was below 1×10-4.Then add oxydol (H2O2) at proportion of 100 g raw materials per 8 mL H2O2,and add active carbon and small quantity of sodium hydroxide.Finally,iron could be get rid of when pH was controlled below 10.Mass fraction of iron in barium hydroxide product was less than 1×10-5 when using the iron - removed barium chaloride as raw material.Therefore,purified barium chloride by this method can be used to produce purity barium hydroxide.%研究了粗氯化钡原料中锶和铁杂质的脱除工艺,探讨了脱除锶和铁的优化工艺条件.在粗氯化钡原料中加入去离子水,液固质量比为0.25: 1,在60 ℃下搅拌溶解40 min,可除去锶和钙杂质,所得氯化钡固体中锶质量分数低于1×10-4.在氯化钡溶液中加入双氧水,每100 g原料中加入双氧水8 mL,加入活性炭和少量氢氧化钠,控制pH低于10时,可除去铁杂质,用除铁后的氯化钡制取氢氧化钡,产品中铁质量分数低于1×10-5.用除杂后的氯化钡可制得高纯氢氧化钡.

  7. Doping in mercuric iodide crystals and its influence on electronic properties and material structure

    International Nuclear Information System (INIS)

    Doping of mercuric iodide single crystals with SbI3 was studied. Three major aspects of the influence of doping were investigated: the α to β solid phase transition, the crystal structure and the semiconducting properties. A controlled doping method and a new growth technique from the melt were developed. A quantitative correlation between the antimony concentration and the charge carrier transport properties as well as the nuclear detector characteristics of HgI2 were established for the first time. In the present work the influence of various impurities (Sb, Cu, Ag, Bi) on the solid state phase transformation of mercuric iodide has been investigated. In the second part of the work a new growth method for mercuric iodide single crystals containing a controlled amount of SbI3, has been developed. In the last part of this work the influence of the presence of impurities in the crystal on the charge carrier transport properties has been investigated. (author)

  8. Quantification of propidium iodide delivery with millisecond electric pulses: A model study

    CERN Document Server

    Yu, Miao

    2014-01-01

    A model study of propidium iodide delivery with millisecond electric pulses is presented; this work is a companion of the experimental efforts by Sadik et al. [1]. Both membrane permeabilization and delivery are examined with respect to six extra-cellular conductivities. The transmembrane potential of the permeabilized regions exhibits a consistent value, which corresponds to a bifurcation point in the pore-radius-potential relation. Both the pore area density and membrane conductance increase with an increasing extra-cellular conductivity. On the other hand, the inverse correlation between propidium iodide delivery and extra-cellular conductivity as observed in the experiments is quantitatively captured by the model. This agreement confirms that this behavior is primarily mediated by electrophoretic transport during the pulse. The results suggest that electrophoresis is important even for the delivery of small molecules such as propidium iodide. The direct comparison between model prediction and experimental...

  9. Iodide retention by cinnabar (HgS) and chalcocite (Cu{sub 2}S)

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, H.L.; Balsley, S.D.; Brady, P.V.

    1995-07-01

    Sorption of iodide (I{sup {minus}}) on cinnabar (HgS) and chalcocite (Cu{sub 2}S) was examined as a function of pH at 25{degrees}C in a series of batch experiments. Calculated distribution ratios (K{sub d}) far exceed those reported for other minerals; maximal K{sub d}`s of 1375 cc/g (Cu{sub 2}S) and 3080 c/g (HgS) were observed between pH 4-5, but wre substantial at all pH`s measured (4 < pH < 10). Iodide sorption apparently occurs by the formation of an insoluble surface solid solution with exposed Hg and Cu sites. Surface solid solution formation is favored at low pH due to the lessened electrostatic repulsion of the iodide ion by the sulfide surfaces.

  10. All-Solid-State Iodide Selective Electrode for Iodimetry of Iodized Salts and Vitamin C

    Directory of Open Access Journals (Sweden)

    TIRUWORK MEQUANINT

    2012-12-01

    Full Text Available A laboratory-made all-solid state iodide selective electrode, with Ag2S-AgI coated on a graphite rod recovered from dry cell battery, was prepared according to previous procedures. The electrode’s linear response to iodide was in the concentration range of 10-6 M to 10-1 M with a slope of 56.85 mV/decade and a detection limit of 6×10-7M. Iodate recovery test for laboratory formulated iodate-iodized salt was found to be 98.6 % with a standard deviation of 1.14%. The titratability of the iodized salt solution was at least 10-200 ppm potassium iodate (6-120 ppm iodine, exhibiting distinct endpoints in the range wider than the ones set in regulatory standards and reflecting that QC monitoring in production and stability decline of iodine content upon storage can be performed with the electrode method. On the basis this potentiometric titration, the application of the laboratory-made iodide electrode (vs. a saturated calomel reference electrode was extended to the determination of iodine in commercial iodized salts. In all the iodine assays, the iodate-iodized salt was initially treated with acid and an excess of iodide before titration against Na2S2O3 solution. The iodine content in table salts iodized with iodide was determined by direct potentiometry. The electrode was further used for vitamin C (ascorbic acid determinations in pharmaceutical tablets and orange juice by back titrating excess I3- against standard Na2S2O3 in acidic media. The overall outcome is that the iodide ISE can be used as sharp endpoint indicator for these titrimetric reactions in place of the well known official, but visually monitored, starch- triodide end-point reaction detection.

  11. Spectroscopic (multi-energy) CT distinguishes iodine and barium contrast material in MICE

    International Nuclear Information System (INIS)

    Spectral CT differs from dual-energy CT by using a conventional X-ray tube and a photon-counting detector. We wished to produce 3D spectroscopic images of mice that distinguished calcium, iodine and barium. We developed a desktop spectral CT, dubbed MARS, based around the Medipix2 photon-counting energy-discriminating detector. The single conventional X-ray tube operated at constant voltage (75 kVp) and constant current (150 μA). We anaesthetised with ketamine six black mice (C57BL/6). We introduced iodinated contrast material and barium sulphate into the vascular system, alimentary tract and respiratory tract as we euthanised them. The mice were preserved in resin and imaged at four detector energy levels from 12 keV to 42 keV to include the K-edges of iodine (33.0 keV) and barium (37.4 keV). Principal component analysis was applied to reconstructed images to identify components with independent energy response, then displayed in 2D and 3D. Iodinated and barium contrast material was spectrally distinct from soft tissue and bone in all six mice. Calcium, iodine and barium were displayed as separate channels on 3D colour images at <55 μm isotropic voxels. Spectral CT distinguishes contrast agents with K-edges only 4 keV apart. Multi-contrast imaging and molecular CT are potential future applications. (orig.)

  12. SALT reveals the barium central star of the planetary nebula Hen 2-39

    CERN Document Server

    Miszalski, B; Jones, D; Karakas, A I; Köppen, J; Tyndall, A A; Mohamed, S S; Rodríguez-Gil, P; Santander-García, M

    2013-01-01

    Classical barium stars are binary systems which consist of a late-type giant enriched in carbon and slow neutron capture (s-process) elements and an evolved white dwarf (WD) that is invisible at optical wavelengths. The youngest observed barium stars are surrounded by planetary nebulae (PNe), ejected soon after the wind accretion of polluted material when the WD was in its preceeding asymptotic giant branch (AGB) phase. Such systems are rare but powerful laboratories for studying AGB nucleosynthesis as we can measure the chemical abundances of both the polluted star and the nebula ejected by the polluter. Here we present evidence for a barium star in the PN Hen 2-39. The polluted giant is very similar to that found in WeBo 1. It is a cool (Teff=4250 +/- 150 K) giant enhanced in carbon ([C/H]=0.42 +/- 0.02 dex) and barium ([Ba/Fe]=1.50 +/- 0.25 dex). A spectral type of C-R3 C_24 nominally places Hen 2-39 amongst the peculiar early R-type carbon stars, however the barium enhancement and likely binary status mea...

  13. Determination of barium in surface and ground waters at Centro Experimental Aramar area

    Energy Technology Data Exchange (ETDEWEB)

    Matoso, Erika, E-mail: ematoso@hotmail.com [Centro Tecnologico da Marinha em Sao Paulo (CEA/CTMS), Ipero, SP (Brazil). Centro Experimental Aramar; Cadore, Solange, E-mail: cadore@iqm.unicamp.br [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Quimica. Departamento de Quimica Analica

    2015-07-01

    Barium can be found in waters up to 1 mg L{sup -1} and came from natural sources such as sedimentary rocks erosion rich in feldspar and barite. Also anthropogenic activities can release this element such as oil and gas industry, agricultural defensives, chemical industry and waste disposal. At high doses, barium can be harmful to human central nervous system and can also cause high blood pressure, heart problems, fatigue and anxiety. The water potability defined by Brazilian's Ministry of Healthy sets barium concentration up to 0.7 mg L{sup -1} and official regulation defines the same limit of this element to superficial waters (according CONAMA resolution 357/2005) and ground waters (Sao Paulo state regulation). In this work, barium was analyzed monthly in superficial waters from 4 different sampling locations, located in a ratio of 10-km-long from Centro Experimental Aramar (CEA) at Ipanema River, during one year, in order to evaluate the river in different conditions (seasons, temperature and rain period). The ground water was collected every six months. The analytical technique applied was ICP OES and the method conditions were optimized: wavelength, linearity, signal background ratio, detection and quantification limits. Data obtained in this work will contribute to evaluate the presence of barium at CEA region and nearby in order to compare it with current Brazilian regulations. (author)

  14. Spectroscopic (multi-energy) CT distinguishes iodine and barium contrast material in MICE

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, N.G. [University of Otago, Department of Radiology, Christchurch (New Zealand); Butler, A.P. [University of Otago, Department of Radiology, Christchurch (New Zealand); University of Canterbury, Physics and Astronomy, Christchurch (New Zealand); Scott, N.J.A. [University of Otago, Department of Medicine, Christchurch (New Zealand); Cook, N.J. [Christchurch Hospital, Medical Physics and Bioengineering, Christchurch (New Zealand); Butzer, J.S. [Karlsruhe Institute of Technology, Physics Department, Karlsruhe (Germany); Schleich, N. [University of Canterbury, Physics and Astronomy, Christchurch (New Zealand); Christchurch Hospital, Medical Physics and Bioengineering, Christchurch (New Zealand); Firsching, M. [Friedrich Alexander University, Physics Department, Erlangen (Germany); Grasset, R.; Ruiter, N. de [University of Canterbury, Hitlab NZ, Christchurch (New Zealand); Campbell, M. [European Organisation for Nuclear Research, Physics Section, Geneva (Switzerland); Butler, P.H. [University of Canterbury, Physics and Astronomy, Christchurch (New Zealand)

    2010-09-15

    Spectral CT differs from dual-energy CT by using a conventional X-ray tube and a photon-counting detector. We wished to produce 3D spectroscopic images of mice that distinguished calcium, iodine and barium. We developed a desktop spectral CT, dubbed MARS, based around the Medipix2 photon-counting energy-discriminating detector. The single conventional X-ray tube operated at constant voltage (75 kVp) and constant current (150 {mu}A). We anaesthetised with ketamine six black mice (C57BL/6). We introduced iodinated contrast material and barium sulphate into the vascular system, alimentary tract and respiratory tract as we euthanised them. The mice were preserved in resin and imaged at four detector energy levels from 12 keV to 42 keV to include the K-edges of iodine (33.0 keV) and barium (37.4 keV). Principal component analysis was applied to reconstructed images to identify components with independent energy response, then displayed in 2D and 3D. Iodinated and barium contrast material was spectrally distinct from soft tissue and bone in all six mice. Calcium, iodine and barium were displayed as separate channels on 3D colour images at <55 {mu}m isotropic voxels. Spectral CT distinguishes contrast agents with K-edges only 4 keV apart. Multi-contrast imaging and molecular CT are potential future applications. (orig.)

  15. High pressure–low temperature phase diagram of barium: Simplicity versus complexity

    Energy Technology Data Exchange (ETDEWEB)

    Desgreniers, Serge [Laboratoire de Physique des Solides Denses, Université d' Ottawa, Ottawa, Ontario K1N 6N5 (Canada); Tse, John S., E-mail: John.Tse@usask.ca [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B2 (Canada); State Key Laboratory of Superhard Materials, Jilin University, 130012 Changchun (China); Matsuoka, Takahiro [SPring-8/JASRI, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Department of Electrical, Electronic and Computer Engineering, Gifu University, 1-1 Yanagido, Gifu 501-1193 (Japan); Ohishi, Yasuo [SPring-8/JASRI, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Li, Quan; Ma, Yanming [State Key Laboratory of Superhard Materials, Jilin University, 130012 Changchun (China)

    2015-11-30

    Barium holds a distinctive position among all elements studied upon densification. Indeed, it was the first example shown to violate the long-standing notion that high compression of simple metals should preserve or yield close-packed structures. From modest pressure conditions at room temperature, barium transforms at higher pressures from its simple structures to the extraordinarily complex atomic arrangements of the incommensurate and self-hosting Ba-IV phases. By a detailed mapping of the pressure/temperature structures of barium, we demonstrate the existence of another crystalline arrangement of barium, Ba-VI, at low temperature and high pressure. The simple structure of Ba-VI is unlike that of complex Ba-IV, the phase encountered in a similar pressure range at room temperature. First-principles calculations predict Ba-VI to be stable at high pressure and superconductive. The results illustrate the complexity of the low temperature-high pressure phase diagram of barium and the significant effect of temperature on structural phase transformations.

  16. Modeling of Turing Structures in the Chlorite-Iodide-Malonic Acid-Starch Reaction System

    Science.gov (United States)

    Lengyel, Istivan; Epstein, Irving R.

    1991-02-01

    Recent experiments on the chlorite-iodide-malonic acid-starch reaction in a gel reactor give the first evidence of the existence of the symmetry breaking, reaction-diffusion structures predicted by Turing in 1952. A five-variable model that describes the temporal behavior of the system is reduced to a two-variable model, and its spatial behavior is analyzed. Structures have been found with wavelengths that are in good agreement with those observed experimentally. The gel plays a key role by binding key iodine species, thereby creating the necessary difference in the effective diffusion coefficients of the activator and inhibitor species, iodide and chlorite ions, respectively.

  17. Iodide uptake in human anaplastic thyroid carcinoma cells after transfer of the human thyroid peroxidase gene

    Energy Technology Data Exchange (ETDEWEB)

    Haberkom, U. [Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg (Germany); Dept. of Nuclear Medicine, Univ. of Heidelberg (Germany); Altmann, A.; Jiang, S.; Morr, I.; Mahmut, M. [Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg (Germany); Eisenhut, M. [Dept. of Nuclear Medicine, Univ. of Heidelberg (Germany)

    2001-05-01

    Human thyroperoxidase (hTPO) is critical for the accumulation of iodide in thyroid tissues. Poorly differentiated and anaplastic thyroid tumours which lack thyroid-specific gene expression fail to accumulate iodide and, therefore, do not respond to iodine-131 therapy. We consequently investigated whether transfer of the hTPO gene is sufficient to restore the iodide-trapping capacity in undifferentiated thyroid and non-thyroid tumour cells. The human anaplastic thyroid carcinoma cell lines C643 and SW1736, the rat Morris hepatoma cell line MH3924A and the rat papillary thyroid carcinoma cell line L2 were used as in vitro model systems. Employing a bicistronic retroviral vector based on the myeloproliferative sarcoma virus for the transfer of the hTPO and the neomycin resistance gene, the C643 cells and SW1736 cells were transfected while the L2 cells and MH3924A cells were infected with retroviral particles. Seven recombinant C643 and seven SW1736 cell lines as well as four recombinant L2 and four MH3924A cell lines were established by neomycin selection. They were studied for hTPO expression using an antibody-based luminescence kit, followed by determination of the enzyme activity in the guaiacol assay and of the iodide uptake capacity in the presence of Na{sup 125}I. Genetically modified cell lines expressed up to 1,800 times more hTPO as compared to wild type tumour cells. The level of hTPO expression varied significantly between individual neomycin-resistant cell lines, suggesting that the recombinant retroviral DNA was integrated at different sites of the cellular genome. The accumulation of iodide, however, was not significantly enhanced in individual recombinant cell lines, irrespective of low or high hTPO expression. Moreover, there was no correlation between hTPO expression and enzyme activity in individual cell lines. The transduction of the hTPO gene per se is not sufficient to restore iodide trapping in non-iodide-concentrating tumour cells. Future

  18. A Selective Iodide Ion Sensor Electrode Based on Functionalized ZnO Nanotubes

    OpenAIRE

    Magnus Willander; Zafar Hussain Ibupoto; Kimleang Khun

    2013-01-01

    In this research work, ZnO nanotubes were fabricated on a gold coated glass substrate through chemical etching by the aqueous chemical growth method. For the first time a nanostructure-based iodide ion selective electrode was developed. The ZnO nanotubes were functionalized with miconazole ion exchanger and the electromotive force (EMF) was measured by the potentiometric method. The iodide ion sensor exhibited a linear response over a wide range of concentrations (1 × 10−6 to 1 × 10−1 M) and ...

  19. Tris(1,2-dimethoxyethane-κ2O,O′iodidocalcium iodide

    Directory of Open Access Journals (Sweden)

    Siou-Wei Ou

    2012-02-01

    Full Text Available In the title complex, [CaI(C4H10O23]I, the CaII atom is seven-coordinated by six O atoms from three 1,2-dimethoxyethane (DME ligands and one iodide anion in a distorted pentagonal–bipyramidal geometry. The I atom and one of the O atoms from a DME ligand lie in the axial positions while the other O atoms lie in the basal plane. The other iodide anion is outside the complex cation.

  20. Efficiency enhancement in dye sensitized solar cells using gel polymer electrolytes based on a tetrahexylammonium iodide and MgI2 binary iodide system.

    Science.gov (United States)

    Bandara, T M W J; Dissanayake, M A K L; Jayasundara, W J M J S R; Albinsson, I; Mellander, B-E

    2012-06-28

    Quasi-solid-state dye-sensitized solar cells have drawn the attention of scientists and technologists as a potential candidate to supplement future energy needs. The conduction of iodide ions in quasi-solid-state polymer electrolytes and the performance of dye sensitized solar cells containing such electrolytes can be enhanced by incorporating iodides having appropriate cations. Gel-type electrolytes, based on PAN host polymers and mixture of salts tetrahexylammonium iodide (Hex4N(+)I(-)) and MgI2, were prepared by incorporating ethylene carbonate and propylene carbonate as plasticizers. The salt composition in the binary mixture was varied in order to optimize the performance of solar cells. The electrolyte containing 120% Hex4N(+)I(-) with respect to weight of PAN and without MgI2 showed the highest conductivity out of the compositions studied, 2.5 × 10(-3) S cm(-1) at 25 °C, and a glass transition at -102.4 °C. However, the electrolyte containing 100% Hex4N(+)I(-) and 20% MgI2 showed the best solar cell performance highlighting the influence of the cation on the performance of the cell. The predominantly ionic behaviour of the electrolytes was established from the dc polarization data and all the electrolytes exhibit iodide ion transport. Seven different solar cells were fabricated employing different electrolyte compositions. The best cell using the electrolyte with 100% Hex4N(+)I(-) and 20% MgI2 with respect to PAN weight showed 3.5% energy conversion efficiency and 8.6 mA cm(-2) short circuit current density.

  1. FIRST DIRECT EVIDENCE THAT BARIUM DWARFS HAVE WHITE DWARF COMPANIONS

    International Nuclear Information System (INIS)

    Barium II (Ba) stars are chemically peculiar F-, G-, and K-type objects that show enhanced abundances of s-process elements. Since s-process nucleosynthesis is unlikely to take place in stars prior to the advanced asymptotic giant branch (AGB) stage, the prevailing hypothesis is that each present Ba star was contaminated by an AGB companion which is now a white dwarf (WD). Unless the initial mass ratio of such a binary was fairly close to unity, the receiving star is thus at least as likely to be a dwarf as a giant. So although most known Ba stars appear to be giants, the hypothesis requires that Ba dwarfs be comparably plentiful and moreover that they should all have WD companions. However, despite dedicated searches with the IUE satellite, no WD companions have been directly detected to date among the classical Ba dwarfs, even though some 90% of those stars are spectroscopic binaries, so the contamination hypothesis is therefore presently in some jeopardy. In this paper, we analyze recent deep, near-UV and far-UV Galaxy Evolution Explorer (GALEX) exposures of four of the brightest of the class (HD 2454, 15360, 26367, and 221531), together with archived GALEX data for two newly recognized Ba dwarfs: HD 34654 and HD 114520 (which also prove to be spectroscopic binaries). The GALEX observations of the Ba dwarfs as a group show a significant far-UV excess compared to a control sample of normal F-type dwarfs. We suggest that this ensemble far-UV excess constitutes the first direct evidence that Ba dwarfs have WD companions.

  2. Radiation doses to children during modified barium swallow studies

    International Nuclear Information System (INIS)

    There are minimal data on radiation doses to infants and children undergoing a modified barium swallow (MBS) study. To document screening times, dose area product (DAP) and effective doses to children undergoing MBS and to determine factors associated with increased screening times and effective dose. Fluoroscopic data (screening time, DAP, kVp) for 90 consecutive MBS studies using pulse fluoroscopy were prospectively recorded; effective dose was calculated and data were analyzed for effects of behavior, number of swallow presentations, swallowing dysfunction and medical problems. Mean effective dose for the entire group was 0.0826 ± 0.0544 mSv, screening time 2.48 ± 0.81 min, and DAP 28.79 ± 41.72 cGy cm2. Significant differences were found across three age groups (≤1.0, >1.0-3.0 and >3.0 years) for effective dose (mean 0.1188, 0.0651 and 0.0529 mSv, respectively; P < 0.001), but not for screening time or DAP. Effective dose was correlated with screening time (P 0.007), DAP (P < 0.001), number of swallow presentations (P = 0.007), lower age (P = 0.017), female gender (P = 0.004), and height (P < 0.001). Screening time was correlated with total number of swallow presentations (P < 0.001) and DAP (P < 0.001). Screening times, DAP, effective dose, and child and procedural factors associated with higher effective doses are presented for children undergoing MBS studies. (orig.)

  3. Radiation doses to children during modified barium swallow studies

    Energy Technology Data Exchange (ETDEWEB)

    Weir, Kelly A. [University of Queensland, Discipline of Paediatrics and Child Health, School of Medicine, Herston, Queensland (Australia); McMahon, Sandra M. [SpeechNet Speech Pathology Services, Brisbane (Australia); Long, Gillian; Bunch, Judith A. [Royal Children' s Hospital, Department of Medical Imaging, Herston (Australia); Pandeya, Nirmala [Queensland Institute of Medical Research, Herston (Australia); Coakley, Kerry S. [Biomedical Technology Services, Royal Brisbane and Women' s Hospital, Herston (Australia); Chang, Anne B. [Royal Children' s Hospital, Department of Respiratory Medicine, Herston (Australia)

    2007-03-15

    There are minimal data on radiation doses to infants and children undergoing a modified barium swallow (MBS) study. To document screening times, dose area product (DAP) and effective doses to children undergoing MBS and to determine factors associated with increased screening times and effective dose. Fluoroscopic data (screening time, DAP, kVp) for 90 consecutive MBS studies using pulse fluoroscopy were prospectively recorded; effective dose was calculated and data were analyzed for effects of behavior, number of swallow presentations, swallowing dysfunction and medical problems. Mean effective dose for the entire group was 0.0826 {+-} 0.0544 mSv, screening time 2.48 {+-} 0.81 min, and DAP 28.79 {+-} 41.72 cGy cm{sup 2}. Significant differences were found across three age groups ({<=}1.0, >1.0-3.0 and >3.0 years) for effective dose (mean 0.1188, 0.0651 and 0.0529 mSv, respectively; P < 0.001), but not for screening time or DAP. Effective dose was correlated with screening time (P = 0.007), DAP (P < 0.001), number of swallow presentations (P = 0.007), lower age (P = 0.017), female gender (P = 0.004), and height (P < 0.001). Screening time was correlated with total number of swallow presentations (P < 0.001) and DAP (P < 0.001). Screening times, DAP, effective dose, and child and procedural factors associated with higher effective doses are presented for children undergoing MBS studies. (orig.)

  4. Sputtered Modified Barium Titanate for Thin-Film Capacitor Applications

    Directory of Open Access Journals (Sweden)

    Robert Mamazza

    2012-04-01

    Full Text Available New apparatus and a new process for the sputter deposition of modified barium titanate thin-films were developed. Films were deposited at temperatures up to 900 °C from a Ba0.96Ca0.04Ti0.82Zr0.18O3 (BCZTO target directly onto Si, Ni and Pt surfaces and characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM and X-ray photoelectron spectroscopy (XPS. Film texture and crystallinity were found to depend on both deposition temperature and substrate: above 600 °C, the as-deposited films consisted of well-facetted crystallites with the cubic perovskite structure. A strongly textured Pt (111 underlayer enhanced the (001 orientation of BCZTO films deposited at 900 °C, 10 mtorr pressure and 10% oxygen in argon. Similar films deposited onto a Pt (111 textured film at 700 °C and directly onto (100 Si wafers showed relatively larger (011 and diminished intensity (00ℓ diffraction peaks. Sputter ambients containing oxygen caused the Ni underlayers to oxidize even at 700 °C: Raising the process temperature produced more diffraction peaks of NiO with increased intensities. Thin-film capacitors were fabricated using ~500 nm thick BCZTO dielectrics and both Pt and Ni top and bottom electrodes. Small signal capacitance measurements were carried out to determine capacitance and parallel resistance at low frequencies and from these data, the relative permittivity (er and resistivity (r of the dielectric films were calculated; values ranged from ~50 to >2,000, and from ~104 to ~1010 Ω∙cm, respectively.

  5. Studying Equilibrium in the Chemical Reaction between Ferric and Iodide Ions in Solution Using a Simple and Inexpensive Approach

    Science.gov (United States)

    Nikolaychuk, Pavel Anatolyevich; Kuvaeva, Alyona Olegovna

    2016-01-01

    A laboratory experiment on the study of the chemical equilibrium based on the reaction between ferric and iodide ions in solution with the formation of ferrous ions, free iodine, and triiodide ions is developed. The total concentration of iodide and triiodide ions in the reaction mixture during the reaction is determined by the argentometric…

  6. Analysis of iodide and iodate in Lake Mead, Nevada using a headspace derivatization gas chromatography-mass spectrometry.

    Science.gov (United States)

    Dorman, James W; Steinberg, Spencer M

    2010-02-01

    We report here a derivatization headspace method for the analysis of inorganic iodine in water. Samples from Lake Mead, the Las Vegas Wash, and from Las Vegas tap water were examined. Lake Mead and the Las Vegas Wash contained a mixture of both iodide and iodate. The average concentration of total inorganic iodine (TII) for Lake Mead was approximately 90 nM with an iodide-to-iodate ratio of approximately 1. The TII concentration (approximately 160 nM) and the ratio of iodide to iodate were higher for the Las Vegas Wash (approximately 2). The TII concentration for tap water was close to that of Lake Mead (approximately 90 nM); however, tap water contained no detectable iodide as a result of ozonation and chlorine treatment which converts all of the iodide to iodate. PMID:19184627

  7. Use of the barium enema in the diagnosis of necrotizing enterocolitis

    Energy Technology Data Exchange (ETDEWEB)

    Uken, P.; Smith, W.; Franken, E.A.; Frey, E.; Sato, Y.; Ellerbroek, C.

    1988-01-01

    Necrotizing enterocolitis (NEC) is associated with considerable morbidity and mortality in infants. The diagnosis relies heavily upon radiographic and clinical features. Failure to accurately diagnose NEC is associated with a risk of complications and death, however overdiagnosis also causes both morbidity and mortality as well as excessive medical costs. This report documents the use of barium enema to evaluate suspected clinical or radiographic NEC in 31 premature infants with ambiguous clinical and radiographic signs. The enema was normal in 26 infants and no treatment for NEC was given. Only one of these infants developed signs of NEC subsequent to the examination. Five infants had radiographic evidence of colitis including small ulcerations, spasm, intramural extravasation of barium and mucosal irregularity. Two of the five positive cases are pathologically documented. The barium enema can represent a significant improvement in the specificity of the diagnosis of NEC. Its greatest value is in the exclusion of NEC in ambiguous cases.

  8. Highly aligned arrays of high aspect ratio barium titanate nanowires via hydrothermal synthesis

    International Nuclear Information System (INIS)

    We report on the development of a hydrothermal synthesis procedure that results in the growth of highly aligned arrays of high aspect ratio barium titanate nanowires. Using a multiple step, scalable hydrothermal reaction, a textured titanium dioxide film is deposited on titanium foil upon which highly aligned nanowires are grown via homoepitaxy and converted to barium titanate. Scanning electron microscope images clearly illustrate the effect the textured film has on the degree of orientation of the nanowires. The alignment of nanowires is quantified by calculating the Herman's Orientation Factor, which reveals a 58% improvement in orientation as compared to growth in the absence of the textured film. The ferroelectric properties of barium titanate combined with the development of this scalable growth procedure provide a powerful route towards increasing the efficiency and performance of nanowire-based devices in future real-world applications such as sensing and power harvesting

  9. TiO2 ceramic varistor modified with tantalum and barium

    International Nuclear Information System (INIS)

    The non-linear current (I)-voltage (V) characteristics of titanium dioxide doped with small quantities of tantalum and barium (99.9 TiO2 + 0.1 Ta and 99.4 TiO2 + 0.1 Ta + 0.5 Ba, all are in at.%) were investigated. These samples have the non-linear coefficient (α) values of (20-30) with high breakdown voltages (E B ∼ 400-700 V mm-1). The pentavalent tantalum acts as donor and increases the electronic conductivity. The higher electrical conductivity and decrease in the breakdown field strength with barium addition is attributed to higher density. The acceptor like surface states formed by barium ions segregate to grain boundaries due size misfit to thereby modifying the electrical barrier characteristics of grain boundaries

  10. Improved thermal stability and wettability behavior of thermoplastic polyurethane / barium metaborate composites

    Energy Technology Data Exchange (ETDEWEB)

    Baştürka, Emre; Madakbaş, Seyfullah; Kahraman, Memet Vezir, E-mail: smadakbas@marmara.edu.tr [Department of Chemistry, Marmara University, Istanbul (Turkey)

    2016-03-15

    In this paper, it was targeted to the enhance thermal stability and wettability behavior of thermoplastic polyurethane (TPU) by adding barium metaborate. TPU-Barium metaborate composites were prepared by adding various proportions of barium metaborate to TPU. The chemical structures of the composites were characterised by fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. All prepared composites have extremely high Tg and thermal stability as determined from DSC and TGA analysis. All composite materials have the Tg ranging from 15 to 35 °C. The surface morphologies of the composites were investigated by a scanning electron microscopy. Mechanical properties of the samples were characterized with stress-strain test. Hydrophobicity of the samples was determined by the contact angle measurements. The obtained results proved that thermal, hydrophobic and mechanical properties were improved. (author)

  11. Improved thermal stability and wettability behavior of thermoplastic polyurethane / barium metaborate composites

    International Nuclear Information System (INIS)

    In this paper, it was targeted to the enhance thermal stability and wettability behavior of thermoplastic polyurethane (TPU) by adding barium metaborate. TPU-Barium metaborate composites were prepared by adding various proportions of barium metaborate to TPU. The chemical structures of the composites were characterised by fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. All prepared composites have extremely high Tg and thermal stability as determined from DSC and TGA analysis. All composite materials have the Tg ranging from 15 to 35 °C. The surface morphologies of the composites were investigated by a scanning electron microscopy. Mechanical properties of the samples were characterized with stress-strain test. Hydrophobicity of the samples was determined by the contact angle measurements. The obtained results proved that thermal, hydrophobic and mechanical properties were improved. (author)

  12. Plasma irregularities caused by cycloid bunching of the CRRES G-2 barium release

    Science.gov (United States)

    Bernhardt, P. A.; Huba, J. D.; Pongratz, M. B.; Simons, D. J.; Wolcott, J. H.

    1993-01-01

    The Combined Release and Radiation Effects Satellite (CRRES) spacecraft carried a number of barium thermite canisters for release into the upper atmosphere. The barium release labeled G-2 showed evidence of curved irregularities not aligned with the ambient magnetic field B. The newly discovered curved structures can be explained by a process called cycloid bunching. Cycloid bunching occurs when plasma is created by photoionization of a neutral cloud injected at high velocity perpendicular to B. If the injection velocity is much larger than the expansion speed of the cloud, the ion trail will form a cycloid that has irregularities spaced by the product of the perpendicular injection speed and the ion gyroperiod, Images of the solar-illuminated barium ions are compared with the results of a three-dimensional kinetic simulation. Cycloid bunching is shown to be responsible for the rapid generation of both curved and field-aligned irregularities in the CRRES G-2 experiment.

  13. Unexpected finding of barium sulphate on the surface of a microspinal catheter

    International Nuclear Information System (INIS)

    During a study with a scanning electron microscope to evaluate the structure of microspinal catheter after its removal from subarachnoid space, we found an unusual case. The observation with the microscope of the tip of a catheter removed at the end of an operation for hip replacement in a old female showed the presence of grounded particles with a crystal shape covering the outer surface. Further analysis of this material with an Energy-Dispersive Spectrometer (EDS) showed that it was barium. The patient performed a large bowel barium enema 8 months earlier for a painful syndrome to the lower abdomen. Authors rule out the contamination from the skin and suggest two possible mechanisms of passage of barium from blood to cerebrospinal fluid (CSF) and so to the surface of the catheter

  14. Barium sulphate preparations for use in double contrast examination of the upper gastrointestinal tract

    International Nuclear Information System (INIS)

    Physical properties relevant to upper gastrointestinal radiology have been compared for five barium sulphate preparations and related to radiographic results. Evaluation of particles (size and stability) and whole suspension (dispersibility and fluidity) resulted in ranking of the preparations generally in accord with that based on radiological experience in double contrast examinations of the stomach. Experiments with extirpated pig stomach revealed a tendency for large particles in a low viscosity barium sulphate suspension to settle in mucosal grooves. This is believed to contribute to good radiographic definition of both the areae gastricae and small lesions. Particle size is therefore important and susceptibility to flocculation, a possible cause of random change in size during use, was assessed by measuring particle electrophoretic mobility under varying conditions; quantitative differences in suspension flow and dispersibility were also demonstrated. Fluidity and dispersibility together with rapid sedimentation of suitably sized particles resistant to flocculation underlie the successful use of low viscosity high density barium sulphate suspensions. (U.K.)

  15. Barium and strontium sulfate solid solution formation in relation to North Sea scaling problems

    International Nuclear Information System (INIS)

    This paper presents the results of laboratory experiments carried out to investigate barium sulphate and strontium sulphate solid solution formation in multi-pressure tapped cores. Two brines, one barium and strontium rich and the other sulphate rich, were mixed in a core plug. Pressure differentials were measured and the changing permeability distribution along the length of the core calculated. The morphology and chemical analysis of scaling crystals are presented based on Scanning electron Microsocpy (SEM) and Energy Dispersive X-ray Analysis (EDAX). The results show the large extent of permeability damage caused by (Ba, SR) SO/sub 4/ solid solution depositing on the rock pore surface. The rock permeability decline and morphology and size of the scaling crystals indicate the influence of the supersaturations of BaSO/sub 4/ and SrSO/sub 4/ as well as the concentration ratio of barium ions to strontium ions

  16. Therapeutic barium enema for bleeding colonic diverticula:Four case series and review of the literature

    Institute of Scientific and Technical Information of China (English)

    Jun-ichi Iwamoto; Yuji Mizokami; Koichi Shimokobe; Takeshi Matsuoka; Yasushi Matsuzaki

    2008-01-01

    The prevalence of diverticular diseases of the colon, including severe and persistent bleeding in Eastern countries, has increased in the last decades. The bleeding from colonic diverticula is the most common cause of acute lower gastrointestinal bleeding. Herein, we report four cases of severe and persistent bleeding of colonic diverticular disease that could be treated with a high concentration barium enema. These four cases showed a similar pattern of bleeding whose source could not be identified. Colonoscopy revealed fresh blood in the entire colon and many diverticula were noted throughout the colon. No active bleeding source was identified, but large adherent clots in some diverticula were noted. After endoscopic and angiographic therapies failed, therapeutic barium enema stopped the severe bleeding. These patients remained free of re-bleeding in the follow-up period (range 17-35 mo) after the therapy. We report the four case series of therapeutic barium enema and reviewed the literature pertinent to this procedure.

  17. Individual-specific transgenerational marking of fish populations based on a barium dual-isotope procedure.

    Science.gov (United States)

    Huelga-Suarez, Gonzalo; Moldovan, Mariella; Garcia-Valiente, America; Garcia-Vazquez, Eva; Alonso, J Ignacio Garcia

    2012-01-01

    The present study focuses on the development and evaluation of an individual-specific transgenerational marking procedure using two enriched barium isotopes, (135)Ba and (137)Ba, mixed at a given and selectable molar ratio. The method is based on the deconvolution of the isotope patterns found in the sample into four molar contribution factors: natural xenon (Xe nat), natural barium (Ba nat), Ba135, and Ba137. The ratio of molar contributions between Ba137 and Ba135 is constant and independent of the contribution of natural barium in the sample. This procedure was tested in brown trout ( Salmo trutta ) kept in captivity. Trout were injected with three different Ba137/Ba135 isotopic signatures ca. 7 months and 7 days before spawning to compare the efficiency of the marking procedure at long and short term, respectively. The barium isotopic profiles were measured in the offspring by means of inductively coupled plasma mass spectrometry. Each of the three different isotopic signatures was unequivocally identified in the offspring in both whole eggs and larvae. For 9 month old offspring, the characteristic barium isotope signatures could also be detected in the otoliths even in the presence of a high and variable amount of barium of natural isotope abundance. In conclusion, it can be stated that the proposed dual-isotope marking is inheritable and can be detected after both long-term and short-term marking. Furthermore, the dual-isotope marking can be made individual-specific, so that it allows identification of offspring from a single individual or a group of individuals within a given fish group.

  18. Barium hydrogen phosphate/gelatin composites versus gelatin-free barium hydrogen phosphate: synthesis and characterization of properties.

    Science.gov (United States)

    Gashti, Mazeyar Parvinzadeh; Burgener, Matthias; Stir, Manuela; Hulliger, Jürg

    2014-10-01

    Recently, attention has been spent on crystal growth of phosphate compounds in gels for studying the mechanism of in vitro crystallization processes. Here, we present a gel-based approach for the synthesis of barium hydrogen phosphate (BHP) crystals using single and double diffusion techniques in gelatin. The composite crystals were compared with analytical grade BHP powder, single and polycrystalline BHP materials using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), scanning pyroelectric microscopy (SPEM), optical microscopy (OM), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). FTIR spectra showed surface adsorption of gelatin molecules by using BHP stacked sheets due to CH2 stretching, CH2 bending and amide I vibrations are found in a gelatin content of about 2% determined by dissolution. SEM shows various crystal morphologies of the BHP/gelatin composites forming bundled micro-flakes to irregular bundled needles and spheres different from gel-free crystals. The variety in morphology depends on the ion concentration, pH of gel as well as the method of crystal growth. SPEM investigation of BHP/gelatin aggregates revealed polar domains showing alteration of the polarization. Moreover, BHP/gelatin composite crystals showed a higher thermal stability in comparison with analytical grade BHP or/and BHP single crystals due to strong interactions between gelatin and BHP. The XRD diffraction analysis demonstrated that the single and double diffusion techniques in gelatin led to the formation of orthorhombic BHP. This study demonstrates that gelatin is a useful high molecular weight biomacromolecule for controlling the crystallization of a composite material by producing a variety of morphological forms. PMID:24996024

  19. Calcium barium niobate as a functional material for broadband optical frequency conversion.

    Science.gov (United States)

    Sheng, Yan; Chen, Xin; Lukasiewicz, Tadeusz; Swirkowicz, Marek; Koynov, Kaloian; Krolikowski, Wieslaw

    2014-03-15

    We demonstrate the application of as-grown calcium barium niobate (CBN) crystal with random-sized ferroelectric domains as a broadband frequency converter. The frequency conversion process is similar to broadband harmonic generation in commonly used strontium barium niobate (SBN) crystal, but results in higher conversion efficiency reflecting a larger effective nonlinear coefficient of the CBN crystal. We also analyzed the polarization properties of the emitted radiation and determined the ratio of d32 and d33 components of the second-order susceptibility tensor of the CBN crystal. PMID:24690779

  20. Study of the microstructural transformations of borate glass and barium metaborate crystals induced by femtosecond laser

    Institute of Scientific and Technical Information of China (English)

    Chen Bin; Yu Bing-Kun; Yan Xiao-Na; Qiu Jian-Rong; Jiang Xiong-Wei; Zhu Cong-Shan

    2004-01-01

    This paper describes the microstructural transformations of borate glass and barium metaborate crystals induced by femtosecond laser. Such structural transformations were verified by Raman spectroscopy. The borate glass is transformed into low temperature (LT) phase of barium metaborate (BaB2O4) crystals after being irradiated for 10 min by a femtosecond laser. In addition, after 20 min of irradiation, high temperature (HT) phase of BaB2O4 crystals is also produced. Further studies demonstrate that LT phase BaB2O4 crystals are formed in the HT phase BaB2O4 crystals after femtosecond laser irradiation for 10 s.

  1. Temperature-Dependent Raman Spectra and Microstructure of Barium Metaborate Crystals and Its Melts

    Institute of Scientific and Technical Information of China (English)

    尤静林; 蒋国昌; 侯怀宇; 吴永全; 陈辉; 徐匡迪

    2002-01-01

    We have measured the Raman spectra of β- and α-barium metaborate in crystal and liquid states from room temperature to 1873K, with a semiconductor laser as the laser source, coupled with a time-resolved detection system to eliminate the dense thermal emission background when temperature was considerably high.Temperature-dependent Raman spectra can clearly indicate that the phase transformation from β- to α-barium metaborate has been completed during 1273 - 1300 K. Variations of different kinds of microstructure units with temperature are identified and discussed.

  2. Synthesis, characterization and thermostability of barium β-diketonate with tetraethylenepentamine ligand

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The metal-organic chemical vapor deposition (MOCVD) technique is a promising process for high-temperature superconductor YBa2Cu3O7-δ(YBCO) preparation. In this technique, it is a challenge to obtain barium precursors with high volatility. In addition, the purity, evaporation characteristics and thermostability of adopted precursors in the whole process would decide the quality and reproducible results of YBCO film. In the present report, the barium precursor containing 2,2,6,6-tetramethylheptane-3,5-dionate...

  3. Chemical composition of nanomodified composite binder with nano- and microsized barium silicate

    Directory of Open Access Journals (Sweden)

    KOROLEV Evgenij Valerjevich

    2014-08-01

    Full Text Available There are several possibilities to improve cement-based binders. In particular, many properties of cement stone can be enhanced by means of micro- and nanoscale modification. In a number of previous works we had shown that application of barium hydrosilicates leads to such improvement. The present article is devoted to the investigation of the chemical composition of the cement stone which is modified by means of addition of barium hydrosilicates. The modification was performed on different scales: micro- and nanoscale; the results of simultaneous multi-scale modification are also presented. The examination was carried out with help of different modern research techniques – FT IR spectroscopy, differential thermal analysis and X-ray phase analysis. Identification of the new phases and comparative quantitative assessment of their content are performed. It is found that the use of nano- and micro-sized barium hydrosilicates as additives leads to reduction of portlandite by 27...28%; by means of multi-scale modification it is possible to reduce the content of portlandite much more (by 83.3%. Due to addition of nano- and micro-sized barium-based modifiers both the amount of calcium hydrosilicates in reaction products is enlarged, and structure of the mentioned hydrosilicates is changed (the formation of a fine-grained structure of hydration products takes place. Micro-sized barium hydrosilicates are chemically active additives and promote the formation of an additional quantity of calcium hydrosilicates of type CSH (I. The use of nanoscale barium hydrosilicates promotes the formation of CSH (I and CSH (II calcium hydrosilicates, and also both riversidite and xonotlite. As a result of simultaneous application of nano- and micro-sized barium hydrosilicates the content of CSH (II increases. This can be confirmed by means of differential thermal and X-ray analysis. The amount of CSH (I, riversidite and various tobermorites is also increases. It is

  4. Physical states and properties of barium titanate films in a plane electric field

    Science.gov (United States)

    Shirokov, V. B.; Kalinchuk, V. V.; Shakhovoi, R. A.; Yuzyuk, Yu. I.

    2016-07-01

    The influence of a plane electric field on the phase states of barium titanate thin films under the conditions of forced deformation has been studied. The field dependence of a complete set of material constants has been taken in the region of the c-phase, where polarization losses are absent. The material constants are calculated using equations of the piezoelectric effect derived by linearizing the nonlinear equations of state from the phenomenological; theory for barium titanate. It has been shown that there is a critical value of the field at which the electromechanical coupling coefficient reaches a maximum.

  5. Barium meal examination of infants under four months of age presenting with vomiting

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, R.J.; Ziervogel, M.A.; Azmy, A.F.

    1984-02-01

    One hundred barium meal examinations performed on infants of less than 4 months of age are reviewed. All the infants presented with vomiting as a major symptom and the diagnosis remained in doubt following the initial clinical assessment. Fifty seven per cent of the examinations showed an abnormality of which 45% were throught to be significant. Hypertrophic pyloric stenosis was demonstrated in 23 infants. Other abnormalities included hiatus hernia, gastrooesophageal reflux, and duodenal abnormalities. The value of barium meal examinations in this group of infants is emphasised.

  6. Magnetic properties of barium ferrite dispersed within polystyrene-butadiene-styrene block copolymers.

    Science.gov (United States)

    Chipara, M; Skomski, R; Ali, N; Hui, D; Sellmyer, D J

    2009-06-01

    Magnetic properties of nanocomposite materials obtained by dispersing barium ferrite nanoparticles within polystyrene-butadiene-styrene block copolymer, in the temperature range, 300 to 500 K are reported. The temperature dependence of the magnetization at saturation, averaged uniaxial magnetocrystalline anisotropy, and coercive field of thick films are analyzed. A "matrix effect" was noticed within the glass transition range of the hard component (polystyrene) of the polymeric matrix. The reported modifications of the magnetic properties were assigned to the competition between the magnetic and mechanical reorientation of nanoparticles within the polymeric matrix. Such modifications were not observed in barium ferrite dispersed in cement. PMID:19504902

  7. Effects of oleic acid on the high threshold barium current in seabass Dicentrarchus labrax ventricular myocytes

    OpenAIRE

    Chatelier, Aurelien; Imbert, Nathalie; Zambonino, Jose-luis; McKenzie, David; Bois, P.

    2006-01-01

    The present study employed a patch clamp technique in isolated seabass ventricular myocytes to investigate the hypothesis that oleic acid (OA), a mono-unsaturated fatty acid, can exert direct effects upon whole-cell barium currents. Acute application of free OA caused a dose-dependent depression of the whole-cell barium current that was evoked by a voltage step to 0 mV from a holding potential of -80 mV. The derived 50% inhibitory concentration (IC50) was 12.49 +/- 0.27 mu mol l(-1). At a con...

  8. The structural and magnetic properties of barium ferrite powders prepared by the sol-gel method

    Institute of Scientific and Technical Information of China (English)

    Li Jie; Zhang Huai-Wu; Li Yuan-Xun; Liu Ying-Li; Ma Yan-Bing

    2012-01-01

    In this paper,M-type hexagonal barium ferrite powders are synthesized using the sol-gel method.A dried precursor heated in air is analyzed in the temperature range from 50 to 1200 ℃ using thermo-gravimetric analysis and differential scanning calorimetry. The effects of the additives and the cacinating temperature on the magnetic properties are investigated,and the results show that single-phase barium ferrite powders can be formed. After heat-treating at 950 ℃ for 4h with 3 wt% additive,the coercivity and saturation magnetization are found to be 440 Oe and 57.9 emu/g,respectively.

  9. Dielectric properties of piezoelectric 3–0 composites of lithium ferrite/barium titanate

    Indian Academy of Sciences (India)

    P Sarah; S V Suryanarayana

    2003-12-01

    Piezoelectric 3–0 composite ceramics are prepared from a mixture of barium titanate and lithium ferrite phase constituents. Dielectric properties of composites are affected by a number of parameters that include electrical properties, size, shape and amount of constituent phases. The frequency dependent measurements can provide additional insight into mechanisms controlling electrical response. Frequency dependence of dielectric constant plots of lithium ferrite/barium titanate composites will be given and the relevance of trends seen in them will be discussed. Connectivity in composites developed is studied.

  10. Features of Raman amplification in KGW and barium nitrate crystals at excitation by femtosecond pulses

    International Nuclear Information System (INIS)

    Measurements of Raman amplification in KGd(WO4)2 (KGW) and barium nitrate crystals at femtosecond excitation demonstrate spectral transformation of amplification band with change of pump parameters. The half-height amplification bandwidth of up to 45 nm (650 cm-1) what is 5 times larger than the pumping pulse spectral band 8.5 nm (130 cm-1) was observed for KGW crystal. Implementation of impulsive excitation for the low-frequency vibrations allows estimations of the dephasing times and linewidths for the 87 and 83 cm-1 Raman lines in KGW and barium nitrate

  11. Iodide-induced thyrotoxicosis in a thyroidectomized patient with metastatic thyroid carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Yoshinari, M.; Tokuyama, T.; Okamura, K.; Sato, K.; Kusuda, K.; Fujishima, M.

    1988-04-15

    An unusual case of iodide-induced thyrotoxicosis is documented in this article. The patient was a 64-year-old euthyroid man with acromegaly. He also had multiple follicular and papillary thyroid carcinomas with a metastatic lesion in the lumbar vertebrae. After a total thyroidectomy, he became slightly hypothyroid, and the lumbar lesion began to incorporate /sup 131/I by scintigraphy. When an iodine-containing contrast medium happened to be injected, a transient increase of serum thyroid hormone level was observed. After complete thyroid ablation with 83 mCi of /sup 131/I, the oral administration of 100 mg of potassium iodide for 7 days induced a prominent increase of serum thyroid hormone level. These findings indicated that the metastatic thyroid carcinoma could produce excess thyroid hormone insofar as a sufficient amount of iodide was given. Although this is the first report of such a case, iodide-induced thyrotoxicosis may not be rare in patients with thyroid carcinomas because the Wolff-Chaikoff effect is thought to be lost, and the organic iodinating activity and lysosomal protease activity are well-preserved.

  12. Reductive degradation of perfluoroalkyl compounds with aquated electrons generated from iodide photolysis at 254 nm

    OpenAIRE

    Park, Hyunwoong; vecitis, Chad D.; Cheng, Jie; Dalleska, Nathan F; Mader, Brian T.; Hoffmann, Michael R.

    2011-01-01

    The perfluoroalkyl compounds (PFCs), perfluoroalkyl sulfonates (PFXS) and perfluoroalkyl carboxylates (PFXA) are environmentally persistent and recalcitrant towards most conventional water treatment technologies. Here, we complete an in depth examination of the UV-254 nm production of aquated electrons during iodide photolysis for the reductive defluorination of six aquated perfluoroalkyl compounds (PFCs) of various headgroup and perfluorocarbon tail length. Cyclic voltammograms (CV) show tha...

  13. The sodium iodide symporter (NIS) and potential regulators in normal, benign and malignant human breast tissue.

    LENUS (Irish Health Repository)

    Ryan, James

    2011-01-01

    The presence, relevance and regulation of the Sodium Iodide Symporter (NIS) in human mammary tissue remains poorly understood. This study aimed to quantify relative expression of NIS and putative regulators in human breast tissue, with relationships observed further investigated in vitro.

  14. Relaxation of the Silver/Silver Iodide Electrode in Aqueous Solution

    NARCIS (Netherlands)

    Peverelli, K.J.

    1979-01-01

    The aim of this study is to detect and characterize relaxation processes on silver/silver iodide electrodes in aqueous electrolyte solution. The information obtained is to be used for an estimation of the consequences of similar processes on colloidal AgI particles during encounter.In chapter 1 a ge

  15. LIQUID-CRYSTALLINE AND THERMOCHROMIC BEHAVIOR OF 4-SUBSTITUTED 1-METHYLPYRIDINIUM IODIDE SURFACTANTS

    NARCIS (Netherlands)

    NUSSELDER, JJH; ENGBERTS, JBFN; VANDOREN, HA

    1993-01-01

    The mesogenic behaviour of a series of thirty-one 1-alkyl-4-(or 2-)alkyl-pyridinium salts and of a homologous series of four 1-methyl-4-n-alkoxycarbonylpyridinium iodides is described. The occurrence and stability range of the thermotropic phases depend dramatically on the structure of the surfactan

  16. Theoretical calculations of primary particle condensation for cadmium and caesium iodide vapours

    International Nuclear Information System (INIS)

    This report considers a model of aerosol nucleation from the vapour phase which has been developed by Buckle. The applicability of the model has been tested by considering the condensation of caesium iodide and cadmium vapours under a wide variety of pre-mixed flow conditions of interest to PWR severe accident studies. (U.K.)

  17. Photodissociation of sodium iodide and resonant ionization of sodium atom produced

    Institute of Scientific and Technical Information of China (English)

    HUO Bing-hai; Z.T.Salim; A.H.Bakery

    2004-01-01

    Resonant ionization spectroscopy (RIS) and resonant ionization mass spectroscopy (RIMS) are employed to detect the photodissociation product of sodium iodide molecules in a molecular beam in an intense laser field in the absence of the buffer gases. Time of flight mass spectra is recorded. In particular, the appearances of multiphoton ionization are discussed.

  18. Regioselective iodination of aromatic compounds with potassium iodide in the presence of benzyltriphenylphosphonium perchlorate

    Institute of Scientific and Technical Information of China (English)

    Jalal Albadi; Masoumeh Abedini; Nasir Iravani

    2012-01-01

    A simple and efficient method for the selective iodination of various aromatic compounds by using potassium iodide in the presence of benzyltriphenylphosphonium perchlorate,is reported.This method provides several advantages such as good selectivity between ortho and para positions of aromatic compounds and high yields of the products.

  19. Kinetic modeling of the purging of activated carbon after short term methyl iodide loading

    International Nuclear Information System (INIS)

    A bimolecular reaction model containing the physico-chemical parameters of the adsorption and desorption was developed earlier to describe the kinetics of methyl iodide retention by activated carbon adsorber. Both theoretical model and experimental investigations postulated constant upstream methyl iodide concentration till the maximum break-through. The work reported here includes the extension of the theoretical model to the general case when the concentration of the challenging gas may change in time. The effect of short term loading followed by purging with air, and an impulse-like increase in upstream gas concentration has been simulated. The case of short term loading and subsequent purging has been experimentally studied to validate the model. The investigations were carried out on non-impregnated activated carbon. A 4 cm deep carbon bed had been challenged by methyl iodide for 30, 90, 120 and 180 min and then purged with air, downstream methyl iodide concentration had been measured continuously. The main characteristics of the observed downstream concentration curves (time and slope of break-through, time and amplitude of maximum values) showed acceptable agreement with those predicted by the model

  20. Ammonium-iodide route to anhydrous EuI2:mechanism and preparation

    Institute of Scientific and Technical Information of China (English)

    刁成鹏; 余金秋; 李红卫; 彭鹏; 吴浩; 何华强; 颜世宏; 胡运生

    2015-01-01

    Anhydrous EuI2 is an essential raw material for novel Eu2+-doped halide scintillators such as SrI2:Eu, CsBa2I5:Eu and BaBrI:Eu. An efficient and economic method to produce high purity anhydrous EuI2 is critical for future development and applications of these scintillators. In this paper, the ammonium-iodide route to anhydrous EuI2 was investigated, and anhydrous EuI2 with purity of 99.95 wt.%was successfully prepared. The dehydration mechanisms of europium iodide hydrate and its mixture with NH4I were comparatively investigated by X-ray diffraction (XRD), thermal analysis and fluorescence spectroscopy. The thermal decomposition process of individual europium iodide hydrate was revealed as follows:EuI3·9H2O→EuI3·8H2O→EuI3·7H2O→EuI2·H2O→EuI2, and the hydrolysis mechanism of europium hydrate was comprehensively studied. When europium iodide hydrate was dehydrated with NH4I, NH4Eu2I5 formed as an intermediate product, and the hydrolysis of EuI2 was effectively restrained. The role of NH4I as an io-dination agent was also discussed.

  1. Leaching of iodide (I(-)) and iodate (IO3(-)) anions from synthetic layered double hydroxide materials.

    Science.gov (United States)

    Theiss, Frederick L; Ayoko, Godwin A; Frost, Ray L

    2016-09-15

    Several studies have previously demonstrated that layered double hydroxides (LDHs) show considerable potential for the adsorption of radioiodine from aqueous solution; however, few studies have demonstrated that these materials are able to store radioactive (131)I for an acceptable period. The leaching of iodide (I(-)) and iodate (IO3(-)) form Mg/Al LDHs has been carried out. Contact time appeared to be a more significant variable for the leaching of iodate (IO3(-)) compared to that of iodide (I(-)). Experimental results are fitted to the pseudo second order model, suggesting that diffusion is likely to be the rate-limiting step. The presence of carbonate in the leaching solution appeared to significantly increase the leaching of iodide (I(-)) as did the presence of chloride to a lesser extent. The maximum amount of iodate (IO3(-)) leached using ultrapure water as the leaching solution was 21% of the iodate (IO3(-)) originally present. The corresponding result for iodide (I(-)) was even lower at 3%. PMID:27309951

  2. Activation of lactoperoxidase by heme-linked protonation and heme-independent iodide binding.

    Science.gov (United States)

    Toyama, Akira; Tominaga, Aya; Inoue, Tatsuo; Takeuchi, Hideo

    2010-01-01

    Lactoperoxidase (LPO), a mammalian secretory heme peroxidase, catalyzes the oxidation of thiocyanate by hydrogen peroxide to produce hypothiocyanate, an antibacterial agent. Although LPO is known to be activated at acidic pH and in the presence of iodide, the structural basis of the activation is not well understood. We have examined the effects of pH and iodide concentration on the catalytic activity and the structure of LPO. Electrochemical and colorimetric assays have shown that the catalytic activity is maximized at pH 4.5. The heme Soret absorption band exhibits a small red-shift at pH 5.0 upon acidification, which is ascribable to a structural transition from a neutral to an acidic form. Resonance Raman spectra suggest that the heme porphyrin core is slightly contracted and the Fe-His bond is strengthened in the acidic form compared to the neutral form. The structural change of LPO upon activation at acidic pH is similar to that observed for myeloperoxidase, another mammalian heme peroxidase, upon activation at neutral pH. Binding of iodide enhances the catalytic activity of LPO without affecting either the optimum pH of activity or the heme structure, implying that the iodide binding occurs at a protein site away from the heme-linked protonation site.

  3. Iodide accumulation provides kelp with an inorganic antioxidant impacting atmospheric chemistry

    Science.gov (United States)

    Küpper, Frithjof C.; Carpenter, Lucy J.; McFiggans, Gordon B.; Palmer, Carl J.; Waite, Tim J.; Boneberg, Eva-Maria; Woitsch, Sonja; Weiller, Markus; Abela, Rafael; Grolimund, Daniel; Potin, Philippe; Butler, Alison; Luther, George W.; Kroneck, Peter M. H.; Meyer-Klaucke, Wolfram; Feiters, Martin C.

    2008-01-01

    Brown algae of the Laminariales (kelps) are the strongest accumulators of iodine among living organisms. They represent a major pump in the global biogeochemical cycle of iodine and, in particular, the major source of iodocarbons in the coastal atmosphere. Nevertheless, the chemical state and biological significance of accumulated iodine have remained unknown to this date. Using x-ray absorption spectroscopy, we show that the accumulated form is iodide, which readily scavenges a variety of reactive oxygen species (ROS). We propose here that its biological role is that of an inorganic antioxidant, the first to be described in a living system. Upon oxidative stress, iodide is effluxed. On the thallus surface and in the apoplast, iodide detoxifies both aqueous oxidants and ozone, the latter resulting in the release of high levels of molecular iodine and the consequent formation of hygroscopic iodine oxides leading to particles, which are precursors to cloud condensation nuclei. In a complementary set of experiments using a heterologous system, iodide was found to effectively scavenge ROS in human blood cells. PMID:18458346

  4. Preparation and Luminescence Thermochromism of Tetranuclear Copper(I)-Pyridine-Iodide Clusters

    Science.gov (United States)

    Parmeggiani, Fabio; Sacchetti, Alessandro

    2012-01-01

    A simple and straightforward synthesis of a tetranuclear copper(I)-pyridine-iodide cluster is described as a laboratory experiment for advanced inorganic chemistry undergraduate students. The product is used to demonstrate the fascinating and visually impressive phenomenon of luminescence thermochromism: exposed to long-wave UV light, the…

  5. CT-Guided Percutaneous Transthoracic Localization of Pulmonary Nodules Prior to Video-Assisted Thoracoscopic Surgery Using Barium Suspension

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Nyoung Keun; Park, Chang Min; Kang, Chang Hyun; Jeon, Yoon Kyung; Choo, Ji Yung; Lee, Hyun Ju; Goo, Jin Mo [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2012-11-15

    To describe our initial experience with CT-guided percutaneous barium marking for the localization of small pulmonary nodules prior to video-assisted thoracoscopic surgery (VATS). From October 2010 to April 2011, 10 consecutive patients (4 men and 6 women; mean age, 60 years) underwent CT-guided percutaneous barium marking for the localization of 10 small pulmonary nodules (mean size, 7.6 mm; range, 3-14 mm): 6 pure ground-glass nodules, 3 part-solid nodules, and 1 solid nodule. A 140% barium sulfate suspension (mean amount, 0.2 mL; range, 0.15-0.25 mL) was injected around the nodules with a 21-gauge needle. The technical details, surgical findings and pathologic features associated with barium localizations were evaluated. All nodules were marked within 3 mm (mean distance, 1.1 mm; range, 0-3 mm) from the barium ball (mean diameter, 9.6 mm; range, 8-16 mm) formed by the injected barium suspension. Pneumothorax occurred in two cases, for which one needed aspiration. However, there were no other complications. All barium balls were palpable during VATS and visible on intraoperative fluoroscopy, and were completely resected. Both the whitish barium balls and target nodules were identifiable in the frozen specimens. Pathology revealed one invasive adenocarcinoma, five adenocarcinoma-in-situ, two atypical adenomatous hyperplasias, and two benign lesions. In all cases, there were acute inflammations around the barium balls which did not hamper the histological diagnosis of the nodules. CT-guided percutaneous barium marking can be an effective, convenient and safe pre-operative localization procedure prior to VATS, enabling accurate resection and diagnosis of small or faint pulmonary nodules.

  6. Experimental study on iodine chemistry (EXSI) - Containment experiments with methyl iodide

    Energy Technology Data Exchange (ETDEWEB)

    Holm, J.; Ekberg, C. (Chalmers Univ. of Technology, Goeteborg (Sweden)); Kaerkelae, T.; Auvinen, A. (VTT, Espoo (Finland)); Glaenneskog, H. (Vattenfall Power Consultant, Goeteborg (Sweden))

    2011-05-15

    An experimental study on radiolytic decomposition of methyl iodide was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. In year 2008 the NROI project, a Nordic collaboration studying iodine chemistry in the containment, was started. During year 2008 (NROI-1) the radiolytic oxidation of elemental iodine was investigated and during 2009 (NROI-2), the radiolytic oxidation of organic iodine was studied. This project (NROI-3) is a continuation of the investigation of the oxidation of organic iodine. The project has been divided into two parts. 1. The aims of the first part were to investigate the effect of ozone and UV-radiation, in dry and humid conditions, on methyl iodide. 2. The second project was about gamma radiation (approx20 kGy/h) and methyl iodide in dry and humid conditions. 1. Experimental results showed that the methyl iodide concentration in the facility was reduced with increasing temperature and increasing UV-radiation intensity. Similar behaviour occurred when ozone was present in the system. Formed organic gas species during the decomposition of methyl iodide was mainly formaldehyde and methanol. The particle formation was instant and extensive when methyl iodide was exposed to ozone and/or radiation at all temperatures. The size of the formed primary particles was about 10 nm and the size of secondary particles was between 50-200 nm. From the SEM-EDX analyses of the particles, the conclusion was drawn that these were some kind of iodine oxides (I{sub xO{sub y}). However, the correct speciation of the formed particles was difficult to obtain because the particles melted and fused together under the electron beam. 2. The results from this sub-project are more inconsistent and hard to interpret. The particle formation was significant lesser than corresponding experiments when ozone/UV-radiation was used instead of gamma radiation. The transport of gaseous methyl iodide through the facility was

  7. Growth rate controlled barium partitioning in calcite and aragonite

    Science.gov (United States)

    Goetschl, Katja Elisabeth; Mavromatis, Vasileios; Baldermann, Andre; Purgstaller, Bettina; Dietzel, Martin

    2016-04-01

    The barium (Ba) content and the Ba/Ca molar ratios in biogenic and abiotic carbonates have been widely used from the scientific community as a geochemical proxy especially in marine and early diagenetic settings. The Ba content of carbonate minerals has been earlier associated to changes in oceanic circulation that may have been caused by upwelling, changes in weathering regimes and river-runoff as well as melt water discharge. The physicochemical controls of Ba ion incorporation in the two most abundant CaCO3 polymorphs found in Earth's surface environments, i.e. calcite and aragonite, have adequately been studied only for calcite. These earlier studies (i.e. [1]) suggest that at increasing growth rate, Ba partitioning in calcite is increasing as well. In contrast, to date the effect of growth rate on the partitioning of Ba in aragonite remains questionable, despite the fact that this mineral phase is the predominant carbonate-forming polymorph in shallow marine environments. To shed light on the mechanisms controlling Ba ion uptake in carbonates in this study we performed steady-state Ba co-precipitation experiments with calcite and aragonite at 25°C. The obtained results for the partitioning of Ba in calcite are in good agreement with those reported earlier by [1], whereas those for aragonite indicate a reduction of Ba partitioning at elevated aragonite growth rates, with the partitioning coefficient value between solid and fluid to be approaching the unity. This finding is good agreement with the formation of a solid solution in the aragonite-witherite system, owing to the isostructural crystallography of the two mineral phases. Moreover, our data set provides new insights that are required for reconstructing the evolution of the Ba content of pristine marine versus diagenetically altered carbonate minerals commonly occurring in marine subfloor settings, as the thermodynamically less stable aragonite will transform to calcite enriched in Ba, whilst affecting

  8. Conversion of Iodide to Hypoiodous Acid and Molecular Iodine at the Air-Water Interface

    Science.gov (United States)

    Pillar, E. A.; Guzman, M. I.

    2013-12-01

    Sea spray aerosols continuously transfer a significant amount of halides to the marine boundary layer, where they play a major role in the depletion of tropospheric ozone. The reactivity of iodide is of special interest in sea spray aerosols, where this species is enriched relative to chloride and bromide in surface seawater. This work presents laboratory experiments that provide mechanistic information to understand the reactivity of halides in atmospheric aerosols. Pneumatically assisted electrospray is used to aerosolize solutions of sodium iodide (0.01-100 μM), which are rapidly (~3 μs) oxidized by ozone at 25 °C. Reaction products include HIO, IO2-, IO3-, I2, HI2O-, and I3-, all identified by mass spectrometry. The distribution of products varies along two different reaction pathways, one favoring the production of I2 and HIO for typical tropospheric ozone levels (~50 ppbv), and another one directed to the production of IO3- at higher oxidizer concentrations. The formation of products increases exponentially with rising concentrations of initial sodium iodide, [NaI]0. The process is determined to be pH independent for the pH range 6-8 representative of surface waters. The substitution of aqueous solutions by organic solvents, such as methanol or acetonitrile, causes a decrease in the surface tension and lifetime of the droplets, leading to larger I2 production. The presence of surface active organic compounds, which alter the structure of the interfacial region, promote the pathway of I2 formation over IO3-. In conclusion, this presentation will show how the oxidation of iodide in aqueous microdroplets can release reactive gas-phase species, such as I2 and HIO, capable to affect tropospheric ozone globally. Normalized intensity of products observed during the ozonolysis of iodide solutions at 130 ppbv ozone. Cone voltage = 70 V, needle voltage = 2.5 kV.

  9. [The application of eosin and propidium iodide in evaluation of vitality of human spermatozoa].

    Science.gov (United States)

    Ploskonos, М В

    2014-11-01

    The article analyzes comparative assessment of vitality of spermatozoa by condition of permeability of membranes for eosin and propidium iodide and comparison of results acquired using technique of light and fluorescent microscopy. The comparison of data of light microscopy with eosin staining with data of fluorescent microscopy with propidium iodide staining demonstrated that percentage of content of spermatozoa separated from ejaculates of 28 fertile males and stained with eosin was reliably higher (34.8 ± 3.2) than percentage of content of spermatozoa with stained with propidium iodide (2.1 ± 4.0). After incubation of spermatozoa under room temperature during 24 hours percentage of unviable cells with stained eosin also was higher than in case of propidium iodide staining correspondingly (44.5 ± 3.3% and 34.7 ± 3.6%). The analysis of vitality of spermatozoa under damaging effect of oxidative stress on cell membrane developed by 4 hours incubation with 200 mkM of hydrogen peroxide (H2O2) demonstrated that under staining of spermatozoa with propidium iodide significantly higher percentage of damaged cells is detected. In such cases, eosin staining is less suitable for detection of vitality of spermatozoa (73.6 ± 5.8% against 51.7 ± 6.4%). The carried out experiment demonstrates that in case of detected effects on spermatozoa (for example, effect of oxidative stress) the light microscopy insufficiently adequate reflects degree of damage of membranes of spermatozoa. The fluorescent microscopy detects a higher percentage of spermatozoa with damaged membrane.

  10. Regeneration of barium carbonate from barium sulphide in a pilot-scale bubbling column reactor and utilization for acid mine drainage.

    Science.gov (United States)

    Mulopo, J; Zvimba, J N; Swanepoel, H; Bologo, L T; Maree, J

    2012-01-01

    Batch regeneration of barium carbonate (BaCO(3)) from barium sulphide (BaS) slurries by passing CO(2) gas into a pilot-scale bubbling column reactor under ambient conditions was used to assess the technical feasibility of BaCO(3) recovery in the Alkali Barium Calcium (ABC) desalination process and its use for sulphate removal from high sulphate Acid Mine Drainage (AMD). The effect of key process parameters, such as BaS slurry concentration and CO(2) flow rate on the carbonation, as well as the extent of sulphate removal from AMD using the recovered BaCO(3) were investigated. It was observed that the carbonation reaction rate for BaCO(3) regeneration in a bubbling column reactor significantly increased with increase in carbon dioxide (CO(2)) flow rate whereas the BaS slurry content within the range 5-10% slurry content did not significantly affect the carbonation rate. The CO(2) flow rate also had an impact on the BaCO(3) morphology. The BaCO(3) recovered from the pilot-scale bubbling column reactor demonstrated effective sulphate removal ability during AMD treatment compared with commercial BaCO(3). PMID:22233912

  11. Synergistic Effect of Azadirachta Indica Extract and Iodide Ions on the Corrosion Inhibition of Aluminium in Acid Media

    International Nuclear Information System (INIS)

    The synergistic action caused by iodide ions on the corrosion inhibition of aluminium (Al) in 0.5 M HCl in the presence of Azadirachta Indica (AZI) plant extract has been investigated using potintiodynamic polarization and impedance techniques. It is found that AZI extract inhibits the corrosion of aluminium in 0.5 M HCl. The inhibition efficiency increases with the increase in AZI extract concentration, until 24% v/v of AZI extract, then Inh.% is decreased with father increase in AZI extract concentration. The adsorption of this extract in the studied concentration is found to obey Frewendlish adsorption isotherm. The addition of iodide ions enhances the inhibition efficiency to a considerable extent. The increase in Inh.% values in presence of fixed concentration of iodide ions indicates that AZI extract forms an insoluble complex at lower AZI extract concentrations by undergoing a joint adsorption. But at higher concentrations of AZI extract, competitive adsorption is found between iodide ions and the formed complex leading to less Inh.%. The Inh.% decreased in presence of iodide ions with AZI extract than in presence of AZI extract alone at all studied iodide concentrations. The synergism parameter S θ is defined and calculated from surface coverage values. This parameter in the case of AZI extract is found to be more than unity, indicating that the enhanced inhibition efficiency caused by the addition of iodide ions

  12. Contrasting the surface ocean distribution of bromoform and methyl iodide; implications for boundary layer physics, chemistry and climate

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, C J, E-mail: carl.j.palmer@gmail.co [Department of Oceanography, University of Cape Town, 7701 (South Africa)

    2010-08-15

    Bromoform and methyl iodide are both methane-like hydrocarbons with a halogen atom replacing one or more of the hydrogen atoms. Both of these compounds occur naturally in the environment as a result of their production from seaweed and kelp. They are of interest to climate science as a result of their catalytic destruction of boundary layer ozone (a potent greenhouse gas) and, specifically for methyl iodide, the proposed role in the formation of new cloud condensation nuclei with implications for climate. In this paper, the currently available data on the distribution of bromoform and methyl iodide are analysed and contrasted to show that the concentrations of bromoform and methyl iodide do not correlate, that, in contrast to bromoform, the parameterization of sea surface methyl iodide concentrations demands only the sea surface temperature, and that the pelagic distribution of methyl iodide appears to follow the solar zenith angle. These three observations together suggest that, while the pelagic source of bromoform is mostly biogenic, the source of methyl iodide is photochemical. This has implications for the understanding of planetary boundary layer chemistry and potential organohalogen mediated feedbacks to climate.

  13. Contrasting the surface ocean distribution of bromoform and methyl iodide; implications for boundary layer physics, chemistry and climate

    International Nuclear Information System (INIS)

    Bromoform and methyl iodide are both methane-like hydrocarbons with a halogen atom replacing one or more of the hydrogen atoms. Both of these compounds occur naturally in the environment as a result of their production from seaweed and kelp. They are of interest to climate science as a result of their catalytic destruction of boundary layer ozone (a potent greenhouse gas) and, specifically for methyl iodide, the proposed role in the formation of new cloud condensation nuclei with implications for climate. In this paper, the currently available data on the distribution of bromoform and methyl iodide are analysed and contrasted to show that the concentrations of bromoform and methyl iodide do not correlate, that, in contrast to bromoform, the parameterization of sea surface methyl iodide concentrations demands only the sea surface temperature, and that the pelagic distribution of methyl iodide appears to follow the solar zenith angle. These three observations together suggest that, while the pelagic source of bromoform is mostly biogenic, the source of methyl iodide is photochemical. This has implications for the understanding of planetary boundary layer chemistry and potential organohalogen mediated feedbacks to climate.

  14. Synthesis and characterization of barium titanate, doped with europium and neodymium

    International Nuclear Information System (INIS)

    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

  15. Seasonal variability in the input of lead, barium and indium to Law Dome, Antarctica

    DEFF Research Database (Denmark)

    Burn-Nunes...[], L.J.; Vallelonga, Paul Travis; Loss, R.D.;

    2011-01-01

    Lead (Pb) isotopic compositions and concentrations, and barium (Ba) and indium (In) concentrations have been determined at monthly resolution in five Law Dome (coastal Eastern Antarctica) ice core sections dated from similar to 1757 AD to similar to 1898 AD. 'Natural' background Pb concentrations...

  16. A plasmonic modulator based on metal-insulator-metal waveguide with barium titanate core

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Lavrinenko, Andrei

    2013-01-01

    We design a plasmonic modulator which can be utilized as a compact active device in photonic integrated circuits. The active material, barium titanate (BaTiO3), is sandwiched between metal plates and changes its refractive index under applied voltage. Some degree of switching of ferroelectric...

  17. Diffuse X-ray scattering and far infrared absorption of barium and lead β" aluminas

    DEFF Research Database (Denmark)

    Hayes, W.; Kjær, Kristian; Pratt, F. L.;

    1985-01-01

    The authors have carried out high-momentum-resolution studies in diffuse X-ray scattering of barium and lead B" aluminas in the temperature range 20-700 degrees C. They have also measured the vibrational spectra of these compounds between 2K and 300K in the energy range 10-100 cm-1. The results...

  18. The Precipitation Process of Liquid Wastes Containing Contaminant Am withBarium Sulfate

    International Nuclear Information System (INIS)

    The investigated of the reduction volume liquid wastes containing ofAmericium nuclide contaminant has been done. The reduction volume was done byadding barium sulfate coagulant. The experimental procedure that has beendone by adding regent of barium nitrate and natrium sulfate to the wasteswith its preadjusted pH, then by utilizing the jar test equipment was carriedout the fast stirring speed for 5 minutes and the gentle agitation for 30minutes, therefor its floc and supernatant will be formed. The resultedbarium sulfate floc will trap radionuclide in the wastes. The Variableinvestigated were: the concentration of barium sulfate, pH of the wastes, theflash mixing rate, the gentle agitation rate. The investigated barium sulfateconcentration variable was started from 100 ppm up to 800 ppm. Theinvestigated pH variable was started from pH 7 up to pH 13. The investigatedflash mixing rate were 75, 100, 125, 150, 175, 200, 225, 250 rpm. Theinvestigated gentle agitation variable were 20, 30, 40, 50 rpm. The bestresult which was represented by decontaminating factor (DF) was found frombarium sulfate concentration of 300 ppm and pH 11, and the flash mixing rateof 200 rpm and the gentle agitation rate of 20 rpm, with the separationefficiency = 97.2 %. (author)

  19. Study of structural, ferromagnetic and ferroelectric properties of nanostructured barium doped Bismuth Ferrite

    International Nuclear Information System (INIS)

    Nanostructured multiferroic Bi(1−x)BaxFeO3x=0.0, 0.1, 0.2 were prepared by hydrothermal technique. All samples belonged to the rhombohedrally distorted perovskite structure. The morphology of the particles changed with the doping of barium. Effect of barium doping on the dielectric constant was studied over a wide frequency range of 1000 Hz–1 MHz. The activation energy due to relaxation and due to conduction was measured from the Cole Cole plot and the AC conductivity versus frequency plot respectively. The activation energy estimated from both the studies was close to each other. The activation energy also enhanced with the increase in the barium content. The magnetization at the highest available field (∼1.6 T) increased from 0.05 emu/g for the sample with x=0.0–12 emu/g for the sample with x=0.2. The magnetic measurements show a significant increase in magnetization around 400 °C. Remnant polarization for x=0.0 was negligible and it increased to 0.06 µC/cm2 for x=0.2. - Highlights: • Bismuth Ferrite nanostructures were synthesized by the hydrothermal technique. • Barium was doped in Bismuth site. • Morphology changed with doping. • Ferromagnetic, Ferroelectric and Dielectric properties enhanced with doping. • An unreported magnetic transition due to spin canting was observed near 550 °C

  20. Adsorption of Pb(II) present in aqueous solution on calcium, strontium and barium hydroxy apatites

    International Nuclear Information System (INIS)

    Calcium, strontium and barium hydroxy apatites were successfully synthesized by chemical precipitation method, the obtained powders were characterized by the techniques of X-ray diffraction (XRD), scanning electron microscopy (Sem), semi-quantitative elemental analysis (EDS), infrared spectroscopy (IR), and N2 physisorption studies, complementary to these analytical techniques, was determined the surface fractal dimension (Df), and the amount of surface active sites of the materials, in order to know application as ceramic for water remediation. The ability of Pb(II) ion adsorption present in aqueous solution on the hydroxy apatites synthesized by batch type experiments was studied as a function of contact time, concentration of the adsorbate and temperature. The maximum lead adsorption efficiencies obtained were 0.31, 0.32 and 0.26 mg/g for calcium, strontium and barium hydroxy apatites respectively, achieved an equilibrium time of 20 minutes in the three solid-liquid systems studied. Experimental data were adequately adjusted at the adsorption kinetic model pseudo-second order, for the three cases. Moreover, experimental data of the strontium and calcium hydroxy apatites were adjusted to the Langmuir adsorption isotherm, indicating that the adsorption was through a monolayer, whereas barium hydroxyapatite was adjusted to the Freundlich adsorption isotherm, indicating a multilayer adsorption. The thermodynamic parameters obtained during adsorption studies as a function of temperature showed physisorption, exothermic and spontaneous processes respectively. The results showed that the calcium hydroxyapatite, strontium and barium are an alternative for the Pb(II) ion adsorption present in wastewaters. (Author)

  1. A comparison of radiographer and radiologist reports on radiographer conducted barium enemas

    International Nuclear Information System (INIS)

    Purpose: To compare radiographer and radiologist reports on radiographer conducted barium enemas. Method: Two specially trained, experienced radiographers performed barium enemas and prepared provisional reports without consulting radiologists. Later, formal radiologist reports were issued. The reports of each were compared and correlated with clinical findings derived from case note review. Results:Seven hundred and eighty eight patients had barium enemas. Males numbered 295 (37.5%) and females 493 (62.5%). Patients ages ranged from 17 to 95 years (mean 62). The radiologist reported 244 as normal, 432 as diverticular change, 70 with polyps (31 of which had co-existent diverticular disease), 31 with carcinomas and 12 with colitis (three of which had co-existent diverticular disease). Taking the radiologist reports as gold-standard radiographer reports were concordant in 753 (95.5%). There were 35 (4.5%) discordant radiographer reports of these 19 were false-positive diagnoses of polyps and six false positive diagnoses of diverticular change. There were seven false-negative diagnoses of polyps (only one of these was found to have a polyp at follow-up endoscopy). There was one false-negative diagnosis of colitis and two false-negative reports of diverticular change. On follow up there were no false negative diagnoses of carcinoma by either radiographer or radiologist. There was one concordant false-positive diagnosis of carcinoma. Conclusion:Radiographers with specialized training can report barium enemas to a high standard

  2. Spectroscopic (multi-energy) CT distinguishes iodine and barium contrast material in MICE

    CERN Document Server

    Anderson, NG; Firsching, M; de Ruiter, N; Schleich, N; Butzer, J S; Cook, N J; Grasset, R; Campbell, M; Scott, N J A; Anderson, N G

    2010-01-01

    Spectral CT differs from dual-energy CT by using a conventional X-ray tube and a photon-counting detector. We wished to produce 3D spectroscopic images of mice that distinguished calcium, iodine and barium. We developed a desktop spectral CT, dubbed MARS, based around the Medipix2 photon-counting energy-discriminating detector. The single conventional X-ray tube operated at constant voltage (75 kVp) and constant current (150 A mu A). We anaesthetised with ketamine six black mice (C57BL/6). We introduced iodinated contrast material and barium sulphate into the vascular system, alimentary tract and respiratory tract as we euthanised them. The mice were preserved in resin and imaged at four detector energy levels from 12 keV to 42 keV to include the K-edges of iodine (33.0 keV) and barium (37.4 keV). Principal component analysis was applied to reconstructed images to identify components with independent energy response, then displayed in 2D and 3D. Iodinated and barium contrast material was spectrally distinct f...

  3. Physical and biological dosimetry at the barium sulphate-culture medium interface

    International Nuclear Information System (INIS)

    The present study suggests that a thin layer of Barium sulphate suspension forms an interface with tissues which results in high dose regions on both sides of the BSS-tissue interface when irradiated with 250 kVp X rays. The magnitude of dose increase depends on the density of the BSS. (U.K.)

  4. Assessment of barium sulphate formation and inhibition at surfaces with synchrotron X-ray diffraction (SXRD)

    International Nuclear Information System (INIS)

    The precipitation of barium sulphate from aqueous supersaturated solutions is a well-known problem in the oil industry often referred to as 'scaling'. The formation and growth of barite on surfaces during the oil extraction process can result in malfunctions within the oil facilities and serious damage to the equipment. The formation of barium sulphate at surfaces remains an important topic of research with the focus being on understanding the mechanisms of formation and means of control. In situ synchrotron X-ray diffraction (SXRD) was used to investigate the formation of barium sulphate on a stainless steel surface. The effect of Poly-phosphinocarboxylic acid (PPCA) and Diethylenetriamine-penta-methylenephosphonic acid (DETPMP) which are two commercial inhibitors for barium sulphate was examined. The in situ SXRD measurements allowed the identification of the crystal faces of the deposited barite in the absence and presence of the two inhibitors. The preferential effect of the inhibitors on some crystal planes is reported and the practical significance discussed.

  5. Performance of cement solidification with barium for high activity liquid waste including sulphate

    International Nuclear Information System (INIS)

    The target liquid waste to be solidified is generated from PWR primary loop spent resin treatment with sulphate acid, so, its main constituent is sodium sulphate and the activity of this liquid is relatively high. Waste form of this liquid waste is considered to be a candidate for the subsurface disposal. The disposed waste including sulphate is anticipated to rise a concentration of sulphate ion in the ground water around the disposal facility and it may cause degradation of materials such as cement and bentonite layer and comprise the disposal facility. There could be two approaches to avoid this problem, the strong design of the disposal facility and the minimization of sulphaste ion migration from the solidified waste. In this study, the latter approach was examined. In order to keep the low concentration of sulphate ion in the ground water, it is effective to make barium sulphate by adding barium compound into the liquid waste in solidification. However, adding equivalent amount of barium compound with sulphate ion causes difficulty of mixing, because production of barium sulphate causes high viscosity. In this study, mixing condition after and before adding cement into the liquid waste was estimated. The mixing condition was set with consideration to keep anion concentration low in the ground water and of mixing easily enough in practical operation. Long term leaching behavior of the simulated solidified waste was also analyzed by PHREEQC. And the concentration of the constitution affected to the disposal facility was estimated be low enough in the ground water. (author)

  6. Study of structural, ferromagnetic and ferroelectric properties of nanostructured barium doped Bismuth Ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, A., E-mail: arkac123@gmail.com [Department of Applied Science, Haldia Institute of Technology, Dist.- Purba Medinipur, Haldia- 721657, West Bengal (India); Department of Condensed Matter Physics and Material Science, S.N. Bose National Center for Basic Sciences, Block JD, Salt Lake, Kolkata 700098 (India); Mandal, K. [Department of Applied Science, Haldia Institute of Technology, Dist.- Purba Medinipur, Haldia- 721657, West Bengal (India); Department of Condensed Matter Physics and Material Science, S.N. Bose National Center for Basic Sciences, Block JD, Salt Lake, Kolkata 700098 (India)

    2014-03-15

    Nanostructured multiferroic Bi{sub (1−x)}Ba{sub x}FeO{sub 3}x=0.0, 0.1, 0.2 were prepared by hydrothermal technique. All samples belonged to the rhombohedrally distorted perovskite structure. The morphology of the particles changed with the doping of barium. Effect of barium doping on the dielectric constant was studied over a wide frequency range of 1000 Hz–1 MHz. The activation energy due to relaxation and due to conduction was measured from the Cole Cole plot and the AC conductivity versus frequency plot respectively. The activation energy estimated from both the studies was close to each other. The activation energy also enhanced with the increase in the barium content. The magnetization at the highest available field (∼1.6 T) increased from 0.05 emu/g for the sample with x=0.0–12 emu/g for the sample with x=0.2. The magnetic measurements show a significant increase in magnetization around 400 °C. Remnant polarization for x=0.0 was negligible and it increased to 0.06 µC/cm{sup 2} for x=0.2. - Highlights: • Bismuth Ferrite nanostructures were synthesized by the hydrothermal technique. • Barium was doped in Bismuth site. • Morphology changed with doping. • Ferromagnetic, Ferroelectric and Dielectric properties enhanced with doping. • An unreported magnetic transition due to spin canting was observed near 550 °C.

  7. Barium versus Nonbarium Stimuli: Differences in Taste Intensity, Chemesthesis, and Swallowing Behavior in Healthy Adult Women

    Science.gov (United States)

    Nagy, Ahmed; Steele, Catriona M.; Pelletier, Cathy A.

    2014-01-01

    Purpose: The authors examined the impact of barium on the perceived taste intensity of 7 different liquid tastant stimuli and the modulatory effect that these differences in perceived taste intensity have on swallowing behaviors. Method: Participants were 80 healthy women, stratified by age group (60) and genetic taste status…

  8. Low temperature phase barium borate: A new optical limiter in continuous wave and nano pulsed regime

    Science.gov (United States)

    Babeela, C.; Girisun, T. C. Sabari

    2015-11-01

    Low temperature phase barium borate was synthesized by hydrothermal method. XRD analysis confirms the formation of γ-BBO or hydrated barium polyborate (Ba3B6O9(OH)6) which crystallizes in monoclinic system in the P2/c space group. The molecular structure analysis shows the presence of dominant BO4 unit and the hydrated nature of material. γ-BBO exhibits sharp absorption edge at 202 nm and highly transparency in the UV-Visible-NIR region. The peak at 347 nm in the emission spectrum is due to the presence of self-trapped exciton. The third order nonlinear optical properties and limiting behavior of low temperature barium borate in both pulsed and continuous wave regime were studied. The effective 2PA absorption coefficient of γ-BBO under ns pulse excitation is estimated to be 0.38 × 10-10 m/W. The nonlinear absorption coefficient, refractive index and optical susceptibility of the material in cw regime were found to be in the order of 10-5 m W-1, 10-12 m2 W-1, 10-6 esu respectively. In both regimes, low temperature phase barium borate exhibits better optical limiting properties than high temperature phase β-BBO.

  9. Barium borosilicate glass as a matrix for the uptake of dyes

    International Nuclear Information System (INIS)

    Barium borosilicate (BBS) and sodium borosilicate (SBS) glass samples, prepared by the conventional melt-quench method, were used for the uptake of Rhodamine 6G dye from aqueous solution. The experimental conditions were optimized to get maximum uptake and was found to be 0.4 mg of dye per gram of BBS glass sample. For the same network former to modifier ratio, barium borosilicate glasses are found to have improved extent of uptake for the dye molecules from aqueous solutions compared to sodium borosilicate glasses. Based on 29Si MAS NMR studies on these glasses, it is inferred that significantly higher number of non-bridging oxygen atoms present in barium borosilicate glasses compared to sodium borosilicate glasses is responsible for its improved uptake of Rhodamine 6G dye. 11B MAS NMR studies have confirmed the simultaneous existence of boron in BO3 and BO4 configurations in both barium borosilicate and sodium borosilicate glasses. The luminescence studies have established that the dye molecule is incorporated into the glass matrix through ion exchange mechanism by replacing the exchangeable ions like Na+/Ba2+ attached with the non-bridging oxygen atoms present in the glass.

  10. Possible discovery of the r-process characteristics in the abundances of metal-rich barium stars

    CERN Document Server

    Cui, W Y; Shi, J R; Zhao, G; Wang, W J; Niu, P

    2014-01-01

    We study the abundance distributions of a sample of metal-rich barium stars provided by Pereira et al. (2011) to investigate the s- and r-process nucleosynthesis in the metal-rich environment. We compared the theoretical results predicted by a parametric model with the observed abundances of the metal-rich barium stars. We found that six barium stars have a significant r-process characteristic, and we divided the barium stars into two groups: the r-rich barium stars ($C_r>5.0$, [La/Nd]\\,$<0$) and normal barium stars. The behavior of the r-rich barium stars seems more like that of the metal-poor r-rich and CEMP-r/s stars. We suggest that the most possible formation mechanism for these stars is the s-process pollution, although their abundance patterns can be fitted very well when the pre-enrichment hypothesis is included. The fact that we can not explain them well using the s-process nucleosynthesis alone may be due to our incomplete knowledge on the production of Nd, Eu, and other relevant elements by the ...

  11. Synthesis of cholesteryl-α-D-lactoside via generation and trapping of a stable β-lactosyl iodide

    Science.gov (United States)

    Davis, Ryan A.; Fettinger, James C.; Gervay-Hague, Jacquelyn

    2015-01-01

    The generation of β-lactosyl iodide was carried out under non-in situ-anomerization, metal free conditions by reacting commercially available β-per-O-acetylated lactose with trimethylsilyl iodide (TMSI). The β-iodide was surprisingly stable as evidenced by NMR spectroscopy. Introduction of octanol or cholesterol under microwave conditions gave high yields of α-linked glycoconjugates. Careful analysis of the reaction products and mechanistic considerations suggest an acid catalyzed rearrangement that provides α-linked glycosylation products with a free C2-hydroxyl. Accessibility to these compounds may further advance glycolipidomic profiling of immune modulating bacterial derived-glycans. PMID:26543257

  12. Part I. Voltammetric studies of potassium iodide at gold and platinum electrodes. Part II. Electrodeposition and characterization of poly(vinylferrocene) films

    Energy Technology Data Exchange (ETDEWEB)

    Holt, R.J.

    1993-01-01

    A mechanism for the adsorption of iodide on platinum and gold has been proposed in the literature which assumes hydrogen gas is evolved along with an adsorbed iodide atom. A rotating platinum ring-disk electrode was used here to detect the presence of any hydrogen produced upon iodide adsorption. No evidence for hydrogen formation was found. A gold-gold/platinum gas permeable double membrane electrode also did not show any evidence of hydrogen gas produced at gold during iodide adsorption. The voltammetry of iodide and iodate was examined using both gold and platinum ring-disk electrodes and a gas permeable double membrane electrode. The oxidation of adsorbed iodide was examined. The successful determination of the various oxidation states of iodide in acid media were performed: I[sub 2], IO[sup [minus

  13. Influence of barium substitution on bioactivity, thermal and physico-mechanical properties of bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Arepalli, Sampath Kumar, E-mail: askumar.rs.cer11@iitbhu.ac.in; Tripathi, Himanshu; Vyas, Vikash Kumar; Jain, Shubham; Suman, Shyam Kumar; Pyare, Ram; Singh, S.P., E-mail: spsinghceram@gmail.com

    2015-04-01

    Barium with low concentration in the glasses acts as a muscle stimulant and is found in human teeth. We have made a primary study by substituting barium in the bioactive glass. The chemical composition containing (46.1 − X) SiO{sub 2−}–24.3 Na{sub 2}O–26.9 CaO–2.6 P{sub 2}O{sub 5}, where X = 0, 0.4, 0.8, 1.2 and 1.6 mol% of BaO was chosen and melted in an electric furnace at 1400 ± 5 °C. The glasses were characterized to determine their use in biomedical applications. The nucleation and crystallization regimes were determined by DTA and the controlled crystallization was carried out by suitable heat treatment. The crystalline phase formed was identified by using XRD technique. Bioactivity of these glasses was assessed by immersion in simulated body fluid (SBF) for various time periods. The formation of hydroxy carbonate apatite (HCA) layer was identified by FTIR spectrometry, scanning electron microscope (SEM) and XRD which showed the presence of HCA as the main phase in all tested bioactive glass samples. Flexural strength and densities of bioactive glasses have been measured and found to increase with increasing the barium content. The human blood compatibility of the samples was evaluated and found to be pertinent. - Highlights: • In vitro bioactivity of soda-lime–baria-phospho-silicate glass was investigated. • HCA formed on surface of glasses was confirmed by XRD, SEM and FTIR spectrometry. • Mechanical properties of glasses were found to increase with barium addition. • Hemolysis showed that 1.2 mol% BaO bioactive glass exhibited better biocompatibility. • Barium substituted bioactive glasses can be used as bone implants.

  14. A study of the microchemistry of nanocrystalline barium titanate with tetragonal and pseudocubic room temperature symmetries

    Science.gov (United States)

    Lacey, Robert A.

    The investigation of possible effects of undesired surface species on barium titanate, one of the most utilized ferroelectric ceramics, constitutes the focus of this work. Six commercial barium titanate powders from three manufacturers representing two different synthesis processes, with average particle sizes from 40 nm to 470 nm, were analyzed in this study. Four of the nanopowders exhibited pseudocubic room temperature symmetry. Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopic analysis of the nanopowders was conducted in ambient atmosphere at room temperature. High temperature DRIFT followed incorporating four avenues of analysis: moisture adsorption studies, deuterium oxide exchange studies, carbon dioxide adsorption studies, and high temperature analysis under dry air and UHP nitrogen atmospheres. At the highest temperature used in this study, 1173K, moisture and the accompanying incorporated protonic impurities were still present. The powders readily readsorbed moisture during rapid cooling, 170K/minute, to room temperature. The smallest powder, as received, formed spherical agglomerates up to 10 mum diameter. These sintered as separate units attaining diameters up to 60 mum during intermediate stage sintering. X-ray photoelectron spectroscopy indicated a surface contamination layer of 10 A to 18 A; 50--70% of which was barium carbonate, the balance being atmospheric adsorbed species. Samples cooled at 3K/minute after an 1173K calcine retained cubic symmetry as indicated with high temperature X-ray diffraction. However, spectral evidence was obtained indicating that upon the rapid cooling from the 1173K calcine, a reorientation to the room temperature tetragonal symmetry was observed. Further, SEM and TEM supported this finding with visual evidence of interfacial rearrangement including corroborating electron diffraction analysis. This data, therefore, substantiated the hypothesis that the cause of the room temperature pseudocubic

  15. AFM studies of swift heavy ion and electron irradiated mixed barium strontium borate nonlinear optical crystal

    International Nuclear Information System (INIS)

    Single crystals of novel nonlinear optical material of mixed barium strontium borate is grown in our laboratory by employing the low-temperature solution technique. Equal proportion (1:1 molar ratio) of AR grade barium borate and strontium borate are mixed together in double distilled water to prepare a supersaturated solution. The solution is allowed to evaporate at constant temperature (30 deg. C) in a Petri dish for about a week which resulted in the formation of seed crystals. These seed crystals are used to grow larger crystals by suspending them using fine silk thread in the supersaturated mother solution. The solution is allowed to evaporate at constant temperature. This resulted in the growth of good transparent crystals of dimension 15 mmx10 mmx1 mm after about one month. These crystals show good second harmonic generation (SHG) efficiency. The mixed barium strontium borate crystal is found to be a promising nonlinear optical crystal, which possibly can be used for fabrication of photonic devices. The single crystals of mixed barium strontium borate are irradiated by 120 MeV Ag+13 swift heavy ions (SHI) of fluence 5x1011 ions/cm2 at Nuclear Science Centre, New Delhi and also by electrons of 8 MeV energy with a fluence 5.7x109/cm2 using Microtron accelerator at Mangalore University. Surface morphology studies of these crystals are carried out using atomic force microscope. The AFM topographical images of these SHI/electron irradiated single crystals of mixed barium strontium borate are obtained from different frames of the sample taken at different magnifications using atomic force microscope. An attempt is made to explain the surface damage caused due to SHI/electron irradiation using the observed AFM images

  16. Experimental study on iodine chemistry (EXSI) - Containment experiments with methyl iodide

    Energy Technology Data Exchange (ETDEWEB)

    Holm, J.; Glaenneskog, H.; Ekberg, C. (Chalmers Univ. of Technology (Sweden)); Kaerkelae, T.; Auvinen, A. (VTT Technical Research Centre of Finland (Finland))

    2010-05-15

    An experimental study on radiolytic decomposition of methyl iodide was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. The behaviour of iodine during a severe accident has been studied in several experimental programs, ranging from the large-scale PHEBUS FP tests and intermediate-scale ThAI tests to numerous separate effect studies. In year 2008 the NROI project, a Nordic collaboration studying iodine chemistry in the containment was started. During 2009, oxidation of iodine, especially organic iodine, was studied within the NROI project. The chemistry of organic iodine in the gas phase is still one of the greatest remaining uncertainties concerning iodine behaviour during a severe accident. During the first year of the NROI project the oxidation of elemental iodine, I2, with ozone and UV-light was investigated. In this study organic iodide, in this case methyl iodide, was investigated in similar conditions as in the NROI-1 project. The experimental facility applied in this study is based on the sampling system built at VTT for the ISTP project CHIP conducted by IRSN. The experimental facility and the measuring technology are sophisticated and unique in the area of nuclear research as well as in the field of aerosol science. Experimental results showed that the methyl iodide concentration in the facility was reduced with increasing temperature and increasing UVC intensity. Similar behaviour occurred when ozone was present in the system. Formed organic gas species during the decomposition of methyl iodide was mainly formaldehyde and methanol. Instant and extensive particle formation occurred when methyl iodide was transported through a UVC radiation field and/or when ozone was present. The size of the formed primary particles was about 10 nm and the size of secondary particles was between 50-150 nm. From the SEM-EDX analyses of the particles, the conclusion was drawn that these were some kind of iodine

  17. THERMAL DECOMPOSITION MECHANISM OF BARIUM BENZOATE%苯甲酸钡的热分解机理

    Institute of Scientific and Technical Information of China (English)

    张克立; 袁继兵; 袁良杰; 孙聚堂

    1999-01-01

    Barium benzoate was synthesized in semi-solid phase reaction. The complex was characterized by elemental analysis, IR, X-ray powder diffraction. It is layered structure, monoclinic system. The mechanism of thermal decomposition for barium benzoate was studied by using TG, DTA, IR and gas chromatography-mass spectrometer. The thermal decompositon of barium benzoate in nitrogen proceeded in one stage: it decomposed to form BaCO3 and organic compounds. The organic compounds obtained from decomposition reaction are mainly benzophenone, triphenylmethane and so on.

  18. CT colonography: optimisation, diagnostic performance and patient acceptability of reduced-laxative regimens using barium-based faecal tagging

    OpenAIRE

    Stuart A Taylor; Slater, Andrew; Burling, David N.; Tam, Emily; Greenhalgh, Rebecca; Gartner, Louise; Scarth, Julia; Pearce, Robert; Bassett, Paul; Halligan, Steve

    2007-01-01

    To establish the optimum barium-based reduced-laxative tagging regimen prior to CT colonography (CTC). Ninety-five subjects underwent reduced-laxative (13 g senna/18 g magnesium citrate) CTC prior to same-day colonoscopy and were randomised to one of four tagging regimens using 20 ml 40%w/v barium sulphate: regimen A: four doses, B: three doses, C: three doses plus 220 ml 2.1% barium sulphate, or D: three doses plus 15 ml diatriazoate megluamine. Patient experience was assessed immediately af...

  19. Reversible radiochromic plate based on polyvinyl alcohol-iodide complex containing silica nanoparticles

    International Nuclear Information System (INIS)

    A radiochromic plate based on a reversible change between iodide and iodine was prepared using a polyvinyl alcohol-iodide complex, silica nanoparticles, and agarose. X-ray (30 kV, 15 mA) irradiation of the plate changed it to a red color, which gradually disappeared and was completely erased within a day after stopping X-ray irradiation. The minimum detection dose was about 0.5 Gy for X-rays and 10 Gy for 137Cs γ-rays. The G-value for the oxidation of I- was estimated to be about 19.6 in a neutral solution and about 20.64 in an acidic solution. (author)

  20. Parametric study on removal efficiency of impregnated activated charcoal and silver zeolite for radioactive methyl iodide

    International Nuclear Information System (INIS)

    The removal efficiency of impregnated activated charcoal and silver zeolite for radioactive methyl iodide is influenced by various parameters such as temperature, relative humidity, face velocity and packing density. This study is to evaluate the dependency of the removal efficiency on each parameter and these combined parameters, quantitatively. Four types of adsorbents, BC-727, AgX, CHC-50 and SS 208C 5KI3, were tested. From experimental data and mass transfer theory, an experimental equation for evaluating the removal efficiency of adsorbents was derived under a series of experiments for radioactive methyl iodine-131. It was concluded that the removal efficiency calculated from the experimental equation agreed well with the experimental value. Effects of experimental specific parameters, such as Pre-flow time, methyl iodide injection time and After-flow time, on the removal efficiency of adsorbent are also described

  1. Iodide Recognition and Sensing in Water by a Halogen-Bonding Ruthenium(II)-Based Rotaxane.

    Science.gov (United States)

    Langton, Matthew J; Marques, Igor; Robinson, Sean W; Félix, Vítor; Beer, Paul D

    2016-01-01

    The synthesis and anion-recognition properties of the first halogen-bonding rotaxane host to sense anions in water is described. The rotaxane features a halogen-bonding axle component, which is stoppered with water-solubilizing permethylated β-cyclodextrin motifs, and a luminescent tris(bipyridine)ruthenium(II)-based macrocycle component. (1) H NMR anion-binding titrations in D2 O reveal the halogen-bonding rotaxane to bind iodide with high affinity and with selectively over the smaller halide anions and sulfate. The binding affinity trend was explained through molecular dynamics simulations and free-energy calculations. Photo-physical investigations demonstrate the ability of the interlocked halogen-bonding host to sense iodide in water, through enhancement of the macrocycle component's Ru(II) metal-ligand charge transfer (MLCT) emission. PMID:26626866

  2. Induction of iodide uptake in transformed thyrocytes: a compound screening in cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Eleonore [University of Tuebingen, Department of Endocrinology, Metabolism, Nephrology and Clinical Chemistry, Internal Medicine, Tuebingen (Germany); Brossart, Peter [University of Tuebingen, Department of Haematology, Oncology, Immunology and Rheumatology, Internal Medicine, Tuebingen (Germany); Wahl, Richard [University of Tuebingen, Department of Endocrinology, Metabolism, Nephrology and Clinical Chemistry, Internal Medicine, Tuebingen (Germany); Department IV, Internal Medicine, Tuebingen (Germany)

    2009-05-15

    Retinoic acid presently is the most advanced agent able to improve the efficacy of radioiodine therapy in differentiated thyroid carcinoma. In order to identify compounds with higher efficacy a panel of pharmacologically well-characterized compounds with antitumour action in solid cancer cell lines was screened. The effects of the compounds on iodide uptake, cell number, proliferation and apoptosis were evaluated. In general, compounds were more effective in cell lines derived from more aggressive tumours. The effectiveness in terms of number of responsive cell lines and maximal increase in iodide uptake achieved decreased in the order: APHA > valproic acid {approx} sirolimus {approx} arsenic trioxide > retinoic acid {approx} lovastatin > apicidine {approx} azacytidine {approx} retinol {approx} rosiglitazone {approx} bortezomib. We hypothesize that testing of cells from primary tumours or metastases in patients may be a way to identify compounds with optimum therapeutic efficacy for individualized treatment. (orig.)

  3. Gap energy studied by optical transmittance in lead iodide monocrystals grown by Bridgman's Method

    Directory of Open Access Journals (Sweden)

    Veissid N.

    1999-01-01

    Full Text Available The bandgap energy as a function of temperature has been determined for lead iodide. The monocrystal was obtained in a vacuum sealed quartz ampoule inside a vertical furnace by Bridgman's method. The optical transmittance measurement enables to evaluate the values of Eg. By a fitting procedure of Eg as a function of temperature is possible to extract the parameters that govern its behavior. The variation of Eg with temperature was determined as: Eg(T = Eg(0 - aT2/(a + T, with: Eg(0 = (2.435 ± 0.008 eV, a = (8.7 ± 1.3 x 10-4 eV/K and a = (192 ± 90 K. The bandgap energy of lead iodide at room temperature was found to be 2.277 ± 0.007 eV.

  4. Non-isothermal adsorption of radioactive methyl iodide at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Byung Seon; Park, Geun Il; Lee, Jung Won; Yoon, Ju Hyeon [KAERI, Taejon (Korea, Republic of); Yang, Ho Yeon [KHNPC, Taejon (Korea, Republic of); Ryu, Seung Kon [Chungnam National Univ., Taejon (Korea, Republic of)

    2003-07-01

    Although activated carbon has been successfully used in nuclear power plants, it cannot be considered as a primary adsorbent in a high temperature system, because of its low ignition temperature and its adverse reaction with nitrogen oxide. Therefore, activated carbon is virtually ruled out for high temperature operating systems. The adsorption and dynamic characteristics of gaseous methyl iodide for silver ion-exchanged zeolites at high temperatures up to 400 .deg. C was evaluated. In this study a simple nonisothermal and axially dispersed plug-flow was adopted to simulate the experimental breakthrough curves. The Langmuir-Freundlich isotherm model was used to represent the equilibrium relationship, and the linear driving force (LDF) approximation was used to represent the article uptake. From the viewpoint of silver utilization for the removal of methyl iodide, both the optimal operating temperature and the effective silver ion-exchange level were also determined.

  5. Performance of non-coconut base adsorbers in removal of iodine and organic iodides

    International Nuclear Information System (INIS)

    Systems for the removal of radioactive iodine and organic iodides have used impregnated coconut shell activated carbons almost exclusively. Coconut shell carbons have some disadvantages: their geographical origin determines their trace chemical content; pore structures and impregnant effectiveness are highly dependent on activation and impregnation techniques. The authors report laboratory performance of a group of iodine-organic iodide adsorbers using bases other than coconut shell carbon. These have been evaluated in conformity with USAEC Regulatory Guide 1.52 and RDT M16 1T. Performance with regard to 131I2 and CH3131I penetration and high-temperature elution have equaled or exceeded both the requirements of Guide 1.52 and results on typical coconut-shell carbons. Some performance outside Guide 1.52 ranges is included. Experimental problems in simulated LOCA testing are discussed. (U.S.)

  6. Heck Arylation of Acrylonitrile with Aryl Iodides Catalyzed by a Silica-bound Arsine Palladium(0) Complex

    Institute of Scientific and Technical Information of China (English)

    Ming Zhong CAI; Hong ZHAO; Rong Li ZHANG

    2005-01-01

    Acrylonitrile reacts with aryl iodides in the presence of tri-n-butylamine and a catalytic amount of a silica-bound arsine palladium(0) complex to afford stereoselectively (E)-cinnamonitriles in high yields.

  7. A mercuric ensemble based on a cycloruthenated complex as a visual probe for iodide in aqueous solution

    Science.gov (United States)

    Su, Xianlong; Guo, Lieping; Ma, Yajuan; Li, Xianghong

    2016-01-01

    A new water-soluble cycloruthenated complex Ru(bthiq)(dcbpy)2+ (1, Hbthiq = 1-(2-benzo[b]thiophenyl)isoquinoline, dcbpy = 4,4‧-dicarboxylate-2,2‧-bipyridine) was designed and synthesized to form its mercuric ensemble (1-Hg2+) to achieve visual detection of iodide anions. The binding constant of 1-Hg2+ is calculated to be 2.40 × 104 M-1, which is lower than that of HgI2. Therefore, the addition of I- to the aqueous solution of 1-Hg2+lead to significant color changes from yellow to deep-red by the release of 1. The results showed that iodide anions could be easily detected by the naked eyes. The detection limit of iodide anion is calculated as 0.77 μM. In addition, an easily-prepared test strip of 1-Hg2+ was obtained successfully to detect iodide anions.

  8. Cooperative effect of silver in copper-catalyzed trifluoromethylation of aryl iodides using Me3SiCF3

    KAUST Repository

    Weng, Zhiqiang

    2011-06-13

    An effective model of cooperative effect of silver for the coppercatalyzed trifluoromethylation of activated and unactivated aryl iodides to trifluoromethylated arenes using Me3SiCF3 was achieved with a broad substrate scope. © 2011 American Chemical Society.

  9. Furnace design for the mercuric iodide crystal growth for new semiconductor radiation detector

    International Nuclear Information System (INIS)

    Mercuric iodide has been attracted an interest for 40 years due to its efficiency as room temperature detector for X and γ-rays. It is worthy to note that commercial γ-ray detectors such as Ge semiconductor detectors should cool down to liquid nitrogen temperature. Compared to other semiconductor detectors such as CdZnTe and CdTe, mercuric iodide has higher efficiency, lower leakage current and less degradation. In addition, mercuric iodide has useful properties such as large band gap of 2.15 eV, low electron-hole pair creation energy of 4.2 eV, and high atomic number (Hg : 80 and I : 53). However, it is difficult to obtain high quality single crystals and the long term reliability problem in devices so that the applications of α-HgI2 are limited. Mercuric iodide undergoes a structural phase transition from an orthorhombic yellow phase (β-HgI2) to a tetragonal red phase (α-HgI2) at 127 .deg. C. In addition, the melting temperature of HgI2 is 259 .deg. C. Thus, when it grows through a melting method over 259 .deg. C, the β-HgI2 phase can be included in the final crystals in the room temperature. In general, in order to grow α-HgI2single crystals, the operating temperature is below 127 .deg. C. Note that the crystals from the solution method have contamination problems and the crystals from the physical vapor method usually display a higher quality with a well defined structure. A good thing for the physical vapor method is that α-HgI2 has high vapor pressure (∼0.1 Torr at 120 .deg. C) indicating that α-HgI2 can be grown in closed ampoules

  10. Nickel-catalyzed reductive arylation of activated alkynes with aryl iodides

    Science.gov (United States)

    Dorn, Stephanie C. M.; Olsen, Andrew K; Kelemen, Rachel E.; Shrestha, Ruja; Weix, Daniel J.

    2015-01-01

    The direct, regioselective, and stereoselective arylation of activated alkynes with aryl iodides using a nickel catalyst and manganese reductant is described. The reaction conditions are mild (40 °C in MeOH, no acid or base) and an intermediate organomanganese reagent is unlikely. Functional groups tolerated include halides and pseudohalides, free and protected anilines, and a benzyl alcohol. Other activated alkynes including an amide and a ketone also reacted to form arylated products in good yields. PMID:26028781

  11. Use of potassium iodide in Dermatology: updates on an old drug*

    OpenAIRE

    Costa, Rosane Orofino; de Macedo, Priscila Marques; Carvalhal, Aline; Bernardes-Engemann, Andréa Reis

    2013-01-01

    Potassium iodide, as a saturated solution, is a valuable drug in the dermatologist's therapeutic arsenal and is useful for the treatment of different diseases due to its immunomodulatory features. However, its prescription has become increasingly less frequent in dermatology practice. Little knowledge about its exact mechanism of action, lack of interest from the pharmaceutical industry, the advent of new drugs, and the toxicity caused by the use of high doses of the drug are some possible ex...

  12. Nitro-Grela-type complexes containing iodides - robust and selective catalysts for olefin metathesis under challenging conditions.

    Science.gov (United States)

    Tracz, Andrzej; Matczak, Mateusz; Urbaniak, Katarzyna; Skowerski, Krzysztof

    2015-01-01

    Iodide-containing nitro-Grela-type catalysts have been synthesized and applied to ring closing metathesis (RCM) and cross metathesis (CM) reactions. These new catalysts have exhibited improved efficiency in the transformation of sterically, non-demanding alkenes. Additional steric hindrance in the vicinity of ruthenium related to the presence of iodides ensures enhanced catalyst stability. The benefits are most apparent under challenging conditions, such as very low reaction concentrations, protic solvents or with the occurrence of impurities. PMID:26664602

  13. Peroxide effects of iodide excess on mitochondria in Fischer rat thyroid cell line in the early period

    Institute of Scientific and Technical Information of China (English)

    李敏

    2014-01-01

    Objective To investigate the peroxide effects of iodide excess on mitochondria in Fischer rat thyroid cell line(FRTL)in the early period.Methods After treatment with 0.0 mmol/L(control group)or 0.1 mmol/L potassium iodide(KI)for 2,4 and 24 h,respectively,changes of mitochondrial superoxide formation were assayed by flow cytometry and fluorescence microscopy using mitochondria-targeted hydroethidine(Mito SOX).

  14. Chlorine Dioxide-Iodide-Methyl Acetoacetate Oscillation Reaction Investigated by UV-Vis and Online FTIR Spectrophotometric Method

    OpenAIRE

    Laishun Shi; Xiaomei Wang; Na Li; Jie Liu; Chunying Yan

    2012-01-01

    In order to study the chemical oscillatory behavior and mechanism of a new chlorine dioxide-iodide ion-methyl acetoacetate reaction system, a series of experiments were done by using UV-Vis and online FTIR spectrophotometric method. The initial concentrations of methyl acetoacetate, chlorine dioxide, potassium iodide, and sulfuric acid and the pH value have great influence on the oscillation observed at wavelength of 289 nm. There is a preoscillatory or induction period, and the amplitude and...

  15. Nitro-Grela-type complexes containing iodides – robust and selective catalysts for olefin metathesis under challenging conditions

    Directory of Open Access Journals (Sweden)

    Andrzej Tracz

    2015-10-01

    Full Text Available Iodide-containing nitro-Grela-type catalysts have been synthesized and applied to ring closing metathesis (RCM and cross metathesis (CM reactions. These new catalysts have exhibited improved efficiency in the transformation of sterically, non-demanding alkenes. Additional steric hindrance in the vicinity of ruthenium related to the presence of iodides ensures enhanced catalyst stability. The benefits are most apparent under challenging conditions, such as very low reaction concentrations, protic solvents or with the occurrence of impurities.

  16. Nitro-Grela-type complexes containing iodides – robust and selective catalysts for olefin metathesis under challenging conditions

    Science.gov (United States)

    Tracz, Andrzej; Matczak, Mateusz; Urbaniak, Katarzyna

    2015-01-01

    Summary Iodide-containing nitro-Grela-type catalysts have been synthesized and applied to ring closing metathesis (RCM) and cross metathesis (CM) reactions. These new catalysts have exhibited improved efficiency in the transformation of sterically, non-demanding alkenes. Additional steric hindrance in the vicinity of ruthenium related to the presence of iodides ensures enhanced catalyst stability. The benefits are most apparent under challenging conditions, such as very low reaction concentrations, protic solvents or with the occurrence of impurities. PMID:26664602

  17. Nitro-Grela-type complexes containing iodides - robust and selective catalysts for olefin metathesis under challenging conditions.

    Science.gov (United States)

    Tracz, Andrzej; Matczak, Mateusz; Urbaniak, Katarzyna; Skowerski, Krzysztof

    2015-01-01

    Iodide-containing nitro-Grela-type catalysts have been synthesized and applied to ring closing metathesis (RCM) and cross metathesis (CM) reactions. These new catalysts have exhibited improved efficiency in the transformation of sterically, non-demanding alkenes. Additional steric hindrance in the vicinity of ruthenium related to the presence of iodides ensures enhanced catalyst stability. The benefits are most apparent under challenging conditions, such as very low reaction concentrations, protic solvents or with the occurrence of impurities.

  18. Determination of microamounts of potassium in sodium iodide by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Microdetermination of potassium in sodium iodide was developed by the standard addition method. Twenty grams of sample were dissolved in 50 ml of water in a quartz beaker. To the solution, 30 ml of concentrated hydrochloric acid and 30 ml of 30% hydrogen peroxide were added, and evaporated to dryness. By this process sodium iodide was converted into sodium chloride. The cake thus obtained was dissolved in water and diluted to exactly 200 ml. To 25 ml aliquots of the solution, the standard potassium and cesium chloride solutions were added and diluted to 50 ml with water; the concentration of potassium was 0 -- 1 mg/l and that of cesium 4 mM. These solutions were introduced into an air-propane flame and the absorbances were measured at 769.9 nm. During the conversion reaction, hydrochloric acid was completely decomposed, and remained hydrogen peroxide had no influence for absorbance, and other backgrounds were negligible. The linear calibration curve was obtained in the range 0 -- 2 mg of potassium per liter. Potassium in sodium iodide was determined by this method within the coefficient of variation of +-(20 -- 3)% in the range (1.7 -- 32.5) ppm. (author)

  19. Iodide Sorption to Clays and the Relationship to Surface Charge and Clay Texture - 12356

    International Nuclear Information System (INIS)

    Iodine is assumed to behave conservatively in clay barriers around nuclear waste repositories and in natural sediments. Batch experiments tend to show little to no sorption, while in column experiments iodine is often retarded relative to tritiated water. Current surface complexation theory cannot account for negatively charged ion sorption to a negatively charged clay particle. Surface protonation and iodide sorption to clay minerals were examined using surface titrations and batch sorption experiments with a suite of clay minerals. Surface titrations were completed spanning a range of both pH values and ionic strengths. For reference, similar titrations were performed on pure forms of an Al-O powder. The titration curves were deconvoluted to attain the pKa distribution for each material at each ionic strength. The pKa distribution for the Al-O shows two distinct peaks at 4.8 and 7.5, which are invariant with ionic strength. The pKa distribution of clays was highly variable between the different minerals and as a function of ionic strength. Iodide sorption experiments were completed at high solid:solution ratios to exacerbate sorption properties. Palygorskite and kaolinite had the highest amount of iodide sorption and montmorillonite had the least. (authors)

  20. Study on multiphoton ionization dissociation processes of ethyl iodide at 800 nm laser radiation

    International Nuclear Information System (INIS)

    Multiphoton ionization-dissociation (MPID) process of ethyl iodide are studied at 800 nm femto-second laser, and time-of-flight mass spectrometer of ethyl iodide are obtained. The result of laser power index shows that the parent-ion mainly undergoes the 3 + 3 resonant enhanced multiphoton ionization (REMPI) process. The percentage of part fragment ions to the total ion current and the laser intensity dependence of the molecule are measured. Based on the experiment results, the multiphoton ionization- dissociation mechanism of ethyl iodide is discussed. The conclusion is that most of ion fragments are produced by C2H5I+ dissociation, this is consistent with the parent-ion dissociation staircase. The two possible dissociation channels of parent-ion are analyzed, but the C-I dissociation is the main channel. We also use Gaussian 03 calculated the energy change of the two channels with B3LYP/3-21G basis set, the theoretical results further demonstrated the experiment. (authors)

  1. Radiofrequency induction on sodium/iodide symporter expression of thyroid cancer

    Institute of Scientific and Technical Information of China (English)

    Youxin Tian; Qinjiang Liu; Yaqiong Ni

    2013-01-01

    Objective:The aim of this study was to investigate the ef ects of radiofrequency treatment on sodium/iodide symporter expression of thyroid cancer cells. Methods:In 29 thyroid cancer patients with low or no expression of soda\\iodide symporter, the radio frequency combined 131I therapy was used, the whole-body scintigraphy and serum Ig were detected before and after the radiofrequency treatment. Results:The whole-body scintigraphy showed that 4 cases (4/29) before radiofrequency treatment had positive iodine uptake, 19 cases (19/29) two weeks after radiofrequency treatment had the positive iodine uptake, 12 cases (12/29) four weeks after radiofrequency treatment had the positive iodine uptake. Four weeks after radiofrequency treatment, 5 cases had increased serum Ig levels, 17 cases had decreased serum Ig levels, 7 cases showed no change. 25 cases (25/29) were ef ective, 15 cases (15/29) were cured. Conclusion:The radiofrequency induced the non-expressed the sodium/iodide symporter of thyroid cancer cells regain the iodine intake ability, it improved the clinical ef icacy of 131I therapy in dedif erentiated thyroid cancer.

  2. Toxic impact of bromide and iodide on drinking water disinfected with chlorine or chloramines.

    Science.gov (United States)

    Yang, Yang; Komaki, Yukako; Kimura, Susana Y; Hu, Hong-Ying; Wagner, Elizabeth D; Mariñas, Benito J; Plewa, Michael J

    2014-10-21

    Disinfectants inactivate pathogens in source water; however, they also react with organic matter and bromide/iodide to form disinfection byproducts (DBPs). Although only a few DBP classes have been systematically analyzed for toxicity, iodinated and brominated DBPs tend to be the most toxic. The objectives of this research were (1) to determine if monochloramine (NH2Cl) disinfection generated drinking water with less toxicity than water disinfected with free chlorine (HOCl) and (2) to determine the impact of added bromide and iodide in conjunction with HOCl or NH2Cl disinfection on mammalian cell cytotoxicity and genomic DNA damage induction. Water disinfected with chlorine was less cytotoxic but more genotoxic than water disinfected with chloramine. For both disinfectants, the addition of Br(-) and I(-) increased cytotoxicity and genotoxicity with a greater response observed with NH2Cl disinfection. Both cytotoxicity and genotoxicity were highly correlated with TOBr and TOI. However, toxicity was weakly and inversely correlated with TOCl. Thus, the forcing agents for cytotoxicity and genotoxicity were the generation of brominated and iodinated DBPs rather than the formation of chlorinated DBPs. Disinfection practices need careful consideration especially when using source waters containing elevated bromide and iodide.

  3. Simple and rapid determination of iodide in table salt by stripping potentiometry at a carbon-paste electrode.

    Science.gov (United States)

    Svancara, Ivan; Ogorevc, Bozidar; Nović, Milko; Vytras, Karel

    2002-04-01

    A simple and rapid procedure, utilising constant-current stripping analysis (CCSA) at a carbon-paste electrode containing tricresyl phosphate as a pasting liquid (TCP-CPE), has been developed for the determination of iodide in table salt. Because of a synergistic accumulation mechanism based on ion-pairing and extraction of iodide in combination with electrolytic pretreatment of the TCP-CPE, the method is selective for iodide and enables direct determination of iodide in samples of table salt containing anti-caking agents such as K(4)[Fe(CN)(6)] (food additive "E 536") or MgO. The iodide content (calculated as KI) can be determined in a concentration range of 2 to 100 mg kg(-1) salt, with a detection limit (S/N=3) of 1 mg kg(-1), and a recovery from 90 to 115%. The proposed method has been used to determine iodide in several types of artificially iodised table salt and in one sample of natural sea salt. The results obtained agreed well with those obtained by use of three independent reference methods (titration, spectrophotometry, and ICP-MS) used to validate the CCSA method, indicating that the developed method is applicable as a routine procedure for rapid testing in salt production process control and in the analysis of marketed table salts.

  4. Effects of barium on the nonlinear electrical characteristics and dielectric properties of SnO2-based varistors

    Institute of Scientific and Technical Information of China (English)

    Wang Chun-Ming; Wang Jin-Feng; Wang Chun-Lei; Chen Hong-Cun; Su Wen-Bin; Zang Guo-Zhong; Qi Peng; Zhao Ming-Lei; Ming Bao-Quan

    2004-01-01

    The effects of barium on electrical and dielectric properties of the SnO2·Co2Oa.Ta2O5 varistor system sintered at 1250℃ for 60min were investigated. It is found that barium significantly improves the nonlinear properties. The breakdown electrical field increases from 378.0 to 2834.5V/mm, relative dielectric constant (at 1kHz) falls from 1206 to 161 and the resistivity (at 1kHz) rises from 60.3 to 1146.5kΩ·cm with an increase of BaCO3 concentration from 0mol%to 1.00mol%. The sample with 1.00mol% barium has the best nonlinear electrical property and the highest nonlinear coefficient (α=29.2). A modified defect barrier model is introduced to illustrate the grain-boundary barrier formation of barium-doped SnO2-based varistors.

  5. Enhanced sintering and conductivity study of cobalt or nickel doped solid solution of barium cerate and zirconate

    DEFF Research Database (Denmark)

    Ricote, Sandrine; Bonanos, Nikolaos

    2010-01-01

    atmospheres and compared to the undoped compounds. The ionic and p-type conductivities have been determined, as well as the activation energy in wet reducing atmospheres, in which protonic conduction is dominant. A decrease of the ionic conductivity is noticeable for the cobalt or nickel doped barium...... zirconate (x = 0), while not for cobalt or nickel solid solution of barium cerate and zirconate (x = 0.2)....

  6. The use of mercuric iodide in instruments for safeguards and non-proliferation applications

    International Nuclear Information System (INIS)

    Mercuric Iodide is a material exceptionally suited for solid state detectors operating at room temperature. The high density and the high atomic numbers of the constituent elements provide a large absorption factor and a high full-energy-peak efficiency at gamma ray energies. The large electronic bandgap results in a very high resistivity and therefore a low leakage current at temperatures within and outside the personal comfort range. Constellation Technology has developed the technology to grow large, high quality crystals from mercuric iodide. Spectrometry grade detectors with dimensions of 25 mm x 25 mm x 3 mm and with an energy resolution of approximately 3% FWHM at 662 keV can be fabricated from these mercuric iodide crystals. The resolution of this detector approximately 1.8% FWHM and the peak-to-valley ratio is larger than twelve. Standard semi-Gaussian processing and no pulse-shape discrimination was used. These detectors can be conveniently incorporated into hand-held instruments to detect weak sources or heavily shielded sources. Previous measurements have shown that the Minimum Detectable Activity (MDA) of a 3 mm thick mercuric iodide detector with dimensions as given above is about 10% less than the MDA of a 50 mm x 50 mm sodium iodide detector, due to the superior energy resolution. Software methods are being developed to improve the identification of weak sources against a large background. Results of these measurements will be presented. Smaller detectors can be used in safeguards applications where the intensity of the radiation is relatively high. The spectral resolution of the detectors is high enough to clearly identify the significant energy lines in the spectra of stored uranium and plutonium. The shape of the spectral peaks is constant over a large range of energies so that existing software systems can be used to analyze the spectra. The small size, ruggedness, temperature stability and high efficiency of these detectors makes them good

  7. Reduction of stimulated sodium iodide symporter expression by estrogen receptor ligands in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Su-Jin; Jang, DooRye; Jeong, Hwan-Jeong; Lim, Seok Tae; Sohn, Myung-Hee [Department of Nuclear Medicine, Cyclotron Research Center, Research Institute of Clinical Medicine, Chonbuk National University Medical School, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Katzenellenbogen, John A., E-mail: jkatzene@illinois.ed [Department of Chemistry, University of Illinois, Urbana, IL 61801 (United States); Kim, Dong Wook, E-mail: kimdw@chonbuk.ac.k [Department of Nuclear Medicine, Cyclotron Research Center, Research Institute of Clinical Medicine, Chonbuk National University Medical School, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

    2011-02-15

    Purpose: The sodium iodide symporter (NIS) mediates active iodide uptake in lactating breast tissue, and when its levels are enhanced by all-trans retinoic acid (atRA), NIS has been proposed as a target for the imaging and radiotherapy of breast cancer. Importantly, the estrogen receptor {alpha} (ER{alpha}) is an important regulator of atRA induced NIS gene expression in breast cancer cells. In this study, we investigated the effect of an ER agonist (17{beta}-estradiol, E{sub 2}) or antagonist [trans-hydroxytamoxifen (TOT) or raloxifene (RAL)] treatment on the regulation of NIS gene expression and iodide uptake in an ER{alpha}-positive breast cancer (MCF-7) model. Methods: NIS functional activity was measured in vitro by {sup 125}I uptake assay after incubation with E{sub 2} (from 10{sup -15} to 10{sup -5} M), TOT (from 5x10{sup -8} to 5x10{sup -6} M), or RAL (from 5x10{sup -8} to 5x10{sup -6} M) in the presence or absence of atRA (10{sup -7} M). Under the same conditions, NIS mRNA expression was examined by reverse transcriptase polymerase chain reaction. Athymic mice with MCF-7 xenograft tumors were treated with atRA alone or atRA together with E{sub 2} to evaluate the change of {sup 125}I uptake in tumor tissues in vivo. Results: In the iodide uptake study in cells, E{sub 2}, TOT, or RAL treatment alone did not stimulate {sup 125}I uptake. However, when iodide uptake was stimulated by atRA, cotreatment with E{sub 2}, TOT or RAL decreased {sup 125}I uptake in a concentration-dependent manner. The hormone effects on NIS mRNA expression levels in MCF-7 cells were similar. The results of the in vivo biodistribution study showed that {sup 125}I uptake was reduced 50% in tumor tissues of mice treated with atRA/E{sub 2} as compared to tumors treated only with atRA. Conclusion: Our results suggest that combination treatment of atRA and ER ligands could limit the functional activity of the NIS gene induced by atRA, thereby compromising its use as a target for diagnosis

  8. Intra-individual comparison of patient acceptability of multidetector-row CT colonography and double-contrast barium enema

    International Nuclear Information System (INIS)

    AIMS: To compare the subjective acceptability of CT colonography in comparison with barium enema in older symptomatic patients, and to ascertain preferences for future colonic investigation. MATERIALS AND METHODS: The study population comprised 78 persons aged 60 years or over with symptoms suggestive of colorectal neoplasia, who underwent CT colonography followed the same day by barium enema. A 25-point questionnaire was administered after each procedure and an additional follow-up questionnaire a week later. Responses were compared using Wilcoxon matched pairs testing, Mann-Whitney test statistics and binomial exact testing. RESULTS: Participants suffered less physical discomfort during CT colonography (p=0.03) and overall satisfaction was greater compared with barium enema (p=0.03). On follow-up, respondents reported significantly better tolerance of CT colonography (p=0.002), and were less prepared to undergo barium enema again (p<0.001). Of 52 subjects expressing an opinion, all preferred CT to barium enema. CONCLUSION: Patient satisfaction was higher with CT colonography than barium enema. CT colonography caused significantly less physical discomfort and was overwhelmingly preferred by patients

  9. Site-selective spectroscopy of the solid-state defect chemistry in erbium-doped barium titanate.

    Science.gov (United States)

    Bak, John D; Wright, John C

    2005-10-01

    Erbium-doped barium titanate crystals were studied by laser-induced fluorescence spectroscopy. Thirteen spectroscopically distinct erbium ion sites were found. The relative concentrations of the different sites changed as a function of the crystal and its preparation and treatment. One major site was present in all crystals. The site distribution was changed either by growing codoped crystals with donor (La3+) and acceptor (Sc3+) ions or by changing the temperature and partial pressure of the oxygen in the annealing atmosphere. Equilibrium calculations were done to simulate the defect distributions that result from the charge compensation of the erbium ions. Comparison with the observed dependence of the site spectral intensities indicated that the erbium enters the lattice on barium sites. We assigned the dominant site to an erbium ion on a barium site that is locally compensated by a barium vacancy, whereas the other lower-intensity sites corresponded to erbium ions that are locally compensated by an electron and a more complex center of an erbium, a barium vacancy, and a hole. The spectra of one sample showed that its defects were different and were characteristic of a sample that had not equilibrated. The new sites in this sample were assigned to erbium entering the lattice on a titanium site, which was then locally compensated by an oxygen vacancy or a hole. Heating equilibrated the sample and changed the erbium to a barium site. PMID:16853368

  10. Use of Different Barium Salts to Inhibit the Thaumasite Form of Sulfate Attack in Cement-based Materials

    Institute of Scientific and Technical Information of China (English)

    SU Ying; WEI Xiaochao; HUANG Jian; WANG Yingbin; HE Xingyang; WANG Xiongjue; MA Baoguo

    2016-01-01

    We investigated the effects of different barium compounds on the thaumasite form of sulphate attack (TSA) resistance of cement-based materials when they were used as admixtures in mortars. Moreover, we analyzed the inhibition mechanisms within different types of barium salts, namely BaCO3 and Ba(OH)2, on the thaumasite formation. The control cement mortar and mortars with barium salts to cement and limestone weight ratios of 0.5%, 1.0%, and 1.5% were immersed in 5% (by weight) MgSO4 solution at 5℃ to mimic TSA. Appearance, mass, and compressive strength of the mortar samples were monitored and measured to assess the general degradation extent of these samples. The products of sulphate attack were further analyzed by XRD, FTIR, and SEM, respectively. Experimental results show that different degradation extent is evident in all mortars cured in MgSO4 solution. However, barium salts can greatly inhibit such degradation. Barium in hydroxide form has better effectiveness in protection against TSA than carbonate form, which may be due to their solubility difference in alkaline cement pore solution, and the presence of these barium compounds can reduce the degree of TSA by comparison with the almost completely decomposed control samples.

  11. Study on the preparation and formation mechanism of barium sulphate nanoparticles modified by different organic acids

    Indian Academy of Sciences (India)

    Yuhua Shen; Chuanhao Li; Xuemei Zhu; Anjian Xie; Lingguang Qiu; Jinmiao Zhu

    2007-07-01

    This paper reports a simple method to prepare barium sulphate nanoparticles by use of tetradecanoic acid, hexadecanoic acid and stearic acid as modifier. The barium sulphate nanoparticles obtained are characterized by using Fourier transform infra-red spectroscopy (FT-IR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic laser light scatter (DLLS) and thermogravimetric analysis (TGA), respectively. The results show that the BaSO4 particles are all spherical and in the nano-scale. Our method has a better dispersion and controllable diameter dependent on the length of the chain of organic acid and the pH value of the system. A possible mechanism is also discussed.

  12. Barium enema carried out by digital luminescent radiography (DLR) and conventional screen-film system combinations

    International Nuclear Information System (INIS)

    120 double-contrast barium enemas were obtained by both digital luminescent radiography (DLR) and conventional screen-film systems, the digital exposure dose being 50% of the conventional one. In DLR two differently post processed images were obtained from one X-ray exposure: a display with low spatial frequency enhancement was processed to look like a conventional radiograph and was complemented by a display with high spatial frequency enhancement. Analysing the results statistically DLR proved to be diagnostically equivalent to conventional radiography despite the reduction in exposure dose and a slightly diminished image quality. High spatial frequency enhancement did not provide further diagnostic information and is therefore superfluous in barium enemas. (orig.)

  13. Elastic properties investigation of gamma-radiated barium lead borosilicate glass using ultrasonic technique

    International Nuclear Information System (INIS)

    Highlights: → Change in acoustical parameter due to composition effect and irradiation effect. → Changes in the structure of the glass (BO3 → BO4) due to the effect of radiation. → Structural changes in the BO3 to BO4 have a more compactness structure. - Abstract: The ultrasonic velocities were measured in barium lead borosilicate glass samples of different compositions before and after irradiation with γ-rays. Measurements were carried out at room temperature and 4 MHz frequency using ultrasonic technique. The ultrasonic velocities data of glass samples have been used to find the elastic modulus and micro-hardness. Densities of glass samples were measured by Archimedes's principle using n-hexane as immersion liquid. It was found that ultrasonic velocity, elastic modulus and micro-hardness increase with increasing barium oxide content and increasing γ-radiation dose.

  14. Synthesis and Fluorescence of Europium-Doped Barium Fluoride Cubic Nanocolumns

    Institute of Scientific and Technical Information of China (English)

    连洪州; 刘洁; 叶泽人; 石春山

    2004-01-01

    Europium-doped barium fluoride cubic nanocolumns were synthesized from the quaternary water in oil reverse microemulsions. In this process, the aqueous cores of water/cetyl trimethyl ammonium bromide(CTAB)/n-butanol/n-octane reverse microemulsions were used as microreactors for the precipitation of europium doped barium fluoride. XRD analysis shows that under the dopant concentration of 0.06%(molar fraction), the products are single phase. The result products are cubic column-like with about 30~50 nm edge length of cross section, and about 200 nm of length obtained from the transmission electron microscopy(TEM), and atomic force microscopy(AFM). Under the 0.06%(molar fraction) of dopant concentration, the fluorescence of Eu2+ and Eu3+ under the 589 of excitation wavelength is observed.

  15. Barium phosphate conversion coating on die-cast AZ91D magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Poor corrosion resistance limits the application of magnesium alloys.Conversion coating is widely used to protect magnesium alloys because of easy operation and low cost.A novel conversion coating on die.cast AZ91D magnesium alloy containing barium salts was studied.The optimum concentrations of Ba(NO3)2,Mn(NO3)2 and NH4H2PO4 are 25 g/L,15 mL/L and 20 g/L,respectively,based on orthogonal test resulm.The treating time,solution temperature and PH value are settled to be 5-30 min,50-70℃and 2.35-3.0.respectively.The corrosion resistance of barium conversion coating is better than that of manganese-based phosphate conversion coating by immersion test.The coating is composed of Ba,P, O,Mg,Zn,Mn and Al by EDX analysis.

  16. Absolute Te$_2$ reference for barium ion at $455.4~$nm

    CERN Document Server

    Dutta, T; Mukherjee, M

    2016-01-01

    Precision atomic spectroscopy is presently the work horse in quantum information technology, metrology, trace analysis and even for fundamental tests in physics. Stable lasers are inherent part of precision spectroscopy which in turn requires absolute wavelength markers suitably placed corresponding to the atomic species being probed. Here we present, new lines of tellurium (Te$_2$) which allows locking of external cavity diode laser (ECDL) for precision spectroscopy of singly charged barium ions. In addition, we have developed an ECDL with over 100 GHz mod-hop-free tuning range using commercially available diode from $\\textit{Nichia}$. These two developments allow nearly drift-free operation of a barium ion trap set-up with one single reference cell thereby reducing the complexity of the experiment.

  17. Efficient photoionization for barium ion trapping using a dipole-allowed resonant two-photon transition

    CERN Document Server

    Leschhorn, G; Schaetz, T

    2011-01-01

    Two efficient and isotope-selective resonant two-photon ionization techniques for loading barium ions into radio-frequency (RF)-traps are demonstrated. The scheme of using a strong dipole-allowed transition at \\lambda=553 nm as a first step towards ionization is compared to the established technique of using a weak intercombination line (\\lambda=413 nm). An increase of two orders of magnitude in the ionization efficiency is found favoring the transition at 553 nm. This technique can be implemented using commercial all-solid-state laser systems and is expected to be advantageous compared to other narrowband photoionization schemes of barium in cases where highest efficiency and isotope-selectivity are required.

  18. Scaled-energy spectroscopy of a |M|=1 Rydberg barium atom in an electric field

    Institute of Scientific and Technical Information of China (English)

    Wang Lei; Quan Wei; Shen Li; Yang Hai-Feng; Shi Ting-Yun; Liu Xiao-Jun; Liu Hong-Ping; Zhan Ming-Sheng

    2009-01-01

    We observe strong energy-dependent quantum defects in the scaled-energy Stark spectra for |M|=1 Rydberg states of barium atoms at three scaled energies: ε= -2.000, ε= -2.500 and ε=-3.000. In an attempt to explain the observations, theoretical calculations of closed orbit theory based on a model potential including core effect are performed for non-hydrogenic atoms. While such a potential has been uniformly successful for alkali atoms with a single valence electron, it fails to match experimental results for barium atoms in the 6snp Rydberg states with two valence electrons. Our study points out that this discrepancy is due to the strong perturbation from the 5d8p state, which voids the simple approximation for constant quantum defects of principle quantum number n.

  19. Laser plasma channel formation in barium vapor based on superelastic heating of electrons

    International Nuclear Information System (INIS)

    Computational study of plasma channel formation kinetics in optically dense barium vapor irradiated by pulsed laser light tuned to the Ba I resonance transition at λ = 553.5 nm has been performed. Seed electrons are produced due to the mechanism of atoms associative ionization, which then gain energy in superelastic collisions and initiate the avalanche ionization of atoms by electron impact. We have studied the influence of radiative transfer effects in cylindrically symmetric gas volume on the excitation kinetics of multilevel barium atoms, dynamics of absorption of laser radiation, and the plasma channel expansion in the form of a halo in condition of competition between the ionizing and quenching electron collisions with excited atoms. (paper)

  20. Effect of CaF2 addition on optical properties of barium phosphate glasses

    Science.gov (United States)

    Kumar, N. Manoj; Rao, G. Venkateswara; Akhila, B. E.; Shashikala, H. D.

    2014-04-01

    Ternary barium phosphate glasses, (50-X)BaO-XCaF2-50P2O5 have been prepared by adding 0-10 mol% of CaF2 to binary barium phosphate glasses. The amorphous nature of the prepared glasses was confirmed by X-ray diffraction technique. The UV-Visible absorption spectra have been recorded, optical band gap energy Eopt and Urbach energy Etail were determined. Shift in Eopt and Etail with increase in concentration of CaF2 is noted. FTIR analysis was carried out to investigate the short and intermediate-range orders in glasses. Shift of (P-O-P) band to higher wave number with the substitution of BaO with CaF2 shows the shortening of the phosphate chains. Hardness and density of glass samples were measured and correlated with the composition of glasses.

  1. Removal of hexavalent chromium from aqueous solution by barium ion cross-linked alginate beads

    Directory of Open Access Journals (Sweden)

    Uzaşçı Sesil

    2014-07-01

    Full Text Available Barium ion cross-linked alginate beads have shown great affinity to toxic hexavalent chromium ions in aqueous solution, contrary to the traditional calcium alginate beads. The adsorption experiments were carried out by the batch contact method. The optimal pH for removal was found to be pH 4. The equilibrium was established in 4 h and the removal efficiency of chromium (VI was found as 95%. The adsorption data fit well with Langmuir and Freundlich isotherms. The maximum chromium (VI adsorption capacity determined from Langmuir isotherm was 36.5 mg/g dry alginate beads. Our study suggests that barium alginate beads can be used as cost-effective and efficient adsorbents for the removal of chromium (VI from contaminated waters.

  2. Single-step synthesis of well-crystallized and pure barium titanate nanoparticles in supercritical fluids

    Science.gov (United States)

    Reverón, Helen; Aymonier, Cyril; Loppinet-Serani, Anne; Elissalde, Catherine; Maglione, Mario; Cansell, François

    2005-08-01

    Single-step synthesis of ultra-fine barium titanate powder with a crystallinity as high as 90% and without barium carbonate contamination has been successfully performed under supercritical conditions using a continuous-flow reactor in the temperature range 150-380 °C at 16 MPa. To synthesize this bimetallic oxide, alkoxides, ethanol and water were used. The influence of the synthesis parameters on the BaTiO3 powder characteristics was investigated. The results show that the water to alkoxide precursor ratio, the reactor temperature and the Ba:Ti molar ratio of alkoxide precursor play a major role in the crystallization of pure and well-crystallized BaTiO3 nanoparticles. The continuous mode of operation without post-treatments for powder washing, drying or crystallization increase the industrial interest.

  3. Barium hexaferrite/graphene oxide: controlled synthesis and characterization and investigation of its magnetic properties

    Science.gov (United States)

    Maddahfar, Mahnaz; Ramezani, Majid; Mostafa Hosseinpour-Mashkani, S.

    2016-08-01

    In the present study, barium hexaferrite nanocrystals (BaFe12O19) were successfully synthesized through the two-step sol-gel method in an aqueous solution in the presence of barium nitrate and iron (III) nitrate. Besides, the effect of the molar ratio of graphene oxide on the particle size and magnetic properties of final product was investigated. In this research, glucose plays a role as capping and chelating agent in the synthesis of BaFe12O19/graphene oxide. Moreover, it was found that the size, morphology, and magnetic properties of the final products could be greatly influenced by the molar ratio of graphene oxide. BaFe12O19/graphene oxide was characterized by using X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, vibrating sample magnetometer, and energy-dispersive spectrometry.

  4. Magnetic and dielectric properties of 3Y-TZP/strontium doped barium ferrite composite

    Science.gov (United States)

    Zhang, Chao; Wang, Shan-Shan; Guo, Rui-Song; Cai, Guang-Lan; Guo, Wei-Na; Wu, Chen

    2015-02-01

    Magnetic and dielectric properties of 3Y-TZP/20 wt.% Ba1-xSrxFe12O19 (x = 0, 0.25, 0.5, 0.75) composites prepared by solid state reaction method are investigated. The magnetic properties are improved in the composites with the strontium doped barium ferrite. When x = 0.25, the saturation magnetization of the ferrite reaches the maximum. This is due to the migration of Fe3+ induced by the Sr2+ doping. The dielectric properties are also improved in the composite with the strontium doped barium ferrite. When x = 0.5, the dielectric constant and dielectric loss possess the maximum. This is caused by the lattice distortion resulting from the Sr2+ doping. The dielectric properties are analyzed by the universal relaxation law.

  5. The CAMEO barium release - E/parallel/ fields over the polar cap

    Science.gov (United States)

    Heppner, J. P.; Miller, M. L.; Pongratz, M. B.; Smith, G. M.; Smith, L. L.; Mende, S. B.; Nath, N. R.

    1981-01-01

    Four successive thermite barium releases at an altitude of 965 km over polar cap invariant latitudes 84 to 76 deg near magnetic midnight were conducted from the orbiting second stage of the vehicle that launched Nimbus 7; the releases were made as part of the CAMEO (Chemically Active Material Ejected in Orbit) program. This was the first opportunity to observe the behavior of conventional barium release when conducted at orbital velocity in the near-earth magnetic field. The principal unexpected characteristic in the release dynamics was the high, 1.4 to 2.6 km/s, initial Ba(+) expansion velocity relative to an expected velocity of 0.9 km/s. Attention is also given to neutral cloud expansion, initial ion cloud expansion, convective motion, and the characteristics of field-aligned motion. The possibility of measuring parallel electric fields over the polar cap by observing perturbations in the motion of the visible ions is assessed.

  6. Examination of colon with diluted barium contrast medium by the irrigoscopic (irrigographic) method

    International Nuclear Information System (INIS)

    By analogy with the work of C.Tavernier et al. (1974), who examined the eosophagus, stomach and duodenum with diluted 23% barium sulphate solution, the authors examined 58 patients by irrigoscopy (irrigography) with 20% barium sulphate solution. The rationality and the advantages of the method over the standard one were demonstrated. Early lesions measuring 3 or 4 mm were detected; the mucosal relief was very well presented. The injurious effect of tannic acid on the liver parenchyma was avoided by the use of low 0.15% tannin solution. In comparison with the method of Fischer (with double contrast) the examination time was shortened and the radiation load to the patients and attending personal reduced. The method is technically easy to perform. (author)

  7. Isolation and characterisation of barium sulphate and titanium oxides in monument crusts

    International Nuclear Information System (INIS)

    Black crusts from historical ornamental materials contain Ba and Ti. These elements are in low proportion, making their determination difficult and especially the characterisation of the phases in which they are present. For this reason, works on the mineralogical composition of the two elements in black crusts is scarce. Thus the isolation, previous to their characterisation, is important for the study of the surface layer in altered monuments. An acid attack for the isolation of barium sulphate and titanium oxides in black crusts from polluted areas has been used. The acid employed is a mixture of HF, HNO3 and HClO4. The residue isolated by acid attack was analysed by energy dispersive X-ray fluorescence and X-ray diffraction. It was characterised, and the percentages of barite (barium sulphate), anatase (titanium oxide), and rutile (titanium oxide) phases present in the surface layers were calculated

  8. The removal of radiostrontium by means of barium sulphate precipitation, ch. 4

    International Nuclear Information System (INIS)

    The barium sulphate precipitation method which is less-commonly used for the purification of radioactive wastewater is examined. In batch experiments, source variables influencing the process are studied. Results are tested in continuous processes. It was shown that the addition of stoichiometric amounts of precipitants at the same time rendered no more than 60% removal of radiostrontium; the addition of excess sulphate ions resulted in 99.7% removal. This can also be achieved by slow addition of a stoichiometric amount of barium ions to a solution containing sulphate ions and the radioisotope. The binding process is multilayer occlusion, but when more than the stoichiometric amount is added the continuing process is normal adsorption. The process is pH-independent; there is little interference of foreign ions. The method was also tested for the removal of ruthenium-106 and cobalt-60 and was successfully applied in the case of ruthenium

  9. Effects of barium sulfate as a contrast medium to enterocutaneous fistulas

    International Nuclear Information System (INIS)

    Fistulation following thoracic and epigastric interventions are conservatively treated, as a rule, because of the high rate of complications expected from reoperation. With properly functioning anastomotic transit, insufficiencies usually undergo spontaneous healing, within four to six weeks. Enterocutaneous fistulae developed in 29 of 271 patients with intrathoracic oesophagastric or oesophagojejunal anastomosis. Syringeal ramification into pleural or abdominal cavities were eliminated by means of an absorbable contrast medium, before barium sulphate was orally administered to all patients. Thoracic fistulae were closed after 21.8 days on average, while 20.3 days was the average period required for closure of epigastric fistulae. Barium sulphate was found to stimulate fistular tissue granulation, so that obliteration of the fistular system occurred much sooner, as compared to conservative treatment. The patient's quality of life can thus be improved, and hospitalisation can be shortened. Neither locally delimited nor systemic complications were observed in any of the cases described. (author)

  10. Gamma-ray shielding and structural properties of barium-bismuth-borosilicate glasses

    Science.gov (United States)

    Bootjomchai, Cherdsak; Laopaiboon, Jintana; Yenchai, Chadet; Laopaiboon, Raewat

    2012-07-01

    The attenuation coefficients of barium-bismuth-borosilicate glasses have been measured for gamma-ray photon energies of 662, 1173 and 1332 keV using a narrow beam transmission geometry. These coefficients were then used to obtain the values of mass attenuation coefficients, effective atomic number, effective electron density and mean free path. Good agreement has been observed between experimental and theoretical values of these parameters. From the obtained results it is reported here that from the barium-bismuth-borosilicate glasses are better shields to gamma-radiations in comparison to the standard radiation shielding concretes from the shielding point of view. The molar volume, FTIR and acoustic investigations have been used to study the structural properties of the prepared glass system. The obtained results reveal that the formation of non-bridging oxygens occurs at higher concentration of Bi2O3.

  11. Correlated Strontium and Barium Isotopic Compositions of Acid-Cleaned Single Silicon Carbides from Murchison

    CERN Document Server

    Liu, Nan; Gallino, Roberto; Davis, Andrew M; Bisterzo, Sara; Gyngard, Frank; Kaeppeler, Franz; Cristallo, Sergio; Dauphas, Nicolas; Pellin, Michael J; Dillmann, Iris

    2015-01-01

    We present strontium, barium, carbon, and silicon isotopic compositions of 61 acid-cleaned presolar SiC grains from Murchison. Comparison with previous data shows that acid washing is highly effective in removing both strontium and barium contamination. For the first time, by using correlated $^{88}Sr$/$^{86}Sr$ and $^{138}Ba$/$^{136}Ba$ ratios in mainstream SiC grains, we are able to resolve the effect of $^{13}C$ concentration from that of $^{13}C$-pocket mass on s-process nucleosynthesis, which points towards the existence of large $^{13}C$-pockets with low $^{13}C$ concentration in AGB stars. The presence of such large $^{13}$R-pockets with a variety of relatively low $^{13}C$ concentrations seems to require multiple mixing processes in parent AGB stars of mainstream SiC grains.

  12. Effect of Mg-Zr substitution and microwave processing on magnetic properties of barium hexaferrite

    Science.gov (United States)

    Sharma, Manju; Kashyap, Subhash C.; Gupta, H. C.

    2014-09-01

    The effect of substitution of Mg-Zr for Fe in M-type barium hexaferrite (BHF) and of processing technique on the magnetic properties and microstructure has been reported in the present paper. Significant changes in magnetic properties have been observed on substituting Fe ions by Mg and Zr ions in M-type barium hexaferrite, i.e. BaFe12O19 as well as by single mode microwave processing. The single mode microwave processing of the undoped sample reduced the coercivity to nearly 25% of the value for the sintered sample along with the enhancement in magnetization, thereby making it suitable for memory devices. The improvement in magnetic properties is explained on the basis of microstructure. The addition of substituents, though assisted in the formation of single phase, it, however, degraded the magnetization besides decreasing the coercivity, possibly due to substitution at the octahedral sites.

  13. Neutron beam test of barium fluoride crystal for dark matter direct detection

    Science.gov (United States)

    Guo, C.; Ma, X. H.; Wang, Z. M.; Bao, J.; Dai, C. J.; Guan, M. Y.; Liu, J. C.; Li, Z. H.; Ren, J.; Ruan, X. C.; Yang, C. G.; Yu, Z. Y.; Zhong, W. L.

    2016-10-01

    In order to test the capabilities of Barium Fluoride (BaF2) crystal for dark matter direct detection, nuclear recoils are studied with mono-energetic neutron beam. The energy spectra of nuclear recoils, quenching factors for elastic scattering neutrons and discrimination capability between neutron inelastic scattering events and γ events are obtained for various recoil energies of the F content in BaF2.

  14. Barium strontium titanate thin film varactors for room-temperature microwave device applications

    International Nuclear Information System (INIS)

    Recent progress in the development of barium strontium titanate thin film varactors for room temperature tunable microwave devices applications is reviewed, with emphasis on efforts towards the improvement in the quality of BST thin films and the fabrication issues crucial for the performance of microwave devices based on BST varactors. The paper provides examples of tunable microwave devices employing BST varactors. Other thin film materials currently competing with BST thin films are discussed. Topics which deserve further investigation are suggested. (topical review)

  15. Radiographer and radiologist perception error in reporting double contrast barium enemas: A pilot study

    International Nuclear Information System (INIS)

    Purpose: The practice of radiographers performing double contrast barium enemas (DCBE) is now widespread and in many centres the radiographer's opinion is, at least, contributing to a dual reporting system [Bewell J, Chapman AH. Radiographer performed barium enemas - results of a survey to assess progress. Radiography 1996;2:199-205; Leslie A, Virjee JP. Detection of colorectal carcinoma on double contrast barium enema when double reporting is routinely performed: an audit of current practice. Clin Radiol 2001;57:184-7; Culpan DG, Mitchell AJ, Hughes S, Nutman M, Chapman AH. Double contrast barium enema sensitivity: a comparison of studies by radiographers and radiologists. Clin Radiol 2002;57:604-7]. To ensure this change in practice does not lead to an increase in reporting errors, this study aimed to compare the perception abilities of radiographers with those of radiologists. Methods: Three gastro-intestinal (GI) radiographers and three consultant radiologists independently reported on a selection of 50 DCBE examinations, including the level of certainty in their comments for each examination. A blinded comparison of the results with an independent 'standard report' was recorded. Results: The results demonstrate there was no significant difference in perception error for any of the levels of certainty, for single reporting, for double reading by a radiographer/radiologist or by two radiologists. Conclusions: The study shows that radiographers can perceive abnormalities on DCBE at similar sensitivities and specificities as radiologists. While the participants in the study may be typical of a district general hospital, the nature of the study gives it limited external validity. As a pilot, the results demonstrate that, with slight modification, the methodology could be used for a larger study

  16. High Performance, Low Temperature Solution-Processed Barium and Strontium Doped Oxide Thin Film Transistors

    OpenAIRE

    Banger, Kulbinder K.; Peterson, Rebecca L.; Mori, Kiyotaka; Yamashita, Yoshihisa; Leedham, Timothy; Sirringhaus, Henning

    2013-01-01

    Amorphous mixed metal oxides are emerging as high performance semiconductors for thin film transistor (TFT) applications, with indium gallium zinc oxide, InGaZnO (IGZO), being one of the most widely studied and best performing systems. Here, we investigate alkaline earth (barium or strontium) doped InBa(Sr)ZnO as alternative, semiconducting channel layers and compare their performance of the electrical stress stability with IGZO. In films fabricated by solution-processing from metal alkoxide ...

  17. Phase conjugation, isotropic and anisotropic higher order diffraction generation, and image correlation using photorefractive barium titanate

    Science.gov (United States)

    Buranasiri, Prathan

    2005-04-01

    Using barium titanate as the photorefractive material, we demonstrate phase conjugation, beam coupling, higher diffraction order generation. At small incident angles less than 0.015 radian, both codirectional isotropic self-diffraction (CODIS) and contradirectional isotropic self-diffraction (CONDIS) are generated simultaneously. At bigger incident angles approximately more than 0.2094 radian, only codirectional anisotropic-self diffraction (CODAS) are generated. On going imaging correlation is also showing.

  18. Barium ferrite/epoxy resin nanocomposite system: Fabrication, dielectric, magnetic and hydration studies

    OpenAIRE

    A. Kanapitsas; C. Tsonos; G. C. Psarras; S. Kripotou

    2016-01-01

    Composite systems of epoxy resin and barium ferrite nanoparticles have been prepared, and studied varying the content of the inclusions. Morphology of prepared samples has been examined via scanning electron microscopy and X-ray diffraction spectra, while electrical and magnetic properties were investigated by means of broadband dielectric spectroscopy, and magnetization tests respectively. Finally, water vapor sorption measurements were conducted in order to study the water sorption dynamics...

  19. Neutron Beam Tests of Barium Fluoride Crystal for Dark Matter Direct Detection

    CERN Document Server

    Guo, Cong; Wang, Zhimin; Bao, Jie; Dai, Changjiang; Guan, Mengyun; Liu, Jinchang; Li, Zuhao; Ren, Jie; Ruan, Xichao; Yang, Changgen; Yu, Zeyuan; Zhong, Weili

    2016-01-01

    In order to test the capabilities of Barium Fluoride (BaF2) Crystal for dark matter direct detection, nuclear recoils are studied with mono-energetic neutron beam. The energy spectra of nuclear recoils, quenching factors for elastic scattering neutrons and discrimination capability between neutron inelastic scattering events and {\\gamma} events are obtained for various recoil energies of the F content in BaF2.

  20. Effect of boric acid sintering aid on densification of barium ferrite

    Indian Academy of Sciences (India)

    S S Vidyawathi; R Amaresh; L N Satapathy

    2002-11-01

    Boric acid has been added in 0.1–0.6% range for studying the densification characteristics of solid state sintered barium hexaferrite. Sintering studies have been carried out at three different temperatures. Physical properties like density and porosity have been studied for all compositions. The phase identification and microstructural investigation on the fractured surface have been carried out to understand the effect of sintering aid on the densification characteristics.

  1. Modification of gray iron produced by induction melting with barium strontium

    Science.gov (United States)

    Modzelevskaya, G.; Feoktistov, A. V.; Selyanin, I. F.; Kutsenko, A. I.; Kutsenko, A. A.

    2016-09-01

    The article provides analysis of results of gray iron experimental melts in induction furnace and the following melt modification with barium-strontium carbonate (BSC-2). It is shown that modification positively affects mechanical and casting properties and as-cast iron structure. It was established that BSC-2 granulated immediately prior to use has greater impact on melt than BSC-2 of the same faction, supplied by the manufacturer.

  2. Electrical Properties of Thin-Film Capacitors Fabricated Using High Temperature Sputtered Modified Barium Titanate

    OpenAIRE

    Robert Mamazza; Heinz Felzer; Martin Dubs; Glyn J. Reynolds; Martin Kratzer

    2012-01-01

    Simple thin-film capacitor stacks were fabricated from sputter-deposited doped barium titanate dielectric films with sputtered Pt and/or Ni electrodes and characterized electrically. Here, we report small signal, low frequency capacitance and parallel resistance data measured as a function of applied DC bias, polarization versus applied electric field strength and DC load/unload experiments. These capacitors exhibited significant leakage (in the range 8–210 μA/cm2) and dielectric loss. Measur...

  3. The use of radioanalytical methods in nucleation and crystal growth studies. The barium sulphate system

    International Nuclear Information System (INIS)

    The spontaneous precipitation of barium sulphate in aqueous solutions was followed by counting the 131Ba specific activity in the aqueous phase. The main advantages of this method were the increased sensitivity and the possibility of monitoring the process to a larger extent in comparison with other techniques. Kinetics parameters including the size of the critical nucleus and the surface energy of the precipitating solid were estimated according to the model for polynuclear growth. (Author)

  4. Establishment of a protocol for determining gastrointestinal transit time in mice using barium and radiopaque markers

    Energy Technology Data Exchange (ETDEWEB)

    Myagmarjaibuu, Bilomaa; Moon, Myeong Ju; Heo, Suk Hee; Jeong, Seo In; Jeong, Yong Yeon; Kang, Heoung Keun [Dept. of Radiology, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun (Korea, Republic of); Park, Jong Seong [Dept. of Physiology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Jun, Jae Yeoul [Dept. of Physiology, College of Medicine, Chosun University, Gwangju (Korea, Republic of)

    2013-01-15

    The purpose of this study was to establish a minimally invasive and reproducible protocol for estimating the gastrointestinal (GI) transit time in mice using barium and radiopaque markers. Twenty 5- to 6-week-old Balb/C female mice weighing 19-21 g were used. The animals were divided into three groups: two groups that received loperamide and a control group. The control group (n = 10) animals were administered physiological saline (1.5 mL/kg) orally. The loperamide group I (n = 10) and group II (n = 10) animals were administered 5 mg/kg and 10 mg/kg loperamide orally, respectively. Thirty minutes after receiving the saline or loperamide, the mice was administered 80 μL of barium solution and six iron balls (0.5 mm) via the mouth and the upper esophagus by gavage, respectively. Afterwards, the mice were continuously monitored with fluoroscopic imaging in order to evaluate the swallowing of the barium solution and markers. Serial fluoroscopic images were obtained at 5- or 10-min intervals until all markers had been excreted from the anal canal. For analysis, the GI transit times were subdivided into intestinal transit times (ITTs) and colon transit times (CTTs). The mean ITT was significantly longer in the loperamide groups than in the control group (p < 0.05). The mean ITT in loperamide group II (174.5 ± 32.3) was significantly longer than in loperamide group I (133.2 ± 24.2 minute) (p < 0.05). The mean CTT was significantly longer in loperamide group II than in the control group (p < 0.05). Also, no animal succumbed to death after the experimental procedure. The protocol for our study using radiopaque markers and barium is reproducible and minimally invasive in determining the GI transit time of the mouse model.

  5. Hybrid Nd-Fe-B/barium ferrite magnetic materials with epoxy matrix

    OpenAIRE

    Stajčić Aleksandar P.; Stajić-Trošić Jasna T.; Aleksić Radoslav R.; Žák Tomáš; Lazić Nada L.; Stijepović Mirko Z.; Grujić Aleksandar S.

    2012-01-01

    Lately a great attention has been paid to the research of bonded hybrid composites with improved dynamic mechanical capacities capable of replacing bonded Nd-Fe-B magnetic materials, by using the cheaper (ferrite) materials instead of the Nd-Fe-B powder while retaining the satisfying values of the maximal magnetic energy. The objective of this study is to assess how different contents of Nd-Fe-B and/or barium ferrite particles can affect morphological, dynamic mechanical and magnetic pr...

  6. Transfer of cadmium and barium from soil to crops grown in tropical soils

    OpenAIRE

    Leônidas Carrijo Azevedo Melo; Evandro Barbosa da Silva; Luís Reynaldo Ferracciú Alleoni

    2014-01-01

    Phytotoxicity and transfer of potentially toxic elements, such as cadmium (Cd) or barium (Ba), depend on the availability of these elements in soils and on the plant species exposed to them. With this study, we aimed to evaluate the effect of Cd and Ba application rates on yields of pea (Pisum sativum L.), sorghum (Sorghum bicolor L.), soybean (Glycine max L.), and maize (Zea mays L.) grown under greenhouse conditions in an Oxisol and an Entisol with contrasting physical and chemical properti...

  7. Growth and study of barium oxalate single crystals in agar gel

    Indian Academy of Sciences (India)

    P V Dalal; K B Saraf

    2006-10-01

    Barium oxalate was grown in agar gel at ambient temperature. The effect of various parameters like gel concentration, gel setting time and concentration of the reactants on the growth of these crystals was studied. Prismatic platy shaped spherulites and dendrites were obtained. The grown crystals were characterized by X-ray powder diffractometry, infrared spectroscopy, thermogravimetric and differential thermal analysis. An attempt is made to explain the spherulitic growth mechanism.

  8. Randomized clinical trial on the use of antispasmodic drugs in barium enema: impact on radiological practice

    International Nuclear Information System (INIS)

    Purpose: To assess the willingness of radiologists to change their practice when the results of a randomized clinical trial (RCT) on the use of antispasmodic drugs in barium enema are presented. Materials and Methods: During the years 1994 and 1995 two postal questionnaires were sent to 481 practicing radiologists who were all members of the Netherlands Society of Radiology. In the first questionnaire the respondents were asked to give the characteristics of their practices in performing daily barium enema. The data from this questionnaire was used as a reference. The second questionnaire was sent to the respondents together with an abstract on the randomized clinical trial supporting the use of antispasmodic drugs in barium enema. We also indicated a preference for Buscopan over Glucagon as the antispasmodic drug. The willingness to change prescription habits was measured by comparing the data of the two questionnaires. Results: Of 481 practicing radiologists, 312 responded to the first questionnaire and gave information of their prescription habits (response rate 64%). These 312 responders were sent an abstract of the RCT and were asked to fill out a second questionnaire to determine their willingness to change their practice. Two hundred and sixty-seven radiologists responded (response rate 86%). A significant number of 119 (51%) were willing to increase the use of antispasmodic drugs. A significant number of 128 (55%) chose to increase the use of Buscopan, while a significant number of 81 (32%) were willing to decrease the use of Glucagon. Conclusion: Direct exposure to the results of an RCT recommending the use of antispasmodic drugs in barium enema, especially Buscopan, is likely to increase its use by practicing radiologists

  9. Yield and ion distribution for the barium cloud at 31,000 kilometers, September 21, 1971.

    Science.gov (United States)

    Manring, E. R.; Patty, R. R.

    1973-01-01

    The photon flux density associated with the 4554-A resonance radiation for Ba II was measured at Mount Hopkins, Arizona, and Cerro Morado, Chile, and was determined to be 36,000 photon/sq cm sec outside the atmosphere; this measurement was made when the cloud was optically thin at 120 sec after release. Using this and a photon scattering efficiency of 0.66 photon/ion sec we estimate a 1.7-kg yield of barium ions that are formed from the initially released atomic barium and are thus associated with the main core of the cloud. Photographic and photometric data are combined to obtain preliminary values for the brightness throughout the cloud for two photographs, and isobrightness plots are presented. These plots indicate that the cloud is quite narrow, that a considerable portion of the ionized barium is outside the main core after a few minutes, and that the striations contain only a small fraction of the total material.

  10. Luminescence of Er3+ Doped Titanium Barium Glass Microsphere under 514 nm Excitation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The titanium barium glass microspheres doped with Er2O3 were designed and prepared. The components of the glass sample were 25TiO2-27BaCO3-8Ba(NO3)2-5ZnO2-10CaCO3-5H3BO3-10SiO2-7water glass-3Er2O3 (%, mass fraction). The emission spectra of titanium barium glass matrix and the titanium barium glass microsphere under 514 nm excitation were measured with micro-Raman spectrometer. Whispering gallery modes in the emission spectra from a 31 μm glass microsphere were observed. Many regularly spaced, sharp peaks appeared in the emission spectra of the Er2O3-doped glass microsphere. The wavelength separation between the two adjacent peaks is 1.92 nm for the 31 μm microsphere. According to the Lorenz-Mie formula, the calculated value of the wavelength separation between the two adjacent peaks is 1.95 nm. The observed resonances could be assigned by using the well-known Lorenz-Mie formula.

  11. An effective quantum defect theory for the diamagnetic spectrum of a barium Rydberg atom

    Institute of Scientific and Technical Information of China (English)

    Li Bo; Liu Hong-Ping

    2013-01-01

    A theoretical calculation is carried out to investigate the spectrum of a barium Rydberg atom in an external magnetic field.Using an effective approach incorporating quantum defect into the centrifugal term in the Hamiltonian,we reexamine the reported spectrum of the barium Rydberg atom in a magnetic field of 2.89 T [J.Phys.B 28 L537 (1995)].Our calculation employs B-spline basis expansion and complex coordinate rotation techniques.For single photon absorption from the ground 6s2 to 6snp Rydberg states,the spectrum is not influenced by quantum defects of channels ns and nd.The calculation is in agreement with the experimental observations until the energy reaches E =-60 cm-1.Beyond this energy,closer to the threshold,the calculated and experimental results do not agree with each other.Possible reasons for their discrepancies are discussed.Our study affirms an energy range where the diamagnetic spectrum of the barium atom can be explained thoroughly using a hydrogen model potential.

  12. Effects of Dysprosium Oxide Doping on Microstructure and Properties of Barium Titanate Ceramic

    Institute of Scientific and Technical Information of China (English)

    Pu Yongping; Ren Huijun; Chen Wei; Chen Shoutian

    2005-01-01

    Different amounts of dysprosium oxide were incorporated into barium titanate powders synthesized by hydrothermal method. Relations of substitution behaviors and lattice parameters with solid-solubility were studied. Furthermore, the influences of dysprosium oxide doping fraction on grain size and dielectric properties of barium titanate ceramic, including dielectric constant and breakdown electric field strength, were investigated via scanning electron microscope, X-ray diffraction and electric property tester. The results show that dysprosium oxide can restrain abnormal grain growth during sintering and that fine-grained and high density of barium titanate ceramic can result in excellent dielectric properties. As mass fraction of dysprosium oxide is 0.6%, the lattice parameters of grain increase to the maximum because of the lowest vacancy concentration. The electric property parameters are cited as following: dielectric constant (25 ℃) reaches 4100, the change in relative dielectric constant with temperature is -10% to 10% within the range of -15~100 ℃, breakdown electric field strength (alternating current) achieves 3.2 kV·mm-1, which can be used in manufacturing high voltage ceramic capacitors.

  13. Er3+-substituted W-type barium ferrite: preparation and electromagnetic properties

    Institute of Scientific and Technical Information of China (English)

    HUANG

    2010-01-01

    Er3+-substituted W-type barium ferrites Ba1-xErx(Zn0.3Co0.7)2Fe16O27(x=0.00,0.05,0.10,0.15,0.20)were synthesized by polymer adsorbent combustion method.Samples were characterized by X-ray diffraction analysis(XRD),X-ray fluorescence(XRF),scanning electron microscopy(SEM)and network analyzer to investigate the relationships among Er3+concentration,crystal structure,surface mcrphology and electromagnetic properties.All the XRD patterns showed pure phase of W-type barium ferrite when x≤0.15,while the impurity phase of ErFeO3 appeared when x=0.20.The pure W-type barium ferrite showed a hexagonal flake shape.In addition,the microwave electromagnetic properties of samples were analyzed in the frequency range of 2-18 GHz.It was indicated that the electromagnetic properties were significantly improved when Er3+doping content was 0.10.The reasons were also discussed using electromagnetic theory.The optimized ferrite exhibited excellent microwave absoption performance.The maximum of reflection loss(RL)reached about-27.4 dB and RL was below-10dB at the frequency range from 8.4 GHz to 18 GHz,when the thickness was 2.6 mm.

  14. A barium central star binary in the Type-I diamond ring planetary nebula Abell 70

    CERN Document Server

    Miszalski, B; Frew, D J; Acker, A; Köppen, J; Moffat, A F J; Parker, Q A

    2011-01-01

    Abell 70 (PN G038.1-25.4, hereafter A 70) is a planetary nebula (PN) known for its diamond ring appearance due a superposition with a background galaxy. The previously unstudied central star is found to be a binary consisting of a G8IV-V secondary at optical wavelengths and a hot white dwarf (WD) at UV wavelengths. The secondary shows Ba II and Sr II features enhanced for its spectral type that, combined with the chromospheric Halpha emission and possible 20-30 km/s radial velocity amplitude, firmly classifies the binary as a Barium star. The proposed origin of Barium stars is intimately linked to PNe whereby wind accretion pollutes the companion with dredged-up material rich in carbon and s-process elements when the primary is experiencing thermal pulses on the Asymptotic Giant Branch (AGB). A 70 provides further evidence for this scenario together with the other very few examples of Barium central stars. The nebula is found to have Type-I chemical abundances with helium and nitrogen enrichment, which when c...

  15. Hydrothermal Synthesis and Characterization of Europium-dop ed Barium Titanate Nano crys-tallites

    Institute of Scientific and Technical Information of China (English)

    Margarita Garca-Hernandez; Genevieve Chadeyron; Damien Boyer; Antonieta Garca-Murillo; Felipe Carrillo-Romo; Rachid Mahiou

    2013-01-01

    Barium titanate nanocrystallites were synthesized by a hydrothermal technique from barium chlo-ride and tetrabutyl titanate. Single-crystalline cubic perovskite BaTiO3 consisting of spherical particles with diameters ranging from 10 to 30 nm was easily achieved by this route. In order to study the influence of the syn-thesis process on the morphology and the optical properties, barium titanate was also prepared by a solid-state reaction. In this case, only the tetragonal phase which crystallizes above 900℃ was observed. High-temperature X-ray diffraction measurements were performed to investigate the crystallization temperatures as well as the particle sizes via the Scherrer formula. The lattice vibrations were evidenced by infrared spectroscopy. Eu3+was used as a structural probe, and the luminescence properties recorded from BaTiO3:Eu3+and elaborated by a solid-state reaction and hydrothermal process were compared. The reddish emission of the europium is increased by the nanometric particles.

  16. Studies of the processes of incorporation of calcium, strontium, barium and radium into bone tissue

    International Nuclear Information System (INIS)

    Alkaline earth elements incorporation into bone tissue are investigated. The study is aimed at collecting the data on improvement of metabolism model of these elements. The study includes kinetics of calcium, strontium, barium and radium - carried out on 120 rats of Wistar strain: incorporation processes of light and heavy alkaline earth elements (strontium and barium) as a function of age of the organism - carried out on 30 rabbits of Chinchilla strain in different age groups, as well as the rate of incorporation of calcium and barium into different bone tissue areas - carried out on 68 rabbits of the same strain in one age group. The main investigative techniques are: radiochemical methods, whole-body counting technique, quantitative autoradiography and microradiography, ''tetracycline test'', computer calculation methods. The following conclusions are reached: incorporation of alkaline earth elements into bone tissue is differentiated and depends on whether or not it is a light element (Ca, Sr) or heavy one (Ba, Ra), it depends also on the area of bone tissue in which the incorporation occurs

  17. A Preliminary Trial on the Use of Barium Chloride for Pregnancy Diagnosis in Sows

    Directory of Open Access Journals (Sweden)

    Ndu, A.

    2000-01-01

    Full Text Available Urine was collected twice daily (once in the morning and once in the afternoon for 5 days from 80 Yorkshire x Landrace crossbred gilts/sows made up of 40 non-pregnant and 40 pregnant pigs in an investigation to determine the possibility of using 1 % barium chloride solution for pregnancy diagnosis in pigs based on a previous report that addition of a few drops of 1 % barium chloride solution to bovine urine caused a white precipitate with non-pregnant but not with pregnant cows. The pregnant pigs were in various stages of gestation. Urine reaction to 1 % barium chloride was highly (P <0.01 dependent on the pregnancy status of the sows, the test being 100 % and 81 % effective in identifying non-pregnant and pregnant sows respectively. The sensitivity of the test in the gravid sows was significantly (P <0.05 influenced by and tended to increa-se with the stage of gestation, with 59 % of the sows in their first stage of gestation (<38 days post-coitum being correctly diagnosed as pregnant, and 95-100 % of those in their latter stages of gestation being so correctly diagnosed. Parity and time of day of performance of the test had no effect on urine reaction. It was concluded that the test was at least 95 % accurate when used as from about 39 days after breeding for pregnancy diagnosis in sows.

  18. Electric fields and plasma waves resulting from a barium injection experiment

    International Nuclear Information System (INIS)

    A shaped-charge, barium plasma injection experiment was performed in June 1976 from the DOE Kauai test facility. The rocket payload contained seven shaped charges, a sevenfold larger package than the typical payloads employed in previous barium plasma injections conducted in this program. An attitude control system oriented the injection perpendicular to the local geomagnetic field. The injection altitude was 450 km. The second-stage motor section contained a payload to measure dc and ac electric fields using a 5-m-long, tip-to-tip dual spherical probe antenna. The ac electric field frequency response was from 100 Hz to 12 kHz. The dc channel responds up to 160 Hz. Shortly after the detonation, the dc electric field was parallel to the geomagnetic field. A few seconds later the measured electric field was the v x B field induced by the motion of the antenna through the plasma. A variety of plasma waves were detected for approximately 20 s following the injection. The initial impulse in the dc channel was measured to be 115 mV/m. The injection generated barium cyclotron waves at 3.4, 7.2, and 10.6 Hz. The barium gyrofrequency at the altitude of the injection was 3.3 Hz. The initial amplitude at 3.4 Hz was 25 mV/m peak-to-peak. These waves were evident in the data for approximately 6 s. Between 3 and 8 after the explosion, band-limited noise was intermittently present between 1.6 and 3.2 kHz. These emissions were lower-hybrid-resonance emissions in a barium plasma. The instability responsible for these emissions is tentatively identified as the modified two-stream instability. Wide-band noise with a decreasing intensity as a function of frequency in the band from 100 Hz to 5 kHz was present from 4 to 30 s following the explosion. The intensity maximized when the antenna was most nearly parallel to the geomagnetic field. This suggests that the waves were ion acoustic waves. Highly structured emission occurred between 500 Hz for several seconds after the explosion

  19. Mobility and fluorescence of barium ions in xenon gas for the exo experiment

    Science.gov (United States)

    Benitez Medina, Julio Cesar

    The Enriched Xenon Observatory (EXO) is an experiment which aims to observe the neutrinoless double beta decay of 136Xe. The measurement of this decay would give information about the absolute neutrino mass and whether or not the neutrino is its own antiparticle. Since this is a very rare decay, the ability to reject background events by detecting the barium ion daughter from the double beta decay would be a major advantage. EXO is currently operating a detector with 200 kg of enriched liquid xenon, and there are plans to build a ton scale xenon detector. Measurements of the purity of liquid xenon in our liquid xenon test cell are reported. These results are relevant to the research on detection of single barium ions by our research group at Colorado State University. Details of the operation of the purity monitor are described. The effects of using a purifier, recirculation and laser ablation on the purity of liquid xenon are discussed. Mobility measurements of barium in xenon gas are reported for the first time. The variation of mobility with xenon gas pressure suggests that a significant fraction of molecular ions are formed when barium ions interact with xenon gas at high pressures. The measured mobility of Ba+ in Xe gas at different pressures is compared with the predicted theoretical value, and deviations are explained by a model that describes the fraction of molecular ions in Xe gas as a function of pressure. The results are useful for the analysis of experiments of fluorescence of Ba+ in xenon gas. It is also important to know the mobility of the ions in order to calculate the time they interact with an excitation laser in fluorescence experiments and in proposed 136 Ba+ daughter detection schemes. This thesis presents results of detection of laser induced fluorescence of Ba+ ions in Xe gas. Measurements of the pressure broadening of the excitation spectra of Ba+ in xenon gas are presented. Nonradiative decays due to gas collisions and optical pumping

  20. Comparison of Barium and Arsenic Concentrations in Well Drinking Water and in Human Body Samples and a Novel Remediation System for These Elements in Well Drinking Water

    Science.gov (United States)

    Kato, Masashi; Kumasaka, Mayuko Y.; Ohnuma, Shoko; Furuta, Akio; Kato, Yoko; Shekhar, Hossain U.; Kojima, Michiyo; Koike, Yasuko; Dinh Thang, Nguyen; Ohgami, Nobutaka; Ly, Thuy Bich; Jia, Xiaofang; Yetti, Husna; Naito, Hisao; Ichihara, Gaku; Yajima, Ichiro

    2013-01-01

    Health risk for well drinking water is a worldwide problem. Our recent studies showed increased toxicity by exposure to barium alone (≤700 µg/L) and coexposure to barium (137 µg/L) and arsenic (225 µg/L). The present edition of WHO health-based guidelines for drinking water revised in 2011 has maintained the values of arsenic (10 µg/L) and barium (700 µg/L), but not elements such as manganese, iron and zinc. Nevertheless, there have been very few studies on barium in drinking water and human samples. This study showed significant correlations between levels of arsenic and barium, but not its homologous elements (magnesium, calcium and strontium), in urine, toenail and hair samples obtained from residents of Jessore, Bangladesh. Significant correlation between levels of arsenic and barium in well drinking water and levels in human urine, toenail and hair samples were also observed. Based on these results, a high-performance and low-cost adsorbent composed of a hydrotalcite-like compound for barium and arsenic was developed. The adsorbent reduced levels of barium and arsenic from well water in Bangladesh and Vietnam to <7 µg/L within 1 min. Thus, we have showed levels of arsenic and barium in humans and propose a novel remediation system. PMID:23805262

  1. Comparison of Barium and Arsenic Concentrations in Well Drinking Water and in Human Body Samples and a Novel Remediation System for These Elements in Well Drinking Water.

    Directory of Open Access Journals (Sweden)

    Masashi Kato

    Full Text Available Health risk for well drinking water is a worldwide problem. Our recent studies showed increased toxicity by exposure to barium alone (≤700 µg/L and coexposure to barium (137 µg/L and arsenic (225 µg/L. The present edition of WHO health-based guidelines for drinking water revised in 2011 has maintained the values of arsenic (10 µg/L and barium (700 µg/L, but not elements such as manganese, iron and zinc. Nevertheless, there have been very few studies on barium in drinking water and human samples. This study showed significant correlations between levels of arsenic and barium, but not its homologous elements (magnesium, calcium and strontium, in urine, toenail and hair samples obtained from residents of Jessore, Bangladesh. Significant correlation between levels of arsenic and barium in well drinking water and levels in human urine, toenail and hair samples were also observed. Based on these results, a high-performance and low-cost adsorbent composed of a hydrotalcite-like compound for barium and arsenic was developed. The adsorbent reduced levels of barium and arsenic from well water in Bangladesh and Vietnam to <7 µg/L within 1 min. Thus, we have showed levels of arsenic and barium in humans and propose a novel remediation system.

  2. Towards a biochemical and structural characterisation of the sodium-iodide sym-porter (Nis)

    International Nuclear Information System (INIS)

    Iodide is essential for thyroid hormone biosynthesis in mammals, and therefore for the control of cell metabolism and the development of the central nervous system in the foetus and newborns, but is relatively scarce element in the environment. To ensure its accumulation, the thyroid gland has evolved a remarkably efficient system, the sodium-iodide sym-porter (NIS), that was first characterized at the molecular level 10 years ago (1). NIS is an intrinsic protein mainly located in the basolateral membrane of thyroid follicular cells where it actively transports iodide ions using the sodium gradient as a driving force (2,3). In addition, this transporter has been found in lactating mammary gland, stomach, and salivary glands, and its mRNA was detected in brain, ovaries, testis. To date, the physiological role of NIS in these organs is not yet identified (3,4).The capacity of NIS to mediate the accumulation of radioactive iodide has been exploited for many years in the diagnosis of thyroid cancer as well as for the detection and radiotherapy of derived metastases. Moreover, the presence of NIS in some breast tumours and the possibility to express it by targeted gene therapy in tumour cells where it is not naturally present could also widen its medical application (4-7). In case of accidental contamination, NIS would also be responsible for accumulation of radioisotopes in the thyroid and for their transfer to the milk and the newborn, eventually causing thyroid cancers. This has motivated our research program in the perspective of designing novel specific therapeutics. During the last decade, the gene encoding the thyroid NIS has been identified and sequenced in various species including rat, mouse and human (1, 8). It was also demonstrated that the protein expression and activity are highly regulated both at the transcriptional and post-translational levels (3). A preliminary topological mode could be drawn from the protein sequence. It proposes a general

  3. Iodide Sorption to Clays and the Relationship to the Surface Charge Environment

    Science.gov (United States)

    Miller, A. W.; Wang, Y.

    2011-12-01

    In performance assessments of nuclear waste repositories, iodine-129 is often the major contributor to dose at time scales ≥10,000 years. The breakthrough behavior of iodine is determined by the monovalent, anionic nature and the assumed lack of surface reactivity of the iodide ion. This assumption is corroborated by batch sorption data where iodide sorption to clays is typically very small, and only measurable under specific conditions. This result is consistent with charge repulsion arguments due to the fixed negative charge of clays repelling the anionic iodide. However, in compacted column diffusion experiments, iodide is routinely retarded relative to tritium, and is described with Kd values from ≈0.001-2.9ml/g. While small, these values can dramatically change the dose profile in performance assessment calculations. We hypothesize that contributions from the basal plane and edge charge of individual clay particles as well as the physical morphology of the clay particles are contributing to the conflicting behavior. In a series of experiments involving a wide range of clay minerals from the clay bank repository, both surface charge and iodide sorption were examined using surface titrations and batch sorption experiments. The clay minerals studied include: kaolinite, ripidolite, illite, montmorillonite, palygorskite, sepiolite, and an illite/smectite mixed layer clay. Each of these clays was characterized using XRD, and surface titrations in 0.01, 0.1, and 0.5 M NaCl electrolyte. The titrations spanned the pH range from 2.5-10.5 and were automated using an autotitrator. For reference, similar titrations were performed on pure forms of an Al-O powder. The titration curves were interpreted using an inversion method to attain the pKa distribution for each clay and metal oxide at each ionic strength. The pKa distribution for the Al-O shows two distinct peaks at 4.8 and 7.5, which are invariant with ionic strength. The pKa distribution of clays was highly

  4. Distribution and leaching of methyl iodide in soil following emulated shank and drip application.

    Science.gov (United States)

    Guo, Mingxin; Zheng, Wei; Papiernik, Sharon K; Yates, Scott R

    2004-01-01

    Methyl iodide (MeI) is a promising alternative to methyl bromide in soil fumigation. The pest-control efficacy and ground water contamination risks of MeI as a fumigant are highly related to its gas-phase distribution and leaching after soil application. In this study, the distribution and leaching of MeI in soil following shank injection and subsurface drip application were investigated. Methyl iodide (200 kg ha(-1)) was directly injected or drip-applied at a 20-cm depth into Arlington sandy loam (coarse-loamy, mixed, thermic Haplic Durixeralfs) columns (12-cm i.d., 70-cm height) tarped with virtually impermeable film. Concentration profiles of MeI in the soil air were monitored for 7 d. Methyl iodide diffused rapidly after soil application, and reached a 70-cm depth within 2 h. Relative to shank injection, drip application inhibited diffusion, resulting in significantly lower concentration profiles in the soil air. Seven days after MeI application, fumigated soil was uncapped, aerated for 7 d, and leached with water. Leaching of MeI was significant from the soil columns under both application methods, with concentrations of >10 mug L(-1) in the early leachate. The leaching was greater following shank injection than drip application, with an overall potential of 33 g ha(-1) for shank injection and 19 g ha(-1) for drip application. Persistent residues of MeI remaining in soils after leaching were 50 to 240 ng kg(-1), and the contents were slightly higher following shank injection than drip application. The results suggest that fumigation with MeI may pose a risk of ground water contamination in vulnerable areas. PMID:15537937

  5. Equations of state for crystalline zirconium iodide: The role of dispersion

    Science.gov (United States)

    Rossi, Matthew L.; Taylor, Christopher D.

    2013-02-01

    We present the first-principle equations of state of several zirconium iodides, ZrI2, ZrI3, and ZrI4, computed using density functional theory methods that apply various methods for introducing the dispersion correction. Iodides formed due to reaction of molecular or atomic iodine with zirconium and zircaloys are of particular interest due to their application to the cladding material used in the fabrication of nuclear fuel rods. Stress corrosion cracking (SCC), associated with fission product chemistry with the clad material, is a major concern in the life cycle of nuclear fuels, as many of the observed rod failures have occurred due to pellet-cladding chemical interactions (PCCI) [A. Atrens, G. Dannhäuser, G. Bäro, Stress-corrosion-cracking of zircaloy-4 cladding tubes, Journal of Nuclear Materials 126 (1984) 91-102; P. Rudling, R. Adamson, B. Cox, F. Garzarolli, A. Strasser, High burn-up fuel issues, Nuclear Engineering and Technology 40 (2008) 1-8]. A proper understanding of the physical properties of the corrosion products is, therefore, required for the development of a comprehensive SCC model. In this particular work, we emphasize that, while existing modeling techniques include methods to compute crystal structures and associated properties, it is important to capture intermolecular forces not traditionally included, such as van der Waals (dispersion) correction. Furthermore, crystal structures with stoichiometries favoring a high I:Zr ratio are found to be particularly sensitive, such that traditional density functional theory approaches that do not incorporate dispersion incorrectly predict significantly larger volumes of the lattice. This latter point is related to the diffuse nature of the iodide electron cloud.

  6. Phase partitioning, retention kinetics, and leaching of fumigant methyl iodide in agricultural soils

    International Nuclear Information System (INIS)

    Although it is not currently being sold in the USA, the recent US registration of the fumigant methyl iodide has led to an increased interest in its environmental fate and transport. Although some work has now considered its volatile emissions from soil, there remains a lack of experimental data regarding its ability to be retained in soil and ultimately become transported with irrigation/rain waters. Using laboratory batch and soil column experiments, we aimed to better understand the phase partitioning of MeI, the ability of soils to retain MeI on the solid phase, and the potential for leaching of MeI and its primary degradation product, iodide, down a soil profile. Results indicated that MeI was retained by the solid phase of soil, being protected from volatilization and degradation, particularly in the presence of elevated organic matter. Retention was greater at lower moisture content, and maximum retention occurred after 56 days of incubation. At higher moisture content, the liquid phase also became important in retaining MeI within soil. Together with low observed KD values (0.10 to 0.57 mL g−1), these data suggest that MeI may be prone to leaching. Indeed, in a steady-state soil column study, initially retained MeI was transported with interstitial water. The MeI degradation product, iodide, was also readily transported in this manner. The data highlight a potentially significant process by which MeI fate and transport within the environment may be impacted. -- Highlights: ► Following fumigation and venting, MeI is retained by soil. ► Soil organic matter status is highly significant in MeI retention. ► Retained MeI is protected from degradation and volatilization. ► Retained MeI can be removed from the solid phase to the liquid phase and leached.

  7. Electrical properties of solid iodo mercurates resulting from the reaction of HgI2 with alcaline iodides

    Science.gov (United States)

    Ponpon, J. P.; Amann, M.

    2005-01-01

    Potassium iodide solutions are currently used during the fabrication process of mercuric iodide based nuclear radiation detectors. However, KI treatment leaves the HgI2 surface covered with a residual compound (namely the potassium tri-iodo mercurate) which has a significant influence on the surface properties and stability of mercuric iodide devices and therefore on the detectors characteristics. Looking for other solutions to etch mercuric iodide, we found it interesting to investigate the electrical properties of the compounds which may form when etching HgI2 in NH4I, NaI, and RbI. For this purpose, solid iodo mercurates with the cations ammonium, sodium, and rubidium, have been prepared by reacting HgI2 with the solutions of interest. Study of the electrical properties of these samples and comparison with those of potassium tri-iodo mercurate ones, especially with respect to humidity, indicates noticeable stability differences in presence of water vapour. This could have interesting consequences on the surface cleaning of mercuric iodide.

  8. Efficient radiation production in a weakly ionized, low-pressure, nonequilibrium gallium-iodide positive column discharge plasma

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David J; Michael, J Darryl; Midha, Vikas; Cotzas, George M; Sommerer, Timothy J [General Electric Research, One Research Circle, Niskayuna, NY 12309 (United States)

    2007-07-07

    Electric-discharge plasmas in gallium-iodide vapours are experimentally found to convert 40% of input electric power into ultraviolet and visible radiation (200-800 nm). The conditions are a weakly ionized positive column consisting of 5-10 Torr argon, and the gallium-iodide vapour is formed by heating condensed gallium-iodide to 100-120 deg. C. The input power density is 50-100 mW cm{sup -3}. The plasma is contained in a sealed silica tube and excited by an external radiofrequency antenna. Computational analysis and plasma diagnostics lead to a quantitative understanding that gallium atoms are formed by electron-impact dissociation of gallium-iodide compounds that evaporate into the plasma volume, and that further electron collisions excite the gallium atoms, which then decay by photon emission. High efficiency is possible only because several photons are emitted per dissociation event, and because nonradiative power channels such as electron-impact elastic heating and vibrational excitation are not dominant. The dissociated species recombine on the wall to reform the species that evaporates. The plasma properties change discontinuously as the molar ratio of iodine to gallium (I/Ga) in the system crosses the values I/Ga = 3 and I/Ga = 2, consistent with the thermodynamic properties of condensed gallium-iodide compounds.

  9. Synergy between iodide ions and mangrove tannins as inhibitors of mild steel corrosion

    OpenAIRE

    Adam, Mohd Ridhwan; Rahim, Afidah Abdul; Shah, Affaizza Mohamad

    2015-01-01

    Context Corrosion of materials is a problem faced by many industries. One of the solutions to this problem is to apply corrosion inhibitors.Aims In this study, the synergy between iodide ions and mangrove tannin extracted from mangrove bark (waste products of the charcoal industry) was tested on the inhibition of corrosion of mild steel in 0.5 M HCl and 0.25 M H2SO4. It was compared with the inhibition provided by mimosa and chestnut tannins.MethodsPotentiodynamic and electrochemical impedanc...

  10. Indirect Complexometric Determination of Mercury Using Potassium Iodide as Selective Masking Agent

    OpenAIRE

    RAO, B. Muralidhara

    1998-01-01

    This paper describes a indirect complexometric method for the determination of mercury in the presence of co-ions, based on the selective masking ability of potassium iodide. To the mixture of mercury (II) and other metal ion solution, EDTA solution was added in excess of the metal ions present. The pH of the solution was adjusted to 5.0-6.0 using solid hexamine (10 \\pm 2 g) and surplus EDTA was titrated with zinc sulfate solution using xylenol orange indicator. An excess of solid potassium i...

  11. Introduction to fifth international workshop on mercuric iodide nuclear radiation detectors

    International Nuclear Information System (INIS)

    Mercuric iodide is a wide bandgap semiconductor, with Eg approx. = 2.14 eV at room temperature. Therefore, HgI2 is totally different from the well-studied, narrower gap, elemental semiconductors such as Si and Ge, and also different in its physical and chemical properties from the known semiconductor binary zinc-blend compounds such as GaAs or InP. The purpose of studies in the last decade was to further our understanding of HgI2; recent progress is reported

  12. Detection of experimentally produced acute pulmonary arterial occlusion by methyl iodide-131 inhalation imaging

    International Nuclear Information System (INIS)

    Methyl iodide-131 (CH3I-131) is described as an agent for detection of acute experimentally produced pulmonary arterial occlusion in dogs. When gaseous CH3I-131 is inhaled, radioactivity passes instantaneously from the alveoli to the lung capillary bed. Where pulmonary blood flow exists, activity is washed out into the systemic circulation, but in areas of blood stasis, a transient pulmonary hot spot remains. CH3I-131 is easily produced and inexpensive, but administration is awkward and strict radiation safety precautions are mandatory

  13. Atypical cutaneous sporotrichosis in an immunocompetent adult: Response to potassium iodide

    Directory of Open Access Journals (Sweden)

    Nikita Gandhi

    2016-01-01

    Full Text Available Cutaneous sporotrichosis, also known as “Rose Gardener's disease,” caused by dimorphic fungus Sporothrix schenkii, is usually characterized by indolent nodular or nodulo-ulcerative lesions arranged in a linear pattern. We report bizarre nonlinear presentation of Sporotrichosis, in an immunocompetent adult occurring after a visit to Amazon rain forest, speculating infection with more virulent species of Sporothrix. The diagnosis was reached with the help of periodic acid-Schiff positive yeast cells and cigar shaped bodies seen in skin biopsy along with the therapeutic response to potassium iodide.

  14. A study on sodium iodide symporter gene mutation in congenital hypothyroidism

    International Nuclear Information System (INIS)

    Objective: To investigate the mutation of sodium iodide symporter (NIS) gene in the patients with congenital hypothyroidism (CH) in Tianjin area. Methods: Total genomic DNA was extracted from peripheral blood of 18 patients with CH and 35 normal subjects randomly selected. All 15 exons of NIS gene were individually amplified. Mutation was detected by single-strand conformational polymorphism(SSCP) technique and confirmed with direct sequencing. Results: Exons of NIS gene of all the subjects were successfully amplified by polymerase chain reaction. SSCP analysis displayed no abnormality. No mutation was found in these patients Conclusion: The CH in Tianjin urban area had no mutation of NIS gene. (authors)

  15. Towards Renewable Iodide Sources for Electrolytes in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Iryna Sagaidak

    2016-03-01

    Full Text Available A novel family of iodide salts and ionic liquids based on different carbohydrate core units is herein described for application in dye-sensitized solar cell (DSC. The influence of the molecular skeleton and the cationic structure on the electrolyte properties, device performance and on interfacial charge transfer has been investigated. In combination with the C106 polypyridyl ruthenium sensitizer, power conversion efficiencies lying between 5.0% and 7.3% under standard Air Mass (A.M. 1.5G conditions were obtained in association with a low volatile methoxypropionitrile (MPN-based electrolyte.

  16. Introduction to fifth international workshop on mercuric iodide nuclear radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, M.

    1982-01-01

    Mercuric iodide is a wide bandgap semiconductor, with Eg approx. = 2.14 eV at room temperature. Therefore, HgI/sub 2/ is totally different from the well-studied, narrower gap, elemental semiconductors such as Si and Ge, and also different in its physical and chemical properties from the known semiconductor binary zinc-blend compounds such as GaAs or InP. The purpose of studies in the last decade was to further our understanding of HgI/sub 2/; recent progress is reported. (WHK)

  17. Effect of heat treatment on the phase composition, structure and magnetic properties of M-type barium hexaferrite

    International Nuclear Information System (INIS)

    Effect of the heat treatment of carbonate-hydroxide precipitates on the phase composition, structure and magnetic properties of M-type barium hexaferrite has been investigated using the Mőssbauer spectroscopy, X-ray phase analysis and magnetic measurements. The distribution of Fe3+ ions over structural sites of barium hexaferrite with different degree of ferritizations has been defined. The conditions of single-domain behavior of barium hexaferrite nanoparticles in the magnetic field have been discussed. Obtained results explain the formation of magnetic structure during the synthesis of barium hexaferrite. This information could further be used for optimizing conditions for synthesis of nanosized barium hexaferrite with high-level properties. - Highlights: • In the T=973–1273 K range, BaFe12O19 (BHF) phase are formed from precipitates. • Fe3+ ions prefer to occupy 12k,2a,2b (at 1073 K) and 4f1,4f2 (at 1273 K) sites. • The most favorable magnetic structure for high Ms forms at T=1073 K. • The presence of 5–10% of α-Fe2O3 phase can improve magnetic properties of BHF

  18. High-Jc YBCO films using precursors with barium concentration gradient in film thickness by TFA-MOD process

    International Nuclear Information System (INIS)

    YBa2Cu3O7-δ (YBCO) films were grown by using precursor films with barium concentration gradient in film thickness by an advanced metal organic deposition process using trifluoroacetates (TFA-MOD). We have reported previously that a lot of non-reacted particles such as Y- and Cu-oxides were remained for the YBCO film surface grown by the precursors using a starting solution with barium-poor (cation ratio as Y:Ba:Cu 1:1.5:3). Then, the barium concentration was increased in the film surface to complete the reaction among these Y and Cu residues and Ba and to increase the Y123 growth thickness for realizing higher Jc performance. Transmission electron microscopy (TEM) observation showed the increase of film thickness of YBCO grown by the precursors with barium concentration gradient in film thickness, indicating that the reaction between these Y and Cu-oxides and Ba proceeded to form Y123 phase. Consequently, higher Jc was obtained for the YBCO film by the precursors mentioned above than that of the YBCO film by the precursors with a constant concentration. Effects of barium concentration gradient in the precursors on the superconducting properties and microstructures in the YBCO film were discussed.

  19. A study of the Arrhenius behavior of the co-precipitation of radium, barium and strontium sulfate

    International Nuclear Information System (INIS)

    Co-precipitation of radium, barium and strontium is an important process in many contexts, such as uranium mining, oil extraction and in the safety assessment of a final repository for used nuclear fuel. Co-precipitation to a solid solution is possible since radium, barium and strontium act as chemical analogues. In this work the co-precipitation of radium, barium and strontium was studied and the kinetic behavior of the co-precipitation process was investigated. It was shown that radium, barium and strontium co-precipitate congruently and that the precipitation followed an Arrhenius behavior and the Arrhenius parameters for the systems was determined. When studying the differences of the Arrhenius constants by using a student t test (95 % confidence interval) it was observed that the only significant difference in the activation energy, Ea, is between radium and barium and between radium and strontium respectively, the pure strontium having the larger activation energy in comparison. This is most likely coupled to the metal ion size; since the hydration waters are more strongly bound, which leads to them having a slower exchange rate, which in turn effects the rate of co-precipitation to the metal these reactions will be slower. (author)

  20. Zinc iodide-osmium staining of membrane-coating granules in keratinized and non-keratinized mammalian oral epithelium.

    Science.gov (United States)

    Squier, C A

    1982-01-01

    Specimens of keratinized and non-keratinized oral epithelium were examined in the electron microscope after being stained with zinc iodide-osmium. In both types of tissue, reaction was seen in unmyelinated nerves, in the specific granules of epithelial Langerhans cells and within lysosome-like organelles and small vesicles associated with Golgi systems. In keratinized epithelia, the reaction was also present in the membrane-coating granules and between the deepest cells of the keratinized layer. In contrast, the membrane-coating granules of non-keratinized epithelia lacked Zn iodide-osmium staining despite the presence of reaction in adjacent Golgi systems. It is suggested that Zn iodide-osmium stains glycolipid or glycoprotein material in the cell. This material is elaborated in the Golgi systems from which lysosomes and the membrane-coating granules of keratinized tissues are probably derived.