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Sample records for cerium-doped yttrium pyrosilicate

  1. Combustion synthesis and photoluminescence in novel red emitting yttrium gadolinium pyrosilicate nanocrystalline phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Hedaoo, V.P., E-mail: vraikwar@rediffmail.com [Department of Physics, R. J. College, Ghatkopar, Mumbai, MS 400086 (India); Bhatkar, V.B. [Department of Physics, Shri Shivaji Science College, Amravati, MS 444602 (India); Omanwar, S.K. [Department of Physics, SGB Amravati University, Amravati, MS 444602 (India)

    2016-07-05

    Yttrium Gadolinium Pyrosilicate Y{sub 2-x}Gd{sub x}Si{sub 2}O{sub 7}:Eu{sup 3+} (x = 0.05, 0.10, 0.15) phosphor powder was prepared by facile and time efficient modified combustion method for the first time. The phosphor was characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), photoluminescence excitation (PLE) and emission (PL) spectroscopy and color chromaticity coordinates. XRD revealed the monoclinic crystal structure with space group P1¯. The crystallite size was calculated by Williamson-Hall (W–H) analysis. Nanoplates-like morphology was observed in FESEM analysis with size in the range 50–80 nm. TEM images confirmed the particle size and shape. Upon excitation by 254 nm UV light, the phosphor showed the characteristic red emission peaks at 589 nm and 613 nm corresponding to {sup 5}D{sub 0} → {sup 7}F{sub 1} and {sup 5}D{sub 0} → {sup 7}F{sub 2} transitions respectively. It was observed that the nanocrystalline phosphor Y{sub 2-x}Gd{sub x}Si{sub 2}O{sub 7}:Eu{sup 3+}can be tuned to emit orange to red color by adjusting the ratio Y/Gd. This phosphor thus can be a potential candidate as orange to red color emitting tunable nanocrystalline phosphor for optical devices. - Highlights: • A novel Yttrium Gadolinium Pyrosilicate doped with Eu{sup 3+} is reported. • Facile and time efficient modified combustion method is used. • The nanocrystalline structure was shown by X-ray diffraction, W–H analysis. • FESEM and TEM images confirmed the nanocrystalline structure. • The reported phosphor can be tuned from orange to red by varying Y/Gd ratio.

  2. Fabrication of cerium-doped yttrium aluminum garnet thin films by a mist CVD method

    Energy Technology Data Exchange (ETDEWEB)

    Murai, Shunsuke, E-mail: murai@dipole7.kuic.kyoto-u.ac.jp; Sato, Takafumi; Yao, Situ; Kamakura, Ryosuke; Fujita, Koji; Tanaka, Katsuhisa

    2016-02-15

    We synthesized thin films, consisting of yttrium aluminum garnet doped with Ce{sup 3+} (YAG:Ce), using the mist chemical vapor deposition (CVD) method, which allows the fabrication of high-quality thin films under atmospheric conditions without the use of vacuum equipment. Under a deposition rate of approximately 1 μm/h, the obtained thin films had a typical thickness of 2 μm. The XRD analysis indicated that the thin films consisted of single-phase YAG:Ce. The Rutherford backscattering confirmed the stoichiometry; the composition of the film was determined to be (Y, Ce){sub 3}Al{sub 5}O{sub 12}, with a Ce content of Ce/(Y+Ce)=2.5%. The YAG:Ce thin films exhibited fluorescence due to the 5d–4f electronic transitions characteristic of the Ce ions occupying the eight-coordinated dodecahedral sites in the YAG lattice. - Highlights: • We have synthesized thin films of yttrium aluminum garnet doped with Ce{sup 3+} (YAG:Ce) by using a mist chemical vapor deposition (CVD) method for the first time. • The thickness of the single-phase and stoichiometric thin film obtained by 2 h deposition and following heat treatments is 2 μm. • The thin film is porous but optically transparent, and shows yellow fluorescence upon irradiation with a blue light. • Mist-CVD is a green and sustainable technique that allows fabrication of high-quality thin films at atmospheric conditions without vacuum equipment.

  3. Effect of ultrasound treatment on the morpho-structural and luminescent characteristics of cerium doped yttrium silicate phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Muresan, L.E., E-mail: laura_muresan2003@yahoo.com [“Raluca Ripan” Institute for Research in Chemistry, Babeş Bolyai University, Fântânele 30, 400294 Cluj-Napoca (Romania); Cadis, A.I.; Perhaita, I. [“Raluca Ripan” Institute for Research in Chemistry, Babeş Bolyai University, Fântânele 30, 400294 Cluj-Napoca (Romania); Silipas, D.T. [National Institute for R& D of Isotopic and Molecular Technologies, Donath 67-103, 400293 Cluj-Napoca (Romania); Tudoran, L. Barbu [Electronic Microscopy Centre, Babeş Bolyai University, Clinicilor 37, 400006 Cluj-Napoca (Romania)

    2015-08-15

    Highlights: • Y{sub 2}SiO{sub 5}:Ce is prepared by gel combustion in ultrasound conditions (US). • Morpho-structural characteristics are revealed based on FTIR, SEM, XRD, BET. • Incorporation of Ce{sup 3+} in X1/X2 type centers depends on preparative conditions. • US treatment increases the luminescent performances up to 151%. - Abstract: Cerium activated yttrium silicate (Y{sub 2}SiO{sub 5}:Ce) phosphors were prepared by gel-combustion, using yttrium–cerium nitrate as oxidizer, aspartic acid as fuel and TEOS as source of silicon. Two modalities for samples preparation were approached namely: the classical gel-combustion and sonication gel-combustion. The ultrasound treatment during the gelling stage has a positive effect on the structural and luminescent characteristics of the final product. Therefore, a well crystallized single X2–Y{sub 2}SiO{sub 5} phase phosphor was obtained at 1200 °C. Based on FT-IR and XRD investigations, conversion of X1 to X2–Y{sub 2}SiO{sub 5} phases is observed as the firing temperature is varied (1100 °C, 1200 °C, 1300 °C 1400 °C). The ultrasound treatment leads to smaller particle size and enhances the luminescent performances up to 151% in comparison with samples prepared by classical way.

  4. Cerium-doped scintillating fused-silica fibers

    Science.gov (United States)

    Akchurin, N.; Cowden, C.; Damgov, J.; Dragoiu, C.; Dudero, P.; Faulkner, J.; Kunori, S.

    2018-04-01

    We report on a set of measurements made on (scintillating) cerium-doped fused-silica fibers using high-energy particle beams. These fibers were uniformly embedded in a copper absorber in order to utilize electromagnetic showers as a source of charged particles for generating signals. This new type of cerium-doped fiber potentially offers myriad new applications in calorimeters in high-energy physics, tracking systems, and beam monitoring detectors for future applications. The light yield, pulse shape, attenuation length, and light propagation speeds are given and discussed. Possible future applications are also explored.

  5. Preparation of cerium doped calcium pyrophosphate: Study of luminescent behavior

    Energy Technology Data Exchange (ETDEWEB)

    Lozano, I.B., E-mail: ivonne.berenice@gmail.com [Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, 11500 México D.F., México (Mexico); Roman-Lopez, J. [CONACYT Research Fellow-Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70-543, 04510 México D.F., México (Mexico); Sosa, R. [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, 09340 México D.F., México (Mexico); Díaz-Góngora, J.A.I [Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, 11500 México D.F., México (Mexico); Azorín, J. [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, 09340 México D.F., México (Mexico)

    2016-05-15

    Thermoluminescent (TL) and photoluminescent (PL) band emissions of cerium doped calcium pyrophosphate (Ca{sub 2}O{sub 7}P{sub 2}:Ce{sup 3+}) were studied. Wet precipitation method was used to synthesize calcium pyrophosphate, doped with Ce{sup 3+} (1.0 at%) impurities, from orthophosphoric acid and calcium acetate, as raw materials. The effect of temperature annealing at 800 and 900 °C was investigated. X-Ray diffraction (XRD) and Scanning Electron Microscope (SEM) were used to characterize both as-precipitated and annealed powders samples. The PL emission spectrum of samples annealed at 900 °C displayed characteristics 5d–4f transitions of Ce{sup 3+} at 333 nm and 360 nm. TL measurements were carried out on as-precipitated and annealed samples from room temperature (RT) up to 350 °C. The TL results of annealed samples showed complex TL glow curves, a linear response in the absorbed dose range of 0.5–5 Gy and a good reproducibility after 10 cycles of irradiation-readout. The complex TL glow curves of annealed samples were analyzed by the methods of T{sub max}–T{sub Stop}, Initial Rise (IR) and Computational Glow-Curve Deconvolution (CGCD) assuming a General Order Kinetic (GOK).

  6. Cerium doped lanthanum halides: fast scintillators for medical imaging

    International Nuclear Information System (INIS)

    Selles, O.

    2006-12-01

    This work is dedicated to two recently discovered scintillating crystals: cerium doped lanthanum halides (LaCl 3 :Ce 3+ and LaBr 3 :Ce 3+ ).These scintillators exhibit interesting properties for gamma detection, more particularly in the field of medical imaging: a short decay time, a high light yield and an excellent energy resolution. The strong hygroscopicity of these materials requires adapting the usual experimental methods for determining physico-chemical properties. Once determined, these can be used for the development of the industrial manufacturing process of the crystals. A proper comprehension of the scintillation mechanism and of the effect of defects within the material lead to new possible ways for optimizing the scintillator performance. Therefore, different techniques are used (EPR, radioluminescence, laser excitation, thermally stimulated luminescence). Alongside Ce 3+ ions, self-trapped excitons are involved in the scintillation mechanism. Their nature and their role are detailed. The knowledge of the different processes involved in the scintillation mechanism leads to the prediction of the effect of temperature and doping level on the performance of the scintillator. A mechanism is proposed to explain the thermally stimulated luminescence processes that cause slow components in the light emission and a loss of light yield. Eventually the study of afterglow reveals a charge transfer to deep traps involved in the high temperature thermally stimulated luminescence. (author)

  7. Magnetic hysteresis of cerium doped bismuth ferrite thin films

    International Nuclear Information System (INIS)

    Gupta, Surbhi; Tomar, Monika; Gupta, Vinay

    2015-01-01

    The influence of Cerium doping on the structural and magnetic properties of BiFeO 3 thin films have been investigated. Rietveld refinement of X-ray diffraction data and successive de-convolution of Raman scattering spectra of Bi 1−x Ce x FeO 3 (BCFO) thin films with x=0–0.20 reflect the single phase rhombohedral (R3c) formation for x<0.08, whereas concentration-driven gradual structural phase transition from rhombohedral (R3c) to partial tetragonal (P4mm) phase follows for x≥0.08. All low wavenumber Raman modes (<300 cm −1 ) showed a noticeable shift towards higher wavenumber with increase in doping concentration, except Raman E-1 mode (71 cm −1 ), shows a minor shift. Sudden evolution of Raman mode at 668 cm −1 , manifested as A 1 -tetragonal mode, accompanied by the shift to higher wavenumber with increase in doping concentration (x) affirm partial structural phase transition. Anomalous wasp waist shaped (M–H) hysteresis curves with improved saturation magnetization (M s ) for BCFO thin films is attributed to antiferromagnetic interaction/hybridization between Ce 4f and Fe 3d electronic states. The contribution of both hard and soft phase to the total coercivity is calculated. Polycrystalline Bi 0.88 Ce 0.12 FeO 3 thin film found to exhibit better magnetic properties with M s =15.9 emu/g without any impure phase. - Highlights: • Synthesis of single phase Bi 1−x Ce x FeO 3 thin films with (x=0–0.2) on cost effective corning glass and silicon substrates using CSD technique. • Structural modification studies using Rietveld refinement of XRD and de-convolution of Raman spectra revealed partial phase transition from rhombohedral (R3c) to tetragonal (P4mm) phase. • Possible reasons for origin of pinched magnetic behavior of BCFO thin films are identified. • Contribution of both hard and soft magnetic phase in coercivity of BCFO thin films is calculated and practical applications of such materials exhibiting pinching behavior are conferred

  8. Magnetic hysteresis of cerium doped bismuth ferrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Surbhi [Department of Physics and Astrophysics, University of Delhi (India); Tomar, Monika [Physics Department, Miranda House, University of Delhi (India); Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi (India)

    2015-03-15

    The influence of Cerium doping on the structural and magnetic properties of BiFeO{sub 3} thin films have been investigated. Rietveld refinement of X-ray diffraction data and successive de-convolution of Raman scattering spectra of Bi{sub 1−x}Ce{sub x}FeO{sub 3} (BCFO) thin films with x=0–0.20 reflect the single phase rhombohedral (R3c) formation for x<0.08, whereas concentration-driven gradual structural phase transition from rhombohedral (R3c) to partial tetragonal (P4mm) phase follows for x≥0.08. All low wavenumber Raman modes (<300 cm{sup −1}) showed a noticeable shift towards higher wavenumber with increase in doping concentration, except Raman E-1 mode (71 cm{sup −1}), shows a minor shift. Sudden evolution of Raman mode at 668 cm{sup −1}, manifested as A{sub 1}-tetragonal mode, accompanied by the shift to higher wavenumber with increase in doping concentration (x) affirm partial structural phase transition. Anomalous wasp waist shaped (M–H) hysteresis curves with improved saturation magnetization (M{sub s}) for BCFO thin films is attributed to antiferromagnetic interaction/hybridization between Ce 4f and Fe 3d electronic states. The contribution of both hard and soft phase to the total coercivity is calculated. Polycrystalline Bi{sub 0.88}Ce{sub 0.12}FeO{sub 3} thin film found to exhibit better magnetic properties with M{sub s}=15.9 emu/g without any impure phase. - Highlights: • Synthesis of single phase Bi{sub 1−x}Ce{sub x}FeO{sub 3} thin films with (x=0–0.2) on cost effective corning glass and silicon substrates using CSD technique. • Structural modification studies using Rietveld refinement of XRD and de-convolution of Raman spectra revealed partial phase transition from rhombohedral (R3c) to tetragonal (P4mm) phase. • Possible reasons for origin of pinched magnetic behavior of BCFO thin films are identified. • Contribution of both hard and soft magnetic phase in coercivity of BCFO thin films is calculated and practical

  9. The effects of cerium doping on the size, morphology, and optical properties of α-hematite nanoparticles for ultraviolet filtration

    Energy Technology Data Exchange (ETDEWEB)

    Cardillo, Dean [Institute for Superconducting and Electronic Materials, AIIM Facility, University of Wollongong Innovation Campus, Squires Way, North Wollongong, NSW 2500 (Australia); Konstantinov, Konstantin, E-mail: konstan@uow.edu.au [Institute for Superconducting and Electronic Materials, AIIM Facility, University of Wollongong Innovation Campus, Squires Way, North Wollongong, NSW 2500 (Australia); Devers, Thierry [Centre de Recherche sur la Matière Divisée, Institut de Physique, site de Chartres, Université d’Orléans (France)

    2013-11-15

    Highlights: • Possible application of cerium-doped α-hematite as ultraviolet filter. • Nanoparticles obtained through co-precipitation technique using various cerium doping levels followed by annealing. • Comprehensive materials characterisation utilizing XRD, DSC/TGA, STEM, UV–vis spectroscopy. • Increasing cerium content reduces particle sizing and alters morphology. • Solubility of cerium in hematite seen between 5 and 10% doping, 10% cerium doping greatly enhances attenuation in ultraviolet region and increases optical bandgap. - Abstract: Metal oxide nanoparticles have potential use in energy storage, electrode materials, as catalysts and in the emerging field of nanomedicine. Being able to accurately tailor the desirable properties of these nanoceramic materials, such as particle size, morphology and optical bandgap (E{sub g}) is integral in the feasibility of their use. In this study we investigate the altering of both the structure and physical properties through the doping of hematite (α-Fe{sub 2}O{sub 3}) nanocrystals with cerium at a range of concentrations, synthesised using a one-pot co-precipitation method. This extremely simple synthesis followed by thermal treatment results in stable Fe{sub 2−x}Ce{sub x}O{sub y} nanoceramics resulting from the burning of any unreacted precursors and transformation of goethite-cerium doped nanoparticle intermediate. The inclusion of Ce into the crystal lattice of these α-Fe{sub 2}O{sub 3} nanoparticles causes a significantly large reduction in mean crystalline size and alteration in particle morphology with increasing cerium content. Finally we report an increase optical semiconductor bandgap, along with a substantial increase in the ultraviolet attenuation found for a 10% Ce-doping concentration which shows the potential application of cerium-doped hematite nanocrystals to be used as a pigmented ultraviolet filter for cosmetic products.

  10. Luminescence study on Eu or Tb doped lanthanum-gadolinium pyrosilicate crystal

    Czech Academy of Sciences Publication Activity Database

    Kurosawa, S.; Shishido, T.; Sugawara, T.; Nomura, A.; Yubuta, K.; Pejchal, Jan; Murakami, R.; Yokota, Y.; Shoji, Y.; Ohashi, Y.; Kamada, K.; Yoshikawa, A.

    2015-01-01

    Roč. 41, Mar (2015), s. 80-83 ISSN 0925-3467 Institutional support: RVO:68378271 Keywords : scintillator * gadolinium pyrosilicate Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.183, year: 2015

  11. Study of cerium doped magnetite (Fe3O4:Ce)/PMMA nanocomposites

    International Nuclear Information System (INIS)

    Padalia, Diwakar; Johri, U.C.; Zaidi, M.G.H.

    2012-01-01

    The paper presents the synthesis and properties of polymer nanocomposite material based on cerium doped magnetite (Fe 3 O 4 ) as filler material and poly methyl methacrylate (PMMA) as host matrix. The magnetite (Fe 3 O 4 ) particles were synthesized by co-precipitation route using stable ferrous and ferric salts with ammonium hydroxide as precipitating agent. Further, they doped by cerium oxide (CeO 2 ) non-stoichiometrically. The composite material was fabricated by solvent evaporation method. Here 2.4 GHz microwaves were used to study the effect of microwaves heating on polymerization. The phase and crystal structure is determined by X-ray diffraction (XRD). The average crystallite size of the composites varies from 28 to 35 nm. The chemical structure is confirmed by Fourier transform infrared (FTIR) spectroscopy. The magnetic and thermal properties are investigated by vibrating sample magnetometer (VSM) and differential scanning calorimetry (DSC). The thermal study shows that the microwave heated samples possess higher glass transition temperature (T g ). The magnetic results suggest that coercivity (H C ) and squareness (M r /M s ) of the loop increases with increasing doping percent of cerium.

  12. Study of cerium doped magnetite (Fe 3O 4:Ce)/PMMA nanocomposites

    Science.gov (United States)

    Padalia, Diwakar; Johri, U. C.; Zaidi, M. G. H.

    2012-03-01

    The paper presents the synthesis and properties of polymer nanocomposite material based on cerium doped magnetite (Fe 3O 4) as filler material and poly methyl methacrylate (PMMA) as host matrix. The magnetite (Fe 3O 4) particles were synthesized by co-precipitation route using stable ferrous and ferric salts with ammonium hydroxide as precipitating agent. Further, they doped by cerium oxide (CeO 2) non-stoichiometrically. The composite material was fabricated by solvent evaporation method. Here 2.4 GHz microwaves were used to study the effect of microwaves heating on polymerization. The phase and crystal structure is determined by X-ray diffraction (XRD). The average crystallite size of the composites varies from 28 to 35 nm. The chemical structure is confirmed by Fourier transform infrared (FTIR) spectroscopy. The magnetic and thermal properties are investigated by vibrating sample magnetometer (VSM) and differential scanning calorimetry (DSC). The thermal study shows that the microwave heated samples possess higher glass transition temperature ( Tg). The magnetic results suggest that coercivity ( HC) and squareness ( Mr/ Ms) of the loop increases with increasing doping percent of cerium.

  13. Assessment of the abatement of acelsulfame K using cerium doped ZnO as photocatalyst

    International Nuclear Information System (INIS)

    Calza, P.; Gionco, C.; Giletta, M.; Kalaboka, M.; Sakkas, V.A.; Albanis, T.; Paganini, M.C.

    2017-01-01

    Highlights: • Hydrothermal synthesis and characterization of Ce doped ZnO. • The abatement of ACE K is assessed in ultrapure water and in river water matrix. • Demonstrated higher degradation activity than P25 under visible light. • The degradation activity is less affected in river water than for P25. - Abstract: In the present study, we investigated the possibility to abate Acesulfame K, a persistent emerging contaminant, in aqueous media using zinc oxide based materials. For this purpose, bare and Ce-doped zinc oxide was prepared via an easy and cheap hydrothermal process using different cerium salts as precursors. Their photocatalytic performance was evaluated in different media, namely ultrapure and river water under both UV–vis and visible light. Commercial TiO_2 P25 was also employed and used as a reference photocatalyst for comparison purposes. The obtained results pointed out that cerium doped zinc oxide composites exhibit higher performance than TiO_2 P25, especially under visible light and in the presence of organic matter, when the activity of the latter is greatly depressed. In particular, ZnO doped with cerium (1%) was the most effective material, and could be a promising alternative to TiO_2 P25, especially in the treatment of natural waters.

  14. Biomineralization-Inspired Synthesis of Cerium-Doped Carbonaceous Nanoparticles for Highly Hydroxyl Radical Scavenging Activity

    Science.gov (United States)

    Zou, Shenqiang; Zhu, Xiaofang; Zhang, Lirong; Guo, Fan; Zhang, Miaomiao; Tan, Youwen; Gong, Aihua; Fang, Zhengzou; Ju, Huixiang; Wu, Chaoyang; Du, Fengyi

    2018-03-01

    Cerium oxide nanoparticles recently have received extensive attention in biomedical applications due to their excellent anti-oxidation performance. In this study, a simple, mild, and green approach was developed to synthesize cerium-doped carbonaceous nanoparticles (Ce-doped CNPs) using bio-mineralization of bull serum albumin (BSA) as precursor. The resultant Ce-doped CNPs exhibited uniform and ultrasmall morphology with an average size of 14.7 nm. XPS and FTIR results revealed the presence of hydrophilic group on the surface of Ce-doped CNPs, which resulted in excellent dispersity in water. The CCK-8 assay demonstrated that Ce-doped CNPs possessed favorable biocompatibility and negligible cytotoxicity. Using H2O2-induced reactive oxygen species (ROS) as model, Ce-doped CNPs showed highly hydroxyl radical scavenging capability. Furthermore, flow cytometry and live-dead staining results indicated that Ce-doped CNPs protected cells from H2O2-induced damage in a dose-dependent effect, which provided a direct evidence for anti-oxidative performance. These findings suggest that Ce-doped CNPs as novel ROS scavengers may provide a potential therapeutic prospect in treating diseases associated with oxidative stress.

  15. A Low-cost Beam Profiler Based On Cerium-doped Silica Fibers

    Science.gov (United States)

    Potkins, David Edward; Braccini, Saverio; Nesteruk, Konrad Pawel; Carzaniga, Tommaso Stefano; Vedda, Anna; Chiodini, Norberto; Timmermans, Jacob; Melanson, Stephane; Dehnel, Morgan Patrick

    A beam profiler called the Universal Beam Monitor (UniBEaM) has been developed by D-Pace Inc. (Canada) and the Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics, University of Bern (Switzerland). The device is based on passing 100 to 600 micron cerium-doped optical fibers through a particle beam. Visible scintillation light from the sensor fibers is transmitted over distances of tens of meters to the light sensors with minimal signal loss and no susceptibility to electromagnetic fields. The probe has an insertion length of only 70 mm. The software plots the beam intensity distribution in the horizontal and vertical planes, and calculates the beam location and integrated profile area, which correlates well with total beam current. UniBEaM has a large dynamic range, operating with beam currents of ∼pA to mA, and a large range of particle kinetic energies of ∼keV to GeV, depending on the absorbed power density. Test data are presented for H- beams at 25keV for 500 μA, and H+ beams at 18MeV for 50pA to 10 μA. Maximum absorbed power density of the optical fiber before thermal damage is discussed in relation to dE/dx energy deposition as a function of particle type and kinetic energy. UniBEaM is well suited for a wide variety of beamlines including discovery science applications, radio-pharmaceutical production, hadron therapy, industrial ion beam applications including ion implantation, industrial electron beams, and ion source testing.

  16. Structure, dielectric and electrical properties of cerium doped barium zirconium titanate ceramics

    International Nuclear Information System (INIS)

    Feng Hongjun; Hou Jungang; Qu Yuanfang; Shan Dan; Yao Guohua

    2012-01-01

    Highlights: ► Rare-earth doped barium zirconate titanate (BZT) ceramics, Ba(Zr 0.25 Ti 0.75 )O 3 + xCeO 2 , (x = 0–1.5 at%) were obtained by a solid state reaction route. ► Morphological analysis on sintered samples by scanning electron microscopy shows that the addition of rare-earth ions affects the growth of the grain and remarkably changes the grain morphology. ► The effect of rare-earth addition to BZT on dielectric and electrical properties is analyzed, demonstrating that the samples with x = 0.4 and x = 0.6 could be semiconducting in air atmosphere. - Abstract: Rare-earth doped barium zirconium titanate (BZT) ceramics, Ba(Zr 0.25 Ti 0.75 )O 3 + xCeO 2 , (x = 0–1.5 at%) were obtained by a solid state reaction route. Perovskite-like single-phase compounds were confirmed from X-ray diffraction data and the lattice parameters were refined by the Rietveld method. It is found that, integrating with the lattice parameters and the distortion of crystal lattice, there is an alternation of substitution preference of cerium ions for the host cations in perovskite lattice. Morphological analysis on sintered samples by scanning electron microscopy shows that the addition of rare-earth ions affects the growth of the grain and remarkably changes the grain morphology. The effect of rare-earth addition to BZT on dielectric and electrical properties is analyzed. High values of dielectric tunability are obtained for cerium doped BZT. Especially, the experimental results on the effect of the contents of rare-earth addition on the resistivity of BZT ceramics were investigated, demonstrating that the samples with x = 0.4 and x = 0.6 could be semiconducting in air atmosphere.

  17. Imaging properties of cerium doped Yttrium Aluminum Oxide (YAP:Ce) powder scintillating screens under X-ray excitation

    Energy Technology Data Exchange (ETDEWEB)

    Kalivas, N. [Greek Atomic Energy Commission, 15310 Ag. Paraskevi, P.O. Box 60092 (Greece); Valais, I. [Department of Medical Physics, Medical School, University of Patras, 26500 Patras (Greece)]|[Department of Medical Instruments Technology, Technological Educational Institution of Athens, Ag. Spyridonos Street, Aigaleo, 12210 Athens (Greece); Salemis, G.; Karagiannis, C.; Konstantinidis, A.; Nikolopoulos, D. [Department of Medical Instruments Technology, Technological Educational Institution of Athens, Ag. Spyridonos Street, Aigaleo, 12210 Athens (Greece); Loudos, G.; Sakelios, N.; Karakatsanis, N.; Nikita, K. [Department of Electrical and Computer Engineering, National Technical University of Athens, 9 Iroon Polytechniou, 15780 Zografos (Greece); Gayshan, V.L.; Gektin, A.V. [Institute of Scintillation Materials, Lenin Avenue 60, 310072 Kharkov (Ukraine); Sianoudis, I. [Department of Physics, Chemistry and Materials Technology, Technological Educational Institution of Athens, Aigaleo, 12210 Athens (Greece); Giokaris, N. [Physics Department National Capodistrian University of Athens, Panepistimioupolis Ilisia, 15771 Athens (Greece)]|[Institute of Accelerating Systems and Applications, P.O. Box 17214, 10024 Athens (Greece); Nomicos, C.D. [Department of Electronics, Technological Educational Institution of Athens, Aigaleo, 12210 Athens (Greece); Dimitropoulos, N. [Department of Medical Imaging, ' Euromedica' Medical Center, Mesogeion 2-4, 11527 Athens (Greece); Cavouras, D. [Department of Medical Instruments Technology, Technological Educational Institution of Athens, Ag. Spyridonos Street, Aigaleo, 12210 Athens (Greece); Panayiotakis, G. [Department of Medical Physics, Medical School, University of Patras, 26500 Patras (Greece); Kandarakis, I. [Department of Medical Instruments Technology, Technological Educational Institution of Athens, Ag. Spyridonos Street, Aigaleo, 12210 Athens (Greece)]. E-mail: kandarakis@teiath.gr

    2006-12-20

    The aim of the present study was to evaluate the imaging performance of YAP:Ce powder scintillating screens under exposure conditions employed in diagnostic radiology (50-140 kV). Various screens were prepared in our laboratory from YAP: Ce powder (Phosphor Technology, Ltd.), with coating thickness ranging from 53 to 110 mg/cm{sup 2}. The imaging performance of the screens was assessed by experimental determination of the modulation transfer function (MTF) and the noise transfer function (NTF). MTF was determined by the edge spread function (ESF) method while NTF was estimated by noise power spectrum (NPS) measurements after uniform screen irradiation. In addition, parameters related to overall image quality, such as the signal-to-noise ratio transfer (MTF/NTF), were estimated. MTF curves were affected by the beam hardening effects caused by the patient simulating 20 mm thick aluminum phantom. Under these conditions MTF values were found to increase with the mean X-ray photon energy. A similar effect was observed for NTF curves. Results were compared with data obtained on CsI:Tl scintillator. Taking into consideration the very fast response of YAP:Ce, these data may be of interest in designing X-ray imaging detectors.

  18. Scintillation properties of a La,Lu-admix gadolinium pyrosilicate crystal

    Czech Academy of Sciences Publication Activity Database

    Kurosawa, S.; Shishido, T.; Suzuki, A.; Sugawara, T.; Nomura, A.; Yubuta, K.; Shoji, Y.; Yokota, Y.; Pejchal, Jan; Ohashi, Y.; Kamada, K.; Yoshikawa, A.

    2015-01-01

    Roč. 784, Jun (2015), s. 115-118 ISSN 0168-9002 Institutional support: RVO:68378271 Keywords : scintillator * pyrosilicate crystal * Ce-doped (La, Lu, Gd) Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.200, year: 2015

  19. Effect of cerium doping on the electrical properties of ultrathin indium tin oxide films for application in touch sensors

    International Nuclear Information System (INIS)

    Kang, Saewon; Cho, Sanghyun; Song, Pungkeun

    2014-01-01

    The electrical and microstructure properties of cerium doped indium tin oxide (ITO:Ce) ultrathin films were evaluated to assess their potential application in touch sensors. 10 to 150-nm ITO and ITO:Ce films were deposited on glass substrates (200 °C) by DC magnetron sputtering using different ITO targets (doped with CeO 2 : 0, 1, 3, 5 wt.%). ITO:Ce (doped with CeO 2 : 3 wt.%) films with thickness < 25 nm showed lower resistivity than ITO. This lower resistivity was accompanied by a significant increase in the Hall mobility despite a decrease in crystallinity. In addition, the surface morphology and wetting properties improved with increasing Ce concentration. This is related to an earlier transition from an island structure to continuous film formation caused by an increase in the initial nucleation density. - Highlights: • 10 to 150-nm InSnO 2 (ITO) and ITO:Ce thin films were deposited by sputtering. • ITO:Ce films with thickness < 25 nm showed lower resistivity than ITO. • Hall mobility was strongly affected by initial film formation. • Surface morphology and wetting property improved with increasing Ce concentration. • Such behavior is related to an earlier transition to continuous film formation

  20. Study of cerium doped magnetite (Fe{sub 3}O{sub 4}:Ce)/PMMA nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Padalia, Diwakar, E-mail: Padalia.diwakar@gmail.com [Department of Physics, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttrakhand (India); Johri, U.C. [Department of Physics, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttrakhand (India); Zaidi, M.G.H. [Supercritical Fluid Processing Laboratory, Department of Chemistry, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttrakhand (India)

    2012-03-01

    The paper presents the synthesis and properties of polymer nanocomposite material based on cerium doped magnetite (Fe{sub 3}O{sub 4}) as filler material and poly methyl methacrylate (PMMA) as host matrix. The magnetite (Fe{sub 3}O{sub 4}) particles were synthesized by co-precipitation route using stable ferrous and ferric salts with ammonium hydroxide as precipitating agent. Further, they doped by cerium oxide (CeO{sub 2}) non-stoichiometrically. The composite material was fabricated by solvent evaporation method. Here 2.4 GHz microwaves were used to study the effect of microwaves heating on polymerization. The phase and crystal structure is determined by X-ray diffraction (XRD). The average crystallite size of the composites varies from 28 to 35 nm. The chemical structure is confirmed by Fourier transform infrared (FTIR) spectroscopy. The magnetic and thermal properties are investigated by vibrating sample magnetometer (VSM) and differential scanning calorimetry (DSC). The thermal study shows that the microwave heated samples possess higher glass transition temperature (T{sub g}). The magnetic results suggest that coercivity (H{sub C}) and squareness (M{sub r}/M{sub s}) of the loop increases with increasing doping percent of cerium.

  1. Fabrication of cerium-doped β-Ga2O3 epitaxial thin films and deep ultraviolet photodetectors.

    Science.gov (United States)

    Li, Wenhao; Zhao, Xiaolong; Zhi, Yusong; Zhang, Xuhui; Chen, Zhengwei; Chu, Xulong; Yang, Hujiang; Wu, Zhenping; Tang, Weihua

    2018-01-20

    High-quality cerium-doped β-Ga 2 O 3 (Ga 2 O 3 :Ce) thin films could be achieved on (0001)α-Al 2 O 3 substrates using a pulsed-laser deposition method. The impact of dopant contents concentration on crystal structure, optical absorption, photoluminescence, and photoelectric properties has been intensively studied. X-ray diffraction analysis results have shown that Ga 2 O 3 :Ce films are highly (2¯01) oriented, and the lattice spacing of the (4¯02) planes is sensitive to the Ce doping level. The prepared Ga 2 O 3 :Ce films show a sharp absorption edge at about 250 nm, meaning a high transparency to deep ultraviolet (DUV) light. The photoluminescence results revealed that the emissions were in the violet-blue-green region, which are associated with the donor-acceptor transitions with the Ce 3+ and oxygen vacancies related defects. A simple DUV photodetector device with a metal-semiconductor-metal structure has also been fabricated based on Ga 2 O 3 :Ce thin film. A distinct DUV photoresponse was obtained, suggesting a potential application in DUV photodetector devices.

  2. Scintillation properties of a La, Lu-admix gadolinium pyrosilicate crystal

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, Shunsuke, E-mail: kurosawa@imr.tohoku.ac.jp [Institute for Materials Research (IMR), Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); New Industry Creation Hatchery Center (NICHe) 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Shishido, Toetsu; Suzuki, Akira; Sugawara, Takamasa; Nomura, Akiko; Yubuta, Kunio [Institute for Materials Research (IMR), Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Shoji, Yasuhiro [Institute for Materials Research (IMR), Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); C& A Corporation, 6-6-40 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Yokota, Yuui [New Industry Creation Hatchery Center (NICHe) 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Pejchal, Jan [New Industry Creation Hatchery Center (NICHe) 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Institute of Physics, AS CR, Cukrovarnická 10, 162 53 Prague (Czech Republic); Ohashi, Yuji [Institute for Materials Research (IMR), Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Kamada, Kei [New Industry Creation Hatchery Center (NICHe) 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); C& A Corporation, 6-6-40 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Yoshikawa, Akira [Institute for Materials Research (IMR), Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); New Industry Creation Hatchery Center (NICHe) 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); C& A Corporation, 6-6-40 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)

    2015-06-01

    In order to obtain new scintillator with higher effective atomic number, a pyrosilicate crystal with a composition (Ce{sub 0.01}, Gd{sub 0.54}, La{sub 0.25}, Lu{sub 0.20}){sub 2}Si{sub 2}O{sub 7} (Ce:LaLu-GPS) was grown by the floating zone method. Emission wavelengths of this material were at 370 and 390 nm. Gamma-ray-excited pulse height and scintillation decay measurement showed that Ce:LaLu-GPS had a light output of 34,000±2000 photons/MeV, an FWHM energy resolution of 6.9±0.2%, and the decay time components of 59±1 ns (13%) and 570±20 ns (87%)

  3. Spectroscopic studies of lutetium pyro-silicates Lu2Si2O7 doped with bismuth and europium

    International Nuclear Information System (INIS)

    Bretheau-Raynal, Francoise

    1981-01-01

    Single crystals of thortveitite structure pyro-silicates were grown by a floating zone technique associated with an arc image furnace. The samples were systematically characterized by X-Ray diffraction and microprobe analysis. Thanks to oriented single crystals of Lu 2 Si 2 O 7 , Yb 2 Si 2 O 7 and Sc 2 Si 2 O 7 , the recorded infrared and Raman spectra allow complete attribution of internal and external vibration modes, in good agreement with group theory predictions for C 2h factor group. Spectroscopic studies of Eu 3+ doping ion in Lu 2 Si 2 O 7 confirm C 2 point symmetry for the cationic site. Oscillator strengths and Judd-Ofelt parameters for Eu 3+ were calculated. A three level scheme ( 1 S 0 , 3 P 0 , 3 P 1 ) of Bi 3+ ion is used to explain radiative and non radiative mechanisms in Lu 2 Si 2 O 7 doped with bismuth. Finally, the mechanisms of low temperature (T =9 K) energy transfer between Bi 3+ and Eu 3+ in lutetium pyro-silicate was studied. The transfer occurs by non radiative process, without any diffusion of the excitation energy within the donor system and is due to dipole-dipole interactions between Bi 3+ and Eu 3+ ions. (author) [fr

  4. Cerium doped lanthanum halides: fast scintillators for medical imaging; Halogenures de lanthane dopes cerium des scintillateurs rapides pour l'imagerie medicale

    Energy Technology Data Exchange (ETDEWEB)

    Selles, O

    2006-12-15

    This work is dedicated to two recently discovered scintillating crystals: cerium doped lanthanum halides (LaCl{sub 3}:Ce{sup 3+} and LaBr{sub 3}:Ce{sup 3+}).These scintillators exhibit interesting properties for gamma detection, more particularly in the field of medical imaging: a short decay time, a high light yield and an excellent energy resolution. The strong hygroscopicity of these materials requires adapting the usual experimental methods for determining physico-chemical properties. Once determined, these can be used for the development of the industrial manufacturing process of the crystals. A proper comprehension of the scintillation mechanism and of the effect of defects within the material lead to new possible ways for optimizing the scintillator performance. Therefore, different techniques are used (EPR, radioluminescence, laser excitation, thermally stimulated luminescence). Alongside Ce{sup 3+} ions, self-trapped excitons are involved in the scintillation mechanism. Their nature and their role are detailed. The knowledge of the different processes involved in the scintillation mechanism leads to the prediction of the effect of temperature and doping level on the performance of the scintillator. A mechanism is proposed to explain the thermally stimulated luminescence processes that cause slow components in the light emission and a loss of light yield. Eventually the study of afterglow reveals a charge transfer to deep traps involved in the high temperature thermally stimulated luminescence. (author)

  5. Yttrium-90

    International Nuclear Information System (INIS)

    Ammerich, Marc; Frot, Patricia; Gambini, Denis-Jean; Gauron, Christine; Moureaux, Patrick; Herbelet, Gilbert; Lahaye, Thierry; Pihet, Pascal; Rannou, Alain; Vial, Eric

    2013-03-01

    This sheet belongs to a collection which relates to the use of radionuclides essentially in unsealed sources. Its goal is to gather on a single document the most relevant information as well as the best prevention practices to be implemented. These sheets are made for the persons in charge of radiation protection: users, radioprotection-skill persons, labor physicians. Each sheet treats of: 1 - the radio-physical and biological properties; 2 - the main uses; 3 - the dosimetric parameters; 4 - the measurement; 5 - the protection means; 6 - the areas delimitation and monitoring; 7 - the personnel classification, training and monitoring; 8 - the effluents and wastes; 9 - the authorization and declaration administrative procedures; 10 - the transport; and 11 - the right conduct to adopt in case of incident or accident. This sheet deals specifically with Yttrium-90

  6. Production of yttrium

    International Nuclear Information System (INIS)

    Day, J.G.

    1980-01-01

    A process is described for the production of yttrium metal, or of an alloy comprising a major proportion of yttrium, in which calcium (metal) and yttrium fluoride are reacted together by use of a submerged electric arc in a molten slag. (author)

  7. Unactivated yttrium tantalate phosphor

    International Nuclear Information System (INIS)

    Reddy, V.B.; Cheung, H.K.

    1992-01-01

    This patent describes an unactivated yttrium tantalate phosphor having M prime monoclinic structure and containing one or more additives of Rb and Al in an amount of between about 0.001 to 0.1 moles per mole of yttrium tantalate to improve brightness under X-radiation. This patent also describes an unactivated yttrium tantalate phosphor having M prime monoclinic structure and containing additives of Sr in an amount of between 0.001 to 0.1 moles per mole of yttrium tantalate and one or more of Rb and Al in an amount of between 0.001 to 0.1 moles per mole of yttrium tantalate the phosphor exhibiting a greater brightness under X-radiation than the phosphor absent Rb and Al

  8. Yttrium silicate as an oxidation protection layer for C/C-SiC materials. Synthesis, electrophoretic deposition and high temperature oxidation; Yttriumsilikat als Oxidationsschutzschicht fuer C/C-SiC-Werkstoffe. Synthese, elektrophoretische Abscheidung und Hochtemperaturoxidation

    Energy Technology Data Exchange (ETDEWEB)

    Grosse-Brauckmann, Jana

    2012-07-01

    Carbon fibre reinforced carbon composites are promising materials for high temperature applications. They exhibit excellent thermal shock resistance and nearly constant mechanical strength. A serious draw-back of this material is their poor resistivity towards oxidation at temperatures above 400 C. To make use of the very good thermal stability the material needs an outer oxidation protection coating. Silicon carbide has been successfully employed at temperatures up to 1300 C. To increase the application range towards higher temperatures an outer environmental barrier coating is needed. In the present work yttrium silicates were used to complement the silicon carbide coated carbon fibre reinforced carbon material. Both stable compounds in the quasi-binary system Y{sub 2}O{sub 3}-SiO{sub 2}, yttrium orthosilicate (Y{sub 2}SiO{sub 5}) and yttrium pyrosilicate (Y{sub 2}Si{sub 2}O{sub 7}), were separately applied to the test samples via electrophoretic deposition. Suitable suspensions were prepared in butanone with iodine as charging agent to adjust conductivity and particle charge. Galvanostatic deposition obeys a linear growth law for the selected deposition times. Alternatively the feasibility of direct electrophoretic deposition from an yttrium silicate precursor sol was tested. Emphasis was put on the development of a suitable sol-system based on alkoxide precursors. Samples coated either with Y{sub 2}SiO{sub 5} or Y{sub 2}Si{sub 2}O{sub 7} were investigated using thermogravimetric high temperature oxidation in the temperature range from 1450 C to 1650 C, respectively. The coated samples exhibited very good oxidation resistance up to temperatures of 1600 C, while the performance was reduced at 1650 C to a few hours. All samples showed a parabolic mass increase with time indicating a diffusion limited process governing the oxidation kinetics. The cross sections of the samples show a sharp border between the SiO{sub 2} that crystallizes to cristobalite and the

  9. Diffusion of hydrogen in yttrium

    International Nuclear Information System (INIS)

    Vorobyov, V.V.; Ryabchikov, L.N.

    1966-01-01

    In this work the diffusion coefficients of hydrogen in yttrium were determined from the rate at which the hydrogen was released from yttrium samples under a vacuum at temperatures of 450 to 850 0 C and from the quantity of hydrogen retained by yttrium at hydrogen pressures below 5 x 10 - 4 mm Hg in the same temperature range

  10. Lanthanoid and yttrium tellurates

    Energy Technology Data Exchange (ETDEWEB)

    Gonalez, C G; Guedes de Carvalho, R A [Faculdade de Engenharia, Porto (Portugal). Centro de Engenharia Quimica

    1978-05-01

    Preparation in aqueous medium of all the lanthanoid (except Ce and Pm) and yttrium tellurates is described. Chemical analyses, solubilities at 25/sup 0/C in water and thermograms of all the products prepared were determined. X-ray diffractograms and DTA and DTG curves of La, Gd and Yb tellurates were obtained and commented. Partial volatilization of lanthanoid is observed in the thermal analysis of tellurates.

  11. Yttrium-90 - ED 4310

    International Nuclear Information System (INIS)

    Ammerich, M.; Frot, P.; Gambini, D.; Gauron, C.; Moureaux, P.; Herbelet, G.; Lahaye, T.; Pihet, P.; Rannou, A.; Vidal, E.

    2013-03-01

    This sheet presents the characteristics of yttrium-90, its origin, and its radio-physical and biological properties. It briefly describes its use in nuclear medicine. It indicates its dosimetric parameters for external exposure, cutaneous contamination, and internal exposure due to acute contamination or to chronic contamination. It indicates and comments the various exposure control techniques: ambient dose rate measurement, surface contamination measurement, atmosphere contamination. It addresses the means of protection: premise design, protection against external exposure and against internal exposure. It describes how areas are delimited and controlled within the premises: regulatory areas, controls to be performed. It addresses the personnel classification, training and medical survey. It addresses the issue of solid and liquid wastes and liquid or gaseous effluents. It briefly recalls the administrative procedures related to the authorization and declaration of possession and use of sealed and unsealed sources. It indicates regulatory aspects related to the transport of yttrium-90, describes what is to be done in case of incident or accident (for the different types of contamination or exposure)

  12. Scandium, yttrium and the lanthanides

    International Nuclear Information System (INIS)

    Hart, F.A.

    1987-01-01

    This chapter on the chemistry of the coordination complexes of scandium, yttrium and the lanthanides includes sections on the nitrogen and oxygen donor ligands and complex halides of scandium, and the phosphorus and sulfur donor ligands of yttrium and the lanthanides. Complexes with the macrocylic ligands and with halides are also discussed. Sections on the NMR and electronic spectra of the lanthanides are also included. (UK)

  13. Yttrium and lanthanum recovery from low cerium carbonate, yttrium carbonate and yttrium concentrate

    International Nuclear Information System (INIS)

    Vasconcelos, Mari Estela de

    2006-01-01

    In this work, separation, enrichment and purification of lanthanum and yttrium were performed using as raw material a commercial low cerium rare earth concentrate named LCC (low cerium carbonate), an yttrium concentrate named 'yttrium carbonate', and a third concentrated known as 'yttrium earths oxide. The first two were industrially produced by the late NUCLEMON - NUCLEBRAS de Monazita e Associados Ltda, using Brazilian monazite. The 'yttrium earths oxide' come from a process for preparation of lanthanum during the course of the experimental work for the present thesis. The following techniques were used: fractional precipitation with urea; fractional leaching of the LCC using ammonium carbonate; precipitation of rare earth peroxycarbonates starting from the rare earth complex carbonates. Once prepared the enriched rare earth fractions the same were refined using the ion exchange chromatography with strong cationic resin without the use of retention ion and elution using the ammonium salt of ethylenediaminetetraacetic acid. With the association of the above mentioned techniques were obtained pure oxides of yttrium (>97,7%), lanthanum (99,9%), gadolinium (96,6%) and samarium (99,9%). The process here developed has technical and economic viability for the installation of a large scale unity. (author)

  14. Plasma spraying of cerium-doped YAG

    Czech Academy of Sciences Publication Activity Database

    Ctibor, Pavel; Kubát, J.; Pala, Zdeněk; Nevrlá, Barbara

    2014-01-01

    Roč. 29, č. 19 (2014), s. 2344-2351 ISSN 0884-2914 R&D Projects: GA ČR(CZ) GAP108/12/1872 Institutional support: RVO:61389021 Keywords : plasma spraying * water-stabilized plasma Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 1.647, year: 2014 http://dx.doi.org/10.1557/jmr.2014.251

  15. Coprecipitation of yttrium and aluminium hydroxide for preparation of yttrium aluminium garnet

    NARCIS (Netherlands)

    Vrolijk, J.W.G.A.; Willems, J.W.M.M.; Metselaar, R.

    1990-01-01

    Coprecipitation of yttrium and aluminium hydroxide for the preparation of pure yttrium aluminium garnet (YAG) powder with small grain size is the subject of this study. Starting materials are sulphates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3Al5O12), the pH during flocculation

  16. Texture and deformation mechanism of yttrium

    International Nuclear Information System (INIS)

    Adamesku, R.A.; Grebenkin, S.V.; Stepanenko, A.V.

    1992-01-01

    X-ray pole figure analysis was applied to study texture and deformation mechanism in pure and commercial polycrystalline yttrium on cold working. It was found that in cast yttrium the texture manifected itself weakly enough both for pure and commercial metal. Analysis of the data obtained made it possible to assert that cold deformation of pure yttrium in the initial stage occurred mainly by slip the role of which decreased at strains higher than 36%. The texture of heavily deformed commercial yttrium contained two components, these were an 'ideal' basic orientation and an axial one with the angle of inclination about 20 deg. Twinning mechanism was revealed to be also possible in commercial yttrium

  17. Reaction of yttrium polonides with carbon dioxide

    International Nuclear Information System (INIS)

    Abakumov, A.S.; Khokhlov, A.D.; Reznikova, N.F.

    1986-01-01

    It has been proved that heating of yttrium and tantalum in carbon dioxide to 500 and 800 0 C alters the gas phase composition, causing formation of carbon monoxide and reduction of oxygen content. A study of the thermal stability of yttrium polonides in carbon dioxide showed that yttrium sesqui- and monopolonides decompose at 400-430 0 C. The temperature dependence of the vapor pressure of polonium obtained upon decomposition of the referred polonides has been determined in a carbon dioxide environment radiotensometrically. The enthalpy of the process calculated from this dependence is close to the enthalpy of vaporization of elemental polonium in vacuo. The mechanism of the reactions has been suggested

  18. Yttrium doped BSCF membranes for oxygen separation

    DEFF Research Database (Denmark)

    Haworth, P.; Smart, S.; Glasscock, Julie

    2011-01-01

    This work investigates the partial substitution of yttrium in place of iron in BSCF to form Ba0.5Sr0.5Co0.8Fe0.2−xYxO3−δ, where x varied between 0 and 0.2. X-ray diffraction patterns showed the formation of a perovskite cubic phase structure up to x = 0.15, whilst the full substitution of yttrium...

  19. Crystallization of Yttrium and Samarium Aluminosilicate Glasses

    OpenAIRE

    Lago, Diana Carolina; Prado, Miguel Oscar

    2016-01-01

    Aluminosilicate glasses containing samarium and yttrium (SmAS and YAS glasses) exhibit high glass transition temperatures, corrosion resistance, and glass stability on heating which make them useful for technological applications. Yttrium aluminosilicate glass microspheres are currently being used for internal selective radiotherapy of liver cancer. During the preparation process, crystallization needs to be totally or partially avoided depending on the final application. Thus knowing the cry...

  20. Interaction of oxygen vacancies in yttrium germanates

    KAUST Repository

    Wang, Hao

    2012-01-01

    Forming a good Ge/dielectric interface is important to improve the electron mobility of a Ge metal oxide semiconductor field-effect transistor. A thin yttrium germanate capping layer can improve the properties of the Ge/GeO 2 system. We employ electronic structure calculations to investigate the effect of oxygen vacancies in yttrium-doped GeO 2 and the yttrium germanates Y 2Ge 2O 7 and Y 2GeO 5. The calculated densities of states indicate that dangling bonds from oxygen vacancies introduce in-gap states, but the system remains insulating. However, yttrium-doped GeO 2 becomes metallic under oxygen deficiency. Y-doped GeO 2, Y 2Ge 2O 7 and Y 2GeO 5 are calculated to be oxygen substoichiometric under low Fermi energy conditions. The use of yttrium germanates is proposed as a way to effectively passivate the Ge/dielectric interface. This journal is © 2012 the Owner Societies.

  1. Kinetics of yttrium dissolution from waste ceramic dust

    OpenAIRE

    STOPIC SRECKO R.; FRIEDRIH BERND G.

    2016-01-01

    Yttrium is a silvery transition metal and has similar chemical properties to lanthanoids. Because of this similarity, yttrium belongs to rare earth elements. Ytttrium and yttrium oxide are mostly used in fluoroscent lamps, production of electrodes, in electronic filters, lasers, superconductors and as additives in various materials to improve their properties. Yttrium is mainly recovered from the minerals monazite [(Ce,La,Th,Nd,Y)PO4] and xenotime YPO4.The presence of radioactive elements suc...

  2. Features of solid solutions composition in magnesium with yttrium alloys

    International Nuclear Information System (INIS)

    Drits, M.E.; Rokhlin, L.L.; Tarytina, I.E.

    1983-01-01

    Additional data on features of yttrium solid solutions composition in magnesium in the course of their decomposition investigation in the case of aging are obtianed. The investigation has been carried out on the base of a binary magnesium-yttrium alloy the composition of which has been close to maximum solubility (at eutectic temperature) and magnesium-yttrium alloys additionally doped with zinc. It is shown that higher yttrium solubility in solid magnesium than it has been expected, issueing from the difference in atomic radii of these metals indicates electron yttrium-magnesium atoms interaction. In oversaturated magnesium-yttrium solid solutions at earlier decomposition stages Mg 3 Cd type ordering is observed. At aging temperatures up to 250 deg C and long exposures corresponding to highest strengthening in oversaturated magnesium yttrium solid solutions a rhombic crystal lattice phase with three symmetric orientations is formed

  3. Method for production of transparent yttrium oxide

    International Nuclear Information System (INIS)

    Dutta, S.K.; Gazza, G.A.

    1975-01-01

    The method comprises vacuum hot pressing the yttrium oxide (Y 2 O 3 ) powder in a graphite die at temperatures of between 1300 to 1500 0 C and uniaxial pressures of between 5000 to 7000 psi, for a period of 1 to 2 hours. (U.S.)

  4. Method for chromatographically recovering scandium and yttrium

    International Nuclear Information System (INIS)

    Snyder, T.S.; Stoltz, R.A.

    1991-01-01

    This paper describes a method for chromatographically recovering scandium and yttrium from the residue of a sand chlorinator. It comprises: providing a residue from a sand chlorinator, the residue containing scandium, yttrium, sodium, calcium and at least one radioactive metal of the group consisting of radium, thorium and uranium; digesting the residue with an acid to produce an aqueous liquid containing scandium, yttrium, sodium, calcium and at least one radioactive metal of the group consisting of radium, thorium and uranium; feeding the metal containing liquid through a cation exchanger; eluding the cation exchanger with an acid eluant to to produce: a first eluate containing at least half of the total weight of the calcium and sodium in the feed liquid; a second eluate containing at least half of the total weight of the one or more radioactive metals in the feed liquid; a third eluate containing at least half of the yttrium in the feed liquid, and a fourth eluate containing at least half of the weight of the scandium in the feed liquid

  5. New hydrotalcite-like compounds containing yttrium

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.M.; Barriga, C.; Ulibarri, M.A. [Universidad de Cordoba (Spain)] [and others

    1997-01-01

    The synthesis of hydrotalcite-type compounds containing yttrium was carried out by the coprecipitation of Mg(II), Al(III), and Y(III) cations at 60 degrees C with strong alkaline solutions. Thermal treatments were applied and changes studied.

  6. Luminescence characteristics of the Ce.sup.3+./sup.-doped pyrosilicates: the case of La-admixed Gd.sub.2./sub.Si.sub.2./sub.O.sub.7./sub. single crystals

    Czech Academy of Sciences Publication Activity Database

    Jarý, Vítězslav; Nikl, Martin; Kurosawa, S.; Shoji, Y.; Mihóková, Eva; Beitlerová, Alena; Pazzi, G.P.; Yoshikawa, A.

    2014-01-01

    Roč. 118, č. 46 (2014), s. 26521-26529 ISSN 1932-7447 R&D Projects: GA MŠk(CZ) LH14266 Institutional support: RVO:68378271 Keywords : lutetium silicate sci ntillators * floating-zone growth * electronic-structure * yttrium content * lyso crystals Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.772, year: 2014

  7. Scandium, yttrium and the lanthanide metals

    International Nuclear Information System (INIS)

    Brown, Paul L.; Ekberg, Christian

    2016-01-01

    The hydroxide and oxide phases that exist for scandium(III) include scandium hydroxide, which likely has both amorphous and crystalline forms, ScOOH(s), and scandium oxide. This chapter presents the data selected for the stability constants of the polymeric hydrolysis species of scandium at zero ionic strength. The behaviour of yttrium, and the lanthanide metals, in the environment is largely dependent on their solution equilibria. Hydrolysis and other complexation reactions of yttrium and the lanthanide metals are important in the disposal of nuclear waste. The trivalent lanthanide metals include lanthanum(III) through lutetium(III). A number of studies have reported a tetrad effect for the geochemical behaviour of the lanthanide series, including stability constants and distribution coefficients. The solubility of many of the lanthanide hydroxide phases has been studied at fixed ionic strength. In studying the hydrolysis of cerium(IV), a number of studies have utilised oxidation-reduction reactions in determining the relevant stability constants.

  8. Magnetic structure of holmium-yttrium superlattices

    DEFF Research Database (Denmark)

    Jehan, D.A.; McMorrow, D.F.; Cowley, R.A.

    1993-01-01

    We present the results of a study of the chemical and magnetic structures of a series of holmium-yttrium superlattices and a 5000 angstrom film of holmium, all grown by molecular-beam epitaxy. By combining the results of high-resolution x-ray diffraction with detailed modeling, we show...... that the superlattices have high crystallographic integrity: the structural coherence length parallel to the growth direction is typically almost-equal-to 2000 angstrom, while the interfaces between the two elements are well defined and extend over approximately four lattice planes. The magnetic structures were...... determined using neutron-scattering techniques. The moments on the Ho3+ ions in the superlattices form a basal-plane helix. From an analysis of the superlattice structure factors of the primary magnetic satellites, we are able to determine separately the contributions made by the holmium and yttrium...

  9. Treatment of acromegaly by yttrium implantation

    Energy Technology Data Exchange (ETDEWEB)

    Hibbert, J.; Shaheen, O.H.

    1977-01-01

    Yttrium implantation is one of the many ways of treating acromegaly. The advantages are the minor nature of the procedure and the fact that pituitary replacement is not as commonly required as after hypophysectomy. Thus in young female patients menstruation may be resumed following treatment and pregnancy has occurred. The procedure is not as free from complications as external irradiation but the response is more satisfactory.

  10. Yttrium and rare earths separation by ion exchange resin

    International Nuclear Information System (INIS)

    Pinatti, D.G.; Ayres, M.J.G.; Ribeiro, S.; Silva, G.L.J.P.; Silva, M.L.C.P.; Martins, A.H.

    1988-01-01

    The experimental results of yttrium and rare earths separation from Brazilian xenotime are presented. The research consist in five stage: 1) Preparation of yttrium, erbium and lutetium standard solutions, from solubilization of pure oxides 2) yttrium and rare earths separation by ion exchange chromatrography 3) Separation and recovery of EDTA 4) Precipitation and calcination and 4) Analytical control of process. (C.G.C.) [pt

  11. Characterisation of cerium-doped lanthanum bromide scintillation detector

    International Nuclear Information System (INIS)

    Etim, I. P.; Obu, J. A.; Ushie, J. O.

    2011-01-01

    LaBr 3 (Ce) crystals is one of the new scintillating detectors that has been developed in recent years which has proven to be superior to other scintillating materials in terms of resolution and efficiency. The energy resolution, intrinsic photo peak, total intrinsic and total absolute efficiency of this detector have been measured for a 25mm x 25mm Brillance T M 380 LaBr 3 (Ce) detector. The energy dependence of the resolution has been studied with a variety of gamma ray sources with variable energy range (122KeV-1408KeV). LaBr 3 (Ce) detector shows an excellent energy resolution of 2.6% (FWHM) at 662KeV photons ( 137 Cs source) at room temperature. A full-energy peak efficiency of 90.1-4.3% has been obtained for the 122 - 1408KeV energy range for a source-detector distance of 150mm.

  12. Cerium doped hydroxyapatite nanoparticles synthesized by coprecipitation method

    Directory of Open Access Journals (Sweden)

    Ciobanu Carmen Steluta

    2016-01-01

    Full Text Available The present work reports a simple coprecipitation adapted method for the synthesis of stable Ce substituted to Ca hydroxyapatite (HAp nanoparticles. The structural and morphological properties of Ce doped hydroxyapatite (Ce:HAp were characterized by X-ray diffraction (XRD, Transmission Electron Microscopy (TEM, Scanning Electron Microscopy (SEM and Energy Dispersive X-ray analysis (EDAX. The optical properties of Ce doped hydroxyapatite were also investigated using Fourier Transform Infrared (FTIR spectroscopy, FT Raman spectroscopy and photoluminescence analysis. The results of the XRD studies revealed the progressive increase in the a- and c-axes with increasing of Ce concentrations. In the FTIR studies of Ce:HAp powders a similar structure to hydroxyapatite was observed. IR and Raman wavenumbers and the peak strength of the bands associated to the P-O and O-H bonds decreases progressively with the increase of Ce concentration. All the emission maxima could be attributed to the 5d-4f transitions of Ce ions. The displacement of maximum emission bands with the increase of Cerium in the samples is in agreement with the results obtained by XRD studies. The Ce:HAp samples with xCe =0.03 and 0.05 exhibited significant antibacterial activity against Staphylococcus aureus ATCC 6538 and E. coli 714 bacterial strains compared to Ce:HAp samples with xCe =0 (pure HAp and 0.01.

  13. Role of nitrogen vacancies in cerium doped aluminum nitride

    Energy Technology Data Exchange (ETDEWEB)

    Majid, Abdul, E-mail: abdulmajid40@yahoo.com [Department of Physics, University of Gujrat, Gujrat (Pakistan); Department of Adaptive Machine Systems, Osaka University, Osaka (Japan); Asghar, Farzana [Department of Physics, University of Gujrat, Gujrat (Pakistan); Rana, Usman Ali; Ud-Din Khan, Salah [Sustainable Energy Technologies Center, College of Engineering, King Saud University, PO-Box 800, Riyadh 11421 (Saudi Arabia); Yoshiya, Masato [Department of Adaptive Machine Systems, Osaka University, Osaka (Japan); Hussain, Fayyaz [Physics Department, Bahauddin Zakarya University, Multan (Pakistan); Ahmad, Iftikhar [Department of Mathematics, University of Gujrat, Gujrat (Pakistan)

    2016-08-15

    In this report, a systematic density functional theory based investigation to explain the character of nitrogen vacancies in structural, electronic and magnetic properties of Ce doped wurtzite AlN is presented. The work demonstrates the modification in the properties of the material upon doping thereby addressing dopant concentration and inter-dopant distance. The presence of anionic vacancy reveals spin polarization and introduction of magnetic character in the structure. The doping produced the magnetic character in the material which was of ferromagnetic nature in most cases except the situation when dopants separated by largest distance of 5.873 Å. The calculated values of total energy and exchange energy suggested the configuration including Ce{sub Al}–V{sub N} complex is more favorable and exhibits ferromagnetic ordering. - Highlights: • Ce doped AlN with and without nitrogen vacancy. • Dopant at nearest neighbor site introduce ferromagnetism. • Ce{sub Al}–V{sub N} complex is favorable in Ce:AlN.

  14. Role of nitrogen vacancies in cerium doped aluminum nitride

    International Nuclear Information System (INIS)

    Majid, Abdul; Asghar, Farzana; Rana, Usman Ali; Ud-Din Khan, Salah; Yoshiya, Masato; Hussain, Fayyaz; Ahmad, Iftikhar

    2016-01-01

    In this report, a systematic density functional theory based investigation to explain the character of nitrogen vacancies in structural, electronic and magnetic properties of Ce doped wurtzite AlN is presented. The work demonstrates the modification in the properties of the material upon doping thereby addressing dopant concentration and inter-dopant distance. The presence of anionic vacancy reveals spin polarization and introduction of magnetic character in the structure. The doping produced the magnetic character in the material which was of ferromagnetic nature in most cases except the situation when dopants separated by largest distance of 5.873 Å. The calculated values of total energy and exchange energy suggested the configuration including Ce Al –V N complex is more favorable and exhibits ferromagnetic ordering. - Highlights: • Ce doped AlN with and without nitrogen vacancy. • Dopant at nearest neighbor site introduce ferromagnetism. • Ce Al –V N complex is favorable in Ce:AlN.

  15. Yttrium addition for high temperatures stainless steel

    International Nuclear Information System (INIS)

    Furtado, Nelson Cesar Chaves Pinto

    1997-07-01

    The current work studied the effect of Yttrium on the microstructure of 2% Nb, modified - HP steel, with respect to its mechanical properties. Alloys were prepared with nominal Yttrium additions of 0,1% and 0,25%. Microstructural analyses and mechanical tests were undertaken in the as-cast condition and after ageing for 100 h at 700 deg C, 900 deg C and 1100 deg C. Structural characterization was performed by optical microscopy, scanning and transmission electron microscopy (SEM/TEM/EDS), X-ray diffractometry and X-ray photoelectron spectroscopy (XPS). Tensile testing was performed at room temperature and 871 deg C and creep testing at 925 deg C at a loading of 55 MPa. The material produced exhibited superior mechanical properties and surface oxidation resistance than traditional alloys of this class, even through gravity cast in a magnetic furnace. Agglomerates of Yttrium-rich phases were identifies in both as-cast and aged specimens, always associated with chromium carbides of characteristic morphologies. These morphologies, combined with the microstructural constituents, may have established the factors which resulted in the improved metallurgical stability of these alloys under the experimental testing conditions and temperatures which simulated real industrial service conditions and temperatures. (author)

  16. Yttrium aluminum garnet coating on glass substrate

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J., E-mail: eduardo.nassar@unifran.edu.br

    2016-02-15

    Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu{sup 3+} onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min{sup −1} and evaporation led to deposition of different numbers of layers of the YAG:Eu{sup 3+} film onto the glass substrate from a YAG:Eu{sup 3+} powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu{sup 3+}. • The matrix was deposited as transparent films. • The YAG:Eu{sup 3+} was deposited by sol–gel process onto glass substrate.

  17. Yttrium aluminum garnet coating on glass substrate

    International Nuclear Information System (INIS)

    Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J.

    2016-01-01

    Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu 3+ onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min −1 and evaporation led to deposition of different numbers of layers of the YAG:Eu 3+ film onto the glass substrate from a YAG:Eu 3+ powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu 3+ . • The matrix was deposited as transparent films. • The YAG:Eu 3+ was deposited by sol–gel process onto glass substrate.

  18. Sol gel synthesis for preparation of yttrium aluminium garnet

    NARCIS (Netherlands)

    Vrolijk, J.W.G.A.; Willems, J.W.M.M.; Metselaar, R.; With, de G.; Terpstra, R.A.; Metselaar, R.

    1989-01-01

    Sol-gel—synthesis for preparation of pure yttrium aluminium garnet powder with small grain size is subject of this ongoing study. Starting materials were sulfates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3A1SO1Z) pH during hydrolysis as well as temperature during calcination and

  19. Abscopal Effects and Yttrium-90 Radioembolization

    Energy Technology Data Exchange (ETDEWEB)

    Ghodadra, Anish; Bhatt, Sumantha [University Pittsburgh School of Medicine, Department of Radiology (United States); Camacho, Juan C. [Emory University School of Medicine, Department of Radiology and Imaging Sciences (United States); Kim, Hyun S., E-mail: kevin.kim@yale.edu [University Pittsburgh School of Medicine, Department of Radiology (United States)

    2016-07-15

    We present the case of an 80-year-old male with squamous cell carcinoma with bilobar hepatic metastases who underwent targeted Yttrium-90 radioembolization of the right hepatic lobe lesion. Subsequently, there was complete regression of the nontargeted, left hepatic lobe lesion. This may represent the first ever reported abscopal effect in radioembolization. The abscopal effect refers to the phenomenon of tumor response in nontargeted sites after targeted radiotherapy. In this article, we briefly review the immune-mediated mechanisms responsible for the abscopal effect.

  20. Nonlinear FMR spectra in yttrium iron garnet

    Directory of Open Access Journals (Sweden)

    Yu.M. Bunkov, P.M. Vetoshko, I.G. Motygullin, T.R. Safin, M.S. Tagirov, N.A. Tukmakova

    2015-12-01

    Full Text Available Results of demagnetizing effect studies in yttrium iron garnet Y3Fe5O12 thin films are reported. Experiments were performed on X-Band of electron paramagnetic resonance spectrometer at room temperature. The ferromagnetic resonance (FMR spectra were obtained for one-layer single crystal YIG films for different values of the applied microwave power. Nonlinear FMR spectra transformation by the microwave power increasing in various directions of magnetic field sweep was observed. It is explained by the influence of the demagnetization action of nonequilibrium magnons.

  1. Cerium and yttrium oxide nanoparticles are neuroprotective

    International Nuclear Information System (INIS)

    Schubert, David; Dargusch, Richard; Raitano, Joan; Chan, S.-W.

    2006-01-01

    The responses of cells exposed to nanoparticles have been studied with regard to toxicity, but very little attention has been paid to the possibility that some types of particles can protect cells from various forms of lethal stress. It is shown here that nanoparticles composed of cerium oxide or yttrium oxide protect nerve cells from oxidative stress and that the neuroprotection is independent of particle size. The ceria and yttria nanoparticles act as direct antioxidants to limit the amount of reactive oxygen species required to kill the cells. It follows that this group of nanoparticles could be used to modulate oxidative stress in biological systems

  2. Yttrium synovectomy: a meta-analysis of the literature

    International Nuclear Information System (INIS)

    Jones, G.

    1993-01-01

    Yttrium synovectomy for chronic synovitis of the knee enjoys widespread usage in Australia with approximately 400 patients receiving yttrium-90 in 1991. Despite abundant anecdotal evidence of its efficacy there is a paucity of controlled trials and those that have been done have produced conflicting results and have been of insufficient sample size. To critically and quantitatively evaluate the published English literature on comparative trials of yttrium-90 therapy for chronic synovitis of the knee, the technique of meta-analysis was utilised. The literature search was carried out using the MeSH terms of synovectomy and knee; and yttrium. This was augmented by referring to reviews, current textbooks and back-references. Outcome measures varied between trials but could be grouped as treatment success. The Peto modification of Mantel and Haenszl was used for statistical pooling of data yielding a pooled odds ratio (OR). The literature search revealed ten controlled trials of which two were excluded from further analysis. It was found that yttrium was superior to placebo (OR 2.42, 95% CI 1.02-5.73) but it is recommended that this result should be interpreted with caution due to possible publication bias. It is concluded that there is insufficient evidence from comparative trials of yttrium in the English literature to show that yttrium synovectomy is convincingly superior to triamcinolone (OR 1.89, 95% CI 0.81-10.55) or other active modalities (OR 1.04, 95% CI 0.72-1.52). 25 refs., 4 tabs

  3. Extraction of nitrates of lanthanoids (3) of the yttrium group and yttrium (3) by trialkylbenzylammonium nitrate in toluene

    International Nuclear Information System (INIS)

    Pyartman, A.K.; Kovalev, S.V.; Keskinov, V.A.; Kopyrin, A.A.

    1997-01-01

    A study was made on extraction of nitrates of lanthanoids (3) of the yttrium group (terbium-lutetium) and yttrium (3) by trialkylbensylammonium nitrate in toluene at T=298.15 K pH 2. Extraction isotherms are described with account of formation of compound of (R 4 N) 2 [Ln(NO 3 ) 5 ] composition in organic phase. Values of extraction constants decreasing in terbium (3)-lutetium (3) series, were calculated. Value of extraction constant for yttrium (3) is close to the value of extraction constant for ytterbium (3). 13 refs., 2 figs., 3 tabs

  4. Radiolabeling Of Albumin Particles With Yttrium-90

    International Nuclear Information System (INIS)

    Nguyen Thi Thu; Nguyen Thi Khanh Giang; Bui Van Cuong, Vo Thi Cam Hoa

    2011-01-01

    This paper presents the process of the radiolabeling of microaggregated albumin particles with radionuclide Yttrium-90 using the directed method. The albumin microsphere kit was prepared in sodium phosphate buffer. The original solution includes 2 mg albumin particle and 0.5 mg stannous chloride dihydrate. The albumin particles size was ranged from 5 ?m to 30 ?m. The mixture was washed three times with phosphate buffer saline, pH 7.2 by centrifugation and suspended in 0.5 M sodium acetate buffer, pH 6. Yttrium - 90 in 1.0 M acetic acid was collected from 90 Sr/ 90 Y generator. The labeling of the particles with Y-90 (185 MBq) was performed at pH 5.5 in acetate buffer with agitating for 60 min at room temperature. The labeled albumin suspensions were centrifuged at 3000 rpm for 15 min. Labeling yields was calculated using centrifugation, filtration and compared with paper chromatography, which is developed in the Tris Acetic EDTA. In this system, the unbound of Y-90 migrates to an R f of 0.9-1.0 and the radiolabeled albumin particles remains at the point of origin (R f = 0). The size of 90 Y-albumin particles was compared with the albumin particles in the original solution to be sure that they did not change during the labeling treatment. The radiolabeling yields were more than 80%. The labeled compound was dialysis in phosphate buffer. The radiochemical purity was 98%. The 90 Y- albumin is an ideal radiopharmaceutical for potential use in malignant cancer treatment as brachytherapy. (author)

  5. Solvent extraction studies on separation of yttrium from xenotime

    International Nuclear Information System (INIS)

    Singh, D.K.; Anitha, M.; Kain, V.

    2017-01-01

    Rare earths consists a group of 15 element from La to Lu in the periodic table and it also includes Sc and Y since they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties. The unique physical-chemical properties of the REEs render them important in applications as varies as high strength magnets, lighting phosphors, policing compounds and ceramics. In particular, yttrium finds numerous applications in many areas including superconductors, lasers, phosphors, nuclear reactors, astronavigation, ceramics etc. Yttrium is chemically similar to heavy rare earths (HRE: terbium, dysprosium, erbium, holmium, ytterbium, thulium and lutecium). Yttrium behaves like HRE due to similarity in ionic radius and finds place between Ho and Er. The cross current profile in terms of the plot of concentration of yttrium in raffinate as a function of contact number indicated the complete recovery of rare earths from nitrate solution of xenotime wet cake

  6. Thermoanalytical study of the decomposition of yttrium trifluoroacetate thin films

    International Nuclear Information System (INIS)

    Eloussifi, H.; Farjas, J.; Roura, P.; Ricart, S.; Puig, T.; Obradors, X.; Dammak, M.

    2013-01-01

    We present the use of the thermal analysis techniques to study yttrium trifluoroacetate thin films decomposition. In situ analysis was done by means of thermogravimetry, differential thermal analysis, and evolved gas analysis. Solid residues at different stages and the final product have been characterized by X-ray diffraction and scanning electron microscopy. The thermal decomposition of yttrium trifluoroacetate thin films results in the formation of yttria and presents the same succession of intermediates than powder's decomposition, however, yttria and all intermediates but YF 3 appear at significantly lower temperatures. We also observe a dependence on the water partial pressure that was not observed in the decomposition of yttrium trifluoroacetate powders. Finally, a dependence on the substrate chemical composition is discerned. - Highlights: • Thermal decomposition of yttrium trifluoroacetate films. • Very different behavior of films with respect to powders. • Decomposition is enhanced in films. • Application of thermal analysis to chemical solution deposition synthesis of films

  7. Yttrium Nitrate mediated Nitration of Phenols at room temperature in ...

    Indian Academy of Sciences (India)

    The described method is selective for phenols. ... the significant cause of post translational modification that can ... decades, significant attention was paid on nitration of phenols to .... Progress of the reaction can be noted visually. Yttrium.

  8. Attempts at treating rheumatoid arthritis with radioactive yttrium

    International Nuclear Information System (INIS)

    Scott, J.T.

    1979-01-01

    Two years' observations on 33 knee joints in 33 patients with rheumatoid arthritis did not prove a therapeutic effect of Y 90 , which was tested in a randomized study against non-radioactive yttrium. It was noticable that 9 knee joints of the isotope group but only one of the control group became unstable. Independent of the yttrium treatment, significant improvement was noticed in patients where fibrin clots had been washed out of the joints in the course of arthroscopies. (orig.) [de

  9. Treatment of rheumatoid arthritis with 90yttrium. Follow up studies

    International Nuclear Information System (INIS)

    Teuber, J.; Baenkler, H.W.; Regler, G.; Erlangen-Nuernberg Univ., Erlangen

    1978-01-01

    90 Yttrium-silicate was injected into 131 knee-joints from patients with rheumatoid arthritis with stadium II-IV according to Steinbrocker. The observation period lasted until two years. After three months about 80% and after 24 months still more than 50% of the patients treated showed complete or partial remission. Side-effects as formerly observed with 198 -goldpreparations did not occur. Therefore the treatment with 90 Yttrium-silicate offers an alternative to surgical synovectomy. (orig.) [de

  10. Thermal decomposition of yttrium(III) propionate and butyrate

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude

    2013-01-01

    The thermal decompositions of yttrium(III) propionate monohydrate (Y(C2H5CO2)3·H2O) and yttrium(III) butyrate dihydrate (Y(C3H7CO2)3·2H2O) were studied in argon by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction and hot-stage microscopy. These two...

  11. Mechanical properties of lanthanum and yttrium chromites

    Energy Technology Data Exchange (ETDEWEB)

    Paulik, S.W.; Armstrong, T.R. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-12-31

    In an operating high-temperature (1000{degrees}C) solid oxide fuel cell (SOFC), the interconnect separates the fuel (P(O{sub 2}){approx}10{sup -16} atm) and the oxidant (P(O2){approx}10{sup 0.2} atm), while being electrically conductive and connecting the cells in series. Such severe atmospheric and thermal demands greatly reduce the number of viable candidate materials. Only two materials, acceptor substituted lanthanum chromite and yttrium chromite, meet these severe requirements. In acceptor substituted chromites (Sr{sup 2+} or Ca{sup 2+} for La{sup 3+}), charge compensation is primarily electronic in oxidizing conditions (through the formation of Cr{sup 4+}). Under reducing conditions, ionic charge compensation becomes significant as the lattice becomes oxygen deficient. The formation of oxygen vacancies is accompanied by the reduction of Cr{sup 4+} ions to Cr{sup 3+} and a resultant lattice expansion. The lattice expansion observed in large chemical potential gradients is not desirable and has been found to result in greatly reduced mechanical strength.

  12. Tungsten - Yttrium Based Nuclear Structural Materials

    Science.gov (United States)

    Ramana, Chintalapalle; Chessa, Jack; Martinenz, Gustavo

    2013-04-01

    The challenging problem currently facing the nuclear science community in this 21st century is design and development of novel structural materials, which will have an impact on the next-generation nuclear reactors. The materials available at present include reduced activation ferritic/martensitic steels, dispersion strengthened reduced activation ferritic steels, and vanadium- or tungsten-based alloys. These materials exhibit one or more specific problems, which are either intrinsic or caused by reactors. This work is focussed towards tungsten-yttrium (W-Y) based alloys and oxide ceramics, which can be utilized in nuclear applications. The goal is to derive a fundamental scientific understanding of W-Y-based materials. In collaboration with University of Califonia -- Davis, the project is designated to demonstrate the W-Y based alloys, ceramics and composites with enhanced physical, mechanical, thermo-chemical properties and higher radiation resistance. Efforts are focussed on understanding the microstructure, manipulating materials behavior under charged-particle and neutron irradiation, and create a knowledge database of defects, elemental diffusion/segregation, and defect trapping along grain boundaries and interfaces. Preliminary results will be discussed.

  13. Neutron scattering study of yttrium iron garnet

    Science.gov (United States)

    Shamoto, Shin-ichi; Ito, Takashi U.; Onishi, Hiroaki; Yamauchi, Hiroki; Inamura, Yasuhiro; Matsuura, Masato; Akatsu, Mitsuhiro; Kodama, Katsuaki; Nakao, Akiko; Moyoshi, Taketo; Munakata, Koji; Ohhara, Takashi; Nakamura, Mitsutaka; Ohira-Kawamura, Seiko; Nemoto, Yuichi; Shibata, Kaoru

    2018-02-01

    The nuclear and magnetic structure and full magnon dispersions of yttrium iron garnet Y3Fe5O12 have been studied using neutron scattering. The refined nuclear structure is distorted to a trigonal space group of R 3 ¯ . The highest-energy dispersion extends up to 86 meV. The observed dispersions are reproduced by a simple model with three nearest-neighbor-exchange integrals between 16 a (octahedral) and 24 d (tetrahedral) sites, Ja a, Ja d, and Jd d, which are estimated to be 0.00 ±0.05 , -2.90 ±0.07 , and -0.35 ±0.08 meV, respectively. The lowest-energy dispersion below 14 meV exhibits a quadratic dispersion as expected from ferromagnetic magnons. The imaginary part of q -integrated dynamical spin susceptibility χ″(E ) exhibits a square-root energy dependence at low energies. The magnon density of state is estimated from χ″(E ) obtained on an absolute scale. The value is consistent with the single chirality mode for the magnon branch expected theoretically.

  14. Studies on yttrium-containing smart alloys

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Felix; Wegener, Tobias; Litnovsky, Andrey; Rasinski, Marcin; Linsmeier, Christian [Forschungszentrum Juelich GmbH, Institut fuer Energie- und Klimaforschung - Plasmaphysik (Germany); Mayer, Joachim [Ernst Ruska-Centrum, 52425 Juelich (Germany)

    2016-07-01

    Tungsten is the main candidate as plasma-facing armour material for future fusion reactors, like DEMO. Advantages of tungsten include high melting point, high thermal conductivity, low tritium retention, and low erosion yield. A problem is oxide volatilisation under accidental conditions where the temperature of the first wall can reach 1200 K to 1450 K and air ingress occurs. Therefore smart tungsten alloys are developed. Smart alloys are supposed to preserve properties of tungsten during plasma operation coupled with suppressed tungsten oxide formation in case of an accident. Lab-scale tungsten-chromium-yttrium (W-Cr-Y) samples prepared by magnetron sputtering are used as model system. The mechanisms of oxidation and its dynamics are studied using a thermogravimetric system, focussed ion beam, and electron microscopy. A composition scan was conducted: The new material composition featuring W, ∝ 12 wt.% Cr, ∝ 0.3 wt.% Y showed strongest suppression of oxidation, no pores, and least internal oxidation. At 1273 K in argon-oxygen atmosphere an oxidation rate of 3 . 10{sup -6} mg{sup 2}cm{sup -4}s{sup -1} was measured. At 1473 K ternary W-Cr-Y alloys suppressed evaporation up to 20 min while for W-Cr evaporation was already evident after 5 min. Comparison of passivation in dry and humid atmosphere, at temperatures of 1073 K to 1473 K is performed.

  15. Yttrium-90 microsphere induced gastrointestinal tract ulceration

    Directory of Open Access Journals (Sweden)

    Rikabi Ali A

    2008-09-01

    Full Text Available Abstract Background Radiomicrosphere therapy (RT utilizing yttrium-90 (90Y microspheres has been shown to be an effective regional treatment for primary and secondary hepatic malignancies. We sought to determine a large academic institution's experience regarding the extent and frequency of gastrointestinal complications. Methods Between 2004 and 2007, 27 patients underwent RT for primary or secondary hepatic malignancies. Charts were subsequently reviewed to determine the incidence and severity of GI ulceration. Results Three patients presented with gastrointestinal bleeding and underwent upper endoscopy. Review of the pretreatment angiograms showed normal vascular anatomy in one patient, sclerosed hepatic vasculature in a patient who had undergone prior chemoembolization in a second, and an aberrant left hepatic artery in a third. None had undergone prophylactic gastroduodenal artery embolization. Endoscopic findings included erythema, mucosal erosions, and large gastric ulcers. Microspheres were visible on endoscopic biopsy. In two patients, gastric ulcers were persistent at the time of repeat endoscopy 1–4 months later despite proton pump inhibitor therapy. One elderly patient who refused surgical intervention died from recurrent hemorrhage. Conclusion Gastrointestinal ulceration is a known yet rarely reported complication of 90Y microsphere embolization with potentially life-threatening consequences. Once diagnosed, refractory ulcers should be considered for aggressive surgical management.

  16. Yttrium implantation effects on extra low carbon steel and pure iron

    Energy Technology Data Exchange (ETDEWEB)

    Caudron, E.; Buscail, H. [Clermont-Ferrand-2 Univ., Le Puy en Velay (France). Lab. Vellave d`Elaboration; Jacob, Y.P.; Stroosnijder, M.F. [Institute for Advanced Materials, Joint Research Center, The European Commission, 21020, Ispra (Vatican City State, Holy See) (Italy); Josse-Courty, C. [Laboratoire de Recherche sur la Reactivite des Solides, UMR 56-13 CNRS, UFR Sciences et Techniques, 9 Avenue A. Savary, B.P. 400, 21011, Dijon Cedex (France)

    1999-05-25

    Extra low carbon steel and pure electrolytic iron samples were yttrium implanted using ion implantation technique. Compositions and structures of pure iron and steel samples were investigated before and after yttrium implantation by several analytical and structural techniques (RBS, SIMS, RHEED and XRD) to observe the yttrium implantation depth profiles in the samples. This paper shows the different effects of yttrium implantations (compositions and structures) according to the implanted sample nature. (orig.) 23 refs.

  17. Studies on yttrium oxide coatings for corrosion protection against molten uranium

    International Nuclear Information System (INIS)

    Chakravarthy, Y.; Bhandari, Subhankar; Pragatheeswaran; Thiyagarajan, T.K.; Ananthapadmanabhan, P.V.; Das, A.K.; Kumar, Jay; Kutty, T.R.G.

    2012-01-01

    Yttrium oxide is resistant to corrosion by molten uranium and its alloys. Yttrium oxide is recommended as a protective oxide layer on graphite and metal components used for melting and processing uranium and its alloys. This paper presents studies on the efficacy of plasma sprayed yttrium oxide coatings for barrier applications against molten uranium

  18. Pressure of saturated vapor of yttrium and zirconium acetylacetonates

    Energy Technology Data Exchange (ETDEWEB)

    Trembovetskij, G.V.; Berdonosov, S.S.; Murav' eva, I.A.; Martynenko, L.I. (Moskovskij Gosudarstvennyj Univ. (USSR))

    1984-08-01

    The static method and the flow method using /sup 91/Y and /sup 95/Zr radioactive indicators have been applied to determine pressure of saturated vapour of yttrium and zirconium acetylacetonates. Values of thermodynamic functions ..delta..Hsub(subl)=(98+-16)kJ/mol and ..delta..Ssub(subl.)=(155+-30)J/mol x K are calculated for sublimation of yttrium acetylacetonate. For sublimation of zirconium acetylacetonates ..delta..Hsub(subl) equals (116+-38) kJ/mol and ..delta..Ssub(subl) is equal to (198+-65) J/molxK.

  19. Determination of copper oxidizing power in superconducting yttrium ceramics

    International Nuclear Information System (INIS)

    Pontaler, R.P.; Lebed', N.B.

    1989-01-01

    A new photometric method for determining the formal copper degree of oxidation and oxygen deficiency in superconducting high-temperature oxides containing yttrium, barium and copper is developed. The method is based on oxidation of Co(2) complex with EDTA by Cu(3) ions in acetrate buffer solution with pH 4.2-4.7 and allows one to determine 1-10% of Cu(3). Relative standard deviation when determining Cu(3) makes up 0.03-0.05. Using a qualitative reaction with the application of sodium vanadate hydrochloride solution the absence of peroxide compound in superconducting yttrium ceramics is ascertained

  20. Surface modifications induced by yttrium implantation on low manganese-carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Caudron, E.; Buscail, H. [Univ. Blaise Pascal Clermont-Fd II, Le Puy en Velay (France). Lab. Vellave d' Elaboration et d' Etude des Materiaux; Haanapel, V.A.C.; Jacob, Y.P.; Stroosnijder, M.F. [Institute for Health and Consumer Protection, Joint Research Center, The European Commission, 21020, Ispra (Italy)

    1999-12-15

    Low manganese-carbon steel samples were ion implanted with yttrium. Sample compositions and structures were investigated before and after yttrium implantations to determine the yttrium distribution in the sample. Yttrium implantation effects were characterized using several analytical and structural techniques such as X-ray photoelectron spectroscopy, reflection high energy electron diffraction, X-ray diffraction, glancing angle X-ray diffraction and Rutherford backscattering spectrometry. In this paper it is shown that correlation between composition and structural analyses provides an understanding of the main compounds induced by yttrium implantation in low manganese-carbon steel. (orig.)

  1. On the use of hydrogen peroxide as a masking agent for the determination of yttrium in uranium oxide - yttrium oxide mixture

    International Nuclear Information System (INIS)

    Rastogi, R.K.; Chaudhuri, N.K.; Rizvi, G.H.; Subramanian, M.S.

    1985-01-01

    The use of peroxide as a masking agent for uranium during the EDTA titration of yttrium in an yttrium-uranium mixture containing large amounts of uranium was investigated. High acetate ion concentration was necessary to keep the peroxy complex of uranium in solution during the titration. It was observed that uranium could be tolerated up to 500 mg in the determination of yttrium with 0.5 ml of 30% hydrogen peroxide in approx. 1M acetate medium. The precision and accuracy of the method based on 16 determinations of yttrium at 6-16 mg level in the presence of 300 mg uranium was found to be +-0.2%. (author)

  2. High performance yttrium-doped BSCF hollow fibre membranes

    DEFF Research Database (Denmark)

    Haworth, P.; Smart, S.; Glasscock, Julie

    2012-01-01

    measurements in air was similar for both compositions, suggesting that the higher oxygen fluxes obtained for BSCFY hollow fibres could be attributed to the higher non-stoichiometry due to yttrium addition to the BSCF crystal structure. In addition, the improvement of oxygen fluxes for small wall thickness (∼0...

  3. Microstructure and defect chemistry of yttrium aluminium garnet ceramics

    International Nuclear Information System (INIS)

    Schuh, L.H.

    1989-01-01

    This thesis describes basic aspects concerning the defect chemistry and the microstructure of yttrium aluminium garnet ceramics. The work consists of three parts: a literature study, an experimental part and a section giving computer simulation data of defects. (author). 320 refs.; 68 figs.; 72 schemes; 32 tabs

  4. A thermal neutron scattering law for yttrium hydride

    Science.gov (United States)

    Zerkle, Michael; Holmes, Jesse

    2017-09-01

    Yttrium hydride (YH2) is of interest as a high temperature moderator material because of its superior ability to retain hydrogen at elevated temperatures. Thermal neutron scattering laws for hydrogen bound in yttrium hydride (H-YH2) and yttrium bound in yttrium hydride (Y-YH2) prepared using the ab initio approach are presented. Density functional theory, incorporating the generalized gradient approximation (GGA) for the exchange-correlation energy, is used to simulate the face-centered cubic structure of YH2 and calculate the interatomic Hellmann-Feynman forces for a 2 × 2 × 2 supercell containing 96 atoms. Lattice dynamics calculations using PHONON are then used to determine the phonon dispersion relations and density of states. The calculated phonon density of states for H and Y in YH2 are used to prepare H-YH2 and Y-YH2 thermal scattering laws using the LEAPR module of NJOY2012. Analysis of the resulting integral and differential scattering cross sections demonstrates adequate resolution of the S(α,β) function. Comparison of experimental lattice constant, heat capacity, inelastic neutron scattering spectra and total scattering cross section measurements to calculated values are used to validate the thermal scattering laws.

  5. Structural and dielectric properties of yttrium substituted nickel ferrites

    International Nuclear Information System (INIS)

    Ognjanovic, Stevan M.; Tokic, Ivan; Cvejic, Zeljka; Rakic, Srdjan; Srdic, Vladimir V.

    2014-01-01

    Graphical abstract: - Highlights: • Dense NiFe 2−x Y x O 4 ceramics (with 0 ≤ x ≤ 0.3) were prepared. • Pure spinels were obtained for x ≤ 0.07 while for x ≥ 0.15 samples had secondary phases. • With addition of yttrium, ac conductivity slightly increased. • We suggest several effects that can explain the observed changes in ac conduction. • With addition of yttrium, dielectric constant increased while the tg δ decreased. - Abstract: The influence of Y 3+ ions on structural and dielectric properties of nickel ferrites (NiFe 2−x Y x O 4 , where 0 ≤ x ≤ 0.3) has been studied. The as-synthesized samples, prepared by the co-precipitation method, were analyzed by XRD and FTIR which suggested that Y 3+ ions were incorporated into the crystal lattice for all the samples. However, the XRD analysis of the sintered samples showed that secondary phases appear in the samples with x > 0.07. The samples have densities greater than 90% TD and the SEM images showed that the grain size decreases with the addition of yttrium. Dielectric properties measured from 150 to 25 °C in the frequency range of 100 Hz–1 MHz showed that the addition of yttrium slightly increases the ac conductivity and decreases the tg δ therefore making the materials better suited for the use in microwave devices

  6. Thermal decomposition of yttrium(III) hexanoate in argon

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Suarez Guevara, Maria Josefina; Attique, Fahmida

    2015-01-01

    The thermal decomposition of yttrium(III) hexanoate (Y(C5H11CO2)3)·xH2O in argon was studied by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction at a laboratory Cu-tube source and in-situ experiments at a synchrotron radiation source as well as hot...

  7. Thermal decomposition of Yttrium(III) isovalerate in argon

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Yue, Zhao; Tang, Xiao

    2016-01-01

    The thermal behaviour of yttrium(III) isovalerate (Y(C4H9CO2)3) was studied in argon by means of thermogravimetry, differential thermal analysis, FTIR-spectroscopy, hot-stage optical microscopy and X-ray diffraction with a laboratory Cu-tube source as well as with a synchrotron radiation source...

  8. Thermal decomposition of yttrium(III) valerate in argon

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Yue, Zhao; Tang, Xiao

    2014-01-01

    The thermal decomposition of yttrium(III) valerate (Y(C4H9CO2)3) was studied in argon by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction, in-situ synchrotron diffraction and hot-stage microscopy as well as room temperature optical microscopy. Melting...

  9. Polymorphism and electrical behaviour of yttrium thin films

    International Nuclear Information System (INIS)

    Kaul, U.K.; Srivastava, O.N.

    1978-01-01

    It appears that the thickness-resistivity behaviour of yttrium embodying a thickness-dependent polymorphic phase transition can be explained in terms of surface scattering by taking into account the effect of the change in phase. It is interesting to note that, as a result of the polymorphic transition, the resistivity-thickness curve has an unusual shape. (Auth.)

  10. A new f.c.c. phase in yttrium films

    International Nuclear Information System (INIS)

    Kaul, V.K.; Srivastava, O.N.

    1976-01-01

    A new polymorphic phase characterised by a face-centered cubic structure, with lattice parameter 5.83 +- 0.02A, has been identified in thin films of yttrium. Electron diffraction evidence and electrical resistivity measurements have been carried out in order to detect the new f.c.c. phase. (Auth.)

  11. Evidence of yttrium silicate inclusions in YSZ-porcelain veneers.

    Science.gov (United States)

    Stoner, Brian R; Griggs, Jason A; Neidigh, John; Piascik, Jeffrey R

    2014-04-01

    This report introduces the discovery of crystalline defects that can form in the porcelain veneering layer when in contact with yttria-stabilized zirconia (YSZ). The focus was on dental prostheses and understanding the defects that form in the YSZ/porcelain system; however the data reported herein may have broader implications toward the use and stability of YSZ-based ceramics in general. Specimens were cut from fully sintered YSZ plates and veneering porcelain was applied (X-ray (EDAX) was used for microstructural and elemental analysis. EDAX, for chemical analysis and transmission electron diffraction (TED) for structural analysis were both performed in the transmission electron microscope (TEM). Additionally, in order to spatially resolve Y-rich precipitates, micro-CT scans were conducted at varying depths within the porcelain veneer. Local EDAX (SEM) was performed in the regions of visible inclusions and showed significant increases in yttrium concentration. TEM specimens also showed apparent inclusions in the porcelain and selected area electron diffraction was performed on these regions and found the inclusions to be crystalline and identified as either yttrium-silicate (Y2 SiO5 ) or yttrium-disilicate (Y2 Si2 O7 ). Micro-CT data showed that yttrium-silicate precipitates were distributed throughout the thickness of the porcelain veneer. Future studies are needed to determine whether many of the premature failures associated with this materials system may be the result of crystalline flaws that form as a result of high temperature yttrium diffusion near the surfaces of YSZ. © 2013 Wiley Periodicals, Inc.

  12. Yttrium-90 microspheres for the treatment of hepatocellular carcinoma.

    Science.gov (United States)

    Geschwind, Jean Francois H; Salem, Riad; Carr, Brian I; Soulen, Michael C; Thurston, Kenneth G; Goin, Kathleen A; Van Buskirk, Mark; Roberts, Carol A; Goin, James E

    2004-11-01

    Unresectable hepatocellular carcinoma is extremely difficult to treat. TheraSphere consists of yttrium-90 (a pure beta emitter) microspheres, which are injected into the hepatic arteries. This article reviews the safety and survival of patients with hepatocellular carcinoma who were treated with yttrium-90 microspheres. Eighty patients were selected from a database of 108 yttrium-90 microsphere-treated patients and were staged by using Child-Pugh, Okuda, and Cancer of the Liver Italian Program scoring systems. Patients were treated with local, regional, and whole-liver approaches. Survival from first treatment was analyzed with Kaplan-Meier and Cox regression methods. Adverse events and complications of treatment were coded by using the Southwest Oncology Group toxicity scoring system. Patients received liver doses ranging from 47 to 270 Gy. Thirty-two patients (40%) received more than 1 treatment. Survival correlated with pretreatment Cancer of the Liver Italian Program scores ( P = .002), as well as with the individual Cancer of the Liver Italian Program components, Child-Pugh class, alpha-fetoprotein levels, and percentage of tumor replacement. Patients classified as Okuda stage I (n = 54) and II (n = 26) had median survival durations and 1-year survival rates of 628 days and 63%, and 384 days and 51%, respectively ( P = .02). One patient died of liver failure judged as possibly related to treatment. Thus, in selected patients with hepatocellular carcinoma, yttrium-90 microsphere treatment is safe and well tolerated. On the basis of these results, a randomized controlled trial is warranted comparing yttrium-90 microsphere treatment with transarterial chemoembolization by using the Cancer of the Liver Italian Program system for prospective stratified randomization.

  13. Preparation of high purity yttrium single crystals by electrotransport

    International Nuclear Information System (INIS)

    Volkov, V.T.; Nikiforova, T.V.; Ionov, A.M.; Pustovit, A.N.; Sikharulidse, G.G.

    1981-01-01

    The possibility of obtaining yttrium crystals of high purity by the method of solid state electrotransport (SSE) was investigated in the present work. The behaviour of low contents of iron, aluminium, silicon, tantalum, copper, silver and vanadium as metallic impurities was studied using mass spectrometry. It is shown that all the impurities investigated, except copper, migrate to the anode. During electrotransfer a purification with respect to these impurities by a factor of 4 - 6 is obtained. It is proposed that the diffusion coefficients of the metallic impurities investigated are anomalously high and that the behaviour of the impurities during SSE in adapters necessitates further investigation. By using a three-stage process with intermediate removal of the anode end yttrium single crystals with a resistance ratio rho 293 /rhosub(4.2)=570 were produced. (Auth.)

  14. Acromegaly with sleep disturbances relieved by yttrium-90 pituitary implantation

    International Nuclear Information System (INIS)

    Rosenstock, J.; Doyle, F.H.; Joplin, G.F.; Jung, R.T.; Mashiter, K.

    1982-01-01

    A brief case history is presented of a patient, who, after yttrium-90 implantation, showed a complete clinical and hormonal remission of her acromegaly, maintaining normal pituitary function. The remarkable feature was the rapid disappearance of her attacks of somnolence within 96 hours of pituitary implantation, despite persistence of nocturnal snoring and well before any remodelling of soft tissues could have occurred. This response suggests that her daytime somnolence had a narcoleptic component. (author)

  15. Temperature dependence of sound velocity in yttrium ferrite

    International Nuclear Information System (INIS)

    L'vov, V.A.

    1979-01-01

    The effect of the phonon-magnon and phonon-phonon interoctions on the temperature dependence of the longitudinal sound velocity in yttrium ferrite is considered. It has been shown that at low temperatures four-particle phonon-magnon processes produce the basic contribution to renormalization of the sound velocity. At higher temperatures the temperature dependence of the sound velocity is mainly defined by phonon-phonon processes

  16. Acromegaly with sleep disturbances relieved by yttrium-90 pituitary implantation

    Energy Technology Data Exchange (ETDEWEB)

    Rosenstock, J.; Doyle, F.H.; Joplin, G.F.; Jung, R.T.; Mashiter, K. (Hammersmith Hospital, London (UK). Postgraduate Medical School)

    1982-03-01

    A brief case history is presented of a patient, who, after yttrium-90 implantation, showed a complete clinical and hormonal remission of her acromegaly, maintaining normal pituitary function. The remarkable feature was the rapid disappearance of her attacks of somnolence within 96 hours of pituitary implantation, despite persistence of nocturnal snoring and well before any remodelling of soft tissues could have occurred. This response suggests that her daytime somnolence had a narcoleptic component.

  17. Growth and scintillation properties of gadolinium and yttrium orthovanadate crystals

    International Nuclear Information System (INIS)

    Voloshina, O.V.; Baumer, V.N.; Bondar, V.G.; Kurtsev, D.A.; Gorbacheva, T.E.; Zenya, I.M.; Zhukov, A.V.; Sidletskiy, O.Ts.

    2012-01-01

    Aiming to explore the possibility of using the undoped rare-earth orthovanadates as scintillation materials, we developed the procedure for growth of gadolinium (GdVO 4 ) and yttrium (YVO 4 ) orthovanadate single crystals by Czochralski method, and determined the optimal conditions of their after-growth annealing. Optical, luminescent, and scintillation properties of YVO 4 and GdVO 4 were discussed versus known literature data. Scintillation characteristics of GdVO 4 were determined for the first time.

  18. Treatment of exhaust fluorescent lamps to recover yttrium: Experimental and process analyses

    International Nuclear Information System (INIS)

    De Michelis, Ida; Ferella, Francesco; Varelli, Ennio Fioravante; Veglio, Francesco

    2011-01-01

    Highlights: → Recovery of yttrium from spent fluorescent lamps by sulphuric acid leaching. → The use of sulphuric acid allows to reduce calcium dissolutions. → Main contaminant of fluorescent powder are Si, Pb, Ca and Ba. → Hydrated yttrium oxalate, recovered by selective precipitation, is quite pure (>90%). → We have studied the whole process for the treatment of dangerous waste (plant capability). - Abstract: The paper deals with recovery of yttrium from fluorescent powder coming from dismantling of spent fluorescent tubes. Metals are leached by using different acids (nitric, hydrochloric and sulphuric) and ammonia in different leaching tests. These tests show that ammonia is not suitable to recover yttrium, whereas HNO 3 produces toxic vapours. A full factorial design is carried out with HCl and H 2 SO 4 to evaluate the influence of operating factors. HCl and H 2 SO 4 leaching systems give similar results in terms of yttrium extraction yield, but the last one allows to reduce calcium extraction with subsequent advantage during recovery of yttrium compounds in the downstream. The greatest extraction of yttrium is obtained by 20% w/v S/L ratio, 4 N H 2 SO 4 concentration and 90 deg. C. Yttrium and calcium yields are nearly 85% and 5%, respectively. The analysis of variance shows that acid concentration alone and interaction between acid and pulp density have a significant positive effect on yttrium solubilization for both HCl and H 2 SO 4 medium. Two models are empirically developed to estimate yttrium and calcium concentration during leaching. Precipitation tests demonstrate that at least the stoichiometric amount of oxalic acid is necessary to recover yttrium efficiently and a pure yttrium oxalate n-hydrate can be produced (99% grade). The process is economically feasible if other components of the fluorescent lamps (glass, ferrous and non-ferrous scraps) are recovered after the equipment dismantling and valorized, besides the cost that is usually paid

  19. Thermoanalytical study of the formation mechanism of yttria from yttrium acetate

    International Nuclear Information System (INIS)

    Farjas, J.; Camps, J.; Roura, P.; Ricart, S.; Puig, T.; Obradors, X.

    2011-01-01

    Highlights: → Thermal decomposition of yttrium acetate: three endothermic stages. → Intermediates: yttrium hydroxide and carbonate. → Product: cubic yttria (the degree of transformation is at least 99%). → The decomposition does not depend on the oxygen partial pressure. - Abstract: The processes involved in the thermal decomposition of yttrium acetate tetrahydrate, Y(CH 3 COO) 3 .4H 2 O, in air and in an inert atmosphere have been analyzed by thermoanalytical techniques (thermogravimetry, differential thermal analysis and evolved gas analysis) and by the structural characterization (X-ray diffraction, infrared spectroscopy, elemental analysis and scanning electron microscopy) of intermediates and final products. Decomposition of yttrium acetate is an endothermic transformation that takes place in a temperature range between 350 and 900 o C. The evolution of the mass during the decomposition process is not affected by the presence of oxygen. The process is initiated by the rupture of the bond between the metallic cation and the acetate ligand. This initial step (350-450 o C) involves the formation of amorphous yttrium hydroxide and yttrium carbonate and is characterized by a fast mass loss rate. A sudden decrease of the mass loss rate indicates a change in the decomposition kinetics that continues with the decomposition of yttrium hydroxide and yttrium carbonate. The main effect of an oxygen atmosphere is an intense exothermic process due to the combustion of organic species in the gas phase.

  20. Process for recovering yttrium and lanthanides from wet-process phosphoric acid

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, J.A.; Weterings, C.A.

    1983-06-28

    Process for recovering yttrium and lanthanides from wet-process phosphoric acid by adding a flocculant to the phosphoric acid, separating out the resultant precipitate and then recovering yttrium and lanthanides from the precipitate. Uranium is recovered from the remaining phosphoric acid.

  1. Preparation, characterization and thermal behaviour study of double selenates of lanthanides, yttrium and beryllium

    International Nuclear Information System (INIS)

    Ribeiro, C.A.

    1988-01-01

    The lanthanides (III) and yttrium (III) double selenates were studied using common analytical methods, atomic absorption, X-ray diffraction infra-red absorption, thermogravimetry and differential thermal analysis. These compounds were prepared from the mixture of lanthanides (III) and yttrium (III) selenates aqueous solution and basic beryllium selenates aqueous solution, obeying equimolar relation (1:1) to the cation

  2. Yttrium implantation and addition element effects on the oxidation behaviour of reference steels at 973 K

    Energy Technology Data Exchange (ETDEWEB)

    Caudron, E.; Buscail, H.; Cueff, R.; Issartel, C.; El Messki, S.; Perrier, S.; Riffard, F. [Lab. Vellave d' Elaboration et d' Etude des Materiaux, Univ. Blaise Pascal Clermont-Fd 2, Le Puy en Velay (France)

    2004-07-01

    Yttrium implantation effects on reference steels (extra low carbon and low manganese steel) were studied by rutherford backscattering spectrometry (RBS), reflection high energy electron diffraction (RHEED), X-ray diffraction (XRD) and glancing angle X-ray diffraction (GAXRD). Thermogravimetry and in situ X-ray diffraction at 700 C and P{sub O2}=0.04 Pa for 24h were used to determine the yttrium implantation and addition element effects on sample oxidation resistance at high temperatures. This study clearly shows that yttrium implantation and subsequent high temperature oxidation induced the formation of several yttrium mixed oxides which closely depend on the reference steel addition elements. Moreover, these yttrium mixed oxides seem to be responsible for the improved reference steel oxidation resistance at high temperatures. (orig.)

  3. Tattoo removal by Q-switched yttrium aluminium garnet laser

    DEFF Research Database (Denmark)

    Hutton Carlsen, K; Esmann, J; Serup, J

    2017-01-01

    BACKGROUND: Tattoo removal by Q-switched yttrium aluminium garnet (YAG) lasers is golden standard; however, clients' satisfaction with treatment is little known. OBJECTIVE: To determine clients' satisfaction with tattoo removal. METHODS: One hundred and fifty-four tattoo removal clients who had...... relative to colour of tattoo on a scale from 0 (no effect) to 10 (complete removal) scored a mean of blue 9.5, black 9.4, yellow 8.9, red 8.8 and green 6.5. Clients were dissatisfied with green pigment remnants, which could mimic bruising. One hundred and twenty-nine clients (84%) experienced moderate...

  4. Phase composition of yttrium-doped zirconia ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Hennig, Christoph; Scheinost, Andreas C. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Molecular Structures; Weiss, Stephan [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes; Ikeda-Ohno, Atsushi [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Chemistry of the F-Elements; Gumeniuk, R. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Experimentelle Physik

    2017-06-01

    Ceramic material might be an alternative to borosilicate glass for the immobilization of nuclear waste. The crystallinity of ceramic material increases the corrosion resistance over several magnitudes in relation to amorphous glasses. The stability of such ceramics depend on several parameters, among them the crystal phase composition. A reliable quantitative phase analysis is necessary to correlate the macroscopic material properties with structure parameters. We performed a feasibility study based on yttrium-doped zirconia ceramics as analogue for trivalent actinides to ascertain that the nanosized crystal phases in zirconia ceramics can be reliably determined.

  5. Structure-terahertz property relationship in yttrium aluminum garnet ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Steere, D.W.; Clark, B.M.; Sundaram, S.K. [Alfred University, Terahertz and Millimeter Waves Laboratory (T-Lab), Kazuo Inamori School of Engineering, The New York State College of Ceramics, Alfred, NY (United States); Gaume, R. [Townes Laser Institute and the NanoScience Technology Center, CREOL, The College of Optics and Photonics, Orlando, FL (United States)

    2017-08-15

    Terahertz (THz) transmission measurements on chemically variant yttrium aluminum garnet (YAG) ceramics are described. Chemical compositions and processing parameters were varied to determine the effect of stoichiometry, density, and pore volume distribution on the optical and dielectric properties in the THz frequency regime. Density has the largest effect on properties out of the parameters that were investigated. In addition, a linear correlation between cubic root of real permittivity at 1 THz and average density of these samples is observed. Our results show promise for design and fabrication of advanced optical materials and devices with desired THz properties via controlling density and porosity of the materials. (orig.)

  6. Study on the coextraction of scandium-yttrium-lumogallion complex

    International Nuclear Information System (INIS)

    Okada, T.; Shimoishi, Y.; Miyata, H.; Toei, K.

    1977-01-01

    The coextraction of scandium-yttrium-lumogallion [LMG;4-chloro-6-(2,4-dihydroxyphenylazo)-1-hydroxybenzene-2-sulfonic acid] into diethyl ether has been studied. The acid dissociation constants of LMG, pKsub(a2) and pKsub(a3), were estimated to be 6.24 and 8.05 respectively. The composition of the complex extracted was determined by using the radioisotopes 46 Sc and 90 Y and by spectrophotometry of LMG and the ratio of the components was Sc:Y:LMG = 1:1:3. The coextraction scheme was discussed briefly. (author)

  7. Optical properties of Dy3+ doped yttrium aluminium borate

    International Nuclear Information System (INIS)

    Vazquez, R MartInez; Osellame, R; Marangoni, M; Ramponi, R; Dieguez, E; Ferrari, M; Mattarelli, M

    2004-01-01

    A Dy 3+ doped yttrium aluminium borate (Dy:YAB) crystal has been optically characterized. The refractive indices at seven different wavelengths, ranging from the visible to the near infrared (IR), have been measured and the Sellmeier curves have been calculated. The polarized optical absorption spectra have been obtained at room temperature, and the Judd-Ofelt parameters have been calculated. The lifetime of the upper laser level 4 F 9/2 has been estimated and compared with the experimental value. Evidence of high luminescence quantum efficiency of the 4 F 9/2 state in YAB is provided by measured lifetimes

  8. Kinetic properties of solid yttrium at high temperatures

    International Nuclear Information System (INIS)

    Ivliev, A.D.

    1993-01-01

    Analysis of results of experimental investigation into temperature-diffusivity, specific electroresistance and heat conductivity of yttrium is carried out. Peculiarities of variation of its kinetic characteristics under high temperatures are shown to result from two-band character of energy spectrum of collectivized electrons. In particular, growth of heat conductivity results from reduction of density of heavy electron states under heating. The suggested model describes kinetic characteristics of lutetium, as well. Usage of this model for the rest heavy rare-earth metals enables to make conclusion about reduction of magnetic scattering effcieincy in the rare-earth metals in proportion to approximation to melting temperature

  9. Knee arthroscopy after yttrium or osmic acid injection

    International Nuclear Information System (INIS)

    Guaydier-Souquieres, C.; Beguin, J.; Ollivier, D.; Loyau, G.

    1989-01-01

    This study presents the macroscopic and histologic results of 35 knee arthroscopies performed on patients with rheumatoid arthritis, some months after an yttrium or osmic acid intraarticular injection. The procedure was most often performed after a failure of the injection or a relapse of synovitis. Arthroscopy provides an understanding of the cause of synoviorthesis failure--insufficient action of the product on the synovitis or its poor diffusion, fibri-nonecrotic deposits, or cartilaginous lesions--and may be used both diagnostically and therapeutically

  10. Spectrographic determination of strontium in yttrium-90 solutions

    International Nuclear Information System (INIS)

    Roca, M.; Capdevila, C.

    1970-01-01

    The copper spark method has been used for determining strontium in the concentration range 1-100 g/ml in yttrium-90 solutions containing 0,5 % or thereabouts of ammonium citrate. The influence of the citric acid as well as the ammonium citrate with regard to 2N HCL solutions has been studied: the citric acid enhances the line intensities of strontium. The employment of either barium or lanthanum as reference element compensates for this enhancement. Because of the increase in sensitivity mentioned above, the study of influence of the citric acid has been extended and several impurities usually determined in radioisotope solutions have been considered. (Author) 4 refs

  11. Scattering of polarized protons by yttrium, iron and nickel nuclei

    International Nuclear Information System (INIS)

    Melssen, J.P.M.G.

    1978-01-01

    Results are presented of scattering experiments performed on yttrium and some iron and nickel isotopes with polarized proton beams at energies around 20 MeV. The angular distributions of the differential cross sections and analyzing powers have been measured and comparison of these with predictions from theoretical models has led to information about excited nuclear states like spin, parity and details of the wavefunctions. The DWBA has been mostly used to describe the reaction at the bombarding energies and for the target nuclei investigated. (C.F.)

  12. Childhood acromegaly successfully treated with interstitial irradiation using Yttrium-90

    International Nuclear Information System (INIS)

    Rosenstock, J.; Doyle, F.H.; Mashiter, K.; Joplin, G.F.

    1982-01-01

    A child with a growth hormone producing tumour presented at the age of 4 1/2 years. The onset of the disease was at 18 months of age. Treatment was given with three doses of interstitial irradiation using yttrium-90 implants. There were no local complications from the procedures. Now, 11 years after diagnosis, she is asymptomatic, of normal appearance, and her height and the size of the pituitary fossa are normal. Growth hormone levels are almost normal, thyroid function is intact, and she is maintained on prednisone and sex hormones. (Authors)

  13. Childhood acromegaly successfully treated with interstitial irradiation using Yttrium-90

    Energy Technology Data Exchange (ETDEWEB)

    Rosenstock, J.; Doyle, F.H.; Mashiter, K.; Joplin, G.F. (Royal Postgraduate Medical School, Hammersmith Hospital, London (UK). Dept. of Medicine and Radiology); Hall, R. (Royal Victoria Infirmary, Newcastle upon Tyne (UK))

    1982-01-01

    A child with a growth hormone producing tumour presented at the age of 4 1/2 years. The onset of the disease was at 18 months of age. Treatment was given with three doses of interstitial irradiation using Yttrium-90 implants. There were no local complications from the procedures. Now, 11 years after diagnosis, she is asymptomatic, of normal appearance, and her height and the size of the pituitary fossa are normal. Growth hormone levels are almost normal, thyroid function is intact, and she is maintained on prednisone and sex hormones.

  14. Photometric determination of yttrium in zirconium-containing materials

    International Nuclear Information System (INIS)

    Barbina, T.M.; Polezhaev, Yu.M.

    1984-01-01

    Comparative evaluation of the effect of different ways of eliminating the zirconium interfering effect on the results of yttrium photometric determination with arsenazo 2 in artificial mixtures of Y 2 O 3 and ZrO 2 , containing 5 and 10 mol.% Y 2 O 3 , has been carried out. The effect of Zr is eliminated by means of its precipitation by ammonium solution in the form of hydroxide and using camouflaging with 25% sulfosalicylic acid. Both ways do not provide a correct enough result. The use of non-reagent thermohydrolytic Zr precipitation during the analysis of zirconium-containing materials permits to obtain correct and well-reproducible results

  15. Thiocarbomide coordination compounds of yttrium subgroup rare earth chlorides

    International Nuclear Information System (INIS)

    Sakharova, Yu.G.; Perov, V.N.; Loginov, V.I.

    1978-01-01

    Thiocarbamide coordination compounds of chlorides of elements of the yttrium subgroup 4MeCl 3 x5Cs(NH 2 ) 2 x2OH 2 O (where Me stands for Tb, Dy, Ho, Er, Tm, Yb, Lu, Y) were produced for the first time. The compounds obtained are stable in air, have definite melting points, are highly soluble in methyl and ethyl alcohols, and are unstable in water. They recrystallize from ethyl alcohol without changing their chemical composition. The identity of these compounds was confirmed by X-ray analysis

  16. Hydrogen sensor based on palladium-yttrium alloy nanosheet

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Boyi [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia); Zhu, Yong, E-mail: y.zhu@griffith.edu.au [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia); Chen, Youping; Song, Han; Huang, Pengcheng [School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074 (China); Dao, Dzung Viet [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia)

    2017-06-15

    This paper presents a hydrogen sensor based on palladium-yttrium (Pd-Y) alloy nanosheet. Zigzag-shaped Pd-Y nanosheet with a thickness of 19.3 nm was deposited on a quartz substrate by using an ultrahigh-vacuum magnetron sputtering system and shadow mask. The atomic ratio of palladium to yttrium in the nanosheet was 0.92/0.08. The fabrication process was simple and low-cost, and the sensor can be mass-produced. The experimental results show the sensor has a superior sensitivity, reversibility, and reproducibility. The resistive-based hydrogen detection mechanism in this research is much simpler and more compact compared to the optical-based detection method. - Highlights: • Pd-Y sensing element was fabricated using a magnetron sputtering system and shadow mask. • The Pd-Y compound consisted of 92% Pd and 8% Y. • The fabrication process was simple, low-cost, and mass-production compatible. • The sensor showed superior sensitivity, reversibility, and reproducibility to hydrogen gas. • The device is more compact than the optical-based counterpart.

  17. Yttrium ion implantation on the surface properties of magnesium

    International Nuclear Information System (INIS)

    Wang, X.M.; Zeng, X.Q.; Wu, G.S.; Yao, S.S.

    2006-01-01

    Owing to their excellent physical and mechanical properties, magnesium and its alloys are receiving more attention. However, their application has been limited to the high reactivity and the poor corrosion resistance. The aim of the study was to investigate the beneficial effects of ion-implanted yttrium using a MEVVA ion implanter on the surface properties of pure magnesium. Isothermal oxidation tests in pure O 2 at 673 and 773 K up to 90 min indicated that the oxidation resistance of magnesium had been significantly improved. Surface morphology of the oxide scale was analyzed using scanning electron microscope (SEM). Auger electron spectroscopy (AES) and X-ray diffraction (XRD) analyses indicated that the implanted layer was mainly composed of MgO and Y 2 O 3 , and the implanted layer with a duplex structure could decrease the inward diffusion of oxygen and reduce the outward diffusion of Mg 2+ , which led to improving the oxidation resistance of magnesium. Potentiodynamic polarization curves were used to evaluate the corrosion resistance of the implanted magnesium. The results show yttrium implantation could enhance the corrosion resistance of implanted magnesium compared with that of pure magnesium

  18. Hydrogen sensor based on palladium-yttrium alloy nanosheet

    International Nuclear Information System (INIS)

    Wang, Boyi; Zhu, Yong; Chen, Youping; Song, Han; Huang, Pengcheng; Dao, Dzung Viet

    2017-01-01

    This paper presents a hydrogen sensor based on palladium-yttrium (Pd-Y) alloy nanosheet. Zigzag-shaped Pd-Y nanosheet with a thickness of 19.3 nm was deposited on a quartz substrate by using an ultrahigh-vacuum magnetron sputtering system and shadow mask. The atomic ratio of palladium to yttrium in the nanosheet was 0.92/0.08. The fabrication process was simple and low-cost, and the sensor can be mass-produced. The experimental results show the sensor has a superior sensitivity, reversibility, and reproducibility. The resistive-based hydrogen detection mechanism in this research is much simpler and more compact compared to the optical-based detection method. - Highlights: • Pd-Y sensing element was fabricated using a magnetron sputtering system and shadow mask. • The Pd-Y compound consisted of 92% Pd and 8% Y. • The fabrication process was simple, low-cost, and mass-production compatible. • The sensor showed superior sensitivity, reversibility, and reproducibility to hydrogen gas. • The device is more compact than the optical-based counterpart.

  19. Effects of hepatic arterial yttrium 90 glass microspheres in dogs.

    Science.gov (United States)

    Wollner, I; Knutsen, C; Smith, P; Prieskorn, D; Chrisp, C; Andrews, J; Juni, J; Warber, S; Klevering, J; Crudup, J

    1988-04-01

    A 22-micron glass microsphere called TheraSphere (Theragenics Corp., Atlanta, GA) has been developed in which yttrium 89 oxide is incorporated into the glass matrix and is activated by neutron bombardment to form the beta-emitting isotope yttrium 90 (Y 90) before using the spheres as radiotherapeutic vehicles. The injection of up to 12 times (on a liver weight basis) the anticipated human dose of nonradioactive TheraSphere into the hepatic arteries of dogs was well tolerated and produced clinically silent alterations within centrolobular areas. The hepatic arterial (HA) injection of radioactive TheraSphere also produced portal changes similar to those observed in humans after external beam therapy. While the extent of damage increased with the delivered dose, radiation exposures in excess of 30,000 cGy did not cause total hepatic necrosis and were compatible with survival. No microspheres distributed to the bone marrow and absolutely no myelosuppression was encountered in any animal. Proposed hepatic exposures to humans of 5000 to 10,000 cGy by means of these microspheres, therefore, would appear to be feasible and tolerable. Radiotherapeutic microsphere administration preceded by regional infusion of a radiosensitizing agent and/or immediately following the redistribution of blood flow toward intrahepatic tumor by vasoactive agents can potentially yield a synergistic, highly selective attack on tumors confined to the liver.

  20. MCrAlY bond coat with enhanced Yttrium layer

    Science.gov (United States)

    Jablonski, Paul D; Hawk, Jeffrey A

    2015-04-21

    One or more embodiments relates to an MCrAlY bond coat comprising an MCrAlY layer in contact with a Y--Al.sub.2O.sub.3 layer. The MCrAlY layer is comprised of a .gamma.-M solid solution, a .beta.-MAl intermetallic phase, and Y-type intermetallics. The Y--Al.sub.2O.sub.3 layer is comprised of Yttrium atoms coordinated with oxygen atoms comprising the Al.sub.2O.sub.3 lattice. Both the MCrAlY layer and the Y--Al.sub.2O.sub.3 layer have a substantial absence of Y--Al oxides, providing advantage in the maintainability of the Yttrium reservoir within the MCrAlY bulk. The MCrAlY bond coat may be fabricated through application of a Y.sub.2O.sub.3 paste to an MCrAlY material, followed by heating in a non-oxidizing environment.

  1. Effect of vanadium and yttrium doping on BSCCO superconductors

    International Nuclear Information System (INIS)

    Mohamed, S.B.; Halim, S.A.; Azhan, H.; Sidek, H.A.A; Tee, T.W.; Hassan, Z.A.

    1999-01-01

    The effect of vanadium and yttrium doping on the superconductivity is investigated. The doping was done on the calcium site ranging from x=0.00-0.10. The temperature dependence of electrical resistance and AC susceptibility measurements were made on these samples. The zero resistance for vanadium doped samples varied from 107 K (x = 0.00) to 68.5K (x = 0.10), whereas for yttrium doped samples it varied from 107 K (x = 0.00) to 54K (x 0.10). The volume fraction of the 2223 phase for both dopalit decreases witli increasing doping concentration. The nature of the temperature derivative of the resistance curves indicates the presence of a superconducting transition between grains coupled by weak links. The AC susceptibility data show enrichment of the volume fraction of the low Tc phase at higher compositions. The presence of low Tc phase (∼70 K) is visible in the susceptibility data. X-ray diffraction confirms the presence of mixed phases in the samples. (author)

  2. The reactive element effect of yttrium and yttrium silicon on high temperature oxidation of NiCrAl coating

    Science.gov (United States)

    Ramandhany, S.; Sugiarti, E.; Desiati, R. D.; Martides, E.; Junianto, E.; Prawara, B.; Sukarto, A.; Tjahjono, A.

    2018-03-01

    The microstructure formed on the bond coat affects the oxidation resistance, particularly the formation of a protective oxide layer. The adhesion of bond coat and TGO increased significantly by addition of reactive element. In the present work, the effect of yttrium and yttrium silicon as reactive element (RE) on NiCrAl coating was investigated. The NiCrAl (without RE) and NiCrAlX (X:Y or YSi) bond coating were deposited on Hastelloy C-276 substrate by High Velocity Oxygen Fuel (HVOF) method. Isothermal oxidation was carried out at 1000 °C for 100 hours. The results showed that the addition of RE could prevent the breakaway oxidation. Therefore, the coating with reactive element were more protective against high temperature oxidation. Furthermore, the oxidation rate of NiCrAlY coating was lower than NiCrAlYSi coating with the total mass change was ±2.394 mg/cm2 after 100 hours of oxidation. The thickness of oxide scale was approximately 1.18 μm consisting of duplex oxide scale of spinel NiCr2O4 in outer scale and protective α-Al2O3 in inner scale.

  3. Recovery of yttrium from cathode ray tubes and lamps’ fluorescent powders: experimental results and economic simulation

    International Nuclear Information System (INIS)

    Innocenzi, V.; De Michelis, I.; Ferella, F.; Vegliò, F.

    2013-01-01

    Highlights: • Fluorescent powder of lamps. • Fluorescent powder of cathode ray rubes. • Recovery of yttrium from fluorescent powders. • Economic simulation for the processes to recover yttrium from WEEE. - Abstract: In this paper, yttrium recovery from fluorescent powder of lamps and cathode ray tubes (CRTs) is described. The process for treating these materials includes the following: (a) acid leaching, (b) purification of the leach liquors using sodium hydroxide and sodium sulfide, (c) precipitation of yttrium using oxalic acid, and (d) calcinations of oxalates for production of yttrium oxides. Experimental results have shown that process conditions necessary to purify the solutions and recover yttrium strongly depend on composition of the leach liquor, in other words, whether the powder comes from treatment of CRTs or lamp. In the optimal experimental conditions, the recoveries of yttrium oxide are about 95%, 55%, and 65% for CRT, lamps, and CRT/lamp mixture (called MIX) powders, respectively. The lower yields obtained during treatments of MIX and lamp powders are probably due to the co-precipitation of yttrium together with other metals contained in the lamps powder only. Yttrium loss can be reduced to minimum changing the experimental conditions with respect to the case of the CRT process. In any case, the purity of final products from CRT, lamps, and MIX is greater than 95%. Moreover, the possibility to treat simultaneously both CRT and lamp powders is very important and interesting from an industrial point of view since it could be possible to run a single plant treating fluorescent powder coming from two different electronic wastes

  4. Neutron activation determination of oxygen in ceramic materials on the basis of yttrium, barium and copper

    International Nuclear Information System (INIS)

    Goldshtein, M.M.; Yudelevich, I.G.

    1991-01-01

    A procedure of determining oxygen in superconducting materials on the basis of yttrium, barium and copper oxides with the application of 14 MeV-neutron activation was developed. The method is based on determining the relation between oxygen and yttrium in the compounds investigated. In order to minimize systematic errors, expressions accounting for spectrometer dead time under conditions of varying component activity are proposed. The procedure ensures determination of the relation between oxygen and yttrium with a relative error of 0.4% with NAA using a neutron generator. (author) 4 refs.; 1 fig

  5. Study of behaviour of lanthanum- and yttrium electrodes in chloride melts

    International Nuclear Information System (INIS)

    Shkol'nikov, S.I.; Tolypin, E.S.; Yur'ev, B.P.

    1984-01-01

    A study was made on the lanthanum- and yttrium behaviour in a mixture of molten potassium- and sodium chlorides at various temperatures. It is shown that the lanthanum- and yttrium behaviour in KCl-NaCl melt is similar to the behaviour of other metals. Their corrosion rate is much higher as compared to other metals and it grows rapidly with increasing melt temperature. The temperature growth by 200 deg C results in an increase in the corrosion rate almost by an order. The potentials of lanthanum- and yttrium electrodes at the instant they are immersed in the melt have more negative values than the potentials of alkali metals under similar conditions

  6. Effect of yttrium chromite doping on its resistance to high-temperature salt and gas corrosions

    International Nuclear Information System (INIS)

    Oryshich, I.V.; Poryadchenko, N.E.; Rakitskij, A.N.; Bega, N.D.

    1996-01-01

    Effect of yttrium chromite doping with 2-4 group metal oxides on the corrosion resistance in the air at 1300 C during 5 hours and in sodium chloride and sulfate melts at 900 C during 20 hours is investigated. A notable increase of corrosion resistance is achieved under complex doping with zirconium and magnesium oxides in a quantity, close to solubility in yttrium oxide and solubility by aluminium oxide. Doping with calcium and strontium oxides in the quantities, dose to solubility in yttrium oxide does not produce any notable effect, and at higher concentrations it reduces the corrosion resistance in media indicated. Refs. 8, refs. 2, tabs. 1

  7. The spectrum of singly ionized yttrium, Y II

    International Nuclear Information System (INIS)

    Nilsson, A.E.; Johansson, S.; Kurucz, R.L.

    1991-01-01

    Hollow-cathode spectra of yttrium have been registered in the wavelength region 1000-48800 A. Resonant charge transfer reactions in the light source favour the excitation of Y II, where 174 new levels have been established by means of 1284 newly classified lines. Altogether we report 1521 lines between 235 levels in Y II. The ground complex (4d+5s) 2 is now completely known and a number of Rydberg series have been extended. The new levels belong to the 4dnl (nl=7s, 8s, 9s, 6p, 7p, 4d, 5d, 6d, 7d, 8d, 4f, 5f, 6f, 7f, 5g) and 5snl (nl=7s, 8s, 6p, 6d, 4f, 5f) configurations. Eigenvector compositions, based on paramagnetic calculations including configuration interaction, are given for all levels. The ionization limit has been determined to 98590 ± 5 cm -1 . (orig.)

  8. Calorimetric investigation of an yttrium-dysprosium spin glass

    International Nuclear Information System (INIS)

    Wenger, L.E.

    1978-01-01

    In an effort to compare the spin glass characteristics of yttrium--rare earth alloys with those of the noble-metal spin glasses, the susceptibility and heat capacity of Y/sub 0.98/Dy/sub 0.02/ have been measured in the temperature range 2.5--40 K. The low-field ac susceptibility measurement shows the characteristic cusp-like peak at 7.64 K. The magnetic specific heat of the same sample shows a peak at 7.0 K and may be qualitatively described as a semi-cusp. The magnetic entropy change from absolute zero to 7 K is approximately 0.52 of cR ln(2J+1). These results are qualitatively different than previous calorimetric results on the archetypal spin glasses, AuFe and CuMn, where rounded maxima are observed at temperatures above the spin glass transition temperatures

  9. RBS Characterization of Yttrium Iron Garnet Thin Films

    International Nuclear Information System (INIS)

    Roumie, M; Abdel samad, B.

    2008-01-01

    Magnetic materials such as yttrium iron garnet (YIG) are of great importance for its magneto-optic properties and for their potential applications in the domain of optical telecommunications. The deposition of thin films of YIG, on quartz or GGG (gadolinium gallium garnet) substrate, was performed using radio frequency non reactive magnetron sputtering, followed by high temperature annealing which is needed to enhance the crystallinity of the layers. Rutherford backscattering spectrometry RBS was used to determine the thickness and stoichiometry of the performed layers in order to investigate correlations between growth conditions and the quality of the final material. RBS measurements showed the influence of the deposition time and the temperature substrate on the film growth and its stoichiometry. (author)

  10. A divalent rare earth oxide semiconductor: Yttrium monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Kaminaga, Kenichi; Sei, Ryosuke [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan); Department of Chemistry, Tohoku University, Sendai 980-8578 (Japan); Hayashi, Kouichi [Department of Environmental and Materials Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Happo, Naohisa [School of Information Sciences, Hiroshima City University, Hiroshima 731-3194 (Japan); Tajiri, Hiroo [Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8, Sayo 679-5198 (Japan); Oka, Daichi; Fukumura, Tomoteru, E-mail: tomoteru.fukumura.e4@tohoku.ac.jp [Department of Chemistry, Tohoku University, Sendai 980-8578 (Japan); Hasegawa, Tetsuya [Department of Chemistry, The University of Tokyo, Tokyo 113-0033 (Japan)

    2016-03-21

    Rare earth oxides are usually widegap insulators like Y{sub 2}O{sub 3} with closed shell trivalent rare earth ions. In this study, solid phase rock salt structure yttrium monoxide, YO, with unusual valence of Y{sup 2+} (4d{sup 1}) was synthesized in a form of epitaxial thin film by pulsed laser deposition method. YO has been recognized as gaseous phase in previous studies. In contrast with Y{sub 2}O{sub 3}, YO was dark-brown colored and narrow gap semiconductor. The tunable electrical conductivity ranging from 10{sup −1} to 10{sup 3} Ω{sup −1 }cm{sup −1} was attributed to the presence of oxygen vacancies serving as electron donor. Weak antilocalization behavior observed in magnetoresistance indicated significant role of spin-orbit coupling as a manifestation of 4d electron carrier.

  11. Tunable negative index metamaterial using yttrium iron garnet

    International Nuclear Information System (INIS)

    He, Yongxue; He, Peng; Dae Yoon, Soack; Parimi, P.V.; Rachford, F.J.; Harris, V.G.; Vittoria, C.

    2007-01-01

    A magnetic field tunable, broadband, low-loss, negative refractive index metamaterial is fabricated using yttrium iron garnet (YIG) and a periodic array of copper wires. The tunability is demonstrated from 18 to 23 GHz under an applied magnetic field with a figure of merit of 4.2 GHz/kOe. The tuning bandwidth is measured to be 5 GHz compared to 0.9 GHz for fixed field. We measure a minimum insertion loss of 4 dB (or 5.7 dB/cm) at 22.3 GHz. The measured negative refractive index bandwidth is 0.9 GHz compared to 0.5 GHz calculated by the transfer function matrix theory and 1 GHz calculated by finite element simulation

  12. {alpha}-particle induced reactions on yttrium and terbium

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, S.; Kumar, B.B. [School of Studies in Physics, Vikram University, Ujjain-456010 (India); Rashid, M.H. [Variable Energy Cyclotron Center, 1/AF, Bidhan Nagar, Calcutta (India); Chintalapudi, S.N. [Inter-University Consortium for DAE Facilities, 3/LB, Bidhan Nagar, Calcutta (India)

    1997-05-01

    The stacked foil activation technique has been employed for the investigation of {alpha}-particle induced reactions on the target elements yttrium and terbium up to 50 MeV. Six excitation functions for the ({alpha},xn) type of reactions were studied using high-resolution HPGe {gamma}-ray spectroscopy. A comparison with Blann{close_quote}s geometric dependent hybrid model has been made using the initial exciton number n{sub 0}=4(4p0h) and n{sub 0}=5(5p0h). A broad general agreement is observed between the experimental results and theoretical predictions with an initial exciton number n{sub 0}=4(4p0h). {copyright} {ital 1997} {ital The American Physical Society}

  13. α-particle induced reactions on yttrium and terbium

    International Nuclear Information System (INIS)

    Mukherjee, S.; Kumar, B.B.; Rashid, M.H.; Chintalapudi, S.N.

    1997-01-01

    The stacked foil activation technique has been employed for the investigation of α-particle induced reactions on the target elements yttrium and terbium up to 50 MeV. Six excitation functions for the (α,xn) type of reactions were studied using high-resolution HPGe γ-ray spectroscopy. A comparison with Blann close-quote s geometric dependent hybrid model has been made using the initial exciton number n 0 =4(4p0h) and n 0 =5(5p0h). A broad general agreement is observed between the experimental results and theoretical predictions with an initial exciton number n 0 =4(4p0h). copyright 1997 The American Physical Society

  14. Thermal conductivity of yttrium iron garnet at low temperatures

    International Nuclear Information System (INIS)

    Joshi, Y.P.; Sing, D.P.

    1979-01-01

    An analysis of the low-temperature thermal conductivity of yttrium iron garnet is presented giving consideration to the fact that in a conventional conductivity experiment the magnon temperature gradient inside a magnetic insulator need not be necessarily equal to the phonon temperature gradient. Consequently the effective conductivity can be less than the algebraic sum of the phonon and magnon intrinsic conductivities, depending on the magnon-phonon thermal relaxation rate. This relaxation rate has been distinguished from the individual phonon and magnon relaxation rates and an expression is derived for it. Theoretical calculations of the effective conductivity are found to be in good agreement with experimental results. The contribution of magnons to the effective conductivity is observed to be small at all temperatures below the conductivity maximum. (author)

  15. Yttrium orthoferrite powder obtained by the mechanochemical synthesis

    Directory of Open Access Journals (Sweden)

    Lazarević Zorica Ž.

    2017-01-01

    Full Text Available Yttrium orthoferrite (YFeO3 powder was prepared by a mechanochemical synthesis from a mixture of Y2O3 and α-Fe2O3 powders in a planetary ball mill for 2.5 h. The obtained YFeO3 powder sample was characterized by X-ray diffraction (XRD, Raman and infrared spectroscopy. The average crystallite size calculated by the Scherrer equation was 12 nm. The Mössbauer spectroscopy at room temperature confirms the superparamagnetic character of YFeO3 orthoferrite sample. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 45003, Grant no. III 45015, Grant no. III 45018

  16. Nanoscale nonlinear effects in Erbium-implanted Yttrium Orthosilicate

    Energy Technology Data Exchange (ETDEWEB)

    Kukharchyk, Nadezhda, E-mail: nadezhda.kukharchyk@physik.uni-saarland.de [Experimentalphysik, Universität des Saarlandes, D-66123 Saarbrücken (Germany); Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Shvarkov, Stepan [Optoelektronische Materialien und Bauelemente, Universität Paderborn, D-33098 Padeborn (Germany); Probst, Sebastian [Quantronics group, Service de Physique de l' Etat Condense, DSM/IRAMIS/SPEC, CNRS UMR 3680, CEA-Saclay, 91191 Gif-sur-Yvette cedex (France); Xia, Kangwei [3. Physikalisches Institut, Universität Stuttgart, D-70569 Stuttgart (Germany); Becker, Hans-Werner [RUBION, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Pal, Shovon [Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); AG THz Spectroscopie und Technologie, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Markmann, Sergej [AG THz Spectroscopie und Technologie, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Kolesov, Roman; Siyushev, Petr; Wrachtrup, Jörg [3. Physikalisches Institut, Universität Stuttgart, D-70569 Stuttgart (Germany); Ludwig, Arne [Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Ustinov, Alexey V. [Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe (Germany); Wieck, Andreas D. [Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); and others

    2016-09-15

    Doping of substrates at desired locations is a key technology for spin-based quantum memory devices. Focused ion beam implantation is well-suited for this task due to its high spacial resolution. In this work, we investigate ion-beam implanted Erbium ensembles in Yttrium Orthosilicate crystals by means of confocal photoluminescence spectroscopy. The sample temperature and the post-implantation annealing step strongly reverberate in the properties of the implanted ions. We find that hot implantation leads to a higher activation rate of the ions. At high enough fluences, the relation between the fluence and final concentration of ions becomes non-linear. Two models are developed explaining the observed behavior.

  17. Successful treatment of Cushing's disease using yttrium-90 rods

    International Nuclear Information System (INIS)

    White, M.C.; Doyle, F.H.; Mashiter, K.; Joplin, G.F.

    1982-01-01

    Interstitial irradiation using yttrium-90 ( 90 Y) rods implanted by needle into the pituitary gland was used as primary treatment in 16 patients with pituitary dependent Cushing's disease. Clinical and biochemical remission was observed within three to six months in 13 and in the remaining three after a supplementary implant. There was no perioperative morbidity. Follow-up from the time of definitive operation ranged from six to 123 months (mean 39). No recurrence has been observed. The return of a normal diurnal cortisol rhythm has been observed in 10/12 patients studied after remission. Some form of long-term pituitary hormone replacement therapy was required in only the six patients who had received the largest irradiation dose. Implantation of 90 Y is safe and effective treatment for patients with Cushing's disease, comparing favourably with selective trans-sphenoidal pituitary surgery. (author)

  18. Photocatalysis of Yttrium Doped BaTiO3 Nanofibres Synthesized by Electrospinning

    Directory of Open Access Journals (Sweden)

    Zhenjiang Shen

    2015-01-01

    Full Text Available Yttrium doped barium titanate (BT nanofibres (NFs with significant photocatalytic effect were successfully synthesized by electrospinning. Considering the necessary factors for semiconductor photocatalysts, a well-designed procedure was carried out to produce yttrium doped BT (BYT NFs. In contrast to BYT ceramics powders and BT NFs, BYT NFs with pure perovskite phase showed much enhanced performance of photocatalysis. The surface modification in electrospinning and subsequent annealing, the surface spreading of transition metal yttrium, and the narrowed band gap energy in yttrium doping were all contributed to the final novel photocatalytic effect. This work provides a direct and efficient route to obtain doped NFs, which has a wide range of potential applications in areas based on complex compounds with specific surface and special doping effect.

  19. Polymer Derived Yttrium Silicate Ablative TPS Materials for Next-Generation Exploration Missions, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Through the proposed NASA SBIR program, NanoSonic will optimize its HybridSil® derived yttrium silicates to serve as next-generation reinforcement for carbon and...

  20. Synthesis of yttrium oxide nanoparticles via a facile microplasma-assisted process

    NARCIS (Netherlands)

    Lin, Liangliang; Starostin, Sergey A.; Li, Sirui; Khan, Saif A.; Hessel, Volker

    2018-01-01

    Plasma electrochemistry is an emerging technique for nanomaterial synthesis. The present study reports the preparation of yttrium oxide nanoparticles via a simple, environmentally benign, microplasma-assisted process operated in pin-to-liquid configuration under ambient atmospheric conditions using

  1. Cathodoluminescence properties of yttrium aluminum garnet doped with Eu2+ and Eu3+ ions

    International Nuclear Information System (INIS)

    Trofimov, A. N.; Petrova, M. A.; Zamoryanskaya, M. V.

    2007-01-01

    Yttrium aluminium garnet (YAG) doped with Eu 2+ and Eu 3+ ions is very interesting as a phosphor for conversion of light-emitting diode light for white light sources. The europium ion occupies the structural position of yttrium in yttrium aluminium garnet and has valence state Eu 3+ . Our sample was doped with Zr 4+ , which is why some of the europium ions had valence state Eu 2+ . As a rule, luminescence of Eu 3+ ions is observed in the orange and red range of spectrum. The luminescence of Eu 2+ in yttrium aluminum garnet is characterized by an intensive broad band with maximum of intensity at about 560 nm (green color). In this work, we studied the intensity and decay time dependences on europium concentration, and the influence of excitation power density on the cathodoluminescence of the sample. The most interesting result is the change of visible cathodoluminescence color in dependence on the density of the exciting power

  2. Recovery of yttrium from fluorescent powder of cathode ray tube, CRT: Zn removal by sulphide precipitation

    International Nuclear Information System (INIS)

    Innocenzi, Valentina; De Michelis, Ida; Ferella, Francesco; Beolchini, Francesca; Kopacek, Bernd; Vegliò, Francesco

    2013-01-01

    Highlights: • Treatment of fluorescent powder of CRT waste. • Factorial experimental designs to study acid leaching of fluorescent powder and the purification of leach liquors. • Recover of yttrium by precipitation using oxalic acid. • Suitable flowsheet to recover yttrium from fluorescent powder. - Abstract: This work is focused on the recovery of yttrium and zinc from fluorescent powder of cathode ray tube (CRT). Metals are extracted by sulphuric acid in the presence of hydrogen peroxide. Leaching tests are carried out according to a 2 2 full factorial plan and the highest extraction yields for yttrium and zinc equal to 100% are observed under the following conditions: 3 M of sulphuric acid, 10% v/v of H 2 O 2 concentrated solution at 30% v/v, 10% w/w pulp density, 70 °C and 3 h of reaction. Two series of precipitation tests for zinc are carried out: a 2 2 full factorial design and a completely randomized factorial design. In these series the factors investigated are pH of solution during the precipitation and the amount of sodium sulphide added to precipitate zinc sulphide. The data of these tests are used to describe two empirical mathematical models for zinc and yttrium precipitation yields by regression analysis. The highest precipitation yields for zinc are obtained under the following conditions: pH equal to 2–2.5% and 10–12% v/v of Na 2 S concentrated solution at 10% w/v. In these conditions the coprecipitation of yttrium is of 15–20%. Finally further yttrium precipitation experiments by oxalic acid on the residual solutions, after removing of zinc, show that yttrium could be recovered and calcined to obtain the final product as yttrium oxide. The achieved results allow to propose a CRT recycling process based on leaching of fluorescent powder from cathode ray tube and recovery of yttrium oxide after removing of zinc by precipitation. The final recovery of yttrium is 75–80%

  3. Recovery of yttrium from fluorescent powder of cathode ray tube, CRT: Zn removal by sulphide precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Innocenzi, Valentina, E-mail: valentina.innocenzi1@univaq.it [Department of Industrial Engineering and Information and Economy, University of L’Aquila, Via Giovanni Gronchi n.18, Nucleo Ind.le di Pile, 67100 L’Aquila (Italy); De Michelis, Ida; Ferella, Francesco [Department of Industrial Engineering and Information and Economy, University of L’Aquila, Via Giovanni Gronchi n.18, Nucleo Ind.le di Pile, 67100 L’Aquila (Italy); Beolchini, Francesca [Department of Marine Sciences, Polytechnic Institute of Marche, Via Brecce Bianche, 60131 Ancona (Italy); Kopacek, Bernd [SAT, Austrian Society for Systems Engineering and Automation, Gurkasse 43/2, A-1140 Vienna (Austria); Vegliò, Francesco [Department of Industrial Engineering and Information and Economy, University of L’Aquila, Via Giovanni Gronchi n.18, Nucleo Ind.le di Pile, 67100 L’Aquila (Italy)

    2013-11-15

    Highlights: • Treatment of fluorescent powder of CRT waste. • Factorial experimental designs to study acid leaching of fluorescent powder and the purification of leach liquors. • Recover of yttrium by precipitation using oxalic acid. • Suitable flowsheet to recover yttrium from fluorescent powder. - Abstract: This work is focused on the recovery of yttrium and zinc from fluorescent powder of cathode ray tube (CRT). Metals are extracted by sulphuric acid in the presence of hydrogen peroxide. Leaching tests are carried out according to a 2{sup 2} full factorial plan and the highest extraction yields for yttrium and zinc equal to 100% are observed under the following conditions: 3 M of sulphuric acid, 10% v/v of H{sub 2}O{sub 2} concentrated solution at 30% v/v, 10% w/w pulp density, 70 °C and 3 h of reaction. Two series of precipitation tests for zinc are carried out: a 2{sup 2} full factorial design and a completely randomized factorial design. In these series the factors investigated are pH of solution during the precipitation and the amount of sodium sulphide added to precipitate zinc sulphide. The data of these tests are used to describe two empirical mathematical models for zinc and yttrium precipitation yields by regression analysis. The highest precipitation yields for zinc are obtained under the following conditions: pH equal to 2–2.5% and 10–12% v/v of Na{sub 2}S concentrated solution at 10% w/v. In these conditions the coprecipitation of yttrium is of 15–20%. Finally further yttrium precipitation experiments by oxalic acid on the residual solutions, after removing of zinc, show that yttrium could be recovered and calcined to obtain the final product as yttrium oxide. The achieved results allow to propose a CRT recycling process based on leaching of fluorescent powder from cathode ray tube and recovery of yttrium oxide after removing of zinc by precipitation. The final recovery of yttrium is 75–80%.

  4. Synthesis of yttrium silicate luminescent materials by sol-gel method

    International Nuclear Information System (INIS)

    Arkhipov, D.V.; Vasina, O.Yu.; Popovich, N.V.; Galaktionov, S.S.; Soshchin, N.P.

    1996-01-01

    Several yttrium-silicate composition with Y 2 O 3 content within 44-56% have been synthesized. it is ascertained that employment of sol-gel technique permits preparation of luminescent materials on yttrium silicate basis, which compare favourably with bath-produced specimens. The influence of phase composition of sol-gel phosphors on basic performance indices: intensity and luminescence spectrum, has been analyzed

  5. Radiation protection data sheets for the use of Strontium 90-Yttrium 90 in unsealed sources

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    This radiation protection data sheet is intended for supervisors and staff in the different medical, hospital, pharmaceutical, university and industrial laboratories and departments where Strontium 90-Yttrium 90 is handled, and also for all those involved in risk prevention in this field. It provides essential data on radiation protection measures during the use of Strontium 90-Yttrium 90 in unsealed sources: physical characteristics, risk assessment, administrative procedures, recommendations, regulations and bibliography

  6. Temperature effect on elastic properties of yttrium ferrite garnet Y3Fe5O12

    International Nuclear Information System (INIS)

    Burenkov, Yu.A.; Nikanorov, S.P.

    2002-01-01

    One studied temperature dependence of all independent elastic constants describing comprehensively elastic anisotropy of yttrium ferrite garnet within temperature wide range covering T c . One measured the Young modules for [100] and [110] crystallographic directions and the module of shift for [100] direction of specially pure single crystal of yttrium ferrite garnet within 20-600 deg C temperature range. One analyzed behavior of elastic modules and of elastic anisotropy factor near the critical temperature of magnetic phase transition [ru

  7. Quantitative description of yttrium aluminate ceramic composition by means of Er+3 microluminescence spectrum

    Science.gov (United States)

    Videla, F. A.; Tejerina, M. R.; Moreira-Osorio, L.; Conconi, M. S.; Orzi, D. J. O.; Flores, T.; Ponce, L. V.; Bilmes, G. M.; Torchia, G. A.

    2018-05-01

    The composition of erbium-doped yttrium aluminate ceramics was analyzed by means of confocal luminescence spectroscopy, EDX, and X-ray diffraction. A well-defined linear correlation was found between a proposed estimator computed from the luminescence spectrum and the proportion of ceramic phases coexisting in different samples. This result shows the feasibility of using erbium luminescence spectroscopy to perform a quantitative determination of different phases of yttrium aluminates within a micrometric region in nanograined ceramics.

  8. Structural and magnetic properties of yttrium iron garnet (YIG) and yttrium aluminum iron garnet (YAIG) nanoferrites prepared by microemulsion method

    Energy Technology Data Exchange (ETDEWEB)

    Akhtar, Majid Niaz, E-mail: majidniazakhtar@ciitlahore.edu.pk [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Bakar Sulong, Abu [Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Khan, Muhammad Azhar [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Ahmad, Mukhtar [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Murtaza, Ghulam [Centre for Advanced Studies in Physics, G.C. University, Lahore, Pakistan" f Department of Mechanical Engineering, COMSATS Institute of Information Technology Sahiwal Pakistan (Pakistan); Raza, M.R. [Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Department of Mechanical Engineering, COMSATS Institute of Information Technology Sahiwal (Pakistan); Raza, R.; Saleem, M. [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Kashif, M. [Department of Physics, Govt. College University Faisalabad (Pakistan)

    2016-03-01

    Yttrium iron garnet (YIG) and yttrium aluminum iron garnet (YAIG) nanoferrite samples were synthesized by microemulsion method. The effect of sintering was examined by heating the samples at 900, 1000, and 1100 °C. The YIG and YAIG samples were then characterized using X-ray diffraction and field-emission scanning electron microscopy. Static and dynamic magnetic properties were measured by evaluating initial permeability, Q factor, and vibrating sample magnetometry properties of YIG and YAIG samples. YIG samples sintered at 1100 °C showed higher initial permeability and Q factor compared with YAIG samples. However, hysteresis loops also showed variations in the saturation magnetization, remanence, and coercivity of YIG and YAIG samples sintered at 900, 1000, and 1100 °C. The observed magnetic parameter such as saturation magnetization, coercivity and initial permeability are strongly affected by increasing temperature. The saturation magnetization and coercivity of YIG and YAIG nanoferrites were found in the range 11.56–19.92 emu/g and 7.30–87.70 Oe respectively. Furthermore, the decreasing trends in the static and magnetic properties of YAIG samples may be due to the introduction of Al ions in the YIG crystal lattice. Thus, YIG and YAIG sintered at 1100 °C can be used for wide-ranging frequency applications. - Highlights: • Static and dynamic magnetic properties of YIG and YAIG nanoferrites were determined. • Saturation magnetization, Q and initial permeability increased in YIG nanoferites. • Possible use of these nanoferrites for sensing and switching applications.

  9. N-m-nitrocinnamoylphenylhydroxyl-amine as reagent for amperometric determination of yttrium

    International Nuclear Information System (INIS)

    Oliferenko, G.L.; Gallaj, Z.A.; Sheina, N.M.; Shvedene, N.V.

    1983-01-01

    Possibility of using organic reagent of unsaturated N-arylsubstituted derivatives class of hydroxamic acids N-m-nitrocinnamoyl phenylhydroxylamire (NCPHA) for amperometric titration of yttrium using indication of e.t.p. by current of reagent oxidation on graphite electrode is investigated. Metal and the NCPHA form difficultly soluble complex with ratio of yttrium to the NCPHA, which is equal to 1:3. Buffer mixtures of 0.1MNH 3 +0.1MCH 3 COOH composis tion with pH 6.3-7.5 are optimal background solutions for amperometric titration of yttrium. The proposed method permits to determine 10-600 μkg of yttrium in the volume of 10 ml. Effect of the series of strange elements on titration of yttrium with NCPHA (Ca, Mg, Mn (2), Al, CU (2), Fe (3) REE and others) is studied. The developed method is used for yttrium determination in luminophores of Casub(n)-- Ysub(m)Fsub(z)xMn(2) (1-10%) composition

  10. The behaviour of selected yttrium containing bioactive glass microspheres in simulated body environments.

    Science.gov (United States)

    Cacaina, D; Ylänen, H; Simon, S; Hupa, M

    2008-03-01

    The study aims at the manufacture and investigation of biodegradable glass microspheres incorporated with yttrium potentially useful for radionuclide therapy of cancer. The glass microspheres in the SiO2-Na2O-P2O5-CaO-K2O-MgO system containing yttrium were prepared by conventional melting and flame spheroidization. The behaviour of the yttrium silicate glass microspheres was investigated under in vitro conditions using simulated body fluid (SBF) and Tris buffer solution (TBS), for different periods of time, according to half-life time of the Y-90. The local structure of the glasses and the effect of yttrium on the biodegradability process were evaluated by Fourier Transform Infrared (FT-IR) spectroscopy and Back Scattered Electron Imaging of Scanning Electron Microscopy (BEI-SEM) equipped with Energy Dispersive X-ray (EDX) analysis. UV-VIS spectrometry and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used for analyzing the release behaviour of silica and yttrium in the two used solutions. The results indicate that the addition of yttrium to a bioactive glass increases its structural stability which therefore, induced a different behaviour of the glasses in simulated body environments.

  11. Size-dependent cytotoxicity of yttrium oxide nanoparticles on primary osteoblasts in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Guoqiang, E-mail: zhougq1982@163.com; Li, Yunfei; Ma, Yanyan; Liu, Zhu; Cao, Lili; Wang, Da; Liu, Sudan; Xu, Wenshi; Wang, Wenying [Hebei University, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science (China)

    2016-05-15

    Yttrium oxide nanoparticles are an excellent host material for the rare earth metals and have high luminescence efficiency providing a potential application in photodynamic therapy and biological imaging. In this study, the effects of yttrium oxide nanoparticles with four different sizes were investigated using primary osteoblasts in vitro. The results demonstrated that the cytotoxicity generated by yttrium oxide nanoparticles depended on the particle size, and smaller particles possessed higher toxicological effects. For the purpose to elucidate the relationship between reactive oxygen species generation and cell damage, cytomembrane integrity, intracellular reactive oxygen species level, mitochondrial membrane potential, cell apoptosis rate, and activity of caspase-3 in cells were then measured. Increased reactive oxygen species level was also observed in a size-dependent way. Thus, our data demonstrated that exposure to yttrium oxide nanoparticles resulted in a size-dependent cytotoxicity in cultured primary osteoblasts, and reactive oxygen species generation should be one possible damage pathway for the toxicological effects produced by yttrium oxide particles. The results may provide useful information for more rational applications of yttrium oxide nanoparticles in the future.

  12. Studies for the yttrium determination by activation analysis, in the presence of lanthanides. Application of the substoichiometric technique

    International Nuclear Information System (INIS)

    Silva, D.I.T. da.

    1978-01-01

    Some methods using extraction chromatography for the separation of yttrium from the lanthanide elements were applied. The separation of yttrium was studied, using di-(2 ethylhexyl) orthophosphoric acid as stationary phase, Kieselguhr as support and HNO 3 of concentration between 4,5 and 5,0 N as the mobile phase. In these conditions, about 50% of pure yttrium was obtained. The substoichiometric technique was applied to the determination of yttrium. The elements was partially complexed and the Y 3 + ions were separated from the complex (EDTA-Y) - by means of a cationic resin. The sensitivity, precision and accuracy which can be expected in the analytical results were studied. The possibility of the analysis of a sample containing 1 part per million of yttrium with an error just above 8% was demonstrated. It was also shown that, admitting an error of 10%, it is possible to determine 60 parts per billion of yttrium [pt

  13. Characterization of composite metal-ceramic of nickel-oxide cerium doped gadolinium

    International Nuclear Information System (INIS)

    Silva, M.L.A. da; Varela, M.C.R.S.

    2016-01-01

    Composite nickel doped cerium oxide are used in SOFC anode materials. In this study we evaluated the effect of the presence of gadolinium on the properties of composite nickel and ceria and. The supports were synthesized by sol-gel method. The impregnation with nickel nitrate was taken sequentially, followed by calcination. The materials were characterized by X-ray diffraction, measurement of specific surface area, temperature programmed reduction, Raman spectroscopy. The presence of gadolinium retained the fluorite structure of ceria by forming a solid solution, also not influencing significantly on the specific surface area of the support. On the other hand, there was a decrease in the area catalysts, which can be attributed to sintering of nickel. Furthermore, addition of gadolinium favored the formation of intrinsic and extrinsic vacancies in cerium oxide, which leads to an increase in the ionic conductivity of the solid, desirable property for an SOFC anode catalyst. (author)

  14. Dielectric studies on cerium doped BaLa2Ti3O10

    Directory of Open Access Journals (Sweden)

    Parshuram B. Abhange

    2015-12-01

    Full Text Available The BaLa2-xCexTi3O10 samples (with x = 0.2, 0.4, 0.6 and 0.8 were prepared by hydroxide co-precipitation method and finally sintered at 1150 °C. The structure of the prepared samples was characterized by XRD and SEM. The single phase material was confirmed only for the BaLa1.8Ce0.2Ti3O10 ceramics. However, at higher cerium concentration secondary phase was observed. The characteristic plate-like structure, having grains with submicrometer thickness and high aspect ratio, was clearly observed by SEM. The results of dielectric measurement suggest that the appropriate adjustment of doping (with x between 0.2 and 0.8 will give sufficient high dielectric constant at very low loss. The resistivity of samples decreases with increase in temperature indicating the normal semiconducting electrical behaviour.

  15. Effects of nuclear radiation on the optical properties of cerium-doped glass (accelerator applications)

    CERN Document Server

    McGrath, B; Van de Voorde, M H

    1976-01-01

    Some twenty types of glass containing 0.5-4% CeO/sub 2/ have been irradiated in a /sup 60/Co gamma cell and in the mixed neutron-gamma field of a nuclear reactor, at total integrated doses of up to 5*10 /sup 9/ rad (CH). The resulting colouration has been assessed quantitatively by measuring the light transmission with reference to air, in the range 360-510 nm. From the results, certain types of glass suitable for applications in nuclear engineering can be selected. Specifically, it was found that 1-2% CeO/sub 2/ content is usually sufficient to obtain radiation-resistant optical glass: the reduction in light transmission above 450 nm is nil at 10/sup 8/ rad (CH), below 10% at 10/sup 9/ rad (CH), and below 20% at 5*10/sup 9/ rad (CH); the post-irradiation fading is negligible.

  16. Cerium doped heavy metal fluoride glasses, a possible alternative for electromagnetic calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Auffray, E. [CERN, Geneva (Switzerland); Bouttet, D. [LPCM Lyon, CNRS and Universite Claude Bernard, Villeurbanne (France); Dafinei, I. [CERN, Geneva (Switzerland); Fay, J. [IPN Lyon, IN2P3-CNRS and Universite Claude Bernard, Villeurbanne (France); Lecoq, P. [CERN, Geneva (Switzerland); Mares, J.A. [Institute of Physics, Praha (Czech Republic); Martini, M. [University of Milan, Department of Physics, Milan (Italy); Maze, G. [Le Verre Fluore, F - 35770 Vern/Seiche, Bretagne (France); Meinardi, F. [University of Milan, Department of Physics, Milan (Italy); Moine, B. [LPCM Lyon, CNRS and Universite Claude Bernard, Villeurbanne (France); Nikl, M. [Institute of Physics, Praha (Czech Republic); Pedrini, C. [LPCM Lyon, CNRS and Universite Claude Bernard, Villeurbanne (France); Poulain, M. [Le Verre Fluore, F - 35770 Vern/Seiche, Bretagne (France); Schneegans, M. [LAPP, IN2P3-CNRS, Annecy-le-Vieux (France); Tavernier, S. [VUB, Vrije Universiteit Brussels, Brussels (Belgium); Vedda, A. [University of Milan, Department of Physics, Milan (Italy)

    1996-10-11

    The article is an overview of the research activity made in the framework of the Crystal Clear Collaboration aimed at obtaining scintillating glasses able to fit the constraints imposed for the active medium of the central Electromagnetic Calorimeter at CMS. The manufacturing of heavy metal fluoride glasses doped with Ce{sup 3+} is discussed. The luminescence and scintillation characteristics as well as the radiation hardness properties are extensively studied in the case of Ce doped fluorohafnate, found to be the most convenient glass scintillator for high energy physics applications. (orig.).

  17. Cerium doped heavy metal fluoride glasses, a possible alternative for electromagnetic calorimetry

    International Nuclear Information System (INIS)

    Auffray, E.; Bouttet, D.; Dafinei, I.; Fay, J.; Lecoq, P.; Mares, J.A.; Martini, M.; Maze, G.; Meinardi, F.; Moine, B.; Nikl, M.; Pedrini, C.; Poulain, M.; Schneegans, M.; Tavernier, S.; Vedda, A.

    1996-01-01

    The article is an overview of the research activity made in the framework of the Crystal Clear Collaboration aimed at obtaining scintillating glasses able to fit the constraints imposed for the active medium of the central Electromagnetic Calorimeter at CMS. The manufacturing of heavy metal fluoride glasses doped with Ce 3+ is discussed. The luminescence and scintillation characteristics as well as the radiation hardness properties are extensively studied in the case of Ce doped fluorohafnate, found to be the most convenient glass scintillator for high energy physics applications. (orig.)

  18. Redox-induced reversible luminescence switching of cerium-doped upconversion nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanan [College of Sciences, Shanghai University, Shanghai 200444 (China); International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China); Xiao, Qingbo, E-mail: qbxiao2011@sinano.ac.cn [International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China); Wang, Jian [College of Sciences, Shanghai University, Shanghai 200444 (China); International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China); Xi, Yonglan [Laboratory for Agricultural Wastes Treatment and Recycling Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Science, Nanjing 210014 (China); Li, Fujin [International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China); Feng, Yamin [College of Sciences, Shanghai University, Shanghai 200444 (China); International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China); Shi, Liyi [College of Sciences, Shanghai University, Shanghai 200444 (China); Lin, Hongzhen, E-mail: hzlin2010@sinano.ac.cn [International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China)

    2016-05-15

    Smart upconversion nanophosphors (UCNPs) that can be reversibly switched between two or more luminescent states by certain external stimuli have attracted considerable attention due to their great potential in biological applications. Here we report for the first time a type of redox-switchable UCNPs by codoping NaGdF{sub 4}:Yb/Er nanorods with the redox-active Ce{sup 3+}/Ce{sup 4+} ion pairs. A reversible switching of their UC luminescence intensity was observed upon the variation of the surrounding redox environments. We show solid proof that the luminescence switching is caused by the tailoring of the NaGdF{sub 4} host crystal structure in response to changing redox state of the codoped cerium ions. A proof-of-concept example is further demonstrated by using these UCNPs for probing the dynamical variation of redox environments in biological tissues. - Highlights: • Synthesis of upconversion nanoparticles doped with Ce{sup 3+}/Ce{sup 4+} ions. • The precise and reversible modification of crystal structure by redox reactions. • Tuning the upconversion luminescence by tailoring the crystal structure.

  19. Novel cerium doped glass-reinforced hydroxyapatite with antibacterial and osteoconductive properties for bone tissue regeneration

    International Nuclear Information System (INIS)

    Morais, D S; Fernandes, S; Santos, J D; Lopes, M A; Gomes, P S; Fernandes, M H; Sampaio, P; Ferraz, M P; Sooraj Hussain, N

    2015-01-01

    The aim of this work was to develop a bioactive bone substitute with an effective antibacterial ability based on a cerium (Ce) doped glass-reinforced hydroxyapatite (GR-HA) composite. Developed composites were physicochemically characterized, using x-ray diffraction (XRD) analysis, SEM, energy dispersive x-ray spectroscopy (EDS), and flexural bending strength (FBS) tests. X-ray photoelectron spectroscopy (XPS) analysis was performed to analyze the oxidation state of Ce in the prepared doped glass. The antimicrobial activity of the composites was evaluated against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa; whether the cytocompatibility profile was assayed with human osteoblastic-like cells (Mg-63 cell line). The results revealed that the Ce inclusion in the GR-HA matrix induced the antimicrobial ability of the composite. In addition, Ce-doped materials reported an adequate biological behavior following seeding of osteoblastic populations, by inducing cell adhesion and proliferation. Developed materials were also found to enhance the expression of osteoblastic-related genes. Overall, the developed GR-HA-Ce composite is a prospective candidate to be used within the clinical scenario with a successful performance due to the effective antibacterial properties and capability of enhancing the osteoblastic cell response. (paper)

  20. Synthesis and characterization of Cerium-doped hydroxyapatite/polylactic acid composite coatings on metal substrates

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Qiuhua, E-mail: yuanqiuh@szu.edu.cn; Qin, Caoping; Wu, Jianbo; Xu, Anping; Zhang, Ziqiang; Liao, Junquan; Lin, Songxin; Ren, Xiangzhong; Zhang, Peixin

    2016-10-01

    Ce-doped hydroxyapatite/polylactic acid (HA/PLA) composites serving as implant coatings have rarely been studied by other researchers in recent years. This paper was focused to study the existence of Ce ions in structure, chemical composition and surface morphology of HA and its composite coatings. Ce-doped HA powders were synthesized by chemical precipitation method with different Ce molar fractions (0(pure HA), 0.5 mol%, 1 mol% and 2 mol%). And Ce-doped HA/PLA composite coatings were fabricated for the first time on stainless steel substrates by spin coating technique. The obtained samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) coupled with energy dispersive X-ray detector (EDX), thermo gravimetric-differential thermal analysis (TG-DTA) and X-ray photoelectron spectroscopy (XPS). The results showed that Ce ions were doped into the crystal lattice of apatite successfully. The (Ce + Ca)/P atomic ratios in the doped HA/PLA samples ranged from 1.614 to 1.673, which were very close to the theoretical value of 1.67 for the stoichiometric HA. The addition of PLA could keep metal substrates from catalyzing the decomposition of HA. TG-DTA analysis indicated that Ce-doped HA powder had high thermal stability, and the SEM micrographs revealed that the surface topography of Ce-doped HA/PLA composite coatings was uniform and dense when the Ce molar fraction was 2 mol%. XPS results indicated that the Ce ions doped in HA showed mixed valences of Ce{sup 3+} and Ce{sup 4+}. - Highlights: • Ce-doped HA composite coatings were synthesized by spin-coating technique for the first time. • Ce ions were demonstrated to dope into HA crystal lattice successfully. • The addition of PLA could keep metal substrates from catalyzing the decomposition of HA. • XPS results showed that Ce ions doped in HA have mixed valences of Ce{sup 3+} and Ce{sup 4+}.

  1. Preparation and investigation of structural, magnetic and microwave absorption properties of cerium doped barium hexaferrite

    Directory of Open Access Journals (Sweden)

    P Kameli

    2015-01-01

    Full Text Available In this study the structure, magnetic and microwave absorption properties of cerium (Ce doped barium hexaferrite with general formulae BaCexFe12-xO19 (x=0.0, 0.05, 0.1, 0.15, 0.2 have been investigated. These samples have been prepared by sol- gel method. Influence of replacing Fe+3 ion by rare- earth Ce+3 ion on the structural, magnetic and microwave absorption properties have been investigated by X- ray diffraction (XRD, Fourier transform infrared (FT-IR, Vibrating sample magnetometer (VSM and vector network analyzer (VNA. X-ray diffraction analysis indicated that the samples are of single phase with space group p63/mmc. The magnetic properties of samples indicated that with the Ce doping the saturation magnetization show no regular behavior. Moreover, coercivity (Hc first decreased and reached to the minimum value for x=0.1 sample and then increased with Ce content increasing. Also, measurement of electromagnetic wave absorption in X and Ku frequency bands indicated that the maximum of reflection loss obtained for x=0.15 sample. Moreover, result indicated that absorption peak shifted toward a lower frequency when thickness was increased.

  2. Cerium doped GSO scintillators and its application to position sensitive detectors

    International Nuclear Information System (INIS)

    Ishibashi, H.; Shimizu, K.; Susa, K.; Kubota, S.

    1989-01-01

    The dependence of the light output and the decay times of Ce doped Gd/sub 2/SiO/sub 5/ on Ce concentration is measured. By using the difference in decay times on Ce concentration for GSO(Ce), the combination of different concentration of GSO(Ce) scintillators is shown to be useful as position sensitive detectors. A Ce doped Gd/sub 2/SiO/sub 5/ (GSO(Ce)) single crystal is an excellent scintillator featuring, a large light output, a short decay time and a high absorption coefficient. Further investigation aimed at its implementation to scintillators has been carried out previously. An application of the GSO(Ce) scintillators to the gamma-ray detectors of positron emission computed tomography has also been shown. The authors have investigated the dependence of its scintillation properties on the Ce concentration and its application to position sensitive detectors

  3. Cerium-doped single crystal and transparent ceramic lutetium aluminum garnet scintillators

    International Nuclear Information System (INIS)

    Cherepy, Nerine J.; Kuntz, Joshua D.; Tillotson, Thomas M.; Speaks, Derrick T.; Payne, Stephen A.; Chai, B.H.T.; Porter-Chapman, Yetta; Derenzo, Stephen E.

    2007-01-01

    For rapid, unambiguous isotope identification, scintillator detectors providing high-resolution gamma ray spectra are required. We have fabricated Lutetium Aluminum Garnet (LuAG) using transparent ceramic processing, and report a 2-mm thick ceramic exhibiting 75% transmission and light yield comparable to single-crystal LuAG:Ce. The LuAG:Ce luminescence peaks at 550 nm, providing an excellent match for Silicon Photodiode readout. LuAG is dense (6.67 g/cm 3 ) and impervious to water, exhibits good proportionality and a fast decay (∼40 ns), and we measure light yields in excess of 20,000 photons/MeV

  4. Electro-catalytic oxidation of reactive Orange 107 using cerium doped oxides of Nd3+ nanoparticle

    International Nuclear Information System (INIS)

    Rajkumar, K.; Muthukumar, M.; Mangalaraja, R.V.

    2011-01-01

    A new rare earth doped cerium oxide powder was used as a catalyst to investigate the removal of colour and TOC from simulated wastewater of Reactive Orange 107. The electro oxidation process was carried out in the reactor in presence of an electrolyte NaCl. Graphite electrode was used as anode and cathode and electrolysis were carried out at a current density of 34.96 mAcm -2 with a catalyst concentration of 0.05g L -1 . In order to find the efficiency of nanocatalyst, experiments were also conducted without catalyst. From the experiment, it was found that complete colour removal was achieved on electrocatalytic oxidation as well as electro oxidation. When comparing the above processes, catalytic oxidation shows more efficient than electro oxidation. With respect to the degradation of the dye, catalytic oxidation shows more TOC removal than the oxidation taken place without catalyst. It infers that even though the electro-catalytic oxidation process achieves complete decolouration but it does not achieve complete mineralisation. The FTIR and GCMS studies confirmed the formation of by-products. (author)

  5. Study of decomposition kinetics of volatile β-diketonates of yttrium, barium and copper in flow reactor

    International Nuclear Information System (INIS)

    Devyatykh, G.G.; Gavrishchuk, E.M.; Gibin, A.M.; Dadanov, A.Yu.; Dzyubenko, N.G.; Kaul', A.R.; Nichiporuk, R.V.; Snezhko, N.T.; Ul'yanov, A.A.

    1990-01-01

    Heterogeneous oxidative decomposition of adduct of yttrium acetylacetonate with o-phenanthroline, copper acetylacetonate and barium dipivaloylmethanate in a flow-type reactor was carried out. The basic kinetic characteristics of chemical precipitation processes of films of yttrium, copper and barium oxides, which are components of high-temperature superconductors, were obtained. The values of activation energy of precipitation process of yttrium, copper and barium oxides constituted 76±10, 108±15, 81±12 (t 600 deg C) respectively

  6. Surface characterization of low-temperature grown yttrium oxide

    Science.gov (United States)

    Krawczyk, Mirosław; Lisowski, Wojciech; Pisarek, Marcin; Nikiforow, Kostiantyn; Jablonski, Aleksander

    2018-04-01

    The step-by-step growth of yttrium oxide layer was controlled in situ using X-ray photoelectron spectroscopy (XPS). The O/Y atomic concentration (AC) ratio in the surface layer of finally oxidized Y substrate was found to be equal to 1.48. The as-grown yttrium oxide layers were then analyzed ex situ using combination of Auger electron spectroscopy (AES), elastic-peak electron spectroscopy (EPES) and scanning electron microscopy (SEM) in order to characterize their surface chemical composition, electron transport phenomena and surface morphology. Prior to EPES measurements, the Y oxide surface was pre-sputtered by 3 kV argon ions, and the resulting AES-derived composition was found to be Y0.383O0.465C0.152 (O/Y AC ratio of 1.21). The SEM images revealed different surface morphology of sample before and after Ar sputtering. The oxide precipitates were observed on the top of un-sputtered Y oxide layer, whereas the oxide growth at the Ar ion-sputtered surface proceeded along defects lines normal to the layer plane. The inelastic mean free path (IMFP) characterizing electron transport was evaluated as a function of energy in the range of 0.5-2 keV from the EPES method. Two reference materials (Ni and Au) were used in these measurements. Experimental IMFPs determined for the Y0.383O0.465C0.152 and Y2O3 surface compositions, λ, were uncorrected for surface excitations and approximated by the simple function λ = kEp at electron energies E between 500 eV and 2000 eV, where k and p were fitted parameters. These values were also compared with IMFPs resulting from the TPP-2 M predictive equation for both oxide compositions. The fitted functions were found to be reasonably consistent with the measured and predicted IMFPs. In both cases, the average value of the mean percentage deviation from the fits varied between 5% and 37%. The IMFPs measured for Y0.383O0.465C0.152 surface composition were found to be similar to the IMFPs for Y2O3.

  7. Optimized conditions for chelation of yttrium-90-DOTA immunoconjugates.

    Science.gov (United States)

    Kukis, D L; DeNardo, S J; DeNardo, G L; O'Donnell, R T; Meares, C F

    1998-12-01

    Radioimmunotherapy (RIT) with 90Y-labeled immunoconjugates has shown promise in clinical trials. The macrocyclic chelating agent 1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid (DOTA) binds 90Y with extraordinary stability, minimizing the toxicity of 90Y-DOTA immunoconjugates arising from loss of 90Y to bone. However, reported 90Y-DOTA immunoconjugate product yields have been typically only BAD) was conjugated to the monoclonal antibody Lym-1 via 2-iminothiolane (2IT). The immunoconjugate product, 2IT-BAD-Lym-1, was labeled in excess yttrium in various buffers over a range of concentrations and pH. Kinetic studies were performed in selected buffers to estimate radiolabeling reaction times under prospective radiopharmacy labeling conditions. The effect of temperature on reaction kinetics was examined. Optimal radiolabeling conditions were identified and used in eight radiolabeling experiments with 2IT-BAD-Lym-1 and a second immunoconjugate, DOTA-peptide-chimeric L6, with 248-492 MBq (6.7-13.3 mCi) of 90Y. Ammonium acetate buffer (0.5 M) was associated with the highest uptake of yttrium. On the basis of kinetic data, the time required to chelate 94% of 90Y (four half-times) under prospective radiopharmacy labeling conditions in 0.5 M ammonium acetate was 17-148 min at pH 6.5, but it was only 1-10 min at pH 7.5. Raising the reaction temperature from 25 degrees C to 37 degrees C markedly increased the chelation rate. Optimal radiolabeling conditions were identified as: 30-min reaction time, 0.5 M ammonium acetate buffer, pH 7-7.5 and 37 degrees C. In eight labeling experiments under optimal conditions, a mean product yield (+/- s.d.) of 91%+/-8% was achieved, comparable to iodination yields. The specific activity of final products was 74-130 MBq (2.0-3.5 mCi) of 90Y per mg of monoclonal antibody. The immunoreactivity of 90Y-labeled immunoconjugates was 100%+/-11%. The optimization of 90Y-DOTA chelation conditions represents an important advance in 90Y RIT

  8. Treatment of persistent knee effusions with Yttrium 90

    International Nuclear Information System (INIS)

    Bouyoucef, S.E.; Drahmoune, R.; Mechken, F.; Amimour, A.; Hanni-Haddam, F.; Abtroun, F.; Sellah, M.; Mansouri, B.

    2002-01-01

    Yttrium 90 intra-articular injection is used in persisting active joint of the knee, where medication has failed to resolve chronic inflammation. The effective dose delivered to the synovia is linked to Y 90 activity and depends on the size of the joint space, the synovial structure and thickness and the inflammatory activity of the synovitis. The amount of the injected activity of Y90 was estimated according the volume effusion in 28 pathologic knee of 18 patients aged 18 years and more (mean age 46 years). All patients have persistent knee effusions and most of them have rheumatoid arthritis but others had ankylosing spondylitis, Behcet disease, psoriatic arthritis. According the radiological classification of Steinbrocker, 19 pathological knees were in stage 1, 5 in stage 2 and 4 in stage 3. The mean value of the monthly removed volume of the synovial liquid from the pathological knee was determined during the last month preceding the radiosynoviorthesis and four groups were identified: V0 no evidence of effusion liquid, 0 ml 100ml. The activity of Y 90 was estimated in order to obtain a total of 100 Gray in the envelope of 3 spherical phantoms with the same range of volume as defined above. The lowest activity of Y90, 111 MBq (3mCi) was determined for V0 according a mean value of standard sizes of knees. An activity of 18 MBq (0.5mCi) was added for each stage of 50 ml, so 129 MBq (3.5 mCi) for G1, 148 MBq (4 mCi) for G2 and 166 MBq (4.5 mCi) for G3. Efficacy of Y90 treatment was clinically assessed in all patients according to three parameters: pain, hydrarthrosis and range of joint movement at 1, 3, 6 and 12 months. The results were excellent in 13 knees and good in 9 and for most of them the efficacy of Y 90 was observed after 6 months. The results were less good in 3 knees but with an initial good evolution for all at 1 month. For 4 knees, the efficacy of Y 90 was bad. Although the small number of patients, these results show a high rate, 75%, of successful

  9. Enrichment of yttrium from rare earth concentrate by ammonium carbonate leaching and peroxide precipitation

    International Nuclear Information System (INIS)

    Vasconcellos, Mari E. de; Rocha, S.M.R. da; Pedreira, W.R.; Queiroz S, Carlos A. da; Abrao, Alcidio

    2006-01-01

    The rare earth elements (REE) solubility with ammonium carbonate vary progressively from element to element, the heavy rare earth elements (HRE) being more soluble than the light rare earth elements (LRE). Their solubility is function of the carbonate concentration and the kind of carbonate as sodium, potassium and ammonium. In this work, it is explored this ability of the carbonate for the dissolution of the REE and an easy separation of yttrium was achieved using the precipitation of the peroxide from complex yttrium carbonate. For this work is used a REE concentrate containing (%) Y 2 O 3 2.4, Dy 2 O 3 0.6, Gd 2 O 3 2.7, CeO 2 2.5, Nd 2 O 3 33.2, La 2 O 3 40.3, Sm 2 O 3 4.1 and Pr 6 O 11 7.5. The mentioned concentrate was produced industrially from the chemical treatment of monazite sand by NUCLEMON in Sao Paulo. The yttrium concentrate was treated with 200 g L -1 ammonium carbonate during 10 and 30 min at room temperature. The experiments indicated that a single leaching operation was sufficient to get a rich yttrium solution with about 60.3% Y 2 O 3 . In a second step, this yttrium solution was treated with an excess of hydrogen peroxide (130 volumes), cerium, praseodymium and neodymium peroxides being completely precipitated and separated from yttrium. Yttrium was recovered from the carbonate solution as the oxalate and finally as oxide. The final product is an 81% Y 2 O 3 . This separation envisages an industrial application. The work discussed the solubility of the REE using ammonium carbonate and the subsequent precipitation of the correspondent peroxides

  10. Impacts of yttrium substitution on FMR line-width and magnetic properties of nickel spinel ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Ishaque, M., E-mail: ishaqdgk1@gmail.com [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Khan, Muhammad Azhar, E-mail: azhar.khan@iub.edu.pk [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Ali, Irshad; Khan, Hasan M. [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Iqbal, M. Asif [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); College of E & ME, National University of Science and Technology, Islamabad (Pakistan); Islam, M.U. [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Warsi, Muhammad Farooq [Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan)

    2015-05-15

    The influence of yttrium (Y) substitution on ferromagnetic resonance (FMR), initial permeability, and magnetic properties of NiFe{sub 2}O{sub 4} ferrites were investigated. It was observed that the FMR line-width decreases with yttrium contents for the substitution level 0≤×≤0.06. Beyond this, the FMR line-width increases with yttrium contents. The nominal composition NiY{sub 0.12}Fe{sub 1.88}O{sub 4} exhibited the smallest FMR line-width ~282 Oe. A significant change in FMR position of nickel–yttrium (Ni–Y) ferrites was observed and it found to exist between 4150 and 4600 Oe. The saturation magnetization was observed to decrease with the increase of yttrium contents and this was referred to the redistribution of cations on octahedral. The coercivity increased from 15 Oe to 59 Oe by increasing the yttrium concentration. The initial permeability decreased from 110 to 35 at 1 MHz by the incorporation of yttrium and this was attributed to the smaller grains which may obstruct the domain wall movement and impede the domain wall motion. The magnetic loss factors of substituted samples exhibit decreasing behavior in the frequency range 1 kHz to 10 MHz. The smaller FMR line-width and reduced magnetic loss factor of the investigated samples suggest the possible use of these materials in high frequency applications. - Highlights: • Influence of Y{sup 3+} substitution on the properties of nickel ferrites is investigated. • Very small FMR line-width (282 Oe) is exhibited by these substituted ferrites. • Fourfold increase in coercivity was observed for NiY{sub 0.24}Fe{sub 1.76}O{sub 4} ferrites.

  11. MCrAlY bond coat with enhanced yttrium

    Science.gov (United States)

    Jablonski, Paul D.; Hawk, Jeffrey A.

    2016-08-30

    One or more embodiments relates to a method of producing an MCrAlY bond coat comprising an MCrAlY layer in contact with a Y--Al.sub.2O.sub.3 layer. The MCrAlY layer is comprised of a .gamma.-M solid solution, a .beta.-MAl intermetallic phase, and Y-type intermetallics. The Y--Al.sub.2O.sub.3 layer is comprised of Yttrium atoms coordinated with oxygen atoms comprising the Al.sub.2O.sub.3 lattice. The method comprises depositing an MCrAlY material on a substrate, applying an Y.sub.2O.sub.3 paste, and heating the substrate in a non-oxidizing atmosphere at a temperature between 400-1300.degree. C. for a time sufficient to generate the Y--Al.sub.2O.sub.3 layer. Both the MCrAlY layer and the Y--Al.sub.2O.sub.3 layer have a substantial absence of Y.sub.2O.sub.3, YAG, and YAP phases.

  12. A divalent rare earth oxide semiconductor: Yttrium monoxide

    Science.gov (United States)

    Kaminaga, Kenichi; Sei, Ryosuke; Hayashi, Kouichi; Happo, Naohisa; Tajiri, Hiroo; Oka, Daichi; Fukumura, Tomoteru; Hasegawa, Tetsuya

    Rare earth sesquioxides like Y2O3 are known as widegap insulators with the highly stable closed shell trivalent rare earth ions. On the other hand, rare earth monoxides such as YO have been recognized as gaseous phase, and only EuO and YbO were thermodynamically stable solid-phase rock salt monoxides. In this study, solid-phase rock salt yttrium monoxide, YO, was synthesized in a form of epitaxial thin film by pulsed laser deposition method. YO possesses unusual valence of Y2+ ([Kr] 4d1) . In contrast with Y2O3, YO was narrow gap semiconductor with dark-brown color. The electrical conductivity was tunable from 10-1 to 103 Ω-1 cm-1 by introducing oxygen vacancies as electron donor. Weak antilocalization behavior was observed indicating significant spin-orbit coupling owing to 4 d electron carrier. The absorption spectral shape implies the Mott-Hubbard insulator character of YO. Rare earth monoixdes will be new platform of functional oxides. This work was supported by JST-CREST, the Japan Society for the Promotion of Science (JSPS) with Grant-in-Aid for Scientific Research on Innovative Areas (Nos. 26105002 and 26105006), and Nanotechnology Platform (Project No.12024046) of MEXT, Japan.

  13. Optical properties of ytterbium-doped yttrium oxide ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Solomonov, V.I.; Maksimov, R.N. [Institute of Electrophysics UrB RAS, Amundsena 106, 620016 Ekaterinburg (Russian Federation); Ural Federal University Named After the First President of Russia B.N. Yeltsin, Mira 19, 620002 Ekaterinburg (Russian Federation); Osipov, V.V.; Shitov, V.A.; Lipchak, A.I. [Institute of Electrophysics UrB RAS, Amundsena 106, 620016 Ekaterinburg (Russian Federation)

    2017-05-15

    Ytterbium-doped yttrium oxide (Yb:Y{sub 2}O{sub 3}) transparent ceramics with different sintering additives (Lu{sub 2}O{sub 3}, Sc{sub 2}O{sub 3}, CeO{sub 2}, ZrO{sub 2}, or HfO{sub 2}) were fabricated using nanopowders produced by laser ablation. Transmission and photoluminescence spectra of the obtained ceramics were investigated at room temperature. Highest in-line transmittance was over 80% at the wavelength of 1060 nm for 2 mm thick Yb:Y{sub 2}O{sub 3} ceramics with zirconium and hafnium. Divalent Yb ions with the ground state electron configuration 4f{sup 13}6s were revealed. The absorption and emission bands caused by s <-> s transitions of these ions were observed in the IR spectral range of Yb{sup 3+} ions. The superposition of both Yb{sup 3+} and Yb{sup 2+} emission bands leads to an effective broadening of the whole luminescence band. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Structural and dielectric properties of yttrium-substituted hydroxyapatites

    Energy Technology Data Exchange (ETDEWEB)

    Kaygili, Omer, E-mail: okaygili@firat.edu.tr [Department of Physics, Faculty of Science, Firat University, 23119 Elazig (Turkey); Dorozhkin, Sergey V. [Kudrinskaja sq. 1-155, 123242 Moscow (Russian Federation); Ates, Tankut [Department of Physics, Faculty of Science, Firat University, 23119 Elazig (Turkey); Canan Gursoy, N. [Department of Microbiology and Clinic Microbiology, Inonu University, 44280 Malatya (Turkey); Keser, Serhat [Department of Chemistry, Faculty of Science, Firat University, 23119 Elazig (Turkey); Yakuphanoglu, Fahrettin [Department of Physics, Faculty of Science, Firat University, 23119 Elazig (Turkey); Birkan Selçuk, A. [Technology Department, Saraykoy Nuclear Research and Training Centre, 06983 Ankara (Turkey)

    2015-02-01

    Hydroxyapatite (HAp) samples doped with 0, 2 and 4 at.% of yttrium (Y) were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy attached with energy dispersive X-ray (EDX) spectroscopy, antimicrobial activity tests and dielectric studies. The hydroxyl groups observed in FTIR spectra confirmed the formation of HAp phase in the studied samples. The crystallite size, crystallinity degree and lattice parameters of the samples were changed with Y content. The volume of the unit cell was gradually decreased with the addition of Y. Undoped and Y-containing HAp samples were screened to determine their in vitro antimicrobial activities against the standard strains. It was found that no samples have any antimicrobial effect. The relative dielectric permittivity and dielectric loss are affected by Y content. While the alternating current conductivity increases with increasing frequency, it decreases with increasing Y content. - Highlights: • The lattice parameters and crystal size are affected by Y content. • The volume of the unit cell was gradually decreased with the addition of Y. • No samples have any antimicrobial effect. • The alternating current conductivity decreases with increasing Y content.

  15. High density Gd-substituted yttrium iron garnets by coprecipitation

    International Nuclear Information System (INIS)

    Lamastra, Francesca Romana; Bianco, Alessandra; Leonardi, Federica; Montesperelli, Giampiero; Nanni, Francesca; Gusmano, Gualtiero

    2008-01-01

    Gadolinium-substituted yttrium iron garnets are ferrite materials of primary importance in microwave engineering. Stoichiometric powders of nominal composition Y 2.6 Gd 0.4 Fe 5 O 12 (i.e. Fe/(Y + Gd) = 1.67) were prepared by reverse strike coprecipitation of metal nitrates. In order to investigate the influence of composition on phase formation, non-stoichiometric powders were also synthesised. On the basis of DTA/TGA analysis, dried coprecipitates were calcined between 600 deg. C and 1200 deg. C and then characterised by ICP, XRD and HT-XRD. Amorphous coprecipitates crystallise around 700 deg. C in cubic garnet phase along with small amounts of YFeO 3 and/or α-Fe 2 O 3 . Only iron-rich garnets, either pure or Gd-substituted, calcined at 1200 deg. C or above display a single-phase cubic garnet. According to thermal dilatometry results, calcined powders were sintered in air up to 1470 deg. C. The microstructure of sintered ceramics is made up of fine grains, the average size ranging between 3 μm and 13 μm. Density of sintered bodies ranged from 88% to 98%. Ferromagnetic resonance linewidth (ΔH -3dB ) ranged between 4352.9 A m -1 and 4392.7 A m -1 , depending on composition and microstructure

  16. Dielectronic satellites to the Ne-like yttrium resonance lines

    International Nuclear Information System (INIS)

    Osterheld, A.L.; Nilsen, J.; Khakhalin, S.Ya.; Faenov, A.Ya.; Pikuz, S.A.

    1996-01-01

    We present a detailed analysis of the spectrum of satellite transitions to the n=2-3 and n=2-4 Ne-like yttrium resonance lines. Satellite lines from the double excited 2s 2 2p 5 3l3l', 2s 2 2p 5 3l4l', 2s2p 6 3l3l' and 2s2p 6 3l4l' levels of Na-like Y as well as from 2s 2 2p 5 3l3l'3l '' and 2s2p 6 3l3l'3l '' levels of Mg-like Y were observed in spectra from a laser-produced plasma. The X-ray spectra were recorded with high spectral resolution λ/Δλ∼3500-5000 in the wavelength region of the n=2-3 Ne-like resonance lines and with λ/Δλ>1000 in the region of the n=2-4 Ne-like resonance lines. A total of more than 50 spectral features were identified, and their wavelengths were measured. A simple intensity model was developed, which agreed well with the measured spectra and assisted the line identification. The consistency of the model for different spectral regions demonstrates the potential of the Na-like and Mg-like satellite lines for diagnosing plasma conditions. (orig.)

  17. Phase Diagram for Magnon Condensate in Yttrium Iron Garnet Film

    Science.gov (United States)

    Li, Fuxiang; Saslow, Wayne M.; Pokrovsky, Valery L.

    2013-01-01

    Recently, magnons, which are quasiparticles describing the collective motion of spins, were found to undergo Bose-Einstein condensation (BEC) at room temperature in films of Yttrium Iron Garnet (YIG). Unlike other quasiparticle BEC systems, this system has a spectrum with two degenerate minima, which makes it possible for the system to have two condensates in momentum space. Recent Brillouin Light Scattering studies for a microwave-pumped YIG film of thickness d = 5 μm and field H = 1 kOe find a low-contrast interference pattern at the characteristic wavevector Q of the magnon energy minimum. In this report, we show that this modulation pattern can be quantitatively explained as due to unequal but coherent Bose-Einstein condensation of magnons into the two energy minima. Our theory predicts a transition from a high-contrast symmetric state to a low-contrast non-symmetric state on varying the d and H, and a new type of collective oscillation. PMID:23455849

  18. Few-MeV neutrons incident on yttrium

    International Nuclear Information System (INIS)

    Budtz-Jorgensen, C.; Guenther, P.; Smith, A.; Whalen, J.

    1982-09-01

    Neutron total and scattering cross sections of elemental yttrium are measured in the few-MeV region with broad resolutions. The total-cross section measurements extend from approx. = 0.5 to 4.2 MeV in steps of less than or equal to 0.1 MeV. Neutron elastic- and inelastic-scattering cross sections are measured from approx. = 1.5 to 4.0 MeV, at incident-neutron energy intervals of less than or equal to 50 keV and at ten or more scattering angles distributed between 20 and 160 deg. Inelastically-scattered neutron groups are observed corresponding to the excitation of levels at 909 +- 23, 1504 +- 20, 1747 +- 16, 2224 +- 16, 2567 +- 26, 2889 +- 12 and 3104 +- 10 keV. The experimental results are discussed in terms of the spherical optical-statistical, coupled-channels and core-coupling models and compared with corresponding quantities given in the evaluated nuclear data file ENDF/B-V

  19. Deposition of yttrium oxysulfide thin films by atomic layer epitaxy

    International Nuclear Information System (INIS)

    Kukli, K.; University of Tartu, Tartu,; Johansson, L-S.; Nykaenen, E.; Peussa, M.; Ninistoe, L.

    1998-01-01

    Full text: Yttrium oxysulfide is a highly interesting material for optoelectronic applications. It is industrially exploited in the form of doped powder in catholuminescent phosphors, e.g. Y 2 O 2 S: Eu 3+ for colour TV. Attempts to grow thin films of Y 2 O 2 S have not been frequent and only partially successful due to the difficulties in obtaining crystalline films at a reasonable temperature. Furthermore, sputtering easily leads to a sulphur deficiency. Evaporation of the elements from a multi-source offers a better control of the stoichiometry resulting in hexagonal (0002) oriented films at 580 deg C. In this paper we present the first successful thin film growth experiments using a chemical process with molecular precursors. Atomic layer epitaxy (ALE) allows the use of a relatively low deposition temperature and thus compatibility with other technologies. Already at 425 deg C the reaction between H 2 S and Y(thd) 3 (thd = 2,2,6,6 - tetramethyl-heptane-3,5- dione) yields a crystalline Y 2 O 2 S thin film which was characterized by XRD, XRF and XPS

  20. Yttrium 90 microspheres for the treatment of hepatocellular carcinoma.

    Science.gov (United States)

    Memon, Khairuddin; Lewandowski, Robert J; Riaz, Ahsun; Salem, Riad

    2013-01-01

    Yttrium-90 microspheres are radioactive particles which are increasingly being employed for treating patients with unresectable hepatocellular carcinoma (HCC). The procedure is called radioembolization. It involves the injection of micron-sized embolic particles loaded with a radioisotope by use of transarterial techniques. Because of the sensitivity of liver parenchyma and relative insensitivity of tumor, external radiation has played a limited role in treating HCC. (90)Y administered via arterial route directs the highly concentrated radiation to the tumor while healthy liver parenchyma is relatively spared due to its preferential blood supply from portal venous blood. This technique has proven useful for the majority of patients with HCC as most of them present in advanced stage, beyond potentially curative options (resection/liver transplantation). (90)Y microspheres can be used in downstaging large tumors to bring within transplantable criteria, in patients with portal venous thrombosis due to tumor invasion and as palliative therapy. There are two available devices for (90)Y administration; TheraSphere® (glass based) and SIR-Spheres® (resin based). The procedure is performed on an outpatient basis. The incidence of complications is comparatively less and may include nausea, fatigue, abdominal pain, hepatic dysfunction, biliary injury, fibrosis, radiation pneumonitis, GI ulcers, and vascular injury; however, these can be avoided by meticulous pretreatment assessment, careful patient selection, and adequate dosimetry. This article explores the technical and clinical aspects of (90)Y radioembolization with keeping emphasis on patient selection, uses, and complications.

  1. Structural and dielectric properties of yttrium-substituted hydroxyapatites

    International Nuclear Information System (INIS)

    Kaygili, Omer; Dorozhkin, Sergey V.; Ates, Tankut; Canan Gursoy, N.; Keser, Serhat; Yakuphanoglu, Fahrettin; Birkan Selçuk, A.

    2015-01-01

    Hydroxyapatite (HAp) samples doped with 0, 2 and 4 at.% of yttrium (Y) were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy attached with energy dispersive X-ray (EDX) spectroscopy, antimicrobial activity tests and dielectric studies. The hydroxyl groups observed in FTIR spectra confirmed the formation of HAp phase in the studied samples. The crystallite size, crystallinity degree and lattice parameters of the samples were changed with Y content. The volume of the unit cell was gradually decreased with the addition of Y. Undoped and Y-containing HAp samples were screened to determine their in vitro antimicrobial activities against the standard strains. It was found that no samples have any antimicrobial effect. The relative dielectric permittivity and dielectric loss are affected by Y content. While the alternating current conductivity increases with increasing frequency, it decreases with increasing Y content. - Highlights: • The lattice parameters and crystal size are affected by Y content. • The volume of the unit cell was gradually decreased with the addition of Y. • No samples have any antimicrobial effect. • The alternating current conductivity decreases with increasing Y content

  2. Hydrothermal synthesis and formation mechanism of hexagonal yttrium hydroxide fluoride nanobundles

    International Nuclear Information System (INIS)

    Tian, Li; Sun, QiLiang; Zhao, RuiNi; He, HuiLin; Xue, JianRong; Lin, Jun

    2013-01-01

    Graphical abstract: The formation of yttrium hydroxide fluorides nanobundles can be expressed as a precipitation transformation from cubic NaYF 4 to hexagonal NaYF 4 and to hexagonal Y(OH) 2.02 F 0.98 owing to ion exchange. - Highlights: • Novel Y(OH) 2.02 F 0.98 nanobundles have been successfully prepared by hydrothermal method. • The branched nanobundles composed of numerous oriented-attached nanoparticles has been studied. • The growth mechanism is proposed to be ion exchange and precipitation transformation. - Abstract: This article presents the fabrication of hexagonal yttrium hydroxide fluoride nanobundles via one-pot hydrothermal process, using yttrium nitrate, sodium hydroxide and ammonia fluoride as raw materials to react in propanetriol solvent. The X-ray diffraction pattern clearly reveals that the grown product is pure yttrium hydroxide fluoride, namely Y(OH) 2.02 F 0.98 . The morphology and microstructure of the synthesized product is testified to be nanobundles composed of numerous oriented-attached nanoparticles as observed from the field emission scanning electron microscopy (FESEM). The chemical composition was analyzed by the energy dispersive spectrum (EDS), confirming the phase transformation of the products which was clearly consistent with the result of XRD analysis. It is proposed that the growth of yttrium hydroxide fluoride nanobundles be attributed to ion exchange and precipitation transformation

  3. Development of 2024 AA-Yttrium composites by Spark Plasma Sintering

    Science.gov (United States)

    Vidyasagar, CH S.; Karunakar, D. B.

    2018-04-01

    The method of fabrication of MMNCs is quite a challenge, which includes advanced processing techniques like Spark Plasma Sintering (SPS), etc. The objective of the present work is to fabricate aluminium based MMNCs with the addition of small amounts of yttrium using Spark Plasma Sintering and to evaluate their mechanical and microstructure properties. Samples of 2024 AA with yttrium ranging from 0.1% to 0.5 wt% are fabricated by Spark Plasma Sintering (SPS). Hardness of the samples is determined using Vickers hardness testing machine. The metallurgical characterization of the samples is evaluated by Optical Microscopy (OM), Field Emission Scanning Electron Microscopy (FE-SEM). Unreinforced 2024 AA sample is also fabricated as a benchmark to compare its properties with those of the composite developed. It is found that the yttrium addition increases the above mentioned properties by altering the precipitation kinetics and intermetallic formation to some extent and then decreases gradually when yttrium wt% increases beyond 0.3 wt%. High density (˂ 99.75) is achieved in the samples and highest hardness achieved is 114 Hv, fabricated by spark plasma sintering and uniform distribution of yttrium is observed.

  4. Separation of Yttrium from Rare Earth Concentrates in Fractional Hydroxide Precipitation

    International Nuclear Information System (INIS)

    Tri Handini; Purwoto; Mulyono

    2007-01-01

    Yttrium has been separated from rare earth concentrates by precipitation in fractional hydroxide using urea. The purpose of this research is to increase the yttrium rate resulting from the sedimentary process through separation of yttrium from other rare earth in fractional hydroxide precipitation using urea. In this research, we study the process variable of the concentration of urea, the ratio of feed volume to condensation volume of urea, as well as the temperature. Determination analysis of the rare earth rate is conducted using an X-ray spectrometer. The best result Y=92.89 % is obtained at a concentration of urea of 50 %, a level of precipitation of 3 times, and a temperature of 80°C. (author)

  5. Fabrication of dense yttrium oxyfluoride ceramics by hot pressing and their mechanical, thermal, and electrical properties

    Science.gov (United States)

    Tahara, Ryuki; Tsunoura, Toru; Yoshida, Katsumi; Yano, Toyohiko; Kishi, Yukio

    2018-06-01

    Excellent corrosion-resistant materials have been strongly required to reduce particle contamination during the plasma process in semiconductor production. Yttrium oxyfluoride can be a candidate as highly corrosion-resistant material. In this study, three types of dense yttrium oxyfluoride ceramics with different oxygen contents, namely, YOF, Y5O4F7 and Y5O4F7 + YF3, were fabricated by hot pressing, and their mechanical, thermal, and electrical properties were evaluated. Y5O4F7 ceramics showed an excellent thermal stability up to 800 °C, a low loss factor, and volume resistivity comparable to conventional plasma-resistant oxides, such as Y2O3. From these results, yttrium oxyfluoride ceramics are strongly suggested to be used as electrostatic chucks in semiconductor production.

  6. Tribological effects of yttrium and nitrogen ion implantation on a precipitation hardening stainless steel

    International Nuclear Information System (INIS)

    Alonso, F.; Arizaga, A.; Garcia, A.; Onate, J.I.

    1994-01-01

    Yttrium, nitrogen and combined yttrium and nitrogen implantations have been carried out on an ASTM A286 precipitation hardening iron base alloy to evaluate the benefits in their tribological behaviour. Microindentation tests have shown a significant 20%-60% increment in hardness on the nitrogen implanted material, with a limited improvement in elastic recovery of the indentation. An abrasive test on the same material has also produced a 50% reduction in scratch depth. Y + and Y + +N + implantations also hardened the material but to a lesser extent. Reciprocating ball on disk friction and wear testing at 400 C resulted in very severe damage in all cases. X-ray photoelectron spectroscopy analyses combined with Ar sputtering have disclosed that nitrogen is mainly in a nitrided form, yttrium remains oxidized at the surface, below which there is an apparent increase in the metallic bond. ((orig.))

  7. Physicochemical analysis of cryocrystallization processes of aqueous solutions of yttrium, barium, copper nitrates and their mixtures

    International Nuclear Information System (INIS)

    Kulakov, A.B.; Mozhaev, A.P.; Tesker, A.M.; Churagulov, B.R.

    1992-01-01

    Products of fast hardening of aqueous solutions of different concentration of yttrium, barium copper nitrates and their mixtures including mixture of three nitrates with molar ratio equal to 1:2:3 used for synthesis of YBa 2 Cu 3 O 7-x HTSC by cryochemical technique, in liquid nitrogen, are studied using low-temperature, differential thermal and X-ray phase analyses. Aqueous solutions of barium, copper, yttrium nitrates are shown to belong to three different classes which differ in behaviour at fast cooling and subsequent slow heating. Cryogranulate at YBa 2 Cu 2 O 7-x synthesis using cryochemical technique represents mixture of X-ray amorphous Ba(NO 3 ) 2 , crystalline Cu(NO 3 ) 2 ·6H 2 O and ice, as well as, supercooled aqueous solution of yttrium and copper nitrates

  8. Fluorimetric determination of yttrium by methyl-bis(8-hydraxy--- 2-quinolyl)amine

    International Nuclear Information System (INIS)

    Golovina, A.P.; Kachin, S.V.; Runov, V.K.; Fakeeva, O.A.

    1982-01-01

    Using a method of mathematical Box-Wilson experiment planning the optimum conditions of yttrium fluorimetric determination by methyl-bis (8-hydroxy-2-quinolyl) amine (pH 7.5, csub(R)=1.4x10sup(-5) M) with the determination limit=0.05 μg/ml are found. An extraction-fluorimetric method of yttrium determination by methyl-bis (8-hydroxy-2-quinolyl) amine is developed. The extraction has been realized with aliphatic alcohols at pH > 11. The method is characteristic of the lowest determination limit (0.01 μg/ml) as compared with the known ones. The possibility is shown of yttrium determination in the presence of 5000-multiple aluminium contents, stoichiometric contents of La, Lu, Fe (3), U (6), tartrates, citrates

  9. Positive effect of yttrium on the reduction of pores in cast Al alloy

    International Nuclear Information System (INIS)

    Hua, Guomin; Ahmadi, Hojat; Nouri, Meisam; Li, Dongyang

    2015-01-01

    Mechanical and electrochemical properties of Al alloys can be improved by adding a small amount of rare-earth such as yttrium. Here we demonstrate that adding yttrium also helps suppress the porosity in cast Al alloys, thus minimizing its detrimental effect on mechanical properties of the alloys. The mechanism behind is elucidated based on the hydrogen binding energies and the diffusion activation energies of hydrogen atoms in Al and Al–Y phases, calculated using the first-principle method. - Highlights: • The porosity of commercial Al alloy can be reduced by additive yttrium. • Formed Al 3 Y phase helps reduce homogeneous nucleation of hydrogen bubbles. • Formed Al 3 Y and Al 2 Y phases could suppress the growth of hydrogen bubbles

  10. Root Cause Analysis of Gastroduodenal Ulceration After Yttrium-90 Radioembolization

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Marnix G. E. H. [Stanford University School of Medicine, Division of Interventional Radiology (United States); Banerjee, Subhas [Stanford University School of Medicine, Division of Gastroenterology and Hepatology (United States); Louie, John D.; Abdelmaksoud, Mohamed H. K. [Stanford University School of Medicine, Division of Interventional Radiology (United States); Iagaru, Andrei H. [Stanford University School of Medicine, Division of Nuclear Medicine and Molecular Imaging (United States); Ennen, Rebecca E.; Sze, Daniel Y., E-mail: dansze@stanford.edu [Stanford University School of Medicine, Division of Interventional Radiology (United States)

    2013-12-15

    IntroductionA root cause analysis was performed on the occurrence of gastroduodenal ulceration after hepatic radioembolization (RE). We aimed to identify the risk factors in the treated population and to determine the specific mechanism of nontarget RE in individual cases. Methods: The records of 247 consecutive patients treated with yttrium-90 RE for primary (n = 90) or metastatic (n = 157) liver cancer using either resin (n = 181) or glass (n = 66) microspheres were reviewed. All patients who developed a biopsy-proven microsphere-induced gastroduodenal ulcer were identified. Univariate and multivariate analyses were performed on baseline parameters and procedural data to determine possible risk factors in the total population. Individual cases were analyzed to ascertain the specific cause, including identification of the culprit vessel(s) leading to extrahepatic deposition of the microspheres. Results: Eight patients (3.2 %) developed a gastroduodenal ulcer. Stasis during injection was the strongest independent risk factor (p = 0.004), followed by distal origin of the gastroduodenal artery (p = 0.004), young age (p = 0.040), and proximal injection of the microspheres (p = 0.043). Prolonged administrations, pain during administration, whole liver treatment, and use of resin microspheres also showed interrelated trends in multivariate analysis. Retrospective review of intraprocedural and postprocedural imaging showed a probable or possible culprit vessel, each a tiny complex collateral vessel, in seven patients. Conclusion: Proximal administrations and those resulting in stasis of flow presented increased risk for gastroduodenal ulceration. Patients who had undergone bevacizumab therapy were at high risk for developing stasis.

  11. Effects of yttrium 90 on experimental allergic arthritis in rabbits

    International Nuclear Information System (INIS)

    Meier-Ruge, W.; Mueller, W.; Pavelka, K.

    1976-01-01

    Fifteen weeks after allergic arthritis developed in the knee joint of 17 immunized rabbits, 8 animals were given an injection of 200 μCi yttrium 90( 90 Y) into the left joint cavity and 7 were injected with 400 μCi. The animals were sacrificed at 2, 4, 8, 12, and 16 weeks, and at 6 to 12 months after the injection. Two uninjected animals used as morphological controls were sacrificed 13 weeks after immunization, and showed allergic arthritis had progressed to severe inflammation of the knee joint marked by massive round-cell infiltration, oedema, and proliferation of synovial mesothelium in the synovial villi and joint capsule. Treatment with 90 Y was effective 2 weeks after injection and the disappearance of inflammatory odema and marked regression of round-cell infiltration. This was accompanied by degeneration of the synovial mesothelium and fibrosis of the subsynovial tissue and synovial vessels as a secondary effect of the radiation. In the animals with severe allergic arthritis, the healing effects of 90 Y were more marked than the secondary effects of the radiation which were dose-dependent. Treatment with 90 Y of arthritic knee joints with the lowest effective dose of the isotope - if necessay with repeated application - seems justified. A single large dose does not have a greater therapeutic effect and causes more radiation damage to the joint. In view of the possible secondary effects in the joint, the indication for 90 Y therapy should be restricted, particularly in young patients, to cases of chronic relapsing arthritis unresponsive to other treatment. (U.K.)

  12. Planar gamma camera imaging and quantitation of Yttrium-90 bremsstrahlung

    International Nuclear Information System (INIS)

    Shen, S.; DeNardo, G.L.; Yuan, A.

    1994-01-01

    Yttrium-90 is a promising radionuclide for radioimmunotherapy of cancer because of its energetic beta emissions. Therapeutic management requires quantitative imaging to assess the pharmacokinetics and radiation dosimetry of the 90 Y-labeled antibody. Conventional gamma photon imaging methods cannot be easily applied to imaging of 90 Y-bremsstrahlung because of its continuous energy spectrum. The sensitivity, resolution and source-to-background signal ratio (S/B) of the detector system for 90 Y-bremsstrahlung were investigated for various collimators and energy windows in order to determine optimum conditions for quantitative imaging. After these conditions were determined, the accuracy of quantitation of 90 Y activity in an Alderson abdominal phantom was examined. When the energy-window width was increased, the benefit of increased sensitivity outweighed degradation in resolution and S/B ratio until the manufacturer's energy specifications for the collimator were exceeded. Using the same energy window, the authors improved resolution and S/B for the medium-energy (ME) collimator when compared to the low-energy, all-purpose (LEAP) collimator, and there was little additional improvement using the high-energy (HE) collimator. Camera sensitivity under tissue equivalent conditions was 4.2 times greater for the LEAP and 1.7 times greater for the ME collimators when compared to the HE collimator. Thus, the best, most practical selections were found to be the ME collimator and an energy window of 55-285 keV. When they used these optimal conditions for image acquisition, the estimation of 90 Y activity in organs and tumors was within 15% of the true activities. The results for this study suggest that reasonable accuracy can be achieved in clinical radioimmunotherapy using 90 Y-bremsstrahlung quantitation. 28 refs., 5 figs., 7 tabs

  13. Hanford isotope project strategic business analysis yttrium-90 (Y-90)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    The purpose of this analysis is to address the short-term direction for the Hanford yttrium-90 (Y-90) project. Hanford is the sole DOE producer of Y-90, and is the largest repository for its source in this country. The production of Y-90 is part of the DOE Isotope Production and Distribution (IP and D) mission. The Y-90 is ``milked`` from strontium-90 (Sr-90), a byproduct of the previous Hanford missions. The use of Sr-90 to produce Y-90 could help reduce the amount of waste material processed and the related costs incurred by the clean-up mission, while providing medical and economic benefits. The cost of producing Y-90 is being subsidized by DOE-IP and D due to its use for research, and resultant low production level. It is possible that the sales of Y-90 could produce full cost recovery within two to three years, at two curies per week. Preliminary projections place the demand at between 20,000 and 50,000 curies per year within the next ten years, assuming FDA approval of one or more of the current therapies now in clinical trials. This level of production would incentivize private firms to commercialize the operation, and allow the government to recover some of its sunk costs. There are a number of potential barriers to the success of the Y-90 project, outside the control of the Hanford Site. The key issues include: efficacy, Food and Drug Administration (FDA) approval and medical community acceptance. There are at least three other sources for Y-90 available to the US users, but they appear to have limited resources to produce the isotope. Several companies have communicated interest in entering into agreements with Hanford for the processing and distribution of Y-90, including some of the major pharmaceutical firms in this country.

  14. Hanford isotope project strategic business analysis yttrium-90 (Y-90)

    International Nuclear Information System (INIS)

    1995-10-01

    The purpose of this analysis is to address the short-term direction for the Hanford yttrium-90 (Y-90) project. Hanford is the sole DOE producer of Y-90, and is the largest repository for its source in this country. The production of Y-90 is part of the DOE Isotope Production and Distribution (IP and D) mission. The Y-90 is ''milked'' from strontium-90 (Sr-90), a byproduct of the previous Hanford missions. The use of Sr-90 to produce Y-90 could help reduce the amount of waste material processed and the related costs incurred by the clean-up mission, while providing medical and economic benefits. The cost of producing Y-90 is being subsidized by DOE-IP and D due to its use for research, and resultant low production level. It is possible that the sales of Y-90 could produce full cost recovery within two to three years, at two curies per week. Preliminary projections place the demand at between 20,000 and 50,000 curies per year within the next ten years, assuming FDA approval of one or more of the current therapies now in clinical trials. This level of production would incentivize private firms to commercialize the operation, and allow the government to recover some of its sunk costs. There are a number of potential barriers to the success of the Y-90 project, outside the control of the Hanford Site. The key issues include: efficacy, Food and Drug Administration (FDA) approval and medical community acceptance. There are at least three other sources for Y-90 available to the US users, but they appear to have limited resources to produce the isotope. Several companies have communicated interest in entering into agreements with Hanford for the processing and distribution of Y-90, including some of the major pharmaceutical firms in this country

  15. Rare earth activated yttrium aluminate phosphors with modulated luminescence.

    Science.gov (United States)

    Muresan, L E; Popovici, E J; Perhaita, I; Indrea, E; Oro, J; Casan Pastor, N

    2016-06-01

    Yttrium aluminate (Y3 A5 O12 ) was doped with different rare earth ions (i.e. Gd(3+) , Ce(3+) , Eu(3+) and/or Tb(3+) ) in order to obtain phosphors (YAG:RE) with general formula,Y3-x-a Gdx REa Al5 O12 (x = 0; 1.485; 2.97 and a = 0.03). The synthesis of the phosphor samples was done using the simultaneous addition of reagents technique. This study reveals new aspects regarding the influence of different activator ions on the morpho-structural and luminescent characteristics of garnet type phosphor. All YAG:RE phosphors are well crystallized powders containing a cubic-Y3 Al5 O12 phase as major component along with monoclinic-Y4 Al2 O9 and orthorhombic-YAlO3 phases as the impurity. The crystallites dimensions of YAG:RE phosphors vary between 38 nm and 88 nm, while the unit cell slowly increase as the ionic radius of the activator increases. Under UV excitation, YAG:Ce exhibits yellow emission due to electron transition in Ce(3+) from the 5d level to the ground state levels ((2) F5/2 , (2) F7/2 ). The emission intensity of Ce(3+) is enhanced in the presence of the Tb(3+) ions and is decreased in the presence of Eu(3+) ions due to some radiative or non-radiative processes that take place between activator ions. By varying the rare earth ions, the emission colour can be modulated from green to white and red. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Yttrium bismuth titanate pyrochlore mixed oxides for photocatalytic hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Merka, Oliver

    2012-10-18

    In this work, the sol-gel synthesis of new non-stoichiometric pyrochlore titanates and their application in photocatalytic hydrogen production is reported. Visible light response is achieved by introducing bismuth on the A site or by doping the B site by transition metal cations featuring partially filled d orbitals. This work clearly focusses on atomic scale structural changes induced by the systematical introduction of non-stoichiometry in pyrochlore mixed oxides and the resulting influence on the activity in photocatalytic hydrogen production. The materials were characterized in detail regarding their optical properties and their atomic structure. The pyrochlore structure tolerates tremendous stoichiometry variations. The non-stoichiometry in A{sub 2}O{sub 3} rich compositions is compensated by distortions in the cationic sub-lattice for the smaller Y{sup 3+} cation and by evolution of a secondary phase for the larger Bi{sup 3+} cation on the A site. For TiO{sub 2} rich compositions, the non-stoichiometry leads to a special vacancy formation in the A and optionally O' sites. It is shown that pyrochlore mixed oxides in the yttrium bismuth titanate system represent very active and promising materials for photocatalytic hydrogen production, if precisely and carefully tuned. Whereas Y{sub 2}Ti{sub 2}O{sub 7} yields stable hydrogen production rates over time, the bismuth richer compounds of YBiTi{sub 2}O{sub 7} and Bi{sub 2}Ti{sub 2}O{sub 7} are found to be not stable under irradiation. This drawback is overcome by applying a special co-catalyst system consisting of a precious metal core and a Cr{sub 2}O{sub 3} shell on the photocatalysts.

  17. Treatment of persistent knee synovitis with Yttrium 90

    International Nuclear Information System (INIS)

    Bouyoucef, S.E.

    2007-01-01

    Full text: Management of persistent knee synovitis includes both systemic and local articular treatment relevant to specific etiology. Local treatment may involve attempts to control inflammation and pain in knee joints by intra articular application of analgesics or glucocorticoids. However, in many patients these fail to reduce significantly the synovitis phenomenon and moreover they may lead to severe side effects. Radiosynoviorthesis with Y90 has been in use for many years in several joint pathologies. Indications of Radiosynoviorthesis include various inflammatory and degenerative diseases and its use should be envisaged when other conservative methods have failed like intra articular injections of long acting corticosteroids. Persistent knee synovitis is defined by the presence of hydrops in the joint or functional impairment with warmth, pain and local signs and symptoms requiring intra articular injection of glucocorticoids. In this study, 151 knees with persistent knee synovitis have been treated with Y 90 and have had all a minimum of one year follow up. Many parameters have been identified to measure efficiency of the RSO including pain, hydarthrosis, mobility, as well as global perception of the patients. Excellent and good responses have been appreciated through pain at rest, pain at stress, volume of effusion, and articular mobility. Results showed that percentage of excellent and good response is superior to 80% at three and six months. Success of Y 90 appears to be higher for rheumatoid arthritis as well as for oligoarthritis. Whatever the etiology, intensity of the inflammatory process appears one the major parameters which could better predict the outcomes of yttrium 90 in persistent knee synovitis. (author)

  18. Root Cause Analysis of Gastroduodenal Ulceration After Yttrium-90 Radioembolization

    International Nuclear Information System (INIS)

    Lam, Marnix G. E. H.; Banerjee, Subhas; Louie, John D.; Abdelmaksoud, Mohamed H. K.; Iagaru, Andrei H.; Ennen, Rebecca E.; Sze, Daniel Y.

    2013-01-01

    IntroductionA root cause analysis was performed on the occurrence of gastroduodenal ulceration after hepatic radioembolization (RE). We aimed to identify the risk factors in the treated population and to determine the specific mechanism of nontarget RE in individual cases. Methods: The records of 247 consecutive patients treated with yttrium-90 RE for primary (n = 90) or metastatic (n = 157) liver cancer using either resin (n = 181) or glass (n = 66) microspheres were reviewed. All patients who developed a biopsy-proven microsphere-induced gastroduodenal ulcer were identified. Univariate and multivariate analyses were performed on baseline parameters and procedural data to determine possible risk factors in the total population. Individual cases were analyzed to ascertain the specific cause, including identification of the culprit vessel(s) leading to extrahepatic deposition of the microspheres. Results: Eight patients (3.2 %) developed a gastroduodenal ulcer. Stasis during injection was the strongest independent risk factor (p = 0.004), followed by distal origin of the gastroduodenal artery (p = 0.004), young age (p = 0.040), and proximal injection of the microspheres (p = 0.043). Prolonged administrations, pain during administration, whole liver treatment, and use of resin microspheres also showed interrelated trends in multivariate analysis. Retrospective review of intraprocedural and postprocedural imaging showed a probable or possible culprit vessel, each a tiny complex collateral vessel, in seven patients. Conclusion: Proximal administrations and those resulting in stasis of flow presented increased risk for gastroduodenal ulceration. Patients who had undergone bevacizumab therapy were at high risk for developing stasis

  19. Effects of yttrium 90 on experimental allergic arthritis in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Meier-Ruge, W [Sandoz A.G., Basel (Switzerland); Mueller, W; Pavelka, K

    1976-02-01

    Fifteen weeks after allergic arthritis developed in the knee joint of 17 immunized rabbits, 8 animals were given an injection of 200 ..mu..Ci yttrium 90(/sup 90/Y) into the left joint cavity and 7 were injected with 400 ..mu..Ci. The animals were sacrificed at 2, 4, 8, 12, and 16 weeks, and at 6 to 12 months after the injection. Two uninjected animals used as morphological controls were sacrificed 13 weeks after immunization, and showed allergic arthritis had progressed to severe inflammation of the knee joint marked by massive round-cell infiltration, oedema, and proliferation of synovial mesothelium in the synovial villi and joint capsule. Treatment with /sup 90/Y was effective 2 weeks after injection and the disappearance of inflammatory odema and marked regression of round-cell infiltration. This was accompanied by degeneration of the synovial mesothelium and fibrosis of the subsynovial tissue and synovial vessels as a secondary effect of the radiation. In the animals with severe allergic arthritis, the healing effects of /sup 90/Y were more marked than the secondary effects of the radiation which were dose-dependent. Treatment with /sup 90/Y of arthritic knee joints with the lowest effective dose of the isotope - if necessay with repeated application - seems justified. A single large dose does not have a greater therapeutic effect and causes more radiation damage to the joint. In view of the possible secondary effects in the joint, the indication for /sup 90/Y therapy should be restricted, particularly in young patients, to cases of chronic relapsing arthritis unresponsive to other treatment.

  20. Dielectronic satellites to the Ne-like yttrium resonance lines

    Energy Technology Data Exchange (ETDEWEB)

    Osterheld, A.L. [Lawrence Livermore National Lab., CA (United States); Nilsen, J. [Lawrence Livermore National Lab., CA (United States); Khakhalin, S.Ya. [MISDC, VNIIFTRI, Mendeleevo (Russian Federation); Faenov, A.Ya. [MISDC, VNIIFTRI, Mendeleevo (Russian Federation); Pikuz, S.A. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Fizicheskij Inst.

    1996-09-01

    We present a detailed analysis of the spectrum of satellite transitions to the n=2-3 and n=2-4 Ne-like yttrium resonance lines. Satellite lines from the double excited 2s{sup 2}2p{sup 5}3l3l`, 2s{sup 2}2p{sup 5}3l4l`, 2s2p{sup 6}3l3l` and 2s2p{sup 6}3l4l` levels of Na-like Y as well as from 2s{sup 2}2p{sup 5}3l3l`3l{sup ``} and 2s2p{sup 6}3l3l`3l{sup ``} levels of Mg-like Y were observed in spectra from a laser-produced plasma. The X-ray spectra were recorded with high spectral resolution {lambda}/{Delta}{lambda}{approx}3500-5000 in the wavelength region of the n=2-3 Ne-like resonance lines and with {lambda}/{Delta}{lambda}>1000 in the region of the n=2-4 Ne-like resonance lines. A total of more than 50 spectral features were identified, and their wavelengths were measured. A simple intensity model was developed, which agreed well with the measured spectra and assisted the line identification. The consistency of the model for different spectral regions demonstrates the potential of the Na-like and Mg-like satellite lines for diagnosing plasma conditions. (orig.).

  1. Spectrophotometric determination of yttrium with 2-(2-thiazolylazo)-5-dimethylaminophenol

    International Nuclear Information System (INIS)

    Tsurumi, Chikao; Furuya, Keiichi.

    1975-01-01

    Spectrophotometric determination of small amounts of yttrium with 2-(2-thiazolylazo)-5-dimethylaminophenol (TAM) in the presence of zephiramine was investigated. The recommended procedures were as follows; 2.0 ml of water, 7.0 ml of TAM-methanolic solution (2x10 -4 mol/l) and 2.0 ml of zephiramine-aqueous solution (1x10 -2 mol/l) were added to a solution containing less than 35 μg of yttrium and its pH was adjusted to 8.0 with 0.1 mol/l ammonium chloride-0.1 mol/l ammonium hydroxide solution. The solution was transferred to a 25 ml volumetric flask and diluted to the mark with water. After 20 minutes, the absorbance at 575 nm against a reagent blank was measured. The color of yttrium-TAM complex is reddish-violet in the presence of zephiramine and is stable for 90 minutes after color development. The yttrium-TAM complex shows an absorption maximum at 575 nm. The absorbance at 575 nm is constant in a pH range from 7.5 to 8.3. The molar extinction coefficient at this wavelength is 7.2x10 4 l.mol -1 .cm -1 . The band obeys Beer's law up to the concentration of 1.4 μg/ml of yttrium. The molar ratio of yttrium to TAM in the complex is 1 : 2. A number of ions interfere with the determination can be masked by the addition of various masking agents and removed in terms of trioctylamine-xylene extraction. Manganese, tantalum, tin(II), citrate and tartrate ions interfere with the determination. (auth.)

  2. Optical bistability in erbium-doped yttrium aluminum garnet crystal combined with a laser diode.

    Science.gov (United States)

    Maeda, Y

    1994-01-10

    Optical bistability was observed in a simple structure of an injection laser diode combined with an erbium-doped yttrium aluminum garnet crystal. Since a hysteresis characteristic exists in the relationship between the wavelength and the injection current of a laser diode, an optical memory function capable of holding the output status is confirmed. In addition, an optical signal inversion was caused by the decrease of transmission of the erbium-doped yttrium aluminum garnet crystal against the red shift (principally mode hopping) of the laser diode. It is suggested that the switching time of this phenomenon is the time necessary for a mode hopping by current injection.

  3. Ultrasonic measurements and other allied parameters of yttrium soaps in mixed organic solvents

    International Nuclear Information System (INIS)

    Mehrotra, K.N.; Tandon, K.

    1990-01-01

    The ultrasonic measurements of yttrium soaps were made in a mixture of 70 % benzene and 30 % dimethylsulfoxide (ν/ν) to determine the critical micelle concentration, soap-solvent interaction and various acoustic and thermodynamic parameters. The values of the CMC decrease with increasing chainlength of fatty acid constituent of the soap molecule and are in agreement with the values obtained from other micellar properties. The various acoustic parameters (intermolecular freelength, adiabatic compressibility, apparent molar compressibility, specific acoustic impedance, apparent molar volume, molar sound velocity, solvation number, available volume and relative association) for yttrium soaps (myristate, palmitate, stearate and oleate) have been evaluated by ultrasonic velocity measurements. (Authors)

  4. Method of growing yttrium aluminate and/or lanthanide single crystals with perovskite structure

    International Nuclear Information System (INIS)

    Kvapil, Jiri; Perner, B.; Kvapil, Josef; Blazek, K.

    1989-01-01

    Single crystals of yttrium aluminate and/or lanthanide with perovskite structure are grown from melt in a vacuum at a pressure of gas residues of max. 0.01 Pa. The melt contains 1±0.05 gram-ions of aluminium per gram-ion of yttrium and/or lanthanides. The single crystals are then heated in a vacuum (0.01 Pa) at temperatures of 1,450 to 1,800 degC for 2 to 3 hours. (B.S.)

  5. Elaboration and characterisation of yttrium oxide and hafnium oxide powders by the sol-gel process

    International Nuclear Information System (INIS)

    Hours, T.

    1988-01-01

    The two classical sol-gel processes, colloidal and polymeric are studied for the preparation of yttrium oxide and hafnium oxide high performance powders. In the colloidal process, controlled and reproducible conditions for the preparation of yttrium oxide and hafnium oxide sols from salts or alkoxides are developed and the hydrothermal synthesis monodisperse hafnium oxide colloids is studied. The polymeric process is studied with hafnium ethyl-hexylate, hydrolysis kinetics for controlled preparation of sols and gels is investigated. Each step of preparation is detailed and powders obtained are characterized [fr

  6. Separation coefficients of liquid-vapor in systems formed by yttrium chloride with some impurities

    International Nuclear Information System (INIS)

    Volkov, V.T.; Nikiforova, T.V.; Nisel'son, L.A.; Telegin, G.F.

    1990-01-01

    Using equilibrium Rayleigh distillation in the 800-950 deg C temperature range, separation coefficients of liquid-vapor for systems, formed by yttrium chloride with Co, Cr, Ni, Mn, Fe, Cu, Na, K, Mg, Ca, Li impurities are determined. The impurity concentration lies within 0.02-0.4 mass. % limits of each impurity, and total impurity concentration does not exceed 1 mass. %. The tested impurities, except for calcium, are more volatile than the base, yttrium trichloride. In most systems negative deviation from the Raoult's law is observed

  7. Lack of rise in serum prolactin following yttrium-90 interstitial irradiation for acromegaly

    International Nuclear Information System (INIS)

    Clark, A.J.L.; Chahal, P.; Mashiter, K.; Joplin, G.F.

    1983-01-01

    The authors have investigated the possibility that the increase in serum PRL levels observed in patients with acromegaly treated with external irradiation could be due to damage to the hypothalamus or portal vessels, by comparing the effects of yttrium-90 interstitial irradiation, which is highly localised and does not normally extend to the hypothalamus, in a similar series of patients. These results are consistent with the hypothesis; a less likely explanation is that an overgrowth of radio-resistant PRL-secreting tumour cells is occurring after external irradiation, but not after yttrium-90 implantation. (author)

  8. Lack of rise in serum prolactin following yttrium-90 interstitial irradiation for acromegaly

    Energy Technology Data Exchange (ETDEWEB)

    Clark, A.J.L.; Chahal, P.; Mashiter, K.; Joplin, G.F. (Royal Postgraduate Medical School, London (UK))

    1983-11-01

    The authors have investigated the possibility that the increase in serum PRL levels observed in patients with acromegaly treated with external irradiation could be due to damage to the hypothalamus or portal vessels, by comparing the effects of yttrium-90 interstitial irradiation, which is highly localised and does not normally extend to the hypothalamus, in a similar series of patients. These results are consistent with the hypothesis; a less likely explanation is that an overgrowth of radio-resistant PRL-secreting tumour cells is occurring after external irradiation, but not after yttrium-90 implantation.

  9. Study on stability of labeled yttrium-90 with lipiodol by chemical extraction for liver cancer

    International Nuclear Information System (INIS)

    Mu, P.Y.; Jiang, X.L.; Chen, J.; Zhu, Y.J.

    2005-01-01

    Liver cancer, particularly hepatocellular carcinoma, is one of the most common malignant diseases in many developed and developing countries. It is also one of the most common diseases endangering the people's lives and health heavily. Surgery is very effective in early-stage patients. Unfortunately, there is less than 10% of the patients with hepatocellular carcinoma fitting for surgical therapy. Instead of surgical therapy, other methods are considered for patients in whom surgery may not work well. Systemic administration of chemotherapeutic agents is not often considered in liver cancer patients, due to discouraging result and adverse side effects. Also, hepatocellular carcinoma is not keen on usual radioactive therapy. However, method of inner interventional radioactive nuclide is a potential way to cure liver tumors. Hepatocellular carcinoma would be cured with inner interventional radioactive nuclide, which is a hot topic in experimental research on hepatocellular carcinoma at home and abroad. The purpose of the study is to label Yttrium-90 with lipiodol by means of the chemical extraction method and research the stability of labeled Yttrium-90 ( 90 Y-P204-Lipiodol) in serum of a newly-born cattle and human's blood. We chose to label steady yttrium with lipiodol, because radioactive yttrium has great nuclear character for liver cancer, yttrium-90 can eradiate pure β radial, and it's half time is 64 hours. Average energy of it is 0.93 Mev, the highest energy is 2.27 Mev. Yttrium-90 can be labeled with lipiodol by means of the chemical extraction method, which is mature in chemical techniques, combined with method of radioactive nuclide labeled in. nuclear medicine. At first, yttrium-90 is extracted in certain condition(pH, temperature, whisk time, whisk frequency, etc ) after adding yttrium-90 solution. We use some distilled water to balance the labeled organic phase twice, and test the stability of labeled yttrium-90 in serum of a newly-born cattle and

  10. Separation of yttrium from strontium in the aqueous phase of the water/nitrobenzene system

    Czech Academy of Sciences Publication Activity Database

    Vaňura, P.; Makrlík, E.; Vobecký, Miloslav

    2002-01-01

    Roč. 253, č. 1 (2002), s. 171-172 ISSN 0236-5731 Institutional research plan: CEZ:AV0Z4031919 Keywords : stroncium * yttrium * separation Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.502, year: 2002

  11. Separation of microamounts of yttrium from strontium in the two-phase water/nitrobenzene system

    Czech Academy of Sciences Publication Activity Database

    Makrlík, E.; Vaňura, P.; Vobecký, Miloslav

    2002-01-01

    Roč. 253, č. 1 (2002), s. 153-155 ISSN 0236-5731 Institutional research plan: CEZ:AV0Z4031919 Keywords : separation * stroncium * yttrium Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.502, year: 2002

  12. Separation of yttrium from strontium in the aqueous phase of the water/nitrobenzene extraction system

    Czech Academy of Sciences Publication Activity Database

    Vaňura, P.; Makrlík, E.; Vobecký, Miloslav

    2003-01-01

    Roč. 256, č. 1 (2003), s. 171-172 ISSN 0236-5731 R&D Projects: GA MŠk LN00B084 Institutional research plan: CEZ:AV0Z4031919; CEZ:MSM 230000009 Keywords : extraction * strontium * yttrium Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.472, year: 2003

  13. Reaction scheme of partial oxidation of methane to synthesis gas over yttrium-stabilized zirconia

    NARCIS (Netherlands)

    Zhu, J.J.; van Ommen, J.G.; Lefferts, Leonardus

    2004-01-01

    The partial oxidation of methane to synthesis gas over yttrium-stabilized zirconia (YSZ) was studied with in situ FTIR and both steady-state and transient experiments. The four major products, CO, H2, CO2, and H2O, are primary products of CPOM over YSZ. Besides these major products and traces of

  14. Adducts compounds of lanthanides (III) trifluoreacetates and yttrium and the N,N - dimenthylformamide

    International Nuclear Information System (INIS)

    Silva, M. das G. da.

    1983-01-01

    Some studies on lanthanides, f transition elements, and yttrium are presented. Adducts of lanthanides trifluoroacetates and N,N -dimethylformamide are described. The characterization of complexes from elementar analysis, conductance measurements, X-ray patterns, vibrational, electronics and fluorescence spectra are analysed. (M.J.C.) [pt

  15. Yttrium deposition on mesoporous TiO2: textural design and UV ...

    Indian Academy of Sciences (India)

    The mesoporous yttrium-doped TiO2 substrates prepared in this research work operate ... bond lengths in the nanoparticles (0.192 and 0.196 nm).18. Additionally ...... Fisicoquímica de Materiales Mesoporosos' (UAM-I CA-31. Fisicoquímica de ...

  16. Monte carlo simulations of Yttrium reaction rates in Quinta uranium target

    Directory of Open Access Journals (Sweden)

    Suchopár M.

    2017-01-01

    Full Text Available The international collaboration Energy and Transmutation of Radioactive Waste (E&T RAW performed intensive studies of several simple accelerator-driven system (ADS setups consisting of lead, uranium and graphite which were irradiated by relativistic proton and deuteron beams in the past years at the Joint Institute for Nuclear Research (JINR in Dubna, Russia. The most recent setup called Quinta, consisting of natural uranium target-blanket and lead shielding, was irradiated by deuteron beams in the energy range between 1 and 8 GeV in three accelerator runs at JINR Nuclotron in 2011 and 2012 with yttrium samples among others inserted inside the setup to measure the neutron flux in various places. Suitable activation detectors serve as one of possible tools for monitoring of proton and deuteron beams and for measurements of neutron field distribution in ADS studies. Yttrium is one of such suitable materials for monitoring of high energy neutrons. Various threshold reactions can be observed in yttrium samples. The yields of isotopes produced in the samples were determined using the activation method. Monte Carlo simulations of the reaction rates leading to production of different isotopes were performed in the MCNPX transport code and compared with the experimental results obtained from the yttrium samples.

  17. Structural differences of half-sandwich complexes of scandium and yttrium containing bulky substituents

    Czech Academy of Sciences Publication Activity Database

    Fridrichová, Adéla; Růžička, A.; Lamač, Martin; Horáček, Michal

    2017-01-01

    Roč. 76, FEB 2017 (2017), s. 62-66 ISSN 1387-7003 R&D Projects: GA ČR(CZ) GAP207/12/2368 Institutional support: RVO:61388955 Keywords : scandium * yttrium * half-sandwich Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.640, year: 2016

  18. Monte carlo simulations of Yttrium reaction rates in Quinta uranium target

    Science.gov (United States)

    Suchopár, M.; Wagner, V.; Svoboda, O.; Vrzalová, J.; Chudoba, P.; Tichý, P.; Kugler, A.; Adam, J.; Závorka, L.; Baldin, A.; Furman, W.; Kadykov, M.; Khushvaktov, J.; Solnyshkin, A.; Tsoupko-Sitnikov, V.; Tyutyunnikov, S.; Bielewicz, M.; Kilim, S.; Strugalska-Gola, E.; Szuta, M.

    2017-03-01

    The international collaboration Energy and Transmutation of Radioactive Waste (E&T RAW) performed intensive studies of several simple accelerator-driven system (ADS) setups consisting of lead, uranium and graphite which were irradiated by relativistic proton and deuteron beams in the past years at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The most recent setup called Quinta, consisting of natural uranium target-blanket and lead shielding, was irradiated by deuteron beams in the energy range between 1 and 8 GeV in three accelerator runs at JINR Nuclotron in 2011 and 2012 with yttrium samples among others inserted inside the setup to measure the neutron flux in various places. Suitable activation detectors serve as one of possible tools for monitoring of proton and deuteron beams and for measurements of neutron field distribution in ADS studies. Yttrium is one of such suitable materials for monitoring of high energy neutrons. Various threshold reactions can be observed in yttrium samples. The yields of isotopes produced in the samples were determined using the activation method. Monte Carlo simulations of the reaction rates leading to production of different isotopes were performed in the MCNPX transport code and compared with the experimental results obtained from the yttrium samples.

  19. Influence of neodymium-doping on structure and properties of yttrium aluminium garnet

    DEFF Research Database (Denmark)

    Zhang, X.D.; He, W.; Yue, Yuanzheng

    2013-01-01

    We study the impact of the Nd-doping on the grain formation, the crystal structure, and the fluorescence of the Yttrium Aluminum Garnet (YAG). The results show that Nd-doping leads to the YAG lattice expansion and distortion, and hence to an increase in defect concentration. This is attributed to...

  20. Thermal decomposition of double selenates of lanthanides (III), yttrium (III) and ammonium

    International Nuclear Information System (INIS)

    Crespi, M.S.

    1989-01-01

    Double selenates of lanthanides, yttrium and ammonium were prepared by treating mixtures of simple selenates with equimolar amounts and then dried in a vacuum desiccator containing anhydrous calcium chloride, protected from light. The compounds were studied using the conventional analytical methods such as infrared absorption spectra, X-ray diffraction, differential thermal analysis (DTA), and thermogravimetry (TG). (author)

  1. Optimization of the personnel radiation protection during the treatment by antibodies labelled by yttrium 90

    International Nuclear Information System (INIS)

    Legrand, J.; Prangere, T.; Cougnenc, O.; Leleu, C.; Huglo, D.; Morschhauser, F.

    2007-01-01

    Beyond the acquired experience limiting the exposure time, measures of adequate radiation protection allow to reduce the doses of surface received to extremities by the personnel participating to the preparation of treatments by antibodies labelled by yttrium 90. (N.C.)

  2. High-pressure structural study of yttrium monochalcogenides from experiment and theory

    DEFF Research Database (Denmark)

    Vaitheeswaran, G.; Kanchana, V.; Svane, A.

    2011-01-01

    High-pressure powder x-ray diffraction experiments using synchrotron radiation are performed on the yttrium monochalcogenides YS, YSe, and YTe up to a maximum pressure of 23 GPa. The ambient NaCl structure is stable throughout the pressure range covered. The bulk moduli are determined to be 93, 82...

  3. Yttrium recovery from primary and secondary sources: A review of main hydrometallurgical processes

    Energy Technology Data Exchange (ETDEWEB)

    Innocenzi, Valentina, E-mail: valentina.innocenzi1@univaq.it [Department of Industrial Engineering, of Information and Economy, University of L’Aquila, Via Giovanni Gronchi 18, Zona industriale di Pile, 67100 L’Aquila (Italy); De Michelis, Ida [Department of Industrial Engineering, of Information and Economy, University of L’Aquila, Via Giovanni Gronchi 18, Zona industriale di Pile, 67100 L’Aquila (Italy); Kopacek, Bernd [SAT, Austrian Society for Systems Engineering and Automation, Gurkasse 43/2, A-1140 Vienna (Austria); Vegliò, Francesco [Department of Industrial Engineering, of Information and Economy, University of L’Aquila, Via Giovanni Gronchi 18, Zona industriale di Pile, 67100 L’Aquila (Italy)

    2014-07-15

    Highlights: • Review of the main hydrometallurgical processes to recover yttrium. • Recovery of yttrium from primary sources. • Recovery of yttrium from e-waste and other types of waste. - Abstract: Yttrium is important rare earths (REs) used in numerous fields, mainly in the phosphor powders for low-energy lighting. The uses of these elements, especially for high-tech products are increased in recent years and combined with the scarcity of the resources and the environmental impact of the technologies to extract them from ores make the recycling waste, that contain Y and other RE, a priority. The present review summarized the main hydrometallurgical technologies to extract Y from ores, contaminated solutions, WEEE and generic wastes. Before to discuss the works about the treatment of wastes, the processes to retrieval Y from ores are discussed, since the processes are similar and derived from those already developed for the extraction from primary sources. Particular attention was given to the recovery of Y from WEEE because the recycle of them is important not only for economical point of view, considering its value, but also for environmental impact that this could be generated if not properly disposal.

  4. Separation and purification of gadolinium and others rare earths, and yttrium

    International Nuclear Information System (INIS)

    Awwal, M.A.; Filgueiras, S.A.C.

    1988-01-01

    The experimental works in laboratories for developing a solvent extraction process with the purpose of gadolinium separation and purification, and secondarily samarium, europium, lanthanum and yttrium are described. Using as solvent di-2-ethylhexylphosphoric acid (DEHPA) a preliminary flow chart for separation for these elements are developed. (author)

  5. Element selective X-ray magnetic circular and linear dichroisms in ferrimagnetic yttrium iron garnet films

    Energy Technology Data Exchange (ETDEWEB)

    Rogalev, A. [European Synchrotron Radiation Facility (ESRF), B.P. 220, F-38043 Grenoble Cedex (France); Goulon, J. [European Synchrotron Radiation Facility (ESRF), B.P. 220, F-38043 Grenoble Cedex (France)], E-mail: goulon@esrf.fr; Wilhelm, F. [European Synchrotron Radiation Facility (ESRF), B.P. 220, F-38043 Grenoble Cedex (France); Brouder, Ch. [Institut de Mineralogie et de Physique des Milieux Condenses, UMR-CNRS 7590, Universite Paris VI-VII, 4 place Jussieu, F-75252 Paris Cedex 05 (France); Yaresko, A. [Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart (Germany); Ben Youssef, J.; Indenbom, M.V. [Laboratoire de Magnetisme de Bretagne, CNRS FRE 2697, UFR Sciences et Techniques, F-29328 Brest Cedex (France)

    2009-12-15

    X-ray magnetic circular dichroism (XMCD) was used to probe the existence of induced magnetic moments in yttrium iron garnet (YIG) films in which yttrium is partly substituted with lanthanum, lutetium or bismuth. Spin polarization of the 4d states of yttrium and of the 5d states of lanthanum or lutetium was clearly demonstrated. Angular momentum resolved d-DOS of yttrium and lanthanun was shown to be split by the crystal field, the two resolved substructures having opposite magnetic polarization. The existence of a weak orbital moment involving the 6p states of bismuth was definitely established with the detection of a small XMCD signal at the Bi M{sub 1}-edge. Difference spectra also enhanced the visibility of subtle changes in the Fe K-edge XMCD spectra of YIG and {l_brace}Y, Bi{r_brace}IG films. Weak natural X-ray linear dichroism signatures were systematically observed with all iron garnet films and with a bulk YIG single crystal cut parallel to the (1 1 1) plane: this proved that, at room temperature, the crystal cannot satisfy all requirements of perfect cubic symmetry (space group: Ia3-bar d), crystal distortions preserving at best trigonal symmetry (R3-bar or R3m). For the first time, a very weak X-ray magnetic linear dichroism (XMLD) was also measured in the iron K-edge pre-peak of YIG and revealed the presence of a tiny electric quadrupole moment in the ground-state charge distribution of iron atoms. Band-structure calculations carried out with fully relativistic LMTO-LSDA methods support our interpretation that ferrimagnetically coupled spins at the iron sites induce a spin polarization of the yttrium d-DOS and reproduce the observed crystal field splitting of the XMCD signal.

  6. Element selective X-ray magnetic circular and linear dichroisms in ferrimagnetic yttrium iron garnet films

    International Nuclear Information System (INIS)

    Rogalev, A.; Goulon, J.; Wilhelm, F.; Brouder, Ch.; Yaresko, A.; Ben Youssef, J.; Indenbom, M.V.

    2009-01-01

    X-ray magnetic circular dichroism (XMCD) was used to probe the existence of induced magnetic moments in yttrium iron garnet (YIG) films in which yttrium is partly substituted with lanthanum, lutetium or bismuth. Spin polarization of the 4d states of yttrium and of the 5d states of lanthanum or lutetium was clearly demonstrated. Angular momentum resolved d-DOS of yttrium and lanthanun was shown to be split by the crystal field, the two resolved substructures having opposite magnetic polarization. The existence of a weak orbital moment involving the 6p states of bismuth was definitely established with the detection of a small XMCD signal at the Bi M 1 -edge. Difference spectra also enhanced the visibility of subtle changes in the Fe K-edge XMCD spectra of YIG and {Y, Bi}IG films. Weak natural X-ray linear dichroism signatures were systematically observed with all iron garnet films and with a bulk YIG single crystal cut parallel to the (1 1 1) plane: this proved that, at room temperature, the crystal cannot satisfy all requirements of perfect cubic symmetry (space group: Ia3-bar d), crystal distortions preserving at best trigonal symmetry (R3-bar or R3m). For the first time, a very weak X-ray magnetic linear dichroism (XMLD) was also measured in the iron K-edge pre-peak of YIG and revealed the presence of a tiny electric quadrupole moment in the ground-state charge distribution of iron atoms. Band-structure calculations carried out with fully relativistic LMTO-LSDA methods support our interpretation that ferrimagnetically coupled spins at the iron sites induce a spin polarization of the yttrium d-DOS and reproduce the observed crystal field splitting of the XMCD signal.

  7. Properties of zirconium ceramics and film stabilized by yttrium

    International Nuclear Information System (INIS)

    Korobova, N.

    2004-01-01

    Full text: Unstable zirconium dioxide phase transformation can be eliminated by stabilization of the cubic phase with an addition of a selected alkaline earth or rare-earth oxide. Stabilized ZrO 2 has been widely utilized in various high-temperature refractory applications. These stabilized ZrO 2 -base solid solutions also possess rather unique electrical properties, and as a result have considerable potential as solid electrolytes in galvanic and fuel cells and, possibly, as heating elements in high-temperature furnaces. The complex study of synthesis processes, structure and properties of metal alkoxide organic sols have been developed. These have allowed to create main principles of their formation and to show the practical realization of obtained theoretical and experimental results. The correlation between hydrolysis conditions of (Zr+Y) metal alkoxide sols and synthesis of stable colloid multi-component systems has been established. Systematic research of zirconium and yttrium bi-alkoxide electrophoretic deposition was conducted for the first time. The formation mechanism of electrophoretic deposits has been offered and general scientific principles of the electrophoretic process have been formulated. The model of gel deposits structure was proposed. It has enabled to analyze the main (for example, cluster) effects, which have been exhibited in technological procedure for thin film preparation. The structure investigation of stabilized zirconium dioxide thin films and ceramics has been studied. The researches were based on the comparative analysis of the initial gel microstructure and dried gel by the various drying methods. The new approach for drying of gel electrophoretic deposits was formulated theoretically and experimentally has been proved. The modeling of the aggregate kinetics as a type of 'cluster-cluster' has been proposed like a qualitative description of the process. The data of fractal dimensions of aggregates which have been formed at the

  8. Occupational exposure following Yttrium-90 microspheres SIR therapy

    International Nuclear Information System (INIS)

    Fontaine, P.; Boirie, G.; Dieudonne, A.; Leguludec, D.; Lebtahi, R.; Ben Reguiga, M.

    2015-01-01

    Full text of publication follows. Introduction: Selective Internal Radiation Therapy (SIRT) is a promising technique for solid hepatic neoplasms treatment. SIRT consists in implanting radioactive microspheres (RMS) in targeted hepatic lesions via femoral artery. Two RMS-Therapsheres [glass-microspheres/TSR] and Sir-Spheres [resin-spheres/SSR]- are marketed in the European market, both radiolabeled with Yttrium-90. The objective of this study is to assess occupational exposure for nuclear medicine, radiology and clinical staff involved in Y 90 -RMS preparation and implantation. Materials and methods: The study was conducted on 20 patients treated for Hepato-Cellular Carcinoma: 10 treated with TSR and 10 with SSR. Dose rate (DR, mSv/h) or absorbed doses (mSv) measurements were made during all steps of TSR and SSR handling: sources receipt and unpacking, preparation, transport to radiology, implantation, and patient care. Measurements were made with portable ionization chamber(Babyline/Nardeux), spectrometer(FieldSpect/Aries), digital dosimeter (NED/Unfors) and operational dosimeter (Mk2/Siemens). Values were expressed as mean±SD. Results: patients received of 1.8 GBq to 3.1 GBq of TSR and 0.55 GBq to 2.4 GBq of SSR. TSR were delivered ready-to-use with the prescribed activity. For SSR only one activity was commercially available and shipped (3 GBq at calibration-time)requiring a preparation step to adjust needed activity. DR measured during RMS was 1723 ± 157 μSv/h SSR and 1189 ± 92 μSv/h for TSR. When preparing spheres in radiopharmacy, fingers and whole body doses were respectively 8326 ± 2360 μSv and 12.3 ± 5,2 μSv for Sir-Spheres vs. 33.5 ± 7.8 μSv and 1.1 ± 0.3 μSv for TSR. DR in contact with carrying case during RMS transfer to radiology were 299 ± 102 μSv/h for SSR and 5.3 ± 1.2 μSv/h for TSR. During RMS infusion, radiologist's finger doses were limited to 3.6 ± 1 μSv for SSR and 0.7± 0.3 μSv for TSR. Finally, following RMS

  9. Effect of yttrium on the oxide scale adherence of pre-oxidized silicon-containing heat-resistant alloy

    International Nuclear Information System (INIS)

    Yan Jingbo; Gao Yimin; Shen Yudi; Yang Fang; Yi Dawei; Ye Zhaozhong; Liang Long; Du Yingqian

    2011-01-01

    Highlights: → AE experiment shows yttrium has a beneficial effect on the pre-oxidized HP40 alloy. → Yttrium facilitates the formation of internal oxide after 10 h of oxidation. → Internal oxide changes the rupture behaviour of the oxide scale. → Twins form in the internal oxide and improve the binding strength of the scale. - Abstract: This paper investigates the effect of the rare earth element yttrium on the rupture behaviour of the oxide scale on the silicon-containing heat-resistant alloy during cooling. After 10 h of oxidation, yttrium is found to facilitate the formation of internal oxides (silica) at the scale-matrix interface. Due to the twinning observed by scanning transmission electron microscopy (STEM) in silica, the critical strain value for the scale failure can be dramatically improved, and the formation of cracks at the scale-matrix interface is inhibited.

  10. An ICP AES method for determination of dysprosium and terbium in high purity yttrium oxide

    International Nuclear Information System (INIS)

    Rupawate, V.H.; Hareendran, K.N.; Roy, S.B.

    2011-01-01

    High purity yttrium finds interesting application in astronavigation, luminescence, nuclear energy and metallurgical industries. Most of these applications require yttrium oxide of highest purity. Consequently there is a need for production of high purity yttrium oxide. Separation and purification of yttrium from other rare earths is a challenging task due to their close chemical properties. Liquid-liquid extraction and ion exchange have been widely used in the production of yttrium oxide of highest purity. Determination of impurities, especially other rare earths, in ppm level is required for process development and chemical characterization of the high purity Y 2 O 3 . Many methods have been described in literature. However since the advent of ICP AES much work in this area has been carried out by this technique. This paper describes the work done for determination of dysprosium (Dy) and terbium (Tb) in yttrium oxide using a high resolution sequential ICP AES. Emission spectra of rare earth elements are very complex and due to this complexity it is important to select spectral interference free analyte lines for determination of rare earths in rare earth matrix. For the determination of Dy and Tb in Y 2 O 3 , sensitive lines of Dy and Tb are selected from the instrument wavelength table and spectral interference free emission lines for the determination is selected by scanning around the selected wavelengths using 5 g/L Y solution and 5 mg/L standard solutions of Dy and Tb prepared in 4% nitric acid. It is found 353.170 nm line of Dy and 350.917 nm line Tb is suitable for quantitative determination. The signal to background ratio increases with increase in matrix concentration, i.e. from 1 to 5 mg/L. The optimum forward power is determined and it is found to be 1100W for Dy and 1000W for Tb. The instrument is calibrated using matrix matched standards containing 5g/L of Y matrix. Samples are dissolved in nitric acid and Y concentration is maintained at 5g/L. Two

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

    International Nuclear Information System (INIS)

    Luiz, J.M.

    1989-01-01

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

  12. Some peculiarities of thermoemission of the cathodes on the base of tanthanum and yttrium oxides

    International Nuclear Information System (INIS)

    Podgornyj, V.I.

    1982-01-01

    Thermoemission cathode characteristics on the basis of (La 2 O 3 ) lanthanum, and yttrium oxides which are used already in prctice but emission mechanism of which remains yet insufficiently elucidated, were investigated. It is shown that the heating of cathodes on the basis of Y 2 O 3 and La 2 O 3 at activation temperatures during 2-3 h with successive cooling results in the state of surface with increased thermoemission activity. It is established that the cathode heating in electric field of positive polarity results in decreasing thermoemission activity of lanthanum oxide by approximately 0.35 eV and for yttrium oxide - by approximately 0.05 eV as compared with the heating in the field of negative polarity. The effect obtained is related to the change in the metal adatom concentration on the cathode surface

  13. An XRF method for determination of common rare earth impurities in high purity yttrium oxide

    International Nuclear Information System (INIS)

    Dixit, R.M.; Deshpande, S.S.

    1975-01-01

    An XRF method for the estimation of Eu, Gd, Tb, Dy, Ho, Er and Yb in yttrium oxide has been developed. Samples are converted to yttrium oxalate and presented to the spectrometer in the form of pressed pellets. Philips PW-1220, a semi-automatic x-ray spectrometer, is used for the analysis. Line interference problems are studied for selecting analysis lines. For the elements except that of Yb, the lower estimation limit is 0.005% and for Yb, it is 0.01%. The average standard deviation is approximately 5% for various elements in the concentration range of 0.005% to 1.0%. The method has been tested for its accuracy by analysing synthesized samples with known composition at three different concentrations. (author)

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

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  15. Separation of yttrium using carbon nanotube doped polymeric beads impregnated with D2EHPA

    International Nuclear Information System (INIS)

    Dasgupta, Kinshuk; Yadav, Kartikey K.; Singh, D.K.; Anitha, M.; Singh, H.

    2013-01-01

    Di-2-ethylhexyl phosphoric acid impregnated polyethersulfone based composite beads in combination with additives such as polyvinyl alcohol (PVA) and multiwalled carbon nanotube (MWCNT) has been prepared by non-solvent phase inversion method. The synthesized beads were characterized by scanning electron microscopy, thermogravimetry and infra-red spectroscopy. Effect of additives on bead morphology, solvent impregnation capacity, extractability and stability has been examined to compare their suitability for yttrium recovery from acidic medium. Microstructural investigation as well as experimental findings confirmed the role of additives in modifying the pore structures in beads, responsible for varied degree of yttrium extraction. Further the role of metal ion concentration in aqueous phase on its recovery by polymeric beads was also evaluated. Among the tested beads PES/D2EHPA/MWCNT/PVA beads were found to be superior for Y(Ill) extraction. (author)

  16. Preparation of yttrium iron garnet (YIG) by modified domestic iron oxide

    International Nuclear Information System (INIS)

    Mozaffari, M.; Amighian

    2002-01-01

    Iron oxide by product of a local steel complex was modified to use for preparation of Yttrium iron garnet (YIG). The improvement was necessary to reduce impurities, especially the Si0 2 and Cl contents, which have deteriorative effects on magnetic properties and equipment used for preparation of the samples. The modified iron oxide was then mixed with Yttrium oxide of Merck Company in appropriate proportion to obtain a stoichiometric single phase YIG, using the conventional ceramic technique. XRD and SEM equipments were used to identify the resulting phases and microstructure respectively. Magnetic parameters were measured by VSM. Curie temperature of the samples was obtained by DTG (M) method. The results were compared with those obtained from samples that made by Merck iron oxide. There are small differences between the results. This was discussed according to extra pores and minute secondary phase in the samples made by domestic iron oxide. (Author)

  17. Determination of yttrium using YO band head obtained by laser enhanced ionization spectrometry

    International Nuclear Information System (INIS)

    Deshpande, S.S.; Khanna, P.P.

    1997-04-01

    The determination of yttrium (Y) in water in the concentration range of 2 μg/ml to 200 μg/ml by laser enhanced ionisation (LEI) technique is reported. The YO band head at 584.27 nm belonging to A 2 Π - X 2 Σ + system is used for LEI signal detection. It is also shown that the LEI signal is enhanced when the mixture of air - acetylene - argon (AAA) is used instead of commonly used air-acetylene (AA) mixture. In the present work an XeCl laser (308 nm) pumped rhodamine 6G dye laser, covering a range of 570-610 nm is used. The sample/standard in solution form is aspirated into the flame with pneumatic nebulizer. The working curve is a straight line showing linear dependence of LEI signal with yttrium concentration. The relative standard deviation calculated at 100 μg/ml is found to be 2.4 %. (author)

  18. Quantum design and synthesis of a boron-oxygen-yttrium phase

    International Nuclear Information System (INIS)

    Music, Denis; Chirita, Valeriu; Kreissig, Ulrich; Czigany, Zsolt; Schneider, Jochen M.; Helmersson, Ulf

    2003-01-01

    Ab initio calculations are used to design a crystalline boron-oxygen-yttrium (BOY) phase. The essential constituent is yttrium substituting for oxygen in the boron suboxide structure (BO 0.17 ) with Y/B and O/B ratios of 0.07. The calculations predict that the BOY phase is 0.36 eV/atom more stable than crystalline BO 0.17 and experiments confirm the formation of crystalline thin films. The BOY phase was synthesized with reactive rf magnetron sputtering and identified with x-ray and selected area electron diffraction. Films with Y/B ratios ranging from 0.10 to 0.32, as determined via elastic recoil detection analysis, were grown over a wide range of temperatures (300-600 deg. C) and found to withstand 1000 deg. C

  19. Yttrium-90 used to treat colon cancer: Awaiting investigational new drug approval

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    A new radiation treatment takes just 14 to 21 days to shrink colorectal tumors in laboratory mice, is under review for clinical trials with human cancer patients. The treatment has succeeded in reducing the size of tumors by up to 95%. Colon cancer, the second leading cause of cancer deaths in the US, is extremely difficult to treat unless it is detected early enough for surgical procedures. In laboratory tests over the last 5 years, a team of researchers has developed the treatment using yttrium-90. The yttrium-90 is transported to the tumors by attaching it to monoclonal antibodies that seek out the cancer cells. Once the radioisotope has been targeted to the tumor, the radiation destroys many of the cells, dramatically reducing the size of the tumor. Since this treatment usually does not completely eliminate all the cancer cells, it cannot be called a cure, but it does seem to be an effective method of shrinking colorectal tumors

  20. Mass synthesis of yttrium oxide nano-powders using radio frequency (RF) plasma

    International Nuclear Information System (INIS)

    Ghorui, S.; Sahasrabudhe, S.N.; Chakravarthy, Y.; Nagaraj, A.; Das, A.K.; Dhamale, G.

    2014-01-01

    Mass synthesis of nano-phase Yttrium Oxide (Y 2 O 3 ) from commercially available coarse grain powder is reported. Nano-sized high purity Y 2 O 3 is an important and critical constituent of ceramics like YAG (Yttrium aluminum garnet: Y 3 Al 5 O 12 ) for laser applications. The system is characterized in terms of its thermal and electrical behavior. Boltzmann plot technique is used to measure axial variation of temperature of the generated plasma. The synthesized particles are characterized in terms of XRD, SEM, TEM and BET analyses for qualification of the developed system. Major features observed are efficient conversion into nanometer-sized highly spherical particles, narrow size distribution, highly crystallite nature and highly pure phases. The particle distribution (from TEM) peaks within 20-30 nm. Average particle sizes determined from different methods like XRD, TEM and BET are very close to each other and point toward particle sizes within 20 to 30 nm

  1. Preparation of polycrystalline lithium-yttrium fluoride for subsequent mono crystallization

    International Nuclear Information System (INIS)

    Kowalczyk, E.; Radomski, J.; Diduszko, R.; Iwanejko, J.; Kowalczyk, Z.; Grasza, K.

    1994-01-01

    High purity lithium-yttrium (YLF) doped with rare earth elements (Nd, Pr, Ho or Tm) was obtained in a two-stage synthesis consisting of (1) reaction of ammonium fluoride with a mixture of lithium carbonate, yttrium oxide, and oxides of lanthanides, and (2) heating of the obtained reaction products at a temperature of about 700 C in an inert gas atmosphere. The phase and chemical purities of the obtained materials were characterized by X-ray diffraction and mass spectrometry techniques. Single crystal growth tests were carried out by means of the Bridgman method. The results showed that the proposed method for manufacture of polycrystalline YLF doped with rare earth elements is appropriate in principle but some parameters of the preparation process are to be more strictly defined. (author). 9 refs, 4 figs, 1 tab

  2. Preparation of polycrystalline lithium-yttrium fluoride for subsequent mono crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Kowalczyk, E.; Radomski, J.; Diduszko, R.; Iwanejko, J. [Institute of Vacuum Technology, Warsaw (Poland); Kowalczyk, Z. [Warsaw Univ. (Poland); Grasza, K. [Polska Akademia Nauk, Warsaw (Poland). Inst. Fizyki

    1994-12-31

    High purity lithium-yttrium (YLF) doped with rare earth elements (Nd, Pr, Ho or Tm) was obtained in a two-stage synthesis consisting of (1) reaction of ammonium fluoride with a mixture of lithium carbonate, yttrium oxide, and oxides of lanthanides, and (2) heating of the obtained reaction products at a temperature of about 700 C in an inert gas atmosphere. The phase and chemical purities of the obtained materials were characterized by X-ray diffraction and mass spectrometry techniques. Single crystal growth tests were carried out by means of the Bridgman method. The results showed that the proposed method for manufacture of polycrystalline YLF doped with rare earth elements is appropriate in principle but some parameters of the preparation process are to be more strictly defined. (author). 9 refs, 4 figs, 1 tab.

  3. Yttrium and lanthanum recovery from low cerium carbonate, yttrium carbonate and yttrium concentrate; Aproveitamento de itrio e lantanio de um carbonato de terras raras de baixo teor em cerio, de um carbonato de itrio e de um oxido de terras itricas

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, Mari Estela de

    2006-07-01

    In this work, separation, enrichment and purification of lanthanum and yttrium were performed using as raw material a commercial low cerium rare earth concentrate named LCC (low cerium carbonate), an yttrium concentrate named 'yttrium carbonate', and a third concentrated known as 'yttrium earths oxide. The first two were industrially produced by the late NUCLEMON - NUCLEBRAS de Monazita e Associados Ltda, using Brazilian monazite. The 'yttrium earths oxide' come from a process for preparation of lanthanum during the course of the experimental work for the present thesis. The following techniques were used: fractional precipitation with urea; fractional leaching of the LCC using ammonium carbonate; precipitation of rare earth peroxycarbonates starting from the rare earth complex carbonates. Once prepared the enriched rare earth fractions the same were refined using the ion exchange chromatography with strong cationic resin without the use of retention ion and elution using the ammonium salt of ethylenediaminetetraacetic acid. With the association of the above mentioned techniques were obtained pure oxides of yttrium (>97,7%), lanthanum (99,9%), gadolinium (96,6%) and samarium (99,9%). The process here developed has technical and economic viability for the installation of a large scale unity. (author)

  4. Hydrothermal synthesis, crystal structures and photoluminescence properties of mixed europium–yttrium organic frameworks

    International Nuclear Information System (INIS)

    Han Yinfeng; Fu Lianshe; Mafra, Luís; Shi, Fa-Nian

    2012-01-01

    Three mixed europium–yttrium organic frameworks: Eu 2−x Y x (Mel)(H 2 O) 6 (Mel=mellitic acid or benzene-1,2,3,4,5,6-hexacarboxylic acid, x=0.38 1, 0.74 2, and 0.86 3) have been synthesized and characterized. All the compounds contain a 3-D net with (4, 8)-flu topology. The study indicates that the photoluminescence properties are effectively affected by the different ratios of europium and yttrium ions, the quantum efficiency is increased and the Eu 3+ lifetime becomes longer in these MOFs than those of the Eu analog. - Graphical abstract: Three mixed europium and yttrium organic frameworks: Eu 2−x Y x (Mel)(H 2 O) 6 (Mel=mellitic acid) have been synthesized and characterized. All the compounds contain a 3-D net with (4, 8)-flu topology. The study indicates that the photoluminescence properties are effectively affected by the different ratios of europium and yttrium ions, the quantum efficiency is increased and the Eu 3+ lifetime becomes longer in these MOFs than those of the Eu analog. Highlights: ► Three (4, 8)-flu topological mixed Eu and Y MOFs were synthesized under mild conditions. ► Metal ratios were refined by the single crystal data consistent with the EDS analysis. ► Mixed Eu and Y MOFs show longer lifetime and higher quantum efficiency than the Eu analog. ► Adding inert lanthanide into luminescent MOFs enlarges the field of luminescent MOFs.

  5. Peripheral Blood Lymphocyte Depletion After Hepatic Arterial {sup 90}Yttrium Microsphere Therapy for Hepatocellular Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Carr, Brian I., E-mail: brianicarr@hotmail.com [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA and Department of Nutrition and Exptl Biology, Saverio De Bellis Medical Research Institute, Castellana Grotte, Bari (Italy); Metes, Diana M. [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA and Department of Nutrition and Exptl Biology, Saverio De Bellis Medical Research Institute, Castellana Grotte, Bari (Italy)

    2012-03-01

    Purpose: The short- and long-term effects of {sup 90}Yttrium microspheres therapy for hepatocellular carcinoma (HCC) on peripheral blood lymphocytes are unknown and were therefore examined. Methods and Materials: Ninety-two HCC patients were enrolled in a {sup 90}Yttrium therapy study and routine blood counts were examined as part of standard clinical monitoring. Results: We found an early, profound, and prolonged lymphopenia. In a subsequent cohort of 25 additional HCC patients, prospective flow cytometric immune-monitoring analysis was performed to identify specific changes on distinct lymphocyte subsets (i.e., CD3, CD4, CD8 T, and CD19 B lymphocytes) and NK cells absolute numbers, in addition to the granulocytes and platelets subsets. We found that the pretreatment lymphocyte subset absolute numbers (with the exception of NK cells) had a tendency to be lower compared with healthy control values, but no significant differences were detected between groups. Posttherapy follow-up revealed that overall, all lymphocyte subsets, except for NK cells, were significantly (>50% from pretherapy values), promptly (as early as 24 h) and persistently (up to 30 months) depleted post-{sup 90}Yttrium microspheres therapy. In contrast, granulocytes increased rapidly (24 h) to compensate for lymphocyte depletion, and remained increased at 1-year after therapy. We further stratified patients into two groups, according to survival at 1 year. We found that lack of recovery of CD19, CD3, CD8, and especially CD4 T cells was linked to poor patient survival. No fungal or bacterial infections were noted during the 30-month follow-up period. Conclusions: The results show that lymphocytes (and not granulocytes, platelets, or NK cells) are sensitive to hepatic arterial {sup 90}Yttrium without associated clinical toxicity, and lack of lymphocyte recovery (possibly leading to dysregulation of adaptive cellular immunity) posttherapy indicates poor survival.

  6. The effect of yttrium substitution on the magnetic properties of magnetite nanoparticles

    International Nuclear Information System (INIS)

    Mozaffari, M.; Amighian, J.; Tavakoli, R.

    2015-01-01

    Superparamagnetic Y-substituted magnetite (Y x Fe 3–x O 4 ,with x=0.00, 0.10, 0.15, 0.20 and 0.40) nanoparticles were synthesized via hydrothermal reduction route in the presence of citric acid. The synthesized nanoparticles were characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), vibrating sample magnetometry (VSM) and gradient field thermomagnetic measurement. The results showed that a minimum amount of citric acid is required to obtain single phase Y-substituted magnetite nanoparticles. Citric acid acts as a modulator and reducing agent in the formation of spinel structure and controls nanoparticle size and crystallinity. Mean crystallite sizes of the single-phase powders were estimated by Williamson–Hall method. Curie temperature measurement of the samples shows that as yttrium content increases, the Curie temperature decreases. Magnetic measurements show that the saturation magnetization of the samples decreases as x increases up to 0.15 and then increases to x=0.20 and finally decreases again for x=0.40. - Highlights: • Single phase yttrium substituted magnetite nanoparticles were synthesized by hydrothermal-reduction route. • Citric acid plays a key role in reduction of Fe 3+ to Fe 2+ , which is necessary for the formation of magnetite phase. • It is possible to substitute yttrium ions for iron ones as high as x=0.4 by hydrothermal reduction route. • Pure magnetite nanoparticles prepared by this route has a high saturation magnetization. • Yttrium substituted magnetite nanoparticles are superparamagnet at room temperature

  7. Studies on the pressed yttrium oxide-tungsten matrix as a possible dispenser cathode material

    International Nuclear Information System (INIS)

    Yang, Fan; Wang, Jinshu; Liu, Wei; Liu, Xiang; Zhou, Meiling

    2015-01-01

    Yttrium oxide was chosen as the secondary emission substance based on calculation results through first principle theory method. A new kind of pressed yttrium oxide-tungsten matrix dispenser cathodes are prepared by a sol–gel method combined with high temperature sintering in dry hydrogen atmosphere. The results show that the growth of the grains is hampered by the pinning effect of Y 2 O 3 distributing uniformly between the tungsten particles, resulting in the formation of small grain size. It is found that Y 2 O 3 improves the secondary electron emission property, i.e., the secondary emission yield increases with the increase of Y 2 O 3 content in the samples. The maximum secondary emission yield δ max of the cathode with 15% amount of Y 2 O 3 can reach 2.92. Furthermore, the cathode shows a certain thermionic emission performance. The zero field emission current density J 0 of 4.18A/cm 2 has reached at 1050 °C b for this kind of cathode after being activated at 1200 °C b , which are much higher than that of rare earth oxide doped molybdenum (REO-Mo) cathode reported in the previous work. - Highlights: • Yttrium oxide was chosen as the secondary emission substance based on first principle calculation result. • A new kind of cathode has been successfully obtained. • Pressed yttrium oxide-tungsten matrix dispenser cathode exhibits good emission properties. • The improvement of the cathode emission can be well explained by the surface analysis results presented in this work

  8. Recurrent thermo-luminescence phenomenon in yttrium-aluminum garnet crystals

    International Nuclear Information System (INIS)

    Islamov, A.Kh.; Nuritdinov, I.; Esanov, Z.U.; Eshchanov, B.Kh.; Khayitov, I.A.

    2014-01-01

    Full text : The crystals of yttrium-aluminum garnet Y 2 Al 2 O 1 2 activated by cerium and praseodymium ions by their thermal and chemical durability as well as fast response are perspective scintillation materials. In this work the capture centres formed by action of the ionizing radiation on pure and doped by praseodymium and cerium crystals were investigated. The samples were grown using Chokhralsky method

  9. Trends in metallo-organic chemistry of scandium, yttrium, and the lanthanides

    International Nuclear Information System (INIS)

    Singh, A.

    1994-01-01

    Several interesting aspects of the metallo-organic chemistry of group 3 and the lanthanides have been highlighted, which include: (a) the chemistry of a few notable organolanthanide compounds, alkoxo and aryloxo derivatives derived from sterically demanding ligands, (b) new trends in the chemistry of lanthanide heterometallic alkoxides, (c) an account of zero valent organometallics of yttrium and the lanthanides, and (d) aspects of agostic interactions in the lanthanide metallo-organic compounds. (author). 49 refs

  10. Studies on the pressed yttrium oxide-tungsten matrix as a possible dispenser cathode material

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Fan; Wang, Jinshu, E-mail: wangjsh@bjut.edu.cn; Liu, Wei; Liu, Xiang; Zhou, Meiling

    2015-01-15

    Yttrium oxide was chosen as the secondary emission substance based on calculation results through first principle theory method. A new kind of pressed yttrium oxide-tungsten matrix dispenser cathodes are prepared by a sol–gel method combined with high temperature sintering in dry hydrogen atmosphere. The results show that the growth of the grains is hampered by the pinning effect of Y{sub 2}O{sub 3} distributing uniformly between the tungsten particles, resulting in the formation of small grain size. It is found that Y{sub 2}O{sub 3} improves the secondary electron emission property, i.e., the secondary emission yield increases with the increase of Y{sub 2}O{sub 3} content in the samples. The maximum secondary emission yield δ{sub max} of the cathode with 15% amount of Y{sub 2}O{sub 3} can reach 2.92. Furthermore, the cathode shows a certain thermionic emission performance. The zero field emission current density J{sub 0} of 4.18A/cm{sup 2} has reached at 1050 °C{sub b} for this kind of cathode after being activated at 1200 °C{sub b}, which are much higher than that of rare earth oxide doped molybdenum (REO-Mo) cathode reported in the previous work. - Highlights: • Yttrium oxide was chosen as the secondary emission substance based on first principle calculation result. • A new kind of cathode has been successfully obtained. • Pressed yttrium oxide-tungsten matrix dispenser cathode exhibits good emission properties. • The improvement of the cathode emission can be well explained by the surface analysis results presented in this work.

  11. Alkylation of pyridines at their 4-positions with styrenes plus yttrium reagent or benzyl Grignard reagents.

    Science.gov (United States)

    Mizumori, Tomoya; Hata, Takeshi; Urabe, Hirokazu

    2015-01-02

    A new regioselective alkylation of pyridines at their 4-position was achieved with styrenes in the presence of yttrium trichloride, BuLi, and diisobutylaluminium hydride (DIBAL-H) in THF. Alternatively, similar products were more simply prepared from pyridines and benzyl Grignard reagents. These reactions are not only a useful preparation of 4-substituted pyridines but are also complementary to other relevant reactions usually giving 2-substituted pyridines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Substitution of yttrium for boron in the structure of YBa2Cu3O7-δ

    International Nuclear Information System (INIS)

    Dwelk, H.; Herrmann, R.; Pruss, N.; Freude, D.; Pfeifer, H.

    1989-01-01

    The influence of boron on superconducting properties of Y 1-x B x Ba 2 Cu 3 O 7-δ with x = 0 to 0.4 is studied. The analysis of 11 B NMR spectra and measurements of electric conductivity as a function of temperature show that boron is not incorporated into the YBa 2 Cu 3 O 7-δ framework on yttrium positions. (author)

  13. Study of yttrium 4-nitrocinnamate to promote surface interactions with AS1020 steel

    Energy Technology Data Exchange (ETDEWEB)

    Hien, P.V. [Department of Chemical Engineering, Bach Khoa University, VNU-HCM, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City (Viet Nam); Vu, N.S.H.; Thu, V.T.H. [Faculty of Physics and Engineering Physics, University of Science, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City (Viet Nam); Somers, A. [Institute for Frontier Materials, Deakin University, Geelong, Victoria 3220 (Australia); Nam, N.D., E-mail: namnd@pvu.edu.vn [PetroVietnam University, 762 Cach Mang Thang Tam Street, Long Toan Ward, Ba Ria City, Ba Ria—Vung Tau Province (Viet Nam)

    2017-08-01

    Highlights: • Yttrium 4-nitrocinnamate is a new corrosion inhibitor alternative to chromate technologies. • The inhibition performance is increased with increase of the inhibitor concentration. • Yttrium 4-nitrocinnamate mitigates corrosion by promoting random distribution of minor anodes. • Yttrium 4-nitrocinnamate is a good candidate for substitution of chromate inhibitors. - Abstract: Yttrium 4-nitrocinnamate (Y(4-NO{sub 2}Cin){sub 3}) was added to an aqueous chloride solution and studied as a possible corrosion inhibition system. Electrochemical techniques and surface analysis have been powerful tools to better understand the corrosion and inhibition processes of mild steel in 0.01 M NaCl solution. A combination of scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), Potentiodynamic polarization (PD), electrochemical impedance spectroscopy (EIS) and wire beam electrode (WBE) techniques was found to be useful in the characterization of this system. The result indicated that Y(4-NO{sub 2}Cin){sub 3} is able to effectively inhibit corrosion at a low concentration of 0.45 mM. Surface analysis clearly shows that the surface of steel coupons exposed to Y(4-NO{sub 2}Cin){sub 3} solution remained uniform and smooth, whereas the surface of steel coupons exposed to solution without inhibitor addition was severely corroded. The results suggest that Y(4-NO{sub 2}Cin){sub 3} behaves as a mixed inhibitor and mitigates corrosion by promoting random distribution of minor anodes. These are attributed to the formation of metal species bonding to the 4-nitrocinnamate component and hydrolysis of the Y(4-NO{sub 2}Cin){sub 3} to form oxide/hydroxides as a protective film layer.

  14. Addition compounds of lanthamide (III) and yttrium (III) hexafluorophosphates and N,N - dimethylformamide

    International Nuclear Information System (INIS)

    Braga, L.S.P.

    1983-01-01

    Addition compounds of lanthanide (III) and yttrium (III) hexafluorophosphates and N-N-Dimetylformamide are described to characterize the complexes, elemental analysis, melting ranges, molar conductance measurements, X-ray powder patters infrared and Raman spectra, TG and DTA curves, are studied. Information concerning the decomposition of the adducts through the thermogravimetric curves and the differential thermal analysis curves is obtained. (M.J.C.) [pt

  15. Preparation and characterization of Yttrium-Aluminium garnet (Y3Al5O12)

    International Nuclear Information System (INIS)

    Ruzicka, J.; Niznansky, D.; Houzvicka, J.; Nikl, M.; Cerny, R.

    2009-01-01

    This work deals with the preparation of powders and transparent yttrium aluminium garnet (Y 3 Al 5 O 12 - YAG) from nanopowders. Stoichiometric amounts of nanocrystalline Al 2 O 3 and Y 2 O 3 were mixed and chemically pretreated using different basic agents and using ultrasonic bath. Resulting mixture was dried, pressed and heated up to 1750°C. Final material was characterized by X-ray diffraction, DTA and optical and electron microscopy

  16. A study of the dynamics of hydrogen in yttrium using inelastic neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bennington, S M; Benham, M J; Ross, D K [Birmingham Univ. (UK). School of Physics and Space Research; Taylor, A D; Bowden, Z A [Rutherford Appleton Lab., Chilton (UK)

    1989-01-01

    The results of several high resolution inelastic scattering experiments on {alpha}-phase yttrium-hydrogen are presented including measurements of energy levels up to the fourth and a study of the splitting of certain states due to hydrogen-hydrogen interactions. An attempt is made to model the energy levels by using perturbed simple harmonic oscillator wavefunctions. This can account for most of the major features of the spectrum. (orig.).

  17. Thermodynamic Functions of Yttrium Trifluoride and Its Dimer in the Gas Phase

    Science.gov (United States)

    Osina, E. L.; Kovtun, D. M.

    2018-05-01

    New calculations of the functions for YF3 and Y2F6 in the gas phase using quantum-chemical calculations by MP2 and CCSD(T) methods are performed in connection with the ongoing work on obtaining reliable thermodynamic data of yttrium halides. The obtained values are entered in the database of the IVTANTERMO software complex. Equations approximating the temperature dependence of the reduced Gibbs energy in the T = 298.15-6000 K range of temperatures are presented.

  18. Purification in the interaction between yttria mould and Nb-silicide-based alloy during directional solidification: A novel effect of yttrium

    International Nuclear Information System (INIS)

    Ma, Limin; Tang, Xiaoxia; Wang, Bin; Jia, Lina; Yuan, Sainan; Zhang, Hu

    2012-01-01

    Nb-silicide-based alloys were directionally solidified in yttria moulds. As a result of thermal dissociation of yttria, the alloys were slightly contaminated with oxygen, which caused a competitive oxidation between yttrium and hafnium. The addition of 0.15 at.% yttrium reduced the oxygen increment by 42%, because the buoyant inclusions concentrated around the top surface. The yttrium addition caused a significant purification of the interaction between the yttria mould and the Nb-silicide-based alloys during the directional solidification.

  19. Yttrium and lanthanides in human lung fluids, probing the exposure to atmospheric fallout

    Energy Technology Data Exchange (ETDEWEB)

    Censi, P., E-mail: censi@unipa.it [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy); I.A.M.C.-CNR - UOS di Capo Granitola, Via faro, 1 - 91026 Torretta Granitola, Campobello di Mazara (TP) (Italy); En.Bio.Tech. - Via Aquileia, 35 90100 Palermo (Italy); Tamburo, E. [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy); Speziale, S. [Deutsches GeoForschungsZentrum, Telegrafenberg, Potsdam, 14473 (Germany); Zuddas, P. [Institut Genie de l' Environnement et Ecodeveloppement and Departement Sciences de la Terre, UMR 5125, Universite Claude Bernard Lyon 1, 2 rue R. Dubois, Bat GEODE 69622 Villeurbanne Cedex (France); Randazzo, L.A. [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy); I.A.M.C.-CNR - UOS di Capo Granitola, Via faro, 1 - 91026 Torretta Granitola, Campobello di Mazara (TP) (Italy); En.Bio.Tech. - Via Aquileia, 35 90100 Palermo (Italy); Institut Genie de l' Environnement et Ecodeveloppement and Departement Sciences de la Terre, UMR 5125, Universite Claude Bernard Lyon 1, 2 rue R. Dubois, Bat GEODE 69622 Villeurbanne Cedex (France); Punturo, R. [Dipartimento di Scienze Geologiche, Universita di Catania, Corso Italia, 55 - 95129 Catania (Italy); Cuttitta, A. [I.A.M.C.-CNR - UOS di Capo Granitola, Via faro, 1 - 91026 Torretta Granitola, Campobello di Mazara (TP) (Italy); Arico, P. [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy)

    2011-02-28

    Inhalation of airborne particles can produce crystallization of phosphatic microcrysts in intraaveolar areas of lungs, sometimes degenerating into pulmonary fibrosis. Results of this study indicate that these pathologies are induced by interactions between lung fluids and inhaled atmospheric dust in people exposed to volcanic dust ejected from Mount Etna in 2001. Here, the lung solid-liquid interaction is evaluated by the distribution of yttrium and lanthanides (YLn) in fluid bronchoalveolar lavages on selected individuals according the classical geochemical approaches. We found that shale-normalised patterns of yttrium and lanthanides have a 'V shaped' feature corresponding to the depletion of elements from Nd to Tb when compared to the variable enrichments of heavy lanthanides, Y, La and Ce. These features and concurrent thermodynamic simulations suggest that phosphate precipitation can occur in lungs due to interactions between volcanic particles and fluids. We propose that patterns of yttrium and lanthanides can represent a viable explanation of some pathology observed in patients after prolonged exposure to atmospheric fallout and are suitable to become a diagnostic parameter of chemical environmental stresses.

  20. The influence of implanted yttrium on the cyclic oxidation behaviour of 304 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Riffard, F. [Laboratoire Vellave sur l' Elaboration et l' Etude des Materiaux (LVEEM), CNRS-EA 3864, Universite Blaise Pascal Clermont-Fd II, 8 rue J.B. Fabre, B. P. 219, 43006 Le Puy-en-Velay (France)]. E-mail: riffard@iut.u-clermont1.fr; Buscail, H. [Laboratoire Vellave sur l' Elaboration et l' Etude des Materiaux (LVEEM), CNRS-EA 3864, Universite Blaise Pascal Clermont-Fd II, 8 rue J.B. Fabre, B. P. 219, 43006 Le Puy-en-Velay (France); Caudron, E. [Laboratoire Vellave sur l' Elaboration et l' Etude des Materiaux (LVEEM), CNRS-EA 3864, Universite Blaise Pascal Clermont-Fd II, 8 rue J.B. Fabre, B. P. 219, 43006 Le Puy-en-Velay (France); Cueff, R. [Laboratoire Vellave sur l' Elaboration et l' Etude des Materiaux (LVEEM), CNRS-EA 3864, Universite Blaise Pascal Clermont-Fd II, 8 rue J.B. Fabre, B. P. 219, 43006 Le Puy-en-Velay (France); Issartel, C. [Laboratoire Vellave sur l' Elaboration et l' Etude des Materiaux (LVEEM), CNRS-EA 3864, Universite Blaise Pascal Clermont-Fd II, 8 rue J.B. Fabre, B. P. 219, 43006 Le Puy-en-Velay (France); Perrier, S. [Laboratoire Vellave sur l' Elaboration et l' Etude des Materiaux (LVEEM), CNRS-EA 3864, Universite Blaise Pascal Clermont-Fd II, 8 rue J.B. Fabre, B. P. 219, 43006 Le Puy-en-Velay (France)

    2006-03-15

    High-temperature alloys are frequently used in power plants, gasification systems, petrochemical industry, combustion processes and in aerospace applications. Depending on the application, materials are subjected to corrosive atmospheres and thermal cycling. In the present work, thermal cycling was carried out in order to study the influence of implanted yttrium on the oxide scale adherence on 304 steel specimens oxidised in air at 1273 K. In situ X-ray diffraction indicates that the oxides formed at 1273 K are different on blank specimens compared to implanted specimens. Glancing angle XRD allows to analyse the oxide scale composition after cooling to room temperature. Experimental results show that yttrium implantation at a nominal dose of 10{sup 17} ions cm{sup -2} does not improve significantly the cyclic oxidation behaviour of the austenitic AISI 304 steel. However, it appears that yttrium implantation remarkably enhance the oxidation resistance during isothermal oxidation. It reduces the transient oxidation stage and the parabolic oxidation rate constant by one order of magnitude.

  1. Spark plasma sintering of tungsten-yttrium oxide composites from chemically synthesized nanopowders and microstructural characterization

    International Nuclear Information System (INIS)

    Yar, M.A.; Wahlberg, Sverker; Bergqvist, Hans; Salem, H.G.; Johnsson, Mats; Muhammed, Mamoun

    2011-01-01

    Nano-crystalline W-1%Y 2 O 3 (wt.%) powder was produced by a modified solution chemical reaction of ammonium paratungstate (APT) and yttrium nitrate. The precursor powder was found to consist of particles of bimodal morphology i.e. large APT-like particles up to 20 μm and rectangular yttrium containing ultrafine plates. After thermal processing tungsten crystals were evolved from W-O-Y plate like particles. spark plasma sintering (SPS) was used to consolidate the powder at 1100 and 1200 deg. C for different holding times in order to optimize the sintering conditions to yield high density but with reduced grain growth. Dispersion of yttrium oxide enhanced the sinterability of W powder with respect to lanthanum oxide. W-1%Y 2 O 3 composites with sub-micron grain size showed improved density and mechanical properties as compared to W-La 2 O 3 composites. Sample sintered in two steps showed improved density, due to longer holding time at lower temperature (900 deg. C) and less grain growth due to shorter holding time at higher temperature i.e. 1 min at 1100 deg. C.

  2. Cold laser machining of nickel-yttrium stabilised zirconia cermets: Composition dependence

    International Nuclear Information System (INIS)

    Sola, D.; Gurauskis, J.; Pena, J.I.; Orera, V.M.

    2009-01-01

    Cold laser micromachining efficiency in nickel-yttrium stabilised zirconia cermets was studied as a function of cermet composition. Nickel oxide-yttrium stabilised zirconia ceramic plates obtained via tape casting technique were machined using 8-25 ns pulses of a Nd: YAG laser at the fixed wavelength of 1.064 μm and a frequency of 1 kHz. The morphology of the holes, etched volume, drill diameter, shape and depth were evaluated as a function of the processing parameters such as pulse irradiance and of the initial composition. The laser drilling mechanism was evaluated in terms of laser-material interaction parameters such as beam absorptivity, material spallation and the impact on the overall process discussed. By varying the nickel oxide content of the composite the optical absorption (-value is greatly modified and significantly affected the drilling efficiency of the green state ceramic substrates and the morphology of the holes. Higher depth values and improved drilled volume upto 0.2 mm 3 per pulse were obtained for substrates with higher optical transparency (lower optical absorption value). In addition, a laser beam self-focussing effect is observed for the compositions with less nickel oxide content. Holes with average diameter from 60 μm to 110 μm and upto 1 mm in depth were drilled with a high rate of 40 ms per hole while the final microstructure of the cermet obtained by reduction of the nickel oxide-yttrium stabilised zirconia composites remained unchanged.

  3. Influence of radiant heating treatments on fusion of high-temperature superconducting yttrium ceramics

    International Nuclear Information System (INIS)

    Bitenbaev, M.I.; Polyakov, A.I.

    1999-01-01

    Regardless of the fact that the materials made of HTSC-ceramics are promising, there is no any information about their successful practical application in publications. To our opinion, it is explained by the fact, first of all, that the conservative technologies of the powder metallurgy do not allow producing HTSC systems with excellent operating performance (structure homogeneity, long-term stability of Sc properties and etc.). This report presents outcomes of experiments on fusion of yttrium ceramics containing raw components irradiated by g-rays 60 Co under the temperature exceeding 500 degrees C. HTSC properties of ceramics were studied according to their differential spectra of radio-frequency (RF) field absorption. The RF absorption spectrum of yttrium ceramics samples produced according to conservative technology is sufficiently permitted triplet with the Sc transition temperatures range of 80 K, 90 K, 95 K. Irradiation under the increased temperatures and mechanical limitation allow producing samples of yttrium HTSC-ceramics with sufficient homogeneous structure and superconducting properties that are stable to air conditions for not less than one year

  4. Yttrium-90 microspheres for the treatment of hepatocellular carcinoma: A review

    International Nuclear Information System (INIS)

    Salem, Riad; Hunter, Russell D.

    2006-01-01

    To present a critical review of yttrium-90 (TheraSphere) for the treatment of hepatocellular carcinoma (HCC). Medical literature databases (Medline, Cochrane Library, and CANCERLIT) were searched for available literature concerning the treatment of HCC with TheraSphere. These publications were reviewed for scientific and clinical validity. Studies pertaining to the use of yttrium-90 for HCC date back to the 1960s. The results from the early animal safety studies established a radiation exposure range of 50-100 Gy to be used in human studies. Phase I dose escalation studies followed, which were instrumental in delineating radiation dosimetry and safety parameters in humans. These early studies emphasized the importance of differential arteriolar density between hypervascular HCC and surrounding liver parenchyma. Current trends in research have focused on advancing techniques to safely implement this technology as an alternative to traditional methods of treating unresectable HCC, such as external beam radiotherapy, conformal beam radiotherapy, ethanol ablation, trans-arterial chemoembolization, and radiofrequency ablation. Yttrium-90 (TheraSphere) is an outpatient treatment option for HCC. Current and future research should focus on implementing multicenter phase II and III trials comparing TheraSphere with other therapies for HCC

  5. Electrochemical corrosion of lanthanum chromite and yttrium chromite in coal slag

    Energy Technology Data Exchange (ETDEWEB)

    Marchant, D.D.; Bates, J.L.

    1981-01-01

    Lanthanum chromites have long been considered as electrodes for magnetohydrodynamic (MHD) generator channels. These chromites, when doped with divalent ions such as Ca, Mg or Sr, have adequate electronic and electrical conductivity (2), and melting points greater than 2500/sup 0/K. However, above approx. 1850/sup 0/K, selective vapor loss of chromium results in the formation of a La/sub 2/O/sub 3/ phase. The La/sub 2/O/sub 3/ is hydroscopic at room temperature, resulting in a large volume change and loss of mechanical integrity when exposed to H/sub 2/O. The analogous yttrium chromites have thermal and electrical properties similar to that for the lanthanum chromites. Although vapor loss of Cr results in the formation of Y/sub 2/O/sub 3/, this oxide does not hydrate. Corrosion studies of yttrium chromite compositions show that doped YCrO/sub 3/ may be a viable MHD electrode. An electrochemical corrosion study of both magnesium-doped lanthanum and yttrium chromites in synthetic coal slag electrolytes is described. Possible chemical and electrochemical degradation phenomena, as well as the relative rates of corrosion are emphasized.

  6. Yttrium-90 microspheres for the treatment of hepatocellular carcinoma: a review.

    Science.gov (United States)

    Salem, Riad; Hunter, Russell D

    2006-01-01

    To present a critical review of yttrium-90 (TheraSphere) for the treatment of hepatocellular carcinoma (HCC). Medical literature databases (Medline, Cochrane Library, and CANCERLIT) were searched for available literature concerning the treatment of HCC with TheraSphere. These publications were reviewed for scientific and clinical validity. Studies pertaining to the use of yttrium-90 for HCC date back to the 1960s. The results from the early animal safety studies established a radiation exposure range of 50-100 Gy to be used in human studies. Phase I dose escalation studies followed, which were instrumental in delineating radiation dosimetry and safety parameters in humans. These early studies emphasized the importance of differential arteriolar density between hypervascular HCC and surrounding liver parenchyma. Current trends in research have focused on advancing techniques to safely implement this technology as an alternative to traditional methods of treating unresectable HCC, such as external beam radiotherapy, conformal beam radiotherapy, ethanol ablation, trans-arterial chemoembolization, and radiofrequency ablation. Yttrium-90 (TheraSphere) is an outpatient treatment option for HCC. Current and future research should focus on implementing multicenter phase II and III trials comparing TheraSphere with other therapies for HCC.

  7. Electrochemical separation of cerium and yttrium in molten chlorides on liquid-metallic electrodes

    International Nuclear Information System (INIS)

    Yamshchikov, L.F.; Lebedev, V.A.; Nichkov, I.F.

    1978-01-01

    An estimating calculation of the coefficients of separation of cerium and yttrium in the process of electrolysis in molten salts on liquid electrodes of aluminium, gallium, indium, lead, tin, antimonium and zinc is carried out. The calculation of the separation coefficients was carried out according to the known values of activation coefficients of cerium and yttrium in fusible metals. The electrolysis was carried out at 973 K in the argon air in the cell with an eutectic mixture of NaCl and KCl as an elactrolyte. It is shown that the salten phase is concentrated by yttrium, and the melallic one- by cerium on all the electrodes. The value of the separation coefficient of Ce and Y is considerably high and continuously increases on the fusible metals in the Zn, In, Ga, Al, Pb, Sn, Sb series. The experimental values of the separation coefficients practically coincide with the theoretically calculated ones, testifying to the possibility of the effective separation of elements even in a single-staged possibility of the effective separation of elements even in a single-staged process. An electrolysis of molten salts is not inferior in its selectivity to the universally recognized methods of the fine purification of substances permitting to separate Ce and Y with the Ksub(sep) approximately equal to 10

  8. Fabrication and electrical characterization of 15% yttrium-doped barium zirconate-nitrate freeze drying method combined with vacuum heating

    International Nuclear Information System (INIS)

    Imashuku, Susumu; Uda, Tetsuya; Nose, Yoshitaro; Awakura, Yasuhiro

    2011-01-01

    Research highlights: → Very fine 15% yttrium-doped barium zirconate powder of particle size about 30 nm was obtained by synthesizing at 500 deg. C in vacuum from powder mixed by the nitrate freeze-drying method. → Large and homogeneous grains of 15% yttrium-doped barium zirconate were easily obtained using the synthesized powder. → Grain boundary resistance was not inversely proportional to the grain size as theoretically expected. → Specific grain boundary conductivity varies with samples because impurities and/or evaporation loss of barium oxide might affect the grain-boundary resistance in 15% yttrium-doped barium zirconate. - Abstract: We applied a nitrate freeze-drying method to obtain a fine synthesized powder of 15% yttrium-doped barium zirconate. Fine 15% yttrium-doped barium zirconate powder of particle size about 30 nm was obtained by synthesizing at 500 deg. C in vacuum from a powder mixed by the nitrate freeze-drying method. However, we could not obtain such fine powder by synthesizing in air. Using the powder synthesized in vacuum, large and homogeneous grains of 15% yttrium-doped barium zirconate were easily obtained after sintering. Then, the bulk and grain boundary resistance were evaluated by AC 2-terminal measurement of sample in the form of bar and pellet and DC 4-terminal measurement of bar-shape sample. The grain boundary resistance was not inversely proportional to the grain size as theoretically expected. We concluded that specific grain boundary conductivity varies with samples. Some impurities, evaporation loss of barium oxide and/or other unexpected reasons might affect the grain boundary resistance in 15% yttrium-doped barium zirconate.

  9. Nature of the bifunctional chelating agent used for radioimmunotherapy with yttrium-88 monoclonal antibodies: critical factors in determining in vivo survival and organ toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Kozak, R.W.; Raubitschek, A.; Mirzadeh, S.; Brechbiel, M.W.; Junghaus, R.; Gansow, O.A.; Waldmann, T.A. (Center for Biologics Evaluation and Research, FDA, Bethesda, MD (USA))

    1989-05-15

    One factor that is critical to the potential effectiveness of radioimmunotherapy is the design of radiometal-chelated antibodies that will be stable in vivo. Stability in vivo depends on the condition that both the chelate linkage and radiolabeling procedures not alter antibody specificity and biodistribution. In addition, synthesis and selection of the chelating agent is critical for each radiometal in order to prevent inappropriate release of the radiometal in vivo. In the present study, we compare the in vivo stability of seven radioimmunoconjugates that use different polyaminocarboxylate chelating agents to complex yttrium-88 to the mouse anti-human interleukin-2 receptor monoclonal antibody, anti-Tac. Chelate linkage and radiolabeling procedures did not alter the immunospecificity of anti-Tac. In order to assess whether yttrium was inappropriately released from the chelate-coupled antibody in vivo, iodine-131-labeled and yttrium-88 chelate-coupled antibodies were simultaneously administered to the same animals to correlate the decline in yttrium and radioiodinated antibody activity. The four stable yttrium-88 chelate-coupled antibodies studied displayed similar iodine-131 and yttrium-88 activity, indicating minimal elution of yttrium-88 from the complex. In contrast, the unstable yttrium-88 chelate-coupled antibodies had serum yttrium-88 activities that declined much more rapidly than their iodine-131 activities, suggesting loss of the radiolabel yttrium-88 from the chelate. Furthermore, high rates of yttrium-88 elution correlated with deposition in bone. Four chelating agents emerged as promising immunotherapeutic reagents: isothiocyanate benzyl DTPA and its derivatives 1B3M, MX, and 1M3B.

  10. Improvement of the oxidation resistance of Tribaloy T-800 alloy by the additions of yttrium and aluminium

    International Nuclear Information System (INIS)

    Zhang, Y.-D.; Zhang, C.; Lan, H.; Hou, P.Y.; Yang, Z.-G.

    2011-01-01

    Research highlights: → The additions of yttrium (Y) reduced the oxidation rate of Tribaloy T-800 alloy. → Y promoted selective oxidation of Cr due to refinement of alloy phase size. → The oxidation rate was further reduced by Y plus Al with a protective Al 2 O 3 scale. → The positive effect of Y and Al being more pronounced at the higher temperature. - Abstract: The microstructures and oxidation behaviour of the modified Tribaloy T-800 alloys by additions of yttrium and yttrium plus aluminium have been studied. At the presence of yttrium alone, the oxidation rate decreased, and the selective oxidation of chromium was promoted, which was related to the refinement of alloy phase size. The addition of yttrium plus aluminium further reduced the oxidation rate. The selective oxidation of chromium and aluminium were both promoted significantly. The benefits were especially pronounced at 1000 o C, with the formation of protective alumina external layer and no internal oxides, which may be detrimental to the alloy mechanical property.

  11. Determination of the emission rate for the 14 MeV neutron generator with the use of radio-yttrium

    Directory of Open Access Journals (Sweden)

    Laszynska Ewa

    2015-06-01

    Full Text Available The neutron emission rate is a crucial parameter for most of the radiation sources that emit neutrons. In the case of large fusion devices the determination of this parameter is necessary for a proper assessment of the power release and the prediction for the neutron budget. The 14 MeV neutron generator will be used for calibration of neutron diagnostics at JET and ITER facilities. The stability of the neutron generator working parameters like emission and angular homogeneity affects the accuracy of calibration other neutron diagnostics. The aim of our experiment was to confirm the usefulness of yttrium activation method for monitoring of the neutron generator SODERN Model: GENIE 16. The reaction rate induced by neutrons inside the yttrium sample was indirectly measured by activation of the yttrium sample, and then by means of the γ-spectrometry method. The pre-calibrated HPGe detector was used to determine the yttrium radioactivity. The emissivity of neutron generator calculated on the basis of the measured radioactivity was compared with the value resulting from its electrical settings, and both of these values were found to be consistent. This allowed for a positive verification of the reaction cross section that was used to determine the reaction rate (6.45 × 10−21 reactions per second and the neutron emission rate (1.04 × 108 n·s−1. Our study confirms usefulness of the yttrium activation method for monitoring of the neutron generator.

  12. Nuclear magnetic resonance of iron-57 nuclei in local fields in yttrium and iron garnets; Resonance magnetique nucleaire des noyaux du fer 57 dans les champs locaux du grenat d'yttrium et de fer

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-07-01

    We have demonstrated the nuclear resonance of {sup 57}Fe nuclei in the local field of each of the two magnetic sub-lattices of yttrium and iron garnets. The resonance frequencies and the relaxation times have been measured as a function of the temperature. (author) [French] Nous avons mis en evidence la resonance nucleaire des noyaux de {sup 57}Fe dans le champ local de chacun des deux sous-reseaux magnetiques du grenat d'yttrium et de fer. Les frequences de resonances et les temps de relaxation ont ete mesures en fonction de la temperature. (auteur)

  13. Status and prospects on development of yttrium-based high-temperature superconducting coated conductor

    International Nuclear Information System (INIS)

    Izumi, Teruo; Yanagi, Nagato

    2017-01-01

    Development of a large-sized large-current conductor using a high-temperature superconducting wire rod based on copper oxide has been started worldwide for the purpose of applying it as an option of a magnet for a nuclear fusion prototype reactor. There is yttrium-based thin film wire rod as a promising candidate. Japan is leading the development of this wire rod for many years, aiming to apply it to power equipment and the like. This paper explained the history of wire rod development, basic superconducting properties and manufacturing method, and latest achievements, and overviewed the feasibility of application to nuclear fusion reactor magnets. At present, the use of niobium-based low-temperature superconducting wire rod that is used in ITER is the basic idea. On the other hand, the development of wire rod using a copper oxide type high-temperature superconductor (HTS) has also been started. HTS wire rod is evaluated as suitable for application to nuclear fusion magnets due to its superior critical current characteristics and high mechanical rigidity up to high magnetic fields at high temperatures of yttrium. As current development progress, there are development of high-quality wire rod in the magnetic field and development of low AC loss wire rod. As future prospects, cost reduction due to mass production and improvement of yield, and investigation of low-resistance connection technology are being studied. The remaining future challenges of yttrium-based HTS are improvement of the anisotropy, influence on neutron irradiation, and problem of activation. (A.O.)

  14. Processes leading to yttrium-barium cuprates formation in synthesis using nitrates

    International Nuclear Information System (INIS)

    Kulakov, A.B.; Tesker, A.M.; Zalishchanskij, M.E.; Tret'yakov, Yu.D.; Gipius, A.A.

    1989-01-01

    An attempt to determine sequence and conditions for transformations occuring at heating both of mechanical mixture of copper, yttrium and barium nitrates and salt product of sublimated dehydration of quick frozen solution of nitrates in question of correlation which corresponds to YBa 2 Cu 3 O 7-σ final compounds is made. It is shown that unlike individual nitrates their thermolysis in the mixture occurs at lower temperatures with mechanism variation of decomposition separate stages. Specimens of superconducting ceramics with 4.3 g/cm 3 density phase composition and oxygen content which correspond to YBa 2 Cu 3 O 6.85±0.05 formula are obtaied

  15. Ultrasonic and viscometric studies of yttrium soaps in mixed organic solvents

    International Nuclear Information System (INIS)

    Mehrotra, K.N.; Tandon, K.; Rawat, M.K.

    1992-01-01

    The ultrasonic and viscosity measurements of yttrium soaps (caprylate, caprate and laurate) in a mixture of benzene and dimethyl formamide (3:2) have been carried out with a view to determine the critical micellar concentration soap-solvent interaction and other allied parameters. The various acoustic parameters (intermolecular free-length adiabatic compressibility, apparent molar compressibility, specific acoustic impedance, molar sound velocity, solvation number available volume and relative association) have been evaluated by ultrasonic velocity measurements. The results of viscosity measurement have been explained in terms of well known equations. (author). 18 refs., 2 figs., 3 tabs

  16. Erbium-doped yttrium aluminium garnet ablative laser treatment for endogenous ochronosis.

    Science.gov (United States)

    Chaptini, Cassandra; Huilgol, Shyamala C

    2015-08-01

    Ochronosis is a rare disease characterised clinically by bluish-grey skin discolouration and histologically by yellow-brown pigment deposits in the dermis. It occurs in endogenous and exogenous forms. Endogenous ochronosis, also known as alkaptonuria, is an autosomal recessive disease of tyrosine metabolism, resulting in the accumulation and deposition of homogentisic acid in connective tissue. We report a case of facial endogenous ochronosis and coexistent photodamage, which was successfully treated with erbium-doped yttrium aluminium garnet laser resurfacing and deep focal point treatment to remove areas of residual deep pigment. © 2014 The Australasian College of Dermatologists.

  17. Radio-synoviorthesis with yttrium 90 in the knee-joint in rheumatoid arthritis

    International Nuclear Information System (INIS)

    Hagena, F.W.; Muenchen Univ.

    1982-01-01

    The radio-synoviorthesis with yttrium 90 in the knee-joint in rheumatoid arthritis was performed and controlled in 106 knees of patients with rheumatoid arthritis over a span of time between 6 and 49 months. The results are similar to those of other authors. As compared to synovectomy radio-synoviorthesis seems less successful as far as long-term results are concerned. As local treatment radio-synoviorthesis seems a good supplementory element in the therapeutic plan of rheumatoid arthritis. The indication to alternative procedures has been considered carefully for each individual case and joint. (orig.) [de

  18. Nature of the magnetic susceptibility of dysprosium. Paramagnetic susceptibility of dysprosium - yttrium alloys

    International Nuclear Information System (INIS)

    Demidov, V.G.; Levitin, R.Z.; Chistyakov, O.D.

    1976-01-01

    The paramagnetic susceptibility of single crystals of dysprosium-yttirum alloys is measured in the basal plane and along the hexagonal axis. It is shown that the susceptibility of the alloys obeys the Curie-Weiss law, the effective magnetic moments allong the different directions being the same and the paramagnetic Curie temperatures being different. The difference between the paramagnetic Curie temperatures in the basal plane and along the hexagonal axis is independent of the dysprosium concentration in the alloy. As a comparison with the theoretical models of magnetic anisotropy shows, this is an indication that the magnetic anisotropy of dysprosium - yttrium alloys is of a single-ion nature

  19. Solid-phase synthesis of yttrium ferrites with structures of perovskite and garnet

    Energy Technology Data Exchange (ETDEWEB)

    Tkachenko, E V; Shapovalov, A G; Aksel' rod, N L; Pazdnikov, I P [Ural' skij Gosudarstvennyj Univ., Sverdlovsk (USSR)

    1980-09-01

    The solid phase synthesis of yttrium ferrites having a perovskite- and garnet-like structure has been investigated in the temperature range from 800 to 1500 deg C and temper times of up to 80 hours by reaction zone simulation and magnetic phase analysis. It is shown that for conversion degrees d<0.15 the reactions are diffusion-controlled. The rate constants and effective diffusion in the formation of YFeO/sub 3/ and Y/sub 3/Fe/sub 5/O/sub 12/ have been determined.

  20. PET imaging of soluble yttrium-86-labeled carbon nanotubes in mice.

    Directory of Open Access Journals (Sweden)

    Michael R McDevitt

    2007-09-01

    Full Text Available The potential medical applications of nanomaterials are shaping the landscape of the nanobiotechnology field and driving it forward. A key factor in determining the suitability of these nanomaterials must be how they interface with biological systems. Single walled carbon nanotubes (CNT are being investigated as platforms for the delivery of biological, radiological, and chemical payloads to target tissues. CNT are mechanically robust graphene cylinders comprised of sp(2-bonded carbon atoms and possessing highly regular structures with defined periodicity. CNT exhibit unique mechanochemical properties that can be exploited for the development of novel drug delivery platforms. In order to evaluate the potential usefulness of this CNT scaffold, we undertook an imaging study to determine the tissue biodistribution and pharmacokinetics of prototypical DOTA-functionalized CNT labeled with yttrium-86 and indium-111 ((86Y-CNT and (111In-CNT, respectively in a mouse model.The (86Y-CNT construct was synthesized from amine-functionalized, water-soluble CNT by covalently attaching multiple copies of DOTA chelates and then radiolabeling with the positron-emitting metal-ion, yttrium-86. A gamma-emitting (111In-CNT construct was similarly prepared and purified. The constructs were characterized spectroscopically, microscopically, and chromatographically. The whole-body distribution and clearance of yttrium-86 was characterized at 3 and 24 hours post-injection using positron emission tomography (PET. The yttrium-86 cleared the blood within 3 hours and distributed predominantly to the kidneys, liver, spleen and bone. Although the activity that accumulated in the kidney cleared with time, the whole-body clearance was slow. Differential uptake in these target tissues was observed following intravenous or intraperitoneal injection.The whole-body PET images indicated that the major sites of accumulation of activity resulting from the administration of (86Y-CNT were

  1. Optimization Recovery of Yttrium Oxide in Precipitation, Extraction, and Stripping Process

    Science.gov (United States)

    Perwira, N. I.; Basuki, K. T.; Biyantoro, D.; Effendy, N.

    2018-04-01

    Yttrium oxide can be used as a dopant control rod of nuclear reactors in YSH material and superconductors. Yttrium oxide is obtained in the Xenotime mineral derived from byproduct of tin mining PT Timah Bangka which contain rare earth elements (REE) dominant Y, Dy, and Gd whose content respectively about 29.53%, 7.76%, and 2.58%. Both usage in the field of nuclear and non-nuclear science and technology is need to pure from the impurities. The presence of impurities in the yttrium oxide may affect the characteristic of the material and the efficiency of its use. Thus it needs to be separated by precipitation and extraction-stripping and calcination in the making of the oxide. However, to obtain higher levels of Yttrium oxide, it is necessary to determine the optimum conditions for its separation. The purpose of this research was to determine the optimum pH of precipitation, determine acid media and concentration optimum in extraction and stripping process and determine the efficiency of the separation of Y from REE concentrate. This research was conducted with pH variation in the precipitation process that pHs were 4 - 8, the difference of acid media for the extraction process, i.e., HNO3, HCl and H2SO4 with each concentration of 0,5 M; 1 M; 1,5 M; and 2 M and for stripping process were HNO3, HCl, and H2SO4 with each concentration of 1 M; 2M; and 3 M. Based on the result, the optimum pH of precipitation process was 6,5, the optimumacid media was HNO3 0,5 M, and for stripping process media was HNO3 3 M. The efficiency of precipitation process at pH 6,5 was 69,53 %, extraction process was 96.39% and stripping process was 4,50%. The separation process from precipitation to extraction had increased the purity and the highest efficiency recovery of Y was in the extraction process and obtained Y2O3 purer compared to the feed with the Y2O3 content of 92.87%.

  2. Quantitative and Qualitative Assessment of Yttrium-90 PET/CT Imaging

    OpenAIRE

    Attarwala, Ali Asgar; Molina-Duran, Flavia; Büsing, Karen-Anett; Schönberg, Stefan O.; Bailey, Dale L.; Willowson, Kathy; Glatting, Gerhard

    2014-01-01

    Yttrium-90 is known to have a low positron emission decay of 32 ppm that may allow for personalized dosimetry of liver cancer therapy with (90)Y labeled microspheres. The aim of this work was to image and quantify (90)Y so that accurate predictions of the absorbed dose can be made. The measurements were performed within the QUEST study (University of Sydney, and Sirtex Medical, Australia). A NEMA IEC body phantom containing 6 fillable spheres (10-37 mm ∅) was used to measure the 90Y distribut...

  3. Phonon-impurity relaxation and acoustic wave absorption in yttrium-aluminium garnet crystals with impurities

    International Nuclear Information System (INIS)

    Ivanov, S.N.; Kotelyanskij, I.M.; Medved', V.V.

    1983-01-01

    The experimental results of investigations of the influence of substitution impurities in the yttrium-aluminium garnet lattice on absorption of high-frequency acoustic waves are presented. It is shown that the phonon-impurity relaxation processses affect at most the wave absorption and have resonance character when the acoustic wave interacts with the thermal phonon group in the vicinity of the perturbed part of the phonon spectrum caused by the impurity. The differences of time values between inelastic and elastic thermal phonons relaxations determined from the data on longitudinal and shear waves in pure and impurity garnet crystals are discussed

  4. Yttrium-90 radioembolization using TheraSphere in the management of primary and secondary liver tumors.

    Science.gov (United States)

    Riaz, A; Lewandowski, R J; Kulik, L; Salem, R

    2009-06-01

    Locoregional therapies, such as transarterial chemoembolization, radioembolization and thermal ablation (e.g., radiofrequency ablation) are establishing their roles in the management of liver malignancies. With yYttrium-90 radioembolization therapy (90Y) radionuclide labeled microspheres are injected into the tumor feeding artery. This allows the delivery of a high radioactive dose to the tumor with minimal toxicity to normal tissues. 90Y has demonstrated to be safe and effective in the management of liver tumors. Authors present a review of the literature available for the use of TheraSphere for radioembolization in the management of liver tumors.

  5. Treatment of diffuse large B-cell lymphoma of the liver with yttrium-90 microsphere embolization.

    Science.gov (United States)

    Fenske, Timothy S; Benjamin, Heather; Kroft, Steven H; Hohenwalter, Eric J; Rilling, William S

    2008-11-01

    A 41-year-old male with a 4-year history of chronic hepatitis C presented with a 1-month history of abdominal pain, fatigue, weight loss, and night sweats. Laboratory examinations, chest, abdomen, and pelvic CT scans, PET-CT scans, ultrasound-guided needle biopsies of liver lesions, bone-marrow biopsy, flow cytometry, and immunohistochemical staining for B-cell markers including CD20. Chemoresistant diffuse large B-cell lymphoma, with gradual loss of CD20 antigen expression. Embolization of hepatic tumors using yttrium-90 microspheres (Therasphere, Theragenics Corporation, Buford, GA).

  6. Yttrium-90 radioembolization of hepatocellular carcinoma and metastatic disease to the liver.

    Science.gov (United States)

    Lewandowski, Robert J; Salem, Riad

    2006-03-01

    Yttrium-90 ((90)Y) radioembolization is a catheter-based therapy that delivers internal radiation to hepatic tumors in the form of microspheres. (90)Y can be delivered to the hepatic tumor as either a constituent of a glass microsphere, TheraSphere(®), or as a biocompatible resin-based microsphere, SIR-Spheres(®). Once embedded within the tumor microcirculation, these microspheres emit β-radiation at therapeutic levels. While the technical aspects of radioembolization are quite complex, the collective clinical experience presented in the literature supports the use of (90)Y radioembolization for unresectable hepatic malignancies.

  7. Metastable phases in yttrium oxide plasma spray deposits and their effect on coating properties

    International Nuclear Information System (INIS)

    Gourlaouen, V.; Schnedecker, G.; Boncoeur, M.; Lejus, A.M.; Collongues, R.

    1993-01-01

    Yttrium oxide coatings were obtained by plasma spray. Structural investigations on these deposits show that, due to the drastic conditions of this technique, a minor monoclinic B phase is formed in the neighborhood of the major cubic C form. The authors discuss here the influence of different plasma spray parameters on the amount of the B phase formed. They describe also the main properties of Y 2 O 3 B and C phases in these deposits such as structural characteristics, thermal stability and mechanical behavior

  8. Electrical properties of single crystal Yttrium Iron Garnet ultra-thin films at high temperatures

    OpenAIRE

    Thiery, Nicolas; Naletov, Vladimir V.; Vila, Laurent; Marty, Alain; Brenac, Ariel; Jacquot, Jean-François; de Loubens, Grégoire; Viret, Michel; Anane, Abdelmadjid; Cros, Vincent; Youssef, Jamal Ben; Demidov, Vladislav E.; Demokritov, Sergej O.; Klein, Olivier

    2017-01-01

    We report a study on the electrical properties of 19 nm thick Yttrium Iron Garnet (YIG) films grown by liquid phase epitaxy. The electrical conductivity and Hall coefficient are measured in the high temperature range [300,400]~K using a Van der Pauw four-point probe technique. We find that the electrical resistivity decreases exponentially with increasing temperature following an activated behavior corresponding to a band-gap of $E_g\\approx 2$ eV, indicating that epitaxial YIG ultra-thin film...

  9. The enhanced visible light photocatalytic activity of yttrium-doped BiOBr synthesized via a reactable ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    He, Minqiang; Li, Weibing [School of Chemistry and Chemical Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013 (China); Xia, Jiexiang, E-mail: xjx@ujs.edu.cn [School of Chemistry and Chemical Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013 (China); Xu, Li; Di, Jun [School of Chemistry and Chemical Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013 (China); Xu, Hui [School of the Environment, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013 (China); Yin, Sheng [School of Chemistry and Chemical Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013 (China); Li, Huaming, E-mail: lhm@ujs.edu.cn [School of Chemistry and Chemical Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013 (China); Li, Mengna [School of Chemistry and Chemical Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013 (China)

    2015-03-15

    Graphical abstract: Yttrium (Y)-doped BiOBr with different Y doping concentrations has been synthesized via solvothermal method in the presence of reactable ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C16mim]Br). The photocatalytic activities of the yttrium doped BiOBr samples were evaluated by the degradation of ciprofloxacin (CIP) and rhodamine B (RhB) under visible-light irradiation. The yttrium doped BiOBr exhibited enhanced photocatalytic activity for the degradation of the two types of pollutants, and the 5wt%Y-doped BiOBr showed the highest photocatalytic activity. The enhanced photocatalytic performance could be attributed to the reduced band gap and improved separation of electron–hole pairs. - Highlights: • Yttrium (Y)-doped BiOBr composites have been synthesized via solvothermal method in the presence of reactable ionic liquid [C16mim]Br. • The yttrium doped BiOBr exhibited enhanced photocatalytic activity for the degradation of ciprofloxacin (CIP) and rhodamine B (RhB). • The enhanced photocatalytic performance could be attributed to the reduced band gap and improved separation of electron–hole pairs. - Abstract: Yttrium (Y)-doped BiOBr with different Y doping concentrations has been synthesized via solvothermal method in the presence of reactable ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C{sub 16}mim]Br). Their structures, morphologies and optical properties were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and UV–vis diffuse reflectance spectroscopy (DRS). The photocatalytic activities of the yttrium doped BiOBr samples were evaluated by the degradation of ciprofloxacin (CIP) and rhodamine B (RhB) under visible-light irradiation. The yttrium doped BiOBr exhibited enhanced photocatalytic activity for the degradation of the two types of pollutants, and the 5wt%Y-doped BiOBr showed the highest

  10. ELECTRON MICROSCOPIC INVESTIGATION OF YTTRIUM ALUMINUM GARNET POWDERS Y3AL5O12, SYNTHESIZED BY SOL–GEL METHOD

    OpenAIRE

    A. E. Baranchikov; V. A. Maslov; S. V. Shcherbakov; V. A. Usachyov; N. E. Kononenko; P. P. Fedorov; K. V. Dukelskiy

    2015-01-01

    Subject of Study. The paper presents results of characterization for neodymium doped yttrium aluminum garnet nanopowders - YAG:Nd3+ by the method of scanning electronic microscopy. Method. Synthesis of YAG:Nd3+ was carried out by sol-gel method from nitrate or acetate - nitrate solutions with addition of some organic compounds and ammonia as well. Such substances were used as the source ones: oxides of neodymium and yttrium with the content of the basic substance equal to 99.999 %; organic co...

  11. Process for making a titanium diboride-chromium diboride-yttrium titanium oxide ceramic composition

    Science.gov (United States)

    Holcombe, C.E.; Dykes, N.L.

    1992-04-28

    A ceramic composition is described. The ceramic composition consists essentially of from about 84 to 96 w/o titanium diboride, from about 1 to 9 w/o chromium diboride, and from about 3 to about 15 w/o yttrium-titanium-oxide. A method of making the ceramic composition is also described. The method of making the ceramic composition comprises the following steps: Step 1--A consolidated body containing stoichiometric quantities of titanium diboride and chromium diboride is provided. Step 2--The consolidated body is enclosed in and in contact with a thermally insulated package of yttria granules having a thickness of at least 0.5 inches. Step 3--The consolidated body enclosed in the thermally insulated package of yttria granules is heated in a microwave oven with microwave energy to a temperature equal to or greater than 1,900 degrees centigrade to sinter and uniformly disperse yttria particles having a size range from about 1 to about 12 microns throughout the consolidated body forming a densified body consisting essentially of titanium diboride, chromium diboride, and yttrium-titanium-oxide. The resulting densified body has enhanced fracture toughness and hardness. No Drawings

  12. Studies on Characterization, Optical Absorption, and Photoluminescence of Yttrium Doped ZnS Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ranganaik Viswanath

    2014-01-01

    Full Text Available Pure ZnS and ZnS:Y nanoparticles were synthesized by a chemical coprecipitation route using EDTA-ethylenediamine as a stabilizing agent. X-ray diffraction (XRD, high resolution transmission electron microscopy (HRTEM, field emission scanning electron microscopy (FE-SEM, Fourier transform infrared spectrometry (FTIR, thermogravimetric-differential scanning calorimetry (TG-DSC, and UV-visible and photoluminescence (PL spectroscopy were employed to characterize the as-synthesized ZnS and ZnS:Y nanoparticles, respectively. XRD and TEM studies show the formation of cubic ZnS:Y particles with an average size of ~4.5 nm. The doping did not alter the phase of the zinc sulphide, as a result the sample showed cubic zincblende structure. The UV-visible spectra of ZnS and ZnS:Y nanoparticles showed a band gap energy value, 3.85 eV and 3.73 eV, which corresponds to a semiconductor material. A luminescence characteristics such as strong and stable visible-light emissions in the orange region alone with the blue emission peaks were observed for doped ZnS nanoparticles at room temperature. The PL intensity of orange emission peak was found to be increased with an increase in yttrium ions concentration by suppressing blue emission peaks. These results strongly propose that yttrium doped zinc sulphide nanoparticles form a new class of luminescent material.

  13. Thermoelectric Properties of the Yttrium-Doped Ceramic Oxide SrTiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Tamal Tahsin; Ur, Soon-Chul [Korea National University of Transportation, Chungju (Korea, Republic of)

    2017-01-15

    The doping dependence of the thermoelectric figure of merit, ZT, of the ceramic oxide SrTiO{sub 3} at high temperature has been studied. In this study, yttrium was used as the doping element. A conventional solid-state reaction method was used for the preparation of Y-doped SrTiO{sub 3}. The doping level in SrTiO{sub 3} was controlled to be in the doping range of 2 - 10 mole%. Almost all the yttrium atoms incorporated into the SrTiO{sub 3} provided charge carriers, as was observed by using X-ray diffraction pattern. The relative densities of all the samples varied from 98.53% to 99.45%. The thermoelectric properties, including the electrical conductivity σ, Seebeck coefficient S, thermal conductivity k, and the figure of merit, ZT, were investigated at medium temperatures. The ZT value showed an obvious doping level dependence, in which a value as high as 0.18 is realized at 773 K for a doping of 8 mole%.

  14. Aspects of radiation protection during the treatment of liver cancer using yttrium-90 labelled microspheres

    International Nuclear Information System (INIS)

    Klemp, P.F.B.; Perry, A.M.; Fox, R.A.; Gray, B.N.; Burton, M.A.

    1989-01-01

    Twenty eight patients have received treatment for liver cancer by the intra-hepatic arterial injection of between 1 and 4 GBq of yttrium-90 labelled microspheres. The injection was performed at laparotomy. If 11.1 MBq of yttrium-90 are distributed evenly over 1 sq cm of tissue, the tissue surface will suffer an initial beta dose rate of 16.2 Gy h -1 . Special precautions are therefore essential during the injection procedure, subsequently in nursing the patient and if further intervention becomes necessary. A specially designed apparatus is used for the injection, glass spectacles are worn and if the active liver is to be handled, lead rubber gloves are used. The theatre is prepared so that contaminated items can be easily isolated and a 'spill pack' is readily available. At completion of the operation, the bremsstrahlung dose rate at 15 cm from the liver is initially 15 μSv h -1 GBq -1 . Contamination of urine is typically 20 to 50 kBq L -1 while the contamination of other body fluids is negligible. Finger doses to the surgeons has varied from 2 to 5 mSv GBq -1 injected while personnel film badges used to monitor the dose equivalent to the surgeons and ward staff have recorded maximum doses of 1.5 mSv and 300 μSv respectively. 11 refs., 1 fig., 3 tabs

  15. Quantitation in PET using isotopes emitting prompt single gammas: application to yttrium-86

    International Nuclear Information System (INIS)

    Walrand, Stephan; Jamar, Francois; Mathieu, Isabelle; De Camps, Joelle; Lonneux, Max; Pauwels, Stanislas; Sibomana, Merence; Labar, Daniel; Michel, Christian

    2003-01-01

    Several yttrium-90 labelled somatostatin analogues are now available for cancer radiotherapy. After injection, a large amount of the compound is excreted via the urinary tract, while a variable part is trapped in the tumour(s), allowing the curative effect. Unfortunately, the compound may also be trapped in critical tissues such as kidney or bone marrow. As a consequence, a method for assessment of individual biodistribution and pharmacokinetics is required to predict the maximum dose that can be safely injected into patients. However, 90 Y, a pure β - particle emitter, cannot be used for quantitative imaging. Yttrium-86 is a positron emitter that allows imaging of tissue uptake using a PET camera. In addition to the positron, 86 Y also emits a multitude of prompt single γ-rays, leading to significant overestimation of uptake when using classical reconstruction methods. We propose a patient-dependent correction method based on sinogram tail fitting using an 86 Y point spread function library. When applied to abdominal phantom acquisition data, the proposed correction method significantly improved the accuracy of the quantification: the initial overestimation of background activity by 117% was reduced to 9%, while the initial error in respect of kidney uptake by 84% was reduced to 5%. In patient studies, the mean discrepancy between PET total body activity and the activity expected from urinary collections was reduced from 92% to 7%, showing the benefit of the proposed correction method. (orig.)

  16. High-Performance Pyrochlore-Type Yttrium Ruthenate Electrocatalyst for Oxygen Evolution Reaction in Acidic Media

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jaemin [Department; Shih, Pei-Chieh [Department; Tsao, Kai-Chieh [Department; Pan, Yung-Tin [Department; Yin, Xi [Department; Sun, Cheng-Jun [X-ray; Yang, Hong [Department

    2017-08-17

    Development of acid-stable electrocatalysts with low overpotential for oxygen evolution reaction (OER) is a major challenge for the production of hydrogen directly from water. We report in this paper a pyrochlore yttrium ruthenate (Y2Ru2O7-δ) electrocatalyst that has significantly enhanced performance towards OER in acid media over the best-known catalysts, with an onset overpotential of 190 mV and high stability in 0.1-M perchloric acid solution. X-ray absorption near-edge structure (XANES) indicates Y2Ru2O7-δ electrocatalyst had a low valence state that favors the high OER activity. Density functional theory (DFT) calculation shows this pyrochlore has lower band center energy for the overlap between Ru 4d and O 2p orbitals and therefore more stable Ru-O bond than RuO2, highlighting the effect of yttrium on the enhancement in stability. The Y2Ru2O7-δ pyrochlore is also free of expensive iridium metal, thus a cost-effective candidate for practical applications.

  17. Microstructural evolution of 316L stainless steels with yttrium addition after mechanical milling and heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kotan, Hasan, E-mail: hasankotan@gmail.com

    2015-10-28

    Nanocrystalline 316L stainless steels with yttrium addition were prepared by mechanical milling at cryogenic temperature and subjected to annealing treatments at various temperatures up to 1200 °C. The dependence of hardness on the microstructure was utilized to study the mechanical changes in the steels occurring during annealing. The microstructural evolution of the as-milled and annealed steels was characterized by means of X-ray diffraction (XRD), focused ion beam microscopy (FIB) and transmission electron microscopy (TEM) techniques. The results have revealed that austenite in as-received powder partially transformed to martensite phase during mechanical milling whereas the annealing induced reverse transformation of martensite-to-austenite. Furthermore, while the austenite-to-martensite phase ratio increased with increasing annealing temperature, the equilibrium structure was not achieved after three hours heat treatments up to 1200 °C resulting in a dual-phased steels with around 10% martensite. The grain size of 316L steel was 19 nm after mechanical milling and remained around 116 nm at 1100 °C with yttrium addition as opposed to micron size grains of plain 316L steel at the same annealing temperature. Such microstructural features facilitate the use of these materials at elevated temperatures, as well as the development of scalable processing routes into a dense nanocrystalline compact.

  18. Microstructure and tensile properties of yttrium nitride dispersion-strengthened 14Cr–3W ferritic steels

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Liqing [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); School of Mechanical and Mining Engineering, University of Queensland, Brisbane 4067, QLD (Australia); Liu, Zuming, E-mail: lzm@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Chen, Shiqi; Guo, Yang [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China)

    2015-12-15

    Highlights: • Innovative nano yttrium nitride dispersion strengthened steels were fabricated. • Higher content of additives accelerate the steel-ceramic powder milling process more. • Steel with high content (3%) of YN dispersoids can obtain good performance at 500 °C. - Abstract: 14Cr–3W ferritic steel powders were mechanically milled with microscale yttrium nitride (YN) particles to fabricate particle dispersion-strengthened ferritic steels. After hot consolidation and annealing, the steel matrix was homogeneously dispersed with nano-scale YN particles. The steel containing 0.3 wt.% YN particles exhibited a yield strength of 1445 MPa at room temperature. Its total elongation was 10.3%, and the fracture surface exhibited mixed ductile and quasi-cleavage fracture morphologies. The steel with a much higher content of YN particles (3 wt.%) in its matrix was much stronger (1652 MPa) at room temperature at the cost of ductility. In particular, it exhibited a high yield strength (1350 MPa) with applicable ductility (total elongation > 10%) at 500 °C. This study has developed a new kind of reinforcement particle to fabricate high-performance ferritic steels.

  19. Yttrium scandate thin film as alternative high-permittivity dielectric for germanium gate stack formation

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Cimang, E-mail: cimang@adam.t.u-tokyo.ac.jp; Lee, Choong Hyun; Nishimura, Tomonori; Toriumi, Akira [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656 (Japan); JST, CREST, 7-3-1 Hongo, Tokyo 113-8656 (Japan)

    2015-08-17

    We investigated yttrium scandate (YScO{sub 3}) as an alternative high-permittivity (k) dielectric thin film for Ge gate stack formation. Significant enhancement of k-value is reported in YScO{sub 3} comparing to both of its binary compounds, Y{sub 2}O{sub 3} and Sc{sub 2}O{sub 3}, without any cost of interface properties. It suggests a feasible approach to a design of promising high-k dielectrics for Ge gate stack, namely, the formation of high-k ternary oxide out of two medium-k binary oxides. Aggressive scaling of equivalent oxide thickness (EOT) with promising interface properties is presented by using YScO{sub 3} as high-k dielectric and yttrium-doped GeO{sub 2} (Y-GeO{sub 2}) as interfacial layer, for a demonstration of high-k gate stack on Ge. In addition, we demonstrate Ge n-MOSFET performance showing the peak electron mobility over 1000 cm{sup 2}/V s in sub-nm EOT region by YScO{sub 3}/Y-GeO{sub 2}/Ge gate stack.

  20. Scanning-SQUID investigation of spin-orbit torque acting on yttrium iron garnet devices

    Science.gov (United States)

    Rosenberg, Aaron J.; Jermain, Colin L.; Aradhya, Sriharsha V.; Brangham, Jack T.; Nowack, Katja C.; Kirtley, John R.; Yang, Fengyuan; Ralph, Daniel C.; Moler, Kathryn A.

    Successful manipulation of electrically insulating magnets, such as yttrium iron garnet, by by current-driven spin-orbit torques could provide a highly efficient platform for spintronic memory. Compared to devices fabricated using magnetic metals, magnetic insulators have the advantage of the ultra-low magnetic damping and the elimination of shunting currents in the magnet that reduce the torque efficiency. Here, we apply current in the spin Hall metal β-Ta to manipulate the magnetic orientation of micron-sized, electrically-insulating yttrium iron garnet devices. We do not observe spin-torque switching even for applied currents well above the critical current expected in a macrospin switching model. This suggests either inefficient transfer of spin torque at our Ta/YIG interface or a breakdown of the macrospin approximation. This work is supported by FAME, one of six centers of STARnet sponsored by MARCO and DARPA. The SQUID microscope and sensors were developed with support from the NSF-sponsored Center NSF-NSEC 0830228, and from NSF IMR-MIP 0957616.

  1. Use of Yttrium-90 TheraSphere for the treatment of unresectable hepatocellular carcinoma.

    Science.gov (United States)

    Liu, Michael D; Uaje, Michelle B; Al-Ghazi, Muthana S; Fields, Denise; Herman, June; Kuo, Jeffrey V; Milne, Norah; Nguyen, Thong H; Ramsinghani, Nilam S; Tokita, Kenneth M; Tsai, Fong Y; Vajgrt, Duane J; Imagawa, David K

    2004-11-01

    This is a retrospective analysis of a new treatment modality, intra-arterial administration of Yttrium-90 TheraSphere, for unresectable hepatocellular carcinoma (HCC). Patients with HCC not amenable to surgical treatment who had satisfactory physiological function without comorbid disease or significant pulmonary shunting were eligible for treatment. Patients were categorized into complete, partial, or no response based on serum alpha-fetoprotein (AFP) levels and CT or MRI imaging. Fourteen patients were considered candidates for treatment. Three patients were excluded due to significant hepatopulmonary shunting. Eleven patients were treated with TheraSphere. One patient (9%) had a complete response, eight patients (78%) had a partial response, and two patients (18%) showed no response. Partial and complete responders with AFP-associated HCC demonstrated a median decrease in AFP levels of 79 per cent at 73 days. No patients developed liver toxicity nor died due to treatment. Five patients (45%) died of progressive disease at a median of 7 months post-treatment. Six patients (54%) were alive at a median of 11 months (range, 9 to 20 months). Okuda stage 2 and 3 patients showed a median survival of 11 months and 7 months, respectively. Yttrium-90 TheraSphere treatment for unresectable hepatocellular carcinoma is well tolerated and appears to extend survival.

  2. Experimental-statistical method for investigation of multicomponent yttrium garnet systems

    International Nuclear Information System (INIS)

    Kojouharoff, V.; Ionchey, H.

    1986-01-01

    In the present work, some problems are discussed arising in the construction and study of a mathematical model describing the synthesis of multicomponent yttrium garnets with predetermined microwave parameters. To construct the model, the following formula was used for Ca-V YIG substituted with In and Cr: Y/sub 3-2x/Ca/sub 2x/Fe/sub 5-(x+y+z)/In/sub y/Cr/sub z/V/sub x/O/sub 12/. For this purpose, ferrogarnets were synthesized differing in x, y, and z with their values chosen so as to obtain real roots of a set of equations of the type Y/sub k/ = ΣB/sub i/X/sub i/ + ΣB/sub ij/X/sub i/X/sub j/ + ΣB/sub ijk/X/sub i/X/sub j/X/sub k/, where Y/sub k/ are the ferrogarnet microwave properties. The graphical presentation of these solutions as triple diagrams is a very convenient way of obtaining ferrogarnets with predetermined microwave characteristics. The possibility is created of mathematically predicting and determining the influence of the different components on the yttrium ferrogarnet parameters as a function of their concentration

  3. Biochemical investigation of yttrium(III) complex containing 1,10-phenanthroline: DNA binding and antibacterial activity.

    Science.gov (United States)

    Khorasani-Motlagh, Mozhgan; Noroozifar, Meissam; Moodi, Asieh; Niroomand, Sona

    2013-03-05

    Characterization of the interaction between yttrium(III) complex containing 1,10-phenanthroline as ligand, [Y(phen)2Cl(OH2)3]Cl2⋅H2O, and DNA has been carried out by UV absorption, fluorescence spectra and viscosity measurements in order to investigate binding mode. The experimental results indicate that the yttrium(III) complex binds to DNA and absorption is decreasing in charge transfer band with the increase in amount of DNA. The binding constant (Kb) at different temperatures as well as thermodynamic parameters, enthalpy change (ΔH°) and entropy change (ΔS°), were calculated according to relevant fluorescent data and Vant' Hoff equation. The results of interaction mechanism studies, suggested that groove binding plays a major role in the binding of the complex and DNA. The activity of yttrium(III) complex against some bacteria was tested and antimicrobial screening tests shown growth inhibitory activity in the presence of yttrium(III) complex. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Pemisahan Unsur Samarium dan Yttrium dari Mineral Tanah Jarang dengan Teknik Membran Cair Berpendukung (Supported Liquid Membrane

    Directory of Open Access Journals (Sweden)

    Amri Amin

    2009-06-01

    Full Text Available he increasing use of rare earth elements in high technology industries needs to be supported by developmental work for the separation of elements. The research objective is fiercely attracting and challenging considering the similarity of bath physical and chemical properties among these elements. The rate separation of samarium and yttrium elements using supported liquid membrane has been studied. Polytetrafluoroethylene (PTFE with pore size of 0.45 µm has been used as the membrane and di(2-ethylhexyl phosphate (D2EHP in hexane has been used as a carrier and nitric acid solution has been used as receiving phase. Result of experiments showed that the best separation rate of samarium and yttrium elements could be obtained at feeding phase of pH 3.0, di(2-ethylhexyl phosphate (D2EHP concentration of 0.3 M, agitation rate of 700 rpm, agitation time of 2 hours, and nitric acid and its solution concentrations of 1.0 M and 0.1 M, respectively. At this condition, separation rates of samarium and yttrium were 64.4 and 67.6%, respectively.   Keywords: liquid membrane, rare earth elements, samarium, yttrium

  5. Compounds of addition between yttrium and rare-earths (III) nitrates and the N,N,N'N'-tetramethyladipamide (TMAA)

    International Nuclear Information System (INIS)

    Lima, W.N. de.

    1974-01-01

    The synthesis of addition compounds between hydrated rare-earths and yttrium nitrates with the diamine N,N,N',N'-tetramethyladipamide (TMAA) in ethanol, is described. The compounds were characterized by elemental analisys, infrared, Raman, visible and near infrared spectra, molar conductance and molecular weight measurements, conductometric titrations and X-ray powder patterns. (Author) [pt

  6. ICP-MS determination of rare earth elements, yttrium, uranium and thorium in niobium-tantalum rich samples

    International Nuclear Information System (INIS)

    Sunilkumar, Beena; Padmasubashini, V.

    2013-01-01

    ICP-MS is a powerful and extremely sensitive technique which has been applied successfully for the determination of REEs in diverse geological samples. In the present work, ICP-MS has been applied for the rapid determination of REEs, yttrium as well as uranium and thorium in niobium and tantalum rich samples, using a fluoride fusion method for sample dissolution

  7. The influence of predeformations and annealings on yield stress and modulus of elongation essentially yttrium doped copper

    International Nuclear Information System (INIS)

    Neklyudov, I.M.; Sytin, V.I.; Voevodin, V.N.

    2003-01-01

    The researches results of influence of predeformations and annealings on elastic and plastic characteristics of vacuum melting and yttrium doped copper are given. The interrelation between elastic and plastic characteristics has been shown. It is shown that the yield stress and modulus of elongation essentially depend on predeformations and annealings and they are the structurally sensitive characteristics

  8. Effect of surface composition of yttrium-stabilized zirconia on partial oxidation of methane to synthesis gas.

    NARCIS (Netherlands)

    Zhu, J.J.; van Ommen, J.G.; Knoester, A.; Lefferts, Leonardus

    2005-01-01

    Catalytic partial oxidation of methane to synthesis gas (CPOM) over yttrium-stabilized zirconia (YSZ) was studied within a wide temperature window (500¿1100 °C). The catalysts were characterized by X-ray fluorescence (XRF) and low-energy ion scattering (LEIS). The influence of calcination

  9. Effect of phase composition on the corrosion properties of alloys of the magnesium-yttrium system in neutral solutions

    International Nuclear Information System (INIS)

    Krasnoyarskii, V.V.; Petrova, L.M.; Dobatkina, T.V.; Korol'kova, I.G.

    1992-01-01

    A study is made of the effect of phase composition on the corrosive dissolution of binary alloys of the system magnesium-8.2% yttrium. It is shown that the appearance of the intermetallide Mg 24 Y 5 - being the effective cathode - intensifies self-dissolution of the alloy under conditions of anodic galvanostatic polarization

  10. Physicochemical properties and ecotoxicological effects of yttrium oxide nanoparticles in aquatic media: Role of low molecular weight natural organic acids

    International Nuclear Information System (INIS)

    Zhang, Fan; Wang, Zhuang; Wang, Se; Fang, Hao; Chen, Mindong; Xu, Defu; Tang, Lili; Wang, Degao

    2016-01-01

    Understanding how engineered nanoparticles (ENPs) interact with natural organic acids is important to ecological risk assessment of ENPs, but this interaction remains poorly studied. Here, we investigate the dispersion stability, ion release, and toxicity of yttrium oxide nanoparticles (nY_2O_3) suspensions after exposure to two low molecular weight natural organic acids (LOAs), namely benzoic acid and gallic acid. We find that in the presence of LOAs the nY_2O_3 suspensions become more stable with surface zeta potential more positive or negative, accompanied by small agglomerated size. LOA interaction with nY_2O_3 is shown to promote the release of dissolved yttrium from the nanoparticles, depending on the concentrations of LOAs. Toxic effects of the nY_2O_3 suspensions incubated with LOAs on Scenedesmus obliquus as a function of their mixture levels show three types of signs: stimulation, inhibition, and alleviation. The mechanism of the effects of LOAs on the nY_2O_3 toxicity may be mainly associated with the degree of agglomeration, particle-induced oxidative stress, and dissolved yttrium. Our results stressed the importance of LOA impacts on the fate and toxicity of ENPs in the aquatic environment. - Highlights: • LOAs significantly increased aqueous stability of nY2O3 in a dose-dependent manner. • The presence of LOAs promoted dissolution of nY2O3 in a dose-dependent manner. • Toxicity of nY2O3 with LOAs to Scenedesmus obliquus varied with mixture levels. • Stimulation, inhibition, and alleviation effects of nY2O3 with LOAs were observed. • Mechanism may be driven by agglomeration, oxidative stress, and dissolved yttrium. - LOAs elevate the dispersion stability of nano-Y_2O_3, promote the release of dissolved yttrium, and alter the algal toxicity of nano-Y_2O_3.

  11. The influence of annealing on yttrium oxide thin film deposited by reactive magnetron sputtering: Process and microstructure

    Directory of Open Access Journals (Sweden)

    Y. Mao

    2017-01-01

    Full Text Available Yttrium oxide thin films were prepared by reactive magnetron sputtering in different deposition condition with various oxygen flow rates. The annealing influence on the yttrium oxide film microstructure is investigated. The oxygen flow shows a hysteresis behavior on the deposition rate. With a low oxygen flow rate, the so called metallic mode process with a high deposition rate (up to 1.4µm/h was achieved, while with a high oxygen flow rate, the process was considered to be in the poisoned mode with an extremely low deposition rate (around 20nm/h. X-ray diffraction (XRD results show that the yttrium oxide films that were produced in the metallic mode represent a mixture of different crystal structures including the metastable monoclinic phase and the stable cubic phase, while the poisoned mode products show a dominating monoclinic phase. The thin films prepared in metallic mode have relatively dense structures with less porosity. Annealing at 600 °C for 15h, as a structure stabilizing process, caused a phase transformation that changes the metastable monoclinic phase to stable cubic phase for both poisoned mode and metallic mode. The composition of yttrium oxide thin films changed from nonstoichiometric to stoichiometric together with a lattice parameter variation during annealing process. For the metallic mode deposition however, cracks were formed due to the thermal expansion coefficient difference between thin film and the substrate material which was not seen in poisoned mode deposition. The yttrium oxide thin films that deposited in different modes give various application options as a nuclear material.

  12. Decision tree analysis to assess the cost-effectiveness of yttrium microspheres for treatment of hepatic metastases from colorectal cancer

    International Nuclear Information System (INIS)

    Kelley, B.B.; Walker, G.D.; Miles, K.A.

    2002-01-01

    Full text: The aim is to determine the cost-effectiveness of yttrium microsphere treatment of hepatic metastases from colorectal cancer, with and without FDG-PET for detection of extra-hepatic disease. A decision tree was created comparing two strategies for yttrium treatment with chemotherapy, one incorporating PET in addition to CT in the pre-treatment work-up, to a strategy of chemotherapy alone. The sensitivity and specificity of PET and CT were obtained from the Federal Government PET review. Imaging costs were obtained from the Medicare benefits schedule with an additional capital component added for PET (final cost $1200). The cost of yttrium treatment was determined by patient-tracking. Previously published reports indicated a mean gain in life-expectancy from treatment of 0.52 years. Patients with extra-hepatic metastases were assumed to receive no survival benefit. Cost effectiveness was expressed as incremental cost per life-year gained (ICER). Sensitivity analysis determined the effect of prior probability of extra-hepatic disease on cost-savings and cost-effectiveness. The cost of yttrium treatment including angiography, particle perfusion studies and bed-stays, was $10530. A baseline value for prior probability of extra-hepatic disease of 0.35 gave ICERs of $26,378 and $25,271 for the no-PET and PET strategies respectively. The PET strategy was less expensive if the prior probability of extra-hepatic metastases was greater than 0.16 and more cost-effective if above 0.28. Yttrium microsphere treatment is less cost-effective than other interventions for colon cancer but comparable to other accepted health interventions. Incorporating PET into the pre-treatment assessment is likely to save costs and improve cost-effectiveness. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  13. Electrical conductivity of zirconia and yttrium-doped zirconia from Indonesian local zircon as prospective material for fuel cells

    International Nuclear Information System (INIS)

    Apriany, Karima; Permadani, Ita; Rahmawati, Fitria; Syarif, Dani G.; Soepriyanto, Syoni

    2016-01-01

    In this research, zirconium dioxide, ZrO 2 , was synthesized from high-grade zircon sand that was founded from Bangka Island, Sumatra, Indonesia. The zircon sand is a side product of Tin mining plant industry. The synthesis was conducted by caustic fusion method with considering definite stoichiometric mole at every reaction step. Yttrium has been doped into the prepared zirconia by solid state reaction. The prepared materials were then being analyzed by X-ray diffraction equipped with Le Bail refinement to study its crystal structure and cell parameters. Electrical conductivity was studied through impedance measurement at a frequency range of 20 Hz- 5 MHz. Morphological analysis was conducted through Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-ray (EDX) for elemental analysis. The results show that the prepared yttrium stabilized zirconia, YSZ, was crystallized in the cubic structure with a space group of P42/NMC. The sintered zirconia and yttrium stabilized zirconia at 8 mol% of yttrium ions (8YSZ) show dense surface morphology with a grain size less than 10 pm. Elemental analysis on the sintered zirconia and 8YSZ show that sintering at 1500°C could eliminate the impurities, and the purity became 81.30%. Impedance analysis shows that ZrO 2 provide grain and grain boundary conductivity meanwhile 8YSZ only provide grain mechanism. The yttrium doping enhanced the conductivity up to 1.5 orders. The ionic conductivity of the prepared 8YSZ is categorized as a good material with conductivity reach 7.01 x10 -3 at 700 °C. The ionic conductivities are still lower than commercial 8YSZ at various temperature. It indicates that purity of raw material might significantly contribute to the electrical conductivity. (paper)

  14. Seven up. The incorporation of Li{sup +} cations in yttrium tungstate and silicate tungstate

    Energy Technology Data Exchange (ETDEWEB)

    Dorn, Katharina V.; Schustereit, Tanja; Strobel, Sabine; Hartenbach, Ingo [Institute for Inorganic Chemistry, University of Stuttgart (Germany)

    2017-12-13

    Lithium yttrium(III) oxidotungstate(VI), LiY{sub 5}W{sub 8}O{sub 32}, was synthesized by solid-state reaction of a mixture of lithium chloride, yttrium sesquioxide, and tungsten trioxide. It crystallizes monoclinically in space group C2/c (a = 1908.34(5) pm, b = 561.80(1) pm, c = 1147.22(3) pm, β = 111.255(2) , Z = 2). The structure comprises one mixed Li{sup +}/Y{sup 3+} cationic position (molar ratio Li:Y1 = 1:1) and one cationic position exclusively occupied by Y{sup 3+} cations. All W{sup 6+} cations are surrounded by six O{sup 2-} anions, forming distorted octahedral coordination polyhedra, which are mutually linked by both edges and vertices to cascaded {sup 2}{sub ∞}{[W_4O_1_6]"8"-} layers. Lithium yttrium(III) oxidosilicate(IV) oxidotungstate(VI), LiY{sub 5}[SiO{sub 4}]{sub 2}[WO{sub 4}]{sub 4}, was obtained as by-product in the synthesis of YF[WO{sub 4}] by sintering a mixture of Y{sub 2}O{sub 3}, YF{sub 3}, and WO{sub 3} with lithium chloride as fluxing agent in sealed silica ampoules. It crystallizes orthorhombically in space group Pban (a = 512.08(4) pm, b = 1673.35(12) pm, c = 493.68(4) pm, Z = 1) bearing one mixed crystallographic position occupied by Li{sup +} and Y{sup 3+} cations in a molar ratio of 1:3 and one exclusive Y{sup 3+} position in its structure. The coordination polyhedra around the Si{sup 4+} and W{sup 6+} cations are isolated tetrahedra built up by four O{sup 2-} anions each. The crystal structure of this silicate tungstate can be derived from the scheelite-type structure by inserting anionic {sup 2}{sub ∞}{(Y2[SiO_4])"-} layers between cationic {sup 2}{sub ∞}{[(Li/Y1)_2[WO_4]_2]"+} double layers. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Determination of rare earth element content in yttrium aluminium garnet crystals by absorption spectrophotometry method

    International Nuclear Information System (INIS)

    Mejl'man, M.L.; Kolomijtsev, A.I.; Baskakova, Z.M.; Bagdasarov, Kh.S.; Kevorkov, A.M.

    1985-01-01

    Possibility of determination of relative and absolute contents of impurity trivalent REE ions in yttrium aluminium garnet of (YAG) monocrystals has been studied by the absorption spectrophotometry method. Absorption spectra in UV and visible regions YAG monocrystals doped by REE are studied. For each admixture the characteristic lines or absorption bands not overlapping with lines of other admixtures are defined and investigated. The extinction coefficients of characteristic lines are determined which allow one to measure absolute REE admixture concentrations in garnet crystals. A conclusion is drawn that the absorption spectrophotometry method permits to measure REE admixture content in YAG monocrystals within the concentration range of approximately 1x10sup(-3)-5 mas. % with an accuracy not less than 20% (with sample thickness of approximately 1 cm)

  16. Polarized neutron diffraction - a tool for testing extinction models: application to yttrium iron garnet

    International Nuclear Information System (INIS)

    Bonnet, M.; Delapalme, A.; Becker, P.

    1976-01-01

    This paper shows that polarized neutron experiments, which do not depend on any scale factor, are very dependent on extinction and provide original tests for extinction models. Moon, Koehler, Cable and Child (1972) have formulated the problem and proposed a first-order solution applicable only when the extinction is small. In the first part, some analytical derivations of secondary extinction corrections are discussed, using the formalism of Becker and Coppens (1974). In the second part, the main principles governing polarized neutron diffraction are briefly reviewed, with a special discussion of extinction problems. The method is then applied to the case of yttrium iron garnet (YIG). This experiment shows the technique of polarized neutrons to be very powerful for testing extinction models and for deciding whether the crystal behaves dynamically or kinematically (following Kato's criterion). (Auth.)

  17. A study of strain in thin epitaxial films of yttrium silicide on Si(111)

    Science.gov (United States)

    Siegal, Michelle F.; Martínez-Miranda, L. J.; Santiago-Avilés, J. J.; Graham, W. R.; Siegal, M. P.

    1994-02-01

    We present the results of an x-ray diffraction analysis of epitaxial yttrium silicide films grown on Si(111), with thicknesses ranging from 14 to 100 Å. The macroscopic strain along the out-of-plane direction for films containing pits or pinholes follows the trend observed previously in films of thicknesses up to 510 Å. The out-of-plane lattice parameter decreases linearly with film thickness. We show preliminary evidence that pinhole-free films do not follow the above trend, and that strain in these films has the opposite sign than in films with pinholes. Finally, our results also indicate that the mode of growth, coupled to the interfacial thermal properties of the films, affects the observed value for the strain in the films.

  18. A study of strain in thin epitaxial films of yttrium silicide on Si(111)

    International Nuclear Information System (INIS)

    Siegal, M.F.; Martinez-Miranda, L.J.; Santiago-Aviles, J.J.; Graham, W.R.; Siegal, M.P.

    1994-01-01

    We present the results of an x-ray diffraction analysis of epitaxial yttrium silicide films grown on Si(111), with thicknesses ranging from 14 to 100 A. The macroscopic strain along the out-of-plane direction for films containing pits or pinholes follows the trend observed previously in films of thicknesses up to 510 A. The out-of-plane lattice parameter decreases linearly with film thickness. We show preliminary evidence that pinhole-free films do not follow the above trend, and that strain in these films has the opposite sign than in films with pinholes. Finally, our results also indicate that the mode of growth, coupled to the interfacial thermal properties of the films, affects the observed value for the strain in the films

  19. Direct observation of magnon-phonon coupling in yttrium iron garnet

    Science.gov (United States)

    Man, Haoran; Shi, Zhong; Xu, Guangyong; Xu, Yadong; Chen, Xi; Sullivan, Sean; Zhou, Jianshi; Xia, Ke; Shi, Jing; Dai, Pengcheng

    2017-09-01

    The magnetic insulator yttrium iron garnet (YIG) with a ferrimagnetic transition temperature of ˜560 K has been widely used in microwave and spintronic devices. Anomalous features in spin Seeback effect (SSE) voltages have been observed in Pt/YIG and attributed to magnon-phonon coupling. Here, we use inelastic neutron scattering to map out low-energy spin waves and acoustic phonons of YIG at 100 K as a function of increasing magnetic field. By comparing the zero and 9.1 T data, we find that instead of splitting and opening up gaps at the spin wave and acoustic phonon dispersion intersecting points, magnon-phonon coupling in YIG enhances the hybridized scattering intensity. These results are different from expectations of conventional spin-lattice coupling, calling for different paradigms to understand the scattering process of magnon-phonon interactions and the resulting magnon polarons.

  20. Microstructure of thin film platinum electrodes on yttrium stabilized zirconia prepared by sputter deposition

    Energy Technology Data Exchange (ETDEWEB)

    Toghan, Arafat, E-mail: arafat.toghan@pci.uni-hannover.de [Institute of Physical Chemistry and Electrochemistry, Leibniz University of Hannover, Callinstrasse 3-3a, D-30167 Hannover (Germany); Khodari, M. [Chemistry Department, Faculty of Science, South Valley University, Qena, 83523 (Egypt); Steinbach, F.; Imbihl, R. [Institute of Physical Chemistry and Electrochemistry, Leibniz University of Hannover, Callinstrasse 3-3a, D-30167 Hannover (Germany)

    2011-09-01

    (111) oriented thin film Pt electrodes were prepared on single crystals of yttrium-stabilized zirconia (YSZ) by sputter deposition of platinum. The electrodes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), atomic force microscopy (AFM) and by profilometry. SEM images of the as-sputtered platinum film show a compact amorphous Pt film covering uniformly the substrate. Upon annealing at 1123 K, gaps and pores at the interface develop leading to a partial dewetting of the Pt film. Increasing the annealing temperature to 1373 K transforms the polycrystalline Pt film into single crystalline grains exhibiting a (111) orientation towards the substrate.

  1. Spin wave propagation in perpendicularly magnetized nm-thick yttrium iron garnet films

    Science.gov (United States)

    Chen, Jilei; Heimbach, Florian; Liu, Tao; Yu, Haiming; Liu, Chuanpu; Chang, Houchen; Stückler, Tobias; Hu, Junfeng; Zeng, Lang; Zhang, Youguang; Liao, Zhimin; Yu, Dapeng; Zhao, Weisheng; Wu, Mingzhong

    2018-03-01

    Magnonics offers a new way for information transport that uses spin waves (SWs) and is free of charge currents. Unlike Damon-Eshbach SWs, the magneto-static forward volume SWs offer the reciprocity configuration suitable for SW logic devices with low power consumption. Here, we study forward volume SW propagation in yttrium iron garnet (YIG) thin films with an ultra-low damping constant α = 8 ×10-5 . We design different integrated microwave antenna with different k-vector excitation distributions on YIG thin films. Using a vector network analyzer, we measured SW transmission with the films magnetized in perpendicular orientation. Based on the experimental results, we extract the group velocity as well as the dispersion relation of SWs and directly compare the power efficiency of SW propagation in YIG using coplanar waveguide and micro stripline for SW excitation and detection.

  2. Structure and luminescence spectra of lutetium and yttrium borates synthesized from ammonium nitrate melt

    International Nuclear Information System (INIS)

    Klassen, Nikolay V.; Shmurak, Semion Z.; Shmyt'ko, Ivan M.; Strukova, Galina K.; Derenzo, Stephen E.; Weber, Marvin J.

    2005-01-01

    Lutetium and yttrium borates doped with europium, terbium, gadolinium, etc. have been synthesized by dissolving initial oxides and nitrates in ammonium nitrate melt and thermal decomposition of the solvent. Annealings in the range of 500-1100 deg. C modified the dimensions of the grains from 2 to 3 nm to more than 100 nm. Significant dependence of the structure of lutetium borate on slight doping with rare earth ions has been found: terbium makes high-temperature vaterite phase preferential at room temperature, whereas europium stabilizes low-temperature calcite phase. Influence of the structure of the borates on the pattern of the luminescence spectra of europium dopant was observed. Possibilities for manufacturing of scintillating lutetium borate ceramics by means of this method of synthesis are discussed

  3. Structure and luminescence spectra of lutetium and yttrium borates synthesized from ammonium nitrate melt

    Science.gov (United States)

    Klassen, Nikolay V.; Shmurak, Semion Z.; Shmyt'ko, Ivan M.; Strukova, Galina K.; Derenzo, Stephen E.; Weber, Marvin J.

    2005-01-01

    Lutetium and yttrium borates doped with europium, terbium, gadolinium, etc. have been synthesized by dissolving initial oxides and nitrates in ammonium nitrate melt and thermal decomposition of the solvent. Annealings in the range of 500-1100°C modified the dimensions of the grains from 2 to 3 nm to more than 100 nm. Significant dependence of the structure of lutetium borate on slight doping with rare earth ions has been found: terbium makes high-temperature vaterite phase preferential at room temperature, whereas europium stabilizes low-temperature calcite phase. Influence of the structure of the borates on the pattern of the luminescence spectra of europium dopant was observed. Possibilities for manufacturing of scintillating lutetium borate ceramics by means of this method of synthesis are discussed.

  4. Thermal decomposition of lanthanides (III) and yttrium (III) solid complexes from ethyl ene diamine tetraacetic acid

    International Nuclear Information System (INIS)

    Mercadante, A.

    1991-01-01

    Solid state compounds of lanthanides (III) and yttrium derived from ethyl ene diamine tetraacetic acid were prepared from respective basic carbonates, that were neutralized with EDTA stoichiometry quantities. Complexometry with EDTA, thermogravimetry (TG), differential thermal analysis (DTA) and X-ray diffraction have been used in the study of these compounds. The results of complexometry with EDTA as well as TG and DTA curves bed to the stoichiometry of these compounds the following general formula is obeyed: H[Ln(EDTA]. n H 2 O. X-ray powder patterns of these compounds permitted to establish two isomorphous series. The DTA ant TG curves allowed us to study the dehydration process, the thermal stability and thermal decomposition of these compounds. (C.G.C.)

  5. Yttrium and lanthanide nitrate complexes of N,N1-bis(4-antipyryl methylidene) ethylenediamine

    International Nuclear Information System (INIS)

    Joseph, Siby; Radhakrishnan, P.K.

    1998-01-01

    Complexes of yttrium and lanthanide nitrates with a Schiff base, N, N 1 -bis(4-antipyrylmethylidene)ethylenediamine (BAME) having the general formula [Ln(BAME) 2 (NO 3 )](NO 3 ) 2 , where Ln = Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho and Er have been synthesised and characterised by elemental analyses, molar conductance in non-aqueous solvents, electronic, infrared and proton NMR spectra. BAME acts as a neutral bidentate ligand coordinating through both azomethine nitrogen atoms. One of the nitrate groups is coordinated in a bidentate manner. A coordination number of six may be assigned to the metal ion in these complexes. The covalency parameters evaluated from the solid state electronic spectra suggest weak covalent character of the metal-ligand bond. (author)

  6. Spectrum and energy levels of six-times ionized yttrium (Y VII)

    Science.gov (United States)

    Reader, Joseph

    2018-03-01

    The spectrum of six-times ionized yttrium, Y VII, was photographed with a sliding-spark discharge on 10.7 m normal- and grazing-incidence spectrographs. The region of observation was 157-824 Å. The observations extend the known configurations 4s24p3, 4s4p4, 4p5, 4s24p25s, 4s24p26s to the nearly complete 4s24p24d configuration. Our results for 4s24p24d significantly revise results of Rahimullah et al (1978 Phys. Scr. 18 96); Ateqad et al (1984 J. Phys. B: At. Mol. Phys. 17 4617). A total of 168 lines and 56 energy levels are now known for this ion. The observed configurations were interpreted with Hartree-Fock calculations and least-squares fits of the energy parameters to the observed levels. Transition probabilities for all classified lines were calculated with the fitted parameters.

  7. Field and power dependence of auto-oscillations in yttrium-iron-garnet films

    International Nuclear Information System (INIS)

    McMichael, R.D.; Wigen, P.E.

    1988-01-01

    The nonlinear response of the magnetic spin system in yttrium-iron-garnet (YIG) thin films to high-power ferromagnetic resonance (FMR) at perpendicular resonance was studied and the results are presented. A diagram of the regions of auto-oscillation of the system as a function of field and power is presented which shows the modes that appear in low-power FMR becoming unstable to auto-oscillations with increased power. The auto-oscillations exhibit periodic, quasiperiodic, period doubling, and chaotic behavior with typical frequencies in the MHz range. The domains of oscillatory behavior due to individual resonance modes are seen to merge and shift to lower fields as power is increased. Possible mechanisms for the behavior are proposed

  8. Solubility and peculiarities of the yttrium-aluminium borate crystal growth

    International Nuclear Information System (INIS)

    Azizov, A.V.; Leonyuk, N.I.; Rezvyj, V.R.; Timchenko, T.I.; Belov, N.V.

    1982-01-01

    The nature of crystallization media and crystallization peculiarities of IAl 3 [BO 3 ] 4 yttrium-alluminium borate (YAB) were investigated. The investigation of YAB solubility was conducted in the melts of two different compositions: 88.1K 2 Mo 2 O 10 -3.5V 2 O 3 -8.4B 2 O 3 (1) and 89.5K 2 Mo 3 O 10 - - 10.5B 2 O 3 (2) at 1060-900 deg C. The YAB crystals obtained from different crystallization media had different habit and morphology. The revealed peculiarities are significant for the choice of the YAB crystal growing conditions on orientated seedings: more rapid growth can be exercised along the [0001] face from the solution in the melt (2)

  9. Growth of rare-earth doped single crystal yttrium aluminum garnet fibers

    Science.gov (United States)

    Bera, Subhabrata; Nie, Craig D.; Harrington, James A.; Cheng, Long; Rand, Stephen C.; Li, Yuan; Johnson, Eric G.

    2018-02-01

    Rare-earth doped single crystal (SC) yttrium aluminum garnet (YAG) fibers have great potential as high-power laser gain media. SC fibers combine the superior material properties of crystals with the advantages of a fiber geometry. Improving processing techniques, growth of low-loss YAG SC fibers have been reported. A low-cost technique that allows for the growth of optical quality Ho:YAG single crystal (SC) fibers with different dopant concentrations have been developed and discussed. This technique is a low-cost sol-gel based method which offers greater flexibility in terms of dopant concentration. Self-segregation of Nd ions in YAG SC fibers have been observed. Such a phenomenon can be utilized to fabricate monolithic SC fibers with graded index.

  10. Pulsed laser deposition of yttrium photocathode suitable for use in radio-frequency guns

    Science.gov (United States)

    Lorusso, A.; Trovò, M.; Demidovich, A.; Cinquegrana, P.; Gontad, F.; Broitman, E.; Chiadroni, E.; Perrone, A.

    2017-12-01

    Yttrium (Y) thin film was grown by pulsed laser deposition (PLD) on a copper (Cu) polycrystalline substrate. Ex situ morphological and structural characterisations of the circular Y film of 1.2 µm thickness and 3 mm diameter have shown a very low droplet density on the film surface and a crystalline feature with a preferred orientation along the Y (100) plane. Moreover, Y thin film resulted in being very adherent to the Cu substrate and more scratch resistant than Cu bulk. A twin thin film was deposited also on a Cu backflange of a radio-frequency (RF) gun to test the suitability of the metallic thin film as photocathode. It was observed that the Y-coated photocathode was characterised by a quantum efficiency ( QE) higher than that of the Cu bulk photocathode even if the presence of space charge effects didn't allow deriving the absolute maximum value of QE of Y photocathode.

  11. Correlation between evolution of inclusions and pitting corrosion in 304 stainless steel with yttrium addition.

    Science.gov (United States)

    Shi, Weining; Yang, Shufeng; Li, Jingshe

    2018-03-19

    Effects of the evolution of inclusions on the pitting corrosion resistance of 304 stainless steel with different contents of the rare-earth element yttrium (Y) were studied using thermodynamic calculations, accelerated immersion tests, and electrochemical measurements. The experimental results showed that regular Y 2 O 3 inclusions demonstrated the best pitting resistance, followed in sequence by (Al,Mn)O inclusions, the composite inclusions, and irregular Y 2 O 3 inclusions. The pitting resistance first decreased, then increased, and then decreased again with increasing Y content, because sulfide inclusions were easily generated when the Y content was low and YN inclusions were easily generated at higher Y contents. The best pitting corrosion resistance was obtained for 304 stainless steel with addition of 0.019% Y.

  12. The rise of metal radionuclides in medical imaging: copper-64, zirconium-89 and yttrium-86.

    Science.gov (United States)

    Ikotun, Oluwatayo F; Lapi, Suzanne E

    2011-04-01

    Positron emission tomography, with its high sensitivity and resolution, is growing rapidly as an imaging technology for the diagnosis of many disease states. The success of this modality is reliant on instrumentation and the development of effective and novel targeted probes. Initially, research in this area was focused on what we will define in this article as 'standard' PET isotopes (carbon-11, nitrogen-13, oxygen-15 and fluorine-18), but the short half-lives of these isotopes limit radiopharmaceutical development to those that probe rapid biological processes. To overcome these limitations, there has been a rise in nonstandard isotope probe development in recent years. This review focuses on the biological probes and processes that have been examined, in additiom to the preclinical and clinical findings with nonstandard radiometals: copper-64, zirconium-89, and yttrium-86.

  13. Nonlinear dynamics of three-magnon process driven by ferromagnetic resonance in yttrium iron garnet

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, R. O. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Centro Interdisciplinar de Ciências da Natureza, Universidade Federal da Integração Latino-Americana, 85867-970 Foz do Iguaçu, PR (Brazil); Holanda, J.; Azevedo, A.; Rezende, S. M., E-mail: rezende@df.ufpe.br [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Vilela-Leão, L. H. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Centro Acadêmico do Agreste, Universidade Federal de Pernambuco, 55002-970 Caruaru, PE (Brazil); Rodríguez-Suárez, R. L. [Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago (Chile)

    2015-05-11

    We report an investigation of the dynamics of the three-magnon splitting process associated with the ferromagnetic resonance (FMR) in films of the insulating ferrimagnet yttrium iron garnet (YIG). The experiments are performed with a 6 μm thick YIG film close to a microstrip line fed by a microwave generator operating in the 2–6 GHz range. The magnetization precession is driven by the microwave rf magnetic field perpendicular to the static magnetic field, and its dynamics is observed by monitoring the amplitude of the FMR absorption peak. The time evolution of the amplitude reveals that if the frequency is lowered below a critical value of 3.3 GHz, the FMR mode pumps two magnons with opposite wave vectors that react back on the FMR, resulting in a nonlinear dynamics of the magnetization. The results are explained by a model with coupled nonlinear equations describing the time evolution of the magnon modes.

  14. Kinetics and mechanism of the low-temperature yttrium-aluminium garnet synthesis

    International Nuclear Information System (INIS)

    Ivakin, Yu.D.; Danchevskaya, M.N.; Yanchenko, P.A.; Murav'eva, G.P.

    2000-01-01

    Kinetics and formation mechanism of finely crystalline yttrium-aluminium garnet (YAG) during hydrothermal and hot steam treatment of stoichiometric mixture of oxides in the range of temperature 200-400 Deg C and pressures of 1.5-26 MPa were studied. It is ascertained that formation of YAG occurs via intermediate stage of Y(OH) 3 structure formation, whereas the aluminia component is X-ray amorphous. Kinetics of YAG formation is described by the equation of solid phase transformation with the limiting stage of nucleation. The YAG formed contains 7-5 % of water, which corresponds to hydrogarnet structure. Unit cell parameters of the YAG samples synthesized are somewhat high and after heating up to 1200 Deg C they decrease [ru

  15. The study of structural characteristic of yttrium(3+) aquaion by density functional methods

    International Nuclear Information System (INIS)

    Buz'ko, V.Yu.; Sukhno, I.V.; Polushin, A.A.; Panyushkin, V.T.

    2006-01-01

    Structural characteristics of the yttrium aquaion Y(H 2 O) 8 3+ are calculated by DFT technique using density functionals SVWN5, B3LYP, B3P86, O3LYP, B3PW91, B1LYP, B971, MPW1PW9, PBE1PBE, BHandH and BNandHLYP. All calculations are carried out by means of GAUSSIAN-03 code. Structural characteristics of the Y(H 2 O) 8 3+ aquaion obtained by the use of the density functional method agree satisfactorily with the experiment. Hybrid nonlocal GGA-functionals foretell worse the structural characteristics of the Y(H 2 O) 8 3+ aquaion as compared with the reasonable simple combined functional BHandH and the simplest functional SVWN5 of the LSDA theory [ru

  16. High-energy xenon ion irradiation effects on the electrical properties of yttrium iron garnet

    International Nuclear Information System (INIS)

    Costantini, J.M.; Flament, J.L.; Sinopoli, L.; Trochon, J.; Uzureau, J.L.; Groult, D.; Studer, F.; Toulemonde, M.

    1989-01-01

    Thin monocristalline samples of yttrium iron garnet Y 3 Fe 5 O 12 (YIG) were irradiated at room temperature with 27 MeV/A 132 Xe ions at varying fluences up to 3.5 x 10 12 ions cm -2 . Sample thickness (100 μm) was smaller than the mean projected range of ions (170 μm) so that we were able to study the effects of irradiation damage solely. At such a high ion energy the nuclear energy loss is negligible and damage is mainly due to electronic excitation energy loss. YIG d.c conductivity is found to rise by a factor 40 for the highest dose while the permittivity increases only slightly after irradiation (40% max.). The dielectric losses are also enhanced as the ion fluence increases especially at lower frequencies (by a factor 6 at 10 KHz). No dielectric relaxation peak is observed in the frequency range explored here (10 KHz - 10 MHz)

  17. Yttrium-90 resin microspheres and their use in the treatment of intrahepatic cholangiocarcinoma.

    Science.gov (United States)

    Filippi, Luca; Schillaci, Orazio; Cianni, Roberto; Bagni, Oreste

    2018-04-01

    Intrahepatic cholangiocarcinoma (ICC) is a severe and rapidly progressive hepatic tumor. Surgery is often impracticable due to locally advanced presentation. On the other hand, chemotherapy has demonstrated only limited effectiveness. For these reasons, liver-directed therapies have been successfully applied for treating ICC. In particular, radioembolization with Yttrium-90 ( 90 Y)-labeled spheres has been reported to be a promising therapeutic approach for this neoplasia. Two commercial forms of 90 Y-labeled spheres are available: glass (TheraSphere ® ) and resin (SIR-Spheres ® ) microspheres. The aim of the present paper is to review the existing literature on the use of the resin microspheres for the treatment of unresectable and chemorefractory ICC, focusing on the methodology, clinical applications and side effects.

  18. Trace determination of yttrium and some heavy rare-earths by adsorptive stripping voltammetry

    International Nuclear Information System (INIS)

    Wang, J.; Zadeii, J.M.

    1986-01-01

    The interfacial and redox behaviour of rare-earth chelates the Solochrome Violet RS are exploited for developing a sensitive adsorptive stripping procedure. Yttrium and heavy rare earths such as dysprosium, holmium and ytterbium can thus be measured at ng/ml levels and below, by controlled adsorptive accumulation of the metal chelate at the hanging mercury drop electrode, followed by voltammetric measurement of the surface species. With a 3-min preconcentration time, the detection limit ranges from 5 x 10 -10 to 1.4 x 10 -9 M. The relative standard deviation at the 7 ng/ml level ranges from 4 to 7%. A separation method is required to differentiate between the individual rare-earth metals. (author)

  19. Complexes between lanthanide (III) and yttrium (III) picrates and tetra methylene sulfoxide as ligand

    International Nuclear Information System (INIS)

    Silva, M.A.A. da.

    1991-01-01

    The preparation and characterization of addition compounds between lanthanide (III) and yttrium (III) picrates and tetra methylene sulfoxide as ligand were described. The adducts were prepared in the molar relation 1 (salt): 3(ligand) in ethanol. They are microcrystalline with more intense color than those of their respective hydrated salts. At room temperature conditions they are non hygroscopic and do not present perceptible alterations. They became slightly opalescent, when heated between 363 and 423 K. At higher temperatures under several heating ratios, the behavior shown is the same: melting between 439 and 472 K. The characterization of the compounds was made by elemental analysis, electrolytic conductance measurements, X-ray powder patterns, infrared spectroscopy, visible electronic absorption and emission spectra of the neodymium (III) and europium (III), respectively. (author). 116 refs., 17 tabs., 11 figs

  20. Microtensile bond strength of composite resin to human enamel prepared using erbium: Yttrium aluminum garnet laser.

    Science.gov (United States)

    Delfino, Carina Sinclér; Souza-Zaroni, Wanessa Christine; Corona, Silmara Aparecida Milori; Palma-Dibb, Regina Guenka

    2007-02-01

    The Erbium: Yttrium Aluminum Garnet (YAG) laser used for preparation of cavity can alter the substrate and it could influence the bond strength of enamel. The aim of this in vitro study was to evaluate the influence of Er:YAG laser's energy using microtensile bond test. Three groups were obtained (cavity preparation) and each group was divided into two subgroups (adhesive system). After that the adhesive protocol was performed, sections with a cross-sectional area of 0.8 mm2 (+/-0.2 mm2) were obtained. The specimens were mounted in a universal testing machine (0.5 mm/min). Statistical analysis showed a decrease in bond strength for lased groups (p adhesive system was used the laser 300 mJ subgroup showed higher bond strength compared to the laser 250 mJ (p adhesive procedures than conventional bur-cut cavities. Copyright 2006 Wiley Periodicals, Inc.

  1. Evidence of dilute ferromagnetism in rare-earth doped yttrium aluminium garnet

    Energy Technology Data Exchange (ETDEWEB)

    Farr, Warrick G.; Goryachev, Maxim; Le Floch, Jean-Michel; Tobar, Michael E. [ARC Centre of Excellence for Engineered Quantum Systems, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009 (Australia); Bushev, Pavel [Experimentalphysik, Universität des Saarlandes, D-66123 Saarbrücken (Germany)

    2015-09-21

    This work demonstrates strong coupling regime between an erbium ion spin ensemble and microwave hybrid cavity-whispering gallery modes in a yttrium aluminium garnet dielectric crystal. Coupling strengths of 220 MHz and mode quality factors in excess of 10{sup 6} are demonstrated. Moreover, the magnetic response of high-Q modes demonstrates behaviour which is unusual for paramagnetic systems. This behaviour includes hysteresis and memory effects. Such qualitative change of the system's magnetic field response is interpreted as a phase transition of rare earth ion impurities. This phenomenon is similar to the phenomenon of dilute ferromagnetism in semiconductors. The clear temperature dependence of the phenomenon is demonstrated.

  2. Effect of intra-articular yttrium-90 on chronic pyrophosphate arthropathy of the knee

    International Nuclear Information System (INIS)

    Doherty, M.; Dieppe, P.A.

    1981-01-01

    Fifteen patients with bilateral, symmetrical chronic pyrophosphate arthropathy of the knee were given intra-articular injections of yttrium-90 (5 mCi) plus steroid (triamcinolone hexacetonide, 20 mg) into one knee, and saline plus steroid into the other (control) knee. Allocation of the 90 Y injection was random and double blind. After 6 months there was significantly less pain, inactivity stiffness, joint-line tenderness, and effusion in the 90 Y-injected knees than in the controls (p 90 Y-injected and control knees in the changes in range of movement (p 90 Y may be of benefit in chronic pyrophosphate arthropathy, a disease for which there is no treatment. The predilection of this condition to affect the knees of the elderly makes such treatment highly suitable because the joint lends itself readily to injection and the procedure carries very few actual or potential risks in this age group. (author)

  3. Ultra-low damping in lift-off structured yttrium iron garnet thin films

    Science.gov (United States)

    Krysztofik, A.; Coy, L. E.; Kuświk, P.; Załeski, K.; Głowiński, H.; Dubowik, J.

    2017-11-01

    We show that using maskless photolithography and the lift-off technique, patterned yttrium iron garnet thin films possessing ultra-low Gilbert damping can be accomplished. The films of 70 nm thickness were grown on (001)-oriented gadolinium gallium garnet by means of pulsed laser deposition, and they exhibit high crystalline quality, low surface roughness, and the effective magnetization of 127 emu/cm3. The Gilbert damping parameter is as low as 5 ×10-4. The obtained structures have well-defined sharp edges which along with good structural and magnetic film properties pave a path in the fabrication of high-quality magnonic circuits and oxide-based spintronic devices.

  4. A study of an ion-exchange process for separation of strontium and yttrium

    International Nuclear Information System (INIS)

    Mubarek, M.A.

    1980-01-01

    A study has been carried out to determine optimum conditions for the separation of strontium and yttrium by ion-exchange. The parameters of interest for such separation such as the dimensions of the ion-exchange columns, flow rates through the columns and pH values of the solutions, which affect the overall yield in the process, have been investigated. Application of this method for routine quantitative determinations of Sr-90 in environmental samples, particularly the wet-ashed biological materials has also been studied. The method, although a rapid and convenient one has not been found to yield consistent results probably due to the requirement of stringent analytical controls during the process. (author)

  5. radio embolization of yttrium 90 glass microspheres in treatment of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    El Fouly, A.H.A.

    2010-01-01

    Hepatocellular carcinoma (HCC) is a common cancer that typically occurs in the setting of cirrhosis and chronic hepatitis virus infections. HCC is considered currently as global problem; its incidence is expected to increase dramatically by the next few decades. More than 90 % of the accidentally diagnosed patients have non resectable tumor. Portal vein thrombosis, diffuse multifocal liver infiltration and large tumor burden are considered to be a great obstacle in front of the modern lines of treatment, even with Child A liver cirrhosis. Transarterial intrahepatic application of Yttrium-90 glass microspheres may allow effective local ablative treatment of patients with intrahepatic advanced hepatocellular carcinoma (HCC) with or without portal vein thrombosis. The aim of this open-label phase II study was to validate evidence on the safety and efficacy of this treatment in an European cohort of patients with locally advanced HCC such as (large tumor burden, multifocal distribution, portal vein thrombosis). And to assess the response rate according to different approved response assessment guidelines (WHO, RECIST and EASL). Patients and Methods Starting from November 2006 till March 2009, one hundred and eight advanced unresectable HCC patients with and without portal vein thrombosis were included in this prospective study. Yttrium-90 microspheres radiotherapy was performed in a lobar fashion through the right or left hepatic artery. In bilobar disease, right and left liver lobe were treated with 4-6 weeks intervals in between. Response rate was assessed according to different international response assessment criteria (WHO, RECIST and EASL) with sequential computed tomography scans till the last clinical visit or death. The safety of this technique was assessed according to the Common Toxicity Criteria version 3

  6. Sources and distribution of yttrium and rare earth elements in surface sediments from Tagus estuary, Portugal.

    Science.gov (United States)

    Brito, Pedro; Prego, Ricardo; Mil-Homens, Mário; Caçador, Isabel; Caetano, Miguel

    2018-04-15

    The distribution and sources of yttrium and rare-earth elements (YREE) in surface sediments were studied on 78 samples collected in the Tagus estuary (SW Portugal, SW Europe). Yttrium and total REE contents ranged from 2.4 to 32mg·kg -1 and 18 to 210mg·kg -1 , respectively, and exhibited significant correlations with sediment grain-size, Al, Fe, Mg and Mn, suggesting a preferential association to fine-grained material (e.g. aluminosilicates but also Al hydroxides and Fe oxyhydroxides). The PAAS (Post-Archean Australian Shale) normalized patterns display three distinct YREE fractionation pattern groups along the Tagus estuary: a first group, characterized by medium to coarse-grained material, a depleted and almost flat PAAS-normalized pattern, with a positive anomaly of Eu, representing one of the lithogenic components; a second group, characterized mainly by fine-grained sediment, with higher shale-normalized ratios and an enrichment of LREE relative to HREE, associated with waste water treatment plant (WWTP) outfalls, located in the northern margin; and, a third group, of fine-grained material, marked by a significant enrichment of Y, a depletion of Ce and an enrichment of HREE over LREE, located near an inactive chemical-industrial complex (e.g. pyrite roast plant, chemical and phosphorous fertilizer industries), in the southern margin. The data allow the quantification of the YREE contents and its spatial distribution in the surface sediments of the Tagus estuary, identifying the main potential sources and confirming the use of rare earth elements as tracers of anthropogenic activities in highly hydrodynamic estuaries. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Microstructural and mechanical properties of gravity-die-cast A356 alloy inoculated with yttrium and Al-Ti-B grain refiner simultaneously

    Directory of Open Access Journals (Sweden)

    Y.P. Lim

    2011-10-01

    Full Text Available In the present work, the effect of inoculating yttrium and Al-5Ti-1B simultaneously on A356 aluminum alloy has been studied. Gravity die casting process is used to cast the ASTM tensile test specimens for analysis. In each experiment, the Ti and B contents were maintained constantly at 0.1 and 0.02 wt% respectively. The addition of yttrium was manipulated at the amount of 0, 0.1, 0.2, 0.3, 0.4 and 0.5 wt%. Microstructural characterization of the as-cast A356 alloy was investigated by means of optical microscope and its phases are detected by XRD. The mechanical properties tested are tensile strength and hardness. The inoculation of yttrium was found to enhance the grain refinement effect of Al-5Ti-1B grain refiner and improve the mechanical properties. The optimal weight percentage of yttrium was found to be 0.3. The grain refining efficiency of combining yttrium and Al-5Ti-1B on A356 aluminum alloy was mainly attributed to the heterogeneous nucleation of TiB2 and TiAl3 particles which were dispersed more evenly in the presence of yttrium and the grain growth restriction effected by the accumulation of Al-Y compound at grain boundaries.

  8. High-performance carbon-nanotube-based complementary field-effect-transistors and integrated circuits with yttrium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Shibo; Zhang, Zhiyong, E-mail: zyzhang@pku.edu.cn; Si, Jia; Zhong, Donglai; Peng, Lian-Mao, E-mail: lmpeng@pku.edu.cn [Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871 (China)

    2014-08-11

    High-performance p-type carbon nanotube (CNT) transistors utilizing yttrium oxide as gate dielectric are presented by optimizing oxidization and annealing processes. Complementary metal-oxide-semiconductor (CMOS) field-effect-transistors (FETs) are then fabricated on CNTs, and the p- and n-type devices exhibit symmetrical high performances, especially with low threshold voltage near to zero. The corresponding CMOS CNT inverter is demonstrated to operate at an ultra-low supply voltage down to 0.2 V, while displaying sufficient voltage gain, high noise margin, and low power consumption. Yttrium oxide is proven to be a competitive gate dielectric for constructing high-performance CNT CMOS FETs and integrated circuits.

  9. Stability constants of mixed ligand complexes of lanthanide(III) and yttrium(III) with complexone and substituted salicylic acids

    International Nuclear Information System (INIS)

    Kolhe, Vishnu; Dwivedi, K.

    1996-01-01

    Salicylic acid and substituted salicylic acids are potential antimicrobial agents. Binary complexes of salicylic acid and its substituted derivatives with lanthanide(III) and yttrium(III) metal ions have been reported. There are reports on the ternary metal complexing equilibria with some lanthanide(III) and yttrium(III) metal ions involving aminopolycarboxylic acid as one ligand and salicylic acid (SA) and other related compounds as the second ligands. Ethylene glycol bis(2-aminoethylether)- N, N, N', N'-tetraacetic acid (EGTA) is an important member of aminopolycarboxylic acid and finds many applications in medicine and biology. Recently, few ternary complexes have been reported using EGTA as ligand. In view of biological importance of simple and mixed ligand complexes EGTA, SA and DNSA (3,5-dinitrosalicylic acid), a systematic study has been undertaken for the determination of stability constant and the results are reported. (author). 6 refs., 1 fig., 2 tabs

  10. Coupling of erbium dopants to yttrium orthosilicate photonic crystal cavities for on-chip optical quantum memories

    Energy Technology Data Exchange (ETDEWEB)

    Miyazono, Evan; Zhong, Tian; Craiciu, Ioana; Kindem, Jonathan M.; Faraon, Andrei, E-mail: faraon@caltech.edu [T. J. Watson Laboratory of Applied Physics, California Institute of Technology, 1200 E California Blvd, Pasadena, California 91125 (United States)

    2016-01-04

    Erbium dopants in crystals exhibit highly coherent optical transitions well suited for solid-state optical quantum memories operating in the telecom band. Here, we demonstrate coupling of erbium dopant ions in yttrium orthosilicate to a photonic crystal cavity fabricated directly in the host crystal using focused ion beam milling. The coupling leads to reduction of the photoluminescence lifetime and enhancement of the optical depth in microns-long devices, which will enable on-chip quantum memories.

  11. Controls on the composition and extraction of rare earth elements and yttrium (REY) in deep sea polymetallic nodules and sediments

    OpenAIRE

    Menendez Gamella, Amaya

    2017-01-01

    Rising demand for metals is driving a search for new mineral resources and mining of seafloor deposits is likely to commence in the next few years. These include polymetallic nodules and crusts that are highly enriched in Mn, Co, Ni, Cu, Mo, Li and Te, and deep-sea clays that can contain high concentrations of the rare earth elements and yttrium (REY). The potential environmental impacts of mining these deposits are, however, poorly constrained and a better understanding of the processes that...

  12. Separation of yttrium (III) from lanthanoids (III) by solvent extraction with substituted N-Alkylcarbonyl-N-phenylhydroxylamines

    International Nuclear Information System (INIS)

    Haraguchi, K.; Ogata, T.; Nakagawa, K.; Saitoh, T.; Kamidate, T.; Watanabe, H.

    1996-01-01

    A series of substituted N-alkylcarbonyl-N-phenylhydroxylamines(R-PHAs) were synthesized and utilized for the extraction of yttrium(III) and lanthanoids(III) in order to obtain effective extractants for the separation of yttrium(III) from the lanthanoids(III) and the mutual separation of the lanthanoids(III). The distribution ratio of yttrium(III) and the lanthanoids(III) between the carbon tetrachloride and the aqueous phases was measured as functions of the pH and the extractant concentration at 298 K at an ionic strength of 0.1 (NaNO 3 ). Yttrium(III) and the lanthanoids(III) were extracted with R-PHAs(HL) as self-adducted chelates of the form, ML 3 (HL) x , where 'x' is 1, 2 or 3 depending on the extraction system. The extractability of the metal ions decreased in the order of R-PHA having a primary, a secondary and a tertiary alkyl substituent attached to the carbonyl group because of the steric hindrance of the alkyl group. The separation factors for both Yb/Eu and Yb/Y pairs increased with increasing branching of the alkyl group of R-PHA. The excellent selectivity of R-PHAs having a tertiary alkyl group was attributable to a greater inductive effect of the tertiary alkyl group than those of the primary and secondary alkyl groups. The substituents at the phenyl group of R-PHAs gave no significant effect on the selectivity, while the extractability was enhanced considerably by introduction of electron withdrawing substituents at appropriate positions of the phenyl group of R-PHAs. (authors)

  13. Finite temperature magnon spectra in yttrium iron garnet from a mean field approach in a tight-binding model

    Science.gov (United States)

    Shen, Ka

    2018-04-01

    We study magnon spectra at finite temperature in yttrium iron garnet using a tight-binding model with nearest-neighbor exchange interaction. The spin reduction due to thermal magnon excitation is taken into account via the mean field approximation to the local spin and is found to be different at two sets of iron atoms. The resulting temperature dependence of the spin wave gap shows good agreement with experiment. We find that only two magnon modes are relevant to the ferromagnetic resonance.

  14. Determination of strontium-90 from direct separation of yttrium-90 by solid phase extraction using DGA Resin for seawater monitoring.

    Science.gov (United States)

    Tazoe, Hirofumi; Obata, Hajime; Yamagata, Takeyasu; Karube, Zin'ichi; Nagai, Hisao; Yamada, Masatoshi

    2016-05-15

    It is important for public safety to monitor strontium-90 in aquatic environments in the vicinity of nuclear related facilities. Strontium-90 concentrations in seawater exceeding the background level have been observed in accidents of nuclear facilities. However, the analytical procedure for measuring strontium-90 in seawater is highly demanding. Here we show a simple and high throughput analytical technique for the determination of strontium-90 in seawater samples using a direct yttrium-90 separation. The DGA Resin is used to determine the abundance of strontium-90 by detecting yttrium-90 decay (beta-emission) in secular equilibrium. The DGA Resin can selectively collect yttrium-90 and remove naturally occurring radionuclides such as (40)K, (210)Pb, (214)Bi, (238)U, and (232)Th and anthropogenic radionuclides such as (140)Ba, and (140)La. Through a sample separation procedure, a high chemical yield of yttrium-90 was achieved at 95.5±2.3%. The result of IAEA-443 certified seawater analysis (107.7±3.4 mBq kg(-1)) was in good agreement with the certified value (110±5 mBq kg(-1)). By developed method, we can finish analyzing 8 samples per day after achieving secular equilibrium, which is a reasonably fast throughput in actual seawater monitoring. By processing 3 L of seawater sample and applying a counting time of 20 h, minimum detectable activity can be as low as 1.5 mBq kg(-1), which could be applied to monitoring for the contaminated marine environment. Reproducibility was found to be 3.4% according to 10 independent analyses of natural seawater samples from the vicinity of the Fukushima Daiichi Nuclear Power Plant in September 2013. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Bonding mechanism of a yttrium iron garnet film on Si without the use of an intermediate layer

    International Nuclear Information System (INIS)

    Pantzas, Konstantinos; Patriarche, Gilles; Talneau, Anne; Youssef, Jamal Ben

    2014-01-01

    Direct bonding of yttrium iron garnet (YIG) on silicon without the use of an intermediate bonding layer is demonstrated and characterized using scanning transmission electron microscopy and energy-dispersive x-ray spectroscopy. During the bonding experiment, the garnet is reduced in the presence of oxide-free silicon. As a result, a 5 nm thick SiO 2 /amorphous-YIG bilayer is formed and welds the garnet to silicon.

  16. The effect of yttrium addition on oxidation of a sputtered nanocrystalline coating with moderate amount of tantalum in composition

    International Nuclear Information System (INIS)

    Wang, Jinlong; Chen, Minghui; Yang, Lanlan; Liu, Li; Zhu, Shenglong; Wang, Fuhui; Meng, Guozhe

    2016-01-01

    Graphical abstract: - Highlights: • Effect of Y addition on oxidation of nanocrystalline coating is studied. • Y addition delays transformation of q-Al_2O_3 to a-Al_2O_3 during oxidation. • Y addition prevents scale rumpling. • Y segregates at grain boundaries of the nanocrystalline coating. • Y retards the transportation of Ta thus reduces its oxidation. - Abstract: The effect of yttrium addition on isothermal oxidation at 1050 °C of a sputtered nanocrystalline coating with moderate amount of tantalum in composition was investigated. Results indicate that yttrium addition delays transformation of metastable θ-Al_2O_3 to equilibrium α-Al_2O_3 grown on the nanocrystalline coatings. It prevents scale rumpling and promotes the formation of oxide pegs at interface between the oxide scale and the underlying coating. Besides, yttrium prefers to segregate at grain boundaries of the nanocrystalline coating and retards the outward transportation of tantalum from coating to oxide scale, thus reducing the excessive oxidation of tantalum.

  17. Comparison of the air oxidation behaviors of Zircaloy-4 implanted with yttrium and cerium ions at 500 deg. C

    International Nuclear Information System (INIS)

    Chen, X.W.; Bai, X.D.; Xu, J.; Zhou, Q.G.; Chen, B.S.

    2002-01-01

    As a valuable process for surface modification of materials, ion implantation is eminent to improve mechanical properties, electrochemical corrosion resistance and oxidation behaviors of varieties of materials. To investigate and compare the oxidation behaviors of Zircaloy-4, implantation of yttrium ion and cerium ion were respectively employed by using an MEVVA source at the energy of 40 keV with a dose ranging from 1x10 16 to 1x10 17 ions/cm 2 . Subsequently, weight gain curves of the different specimens including as-received Zircaloy-4 and Zircaloy-4 specimens implanted with the different ions were measured after oxidation in air at 500 deg. C for 100 min. It was obviously found that a significant improvement was achieved in the oxidation behaviors of implanted Zircaloy-4 compared with that of the as-received Zircaloy-4, and the oxidation behavior of cerium-implanted Zircaloy-4 was somewhat better than that of yttrium-implanted specimen. To obtain the valence and the composition of the oxides in the scale, X-ray photoemission spectroscopy was used in the present study. Glancing angle X-ray diffraction, employed to analyze the phase transformation in the oxide films, showed that the addition of yttrium transformed the phase from monoclinic zirconia to tetragonal zirconia, yet the addition of cerium transformed the phase from monoclinic zirconia to hexagonal zirconia. In the end, the mechanism of the improvement of the oxidation behavior was discussed

  18. Hydrogen Production from Cyclic Chemical Looping Steam Methane Reforming over Yttrium Promoted Ni/SBA-16 Oxygen Carrier

    Directory of Open Access Journals (Sweden)

    Sanaz Daneshmand-Jahromi

    2017-09-01

    Full Text Available In this work, the modification of Ni/SBA-16 oxygen carrier (OC with yttrium promoter is investigated. The yttrium promoted Ni-based oxygen carrier was synthesized via co-impregnation method and applied in chemical looping steam methane reforming (CL-SMR process, which is used for the production of clean energy carrier. The reaction temperature (500–750 °C, Y loading (2.5–7.4 wt. %, steam/carbon molar ratio (1–5, Ni loading (10–30 wt. % and life time of OCs over 16 cycles at 650 °C were studied to investigate and optimize the structure of OC and process temperature with maximizing average methane conversion and hydrogen production yield. The synthesized OCs were characterized by multiples techniques. The results of X-ray powder diffraction (XRD and energy dispersive X-ray spectroscopy (EDX of reacted OCs showed that the presence of Y particles on the surface of OCs reduces the coke formation. The smaller NiO species were found for the yttrium promoted OC and therefore the distribution of Ni particles was improved. The reduction-oxidation (redox results revealed that 25Ni-2.5Y/SBA-16 OC has the highest catalytic activity of about 99.83% average CH4 conversion and 85.34% H2 production yield at reduction temperature of 650 °C with the steam to carbon molar ratio of 2.

  19. Tomographic bremsstrahlung imaging with yttrium-90 in the context of radioembolisation of liver tumors; Tomografische Bildgebung mit Yttrium-90-Bremsstrahlung im Rahmen der Radioembolisation von Lebertumoren

    Energy Technology Data Exchange (ETDEWEB)

    Grosser, Oliver Stephan

    2013-04-12

    Establish tomographic Bremsstrahlung SPECT imaging (BSPECT) for the clinical validation of Selective Internal Radiotherapy (SIRT) with Yttrium-90 ({sup 90}Y) labelled microspheres. Various energy ranges (75 ± 3.8 keV; 135 ± 6.8 keV; 167 ± 8.4 keV) and the summation window were studied to see if they were suitable for BSPECT. To this end, clinically available reconstruction techniques were analysed for their suitability for BSPECT. The tomographic examinations were performed on a cylindrical phantom filled with spheres of different diameters d = [28; 35; 40; 50; 60] mm in a non-active waterfilled background. The spheres were filled with identical {sup 90}Y activity concentration (AC). Measurements were conducted at AC = [14.58; 5.20; 1.98; 0.66] MBq/cm{sup 3}. The BSPECT were reconstructed with filtered back-projection (FBP), a 2D Ordered-Subset Expectation Maximisation Algorithm (2D-OSEM) and a 3D Geometric Mean Algorithm (3D-GMA). Evaluation was made visually and on the basis of objective performance parameters such as contrast, signal-to-noise ratio (SNR) and image noise. While the 75 keV ± 3.8 keV window was identified as suitable for the BSPECT, limitations were revealed as to use of different implementations of the Point Spread Function (PSF). It was found for all reconstruction techniques that, at a given sphere diameter, there existed a linear relationship between the AC in the spheres and the reconstructed pulse rate per volume element. The recovery effect was verified for small spheres. The iterative techniques were found to be suitable for the BSPECT at all AC. At low AC, the 3D-GMA exhibited the least noise and the highest SNR. The FBP turned out to be entirely inappropriate for the BSPECT. The narrow energy window in which the bremsstrahlung interferes with the characteristic X-radiation of lead can be used for BSPECT. In this approach, the tomographic data reconstructed with different algorithms exhibited a varying image quality, with the iterative

  20. Synthesis and in-depth analysis of highly ordered yttrium doped hydroxyapatite nanorods prepared by hydrothermal method and its mechanical analysis

    International Nuclear Information System (INIS)

    Nathanael, A. Joseph; Mangalaraj, D.; Hong, S.I.; Masuda, Y.

    2011-01-01

    In this study, undoped and yttrium (Y) doped nanocrystalline hydroxyapatite crystals were synthesized by the hydrothermal method at 180 °C for 24 h. Highly ordered and oriented hydroxyapatite (HAp) nanorods were prepared by yttrium doping and their nanostructure and physical properties were compared with those of undoped HAp rods. FESEM images showed that the doping with Y ions reduced the diameter (from 25 nm to 15 nm) and increased the length (from 95 nm to 115 nm) of the synthesized rods. The aspect ratio of the undoped and Y-doped nanorods were calculated to be 4.303 (SD = 0.0959) and 7.61 (SD = 0.0355), respectively. Specific surface area (SSA) analysis showed that SSA also increased from 66.74 m 2 /g to 68.57 m 2 /g with the addition of yttrium. Y-doped HAp nanorod reinforced HMWPE composites displayed the better mechanical performance than those reinforced with pure HAp nanorods. The possible strengthening of nanorods and the increase of SSA due to the reduction in the size of nanorods in the presence of yttrium may have contributed to the strengthening of Y-doped HAp/HMWPE composites. - Graphical Abstract: Highly ordered and oriented yttrium doped hydroxyapatite (HAp) nanorods were prepared by hydrothermal method. For undoped HAp the average length of the nanorod is 95 nm with mean diameter of 24 nm and for a Y doped nanorod the average length is ∼ 115 nm and the mean diameter is 15 nm. Mechanical analysis was carried out by polymer/nanoparticle composite method. Highlights: ► Yttrium doped hydroxyapatite nanorods were prepared by hydrothermal method. ► The nanorods have highly uniform size distribution. ► Yttrium substitution and nanostructure formation was confirmed by careful analysis. ► Mechanical strength was analyzed by polymer nanoparticle reinforcement method.

  1. The influence of gadolinium and yttrium on biomass production and nutrient balance of maize plants

    International Nuclear Information System (INIS)

    Saatz, Jessica; Vetterlein, Doris; Mattusch, Jürgen; Otto, Matthias; Daus, Birgit

    2015-01-01

    Rare earth elements (REE) are expected to become pollutants by enriching in the environment due to their wide applications nowadays. The uptake and distribution of gadolinium and yttrium and its influence on biomass production and nutrient balance was investigated in hydroponic solution experiments with maize plants using increasing application doses of 0.1, 1 and 10 mg L −1 . It could be shown that concentrations of up to 1 mg L −1 of Gd and Y did not reduce or enhance the plant growth or alter the nutrient balance. 10 mg L −1  Gd or Y resulted in REE concentrations of up to 1.2 weight-% in the roots and severe phosphate deficiency symptoms. Transfer rates showed that there was only little transport of Gd and Y from roots to shoots. Significant correlations were found between the concentration of Gd and Y in the nutrient solution and the root tissue concentration of Ca, Mg and P. - Highlights: • Roots accumulate REE in very high concentrations. • Transfer factors from root to shoot tissue are very low, with HREE higher than MREE. • The nutrient balance of the plant is severely influenced by REE addition. • Phosphate deficiency appears at high concentrations of REE addition. - The addition of the rare-earth elements Gd and Y results in less Ca and Mg uptake and phosphate deficiency in maize plants grown in hydroponics

  2. Improved hydrogen absorption and desorption kinetics of magnesium-based alloy via addition of yttrium

    Science.gov (United States)

    Yang, Tai; Li, Qiang; Liu, Ning; Liang, Chunyong; Yin, Fuxing; Zhang, Yanghuan

    2018-02-01

    Yttrium (Y) is selected to modify the microstructure of magnesium (Mg) to improve the hydrogen storage performance. Thereby, binary alloys with the nominal compositions of Mg24Yx (x = 1-5) are fabricated by inexpensive casting technique. Their microstructure and phase transformation during hydriding and dehydriding process are characterized by using X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy analysis. The isothermal hydrogen absorption and desorption kinetics are also measured by a Sievert's-type apparatus at various temperatures. Typical multiphase structures of binary alloy can be clearly observed. All of these alloys can reversibly absorb and desorb large amount of hydrogen at proper temperatures. The addition of Y markedly promotes the hydrogen absorption kinetics. However, it results in a reduction of reversible hydrogen storage capacity. A maximum value of dehydrogenation rate is observed with the increase of Y content. The Mg24Y3 alloy has the optimal desorption kinetic performance, and it can desorb about 5.4 wt% of hydrogen at 380 °C within 12 min. Combining Johnson-Mehl-Avrami kinetic model and Arrhenius equation, the dehydrogenation activation energy of the alloys are evaluated. The Mg24Y3 alloy also has the lowest dehydrogenation activation energy (119 kJ mol-1).

  3. Microstructural evolution and some mechanical properties of nanosized yttrium oxide dispersion strengthened 13Cr steel

    International Nuclear Information System (INIS)

    Nguyen, Van Tich; Doan, Dinh Phuong; Tran, Tran BaoTrung; Luong, Van Duong; Nguyen, Van An; Phan, Anh Tu

    2010-01-01

    Oxide dispersion strengthened (ODS) steels, manufactured by a mechanical alloying method, during the past few years, appear to be promising candidates for structural applications in nuclear power plants. The purpose of this work is to elaborate the manufacturing processes of ODS 13Cr steel with the addition of 1.0 wt% yttrium oxide through the powder metallurgy route using the high energy ball mill. Microstructural analysis by scanning electron microscopy (SEM), x-ray diffraction (XRD) and hardness testing have been used to optimize the technological parameters of milling, hot isostatic pressing and heat-treatment processes. The steel hardness increases with decreasing particle size of 13Cr ODS steel. The best hardness was obtained from more than 70 h of milling in the two tanks planetary ball mill or 30 h of milling in the one tank planetary ball mill and hot isostatic pressing at 1150 °C . The particle size of the steel is less than 100 nm, and the density and hardness are about 7.3 g cm −3 and 490 HB, respectively

  4. The commercial production of compounds of the lanthanides and yttrium as CRT phosphor precursors

    International Nuclear Information System (INIS)

    Kilbourn, B.T.

    1987-01-01

    The consumer acceptance of color television at the start of the 60's was triggered by the phosphor industry's discovery and production of a satisfactory red phosphor using the element europium. This element, in the middle of the lanthanide series, had until that time been an academic curiosity, prepared only in gram quantities for research. The large-scale production by the lanthanide industry, in order to meet the demand for commercial quantities of high purity europium oxide, required the introduction of new technology. Lanthanide elements other than europium, such as cerium and terbium, are also needed as the active ions for many phosphors. In addition, the inert host lattice for those emitting ions can be provided by compounds of yttrium, the element above the lanthanides in the periodic table, with comparable properties. The lanthanide industry has developed processes to produce compounds of such elements in the required quantities and purities. For commercial separation of these elements a technology known as counter-current liquid-liquid extraction has been developed. This technique, commonly called solvent extraction, is illustrated and described. The initial ore preparation steps, together with the final high purity oxide production is also mentioned

  5. Analysis of Prognostic Factors After Yttrium-90 Radioembolization of Advanced Hepatocellular Carcinoma

    International Nuclear Information System (INIS)

    Inarrairaegui, Mercedes; Martinez-Cuesta, Antonio; Rodriguez, Macarena; Bilbao, J. Ignacio

    2010-01-01

    Purpose: To analyze which patient-, tumor-, and treatment-related factors may influence outcome after 90 Y radioembolization ( 90 Y-RE) for hepatocellular carcinoma (HCC). Patients and Methods: Seventy-two consecutive patients with advanced HCC treated with 90 Y-RE were studied to detect which factors may have influenced response to treatment and survival. Results: Median overall survival was 13 months (95% confidence interval, 9.6-16.3 months). In univariate analysis, survival was significantly better in patients with one to five lesions (19 vs. 8 months, p = 0.001) and in patients with alpha-fetoprotein 52 UI/mL, and their survival in the multivariate analysis was significantly worse (hazard ratio, 4.7; 95% confidence interval, 13-1.73) (p = 0.002). Conclusions: Yttrium-90 radioembolization results in control of target lesions in the majority of patients with HCC but does not prevent the development of new lesions. Survival of patients treated with 90 Y-RE seems to depend largely on factors related to the aggressiveness of the disease (number of nodules, levels of alpha-fetoprotein, and presence of microscopic disease).

  6. Marine Phosphorites as Potential Resources for Heavy Rare Earth Elements and Yttrium

    Directory of Open Access Journals (Sweden)

    James R. Hein

    2016-08-01

    Full Text Available Marine phosphorites are known to concentrate rare earth elements and yttrium (REY during early diagenetic formation. Much of the REY data available are decades old and incomplete, and there has not been a systematic study of REY distributions in marine phosphorite deposits that formed over a range of oceanic environments. Consequently, we initiated this study to determine if marine phosphorite deposits found in the global ocean host REY concentrations of high enough grade to be of economic interest. This paper addresses continental-margin (CM and open-ocean seamount phosphorites. All 75 samples analyzed are composed predominantly of carbonate fluorapatite and minor detrital and authigenic minerals. CM phosphorites have low total REY contents (mean 161 ppm and high heavy REY (HREY complements (mean 49%, while seamount phosphorites have 4–6 times higher individual REY contents (except for Ce, which is subequal; mean ΣREY 727 ppm, and very high HREY complements (mean 60%. The predominant causes of higher concentrations and larger HREY complements in seamount phosphorites compared to CM phosphorites are age, changes in seawater REY concentrations over time, water depth of formation, changes in pH and complexing ligands, and differences in organic carbon content in the depositional environments. Potential ore deposits with high HREY complements, like the marine phosphorites analyzed here, could help supply the HREY needed for high-tech and green-tech applications without creating an oversupply of the LREY.

  7. Fluorometric determination of proteins using the yttrium(III)-sodium lauryl sulfate-rutin-protein system

    International Nuclear Information System (INIS)

    Liu Shufang; Yang Jinghe; Wu Xia; Wang Fei; Wang Feng; Jia Zhen

    2006-01-01

    It is found that rutin can react with yttrium(III) (Y 3+ ), and emits fluorescence of rutin. The intensity is greatly enhanced by proteins in the presence of sodium lauryl sulfate (SLS). Based on this, a new fluorimetric method of determination of proteins is developed. Under optimum conditions, the enhanced intensity of fluorescence is in proportion to the concentration of proteins in the range of 5.0x10 -9 -1.0x10 -5 g/mL for bovine serum albumin (BSA), 3.0x10 -8 -1.0x10 -5 g/mL for human serum albumin (HSA) and 1.0x10 -7 -2.0x10 -5 g/mL for egg albumin (EA). Their detection limits (S/N=3) are 1.6x10 -9 , 9.8x10 -9 and 2.1x10 -8 g/mL, respectively. The interaction mechanism is also studied

  8. Fluorometric determination of proteins using the yttrium(III)-sodium lauryl sulfate-rutin-protein system

    Energy Technology Data Exchange (ETDEWEB)

    Liu Shufang [Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Yang Jinghe [Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China)]. E-mail: yjh@sdu.edu.cn; Wu Xia [Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Wang Fei [Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Wang Feng [Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Jia Zhen [Key Laboratory of Colloid and Interface Chemistry (Shandong University), Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China)

    2006-04-15

    It is found that rutin can react with yttrium(III) (Y{sup 3+}), and emits fluorescence of rutin. The intensity is greatly enhanced by proteins in the presence of sodium lauryl sulfate (SLS). Based on this, a new fluorimetric method of determination of proteins is developed. Under optimum conditions, the enhanced intensity of fluorescence is in proportion to the concentration of proteins in the range of 5.0x10{sup -9}-1.0x10{sup -5}g/mL for bovine serum albumin (BSA), 3.0x10{sup -8}-1.0x10{sup -5}g/mL for human serum albumin (HSA) and 1.0x10{sup -7}-2.0x10{sup -5}g/mL for egg albumin (EA). Their detection limits (S/N=3) are 1.6x10{sup -9}, 9.8x10{sup -9} and 2.1x10{sup -8}g/mL, respectively. The interaction mechanism is also studied.

  9. Preparation, microstructure and properties of yttrium aluminum garnet fibers prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Li Chengshun [Key Laboratory for Liquid Structure and Heredity of Materials of Ministry of Education, Shandong University, Jinan 250061 (China); Zhang Yujun [Key Laboratory for Liquid Structure and Heredity of Materials of Ministry of Education, Shandong University, Jinan 250061 (China)], E-mail: yujunzhangcn@sdu.edu.cn; Gong Hongyu; Zhang Jingde; Nie Lifang [Key Laboratory for Liquid Structure and Heredity of Materials of Ministry of Education, Shandong University, Jinan 250061 (China)

    2009-01-15

    Yttrium aluminum garnet (YAG) fiber was prepared by sol-gel method using water as the solvent. The spinnable YAG sol was synthesized using Al powder, Y(CH{sub 3}COOH){sub 3}.4H{sub 2}O and HCl as precursors, polyethylene oxide as viscosity adjusting agent. Gel fibers with diameter of 5-10 {mu}m were prepared from the YAG sol by using centrifugal spinning technique. YAG crystalline fibers were obtained by drying gel fibers and heat-treating at selected temperature. TG/DTA analysis showed an exotherm at 906 deg. C attributed to formation of YAG phase and weight loss of 45% at 1000 deg. C. XRD and FT-IR analysis showed that phase-pure YAG can be formed at 900 deg. C, and no other intermediate was observed. The grain size of YAG fibers increased from 25 to 220 nm and tensile strength decreased rapidly from 970 to 380 MPa when the sintering temperature increased from 900 to 1550 deg. C.

  10. Bio sorption of some Rare Earth Elements and Yttrium by Gram Positive and Gram Negative Bacteria

    International Nuclear Information System (INIS)

    Ibrahim, H.A.

    2012-01-01

    The separate bio sorption of the REEs La, Sm, Eu and Dy together with yttrium upon the Gram positive bacteria Bacillus subtilis (B.subtilis) and Bacillus Licheniformis (B. Licheniformis),the Gram negative bacterium Escherichia coli (E. coli ) and Saccharomyces cervisiae (Yeast) was studied. The revelant factors of ph 1-6, contact time (30-180 min), the initial rare earth concentration (50-200 mg/l) have been studied. The amount of the accumulated element was strongly affected by its concentration.In addition, bio sorptive fractionation of Y and the studied REEs from a solution containing a mixture of these elements was also studied. From the obtained data, it was found that Langmuir isotherm model for both B.licheniformis and E.coli gives a best fit for the studied elements over the working range of concentration (50-200 mg/I). Transmission electron microscopy exhibited accumulation throughout the bacterial cell with some granular deposits in both the cell periphery and cytoplasm

  11. Processing and characterization of yttrium-stabilized zirconia thin films on polyimide from aqueous polymeric precursors

    International Nuclear Information System (INIS)

    Gorman, B.P.; Anderson, H.U.

    2004-01-01

    Low-temperature deposition of dense, nanocrystalline yttrium-stabilized zirconia (YSZ) thin films on polyimide (PI) substrates is illustrated using an aqueous polymeric precursor spin-coating technique. The polymeric precursor uses low-cost materials, is water-soluble and the viscosity and cation concentrations can be easily adjusted in order to vary the film thickness from 0.02 to 0.3 μm. Due to the use of water as the solvent in the YSZ precursor and the hydrophobic nature of the PI surface, surface modification processes were utilized in order to improve the wetting characteristics. Surface modification of PI substrates using wet chemical and oxygen plasma techniques led to a decrease in the precursor contact angle, and ultimately allowed for uniform film formation on both bulk and thin film PI substrates. Scanning electron microscopy, transmission electron microscopy and UV/Vis absorption illustrate that near full-density nanocrystalline thin films of YSZ can be produced at temperatures as low as 350 deg. C. Thermogravimetric analyses illustrate that the PI substrate does not undergo any weight loss up to these temperatures

  12. Thermographic measurements of the spin Peltier effect in metal/yttrium-iron-garnet junction systems

    Science.gov (United States)

    Daimon, Shunsuke; Uchida, Ken-ichi; Iguchi, Ryo; Hioki, Tomosato; Saitoh, Eiji

    2017-07-01

    The spin Peltier effect (SPE), heat-current generation due to spin-current injection, in various metal (Pt, W, and Au single layers and Pt/Cu bilayer)/ferrimagnetic insulator [yttrium-iron-garnet (YIG)] junction systems has been investigated by means of a lock-in thermography (LIT) method. The SPE is excited by a spin current across the metal/YIG interface, which is generated by applying a charge current to the metallic layer via the spin Hall effect. The LIT method enables the thermal imaging of the SPE free from the Joule-heating contribution. Importantly, we observed spin-current-induced temperature modulation not only in the Pt/YIG and W/YIG systems, but also in the Au/YIG and Pt/Cu/YIG systems, excluding the possible contamination by anomalous Ettingshausen effects due to proximity-induced ferromagnetism near the metal/YIG interface. As demonstrated in our previous study, the SPE signals are confined only in the vicinity of the metal/YIG interface; we buttress this conclusion by reducing a spatial blur due to thermal diffusion in an infrared-emission layer on the sample surface used for the LIT measurements. We also found that the YIG-thickness dependence of the SPE is similar to that of the spin Seebeck effect measured in the same Pt/YIG sample, implying the reciprocal relation between them.

  13. Observation of auto-oscillations and chaos in subsidiary absorption in yttrium iron garnet

    International Nuclear Information System (INIS)

    Srinivasan, G.; Chen, M.; Patton, C.E.

    1988-01-01

    Auto-oscillations of the dynamic magnetization and routes to chaos for the first-order transverse pump spin-wave instability have been studied in single-crystal yttrium-iron-garnet (YIG) films. The measurements reported here were made on a 20.8-μm-thick YIG film at 9.4 GHz with the static and microwave fields in the plane of the film. Auto-oscillations at 100--400 kHz were observed in the power absorbed by the film over a relatively narrow static field range of 1100--1460 Oe, compared to the first-order instability (FOI) range of 0--1630 Oe. The auto-oscillation frequency and threshold microwave field amplitude were both strongly field dependent. The threshold amplitudes were about a factor of 2 larger than the FOI threshold amplitudes. At even higher power levels and for an even narrower field range of 1300--1380 Oe, the auto-oscillations showed frequency changes indicative of chaotic behavior. Several different subharmonic bifurcation routes to chaos were observed for different fields within the chaotic region

  14. Study of yttrium 4-nitrocinnamate to promote surface interactions with AS1020 steel

    Science.gov (United States)

    Hien, P. V.; Vu, N. S. H.; Thu, V. T. H.; Somers, A.; Nam, N. D.

    2017-08-01

    Yttrium 4-nitrocinnamate (Y(4-NO2Cin)3) was added to an aqueous chloride solution and studied as a possible corrosion inhibition system. Electrochemical techniques and surface analysis have been powerful tools to better understand the corrosion and inhibition processes of mild steel in 0.01 M NaCl solution. A combination of scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), Potentiodynamic polarization (PD), electrochemical impedance spectroscopy (EIS) and wire beam electrode (WBE) techniques was found to be useful in the characterization of this system. The result indicated that Y(4-NO2Cin)3 is able to effectively inhibit corrosion at a low concentration of 0.45 mM. Surface analysis clearly shows that the surface of steel coupons exposed to Y(4-NO2Cin)3 solution remained uniform and smooth, whereas the surface of steel coupons exposed to solution without inhibitor addition was severely corroded. The results suggest that Y(4-NO2Cin)3 behaves as a mixed inhibitor and mitigates corrosion by promoting random distribution of minor anodes. These are attributed to the formation of metal species bonding to the 4-nitrocinnamate component and hydrolysis of the Y(4-NO2Cin)3 to form oxide/hydroxides as a protective film layer.

  15. Right Gastric Artery Embolization Prior to Treatment with Yttrium-90 Microspheres

    International Nuclear Information System (INIS)

    Cosin, Octavio; Bilbao, Jose Ignacio; Alvarez, Sergio; Luis, Esther de; Alonso, Alberto; Martinez-Cuesta, Antonio

    2007-01-01

    Purpose. Intra-arterial infusion of yttrium-90 microspheres is a form of radiation treatment for unresectable hepatic neoplasms. Misdeposition of particles in the gastroduodenal area such as the right gastric artery (RGA) may occur with serious consequences. We present a series of patients who underwent a detailed vascular study followed by RGA embolization. Special emphasis is placed on anatomic variations and technical considerations .Methods. In a 1 year period, 27 patients were treated. Initial vascular evaluation was performed, with careful attention to anatomic variants or extrahepatic arterial supply, especially to the gastroduodenal area. Embolization of such arteries was planned if needed. RGA embolization was performed antegradely from the hepatic artery or retrogradely via the left gastric artery (LGA). Postprocedural follow-up included clinical interview and gastroscopy if necessary. Results. RGA embolization was performed in 9 patients presenting with primary (n = 3) or metastatic liver tumors (n 6). Six patients underwent antegrade RGA embolization and 3 had embolization done retrogradely via the LGA. Retrograde access was chosen for anatomic reasons. None of the patients complained of gastroduodenal symptoms. Conclusion. RGA embolization can help minimize the gastroduodenal deposition of radioactive particles. RGA embolization should routinely be carried out. The procedure can be performed, with similar technical success, by both anterograde and retrograde approaches

  16. Homogeneous magnetic relaxation in iron-yttrium garnets in the vicinity of a phase transition

    International Nuclear Information System (INIS)

    Luzyanin, I.D.; Khavronin, V.P.

    1977-01-01

    Results are presented of an experimental investigation of the dynamics of homogeneous magnetization during a phase transition of the second kind in iron-yttrium garnet (IYG) single crystals of various shapes. It is shown that homogeneous relaxation significantly depends on both the magnitude of 4πchisub(st) (chisub(st) is static magnetic susceptibility) as well as on the relation between the variable field frequency (at which the investigation is carried out) and the characteristic energies. It is shown that beginning from temperatures such as 4πchisub(st) approximately 1, the characteristic dipole interaction energy becomes frequency dependent; this indicates that in this case Lorentz coupling between the dynamic susceptibility and homogeneous relaxation time is invalid. This is a principle point in investigations of homogeneous relaxation by radio-frequency techniques. The temperature dependence of the homogeneous relaxation time and static susceptibility is determined in the exchange region. It is found that the phase transition in IYG involves anomalous phenomena which manifest in release and absorption of heat by a sample and in the appearance of additional singularities in the temperature dependence of the homogeneous relaxation time

  17. Yttrium aluminium garnet under pressure: Structural, elastic, and vibrational properties from ab initio studies

    International Nuclear Information System (INIS)

    Monteseguro, V.; Rodríguez-Hernández, P.; Muñoz, A.

    2015-01-01

    The structural, elastic, and vibrational properties of yttrium aluminum garnet Y 3 Al 5 O 12 are studied under high pressure by ab initio calculations in the framework of the density functional theory. The calculated ground state properties are in good agreement with the available experimental data. Pressure dependences of bond length and bulk moduli of the constituent polyhedra are reported. The evolution of the elastic constants and the major elastic properties, Young and shear modulus, Poisson's ratios, and Zener anisotropy ratio, are described. The mechanical stability is analyzed, on the light of “Born generalized stability criteria,” showing that the garnet is mechanically unstable above 116 GPa. Symmetries, frequencies, and pressure coefficients of the Raman-active modes are discussed on the basis of the calculated total and partial phonon density of states, which reflect the dynamical contribution of each atom. The relations between the phonon modes of Y 3 Al 5 O 12 and the internal and external molecular modes of the different polyhedra are discussed. Infrared-active modes, as well as the silent modes, and their pressure dependence are also investigated. No dynamical instabilities were found below 116 GPa

  18. Surface modifications of AISI 420 stainless steel by low energy Yttrium ions

    Science.gov (United States)

    Nassisi, Vincenzo; Delle Side, Domenico; Turco, Vito; Martina, Luigi

    2018-01-01

    In this work, we study surface modifications of AISI 420 stainless steel specimens in order to improve their surface properties. Oxidation resistance and surface micro-hardness were analyzed. Using an ion beam delivered by a Laser Ion Source (LIS) coupled to an electrostatic accelerator, we performed implantation of low energy yttrium ions on the samples. The ions experienced an acceleration passing through a gap whose ends had a potential difference of 60 kV. The gap was placed immediately before the samples surface. The LIS produced high ions fluxes per laser pulse, up to 3x1011 ions/cm2, resulting in a total implanted flux of 7x1015 ions/cm2. The samples were characterized before and after ion implantation using two analytical techniques. They were also thermally treated to investigate the oxide scale. The crystal phases were identified by an X-ray diffractometer, while the micro-hardness was assayed using the scratch test and a profilometer. The first analysis was applied to blank, implanted and thermally treated sample surface, while the latter was applied only to blank and implanted sample surfaces. We found a slight increase in the hardness values and an increase to oxygen resistance. The implantation technique we used has the advantages, with respect to conventional methods, to modify the samples at low temperature avoiding stray diffusion of ions inside the substrate bulk.

  19. Surface modifications of AISI 420 stainless steel by low energy Yttrium ions

    Directory of Open Access Journals (Sweden)

    Nassisi Vincenzo

    2018-01-01

    Full Text Available In this work, we study surface modifications of AISI 420 stainless steel specimens in order to improve their surface properties. Oxidation resistance and surface micro-hardness were analyzed. Using an ion beam delivered by a Laser Ion Source (LIS coupled to an electrostatic accelerator, we performed implantation of low energy yttrium ions on the samples. The ions experienced an acceleration passing through a gap whose ends had a potential difference of 60 kV. The gap was placed immediately before the samples surface. The LIS produced high ions fluxes per laser pulse, up to 3x1011 ions/cm2, resulting in a total implanted flux of 7x1015 ions/cm2. The samples were characterized before and after ion implantation using two analytical techniques. They were also thermally treated to investigate the oxide scale. The crystal phases were identified by an X-ray diffractometer, while the micro-hardness was assayed using the scratch test and a profilometer. The first analysis was applied to blank, implanted and thermally treated sample surface, while the latter was applied only to blank and implanted sample surfaces. We found a slight increase in the hardness values and an increase to oxygen resistance. The implantation technique we used has the advantages, with respect to conventional methods, to modify the samples at low temperature avoiding stray diffusion of ions inside the substrate bulk.

  20. A Woman with Black Beads in Her Stomach: Severe Gastric Ulceration Caused by Yttrium-90 Radioembolization

    Directory of Open Access Journals (Sweden)

    Indu S. Voruganti

    2018-01-01

    Full Text Available Radioembolization (RE is a selective internal radiation therapy (SIRT delivering targeted, high-dose, intra-arterial radiation directly to the vascular supply of liver tumors. Complications can occur due to aberrant deposition or migration of radiation microspheres into nontarget locations, including normal hepatic parenchyma, lungs, pancreas, and upper gastrointestinal (UGI tract. We report a case of gastric ulcers due to yttrium-90 (90Y seed migration to the stomach to alert clinicians to this rare cause of gastric injury. A 57-year-old woman with stage IV breast cancer with liver and lung metastases presented to the hospital with 2 months of worsening nausea and vomiting. Two months prior, she had received SIRT with 90Y microspheres without complications. Upper GI endoscopy showed diffuse gastritis and extensive antral ulceration. Biopsies revealed black, spherical foreign bodies, consistent with 90Y microspheres, documenting radiation injury. Radiation-induced UGI ulceration is caused by direct radiation injury from beta-radiation. Delay in diagnosis may be due to the nonspecificity of symptoms and temporal delay of symptom onset from SIRT, which was 2 months in our patient. Also, complaints may be attributed erroneously to adjuvant chemotherapy or widespread metastatic disease. Clinicians must consider radiation-associated toxicity in any SIRT-treated patient developing abdominal symptoms.

  1. Investigation of high- k yttrium copper titanate thin films as alternative gate dielectrics

    International Nuclear Information System (INIS)

    Monteduro, Anna Grazia; Ameer, Zoobia; Rizzato, Silvia; Martino, Maurizio; Caricato, Anna Paola; Maruccio, Giuseppe; Tasco, Vittorianna; Lekshmi, Indira Chaitanya; Hazarika, Abhijit; Choudhury, Debraj; Sarma, D D

    2016-01-01

    Nearly amorphous high- k yttrium copper titanate thin films deposited by laser ablation were investigated in both metal–oxide–semiconductor (MOS) and metal–insulator–metal (MIM) junctions in order to assess the potentialities of this material as a gate oxide. The trend of dielectric parameters with film deposition shows a wide tunability for the dielectric constant and AC conductivity, with a remarkably high dielectric constant value of up to 95 for the thick films and conductivity as low as 6  ×  10 −10 S cm −1 for the thin films deposited at high oxygen pressure. The AC conductivity analysis points out a decrease in the conductivity, indicating the formation of a blocking interface layer, probably due to partial oxidation of the thin films during cool-down in an oxygen atmosphere. Topography and surface potential characterizations highlight differences in the thin film microstructure as a function of the deposition conditions; these differences seem to affect their electrical properties. (paper)

  2. Preparing magnetic yttrium iron garnet nanodot arrays by ultrathin anodic alumina template on silicon substrate

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Hui; Han, Mangui, E-mail: han-mangui@yahoo.com; Deng, Longjiang [National Engineering Research Center of Electromagnetic Radiation Control Materials, University of Electronic Science and Technology of China, Chengdu 610054 (China); Zheng, Liang; Zheng, Peng; Qin, Huibin [Institute of Electron Device and Application, Hangzhou Dianzi University, Hangzhou 310008 (China); Wu, Qiong [Magnetism Key Laboratory of Zhejiang Province, China Jiliang University, Hangzhou 310018 (China)

    2015-08-10

    Ultrahigh density periodically ordered magnetic yttrium iron garnet (Y{sub 3}Fe{sub 5}O{sub 12}, YIG) nanodot arrays have been prepared by pulsed laser deposition through an ultrathin alumina mask (UTAM). UTAM having periodically ordered circularly shaped holes with 350 nm in diameter, 450 nm in inter-pore distance, and 700 nm in height has been prepared on silicon substrate. Furthermore, the microstructure and magnetic properties of YIG nanodot arrays have been characterized. Nanodot arrays with a sharp distribution in diameter centered at 340 nm with standard deviation of 10 nm have been fabricated. Moreover, typical hysteresis loops and ferromagnetic resonance spectra in in-plane and out-of-plane revealed that this unique structure greatly influences the magnetics properties of YIG. First, coercivity of YIG nanodot arrays in in-plane was increased about from 15 Oe of YIG films to 500 Oe. Then, the degree of uniformity about nanodot height decided that two or more resonance peaks in out-of-plane were detected in the spectra. The peak-to-peak linewidth values were about 94 Oe and 40 Oe in the parallel and perpendicular directions, respectively, which indicated that the values were larger by the two-magnon scattering. Consequently, this pattering method creates opportunities for studying physics in oxide nanomagnets and may be applied in spin-wave devices.

  3. Dynamics of laser-induced magnetization in Ce-doped yttrium aluminum garnet

    International Nuclear Information System (INIS)

    Kolesov, Roman

    2007-01-01

    Circularly polarized short laser pulse induces nonequilibrium population of spin levels in the excited state of Ce 3+ -ion embedded in yttrium aluminium garnet crystal and, consequently, the magnetization of the crystal associated with spin polarization. Dynamic behavior of laser-induced magnetization is studied as a function of the external magnetic field. It reveals spin oscillations attributed to the effect of hyperfine magnetic field produced by 27 Al nuclei on the Ce 3+ spin. A simple theoretical model explaining spin oscillations is presented. It shows that circularly polarized light induces spin coherence at the transition between Zeeman sublevels of Ce 3+ ion in the lowest 5d state. Temporal shape of laser-induced magnetization signal reveals the following parameters of this state: (1) the spin-lattice relaxation constant is ≅2x10 7 s -1 , (2) inhomogeneous spin dephasing time is ≅4 ns, and (3) the g tensor of the state seems to be isotropic with the g factor being in the range 0.7-0.9. In addition, the width of the local hyperfine field distribution is ≅40 G

  4. Critical current densities in thick yttrium-barium cuprate (1-2-3) films

    International Nuclear Information System (INIS)

    Ryvkina, G.G.; Gorlanov, S.F.; Vedernikov, G.E.; Telegin, A.B.; Ryabin, V.A.; Khodos, M.Ya.

    1993-01-01

    The study of critical current densities j c of oxide superconductors and their thick films is a very important practical task because the value of j c is one of the main criteria for their utilization in modern cryoelectronics. For most devices based on the Josephson effect, the value of j c ∼ 10 2 - 10 3 A/cm 2 is acceptable, which is easily attainable for polycrystalline thick films obtained by stenciling. The study of the current-transport phenomenon involves a number of difficulties, especially for direct current, because both the sample itself and the lead-in contacts are resistance-heated during the measurements, which, in turn, results in lower values of the j c . Measurements with pulsed currents allow one to lower the power that is applied to the sample; the heat that is released in the sample is reduced, in comparison to measurements with direct current, by a factor of the pulsed-current duty cycle. In addition, measurements with direct current detects only the appearance of resistance; it provides no information on the rest of the transition from the normal to the superconductive state, i.e., on the so-called 'tail' of the transition. In this work, the authors studied critical current densities of thick HTSC yttrium-barium cuprate films of the 1-2-3 composition using pulsed current

  5. The liquid membrane for extraction of Yttrium and Dysprosium from Acid Nitric

    International Nuclear Information System (INIS)

    Johny, W.S.; Raldi-Artono-Koestoer; Kris-Tri-Basuki; Sudibyo

    1996-01-01

    The determination of surfactant in liquid membrane has been done. The surfactant is span-80 (sorbitol-monooleate), the liquid membrane phase was the organic phase (O), the internal liquid phase (W) with ratio O/W = 1, and surfactant. The organic phase using D 2 EHPA in the kerosene and the internal liquid phase using aqua des or acid nitric. The determination of surfactant with variation of span-80 (0,25 - 2%) in the liquid membrane volume. The speed of stirrer was 3500 rpm in 20 minute. The ratio of liquid membrane phase form and external phase (aqua des or acid nitric) was 1, the speed of stirrer was 350 rpm in 10 minute (permeation process). The liquid phase and the liquid membrane phase was separated and then determinated the volume of liquid membrane, the result of percentage of span-80 was 0,25 % volume. The extraction of yttrium and dysprosium in 2 M HNO 3 was Kd y = 2.945 and Kd D y = 0.019

  6. A revised method of labeling mouse IgG with yttrium-90

    International Nuclear Information System (INIS)

    Arbab, A.S.; Koizumi, Kiyoshi; Araki, Tsutomu

    1996-01-01

    We report the successful labeling of mouse IgG with yttrium-90 (Y-90) using isothiocyanatobenzyl-ethylenediaminetetraacetic acid (SCN-Bz-EDTA) as a chelating agent and compared the result with labeling by indium-111 (In-111). After conjugating IgG with SCN-Bz-EDTA, a predetermined volume of conjugated IgG was mixed with different volumes of either Y-90 or In-111 acetate and incubated at 37degC. Labeling efficiency was assessed at specific intervals upto 3 hr. After 3 hr, the mixtures were challenged with Na 2 EDTA to evaluate the transchelation of labeled Y-90 or In-111. All mixtures showed labeling efficiency of around 50% with Y-90 and the leveling was fairly preserved even after Na 2 EDTA challenge. However, labeling with In-111 was unsuccessful when conjugated IgG was not separated from the unconjugated form. When separated, however, In-111 showed more than 80% labeling efficiency though labeling with In-111 could not tolerate Na 2 EDTA challenge. In conclusion IgG was efficiently labeled by Y-90 using SCN-Bz-EDTA though labeling with In-111 showed some problems associated with this method. (author)

  7. Temporary Arterial Balloon Occlusion as an Adjunct to Yttrium-90 Radioembolization

    Energy Technology Data Exchange (ETDEWEB)

    Hagspiel, Klaus D., E-mail: kdh2n@virginia.edu [University of Virginia Health System, Department of Radiology and Medical Imaging (United States); Nambiar, Ashwin, E-mail: uvashwin@gmail.com [SUNY Downstate Medical Center, Department of Radiology (United States); Hagspiel, Lauren M., E-mail: lmh4gg@virginia.edu [University of Virginia, College of Arts and Sciences (United States); Ahmad, Ehab Ali, E-mail: ehabradiodiagnosis@yahoo.com [Minia University, Department of Radiology (Egypt); Bozlar, Ugur, E-mail: ubozlar@yahoo.com [Gulhane Military Medical Academy, Department of Radiology (Turkey)

    2013-06-15

    Purpose. This study was designed to describe the technique of arterial occlusion using a temporary occlusion balloon system as an alternative to coil occlusion during Yttrium-90 radioembolization of hepatic tumors. Methods. Review of charts, angiography, and follow-up imaging studies of consecutive patients undergoing oncological embolization procedures in which a HyperForm system (ev3 Neurovascular, Irvine, CA) was used. Intraprocedural target vessel occlusion and patency of the target vessel on follow-up were recorded. Clinical data and Bremsstrahlung scans were reviewed for evidence of nontarget embolization. Results. Four radioembolization procedures were performed in three patients (all female, age 48-54 (mean 52) years). Five arteries were temporarily occluded (three gastroduodenal arteries, one right gastric artery, and one cystic artery). All radioembolization procedures were successfully completed. Follow-up imaging (either digital subtraction angiography (DSA) or computed tomography angiography (CTA)) was available for all patients between 28-454 (mean 183) days following the procedure, demonstrating all five vessels to be patent. No clinical or imaging evidence for nontarget embolization was found. Conclusions. Temporary balloon occlusion of small and medium-sized arteries during radioembolization allows safe therapy with preserved postprocedural vessel patency on early and midterm follow-up.

  8. Evaluation of magnesium-yttrium alloy as an extraluminal tracheal stent.

    Science.gov (United States)

    Luffy, Sarah A; Chou, Da-Tren; Waterman, Jenora; Wearden, Peter D; Kumta, Prashant N; Gilbert, Thomas W

    2014-03-01

    Tracheomalacia is a relatively rare problem, but can be challenging to treat, particularly in pediatric patients. Due to the presence of mechanically deficient cartilage, the trachea is unable to resist collapse under physiologic pressures of respiration, which can lead to acute death if left untreated. However, if treated, the outcome for patients with congenital tracheomalacia is quite good because the cartilage tends to spontaneously mature over a period of 12 to 18 months. The present study investigated the potential for the use of degradable magnesium-3% yttrium alloy (W3) to serve as an extraluminal tracheal stent in a canine model. The host response to the scaffold included the formation of a thin, vascularized capsule consisting of collagenous tissue and primarily mononuclear cells. The adjacent cartilage structure was not adversely affected as observed by bronchoscopic, gross, histologic, and mechanical analysis. The W3 stents showed reproducible spatial and temporal fracture patterns, but otherwise tended to corrode quite slowly, with a mix of Ca and P rich corrosion product formed on the surface and observed focal regions of pitting. The study showed that the approach to use degradable magnesium alloys as an extraluminal tracheal stent is promising, although further development of the alloys is required to improve the resistance to stress corrosion cracking and improve the ductility. Copyright © 2013 Wiley Periodicals, Inc.

  9. Hepatobiliary effects of 90yttrium microsphere therapy for unresectable hepatocellular carcinoma.

    Science.gov (United States)

    Nalesnik, Michael A; Federle, Michael; Buck, David; Fontes, Paulo; Carr, Brian I

    2009-01-01

    (90)Yttrium (Therasphere) microspheres administered via hepatic artery are a valuable option for treatment of hepatocellular carcinoma. This therapy targets tumor nodules while largely sparing hepatic parenchyma. This retrospective study examines liver explants from 13 adult patients with hepatocellular carcinoma who received intrahepatic Theraspheres and subsequently underwent liver transplantation. Histopathologic and laboratory reviews are performed. Theraspheres preferentially migrated to the lobe(s) supplied by the injected artery branches and frequently localized to tumors. Tumors showed a chronology of changes beginning with confluent necrosis typically accompanied by hemorrhage and later by fibrinoid change. This was followed by fibrosis with regenerative activity at tumor peripheries. Adjacent hepatic parenchyma went through a similar sequence of injury and repair that could lead to markedly fibrotic cirrhotic nodules in the vicinity of treated tumors. No consistent pattern of thrombomodulin loss was seen in endothelial cells of the tumors or adjacent parenchyma, suggesting that direct endothelial cell injury was likely not a major contributor to the necrotic process. However, the pattern of injury and repair is suggestive of a localized and subclinical form of radiation-induced liver disease. The pathologist should be aware of these changes to distinguish them from the diffuse "radiation hepatitis" associated with older forms of radiotherapy.

  10. Surface melting technique of small diameter stainless steel pipe by means of yttrium aluminium garnet laser

    International Nuclear Information System (INIS)

    Katahira, Fujito; Hirano, Kenji; Tanaka, Yasuhiro; Yoshida, Kazuo; Kuribayashi, Munetaka; Umemoto, Tadahiro

    1994-01-01

    A new method of surface melting by using a high power yttrium aluminium garnet laser was developed. This method is applicable to a long distance and narrow space, because of the good accessibility of the laser beam through optical fibre.A desensitization of sensitized type 304 stainless steel pipe was demonstrated by using this technique. A melted layer of thickness approximately 200μm had a very finite solidification structure, which contained approximately 1.5% δ-ferrite. The average chemical composition of this layer was almost the same as that of type 304 stainless steel, and a band of 300μm thickness under the melted layer underwent solution heat treatment (SHT).As a result of such surface melting, the melted layer exhibited superior resistance to intergranular stress corrosion cracking (IGSCC). Since the SHT layer is highly resistant to IGSCC generally, it may be possible to improve the IGSCC resistance of base metal to a comparatively deep extent (500μm from the surface) by this technique. ((orig.))

  11. Crystallization and deuterium permeation behaviors of yttrium oxide coating prepared by metal organic decomposition

    Directory of Open Access Journals (Sweden)

    Takumi Chikada

    2016-12-01

    Full Text Available Yttrium oxide coatings were fabricated on reduced activation ferritic/martensitic steels by metal organic decomposition with a dip-coating technique, and their deuterium permeation behaviors were investigated. The microstructure of the coatings varied with heat-treatment temperature: amorphous at 670ºC (amorphous coating and crystallized at 700ºC (crystallized coating. Deuterium permeation flux of the amorphous coating was lower than the uncoated steel by a factor of 5 at 500ºC, while that of the crystallized coating was lower by a factor of around 100 at 400‒550ºC. The permeation fluxes of both coatings were drastically decreased during the measurements at higher temperatures by a factor of up to 790 for the amorphous coating and 1000 for the crystallized one, indicating a microstructure modification occurred by an effect of test temperature with hydrogen flux. Temperature dependence of deuterium diffusivity in the coatings suggests that the decrease of the permeation flux has been derived from a decrease of the diffusivity. Characteristic permeation behaviors were observed with different annealing conditions; however, they can be interpreted using the permeation mechanism clarified in the previous erbium oxide coating studies.

  12. Yttrium separation of Xenotime waste in Pitinga (Brazil), in order to obtain rare earth elements

    International Nuclear Information System (INIS)

    Melo.

    1996-01-01

    The xenotime (YPO 4 and rare earth elements) found in the mine of Pitinga, Amazonas State, Brazil, has its origin in a primal depository ('eluvio' kind) of cassiterite, having considerable quantities of zirconite, ilmenite, topaz and niobates-tantalates. This xenotime has different characteristics in relation of the depositories that exist in other countries for presenting more concentration of rare earth heavy oxides. The mineralization of this cassiterite is problematic, because of the high level of radioactive elements. In the present work, we will process only the xenotime. The separation of rare earth elements is very difficult due to their great chemical similarity. For a more exactly determination, it is necessary to separate them at least of the macron constituents of the sample. As the Yttrium is considerate one of the rare earth elements, due to its chemical similarity, we can understand the difficulty of a chemical separation, mainly when this one is also a macro constituent of the sample, as in the case of xenotime. The process of separation will be based on the little difference that exists between the constants of complexation and the fluoride. (authors). 5 refs., 1 fig., 2 tabs

  13. Platinum/yttrium iron garnet inverted structures for spin current transport

    Energy Technology Data Exchange (ETDEWEB)

    Aldosary, Mohammed; Li, Junxue; Tang, Chi; Xu, Yadong; Shi, Jing [Department of Physics and Astronomy and SHINES Energy Frontier Research Center, University of California, Riverside, California 92521 (United States); Zheng, Jian-Guo [Irvine Materials Research Institute, University of California, Irvine, California 92697 (United States); Bozhilov, Krassimir N. [Central Facility for Advanced Microscopy and Microanalysis, University of California, Riverside, California 92521 (United States)

    2016-06-13

    30-80 nm thick yttrium iron garnet (YIG) films are grown by pulsed laser deposition on a 5 nm thick sputtered Pt atop gadolinium gallium garnet substrate (GGG) (110). Upon post-growth rapid thermal annealing, single crystal YIG(110) emerges as if it were epitaxially grown on GGG(110) despite the presence of the intermediate Pt film. The YIG surface shows atomic steps with the root-mean-square roughness of 0.12 nm on flat terraces. Both Pt/YIG and GGG/Pt interfaces are atomically sharp. The resulting YIG(110) films show clear in-plane uniaxial magnetic anisotropy with a well-defined easy axis along 〈001〉 and a peak-to-peak ferromagnetic resonance linewidth of 7.5 Oe at 9.32 GHz, similar to YIG epitaxially grown on GGG. Both spin Hall magnetoresistance and longitudinal spin Seebeck effects in the inverted bilayers indicate excellent Pt/YIG interface quality.

  14. Surface melting technique of small diameter stainless steel pipe by means of yttrium aluminium garnet laser

    Energy Technology Data Exchange (ETDEWEB)

    Katahira, Fujito (Ishikawajima-Harima Heavy Industries Co. Ltd., 1 Shin-Nakahara-Cho, Isogo-Ku, Yokohama 235 (Japan)); Hirano, Kenji (Ishikawajima-Harima Heavy Industries Co. Ltd., 1 Shin-Nakahara-Cho, Isogo-Ku, Yokohama 235 (Japan)); Tanaka, Yasuhiro (Ishikawajima-Harima Heavy Industries Co. Ltd., 1 Shin-Nakahara-Cho, Isogo-Ku, Yokohama 235 (Japan)); Yoshida, Kazuo (Ishikawajima-Harima Heavy Industries Co. Ltd., 1 Shin-Nakahara-Cho, Isogo-Ku, Yokohama 235 (Japan)); Kuribayashi, Munetaka (Ishikawajima-Harima Heavy Industries Co. Ltd., 1 Shin-Nakahara-Cho, Isogo-Ku, Yokohama 235 (Japan)); Umemoto, Tadahiro (Ishikawajima-Harima Heavy Industries Co. Ltd., 1 Shin-Nakahara-Cho, Isogo-Ku, Yokohama 235 (Japan))

    1994-12-01

    A new method of surface melting by using a high power yttrium aluminium garnet laser was developed. This method is applicable to a long distance and narrow space, because of the good accessibility of the laser beam through optical fibre.A desensitization of sensitized type 304 stainless steel pipe was demonstrated by using this technique. A melted layer of thickness approximately 200[mu]m had a very finite solidification structure, which contained approximately 1.5% [delta]-ferrite. The average chemical composition of this layer was almost the same as that of type 304 stainless steel, and a band of 300[mu]m thickness under the melted layer underwent solution heat treatment (SHT).As a result of such surface melting, the melted layer exhibited superior resistance to intergranular stress corrosion cracking (IGSCC). Since the SHT layer is highly resistant to IGSCC generally, it may be possible to improve the IGSCC resistance of base metal to a comparatively deep extent (500[mu]m from the surface) by this technique. ((orig.))

  15. Observation of electromagnetically induced transparency and absorption in Yttrium Iron Garnet loaded split ring resonator

    Science.gov (United States)

    Tay, Z. J.; Soh, W. T.; Ong, C. K.

    2018-04-01

    In this paper, we propose a new method of controlling microwave transmission from Electromagnetically Induced Absorption (EIA) to Electromagnetically Induced Transparency (EIT). EIA describes the state where the system strongly absorbs microwaves, whereas EIT describes the state in which the system is transparent to microwaves. Control is achieved via coupling of the 3 GHz photon mode of a metamaterial Split Ring Resonator (SRR) to the spin wave magnon modes of a Yttrium Iron Garnet (YIG) bulk. The system is described by a 2-body interaction matrix with an additional fitting parameter τ which takes into account the fact that the microstrip feed line could excite the SRR as well as the YIG. The parameter τ reveals the effect of geometry and shielding on the coupling behaviour and gives rise to unique physics. In low τ (τ ⩽ 2) configurations, only EIT is reported. However, in high τ (τ ≈ 10) configurations, EIA is reported. Furthermore, we report that the system can be easily changed from a low τ to high τ configuration by shielding the SRR from the microstrip with a thin metal piece. Varying the τ parameter through shielding is thus proposed as a new method of controlling the microwave transmission at the coupling region.

  16. Yttrium aluminum garnet (YAG) obtained by rare-earth mixed oxide (RE2O3)

    International Nuclear Information System (INIS)

    Castro, D.F.; Daguano, J.K.M.F.; Rodrigues Junior, D.; Suzuki, P.A.; Silva, O.M.M.

    2010-01-01

    In this work, the substitution of commercial Y 2 O 3 by a rare earth mixed oxide, RE 2 O 3 , to form Yttrium aluminum Garnet-Y 3 Al 5 O 12 , was investigated. Al 2 O 3 :Y 2 O 3 and Al 2 O 3 :RE 2 O 3 powder-mixtures, in a molar ratio of 60:40, were milled and subsequently cold uniaxially-pressed. Compacts were sintered at 1000, 1400 or 1600 deg C, for 120 minutes. RE 2 O 3 oxide was characterized by high-resolution synchrotron X-ray diffraction (HRXRD) and compared to Y 2 O 3 . X-ray diffraction pattern of the RE 2 O 3 indicates a true solid solution formation. Rietveld refinement of the sintered YAG and (RE)AG reveled a similar crystal structure to the YAGs obtained by the use of Al 2 O 3 -Y 2 O 3 or Al 2 O 3 -RE 2 O 3 respectively. Microstructural analysis of both, YAG or (RE)AG, revealed similar grain sizes of about 2.5 μm besides mechanical properties, with hardness of 400HV and fracture toughness of 3.8MPa.m1/2. It could be, thus, demonstrated that pure Y 2 O 3 can be substituted by the rare-earth solid solution, RE 2 O 3 , in the formation YAGs, presenting similar microstructural and mechanical properties. (author)

  17. Graphite furnace atomic absorption spectrometry with a tantalum boat for the determination of yttrium, samarium, and dysprosium in a mish metal

    International Nuclear Information System (INIS)

    Daidoji, Hidehiro; Tamura, Shohei

    1982-01-01

    The determination of yttrium, samarium, and dysprodium by means of graphite-furnace atomic absorption spectrometry (AAS) was studied by a tantalum boat inserted into a graphite tube atomizer. These elements could not be determined by the use of a commercial graphite tube, In the atomization from a tantalum boat, better analytical sensitivities and negligible memory effects for these rare earths are obtained. The analytical sensitivities of yttrium, samarium, and dysprodium with the tantalum boat were 0.60 ng, 0.86 ng, and 0.17 ng respectively. This method was applied for the determination of yttrium, samarium, and dysprosium in a mish metal. The measurements were performed with slightly acidified solutions (0.01 mol dm 3 HCI or HNO 3 ). The sensitivities and the precisions for these elements decreased with increasing acid concentration. An enhancement in the sensitivities of yttrium and dysprosium upon the addition of a large excess of lanthanum, neodymium, and praseodymium salts were observed. The yttrium, samarium, and dysprosium in a mish metal were determined with both analytical curves of standard solutions containing an excess of lanthanum, cerium, and neodymium ions and of the standard addition. The precisions for this work were in the 3 - 9.3% range. (author)

  18. Yttrium 3-(4-nitrophenyl)-2-propenoate used as inhibitor against copper alloy corrosion in 0.1 M NaCl solution

    International Nuclear Information System (INIS)

    Nam, Nguyen Dang; Thang, Vo Quoc; Hoai, Nguyen To; Hien, Pham Van

    2016-01-01

    Highlights: • Yttrium 3-(4-nitrophenyl)-2-propenoate has been studied as an effective corrosion inhibitor for copper. • A high inhibition performance is attributed to the forming protective inhibiting deposits. • Yttrium 3-(4-nitrophenyl)-2-propenoate mitigates corrosion by promoting random distribution of minor anodes. - Abstract: Yttrium 3-(4-nitrophenyl)-2-propenoate has been studied as an effective corrosion inhibitor for copper alloy in 0.1 M chloride solution. The results show that the surface of copper alloy coupons exposed to solutions containing 0.45 mM yttrium 3-(4-nitrophenyl)-2-propenoate had no signs of corrosion attack due to protective film formation, whereas the surface of copper alloy coupons exposed to non-inhibitor and lower concentrations of yttrium 3-(4-nitrophenyl)-2-propenoate containing solutions were severely corroded. A high inhibition performance is attributed to the forming protective inhibiting deposits that slow down the electrochemical corrosion reactions and mitigate corrosion by promoting random distribution of minor anodes.

  19. Comparison by quantitative scanning of the distribution in the body of yttrium-90 and gold-198 after intra-articular injection

    International Nuclear Information System (INIS)

    Williams, E.D.; Caughey, D.E.; John, M.B.; Hurley, P.J.

    1975-01-01

    A new radiopharmaceutical, yttrium-90 ferric hydroxide colloid, has been used to treat knee effusion in patients with rheumatoid arthritis. With a view to assessing absorbed radiation dose, a study was initiated to compare its body distribution with that of gold-198, which has also been used for this purpose. The treated knee was in each case scanned immediately after injection using a dual 5-inch detector scanner, and again two, four and seven days later, when the regional lymph nodes and liver were also scanned. Using calibration factors obtained by scanning water phantoms, data from the scans were used to calculate the percentage of the injected radioactivity in each site. Radioactivity in blood and urine was also measured. Ten knees have been treated, each with five mCi yttrium-90, and twelve with 10 mCi gold-198. The treated knee was immobilized, and the patient rested in bed for four days, to minimize loss of radioactivity from the knee. With this procedure, both radionuclides were found to be equally well retained in the knee. However, the lymph node uptake of yttrium was lower than for gold. Yttrium-90 emits only beta radiation, so the gonadal radiation done in patients treated with yttrium-90 is estimated to be much less than in those treated with gold-198. (author)

  20. Investigation of self-frequency doubling crystals, yttrium calcium oxyborate (YCOB), doped with neodymium or ytterbium

    Science.gov (United States)

    Ye, Qing

    1999-09-01

    There is a need for low cost red, green, and blue (RGB) lasers for a number of commercial applications such as high-resolution laser printing, full color laser display. While semiconductor lasers still have both availability (green and blue) and beam quality (red) problems, nonlinear frequency conversion of diode-pumped solid state lasers are good alternatives. Among them, self- frequency doubling is an attractive approach because of its simpler design and lower cost. Unfortunately, few known crystals possess self-frequency doubling property. A newly discovered yttrium calcium oxyborate (YCOB) can fill in the role because it has adequate lasing and nonlinear frequency conversion efficiency. More importantly, YCOB crystal melts congruently so that high quality, large size single crystals can be grown using conventional Czochralski melt pulling technique. The thermal mechanical properties, linear and nonlinear optical properties of YCOB, laser properties of Nd:YCOB and Yb:YCOB crystals were investigated. Based on the calculated second harmonic phase matching angles, Nd:YCOB laser rods were fabricated. Self-frequency doubled green emission with 62 mW output power and red emission with 16 mW output power were successfully demonstrated using diode-pumping. It is the first time to achieve the continuous wave (cw) red lasing in Nd doped rare-earth calcium oxyborates. Rare-earth ions doping in YCOB crystal can not only achieve lasing, but also affect the physical and chemical properties of the crystal. The stability field of YCOB is reduced in proportion to both the ionic size differences from yttrium and doping concentrations of the rare-earth ions. The doping also changes the linear and nonlinear optical properties of the material. For example, the second harmonic conversion efficiency of 20% Yb doped YCOB was enhanced by more than 15% compared to undoped YCOB. The absorption cutoff edge of 20% Yb:YCOB was red- shift by more than 60 nm. Similar effects were observed in

  1. Treatment of primary liver tumors with Yttrium-90 microspheres (TheraSphere) in high risk patients: analysis of survival and toxicities.

    Science.gov (United States)

    Reardon, Kelli A; McIntosh, Alyson F; Shilling, A Tanner; Hagspiel, Klaus D; Al-Osaimi, Abdullah; Berg, Carl; Caldwell, Stephen H; Northup, Patrick G; Angle, Fritz; Mulder, Robert; Rich, Tyvin A

    2009-02-01

    This retrospective study was undertaken to obtain information regarding the survival and toxicities after Yttrium-90 microspheres treatment in patients with primary liver malignancies. Baseline, treatment, and follow-up data were collected and analyzed for 21 patients treated with Yttrium-90 microspheres. Survival analysis was then performed. The results of this study showed that median survival for all the patients was 120 days. Twenty of 21 patients were categorized as high-risk with a median survival of 114 days. It was also found that one high-risk patient has survived 858 days with no recurrence of disease. Acute grade 3-5 toxicities were recorded for nine patients and consisted of elevations in AST and bilirubin, thrombocytopenia, abdominal pain, ascites, nausea, fatigue, and death. This study concluded that Yttrium-90 is a low-toxicity, outpatient alternative for individuals with liver cancer and without many options. The maximal value, however, may lie in the treatment of low-risk patients.

  2. Equilibrium Studies on the Extraction of Yttrium from Chloride Medium by Mono (2-Ethylhexyl) 2-Ethylhexyl Phosphonic Acid (Ion quest 801)

    International Nuclear Information System (INIS)

    Zaki, E.E.; Ismail, Z.H.; Aly, H.F.; Sabet, S.A.

    2008-01-01

    Since 90 Y is one of the useful radioisotopes in nuclear medicine, liquid-liquid extraction of yttrium from chloride medium has been studied under various conditions using neutralized and un-neutralized mono (2-ethylhexyl) 2-ethylhexyl phosphonic acid (EHEHPA) as an extractant. Effect of reagent concentration, ph of the aqueous medium, metal ion concentration and nature of the diluent on the extraction process has been carried out. Effect of temperature was studied and thermodynamic parameters were evaluated. Yttrium extracted in organic phase was stripped with various reagents. The stoichiometry of the extracted species of yttrium was determined on the basis of slope analysis of experimental results. Equilibrium equations of the extraction process have been estimated and verified

  3. Long-Term Palliative Effect of Stenting in Gastric Outlet Obstruction Due to Transarterial Chemoembolization with Yttrium-90 in a Patient with Metastatic Neuroendocrine Tumor

    Directory of Open Access Journals (Sweden)

    Erkan Caglar

    2016-09-01

    Full Text Available Internal radioembolization with yttrium-90 is a promising treatment method, predominantly for liver tumors. However, the shifting of yttrium-90-loaded spherules into the arteries and veins that supply the duodenum and stomach, leading to ulceration, hemorrhage, perforation, and outlet obstruction of these organs, is one of the major undesirable consequences of this technique. We report a case of gastric outlet obstruction (GOO due to antropyloric stenosis with ulceration, edema, and inflammation following transarterial yttrium-90 treatment for a metastatic neuroendocrine tumor in a 58-year-old man. Stenting was used for palliation in this case. GOO improved after stenting and recovery of oral intake was permanent after stent removal.

  4. Swift heavy ion-beam induced amorphization and recrystallization of yttrium iron garnet

    International Nuclear Information System (INIS)

    Costantini, Jean-Marc; Miro, Sandrine; Beuneu, François; Toulemonde, Marcel

    2015-01-01

    Pure and (Ca and Si)-substituted yttrium iron garnet (Y 3 Fe 5 O 12 or YIG) epitaxial layers and amorphous films on gadolinium gallium garnet (Gd 3 Ga 5 O 12 , or GGG) single crystal substrates were irradiated by 50 MeV 32 Si and 50 MeV (or 60 MeV) 63 Cu ions for electronic stopping powers larger than the threshold value (∼4 MeV μm −1 ) for amorphous track formation in YIG crystals. Conductivity data of crystalline samples in a broad ion fluence range (10 11 –10 16 cm −2 ) are modeled with a set of rate equations corresponding to the amorphization and recrystallization induced in ion tracks by electronic excitations. The data for amorphous layers confirm that a recrystallization process takes place above ∼10 14 cm −2 . Cross sections for both processes deduced from this analysis are discussed in comparison to previous determinations with reference to the inelastic thermal-spike model of track formation. Micro-Raman spectroscopy was also used to follow the related structural modifications. Raman spectra show the progressive vanishing and randomization of crystal phonon modes in relation to the ion-induced damage. For crystalline samples irradiated at high fluences (⩾10 14 cm −2 ), only two prominent broad bands remain like for amorphous films, thereby reflecting the phonon density of states of the disordered solid, regardless of samples and irradiation conditions. The main band peaked at ∼660 cm −1 is assigned to vibration modes of randomized bonds in tetrahedral (FeO 4 ) units. (paper)

  5. Tattoo removal by Q-switched yttrium aluminium garnet laser: client satisfaction.

    Science.gov (United States)

    Hutton Carlsen, K; Esmann, J; Serup, J

    2017-05-01

    Tattoo removal by Q-switched yttrium aluminium garnet (YAG) lasers is golden standard; however, clients' satisfaction with treatment is little known. To determine clients' satisfaction with tattoo removal. One hundred and fifty-four tattoo removal clients who had attended the private clinic 'Centre for Laser Surgery', Hellerup, Denmark, from 2001 to 2013 completed a questionnaire concerning outcome expectations, level of pain experiences and satisfaction with tattoo removal. The laser surgeon and his team were blinded from data handling. The study design included a minimum 2-year postlaser treatment observation period from 2013 to 2015. Overall, clients were satisfied with their laser treatment; 85% assessed their treatment and results to be acceptable to superb, while 15% assessed their treatment and results to be inferior to unacceptable. Effectiveness relative to colour of tattoo on a scale from 0 (no effect) to 10 (complete removal) scored a mean of blue 9.5, black 9.4, yellow 8.9, red 8.8 and green 6.5. Clients were dissatisfied with green pigment remnants, which could mimic bruising. One hundred and twenty-nine clients (84%) experienced moderate to extreme pain during treatment. Twenty-eight (20%) developed minor scarring. There were many reasons for tattoo removal; e.g. stigmatisation (33%), conspicuousness (29%) and poor artistic quality (22%). One hundred and two clients had expected complete removal of tattoos without a blemish, expectations that were only partly fulfilled. During the treatment period, clients adjusted expectations and adapted more realistic views of outcomes. The majority of clients were satisfied with Q-switched YAG laser removal of tattoos despite high pretreatment expectations which were only partly met. The study supports YAG lasers for tattoo removal as acceptable therapy of today, with room for new approaches. © 2017 European Academy of Dermatology and Venereology.

  6. Corrosion studies of modified organosilane coated magnesium-yttrium alloy in different environments

    Energy Technology Data Exchange (ETDEWEB)

    Xue Dingchuan [College of Engineering, University of Cincinnati, OH 45221 (United States); Tan Zongqing [Internal Medicine, College of Medicine, University of Cincinnati, OH 45221 (United States); Schulz, Mark J. [College of Engineering, University of Cincinnati, OH 45221 (United States); Vanooij, William J. [College of Engineering, University of Cincinnati, OH 45221 (United States); ECOSIL Technologies LLC, Fairfield, OH 45014 (United States); Sankar, Jagannathan [Biomedical Engineering Program, College of Engineering, North Carolina A and T State University, NC 27411 (United States); Yun Yeoheung, E-mail: yyun@ncat.edu [College of Engineering, University of Cincinnati, OH 45221 (United States); Biomedical Engineering Program, College of Engineering, North Carolina A and T State University, NC 27411 (United States); Dong Zhongyun [Internal Medicine, College of Medicine, University of Cincinnati, OH 45221 (United States)

    2012-07-01

    Magnesium (Mg) and its alloys have numerous potential applications as biodegradable implants, but the fast degradation rate of Mg alloys at the initial implanted stage could be a problem. This paper describes the modification of the water-based bis-[triethoxysilyl] ethane (BTSE) silane applied to the surface of magnesium-yttrium (Mg-4Y) to increase its corrosion resistance. Surface characterization by SEM, FTIR, and EDX showed that the hydrolysis and condensation of the silane resulted in a covalent bonding to the Mg-4Y surface. Corrosion behavior of the uncoated and coated Mg-4Y alloy was evaluated in different environments by using a novel self-developed corrosion probe. Based on the electrochemical results of DC polarization and electrochemical impedance spectroscopy (EIS), we conclude that the epoxy-modified BTSE silane coating successfully increases the corrosion resistance at the initial stage of implantation. The corrosion rates in the flesh of dead mice environments such as body cavity and subcutaneous tissue of the mice were lower than the corrosion rates in in vitro environments. - Highlights: Black-Right-Pointing-Pointer Modified silane was used on Mg-4Y for biological applications. Black-Right-Pointing-Pointer Modified silane-treated Mg-4Y increased its corrosion resistance in both In Vitro and In Vivo environments. Black-Right-Pointing-Pointer In Vitro testing environment is not consistent with In Vivo animal environment. Black-Right-Pointing-Pointer The modified silane mixture protecting mechanisms and its biocompatibility were discussed. Black-Right-Pointing-Pointer A novel three-electrode corrosion-monitoring probe was developed for realizing this work's In Vivo testing goals.

  7. Corrosion studies of modified organosilane coated magnesium–yttrium alloy in different environments

    International Nuclear Information System (INIS)

    Xue Dingchuan; Tan Zongqing; Schulz, Mark J.; Vanooij, William J.; Sankar, Jagannathan; Yun Yeoheung; Dong Zhongyun

    2012-01-01

    Magnesium (Mg) and its alloys have numerous potential applications as biodegradable implants, but the fast degradation rate of Mg alloys at the initial implanted stage could be a problem. This paper describes the modification of the water-based bis-[triethoxysilyl] ethane (BTSE) silane applied to the surface of magnesium–yttrium (Mg–4Y) to increase its corrosion resistance. Surface characterization by SEM, FTIR, and EDX showed that the hydrolysis and condensation of the silane resulted in a covalent bonding to the Mg–4Y surface. Corrosion behavior of the uncoated and coated Mg–4Y alloy was evaluated in different environments by using a novel self-developed corrosion probe. Based on the electrochemical results of DC polarization and electrochemical impedance spectroscopy (EIS), we conclude that the epoxy-modified BTSE silane coating successfully increases the corrosion resistance at the initial stage of implantation. The corrosion rates in the flesh of dead mice environments such as body cavity and subcutaneous tissue of the mice were lower than the corrosion rates in in vitro environments. - Highlights: ► Modified silane was used on Mg–4Y for biological applications. ► Modified silane-treated Mg–4Y increased its corrosion resistance in both In Vitro and In Vivo environments. ► In Vitro testing environment is not consistent with In Vivo animal environment. ► The modified silane mixture protecting mechanisms and its biocompatibility were discussed. ► A novel three-electrode corrosion-monitoring probe was developed for realizing this work's In Vivo testing goals.

  8. Fractional versus ablative erbium:yttrium-aluminum-garnet laser resurfacing for facial rejuvenation: an objective evaluation.

    Science.gov (United States)

    El-Domyati, Moetaz; Abd-El-Raheem, Talal; Abdel-Wahab, Hossam; Medhat, Walid; Hosam, Wael; El-Fakahany, Hasan; Al Anwer, Mustafa

    2013-01-01

    Laser is one of the main tools for skin resurfacing. Erbium:yttrium-aluminum-garnet (Er:YAG) was the second ablative laser, after carbon dioxide, emitting wavelength of 2940 nm. Fractional laser resurfacing has been developed to overcome the drawbacks of ablative lasers. We aimed to objectively evaluate the histopathological and immunohistochemical effects of Er:YAG 2940-nm laser for facial rejuvenation (multiple sessions of fractional vs single session of ablative Er:YAG laser). Facial resurfacing with single-session ablative Er:YAG laser was performed on 6 volunteers. Another 6 were resurfaced using fractional Er:YAG laser (4 sessions). Histopathological (hematoxylin-eosin, orcein, Masson trichrome, and picrosirius red stains) and immunohistochemical assessment for skin biopsy specimens were done before laser resurfacing and after 1 and 6 months. Histometry for epidermal thickness and quantitative assessment for neocollagen formation; collagen I, III, and VII; elastin; and tropoelastin were done for all skin biopsy specimens. Both lasers resulted in increased epidermal thickness. Dermal collagen showed increased neocollagen formation with increased concentration of collagen types I, III, and VII. Dermal elastic tissue studies revealed decreased elastin whereas tropoelastin concentration increased after laser resurfacing. Neither laser showed significant difference between their effects clinically and on dermal collagen. Changes in epidermal thickness, elastin, and tropoelastin were significantly more marked after ablative laser. The small number of patients is a limitation, yet the results show significant improvement. Multiple sessions of fractional laser have comparable effects to a single session of ablative Er:YAG laser on dermal collagen but ablative laser has more effect on elastic tissue and epidermis. Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  9. Yttrium-90 Radioembolization for Unresectable Standard-chemorefractory Intrahepatic Cholangiocarcinoma: Survival, Efficacy, and Safety Study

    Energy Technology Data Exchange (ETDEWEB)

    Rafi, Shoaib; Piduru, Sarat M. [Emory University School of Medicine, Division of Interventional Radiology and Image Guided Medicine, Department of Radiology (United States); El-Rayes, Bassel; Kauh, John S. [Emory University School of Medicine, Department of Hematology and Medical Oncology (United States); Kooby, David A.; Sarmiento, Juan M. [Emory University School of Medicine, Department of Surgical Oncology in Surgery (United States); Kim, Hyun S., E-mail: kevin.kim@emory.edu [Emory University School of Medicine, Division of Interventional Radiology and Image Guided Medicine, Department of Radiology (United States)

    2013-04-15

    To assess the overall survival, efficacy, and safety of radioembolization with yttrium-90 (Y90) for unresectable standard-chemorefractory intrahepatic cholangiocarcinoma (ICC). Patients with unresectable standard-chemorefractory ICC treated with Y90 were studied. Survival was calculated from the date of first Y90 procedure. Tumor response was assessed with the Response Evaluation Criteria in Solid Tumors criteria on follow-up computed tomography or magnetic resonance imaging scans. National Cancer Institute Common Terminology Criteria (NCI CTCAE), version 3, were used for complications. Statistical analysis was performed by the Kaplan-Meier estimator by the log rank test. Nineteen patients underwent a total of 24 resin-based Y90 treatments. Median survival from the time of diagnosis and first Y90 procedure was 752 {+-} 193 [95 % confidence interval (CI) 374-1130] and 345 {+-} 128 (95 % CI 95-595) days, respectively. Median survival with Eastern Cooperative Oncology Group (ECOG) performance status 1 (n = 15) and ECOG performance status 2 (n = 4) was 450 {+-} 190 (95 % CI 78-822) and 345 {+-} 227 (95 % CI 0-790) days, respectively (p = .214). Patients with extrahepatic metastasis (n = 11) had a median survival of 404 {+-} 309 (95 % CI 0-1010) days versus 345 {+-} 117 (95 % CI 115-575) days for patients without metastasis (n = 8) (p = .491). No mortality was reported within 30 days from first Y90 radioembolization. One patient developed grade 3 thrombocytopenia as assessed by NCI CTCAE. Fatigue and transient abdominal pain were observed in 4 (21 %) and 6 (32 %) patients, respectively. Y90 radioembolization is effective for unresectable standard-chemorefractory ICC.

  10. Selective separation of yttrium by CA-100 in the presence of a complexing agent

    International Nuclear Information System (INIS)

    Sun Xiaobo; Wang Yige; Li Deqian

    2006-01-01

    The selective separation of Y from yttrium solution containing small heavy rare earth (HRE) impurities (Ho, Er, Tm, Yb, Lu) by liquid-liquid extraction using CA-100 in the presence of a water-soluble complexing agent of ethylenediaminetetraacetic acid (EDTA) was experimentally studied at 298 K. Experiments were carried out in two feeds, Feed-I: [RE] f = 4.94 x 10 -3 M, Y = 98.5%, HRE (Ho, Er, Tm, Yb, Lu) = 1.5%; Feed-II: [RE] f = 4.94 x 10 -3 M, Y = 99.9%, HRE (Ho, Er, Tm, Yb, Lu) = 0.1%, as a function of equilibrium pH (pH eq ), the concentration ratio of [EDTA]:[HRE impurities]. It was shown that the extraction of HRE in the presence of EDTA was suppressed when compared to that of Y because of the masking effect, while the selective extraction of Y was enhanced and the separation factors increased to maximum at appropriate condition for Feed-I: Y/Ho = 1.53, Y/Er 3.09, Y/Tm = 5.61, Y/Yb = 12.04, Y/Lu = 27.51 at pH 4.37 and [EDTA]:[HRE impurities] = 4:1, for Feed-II: Y/Ho = 1.32, Y/Er = 1.91, Y/Tm = 2.00, Y/Yb 3.05, Y/Lu = 3.33 at pH 4.42 and [EDTA]:[HRE impurities] = 8:1. The separation and purification of Y by this method was discussed

  11. Spectrofluorimetric quantification of bilirubin using yttrium-norfloxacin complex as a fluorescence probe in serum samples

    Energy Technology Data Exchange (ETDEWEB)

    Kamruzzaman, Mohammad; Alam, Al-Mahmnur [Department of Chemistry, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Hak Lee, Sang, E-mail: shlee@knu.ac.kr [Department of Chemistry, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Ho Kim, Young, E-mail: youngkim@knu.ac.kr [Research Institute of Advanced Energy Technology, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kim, Gyu-Man [School of Mechanical Engineering, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Hyub Oh, Sang [Center for Gas Analysis, Korea Research Institute of Standards and Science, Daejeon 305-600 (Korea, Republic of)

    2012-11-15

    A simple and sensitive spectrofluorimetric method was developed to determine trace amounts of bilirubin (BR) using yttrium (Y{sup 3+})-norfloxacin (NFLX) complex as a fluorescence (FL) probe. NFLX can form a stable binary complex with Y{sup 3+} and markedly enhances the weak FL signal of the NFLX. The FL intensity of the Y{sup 3+}-NFLX complex decreased significantly in the presence of BR in a buffer solution at pH=7.2. Under optimal conditions, the FL intensity decreased according to the BR concentration and showed a good linear relationship in the range of 0.03-2.3 {mu}g mL{sup -1} of BR with a correlation coefficient of 0.9988. The limit of detection for the determination of BR was 2.8 ng mL{sup -1} with a relative standard deviation (RSD) of 1.55% for five replicate determination of 0.05 {mu}g mL{sup -1} BR. The presented method offers higher sensitivity with simple instrumentation and was applied successfully in detecting BR at low concentrations. Highlights: Black-Right-Pointing-Pointer Weak FL signal of NFLX was enhanced at 419 nm by forming binary complex with Y{sup 3+}. Black-Right-Pointing-Pointer The FL intensity of Y{sup 3+}-NFLX complex was quenched markedly in the presence of ATP. Black-Right-Pointing-Pointer NFLX can transfer energy to Y{sup 3+} and BR and form the Y{sup 3+}-NFLX-ATP ternary complex. Black-Right-Pointing-Pointer The reduced FL intensity of the system was correlated with the concentration of BR. Black-Right-Pointing-Pointer The method is applied to determine BR at low concentration (2.8 ng mL{sup -1}) in serum.

  12. Separation profiles of Sr from irradiated Yttrium matrix using different eluants by ion-exchange chromatography

    International Nuclear Information System (INIS)

    Ashok Kumar, G.V.S.; Vithya, J.; Kumar, R.; VenkataSubramani, C.R.

    2014-01-01

    89 Sr (a pure β - emitter, T 1/2 = 50.5d) is used in palliative care of bone metastases and was produced using the 89 Y(n,p) 89 Sr reaction in Fast Breeder Test Reactor (FBTR), Kalpakkam. The irradiated yttria target was dissolved in nitric acid and bulk separation of yttrium carried out by solvent extraction using TBP-HNO 3 followed by ion exchange chromatography of the aqueous phase with nitric acid as an eluting agent to obtain the pure fraction of 89 Sr. This paper discusses about the feasibility of separation of 89 Sr with other eluting agents in ion exchange chromatography vis-a-vis nitric acid. As this nuclide is injected as the chloride, the purified fraction of Sr in nitric acid medium is finally converted into HCI medium which is the preferred medium of source for its final application. In order to simplify the conversion, HCI medium can be used directly in the purifying stage making the process faster and simpler. Hence the separation profile using HCI was obtained. In addition, the elution pattern using another reagent tri sodium tri meta phosphate (SMP) was also determined. Purification of 89 Sr fraction using the eluants HCI and SMP was established. However, the elution with SMP yielded the 89 Sr fraction in a small volume and shorter period i.e. ∼ 9 h in comparison with 15 h and 22 h in the case of HCI and HNO 3 medium respectively and also generated less liquid waste. This study established that SMP can be a more favoured elution agent for the purification of 89 Sr source during the chemical processing of the bulk irradiated yttria target material. However the direct separation of Sr using the Sr selective crown ether i.e.ditert.butyl dicyclohexano 18 Crown 6, is much preferred over this method which is in progress

  13. Antibody-guided three-step therapy for high grade glioma with yttrium-90 biotin

    International Nuclear Information System (INIS)

    Paganelli, G.; Grana, C.; Chinol, M.; Cremonesi, M.; De Cicco, C.; Zoboli, S.; De Braud, F.; Robertson, C.; Zurrida, S.; Veronesi, U.; Casadio, C.; Siccardi, A.G.

    1999-01-01

    While the incidence of brain tumours seems to be increasing, median survival in patients with glioblastoma remains less than 1 year, despite improved diagnostic imaging and neurosurgical techniques, and innovations in treatment. We have developed an avidin-biotin pre-targeting approach for delivering therapeutic radionuclides to gliomas, using anti-tenascin monoclonal antibodies, which seems potentially effective for treating these tumours. We treated 48 eligible patients with histologically confirmed grade III or IV glioma and documented residual disease or recurrence after conventional treatment. Three-step radionuclide therapy was performed by intravenous administration of 35 mg/m 2 of biotinylated anti-tenascin monoclonal antibody (1st step), followed 36 h later by 30 mg of avidin and 50 mg of streptavidin (2nd step), and 18-24 h later by 1-2 mg of yttrium-90-labelled biotin (3rd step). 90 Y doses of 2.22-2.96 GBq/m 2 were administered; maximum tolerated dose (MTD) was determined at 2.96 GBq/m 2 . Tumour mass reduction (>25%-100%), documented by computed tomography or magnetic resonance imaging, occurred in 12/48 patients (25%), with 8/48 having a duration of response of at least 12 months. At present, 12 patients are still in remission, comprising four with a complete response, two with a parital response, two with a minor response and four with stable disease. Median survival from 90 Y treatment is 11 months for grade IV glioblastoma and 19 months for grade III anaplastic gliomas. Avidin-biotin based three-step radionuclide therapy is well tolerated at the dose of 2.2 GBq/m 2 , allowing the injection of 90 Y-biotin without bone marrow transplantation. This new approach interferes with the progression of high-grade glioma and may produce tumour regression in patients no longer responsive to other therapies. (orig.)

  14. Synthesis and luminescent study of Ce3+-doped terbium–yttrium aluminum garnet

    International Nuclear Information System (INIS)

    Dotsenko, V.P.; Berezovskaya, I.V.; Zubar, E.V.; Efryushina, N.P.; Poletaev, N.I.; Doroshenko, Yu.A.; Stryganyuk, G.B.; Voloshinovskii, A.S.

    2013-01-01

    Highlights: ► Ce 3+ -doped garnets (TYAG) were prepared using nanostructured reagents. ► The Ce 3+ ions cause a very efficient yellow emission of the samples. ► The reasons for the long wavelength position of this emission are discussed. ► Contribution from Al atoms to the conduction band of TYAG is quite essential. - Abstract: Terbium–yttrium aluminum garnets (TYAG) doped with Ce 3+ ions have been prepared by solid state reactions between nanostructured oxides of aluminum and rare earths. The luminescent properties of Ce 3+ ions in (Tb 0.8 Y 0.2 ) 3(1−x) Ce 3x Al 5 O 12 (x = 0.03) have been studied upon excitation in the 2–20 eV region. The substitution of Tb 3+ for Y 3+ in the garnet structure results in broadening the emission band and shifting its maximum towards the longer wavelengths. It was found that in addition to the 4f n → 4f n−1 5d excitation bands of Ce 3+ and Tb 3+ ions, the excitation spectra for the Ce 3+ emission contain broad bands at 6.73 and ∼9.5 eV. These bands are attributed to the Ce 3+ -bound exciton formation and O 2p → Al 3s, 3p transitions, respectively. In contrast to the predictions based on the results of electronic structure calculations on Y 3 Al 5 O 12 and Tb 4 Al 2 O 9 , the threshold of interband transitions in TYAG is at high energies (⩾7.3 eV), and contributions from Al tetr and Al oct atoms to the conduction-band density of states are evaluated as quite essential.

  15. Treating and Downstaging Hepatocellular Carcinoma in the Caudate Lobe with Yttrium-90 Radioembolization

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Saad M. [Northwestern University Feinberg School of Medicine, Robert H. Lurie Comprehensive Cancer Center, Department of Radiology, Section of Interventional Radiology (United States); Kulik, Laura [Northwestern University Feinberg School of Medicine, Department of Medicine, Division of Hepatology (United States); Baker, Talia [Northwestern University Feinberg School of Medicine, Division of Transplant Surgery (United States); Ryu, Robert K. [Northwestern University Feinberg School of Medicine, Robert H. Lurie Comprehensive Cancer Center, Department of Radiology, Section of Interventional Radiology (United States); Mulcahy, Mary F. [Northwestern University Feinberg School of Medicine, Department of Medicine, Division of Hematology and Oncology, Robert H. Lurie Comprehensive Cancer Center (United States); Abecassis, Michael [Northwestern University Feinberg School of Medicine, Division of Transplant Surgery (United States); Salem, Riad; Lewandowski, Robert J., E-mail: r-lewandowski@northwestern.edu [Northwestern University Feinberg School of Medicine, Robert H. Lurie Comprehensive Cancer Center, Department of Radiology, Section of Interventional Radiology (United States)

    2012-10-15

    Purpose: This study was designed to determine the technical feasibility, safety, efficacy, and potential to downstage patients to within transplantation criteria when treating patients with hepatocellular carcinoma (HCC) of the caudate lobe using Y90 radioembolization. Methods: During a 4-year period, 8 of 291 patients treated with radioembolization for unresectable HCC had disease involving the caudate lobe. All patients were followed for treatment-related clinical/biochemical toxicities, serum tumor marker response, and treatment response. Imaging response was assessed with the World Health Organization (WHO) and European Association for the Study of the Liver (EASL) classification schemes. Pathologic response was reported as percent necrosis at explantation. Results: Caudate lobe radioembolization was successfully performed in all eight patients. All patients presented with both cirrhosis and portal hypertension. Half were United Network for Organ Sharing (UNOS) stage T3 (n = 4, 50%). Fatigue was reported in half of the patients (n = 4, 50%). One (13%) grade 3/4 bilirubin toxicity was reported. One patient (13%) showed complete tumor response by WHO criteria, and three patients (38%) showed complete response using EASL guidelines. Serum AFP decreased by more than 50% in most patients (n = 6, 75%). Four patients (50%) were UNOS downstaged from T3 to T2, three of who underwent transplantation. One specimen showed histopathologic evidence of 100% complete necrosis, and two specimens demonstrated greater than 50% necrosis. Conclusions: Radioembolization with yttrium-90 appears to be a feasible, safe, and effective treatment option for patients with unresectable caudate lobe HCC. It has the potential to downstage patients to transplantation.

  16. Enhancement of Er optical efficiency through bismuth sensitization in yttrium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Scarangella, Adriana [CNR IMM-MATIS, Via S. Sofia 64, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Reitano, Riccardo [Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Franzò, Giorgia; Miritello, Maria, E-mail: maria.miritello@ct.infn.it [CNR IMM-MATIS, Via S. Sofia 64, 95123 Catania (Italy); Priolo, Francesco [CNR IMM-MATIS, Via S. Sofia 64, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Scuola Superiore di Catania, Università di Catania, Via Valdisavoia 9, 95123 Catania (Italy)

    2015-07-27

    The process of energy transfer (ET) between optically active ions has been widely studied to improve the optical efficiency of a system for different applications, from lighting and photovoltaics to silicon microphotonics. In this work, we report the influence of Bi on the Er optical emission in erbium-yttrium oxide thin films synthesized by magnetron co-sputtering. We demonstrate that this host permits to well dissolve Er and Bi ions, avoiding their clustering, and thus to stabilize the optically active Er{sup 3+} and Bi{sup 3+} valence states. In addition, we establish the ET occurrence from Bi{sup 3+} to Er{sup 3+} by the observed Bi{sup 3+} PL emission decrease and the simultaneous Er{sup 3+} photoluminescence (PL) emission increase. This was further confirmed by the coincidence of the Er{sup 3+} and Bi{sup 3+} excitation bands, analyzed by PL excitation spectroscopy. By increasing the Bi content of two orders of magnitude inside the host, though the occurrence of Bi-Bi interactions becomes deleterious for Bi{sup 3+} optical efficiency, the ET process between Bi{sup 3+} and Er{sup 3+} is still prevalent. We estimate ET efficiency of 70% for the optimized Bi:Er ratio equal to 1:3. Moreover, we have demonstrated to enhance the Er{sup 3+} effective excitation cross section by more than three orders of magnitude with respect to the direct one, estimating a value of 5.3 × 10{sup −18} cm{sup 2}, similar to the expected Bi{sup 3+} excitation cross section. This value is one of the highest obtained for Er in Si compatible hosts. These results make this material very promising as an efficient emitter for Si-compatible photonics devices.

  17. Treatment of unresectable hepatocellular carcinoma with intrahepatic yttrium 90 microspheres: factors associated with liver toxicities.

    Science.gov (United States)

    Goin, James E; Salem, Riad; Carr, Brian I; Dancey, Janet E; Soulen, Michael C; Geschwind, Jean Francois H; Goin, Kathleen; Van Buskirk, Mark; Thurston, Kenneth

    2005-02-01

    Intraarterial injection of yttrium 90 microspheres (TheraSpheres) is used in the treatment of hepatocellular carcinoma (HCC). This article presents an analysis of the incidence of liver toxicities (liver-related events) and pretreatment factors associated with liver toxicities after TheraSphere treatment. Eighty-eight TheraSphere-treated patients with low 90-day mortality risk were selected for analysis, with liver toxicities coded with use of standard oncology criteria. Descriptive and inferential statistical methods were applied to estimate the incidence of liver toxicities and to evaluate the influence of liver radiation dose and various pretreatment factors on the risk of their occurrence. Sixty-eight liver toxicities occurred in 37 of the 88 patients (42%). Thirty-two patients (36%) experienced 50 liver toxicities after the first treatment and nine of 23 patients (39%) who received a second treatment experienced 18 liver toxicities. Pretreatment total bilirubin and liver radiation dose were found to be associated with the risk of at least one liver toxicity and with the time to first occurrence of a liver toxicity after first treatment. Pretreatment total bilirubin also was associated with liver toxicities after the second treatment. Most of the toxicities resolved; however, those that did not resolve were attributed to tumor progression or advancing cirrhosis. The risk of liver toxicities in patients with unresectable HCC treated with TheraSpheres increases with increasing pretreatment total bilirubin level and liver radiation dose to a maximum of 150 Gy for a single administration. The toxicities attributed to treatment resolved over time, and none of the patients studied had confirmed radiation-induced liver disease. Consequently, doses as high as 150 Gy on a single administration and as high as 268 Gy on repeated administrations were well tolerated.

  18. Erbium-yttrium-aluminum-garnet laser irradiation ameliorates skin permeation and follicular delivery of antialopecia drugs.

    Science.gov (United States)

    Lee, Woan-Ruoh; Shen, Shing-Chuan; Aljuffali, Ibrahim A; Li, Yi-Ching; Fang, Jia-You

    2014-11-01

    Alopecia usually cannot be cured because of the available drug therapy being unsatisfactory. To improve the efficiency of treatment, erbium-yttrium-aluminum-garnet (Er-YAG) laser treatment was conducted to facilitate skin permeation of antialopecia drugs such as minoxidil (MXD), diphencyprone (DPCP), and peptide. In vitro and in vivo percutaneous absorption experiments were carried out by using nude mouse skin and porcine skin as permeation barriers. Fluorescence and confocal microscopies were used to visualize distribution of permeants within the skin. Laser ablation at a depth of 6 and 10 μm enhanced MXD skin accumulation twofold to ninefold depending on the skin barriers selected. DPCP absorption showed less enhancement by laser irradiation as compared with MXD. An ablation depth of 10 μm could increase the peptide flux from zero to 4.99 and 0.33 μg cm(-2) h(-1) for nude mouse skin and porcine skin, respectively. The laser treatment also promoted drug uptake in the hair follicles, with DPCP demonstrating the greatest enhancement (sixfold compared with the control). The imaging of skin examined by microscopies provided evidence of follicular and intercellular delivery assisted by the Er-YAG laser. Besides the ablative effect of removing the stratum corneum, the laser may interact with sebum to break up the barrier function, increasing the skin delivery of antialopecia drugs. The minimally invasive, well-controlled approach of laser-mediated drug permeation offers a potential way to treat alopecia. This study's findings provide the basis for the first report on laser-assisted delivery of antialopecia drugs. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  19. Biodistribution of Yttrium-90-Labeled Anti-CD45 Antibody in a Nonhuman Primate Model

    International Nuclear Information System (INIS)

    Nemecek, Eneida; Hamlin, Donald K.; Fisher, Darrell R.; Krohn, Kenneth A.; Pagel, John M.; Applebaum, F. R.; Press, Oliver W.; Matthews, Dana C.

    2005-01-01

    Radioimmunotherapy may improve the outcome of hematopoietic cell transplantation for hematologic malignancies by delivering targeted radiation to hematopoietic organs while relatively sparing nontarget organs. We evaluated the organ localization of yttrium-90-labeled anti-CD45 (90Y-anti-CD45) antibody in macaques, a model that had previously predicted iodine-131-labeled anti-CD-45 (131I-anti-CD45) antibody biodistribution in humans. Experimental Design: Twelve Macaca nemestrina primates received anti-CD45 antibody labeled with 1 to 2 mCi of 90Y followed by serial blood sampling and marrow and lymph node biopsies, and necropsy. The content of 90Y per gram of tissue was determined by liquid scintillation spectrometry. Time-activity curves were constructed using average isotope concentrations in each tissue at measured time points to yield the fractional residence time and estimate radiation absorbed doses for each organ per unit of administered activity. The biodistribution of 90Y-anti-CD45 antibody was then compared with that previously obtained with 131I-anti-CD45 antibody in macaques. Results: The spleen received 2,120, marrow 1,060, and lymph nodes 315 cGy/mCi of 90Y injected. The liver and lungs were the nontarget organs receiving the highest radiation absorbed doses (440 and 285 cGy/mCi, respectively). Ytrrium-90-labeled anti-CD45 antibody delivered 2.5- and 3.7-fold more radiation to marrow than to liver and lungs, respectively. The ratios previously observed with 131I-antiCD45 antibody were 2.5-and 2.2-fold more radiation to marrow than to liver and lungs, respectively. Conclusions: This study shows that 90Y-anti-CD45 antibody can deliver relatively selective radiation to hematopoietic tissues, with similar ratios of radiation delivered to target versus nontarget organs, as compared with the 131I immunoconjugate in the same animal model

  20. Neodymium:Yttrium aluminum garnet laser in the management of oral leukoplakia: A case series

    Directory of Open Access Journals (Sweden)

    Somdipto Das

    2015-01-01

    Full Text Available Objectives: Oral leukoplakia is a nonscrappable whitish patch described as a potentially malignant disorder with high prevalence in India. Besides medicinal treatment, neodymium: Yttrium aluminum garnet (Nd: YAG laser is also used for the management of oral leukoplakia. This study evaluated the role of Nd: YAG laser in the management of oral leukoplakia and also investigated postoperative complications along with long-term prognosis of the disease. Settings and Designs: The study is a prospective cohort study conducted for 24 months (June 2011 to May 2013 in Lucknow. Materials and Methods: The study comprised of 42 patients, both male and female of Indian origin and diagnosed with oral leukoplakic lesions. Patients with biopsy proven squamous cell carcinoma and medically compromised are excluded from the study. All patients has undergone ablation of lesion by pulsed Nd: YAG laser and were followed after 24 h, 72 h, 1-week and then successively for 1, 3, 6 months and then 1 st and 2 nd postoperative years. Results: Pain and slough were evaluated by Wicoxon rank test (P = 0.0001 statistically significant which decreased from 24 h to 1-week and became nil in subsequent follow-ups. Similarly, McNemar′s test (P = 0.001 statistically significant was used for evaluation of burning sensation, paresthesia, infection and recurrences. Recurrence was noted in 2 patients but following the second application, there were no recurrences over the period of further follow-up. None of the patient suffered from an infection, paresthesia or anesthesia. Conclusion: Hence, Nd: YAG laser was found to be effective in ablating leukoplakia. It is convenient, economical with minimum complications and morbidities.

  1. Magneto-optical properties of yttrium iron garnet (YIG) thin films elaborated by radio frequency sputtering

    International Nuclear Information System (INIS)

    Boudiar, T.; Payet-Gervy, B.; Blanc-Mignon, M.-F.; Rousseau, J.-J.; Le Berre, M.; Joisten, H.

    2004-01-01

    Thin films of yttrium iron garnet (YIG) are grown by radio frequency magnetron non reactive sputtering system. Thin films are crystallised by heat-treatment to obtain magneto-optical properties. On quartz substrate, the network of cracks observed on the annealed samples can be explained by the difference between the thermal expansion coefficient of substrate and YIG. Physico-chemical analysis shown that the obtained material has a correct stoichiometry and is crystallised as FCC. The Faraday rotation of thin films is measured with a classical ellipsometric system based on transmission which allows us to obtained an accuracy of 0.01 deg. The variation of Faraday rotation is studied on the one hand versus radio frequency power applied to the cathode during the deposition and on the other hand versus the applied magnetic field. The results are compared with those obtained by vibrating sample magnetometer analysis in perpendicular configuration. A maximum Faraday rotation is observed to be 1900 deg./cm at the wavelength of 594nm for a YIG thin film formed on quartz substrate and annealed at 740 deg. C. The values of the Faraday rotation coefficients obtained in the study versus the wavelength are comparable to those of the literature for the bulk material. In order to eliminate the stress due to the heat-treatment, we made some films on single crystals of gadolinium gallium garnet (111) substrates for which thermal expansion coefficient is near than the YIG one. The material crystallises with no crackles and the Faraday effect is equivalent

  2. Effect of rare earth element yttrium addition on microstructures and properties of a 21Cr-11Ni austenitic heat-resistant stainless steel

    International Nuclear Information System (INIS)

    Chen, Lei; Ma, Xiaocong; Wang, Longmei; Ye, Xiaoning

    2011-01-01

    Research highlights: → Applications of Y in 21Cr-11Ni austenitic heat-resistant stainless steel. → Sensible characteristics of microstructure and properties have been observed. → Y has been found be effective in improving hot ductility of 21Cr-11Ni steel. → Inhibitory effect of Y on S segregation to the grain boundary has been observed. -- Abstract: In this comparative study, the microstructure and the mechanical properties of a 21Cr-11Ni austenitic heat-resistant stainless steel with and without addition of rare earth (RE) element yttrium have been investigated. The results show that a number of fine spherical yttrium-rich oxide particles are not uniformly distributed in the matrix of steel with yttrium; instead, they are aligned along the rolling direction. The grains surrounding the alignment are nearly one order of magnitude smaller than those farther away from the alignment. The approximate calculation results indirectly show that the grain refinement may be mainly attributed to the stimulation for nucleation of recrystallization rather than to pinning by particles. Furthermore, the alignment has resulted in significant loss in transverse impact toughness and tensile elongation at room temperature. There is a trough in the hot ductility-temperature curve, which is located between 973 and 1173 K. The ductility trough of steel with yttrium becomes shallow within a certain temperature range, especially around 1073 K, indicating that improvement on hot ductility is achieved by yttrium addition. The results may be attributed to the increase of grain boundary cohesion indicated by the effective improvement on intergranular failure tendency, and the inhibitory effect of yttrium on sulfur segregation to grain boundaries is believed to be an important cause.

  3. Microstructural evolution and tensile mechanical properties of thixoformed AZ91D magnesium alloy with the addition of yttrium

    International Nuclear Information System (INIS)

    Zhao Zude; Chen Qiang; Kang Feng; Shu Dayu

    2009-01-01

    The microstructure evolution of AZ91D magnesium alloy in the semi-solid state has been proposed or reported in previous literature. However, no detailed investigation has been conducted regarding the relationship between the microstructure and tensile mechanical properties of the thixoformed AZ91D magnesium alloy. In this paper, the microstructure of AZ91D alloy with the addition of yttrium was produced by the semi-solid thermal transformation (SSTT) route and the strain-induced melt activation (SIMA) route, respectively. Isothermal holding experiments investigated grain coarsening and the degree of spheroidization as a function of holding time in the semi-solid state. The SSTT route and the SIMA route were used to obtain the semi-solid feedstock for thixoforming. The results show that solid particles of the SSTT alloy are spheroidized to some extent but the previous irregular shape is still obvious in some of them. While the SIMA alloy exhibits ideal, fine microstructure, in which completely spheroidized solid particles contain little entrapped liquid. The microstructure of the SSTT alloy is less spheroidized compared with the SIMA alloy under the similar isothermal holding condition. As the holding time increases, the mean solid particle size of the SSTT alloy decreases initially, then increases, while the mean solid particle size of the SIMA alloy increases monotonously at 560 deg. C. Compared with the SSTT alloy, the SIMA alloy obtains finer grains under the similar isothermal holding condition. The mechanical properties of the thixoformed AZ91D alloy with the addition of yttrium produced by the SIMA route are better than those of the thixoformed alloy produced by the SSTT route. The ultimate tensile strength, yield strength and elongation for the thixoformed alloy produced by the SIMA route are 303.1 MPa, 147.6 MPa and 13.27%, respectively. The tensile properties for the AZ91D alloy with the addition of yttrium thixoformed from starting material produced by

  4. Sign of inverse spin Hall voltages generated by ferromagnetic resonance and temperature gradients in yttrium iron garnet platinum bilayers

    International Nuclear Information System (INIS)

    Schreier, Michael; Lotze, Johannes; Gross, Rudolf; Goennenwein, Sebastian T B; Bauer, Gerrit E W; Uchida, Ken-ichi; Daimon, Shunsuke; Kikkawa, Takashi; Saitoh, Eiji; Vasyuchka, Vitaliy I; Lauer, Viktor; Chumak, Andrii V; Serga, Alexander A; Hillebrands, Burkard; Flipse, Joost; Van Wees, Bart J

    2015-01-01

    We carried out a concerted effort to determine the absolute sign of the inverse spin Hall effect voltage generated by spin currents injected into a normal metal. We focus on yttrium iron garnet (YIG)∣platinum bilayers at room temperature, generating spin currents by microwaves and temperature gradients. We find consistent results for different samples and measurement setups that agree with theory. We suggest a right-hand-rule to define a positive spin Hall angle corresponding to the voltage expected for the simple case of scattering of free electrons from repulsive Coulomb charges. (paper)

  5. Magnetophotonic crystals based on yttrium-iron-garnet infiltrated opals: Magnetization-induced second-harmonic generation

    Science.gov (United States)

    Murzina, T. V.; Kim, E. M.; Kapra, R. V.; Moshnina, I. V.; Aktsipetrov, O. A.; Kurdyukov, D. A.; Kaplan, S. F.; Golubev, V. G.; Bader, M. A.; Marowsky, G.

    2006-01-01

    Three-dimensional magnetophotonic crystals (MPCs) based on artificial opals infiltrated by yttrium iron garnet (YIG) are fabricated and their structural, optical, and nonlinear optical properties are studied. The formation of the crystalline YIG inside the opal matrix is checked by x-ray analysis. Two templates are used for the infiltration by YIG: bare opals and those covered by a thin platinum film. Optical second-harmonic generation (SHG) technique is used to study the magnetization-induced nonlinear-optical properties of the composed MPCs. A high nonlinear magneto-optical Kerr effect in the SHG intensity is observed at the edge of the photonic band gap of the MPCs.

  6. Single crystal growth of yttrium calcium oxy borate (YCOB) crystals by flux technique and their characterization. CP-3.5

    International Nuclear Information System (INIS)

    Arun Kumar, R.; Senthilkumar, M.; Dhanasekaran, R.

    2007-01-01

    Yttrium calcium oxy borate single crystals were grown by the flux technique for the first time. Polycrystalline YCOB material was prepared by solid state reaction method. Single crystals of YCOB were grown using boron-tri-oxide flux. Several transparent single crystals of dimensions 10 x 5 x 5 mm 3 were obtained. The grown crystals were characterized by powder XRD and UV- VIS-NIR studies. The results of powder XRD confirm the crystalline structure of YCOB. The UV- VIS-NIR transmission spectrum reveals that the crystal is highly transparent (above 75%) from ultraviolet (220 nm) to near IR regions enabling it as a suitable candidate for high power UV applications

  7. Fluorescence enhancement effect for the determination of curcumin with yttrium(III)-curcumin-sodium dodecyl benzene sulfonate system

    International Nuclear Information System (INIS)

    Wang Feng; Huang Wei; Wang Yanwei

    2008-01-01

    It is found that the fluorescence of curcumin is greatly enhanced by yttrium(III) (Y 3+ ) in the presence of sodium dodecyl benzene sulfonate. Based on this, a sensitive fluorimetric method for the determination of curcumin in aqueous solution is proposed. In the potassium hydrogen phthalate (KHP) buffer, the fluorescence intensity of curcumin is proportional to the concentration of curcumin in the range of 7.37x10 -4 -0.18, 0.18-2.95 μg mL -1 and the detection limit is 0.1583 ng mL -1 . The actual samples are satisfactorily determined. In addition, the interaction mechanism is also studied

  8. Anatase thin film with diverse epitaxial relationship grown on yttrium stabilized zirconia substrate by chemical vapor deposition

    International Nuclear Information System (INIS)

    Miyagi, Takahira; Ogawa, Tomoyuki; Kamei, Masayuki; Wada, Yoshiki; Mitsuhashi, Takefumi; Yamazaki, Atsushi

    2003-01-01

    An anatase epitaxial thin film with diverse epitaxial relationship, YSZ (001) // anatase (001), YSZ (010) // anatase (110), was grown on a single crystalline yttrium stabilized zirconia (YSZ) (001) substrate by metal organic chemical vapor deposition (MOCVD). The full width at half maximum (FWHM) of the (004) reflection of this anatase epitaxial film was 0.4deg, and the photoluminescence of this anatase epitaxial film showed visible emission with broad spectral width and large Stokes shift at room temperature. These results indicate that this anatase epitaxial film possessed almost equal crystalline quality compared with that grown under identical growth conditions on single crystalline SrTiO 3 substrate. (author)

  9. Complexes of (III) lanthanides isothiocyanate and (III) yttrium with 2,6-lutidine-n-oxide (2,6-LNO)

    International Nuclear Information System (INIS)

    Arico, E.M.

    1990-01-01

    The preparation and characterization of the complexes of yttrium and some lanthanides isothiocyanate with 2,6-lutidine-N-oxide (2,6-LNO) are described. The ligand employed in the synthesis of the compounds were prepared by the reaction of 2,6-lutidine with hydrogen peroxide in glacial acetic acid. The complexes were prepared using the relation 1:3 salt-ligand. Their characterization was made by elemental analysis, electrolytic conductance measurements, X-ray powder patterns, infrared spectra, electronic absorption spectra of the neodymium and fluorescence spectra of the europium compounds. (author)

  10. Pregnancies in women with hyperprolactinaemia: clinical course and obstetric complications of 41 pregnancies in 27 women. [Yttrium 90

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, W.F.; Doyle, F.H.; Mashiter, K.; Banks, L.M.; Gordon, H.; Joplin, G.F.

    1979-09-01

    Observations are reported on 41 pregnancies in 27 patients who initially had infertility and raised serum prolactin concentrations. Associated symptoms were secondary amenorrhoea and galactorrhoea. All patients were at risk of pituitary expansion during pregnancy, especially these 19 (70 per cent) with radiological evidence of pituitary tumors. Fifteen patients had 21 pregnancies after pituitary implantation with 90 yttrium; 14 patients had 20 pegnancies without prior pituitary implantation or any other attempt to prevent tumor expansion. The induction and Cesarean section rates were about 30 per cent in 32 term pregnancies in 25 patients. Details of how pregnancy was achieved and the associated obstetric problems are given.

  11. Spectrographic determination of strontium in yttrium-90 solutions; Determinacion espectrografica de estroncio en soluciones de itrio-90

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M; Capdevila, C

    1970-07-01

    The copper spark method has been used for determining strontium in the concentration range 1-100 g/ml in yttrium-90 solutions containing 0,5 % or thereabouts of ammonium citrate. The influence of the citric acid as well as the ammonium citrate with regard to 2N HCL solutions has been studied: the citric acid enhances the line intensities of strontium. The employment of either barium or lanthanum as reference element compensates for this enhancement. Because of the increase in sensitivity mentioned above, the study of influence of the citric acid has been extended and several impurities usually determined in radioisotope solutions have been considered. (Author) 4 refs.

  12. Thermal effects from modified endodontic laser tips used in the apical third of root canals with erbium-doped yttrium aluminium garnet and erbium, chromium-doped yttrium scandium gallium garnet lasers.

    Science.gov (United States)

    George, Roy; Walsh, Laurence J

    2010-04-01

    To evaluate the temperature changes occurring on the apical third of root surfaces when erbium-doped yttrium aluminium garnet (Er:YAG) and erbium, chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) laser energy was delivered with a tube etched, laterally emitting conical tip and a conventional bare design optical fiber tip. Thermal effects of root canal laser treatments on periodontal ligament cells and alveolar bone are of concern in terms of safety. A total of 64 single-rooted extracted teeth were prepared 1 mm short of the working length using rotary nickel-titanium Pro-Taper files to an apical size corresponding to a F5 Pro-Taper instrument. A thermocouple located 2 mm from the apex was used to record temperature changes arising from delivery of laser energy through laterally emitting conical tips or plain tips, using an Er:YAG or Er,Cr:YSGG laser. For the Er:YAG and Er,Cr:YSGG systems, conical fibers showed greater lateral emissions (452 + 69% and 443 + 64%) and corresponding lower forward emissions (48 + 5% and 49 + 5%) than conventional plain-fiber tips. All four combinations of laser system and fiber design elicited temperature increases less than 2.5 degrees C during lasing. The use of water irrigation attenuated completely the thermal effects of individual lasing cycles. Laterally emitting conical fiber tips can be used safely under defined conditions for intracanal irradiation without harmful thermal effects on the periodontal apparatus.

  13. Evidence of organic luminescent centers in sol-gel-synthesized yttrium aluminum borate matrix leading to bright visible emission

    Energy Technology Data Exchange (ETDEWEB)

    Burner, Pauline; Salauen, Mathieu; Ibanez, Alain; Gautier-Luneau, Isabelle [Univ. Grenoble Alpes, Inst NEEL, Grenoble (France); CNRS, Inst NEEL, Grenoble (France); Sontakke, Atul D.; Viana, Bruno [PSL Research University, Chimie ParisTech - CNRS, Institut de Recherche de Chimie Paris (France); Bardet, Michel [Universite Grenoble Alpes, CEA, CNRS, INAC, MEM, Grenoble (France); Mouesca, Jean-Marie; Gambarelli, Serge; Maurel, Vincent [Universite Grenoble Alpes, CEA, CNRS, INAC, SyMMES, Grenoble (France); Barra, Anne-Laure [Laboratoire National des Champs Magnetiques Intenses, UPR CNRS 3228, Universite Grenoble Alpes, Grenoble (France); Ferrier, Alban [PSL Research University, Chimie ParisTech - CNRS, Institut de Recherche de Chimie Paris (France); Sorbonne Universites UPMC Universites Paris 06, Paris (France)

    2017-11-06

    Yttrium aluminum borate (YAB) powders prepared by sol-gel process have been investigated to understand their photoluminescence (PL) mechanism. The amorphous YAB powders exhibit bright visible PL from blue emission for powders calcined at 450 C to broad white PL for higher calcination temperature. Thanks to {sup 13}C labelling, NMR and EPR studies show that propionic acid initially used to solubilize the yttrium nitrate is decomposed into aromatic molecules confined within the inorganic matrix. DTA-TG-MS analyses show around 2 wt % of carbogenic species. The PL broadening corresponds to the apparition of a new band at 550 nm, associated with the formation of aromatic species. Furthermore, pulsed ENDOR spectroscopy combined with DFT calculations enables us to ascribe EPR spectra to free radicals derived from small (2 to 3 rings) polycyclic aromatic hydrocarbons (PAH). PAH molecules are thus at the origin of the PL as corroborated by slow afterglow decay and thermoluminescence experiments. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Hot Corrosion of Yttrium Stabilized Zirconia Coatings Deposited by Air Plasma Spray on a Nickel-Based Superalloy

    Science.gov (United States)

    Vallejo, N. Diaz; Sanchez, O.; Caicedo, J. C.; Aperador, W.; Zambrano, G.

    In this research, the electrochemical impedance spectroscopy (EIS) and Tafel analysis were utilized to study the hot corrosion performance at 700∘C of air plasma-sprayed (APS) yttria-stabilized zirconia (YSZ) coatings with a NiCrAlY bond coat grown by high velocity oxygen fuel spraying (HVOF), deposited on an INCONEL 625 substrate, in contact with corrosive solids salts as vanadium pentoxide V2O5 and sodium sulfate Na2SO4. The EIS data were interpreted based on proposed equivalent electrical circuits using a suitable fitting procedure performed with Echem AnalystTM Software. Phase transformations and microstructural development were examined using X-ray diffraction (XRD), with Rietveld refinement for quantitative phase analysis, scanning electron microscopy (SEM) was used to determinate the coating morphology and corrosion products. The XRD analysis indicated that the reaction between sodium vanadate (NaVO3) and yttrium oxide (Y2O3) produces yttrium vanadate (YVO4) and leads to the transformation from tetragonal to monoclinic zirconia phase.

  15. Growth and characterization of yttrium iron garnet films on Si substrates by Chemical Solution Deposition (CSD) technique

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xin; Chen, Ying; Wang, Genshui [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China); Zhang, Yuanyuan [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Ge, Jun [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China); Tang, Xiaodong [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Ponchel, Freddy; Rémiens, Denis [Institute of Electronics, Microelectronics and Nanotechnology (IEMN)–DOAE, UMR CNRS 8520, Université des Sciences et Technologies de Lille, 59652 Villeneuve d’Ascq Cedex (France); Dong, Xianlin, E-mail: xldong@mail.sic.ac.cn [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China)

    2016-06-25

    Yttrium Iron Garnet (YIG) films were prepared on Si substrates by Chemical Solution Deposition (CSD) technique using acetic acid and deionized water as solvents. Well-crystallized and crack-free YIG films were obtained when annealed at 750 °C and 850 °C respectively, showing a low surface roughness of several nanometers. When annealed at 750 °C for 30 min, the saturated magnetization (Ms) and coercive field (Hc) of YIG films were 0.121 emu/mm{sup 3} (4πMs = 1.52 kGs) and 7 Oe respectively, which were similar to that prepared by PLD technique. The peak-to-peak linewidth of ferromagnetic resonance (FMR) was 220 Oe at 9.10 GHz. The results demonstrated that CSD was an excellent technique to prepare high quality yttrium iron garnet (YIG) films on silicon, which could provide a lower-cost way for large-scale production on Si-based integrated devices. - Highlights: • The preparation of YIG films by Chemical Solution Deposition are demonstrated. • Well-crystallized and crack-free YIG films can be obtained on Si substrate by CSD. • YIG films can be crystallized in 750 °C with good magnetic performances. • It's beneficial to large-scale production of YIG films on Si integrated devices.

  16. Hydrothermal synthesis of Yttrium Orthovanadate (YVO4) and its application in photo catalytic degradation of sewage water

    International Nuclear Information System (INIS)

    Komal, J. K.; Karimi, P.; Hui, K. S.

    2010-01-01

    In this paper; YVO 4 powder was successfully synthesized from Vanadium Pentaoxide (V 2 O 5 ), Yttrium Oxide (Y 2 O 3 ) and ethyl acetate as a mineralizer by hydrothermal method at a low temperature (T=.230 d egree C , and P=100 bars). The as-prepared powders were characterized by X-ray Diffraction, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, UV-V Spectroscopy and Chemical Oxygen Demand of the sewage water, respectively. The results show that hydrothermal method can greatly promote the crystallization and growth of YVO 4 phase. X-ray Diffraction pattern clearly indicates the tetragonal structure and crystallinity. An fourier transform infrared spectrum of the YVO 4 shows the presence of Y-O and V-O bond, respectively. The presence of these two peaks indicates that yttrium vanadate has been formed. UV-V is absorption spectra suggesting that YVO 4 particles have stronger UV absorption than natural sunlight and subsequent photo catalytic degradation data also confirmed their higher photo catalytic activity.

  17. Measurement of cross-sections of yttrium (n,xn) threshold reactions by means of gamma spectroscopy

    CERN Document Server

    Chudoba, Petr; Wagner, V; Vrzalova, J; Svoboda, O; Majerle, M; Stefanik, M; Suchopar, M; Kugler, A; Bielewicz, M; Strugalska-Gola, E; Szuta, M; Hervas, D; Herman, T; Geier, B

    2014-01-01

    Neutron activation and gamma spectrometry are usable also f or the determination of cross-sections of different neutron reactions. We have studied the cross-sections of yttrium (n, x n) threshold reactions using quasi-monoenergetic neutron source based on the reaction on 7 Li target at Nuclear Physics Institute of ASCR in Rez. Yttrium (n, x n) threshold reactions are suitable candidates for fast neutron field measurement by activation detectors. Fast neutron field monitoring is necessary already today at a wide range of accelerator facilities and will gain on importance in future fast reactors of generation IV, accelerator transmutation systems or fusion reactors. The knowledge of the cross-sections is crucial for such purpose. Unfortunately, the cross-section is sufficiently known only for 89 Y(n,2n) 88 Y reaction. For higher orders of reactions there are almost no experimental data. Special attention was paid to t he 89 Y(n,3n) 87 Y reaction. The cross-sections of both 89 Y(n,2n) 88 Y and 89 Y(n,3n) 87 Y re...

  18. Thermoanalytical, spectroscopic and DFT studies of heavy trivalent lanthanides and yttrium(III) with oxamate as ligand

    Energy Technology Data Exchange (ETDEWEB)

    Caires, Flavio Junior; Gaglieri, Caroline, E-mail: caires.flavio@fc.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Bauru, SP (Brazil). Faculdade de Ciencias; Nunes, Wilhan Donizete Goncalves; Nascimento, Andre Luiz Carneiro Soares do; Teixeira, Jose Augusto; Zangaro, Georgia Alvim Coelho; Treu-Filho, Oswaldo; Ionashiro, Massao [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil)

    2017-07-15

    Solid-state LnL{sub 3}∙nH{sub 2}O complexes, where Ln stands for trivalent lanthanides (Tb to Lu) or yttrium(III) and L is oxamate (NH{sub 2}COCO{sub 2}{sup -}), have been synthesized. The characterization of the complexes was performed by using elemental analysis (EA), complexometric titration with EDTA, thermoanalytical techniques such as simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC), evolved gas analysis (TG-FTIR), infrared spectroscopy (IR) and powder X-ray diffraction (XRPD). The results provided information about thermal behavior, crystallinity, stoichiometry, coordination sites, as well as the products released during thermal degradation of the complexes studied. Theoretical calculation of yttrium oxamate, as representative of all complexes was performed using density functional theory (DFT) for studying the molecular structure and vibrational spectrum of the investigated molecule in the ground state. The optimized geometrical parameters and theoretical vibrational spectrum obtained by DFT calculations are in good agreement with the experimental results. (author)

  19. Determination of the fission products yields, lanthanide and yttrium, in the fission of 238U with neutrons of fission spectra

    International Nuclear Information System (INIS)

    Nicoli, I.G.

    1981-06-01

    A radiochemical investigation is performed to measure the cumulative fission product yields of several lantanides and yttrium nuclides in the 238 U by fission neutron spectra. Natural and depleted uranium are irradiated under the same experimental conditions in order to find a way to subtract the contribution of the 235 U fission. 235 U percentage in the natural uranium was 3.5 times higher than in the depleted uranium. Uranium oxides samples are irradiated inside the core of the Argonaut Reactor, at the Instituto de Engenharia Nuclear, and the lantanides and yttrium are chemically separated. The fission products gamma activities were detected, counted and analysed in a system constituted by a high resolution Ge(Li) detector, 4096 multichannel analyser and a PDP-11 computer. Cumulative yields for fission products with half-lives between 1 to 33 hours are measured: 93 Y, 141 La, 142 La, 143 Ce and 149 Nd. The chain total yields are calculated. The cumulative fission yields measured for 93 Y, 141 La, 142 La, 143 Ce and 149 Nd are 4,49%, 4,54%, 4,95%, 4,16% and 1,37% respectively and they are in good agreement with the values found in the literature. (Author) [pt

  20. ELECTRON MICROSCOPIC INVESTIGATION OF YTTRIUM ALUMINUM GARNET POWDERS Y3AL5O12, SYNTHESIZED BY SOL–GEL METHOD

    Directory of Open Access Journals (Sweden)

    A. E. Baranchikov

    2015-09-01

    Full Text Available Subject of Study. The paper presents results of characterization for neodymium doped yttrium aluminum garnet nanopowders - YAG:Nd3+ by the method of scanning electronic microscopy. Method. Synthesis of YAG:Nd3+ was carried out by sol-gel method from nitrate or acetate - nitrate solutions with addition of some organic compounds and ammonia as well. Such substances were used as the source ones: oxides of neodymium and yttrium with the content of the basic substance equal to 99.999 %; organic compounds: citric acid with the content of the basic substance not less than 99.0 %; ethylene glycol (99.5%; the ammonium lauryl sulfate (99.0 %; urea (99.0 % of Alfa Aesar, Fluka, Aldrich companies. Oxides of yttrium and neodymium (5 at. % were dissolved in 50% acetic acid, nitrate aluminum was added with a view to the resulting product Y2,85Nd0,15Al5,0O12, the solution was stirred and heated to 60С before reaching its transparency and uniformity. The weight of the portion corresponding to the stoichiometry YAG was 2.0 g. 50 % aqueous solutions of organic substances or 5% NH4OH in a weight ratio of 1:1 to the weight of the garnet were added in aqueous solutions, placed into glass cups. The solutions were thoroughly mixed first using a conventional stirrer, then on ultrasonic installation with simultaneous 60 С heating for 2 hours. Drying of solutions to the consistency of a powder or a thick gel was carried out at 110 С. Then the samples were placed into platinum cups and annealed in a tube furnace at 950 - 1050 С for the period from 0.5 to 2 hours. Additional annealing of the powders in the air at 950 - 1060С were carried out for the purpose of powders clarifying for residual amorphous carbon removal. Main Results. The synthesized powder precursors and powders after annealing were examined using a polarizing microscope to identify anisotropic crystalline phases. X-ray analysis of the synthesized samples was carried out on a DRON - 4 and UDR - 63

  1. Quantitative and qualitative assessment of Yttrium-90 PET/CT imaging.

    Directory of Open Access Journals (Sweden)

    Ali Asgar Attarwala

    Full Text Available Yttrium-90 is known to have a low positron emission decay of 32 ppm that may allow for personalized dosimetry of liver cancer therapy with (90Y labeled microspheres. The aim of this work was to image and quantify (90Y so that accurate predictions of the absorbed dose can be made. The measurements were performed within the QUEST study (University of Sydney, and Sirtex Medical, Australia. A NEMA IEC body phantom containing 6 fillable spheres (10-37 mm ∅ was used to measure the 90Y distribution with a Biograph mCT PET/CT (Siemens, Erlangen, Germany with time-of-flight (TOF acquisition. A sphere to background ratio of 8:1, with a total (90Y activity of 3 GBq was used. Measurements were performed for one week (0, 3, 5 and 7 d. he acquisition protocol consisted of 30 min-2 bed positions and 120 min-single bed position. Images were reconstructed with 3D ordered subset expectation maximization (OSEM and point spread function (PSF for iteration numbers of 1-12 with 21 (TOF and 24 (non-TOF subsets and CT based attenuation and scatter correction. Convergence of algorithms and activity recovery was assessed based on regions-of-interest (ROI analysis of the background (100 voxels, spheres (4 voxels and the central low density insert (25 voxels. For the largest sphere, the recovery coefficient (RC values for the 30 min -2-bed position, 30 min-single bed and 120 min-single bed were 1.12 ± 0.20, 1.14 ± 0.13, 0.97 ± 0.07 respectively. For the smaller diameter spheres, the PSF algorithm with TOF and single bed acquisition provided a comparatively better activity recovery. Quantification of Y-90 using Biograph mCT PET/CT is possible with a reasonable accuracy, the limitations being the size of the lesion and the activity concentration present. At this stage, based on our study, it seems advantageous to use different protocols depending on the size of the lesion.

  2. Refractory metal superalloys: Design of yttrium aluminum garnet passivating niobium alloys

    Science.gov (United States)

    Bryan, David

    A systems-based approach, integrating computational modeling with experimental techniques to approach engineering problems in a time and cost efficient manner, was employed to design a Nb-based refractory superalloy for use at 1300°C. Ashby-type selection criteria for both thermodynamic and kinetic parameters were employed to identify a suitable protective oxide for Nb alloys. Yttrium aluminum garnet (YAG) was selected as the most promising candidate for its excellent combination of desirable properties. The alloy microstructural concept was based upon the gamma - gamma' nickel-based superalloys in which the multifunctional gamma' phase serves as both a creep strengthening dispersion and a source of reactive elements for oxide passivation. Candidate ternary Pd-Y-Al and Pt-Y-Al compounds were fabricated and characterized by XRD and DTA. Of the intermetallics studied, only PtYAl had a high enough melting point (1580°C) for use in an alloy operating at 1300°C. The alloy matrix design was based upon Wahl's extension of Wagner's criterion for protective oxidation, requiring a reduction of the product N ODO/DAl by 5 orders of magnitude relative to binary Nb-Al. A thermodynamic and kinetic analysis identified elements with large oxygen affinities as the most beneficial for reducing the magnitude of the quantity NOD O. Construction of a combined thermodynamic and mobility database identified increased Al solubility as the best approach for increasing D Al. Utilizing the thermodynamic and mobility databases, obtained from a combination of model alloys, oxidation experiments, and first principles calculations, theoretical designs predicted the large changes in solubility and transport parameters were achievable. Several prototype alloys were then fabricated and evaluated via oxidation tests at both 1300°C and 1100°C. YAG formation was demonstrated as part of multicomponent oxide scales in the alloys that exhibited the greatest reduction in oxidation rates. The oxidation

  3. Determinants of holmium:yttrium-aluminum-garnet laser time and energy during ureteroscopic laser lithotripsy.

    Science.gov (United States)

    Molina, Wilson R; Marchini, Giovanni S; Pompeo, Alexandre; Sehrt, David; Kim, Fernando J; Monga, Manoj

    2014-04-01

    To evaluate the association of preoperative noncontrast computed tomography stone characteristics, laser settings, and stone composition with cumulative holmium:yttrium-aluminum-garnet (Ho:YAG) laser time/energy. We retrospectively reviewed patients who underwent semirigid/flexible ureteroscopy and Ho:YAG laser lithotripsy (200 or 365 μm laser fiber; 0.8-1.0 J energy; and 8-10 Hz rate) at 2 tertiary care centers (April 2010-May 2012). Studied parameters were as follows: patient's characteristics; stone characteristics (location, burden, hardness, and composition); total laser time and energy; and surgical outcomes. One hundred patients met our inclusion criteria. Mean stone size was 1.01 ± 0.42 cm and volume 0.33 ± 0.04 cm(3). Mean stone radiodensity was 990 ± 296 HU, and Hounsfield units density 13.8 ± 6.0 HU/mm. All patients were considered stone free. Stone size and volume had a significant positive correlation with laser energy (R = 0.516, P R = 0.621, P R = 0.477, P R = 0.567, P stone size, only the correlation between HU and laser time was significant (R = 0.262, P = .011). In the multivariate analysis, with exception of stone composition (P = .103), all parameters significantly increased laser energy (R(2) = 0.524). Multivariate analysis revealed a positive significant association of laser time with stone volume (P R(2) = 0.512). In multivariate analysis for laser energy, only calcium phosphate stones required less energy to fragment compared with uric acid stones. No significant differences were found in the multivariate laser time model. Ho:YAG laser cumulative energy and total time are significantly affected by stone dimensions, hardness location, fiber size, and power. Kidney location, laser fiber size, and laser power have more influence on the final laser energy than on the total laser time. Calcium phosphate stones require less laser energy to fragment. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Stress development in thin yttrium films on hard substrates during hydrogen loading

    International Nuclear Information System (INIS)

    Dornheim, M.; Pundt, A.; Kirchheim, R.; Molen, S. J. v. d.; Kooij, E. S.; Kerssemakers, J.; Griessen, R.; Harms, H.; Geyer, U.

    2003-01-01

    Polycrystalline (0002)-textured yttrium (Y) films of 50-500 nm thickness on sapphire substrates were loaded electrolytically with hydrogen (H). The stresses which build up in these films were measured in situ using curvature measurements. The results are compared to the behavior of bulk Y-H. A linear elastic model is used to predict the behavior of clamped thin films. Basic properties of the bulk Y-H phase diagram and elastic constants resemble the measured values of the thin films. Compressive stress builds up during H-loading in the α-Y phase and in the (α-Y+β-YH 2 ) two-phase field, showing an initial stress increase of -1.3 GPa per hydrogen concentration X H (compressive stress). While bulk Y-H samples are known to show a contraction in the β-YH 2 phase during H loading, thin films show no evidence for such a contraction during the first loading cycle of the film. The stress remains constant in the bulk β-phase concentration range (ΔX H =0.1 H/Y). This is attributed to the narrow β-phase field (ΔX H =0.02 H/Y) of the thin film during the first loading. Only samples which have been kept at a hydrogen concentration of about 1.5 H/Y for weeks show tensile stress in the concentration range of the bulk β phase. Amazingly a stress increase of about +0.5 GPa/X H (tensile stress) is measured in the β+γ two-phase field. This is attributed to the smaller in-plane nearest-neighbor distance in the γ phase compared to the β phase. In the γ-phase field compressive stress is built up again, compensating the tensile stress. It increases by -1.3 GPa/X H . In total, the net stress in Y-H films remains comparably small. This could be a reason for the good mechanical stability of such Y-H switchable mirrors during H cycling

  5. White light generation from Dy3+-doped yttrium aluminium gallium mixed garnet nano-powders

    International Nuclear Information System (INIS)

    Praveena, R.; Balasubrahmanyam, K.; Jyothi, L.; Venkataiah, G.; Basavapoornima, Ch.; Jayasankar, C.K.

    2016-01-01

    Yttrium aluminium gallium garnet (here after referred as YAGG), Y 3 Al 5−y Ga y O 12 (where y=1.0, 2.5 and 4.0), nano-powders doped with 1.0 mol% of dysprosium (Dy 3+ ) ions were synthesised by the citrate sol–gel method. The structure, phase evolution, morphology and luminescence properties of these nano-crytalline powders were characterized by means of XRD, FTIR, Raman, electron microscopy and UV–vis spectroscopy. From the XRD results, the crystallite sizes were found to be in the range of 18–26 nm. Excitation spectra of YAGG nano-powders showed that the samples can be efficiently excited by near UV and blue LEDs. Upon excitation at 448 nm, the emission spectra of all these samples showed two bands centred at 485 (blue) and 585 nm (yellow) which corresponds to the 4 F 9/2 → 6 H 15/2 and 4 F 9/2 → 6 H 13/2 transitions of Dy 3+ ion, respectively. Intensity of blue emission was found to be stronger than the yellow emission in all the three samples. Integrated yellow to blue (Y/B) emission intensity was found to be increased with increasing the Ga content in the present YAGG host. Therefore, concentration (0.1, 1.0, 2.0 and 4.0 mol%) of Dy 3+ ions was varied in the Ga rich (Y 3 Ga 4 AlO 12 ) nano-powder. The chromaticity co-ordinates of all the prepared nano-powders were located in the white light region and also found to be dependent on Dy 3+ ion concentration and excitation wavelength. The decay curves for 4 F 9/2 level of Dy 3+ ion exhibited non-exponential nature in all the studied samples and the lifetime values remained constant (~1.0 ms) with increasing the Ga content, but were found to decrease with increasing the Dy 3+ ion concentration. The results indicated that 2.0 mol% of Dy 3+ -doped Y 3 Ga 4 AlO 12 nano-powder under 352 nm excitation is suitable for the white light emitting device applications.

  6. Microstructure and magnetic properties of yttrium alumina silicate glass microspheres containing iron oxide

    International Nuclear Information System (INIS)

    Sharma, K.; Basak, C.B.; Prajapat, C.L.; Singh, M.R.

    2015-01-01

    Yttrium alumino-silicate glass microspheres have been used for localized delivery of high radiation dose to tissues in the treatment of hepatocellular carcinoma (BCC) and synovitis. 90 Y is a pure beta emitter with beta emission energy of 0.9367 MeV, average penetration range in tissue 2.5 mm, physical half-life of 64.2 h, thus an effective radioisotope for delivering high radiation dose to the tumor. The efficacy of radiotherapy can further be improved if the glass microspheres are doped with magnetic particles for targeted delivery of high radiation dose. Magnetic glass microspheres can also be utilized for cancer treatment using the magnetic heating of tumor cell. The magnetic glass microspheres are obtained from the glasses with nominal composition (64-x) SiO 2 -17Y 2 O 3 -19 Al 2 O 3 -xFe 2 O 3 (x=4-16 mol %). Density of glasses increases from 3.5g/cc to 3.8g/cc as iron oxide content is increased from 4 to 16 mol %. The glass transition temperature and peak crystallization temperature decreases as the iron oxide content increases. T g values of glass samples decreases with increase of Fe 2 O 3 , while SiO 2 content is decreased. SiO 2 is a network forming oxide and a decrease in the network former in glass lead to decrease in thermo-physical properties like T g . The development of ferrimagnetic crystallites in glasses arise from the conversion of iron oxide into magnetite, magnemite and hematite, which is influenced by the structural and ordering of magnetic particles. The microstructure of glass-ceramic exhibited the formation of 50-100 nm size particles. The magnetite and hematite are formed as major crystalline phases. The magnetization values increased with an increase of iron oxide content and attributed to formation of magnetite phase. Results have shown that the glass microspheres with magnetic properties can be used as potential materials for cancer treatment. (author)

  7. Retrospective analysis of cystic craniopharyngeomas after intracavital irradiation with yttrium-90 colloid

    International Nuclear Information System (INIS)

    Urbanova, E.; Vizda, J.; Netikova, M.; Kafka, P.; Jakubec, J.

    2002-01-01

    Aim: The authors report about follow up the patients after intracavitary irradiation for cystic craniopharyngeoma. Material and Methods: For retrospective analysis 15 patients were selected. The volume of the cyst was determined by CT or MRI. For dosimetry Backlund's formula was used. The cumulative dose to the inner surface of the cyst wall was about 250Gy. 90 Yttrium silicate colloid was administered directly during stereotactically (CT guided) surgery or through the Ommaya drainage system. Control scintigraphy was performed 2-3 hours after 90 Y injection with gamma camera to detect possible leakage of the radioisotope. None of our patients showed evidence of this. In addition to this, the patients were checked daily to pay attention to visual function, neurological condition and possible meningeal irritation. Results: Cyst shrinkage was monitored by repeated CT examinations. CT cyst volume measurement analysed all patients before and 1,2,3 and 5 years after the treatment. In our study 45% of cysts decreased in volume during 4 month, shrinkage of the initial cyst volume was 75% after 1 year. The cyst disappeared nearly totally in 5 patients. Only 3 cyst remain unchanged and 90 Y treatment was repeated. No patients developed a visual field defect or evidence of hypothalamic dysfunction after the treatment. The neuro-opthalmological state completely recovered in 2 patients and improved in 5 patients. The prognosis was good only when an intact optic discs in time of the treatment was present. In some cases the radioisotope was implanted at a late stage of the disease without the opthalmological and neurological improvement. One patient died due to pulmonary embolism one week after the procedure. One patient died within a one year of the treatment from complications related to a solid cystic recurrence. One of typical signs for recurrence was worsening of neuro-opthalmological state. Conclusion: From our results this intracavitary 90 Y therapy is minimally invasive

  8. Radioembolization with Yttrium-90 microspheres for patients with unresectable hepatocellular carcinoma.

    Science.gov (United States)

    Bhangoo, Munveer Singh; Karnani, Diraj R; Hein, Paul N; Giap, Huan; Knowles, Harry; Issa, Chris; Steuterman, Steve; Pockros, Paul; Frenette, Catherine

    2015-10-01

    Hepatocellular carcinoma (HCC) is aggressive primary malignancy of the liver that most commonly presents late in the disease course. As a result, the majority of patients are not candidates for curative therapies. Locoregional therapies including Yttrium-90 (Y-90) radioembolization play an important role in management of the vast majority of patients with HCC. Patients with unnresectable HCC (n=17) treated with Y-90 radioembolization from 2005 to 2014 were evaluated retrospectively. Data was abstracted from medical records including patient charts, laboratory data, and imaging. Toxicities were recorded using Common Terminology Criteria 3.0. Response was recorded according to modified RECIST (mRECIST) criteria. Seventeen patients received 33 treatments with Y-90 radioembolization. A majority (65%) received TheraSphere with a minority (35%) receiving SIR-Spheres. The median treatment activity delivered was 1.725 gBq (range, 1.4-2.5 gBq). The median treatment dose delivered was 100 Gy (range, 90-120 Gy). The median lung shunt fraction was 2.02% (range, 1.5-4.1%). The most common clinical toxicity among all patients was nausea and vomiting (59%), primarily grade 1 and 2. Other post-treatment findings included abdominal pain (29%), fatigue (53%), and weight loss (18%). One patient developed a grade 5 gastric ulcer after the treatment. A clinical benefit, defined as patients achieving complete response (CR), partial response (PR) or stable disease (SD), was seen in 48% of patients. PR was seen in 24% of cases; progressive disease (PD) was noted in 35%. Patients survived for a median of 8.4 months (range, 1.3 to 21.1 months) after the first radioembolization treatment. Median survival after Y-90 treatment was 8.4 months among patients treated TheraSphere as compared with 7.8 months in patients treated with SIR-Spheres. The mean overall survival from the time of diagnosis was 11.7 months (range, 3.4 to 43.2 months). For patients with unresectable HCC, Y-90

  9. Addition compounds of perchlorates from yttrium and lanthanides elements with the N,N,N',N'tetramethyl amide of phthalic acid

    International Nuclear Information System (INIS)

    Silva, C.P.G. da.

    1974-01-01

    The reaction between lanthanide perchlorates and yttrium with tetra methyl phthalamide (TMPA) was studied, and compounds of the general formula Ln (C 10 4 ) 3 . TMPA have been isolated. The compounds were characterized by analysis of their components, infra-red spectra, molar conductances in nitromethane and nitrobenzene, X ray powder patterns and thermal analysis. (author)

  10. Obtainment of zirconium oxide and partially stabilized zirconium oxide with yttrium and rare earth oxides, from Brazilian zirconite, for ceramic aim

    International Nuclear Information System (INIS)

    Ribeiro, S.

    1991-05-01

    This work presents experimental results for processing of brazilian zirconite in order to obtain zirconium oxide with Yttrium and Rare Earth oxide by mutual coprecipitation for ceramics purposes. Due to analysis of experimental results was possible to obtain the optimum conditions for each one of technological route stage, such as: alkaline fusion; acid leaching; sulfactation and coprecipitation. (author)

  11. Influence of potassium on the competition between methane and ethane in steam reforming over Pt supported on yttrium-stabilized zirconia.

    NARCIS (Netherlands)

    Graf, P.O.; Mojet, Barbara; Lefferts, Leonardus

    2008-01-01

    effect of addition of potassium to Pt supported on yttrium-stabilized zirconia (PtYSZ) catalyst for steam reforming of methane, ethane and methane/ethane mixtures was explored. Addition of potassium has a positive effect on preferential steam reforming of methane in mixtures of methane and ethane

  12. Implantation of titanium, chromium, yttrium, molybdenum, silver, hafnium, tantalum, tungsten and platinum ions generated by a metal vapor vacuum ion source into 440C stainless steel

    International Nuclear Information System (INIS)

    Sasaki, Jun; Hayashi, Kazunori; Sugiyama, Kenji; Ichiko, Osami; Hashiguchi, Yoshihiro

    1992-01-01

    Titanium, yttrium, molybdenum, silver, chromium, hafnium, tantalum, tungsten and platinum ions generated by a metal vapor vacuum arc (MEVVA) ion source were implanted into 440C stainless steel in the dose region 10 17 ions cm -2 with extraction voltages of up to 70 kV. Glow discharge spectroscopy (GDS), friction coefficient, and Vickers microhardness of the specimens were studied. Grooves made by friction tests were investigated by electron probe microanalysis (EPMA). GDS showed incorporation of carbon in the yttrium, hafnium, tantalum, tungsten and platinum implanted specimens, as well as titanium implanted samples. A large amount of oxygen was observed in the yttrium implanted specimen. The friction coefficient was measured by reciprocating sliding of an unimplanted 440C ball without lubricant at a load of 0.245 N. The friction decreased and achieved a stable state after implantation of titanium, hafnium and tantalum. The friction coefficient of the platinum implanted specimen showed a gradual decrease after several cycles of sliding at high friction coefficient. The yttrium implanted sample exhibited a decreased but slightly unstable friction coefficient. Results from EPMA showed that the implanted elements, which gave decreased friction, remained even after sliding of 200 cycles. Implantation of chromium, molybdenum, silver and tungsten did not provide a decrease in friction and the implants were gone from the wear grooves after the sliding tests. (orig.)

  13. A randomized controlled trial of peeling and aspiration of Elschnig pearls and neodymium: yttrium-aluminium-garnet laser capsulotomy.

    Science.gov (United States)

    Bhargava, Rahul; Kumar, Prachi; Sharma, Shiv Kumar; Kaur, Avinash

    2015-01-01

    To compare surgical peeling and aspiration and neodymium yttrium garnet laser capsulotomy for pearl form of posterior capsule opacification (PCO). A prospective, randomized, double blind, study was done at Rotary Eye Hospital, Maranda, Palampur, India, Santosh Medical College Hospital, Ghaziabad, India and Laser Eye Clinic, Noida India. Consecutive patients with pearl form of PCO following surgery, phacoemulsification, manual small incision cataract surgery and conventional extracapsular cataract extraction (ECCE) for age related cataract, were randomized to have peeling and aspiration or neodymium yttrium garnet laser capsulotomy. Corrected distance visual acuity (CDVA), intra-operative and post-operative complications were compared. A total of 634 patients participated in the study, and 314 (49.5%) patients were randomized to surgical peeling and aspiration group and 320 (50.5%) to the Nd:YAG laser group. The mean pre-procedural logMAR CDVA in peeling and neodymium: yttrium-aluminium-garnet (Nd:YAG) laser group was 0.80±0.25 and 0.86±0.22, respectively. The mean final CDVA in peeling group (0.22±0.23) was comparable to Nd:YAG group (0.24±0.28; t test, P=0.240). There was a significant improvement in vision after both the procedures (Ppeeling group (262/83.4%) had a CDVA of 0.5 (20/63) or better at 9mo (Ppeeling group (25/7.7% vs 15/4.7%, respectively). On application of ANCOVA, there was less than 0.001% risk that PCO thickness and total laser energy had no effect on rate of complications in Nd:YAG laser group and less than 0.001 % risk that PCO thickness had no effect on complications in peeling group respectively. Sum of square analysis suggests that in the Nd:YAG laser group, thick PCO had a stronger impact on complications (Fischer test probability, Prpeeling group, thick PCO and preoperative vision had a stronger effect on complications than thin PCO, respectively (Fischer test probability, Prpeeling group. Retinal detachment was more common in patients

  14. Reflection and Transmission Coefficient of Yttrium Iron Garnet Filled Polyvinylidene Fluoride Composite Using Rectangular Waveguide at Microwave Frequencies

    Science.gov (United States)

    Soleimani, Hassan; Abbas, Zulkifly; Yahya, Noorhana; Shameli, Kamyar; Soleimani, Hojjatollah; Shabanzadeh, Parvaneh

    2012-01-01

    The sol-gel method was carried out to synthesize nanosized Yttrium Iron Garnet (YIG). The nanomaterials with ferrite structure were heat-treated at different temperatures from 500 to 1000 °C. The phase identification, morphology and functional groups of the prepared samples were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. The YIG ferrite nanopowder was composited with polyvinylidene fluoride (PVDF) by a solution casting method. The magnitudes of reflection and transmission coefficients of PVDF/YIG containing 6, 10 and 13% YIG, respectively, were measured using rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in X-band frequencies. The results indicate that the presence of YIG in polymer composites causes an increase in reflection coefficient and decrease in transmission coefficient of the polymer. PMID:22942718

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  16. Non-target activity detection by post-radioembolization yttrium-90 PET/CT: Image assessment technique and case examples

    Directory of Open Access Journals (Sweden)

    Yung Hsiang eKao

    2014-02-01

    Full Text Available High-resolution yttrium-90 (90Y imaging of post-radioembolization microsphere biodistribution may be achieved by conventional positron emission tomography with integrated computed tomography (PET/CT scanners that have time-of-flight capability. However, reconstructed 90Y PET/CT images have high background noise, making non-target activity detection technically challenging. This educational article describes our image assessment technique for non-target activity detection by 90Y PET/CT which qualitatively overcomes the problem of background noise. We present selected case examples of non-target activity in untargeted liver, stomach, gallbladder, chest wall and kidney, supported by angiography and 90Y bremsstrahlung single photon emission computed tomography with integrated computed tomography (SPECT/CT or technetium-99m macroaggregated albumin SPECT/CT.

  17. Study of the response of a lithium yttrium borate scintillator based neutron rem counter by Monte Carlo radiation transport simulations

    Science.gov (United States)

    Sunil, C.; Tyagi, Mohit; Biju, K.; Shanbhag, A. A.; Bandyopadhyay, T.

    2015-12-01

    The scarcity and the high cost of 3He has spurred the use of various detectors for neutron monitoring. A new lithium yttrium borate scintillator developed in BARC has been studied for its use in a neutron rem counter. The scintillator is made of natural lithium and boron, and the yield of reaction products that will generate a signal in a real time detector has been studied by FLUKA Monte Carlo radiation transport code. A 2 cm lead introduced to enhance the gamma rejection shows no appreciable change in the shape of the fluence response or in the yield of reaction products. The fluence response when normalized at the average energy of an Am-Be neutron source shows promise of being used as rem counter.

  18. Study of the response of a lithium yttrium borate scintillator based neutron rem counter by Monte Carlo radiation transport simulations

    Energy Technology Data Exchange (ETDEWEB)

    Sunil, C., E-mail: csunil11@gmail.com [Accelerator Radiation Safety Section, Health Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tyagi, Mohit [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Biju, K.; Shanbhag, A.A.; Bandyopadhyay, T. [Accelerator Radiation Safety Section, Health Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2015-12-11

    The scarcity and the high cost of {sup 3}He has spurred the use of various detectors for neutron monitoring. A new lithium yttrium borate scintillator developed in BARC has been studied for its use in a neutron rem counter. The scintillator is made of natural lithium and boron, and the yield of reaction products that will generate a signal in a real time detector has been studied by FLUKA Monte Carlo radiation transport code. A 2 cm lead introduced to enhance the gamma rejection shows no appreciable change in the shape of the fluence response or in the yield of reaction products. The fluence response when normalized at the average energy of an Am–Be neutron source shows promise of being used as rem counter.

  19. MOCVD coating deposition of yttrium stabilized zirconia as backing for high-temperature superconductors on flexible substrates

    International Nuclear Information System (INIS)

    Jakschik, F.; Berger, W.; Seifert, L.; Nowick, W.; Leonhardt, G.

    1993-01-01

    The coating of carbon fibers with YSZ by means of the presented MOCVD process showed that in the bundle at temperatures between 500 - 600 C the coating thickness drops toward the center of the bundle. Sufficient homogeneity can be achieved only when the precipitation rate is selected slow enough to prevent the bundle edge from closing, or when the bundle is spread sufficiently open. The layers are on one hand ZrO 2 with incorporated carbon and on the other hand yttrium stabilized ZrO 2 with incorporated carbon. In both cases exclusively the cubic phase of the oxide was detected. The morphology of layers revealed only slight roughness with incorporation of relatively large nodules consisting of YSZ, caused by homogeneous gas phase reactions which are to be prevented. (orig.) [de

  20. Thermodynamics of coproportionation reactions of homogeneous samarium (3) and yttrium (3) nitrates solvates with neutral organic phosphorus compounds

    International Nuclear Information System (INIS)

    Pyartman, A.K.

    1995-01-01

    Reaction heats of homogeneous samarium (3) and yttrium (3) nitrate solvates coproportionation with neutral organophosphoric compounds (tri-n.-butylphosphate, diisooctylmethylphosphonate, diisoamylmethylphosphonate) at T=298.15 K in hexane have been measured by thermochemical method. It has been ascertained that enthalpies of coproportionation reactions practically do not depend on the nature, concentration of rare earth metal (3) nitrate solvates in hexane, nature of neutral organophosphoric compound and constitute 1.1±-.2 kJ/mol. The Gibbs free energy of coproportionation reactions is -5.43 kJ/mol, while entropy of the reactions in 14.5±0.7 J/mol·K. 8 refs., 1 tab

  1. High-resolution structural characterization and magnetic properties of epitaxial Ce-doped yttrium iron garnet thin films

    Science.gov (United States)

    Li, Zhong; Vikram Singh, Amit; Rastogi, Ankur; Gazquez, Jaume; Borisevich, Albina Y.; Mishra, Rohan; Gupta, Arunava

    2017-07-01

    Thin films of magnetic garnet materials, e.g. yttrium iron garnet (Y3Fe5O12, YIG), are useful for a variety of applications including microwave integrated circuits and spintronics. Substitution of rare earth ions, such as cerium, is known to enhance the magneto-optic Kerr effect (MOKE) as compared to pure YIG. Thin films of Ce0.75Y2.25Fe5O12 (Ce:YIG) have been grown using the pulsed laser deposition (PLD) technique and their crystal structure examined using high resolution scanning transmission electron microscopy. Homogeneous substitution of Ce in YIG, without oxidation to form a separate CeO2 phase, can be realized in a narrow process window with resulting enhancement of the MOKE signal. The thermally generated signal due to spin Seebeck effect for the optimally doped Ce:YIG films has also been investigated.

  2. Growth of yttrium iron garnet single crystals in Na2O-B2O3 flux system in air

    International Nuclear Information System (INIS)

    Bandyopadhyay, Tarun; Saha, Prasenjit

    1977-01-01

    Detailed studies of growth of yttrium iron garnet (YIG) in the flux system Na 2 O-B 2 O 3 were made to delineate the phase stability regions of YIG and the neighbouring crystalline phases, and a tentative working diagram of Na 2 O-B 2 O 3 -YIG in air was drawn from the results of small batch crystal growth runs and solubility studies. The occurrence of a rather narrow field of YIG crystallization in this system was explained on the basis of relative solubilities of different oxides constituting YIG. Several long-time growth runs with some typical compositions were carried out in this system to evaluate its suitability for bulk growth of YIG crystals. The system, although possessing some inherent advantages, was found to suffer from limitations because the maximum size of the self-nucleated crystals grown hardly exceeded 2.00 mm. (author)

  3. High-Pressure Synthesis and Characterization of the Ammonium Yttrium Borate (NH4)YB8O14.

    Science.gov (United States)

    Schmitt, Martin K; Podewitz, Maren; Liedl, Klaus R; Huppertz, Hubert

    2017-11-20

    The first high-pressure yttrium borate (NH 4 )YB 8 O 14 was synthesized at 12.8 GPa/1300 °C using a Walker-type multianvil module. The compound crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a = 17.6375(9), b = 10.7160(5), and c = 4.2191(2) Å. (NH 4 )YB 8 O 14 constitutes a novel structure type but exhibits similarities to the crystal structure of β-BaB 4 O 7 . X-ray single-crystal and powder diffraction, EDX, vibrational spectroscopy as well as quantum chemical calculations were used to characterize (NH 4 )YB 8 O 14 .

  4. Low-relaxation spin waves in laser-molecular-beam epitaxy grown nanosized yttrium iron garnet films

    Energy Technology Data Exchange (ETDEWEB)

    Lutsev, L. V., E-mail: l-lutsev@mail.ru; Korovin, A. M.; Bursian, V. E.; Gastev, S. V.; Fedorov, V. V.; Suturin, S. M.; Sokolov, N. S. [Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation)

    2016-05-02

    Synthesis of nanosized yttrium iron garnet (Y{sub 3}Fe{sub 5}O{sub 12}, YIG) films followed by the study of ferromagnetic resonance (FMR) and spin wave propagation in these films is reported. The YIG films were grown on gadolinium gallium garnet substrates by laser molecular beam epitaxy. It has been shown that spin waves propagating in YIG deposited at 700 °C have low damping. At the frequency of 3.29 GHz, the spin-wave damping parameter is less than 3.6 × 10{sup −5}. Magnetic inhomogeneities of the YIG films give the main contribution to the FMR linewidth. The contribution of the relaxation processes to the FMR linewidth is as low as 1.2%.

  5. Yttrium-90 microspheres (TheraSphere and SIR-Spheres) for the treatment of unresectable hepatocellular carcinoma.

    Science.gov (United States)

    Allison, C

    2007-09-01

    (1) Microspheres containing radioactive yttrium-90 (90Y) are infused into the hepatic artery. These deliver high doses of ionizing radiation to inoperable hepatocellular carcinoma, the most common type of primary liver cancer. (2) Limited evidence from several case series indicates that palliative therapy with 90Y microspheres may reduce tumour size and increase survival time. (3) In some patients, 90Y treatment may result in enough tumour reduction to permit liver resection or transplantation. (4) While 90Y microsphere therapy is generally well tolerated, major complications and several treatment-related deaths have occurred. Improved patient selection criteria and technical changes to microsphere delivery have reduced the risks of complications and death. (5) Patient selection and the technical aspects of 90Y microsphere treatment are complex and require the coordinated expertise of a multidisciplinary team.

  6. The sequential separation of strontium-90, yttrium-90, promethium-147, and cerium-144 from urine and their subsequent estimation

    International Nuclear Information System (INIS)

    Kramer, G.H.; Davies, J.M.

    1981-04-01

    A method has been developed for separating low-level activities of the beta-emitting isotopes strontium-90, yttrium-90, promethium-147 and cerium-144 from urine and aqueous solutions. They are subsequently estimated by planchet or liquid scintillation counting. The radionuclides are separated from each other and from interfering elements by solvent extraction with HDEHP (di-2-ethylhexyl phosphoric acid) in n-heptane. It is possible to separate the elements with a minimum of cross-contamination by selecting appropriate pH's and solvent concentrations. Percentage recoveries for the radionuclides are: 90 Sr, 100 +- 12; 90 Y, 65 +- 4; 147 Pm, 90 +- 8; 144 Ce, 87 +- 11. The limits of detection are: 90 Sr, 0.6 pCi; 90 Y, 0.7 pCi; 147 Pm, 1.0 pCi; 144 Ce, 0.8 pCi. (author)

  7. Pulsed laser deposition of epitaxial yttrium iron garnet films with low Gilbert damping and bulk-like magnetization

    Directory of Open Access Journals (Sweden)

    M. C. Onbasli

    2014-10-01

    Full Text Available Yttrium iron garnet (YIG, Y 3Fe5O12 films have been epitaxially grown on Gadolinium Gallium Garnet (GGG, Gd3Ga5O12 substrates with (100 orientation using pulsed laser deposition. The films were single-phase, epitaxial with the GGG substrate, and the root-mean-square surface roughness varied between 0.14 nm and 0.2 nm. Films with thicknesses ranging from 17 to 200 nm exhibited low coercivity (<2 Oe, near-bulk room temperature saturation moments (∼135 emu cm−3, in-plane easy axis, and damping parameters as low as 2.2 × 10−4. These high quality YIG thin films are useful in the investigation of the origins of novel magnetic phenomena and magnetization dynamics.

  8. Dislocation of polyfocal full-optics accommodative intraocular lens after neodymium-doped yttrium aluminum garnet capsulotomy in vitrectomized eye

    Directory of Open Access Journals (Sweden)

    Kyung Tae Kang

    2013-01-01

    Full Text Available We report a case of dislocation of WIOL-CF® polyfocal full-optics intraocular lens (IOL after neodymium-doped yttrium aluminum garnet (Nd: YAG laser capsulotomy in the vitrectomized eye. At 22 months before the dislocation of the IOL, a 55-year-old male patient underwent phacoemulsification with WIOL-CF® IOL implantation in a local clinic and 10 months after the cataract surgery the patient underwent pars plana vitrectomy, endolaser photocoagulation and 14% C 3 F 8 gas tamponade for the treatment of rhegmatogenous retinal detachment. At 9 months after the vitrectomy, the patient visited our clinic for a sudden decrease of vision after Nd: YAG capsulotomy in the local clinic. On fundus examination, the dislocated IOL was identified and the Nd: YAG capsulotomy site and the larger break, which is suspected to have been a route of the dislocation were observed in the posterior capsule.

  9. Anomalies in the temperature dependence of Faraday rotation on yttrium iron garnets doped with Sn, Zr, or Sb

    International Nuclear Information System (INIS)

    D'Orazio, F.; Giammaria, F.; Lucari, F.

    1991-01-01

    Faraday rotation (FR) measurements on three thin single crystalline samples of yttrium iron garnet doped with Sn, Zr, and Sb as a function of temperature in the near infrared region show a monotonic variation of the magneto-optical signal as the temperature is decreased from 300 to about 50 K. At this point the FR signal levels off. Moreover, the slope of the plot for the sample, doped with Sn, changes sign below this temperature, at particular wavelengths. An explanation of the observed phenomena is given in terms of the energy levels of the Fe 2+ ions in the different sites of the crystal and the temperature dependence of their populations caused by the relative orientation between the local symmetry axis of the specific site and the direction of the sample magnetization. Hysteresis loops of the Faraday rotation as a function of applied magnetic field have been also measured showing the presence of a remanence of the sample magnetization

  10. In situ hydrothermal crystallization of hexagonal hydroxyapatite tubes from yttrium ion-doped hydroxyapatite by the Kirkendall effect

    International Nuclear Information System (INIS)

    Li, Chengfeng; Ge, Xiaolu; Li, Guochang; Lu, Hao; Ding, Rui

    2014-01-01

    An in situ hydrothermal crystallization method with presence of glutamic acid, urea and yttrium ions was employed to fabricate hexagonal hydroxyapatite (HAp, Ca 5 (PO 4 ) 3 (OH)) tubes with length of 200 nm–1 μm. Firstly, yttrium ion-doped HAp (Y-HAp, Ca 5−x Y x (PO 4 ) 3 (OH)) was synthesized after hydrolysis of urea and HPO 4 2− ions at 100 °C with a dwell time of 24 h. The shift of X-ray diffraction peaks of HAp to high angle was caused the substitution of Ca 2+ ions by small-sized Y 3+ ions. At 160 °C, further hydrolysis reactions of urea and HPO 4 2− ions resulted in the generation of ample OH − and PO 4 3− ions, which provided a high chemical potential for the dissolution of Y-HAp and recrystallization of HAp and YPO 4 . Finally, HAp tubes were formed in situ on Y-HAp according to the Kirkendall effect as a result of the difference of diffusion rate of cations (Ca 2+ ions, outward and slow) and anions (OH − and PO 4 3− ions, inward and fast). The formation process of HAp tube was simulated by the encapsulation of fluorescein molecules in precipitates. Photoluminescence properties were enhanced for HAp tubes with thick and dense walls. This novel tubular material could find wide applications as carriers of drugs, dyes and catalysts. - Highlights: • Hexagonal HAp tubes with adjustable sizes are prepared by a hydrothermal method. • A dissolution-recrystallization process occurs during hydrothermal treatment. • The formation mechanism is explained by the Kirkendall effect. • The crystallization is simulated by the encapsulation and release of fluorescein

  11. Co-doping TiO{sub 2} with boron and/or yttrium elements: Effects on antimicrobial activity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuzheng [School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870 (China); Wu, Yusheng, E-mail: henanwys@sina.com [School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870 (China); Yang, He; Xue, Xiangxin; Liu, Zhihua [Institute of Metallurgical Resources and Environmental Engineering, Northeastern University, Shenyang 110819 (China)

    2016-09-15

    Highlights: • B-Y/TiO{sub 2} nano materials firstly applied to the fields of antibacterial materials. • Systems analysis the existence state of boron and yttrium ion in TiO{sub 2}. • Doping B and Y greatly strengthened the antibacterial activity of TiO{sub 2}. - Abstract: Pure TiO{sub 2}, boron and/or yttrium doped TiO{sub 2} nano-materials were synthesized by a sol–gel method and characterized by XRD, SEM, XPS and PL. XRD analysis indicates that, in the pure TiO{sub 2} and B single doped TiO{sub 2} (B-TiO{sub 2}) nano-materials calcinated at 700 °C, the presence of TiO{sub 2} is a mixture of anatase and rutile; in the Y single doped (Y-TiO{sub 2}), B and Y co-doped TiO{sub 2} nano-materials (B/Y-TiO{sub 2}), the presence of TiO{sub 2} is anatase. SEM image shows the prepared materials have a common round morphology and hexagonal plate morphology caused by the agglomeration of particles. Boron atoms are partially embedded into the TiO{sub 2} interstitial structure or incorporated into the TiO{sub 2} lattice through occupying the position of the oxygen atoms. The results of antimicrobial experiment show that B/Y-TiO{sub 2} material has a remarkable antimicrobial activity. Compared with the visible light irradiation, antimicrobial activity of B/Y-TiO{sub 2} in dark is significant poor.

  12. In situ hydrothermal crystallization of hexagonal hydroxyapatite tubes from yttrium ion-doped hydroxyapatite by the Kirkendall effect.

    Science.gov (United States)

    Li, Chengfeng; Ge, Xiaolu; Li, Guochang; Lu, Hao; Ding, Rui

    2014-12-01

    An in situ hydrothermal crystallization method with presence of glutamic acid, urea and yttrium ions was employed to fabricate hexagonal hydroxyapatite (HAp, Ca5(PO4)3(OH)) tubes with length of 200 nm-1 μm. Firstly, yttrium ion-doped HAp (Y-HAp, Ca(5-x)Y(x)(PO4)3(OH)) was synthesized after hydrolysis of urea and HPO4(2-) ions at 100°C with a dwell time of 24h. The shift of X-ray diffraction peaks of HAp to high angle was caused the substitution of Ca(2+) ions by small-sized Y(3+) ions. At 160°C, further hydrolysis reactions of urea and HPO4(2-) ions resulted in the generation of ample OH(-) and PO4(3-) ions, which provided a high chemical potential for the dissolution of Y-HAp and recrystallization of HAp and YPO4. Finally, HAp tubes were formed in situ on Y-HAp according to the Kirkendall effect as a result of the difference of diffusion rate of cations (Ca(2+) ions, outward and slow) and anions (OH(-) and PO4(3-) ions, inward and fast). The formation process of HAp tube was simulated by the encapsulation of fluorescein molecules in precipitates. Photoluminescence properties were enhanced for HAp tubes with thick and dense walls. This novel tubular material could find wide applications as carriers of drugs, dyes and catalysts. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Luminescence properties of cerium-doped di-strontium magnesium di-silicate phosphor by the solid-state reaction method

    Science.gov (United States)

    Prasad Sahu, Ishwar

    2016-05-01

    A series of Sr2MgSi2O7:xCe3+ (x = 1.0%, 2.0%, 3.0%, 4.0% and 5.0%) phosphors were synthesized by the solid-state reaction method. The phosphor with optimum thermoluminescence, photoluminescence and mechanoluminescence (ML) intensity was characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared techniques. The trapping parameters (i.e. activation energy, frequency factor and order of the kinetics) of each synthesized phosphor have been calculated using the peak shape method and the results have been discussed. Under ultraviolet excitation (325 nm), Sr2MgSi2O7:xCe3+ phosphors were composed of a broad band peaking at 385 nm, belonging to the broad emission band which emits violet-blue color. Commission International de I'Eclairage coordinates have been calculated for each sample and their overall emission is near violet-blue light. In order to investigate the suitability of the samples for industrial uses, color purity and color rendering index were calculated. An ML intensity of optimum [Sr2MgSi2O7:Ce3+ (3.0%)] phosphor increases linearly with increasing impact velocity of the moving piston which suggests that these phosphors can be used as fracto-ML-based devices. The time of the peak ML intensity and the decay rate did not change significantly with respect to increasing impact velocity of the moving piston.

  14. Characterization of composite metal-ceramic of nickel-oxide cerium doped gadolinium; Caracterizacao de compositos ceramica-metal de niquel e oxido de cerio dopado com gadolinio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.L.A. da, E-mail: maria.andrade@pro.unifacs.br [Universidade Salvador (UNIFACS), BA (Brazil). Escola de Engenharia, Arquitetura e TI; Universidade Federal da Bahia (UFBA), BA (Brazil); Varela, M.C.R.S. [Universidade Federal da Bahia (UFBA), BA (Brazil)

    2016-07-01

    Composite nickel doped cerium oxide are used in SOFC anode materials. In this study we evaluated the effect of the presence of gadolinium on the properties of composite nickel and ceria and. The supports were synthesized by sol-gel method. The impregnation with nickel nitrate was taken sequentially, followed by calcination. The materials were characterized by X-ray diffraction, measurement of specific surface area, temperature programmed reduction, Raman spectroscopy. The presence of gadolinium retained the fluorite structure of ceria by forming a solid solution, also not influencing significantly on the specific surface area of the support. On the other hand, there was a decrease in the area catalysts, which can be attributed to sintering of nickel. Furthermore, addition of gadolinium favored the formation of intrinsic and extrinsic vacancies in cerium oxide, which leads to an increase in the ionic conductivity of the solid, desirable property for an SOFC anode catalyst. (author)

  15. Effect of Mg$^{2+}$ ions co-doping on timing performance and radiation tolerance of Cerium doped Gd$_{3}$Al$_{2}$Ga$_{3}$O$_{12}$ crystals

    CERN Document Server

    Lucchini, M.T.; Bohacek, P.; Gundacker, S.; Kamada, K.; Nikl, M.; Petrosyan, A.; Yoshikawa, A.; Auffray, E.

    2016-01-01

    Inorganic scintillators with high density and high light yield are of major interest for applications in medical imaging and high energy physics detectors. In this work, the optical and scintillation properties of Mg co-doped Ce:Gd3Al2Ga3O12 crystals, grown using Czochralski technique, have been investigated and compared with Ce:Gd3Al2Ga3O12 ones prepared with identical technology. Improvements in the timing performance of the Mg co-doped samples with respect to Ce:Gd3Al2Ga3O12 ones have been measured, namely a substantial shortening of the rise time and scintillation decay components and lower afterglow were achieved. In particular, a significantly better coincidence time resolution of 233 ps FWHM, being a fundamental parameter for TOF-PET devices, has been observed in Mg co-doped crystals. The samples have also shown a good radiation tolerance under high doses of γ-rays, making them suitable candidates for applications in harsh radiation environments, such as detectors at future collider experiments.

  16. Effect of Mg"2"+ ions co-doping on timing performance and radiation tolerance of Cerium doped Gd_3Al_2Ga_3O_1_2 crystals

    International Nuclear Information System (INIS)

    Lucchini, M.T.; Babin, V.; Bohacek, P.; Gundacker, S.; Kamada, K.; Nikl, M.; Petrosyan, A.; Yoshikawa, A.; Auffray, E.

    2016-01-01

    Inorganic scintillators with high density and high light yield are of major interest for applications in medical imaging and high energy physics detectors. In this work, the optical and scintillation properties of Mg co-doped Ce:Gd_3Al_2Ga_3O_1_2 crystals, grown using Czochralski technique, have been investigated and compared with Ce:Gd_3Al_2Ga_3O_1_2 ones prepared with identical technology. Improvements in the timing performance of the Mg co-doped samples with respect to Ce:Gd_3Al_2Ga_3O_1_2 ones have been measured, namely a substantial shortening of the rise time and scintillation decay components and lower afterglow were achieved. In particular, a significantly better coincidence time resolution of 233 ps FWHM, being a fundamental parameter for TOF-PET devices, has been observed in Mg co-doped crystals. The samples have also shown a good radiation tolerance under high doses of γ-rays, making them suitable candidates for applications in harsh radiation environments, such as detectors at future collider experiments.

  17. Magnetic evolution of itinerant ferromagnetism and interlayer antiferromagnetism in cerium doped LaCo{sub 2}P{sub 2} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Yong; Kong, Yixiu; Liu, Kai; Zhang, Anmin [Department of Physics, Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872 (China); He, Rui [Department of Physics, University of Northern Iowa, Cedar Falls, Iowa 50614 (United States); Zhang, Qingming, E-mail: qmzhang@ruc.edu.cn [Department of Physics, Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872 (China)

    2017-05-01

    ThCr{sub 2}Si{sub 2}-type phosphide ACo{sub 2}P{sub 2} (A=Eu, La, Pr, Nd, Ce) has the same structure as iron arsenides, but their magnetic behaviors are quite distinct. In this paper, we grew a series of La{sub 1−x}Ce{sub x}Co{sub 2}P{sub 2} single crystals (x=0.0 to1.0), made structural and magnetic characterizations. We found the introduction of cerium induces a rapid decrease of c-axis and a change from ferromagnetic to antiferromagnetic states. Compared to other trivalent doped compounds, the enhancement of ferromagnetism with doping is suppressed and the transition from ferromagnetism to antiferromagnetism appear earlier. By employing first-principles band-structure calculations, we identify the increase of Ce valence suppress the itinerant ferromagnetism and leading to formation of P-P bonding with the shortening of c-axis. The bonding effectively drives an increase of interlayer antiferromagnetic interaction, eventually leads to antiferromagnetic ordering of cobalt in high-doping region.

  18. Thermally driven magnon transport in the magnetic insulator Yttrium Iron Garnet

    International Nuclear Information System (INIS)

    Agrawal, Milan

    2014-01-01

    The research work presented in this thesis covers the investigation of spin-caloric phenomena in ferromagnetic-normal metal heterostructures. These phenomena explore the interaction of heat with spin systems and mainly deal with the generation and the manipulation of spin currents by means of heat currents (phonons). The significance of spin currents is widely seen in developing new fundamental concepts of physics as well as in the industry of magnetic memories. Analogous to the classical Seebeck effect, the generation of a spin current in a spin system by the application of heat currents is known as the spin Seebeck effect (SSE). This mode of spin current generation has recently attracted much scientific attention due to the existence of the spin Seebeck effect in a wide variety of magnetic materials (spin systems), considering from insulators to metals. The potential applications of this effect, in particular to generate electricity out of waste heat, make the effect even more attractive. Generally, spin systems can be classified into either a system constituting the traveling spins carried by free electrons or into a system of spin waves, collective excitations of magnetic moments in the wavevector space. Having the advantage of being free from free-electronic charges, an electrical-insulating-ferromagnetic system of spin waves overcomes the limitation of short propagation lengths of pure spin currents in metals. The long propagation length of spin currents carried by propagating spin waves is crucial for building-up spin-electronic (spintronic) circuits and spin logics for fast computation. For such purposes, the ferrimagnetic insulator Yttrium Iron Garnet (YIG) is a promising material candidate due to its lowest known magnetic damping which offers macroscopic propagation lengths of spin currents. In the framework of this thesis, a detailed investigation of the interaction of phonons with magnons, the quanta of spin waves, in single crystalline YIG films are

  19. Profile of yttrium segregation in BaCe0,9Y0,1O3-δ as function of sintering temperature

    International Nuclear Information System (INIS)

    Hosken, C.M.; Souza, D.P.F. de

    2010-01-01

    Researches on solid oxide fuel cells indicate barium cerate perovskite as a very attractive material for using as electrolyte due to its high protonic conductivity. The objective of this work is investigate the yttrium segregation during sintering of BaCe 0,9 Y 0,1 O 3-δ doped with Zn O as a sintering aid. The powders were prepared by citrate process. Powders were isostatic pressed into pellets and sintered in air at 1200, 1275, 1325 and 1400 deg C. The samples were characterized by scanning electron microscopy, X-ray diffraction and impedance spectroscopy. Secondary phase containing Yttrium and Cerium was detected as sintering temperature increased. Increase of the lattice parameter and activation energy for electrical conductivity were also detected on samples sintered at 1400 deg C. (author)

  20. Use of yttrium-90 hydroxyapatite radiosynovectomy as a primary modality of treatment in diffuse pigmented villonodular synovitis of the knee joint: A first case report

    International Nuclear Information System (INIS)

    Kamaleshwaran, Koramadai Karuppusamy; Rajan, David; Krishnan, Boopathi; Gounder, Thirumalaisamy Subbaih; Chakraborty, Sudipta; Kalarickal, Radhakrishnan; Mohanan, Vyshakh; Shinto, Ajit Sugunan

    2015-01-01

    Pigmented villonodular synovitis (PVNS) is a rare, relatively benign, intra-articular lesion characterized by a slowly progressive proliferation of synovial tissue. Knee is the most frequently involved joint. Localized and diffuse forms of synovial involvement were reported. In extensive diffuse cases, total synovectomy is needed, almost impossible to achieve. Hence, other treatment modalities such as intra-articular injection of yttrium-90 have been tried and shown to be effective in reducing the rate of local recurrence with “acceptable” joint damage. Radiosynovectomy is based on the irradiation of the joint synovium by the intra-articular administration of various β-emitting radiopharmaceuticals. We describe the first case report of use of yttrium-90 hydroxyapatite particulates in a 33-year-old male who presented with diffuse PVNS of knee joint as a primary modality of treatment

  1. Molecular-beam-deposited yttrium-oxide dielectrics in aluminum-gated metal - oxide - semiconductor field-effect transistors: Effective electron mobility

    International Nuclear Information System (INIS)

    Ragnarsson, L.-A degree.; Guha, S.; Copel, M.; Cartier, E.; Bojarczuk, N. A.; Karasinski, J.

    2001-01-01

    We report on high effective mobilities in yttrium-oxide-based n-channel metal - oxide - semiconductor field-effect transistors (MOSFETs) with aluminum gates. The yttrium oxide was grown in ultrahigh vacuum using a reactive atomic-beam-deposition system. Medium-energy ion-scattering studies indicate an oxide with an approximate composition of Y 2 O 3 on top of a thin layer of interfacial SiO 2 . The thickness of this interfacial oxide as well as the effective mobility are found to be dependent on the postgrowth anneal conditions. Optimum conditions result in mobilities approaching that of SiO 2 -based MOSFETs at higher fields with peak mobilities at approximately 210 cm 2 /Vs. [copyright] 2001 American Institute of Physics

  2. The effect of the purity and of the materials used for adapters on the purification of yttrium by solid state electrotransport

    International Nuclear Information System (INIS)

    Nikoforova, T.V.; Volkov, V.T.

    1986-01-01

    The influence of tantalum, molybdenum and zirconium adapters on the efficiency of the solid state electrotransport process is investigated with a view to increasing the quality and purity of yttrium. The degree and direction of metallic impurity electromigration in the given metals were studied. The impurities in question were shown to move in different directions depending on the type of adapter. Recommendations for the application of adapters according to their purity are given. The application of high purity tantalum as anode and cathode adapters in three-stage solid state electrotransport enabled us to obtain yttrium single crystals with a ratio of resistance at room temperature to that at helium temperatures of 1200. (orig.)

  3. Preparation, characterization and thermal behaviour study of 4-dimethyl amino benzal pyruvate of lanthanides (III) and yttrium (III) in solid state

    International Nuclear Information System (INIS)

    Miyano, M.H.

    1990-01-01

    Solid state compounds involving Ln and DMBP, where Ln trivalent lanthanides (except promethium) and yttrium; DMBP 4-dimethyl amino benzylidene pyruvate, were prepared by addition of ligand to the corresponding metal ions chlorides, both in aqueous solution. The precipitates were washed with distilled water and dried at 40 0 C in a forced circulation oven. Complexometry with EDTA, thermogravimetry (TG), differential thermal analysis (DTA), infra-red absorption and X-ray diffraction have been used in the study of these compounds. (author)

  4. Temporary balloon occlusion of the common hepatic artery for administration of yttrium-90 resin microspheres in a patient with patent hepatoenteric collaterals.

    Science.gov (United States)

    Mahvash, Armeen; Zaer, Navid; Shaw, Colette; Chasen, Beth; Avritscher, Rony; Murthy, Ravi

    2012-02-01

    The most common serious complication of yttrium-90 ((90)Y) therapy is gastrointestinal ulceration caused by extrahepatic microsphere dispersion. The authors describe the use of a balloon catheter for temporary occlusion of the common hepatic artery to reverse hepatoenteric flow for lobar administration of resin microspheres when coil embolization of a retroportal artery was impossible. At 9 months after treatment, the patient had no gastrointestinal side effects and showed a partial response. Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.

  5. Industrial precipitation of yttrium chloride and zirconyl chloride: Effect of pH on ceramic properties for yttria partially stabilised zirconia

    International Nuclear Information System (INIS)

    Carter, G.A.; Hart, R.D.; Rowles, M.; Ogden, M.I.; Buckley, C.E.

    2009-01-01

    Two 3 mol% partially stabilised zirconia (P-SZ) samples suitable for the SOFC market were manufactured from solutions through to ceramics using a method similar to a known industrial process. The only difference in preparation of the two 3 mol% P-SZ samples was the pH of precipitation which was set at pH 3 or 12. Particle size measurements by dynamic light scattering were used to characterise the precipitate and the filtration rates were investigated. Five point N 2 -BET was used to investigate the specific surface area before and after calcination with the response to temperature tracked. Similarly TGA/DTA investigation was used to determine the calcination point during all of these tests and it was found that both powders behaved similarly. XRD-Rietveld analysis incorporating in situ and ex situ calcination revealed that the pH 3 sample had more monoclinic phase present after calcination and sintering as a ceramic. Ceramic testing incorporating hardness (Vickers), toughness (K 1C ), MOR, density and grain sizing was carried out, all determined that the material produced at pH 12 was superior for SOFC applications than the pH 3 sample. Further investigation using TEM-EDS revealed that the processing of the pH 3 powder had allowed a lower concentration of the yttrium which was incorporated at approximately 2 mol% instead of the required 3. ICP-OES of the after filter liquor indicated that high concentrations of yttrium (797 ppm) were found in the solution with the wash solution having 149 ppm yttrium. In contrast the pH 12 samples had 7 ppm in both the after filter liquor and wash indicating that the yttrium is bound within the matrix more completely at the higher pH.

  6. Magnetic field effect on sublattice contributions into the Faraday effect in Y3Fe5o12 yttrium ferrite-garnet

    International Nuclear Information System (INIS)

    Ivashintsova, V.L.; Pisarev, R.V.

    1980-01-01

    Field dependencies of the Faraday effect in yttrium ferrite-garnet in the 80-600 K temperature range on the 1.15 μm wavelength are studied. It is shown that the changes observed in the Faraday effect under the influence of the external field can be explained by magnetic susceptibility of the tetrahedric and octahedric sublattices, and also by the field effect on the specific sublattice contributions into the Faraday effect

  7. Influence of radiant heating treatments on fusion of high-temperature superconducting yttrium ceramics; Vliyanie termoradiatsionnykh obrabotok na sintez vysokotempiraturnykh sverkhprovodyaschikh ittrievykh keramik

    Energy Technology Data Exchange (ETDEWEB)

    Bitenbaev, M I; Polyakov, A I [Inst. Yadernoj Fiziki Natsionalnogo Yadernogo Tsentra Respubliki Kazakhstan, Almaty (Kazakhstan)

    1999-07-01

    Regardless of the fact that the materials made of HTSC-ceramics are promising, there is no any information about their successful practical application in publications. To our opinion, it is explained by the fact, first of all, that the conservative technologies of the powder metallurgy do not allow producing HTSC systems with excellent operating performance (structure homogeneity, long-term stability of Sc properties and etc.). This report presents outcomes of experiments on fusion of yttrium ceramics containing raw components irradiated by g-rays {sup 60}Co under the temperature exceeding 500 degrees C. HTSC properties of ceramics were studied according to their differential spectra of radio-frequency (RF) field absorption. The RF absorption spectrum of yttrium ceramics samples produced according to conservative technology is sufficiently permitted triplet with the Sc transition temperatures range of 80 K, 90 K, 95 K. Irradiation under the increased temperatures and mechanical limitation allow producing samples of yttrium HTSC-ceramics with sufficient homogeneous structure and superconducting properties that are stable to air conditions for not less than one year.

  8. Long-term result of out-patient neodymium-doped yttrium aluminium garnet laser photocoagulation surgery for patients with epistaxis.

    Science.gov (United States)

    Zhang, J; Qiu, R; Wei, C

    2016-01-01

    To evaluate the long-term efficacy of out-patient neodymium-doped yttrium aluminium garnet laser photocoagulation surgery for patients with epistaxis. A retrospective clinical study was conducted. A total of 217 consecutive patients who presented with acute or recurrent epistaxis received neodymium-doped yttrium aluminium garnet laser photocoagulation treatment in an out-patient setting. At three years, 94 per cent of acute epistaxis patients versus 88 per cent of recurrent epistaxis patients reported no bleeding. The outcome scores at 12 weeks and 3 years after treatment showed no significant differences between the 2 groups (p = 0.207 and p = 0.186). However, there was a significant difference in outcome scores at four weeks after treatment (p = 0.034). The median (and mean ± standard deviation) pain levels experienced during the laser operation (performed in an office setting) were 4.0 (3.75 ± 2.09) in the acute epistaxis group and 4.0 (3.83 ± 2.01) in the recurrent epistaxis group. Neither group had any complications. Neodymium-doped yttrium aluminium garnet laser photocoagulation is desirable in the treatment of both acute and recurrent epistaxis, and has long-lasting efficacy.

  9. A randomized controlled trial of peeling and aspiration of Elschnig pearls and neodymium:yttrium-aluminium-garnet laser capsulotomy

    Directory of Open Access Journals (Sweden)

    Rahul Bhargava

    2015-06-01

    Full Text Available AIM:To compare surgical peeling and aspiration and neodymium yttrium garnet laser capsulotomy for pearl form of posterior capsule opacification (PCO.METHODS:A prospective, randomized, double blind, study was done at Rotary Eye Hospital, Maranda, Palampur, India, Santosh Medical College Hospital, Ghaziabad, India and Laser Eye Clinic, Noida India. Consecutive patients with pearl form of PCO following surgery, phacoemulsification, manual small incision cataract surgery and conventional extracapsular cataract extraction (ECCE for age related cataract, were randomized to have peeling and aspiration or neodymium yttrium garnet laser capsulotomy. Corrected distance visual acuity (CDVA, intra-operative and post-operative complications were compared.RESULTS:A total of 634 patients participated in the study, and 314 (49.5% patients were randomized to surgical peeling and aspiration group and 320 (50.5% to the Nd:YAG laser group. The mean pre-procedural logMAR CDVA in peeling and neodymium:yttrium-aluminium-garnet (Nd:YAG laser group was 0.80±0.25 and 0.86±0.22, respectively. The mean final CDVA in peeling group (0.22±0.23 was comparable to Nd:YAG group (0.24±0.28; t test, P=0.240. There was a significant improvement in vision after both the procedures (P<0.001. A slightly higher percentage of patients in Nd:YAG laser group (283/88.3% than in peeling group (262/83.4% had a CDVA of 0.5 (20/63 or better at 9mo (P<0.001. On the contrary, patients having CDVA worse than 1.00 (20/200 was also significantly higher in Nd:YAG laser group as compared to peeling group (25/7.7% vs 15/4.7%, respectively. On application of ANCOVA, there was less than 0.001% risk that PCO thickness and total laser energy had no effect on rate of complications in Nd:YAG laser group and less than 0.001 % risk that PCO thickness had no effect on complications in peeling group respectively. Sum of square analysis suggests that in the Nd:YAG laser group, thick PCO had a stronger impact

  10. Uranium, yttrium, and rare earth elements accumulation during the Cretaceous anoxic events in carbonaceous rocks in the Pacific Ocean

    Science.gov (United States)

    Savelyeva, Olga; Philosofova, Tatyana; Bergal-Kuvikas, Olga; Savelyeva, Svetlana

    2017-04-01

    We have studied the carbonate-siliceous section of paleooceanic Albian-Cenomanian deposits on the Kamchatsky Mys peninsula (Eastern Kamchatka, Russia) [1].The section is represented by a rhythmic alternation of planktonic limestones and jaspers, accumulated in the open ocean environment. The rhythmicity can be attributed to climate variations that reflect a fluctuation of astronomical parameters (Milankovitch cycles) [2, 3].The section contains two beds enriched in organic carbon, corresponding to the two oceanic anoxic events - MCE and OAE2 [3]. The maximum content of organic matter in those beds reaches 68%. Our geochemical studies revealed an enrichment of the carbonaceous rocks in some major and trace elements including PGE, in comparison with the surrounding limestone and jasper [4].The accumulation of the ore elements in carbonaceous beds is caused by euxinic conditions during sedimentation.The content of uranium, yttrium, and rare earth elements in carbonaceous rocks is up to 60, 142 and 312 ppm respectively. Phosphate grains (bone detritus) with microinclusions of yttrium and uranium minerals were revealed in the carbonaceous rocks using the scanning electron microscope. These data prove the hypothesis of the sorbtion of U and Y by phosphate detritus from seawater. Microprobe analysis also showed an increased content of Cu, Zn, V in some pyrite framboids, which indicates that these elements are fixed in rocks by Fe-sulphide phase or organic matter under euxinic conditions. Our research may bring us closer to understanding the mechanism of syngenetic accumulation of metals in the black shales. This work was supported by the RFBR (No. 16-05-00546). [1] Palechek, T.N., Savelyev, D.P., Savelyeva, O.L. (2010) Stratigraphy and Geological Correlation 18, (1) 63-82. [2] Savelyeva, O.L. (2010). Vestnik Kraunts. Nauki o zemle 1 (15), 45-55 (in Russian). [3] Savelyev, D.P., Savelyeva, O.L., Palechek, T.N., Pokrovsky, B.G. (2012) Geophysical Research Abstracts, 14, EGU

  11. A composite material based on nanoparticles of yttrium (III) oxide for the selective and sensitive electrochemical determination of acetaminophen

    International Nuclear Information System (INIS)

    Baytak, Aysegul Kutluay; Teker, Tugce; Duzmen, Sehriban; Aslanoglu, Mehmet

    2016-01-01

    An electrochemical sensor was prepared by modifying a glassy carbon electrode (GCE) with a composite of yttrium (III) oxide nanoparticles (Y_2O_3NPs) and carbon nanotubes (CNTs) for the determination of acetaminophen (ACT). Compared with a bare GCE and CNTs/GCE, the Y_2O_3NPs/CNTs/GCE exhibited a well-defined redox couple for ACT and highly enhanced the current response. The separations in the anodic and cathodic peak potentials (ΔE_p) for ACT were 552 mV, 24 mV and 10 mV at ba4re GCE, CNTs/GCE and Y_2O_3NPs/CNTs/GCE, respectively. The observation of only 10 mV of ΔE_p for ACT at Y_2O_3NPs/CNTs/GCE was a clear indication of a great acceleration of the electrode process compared to bare GCE and GCE modified with CNTs. Also, L-ascorbic acid (L-AA) and L-tyrosine (L-TRY) did not interfere with the selective determination of ACT. Square wave voltammetry (SWV) was performed for the quantification of ACT. A linear plot was obtained for current responses versus the concentrations of ACT over the range from 1.0 × 10"−"1"0 to 1.8 × 10"−"8 M with a detection limit of 3.0 × 10"−"1"1 M (based on 3S_b/m). The proposed composite material provided high electrocatalytic activity, improved voltammetric behavior, good selectivity and good reproducibility. The accurate quantification of ACT makes the proposed electrode of great interest for the public health. - Highlights: • A voltammetric sensor based on yttrium oxide was prepared for the detection of ACT. • The proposed electrode has greatly accelerated the voltammetric process of ACT. • A detection limit of 0.03 nM was obtained for ACT. • The proposed electrode exhibited great selectivity for ACT in the presence of L-AA and L-TRY. • The composite material exhibited high sensitivity, good stability and excellent reproducibility.

  12. Comparison of the partitioning behaviours of yttrium, rare earth elements, and titanium between hydrogenetic marine ferromanganese crusts and seawater

    Science.gov (United States)

    Bau, M.; Koschinsky, A.; Dulski, P.; Hein, J.R.

    1996-01-01

    In order to evaluate details of the partitioning behaviours of Y, rare earth elements (REEs), and Ti between inorganic metal oxide surfaces and seawater, we studied the distribution of these elements in hydrogenetic marine ferromanganese (Fe-Mn) crusts from the Central Pacific Ocean. Nonphosphatized Fe-Mn crusts display shale-normalized rare earths and yttrium (REYSN) patterns (Y inserted between Dy and Ho) that are depleted in light REEs (LREEs) and which show negative anomalies for YSN, and positive anomalies for LaSN, EuSN, GdSN, and in most cases, CeSN. They show considerably smaller Y/ Ho ratios than seawater or common igneous and clastic rocks, indicating that Y and Ho are fractionated in the marine environment. Compared to P-poor crusts, REYSN patterns of phosphatized Fe-Mn crusts are similar, but yield pronounced positive YSN anomalies, stronger positive LaSN anomalies, and enrichment of the HREEs relative to the MREEs. The data suggest modification of REY during phosphatization and indicate that studies requiring primary REY distributions or isotopic ratios should be restricted to nonphosphatized (layers of) Fe-Mn crusts. Apparent bulk coefficients, KMD, describing trace metal partitioning between nonphosphatized hydrogenetic Fe-Mn crusts and seawater, are similar for Pr to Eu and decrease for Eu to Yb. Exceptionally high values of KCeD, which are similar to those of Ti, result from oxidative scavenging of Ce and support previous suggestions that Ce(IV) is a hydroxide-dominated element in seawater. Yttrium and Gd show lower KD values than their respective neighbours in the REY series. Results of modelling the exchange equilibrium between REY dissolved in seawater and REY sorbed on hydrous Fe-Mn oxides corroborate previous studies that suggested the surface complexation of REY can be approximated by their first hydroxide binding constant. Negative "anomalies" occur for stabilities of bulk surface complexes of Gd, La, and particularly Y. The differences in

  13. Spectroscopic properties of Er/Nd co-doped yttrium lanthanum oxide transparent ceramics pumped at 980 nm

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yingjie; Yang, Qiuhong, E-mail: yangqiuhong@shu.edu.cn; Gui, Yan; Yuan, Ye; Lu, Qing

    2016-05-15

    (Er{sub 0.01}Nd{sub x}Y{sub 0.89-x}La{sub 0.1}){sub 2}O{sub 3} (x = 0, 0.001, 0.002, 0.005, 0.01) transparent ceramics were prepared by conventional ceramic processing. The Nd{sup 3+} content dependencies of mid-infrared, near infrared and up-conversion emission of Er{sup 3+} pumped at 980 nm were fully presented. Mechanism of energy transfer between Er{sup 3+} and Nd{sup 3+} was also demonstrated. The results showed that co-doping 0.1 at% Nd{sup 3+} into 1 at% Er{sup 3+} doped yttrium lanthanum oxide transparent ceramic enhanced the 2.7 μm emission significantly and meanwhile suppressed the 1.5 μm emission effectively which indicated an improvement in population inversion between Er:{sup 4}I{sub 11/2} and Er:{sup 4}I{sub 13/2}. Moreover, green up-conversion emission of Er{sup 3+} ion also showed a great improvement by co-doping 0.1 at% Nd{sup 3+}. Those great results were attributed to energy recycle from Er:{sup 4}I{sub 13/2} to Er:{sup 4}I{sub 11/2}. The energy recycle was mainly built by the two energy transfer between Er{sup 3+} and Nd{sup 3+} (one is from Er to Nd, another is in opposite way). So, Er/Nd co-doped yttrium lanthanum oxide transparent ceramic with Nd in low concentration can be considered as a promising laser material for ∼3 μm and up-conversion laser application. - Highlights: • (Er{sub 0.01}Nd{sub x}Y{sub 0.89-x}La{sub 0.1}){sub 2}O{sub 3} transparent ceramics were prepared. • The emission of 2.7 μm of Er{sup 3+} ion was significantly enhanced as x was 0.001. • The emission of 1.5 μm of Er{sup 3+} ion was suppressed greatly by co-doping Nd{sup 3+} ion. • Mechanism of Er–Nd energy transfer was discussed by the energy sketch.

  14. A composite material based on nanoparticles of yttrium (III) oxide for the selective and sensitive electrochemical determination of acetaminophen

    Energy Technology Data Exchange (ETDEWEB)

    Baytak, Aysegul Kutluay [Department of Medical Laboratory, Vocational School of Health Services, Harran University, Şanlıurfa 63510 (Turkey); Teker, Tugce; Duzmen, Sehriban [Department of Chemistry, Harran University, Şanlıurfa 63510 (Turkey); Aslanoglu, Mehmet, E-mail: maslanoglu@harran.edu.tr [Department of Chemistry, Harran University, Şanlıurfa 63510 (Turkey)

    2016-09-01

    An electrochemical sensor was prepared by modifying a glassy carbon electrode (GCE) with a composite of yttrium (III) oxide nanoparticles (Y{sub 2}O{sub 3}NPs) and carbon nanotubes (CNTs) for the determination of acetaminophen (ACT). Compared with a bare GCE and CNTs/GCE, the Y{sub 2}O{sub 3}NPs/CNTs/GCE exhibited a well-defined redox couple for ACT and highly enhanced the current response. The separations in the anodic and cathodic peak potentials (ΔE{sub p}) for ACT were 552 mV, 24 mV and 10 mV at ba4re GCE, CNTs/GCE and Y{sub 2}O{sub 3}NPs/CNTs/GCE, respectively. The observation of only 10 mV of ΔE{sub p} for ACT at Y{sub 2}O{sub 3}NPs/CNTs/GCE was a clear indication of a great acceleration of the electrode process compared to bare GCE and GCE modified with CNTs. Also, L-ascorbic acid (L-AA) and L-tyrosine (L-TRY) did not interfere with the selective determination of ACT. Square wave voltammetry (SWV) was performed for the quantification of ACT. A linear plot was obtained for current responses versus the concentrations of ACT over the range from 1.0 × 10{sup −10} to 1.8 × 10{sup −8} M with a detection limit of 3.0 × 10{sup −11} M (based on 3S{sub b}/m). The proposed composite material provided high electrocatalytic activity, improved voltammetric behavior, good selectivity and good reproducibility. The accurate quantification of ACT makes the proposed electrode of great interest for the public health. - Highlights: • A voltammetric sensor based on yttrium oxide was prepared for the detection of ACT. • The proposed electrode has greatly accelerated the voltammetric process of ACT. • A detection limit of 0.03 nM was obtained for ACT. • The proposed electrode exhibited great selectivity for ACT in the presence of L-AA and L-TRY. • The composite material exhibited high sensitivity, good stability and excellent reproducibility.

  15. Structural and luminescence effects of Ga co-doping on Ce-doped yttrium aluminate based phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Ayvacikli, M. [Celal Bayar University, Faculty of Arts and Sciences, Department of Physics, Muradiye, Manisa (Turkey); Canimoglu, A. [Nigde University, Faculty of Arts and Sciences, Physics Department, Nigde (Turkey); Muresan, L.E., E-mail: laura_muresan2003@yahoo.com [Babes Bolyai University, Raluca Ripan Institute for Research in Chemistry, Fantanele 30, 400294 Cluj-Napoca (Romania); Barbu Tudoran, L. [Babes Bolyai University, Electronic Microscopy Centre, Clinicilor 37, 400006 Cluj Napoca (Romania); Garcia Guinea, J. [Museo Nacional Ciencias Naturales, Jose Gutierrez Abascal 2, Madrid 28006 (Spain); Karabulut, Y. [Celal Bayar University, Faculty of Arts and Sciences, Department of Physics, Muradiye, Manisa (Turkey); Jorge, A. [Museo Nacional Ciencias Naturales, Jose Gutierrez Abascal 2, Madrid 28006 (Spain); Karali, T. [Ege University, Institute of Nuclear Sciences, 35100 Bornova, İzmir (Turkey); Can, N., E-mail: cannurdogan@yahoo.com [Celal Bayar University, Faculty of Arts and Sciences, Department of Physics, Muradiye, Manisa (Turkey); Jazan University, Physics Department, P.O. Box 114, 45142 Jazan (Saudi Arabia)

    2016-05-05

    Herein, we primarily focus on luminescence spectrum measurements of various types of green emitting yttrium aluminate phosphors modified with gallium (Y{sub 3}Al{sub 5-x}Ga{sub x}O{sub 12}) synthesised by solid state reaction. The luminescent emission of samples depends on sample temperature and excitation radiation such as incident X-ray, electron and laser beam. Here, we measured radioluminescence (RL), cathodoluminescence (CL), photoluminescence (PL) along with XRD in order to clarify relationship between lattice defects and the spectral luminescence emissions. The RL and CL spectra of YAG:Ce exhibit an emission band ranging from 300 to 450 nm related to Y{sub Al} antisite defects. The broad emission band of garnet phosphors is shifted from 526 nm to 498 nm with increasing of Ga{sup 3+} content, while full width at half maximum (FWHM) of the band tends to be greater than the width of unmodified YAG:Ce garnet. Deconvolution of the spectrum reveals that three emission bands centred at 139, 234 and 294 °C occur in aluminate host garnets. - Highlights: • We present preparation of YAG:Ce{sup 3+}, Ga{sup 3+} phosphors by a solid state reaction method. • The shape and size of phosphor particles were investigated. • The luminescence properties were studied by different excitation sources.

  16. Thin yttrium iron garnet films grown by pulsed laser deposition: Crystal structure, static, and dynamic magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, N. S., E-mail: nsokolov@fl.ioffe.ru; Fedorov, V. V.; Korovin, A. M.; Suturin, S. M.; Baranov, D. A.; Gastev, S. V.; Krichevtsov, B. B.; Bursian, V. E.; Lutsev, L. V. [Ioffe Physical-Technical Institute of Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); Maksimova, K. Yu.; Grunin, A. I. [Immanuel Kant Baltic Federal University, Kaliningrad 236041 (Russian Federation); Tabuchi, M. [Synchrotron Radiation Research Center, Nagoya University, Nagoya 464-8603 (Japan)

    2016-01-14

    Pulsed laser deposition has been used to grow thin (10–84 nm) epitaxial layers of Yttrium Iron Garnet Y{sub 3}Fe{sub 5}O{sub 12} (YIG) on (111)–oriented Gadolinium Gallium Garnet substrates at different growth conditions. Atomic force microscopy showed flat surface morphology both on micrometer and nanometer scales. X-ray diffraction measurements revealed that the films are coherent with the substrate in the interface plane. The interplane distance in the [111] direction was found to be by 1.2% larger than expected for YIG stoichiometric pseudomorphic film indicating presence of rhombohedral distortion in this direction. Polar Kerr effect and ferromagnetic resonance measurements showed existence of additional magnetic anisotropy, which adds to the demagnetizing field to keep magnetization vector in the film plane. The origin of the magnetic anisotropy is related to the strain in YIG films observed by XRD. Magneto-optical Kerr effect measurements revealed important role of magnetization rotation during magnetization reversal. An unusual fine structure of microwave magnetic resonance spectra has been observed in the film grown at reduced (0.5 mTorr) oxygen pressure. Surface spin wave propagation has been demonstrated in the in-plane magnetized films.

  17. Clinical evaluation of the partition model for estimating radiation doses from yttrium-90 microspheres in the treatment of hepatic cancer

    International Nuclear Information System (INIS)

    Ho, S.; Lau, W.Y.; Leung, T.W.T.; Chan, M.; Johnson, P.J.; Li, A.K.C.

    1997-01-01

    Radiation doses to the tumour and non-tumorous liver compartments from yttrium-90 microspheres in the treatment of hepatic cancer, as estimated by a partition model, have been verified by correlation with the actual doses measured with a beta probe at open surgery. The validity of the doses to the lungs, the tumour and non-tumours liver compartment as estimated by the partition model was further evaluated in clinical settings. On the basis of the observation that one of three patients who received more than 30 Gy from a single treatment and one of two patients who received more than 50 Gy from multiple treatments developed radiation pneumonitis, it was deduced that an estimated lung dose 30 Gy as estimated by the partition model and were predicted to develop radiation pneumonitis, did so despite the use of partial hepatic embolization to reduce the degree of lung shunting. Furthermore, a higher radiological response rate and prolonged survival were found in the group of patients who received higher tumour doses, as estimated by the partition model, than in the group with lower estimated tumour doses. Thus the radiation doses estimated by the partition model can be used to predict (a) complication rate, (b) response rate and (c) duration of survival in the same manner as the actual radiation doses measured with a beta probe at open surgery. The partition model has made selective internal radiation therapy using 90 Y microspheres safe and repeatable without laparotomy. (orig.)

  18. Thin yttrium iron garnet films grown by pulsed laser deposition: Crystal structure, static, and dynamic magnetic properties

    International Nuclear Information System (INIS)

    Sokolov, N. S.; Fedorov, V. V.; Korovin, A. M.; Suturin, S. M.; Baranov, D. A.; Gastev, S. V.; Krichevtsov, B. B.; Bursian, V. E.; Lutsev, L. V.; Maksimova, K. Yu.; Grunin, A. I.; Tabuchi, M.

    2016-01-01

    Pulsed laser deposition has been used to grow thin (10–84 nm) epitaxial layers of Yttrium Iron Garnet Y 3 Fe 5 O 12 (YIG) on (111)–oriented Gadolinium Gallium Garnet substrates at different growth conditions. Atomic force microscopy showed flat surface morphology both on micrometer and nanometer scales. X-ray diffraction measurements revealed that the films are coherent with the substrate in the interface plane. The interplane distance in the [111] direction was found to be by 1.2% larger than expected for YIG stoichiometric pseudomorphic film indicating presence of rhombohedral distortion in this direction. Polar Kerr effect and ferromagnetic resonance measurements showed existence of additional magnetic anisotropy, which adds to the demagnetizing field to keep magnetization vector in the film plane. The origin of the magnetic anisotropy is related to the strain in YIG films observed by XRD. Magneto-optical Kerr effect measurements revealed important role of magnetization rotation during magnetization reversal. An unusual fine structure of microwave magnetic resonance spectra has been observed in the film grown at reduced (0.5 mTorr) oxygen pressure. Surface spin wave propagation has been demonstrated in the in-plane magnetized films

  19. Improved performance of quantum dot light emitting diode by modulating electron injection with yttrium-doped ZnO nanoparticles

    Science.gov (United States)

    Li, Jingling; Guo, Qiling; Jin, Hu; Wang, Kelai; Xu, Dehua; Xu, Yongjun; Xu, Gang; Xu, Xueqing

    2017-10-01

    In a typical light emitting diode (QD-LED), with ZnO nanoparticles (NPs) serving as the electron transport layer (ETL) material, excessive electron injection driven by the matching conduction band maximum (CBM) between the QD and this oxide layer usually causes charge imbalance and degrades the device performance. To address this issue, the electronic structure of ZnO NPs is modified by the yttrium (Y) doping method. We demonstrate that the CBM of ZnO NPs has a strong dependence on the Y-doping concentration, which can be tuned from 3.55 to 2.77 eV as the Y doping content increases from 0% to 9.6%. This CBM variation generates an enlarged barrier between the cathode and this ZnO ETL benefits from the modulation of electron injection. By optimizing electron injection with the use of a low Y-doped (2%) ZnO to achieve charge balance in the QD-LED, device performance is significantly improved with maximum luminance, peak current efficiency, and maximal external quantum efficiency increase from 4918 cd/m2, 11.3 cd/A, and 4.5% to 11,171 cd/m2, 18.3 cd/A, and 7.3%, respectively. This facile strategy based on the ETL modification enriches the methodology of promoting QD-LED performance.

  20. Importance Role of Low-Cost Sorbent Produced from rice husk in Separation of zirconium from yttrium

    International Nuclear Information System (INIS)

    Kandil, S.A.

    2013-01-01

    The agricultural waste, rice husk, was used as a precursor for the production of low-cost sorbent. Rice husk, a by-product of the rice milling industry, accounts for about 20 % of the whole rice. The argro-residue sorbent extracted from rice husk was employed in separation of zirconium from yttrium. The separation of Zr from the binary systems (Zr-Y) was achieved in batch and column modes. In a batch mode, the adsorption behavior was studied in deferent media, namely, hydrochloric acid, 0.1 M citrate buffer and 0.1 M acetate buffer. In addition, other factors affecting the sorption process of each metal e.g. ph-value of the medium and metal ion concentration were also studied. The breakthrough experiments were carried in the form of mini-column with different bed depths of sorbent at flow rates of 20 ml/min and 40 ml/min. These studies were performed to elucidate the valuable of use of locally, available, agro-residue for separation of Zr from Y target as a promising sorbent for purification of 88 Zr, 89 Zr from Y.