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Sample records for chromiumiii-activated yttrium aluminum

  1. Phase transformations by yttrium implantation into pure aluminum

    International Nuclear Information System (INIS)

    This paper reports on phase transformations by yttrium implantation into pure aluminum using 60 kV ions and 3 x 1017 ions/cm2 dose that have been studied by transmission electron microscopy (TEM). YAl3(12R) particles with an average size of 0.3μm were formed in the modified aluminum surface, which transformed into YFe3.5Alx (predominantly) and YAl3(8H) phase particles with 2 μm average diameter after being annealed at 600 degrees C for one hour. The Fe ions were introduced by ion sputtering from the iron screws of the specimen holder, a previously unnoticed effect during heavy metal ion implantation for surface modification of materials. Electron diffraction experiments indicated that the YFe3.5Alx was a new phase and belongs to the orthorhombic system with a C-face-centered lattice (a = c = 0.887nm, b = 1.024nm). The reciprocal lattice of the YFe3.5Alx phase is related to that of the YFe4Al8 magnetic phase. The microstructure of the modified aluminum surface was also investigated by high-resolution TEM

  2. Polycrystalline yttrium aluminum garnet fibers from colloidal sols

    International Nuclear Information System (INIS)

    Polycrystalline yttrium aluminum garnet (YAG) fibers were prepared from commercially available colloidal sols of Y2O3 and AlOOH and water-soluble polymers. The fibers were dry spun and all processing was performed in air. Transformation to YAG was complete by ≅1,300 C, and the fibers were mostly dense by 1,600 C with a final fired diameter of 120 microm. A bend test was used to characterize mechanical strength, and an average of 522±186 MPa with a Weibull modulus of 3.5 was determined. The bend stress relaxation (BSR) test was used to characterize creep properties. The creep resistance was better than that of all commercially available oxide fibers with the exception of Saphikon single-crystal alumina (c-axis oriented). The creep strain of the YAG fibers compared well with that calculated for YAG monoliths with roughly the same grain size

  3. KINETICS OF GRAIN-GROWTH OF YTTRIUM ALUMINUM GARNET FIBERS PREPARED BY SOL-GEL METHOD

    Directory of Open Access Journals (Sweden)

    Tan H.

    2013-12-01

    Full Text Available The yttrium aluminum garnet (YAG long fibers were prepared by the sol-gel method using aluminum chloride, aluminum powder, yttrium oxide and acetic acid as raw materials. The grain growth law is given by Dn – D0n = Kt (D0 = initial grain size, D = average grain size at time t, n = grain growth exponent and K = reaction constant. The grain growth exponent and activation energy of YAG fibers are ≈ 3 and 200 kJ/mol, respectively. The grain-growth behaviors of YAG were influenced by experimental conditions such as raw materials, initial particle size, initial particle distribution, etc.

  4. High-Pressure Optical Studies of Doped Yttrium Aluminum Garnet

    Science.gov (United States)

    Wamsley, Paula

    This thesis demonstrates the application of high pressure spectroscopy to the study of doped insulator laser materials. We investigated transition metal ion and rare -earth ion doped yttrium aluminum garnet (YAG) crystals. Our goal was to explore the relationship between the local bonding environment of the dopant ion and the bulk optical properties of the crystals. Pressure is a useful probe for this type of investigation because pressure changes the local bonding environment of the dopant ion. We conducted laser induced fluorescence experiments and time-resolved laser induced fluorescence experiments on samples in modified Merrill-Basset style diamond anvil cells. We measured the effect of pressure on the laser induced emission of Cr^{3+} and Tm^{3+} in Cr ^{3+}:YAG and Tm^ {3+}:YAG. These experiments provided information about the energy level structure of Cr ^{3+} and Tm^{3+ } as a function of the crystal field strength. In Cr^{3+}:YAG we were able to correlate changes in the emission spectrum to pressure induced changes in the local site-symmetry of the Cr ^{3+} ions. In Tm^ {3+}:YAG we determined that several emission features were incorrectly assigned and observed previously unreported Tm^{3+} emission features. We also measured the time-resolved laser induced emission of Cr^{3+} in Cr^{3+}:YAG and Cr ^{3+}:Tm^{3+ }:YAG. With these measurements we were able to determine the effect of thermal and spin-orbit coupling on the fluorescence properties of Cr^{3+ }. In addition we determined that the fluorescence properties of Cr^{3+} strongly influence the rate of energy transfer and the efficiency of energy transfer from Cr^{3+ } to Tm^{3+} in Cr^{3+}:Tm ^{3+}:YAG.

  5. 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. PMID:20862016

  6. Effect of trace yttrium on cube texture of high-purity aluminum foils

    Institute of Scientific and Technical Information of China (English)

    刘楚明; 张新明; 陈志永; 蒋红辉; 周卓平

    2001-01-01

    The effect of trace yttrium on cube texture of high-purity aluminum foils has been investigated by means of orientation distribution functions (ODFs). The results show that a small addition of yttrium to high-purity aluminum brings about a considerable increment of the cube texture, and it reduces the content of R texture. The rare earth yttrium may combine with the other impurities to form the metallic compounds, such as FeYAl8, Fe6YAl6, Fe4YAl8 and Si2YAl2. When the precipitation of these particles in the matrix is nearly completed and the Fe concentration in the matrix becomes low, the cube texture can develop well and the R texture can be suppressed.

  7. Raman calibration of the HT-7 yttrium aluminum garnet Thomson scattering for electron density measurements

    International Nuclear Information System (INIS)

    A multipulse neodym doped yttrium aluminum garnet laser Thomson scattering system calibrated by the anti-Stokes rotational Raman scattering from nitrogen gas had been developed in the HT-7 superconducting Tokmak. By virtue of this system, measured electron density results of the plasma were obtained. The results showed good repeatability and its total uncertainty was estimated to be ±18%

  8. Comparison of the erbium-yttrium aluminum garnet and carbon dioxide lasers for in vitro bone and cartilage ablation

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, C.; van de Merwe, W.P.; Smith, M.; Reinisch, L. (Uniformed Services Univ. of the Health Sciences, Bethesda, MD (USA))

    1990-01-01

    The in vitro bone- and cartilage-ablation characteristics of the solid-state erbium:yttrium aluminum garnet laser were compared to those of the carbon dioxide laser. Ablations of fresh, frozen cadaver septal cartilage and maxillary sinus bone were performed using total energies between 1 and 6 J. Specimens were studied using hematoxylin and eosin stain and digitized, computer-assisted measurements of 35-mm photographs. Erbium-yttrium aluminum garnet-ablated bone averaged 5 microns of adjacent tissue thermal injury, compared with 67 microns with carbon dioxide-ablated bone. Erbium-yttrium aluminum garnet-ablated cartilage averaged 2 microns of adjacent tissue thermal injury, compared with 21 microns with the carbon dioxide-ablated cartilage. The tissue-ablation characteristics of the erbium-yttrium aluminum garnet laser are promising for future otolaryngologic applications.

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

    Science.gov (United States)

    Akhtar, Majid Niaz; Bakar Sulong, Abu; Khan, Muhammad Azhar; Ahmad, Mukhtar; Murtaza, Ghulam; Raza, M. R.; Raza, R.; Saleem, M.; Kashif, M.

    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.

  10. Obliterated urethra: holmium:yttrium-aluminum-garnet cut-to-light with urolume stenting.

    Science.gov (United States)

    Monga, M; Gordon, Z; Alexandrescu, B

    2001-12-01

    Antegrade-retrograde urethrotomy, or the cut-to-light procedure, performed for obliterated urethra is associated with a high rate of recurrence of urethra] stricture. With the goal of reducing the stricture recurrence rate, we performed a modified cut-to-light procedure using a holmium:yttrium-aluminum-garnet laser and UroLume stenting in a 76-year-old man with urethral obliteration. PMID:11763485

  11. Effect of aluminum and yttrium doping on zinc sulphide nanoparticles

    Science.gov (United States)

    Sharma, Swati; Kashyap, Jyoti; Gupta, Shubhra; Natasha, Kapoor, A.

    2016-05-01

    In this work, pristine and doped Zinc Sulphide (ZnS) nanoparticles have been synthesized via chemical co-precipitation method. ZnS nanoparticles have been doped with Aluminium (Al) and Yttrium (Y) with doping concentration of 5wt% each. The structural and optical properties of the as prepared nanoparticles have been studied using X-Ray diffraction (XRD) technique and Photoluminescence spectroscopy. Average grain size of 2-3nm is observed through the XRD analysis. Effect of doping on stress, strain and lattice constant of the nanoparticles has also been analyzed. Photoluminescence spectra of the as prepared nanoparticles is enhanced due to Al doping and quenched due to Y doping. EDAX studies confirm the relative doping percentage to be 3.47 % and 3.94% by wt. for Al and Y doped nanoparticles respectively. Morphology of the nanoparticles studied using TEM and SEM indicates uniform distribution of spherical nanoparticles.

  12. Radon test measurements with Ce-doped yttrium aluminum oxide perovskite scintillator

    Directory of Open Access Journals (Sweden)

    F. de Notaristefani

    2002-04-01

    Full Text Available Scintillation properties of a Ce-doped yttrium aluminium oxide perovskite monocrystal optically coupled to a Hamamatsu H5784 photomultiplier are analyzed with a standard bialkali photocathode for radon and radon daughters gamma-ray spectrometry. Tests in water up to 100°C and in acidic solutions of HCl (37%, H2SO4 (48% and HNO3 (65% were performed to simulate environments of geophysical interest, such as geothermal and volcanic areas. Comparative measurements with standard radon sources provided by the National Institute for Metrology of Ionizing Radiations (ENEA confirm the non-hygroscopic properties of the scintillator and small dependence of the light yield on temperature and HNO3.The Ce-doped yttrium aluminum oxide perovskite monocrystal shows high response stability for radon gamma-ray spectrometry in environments with large temperature gradients and high acid concentrations.

  13. Upconversion luminescence in Yb{sup 3+}-doped yttrium aluminum garnets

    Energy Technology Data Exchange (ETDEWEB)

    Xu Xiaodong [Crystal Centre, Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, P.O. Box 800-211, Shanghai 201800 (China) and Graduate School of Chinese Academy of Sciences, Beijing 100039 (China)]. E-mail: xdxu79@yahoo.com.cn; Zhao Zhiwei [Crystal Centre, Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, P.O. Box 800-211, Shanghai 201800 (China)]. E-mail: zzw@mail.siom.ac.cn; Song Pingxin [Crystal Centre, Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, P.O. Box 800-211, Shanghai 201800 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Jiang Benxue [Crystal Centre, Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, P.O. Box 800-211, Shanghai 201800 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Zhou Guoqing [Crystal Centre, Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, P.O. Box 800-211, Shanghai 201800 (China); Xu Jun [Crystal Centre, Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, P.O. Box 800-211, Shanghai 201800 (China); Deng Peizhen [Crystal Centre, Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, P.O. Box 800-211, Shanghai 201800 (China); Bourdet, Gilbert [Laboratoire pour l' Utilisation des Lasers Intenses, UMR7605, CNRS-CEA-Universite Paris VI, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Christophe Chanteloup, Jean [Laboratoire pour l' Utilisation des Lasers Intenses, UMR7605, CNRS-CEA-Universite Paris VI, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Zou, Ji-Ping [Laboratoire pour l' Utilisation des Lasers Intenses, UMR7605, CNRS-CEA-Universite Paris VI, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Fulop, Annabelle [Laboratoire pour l' Utilisation des Lasers Intenses, UMR7605, CNRS-CEA-Universite Paris VI, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2005-03-15

    In this paper, we present results on upconversion luminescence performed on Yb{sup 3+}-doped yttrium aluminum garnets under 940 nm excitation. The upconversion luminescence was ascribed to Yb{sup 3+} cooperative luminescence and the presence of rare earth impurity ions. The cooperative luminescence spectra as a function of Yb concentration were measured and the emission intensity variation with Yb concentration was discussed. Yb{sup 3+} energy migration quenched the cooperative luminescence of Yb:YAG crystals with doping level over 15 at%.

  14. Preparation of neodymium-doped yttrium aluminum garnet powders and fibers

    Institute of Scientific and Technical Information of China (English)

    R.López; J.Zárate; E.A.Aguilar; J.Mu(n)oz-Salda(n)a

    2008-01-01

    Using nitrate precursors, a novel spray-drying assisted citrate gel process for the preparation of neodymium-doped yttrium alumi-num garnet (YAG) phase was developed. Synthesis of single-phase polycrystalline YAG was achieved at temperatures as low as 800 ℃ us-ing the spray-drying methodology whilst conventional approaches currently available require 1000 ℃. Initially, a solution was prepared by mixing aluminum and yttrium nitrates, citric acid, etilenglycol and neodymium oxide. This solution was dried by pulverization (spray dryer) to obtain aggregated precursor powders of the compound. These aggregates were calcined at 800, 850 and 900 ℃ to determine the phase evolution from amorphous to crystalline by X-ray diffraction (XRD). The morphology of aggregates was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Moreover, through XRD it was determined that the crystallization of YAG phase started at about 800 ℃ without any intermediate phases. The powders were composed of spherical aggregates with an average diame-ter of 1 μm. From these powders, ceramic fibers with additions of 2at.% and 5at.% Nd, were extracted from the melt with diameters ranging from 30 μm to 50 μm.

  15. Holmium: yttrium-aluminum-garnet (Ho:YAG laser for resection of bladder tumor in a pediatric patient

    Directory of Open Access Journals (Sweden)

    Suleyman Cakmakci

    2015-09-01

    Full Text Available Bladder tumours are rare in children, with only 0.4% of cases occurring in the first 2 decades of life. Herein, a pediatric patient who underwent TUR-B with a holmium: yttrium-aluminum-garnet (Ho:YAG laser is presented. Its histopathology was reported as urothelial papilloma.

  16. Study on phosphating treatment of aluminum alloy: role of yttrium oxide

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shenglin

    2009-01-01

    Zinc phosphate coatings formed on 6061-Al alloy, after dipping in phosphating solutions containing different amounts of Y2O3(yttrium oxide), were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrochemical measurements. Significant variations in the morphology and corrosion resistance afforded by zinc phosphate coating were especially observed as Y2O3 in phosphating solution varied from 0 to 40 mg/L. The addition of Y2O3 changed the initial potential of the interface between aluminum alloy substrate and phosphating solution and increased the number of nucleation sites. The phosphate coating thereby was less porous structure and covered the surface of aluminum alloy completely within short phosphating time. Phosphate coating was mainly composed of Zn3(PO4)2-4H2O (hopeite) and AIPO4(aluminum phosphate). Y2O3, as an additive of phosphatization, accelerated precipitation and refined the gain size of phosphate coating. The corrosion resistance of zinc phosphate coating in 3% NaCl solution was improved as shown by po-larization measurement. In the present research, the optimal amount of Y2O3 was 10-20 mg/L, and the optimal phosphating time was 600 s.

  17. Creep of polycrystalline yttrium aluminum garnet (YAG) at elevated temperature in air and in steam

    International Nuclear Information System (INIS)

    Compressive creep of high-purity polycrystalline yttrium aluminum garnet (YAG, Y3Al5O12) was investigated at 1300 °C and 50–200 MPa in air and in steam. Compressive creep behavior of silica-doped polycrystalline YAG (Y3Al5O12–0.14 wt% SiO2) was also studied. Creep specimens were microstructurally characterized by optical microscopy and TEM before and after creep. Steam slightly increased creep rates of material with grain size less than 1 μm (the undoped YAG), but otherwise had little effect. The flow stress exponent was n≈1 for both SiO2-doped YAG and undoped YAG. Creep rates and microstructural observations are consistent with the Nabarro-Herring creep mechanism, with creep rate limited by lattice diffusion of yttrium cations (Y3+). Silica-doped YAG had a larger grain size of 2.41 μm and lower creep rates than undoped YAG with 0.92 μm grain size. However, creep rates normalized by grain size for Nabarro-Herring creep were higher in SiO2-doped YAG. Possible effects of SiO2 doping and steam on creep of YAG are discussed

  18. Pulsed neodymium: yttrium aluminum garnet laser (532 nm) melting of crystalline silicon: Experiment and theory

    International Nuclear Information System (INIS)

    Time-resolved reflectivity measurements have been used to determine both the time of onset-of-melting and the duration of melting resulting from frequency-doubled neodymium: yttrium aluminum garnet (532 nm) pulsed-laser irradiation of crystalline silicon. Substantially shorter surface melt durations were obtained with increasing energy density E/sub l/ than were reported earlier by others. Thermal melting model calculations, which take into account the temperature-dependent optical and thermal properties of silicon, are in substantial agreement with the observed E/sub l/ dependence of the onset of melting and surface melt duration. Inclusion of intensity-dependent absorption in the modeling further improves this agreement

  19. Raman and Infrared Spectroscopy of Yttrium Aluminum Borate Glasses and Glass-ceramics

    Science.gov (United States)

    Bradley, J.; Brooks, M.; Crenshaw, T.; Morris, A.; Chattopadhyay, K.; Morgan, S.

    1998-01-01

    Raman spectra of glasses and glass-ceramics in the Y2O3-Al2O3-B2O3 system are reported. Glasses with B2O3 contents ranging from 40 to 60 mole percent were prepared by melting 20 g of the appropriate oxide or carbonate powders in alumina crucibles at 1400 C for 45 minutes. Subsequent heat treatments of the glasses at temperatures ranging from 600 to 800 C were performed in order to induce nucleation and crystallization. It was found that Na2CO3 added to the melt served as a nucleating agent and resulted in uniform bulk crystallization. The Raman spectra of the glasses are interpreted primarily in terms of vibrations of boron - oxygen structural groups. Comparison of the Raman spectra of the glass-ceramic samples with spectra of aluminate and borate crystalline materials reveal that these glasses crystallize primarily as yttrium aluminum borate, YAl3(BO3)4.

  20. Sol-gel Synthesis and Characterisation of NanocrystallineYttrium Aluminum Garnet Nanopowder

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    Kiranmala Devi

    2008-07-01

    Full Text Available The synthesis of  yttrium aluminum garnet (YAG (Y3 Al5O12 nanopowder was carried outby sol-gel method. Y(NO33.6H2O, Al(NO33.9H2O in the presence of citric acid as complexing agent were used as starting materials. YAG nanopowder was characterised by FTIR, TGA, andXRD. To get phase-pure nanocrystalline YAG powder at relatively lower temperature, calcinationat various temperatures was studied and calcination temperature was optimised. Particle size,estimated by XRD using Scherrer's equation, was found to be 28Œ35 nm which was further confirmed by transmission electron microscopy. The particle morphology was studied by SEM.Defence Science Journal, 2008, 58(4, pp.545-549, DOI:http://dx.doi.org/10.14429/dsj.58.1675

  1. Luminescent down shifting effect of Ce-doped yttrium aluminum garnet thin films on solar cells

    International Nuclear Information System (INIS)

    Ce-doped yttrium aluminum garnet (YAG:Ce) thin films as luminescent down shifting (LDS) materials are introduced into the module of crystalline silicon solar cells. The films are deposited by RF magnetron sputtering on the lower surface of the quartz glass. They convert ultraviolet and blue light into yellow light. Experiments show that the introduction of YAG:Ce films improves the conversion efficiency from 18.45% of the cells to 19.27% of the module. The increasing efficiency is attributed to LDS effect of YAG:Ce films and the reduced reflection of short wavelength photons. Two intentionally selected samples with similar reflectivities are used to evaluate roughly the effect of LDS alone on the solar cells, which leads to a relative increase by 2.68% in the conversion efficiency

  2. Luminescent down shifting effect of Ce-doped yttrium aluminum garnet thin films on solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Guojian; Lou, Chaogang; Kang, Jian; Zhang, Hao [School of Electronic Science and Engineering, Southeast University, Nanjing 210096, Jiangsu Province (China)

    2015-12-21

    Ce-doped yttrium aluminum garnet (YAG:Ce) thin films as luminescent down shifting (LDS) materials are introduced into the module of crystalline silicon solar cells. The films are deposited by RF magnetron sputtering on the lower surface of the quartz glass. They convert ultraviolet and blue light into yellow light. Experiments show that the introduction of YAG:Ce films improves the conversion efficiency from 18.45% of the cells to 19.27% of the module. The increasing efficiency is attributed to LDS effect of YAG:Ce films and the reduced reflection of short wavelength photons. Two intentionally selected samples with similar reflectivities are used to evaluate roughly the effect of LDS alone on the solar cells, which leads to a relative increase by 2.68% in the conversion efficiency.

  3. Eu(III) incorporation in sol-gel aluminum-yttrium matrix by non-hydrolytic route

    International Nuclear Information System (INIS)

    The sol-gel method using metal alkoxide has been investigated to prepare aluminum-yttrium oxide as yttrium-aluminum garnet (YAG) matrix composite fiber. In this paper we investigate the influence of yttrium content and temperature in the synthesis of Eu(III)-doped aluminum-yttrium oxide by non-hydrolytic sol-gel route. The formation process and the local structure of the samples were discussed by means of X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy. For temperatures around 800 deg. C, initial crystallization was observed and the phases Y4Al2O9 (YAM) and Y3Al5O12 (YAG) appear. For samples treated at 800 and 1500 deg. C the emission spectra display preferentially the f-f transitions characteristic of the YAM monoclinic phase, whereas the YAG cubic appears as the favored phase at 1100 deg. C, in accordance with the Eu(III) centrosymmetrical local site

  4. “Forbidden” reflections in resonant diffraction of synchrotron radiation in yttrium aluminum garnet Y3Al5O12

    International Nuclear Information System (INIS)

    The purely resonant Bragg reflections (13, 13, 0) and (14, 0, 0) in yttrium aluminum garnet Y3Al5O12 at energies near the K absorption edge of yttrium have been studied experimentally and theoretically. The anisotropic tensor atomic factor of yttrium corresponding to dipole-dipole resonance transitions depends on three independent parameters changing with energy. The intensities of the reflections (14, 0, 0) and (13, 13, 0) are shown to depend on the parameter difference f1(E) − f2(E) and the parameter f3(E), respectively, which are attributable to distortions of the wave functions of the excited atoms and change greatly with photon energy E. Studying various reflections has allowed one to determine the various components of the tensor atomic factor and to compare them with the results of numerical calculations.

  5. Grain growth and microstructural evolution of yttrium aluminum garnet nanocrystallites during calcination process

    International Nuclear Information System (INIS)

    An yttrium aluminum garnet (YAG) precursor precipitate was synthesized by urea method using yttria (Y2O3) and aluminum nitrate (Al(NO3)3.9H2O) as raw materials. The fresh wet precipitate was dried by supercritical carbon dioxide (CO2) fluid and the resulting powder was calcined at temperatures from 600 to 1600 oC. Crystallization of YAG was detected at 800 oC, and completed at 900 oC. HRTEM images of the YAG product obtained above 900 oC revealed crystallographically specific oriented attachment along the [1 1 2] direction. Based on the observation of the particle morphology a possible growth mechanism of YAG nanoparticles was presented. The fast increase on the average crystallite size of YAG at temperatures from 900 to 1300 oC is attributed to the crystallographically specific oriented attachment growth process. As the growth process proceeds at higher temperatures, oriented attachment based growth becomes less important because of the increase on particle size, and the self-integration assisted by the Ostwald ripening becomes dominant.

  6. X-Ray-, Cathodo-, and Photoluminescence of Yttrium-Aluminum Composites on Porous Anodic Alumina Films

    Science.gov (United States)

    Khoroshko, L. S.; Kortov, V. S.; Gaponenko, N. V.; Raichyonok, T. F.; Tikhomirov, S. A.; Pustovarov, V. A.

    2016-07-01

    Yttrium-aluminum composites doped with terbium were synthesized by precipitation on porous anodic alumina fi lms grown on silicon substrates. The fabricated structures demonstrated x-ray-, cathodo-, and photoluminescence with characteristic bands of trivalent terbium upon excitation by Cu Kα x-rays of energy 8.86 keV, a 180-keV electron beam, and optical UV radiation, respectively. The terbium luminescence bands increased in intensity as the terbium concentration increased from 0.01 to 0.25 mol%. The intensity of a broad band in the blue spectral region with a maximum at 410 nm that was due to photoluminescence of the porous anodic alumina fi lm increased as the excitation wavelength increased from 260 to 340 nm. Simultaneously, the intensities of luminescence bands in the range 480-650 nm associated with Tb 3 + 5 D 4 - 7 F j ( j = 3, 4, 5, 6) transitions decreased. The possibility of practical application of the synthesized luminescent structures was discussed.

  7. Fabrication of GaN-Based White Light-Emitting Diodes on Yttrium Aluminum Garnet-Polydimethylsiloxane Flexible Substrates

    OpenAIRE

    Lung-Chien Chen; Wen-Wei Lin; Jun-Wei Chen

    2015-01-01

    This study concerns the characteristics of white GaN-based light-emitting diode (LED) on flexible substrates. The thin film GaN-based blue LEDs were directly transferred from sapphire onto the flexible polydimethylsiloxane (PDMS) substrates by laser lift-off (LLO) process. The PDMS substrates were incorporated 10–40% cerium doped yttrium aluminum garnet phosphor, YAG:Ce3+, and formed the GaN-based white LEDs. The white LEDs prepared by the GaN-based LEDs on the YAG-PDMS substrates reveal one ...

  8. The use of Erbium: Yttrium-aluminum-garnet laser in cavity preparation and surface treatment: 3-year follow-up.

    Science.gov (United States)

    Buyukhatipoglu, Isil; Secilmis, Asli

    2015-01-01

    From the currently available choices, esthetic restorative materials for posterior teeth are limited to composite and ceramic restoration. Ceramic inlays/onlays are reliable solutions for both of these treatments. For successful treatment planning, usable ceramic and adhesive systems should be chosen by the dentist. Since the Federal Drug Administration approval of the erbium: Yttrium-aluminum-garnet (Er:YAG) laser-for caries removal, cavity preparation and the conditioning of tooth substance-in 1997, there have been many reports on the use of this technique in combination with composite resins. In addition, cavity pretreatment with the Er:YAG laser (laser etching) has been proposed as an alternative to acid etching of enamel and dentin. This case report presents the use of the Er:YAG in cavity preparation for composite resin restoration and surface treatment for ceramic onlay restoration of adjacent permanent molars. PMID:26038665

  9. 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.

  10. Mechanical and metallurgical properties of pulsed neodymium-doped yttrium aluminum garnet laser welding of dual phase steels

    International Nuclear Information System (INIS)

    Highlights: → We found that energy input pattern influence the mechanical properties of dual phase steels. → The longitudinal welded specimen showed higher strength than transverse one. → At higher levels of pulse duration the welded samples showed coarse grains in the heat affected zone. → Increasing the effective peak power density caused an increase in strength of the welded specimens. -- Abstract: In this paper, the effect of energy input pattern in pulsed neodymium-doped yttrium aluminum garnet laser welding on mechanical and metallurgical characteristics of a 0.19% carbon dual phase steel is studied. The experimental results showed that the energy input pattern to the fusion zone had a significant effect on the ultimate tensile strength of the welded samples. The longitudinally and transversely tested weld specimens showed higher and lower strength than the base metal respectively. Increase in effective peak power density increased the volume of fusion zone which in turn caused an increase in the strength of the welded specimens. Microstructural studies showed coarse grains in the heat affected zone of welded samples especially at higher levels of pulse duration. Fracture studies showed presence of dimples on the fractured surfaces of the heat affected zone indicating that a ductile fracture had occurred.

  11. Shear bond strength of orthodontic brackets after acid-etched and erbium-doped yttrium aluminum garnet laser-etched

    Science.gov (United States)

    Alavi, Shiva; Birang, Reza; Hajizadeh, Fatemeh

    2014-01-01

    Background: Laser ablation has been suggested as an alternative method to acid etching; however, previous studies have obtained contrasting results. The purpose of this study was to compare the shear bond strength (SBS) and fracture mode of orthodontic brackets that are bonded to enamel etched with acid and erbium-doped yttrium aluminum garnet (Er:YAG) laser. Materials and Methods: In this experimental in vitro study, buccal surfaces of 15 non-carious human premolars were divided into mesial and distal regions. Randomly, one of the regions was etched with 37% phosphoric acid for 15 s and another region irradiated with Er:YAG laser at 100 mJ energy and 20 Hz frequency for 20 s. Stainless steel brackets were then bonded using Transbond XT, following which all the samples were stored in distilled water for 24 h and then subjected to 500 thermal cycles. SBS was tested by a chisel edge, mounted on the crosshead of universal testing machine. After debonding, the teeth were examined under ×10 magnification and adhesive remnant index (ARI) score determined. SBS and ARI scores of the two groups were then compared using t-test and Mann-Whitney U test. Significant level was set at P < 0.05. Results: The mean SBS of the laser group (16.61 ± 7.7 MPa) was not significantly different from that of the acid-etched group (18.86 ± 6.09 MPa) (P = 0.41). There was no significant difference in the ARI scores between two groups (P = 0.08). However, in the laser group, more adhesive remained on the brackets, which is not suitable for orthodontic purposes. Conclusion: Laser etching at 100 mJ energy produced bond strength similar to acid etching. Therefore, Er:YAG laser may be an alternative method for conventional acid-etching. PMID:25097641

  12. Shear bond strength of orthodontic brackets after acid-etched and erbium-doped yttrium aluminum garnet laser-etched

    Directory of Open Access Journals (Sweden)

    Shiva Alavi

    2014-01-01

    Full Text Available Background: Laser ablation has been suggested as an alternative method to acid etching; however, previous studies have obtained contrasting results. The purpose of this study was to compare the shear bond strength (SBS and fracture mode of orthodontic brackets that are bonded to enamel etched with acid and erbium-doped yttrium aluminum garnet (Er:YAG laser. Materials and Methods: In this experimental in vitro study, buccal surfaces of 15 non-carious human premolars were divided into mesial and distal regions. Randomly, one of the regions was etched with 37% phosphoric acid for 15 s and another region irradiated with Er:YAG laser at 100 mJ energy and 20 Hz frequency for 20 s. Stainless steel brackets were then bonded using Transbond XT, following which all the samples were stored in distilled water for 24 h and then subjected to 500 thermal cycles. SBS was tested by a chisel edge, mounted on the crosshead of universal testing machine. After debonding, the teeth were examined under Χ10 magnification and adhesive remnant index (ARI score determined. SBS and ARI scores of the two groups were then compared using t-test and Mann-Whitney U test. Significant level was set at P < 0.05. Results: The mean SBS of the laser group (16.61 ± 7.7 MPa was not significantly different from that of the acid-etched group (18.86 ± 6.09 MPa (P = 0.41. There was no significant difference in the ARI scores between two groups (P = 0.08. However, in the laser group, more adhesive remained on the brackets, which is not suitable for orthodontic purposes. Conclusion: Laser etching at 100 mJ energy produced bond strength similar to acid etching. Therefore, Er:YAG laser may be an alternative method for conventional acid-etching.

  13. Efficacy of the Q-switched Neodymium: Yttrium Aluminum Garnet Laser in the Treatment of Blue-black Amateur and Professional Tattoos

    OpenAIRE

    Chembolli Lakshmi; Gayathri Krishnaswamy

    2015-01-01

    Background: Q-switched neodymium: yttrium aluminum garnet (Nd: YAG) laser at a wavelength of 1064 nm primarily targets dermal melanin and black tattoo ink. Recent studies have shown that this laser is effective in treating black tattoos. There are few studies conducted in India for the same. Aim: The aim was to assess the effectiveness of Q-switched Nd: YAG laser (QSNYL) in the treatment of blue-black tattoos following 3 treatment sessions. Materials and Methods: This study, a prospective int...

  14. Efficacy of the q-switched neodymium: Yttrium aluminum garnet laser in the treatment of blue-black amateur and professional tattoos

    OpenAIRE

    Chembolli Lakshmi; Gayathri Krishnaswamy

    2015-01-01

    Background: Q-switched neodymium: yttrium aluminum garnet (Nd: YAG) laser at a wavelength of 1064 nm primarily targets dermal melanin and black tattoo ink. Recent studies have shown that this laser is effective in treating black tattoos. There are few studies conducted in India for the same. Aim: The aim was to assess the effectiveness of Q-switched Nd: YAG laser (QSNYL) in the treatment of blue-black tattoos following 3 treatment sessions. Materials and Methods: This study, a prospective int...

  15. Comparative Study of Diode Laser Versus Neodymium-Yttrium Aluminum: Garnet Laser Versus Intense Pulsed Light for the Treatment of Hirsutism

    OpenAIRE

    Puri, Neerja

    2015-01-01

    Introduction: Lasers are widely used for the treatment of hirsutism. But the choice of the right laser for the right skin type is very important. Before starting with laser therapy, it is important to assess the skin type, the fluence, the pulse duration and the type of laser to be used. Aims: To compare the efficacy and side effects of Diode laser, Neodymium-yttrium aluminum — garnet (Nd: YAG) laser and intense pulsed light (IPL) on 30 female patients of hirsutism. Materials and Methods: Thi...

  16. Comparative study of diode laser versus neodymium-yttrium aluminum: garnet laser versus intense pulsed light for the treatment of hirsutism

    OpenAIRE

    Neerja Puri

    2015-01-01

    Introduction: Lasers are widely used for the treatment of hirsutism. But the choice of the right laser for the right skin type is very important. Before starting with laser therapy, it is important to assess the skin type, the fluence, the pulse duration and the type of laser to be used. Aims: To compare the efficacy and side effects of Diode laser, Neodymium-yttrium aluminum - garnet (Nd: YAG) laser and intense pulsed light (IPL) on 30 female patients of hirsutism. Materials and Methods: Thi...

  17. The effect of thermal treatment on the corrosion properties of vapor deposited magnesium alloyed with yttrium, aluminum, titanium, and misch metal

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, Ryan C. [Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802 (United States)]. E-mail: rcwolfe@gmail.com; Shaw, Barbara A. [Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802 (United States)

    2007-06-28

    The corrosion susceptibility of magnesium often limits the use of this important metal. Efforts to improve the corrosion resistance of magnesium through alloying are hindered by the limited solid solubility of most metals in magnesium. Moreover, the relatively high melting temperature of most of the less-common metals makes conventional alloying difficult. Vapor deposition has been used in this research to alloy magnesium with nonequilibrium concentrations of normally incompatible metals in an attempt to improve corrosion performance. Aluminum, titanium, yttrium, and misch metal were chosen as candidates likely to impart passivity on vapor deposited magnesium alloys. Although all of these metals afford some degree of corrosion resistance to magnesium, behavior is highly dependent on the thermal history of the alloys. Thermal effects, both during and after alloy deposition, alter the stress state of the alloys, precipitation of second phases, and the mechanical stability of the passive film. An optimal thermal treatment has been developed to maximize the corrosion resistance of vapor deposited magnesium-yttrium-titanium alloys.

  18. The effect of thermal treatment on the corrosion properties of vapor deposited magnesium alloyed with yttrium, aluminum, titanium, and misch metal

    International Nuclear Information System (INIS)

    The corrosion susceptibility of magnesium often limits the use of this important metal. Efforts to improve the corrosion resistance of magnesium through alloying are hindered by the limited solid solubility of most metals in magnesium. Moreover, the relatively high melting temperature of most of the less-common metals makes conventional alloying difficult. Vapor deposition has been used in this research to alloy magnesium with nonequilibrium concentrations of normally incompatible metals in an attempt to improve corrosion performance. Aluminum, titanium, yttrium, and misch metal were chosen as candidates likely to impart passivity on vapor deposited magnesium alloys. Although all of these metals afford some degree of corrosion resistance to magnesium, behavior is highly dependent on the thermal history of the alloys. Thermal effects, both during and after alloy deposition, alter the stress state of the alloys, precipitation of second phases, and the mechanical stability of the passive film. An optimal thermal treatment has been developed to maximize the corrosion resistance of vapor deposited magnesium-yttrium-titanium alloys

  19. In vitro study of the erbium:yttrium aluminum garnet laser cleaning of root canal by the use of shadow photography

    Science.gov (United States)

    Gregorčič, Peter; Lukač, Nejc; Možina, Janez; Jezeršek, Matija

    2016-01-01

    Erbium:yttrium aluminum garnet laser cleaning is a promising technique in endodontic treatment. In our in vitro study, we measured the vapor-bubble dynamics in the root canal by using shadow photography. The canal model was made of a plastic cutout placed between two transparent glass plates. An artificial smear layer was applied to the glass to study cleaning efficiency. In our results, no shock waves have been observed, since the pulp-chamber dimensions have been in the same range as the maximum diameter of the vapor bubble. This leads to the conclusion that shock waves are not the main cleaning mechanism within our model. However, the cleaning effects are also visible in the regions significantly below the bubble. Therefore, it can be concluded that fluid flow induced by the bubble's oscillations contributes significantly to the canal cleaning. We also proposed a simple theoretical model for cleaning efficiency and used it to evaluate the measured data.

  20. Highly Efficient Lasing Action of Nd3+- and Cr3+-Doped Yttrium Aluminum Garnet Ceramics Based on Phonon-Assisted Cross-Relaxation Using Solar Light Source

    Science.gov (United States)

    Saiki, Taku; Nakatsuka, Masahiro; Imasaki, Kazuo

    2010-08-01

    We constructed a theory to explain the mechanism of laser generation with a high optical-optical conversion efficiency for Nd3+- and Cr3+-doped yttrium aluminum ceramics when sunlight or lamplight sources are used for pumping. As a result, a unique mechanism of laser action was found where the solar or lamp-light power could be converted to laser power with a high efficiency close to 80%, which has not previously been observed. The high conversion efficiency was not only considered to be based on one-to-one photon conversion but on two-photon excitation by a single photon with phonon assistance. Thus, the mechanism of lasing action should include a process where thermal energy is converted to photon energy. The theoretical results we obtained were consistent with those of the experiments.

  1. Revised calibration of the Sm:SrB4O7 pressure sensor using the Sm-doped yttrium-aluminum garnet primary pressure scale

    International Nuclear Information System (INIS)

    The pressure-induced shift of Sm:SrB4O7 fluorescence was calibrated in a quasi-hydrostatic helium medium up to 60 GPa using the recent Sm-doped yttrium-aluminum garnet primary pressure scale as a reference. The resulting calibration can be written as P = −2836/14.3 [(1 + Δλ/685.51)−14.3 − 1]. Previous calibrations based on the internally inconsistent primary scales are revised, and, after appropriate correction, found to agree with the proposed one. The calibration extended to 120 GPa was also performed using corrected previous data and can be written as P = 4.20 Δλ (1 + 0.020 Δλ)/(1 + 0.036 Δλ)

  2. Modulatory effects by neodymium-doped yttrium aluminum garnet laser on fibroblast attachment to single rooted tooth surfaces following ultrasonic scaling and root planning: An in vitro study

    Directory of Open Access Journals (Sweden)

    Shanta Negi

    2015-01-01

    Full Text Available Context: One of the most important goals of periodontal therapy is connective tissue reattachment to previously diseased root surfaces. In the recent years, laser therapy has been considered as an important tool in improving the treatment of periodontal disease. Aims: To evaluate the neodymium-doped yttrium aluminum garnet (Nd: YAG lasers effects on root surfaces affected by periodontal disease and compare this treatment with scaling and root planning (SRP in terms of fibroblast attachment. Materials and Methods: A sample of 30 single-rooted human teeth extracted because of advanced periodontal disease was used in this study. Sixty specimens obtained by longitudinal sectioning were randomly divided in three groups. Group A control (untreated; Group B SRP; Group C laser (Nd: YAG and ultrasonic scaling. All specimens were incubated with fibroblast suspension and then fixed and observed under scanning electron microscope. Results: With a median of 8, the control group (Group A exhibited the least number of total fibroblasts among all the three groups. The laser and scaling - treated group (Group C showed the highest number of fibroblasts (median = 49, mean ± standard deviation [SD] = 48.28 ± 17.18, followed by SRP only (Group B, median = 22, mean ± SD = 22.24 ± 8.67. Conclusions: Nd: YAG laser irradiation at specific energy densities can be used as a useful tool to condition the root surfaces, enhancing fibroblast attachment. Hence aiding in re-establishment of the connective tissue attachment to the root surfaces of previously diseased teeth.

  3. A Comparative Histological Study of Bone Healing in Rat Calvarial Defect Using the Erbium-Doped Yttrium Aluminum Garnet Laser and Rotary Instruments

    Science.gov (United States)

    Jung, Mi-Kyung; Kim, Su-Gwan; Oh, Ji-Su; Jin, Seung-Chan; Lee, Sook-Young; Jang, Eun-Sook; Piao, Zheng-Gang; Lim, Sung-Chul; Jeong, Mi-Ae

    2012-01-01

    Erbium-doped yttrium aluminum garnet (Er:YAG) lasers have been used in dentistry for cutting bone and removal of caries. The purpose of this study was to evaluate the bone healing in a skull defect prepared in rats using various instruments including Er:YAG laser. The 7 mm calvarial defects were created in 45 rats and 45 rats were divided into three groups (n = 15): a high-speed rotation engine with carbide round bur (2-mm diameter), a low-speed rotation engine with carbide round bur (2-mm diameter), and an Er:YAG laser. Specimens obtained after 3 days or 4 or 8 weeks were submitted for histological analysis. Three days after surgery, no bone formation had occurred in any of the groups. Four weeks after surgery, 90 ±8.16% new bone formation was observed in the high-speed group, and 8 weeks after surgery, 100 ±0% new bone formation was observed in the low- and high-speed groups. There were significant differences among the periods after surgery, but no significant differences were observed among final results with in different device groups.

  4. Pupil-occluding organized hyphema anterior to the intraocular lens treated by neodymium: yttrium-aluminum-garnet laser: a case report

    Science.gov (United States)

    Kim, Moosang; Lee, Seung-Jun; Han, Sang Beom; Yang, Hee Kyung; Hyon, Joon Young

    2016-01-01

    We report, to our best knowledge, the first case of treatment of pupil-occluding postoperative organized hyphema anterior to the intraocular lens (IOL) using neodymium: yttrium-aluminum-garnet (Nd:YAG) laser. A 78-year-old Asian female underwent uneventful cataract operation. She had been taking aspirin, which she discontinued 1 week before surgery. Iris prolapse occurred at the end of the surgery, which led to intracameral bleeding. Two weeks later, her best-corrected visual acuity was hand motion. Although hyphema had decreased, pupil-occluding organized hematoma had formed anterior to the IOL. The blood clot anterior to the IOL was removed using Nd:YAG laser. One week later, although the hematoma anterior to the IOL resolved, endocapsular hematoma was observed, which was dispersed with Nd:YAG laser posterior capsulotomy. Two weeks later, her best-corrected visual acuity improved to 20/60. There was no complication associated with Nd:YAG laser. In conclusion, pupil-occluding organized hyphema anterior to the IOL can occur as a complication of cataract surgery, in which Nd:YAG laser can be a useful treatment option. PMID:27462181

  5. Synthesis and photoluminescence properties of cerium-doped terbium-yttrium aluminum garnet phosphor for white light-emitting diodes applications

    Science.gov (United States)

    Wang, Jun; Han, Tao; Lang, Tianchun; Tu, Mingjing; Peng, Lingling

    2015-11-01

    Cerium-doped terbium-yttrium aluminum garnet phosphors were synthesized using the solid-state reaction method. The crystalline phase, morphology, and photoluminescence properties were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), and fluorescence spectrophotometer, respectively. The XRD results indicate that with an increase of the amount of x (Tb3+), all of the samples have a pure garnet crystal structure without secondary phases. The SEM images reveal that the samples are composed of sphere-like crystallites, which exhibit different degrees of agglomeration. The luminescent properties of Ce ions in )Al5O12∶Ce0.1 have been studied, and it was found that the emission band shifted toward a longer wavelength. The redshift is attributed to the lowering of the 5d energy level centroid of Ce, which can be explained by the nephelauxetic effect and compression effect. These phosphors were coated on blue light-emitting diode (LED) chips to fabricate white light-emitting diodes (WLEDs), and their color-rendering indices, color temperatures, and luminous efficiencies were measured. As a consequence of the addition of Tb, the blue LED pumped )Al5O12∶Ce0.1 phosphors WLEDs showed good optical properties.

  6. Efficacy of the q-switched neodymium: Yttrium aluminum garnet laser in the treatment of blue-black amateur and professional tattoos

    Directory of Open Access Journals (Sweden)

    Chembolli Lakshmi

    2015-01-01

    Full Text Available Background: Q-switched neodymium: yttrium aluminum garnet (Nd: YAG laser at a wavelength of 1064 nm primarily targets dermal melanin and black tattoo ink. Recent studies have shown that this laser is effective in treating black tattoos. There are few studies conducted in India for the same. Aim: The aim was to assess the effectiveness of Q-switched Nd: YAG laser (QSNYL in the treatment of blue-black tattoos following 3 treatment sessions. Materials and Methods: This study, a prospective interventional study included a total of 12 blue-black tattoos. Following informed consent for the procedure, as well as for photographs, a questionnaire was administered, and improvement perceived by the patient was recorded. In addition, global assessment score (GAS by a blinded physician was also recorded. Photographs were taken at baseline and at every follow-up. Each patient underwent three treatment sessions with 1064 nm QSNYL at 4-6 weekly intervals. Fluences ranged from 1.8 to 9 J/cm 2 . The follow-up was done monthly for 4 months from the first treatment session. The response was assessed by patient assessment (PA and GAS by comparing photographs. Results: After three treatment sessions, although no patient achieved clearance, most patients showed good response with few adverse effects. An average of 64.1% (GAS and 54.2% (PA improvement was observed in 12 tattoos. Tattoos more than 10-year-old showed quicker clearing than those less than 10-year-old. Amateur tattoos also showed a better response in comparison to professional tattoos. Conclusion: Totally, 1064 nm QSNYL is safe and effective for lightening blue-black tattoos in pigmented Indian skin. All patients achieved near complete clearance following the continuation of treatment (an average of six sessions although this was spaced at longer intervals.

  7. Skin healing and collagen changes of rats after fractional erbium:yttrium aluminum garnet laser: observation by reflectance confocal microscopy with confirmed histological evidence.

    Science.gov (United States)

    Yang, Jing; Wang, Sha; Dong, Liyun; An, Xiangjie; Li, Yan; Li, Jun; Tu, Yating; Tao, Juan

    2016-08-01

    The fractional erbium:yttrium aluminum garnet (Er:YAG) laser is widely applied. Microstructural changes after laser treatment have been observed with histopathology. Epidermal and dermal microstructures have also been analyzed using reflectance confocal microscopy (RCM). However, no studies have compared these two types of microstructural changes in the same subject at multiple time points after irradiation, and it is unclear if these two types of changes are consistent. We use RCM to observe the effect of different laser energies on skin healing and collagen changes in the skin of Sprague-Dawley rats that had been irradiated by fractional Er:YAG lasering at different energies. RCM was used to observe skin healing and detect collagen changes at different time points. Collagen changes were observed using hematoxylin and eosin (H&E) staining and quantitatively analyzed by western blot. RCM showed that, irrespective of laser energy, microscopic treatment zones (MTZs) were larger at 1 day after irradiation. The MTZs then reduced in size from 3 to 7 days after irradiation. The higher the energy, the larger the MTZ area. The amount of collagen also increased with time from 1 day to 8 weeks. However, the increase in the collagen amount on both RCM and H&E staining was not influenced by the laser energy. Western blotting confirmed that the amount of type I and type III collagens increased over time, but there were no significant differences between the different energy groups (p > 0.05). In conclusion, RCM is a reliable technique for observing and evaluating skin healing and collagen expression after laser irradiation. PMID:27272747

  8. Multi-channel transition emissions of Sm3+ in lithium yttrium aluminum silicate glasses and derived opalescent glass ceramics

    International Nuclear Information System (INIS)

    Highlights: • Multi-channel transitions of Sm3+ in aluminosilicate glasses are investigated. • Judd–Ofelt parameters are derived to be 4.12 × 10−20, 4.26 × 10−20 and 2.11 × 10−20 cm2. • Cross-section profiles σem for visible and NIR emissions are calculated by FL formula. • 44.9% internal quantum efficiency and 11.58% external quantum yield are exposed. • Orientational crystallization was observed after the heat-treatment testing. -- Abstract: Sm3+-doped lithium–yttrium–aluminum-silicate (LYAS) glasses have been fabricated and effective visible and near-infrared (NIR) emissions are exhibited. The predicated spontaneous emission probabilities (Arad) are derived to be 29.1, 149.2, 150.1 and 39.0 s−1 for conventional visible emissions assigned to 4G5/2 → 6HJ (J = 5/2, 7/2, 9/2 and 11/2) transitions, and Arad are obtained to be 24.8, 4.6 and 2.7 s−1 for the optical transitions 4G5/2 → 6FJ (J = 5/2, 7/2 and 9/2) corresponding to the NIR emissions, respectively. The maximum stimulated emission cross-sections (σem) are obtained to be 7.45 × 10−22 and 0.48 × 10−22 cm2 for visible (4G5/2 → 6H9/2) and NIR (4G5/2 → 6F9/2) emissions, respectively. Internal quantum efficiency for the 4G5/2 level and external quantum yield for visible emissions of Sm3+ are determined to be 44.9% and 11.58%, respectively. High temperature heat treatment testing was carried out on the LYAS glasses and orientational crystallization was observed. Visible transition emissions of Sm3+ with obvious Stark splitting indicate Sm3+ ions have been introduced into the YAG micro-crystal formed in the glass ceramics. Investigations on multi-channel radiative transition emissions of Sm3+ in LYAS glasses provide a new clue to develop tunable lasers, compact light sources and optoelectronic devices

  9. Efficacy and Safety of 120-W Thulium:Yttrium-Aluminum-Garnet Vapoenucleation of Prostates Compared with Holmium Laser Enucleation of Prostates for Benign Prostatic Hyperplasia

    Directory of Open Access Journals (Sweden)

    Kai Hong

    2015-01-01

    Full Text Available Background: This study compared the efficacy and safety between 120-W thulium:yttrium-aluminum-garnet (Tm:YAG vapoenucleation of prostates (ThuVEP and holmium laser enucleation of prostates (HoLEP for patients with lower urinary tract symptoms (LUTS due to benign prostatic hyperplasia (BPH. Methods: A retrospective analysis of 88 consecutive patients with symptomatic BPH was carried out, who underwent either 120-W ThuVEP or HoLEP nonrandomly. Patient demographics and peri-operative and 12-month follow-up data were analyzed with the International Prostate Symptom Score (IPSS, quality of life (QoL score, maximum flow rate (Qmax, postvoid residual urine volume (PVR, and rates of peri-operative and late complications. Results: The patients in each group showed no significant difference in preoperative parameters. Compared with the HoLEP group, patients in the 120-W ThuVEP group required significantly shorter time for laser enucleation (58.3 ± 12.8 min vs. 70.5 ± 22.3 min, P = 0.003, and resulted in a significant superiority in laser efficiency (resected prostate weight/laser enucleation time for 120-W Tm:YAG laser compared to holmium:YAG laser (0.69 ± 0.18 vs. 0.61 ± 0.19, P = 0.048. During 1, 6, and 12 months of follow-ups, the procedures did not demonstrate a significant difference in IPSS, QoL score, Qmax, or PVR (P > 0.05. Mean peri-operative decrease of hemoglobin in the HoLEP group was similar to the ThuVEP group (17.1 ± 12.0 g/L vs. 15.2 ± 10.1 g/L, P = 0.415. Early and late incidences of complications were low and did not differ significantly between the two groups of 120-W ThuVEP and HoLEP patients (P > 0.05. Conclusions: 120-W ThuVEP and HoLEP are potent, safe and efficient modalities of minimally invasive surgeries for patients with LUTS due to BPH. Compared with HoLEP, 120-W ThuVEP offers advantages of reduction of laser enucleation time and improvement of laser efficiency.

  10. Yttrium-90

    International Nuclear Information System (INIS)

    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

  11. Effect of different pre-heat treatment processes on the hardness of AISI 410 martensitic stainless steels surface-treated using pulsed neodymium-doped yttrium aluminum garnet laser

    International Nuclear Information System (INIS)

    Highlights: → The effect of laser surface treatment on the structure of AISI 410 was studied. → The hardness profile was predicted in the sample depth by the finite element simulation. → Laser surface treatment is an effective approach to improve the ferrite hardness. → Laser surface treatment has less positive effects on increasing the martensite hardness. -- Abstract: AISI 410 martensitic stainless steel (MSS) samples were conventionally heat treated in diverse quenching environments to obtain three different microstructures: fine ferrite, fine and coarse martensite. Furthermore, laser surface treatment (LST) was done by pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) laser to compare the effect of short-term diffusion on the hardness of the different microstructures. The microstructure and microhardness of the samples were investigated by means of an optical microscope and Vickers microhardness tester respectively. Moreover, finite element simulation was done using ABAQUS finite element software to predict cooling curves and temperature histories at different depths of workpiece and to calculate the depth of fully hardened and partially hardened material. A comparison between theoretical and experimental results showed a good conformity and that LST is an effective approach to improve the hardness of the ferrite, despite the coarse and fine martensite phases.

  12. Induction of melasma by 1064-nm Q-switched neodymium:yttrium-aluminum-garnet laser therapy for acquired bilateral nevus of Ota-like macules (Hori nevus): A study on related factors in the Chinese population.

    Science.gov (United States)

    Wang, Ben; Xie, Hong-Fu; Tan, Jun; Xie, Hong-Ju; Xu, Lin-Yong; Ding, Rong; Liu, Fang-Fen; Chen, Xiang; Jian, Dan; Li, Ji

    2016-06-01

    Laser treatment has emerged as a common treatment modality for acquired bilateral nevus of Ota-like macules (ABNOM). To identify the ratio of melasma induction and exacerbation before and after laser therapy for ABNOM and to observe the risk factors related to the induction and exacerbation of melasma by laser therapy, we analyzed related factors of 1268 adult Chinese patients who underwent 1064-nm Q-switched neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (QNYL) treatment using case series and case-control studies. Overall, 24.0% of the ABNOM patients had mixed melasma. Among the ABNOM patients without melasma, after laser therapy the development of melasma was more frequently noted in patients older than 35 years (P light (similar to yellow-brown) in color (P = 0.021) and skin types were closer to type IV (P < 0.0001). New melasma lesions also appeared most frequently in the zygomatic region (P < 0.0001). Among the ABNOM patients with melasma, 89.5% experienced worsening of their melasma, irrespective of their related factors above. We concluded that the risk of inducing melasma is great after 1064-nm QNYL treatment in ABNOM patients, and particularly in the patients with both ABNOM and melasma. ABNOM patients should be treated as early as possible and before the age of 35 years. PMID:26777390

  13. Effect of Yttrium Aluminum Garnet on High-Temperature Properties of Alumina-Based Ceramic Cores%钇铝石榴石对氧化铝基陶瓷型芯高温性能的影响

    Institute of Scientific and Technical Information of China (English)

    徐东阳; 李涤尘; 吴海华; 邢建东; 孙博

    2011-01-01

    开发了一种钇溶胶为强化剂、通过真空压力浸渍强化处理改善氧化铝基陶瓷型芯高温性能的新工艺.研究了浸渍工艺对陶瓷型芯高温性能的影响,利用x射线衍射和SEM分析了陶瓷型芯相组成及其断口形貌.实验结果表明高温性能随着浸渍次数的增加而得到明显地改善.三次浸渍强化后,高温挠度从7.38 mm降低至0.72 mm,高温抗弯强度(1550℃)从0.95MPa提高至4.6lMPa,而显气孔率仍保持在40%以上,保证了脱芯工艺性.X射线衍射分析表明真空压力浸渍之后增加了陶瓷型芯中耐高温强化相-钇铝石榴石的含量,SEM观察也证实了这一点.%A new strengthening process was developed to improve the high-temperature properties of alumina-based ceramic cores by vacuum pressure impregnation (VPI) with yttrium sol as reinforcing agent. The experimental results showed that the high-temperature properties of the cores were improved significantly as impregnating times increasing. After three times impregnation strengthening, the deformation at 1550℃/0.5h decreased from 7.38 mm to 0. 72 mm and the flexural strength at 1550℃ increased from 0.95MPa to 4.61 MPa. Meanwhile the apparent porosity still kept above 40% to guarantee the core leach property. X-ray diffraction revealed that the content of YAG( yttrium aluminum garnet, a high-temperature strengthening phase)was increased through VPI, which was obviously observed by SEM.

  14. Effects of two erbium-doped yttrium aluminum garnet lasers and conventional treatments as composite surface abrasives on the shear bond strength of metal brackets bonded to composite resins

    Science.gov (United States)

    Sobouti, Farhad; Dadgar, Sepideh; Sanikhaatam, Zahra; Nateghian, Nazanin; Saravi, Mahdi Gholamrezaei

    2016-01-01

    Background: Bonding brackets to dental surfaces restored with composites are increasing. No studies to date have assessed the efficacy of laser irradiation in roughening of composite and the resulted shear bond strength (SBS) of the bonded bracket. We assessed, for the 1st time, the efficacy of two laser beams compared with conventional methods. Materials and Methods: Sixty-five discs of light-cured composite resin were stored in deionized distilled water for 7 days. They were divided into five groups of 12 plus a group of five for scanning electron microscopy (SEM): Bur-abrasion followed by phosphoric acid etching (bur-PA), hydrofluoric acid conditioning (HF), sandblasting, 3 W and 2 W erbium-doped yttrium aluminum garnet laser irradiation for 12 s. After bracket bonding, specimens were water-stored (24 h) and thermocycled (500 cycles), respectively. SBS was tested at 0.5 mm/min crosshead speed. The adhesive remnant index (ARI) was scored under ×10 magnification. SEM was carried out as well. Data were analyzed using analysis of variance (ANOVA), Kruskal–Wallis, Tukey, Dunn, one-sample t-test/Wilcoxon tests, and Weibull analysis (α =0.05). Results: The SBS values (megapascal) were bur-PA (11.07 ± 1.95), HF (19.70 ± 1.91), sandblasting (7.75 ± 1.10), laser 2 W (15.38 ± 1.38), and laser 3 W (20.74 ± 1.73) (compared to SBS = 6, all P = 0.000). These differed significantly (ANOVA P = 0.000) except HF versus 3 W laser (Tukey P > 0.05). ARI scores differed significantly (Kruskal–Wallis P = 0.000), with sandblasting and 2 W lasers having scores inclined to the higher end (safest debonding). Weibull analysis implied successful clinical outcome for all groups, except for sandblasting with borderline results. Conclusion: Considering its high efficacy and the lack of adverse effects bound with other methods, the 3 W laser irradiation is recommended for clinical usage. PMID:26998473

  15. An in vitro evaluation of the responses of human osteoblast-like SaOs-2 cells to SLA titanium surfaces irradiated by erbium:yttrium-aluminum-garnet (Er:YAG) lasers.

    Science.gov (United States)

    Ayobian-Markazi, Nader; Fourootan, Tahereh; Zahmatkesh, Atieh

    2014-01-01

    Erbium:yttrium-aluminum-garnet (Er:YAG) laser treatment is an effective option for the removal of bacterial plaques. Many studies have shown that Er:YAG lasers cannot re-establish the biocompatibility of titanium surfaces. The aim of this study was to evaluate the responses of the human osteoblast-like cell line, SaOs-2, to sand-blasted and acid-etched (SLA) titanium surface irradiation using different energy settings of an Er:YAG laser by examining cell viability and morphology. Forty SLA titanium disks were irradiated with an Er:YAG laser at a pulse energy of either 60 or 100 mJ with a pulse frequency of 10 Hz under water irrigation and placed in a 24-well plate. Human osteoblast-like SaOs-2 cells were seeded onto the disks in culture media. Cells were then kept in an incubator with 5% carbon dioxide at 37 °C. Each experimental group was divided into two smaller groups to evaluate cell morphology by scanning electron microscope and cell viability using 3-4,5-dimethylthiazol 2,5-diphenyltetrazolium bromide test. In both the 60 and the 100 mJ experimental groups, spreading morphologies, with numerous cytoplasmic extensions, were observed prominently. Similarly, a majority of cells in the control group exhibited spreading morphologies with abundant cytoplasmic extensions. There were no significant differences among the laser and control groups. The highest cell viability rate was observed in the 100 mJ laser group. No significant differences were observed between the cell viability rates of the two experimental groups (p = 1.00). In contrast, the control group was characterized by a significantly lower cell viability rate (p Treatments with an Er:YAG laser at a pulse energy of either 60 or 100 mJ do not reduce the biocompatibility of SLA titanium surfaces. In fact, modifying SLA surfaces with Er:YAG lasers improved the biocompatibility of these surfaces. PMID:23179305

  16. Optical Properties of Irradiated Yttrium Aluminum Garnet

    International Nuclear Information System (INIS)

    The results of investigation of the photoluminescence (PL) and optical absorption of crystals Y3Al5O12(YAG) doped with different concentrations of manganese ions exposed to fast neutron irradiation and electron irradiation are presented. Photoluminescence spectra of YAG before neutron irradiation at T=80 K contain fine lines in orange region of spectrum, ascribed to Mn2+ ions in octahedral position. After irradiation band broadening is observed in the luminescence spectra of garnet crystals. Electron irradiation produced broad band with a complex structure related to Mn4+ ions. Exchange interaction between radiation defect and impurity ions during neutron irradiation and electron irradiation leads to appearance of additional lines and luminescence bands broadening in investigated crystals.

  17. Nd:YAG激光治疗急性局限性智齿冠周炎的临床观察%Clinical observation on treatment of acute wisdom tooth pericoronitis with neodymium:Yttrium-Aluminum-garnet Laser

    Institute of Scientific and Technical Information of China (English)

    栗洪师; 李冬霞; 柯杰

    2015-01-01

    目的:观察口腔钕激光(neodymium:yttrium-aluminum-garnet,Nd:YAG)治疗急性局限性智齿冠周炎的临床疗效。方法:选取114例急性局限性智齿冠周炎患者,局部用3%过氧化氢和生理盐水交替冲洗后棉球擦干,随机分为3组,A组Nd:YAG激光组(n=38):Nd:YAG激光低强度治疗(LLLT)模式,具体选择参数:MSP,1.5 W,100 mJ,15 Hz,非接触局部移动照射病变区肿胀软组织10 min,B组(n=38):局部肿胀龈袋注人适量盐酸米诺环素软膏1次;C组(n=38):局部龈袋置入2%碘甘油,1次/d×3 d。所有治疗组均未全身用药,第4 d观察疗效。结果:和C组比较,A,B组局部炎性肿胀症状均有明显改善,总有效率分别为89.47%和78.95%,A,B两组间疗效无显著性差异(P>0.05)。 A, B组的疗效均显著好于C组(P<0.01;P<0.05.);与B,C组比较,A组患者自觉疼痛明显减轻(P<0.01)。结论:Nd:YAG激光治疗急性局限性智齿冠周炎具有较好临床疗效。%Objective:To study the efficacy of neodymium:yttrium- aluminum-garnet laser of curing acutewisdom tooth pericoronitis,comparing with iodine glycerine. Method:57 cases of acute wisdom tooth pericoronitis were selected and randomly separated into 3 groups,whose local parts were washed with 3 % hydrogen peroxide,and physiological saline consecutively,and dried clearly. For patients in group A test sides were treated with the Nd:YAG laser(1064 nm,MSP,1.5 W,100 mJ,15 Hz). Clinical assessments (total effective rate of local treatment and visual analog scale of pain) were performed pre-treatment and at 4 days post treatment,B,minocycline hydrochloride ointment was injected on their infected areas once. Patients in Group C were treated with 2%iodine glycerine once everyday in 3 days. Efficacy of all experimental treatments were observed at the 4th day. Result:The symptoms of group A an

  18. Dislocations in yttrium orthovanadate

    Science.gov (United States)

    Eakins, D. E.; LeBret, J. B.; Norton, M. G.; Bahr, D. F.

    2004-06-01

    Dislocation structures in single crystals of yttrium orthovanadate have been identified by transmission electron microscopy. Electron diffraction was used to predict possible Burgers vectors for the dislocations. Results suggest vectors of the type {1}/{2}[1 1 1] or {1}/{4}[0 2 1] . Arguments for the likelihood of each possible vector have been presented.

  19. Yttrium-90 - ED 4310

    International Nuclear Information System (INIS)

    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)

  20. Preliminary results on a new method for producing yttrium phosphorous microspheres

    International Nuclear Information System (INIS)

    This paper reports on a new method to embed phosphorus particles into the matrix of yttrium aluminum silicate microspheres. Yttrium phosphorus glass microspheres about 20 µm in size were obtained when an aqueous solution of YCl3 and AlCl3 were added to tetraethyl orthosilicate (TEOS) (phosphoric acid was used to catalyze the hydrolysis and condensation of TEOS) and was pumped into silicone oil under constant stirring. The shapes of the particles produced by this method are regular and nearly spheric in shape. Paper chromatography was used to determine the radiochemical impurity of radioactive microspheres. Radionuclide purity was determined using a gamma spectrometry system and an ultra-low level liquid scintillation spectrometer. The P+ ions implantation stage was eliminated by embedding phosphorus particles in the matrix of the glass microspheres. This paper shows that a high temperature is not required to produce yttrium phosphorus aluminum silicate microspheres. The result shows that the silicone oil spheroidization method is a very suitable way to produce yttrium phosphorus glass microspheres. The topographical analysis of microspheres shows that the Y, P, Si, and Al elements are distributed in the microspheres and the distribution of elements in the samples is homogenous. - Highlights: • A new way to production of phosphorus yttrium aluminum silicate microspheres is reported. • In the new way the requiring high temperature is eliminated. • The glass plate crushing stage is eliminated. • In this paper we could eliminate P+ ion implantation stage by embedding of phosphorus particles in the matrix of glass microspheres

  1. 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...

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

    International Nuclear Information System (INIS)

    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)

  3. The reaction of yttrium-aluminium garnet with t-zirconia

    International Nuclear Information System (INIS)

    The reaction of 6 mol% Y2O3 stabilized tetragonal zirconia (t-ZrO2) with yttrium-aluminum garnet (Y3Al5O12, YAG) was studied at temperatures between 1200 degrees C and 1625 degrees C. Reaction couples were made from polished 0.2 μm grain size plates of hot-pressed Tosoh TZ-3Y t-ZrO2 with 6 mol% yttria. Some plates were not pressed under vacuum in carbon dies with YAG powder prepared from yttrium and aluminum alkoxides. Other plates were coated with a metal alkoxide derived YAG sol or coated by laser vapor deposition of YAG, and then heat-treated in air in a Netzsch thermogravimetric furnace. The reaction products and microstructures are characterized by optical microscopy, scanning electron microscopy and transmission electron microscopy with energy dispersive spectrometry

  4. Biosorption of scandium and yttrium from solutions

    International Nuclear Information System (INIS)

    The usage of biosorbents allows separation of scandium and yttrium from each other and from Fe, Al, Ti, Si, and Ca in hydrometallurgical processing of ores and wastes. It was shown that sorption of scandium and yttrium increased with the increase of pH of solution. Initial rate of scandium sorption depended on the biomass type; however 85-98% of scandium was sorbed within 10-30 min with most biomass types tested. The presence of aluminium, iron (III), and titanium in the solution inhibited sorption of scandium and particularly yttrium. After four cycles of sorption, 98.8% of scandium and 87% of yttrium was extracted from red mud leach solution by the biomass of Saccharomyces cerevisiae and Aspergillus terreus, respectively. Selectively of the process of scandium and yttrium recovery could be achieved during sorption and also desorption, when solubilization of sorbed associated elements was inhibited by high pH values. (Author)

  5. Amorphous yttrium-iron alloys

    International Nuclear Information System (INIS)

    The magnetic properties of amorphous yttrium-iron alloys Ysub(1-x)Fesub(x) have been studied over a wide concentration range 0.32 2Fe17 alloys, lead in the amorphous state to spin-glass behaviour and asperomagnetic order. The dominant positive interactions produce short-range ferromagnetic correlations which persist up to room temperature. However magnetic saturation cannot be achieved for any of the alloys in applied fields of up to 180 kOe, indicating that strong negative interactions are also present. Exchange interactions become increasingly positive with increasing x, and the magnetic properties of iron-rich alloys approach those of a normal ferromagnet. (author)

  6. Scintillation properties of Yb-doped yttrium-aluminum garnets

    International Nuclear Information System (INIS)

    Relative light yield (LY) dependence on temperature for Yb:YAG crystals containing 10% to 100% of Yb dopant is studied for γ and α excitation. The maximum LY is achieved at 120 K3 Ph/MeV at T=140 K for (Yb 25%) YAG. Linearity of the light output is checked. α/γ ratio is found to be 0.42±0.02. Pulse shapes induced by γ and α particles and cosmic rays are investigated by analysing a set of single events recorded. γ events are fast (τ<4 ns), while other kinds of radiation give rise to more complicated and longer profiles, allowing particle discrimination. Dependence of scintillation properties on concentration of Yb and purity is discussed

  7. Preparation and characterization of phosphorus yttrium glass microspheres for radiotherapy applications

    International Nuclear Information System (INIS)

    Full text:Phosphorus yttrium microspheres show promising results in the treatment of cancers. However, phosphorus can be a problem in some types of glasses because it usually plays an important role in the nucleation of crystalline phases, as observed for some silicate glasses.In the previous works P+ ions were implanted in Y2O3-Al2O3-SiO2 glasses at 50-200 keV by an ion implanter. In this paper the novel method to embedding of phosphorus particles into the matrix of yttrium aluminum silicate microspheres is reported. Yttrium phosphorus glass microspheres around 20 μm in size when aqueous solution of YCl3 and AlCl3 was added in to TEOS, phosphoric acid was used to catalyze the hydrolysis and condensation of tetraethyl orthosilicate and pumped in to stirred silicon oil were obtained. The shapes of particles produced by this method are regular and very close to spheres. The amorphous structure, PO43- and Si-O bands, spherical shapes and composition investigated by using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-Ray Fluorescence Spectroscopy (XRF) and the Carbon / Sulfur Determinator, respectively. The result shows that the silicone oil spherodization method can be greatly suitable way to production of yttrium phosphorus glass microspheres. In this paper we could eliminate P+ ion implantation stage by embedding of phosphorus particles in the matrix of glass microspheres. Also this paper shows that the high temperature is not required to production of yttrium phosphorus aluminum silicate microspheres.

  8. Electronic transitions of yttrium monophosphide

    Science.gov (United States)

    Li, Biu Wa; Chan, Man-Chor; Cheung, A. S.-C.

    2015-11-01

    The electronic transition spectrum of the yttrium monophosphide (YP) molecule in the near infrared region between 715 nm and 880 nm has been recorded using laser ablation/reaction free-jet expansion and laser induced fluorescence spectroscopy. The YP molecule was produced by reacting laser - ablated yttrium atoms with PH3 gas seeded in argon. Eleven vibrational bands were analyzed and six electronic transitions have been identified, namely the [12.17] Ω = 3 - X3Π2, [13.27] Ω = 3 - X3Π2, [13.44] Ω = 3 - X3Π2, [13.46] Ω = 3 - X3Π2 and [13.40] Ω = 2 - X3Π2 transitions and a [13.69] Ω = 3 - a1Δ2 transition. Least squares fits of the measured rotational lines yielded molecular constants for the ground and excited states. The ground state has been determined to be a X3Π2 state and the bond length ro and vibrational separation, ΔG1/2, were determined to be 2.4413 Å and 390.77 cm-1 respectively. A molecular orbital energy level diagram has been used to aid the assignment of the observed electronic states. This work represents the first experimental investigation of the electronic spectrum of the YP molecule.

  9. 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.

  10. Low-aluminum content iron-aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Goodwin, G.M.; Alexander, D.J. [and others

    1995-06-01

    The low-aluminum-content iron-aluminum program deals with the development of a Fe-Al alloy with aluminum content such as a produce the minimum environmental effect at room temperature. The FAPY is an Fe-16 at. % Al-based alloy developed at the Oak Ridge National Laboratory as the highest aluminum-containing alloy with essentially no environmental effect. The chemical composition for FAPY in weight percent is: aluminum = 8.46, chromium = 5.50, zirconium = 0.20, carbon = 0.03, molybdenum = 2.00, yttrium = 0.10 and iron = 83.71. The ignots of the alloy can be hot worked by extrusion, forging, and rolling processes. The hot-worked cast structure can be cold worked with intermediate anneals at 800{degrees}C. Typical room-temperature ductility of the fine-grained wrought structure is 20 to 25% for this alloy. In contrast to the wrought structure, the cast ductility at room temperature is approximately 1% with a transition temperature of approximately 100 to 150{degrees}C, above which ductility values exceed 20%. The alloy has been melted and processed into bar, sheet, and foil. The alloy has also been cast into slabs, step-blocks of varying thicknesses, and shapes. The purpose of this section is to describe the welding response of cast slabs of three different thicknesses of FAPY alloy. Tensile, creep, and Charpy-impact data of the welded plates are also presented.

  11. Rare earths, the lanthanides, yttrium and scandium

    Science.gov (United States)

    Hedrick, J.B.

    2006-01-01

    In 2005, rare earths were not mined in the United States. The major supplier, Molycorp, continued to maintain a large stockpile of rare-earth concentrates and compounds. Consumption decreased of refined rare-earth products. The United States remained a major importer and exporter of rare earths in 2005. During the same period, yttrium was not mined or refined in the US. Hence, supply of yttrium compounds for refined yttrium products came from China, France and Japan. Scandium was not also mined. World production was primarily in China, Russia and Ukraine. Demand for rare earths in 2006 is expected to be closely tied to economic conditions in the US.

  12. Absolute measurements of fast neutrons using yttrium

    International Nuclear Information System (INIS)

    Yttrium is presented as an absolute neutron detector for pulsed neutron sources. It has high sensitivity for detecting fast neutrons. Yttrium has the property of generating a monoenergetic secondary radiation in the form of a 909 keV gamma-ray caused by inelastic neutron interaction. It was calibrated numerically using MCNPX and does not need periodic recalibration. The total yttrium efficiency for detecting 2.45 MeV neutrons was determined to be fn∼4.1x10-4 with an uncertainty of about 0.27%. The yttrium detector was employed in the NX2 plasma focus experiments and showed the neutron yield of the order of 108 neutrons per discharge.

  13. Rare earth elements: Yttrium and higher plants

    Directory of Open Access Journals (Sweden)

    Kastori Rudolf R.

    2010-01-01

    Full Text Available Rare earth elements (REEs form a chemically uniform group with very similar physical and chemical properties. The REEs include the elements scandium, yttrium, and the lanthanides from lanthanum to lutetium. They are widely distributed and present in all parts of the biosphere. REEs are required in industry, agriculture, medicine, biotechnology, environmental problems and many other fields. Lately, many experiments show their positive or negative, first of all nonspecific, effect on life processes of higher plants as well as growth and yield of cultivated species, but the physiological mechanisms are still not well understood. It has been determined that yttrium is widely distributed in plants, as well as that certain plant species uptake yttrium at different extent. Its highest accumulation is in the root and the leaf. Although yttrium was discovered more than two centuries ago, its effect on higher plants - their anatomical and morphological built, physiological and biochemical processes etc. - is very little known. One of the basic reasons is that yttrium, as well as other REEs elements, according to current knowledge, is not biogenic for higher plants and - wider - for live organisms. The objective of this paper is to concisely show previous knowledge about yttrium in the plant world.

  14. Aluminum Hydroxide

    Science.gov (United States)

    Aluminum hydroxide is used for the relief of heartburn, sour stomach, and peptic ulcer pain and to ... Aluminum hydroxide comes as a capsule, a tablet, and an oral liquid and suspension. The dose and ...

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

    International Nuclear Information System (INIS)

    Mass synthesis of nano-phase Yttrium Oxide (Y2O3) from commercially available coarse grain powder is reported. Nano-sized high purity Y2O3 is an important and critical constituent of ceramics like YAG (Yttrium aluminum garnet: Y3Al5O12) 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

  16. 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.

  17. 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...

  18. Concentration of yttrium subgroup impurities in high-purity yttrium oxide by TBP-NH4SCN extraction chromatography

    International Nuclear Information System (INIS)

    Separation factors for all the yttrium subgroup elements and yttrium, extracted with TBP from 0.45 M NH4SCN solution at 24 to 42 deg have been determined and found to be >= 1.9. Eight yttrium subgroup impurities in high-purity yttrium oxide have been concentrated by means of TBP-NH4SCN extraction chromatography at 32 deg before spectroscopic determination. Analysis of one real sample and two synthetic samples gave average recoveries of 80 to 100%. (author)

  19. Synthesis and characterization of complex composite oxides of aluminium, titanium and yttrium materials

    International Nuclear Information System (INIS)

    The aluminium, titanium and yttrium composite oxide materials such as tialite (Al/sub 2/TiO/sub 5/) and YAG (Yttrium aluminium garnet, Y/sub 3/Al/sub 5/O/sub 12/) were synthesized by sol spray process and sintered at different temperatures (900-1650 deg. C). YAG is important material for solid state laser which is widely used in luminescence systems, window materials for a variety of lamps and fiber-optics telecommunication systems. The aim of this study was to determine the feasibility of process for the growth of nano sized YAG and Nd-YAG powders. Phase and microstructural analysis of sintered materials were performed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). SEM images of sintered specimens of tialite are shown. XRD and SEM results revealed that crystallization of YAG started around 920 deg. C. The synthesized products had composition uniformity, lower residual oxide, cubic phase with a ratio of yttrium, aluminum and oxygen close to 3:5:12 (Y/sub 2.97/ Al 5.03 O 11.85). Scanning electron microscope results indicated that particle size of Nd-YAG was <150 nm. The morphology of Nd-YAG nano sized powder was rounded. (Orig./A.B.)

  20. 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.

  1. Yttrium doped BSCF membranes for oxygen separation

    DEFF Research Database (Denmark)

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

    2011-01-01

    BSCF (x = 0) membrane. This was attributed to the combined effect of the formation of a greater number of oxygen vacancies, together with improved ion mobility, associated with the beneficial yttrium substitution into the BSCF perovskite structure which stemmed from the crystal lattice expansion....

  2. Band gap, band offsets and dielectric constant improvement by addition of yttrium into lanthanum aluminate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z.Q. [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Chim, W.K., E-mail: elecwk@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Chiam, S.Y., E-mail: chiamsy@imre.a-star.edu.sg [Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Pan, J.S. [Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Ng, C.M. [GLOBALFOUNDRIES Singapore Pte. Ltd, 60 Woodlands Street 2, Singapore 738406 (Singapore)

    2013-05-01

    We studied the effects of adding yttrium (Y) in bulk lanthanum aluminate (LaAlO{sub 3} or LAO) by investigating the quaternary compound oxide, lanthanum yttrium aluminum oxide La{sub 0.3}Y{sub 0.7}AlO{sub 3} (LYAO), on silicon (Si). It is found that the inclusion of Y to LAO increases the band gap by ∼ 0.9 eV without compromising the dielectric constant. The enhancement in the band gap results in larger band offsets in LYAO and we also observe a decrease in leakage current at low voltage accumulation bias for Al/LYAO/Si as compared to Al/LAO/Si. In addition, the interface trap density of the Al/LYAO/Si structure remains comparable to that of Al/LAO/Si. Our findings show that LYAO is an attractive high dielectric constant material for use in next-generation low standby power devices. - Highlights: • We studied the inclusion of yttrium in LaAlO{sub 3} by investigating La{sub 0.3}Y{sub 0.7}AlO{sub 3} on Si. • Inclusion of yttrium in LaAlO{sub 3} (LAO) increases the band gap by 0.9 eV. • Enhancement in the band gap results in larger band offsets in La{sub 0.3}Y{sub 0.7}AlO{sub 3} (LYAO). • Decrease in leakage current at low voltage for Al/LYAO/Si compared to Al/LAO/Si. • LYAO is an attractive high-k material for low standby power devices.

  3. Band gap, band offsets and dielectric constant improvement by addition of yttrium into lanthanum aluminate

    International Nuclear Information System (INIS)

    We studied the effects of adding yttrium (Y) in bulk lanthanum aluminate (LaAlO3 or LAO) by investigating the quaternary compound oxide, lanthanum yttrium aluminum oxide La0.3Y0.7AlO3 (LYAO), on silicon (Si). It is found that the inclusion of Y to LAO increases the band gap by ∼ 0.9 eV without compromising the dielectric constant. The enhancement in the band gap results in larger band offsets in LYAO and we also observe a decrease in leakage current at low voltage accumulation bias for Al/LYAO/Si as compared to Al/LAO/Si. In addition, the interface trap density of the Al/LYAO/Si structure remains comparable to that of Al/LAO/Si. Our findings show that LYAO is an attractive high dielectric constant material for use in next-generation low standby power devices. - Highlights: • We studied the inclusion of yttrium in LaAlO3 by investigating La0.3Y0.7AlO3 on Si. • Inclusion of yttrium in LaAlO3 (LAO) increases the band gap by 0.9 eV. • Enhancement in the band gap results in larger band offsets in La0.3Y0.7AlO3 (LYAO). • Decrease in leakage current at low voltage for Al/LYAO/Si compared to Al/LAO/Si. • LYAO is an attractive high-k material for low standby power devices

  4. Orientation relationships between complex low symmetry oxides: Geometric criteria and interface structure for yttrium aluminate eutectics

    International Nuclear Information System (INIS)

    Solidified eutectics of yttrium-aluminum perovskite (YAP)-yttrium-aluminum monoclinic (YAM) and YAM-yttria were observed by transmission electron microscopy and by optical microscopy. Orientation relationships (ORs), interphase boundary orientations and some boundary structures were determined and compared to those predicted by various geometric criteria. Six ORs were found in YAP-YAM and two were found in YAM-yttria. Near-coincidence site lattices (NCSLs) were calculated for each eutectic. OR predictions based on NCSL energy minimization were compared to NCSLs for the observed ORs. Predictions by symmetry overlap criteria and the edge-to-edge model were also compared to observations. All common ORs had coincident low-index real-space lattice vectors that were consistent with predictions of the edge-to-edge model. Three of these ORs had matching planes cozonal with the coincident real-space directions that were consistent with the edge-to-edge model. Issues with application of geometric criteria to interphase boundaries between complex, low symmetry materials are discussed

  5. Magnetic structure of holmium-yttrium superlattices

    DEFF Research Database (Denmark)

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

    1993-01-01

    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 to the......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...

  6. Extraction of yttrium group rare earth and yttrium(3) nitrates with tri-n-butylphosphates from multicomponent solutions

    International Nuclear Information System (INIS)

    Extraction of yttrium group rare earth metals(3) nitrate and yttrium(3) nitrate from multicomponent solutions of tri-n-butylphosphate at T = 298.15 K and pH 2 was considered. Physicochemical and mathematical models describing distribution of lanthanides (samarium-lutetium) and yttrium(3) in the multicomponent solutions, depending on total concentration of rare earth metal ions in aqueous solution and composition of concentrates, are presented

  7. Synthesis and structural characterisation of an yttrium-alkyl-alkylidene

    OpenAIRE

    Arnold, Polly; Green, J. C.; McMaster, J; Liddle, S.T.

    2008-01-01

    The first structurally authenticated yttrium-alkyl-alkylidene is reported; structural, spectroscopic, and theoretical analyses show that whilst the yttrium-alkylidene bond is short, it possesses a bond order less than one and is comparable to the Y-C-alkyl single bond within the same molecule.

  8. The peculiarities of scandium and yttrium dissolution in aluminium melt

    International Nuclear Information System (INIS)

    The investigation results of dissolution of scandium and yttrium in liquid aluminium at 973-1173 K are presented in this work. It was shown that coefficient value of yttrium diffusion in aluminium melt equals to 3,566-17,9070 m2/sec, and scandium 9,692-4,072 m2/sec.

  9. 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.

  10. The Purification of Yttrium by Extraction

    International Nuclear Information System (INIS)

    The purification of yttrium by extraction process in the solution of nitric acid rare earth with di-(2-ethylhexyl)-phosphoric acid (HDEHP) have been investigated. Feed as nitric acid rare earth solution was prepared by method digestion of xenotime sand. The contents of yttrium (Y), lanthanum (La), and cerium (Ce) rare earth were analyzed using X-ray fluorescence. The purification was done by liquid-liquid extraction process from the feed mixture of rare earth. Variable that effect the distribution of rare earth as function of concentration of nitric acid in the aqueous phase, the concentration of organic phase in kerosene, and time of extraction. The best results at the separation was obtained as follows : concentration of nitric acid = 0.5 M, the concentration of organic phase = 30% di-(2-ethylhexyl)-phosphoric acid in kerosene, and time of extraction = 15 minutes. At this condition were the value of the separation factor of Y-La 126.9403 and separation factor of Y-Ce = 89.7923. (author)

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

    International Nuclear Information System (INIS)

    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

  12. Reversible chain transfer between organoyttrium cations and aluminum: Synthesis of aluminum-terminated polyethylene with extremely narrow molecular-weight distribution

    OpenAIRE

    Kretschmer, Winfried P.; Meetsma, Auke; Hessen, Bart; Schmalz, Thomas; Qayyum, Sadaf; Kempe, Rhett

    2006-01-01

    Aminopyridinato-ligand-stabilized organoyttrium cations are accessible in very good yield through alkane elimination from trialkyl yttrium complexes with sterically demanding aminopyridines, followed by abstraction of one of the two alkyl functions using ammonium borates. At 80 degrees C and in the presence of small amounts of aluminum alkyl compounds, very high ethylene polymerization activities are observed if very bulky aminopyridinato ligands are used. During these polymerizations a rever...

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

    International Nuclear Information System (INIS)

    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 (R4N)2[Ln(NO3)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

  14. Synthesis, formation and stability of yttrium disilicate

    International Nuclear Information System (INIS)

    The disilicates such as TR2Si2O7 (TR= rare earth and Y) show particulars magnetic, electric and optical proprieties. In the case of yttrium disilicate (Y2Si2O7) its phases (Y,α, β,γ,δ) have been studied very much by many authors showing that is not easy to gain stable phases, wherein high temperatures and time are used to stabilize them. In this work, Y2Si2O7 was synthesized by a low cost and simpler hydrothermal method developed by our group. The precursor was treated thermally in the temperature range of 900-1400°C to form different polymorphic phases, being characterized by X-ray Diffraction (XRD), Scanning Electronic Microscopy (SEM) and Photon Correlation Spectroscopy (PCS). The XRD results show by the following synthesis method is possible to form stable phases apart from 1000°C. (author)

  15. Yttrium-90 Radiolabelling of Biotin DOTA

    International Nuclear Information System (INIS)

    Yttrium-90 1,4,7,10-tetraazacyclododecane 1,4,7,10-tetraacetic acid (DOTA) biotin was prepared by adding an equal volume of sodium acetate (1.0M, pH5.0) to the 90YCl3 vial (concentration 37–74 GBq/mL in 0.05M HCl) containing 2.96–4.44 GBq of 90Y followed by 1.0 mg of biotin DOTA dissolved in 0.5 mL of saline (recommended specific activity of 3.7 GBq/mg). After mixing, the reaction vial was incubated for 30 min at 95°C. Aliquots of the mixture were drawn at defined time intervals to determine the radiochemical purity (RCP)

  16. Radiolabeling Of Albumin Particles With Yttrium-90

    International Nuclear Information System (INIS)

    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 90Sr/90Y 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 Rf of 0.9-1.0 and the radiolabeled albumin particles remains at the point of origin (Rf = 0). The size of 90Y-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 90Y- albumin is an ideal radiopharmaceutical for potential use in malignant cancer treatment as brachytherapy. (author)

  17. Yttrium oxide coatings for high power lasers at 351 nm

    International Nuclear Information System (INIS)

    Yttrium oxide has proven to be a useful coating material for high power UV lasers. In combination with silicon dioxide it produces an effective dual wavelength antireflection coating at 351 and 1054 nanometers which has good resistance to damage at both wavelengths. While a durable coating material, yttrium oxide may be removed safely from a lightly damaged optic and reapplied. Index inhomogeneity of the material is investigated as well as modification of the film structure with ion-assisted deposition

  18. Influences of Yttrium on Cyclic Oxidation Behavior of Fe-Cr-Al Alloy

    Institute of Scientific and Technical Information of China (English)

    辛丽; 李美栓; 钱余海; 李铁藩

    2001-01-01

    The 1100 ℃ cyclic oxidation behavior of Fe-23Cr-5Al alloy modified by yttrium was studied. Yttrium was added to this alloy in the form of (1) metallic addition, (2) yttrium oxide dispersion and (3) ion implantation. Cracking and spalling occurred on the convoluted scale formed on Y-free alloy and the substrate was exposed. A flat dense scale without spallation was formed on the yttrium alloying addition or yttrium oxide dispersion alloy. Spallation mainly occurred between two layers of the scale on the 1×1017Y ions/cm2-implanted alloy. The results indicate the main reason that the adhesion of alumina scale was improved by yttrium addition lies in that yttrium is liable to form a stable yttrium sulfide with sulfur in the alloy and prevent sulfur interface segregation. Another reason is that the growth mechanism of alumina scale was changed by yttrium addition.

  19. Neurobehavioral Assessment of Rats Exposed to Yttrium Nitrate during Development

    Institute of Scientific and Technical Information of China (English)

    LI Chen Xi; MA Chuan; FANG Hai Qin; ZHI Yuan; YU Zhou; XU Hai Bin; JIA Xu Dong

    2015-01-01

    Objective The aim of this study was to assess the effects of yttrium nitrate on neurobehavioral development in Sprague-Dawley rats. Methods Dams were orally exposed to 0, 5, 15, or 45 mg/kg daily of yttrium nitrate from gestation day (GD) 6 to postnatal day (PND) 21. Body weight and food consumption were monitored weekly. Neurobehavior was assessed by developmental landmarks and reflexes, motor activity, hot plate, Rota-rod and cognitive tests. Additionally, brain weights were measured on PND 21 and 70. Results No significant difference was noted among all groups for maternal body weight and food consumption. All yttrium-exposed offspring showed an increase in body weight on PND 21;however, no significant difference in body weight for exposed pups versus controls was observed 2 weeks or more after the yttrium solution was discontinued. The groups given 5 mg/kg daily decreased significantly in the duration of female forelime grip strength and ambulation on PND 13. There was no significant difference between yttrium-exposed offspring and controls with respect to other behavioral ontogeny parameters and postnatal behavioral test results. Conclusion Exposure of rats to yttrium nitrate in concentrations up to 45 mg/kg daily had no adverse effects on their neurobehavioral development.

  20. Crystal field and magnetism with Wannier functions: Rare-earth doped aluminum garnets

    OpenAIRE

    Mihokova, Eva; Novak, Pavel; Laguta, Valentin V.

    2015-01-01

    Using the recently developed method we calculate the crystal field parameters in yttrium and lutetium aluminum garnets doped with seven trivalent Kramers rare-earth ions. We then insert calculated parameters into the atomic-like Hamiltonian taking into account the electron-electron, spin-orbit and Zeeman interactions and determine the multiplet splitting by the crystal field as well as magnetic $\\hat{g}$ tensors. We compare calculated results with available experimental data.

  1. Radiation protection in radioimmunotherapy with yttrium-90

    International Nuclear Information System (INIS)

    Full text: Unsealed sources of radioactive isotopes have widely used in the clinical practise. For therapeutic use and with oncological aims, Yttrium-90 has been implemented recently in our hospital. Isotope injection is made by intravenous way slowly at an approximated rate of ten microlitres per second. Low-volume injection, less than ten millilitres, entails the possibility that an important fraction of the prescribed activity could be retained and not incorporated into the patient if a pumping injection system controlled in the distance had been used. To avoid this adversity and in order to get the therapeutic effect, in our hospital the injection is applied directly using a syringe by infirmary personnel of the nuclear medicine department. This circumstance and the radiation emission scheme of Yttrium-90 entails a meticulous radiation safety plan. Measurement of the radiation levels in some different phases of the treatment and at its end, was made by the medical physics department. Also, and before the injection, this department made with the received dose other additional measurements, using ant not using shielding materials, to choose the best option of radiation protection. The use of a syringe protector made of plastic with a thickness between 12 and 17 mm in combination with the use of a leaded apron of 0.25 mm lead thickness worn by the nurse, has been the chosen option. In addition, it was evaluated the most optimized positions for the injection, moving away the nurse from the patient to prevent the risk of radioactive contamination; also the worker was wearing double gloves, glasses and additional protection covering the leaded apron and preventing any kind of accidental contamination. Once the isotope is administrated and bio distributed in the patient's organism, it could be verified that the dose rate around it fell rapidly. The involved personnel were wearing all the time two thermoluminescent dosimeters: for body and for wrist. A maximum of one

  2. 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.

  3. Eu(III)-doped aluminium yttrium oxide

    International Nuclear Information System (INIS)

    In this work, we report the synthesis and the photoluminescence features of Eu(III)-doped yttrium-aluminium oxide obtained by non-hydrolytic sol-gel routes. After heating the powders above 600 deg C the XRD patterns show the presence of the Y4Al2O9 (YAM) and Y3Al5O12 (YAG) phases. At 800 and at 1500 deg C the PL spectra display the Eu(III) lines characteristic of the YAM monoclinic phase. The 5D0→7F2 transition is favored relatively to the 5D0→7F1 lines. However, at 1100 deg C the cubic YAG is the preferential phase and the 5D0→7F1 transition dominates the spectrum. The Eu(III) ions lie in a centro symmetrical site. The different solvents used in the sol-gel synthesis also change the relative proportion between these two phases. This is monitored analyzing the modifications in the relative intensity between the 5D0→7F2 and the 5D0→7F1 transitions. (author)

  4. Crystallization of lanthanum and yttrium aluminosilicate glasses

    International Nuclear Information System (INIS)

    The crystallization behaviour of aluminosilicate glasses of lanthanum (LAS) and yttrium (YAS) containing 2-8 mol% of Ln2O3 (Ln = La or Y), 12-30 mol% of Al2O3, and 64-80 mol% of SiO2 has been studied by DTA, XRD and SEM-EDX analysis. X-ray diffraction results indicate the presence of the mullite phase and La2Si2O7 in the monoclinic high-temperature G form (group space P21/c) for the LAS glasses, and mullite y-Y2Si2O7 in the monoclinic structure (group space C2/m) and a small amount of β-Y2Si2O7 in the orthorhombic structure (space group Pna2) for the YAS. For both cases, very little tridymite phase is observed. The results also show that the values of T g for YAS are higher than those for LAS glasses. The crystallization of LAS glasses is more difficult than that of YAS. For all samples, we observed only one kind of mullite (Al/Si = 3.14)

  5. 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.

  6. Niobium-aluminum base alloys having improved, high temperature oxidation resistance

    Science.gov (United States)

    Hebsur, Mohan G. (Inventor); Stephens, Joseph R. (Inventor)

    1991-01-01

    A niobium-aluminum base alloy having improved oxidation resistance at high temperatures and consisting essentially of 48%-52% niobium, 36%-42% aluminum, 4%-10% chromium, 0%-2%, more preferably 1%-2%, silicon and/or tungsten with tungsten being preferred, and 0.1%-2.0% of a rare earth selected from the group consisting of yttrium, ytterbium and erbium. Parabolic oxidation rates, k.sub.p, at 1200.degree. C. range from about 0.006 to 0.032 (mg/cm.sup.2).sup.2 /hr. The new alloys also exhibit excellent cyclic oxidation resistance.

  7. Influence of Yttrium and Ytterbium on Reaction Performance of Platinum-Rhenium Reforming Catalyst

    Institute of Scientific and Technical Information of China (English)

    Zhang Daqing; Cui Long; Sun Zuolin

    2002-01-01

    The influence of yttrium and ytterbium on the catalyticperformance of Pt-Re reforming cata-lysts was studied in a continuous flow pressurized microreactor-chromatograph system and pilot unit. Theresults of micro-reactor test showed that both yttrium and ytterbium could improve the selectivity of Pt-Recatalysts for the conversion ofn-heptane as well as MCP into aromatics, but also suppressed their activityas well. Pilot test results showed that yttrium and ytterbium enhanced both the selectivity and activity ofPt-Re catalysts for naphtha reforming. Yttrium showed more improvement than ytterbium. The perfor-mance difference between microreactor test and pilot test might be due to the difference in improvement ofcatalytic stability of yttrium or ytterbium modified Pt-Re catalysts. Yttrium and ytterbium improved thecoking resistance of yttrium or ytterbium modified Pt-Re catalysts. TEM determination results indicatedthat both yttrium and ytterbium had improved the thermal stability of Pt-Re catalysts.

  8. Influence of Yttrium and Ytterbium on Reaction Performance of Platinum-Rhenium Reforming Catalyst

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The influence of yttrium and ytterbium on the catalytic performance of Pt-Re reforming cata-lysts was studied in a continuous flow pressurized microreactor-chromatograph system and pilot unit. Theresults of micro-reactor test showed that both yttrium and ytterbium could improve the selectivity of Pt-Recatalysts for the conversion ofn-heptane as well as MCP into aromatics, but also suppressed their activityas well. Pilot test results showed that yttrium and ytterbium enhanced both the selectivity and activity ofPt-Re catalysts for naphtha reforming. Yttrium showed more improvement than ytterbium. The perfor-mance difference between microreactor test and pilot test might be due to the difference in improvement ofcatalytic stability of yttrium or ytterbium modified Pt-Re catalysts. Yttrium and ytterbium improved thecoking resistance of yttrium or ytterbium modified Pt-Re catalysts. TEM determination results indicatedthat both yttrium and ytterbium had improved the thermal stability of Pt-Re catalysts.

  9. Nuclear magnetic resonance wide-line study of hydrogen in the yttrium-yttrium dihydride system

    International Nuclear Information System (INIS)

    The 1H nuclear magnetic resonance was studied in the yttrium-hydrogen system YH/sub x/ in the composition range 0.20 less than or equal to x less than or equal to 1.98 and temperature range 77 K less than or equal to T less than or equal to 4900K. Both α- and β-phases of YH/sub x/ were investigated in polycrystalline (powdered) specimens. Rigid lattice proton resonance second moments were obtained for both α- and β-phase samples. Analysis of the second moment for α-YH/sub x/ (α-phase) indicates that the hydrogen resides in both the tetrahedral and octahedral interstitial sites of the hcp Y lattice. Second moment values for β-YH/sub x/ (β-phase) indicate that a sizeable fraction of the octahedral interstitial sites in the fcc yttrium metal lattice are occupied by hydrogen, while a nonnegligible fraction of the tetrahedral interstitial sites are vacant. For example, in YH/sub 1.98/, 28% of the octahedral sites are occupied, while 15% of the tetrahedral sites are vacant. The results for β-YH/sub x/ also indicate that as the H concentration increases, the probability of H occupation of octahedral sites increases

  10. 40 CFR 721.10013 - Manganese yttrium oxide (Mn2YO5).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Manganese yttrium oxide (Mn2YO5). 721... Substances § 721.10013 Manganese yttrium oxide (Mn2YO5). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as manganese yttrium oxide (Mn2YO5) (PMN...

  11. 40 CFR 721.10009 - Manganese yttrium oxide (MnYO3).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Manganese yttrium oxide (MnYO3). 721... Substances § 721.10009 Manganese yttrium oxide (MnYO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as manganese yttrium oxide (MnYO3) (PMN...

  12. Effect of yttrium on nucleation and growth of zirconium hydrides

    International Nuclear Information System (INIS)

    Addition of yttrium in zirconium causes precipitates of yttrium, which form two types of particles and are oxidized upon heat treatment. One type of particles with sub-micrometer scale sizes has a low population, whereas the other with nano scale sizes has a high population and cluster distribution. Owing to strong affinity of yttrium to hydrogen, the nanoparticles, mostly within the grains of the Zr–Y alloy, attract nucleation of hydrides at the clusters of the nanoparticles and cause preferential distribution of intragranular hydrides. In comparison with that of Zr, additional nanoparticles in the Zr–Y alloy impede further growth of hydride precipitates during hydriding. It is deduced that the impediment of growing hydride precipitates by the nanoparticles is developed during an auto-catalytic nucleation process, which leads to formation of thin and intragranular hydrides, favorable to mitigation of hydride embrittlement

  13. Effect of yttrium on nucleation and growth of zirconium hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Li, Changji; Xiong, Liangyin; Wu, Erdong; Liu, Shi, E-mail: sliu@imr.ac.cn

    2015-02-15

    Addition of yttrium in zirconium causes precipitates of yttrium, which form two types of particles and are oxidized upon heat treatment. One type of particles with sub-micrometer scale sizes has a low population, whereas the other with nano scale sizes has a high population and cluster distribution. Owing to strong affinity of yttrium to hydrogen, the nanoparticles, mostly within the grains of the Zr–Y alloy, attract nucleation of hydrides at the clusters of the nanoparticles and cause preferential distribution of intragranular hydrides. In comparison with that of Zr, additional nanoparticles in the Zr–Y alloy impede further growth of hydride precipitates during hydriding. It is deduced that the impediment of growing hydride precipitates by the nanoparticles is developed during an auto-catalytic nucleation process, which leads to formation of thin and intragranular hydrides, favorable to mitigation of hydride embrittlement.

  14. Role of yttrium in heavy section spheroidal graphite cast iron

    International Nuclear Information System (INIS)

    Magnesium ferrosilicon alloys (Mg = 5-7%) are widely used abroad, while rare earth-magnesium ferrosilicon alloys (Mg = 8-10%, Ce RE = 5-9%) are used predominantly in China. Recently, due to the exploitation of natural resources of yttrium rare earth at home, a new type of alloy--yttrium based-rare earth ferrosilicon (YRE=25-40%, Si=40%) has been developed and put into trail as a substitute for conventional rare earth magnesium ferrosilicon alloy in some of the foundries for manufacturing heavy section spheroidal graphite cast iron. In this paper the effect of yttrium on mechanical properties and microstructures of heavy section spheroidal graphite cast iron are studied. Some simulating experiments were carried out in laboratory

  15. Thermochromism in yttrium iron garnet compounds.

    Science.gov (United States)

    Serier-Brault, Hélène; Thibault, Lucile; Legrain, Magalie; Deniard, Philippe; Rocquefelte, Xavier; Leone, Philippe; Perillon, Jean-Luc; Le Bris, Stéphanie; Waku, Jean; Jobic, Stéphane

    2014-12-01

    Polycrystalline yttrium iron garnet (Y3Fe5O12, hereafter labeled YIG) has been synthesized by solid-state reaction, characterized by X-ray diffraction, Mössbauer spectroscopy, and UV-vis-NIR diffuse reflectance spectroscopy, and its optical properties from room temperature (RT) to 300 °C are discussed. Namely, its greenish color at RT is assigned to an O(2-) → Fe(3+) ligand-to-metal charge transfer at 2.57 eV coupled with d-d transitions peaking at 1.35 and 2.04 eV. When the temperature is raised, YIG displays a marked thermochromic effect; i.e., the color changes continuously from greenish to brownish, which offers opportunities for potential application as a temperature indicator for everyday uses. The origin of the observed thermochromism is assigned to a gradual red shift of the ligand-to-metal charge transfer with temperature while the positioning in energy of the d-d transitions is almost unaltered. Attempts to achieve more saturated colors via doping (e.g., Al(3+), Ga(3+), Mn(3+), ...) remained unsuccessful except for chromium. Indeed, Y3Fe5O12:Cr samples exhibit at RT the same color than the undoped garnet at 200 °C. The introduction of Cr(3+) ions strongly impacts the color of the Y3Fe5O12 parent either by an inductive effect or, more probably, by a direct effect on the electronic structure of the undoped material with formation of a midgap state. PMID:25382733

  16. Enhancement of Superconductivity of Lanthanum and Yttrium Sesquicarbide

    Science.gov (United States)

    Krupka, M. C.; Giorgi, A. L.; Krikorian, N. H.; Szklarz, E. G.

    1972-06-22

    A method of enhancing the superconductivity of body-centered cubic lanthanum and yttrium sesquicarbide through formation of the sesquicarbides from ternary alloys of novel composition (N/sub x/M/sub 1-x/)C/sub z/, where N is yttrium or lanthanum, M is thorium, any of the Group IV and VI transition metals, or gold, germanium or silicon, and z is approximately 1.2 to 1.6. These ternary sesquicarbides have superconducting transition temperatures as high as 17.0/sup 0/K.

  17. The Aluminum Smelting Process

    OpenAIRE

    Kvande, Halvor

    2014-01-01

    This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The me...

  18. Microstructure Characterization Of Oxide Scale Growth On Oxide Dispersion Strengthened (ODS) MA -956 Implanted By Yttrium Ion

    International Nuclear Information System (INIS)

    The microstructure of oxide scale growth on ODS MA-956 implanted by yttrium ion have been studied. The specimen of ferritic Oxide Dispersion Strengthened (ODS) alumina-forming INCOLOY MA-956 with chemical composition (wt.%) of Fe-20Cr-5AI-0.4Ti-0.5Y2O3 used for this investigation. An implantation of certain Y elements applied to the commercial alloys substrate and undertaken by utilizing an acceleration potential of 85 keY at dose of 1x 017 ion/cm2. Result from SEM (Scanning Electron Microscope), have been combined with EPMA (Electron Probe Micro Analysis), EELS (Electron Energy Loss Spectroscopy), and TEMIEDX (Transmission Electron Microscope/Energy Dispersive X-ray-analysis). The results discussed by correlating the microstructural analysis of scale morphology and composition using some microstructural characterization techniques. The results showed the existence of yttrium on the top of the oxide layer, in the substrate and at position 1 μm from the substrate. The existence of aluminum and oxygen K edge only in the oxide layer, the existence of titanium particle in the grain boundary of the oxide layer and in the oxide layer, and the existence of Y and Ti particle in the interface layer between the oxide layer and the substrate

  19. Interfacial Behavior of Sulfur and Yttrium in Yttrium Modified Ni3Al-Based Alloy IC6 during High Temperature Oxidation Process

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The interfacial behavior of sulfur and yttrium in the yttrium-modified Ni3Al-based alloy IC6 during oxidation at 1100 ℃ was analyzed by X-ray line scan of electron probe microstructural analysis(EPMA). The results show that the migration and segregation of sulfur to the interface between oxide scale and the substrate at high temperature is retarded owing to the presence of yttrium. This is attributed to the desulfurization by yttrium in the melt and the trapping of sulfur by yttrium rich phases during oxidation, which leads to improving the coherence between oxide scale and substrate. Another reason of increasing the high temperature oxidation resistance of alloy IC6 by the addition of yttrium is that yttrium migrates to the grain boundaries of oxides during oxidation and hence improve their strength. This results in the transformation of the oxide scale spallation cracks from intergranular cracks for alloy without yttrium to transgranular ones for yttrium-modified alloy.

  20. Discovery of Yttrium, Zirconium, Niobium, Technetium, and Ruthenium Isotopes

    CERN Document Server

    Nystrom, A

    2011-01-01

    Currently, thirty-four yttrium, thirty-five zirconium, thirty-four niobium, thirty-five technetium, and thirty-eight ruthenium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  1. Microstructure and defect chemistry of yttrium aluminium garnet ceramics

    International Nuclear Information System (INIS)

    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

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

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Yue, Zhao; Tang, Xiao; Pallewatta, Pallewatta G A P; Watenphul, A.; Zimmermann, M. v.

    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...

  3. 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...

  4. Graphene-aluminum nanocomposites

    International Nuclear Information System (INIS)

    Highlights: → We investigated the mechanical properties of aluminum and aluminum nanocomposites. → Graphene composite had lower strength and hardness compared to nanotube reinforcement. → Processing causes aluminum carbide formation at graphene defects. → The carbides in between grains is a source of weakness and lowers tensile strength. - Abstract: Composites of graphene platelets and powdered aluminum were made using ball milling, hot isostatic pressing and extrusion. The mechanical properties and microstructure were studied using hardness and tensile tests, as well as electron microscopy, X-ray diffraction and differential scanning calorimetry. Compared to the pure aluminum and multi-walled carbon nanotube composites, the graphene-aluminum composite showed decreased strength and hardness. This is explained in the context of enhanced aluminum carbide formation with the graphene filler.

  5. Graphene-aluminum nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Bartolucci, Stephen F., E-mail: stephen.bartolucci@us.army.mil [U.S. Army Benet Laboratories, Armaments Research Development and Engineering Center, Watervliet, NY 12189-4000 (United States); Paras, Joseph [U.S. Army Benet Laboratories, Armaments Research Development and Engineering Center, Watervliet, NY 12189-4000 (United States); Rafiee, Mohammad A. [Department of Mechanical Engineering and Materials Science, Rice University, Houston, TX 77005 (United States); Rafiee, Javad [Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Lee, Sabrina; Kapoor, Deepak [U.S. Army Benet Laboratories, Armaments Research Development and Engineering Center, Watervliet, NY 12189-4000 (United States); Koratkar, Nikhil, E-mail: koratn@rpi.edu [Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2011-10-15

    Highlights: {yields} We investigated the mechanical properties of aluminum and aluminum nanocomposites. {yields} Graphene composite had lower strength and hardness compared to nanotube reinforcement. {yields} Processing causes aluminum carbide formation at graphene defects. {yields} The carbides in between grains is a source of weakness and lowers tensile strength. - Abstract: Composites of graphene platelets and powdered aluminum were made using ball milling, hot isostatic pressing and extrusion. The mechanical properties and microstructure were studied using hardness and tensile tests, as well as electron microscopy, X-ray diffraction and differential scanning calorimetry. Compared to the pure aluminum and multi-walled carbon nanotube composites, the graphene-aluminum composite showed decreased strength and hardness. This is explained in the context of enhanced aluminum carbide formation with the graphene filler.

  6. A study of dislocations and inclusions in Yttrium Aluminum Garnet crystals with birefringence topography

    OpenAIRE

    Shiu-Ying, Shu; Zhoun-Zhung, Kuo; Duan, Fong

    1980-01-01

    Birefringence images due to dislocations and inclusions in YAG crystals were studied with polarizing microscopy. Birefringence images of dislocations viewed end-on as well as viewed from the side were interpreted by Tanner and Fathers' theory with due considerations of the effect of long-range strain field. The Burgers vectors of dislocations were found to be of the type of [MATH] , and . The effect of long-range strain field on birefringence images was elucidated.

  7. [Treatment of hemangioma with the neodymium:yttrium-aluminum-garnet laser (Nd:YAG laser)].

    Science.gov (United States)

    Werner, J A; Lippert, B M; Godbersen, G S; Rudert, H

    1992-08-01

    Laser therapy and in particular Nd:YAG laser therapy has become of increasing importance amongst the various methods of treating haemangiomas. Nd:YAG laser radiation penetrates deep into the tissue. To avoid undesirable results of treatment, certain treatment guidelines must be observed: to protect the tissue from serious heat damage, the Nd:YAG laser radiation should be applied exclusively with simultaneous tissue cooling. Depending on the location of the haemangioma, this is carried out with ice cubes (if possible, not containing air bubbles) or with an ice-cold Ringer solution. The depth of penetration of the laser radiation can be increased by tissue compression with a piece of ice or with a special glass disc. In very voluminous haemangiomas, the laser light is additionally applied via a bare fibre directly on to the vascular tissue. The laser power densities we use are between 500 and 3,000 watts/cm2. The power chosen depends on the tissue effect of the laser radiation. Blanching of the vascular tissue without carbonisation is aimed at. With consistent observance of the treatment guidelines specified, haemangiomas should be treated as early as possible with the Nd:YAG laser. The treatment principle of "wait and see" is often advocated, but we consider to be obsolete, since cosmetically and functionally unsatisfactory residual scars may remain even after complete haemangioma regression. Moreover, the progressive haemangiomas which often lead to complications cannot be distinguished from regressive haemangiomas. Last but not least, the child and the parents should be spared the (in some cases appreciable) psychological strain of a haemangioma. PMID:1388462

  8. Magnetooptics of quintet states of Tb{sup 3+} ion in terbium-yttrium aluminum garnet

    Energy Technology Data Exchange (ETDEWEB)

    Valiev, U.V.; Rustamov, U.R.; Rakhmatov, A.S. [National University of Uzbekistan, 700174 Tashkent (Uzbekistan); Gruber, J.B. [Department of Physics, San Jose State University, San Jose, California 95192-0106 (United States); Zandi, B. [ARL/Adelphi Laboratory Center, 2800 Powder Mill Road, Adelphi, Maryland 20783-1197 (United States); Dzhuraev, D.R.; Narzullaev, N.M. [Bukhara State University, 705018 Bukhara (Uzbekistan)

    2005-03-01

    The luminescence spectra and the degrees of magnetic circular polarization of luminescence (MCPL) have been studied in paramagnetic garnet Tb{sub 0.2}Y{sub 2.8}Al{sub 5}O{sub 12} (YAG:Tb{sup 3+}) for the radiative 4f-4f transition {sup 5}D{sub 4}{yields}{sup 7}F{sub 6}. The features of the spectral dependencies of the MCPL degree with allowed (in symmetry) optical transitions between the Stark sublevels of the ground {sup 7}F{sub 6} and excited {sup 5}D{sub 4} multiplets of the non-Kramers rare-earth Tb{sup 3+} ion have been found in the YAG garnet structure. In the paramagnetic garnet Tb{sub 0.2}Y{sub 2.8}Al{sub 5}O{sub 12} within the close ultraviolet spectral range, the non-trivial features of the spectra of magnetic circular dichroism (MCD) have been found; they evidence a significant contribution of the quasi-doublet states in the multiplets {sup 5}D{sub 3}, {sup 5}G{sub 5} and {sup 5}L{sub 10} to magnetooptics of the 4f-4f transitions. The results of numerical calculations of the energy and wave functions have been presented for some Stark sublevels of the {sup 5}D{sub 4} and {sup 7}F{sub 6} multiplets of the Tb{sup 3+} ion in the crystalline field of D{sub 2} symmetry. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Percutaneous yttrium aluminum garnet-laser lithotripsy of intrahepatic stones and casts after liver transplantation

    DEFF Research Database (Denmark)

    Schlesinger, Nis Hallundbaek; Svenningsen, Peter; Frevert, Susanne;

    2015-01-01

    Bile duct stones and casts (BDSs) contribute importantly to morbidity after liver transplantation (LT). The purpose of this study was to estimate the clinical efficacy, safety, and long-term results of percutaneous transhepatic cholangioscopic lithotripsy (PTCSL) in transplant recipients and to......% needed additional interventions in the form of percutaneous transhepatic cholangiography and dilation (17%), re-PTCSL (11%), self-expandable metallic stents (22%), or hepaticojejunostomy (6%); and 22% eventually underwent retransplantation. The overall liver graft survival rate was 78%. Two patients died...

  10. Yttrium aluminum garnet (Y3Al5O12) nanopowders synthesized by the chemical method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Huashan; SU Chunhui; HAN Hui; HOU Zhaoxia; WANG Guangzhao

    2005-01-01

    The homogeneously dispersed, less agglomerated YAG nanopowders are synthesized by the citrate-gel method followed by low-temperature self-propagating combustion reaction, using Y2O3, Al(NO3)y9H2O and citric acid as starting materials. This method effectively solves the problems caused by solid-state reaction at high temperature and the hard agglomerates brought by the chemical precipitation method. The powders are characterized by TG-DTA, XRD, FT-IR and TEM respectively. The experiments show that the forming temperature of YAG crystal phase is 850℃ and the pseudo-YAG crystalline appears during the calcination and transforms to pure YAG at 1050℃. The powders with sizes less than 50 nm are observed by TEM micrography, which is consistent with the result calculated by Scherrer's formula. The powders consist of single grains.

  11. CHARACTERIZATION OF VACUUM PLASMA SPRAYED COBALT - NICKEL - CHROMIUM - ALUMINUM - YTTRIUM COATINGS

    OpenAIRE

    MRDAK MIHAILO R.

    2013-01-01

    This paper analyzes the influence of the plasma spray distance on the microstructure and the mechanical properties of the Co32Ni21Cr8Al0.5Y coatings deposited with the vacuum plasma spraying (VPS) procedure. The microstructure and the mechanical properties of the plasma spray coatings were determined by the interaction of the Ar/H2 plasma ions with the powder particles when the transfer of the speed and temperature of ions on the powder particles occurs. The effect of interaction directly dep...

  12. Synthesis of Yttrium and Aluminum Complexes Supported by a Mono-Substituted Ferrocene Ligand

    OpenAIRE

    Gao, Jun

    2015-01-01

    Ferrocene chelating ligands provide good stability of the resulting metal complexes and redox-switchable control in chemical processes catalyzed by those complexes. In comparison to traditional di-substituted ferrocene tetradentate ligands, mono-substituted tridentate ferrocene ligands may form metal complexes with a more open coordination sphere around the metal center that may allow an increased preference for substrate coordination. In addition, a mono-substituted ferrocene ligand allows t...

  13. Aluminum-Free Semiconductors and Packaging

    International Nuclear Information System (INIS)

    The use of laser diodes instead of flashlamps to pump solid state lasers generally results in lighter weight, more compact systems with improved efficiency and reliability. These traits are important to a wide variety of applications in military, industrial and other areas. Common solid state laser systems such as yttrium aluminum garnet doped with neodymium or ytterbium (Nd:YAG and Yb:YAG, respectively) require pump light in the 800 to 1000 nm range, and such laser diodes have typically been fabricated in the AlGaAs material system on a GaAs substrate. Unfortunately, the presence of aluminum in or near the light-generating regions of these devices appears to limit their high-power performance, so for improved performance attention has turned to the aluminum-free (''Al-free'') material system of InGaAsP on a GaAs substrate. Laser diodes in this system offer the wavelength coverage similar to the AlGaAs/GaAs material system, and early results suggest that they may offer improved high-power performance. However, such Al-free diodes are more challenging to manufacture than AlGaAs-based devices. The goal of this LDRD project has been to evaluate Al-free diode technology in comparison with conventional AlGaAs-based structures for use in diode-pumped solid state lasers. This has been done by testing commercially available devices, surveying the literature, developing in-house capability in order to explore new device designs, and by engaging a leading university research group in the field

  14. Aluminum-Free Semiconductors and Packaging

    Energy Technology Data Exchange (ETDEWEB)

    Emanuel, M.A.

    2000-02-03

    The use of laser diodes instead of flashlamps to pump solid state lasers generally results in lighter weight, more compact systems with improved efficiency and reliability. These traits are important to a wide variety of applications in military, industrial and other areas. Common solid state laser systems such as yttrium aluminum garnet doped with neodymium or ytterbium (Nd:YAG and Yb:YAG, respectively) require pump light in the 800 to 1000 nm range, and such laser diodes have typically been fabricated in the AlGaAs material system on a GaAs substrate. Unfortunately, the presence of aluminum in or near the light-generating regions of these devices appears to limit their high-power performance, so for improved performance attention has turned to the aluminum-free (''Al-free'') material system of InGaAsP on a GaAs substrate. Laser diodes in this system offer the wavelength coverage similar to the AlGaAs/GaAs material system, and early results suggest that they may offer improved high-power performance. However, such Al-free diodes are more challenging to manufacture than AlGaAs-based devices. The goal of this LDRD project has been to evaluate Al-free diode technology in comparison with conventional AlGaAs-based structures for use in diode-pumped solid state lasers. This has been done by testing commercially available devices, surveying the literature, developing in-house capability in order to explore new device designs, and by engaging a leading university research group in the field.

  15. The effect of the nature of rare earth elements on the stable activity of an industrial amorphous aluminum silicate catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Skoblo, V.A.; Kapustin, V.M.; Kozlov, L.L.

    1983-01-01

    The promoting effect of fourteen rare earth elements (REE) on the catalytic activity and stability of an industrial aluminum silicate catalyst (Kt) in a reaction of cracking gas oil is studied. It is shown that the individual rare earth elements have a promoting effect on the catalyst to a varying degree. Neodymium in a cerium subgroup has the greatest promoting effect, along with Disprosium and Holmium in a Yttrium subgroup of rare earth elements.

  16. Yttrium aluminium garnet under pressure: Structural, elastic, and vibrational properties from ab initio studies

    Energy Technology Data Exchange (ETDEWEB)

    Monteseguro, V. [Departamento de Física and MALTA Consolider Team, Universidad de La Laguna, 38200 San Cristóbal de La Laguna, Santa Cruz de Tenerife (Spain); Rodríguez-Hernández, P.; Muñoz, A., E-mail: amunoz@ull.es [Departamento de Física and MALTA Consolider Team, Universidad de La Laguna, 38200 San Cristóbal de La Laguna, Santa Cruz de Tenerife (Spain); Instituto de Materiales y Nanotecnología. Universidad de La Laguna, 38200 San Cristóbal de La Laguna, Santa Cruz de Tenerife (Spain)

    2015-12-28

    The structural, elastic, and vibrational properties of yttrium aluminum garnet Y{sub 3}Al{sub 5}O{sub 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{sub 3}Al{sub 5}O{sub 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.

  17. Aluminum powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Flumerfelt, J.F.

    1999-02-12

    The objective of this dissertation is to explore the hypothesis that there is a strong linkage between gas atomization processing conditions, as-atomized aluminum powder characteristics, and the consolidation methodology required to make components from aluminum powder. The hypothesis was tested with pure aluminum powders produced by commercial air atomization, commercial inert gas atomization, and gas atomization reaction synthesis (GARS). A comparison of the GARS aluminum powders with the commercial aluminum powders showed the former to exhibit superior powder characteristics. The powders were compared in terms of size and shape, bulk chemistry, surface oxide chemistry and structure, and oxide film thickness. Minimum explosive concentration measurements assessed the dependence of explosibility hazard on surface area, oxide film thickness, and gas atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization oxidation of aluminum powder. An Al-Ti-Y GARS alloy exposed in ambient air at different temperatures revealed the effect of reactive alloy elements on post-atomization powder oxidation. The pure aluminum powders were consolidated by two different routes, a conventional consolidation process for fabricating aerospace components with aluminum powder and a proposed alternative. The consolidation procedures were compared by evaluating the consolidated microstructures and the corresponding mechanical properties. A low temperature solid state sintering experiment demonstrated that tap densified GARS aluminum powders can form sintering necks between contacting powder particles, unlike the total resistance to sintering of commercial air atomization aluminum powder.

  18. Fabrication of independent nickel microstructures with anodizing of aluminum,laser irradiation, and electrodeposition

    Institute of Scientific and Technical Information of China (English)

    T. Kikuchi; M. Sakairi; H. Takahashi

    2003-01-01

    Independent microstructures made of Ni metal were fabricated by five sequential processes: porous anodic oxide film for-mation, pore sealing, laser irradiation, Ni electroplating, and removal of the aluminum substrate and anodic oxide films. Aluminumplates and rods were anodized in an oxalic acid solution to form porous type anodic oxide films, and then immersed in boiling dis-tilled water for pore sealing. The anodized and pore-sealed specimens were irradiated with a pulsed neodymium-doped yttrium alu-minum garnet (Nd-YAG) laser beam in a Ni plating solution to remove anodic oxide film locally by rotating and moving up / downwith an XYZθ-stage. Nickel was deposited at the area where film had been removed by cathodic polarization in the solution beforeremoving the aluminum substrate and anodic oxide films in NaOH solutions. Cylindrical or plain network structures were fabricated successfully.

  19. Structural study of yttrium substituted BiFeO3

    Science.gov (United States)

    Mejía Gómez, J. A.; Canaria, C.; Ochoa Burgos, R.; Ortiz, C. A.; Supelano, G. I.; Parra Vargas, C. A.

    2016-02-01

    Yttrium-substituted Bi1-xYxFeO3 (x=0, 0.03, 0.07, 0.15, 0.2 and 0.5) samples were prepared by solid state reaction technique. Morphological analysis was obtained by Scanning Electron Microscopy (SEM) technique indicating mainly granular behaviour. In addition, the substitution of yttrium promotes smaller particle size of BiFeO3. The obtained samples were also studied by X-ray diffraction (XRD). The crystal structure and the lattice parameters were confirmed by XRD. Rietveld refinement of experimental X-ray diffraction patterns showed that substituted BiFeO3 compounds crystallize in a R3c type structure and the lattice parameters decrease as Y concentration increases.

  20. Ductility enhancement of extruded magnesium via yttrium addition

    International Nuclear Information System (INIS)

    Two binary Mg-Y alloys and pure magnesium were prepared by extrusion. The effect of yttrium on mechanical properties was investigated in comparison between the pure magnesium and the Mg-Y alloys. The results showed that after extruded and annealed, with increment of the yttrium addition, the elongation-to-failure of magnesium increases, but the strength decreases. This is mainly due to the different textures that make the difference of deformation modes in tensile along ED direction for the pure magnesium and the Mg-Y alloys. The pure magnesium has the texture with {0 0 0 2} pole perpendicular to ED. However more random components of texture are formed in the Mg-Y alloys. Accordingly, the Mg-Y alloys can be deformed with more active dislocation slips than the pure magnesium.

  1. Structural and electrical properties of yttrium oxide with tungsten gate

    International Nuclear Information System (INIS)

    A new gate-stack which consists of tungsten (W) deposited by low-pressure chemical-vapor deposition and yttrium oxide (Y2O3) deposited by RF reactive magnetron sputtering has been investigated as an alternate gate electrode/gate dielectric structure for ULSI metal-oxide-semiconductor field effect transistors (MOSFETs). The crystallinity of the yttrium oxide films was enhanced when the substrate temperature was increased during reactive sputtering. The dielectric constant of Y2O3 deposited at room temperature was higher and the leakage current was lower than those deposited at elevated temperatures. Although reactive sputtering deposition and annealing of Y2O3 led to the growth of an intermediate SiO2 layer at the Y2O3/Si interface, W/Y2O3 (∼330 )/SiO2(∼45 )/Si MIS capacitors showed a high effective dielectric constant of 14 ∼ 18 and good electrical properties

  2. Separation of scandium(III) and yttrium(III) by tris(2-ethylhexyl)phosphate (TEHP).

    Science.gov (United States)

    Chhatre, M H; Shinde, V M

    1998-10-01

    Tris(2-ethylhexyl)phosphate is proposed as an extractant for scandium(III) and yttrium(III) from salicylate media. The optimum extraction conditions are evaluated and described. The method permits mutual separation of scandium(III) and yttrium(III) and can be used for the separation and determination of scandium(III) and yttrium(III) from binary and multicomponent mixtures. PMID:18967342

  3. Transparent yttrium hydride thin films prepared by reactive sputtering

    OpenAIRE

    Mongstad, T.; Platzer-Björkman, C.; Karazhanov, S. Zh.; Holt, A.; Maehlen, J. P.; Hauback, B. C.

    2011-01-01

    Metal hydrides have earlier been suggested for utilization in solar cells. With this as a motivation we have prepared thin films of yttrium hydride by reactive magnetron sputter deposition. The resulting films are metallic for low partial pressure of hydrogen during the deposition, and black or yellow-transparent for higher partial pressure of hydrogen. Both metallic and semiconducting transparent YHx films have been prepared directly in-situ without the need of capping layers and post-deposi...

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

    International Nuclear Information System (INIS)

    Aiming to explore the possibility of using the undoped rare-earth orthovanadates as scintillation materials, we developed the procedure for growth of gadolinium (GdVO4) and yttrium (YVO4) orthovanadate single crystals by Czochralski method, and determined the optimal conditions of their after-growth annealing. Optical, luminescent, and scintillation properties of YVO4 and GdVO4 were discussed versus known literature data. Scintillation characteristics of GdVO4 were determined for the first time.

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

    Science.gov (United States)

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

    2012-02-01

    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.

  6. Transparent yttrium hydride thin films prepared by reactive sputtering

    International Nuclear Information System (INIS)

    Research highlights: → Thin films of transparent (semiconducting) and black (metallic) yttrium hydride. → Magnetron sputtering with an yttrium target and hydrogen as a reactive gas. → Optical transmission and reflection resemble β-YH2 (black) and γ-YH3 (transparent). → XRD shows that transparent films have an expanded fcc lattice with a = 5.35 A. → Samples are stable at ambient conditions. - Abstract: Metal hydrides have earlier been suggested for utilization in solar cells. With this as a motivation we have prepared thin films of yttrium hydride by reactive magnetron sputter deposition. The resulting films are metallic for low partial pressure of hydrogen during the deposition, and black or yellow-transparent for higher partial pressure of hydrogen. Both metallic and semiconducting transparent YHx films have been prepared directly in situ without the need of capping layers and post-deposition hydrogenation. Optically the films are similar to what is found for YHx films prepared by other techniques, but the crystal structure of the transparent films differ from the well-known YH3-η phase, as they have an fcc lattice instead of hcp.

  7. Redox processes in highly yttrium-doped barium titanate

    International Nuclear Information System (INIS)

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

  8. Influences of Yttrium on Adhesion of Oxide Scale of Fe-Cr-Al Alloy

    Institute of Scientific and Technical Information of China (English)

    辛丽; 李美栓; 周龙江; 王福会; 李铁藩

    2001-01-01

    The 1100 ℃ isothermal oxidation behavior of Fe-23Cr-5Al alloy modified by yttrium addition was studied by means of thermogravimetric analysis, scanning electron microscopy and energy dispersive X-ray analysis. Yttrium was added to this alloy in the forms of metallic addition, yttrium oxide and ion implant. Cracking and spalling occurred on the convoluted scale formed on Y-free alloy and exposed the substrate. A flat dense scale without spallation was formed on the yttrium alloying addition or yttrium oxide dispersion alloy. The scale adhesion was also improved by 1×1017Y+/cm2-implantation. The results indicate the convoluted morphology of the scale on Fe-23Cr-5Al-0.21Ti alloy is related to the growth mechanism of the alumina scale, and the spallation of the scale is related to sulfur segregation at the scale/alloy interface. The main reason that the adhesion of alumina scale is improved by yttrium addition lies in the following. Yttrium is liable to form a stable yttrium sulfide with sulfur in the alloy and prevent sulfur interface from segregation. Another reason is that the growth mechanism of alumina scale is changed by yttrium addition.

  9. Isolation of yttrium and strontium from soil samples and rapid determination of Sr-90

    OpenAIRE

    Grahek, Željko; Eškinja, Ivan; Košutić, Katarina; Cerjan-Stefanović, Štefica

    2000-01-01

    A procedure of yttrium and strontium separation from calcium and other cations has been developed for rapid determination of Sr-90 in soil samples. The procedure involves yttrium, strontium and other cations bound on cation exchanger AMBERLITE IR-120, separtion of yttrium and strontium from other cations, e.g, potassium, calcium, sodium, barium, on anion exchangers AMBERLITE CG-400 or DOWEX AG Ix 8 with 0.25 mol l(-1) HNO3 in alcohol mixture as eluent, separation of yttrium from strontium on ...

  10. Isolation of Yttrium and Strontium from Soil Samples and Rapid Determination of 90Sr

    OpenAIRE

    Grahek, Željko; Eškinja, Ivan; Košutić, Katarina; Cerjan-Stefanović, Štefica

    2000-01-01

    A procedure of yttrium and strontium separation from calcium and other cations has been developed for rapid determination of 90Sr in soil samples. The procedure involves yttrium, strontium and other cations bound on cation exchanger AMBERLITE IR-120, separtion of yttrium and strontium from other cations, e.g. potassium, calcium, sodium, barium, on anion exchangers AMBERLITE CG-400 or DOWEX AG 1 × 8 with 0.25 mol l-1 HNO3 in alcohol mixture as eluent, separation of yttrium from strontium on ca...

  11. Is the Aluminum Hypothesis Dead?

    OpenAIRE

    Lidsky, Theodore I.

    2014-01-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed w...

  12. Anodizing Aluminum with Frills.

    Science.gov (United States)

    Doeltz, Anne E.; And Others

    1983-01-01

    "Anodizing Aluminum" (previously reported in this journal) describes a vivid/relevant laboratory experience for general chemistry students explaining the anodizing of aluminum in sulfuric acid and constrasting it to electroplating. Additions to this procedure and the experiment in which they are used are discussed. Reactions involved are also…

  13. The aluminum smelting process.

    Science.gov (United States)

    Kvande, Halvor

    2014-05-01

    This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development. PMID:24806722

  14. Coverage dependent reaction of yttrium on silicon and the oxidation of yttrium silicide investigated by x-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    The reaction of yttrium (Y) on (001) silicon (Si) with low temperature annealing is investigated for different coverages of Y using in situ x-ray photoelectron spectroscopy. The authors have also performed oxidation studies for Y on Si in the formation of yttrium silicate by a two-step process. This consists of an ex situ oxidation of Y-Si film, which is formed from low temperature annealing in vacuum. These films were then probed with depth profiling x-ray photoelectron spectroscopy. They report on three general reaction phases of Y on Si that are coverage dependent. Different coverages show differences in Si mixing and selective ultrahigh vacuum oxidation. They also report on the self-limiting formation of yttrium silicate at room temperature and low annealing temperature, which is insensitive to the annealing ambient. They also highlight the importance of oxygen partial pressure in both initial silicate formation and the extent of oxidation at different annealing temperatures. Finally, the authors also show that a high oxygen diffusion barrier prevents the oxidation of the entire Y-Si film

  15. Fluorescent lighting with aluminum nitride phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Cherepy, Nerine J.; Payne, Stephen A.; Seeley, Zachary M.; Srivastava, Alok M.

    2016-05-10

    A fluorescent lamp includes a glass envelope; at least two electrodes connected to the glass envelope; mercury vapor and an inert gas within the glass envelope; and a phosphor within the glass envelope, wherein the phosphor blend includes aluminum nitride. The phosphor may be a wurtzite (hexagonal) crystalline structure Al.sub.(1-x)M.sub.xN phosphor, where M may be drawn from beryllium, magnesium, calcium, strontium, barium, zinc, scandium, yttrium, lanthanum, cerium, praseodymium, europium, gadolinium, terbium, ytterbium, bismuth, manganese, silicon, germanium, tin, boron, or gallium is synthesized to include dopants to control its luminescence under ultraviolet excitation. The disclosed Al.sub.(1-x)M.sub.xN:Mn phosphor provides bright orange-red emission, comparable in efficiency and spectrum to that of the standard orange-red phosphor used in fluorescent lighting, Y.sub.2O.sub.3:Eu. Furthermore, it offers excellent lumen maintenance in a fluorescent lamp, and does not utilize "critical rare earths," minimizing sensitivity to fluctuating market prices for the rare earth elements.

  16. Burning characteristics of individual aluminum/aluminum oxide particles

    OpenAIRE

    Ruttenberg, Eric C.

    1996-01-01

    Approved for public release; distribution is unlimited An experimental investigation was conducted in which the burning characteristics of individual aluminum/aluminum oxide particles were measured using a windowed combustion bomb at atmospheric pressure and under gravity-fall conditions. A scanning electron microscope (SEM) was used to measure the size distribution of the initial aluminum particles and the aluminum oxide residue. Analysis of the residue indicated that the mass of aluminum...

  17. Purifying Aluminum by Vacuum Distillation

    Science.gov (United States)

    Du Fresne, E. R.

    1985-01-01

    Proposed method for purifying aluminum employs one-step vacuum distillation. Raw material for process impure aluminum produced in electrolysis of aluminum ore. Impure metal melted in vacuum. Since aluminum has much higher vapor pressure than other constituents, boils off and condenses on nearby cold surfaces in proportions much greater than those of other constituents.

  18. Crystal field and magnetism with Wannier functions:rare-earth doped aluminum garnets

    Institute of Scientific and Technical Information of China (English)

    Eva Mihóková; Pavel Novák; Valentin V. Laguta

    2015-01-01

    Using the recently developed method we calculated the crystal field parameters in yttrium and lutetium aluminum garnets doped with seven trivalent Kramers rare-earth ions. We then inserted calculated parameters into the atomic-like Hamiltonian taking into account the electron-electron, spin-orbit and Zeeman interactions and determined the multiplet splitting by the crystal field as well as magneticĝ tensors. We compared calculated results with available experimental data. Very good agreement with the spectro-scopic data and qualitative agreement with experimentalĝ tensors was found.

  19. Controlled ring-opening polymerization of ω-pentadecalactone with yttrium isopropoxide as an initiator

    NARCIS (Netherlands)

    Zhong, Zhiyuan; Dijkstra, Pieter J.; Feijen, Jan

    2000-01-01

    The ring-opening polymerization of ω-pentadecalactone (PDL), a 16-membered lactone, in the bulk and in solution using yttrium isopropoxide as an initiator was investigated. All isopropoxide groups of yttrium isopropoxide participated in the initiation and the polymerization took place via acyl-oxyge

  20. Influence of Yttrium and Ytterbium on Reaction Performance of Platinum-Rhenium Reforming Catalyst

    Institute of Scientific and Technical Information of China (English)

    ZhangDaqing; CuiLong; 等

    2002-01-01

    The influence of yttrium and ytterbium on the catalytic performance of Pt-Re refoming cata-lysts was studied in a continuous flow pressurized microreactor-chromatograph system and pilot unit.The results of micro-reactor test showed that both yttrium and ytterbium could improve the selectivity of Pt-Re catalysts for the conversion of n-heptane as well as MCP into aromatics,but also suppressed their activity as well.Pilot test results showed that yttrium and ytterbium enhanced both the selectivity and activity of Pt-Re catalysts for naphtha reforming.Yttrium showed more improvement than ytterbium.The perfor-mance difference between microreactor test and pilot test might be due to the difference in improvement of catalytic stability of yttrium or ytterbium modified Pt-Re catalysts.Yttrium and ytterbium improved the coking resistance of yttrium or ytterbium modified Pt-Re catalysts.TEM determination results indicated that both yttrium and ytterbium had improved the thermal stability of Pt-Re catalysts.

  1. Effects and side effects of radiosynovectomy with yttrium 90 on rheumatic joint cartilage

    International Nuclear Information System (INIS)

    8 and 12 weeks after Synovectomy with Yttrium 90, cartilage specimens from the femoral condyle of 8 patients with R.A. were examined. Cellular and matrix damage could be detected. Intracellular particles containing Circonium, an Yttrium decay-product could be found using microprobe X-ray analysis. This was verified in experimentally induced arthritis in the rat. (orig.)

  2. Determination of yttrium in complex alloys using microwave dissolution and ICP-AES

    International Nuclear Information System (INIS)

    Yttrium additions to Ni-Cr-Al alloy systems have been shown to improve high temperature cyclic oxidation behavior. In support of similar investigations, a rapid and sensitive method for quantitating yttrium in high temperature nickel base alloys was developed. The yttrium content of Ni-Cr-Al-Y, Fe-Cr-Al-Y, and Co-Cr-Al-Y alloys are routinely determined aqua regia for dissolution and ICP-AES for analysis. Using microwave dissolution, sample preparation time of these alloys has been reduced substantially. The objective of this work was to develop a microwave dissolution procedure not requiring time consuming evaporations without compromising sensitivity and accuracy. Two approaches were taken to evaluate the effect of hydrofluoric concentration on the determination of yttrium by ICP-AES. The first approach uses synthetic yttrium standards to study yttrium emission stability as a function of time. The second approach studies the effectiveness of boron in complexing free fluoride and thereby allowing yttrium to remain in solution longer. The result of this work is a rapid, precise method for analyzing yttrium in complex nickel base alloys with a lower limit of quantitation of approximately 10 ppm

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

    International Nuclear Information System (INIS)

    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

  4. The study of energy band structure and chemical bonding in yttrium carbide, yttrium and strontium dicarbides by the LMTO and Xα DV method

    International Nuclear Information System (INIS)

    The energy band structures of yttrium carbide, yttrium and strontium dicarbides are studied by the LMTO-method. The cohesive energies and the total and partial pressures are calculated. The local electronic structure of yttrium dicarbide is studied by the Xα discrete variational method; the cluster Y6C2 which includes the group C2-2 and all the nearest neighbours of this group is used in this study. The results of this calculations are used to analyse the chemical bonding and some properties of the compounds. It is shown that the main contribution to the chemical bonding between C2-2 group and yttrium atoms is provided by the orbital of the eg-local symmetry which belongs to the zone of metallic state. In the SrC2 this orbital is empty which explains the instablity of its crystal lattice. (author)

  5. Corrosion Inhibitors for Aluminum.

    Science.gov (United States)

    Muller, Bodo

    1995-01-01

    Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

  6. Advances in aluminum anodizing

    Science.gov (United States)

    Dale, K. H.

    1969-01-01

    White anodize is applied to aluminum alloy surfaces by specific surface preparation, anodizing, pigmentation, and sealing techniques. The development techniques resulted in alloys, which are used in space vehicles, with good reflectance values and excellent corrosive resistance.

  7. Two cases of unresectable cholanglocarcinoma treated by Yttrium-90 microspheres

    Energy Technology Data Exchange (ETDEWEB)

    You, Sung Hye; KIm, Yun Hwan; Cho, Sung Bum; Ganbold, Umultsaikhan; Um, Soon Ho; Seo, Yeon Seok; Choe, Jae Gol [Korea University College of Medicine, Anam Hospital, Seoul (Korea, Republic of)

    2013-08-15

    Intrahepatic cholangiocarcinoma (ICC) is a rare malignancy and many cases of ICCs are diagnosed in an unresectable state. Until now there has been no effective palliative treatment for these cases. Recently yttrium-90 ({sup 90}Y) radioembolization has been highlighted as a new palliative treatment for these cases. In Korea, there has been no reported case of unresectable ICC which was treated by {sup 90}Y radioembolization up until now. We treated two cases of unresectable ICCs with {sup 90}Y radioembolization and the ICCs were necrotized effectively without significant toxicity .

  8. Quasiparticles in calcium doped yttrium-iron garnets

    International Nuclear Information System (INIS)

    In yttrium-iron garnets an electrical charge is carried by quasiparticles based on compensating holes which move either at oxygen or iron ions of the tetragonal sublattice. The quasiparticles can also get localized because of their coupling to optical phonons on the iron sites. A multi-band model of holes coupled to phonons is applied to find additional energy levels in the gap between the lower of the narrow 3d bands and the wide 2p band, whose occurrence plays a crucial role in the conductivity mechanism. The density of states is considerably modified by the interaction between the holes and local distortion of the lattice. (author)

  9. ENDOR of odd Gd+3 isotopes in yttrium orthovanadate

    International Nuclear Information System (INIS)

    Results of studying the intrinsic superfine (ISI) and quadrupole (QI) interaction of odd gadolinium isotopes in a YVO4 crystal by nutation ENDOR method are described. It is assumed that the main reason for a notable difference of 155GdVO4 and 155Gd3+ quadrupole interaction parameters in YVO4 consists in the exchange and dipole-dipole interaction in GdVO4, with P20 increase in yttrium orthovanadate as compared to GdVO4 being accompanied by a reduction of b20 according to the absolute value. 8 refs., 2 tabs

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

    Energy Technology Data Exchange (ETDEWEB)

    Voloshina, O.V., E-mail: lvoloshina@isma.kharkov.ua [Institute for scintillation materials NAS of Ukraine, 60, Lenin av., 61001 Kharkov (Ukraine); Baumer, V.N. [SSI ' Institute for single crystals' NAS of Ukraine, 60, Lenin av., 61001 Kharkov (Ukraine); Bondar, V.G.; Kurtsev, D.A.; Gorbacheva, T.E.; Zenya, I.M.; Zhukov, A.V.; Sidletskiy, O.Ts. [Institute for scintillation materials NAS of Ukraine, 60, Lenin av., 61001 Kharkov (Ukraine)

    2012-02-01

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

  11. Fabrication of aluminum foam from aluminum scrap Hamza

    OpenAIRE

    O. A. Osman1 ,; Mining and Petroleum Engineering, Faculty of Engineering- Qena, Al_Azhar University, Egypt

    2015-01-01

    In this study the optimum parameters affecting the preparation of aluminum foam from recycled aluminum were studied, these parameters are: temperature, CaCO3 to aluminum scrap wt. ratio as foaming agent, Al2O3 to aluminum scrap wt. ratio as thickening agent, and stirring time. The results show that, the optimum parameters are the temperature ranged from 800 to 850oC, CaCO3 to aluminum scrap wt. ratio was 5%, Al2O3 to aluminum scrap wt. ratio was 3% and stirring time was 45 second ...

  12. 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...... compounds follow a similar decomposition path starting with dehydration, which is complete at 110°C. The dehydrated salts convert to a dioxycarbonate (Y2O2CO3) via an unstable intermediate product (probably Y2O(C2H5CO2)4 and Y2O(C3H7CO2)4 for the propionate and butyrate respectively), with the evolution of...... CO2 and a symmetrical ketone consisting of 3-pentanone and 4-heptanone respectively. Final conversion to Y2O3 takes pace with release of CO2. Elemental carbon that is left as a by-product is finally slowly burned by the residual oxygen present in the Ar atmosphere. Fusion is observed at ≈110°C in...

  13. Ultrafiltration of solutions of yttrium in trace concentrations

    International Nuclear Information System (INIS)

    The behaviour of 91Y in trace concentrations (approximately 10-11 to 10-12 mol/l) in aqueous solutions was studied by applying the technique of ultrafiltration through a cellophane diaphragm. The fraction of 91Y retained by the ultrafilter generally increases with increasing pH, from low values in the strongly acidic range over a local maximum at pH approximately 4 followed by a not very pronounced local minimum at pH approximately 5 to 7 to the highest values at ph>9. It is concluded that yttrium in aqueous solutions in the concentrations mentioned occurs at pH9 to 11 in the form of a true colloid of the hydroxide 91Y(OH)3. In addition to the predominant forms, molecular forms of yttrium are present in a rather low fraction, too. The retention of 91Y by the filter paper during the filtration of very dilute aqueous solutions through paper filters was proved to be due to adsorption. (author)

  14. Structural and electrical properties of yttrium oxide with tungsten gate

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Kwan Chong; Yang, Seong Woo; Hong, Byung You; Roh, Yong Han; Kim, Jin Mo; Jung, Dong Geun [Sungkyunkwan Univ., Suwon (Korea, Republic of)

    2002-01-01

    A new gate-stack which consists of tungsten (W) deposited by low-pressure chemical-vapor deposition and yttrium oxide (Y{sub 2}O{sub 3}) deposited by RF reactive magnetron sputtering has been investigated as an alternate gate electrode/gate dielectric structure for ULSI metal-oxide-semiconductor field effect transistors (MOSFETs). The crystallinity of the yttrium oxide films was enhanced when the substrate temperature was increased during reactive sputtering. The dielectric constant of Y{sub 2}O{sub 3} deposited at room temperature was higher and the leakage current was lower than those deposited at elevated temperatures. Although reactive sputtering deposition and annealing of Y{sub 2}O{sub 3} led to the growth of an intermediate SiO{sub 2} layer at the Y{sub 2}O{sub 3}/Si interface, W/Y{sub 2}O{sub 3} ({approx}330 )/SiO{sub 2}({approx}45 )/Si MIS capacitors showed a high effective dielectric constant of 14 {approx} 18 and good electrical properties.

  15. Hydrothermal synthesis and characterization of rare earth doped yttrium aluminium perovskite – R:YAlO3 (R = Nd, Eu and Er)

    International Nuclear Information System (INIS)

    Highlights: ► High purity micro-crystalline R:YAP was synthesized by hydrothermal technique. ► The growth temperature does not exceed 700 °C in any step of the synthesis. ► The phase formation was sensitive to the nature of the synthesis temperature and the starting charge. ► R:YAP is considered as direct replacement for YAG owing to its lasing property. -- Abstract: Yttrium aluminium perovskite doped with rare earth ions is a promising material for several technological applications. It is considered as direct replacement for Yttrium Aluminum Garnet (YAG) owing to its structural simplicity and lasing property. It is also known for its mechanical and optical properties. High purity micro crystalline R:YAlO3 (R = Nd3+, Eu3+ and Er3+) is synthesized by employing hydrothermal supercritical fluid technique. The resultant materials were characterized using powder X-ray diffraction for structure and phase identification, scanning electron microscopy and energy dispersive X-ray analysis were performed for particle morphology, phase purity and stoichiometry. These monodispersed polycrystalline materials show high degree of phase purity, good control over the concentration of dopants and exhibit well developed morphological features

  16. Effects of Excess Yttrium Addition on YBCO Thin Films Prepared by TFA-MOD Process

    International Nuclear Information System (INIS)

    [YBa2Cu3O7-x]thin films were fabricated on LaAlO3(100) substrate by TFA-MOD process. Yttrium-excess (0, 2.5, 5, 10, 15, 20 at%) coating solution was prepared by adding extra amount of yttrium into a stoichiometric(Y:Ba:Cu=1:2:3) TFA precursor solution. Results are presented concerning the influence of excess yttrium additions on the microstructure development and superconducting properties of YBa2Cu3O7-x film. Large sized CuO particles was observed by SEM EDS investigation. The addition of excess yttrium affected little on Tc of YBa2Cu3O7-xfilm. Jc of YBCO film was enhanced with excess yttrium addition. Jc maximum of 2.21 MA/cm2 (77 K, self field) appeared with the 15 at% addition of excess yttrium. With further yttrium addition up to 20 at %, Jc decreased down to 0.9 MA/cm2.

  17. Fabrication of aluminum foam from aluminum scrap Hamza

    Directory of Open Access Journals (Sweden)

    O. A. Osman1 ,

    2015-02-01

    Full Text Available In this study the optimum parameters affecting the preparation of aluminum foam from recycled aluminum were studied, these parameters are: temperature, CaCO3 to aluminum scrap wt. ratio as foaming agent, Al2O3 to aluminum scrap wt. ratio as thickening agent, and stirring time. The results show that, the optimum parameters are the temperature ranged from 800 to 850oC, CaCO3 to aluminum scrap wt. ratio was 5%, Al2O3 to aluminum scrap wt. ratio was 3% and stirring time was 45 second with stirring speed 1200 rpm. The produced foam apparent densities ranged from 0.40-0.60 g/cm3. The microstructure of aluminum foam was examined by using SEM, EDX and XRD, the results show that, the aluminum pores were uniformly distributed along the all matrices and the cell walls covered by thin oxide film.

  18. ALUMINUM RECLAMATION BY ACIDIC EXTRACTION OF ALUMINUM-ANODIZING SLUDGES

    Science.gov (United States)

    Extraction of aluminum-anodizing sludges with sulfuric acid was examined to determine the potential for production of commercial-strength solutions of aluminum sulfate, that is liquid alum. The research established kinetic and stoichiometric relationships and evaluates product qu...

  19. Coordination between yttrium ions and amide groups of polyamide 6 and the crystalline behavior of polyamide 6/yttrium composites

    Science.gov (United States)

    Liu, Shaoxuan; Zhang, Chengfeng; Liu, Yuhai; Zhao, Ying; Xu, Yizhuang; Ozaki, Yukihiro; Wu, Jinguang

    2012-08-01

    Different amounts of yttrium ions were introduced into polyamide 6 (PA6) matrix by solution casting process. Structure, morphology and properties of the obtained PA6/Y3+ composite films were investigated by using FT-IR spectroscopy, Raman spectroscopy, scanning electron microscope (SEM), polarized optical microscope (POM) and differential scanning calorimeter (DSC) methods. Yttrium ions show strong coordination ability and their complexation with amide groups of PA6 can be reflected by the appearance of new bands in the amide A and amide I regions in FT-IR and Raman spectra. Furthermore, the FT-IR and Raman spectra of the PA6/Y3+ composite show that the resultant chain conformations of the amide groups in the composite films are twisted from the ideal trans conformation. The DSC results reveal that Y3+ ions cause a significant reduction of the melting point of PA6. In addition, the existence of Y3+ prevents the crystallization of molten PA6/Y3+ composite films during the cooling process. Moreover, the PA6/Y3+ composite can convert into γ phase PA6 or α phase PA6 when different solvents are used to remove Y3+ ions and induce crystallization of PA6.

  20. Separation of yttrium from the lanthanides by DOSO-NH/sub 4/SCN extraction chromatography

    International Nuclear Information System (INIS)

    To separate yttrium from the lanthanides, TBP (tributyl phosphate)-NH/sub 4/SCN extraction chromatography has been proposed. This paper reports DOSO (di-octyl sulphoxide)-NH/sub 4/SCN extraction chromatography. Both systems possess the same chromatographic behavior e.g., the retention volume for yttrium is smaller than those for lanthanide elements, but low chromatographic temperature is necessary to the former. The separation factors between yttrium and lanthanide elements are estimated under selected conditions. It is found that the temperature has a remarkable effect on the separation factors and an increase in the ammonium thiocyante concentration causes a slight increase in the separation factors

  1. Inhalation of monodisperse yttrium-88 labelled fused montmorillonite clay particles by rats

    International Nuclear Information System (INIS)

    Previously reported work on the rate of dissolution in the lung of fused clay particles has been continued, to 270 days post-inhalation. Results are presented for the distribution of yttrium-88 at various times after inhalation of yttrium-88 labelled aerosol, in respiratory tract, lymph nodes, skin, GI tract, soft tissues and skeleton. Whole body retention was measured, yttrium-88 excretion rates, and lung retention. Retention functions are derived. A lung model for fused clay inhaled by rats is proposed. (U.K.)

  2. Synthesis and Characterization of Yttrium Doped Nano-zirconia by a Cationic Surfactant-assisted Route

    Institute of Scientific and Technical Information of China (English)

    YU Jian-Chang; HU Shen-Wei

    2006-01-01

    Recently, more and more interest has been focused on zirconia for its unique characteristics. In this paper, via the preceding preparation technique, yttrium can be successfully incorporated into nano-zirconia by a cationic surfactant-assisted route. The methods of XRD, TEM, EDS, Uv-vis and N2 adsorption-desorption are adopted to characterize the synthesized samples. The results show that the yttrium has been successfully incorporated into the zirconia lattice, and the thermal stability of yttrium doped zirconia has been enhanced remarkably.

  3. Synthesis and thermal stability of polonites of yttrium, dysprosium and praseodymium

    International Nuclear Information System (INIS)

    The interaction of polonium dioxide vapors with oxides of dysprosium, praseodymium, and yttrium were studied by a thermal method of direct synthesis in oxygen medium. As a result of the reaction between these oxides at 710-7200C, the polonites Y2O2PoO3, Pr2O2PoO3, and Dy2Po2O7 were obtained. Dysprosium pyropolonite dissociates thermally, both in oxygen medium and under vacuum at 8200C. Dysprosium, praseodymium, and yttrium oxypyropolonites decompose thermally at 930, 940, and 9600C, respectively. Yttrium and dysprosium oxides do not react with polonium vapors when heated to 10000C

  4. Effect of Yttrium Addition on Glass Forming Ability of ZrCuAlSi Alloy

    International Nuclear Information System (INIS)

    The effect of yttrium addition on glass formation of a ZrCuAlSi alloy is investigated. The maximum diameter 8mm of the glassy rods for (Zr46.3Cu43.3Al8.9Si1.5)100−xYx alloy with x = 2.5 is obtained by copper mould casting. Apparent enhancement of the glass formation ability is found with addition of yttrium, mainly due to the purification of the alloy melt and the suppression of formation of the primary phases by yttrium. (condensed matter: structure, mechanical and thermal properties)

  5. Antibacterial and antibiofilm properties of yttrium fluoride nanoparticles

    Directory of Open Access Journals (Sweden)

    Lellouche J

    2012-11-01

    Full Text Available Jonathan Lellouche,1,2 Alexandra Friedman,2 Aharon Gedanken,2 Ehud Banin11Biofilm Research Laboratory, The Mina and Everard Goodman Faculty of Life Sciences, 2Kanbar Laboratory for Nanomaterials, Department of Chemistry, Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, IsraelAbstract: Antibiotic resistance has prompted the search for new agents that can inhibit bacterial growth. Moreover, colonization of abiotic surfaces by microorganisms and the formation of biofilms is a major cause of infections associated with medical implants, resulting in prolonged hospitalization periods and patient mortality. In this study we describe a water-based synthesis of yttrium fluoride (YF3 nanoparticles (NPs using sonochemistry. The sonochemical irradiation of an aqueous solution of yttrium (III acetate tetrahydrate [Y(Ac3 • (H2O4], containing acidic HF as the fluorine ion source, yielded nanocrystalline needle-shaped YF3 particles. The obtained NPs were characterized by scanning electron microscopy and X-ray elemental analysis. NP crystallinity was confirmed by electron and powder X-ray diffractions. YF3 NPs showed antibacterial properties against two common bacterial pathogens (Escherichia coli and Staphylococcus aureus at a µg/mL range. We were also able to demonstrate that antimicrobial activity was dependent on NP size. In addition, catheters were surface modified with YF3 NPs using a one-step synthesis and coating process. The coating procedure yielded a homogeneous YF3 NP layer on the catheter, as analyzed by scanning electron microscopy and energy dispersive spectroscopy. These YF3 NP-modified catheters were investigated for their ability to restrict bacterial biofilm formation. The YF3 NP-coated catheters were able to significantly reduce bacterial colonization compared to the uncoated surface. Taken together, our results highlight the potential to further develop the concept of utilizing these metal fluoride NPs

  6. Regeneration of aluminum hydride

    Science.gov (United States)

    Graetz, Jason Allan; Reilly, James J; Wegrzyn, James E

    2012-09-18

    The present invention provides methods and materials for the formation of hydrogen storage alanes, AlH.sub.x, where x is greater than 0 and less than or equal to 6 at reduced H.sub.2 pressures and temperatures. The methods rely upon reduction of the change in free energy of the reaction between aluminum and molecular H.sub.2. The change in free energy is reduced by lowering the entropy change during the reaction by providing aluminum in a state of high entropy, and by increasing the magnitude of the change in enthalpy of the reaction or combinations thereof.

  7. Aluminum Hydroxide and Magnesium Hydroxide

    Science.gov (United States)

    Aluminum Hydroxide, Magnesium Hydroxide are antacids used together to relieve heartburn, acid indigestion, and upset stomach. They ... They combine with stomach acid and neutralize it. Aluminum Hydroxide, Magnesium Hydroxide are available without a prescription. ...

  8. Density functional study on structural and electronic properties of bimetallic gold-yttrium clusters: comparison with pure gold and yttrium clusters

    Institute of Scientific and Technical Information of China (English)

    Mao Hua-Ping; Wang Hong-Yan; Sheng Yong

    2008-01-01

    Employing first-principles methods, based on the density functional theory, this paper investigates the ground state geometric and electronic properties of pure gold clusters, pure yttrium clusters and gold clusters doped each with one yttrium atom. It is shown that the average bond lengths in the Aun-lY(n ≤9) bimetallic clusters are shorter than those in the corresponding pure gold and yttrium clusters. The most stable isomers of the yttrium-doped gold clusters tend to equally delocalize valence s, p and d electrons of the constituent atoms over the entire structure. The Y atom has maximum number of neighbouring Au atom, which tends to be energetically favourable in the lowest-energy equilibrium structures, because the Au-Y bond is stronger than the Au-Au bond. The three-dimensional isomers of Aun-1Y structures are found in an early appearance starting at n=5 (Au4Y). Calculated vertical ionization potential and electron affinities as a function of the cluster size show odd-even oscillatory behaviour, and resemble pure gold clusters. However, one of the most striking feature of pure yttrium clusters is the absence of odd-even alternation, in agreement with mass spectrometric observations. The HOMO-LUMO gap of Au3Y is the biggest in all the doped Aun-1Y(n≤9) bimetallic clusters.

  9. RECLAMATION OF ALUMINUM FINISHING SLUDGES

    Science.gov (United States)

    The research study of the reclamation of aluminum-anodizing sludges was conducted in two sequential phases focused on enhanced dewatering of aluminum-anodizing sludges to produce commercial-strength solutions of aluminum sulfate, i.e., liquid alum. The use of high-pressure (14 to...

  10. Electrically conductive anodized aluminum coatings

    Science.gov (United States)

    Alwitt, Robert S. (Inventor); Liu, Yanming (Inventor)

    2001-01-01

    A process for producing anodized aluminum with enhanced electrical conductivity, comprising anodic oxidation of aluminum alloy substrate, electrolytic deposition of a small amount of metal into the pores of the anodized aluminum, and electrolytic anodic deposition of an electrically conductive oxide, including manganese dioxide, into the pores containing the metal deposit; and the product produced by the process.

  11. Biosynthesis of Yttrium oxide nanoparticles using Acalypha indica leaf extract

    Indian Academy of Sciences (India)

    S K Kannan; M Sundrarajan

    2015-08-01

    In this study, the synthesis of Yttrium oxide (Y2O3) nanoparticles was carried out from Acalypha indica leaf extract. The synthesized nanoparticles were characterized by using X-ray diffraction, scanning electron microscope, energy-dispersive X-ray spectrometer and transmission electron microscope for structural confirmation. The studies clearly indicate that the synthesized Y2O3 nanoparticle is a crystalline material with a particle size from 23 to 66 nm. Further analysis was carried out by Fourier transform infrared spectroscopy, to provide the evidence for the presence of Y–O–Y and O–Y–O stretchings in the synthesized Y2O3 nanoparticles. Thermogravimetric and differential scanning calorimetry analyses gave the thermal stability of Y2O3 nanoparticles. The results of the antibacterial studies conducted by using the synthesized Y2O3 revealed an increasing rate of antibacterial behaviour with pathogens.

  12. Sodium yttrium fluoride based upconversion nano phosphors for biosensing

    Science.gov (United States)

    Parameswaran Nampi, Padmaja; Varma, Harikrishna; Biju, P. R.; Kakkar, Tarun; Jose, Gin; Saha, Sikha; Millner, Paul

    2015-06-01

    In the present study, NaYF4-Yb3+/Er3+ having the composition NaYF4-18%Yb3+/2%Er3+ and NaYF4-20%Yb3+/2%Er3+ with and without the addition of PVP (polyvinyl pyrolidone) have been synthesised by a solution method using NaF, yttrium nitrate, ytterbium nitrate and erbium nitrate as precursors. Upconversion spectra of prepared nanomaterial under 980 nm laser excitation have been studied. The variation in upconversion spectra with new born calf serum and myoglobin has been studied. Myoglobin (Mb) may be helpful when used in conjunction with other cardiac markers for rapid determination of acute myocardial ischemia, especially in patients with a typical chest pain or nonspecific ECG changes. The variation of UC fluorescence with addition of Mb indicates the suitability of using NaYF4 based UC nanoparticles in cardiac marker detection. The detailed study is currently under progress.

  13. Lanthanum and yttrium oxisulfide films grown from the vapor phase

    International Nuclear Information System (INIS)

    For the first time lanthanum and yttrium oxysulfide films are grown by light evaporation. The structure, photoluminescence, optical IR transmission of these films are investigated. Luminescent films of Y2O2S:Eu; La2O2S:Tb; La2O2S:Yb, Er are grown on sapphire, molten quartz, barium fluoride sbstrates. It is shown that the films are characterized by intensive photoluminescence, and emission lines of activator rare earth ions belong to, at least, two centre types. While studying IR transmission of La2O2S:Tb thin films absorption lines are observed in the 8-18μm range, which cannot be observed in three-dimensional monocrystals

  14. Invisible Display in Aluminum

    DEFF Research Database (Denmark)

    Prichystal, Jan Phuklin; Hansen, Hans Nørgaard; Bladt, Henrik Henriksen

    2005-01-01

    integrated display in a metal surface is often ruled by design and functionality of a product. The integration of displays in metal surfaces requires metal removal in order to clear the area of the display to some extent. The idea behind an invisible display in Aluminum concerns the processing of a metal...

  15. Aluminum Sulfate 18 Hydrate

    Science.gov (United States)

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) of the chemical, aluminum sulfate 18 hydrate, is presented. The profile lists physical and harmful properties, exposure limits, reactivity risks, and symptoms of major exposure for the benefit of teachers and students using the chemical in the laboratory.

  16. Hot pressing aluminum nitride

    International Nuclear Information System (INIS)

    Experiment was performed on the hot pressing of aluminum nitride, using three kinds of powder which are: a) made by electric arc method, b) made by nitrifying aluminum metal powder, and c) made from alumina and carbon in nitrogen atmosphere. The content of oxygen of these powders was analyzed by activation analysis using high energy neutron irradiation. The density of hot pressed samples was classified into two groups. The high density group contained oxygen more than 3 wt. %, and the low density group contained about 0.5 wt %. Typical density vs. temperature curves have a bending point near 1,5500C, and the sample contains iron impurity of 0.5 wt. %. Needle crystals were found to grow near 1,5500C by VLS mechanism, and molten iron acts a main part of mechanism as a liquid phase. According to the above-mentioned curve, the iron impurity in aluminum nitride prevents densification. The iron impurity accelerates crystal growth. Advance of densification may be expected by adding iron impurity, but in real case, the densification is delayed. Densification and crystal growth are greatly accelerated by oxygen impurity. In conclusion, more efforts must be made for the purification of aluminum nitride. In the present stage, the most pure nitride powder contains about 0.1 wt. % of oxygen, as compared with good silicon carbide crystals containing only 10-5 wt. % of nitrogen. (Iwakiri, K.)

  17. Nonreciprocity of spin waves in magnonic crystals created by surface acoustic waves in structures with yttrium iron garnet

    Energy Technology Data Exchange (ETDEWEB)

    Kryshtal, R.G.; Medved, A.V., E-mail: avm@ms.ire.rssi.ru

    2015-12-01

    Experimental results of investigations of nonreciprocity for surface magnetostatic spin waves (SMSW) in the magnonic crystal created by surface acoustic waves (SAW) in yttrium iron garnet films on a gallium gadolinium garnet substrate as without metallization and with aluminum films with different electrical conductivities (thicknesses) are presented. In structures without metallization, the frequency of magnonic gaps is dependent on mutual directions of propagation of the SAW and SMSW, showing nonreciprocal properties for SMSW in SAW – magnonic crystals even with the symmetrical dispersion characteristic. In metalized SAW – magnonic crystals the shift of the magnonic band gaps frequencies at the inversion of the biasing magnetic field was observed. The frequencies of magnonic band gaps as functions of SAW frequency are presented. Measured dependencies, showing the decrease of magnonic gaps frequency and the expansion of the magnonic band gap width with the decreasing of the metal film conductivity are given. Such nonreciprocal properties of the SAW – magnonic crystals are promising for signal processing in the GHz range. - Highlights: • Spin waves nonreciprocity in YIG magnonic crystals with SAW was studied. • SAW was shown to create nonreciprocity for spin waves in YIG–GGG even without metal. • Frequency and width of magnonic band gaps were measured versus metal conductivity. • Conductivity for practical use of spin waves in the structure YIG–metal was defined.

  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. Yttrium effect on corrosion resistance of the 12Kh18N10T steel welded joints

    International Nuclear Information System (INIS)

    Electrochemical method has been used to investigate the yttrium effect on corrosion resistance of the weld deposited metal and the welded joints of the 12Kh18H1DT chromium-nickel austenitic steel yttrium introduction in the metall of the weld is accomplished through the electrode coating. It is shown, that modification of the welded joints of the 12Kh18N10T steel with yttrium (0.010-O.027%) increases the corrosion resistance, promotes more complete transition of the alloying elements (chromium, nickel, aluminium, niobium) and decreases the content of bad impurities (S and O2) in the weld deposited metal. Yttrium transition factor when using alumoyttrium foundry alloy is 0.05-0.10

  20. Polymer Derived Yttrium Silicate Ablative TPS Materials for Next-Generation Exploration Missions Project

    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...

  1. Structural study of nanosized yttrium-doped CaMnO3 perovskites

    Indian Academy of Sciences (India)

    J Zagorac; A Zarubica; A Radosavljevic-Mihajlovic; D Zagorac; B Matovic

    2014-05-01

    Nanostructured compounds with general formula Ca1-YMnO3 (0 ≤ ≤ 1) were synthesized by modified glycine nitrate procedure. In the next step, we have investigated crystal structure and microstructure of the synthesized samples using X-ray methods and Rietveld analysis. Focus of this research was the structural stability of the yttrium-doped CaMnO3 perovskite phases, which crystallize in orthorhombic space group Pnma. We observed that the unit cell volumes of the investigated compounds increase proportionally with yttrium amount. Furthermore, we investigated the influence of yttrium amount on Mn–O bond angles and distances, tilting of MnO6 octahedra and deformation due to the presence of Jahn–Teller distortion around Mn3+ cation. In order to estimate effective coordination of and sites, bond valence calculations (BVC) were performed for and site cations. Finally, the photoelectron spectroscopy (XPS) method was applied in order to follow yttrium concentration in the perovskite phases.

  2. Effect of yttrium on the twinning and plastic deformation of AE magnesium alloy under ballistic impact

    Energy Technology Data Exchange (ETDEWEB)

    Asgari, H., E-mail: hamed.asgari@usask.ca [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon (Canada); Odeshi, A.G.; Szpunar, J.A. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon (Canada); Zeng, L.J.; Olsson, E. [Department of Applied Physics, Chalmers University of Technology, Göteborg (Sweden); Li, D.Y. [Department of Chemical and Materials Engineering, University of Alberta, Edmonton (Canada)

    2015-01-19

    In this research, effect of yttrium on the texture formation, microstructural evolution and mechanical response of AE42 and AE44 cast magnesium alloys were investigated under ballistic impact. The selected strain rates were 800 and 1100 s{sup −1} and the tests were conducted using Split Hopkinson Pressure Bar. It was inferred that after high velocity impact, a weaker basal texture developed in the samples with lower content of yttrium. Experimental results also showed that by increasing the concentration of yttrium in the cast AE alloys, strength, ductility and dislocation density of the impacted alloys increased but, the fraction of twinning decreased, which indicate the effective influence of yttrium on the nucleation and growth of twins. Moreover, it was inferred that accumulation of dislocations at intersections of the twins led to the cracking and fracture of the samples under shock loading conditions.

  3. Effect of yttrium on the twinning and plastic deformation of AE magnesium alloy under ballistic impact

    International Nuclear Information System (INIS)

    In this research, effect of yttrium on the texture formation, microstructural evolution and mechanical response of AE42 and AE44 cast magnesium alloys were investigated under ballistic impact. The selected strain rates were 800 and 1100 s−1 and the tests were conducted using Split Hopkinson Pressure Bar. It was inferred that after high velocity impact, a weaker basal texture developed in the samples with lower content of yttrium. Experimental results also showed that by increasing the concentration of yttrium in the cast AE alloys, strength, ductility and dislocation density of the impacted alloys increased but, the fraction of twinning decreased, which indicate the effective influence of yttrium on the nucleation and growth of twins. Moreover, it was inferred that accumulation of dislocations at intersections of the twins led to the cracking and fracture of the samples under shock loading conditions

  4. Structure of Yttrium and/or phosphorous-containing microspheres prepared by sol gel method

    International Nuclear Information System (INIS)

    Full text : The spherical shapes, composition and element distribution were investigated by scanning electron microscopy, carbon/sulfur analysis. Paper chromatography was used to identify radiochemical impurities in the radioactive microspheres. The radionuclide purity was determined using a gamma spectrometry system and an ultra-low level liquid scintillation spectrometer. The results indicated that the proposed silicone oil spheroidization method is suitable for the production of yttrium silicate and yttrium phosphorous silicate microspheres

  5. Analysis of Emission Spectra of Yttrium Monoiodide Produced by the Photodissociation of YI3

    Science.gov (United States)

    Chen, Wenting Wendy; Galvin, Thomas C.; Houlahan, Thomas J., Jr.; Eden, J. Gary

    2015-06-01

    Emission spectra of yttrium monoiodide (YI) spanning the 250 - 940 nm spectral region were generated by the photodissociation of yttrium tri-iodide under photoexcitation at 248 nm (KrF laser). Fluorescent spectra in the13,000 - 19,000 cm-1 and 24,000 - 40,000 cm-1 regions will be first reported. New vibrational transitions of YI in the 20,000 - 25,000 cm-1 interval will be presented as well.

  6. State of radionuclides in seawater. Stabilization of yttrium-90 forms in natural seawater

    International Nuclear Information System (INIS)

    State of yttrium-90 in natural seawater with the known characteristics is determined by processes of hydrolysis and sorption proceeding in the solution. Granulometric composition of radionuclide suspended forms in natural seawater depends on the time of solution exposure. Experimental data permit to make a supposition that after plankton dying off and decomposition of its remnants the state of yttrium-90 will not differ from the radionuclide state in stabilized seawater

  7. Structure modification of yttrium iron garnets under the influence of a laser irradiation

    International Nuclear Information System (INIS)

    Magnetoelectric properties of yttrium iron garnets have been investigated by using of the high -sensitive optical polarimetry method - electromagneto-optical effect. We have found out, that irradiation of yttrium iron garnet films by powerful laser impulse leads to essential increase of the electromagneto-optical effect value that can be a result of removal, in them, of local mechanical strain or nonuniform pressure. (authors)

  8. Yttrium segregation and oxygen diffusion along high-symmetry grain boundaries in YSZ

    Energy Technology Data Exchange (ETDEWEB)

    González-Romero, Robert L. [Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas, Caixa Postal 6165, CEP 13083-970, Campinas (Brazil); Meléndez, Juan J. [Department of Physics, University of Extremadura. Avda. de Elvas, s/n, 06006, Badajoz (Spain); Institute for Advanced Scientific Computing of Extremadura (ICCAEx). Avda. de Elvas, s/n, 06006, Badajoz (Spain)

    2015-02-15

    Highlights: • A study of yttrium segregation to three grain boundaries (GB) in YSZ is performed. • A steady concentration of yttrium is reached after a short transient regime. • Segregation does not change the coefficients for oxygen diffusion along the GB. • The main effect after segregation appears for oxygen bulk diffusion. • The effect is related to the rearrangement of oxygen vacancies after segregation. - Abstract: A study by Molecular Dynamics of yttrium segregation to high-symmetry grain boundaries of yttria-stabilized zirconia has been performed for different amounts of dopants. After an initial (and short) transient, segregation reaches a steady regime in which the concentration of the defect species at the grain-boundaries does not change in time. The maximum concentration of yttrium is reached at the grain-boundary planes, while oxygen vacancies screen the electric field created by segregation. Segregation of yttrium does not change appreciably the coefficients for oxygen diffusion along the grain boundaries, but instead modifies those for bulk diffusion. This effect is rationalized in terms of the rearrangement of the oxygen vacancies at the vicinities of the yttrium cations. The activation energies vary smoothly with the concentration of yttria for all the boundaries. Our data for diffusion coefficients and activation energies compare fairly well with experimental values when segregation is explicitly taken into account.

  9. Yttrium segregation and oxygen diffusion along high-symmetry grain boundaries in YSZ

    International Nuclear Information System (INIS)

    Highlights: • A study of yttrium segregation to three grain boundaries (GB) in YSZ is performed. • A steady concentration of yttrium is reached after a short transient regime. • Segregation does not change the coefficients for oxygen diffusion along the GB. • The main effect after segregation appears for oxygen bulk diffusion. • The effect is related to the rearrangement of oxygen vacancies after segregation. - Abstract: A study by Molecular Dynamics of yttrium segregation to high-symmetry grain boundaries of yttria-stabilized zirconia has been performed for different amounts of dopants. After an initial (and short) transient, segregation reaches a steady regime in which the concentration of the defect species at the grain-boundaries does not change in time. The maximum concentration of yttrium is reached at the grain-boundary planes, while oxygen vacancies screen the electric field created by segregation. Segregation of yttrium does not change appreciably the coefficients for oxygen diffusion along the grain boundaries, but instead modifies those for bulk diffusion. This effect is rationalized in terms of the rearrangement of the oxygen vacancies at the vicinities of the yttrium cations. The activation energies vary smoothly with the concentration of yttria for all the boundaries. Our data for diffusion coefficients and activation energies compare fairly well with experimental values when segregation is explicitly taken into account

  10. Effect of yttrium addition on lattice parameter, Young's modulus and vacancy of magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Peng Qiuming, E-mail: pengqiuming@gmail.com [MagIC - Magnesium Innovation Centre, GKSS-Forschungszentrum Geesthacht GmbH, Max-Planck-Str. 1, Geesthacht 21502 (Germany); Meng Jian [State Key Laboratory of Rare Earth Resources Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Li Yangde [E-Ande Scientific Limited Company 523662 (China); Huang Yuangding; Hort, Norbert [MagIC - Magnesium Innovation Centre, GKSS-Forschungszentrum Geesthacht GmbH, Max-Planck-Str. 1, Geesthacht 21502 (Germany)

    2011-02-25

    Research highlights: {yields} The effect of Y on lattice parameter of Mg is investigated by calculation and XRD measurement. {yields} The effects of Y on the modulus of Mg (T4 and T6 states) are investigated by calculation and tensile test. {yields} The effect of RE on the vacancy of Mg alloys is investigated by calculation and density measurement. - Abstract: The effect of yttrium addition on fundamental characters of magnesium has been investigated by calculated and experimental methods. It was found that the lattice parameter increased and the axial ratio c/a decreased with the increment of yttrium in solid solution. The approximately linear relationship between Young's modulus and the content of yttrium in solid solution was observed in the single phase solid solution Mg-Y alloys (T4 state). However, Young's modulus was closely relevant to the fraction of second precipitate except the content of saturated yttrium in matrix for the aged Mg-Y alloys (T6 state). The concentration of vacancy increased with the increased content of yttrium in solid solution, which was mainly caused by the atomic size misfit and the difference of valence electrons between yttrium and magnesium.

  11. Celsian/yttrium silicate protective coating prepared by microwave sintering for C/SiC composites against oxidation

    International Nuclear Information System (INIS)

    A novel celsian/yttrium silicate coating was prepared by microwave sintering on the surface of C/SiC composites. During sintering process, celsian crystallized from BaO-Al2O3-SiO2 (BAS) glass in the coating and yttrium silicate was formed through the reaction of yttrium oxide and molten BAS glass. The composition and microstructure of the coatings were investigated and the efficiency of the composite coating against oxidation was characterized. The result showed the coating was dense and pore-free. The celsian/yttrium silicate coating can protect C/SiC composites for no less than 90 min at 1773 K in air

  12. Aluminum microstructures on anodic alumina for aluminum wiring boards.

    Science.gov (United States)

    Jha, Himendra; Kikuchi, Tatsuya; Sakairi, Masatoshi; Takahashi, Hideaki

    2010-03-01

    The paper demonstrates simple methods for the fabrication of aluminum microstructures on the anodic oxide film of aluminum. The aluminum sheets were first engraved (patterned) either by laser beam or by embossing to form deep grooves on the surface. One side of the sheet was then anodized, blocking the other side by using polymer mask to form the anodic alumina. Because of the lower thickness at the bottom part of the grooves, the part was completely anodized before the complete oxidation of the other parts. Such selectively complete anodizing resulted in the patterns of metallic aluminum on anodic alumina. Using the technique, we fabricated microstructures such as line patterns and a simple wiring circuit-board-like structure on the anodic alumina. The aluminum microstructures fabricated by the techniques were embedded in anodic alumina/aluminum sheet, and this technique is promising for applications in electronic packaging and devices. PMID:20356280

  13. Treatment of persistent knee effusions with Yttrium 90

    International Nuclear Information System (INIS)

    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 ml100ml. 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

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

    International Nuclear Information System (INIS)

    The influence of yttrium (Y) substitution on ferromagnetic resonance (FMR), initial permeability, and magnetic properties of NiFe2O4 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 NiY0.12Fe1.88O4 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 Y3+ 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 NiY0.24Fe1.76O4 ferrites

  15. 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.

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

    International Nuclear Information System (INIS)

    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 (%) Y2O3 2.4, Dy2O3 0.6, Gd2O3 2.7, CeO2 2.5, Nd2O3 33.2, La2O3 40.3, Sm2O3 4.1 and Pr6O11 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% Y2O3. 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% Y2O3. 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

  17. 21 CFR 73.1645 - Aluminum powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum....

  18. A thermodynamic assessment of the iron–yttrium system

    International Nuclear Information System (INIS)

    Highlights: • Rare earth elements are increasingly used in advanced materials (permanent magnets, hydrogen storage alloys, luminescent materials…). • To our knowledge, this system was not previously optimized. • Two formalisms were compared for the excess terms of the solution phases. • A consistent set of thermodynamic parameters was optimized (good agreement between calculation and experiments). • This work is the start point for the study of ternary systems with RE. -- Abstract: The thermodynamic modeling of the Iron–Yttrium binary system was carried out with the help of the CALPHAD (CALculation of PHAse Diagram) method. The excess term of the Gibbs energy of the solution phases (liquid, b.c.c., f.c.c. and h.c.p.) was assessed with the recent exponential temperature dependence of the interaction energies by Kaptay [1–3] and compared with the linear temperature dependence of Redlich–Kister [4] polynomial equation results. The intermetallic compounds Fe23Y6 and Fe2Y in this binary system which have a homogeneity range, were treated by a two-sublattice model with convenient substitution in each sublattice [5,6]. The others were considered as stoichiometric compounds. A consistent set of thermodynamic parameters leading to a reasonable agreement between the calculated results and literature data was obtained for this system which has not been previously optimized

  19. A thermodynamic assessment of the iron–yttrium system

    Energy Technology Data Exchange (ETDEWEB)

    Kardellass, S., E-mail: saidkardellass@yahoo.fr [Laboratoire de Thermodynamique et Energétique, LTE, Université Ibn-Zohr, B.P. 8106 Agadir (Morocco); Servant, C., E-mail: colette.servant@orange.fr [Laboratoire de Physicochimie de l’Etat Solide, ICMMO, Université Paris-Sud, 91405 Orsay Cedex (France); Selhaoui, N.; Iddaoudi, A.; Amar, M. Ait; Bouirden, L. [Laboratoire de Thermodynamique et Energétique, LTE, Université Ibn-Zohr, B.P. 8106 Agadir (Morocco)

    2014-01-15

    Highlights: • Rare earth elements are increasingly used in advanced materials (permanent magnets, hydrogen storage alloys, luminescent materials…). • To our knowledge, this system was not previously optimized. • Two formalisms were compared for the excess terms of the solution phases. • A consistent set of thermodynamic parameters was optimized (good agreement between calculation and experiments). • This work is the start point for the study of ternary systems with RE. -- Abstract: The thermodynamic modeling of the Iron–Yttrium binary system was carried out with the help of the CALPHAD (CALculation of PHAse Diagram) method. The excess term of the Gibbs energy of the solution phases (liquid, b.c.c., f.c.c. and h.c.p.) was assessed with the recent exponential temperature dependence of the interaction energies by Kaptay [1–3] and compared with the linear temperature dependence of Redlich–Kister [4] polynomial equation results. The intermetallic compounds Fe{sub 23}Y{sub 6} and Fe{sub 2}Y in this binary system which have a homogeneity range, were treated by a two-sublattice model with convenient substitution in each sublattice [5,6]. The others were considered as stoichiometric compounds. A consistent set of thermodynamic parameters leading to a reasonable agreement between the calculated results and literature data was obtained for this system which has not been previously optimized.

  20. Improvement of radiosensitive liquid-core microcapsules by Yttrium polymerization

    International Nuclear Information System (INIS)

    Microcapsules comprising alginate and hyaluronic acid that can be decomposed by radiation are under development. Previously, we observed that radiation efficiently decomposes microcapsules comprising alginate and hyaluronic acid in the ratio 2:1 by weight. In this study, Yttrium (Y) was added to these microcapsules to improve their decomposition by radiation. Hyaluronic acid solutions (0.1% weight/volume) were mixed into 0.2% alginate solution, and carboplatin (0.2 mmol) was added; the resultant was used for capsule preparation. Capsules were prepared by spraying the material into mixtures of 4.34% CaCl2 solution supplemented with Y at final concentrations from 0 to 1.0x10-2%. These capsules were irradiated by a single dose of 0.5, 1.0, 1.5, or 2 Gy with 60Co γ-rays. Immediately after irradiation, we observed the release of the core contents of the microcapsule using a micro Particle Induced X-ray Emission (PIXE) camera. The mean diameter of the microcapsules was 37.3±7.8 μm. Maximum content of radiation-induced release was observed for liquid-core microcapsules prepared by polymerization in a 4.34% CaCl2 solution supplemented with 5.5x10-3%Y. (author)

  1. Structural and dielectric properties of yttrium-substituted hydroxyapatites

    International Nuclear Information System (INIS)

    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. Few-MeV neutrons incident on yttrium

    International Nuclear Information System (INIS)

    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

  3. MCrAlY bond coat with enhanced yttrium

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Optical Spectroscopy of Defects in Yttrium Orthovanadate (YVO4) Crystals

    Science.gov (United States)

    Sze Cheung, Wai; Wiechmann, Katrina; Sheldon, Peter; Yochum, Hank; Yochum, Marcia

    2007-04-01

    Yttrium orthovanadate (YVO4) is an insulating crystal used in several important and emerging optical technologies such as a solid-state laser host material and in fiber optic components for telecommunications. We are engaged in a study of the growth-related and radiation-related point defects that result in discoloration of commercial quality YVO4. These defects can reduce the usefulness of the material. Alternatively, these same defects may actually play a beneficial role in the use of YVO4 for other applications, such as the observed Anti-Stokes Luminescence (light which is converted to a higher energy due to a two-photon process in the crystal) which could make the YVO4 a candidate for blue lasers. It has been surmised [1] that some of these ``useful'' defects are related to oxygen vacancies in the crystal, so we are exploring the effects on defects after annealing the YVO4 in Oxygen and other gas atmospheres. [1] Anti-Stokes emission in undoped YVO4, W. Ryba-Romanowksi, S. Golab, P. Solarz, and G. Dominiak-Dzik, Applied Physics Letters, 80, 1183 (2002).

  5. Synthesis and properties of alumo-yttrium-zirconium oxides

    International Nuclear Information System (INIS)

    Crystallization in a three-component Al2O3-ZrO2-Y2O3 system (with the ratio (mass.%) of ceramic components 54.5:36.7:6.8 produced by hot pressing of calcinated powders) and temperature dependences of flexural strength during three-point bending of materials based on this system and also with Mo and MoSi2 additions are studied. It is stated that crystallization of ternary aluminium, yttrium and zirconium hydroxides passes the stage of zirconium dioxide incompleted microcrystal isolationm from aluminium oxide X-ray amorphous matrix. When calcinating the powders their specific surface value is maximum in the range from 600 to 700 deg C. Ceramics of the composition (mass%): Al2O3-54.5; ZrO2-38.7; Y2O3-6.8 is slightly weakened with the temperature growth to 1500 deg C. Introduction of 5-10 mass% Mo ad MoSi2 as additions increases the material strength at room temperature. With the temperature increase the degree of material weakening is higher that is more obvious after 800-1000 deg C

  6. Structural rearrangement at the yttrium-depleted surface of HCl-processed yttrium aluminosilicate glass for 90Y-microsphere brachytherapy

    International Nuclear Information System (INIS)

    Highlights: ► Y-leaching effects in yttrium alumino-silicates are analyzed at the micrometer scale. ► A high degree of structural reconstruction is driven by non-bridging oxygens. ► Core–shell engineered glass microspheres are obtained after Y-leaching in HCl. - Abstract: The design of a process to create yttrium aluminosilicate microspheres with a core–shell structure is of interest in the field of cancer brachytherapy. Glass microspheres with yttrium-depleted shell may indeed reduce the risk of 90Y release into the organism. Here we show – by means of confocal micro-Raman scattering, microfluorescence, X-ray-fluorescence analysis, and IR spectroscopy – that yttrium depletion may be achieved by etching in HCl solution (pH 2) at a rate of 1 μm day−1 in bulk glass and 3 μm day−1 in glass microsphere (35 μm of diameter). Importantly, the spectroscopic results – collected in confocal configuration along the processed layer – indicate a high degree of structural reconstruction of the glass network, with the formation of an interconnected silicate-rich glass that surrounds a core of unmodified yttrium aluminosilicate. We also demonstrate that the process is driven by non-bridging oxygen sites, which regulate the hydroxylation and structural reconstruction of the glass within the Y-depleted layer. The analysis gives also some insight into open fundamental questions about the short-range structure and the chemical stability of this kind of glass, which is also important in photonics and nuclear waste disposal.

  7. Treatment of unresectable intrahepatic cholangiocarcinoma with yttrium-90 radioembolization: A systematic review and pooled analysis

    Science.gov (United States)

    Al-Adra, D.P.; Gill, R.S.; Axford, S.J.; Shi, X.; Kneteman, N.; Liau, S.-S.

    2015-01-01

    Radioembolization with yttrium-90 microspheres offers an alternative treatment option for patients with unresectable intrahepatic cholangiocarcinoma (ICC). However, the rarity and heterogeneity of ICC makes it difficult to draw firm conclusions about treatment efficacy. Therefore, the goal of the current study is to systematically review the existing literature surrounding treatment of unresectable ICCs with yttrium-90 microspheres and provide a comprehensive review of the current experience and clinical outcome of this treatment modality. We performed a comprehensive search of electronic databases for ICC treatment and identified 12 studies with relevant data regarding radioembolization therapy with yttrium-90 microspheres. Based on pooled analysis, the overall weighted median survival was 15.5 months. Tumour response based on radiological studies demonstrated a partial response in 28% and stable disease in 54% of patients at three months. Seven patients were able to be downstaged to surgical resection. The complication profile of radioembolization is similar to that of other intra-arterial treatment modalities. Overall survival of patients with ICC after treatment with yttrium-90 microspheres is higher than historical survival rates and shows similar survival to those patients treated with systemic chemotherapy and/or trans-arterial chemoembolization therapy. Therefore, the use of yttrium-90 microspheres should be considered in the list of available treatment options for ICC. However, future randomized trials comparing systemic chemotherapy, TACE and local radiation will be required to identify the optimal treatment modality for unresectable ICC. PMID:25449754

  8. Treatment of unresectable intrahepatic cholangiocarcinoma with yttrium-90 radioembolization: a systematic review and pooled analysis.

    Science.gov (United States)

    Al-Adra, D P; Gill, R S; Axford, S J; Shi, X; Kneteman, N; Liau, S-S

    2015-01-01

    Radioembolization with yttrium-90 microspheres offers an alternative treatment option for patients with unresectable intrahepatic cholangiocarcinoma (ICC). However, the rarity and heterogeneity of ICC makes it difficult to draw firm conclusions about treatment efficacy. Therefore, the goal of the current study is to systematically review the existing literature surrounding treatment of unresectable ICCs with yttrium-90 microspheres and provide a comprehensive review of the current experience and clinical outcome of this treatment modality. We performed a comprehensive search of electronic databases for ICC treatment and identified 12 studies with relevant data regarding radioembolization therapy with yttrium-90 microspheres. Based on pooled analysis, the overall weighted median survival was 15.5 months. Tumour response based on radiological studies demonstrated a partial response in 28% and stable disease in 54% of patients at three months. Seven patients were able to be downstaged to surgical resection. The complication profile of radioembolization is similar to that of other intra-arterial treatment modalities. Overall survival of patients with ICC after treatment with yttrium-90 microspheres is higher than historical survival rates and shows similar survival to those patients treated with systemic chemotherapy and/or trans-arterial chemoembolization therapy. Therefore, the use of yttrium-90 microspheres should be considered in the list of available treatment options for ICC. However, future randomized trials comparing systemic chemotherapy, TACE and local radiation will be required to identify the optimal treatment modality for unresectable ICC. PMID:25449754

  9. Photoemission study of tris(8-hydroxyquinoline) aluminum/aluminum oxide/tris(8-hydroxyquinoline) aluminum interface

    International Nuclear Information System (INIS)

    The evolution of the interface electronic structure of a sandwich structure involving aluminum oxide and tris(8-hydroxyquinoline) aluminum (Alq), i.e. (Alq/AlOx/Alq), has been investigated with photoemission spectroscopy. Strong chemical reactions have been observed due to aluminum deposition onto the Alq substrate. The subsequent oxygen exposure releases some of the Alq molecules from the interaction with aluminum. Finally, the deposition of the top Alq layer leads to an asymmetry in the electronic energy level alignment with respect to the AlOx interlayer

  10. Synthesis of Neodymium-Doped Yttrium Aluminum Garnet (Nd∶YAG) Nano-Sized Powders by Low Temperature Combustion

    Institute of Scientific and Technical Information of China (English)

    Zhang Huashan; Su Chunhui; Han Hui; Hou Zhaoxia

    2005-01-01

    The homogeneously dispersed, less agglomerated (Nd0.01Y0.99)3Al5O12 nano-sized powders were synthesized by the low temperature combustion (LCS), using Nd2O3, Y2O3, Al(NO3)3·9H2O, ammonia water and citric acid as starting materials. This method effectively solves the problems caused by solid-state reaction at high temperature and hard agglomerates brought by the chemical precipitation method. The powders were characterized by TG-DTA, XRD, FT-IR, TEM respectively and the photoluminescence (PL) spectra of (Nd0.01Y0.99)3Al5O12 green and sintered ceramic disks were measured. The results show that the forming temperature of YAG crystal phase is 850 ℃ and YAP crystal phase appearing during the calcinations transforms to pure YAG at 1050 ℃. The particle size of the powders synthesized by the LCS is in a range of 20~50 nm depending on the thermal treatment temperatures. The effectively induced cross section (σin) with the value 4.03×10-19 cm2 of (Nd0.01Y0.99)3Al5O12 ceramics is about 44% higher than that of single crystal.

  11. Study of corrosion-electrochemical behavior of aluminum-beryllium alloys alloyed with yttrium, lanthanum and cerium

    International Nuclear Information System (INIS)

    Advantage of alloys on the basis of system Al-Be, Al-Be-REM is raised technological, physical, chemical and corrosion resistance properties in damp and excessively aggressive atmospheres. According to literary reviews, this alloys basically are foundry-hypoeuthectic and hypereuthectic, and the technology of moulding of these alloys very difficult and demands application of operations modifying. Difficultly deleted impurity basically (Fe), specifically influence phase structure, naturally influencing on physical and chemical properties industrial silumines with the maintenance not less than 0.4-0.5 %. Many additives as Fe, Mg, Ti, Be, especially in hypoeuthectic silumines increasing strength and foundry properties, can reduce them corrosion-resistance. In connection with the above-stated is of interest researches of influence of impurity such elements as, Be and REM on corrosion resistance industrial alumines. Studies corrosion-resistance spent samples potentiostatic a method on device 'Potentiostate P-50' with a registering recorder in the environment of the muriatic solutions in a mode 'Potential'. he analysis of experimental data have shown, that addition Be, positively modifying structure of foundry alloys, reduces influences containing in it Fe, increases strength and corrosion resistance, which calculations testify experimental data of electrochemical indicators. (author)

  12. Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

    2007-08-16

    Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as “bath” in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

  13. Neurofibrillary pathology and aluminum in Alzheimer's disease

    OpenAIRE

    Shin, R. W.; Lee, V. M. Y; Trojanowski, J Q

    1995-01-01

    Since the first reports of aluminum-induced neurofibrillary degeneration in experimental animals, extensive studies have been performed to clarify the role played by aluminum in the pathogenesis of Alzheimer's disease (AD). Additional evidence implicating aluminum in AD includes elevated levels of aluminum in the AD brain, epidemiological data linking aluminum exposure to AD, and interactions between aluminum and protein components in the pathological lesions o...

  14. Aluminum Nanoholes for Optical Biosensing

    Directory of Open Access Journals (Sweden)

    Carlos Angulo Barrios

    2015-07-01

    Full Text Available Sub-wavelength diameter holes in thin metal layers can exhibit remarkable optical features that make them highly suitable for (biosensing applications. Either as efficient light scattering centers for surface plasmon excitation or metal-clad optical waveguides, they are able to form strongly localized optical fields that can effectively interact with biomolecules and/or nanoparticles on the nanoscale. As the metal of choice, aluminum exhibits good optical and electrical properties, is easy to manufacture and process and, unlike gold and silver, its low cost makes it very promising for commercial applications. However, aluminum has been scarcely used for biosensing purposes due to corrosion and pitting issues. In this short review, we show our recent achievements on aluminum nanohole platforms for (biosensing. These include a method to circumvent aluminum degradation—which has been successfully applied to the demonstration of aluminum nanohole array (NHA immunosensors based on both, glass and polycarbonate compact discs supports—the use of aluminum nanoholes operating as optical waveguides for synthesizing submicron-sized molecularly imprinted polymers by local photopolymerization, and a technique for fabricating transferable aluminum NHAs onto flexible pressure-sensitive adhesive tapes, which could facilitate the development of a wearable technology based on aluminum NHAs.

  15. Aluminum Nanoholes for Optical Biosensing

    Science.gov (United States)

    Barrios, Carlos Angulo; Canalejas-Tejero, Víctor; Herranz, Sonia; Urraca, Javier; Moreno-Bondi, María Cruz; Avella-Oliver, Miquel; Maquieira, Ángel; Puchades, Rosa

    2015-01-01

    Sub-wavelength diameter holes in thin metal layers can exhibit remarkable optical features that make them highly suitable for (bio)sensing applications. Either as efficient light scattering centers for surface plasmon excitation or metal-clad optical waveguides, they are able to form strongly localized optical fields that can effectively interact with biomolecules and/or nanoparticles on the nanoscale. As the metal of choice, aluminum exhibits good optical and electrical properties, is easy to manufacture and process and, unlike gold and silver, its low cost makes it very promising for commercial applications. However, aluminum has been scarcely used for biosensing purposes due to corrosion and pitting issues. In this short review, we show our recent achievements on aluminum nanohole platforms for (bio)sensing. These include a method to circumvent aluminum degradation—which has been successfully applied to the demonstration of aluminum nanohole array (NHA) immunosensors based on both, glass and polycarbonate compact discs supports—the use of aluminum nanoholes operating as optical waveguides for synthesizing submicron-sized molecularly imprinted polymers by local photopolymerization, and a technique for fabricating transferable aluminum NHAs onto flexible pressure-sensitive adhesive tapes, which could facilitate the development of a wearable technology based on aluminum NHAs. PMID:26184330

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

    International Nuclear Information System (INIS)

    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)

  17. Tungsten carbide platelet-containing cemented carbide with yttrium containing dispersed phase

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; CHEN Shu; WANG Yuan-jie; YU Xian-wang; XIONG Xiang-jun

    2008-01-01

    A fine and platelet tungsten carbide patterned structure with fine yttrium containing dispersed phase was observed in liquid phase sintered WC-20%Co-1%Y2O3 cemented carbide with ultrafine tungsten carbide and nano yttrium oxide as starting materials. By comparing the microstructures of the alloy prepared by hot-press at the temperature below the eutectic melting temperature and by conventional liquid phase sintering, it is shown that hexagonal and truncated trigonal plate-like WC grains are formed through the mechanism of dissolution-precipitation (recrystallization) at the stage of liquid phase sintering. Yttrium in the addition form of oxide exhibits good ability in inhibiting the discontinuous or inhomogeneous WC grain growth in the alloy at the stage of solid phase sintering.

  18. Oxidation Behavior of Fe-Ni-Co Based Superalloys and Influence of Yttrium Addition

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@The oxidation behavior of three Fe-Co-Ni based superalloys with different yttrium additions were investigated at 650℃ in air. The oxidation kinetics of the three alloys follows parabolic law initially, then follows linear law. The oxide scale formed on all three alloys consists mainly of Co dissolved Fe3O4 and partly of FeO and Fe2O3, in which Fe3O4 acts as a protective layer.An yttrium addition into the Fe-Co-Ni based superalloys improves their oxidation resistance by reducing the micro-defects in the scales. Thus, the weight gains of the alloys during the oxidation are reduced, and the transition of parabolic law to linear law is postponed. Pegging was observed on the cross section of alloy with 0.08 wt pct yttrium addition after the oxidation.

  19. Influence of Yttrium Implantation on Oxidation Behavior of Pure Nickel at 1 000℃

    Institute of Scientific and Technical Information of China (English)

    JIANG Shi-hang; JIN Hui-ming; YAN Kun; GONG Ze-xiang

    2005-01-01

    Isothermal and cyclic oxidation behaviors of pure and yttrium-implanted nickel were studied at 1000℃ in air. The oxide scales formed on nickel substrates were performed using SEM and TEM. It was found that Yimplantation greatly improved the anti-oxidation ability of nickel both in isothermal and cyclic oxidizing experiments. Laser Raman microscopy was also used to study the stress status of oxide scales formed on nickel with and without yttrium. The main reason for the improvement in antioxidation and adhesion of oxide scale was Y-implantation greatly reduced the grain size of NiO and lowered the compressive stress within the scale. Yttrium implantation enhanced the adhesion of protective NiO oxide scale formed on nickel substrate.

  20. Analysis on insulator–metal transition in yttrium doped LSMO from electron density distribution

    Indian Academy of Sciences (India)

    S Israel; S Saravana Kumar; R Renuretson; R A J R Sheeba; R Saravanan

    2012-02-01

    Yttrium doped LSMO (La1−SrMnO3) was prepared using sol–gel technique and analysed for the insulator–metal transition fromcharge density variation in the unit cell with respect to different stoichiometric inclusion of yttrium. X-ray powder diffraction profiles of the samples were obtained and the well known Rietveld method and a versatile tool called maximum entropy method (MEM) were used for structural and profile refinement. The charge density in the unit cell was constructed using refined structure factors and was analysed. The charge ordering taking place in the insulator–metal transition was investigated and quantified. The insulator–metal transition was found to occur when 20% of La/Sr atoms were replaced by yttrium. The changes in the charge environment have also been analysed.

  1. 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.

  2. Luminescence performance of europium-doped yttrium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jayaramaiah, J.R. [Department of Physics, Bangalore University, Bangalore 560056 (India); Department of Physics, Government First Grade College, Nargund 582207 (India); Lakshminarasappa, B.N., E-mail: bnlnarasappa@rediffmail.com [Department of Physics, Bangalore University, Bangalore 560056 (India); Nagabhushana, K.R. [Department of Physics, PES University, BSK 3rd stage, Bangalore 560085 (India)

    2015-01-15

    Europium-doped yttrium oxide thin films have been deposited by a spray pyrolysis method. The crystallite sizes are calculated to be ∼50 nm using Scherrer's formula. Fourier transformed infrared spectroscopy (FTIR) reveals broad absorption with peak at 875 cm{sup −1}. Surface morphology and elemental composition of the thin films are studied by a field-emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray spectroscopy (EDS). The energy gap (E{sub g}) of the thin film sample is found to be ∼5.37 eV. The film exhibits photoluminescence (PL) emission over 525–550 nm, 585–601 nm, 612 nm and 620–632 nm under the excitation of 240 nm. Gamma (γ)-irradiated films exhibit two well-resolved thermoluminescent (TL) glows with peaks at 460 and 570 K. The TL glow curves are analyzed by a glow curve shape method. The activation energy and the frequency factor are found to be, respectively, ∼0.6 eV, ∼3×10{sup 6} s{sup −1} for 460 K and ∼0.53 eV, ∼46.72×10{sup 3} s{sup −1} for 570 K. - Highlights: • Y{sub 2}O{sub 3}:Eu{sup 3+} thin films deposited by spray pyrolysis. • [2 2 2] planes are a preferential orientation during crystal growth. • FE-SEM shows particles appearing as nonporous in nature. • The energy gap of Y{sub 2}O{sub 3}:Eu{sup 3+} film is found to be ∼5.37 eV. • Thermoluminescence centers at 460 K and 570 K glow peaks are analyzed.

  3. Luminescence performance of europium-doped yttrium oxide thin films

    International Nuclear Information System (INIS)

    Europium-doped yttrium oxide thin films have been deposited by a spray pyrolysis method. The crystallite sizes are calculated to be ∼50 nm using Scherrer's formula. Fourier transformed infrared spectroscopy (FTIR) reveals broad absorption with peak at 875 cm−1. Surface morphology and elemental composition of the thin films are studied by a field-emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray spectroscopy (EDS). The energy gap (Eg) of the thin film sample is found to be ∼5.37 eV. The film exhibits photoluminescence (PL) emission over 525–550 nm, 585–601 nm, 612 nm and 620–632 nm under the excitation of 240 nm. Gamma (γ)-irradiated films exhibit two well-resolved thermoluminescent (TL) glows with peaks at 460 and 570 K. The TL glow curves are analyzed by a glow curve shape method. The activation energy and the frequency factor are found to be, respectively, ∼0.6 eV, ∼3×106 s−1 for 460 K and ∼0.53 eV, ∼46.72×103 s−1 for 570 K. - Highlights: • Y2O3:Eu3+ thin films deposited by spray pyrolysis. • [2 2 2] planes are a preferential orientation during crystal growth. • FE-SEM shows particles appearing as nonporous in nature. • The energy gap of Y2O3:Eu3+ film is found to be ∼5.37 eV. • Thermoluminescence centers at 460 K and 570 K glow peaks are analyzed

  4. 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.

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

    International Nuclear Information System (INIS)

    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

  6. Mott insulator-to-metal transition in yttrium-doped CaIrO3

    OpenAIRE

    Gunasekera, J.; Chen, Y.; Kremenak, J. W.; Miceli, P. F.; Singh, D.K.

    2014-01-01

    We report on the study of insulator-to-metal transition in post-perovskite compound CaIrO3. It is discovered that a gradual chemical substitution of calcium by yttrium leads to the onset of strong metallic behavior in this compound. This observation is in stark contrast to BaIrO3, which preserves its Mott insulating behavior despite excess of charge carriers due to yttrium doping. Magnetic measurements reveal that both compounds tend to exhibit magnetic character irrespective of the chemical ...

  7. Thin film growth of epitaxial gadolinium oxide, gadolinium yttrium oxide, and gadolinium cerium oxide by electrodeposition

    International Nuclear Information System (INIS)

    Thin films of gadolinium oxide, gadolinium yttrium oxide, and gadolinium cerium oxide were electrodeposited from non-aqueous baths. The films were on the order of 15 nm thick, and were grown epitaxially on textured nickel-tungsten substrates. The effect of deposition rate, annealing temperature and secondary metals on crystallinity and crystal orientation was investigated by X-ray diffraction and transmission electron microscopy. Slower rates, higher temperatures and low concentrations of yttrium improve the crystallinity of gadolinium oxide films, whereas the introduction of cerium induced polycrystallinity.

  8. Thin film growth of epitaxial gadolinium oxide, gadolinium yttrium oxide, and gadolinium cerium oxide by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Jonathan R., E-mail: jonathan.mann@nrel.gov; Bhattacharya, Raghu N.

    2010-10-29

    Thin films of gadolinium oxide, gadolinium yttrium oxide, and gadolinium cerium oxide were electrodeposited from non-aqueous baths. The films were on the order of 15 nm thick, and were grown epitaxially on textured nickel-tungsten substrates. The effect of deposition rate, annealing temperature and secondary metals on crystallinity and crystal orientation was investigated by X-ray diffraction and transmission electron microscopy. Slower rates, higher temperatures and low concentrations of yttrium improve the crystallinity of gadolinium oxide films, whereas the introduction of cerium induced polycrystallinity.

  9. Study of yttrium and rare earth oxide concentrates for producing polycrystalline tetragonal zirconia (Pzt)

    International Nuclear Information System (INIS)

    In this paper is studied the influence of the concentration of yttrium - rare earths oxides mixture in zirconium oxide for the obtainment of tetragonal zirconia polycrystals. The starting powders were obtained by coprecipitation in chlorides medium. The values of lattice parameters, obtained from X-ray diffractometry, were refined by the minimum squares method ((2θ)error lower than 0.05 deg) and revealed the presence of the tetragonal phase for 6 wt% of yttrium - rare earths oxides mixture. Our results showed that this phase is stable at low temperature. Contrary to another authors's conclusions. (author)

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

    International Nuclear Information System (INIS)

    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)

  11. Hualu Aluminum Will Construct Large Coal-Power-Aluminum Aluminum Processing Industrial Chain

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The reporter learned from relevant departments of Baiyin City that in order to further push forward industrial upgrading,fulfill expansion and consolidation of the enterprise,Gansu Hualu Aluminum Co.,Ltd(Hualu Aluminum)will implement Out-Of-City-Into-Park project,

  12. Aluminum Zintl anion moieties within sodium aluminum clusters

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haopeng; Zhang, Xinxing; Ko, Yeon Jae; Grubisic, Andrej; Li, Xiang; Ganteför, Gerd; Bowen, Kit H., E-mail: AKandalam@wcupa.edu, E-mail: kiran@mcneese.edu, E-mail: kbowen@jhu.edu [Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Schnöckel, Hansgeorg [Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, 76128 Karlsruhe (Germany); Eichhorn, Bryan W. [Department of Chemistry, University of Maryland at College Park, College Park, Maryland 20742 (United States); Lee, Mal-Soon; Jena, P. [Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Kandalam, Anil K., E-mail: AKandalam@wcupa.edu, E-mail: kiran@mcneese.edu, E-mail: kbowen@jhu.edu [Department of Physics, West Chester University of Pennsylvania, West Chester, Pennsylvania 19383 (United States); Kiran, Boggavarapu, E-mail: AKandalam@wcupa.edu, E-mail: kiran@mcneese.edu, E-mail: kbowen@jhu.edu [Department of Chemistry, McNeese State University, Lake Charles, Louisiana 70609 (United States)

    2014-02-07

    Through a synergetic combination of anion photoelectron spectroscopy and density functional theory based calculations, we have established that aluminum moieties within selected sodium-aluminum clusters are Zintl anions. Sodium–aluminum cluster anions, Na{sub m}Al{sub n}{sup −}, were generated in a pulsed arc discharge source. After mass selection, their photoelectron spectra were measured by a magnetic bottle, electron energy analyzer. Calculations on a select sub-set of stoichiometries provided geometric structures and full charge analyses for both cluster anions and their neutral cluster counterparts, as well as photodetachment transition energies (stick spectra), and fragment molecular orbital based correlation diagrams.

  13. Spray Rolling Aluminum Strip

    Energy Technology Data Exchange (ETDEWEB)

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  14. Ultrahigh vacuum system with aluminum

    International Nuclear Information System (INIS)

    A bakeable vacuum chamber (1500C continuous) consists of aluminum alloy beam pipe (6063-T6) and bellows (5052-F) with an aluminum alloy flange (2219-T87) and a metal seal [Helicoflex-HN: pure aluminum (1050) O-ring with an elastic core (Ni base super alloy Inconel 750) which supplies the sealing force] has been constructed. The beam pipe and the flange (6063-T6/2219-T87), and the bellows and the flange (5052-F/2219-T87) were welded by an alternate current (50 Hz) TIG process using an aluminum alloy filler wire (4043). The mechanical properties of the aluminum alloy (2219-T87) is suitable for using the Helicoflex O-ring but the groove surface for the gasket is weak for scratching. Cromium-nitride coating by ion plating method was carried out on the aluminum surface of the gasket groove [thickness: 16 μm, micro Vickers hardness: 1800]. Ordinary stainless steel vacuum system can be replaced by the aluminum vacuum system in an accelerator. (author)

  15. Application of diffusion barriers to the refractory fibers of tungsten, columbium, carbon and aluminum oxide

    Science.gov (United States)

    Douglas, F. C.; Paradis, E. L.; Veltri, R. D.

    1973-01-01

    A radio frequency powered ion-plating system was used to plate protective layers of refractory oxides and carbide onto high strength fiber substrates. Subsequent overplating of these combinations with nickel and titanium was made to determine the effectiveness of such barrier layers in preventing diffusion of the overcoat metal into the fibers with consequent loss of fiber strength. Four substrates, five coatings, and two metal matrix materials were employed for a total of forty material combinations. The substrates were tungsten, niobium, NASA-Hough carbon, and Tyco sapphire. The diffusion-barrier coatings were aluminum oxide, yttrium oxide, titanium carbide, tungsten carbide with 14% cobalt addition, and zirconium carbide. The metal matrix materials were IN 600 nickel and Ti 6/4 titanium. Adhesion of the coatings to all substrates was good except for the NASA-Hough carbon, where flaking off of the oxide coatings in particular was observed.

  16. [Microbiological corrosion of aluminum alloys].

    Science.gov (United States)

    Smirnov, V F; Belov, D V; Sokolova, T N; Kuzina, O V; Kartashov, V R

    2008-01-01

    Biological corrosion of ADO quality aluminum and aluminum-based construction materials (alloys V65, D16, and D16T) was studied. Thirteen microscopic fungus species and six bacterial species proved to be able to attack aluminum and its alloys. It was found that biocorrosion of metals by microscopic fungi and bacteria was mediated by certain exometabolites. Experiments on biocorrosion of the materials by the microscopic fungus Alternaria alternata, the most active biodegrader, demonstrated that the micromycete attack started with the appearance of exudate with pH 8-9 on end faces of the samples. PMID:18669265

  17. Light-emitting diodes of 'Warm' white luminescence on the basis of p-n heterostructures of the InGaN/AlGaN/GaN type coated with phosphors made of yttrium-gadolinium garnets

    International Nuclear Information System (INIS)

    Electroluminescence spectra and color characteristics of light-emitting diodes of white luminescence based on p-n heterostructures of the InGaN/AlGaN/GaN type with blue emission (λmax ∼ 455 nm) coated with phosphors of the type of aluminum-yttrium-gadolinium garnets activated with the Ce3+ ions are studied. The maximum in the excitation spectra of phosphors varies in the range 460-470 nm. The luminescence spectra of phosphors have the peaks from 530 to 590 nm and a width at half-maximum of intensity from 120 to 135 nm depending of the compound composition. The selection of intensities of blue and yellow-orange bands allows one to shift the coordinates of chromaticity of white light-emitting diodes to the region of 'warm' luminescence with a correlated color temperature to TCC = 3000 K and maximum luminous efficiency up to 50 lm/W.

  18. Listeria monocytogenes septic arthritis following intra-articular yttrium-90 therapy.

    OpenAIRE

    Wilson, A P; Prouse, P J; Gumpel, J. M.

    1984-01-01

    Listeria monocytogenes is a rare cause of septic arthritis, which usually occurs in a host compromised by systemic illness. Intra-articular irradiation with yttrium-90 is generally free of complication. We report a case of intra-articular sepsis of the knee joint by Listeria monocytogenes acquired under unusual circumstances.

  19. Extraction of Yttrium from Xenotime Concentrate by D2EHPA-Dodecane

    International Nuclear Information System (INIS)

    Extraction yttrium from xenotime concentrate has been done. Feed of extraction was rare earth xenotime concentrate (Yttria group) have been separated from ceria group. Stripping process of extract phase used nitric acid and sulphuric acid. Determination of yttrium (Y), and impurities of rare earths other was as lanthanum (La), cerium (Ce), and neodymium (Nd) was analyzed by spectrometer X-ray. The purposed of this research was obtained separated yttrium relative pure. At process of extraction variable influence were concentration of nitric acid in feed, time of extraction, and concentration of extractant in organic phase. At process of stripping variable influence were kind of acid and concentration of acid. At this research optimum condition of extraction process was molarity of nitric acid = 1 M, time of extraction = 15 minutes, and concentration of extractant = 30% organo phosphor D2EHPA in dodecane. At that optimum condition was found extraction efficiency of yttrium = 98.03%, with impurities of La = 198 ppm, Ce = 213 ppm, and Nd = 132 ppm. At stripping process was the best acid used sulphuric acid was 8 M and time of stripping was 29 minutes. At this condition was found efficiency of stripping = 79.29%, with impurities of La = 85 ppm, Ce = 36 ppm, and Nd = 25 ppm. (author)

  20. Growth and hydrogenation of epitaxial yttrium switchable mirrors on CaF2

    NARCIS (Netherlands)

    Kooij, E.S.; Rector, J.H.; Nagengast, D.G.; Kerssemakers, J.W.J.; Dam, B.; Griessen, R.; Remhof, A.; Zabel, H.

    2002-01-01

    Rutherford backscattering (RBS) ion channeling measurements and X-ray diffraction experiments are performed to study the epitaxial nature of as-deposited yttrium on CaF2111 substrates and the effect of hydrogenation on the crystalline quality. The RBS and X-ray results clearly demonstrate the unique

  1. Controlled synthesis and formation mechanism of sodium yttrium fluoride nanotube arrays

    Institute of Scientific and Technical Information of China (English)

    TIAN Li; TAN Li; SUN Qiliang; XIANG Shaobin; XIAO Qiuguo; TANG Jianting; ZHU Guangshan

    2012-01-01

    Cubic and hexagonal sodium yttrium fluoride were successfully synthesized from yttrium nitrate,sodium fluoride and polyethanediol in propanetriol solvent under a facile hydrothermal route.By regulating the molar ratio of yttrium and fluoride,hydrothermal temperature and reaction time,the phase and shape of sodium yttrium fluoride were commendably controlled.The as-prepared products were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM) and energy dispersive X-ray spectrum (EDS) techniques.It was revealed that the hollow-structured Na(Y1.5Na0.5)F6 nanotubes self-assembled and arrayed orientedly to be bamboo raft-shaped.The formation of hexagonal Na(Y1.5Na0.5)F6 nanotube arrays was attributed to solid-liquid-solid process and Oswald ripening.This study provided a simple method to prepare hexagonal bamboo raft-shaped Na(Y1.5Na0.5)F6 on a large scale,which broadened their practical applications.

  2. Elastic properties of single-crystalline and consolidated nano-structured yttrium oxide at room temperature

    International Nuclear Information System (INIS)

    High resolution Brillouin spectroscopy was used to characterize the elastic stiffness properties of consolidated nano-crystalline yttrium oxide as well as of the related single-crystalline state. Defect enriched grain boundaries are discussed as sources for the extremely soft elastic properties of the nano-crystalline state. (author)

  3. Effect of yttrium on the coking behavior of Fe-based superalloy in heavy hydrocarbon

    International Nuclear Information System (INIS)

    Graphical abstract: Compared with bare specimen (a), specimen doped with yttrium (b) shows the elimination of the intergranular coking behavior of Fe-based superalloy and changes the coke morphology. - Highlights: • Effect of Y on the coking behavior of Fe-based superalloy was studied. • The alloy doped with Y exhibits the better coking and carbonizing resistance. • Y doped in the alloy eliminates the intergranular coking and carbonization. - Abstract: Effect of the rare earth element yttrium on the coking behavior of Fe-based superalloy has been studied. The coking process of Fe-based superalloy during dodecane pyrolysis includes three stages – incubation period, coke protrusions growing and graphite layer stacking. Fe-based superalloy with yttrium addition exhibits the better coking and carburization resistance. The reason is that Y doped in Fe-based superalloy eliminates the intergranular coking and carburization by forming yttrium oxides to inhibit the aggregation of Cr2O3 at the grain boundary in initial period of coking behavior, thus internal Cr2O3 layer forms and effectively blocks the permeation of outer graphite

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

    International Nuclear Information System (INIS)

    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.)

  5. Scandium and yttrium phosphasalen complexes as initiators for ring-opening polymerization of cyclic esters.

    Science.gov (United States)

    Bakewell, Clare; White, Andrew J P; Long, Nicholas J; Williams, Charlotte K

    2015-03-01

    The synthesis and characterization of novel scandium and yttrium phosphasalen complexes is reported, where phosphasalen refers to two different bis(iminophosphorane) derivatives of the more ubiquitous salen ligands. The activity of the complexes as initiators for the ring-opening polymerization of cyclic esters is presented. The scandium complexes are inactive for lactide polymerization but slow and controlled initiators for ε-caprolactone polymerization. The lack of activity toward lactide exhibited by these compounds is probed, and a rare example of single-monomer insertion product, unable to undergo further reactions with lactide, is identified. In contrast, the analogous yttrium phosphasalen complex is a very active initiator for the ring-opening polymerization of rac-lactide (kobs = 1.5 × 10(-3) s(-1) at 1:500 [yttrium initiator]:[rac-lactide], 1 M overall concentration of lactide in THF at 298 K). In addition to being a very fast initiator, the yttrium complex also maintains excellent levels of polymerization control and a high degree of isoselectivity, with the probability of isotactic enchainment being Pi = 0.78 at 298 K. PMID:25691212

  6. Thermal decomposition of lanthanum and yttrium oxalates doped with Europium (III)

    International Nuclear Information System (INIS)

    Thermal decomposition of lanthanum and yttrium oxalates doped with europium (III) is studied by the differential thermal analysis (DTA). The influence of the doping process in the thermal decomposition mechanism and the effect caused by sample aging in the decomposition and dehydratation mechanisms is observed. (M.J.C.)

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

    International Nuclear Information System (INIS)

    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

  8. Photo-induced effect on optical absorption coefficient in yttrium iron garnet

    International Nuclear Information System (INIS)

    Photo-induced irreversible change in an optical absorption was observed for a bulk single crystal and a thin film of yttrium-iron garnets (YIG) over the spectral range 700-2000 nm and over the temperature range 79-200 K. We explain the observation as a redistribution of oscillator strength associated with structural change by an irradiation at low temperatures. ((orig.))

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

    International Nuclear Information System (INIS)

    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)

  10. Nuclear magnetic resonance of iron-57 nuclei in local fields in yttrium and iron garnets

    International Nuclear Information System (INIS)

    We have demonstrated the nuclear resonance of 57Fe 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)

  11. Interaction of adsorbed carbon monoxide with surface hydroxyl groups of yttrium erbium and holmium oxides

    International Nuclear Information System (INIS)

    The structure of oxygen-containing organic compounds appeared on the surfaces of yttrium, erbium and holmium oxides during the reaction of CO with hydroxyl groups was studied by diffusion reflection IR spectroscopy . Formiate (HCO-2), formyl (HCO-) and, perhaps, dioxomethylene (H2CO22-) groups was demonstrated to be by them. 16 refs., 3 figs., 1 tab

  12. Study-parameter impact in quantitative Yttrium-90 PET imaging for Radioembolization Treatment Monitoring and Dosimetry

    NARCIS (Netherlands)

    Goedicke, A.; Berker, Y.; Verburg, F. A.; Behrendt, F.F.; Winz, O.; Mottaghy, F.M.

    2013-01-01

    A small positron-generating branch in 90-Yttrium (90Y) decay enablespost-therapy dose assessment in liver cancer radioembolization treatment. The aim of this study was to validate clinical 90Y PET quantification, focusing on scanner linearity as well as acquisition and reconstruction parameter impac

  13. Chrome - Free Aluminum Coating System

    Science.gov (United States)

    Bailey, John H.; Gugel, Jeffrey D.

    2010-01-01

    This slide presentation concerns the program to qualify a chrome free coating for aluminum. The program was required due to findings by OSHA and EPA, that hexavalent chromium, used to mitigate corrosion in aerospace aluminum alloys, poses hazards for personnel. This qualification consisted of over 4,000 tests. The tests revealed that a move away from Cr+6, required a system rather than individual components and that the maximum corrosion protection required pretreatment, primer and topcoat.

  14. Refinement of Aluminum Thermal Chrome

    International Nuclear Information System (INIS)

    Refinement of aluminum thermal chrome of the X98.5 mark by a high-temperature annealing in high vacuum is explored experimentally. It is shown that at the temperature of annealing 1150 C during 1...6 hours the content of such interstitial impurity as nitrogen is essentially depressed in chrome, and also the content of aluminum and iron admixtures is noticeably moderated

  15. The effect of yttrium addition on oxidation of a sputtered nanocrystalline coating with moderate amount of tantalum in composition

    Science.gov (United States)

    Wang, Jinlong; Chen, Minghui; Yang, Lanlan; Liu, Li; Zhu, Shenglong; Wang, Fuhui; Meng, Guozhe

    2016-03-01

    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-Al2O3 to equilibrium α-Al2O3 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.

  16. Anodized aluminum on LDEF

    Science.gov (United States)

    Golden, Johnny L.

    1993-01-01

    A compilation of reported analyses and results obtained for anodized aluminum flown on the Long Duration Exposure Facility (LDEF) was prepared. Chromic acid, sulfuric acid, and dyed sulfuric acid anodized surfaces were exposed to the space environment. The vast majority of the anodized surface on LDEF was chromic acid anodize because of its selection as a thermal control coating for use on the spacecraft primary structure, trays, tray clamps, and space end thermal covers. Reports indicate that the chromic acid anodize was stable in solar absorptance and thermal emittance, but that contamination effects caused increases in absorptance on surfaces exposed to low atomic oxygen fluences. There were some discrepancies, however, in that some chromic acid anodized specimens exhibited significant increases in absorptance. Sulfuric acid anodized surfaces also appeared stable, although very little surface area was available for evaluation. One type of dyed sulfuric acid anodize was assessed as an optical baffle coating and was observed to have improved infrared absorptance characteristics with exposure on LDEF.

  17. Occupational exposure following Yttrium-90 microspheres SIR therapy

    International Nuclear Information System (INIS)

    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 Y90-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 implantation

  18. Gas evolution behavior of aluminum in mortar

    International Nuclear Information System (INIS)

    As a part of study of leaching behavior for solidified dry low level radioactive waste, gas evolution behavior of aluminum in mortar was investigated, and a plan of our research was proposed. The effect of pH on corrosion rate of aluminum, corrosion product, time dependency of corrosion rate of aluminum in mortar, change of corrosion mechanism, the effects of Na, Ca and Cl ions on corrosion rate of aluminum in mortar and corrosion behavior of aluminum when aluminum was used as sacrificed anode in reinforced concrete were previously clarified. Study of the effects of environmental factors such as pH, kind of ions and temperature on gas evolution behavior of aluminum and the effect of aluminum/carbon steel surface ratio no gas evolution behavior of aluminum were planed. (author). 75 refs

  19. Celsian/yttrium silicate protective coating prepared by microwave sintering for C/SiC composites against oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Xiaohui [College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China)], E-mail: zheng_nudt@163.com; Du Yongguo; Xiao Jiayu; Lu Yufeng; Liang Chiyong [College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China)

    2009-04-15

    A novel celsian/yttrium silicate coating was prepared by microwave sintering on the surface of C/SiC composites. During sintering process, celsian crystallized from BaO-Al{sub 2}O{sub 3}-SiO{sub 2} (BAS) glass in the coating and yttrium silicate was formed through the reaction of yttrium oxide and molten BAS glass. The composition and microstructure of the coatings were investigated and the efficiency of the composite coating against oxidation was characterized. The result showed the coating was dense and pore-free. The celsian/yttrium silicate coating can protect C/SiC composites for no less than 90 min at 1773 K in air.

  20. Strontium-90 determination in biological and environmental samples by direct milking of its daughter product, yttrium-90

    International Nuclear Information System (INIS)

    A method is presented for the determination of 90Sr in environmental samples by direct milking of 90Y. Pyridine-2,6-dicarboxylic acid forms an anionic complex with yttrium which is retained on an anionic resin. Most of the matrix elements are washed out of the column as neutral or uncomplexed species and yttrium is eluted by increasing the ionic force of the eluent solution. This method gives yttrium recoveries between 65% to 85% for soil, grass, milk and bone samples with very high radiochemical purity (90Y average half-life of 66 ± 4 hours) and a detection limit of 0.3 Bq/kg of soil. The method supports a calcium content up to 3 g per sample without any decrease in yttrium yield, allowing the measurement of milk, milk-teeth and bone samples with no concentration step in one day. (author)

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

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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.)

  3. Solvent extraction of nitrates of the lanthanides (3) and yttrium (3) by trialkylmethylammonium nitrate from multi-component solutions

    International Nuclear Information System (INIS)

    Extraction of lanthanides (3) and yttrium (3) nitrates from multicomponent solutions by tralkylmethylammonium nitrate at 298.15 K and pH 2 has been considered. Physicochemical and mathematical models describing lanthanide (3) (praseodymium-lutetium) and yttrium (3) distribution in multicomponent solutions, depending on total concentration of rare earth metals ion concentration in aqueous solution and composition of concentrate, are presented. 7 refs., 5 figs., 1 tab

  4. Scaleable Clean Aluminum Melting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q.; Das, S.K. (Secat, Inc.)

    2008-02-15

    The project entitled 'Scaleable Clean Aluminum Melting Systems' was a Cooperative Research and Development Agreements (CRADAs) between Oak Ridge National Laboratory (ORNL) and Secat Inc. The three-year project was initially funded for the first year and was then canceled due to funding cuts at the DOE headquarters. The limited funds allowed the research team to visit industrial sites and investigate the status of using immersion heaters for aluminum melting applications. Primary concepts were proposed on the design of furnaces using immersion heaters for melting. The proposed project can continue if the funding agency resumes the funds to this research. The objective of this project was to develop and demonstrate integrated, retrofitable technologies for clean melting systems for aluminum in both the Metal Casting and integrated aluminum processing industries. The scope focused on immersion heating coupled with metal circulation systems that provide significant opportunity for energy savings as well as reduction of melt loss in the form of dross. The project aimed at the development and integration of technologies that would enable significant reduction in the energy consumption and environmental impacts of melting aluminum through substitution of immersion heating for the conventional radiant burner methods used in reverberatory furnaces. Specifically, the program would couple heater improvements with furnace modeling that would enable cost-effective retrofits to a range of existing furnace sizes, reducing the economic barrier to application.

  5. Crystal and molecular structures of trinitratotris(dimethyl sulfoxide)yttrium(III)

    International Nuclear Information System (INIS)

    Crystal structure of yttrium nitrate dimethylsulfoxide complex Y(NO3)3(DMSO)3 (1) (DMSO = dimethylsulfoxide) has been defined by the method of X-ray diffraction analysis. The crystals are monoclinic: a =11.559(2), b = 12.672(3), c = 13.593(3) A, β = 100.12(3) deg, Z = 4, sp.gr. P21/n. In molecular structure coordination number of yttrium atom equals 9: three O atoms of DMSO groups and three pairs of O atoms in bidentate coordinated NO3-groups. The molecules have polar nature: ligands DMSO and NO3 occupy different halves of Y atom coordination sphere. The Y-O bond lengths differ essentially: average values for NO3 groups are 2.455 (6), for DMSO ones - 2.278 (7) A

  6. Mott insulator-to-metal transition in yttrium-doped CaIrO3

    Science.gov (United States)

    Gunasekera, J.; Chen, Y.; Kremenak, J. W.; Miceli, P. F.; Singh, D. K.

    2015-02-01

    We report on the study of insulator-to-metal transition in post-perovskite compound CaIrO3. It is discovered that a gradual chemical substitution of calcium by yttrium leads to the onset of strong metallic behavior in this compound. This observation is in stark contrast to BaIrO3, which preserves its Mott insulating behavior despite excess of the charge carriers due to yttrium doping. Magnetic measurements reveal that both compounds tend to exhibit magnetic character irrespective of the chemical substitution of Ca or Ba. We analyze these unusual observations in light of recent researches that suggest that CaIrO3 does not necessarily possess j = 1/2 ground state due to structural distortion. The insulator-to-metal transition in CaIrO3 will spur new researches to explore more exotic ground state, including superconductivity, in post-perovskite Mott insulators.

  7. Mott insulator-to-metal transition in yttrium-doped CaIrO₃.

    Science.gov (United States)

    Gunasekera, J; Chen, Y; Kremenak, J W; Miceli, P F; Singh, D K

    2015-02-11

    We report on the study of insulator-to-metal transition in post-perovskite compound CaIrO3. It is discovered that a gradual chemical substitution of calcium by yttrium leads to the onset of strong metallic behavior in this compound. This observation is in stark contrast to BaIrO3, which preserves its Mott insulating behavior despite excess of the charge carriers due to yttrium doping. Magnetic measurements reveal that both compounds tend to exhibit magnetic character irrespective of the chemical substitution of Ca or Ba. We analyze these unusual observations in light of recent researches that suggest that CaIrO3 does not necessarily possess j = 1/2 ground state due to structural distortion. The insulator-to-metal transition in CaIrO3 will spur new researches to explore more exotic ground state, including superconductivity, in post-perovskite Mott insulators. PMID:25605689

  8. Moessbauer study of Al and Cr co-substituted Yttrium iron garnets

    International Nuclear Information System (INIS)

    The Moessbauer spectra of Y3AlxCrXFe5-2xO12 (x = 0.0 to 0.6) measured at 300 K have been fitted with two sextets in the ferrimagnetic state corresponding to Fe3+ at the octahedral (a) and the tetrahedral (d) sites for x ≤ 0.6. The isomer shifts (δ) and quadrupole splitting (ΔEQ) indicate the presence of high spin Fe3+ ions in the tetrahedral (d) and octahedral (a) sites, typical of yttrium of yttrium iron garnet structure. Moessbauer results have shown that Al3+, enters a-sites only but Cr3+ enters both a-and d-sites.

  9. The preparation method of high purity rare earth elements and yttrium

    International Nuclear Information System (INIS)

    The subject of the patent is a method of separation of high purity rare earth elements and yttrium as well as their oxides. Solution containing rare earth ions (concentration 15-30 g/cm3, pH=3-5) is passed through the column with carboxylic cationite and then the complexing agent (EDTA) is introduced into the column and the eluate is directed to another column with sulfonic cationite. The process is then repeated with EDTA in the sequence of three columns containing different forms of sulfonic cationite. To the eluent leaving the last column concentrated HNO3 is added for EDTA precipitation. Oxalic acid is added to the residual solution. The precipitated sediments of high purity rare earths and yttrium oxides is then filtrated, washed and dried. 2 tabs

  10. Permeation behavior of yttrium from nitric acid medium with DNPPA in hollow fibre membrane module

    International Nuclear Information System (INIS)

    High purity yttrium finds applications in superconductors, phosphors, as additives in alloys, in cancer treatment, etc. Monazite mineral contains ∼ 4% yttrium apart from other rare earths. Its separation from the leach solution obtained from processing monazite is primarily done by solvent extraction using di 2-ethyl hexyl phosphoric acid (D2EHPA) and 2-ethyl hexyl 2-ethyl hexyl phosphonic acid (EHEHPA) as extractants. Recently, use of di nonyl phenyl phosphoric acid (DNPPA) in separating metal ions from highly acidic solution has gained importance due to its low pKa value (2.54). It is worth exploring DNPPA for rare earth separation from acidic solutions. Amongst various separation techniques, hollow fibre membrane offer low capital and operating cost, low energy, solvent inventory and high concentration factors. In the present investigation an attempt has been made to study the permeation behavior of Y (III) from nitric acid medium in a hollow fibre supported liquid membrane (HFSLM) module with DNPPA as carrier

  11. THE METHOD OF REMOVAL YTTRIUM (III AND YTTERBIUM (III FROM DILUTE AQUEOUS SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Olga Lobacheva

    2016-04-01

    Full Text Available Yttrium (III and ytterbium (III cations ion flotation from diluted aqueous solutions in the presence of chloride ions using sodium dodecyl sulfate as collector agent were studied. Y (III and Yb (III distribution and recovery coefficients as a function of aqueous phase рН value at different sodium chloride concentrations were received. Yttrium (III and ytterbium (III chloro and hydroxo complexes instability constants were calculated. The calculation of separation coefficient at рН specified values depending on chloride ion concentration was conducted. Maximum separation coefficient was observed when chloride concentration of 0.01 M is 50 at рН 7.8. Ksep is minimal in nitrate medium ans is 3 at рН 7.0. At sodium chloride concentration of 0.05 М Ksep is 9 at рН 7.8.

  12. Exoemission and the donor-acceptor properties of zirconium dioxide modified by yttrium oxide

    International Nuclear Information System (INIS)

    Influence of alloying component Y2O3 on adsorption properties of ZrO2 was studied by the methods of exoemission and IR spectroscopy. Radiation resistance of the ZrO2-Y2O3 system samples under β-radiation (90Sr/90Y) at a dose of 20 rad was determined. Correlation between concentration of the Lewis acid centers and emissivity of alloyed samples in the range of low concentrations of Y2O3 was found. The nature of exoemission and adsorption centers due to donor-acceptor character of active centers on the surface of samples of the system studied was discussed. It is shown that initially high radiation resistance of ZrO2 decreases, when it is modified by yttrium oxide, meanwhile pure yttrium oxide features moderate enough radiation resistance of the surface

  13. Some peculiarities of thermoemission of the cathodes on the base of lanthanum and yttrium oxides

    Energy Technology Data Exchange (ETDEWEB)

    Podgornyj, V.I. (AN SSSR, Moscow. Inst. Radiotekhniki i Ehlektroniki)

    1982-07-01

    Thermoemission cathode characteristics on the basis of (La/sub 2/O/sub 3/) lanthanum, and yttrium oxides which are used already in practice but emission mechanism of which remains yet insufficiently elucidated, were investigated. It is shown that the heating of cathodes on the basis of Y/sub 2/O/sub 3/ and La/sub 2/O/sub 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.

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

    International Nuclear Information System (INIS)

    Thermoemission cathode characteristics on the basis of (La2O3) 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 Y2O3 and La2O3 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

  15. Cubic polycrystalline zirconia stabilized with yttrium and rare earth oxide mixture: processing, phase and microstructure characterization

    International Nuclear Information System (INIS)

    Cubic polycrystalline zirconia ceramics stabilized with yttria are an excellent solid electrolyte used as oxygen sensor. In this work are presented and discussed the processing and microstructure characterization of cubic polycrystalline zirconia stabilized with a concentrate of yttrium and rare earth oxides (YRE). The raw materials are of Brazilian origin. The preparation method of the powder mixtures (15 to 23 wt% YRE) was by chemical coprecipitation of the respective hydroxides with ammonia (NH4OH). The powder mixtures were calcined, isostatically pressed and sintered at 1550 C. Phase analyses by X-rays diffraction (XRD) were made aided by a computer program and a mathematical model for calculation of the lattice parameters. Images from scanning electron microscopy (SEM) were used to make analyses of the sintered ceramic microstructures. The results indicated that cubic polycrystalline zirconia was stabilized with 18 wt% of yttrium and rare earth oxides (YRE) mixtures and its sintered microstructure showed a high densification. (orig.)

  16. Electronic and magnetic properties of yttrium-doped silicon carbide nanotubes: Density functional theory investigations

    Energy Technology Data Exchange (ETDEWEB)

    Khaira, Jobanpreet S., E-mail: joban10173@gmail.com [Department of Nanotechnology, Sri Guru Granth Sahib World University, Fatehgarh Sahib, Punjab -202002 (India); Jain, Richa N. [Indian Institute Of Science, Bangalore, 560012 (India); Chakraborty, Brahmananda; Ramaniah, Lavanya M. [High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

    2015-06-24

    The electronic structure of yttrium-doped Silicon Carbide Nanotubes has been theoretically investigated using first principles density functional theory (DFT). Yttrium atom is bonded strongly on the surface of the nanotube with a binding energy of 2.37 eV and prefers to stay on the hollow site at a distance of around 2.25 Å from the tube. The semi-conducting nanotube with chirality (4, 4) becomes half mettalic with a magnetic moment of 1.0 µ{sub B} due to influence of Y atom on the surface. There is strong hybridization between d orbital of Y with p orbital of Si and C causing a charge transfer from d orbital of the Y atom to the tube. The Fermi level is shifted towards higher energy with finite Density of States for only upspin channel making the system half metallic and magnetic which may have application in spintronic devices.

  17. A yttrium-containing high-temperature titanium alloy additively manufactured by selective electron beam melting

    Institute of Scientific and Technical Information of China (English)

    逯圣路; 汤慧萍; 马前; 洪权; 曾立英

    2015-01-01

    A yttrium-containing high-temperature titanium alloy (Ti-6Al-2.7Sn-4Zr-0.4Mo-0.45Si-0.1Y, mass fraction, %) has been additively manufactured using selective electron beam melting (SEBM). The resulting microstructure and textures were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and electron backscattered diffraction (EBSD) and compared with the conventionally manufactured form. A notable distinct difference of microstructures is that additive manufacturing by SEBM enables homogeneous precipitation of fine Y2O3 dispersoids in the size range of 50−250 nm throughout the as-fabricated alloy, despite the presence of just trace levels of oxygen (7×10−4, mass fraction) and yttrium (10−3, mass fraction) in the alloy. In contrast, the conventionally manufactured alloy shows inhomogeneously distributed coarse Y2O3 precipitates, including cracked or debonded Y2O3 particles.

  18. Electronic and magnetic properties of yttrium-doped silicon carbide nanotubes: Density functional theory investigations

    International Nuclear Information System (INIS)

    The electronic structure of yttrium-doped Silicon Carbide Nanotubes has been theoretically investigated using first principles density functional theory (DFT). Yttrium atom is bonded strongly on the surface of the nanotube with a binding energy of 2.37 eV and prefers to stay on the hollow site at a distance of around 2.25 Å from the tube. The semi-conducting nanotube with chirality (4, 4) becomes half mettalic with a magnetic moment of 1.0 µB due to influence of Y atom on the surface. There is strong hybridization between d orbital of Y with p orbital of Si and C causing a charge transfer from d orbital of the Y atom to the tube. The Fermi level is shifted towards higher energy with finite Density of States for only upspin channel making the system half metallic and magnetic which may have application in spintronic devices

  19. Mechanism for radiation damage resistance in yttrium oxide dispersion strengthened steels

    Science.gov (United States)

    Brodrick, J.; Hepburn, D. J.; Ackland, G. J.

    2014-02-01

    ODS steels based on yttrium oxide have been suggested as potential fusion reactor wall materials due to their observed radiation resistance properties. Presumably this radiation resistance can be related to the interaction of the particle with vacancies, self-interstitial atoms (SIAs) and other radiation damage debris. Density functional theory has been used to investigate this at the atomic scale. Four distinct interfaces, some based on HRTEM observations, between iron and yttrium oxide were investigated. It is been shown that the Y2O3-Fe interface acts as a strong trap with long-range attraction for both interstitial and vacancy defects, allowing recombination without altering the interface structure. The catalytic elimination of defects without change to the microstructure explains the improved behaviour of ODS steels with respect to radiation creep and swelling.

  20. Patient exposure reduction in x-ray CT with yttrium filters

    International Nuclear Information System (INIS)

    Custom-designed yttrium filters were installed on three General Electric CT/T 98000 CT scanners. Measurements were made before and after installation of the yttrium filters. The phantom test evaluations included: radiation exposure, high contrast spatial resolution, low contrast detectability, and CT number linearity/calibration. The reduction in exposure obtained for lucite head and body phantoms ranged from 22% to 27% on the surface and from 13% to 23% at the phantom center. The conclusion drawn is that no detrimental effect on image quality was observed through comparative analysis of the image parameters evaluated, nor were any differences in the quality of the pre- post-filter clinical images reported by the radiologists

  1. Anomalous aryl strengthening of yttrium and neodymium complexes during extraction with methylene-diphosphine dioxides

    International Nuclear Information System (INIS)

    Extraction of yttrium and neodymium with dioxides of tetraphenylmethylenediphosphine (P) and tetraoctylmethylenediphosphine (Oct) has been studied in the acidity range from 0.1 to 10 mol/l. In the range of moderate acidity (up to 5 mol/l) disolvates Me(NO3)3L2 are extracted; at high acidity-acidocomplexes Hsub(p)Me(NOsub(3))sub(3+p)Lsub(2). It is found that in the given system anomalous aryl strengthening of the complexes is observed: inspite of lower basicity (P) extracts lanthanides better than (Oct). Effective constants of extraction with (P) dioxide are anti Ksub(Y)=6x10sup(6), anti Ksub(Nd)=2.7x10sup(7) and those of extraction with (Oct) dioxide are anti Ksub(Y)=9x10sup(5), anti Ksub(Nd)=3x10sup(6). The activity coefficients of yttrium and neodymium nitrates have been calculated

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

    International Nuclear Information System (INIS)

    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 (BO0.17) 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 BO0.17 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

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

    International Nuclear Information System (INIS)

    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

  4. Structure and creep of steels dispersion-strengthened with yttrium oxides

    International Nuclear Information System (INIS)

    The heat resistance is studied in mechanically alloyed sintered steels strengthened by dispersed oxides (DOS-steels). A comparison of creep properties is made for such steels (K2, K5, K7) and commonly used reactor steels Kh16N15M3TF and 12Kh13M2BRF in the temperature range of 600-700 deg C. It is sated that DOS-steels with 0.38-0.39 mass. % of yttrium oxides treated to produce the structure of banded polygonal ferrite, possess a high strength due to precipitation of ultra-dispersed yttrium-titanium oxides, reinforcement of ferrite and locking of dislocations. DOS-steels are noted to offer the advantage over conventional reactor steels for the resistance to creep and fracture which is most pronounced at strain rates of 10-2 %/h and loading time more than 1000 h

  5. 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......, and 67 GPa for YS, YSe, and YTe, respectively. First-principles total energy calculations are carried out using the full-potential linear muffin-tin orbital method. The calculated and measured lattice constants and bulk moduli are in good agrement. Under applied pressure, the yttrium monochalcogenides...... are predicted to undergo a structural transition. Assuming that the high-pressure phase corresponds to the CsCl crystal structure, transition pressures of 53, 36, and 14 GPa are found for YS, YSe, and YTe, respectively....

  6. Recrystallization in Commercially Pure Aluminum

    DEFF Research Database (Denmark)

    Bay, Bent; Hansen, Niels

    1984-01-01

    Recrystallization behavior in commercial aluminum with a purity of 99.4 pct was studied by techniques such as high voltage electron microscopy, 100 kV transmission electron microscopy, and light microscopy. Sample parameters were the initial grain size (290 and 24 microns) and the degree of...... are discussed and compared with results from an earlier study1 covering the recrystallization behavior of commercial aluminum of the same purity deformed at higher degrees of deformation (50 to 90 pct reduction in thickness by cold-rolling)....

  7. 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)

  8. Baise to Build Ecological Aluminum Industry Base

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>The government of Baise announced the construction of an ecological aluminum industry base over the next few years,pledging to turn the city into a major aluminum industry base in China and the rest of Asia.

  9. Decreasing residual aluminum level in drinking water

    Institute of Scientific and Technical Information of China (English)

    王志红; 崔福义

    2004-01-01

    The relativity of coagulant dosage, residual turbidity, temperature, pH etc. with residual aluminum concentration were investigated, and several important conclusions were achieved. Firstly, dosage of alum-coagulant or PAC1 influences residual aluminum concentration greatly. There is an optimal-dosage-to-aluminum, a bit less than the optimal-dosage-to-turbidity. Secondly, it proposes that decreasing residual aluminum concentration can be theoretically divided into two methods, either decreasing (even removing) the concentration of particulate aluminum component, or decreasing dissolved aluminum. In these tests there is an optimal value of residual turbidity of postprecipitation at 7.0 NTU. Thirdly, residual aluminum level will increase while water temperature goes higher. At the last, optimal pH value corresponds a minimum dissolved aluminum at a given turbidity. Data shows the optimal pH value decreases with water temperature's increasing.

  10. Effects of minor yttrium addition on hot deformability of lamellar Ti-45Al-5Nb alloy

    Institute of Scientific and Technical Information of China (English)

    CHEN Yu-yong; LI Bao-hui; KONG Fan-tao

    2007-01-01

    The effects of 0.3%(molar fraction, the same below) yttrium addition on hot deformability of lamellar Ti-45Al-5Nb alloy were investigated by simulated isothermal forging tests. The ingots with the nominal compositions of Ti-45Al-5Nb and Ti-45Al-5Nb-0.3Y were prepared by induction skull melting. Simulated isothermal forging tests were conducted on Gleeble 1500D thermo-simulation machine using a 6 mm in diameter and 10 mm in length compressive specimen at the deformation temperatures of 1 100, 1 150, 1 200 ℃ and strain rates of 1.0, 0.1, 0.01 s-1. The results show that yttrium addition remarkably improves hot deformability of Ti-45Al-5Nb alloy. An appropriate hot deformation processing parameter of Ti-45Al-5Nb-0.3Y alloy is determined as 1 200 ℃, 0.01 s-1. The flow stresses are decreased by yttrium addition under the same compressive conditions. The activation energies of deformation Q are calculated as 448.6 and 399.5 kJ/mol for Y-free and Y-containing alloys, respectively. The deformed microstructure observation under 1 200 ℃, 0.01 s-1 condition indicates that Ti-45Al-5Nb-0.3Y alloy shows more dynamic recrystallization. The improvement of hot deformability of Ti-45Al-5Nb-0.3Y alloy induced by yttrium addition should be attributed to that the smaller the original lamellar colonies, the lower the deformation resistance and activation energy of deformation are, and the more the dynamic recrystallization is.

  11. The influence of deformations on frequency characteristics of the elements based on yttrium iron garnet films

    OpenAIRE

    Lyashenko, M. I.; Talalaevskii, V. M.; Chevnjuk, L. V.

    1997-01-01

    The elements based on ferrite films of Yttrium Iron Garnets (YIG) can be used in communication and radio-location technique, in particular in antenna arrays. Such elements are filters, delay lines, etc. Mechanical stresses with various magnitude and direction can be specially created in the films. The stresses can also be created by some external factors, e.g. temperature. Such stresses can cause internal magnetic fields with uniaxial magnetic crystallographic anisotropy. The magnitude, direc...

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

    International Nuclear Information System (INIS)

    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.)

  13. Preparation of yttrium oxide coating by MOCVD as tritium permeation barrier

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yunyi, E-mail: wuyunyi_80@163.com; He, Di; Zhang, Hua; Li, Shuai; Liu, Xiaopeng; Wang, Shumao; Jiang, Lijun

    2015-01-15

    Highlights: • Yttrium oxide coating was deposited on 316L substrate as hydrogen permeation barrier. • O:Y ratio of the 700 °C annealed coating corresponds well to the stoichiometric Y{sub 2}O{sub 3}. • The original precursor completely decomposed within the coating annealed at 700 °C. • The 700 °C annealed coating offers efficient inhibition to deuterium permeation. • Deuterium permeation of the 700 °C annealed coating is controlled by a hybrid regime. - Abstract: Yttrium oxide coatings were deposited on 316L substrate using metal organic chemical vapor deposition (MOCVD) technique with yttrium β-diketonates organometallic Y(tmhd){sub 3} as precursor. The different microstructures were obtained by annealing coatings at 700 °C or as-deposited. The film was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), infrared spectroscopy and X-ray photoelectron spectroscopy (XPS). The hydrogen permeation inhibition performance of films was investigated by deuterium permeation experiment. The crystalline structure of the coatings depended on the post-anneal; the crystallite size of the coating increases and the surface exhibits compact surface morphology for the coatings post-annealed at 700 °C. The coating post-annealed at 700 °C has the correct oxygen/yttrium ratio corresponding well to the stoichiometric Y2O3, while some concentrations of carbon and hydrogen impurities were found in the as-deposited coating. The impurities are present in the form of unreacted or partially reacted precursor molecules due to the incomplete decomposition of the original precursor. The deuterium permeability of the coating improved obviously after post-anneal and was around 240–410 times less than that of the 316L stainless steel, which means efficient inhibition to deuterium permeation.

  14. The NIMROC reference materials: revised values for thorium, yttrium, lanthanum, and the rare-earth elements

    International Nuclear Information System (INIS)

    This report gives all the analytical results submitted by the contributing laboratories before July 1983 for thorium, yttrium, lanthanum, and the rare-earth elements in the six NIMROC reference materials (SARM 1 to 6), which were prepared in 1966 by the former National Institute for Metallurgy, now the Council for Mineral Technology (Mintek). The statistical evaluation of these results and the assignment of new or revised recommended or provisional values are described

  15. 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.

  16. Ageing effect on the thermoluminescence of X-irradiated yttrium doped KBr crystals

    International Nuclear Information System (INIS)

    Thermoluminescence glow curves were recorded on X-irradiated KBr:Y crystals in as grown, aged and quenched conditions. Two glow peaks around 85 and 110 C were observed in as grown crystals. A marked difference in the glow curve patterns have been observed for aged and quenched crystals. These observations are explained on the basis of the state of dispersion of yttrium impurity in KBr lattice. ((orig.))

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

    International Nuclear Information System (INIS)

    Three mixed europium–yttrium organic frameworks: Eu2−xYx(Mel)(H2O)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 Eu3+ lifetime becomes longer in these MOFs than those of the Eu analog. - Graphical abstract: Three mixed europium and yttrium organic frameworks: Eu2−xYx(Mel)(H2O)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 Eu3+ 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.

  18. Preparation of yttrium oxide coating by MOCVD as tritium permeation barrier

    International Nuclear Information System (INIS)

    Highlights: • Yttrium oxide coating was deposited on 316L substrate as hydrogen permeation barrier. • O:Y ratio of the 700 °C annealed coating corresponds well to the stoichiometric Y2O3. • The original precursor completely decomposed within the coating annealed at 700 °C. • The 700 °C annealed coating offers efficient inhibition to deuterium permeation. • Deuterium permeation of the 700 °C annealed coating is controlled by a hybrid regime. - Abstract: Yttrium oxide coatings were deposited on 316L substrate using metal organic chemical vapor deposition (MOCVD) technique with yttrium β-diketonates organometallic Y(tmhd)3 as precursor. The different microstructures were obtained by annealing coatings at 700 °C or as-deposited. The film was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), infrared spectroscopy and X-ray photoelectron spectroscopy (XPS). The hydrogen permeation inhibition performance of films was investigated by deuterium permeation experiment. The crystalline structure of the coatings depended on the post-anneal; the crystallite size of the coating increases and the surface exhibits compact surface morphology for the coatings post-annealed at 700 °C. The coating post-annealed at 700 °C has the correct oxygen/yttrium ratio corresponding well to the stoichiometric Y2O3, while some concentrations of carbon and hydrogen impurities were found in the as-deposited coating. The impurities are present in the form of unreacted or partially reacted precursor molecules due to the incomplete decomposition of the original precursor. The deuterium permeability of the coating improved obviously after post-anneal and was around 240–410 times less than that of the 316L stainless steel, which means efficient inhibition to deuterium permeation

  19. Peripheral Blood Lymphocyte Depletion After Hepatic Arterial 90Yttrium Microsphere Therapy for Hepatocellular Carcinoma

    International Nuclear Information System (INIS)

    Purpose: The short- and long-term effects of 90Yttrium 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 90Yttrium 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-90Yttrium 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 90Yttrium without associated clinical toxicity, and lack of lymphocyte recovery (possibly leading to dysregulation of adaptive cellular immunity) posttherapy indicates poor survival.

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

    International Nuclear Information System (INIS)

    This work deals with the preparation of powders and transparent yttrium aluminium garnet (Y3Al5O12 - YAG) from nanopowders. Stoichiometric amounts of nanocrystalline Al2O3 and Y2O3 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

  1. Spin orbital theory for the high temperature magnetic phase transitions in Yttrium orthovanadate

    Science.gov (United States)

    de Silva, Theja; Joshi, Anuvrat; Zhang, Fu Chun; Ma, Michael

    2003-03-01

    Motivated by recent diffraction experiments, we develope a theoritical model for Yttrium orthovanadate(YVO_3). The key parameters governing the system are on-site coulomb repulsion, Hund's coupling, crystal field splitting between 3d levels and hopping amplitude between nearest neighbor ions. Then, we use a mean field theory to illustrate the relevent physics of the system and verify the existence of the high temperature G-type orbital transition before C-type spin ordering at a lower temperature.

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

    International Nuclear Information System (INIS)

    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 Y2O3 distributing uniformly between the tungsten particles, resulting in the formation of small grain size. It is found that Y2O3 improves the secondary electron emission property, i.e., the secondary emission yield increases with the increase of Y2O3 content in the samples. The maximum secondary emission yield δmax of the cathode with 15% amount of Y2O3 can reach 2.92. Furthermore, the cathode shows a certain thermionic emission performance. The zero field emission current density J0 of 4.18A/cm2 has reached at 1050 °Cb for this kind of cathode after being activated at 1200 °Cb, 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

  3. 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.

  4. Yttrium deposition on mesoporous TiO2: textural design and UV decolourization of organic dyes

    Indian Academy of Sciences (India)

    M L Ojeda; C Velasquez; V Renteria; A Campero; M A García-Sánchez; F Rojas

    2015-02-01

    This study discusses about the photochemical, topological and textural properties of yttrium-doped titanium dioxide (TiO2) photocatalysts. The mesoporous yttrium-doped TiO2 substrates prepared in this research work operate efficiently via low-cost commercial 13-W UV lamps. A quantity of 2 wt% yttrium deposition on TiO2 accelerates methyl orange UV decolourization kinetics. When Y content increases to 8 wt%, besides anatase, rutile is formed from 600°C. The Y2Ti2O7 photoinactive compound emerges at 800°C. The P-123 surfactant mesopore templating treatment of TiO2 xerogels (when concurrent with the sol–gel Y-doping of Ti alkoxides) features the following two correlated phenomena: (i) The surface area increases while the access to the inner porosity of the substrate becomes much easier, so that a larger portion of the surface is made accessible to the dye molecules as well as to the yttrium dopant; (ii) the inclusion of tubular instead of ink-bottle pores facilitates the transport of organic species in and out of the pore structure. The most active mesoporous substrate resulted to be made of 2 wt% Y; contrastingly, when Y= 8 wt%, photoinactivity arose because of Y2Ti2O7 formation. The involvement of P123 was not the sole factor influencing the efficiency of TiO2 mesoporous photocatalysts. There were additional key factors, such as the surging of co-ordination and nucleophilic species, during the dye photodegradation process, which were also induced by the presence of Y species on the surface of these substrates.

  5. Efficient holmium:yttrium lithium fluoride laser longitudinally pumped by a semiconductor laser array

    Science.gov (United States)

    Hemmati, H.

    1987-01-01

    Optical pumping of a holmium:yttrium lithium floride (Ho:YLF) crystal with a 790-nm continuous-wave diode-laser array has generated 56 mW of 2.1-micron laser radiation with an optical-to-optical conversion slope efficiency of 33 percent while the crystal temperature is held at 77 K. The lasing threshold occurs at 7 mW of input power, and laser operation continues up to a crystal temperature of 124 K.

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

    International Nuclear Information System (INIS)

    Superparamagnetic Y-substituted magnetite (YxFe3–xO4,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 Fe3+ to Fe2+, 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. 75 FR 70689 - Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum-Greenwood Forge Division; Currently...

    Science.gov (United States)

    2010-11-18

    ... in the Federal Register on November 17, 2009 (74 FR 59254). At the request of the State agency and a... Employment and Training Administration Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum- Greenwood... Aluminum Fabricated Products, LLC, Kaiser Aluminum-Greenwood Forge Division, including on- site...

  8. Electrochemical Behavior of Aluminum in Nitric Acid

    Institute of Scientific and Technical Information of China (English)

    CHEN; Hui; ZHU; Li-yang; LIN; Ru-shan; TAN; Hong-bin; HE; Hui

    2013-01-01

    Aluminum is one of cladding materials for nuclear fuel,it is important to investigate the electrolytic dissolution of aluminum in nitric acid.The electrochemical impedance spectroscopy,polarization curve and cyclic voltammetry cure of anodic aluminum electrode in nitric acid under various conditions were collected(Fig.1).It turns out,under steady state,the thickness of the passivated film of aluminum

  9. Mineral resource of the month: aluminum

    Science.gov (United States)

    Bray, E. Lee

    2012-01-01

    The article offers information on aluminum, a mineral resource which is described as the third-most abundant element in Earth's crust. According to the article, aluminum is the second-most used metal. Hans Christian Oersted, a Danish chemist, was the first to isolate aluminum in the laboratory. Aluminum is described as lightweight, corrosion-resistant and an excellent conductor of electricity and heat.

  10. Evaluation of Aluminum in Iranian Consumed Tea

    OpenAIRE

    Alireza Asgari; Mahdi Ahmadi Moghaddam; Amirhossein Mahvi; Masoud Yonesian

    2008-01-01

    Introduction: Black tea leaf is one of the most important sources of Aluminum in dietary. Therefore this research was conducted to assess the amount of Aluminum in Iranian tea infusion. Methods: To assess Aluminum in Iranian consumed tea, 27 tea samples were analyzed for Al concentration for 10 and 60 min infusion, aluminum concentration was measured with atomic absorption and the results were analyzed by SPSS.13 version. Results: The results showed that minimum and maximum concentration of A...

  11. Recovery of lanthanides and yttrium from red mud by selective leaching

    International Nuclear Information System (INIS)

    This study presents a rapid and selective method for the recovery of lanthanides and yttrium, existing in economically interesting concentrations, from red mud, the byproduct of the alumina production. The leaching process is based on the extraction of these elements with diluted nitric acid from red mud under moderate conditions and without using any preliminary treatment. Several parameters such as leaching agents, contact time, temperature, pressure and solid to liquid ratio were investigated in order to achieve an optimum recovery. The process followed here was selected taking into account its efficiency for the selective recovery of yttrium and lanthanides, but also its suitability for the subsequent liquid-liquid extraction of the leaching solution for the separation of the individual lanthanides. The achieved recovery percentages were for Y about 90%, for the investigated heavy lanthanides (Dy, Er, Yb) up to 70%, for the middle ones (Nd, Sm, Eu, Gd) up to 50% and for the group of light lanthanides (La, Ce, Pr) up to 30%. Most of the main elements of the red mud and especially iron are hardly dissolved by this leaching process, leading to an interference free determination of the lanthanides and yttrium in the leachate by inductively coupled plasma-atomic emission spectroscopy (ICP-AES)

  12. Statistical study on yttrium recovery by solvent extraction using mono(2-ethylhexyl)2-ethylhexylphosphonic acid

    International Nuclear Information System (INIS)

    The scope of this experimental work was to study the yttrium extraction and stripping behavior in a solvent extraction system with mono(2-ethylhexyl)2-ethylhexylphosphonic acid (IONQUEST 801) in a chloride system. The study was performed for only one contact between organic and aqueous phases. The experiments were carried out according to a factorial design. Due to the statistical analysis and its experimental proof, the optimum conditions for maximum yttrium loading into the organic phase of the extraction stage were 16 minutes for time of contact between phases, 980 rpm of stirring intensity and pH = 2.3 for the aqueous phase of the solvent extraction system. The optimized experimental conditions by the statistical approach for the stripping stage were: time of contact between phases equal to 20 minutes, 1,050 rpm of stirring intensity and 1.75 M HCl into the stripping aqueous solution. Some important applications of yttrium and heavy rare earth elements range from fluorescent devices, magnetic substances and hydrogen storage alloys to superconductivity

  13. Development of electrodes based on yttrium chromites and rare earth doped hafnia for MHD generator applications

    International Nuclear Information System (INIS)

    Yttrium chromites are being studied as potential high temperature electrodes for MHD. Like lanthanum chromites, the doped yttrium chromites have similar high electrical conductivity, predominantly electronic over a wide temperature range; however, they do not form hydroscopic decomposition products, which cause gross structural degradation. In addition, they exhibit substantially improved resistance to electrochemical attack by slag/seed. The electrical conductivity, thermal diffusivity/conductivity, melting points, thermal expansion, vaporization and electrochemical corrosion for several yttrium chromite compositions are reported and compared with analogous lanthanum chromites. Hafnium oxide containing rare earth additions are also being studied as potential high temperature MHD electrodes. The electrode compositions show a high resistance to electrochemical corrosion in slag/seed. Hafnia-rare earth-M2O3 oxides can be fabricated with sufficient room temperature electrical conductivity to make them candidates for ceramic-to-metal current leadouts. Electrochemical tests of ceramic current leadout: ceramic electrode couples have been conducted at high temperatures and with high current densities for long periods of time with little interaction between the electrodes and leadouts

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

    International Nuclear Information System (INIS)

    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

  15. Effect of yttrium additions on void swelling in Liquid Metal Fast Breeder Reactor candidate cladding alloys

    International Nuclear Information System (INIS)

    Candidate Liquid Metal Fast Breeder Reactor cladding alloys AL1 (Fe-26% Ni-9% Cr) and AL2 (Fe-35% Ni-12% Cr) without and with the addition of 0.1% yttrium were bombarded by 4 MeV56Fe2+ ions without and with simultaneous bombardment by 0.4 MeV 4He+ ions. These bombardments were conducted at various irradiation temperatures to determine the effect of yttrium on void swelling. The addition of yttrium decreased peak swelling for 4 MeV 56Fe2+ ion bombarded AL1 and AL2 by 28% and 20%, respectively. In all cases where similar sample comparisons were made (i.e., undoped with undoped and doped with doped) and where bombardment conditions were similar (i.e., single with single beam and dual with dual beam), AL1 showed less peak swelling than did AL2. Simultaneously implanting helium during heavy-ion bombardment increased peak swelling in undoped and doped AL1 by factors of 2.3 and 2.6, respectively

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

    International Nuclear Information System (INIS)

    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 1017 ions cm-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

  17. Nuclear moments of the yttrium isotopes and relaxation of the 89Ym

    International Nuclear Information System (INIS)

    This thesis is devoted to the study of yttrium isotopes near the shell closures (Z=40, N=40,50) by means of low-temperature nuclear orientation technique. Yttrium oxidizes easily and its solubility in iron is low, so various internal fields may act on the nuclei. We have investigated the magnetic field distribution on nuclear reaction, implanted Yttrium nuclei. Studying the orientation of 87Ym, the magnetic moment of this isomer is known. The magnetic hyperfin fields established were used to extract magnetic moments μ(85Ym, 9/2+), μ(86Yg,4+), μ(86Ym,8+), et μ(90Ym,7+). The odd nuclei magnetic moments are near to the schmidt limit; those of the odd-odd nuclei deviates from the value obtained from the weak coupling of adjacent odd nuclei. The relaxation properties of Y in Fe have been studied on the reorientation of the 89Ym (16 sec) metastable state. Programme based on the spin-latice relaxation theory developed at the carendon laboratory (Oxford), we estimate the corringa constant CK = 0.44(4) Ks from the γ-ray angular distribution

  18. Off-line studies of the laser ionization of yttrium at the IGISOL facility

    CERN Document Server

    Kessler, T; Kudryavtsev, Y; Peräjärvi, K; Popov, A; Ronkanen, P; Sonoda, T; Tordoff, B; Wendt, K D A; Äystö, J

    2007-01-01

    A laser ion source is under development at the IGISOL facility, Jyvaskyla, in order to address deficiencies in the ion guide technique. The key elements of interest are those of a refractory nature, whose isotopes and isomers are widely studied using both laser spectroscopic and high precision mass measurement techniques. Yttrium has been the first element of choice for the new laser ion source. In this work we present a new coupled dye-Ti:Sapphire laser scheme and give a detailed discussion of the results obtained from laser ionization of yttrium atoms produced in an ion guide via joule heating of a filament. The importance of not only gas purity, but indeed the baseline vacuum pressure in the environment outside the ion guide is discussed in light of the fast gas phase chemistry seen in the yttrium system. A single laser shot model is introduced and is compared to the experimental data in order to extract the level of impurities within the gas cell.

  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. Effect of carbon oxide and carbon dioxide atmosphere on ther rate of yttrium oxalate thermal decomposition

    International Nuclear Information System (INIS)

    The kinetics of yttrium oxalate thermal decomposition in carbon monoxide and dioxide atmosphere is studied. It is shown that yttrium oxalate pyrolysis proceeds in two stages and each stage is characterized by a certain rate and activation energy. The rate constant of the first stage of the process has higher values for CO atmosphere than for CO2 atmosphere in the whole range of investigated temperatures (400-1000 deg C). But the difference is not considerable and, thus, the effect of atmosphere composition on the rate of the first stage of the process is insignificant. Carbon dioxide atmosphere slows down the second stage of the process and increases the total time required for yttrium oxalate complete decomposition. However, the composition of the atmosphere does not affect the activation energy of the both stages of the process. The activation energy of the first stage equals 18.2 kJ/mol, and that of the second stage - 33.3 kJ/mol

  1. Guangxi Aluminum Giant Made Investment in Changfeng

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>A aluminum processing and supporting project (450,000 tons) of Hefei Guangyin Aluminum Company kicked off in Xiatang Town of Changfeng County recently. It is a project jointly invested by Guangxi Investment Group and Guangxi Baise Guangyin Aluminum in Xiatang Town of Changfeng County.

  2. 21 CFR 172.310 - Aluminum nicotinate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum nicotinate. 172.310 Section 172.310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Special Dietary and Nutritional Additives § 172.310 Aluminum nicotinate. Aluminum nicotinate may be...

  3. 21 CFR 73.2645 - Aluminum powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.2645 Section 73.2645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and specifications to the requirements...

  4. 21 CFR 182.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

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

  5. 21 CFR 582.1125 - Aluminum sulfate.

    Science.gov (United States)

    2010-04-01

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

  6. 75 FR 80527 - Aluminum Extrusions From China

    Science.gov (United States)

    2010-12-22

    ... Affirmative Countervailing Duty Determination, 75 FR 54302, September 7, 2010, and Aluminum Extrusions From... Antidumping Duty Determination, 75 FR 57441, September 21, 2010. \\3\\ See Aluminum Extrusions From the People's... Determination of Targeted Dumping, 75 FR 69403, November 12, 2010, and Aluminum Extrusions From the...

  7. Characterization of ultrafine aluminum nanoparticles

    International Nuclear Information System (INIS)

    Aluminum nanopowders with particle sizes ranging from ∼25 nm to 80 nm were characterized by a variety of methods. We present and compare the results from common powder characterization techniques including transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), BET gas adsorption surface area analysis, thermogravimetric analysis (TGA), photon correlation spectroscopy (PCS), and low angle laser light scattering (LALLS). Aluminum nanoparticles consist of an aluminum core with an aluminum oxide coating. HRTEM measurements of both the particle diameter and oxide layer thickness tend to be larger than those obtained from BET and TGA. LALLS measurements show a large degree of particle agglomeration in solution; therefore, primary particle sizes could not be determined. Furthermore, results from small-angle scattering techniques (SAS), including small-angle neutron (SANS) and x-ray (SAXS) scattering are presented and show excellent agreement with the BET, TGA, and HRTEM. The suite of analytical techniques presented in this paper can be used as a powerful tool in the characterization of many types of nanosized powders.

  8. Luminescent properties of aluminum hydride

    International Nuclear Information System (INIS)

    We studied cathodoluminescence and photoluminescence of α-AlH3– a likely candidate for use as possible hydrogen carrier in hydrogen-fueled vehicles. Luminescence properties of original α-AlH3 and α-AlH3 irradiated with ultraviolet were compared. The latter procedure leads to activation of thermal decomposition of α-AlH3 and thus has a practical implementation. We showed that the original and UV-modified aluminum hydride contain luminescence centers ‐ structural defects of the same type, presumably hydrogen vacancies, characterized by a single set of characteristic bands of radiation. The observed luminescence is the result of radiative intracenter relaxation of the luminescence center (hydrogen vacancy) excited by electrons or photons, and its intensity is defined by the concentration of vacancies, and the area of their possible excitation. UV-activation of the dehydrogenation process of aluminum hydride leads to changes in the spatial distribution of the luminescence centers. For short times of exposure their concentration increases mainly in the surface regions of the crystals. At high exposures, this process extends to the bulk of the aluminum hydride and ends with a decrease in concentration of luminescence centers in the surface region. - Highlights: • Aluminum hydride contains hydrogen vacancies which serve as luminescence centers. • The luminescence is the result of radiative relaxation of excited centers. • Hydride UV-irradiation alters distribution and concentration of luminescence centers

  9. Luminescent properties of aluminum hydride

    Energy Technology Data Exchange (ETDEWEB)

    Baraban, A.P.; Gabis, I.E.; Dmitriev, V.A. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation); Dobrotvorskii, M.A., E-mail: mstislavd@gmail.com [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation); Kuznetsov, V.G. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation); Matveeva, O.P. [National Mineral Resources University, Saint Petersburg 199106 (Russian Federation); Titov, S.A. [Petersburg State University of Railway Transport, Saint-Petersburg 190031 (Russian Federation); Voyt, A.P.; Elets, D.I. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg 198504 (Russian Federation)

    2015-10-15

    We studied cathodoluminescence and photoluminescence of α-AlH{sub 3}– a likely candidate for use as possible hydrogen carrier in hydrogen-fueled vehicles. Luminescence properties of original α-AlH{sub 3} and α-AlH{sub 3} irradiated with ultraviolet were compared. The latter procedure leads to activation of thermal decomposition of α-AlH{sub 3} and thus has a practical implementation. We showed that the original and UV-modified aluminum hydride contain luminescence centers ‐ structural defects of the same type, presumably hydrogen vacancies, characterized by a single set of characteristic bands of radiation. The observed luminescence is the result of radiative intracenter relaxation of the luminescence center (hydrogen vacancy) excited by electrons or photons, and its intensity is defined by the concentration of vacancies, and the area of their possible excitation. UV-activation of the dehydrogenation process of aluminum hydride leads to changes in the spatial distribution of the luminescence centers. For short times of exposure their concentration increases mainly in the surface regions of the crystals. At high exposures, this process extends to the bulk of the aluminum hydride and ends with a decrease in concentration of luminescence centers in the surface region. - Highlights: • Aluminum hydride contains hydrogen vacancies which serve as luminescence centers. • The luminescence is the result of radiative relaxation of excited centers. • Hydride UV-irradiation alters distribution and concentration of luminescence centers.

  10. Reflectance, Optical Properties, and Stability of Molybdenum/Strontium and Molybdenum/Yttrium Multilayer Mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Kjornrattanawanich, B

    2002-09-01

    The motivation of this work is to develop high reflectance normal-incidence multilayer mirrors in the 8-12 nm wavelength region for applications in astronomy and extreme ultraviolet lithography. To achieve this goal, Mo/Sr and Mo/Y multilayers were studied. These multilayers were deposited with a UHV magnetron sputtering system and their reflectances were measured with synchrotron radiation. High normal-incidence reflectances of 23% at 8.8 nm, 40.8% at 9.4 nm, and 48.3% at 10.5 nm were achieved. However, the reflectance of Mo/Sr multilayers decreased rapidly after exposure to air. Attempts to use thin layers of carbon to passivate the surface of Mo/Sr multilayers were unsuccessful. Experimental results on the refractive index {tilde n} = 1-{delta} + i{beta} of yttrium and molybdenum in the 50-1300 eV energy region are reported in this work. This is the first time ever that values on the refractive index of yttrium are measured in this energy range. The absorption part {beta} was determined through transmittance measurements. The dispersive part {delta} was calculated by means of the Kramers-Kronig formalism. The newly determined values of the refractive index of molybdenum are in excellent agreement with the published data. Those of yttrium are more accurate and contain fine structures around the yttrium M-absorption edges where Mo/Y multilayers operate. These improved sets of optical data lead to better design and modeling of the optical properties of Mo/Y multilayers. The reflectance quality of Mo/Y multilayers is dependent on their optical and structural properties. To correlate these properties with the multilayer reflectance, x-ray diffraction, Rutherford backscattering spectrometry, and transmission electron microscopy were used to analyze samples. Normal-incidence reflectances of 32.6% at 9.27 nm, 38.4% at 9.48 nm, and 29.6% at 9.46 nm were obtained from three representative Mo/Y multilayers which had about 0%, 25%, and 39% atomic oxygen assimilated in their

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

    International Nuclear Information System (INIS)

    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.

  12. Decarbonization process for carbothermically produced aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Marshall J.; Carkin, Gerald E.; DeYoung, David H.; Dunlap, Sr., Ronald M.

    2015-06-30

    A method of recovering aluminum is provided. An alloy melt having Al.sub.4C.sub.3 and aluminum is provided. This mixture is cooled and then a sufficient amount of a finely dispersed gas is added to the alloy melt at a temperature of about 700.degree. C. to about 900.degree. C. The aluminum recovered is a decarbonized carbothermically produced aluminum where the step of adding a sufficient amount of the finely dispersed gas effects separation of the aluminum from the Al.sub.4C.sub.3 precipitates by flotation, resulting in two phases with the Al.sub.4C.sub.3 precipitates being the upper layer and the decarbonized aluminum being the lower layer. The aluminum is then recovered from the Al.sub.4C.sub.3 precipitates through decanting.

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

    International Nuclear Information System (INIS)

    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

  14. Electrodeposition of aluminum on aluminum surface from molten salt

    Institute of Scientific and Technical Information of China (English)

    Wenmao HUANG; Xiangyu XIA; Bin LIU; Yu LIU; Haowei WANG; Naiheng MA

    2011-01-01

    The surface morphology,microstructure and composition of the aluminum coating of the electrodeposition plates in AlC13-NaC1-KC1 molten salt with a mass ratio of 8:1:1 were investigated by SEM and EDS.The binding force was measured by splat-cooling method and bending method.The results indicate that the coatings with average thicknesses of 12 and 9 μm for both plates treated by simple grinding and phosphating are compacted,continuous and well adhered respectively. Tetramethylammonium chloride (TMAC) can effectively prevent the growth of dendritic crystal,and the anode activation may improve the adhesion of the coating. Binding force analysis shows that both aluminum coatings are strongly adhered to the substrates.

  15. Mössbauer Spectral Properties of Yttrium Iron Garnet, Y3Fe5O12, and its Isovalent and Nonisovalent Yttrium-Substituted Solid Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Long, Gary J.; Grandjean, Fernande; Guo, Xiaofeng; Navrotsky, Alexandra; Kukkadapu, Ravi K.

    2016-03-21

    Several high-resolution Mössbauer spectra of yttrium iron garnet, Y3Fe5O12, have been fit as a function of temperature with a new model based on a detailed analysis of the spectral changes that result from a reduction from the cubic Ia–3d space group to the trigonal R–3 space group. These spectral fits, which are all statistically identical, indicate that the magnetic sextet arising from the 16a site in cubic symmetry is subdivided into three sextets arising from the 6f, and the 3d, 3d, and the 1a, 1b, and 2c sites in rhombohedral-axis trigonal symmetry. The 24d site in cubic symmetry is subdivided into four sextets arising from four different 6f sites in R–3 rhombohedral-axis trigonal symmetry, sites that differ only by the angles between the principal axis of the electric field gradient tensor and the magnetic hyperfine field assumed to be parallel with the magnetic easy axis. This analysis, when applied to the potential nuclear waste storage compounds, Y3-xCa0.5xTh0.5xFe5O12 and Y3- xCa0.5xCe0.5xFe5O12, indicates virtually no perturbation of the structural, electronic, and magnetic properties upon substitution of small amounts of calcium(II) and thorium(IV) or cerium(IV) onto the yttrium(III) 24c site as compared with Y3Fe5O12. The observed broadening of the four different 6f sites derived from the 24d site results from the substitution of yttrium(III) by calcium(II) and thorium(IV) or cerium(IV) cations on the next-nearest neighbor 24c site. In contrast, the same analysis, when applied to Y2.8Ce0.2Fe5O12, indicates a local perturbation of the magnetic exchange pathways as a result of the presence of cerium(IV) in the 24c next-nearest neighbor site of the iron(III) 24d site.

  16. Microstructure and Mechanical Properties of AA1235 Aluminum Foil Stocks Produced Directly from Electrolytic Aluminum Melt

    Science.gov (United States)

    Xiong, Hanqing; Yu, Kun; Wen, Li; Yao, Sujuan; Dai, Yilong; Wang, Zhifeng

    2016-02-01

    A new process is developed to obtain high-quality AA1235 aluminum foil stocks and to replace the traditional manufacture process. During the new manufacture process, AA1235 aluminum sheets are twin-roll casted directly through electrolytic aluminum melt (EAM), and subsequently the sheets are processed into aluminum foil stocks by cold rolling and annealing. Microstructure and mechanical properties of the AA1235 aluminum sheets produced through such new process are investigated in each state by optimal microscope, scanning electron microscopy, X-ray diffraction, orientation imaging microscopy, transmission electron microscopy, etc. The results show that compared with the traditional AA1235 aluminum foil stocks produced through re-melted aluminum melt (RAM), the amount of impurities is decreased in the EAM aluminum foil stocks. The EAM aluminum foil stock obtains less β-FeSiAl5 phases, but more α-Fe2SiAl8 phases. The elongation of EAM aluminum foil stocks is improved significantly owing to more cubic orientation. Especially, the elongation value of the EAM aluminum foil stocks is approximately 25 pct higher than that of the RAM aluminum foil stocks. As a result, the EAM aluminum foil stocks are at an advantage in increasing the processing performance for the aluminum foils during subsequent processes.

  17. Determination of micro yttrium in an ytterbium matrix by inductively coupled plasma atomic emission spectrometry and wavelet transform

    Institute of Scientific and Technical Information of China (English)

    MA Xiaoguo

    2005-01-01

    In the determination of trace yttrium (Y) in an ytterbium (Yb) matrix by inductively coupled plasma atomic emission spectrometry (ICP-AES), the most prominent line of yttrium, Y 371.030 nm line, suffers from strong interference due to an emission line of ytterbium. In this work, a method based on wavelet transform was proposed for the spectral interference correction. Haar wavelet was selected as the mother wavelet. The discrete detail after the third decomposition, D3,was chosen for quantitative analysis based on the consideration of both separation degree and peak height. The linear correlation coefficient between the height of the left positive peak in D3 and the concentration of Y was calculated to be 0.9926.Six synthetic samples were analyzed, and the recovery for yttrium varied from 96.3% to 110.0%. The amounts of yttrium in three ytterbium metal samples were determined by the proposed approach with an average relative standard deviation (RSD)of 2.5%, and the detection limit for yttrium was 0.016%. This novel correction technique is fast and convenient, since neither complicated model assumption nor time-consuming iteration is required. Furthermore, it is not affected by the wavelength drift inherent in monochromators that will severely reduce the accuracy of results obtained by some chemometric methods.

  18. Application of aluminide coatings modified with yttrium for protecting corn post-harvest processing equipment against erosion in food industries

    International Nuclear Information System (INIS)

    Recent studies demonstrate that aluminide coatings are beneficial to wear and erosion resistance and also oxygen active elements such as yttrium can remarkably improve this resistance. In this research, the micro-hardness of the aluminide coatings with and without yttrium on carbon steel AISI 1045 was investigated using a micro-mechanical probe in post-harvest processing equipment in food industries. Wear of the samples was measured using a pin-on-disk tribometer. The erosion loss of specimens against five varieties of corn was also evaluated using a slurry erosion test machine. Experimental data were analyzed statistically using a 5-factor completely randomized design to study the effect of corn varieties, moisture content at three levels [13, 15, and 17% (wet basis)], and rotation velocity of the slurry erosion machine at three levels (150, 300, and 450 rpm) on erosion resistance. The results showed that the aluminide coatings improved the wear and erosion resistance of substrate carbon steel AISI 1045; yttrium markedly improved the hardness of the aluminide coating and its wear and erosion resistance. The erosion loss of materials was significantly (P < 0.01) influenced by the variety of corn, moisture content and rotation velocity. Both aluminide coating without yttrium and aluminide coating with yttrium showed higher wear and erosion resistance than carbon steel AISI 1045 substrate. (Author) 14 refs.

  19. Implants of aluminum into silicon

    Science.gov (United States)

    Galvagno, G.; Scandurra, A.; Raineri, V.; Rimini, E.; La Ferla, A.; Sciascia, V.; Frisina, F.; Raspagliesi, M.; Ferla, G.

    1993-04-01

    The electrical behaviour of ion implanted aluminum into silicon was investigated by varying the beam energy in the 80 keV-6 MeV range, the dose in the 1 × 10 13-1 × 10 14/cm 2 range and the annealing procedure. Aluminum atoms precipitate into exten defects at the end of range damage and where the concentration exceeds the solid solubility value (about 2 × 10 19/cm 3 at 1200°C Escape of Al atoms occurs very easily as soon as they reach the external surface during the thermal diffusion. Using high energy implants, 6 MeV, it was possible to follow in detail the broadening of the diffused profiles. The measured trends between the retained dose and the junction depth and between the outdiffused dose and the annealing time are quite well predicted by the solution of the diffusion equation with the surface acting as a perfect sink for the dopant.

  20. Electrically Conductive Anodized Aluminum Surfaces

    Science.gov (United States)

    Nguyen, Trung Hung

    2006-01-01

    Anodized aluminum components can be treated to make them sufficiently electrically conductive to suppress discharges of static electricity. The treatment was conceived as a means of preventing static electric discharges on exterior satin-anodized aluminum (SAA) surfaces of spacecraft without adversely affecting the thermal-control/optical properties of the SAA and without need to apply electrically conductive paints, which eventually peel off in the harsh environment of outer space. The treatment can also be used to impart electrical conductivity to anodized housings of computers, medical electronic instruments, telephoneexchange equipment, and other terrestrial electronic equipment vulnerable to electrostatic discharge. The electrical resistivity of a typical anodized aluminum surface layer lies between 10(exp 11) and 10(exp 13) Omega-cm. To suppress electrostatic discharge, it is necessary to reduce the electrical resistivity significantly - preferably to anodized surface becomes covered and the pores in the surface filled with a transparent, electrically conductive metal oxide nanocomposite. Filling the pores with the nanocomposite reduces the transverse electrical resistivity and, in the original intended outer-space application, the exterior covering portion of the nanocomposite would afford the requisite electrical contact with the outer-space plasma. The electrical resistivity of the nanocomposite can be tailored to a value between 10(exp 7) and 10(exp 12) Omega-cm. Unlike electrically conductive paint, the nanocomposite becomes an integral part of the anodized aluminum substrate, without need for adhesive bonding material and without risk of subsequent peeling. The electrodeposition process is compatible with commercial anodizing production lines. At present, the electronics industry uses expensive, exotic, electrostaticdischarge- suppressing finishes: examples include silver impregnated anodized, black electroless nickel, black chrome, and black copper. In

  1. Microbial corrosion of aluminum alloy.

    Science.gov (United States)

    Yang, S S; Chen, C Y; Wei, C B; Lin, Y T

    1996-11-01

    Several microbes were isolated from the contaminated fuel-oil in Taiwan and the microbial corrosion of aluminum alloy A356-T6 was tested by MIL-STD-810E test method. Penicillium sp. AM-F5 and Cladosporium resinac ATCC 22712 had significant adsorption and pitting on the surface of aluminum alloy, Pseudomonas acruginosa AM-B5 had weak adsorption and some precipitation in the bottom, and Candida sp. AM-Y1 had the less adsorption and few cavities formation on the surface. pH of the aqueous phase decreased 0.3 to 0.7 unit for 4 months of incubation. The corrosion of aluminum alloy was very significant in the cultures of Penicillium sp. AM-F2, Penicillium sp. AM-F5 and C. resinac ATCC 22712. The major metabolites in the aqueous phase with the inoculation of C. resinac were citric acid and oxalic acid, while succinic acid and fumaric acid were the minors. PMID:10592801

  2. Aluminum-lithium target behavior

    Energy Technology Data Exchange (ETDEWEB)

    McDonell, W.R.

    1989-10-01

    Information on physical properties and irradiation behavior of aluminum-lithium target alloys employed for the production of tritium in Savannah River reactors has been reviewed to support development of technology for the New Production Reactor (NPR). Phase compositions and microstructures, thermal conductivity, mechanical properties, and constituent diffusion phenomena of the alloys, established in prior site studies, are presented. Irradiation behavior, including distributions of product tritium and helium and related exposure limits due to swelling and cracking of the target alloys is discussed, along with gas release processes occurring during subsequent product recovery operations. The property review supports designation of the aluminum-lithium alloys as ideally well-suited target materials for low-temperature, tritium-producing reactors, demonstrated over 35 years of Savannah River reactor operation. Low temperature irradiation and reaction with lithium in the alloy promotes tritium retention during reactor exposure, and the aluminum provides a matrix from which the product is readily recovered on heating following irradiation. 33 refs., 26 figs., 8 tabs.

  3. Purification technology of molten aluminum

    Institute of Scientific and Technical Information of China (English)

    孙宝德; 丁文江; 疏达; 周尧和

    2004-01-01

    Various purification methods were explored to eliminate the dissolved hydrogen and nonmetallic inclusions from molten aluminum alloys. A novel rotating impeller head with self-oscillation nozzles or an electromagnetic valve in the gas circuit was used to produce pulse gas currents for the rotary impeller degassing method. Water simulation results show that the size of gas bubbles can be decreased by 10%-20% as compared with the constant gas current mode. By coating ceramic filters or particles with active flux or enamels, composite filters were used to filter the scrap A356 alloy and pure aluminum. Experimental results demonstrate that better filtration efficiency and operation performance can be obtained. Based on numerical calculations, the separation efficiency of inclusions by high frequency magnetic field can be significantly improved by using a hollow cylinder-like separator or utilizing the effects of secondary flow of the melt in a square separator. A multi-stage and multi-media purification platform based on these methods was designed and applied in on-line processing of molten aluminum alloys. Mechanical properties of the processed scrap A356 alloy are greatly improved by the composite purification.

  4. Features of hydrogen trapping and desorption during deposition of yttrium coating on zirconium in a gas discharge

    Science.gov (United States)

    Evsin, A. E.; Begrambekov, L. B.; Dovganyuk, S. S.

    2016-01-01

    Transport of hydrogen isotopes during the various regimes of deposition of yttrium coating on zirconium in argon plasma with addition of deuterium is studied. The influence of oxygen contamination in plasma-generating gas on the processes of trapping and desorption of hydrogen isotopes is also investigated. It is shown that deposition of yttrium coating on zirconium in Ar+5%D2 plasma enhances both hydrogen desorption from zirconium and deuterium trapping into zirconium in comparison to those under plasma exposure without deposition. Yttrium deposition in Ar+25%O2+5%D2 plasma, conversely, mitigates both hydrogen desorption and deuterium trapping. Hydrogen desorption from zirconium increases with the increase of energy of ions, bombarding the sample during deposition of the coating in oxygen-free plasma, but it, on the contrary, decreases in oxygen-containing plasma.

  5. High-temperature corrosion behavior of Ni–16Mo–7Cr–4Fe superalloy containing yttrium in molten LiF–NaF–KF salt

    International Nuclear Information System (INIS)

    Highlights: • Traces of yttrium were doped in Ni–16Mo–7Cr–4Fe nickel-base superalloy. • High-temperature corrosion resistance is improved by proper yttrium addition. • Synchrotron radiation X-ray fluorescence with high sensitivity was adopted. - Abstract: The corrosion tests of a Ni–16Mo–7Cr–4Fe superalloy containing various yttrium contents were performed in molten FLiNaK (LiF–NaF–KF: 46.5–11.5–42 mol%) salt at 850 °C for 620 h, with the goals of investigating the effects of yttrium on the corrosion resistance of Ni–16Mo–7Cr–4Fe alloy and understanding the corrosion mechanisms. The addition of an appropriate amount of yttrium promotes the formation of a Y-rich layer near the surface and inhibits the diffusion of the susceptive elements

  6. High-temperature corrosion behavior of Ni–16Mo–7Cr–4Fe superalloy containing yttrium in molten LiF–NaF–KF salt

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiao-li; He, Shang-ming, E-mail: heshangming@sinap.ac.cn; Zhou, Xing-tai; Huai, Ping; Li, Zhi-jun; Li, Ai-guo; Yu, Xiao-han, E-mail: yuxiaohan@sinap.ac.cn

    2015-09-15

    Highlights: • Traces of yttrium were doped in Ni–16Mo–7Cr–4Fe nickel-base superalloy. • High-temperature corrosion resistance is improved by proper yttrium addition. • Synchrotron radiation X-ray fluorescence with high sensitivity was adopted. - Abstract: The corrosion tests of a Ni–16Mo–7Cr–4Fe superalloy containing various yttrium contents were performed in molten FLiNaK (LiF–NaF–KF: 46.5–11.5–42 mol%) salt at 850 °C for 620 h, with the goals of investigating the effects of yttrium on the corrosion resistance of Ni–16Mo–7Cr–4Fe alloy and understanding the corrosion mechanisms. The addition of an appropriate amount of yttrium promotes the formation of a Y-rich layer near the surface and inhibits the diffusion of the susceptive elements.

  7. Radiographic Response to Yttrium-90 Radioembolization in Anterior Versus Posterior Liver Segments

    International Nuclear Information System (INIS)

    The purpose of our study was to determine if preferential radiographic tumor response occurs in tumors located in posterior versus anterior liver segments following radioembolization with yttrium-90 glass microspheres. One hundred thirty-seven patients with chemorefractory liver metastases of various primaries were treated with yttrium-90 glass microspheres. Of these, a subset analysis was performed on 89 patients who underwent 101 whole-right-lobe infusions to liver segments V, VI, VII, and VIII. Pre- and posttreatment imaging included either triphasic contrast material-enhanced CT or gadolinium-enhanced MRI. Responses to treatment were compared in anterior versus posterior right lobe lesions using both RECIST and WHO criteria. Statistical comparative studies were conducted in 42 patients with both anterior and posterior segment lesions using the paired-sample t-test. Pearson correlation was used to determine the relationship between pretreatment tumor size and posttreatment tumor response. Median administered activity, delivered radiation dose, and treatment volume were 2.3 GBq, 118.2 Gy, and 1,072 cm3, respectively. Differences between the pretreatment tumor size of anterior and posterior liver segments were not statistically significant (p = 0.7981). Differences in tumor response between anterior and posterior liver segments were not statistically significant using WHO criteria (p = 0.8557). A statistically significant correlation did not exist between pretreatment tumor size and posttreatment tumor response (r = 0.0554, p = 0.4434). On imaging follow-up using WHO criteria, for anterior and posterior regions of the liver, (1) response rates were 50% (PR = 50%) and 45% (CR = 9%, PR = 36%), and (2) mean changes in tumor size were -41% and -40%. In conclusion, this study did not find evidence of preferential radiographic tumor response in posterior versus anterior liver segments treated with yttrium-90 glass microspheres.

  8. Influence of yttrium substitution on the magnetic and transport properties of UCu5

    International Nuclear Information System (INIS)

    We have measured the resistivity, magnetoresistance, resistivity under hydrostatic pressure and the magnetization of the compound (U1-xYxCu5 for temperatures between 0.4 and 300 K, fields of up to 12 T and at pressures between 1 bar and 14 kbar. From this series of measurements we have derived compositional, H-T and p-T phase diagrams. Using thermodynamic arguments and a comparison of these phase diagrams we arrive at a nomenclature for the various phases which is consistent with that used for the parent compound UCu5. We observe that the 1-q structure observed below T2 = 1.16 K in UCu5 is stabilized with increasing yttrium. In addition the introduction of yttrium results in a rapid reduction of TN. The effects of 'chemical' pressure are found to be opposite to those observed for hydrostatic pressure, which enhances TN and reduces T2. From an analysis of the dc susceptibility we derive values for χ0 (Pauli susceptibility) which indicate a large reduction of the density of states for x>0.1 and this is consistent with the reduction of the resistivity observed at room temperature. However, this analysis could not rule out the possibility of a change in the source of the Kondo contribution. An analysis of the resistivity and ΘP (paramagnetic Curie-Weiss temperature) for (U0.7Y0.3)Cu5 is consistent with the onset of a Kondo process with increasing yttrium doping. (author)

  9. Yttrium-90 hepatic radioembolization: clinical review and current techniques in interventional radiology and personalized dosimetry.

    Science.gov (United States)

    Tong, Aaron K T; Kao, Yung Hsiang; Too, Chow Wei; Chin, Kenneth F W; Ng, David C E; Chow, Pierce K H

    2016-06-01

    In recent years, yttrium-90 ((90)Y) microsphere radioembolization has been establishing itself as a safe and efficacious treatment for both primary and metastatic liver cancers. This extends to both first-line therapies as well as in the salvage setting. In addition, radioembolization appears efficacious for patients with portal vein thrombosis, which is currently a contraindication for surgery, transplantation and transarterial chemoembolization. This article reviews the efficacy and expanding use of (90)Y microsphere radioembolization with an added emphasis on recent advances in personalized dosimetry and interventional radiology techniques. Directions for future research into combination therapies with radioembolization and expansion into sites other than the liver are also explored. PMID:26943239

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

    International Nuclear Information System (INIS)

    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.)

  11. Cyclic and Linear Polarization of Yttrium-Containing Iron-Based Amorphous Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Day, S D; Lian, T; Farmer, J C; Rebak, R B

    2007-08-10

    Iron-based amorphous alloys are produced by rapid solidification from the melt. These alloys may possess unique mechanical and corrosion resistant properties. The chemical composition of the alloy may influence the cooling rate that is necessary for the alloys to be completely vitreous. At the same time, the corrosion resistance of the amorphous alloys may also depend on their chemical composition. This paper examines the anodic behavior of iron-based amorphous alloys containing three different concentrations (1, 3 and 5 atomic %) of yttrium (Y) in several electrolyte solutions. Results from polarization resistance potentiodynamic polarization show that when the alloy contains 5% atomic Y, the corrosion resistance decreases.

  12. Preparation, characterization and dielectric behaviour of some yttrium doped strontium stannates

    Indian Academy of Sciences (India)

    P K Bajpai; Kuldeep Ratre; Mukul Pastor; T P Sinha

    2003-08-01

    Samples of Sr$_{(1–3x/2)}$Y$_x$SnO3 are prepared by usual solid state reaction route. X-ray diffraction studies confirm the formation of single cubic perovskite single phase. The dielectric constant and dielectric loss at 1 kHz were measured in the temperature range from room temperature up to ≅ 150°C. The dielectric constant decreases and losses increase with increased yttrium content in the samples. The percentage porosity and unit cell parameters are also calculated for the samples.

  13. Structure degradation and conducting properties of the perovskite phase of yttrium ceramics

    CERN Document Server

    Kalanov, M U

    2002-01-01

    It is shown, that under normal conditions the perovskite phase of the yttrium ceramics of the [(Y,Ba)CuO sub 3 sub - subDELTA sub / sub 3] sub 3 is metastable and degrades in time. The degradation results in the YBa sub 2 Cu sub 3 O sub 7 sub - subdelta orthorhombic phase with transition into the superconducting state at T sub c = 91 K. The conductivity type changes thereby from the mixed metal-semiconductor character to the metallic one within the temperature interval of 100-300 K

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

    Directory of Open Access Journals (Sweden)

    Michael R McDevitt

    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

  15. Scaling at the Mott-Hubbard metal-insulator transition in yttrium hydride

    CERN Document Server

    Hoekstra, A F T; Rosenbaum, T F

    2003-01-01

    A single yttrium hydride thin film is conveniently driven through the T 0 metal-insulator transition by fine-tuning the charge carrier density n via persistent photoconductivity at low temperature. Simultaneously, electrical conductivity and Hall measurements are performed for temperatures T down to 350 mK and magnetic fields up to 14 T. A scaling analysis is applied and critical exponents, resolved separately on the metallic and insulating sides of the critical region, are determined consistently. We introduce corrections to scaling to invoke collapse of the data onto a single master curve over an extended region of the (n, T) phase diagram.

  16. Unidirectional anisotropy in the spin pumping voltage in yttrium iron garnet/platinum bilayers

    Science.gov (United States)

    Vilela-Leão, L. H.; Salvador, C.; Azevedo, A.; Rezende, S. M.

    2011-09-01

    Detailed measurements of the dc voltage generated in a thin Pt layer deposited on films of yttrium iron garnet (YIG) have been carried out to study the spin pumping effect produced by magnetostatic (MS) modes excited by a microwave field. In relatively thick YIG films the modes are far apart so that one can identify clearly the spin pumping voltage in VSP produced by each MS mode. We have discovered that when the sputter deposition of the thin Pt layer is made on the YIG film magnetized by a static magnetic field, VSP exhibits a strong unidirectional anisotropy.

  17. Enhanced spin pumping damping in yttrium iron garnet/Pt bilayers

    Science.gov (United States)

    Rezende, S. M.; Rodríguez-Suárez, R. L.; Soares, M. M.; Vilela-Leão, L. H.; Ley Domínguez, D.; Azevedo, A.

    2013-01-01

    Detailed measurements of the magnetic relaxation expressed in the linewidth of the ferromagnetic resonance (FMR) absorption in thick films of yttrium iron garnet (YIG) and in YIG/Pt bilayers carried out at room temperature reveal a very large increase in the relaxation rate with the deposition of a Pt layer. The additional relaxation increases linearly with the microwave frequency characteristics of the spin pumping mechanism. The value of the spin mixing conductance obtained from the data is one order of magnitude larger than the largest possible value determined from measurements of the voltage generated by FMR spin-pumping.

  18. Amplification of spin waves in yttrium iron garnet films through the spin Hall effect

    Science.gov (United States)

    Padrón-Hernández, E.; Azevedo, A.; Rezende, S. M.

    2011-11-01

    We demonstrate that spin waves propagating in a film of yttrium iron garnet (YIG) can be amplified by a dc current in an adjacent Pt layer by means of the spin Hall effect. The experiments are done at room temperature using pulsed currents to avoid sample heating. Amplification occurs only for surface like modes propagating in a direction perpendicular to the applied in-plane field. The results are interpreted with a model for spin-wave propagation in a YIG film with magnetic losses and subject to a spin-transfer torque due to spin currents created by the spin Hall effect in the Pt layer.

  19. Evidence of dilute ferromagnetism in rare-earth doped yttrium aluminium garnet

    International Nuclear Information System (INIS)

    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 106 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

  20. Stabilities of Complexes of Scandium(III) and Yttrium(III) With Catechol Derivatives

    OpenAIRE

    Türkel, Naciye; AYDIN, Rahmiye; ÖZER, Ulviye

    1999-01-01

    The interactions of scandium(III) and yttrium(III) ions with catechol derivatives; catechol(H2L, CAT), 4-nitrocatechol(H2L, 4NCAT) and 2,3-dihydroxynaphthalene- 6-sulphonic acid(H2L, DHN) were investigated in different metal ion:ligand mole ratios, by potentiometry and spectrophotometry. The stoichiometries of formed complexes have been defined by Job's method and formation curves have been drawn for some complexes, whenever possible. The stability contants of the fourteen forme...

  1. High-temperature compatibility of corundum ceramics with yttrium and scandium oxide ceramics

    International Nuclear Information System (INIS)

    The high-temperature compatibility in the Al2O3-Y2O3 and Al2O3-ScO3 systems is studied both in contacting layers and in the powder mixtures. The character of nonequilibrium interaction in these systems is verified. It is shown that even by sufficiently fast heating of the systems with contacting aluminium, yttrium and scandium oxides, their compatibility is limited by the temperatures of eutectics formation. The Al2O3-Y2O3 system is stable to much higher temperature (1860 deg C) as compared to the Al2O3-ScO3 system (1790 deg C)

  2. Highly Sensitive Fiber-Optic Faraday-Effect Magnetic Field Sensor Based on Yttrium Iron Garnet

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The principle and performance of a fiber-optic Faraday-effect magnetic-field sensor based on an yttrium iron garnet (YIG) and two flux concentrations are described. A single polarization maintaining optical fiber links the sensor head to the source and detection system, in which the technique of phase shift cancellation is used to cancel the phase shift that accumulate in the optical fiber. Flux concentrators were exploited to enhance the YIG crystal magneto optic sensitivity .The sensor system exhibited a noise-equivalent field of 8 and a 3 dB bandwidth of ~10 MHz.

  3. TEMPERATURE DEPENDENCE OF LATTICE PARAMETERS OF TERBIUM-YTTRIUM GARNETS IN THE COMPENSATION POINT VICINITY

    OpenAIRE

    Rodic, D.; Szytula, A.; Tomkowicz, Z.; Guillot, M.; Le Gall, H.

    1988-01-01

    Precise determinations of the lattice parameters were performed on polycrystalline TbxY(3-x)FesO12 mixed terbium-yttrium iron garnets using X ray diffraction in the 80-300 K temperature range in absence of applied magnetic field for x equal to 1, 1.98, 2.5 and 3 respectively. In the vicinity of the compensation point, which varies with the terbium concentration from 60 to 242 K, anomalies on the temperature dependences of both lattice parameter and thermal expansion coefficient were observed.

  4. Photoinduced magnetic effects in bulk single-crystalline, polycrystalline, and LPE films of Yttrium Iron Garnet

    Science.gov (United States)

    Hisatake, K.; Matsubara, I.; Maeda, K.; Fujiwara, T.; Peters, M.; Abe, S.; Kudo, K.; Kainuma, S.; Tamaki, T.; Kino, Y.; de Francisco, C.; Munoz, J. M.; Alejos, O.; Hernandez, P.; Torres, C.; Shinagawa, K.

    2002-05-01

    The effect of light on magnetic initial permeability (the so-called photomagnetic effect) and photoinduced disaccommodation were studied in samples of yttrium iron garnet over the temperature range 77-300 K. The samples studied were bulk crystalline, produced by the floating zone method and the flux method, polycrystalline, produced by the usual sintering method, and single-crystalline films, produced by in situ liquid-phase epitaxis. One or both of the studied phenomena were observed in our experimental samples. To explain the experimental results, we suggest there is photoinduced structural distortion around oxygen vacancies due to a photoinduced change of charge imbalance.

  5. Investigation of sol-gel yttrium doped ZnO thin films: structural and optical properties

    Science.gov (United States)

    Ivanova, T.; Harizanova, A.; Koutzarova, T.; Vertruyen, B.

    2016-02-01

    Nanostructured metal oxide films are extensively studied due to their numerous applications such as optoelectronic devices, sensors. In this work, we report the Y-Zn-O nanostructured films prepared by sol-gel technology from sols with different concentration of yttrium precursor, followed by post-annealing treatment. The Y doped ZnO thin films have been deposited on Si and quartz substrates by spin coating method, then treated at temperatures ranging from 300-800oC. XRD analysis reveals modification of the film structure and phases in the doped ZnO films.

  6. Thermal and chemical stability studies of protective plasma sprayed yttrium oxide coatings on tantalum substrate against liquid uranium

    International Nuclear Information System (INIS)

    Yttrium oxide was deposited on tantalum substrates (40 mm x 8 mm x 1 mm thk) by atmospheric plasma spray technique with out any bond coat using optimized coating parameters. Resistance to thermal shock was evaluated upto 6 cycles prior to the chemical compatibility experiments. Thermal shock qualified batch of coupons were tested for compatibility against liquid uranium at 1573 K upto 200 hrs in oxide coating exhibits excellent corrosion resistance vacuum. Experimental results show that yttrium against liquid uranium at 1573 K. (author)

  7. Gibbs free energies of coordination number change for a number of cations of rare-earth metals and yttrium

    International Nuclear Information System (INIS)

    Changes of Gibbs energies (ΔG) were calculated at variation of coordination number of rare earth and yttrium cations during formation of high-temperature superconductors from ordinary oxides. It is established that ΔG data are positive at changing coordination of ions in the range from samarium to lutetium and yttrium, the enthalpy contribution in ΔG prevails as compared with the entropy contribution, heavy alkaline earth metal ions are thermodynamic stabilizers for high-temperature superconductors. Suggested approach admits of evaluation of outlook for selective methods for synthesis of complicated coordination compounds at deficit of thermodynamic information

  8. Complexometric titration of zirconium and yttrium in the same solution for its application in zirconia-yttria ceramics

    International Nuclear Information System (INIS)

    A simple stepwise complexometric method with EDTA has been developed for the determination of zirconium and yttrium in a single aliquot solution involving direct titration of zirconium at 1N HNO3 and 90 degC and of yttrium at pH 5.3 using methyl thymol blue as indicator. Interferences due to Fe, Ti, Al and Cu have been eliminated by masking with acetylacetone. The method has been standardised against synthetic solutions and applied to various zirconia-yttria ceramics and other yttria bearing materials. (author). 7 refs., 4 tabs

  9. Effect of yttrium additions on the tensile properties and hardness of an iron-nickel-chromium alloy

    International Nuclear Information System (INIS)

    Results of the research work show that the addition of 0.1% yttrium does not significantly change the mechanical properties of the AL1 alloy with temperature (even though the yttrium-doped samples did show a slight increase in yield stress and hardness for tests above 7000C); the room temperature strength of the undoped AL1 alloy increases upon annealing at temperatures above 6000C; and the room temperature uniform and fracture strains of the undoped AL1 alloy decrease upon annealing at temperatures above 6000C

  10. Anode properties of Zn 5 Al alloy alloyed by scandium, yttrium and erbium in NaCl medium

    International Nuclear Information System (INIS)

    Present work is devoted to anode properties of Zn 5 Al alloy alloyed by scandium, yttrium and erbium in NaCl medium. The results of studies of influence of scandium, yttrium and erbium additives on anode properties of zink-aluminium alloy Zn 5 Al intended as anode cover for corrosion protection of steel constructions are considered. The dependence of corrosion rate of zink-aluminium alloy Zn 5 Al on rare-earth metals content in NaCl medium is studied.

  11. Highly Active Yttrium Catalysts for the Ring-Opening Polymerization of ε-Caprolactone and δ-Valerolactone

    OpenAIRE

    X. Wang; Brosmer, JL; Thevenon, A; Diaconescu, PL

    2015-01-01

    © 2015 American Chemical Society. The activity of several yttrium alkoxide and aryloxide complexes supported by a ferrocene-based ligand incorporating two thiol phenolates, thiolfan (1,1′-bis(2,4-di-tert-butyl-6-thiomethylenephenoxy)ferrocene), was studied. The tert-butoxide complex could only be isolated in the ate form, while a monophenoxide complex could be obtained for OAr = 2,6-di-tert-butylphenolate. The synthetic utility of these yttrium complexes has been demonstrated by the ring-open...

  12. 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

  13. Theoretical Study of Hydrogenated Tetrahedral Aluminum Clusters

    CERN Document Server

    Ichikawa, Kazuhide; Wagatsuma, Ayumu; Watanabe, Kouhei; Szarek, Pawel; Tachibana, Akitomo

    2011-01-01

    We report on the structures of aluminum hydrides derived from a tetrahedral aluminum Al4 cluster using ab initio quantum chemical calculation. Our calculation of binding energies of the aluminum hydrides reveals that stability of these hydrides increases as more hydrogen atoms are adsorbed, while stability of Al-H bonds decreases. We also analyze and discuss the chemical bonds of those clusters by using recently developed method based on the electronic stress tensor.

  14. Aluminum exclusion and aluminum tolerance in woody plants

    OpenAIRE

    Brunner, Ivano; Sperisen, Christoph

    2013-01-01

    The aluminum (Al) cation Al3 + is highly rhizotoxic and is a major stress factor to plants on acid soils, which cover large areas of tropical and boreal regions. Many woody plant species are native to acid soils and are well adapted to high Al3 + conditions. In tropical regions, both woody Al accumulator and non-Al accumulator plants occur, whereas in boreal regions woody plants are non-Al accumulators. The mechanisms of these adaptations can be divided into those that facilitate the exclusio...

  15. Comparison between 0.5% timolol maleate and 0.2% brimonidine tartrate in controlling increase in intraocular pressure after neodymium: yttrium-aluminium-garnet laser capsulotomy

    International Nuclear Information System (INIS)

    Objective: To compare the effectiveness of prophylactically given 0.5% Timolol maleate and 0.2% Brimonidine tartrate in controlling increase in intraocular pressure after neodymium (Nd) : yttrium aluminum garnet (YAG) laser capsulotomy. Study Design: Randomized controlled trial. Place and Duration of Study: This study was conducted at Ophthalmology Department, Jinnah Hospital, Lahore from 15-05-2009 to 14-05-2010 for a duration of 12 months. Material and Methods: In this study, 90 consecutive patients were referred from outpatient department for Nd: YAG laser capsulotomy. Hospital ethical committee's approval for this research proposal and the informed consent was taken. These patients were equally divided into two groups A and B, comprising of 45 patients in each group. Group A was control group which received 0.5% Timolol maleate. Group B was experimental group which received 0.2% Brimonidine tartrate. Intraocular pressure was measured using Goldmann tonometer before instilling these topical medications. These medications were administered topically 1 hour before the laser procedure. Intraocular pressure (IOP) was recorded 1 and 3 hours after laser capsulotomy. Results: In patients belonging to group A, 42 (93.3%) patients had effective control of IOP (raise of less than or equal to 5 mmHg from the baseline) after 3 hours of Nd:YAG laser capsulotomy whereas 28 (62.2%) patients had effective control of IOP after the same period of time in group-B with significant difference (p<0.001). Conclusion: Use of prophylactic topical antiglaucoma medications before doing Nd: YAG laser capsulotomy is a effective way to reduce post laser spike of intraocular pressure. Present study showed that the use of 0.5% timolol maleate was safe and more effective than 0.2% brimonidine tartrate when given 1 hour before laser capsulotomy. (author)

  16. Investigating aluminum alloy reinforced by graphene nanoflakes

    Energy Technology Data Exchange (ETDEWEB)

    Yan, S.J., E-mail: shaojiuyan@126.com [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Dai, S.L.; Zhang, X.Y.; Yang, C.; Hong, Q.H.; Chen, J.Z. [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Lin, Z.M. [Aviation Industry Corporation of China, Beijing 100022 (China)

    2014-08-26

    As one of the most important engineering materials, aluminum alloys have been widely applied in many fields. However, the requirement of enhancing their mechanical properties without sacrificing the ductility is always a challenge in the development of aluminum alloys. Thanks to the excellent physical and mechanical properties, graphene nanoflakes (GNFs) have been applied as promising reinforcing elements in various engineering materials, including polymers and ceramics. However, the investigation of GNFs as reinforcement phase in metals or alloys, especially in aluminum alloys, is still very limited. In this study, the aluminum alloy reinforced by GNFs was successfully prepared via powder metallurgy approach. The GNFs were mixed with aluminum alloy powders through ball milling and followed by hot isostatic pressing. The green body was then hot extruded to obtain the final GNFs reinforced aluminum alloy nanocomposite. The scanning electron microscopy and transmission electron microscope analysis show that GNFs were well dispersed in the aluminum alloy matrix and no chemical reactions were observed at the interfaces between the GNFs and aluminum alloy matrix. The mechanical properties' testing results show that with increasing filling content of GNFs, both tensile and yield strengths were remarkably increased without losing the ductility performance. These results not only provided a pathway to achieve the goal of preparing high strength aluminum alloys with excellent ductilitybut they also shed light on the development of other metal alloys reinforced by GNFs.

  17. Investigating aluminum alloy reinforced by graphene nanoflakes

    International Nuclear Information System (INIS)

    As one of the most important engineering materials, aluminum alloys have been widely applied in many fields. However, the requirement of enhancing their mechanical properties without sacrificing the ductility is always a challenge in the development of aluminum alloys. Thanks to the excellent physical and mechanical properties, graphene nanoflakes (GNFs) have been applied as promising reinforcing elements in various engineering materials, including polymers and ceramics. However, the investigation of GNFs as reinforcement phase in metals or alloys, especially in aluminum alloys, is still very limited. In this study, the aluminum alloy reinforced by GNFs was successfully prepared via powder metallurgy approach. The GNFs were mixed with aluminum alloy powders through ball milling and followed by hot isostatic pressing. The green body was then hot extruded to obtain the final GNFs reinforced aluminum alloy nanocomposite. The scanning electron microscopy and transmission electron microscope analysis show that GNFs were well dispersed in the aluminum alloy matrix and no chemical reactions were observed at the interfaces between the GNFs and aluminum alloy matrix. The mechanical properties' testing results show that with increasing filling content of GNFs, both tensile and yield strengths were remarkably increased without losing the ductility performance. These results not only provided a pathway to achieve the goal of preparing high strength aluminum alloys with excellent ductilitybut they also shed light on the development of other metal alloys reinforced by GNFs

  18. Gut: An underestimated target organ for Aluminum.

    Science.gov (United States)

    Vignal, C; Desreumaux, P; Body-Malapel, M

    2016-06-01

    Since World War II, several factors such as an impressive industrial growth, an enhanced environmental bioavailability and intensified food consumption have contributed to a significant amplification of human exposure to aluminum. Aluminum is particularly present in food, beverages, some drugs and airbone dust. In our food, aluminum is superimposed via additives and cooking utensils. Therefore, the tolerable intake of aluminum is exceeded for a significant part of the world population, especially in children who are more vulnerable to toxic effects of pollutants than adults. Faced with this oral aluminum influx, intestinal tract is an essential barrier, especially as 38% of ingested aluminum accumulates at the intestinal mucosa. Although still poorly documented to date, the impact of oral exposure to aluminum in conditions relevant to real human exposure appears to be deleterious for gut homeostasis. Aluminum ingestion affects the regulation of the permeability, the microflora and the immune function of intestine. Nowadays, several arguments are consistent with an involvement of aluminum as an environmental risk factor for inflammatory bowel diseases. PMID:26970682

  19. 40 CFR 180.1091 - Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Aluminum isopropoxide and aluminum... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1091 Aluminum isopropoxide and aluminum secondary butoxide; exemption from the requirement of a tolerance. Aluminum isopropoxide (CAS Reg. No....

  20. The Aluminum Deep Processing Project of North United Aluminum Landed in Qijiang

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>On April 10,North United Aluminum Company respectively signed investment cooperation agreements with Qijiang Industrial Park and Qineng Electricity&Aluminum Co.,Ltd,signifying the landing of North United Aluminum’s aluminum deep processing project in Qijiang.

  1. [The corrosion resistance of aluminum and aluminum-based alloys studied in artificial model media].

    Science.gov (United States)

    Zhakhangirov, A Zh; Doĭnikov, A I; Aboev, V G; Iankovskaia, T A; Karamnova, V S; Sharipov, S M

    1991-01-01

    Samples of aluminum and its alloys, designed for orthodontic employment, were exposed to 4 media simulating the properties of biologic media. The corrosion resistance of the tested alloys was assessed from the degree of aluminum migration to simulation media solutions, which was measured by the neutron activation technique. Aluminum alloy with magnesium and titanium has shown the best corrosion resistance. PMID:1799002

  2. Thermal stability studies of plasma sprayed yttrium oxide coatings deposited on pure tantalum substrate

    Science.gov (United States)

    Nagaraj, A.; Anupama, P.; Mukherjee, Jaya; Sreekumar, K. P.; Satpute, R. U.; Padmanabhan, P. V. A.; Gantayet, L. M.

    2010-02-01

    Plasma sprayed Yttrium oxide is used for coating of crucibles and moulds that are used at high temperature to handle highly reactive molten metals like uranium, titanium, chromium, and beryllium. The alloy bond layer is severely attacked by the molten metal. This commonly used layer contributes to the impurity addition to the pure liquid metal. Yttrium oxide was deposited on tantalum substrates (25 mm × 10mm × 1mm thk and 40 mm × 8mm × 1mm thk) by atmospheric plasma spray technique with out any bond coat using optimized coating parameters. Resistance to thermal shock was evaluated by subjecting the coated specimens, to controlled heating and cooling cycles between 300K to 1600K in an induction furnace in argon atmosphere having <= 0.1ppm of oxygen. The experiments were designed to examine the sample tokens by both destructive and non-destructive techniques, after a predetermined number of thermal cycles. The results upto 24 thermal cycles of 25 mm × 10mm × 1mm thk coupons and upto 6 cycles of 40 mm × 8mm × 1mm thk coupons are discussed. The coatings produced with the optimized parameters were found to exhibit excellent thermal shock resistance.

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

    International Nuclear Information System (INIS)

    We investigated yttrium scandate (YScO3) as an alternative high-permittivity (k) dielectric thin film for Ge gate stack formation. Significant enhancement of k-value is reported in YScO3 comparing to both of its binary compounds, Y2O3 and Sc2O3, 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 YScO3 as high-k dielectric and yttrium-doped GeO2 (Y-GeO2) 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 cm2/V s in sub-nm EOT region by YScO3/Y-GeO2/Ge gate stack

  4. Thermally stable yttrium-scandium oxide high-k dielectrics deposited by a solution process

    Science.gov (United States)

    Hu, Wenbing; Frost, Bradley; Peterson, Rebecca L.

    2016-03-01

    We investigated the thermal stability of electrical properties in ternary alloy (Y x Sc1-x )2O3 high-k oxides as a function of yttrium fraction, x. The yttrium-scandium oxide dielectric films are deposited using a facile ink-based process. The oxides have a stoichiometry-dependent relative dielectric constant of 26.0 to 7.7 at 100 kHz, low leakage current density of 10-8 A·cm-2, high breakdown field of 4 MVṡcm-1, and interface trap density of 1012 cm-2·eV-1 with silicon. Compared with binary oxides, ternary alloys exhibit less frequency dispersion of the dielectric constant and a higher crystallization temperature. After crystallization is induced through a 900 °C anneal, ternary (Y0.6Sc0.4)2O3 films maintain their low leakage current and high breakdown field. In contrast, the electrical performance of the binary oxides significantly degrades following the same treatment. The solution-processed ternary oxide dielectrics demonstrated here may be used as high-k gate insulators in complementary metal-oxide semiconductor (CMOS) technologies, in novel electronic material systems and devices, and in printed, flexible thin film electronics, and as passivation layers for high power devices. These oxides may also be used as insulators in fabrication process flows that require a high thermal budget.

  5. Short-range order changes induced by heat treatment in yttrium aluminosilicate glasses

    Science.gov (United States)

    Simon, V.; Turcu, R. V. F.; Eniu, D.; Simon, S.

    2008-01-01

    Short-range order and local atomic configuration in yttrium-aluminosilicate glasses doped with gadolinium were studied by infrared (IR) spectroscopy, 27Al magic-angle-spinning nuclear magnetic resonance (MAS-NMR) and Gd 3+ electron spin resonance (EPR) on as-prepared and heat-treated samples. A small amount of yttrium was replaced by gadolinium in the host glass because Y 3+ and Gd 3+ cations are quite similar and gadolinium ions can be used as structural sensor in electron paramagnetic resonance measurements. The results evidence weak changes in the structure of as-prepared glasses with respect to the coordination of aluminium atoms produced by gadolinium doping (0.2 and 0.5 mol%). New IR bands recorded from heat-treated samples are associated with stretching modes of hexacoordinated aluminium in AlO 6 octahedra. The effect of the heat treatment on aluminium environment is estimated by analysing the relative intensity of the component lines of simulated 27Al MAS-NMR spectra. High-coordinated AlO n species were identified in all samples. EPR results evidence the increase of the number of gadolinium sites with weak crystal field as effect of the structural relaxation.

  6. Paramagnetic centers induced by gamma irradiation of bioactive silica glasses containing yttrium

    International Nuclear Information System (INIS)

    Full text: Silica bioactive glasses containing neutron activated yttrium were investigated as a potential material for internal radiotherapy of cancers. The silica glasses, containing yttrium oxide and different alkali and alkaline-earth oxides as network modifiers, were obtained by melt annealing method. The samples were exposed to gamma radiation from a 60Co source for up to 10 days irradiation time. The radiation induced paramagnetic point defects in the irradiated glasses were analysed by Electron Paramagnetic Resonance (EPR). The EPR spectra of the silica glasses with different modifiers are characterised by a resonance line at g ≅ 2.024, slightly varying with the composition, attributed to a non-bridging oxygen hole centres. The addition of modifier oxides into glass network results in the formation of non-bridging oxygens that are locally charged compensated by modifier cations in neighbouring interstitial positions. The presence of small amount of boron oxide, up to 2.6 wt. %, in some of the glasses induced the formation of boron oxygen hole centres that are the main EPR species in these irradiated glasses. The presence of the EPR evidenced defects have to be taken into account as possible centres for glasses dissolution in human body during the radiotherapy procedure. (author)

  7. Microwave and magneto-optic properties of bismuth-substituted yttrium iron garnet thin films

    Science.gov (United States)

    Butler, J. C.; Kramer, J. J.; Esman, R. D.; Craig, A. E.; Lee, J. N.; Ryuo, T.

    1990-05-01

    Microwave and magneto-optic measurements have been made on bismuth-substituted yttrium iron garnet (BiYIG) films. Forward-volume (FV) magnetostatic-wave (MSW) attenuation has been measured from ferrimagnetic resonance and from pulse delay data. We report the indirect observation of FV MSW in BiYIG using two independent techniques: a pulse transmission technique and a passband measurement technique. Faraday rotation in the films was also recorded at a wavelength of 1.3 μm. The bismuth-substituted films are grown on carefully cleaned substrates and have yttrium:bismuth ratios of 1:1. The composition of the bismuth substituted films is Y1.5Bi1.5Fe5O12 deduced from lattice parameters and absolute Faraday rotation. These films show particular promise for use in waveguide-type high-speed MSW-optical devices where low MSW attenuation and high Faraday rotation are among the necessary criteria for successful operation.

  8. The magnetic structures of holmium-yttrium superlattices in an applied magnetic field

    International Nuclear Information System (INIS)

    The magnetic structures of a rare earth superlattice in an applied magnetic field have been determined using neutron scattering techniques. The sample was grown using the LaMBE facility in Oxford and the periodic unit consisted of 41 planes of holmium and 16 planes of yttrium. The results showed four different types of magnetic phase corresponding to the helix, helifan, fan and ferromagnetic phases observed when a magnetic field is applied in the basal plane of bulk holmium. In the superlattice the correlation length was very long for the ferromagnetic phase, about 10 superlattice periods for the helix, about 4 superlattice periods for the fan and there was little, if any, correlation between the superlattice blocks for the helifan phase. The structures depended in detail upon the history in field and temperature as the configuration was approached. The most striking aspect of the result is that the helical phase is stable to higher fields in the superlattice than in the bulk. It is argued that this is because the conduction electron susceptibility in yttrium favours a modulated structure more strongly than in holmium and that the propagation of conduction electrons throughout the superlattice transfers this enhancement to the holmium blocks. (author)

  9. Hydrogen effects in aluminum alloys

    International Nuclear Information System (INIS)

    The permeability of six commercial aluminum alloys to deuterium and tritium was determined by several techniques. Surface films inhibited permeation under most conditions; however, contact with lithium deuteride during the tests minimized the surface effects. Under these conditions phi/sub D2/ = 1.9 x 10-2 exp (--22,400/RT) cc (NTP)atm/sup --1/2/ s-1cm-1. The six alloys were also tested before, during, and after exposure to high pressure hydrogen, and no hydrogen-induced effects on the tensile properties were observed

  10. Aluminum corrosion product release kinetics

    International Nuclear Information System (INIS)

    Highlights: • Release of Al corrosion product was measured in simulated post-LOCA sump solutions. • Increased boron was found to enhance Al release kinetics at similar pH. • Models of Al release as functions of time, temperature, and pH were developed. - Abstract: The kinetics of aluminum corrosion product release was examined in solutions representative of post-LOCA sump water for both pressurized water and pressurized heavy-water reactors. Coupons of AA 6061 T6 were exposed to solutions in the pH 7–11 range at 40, 60, 90 and 130 °C. Solution samples were analyzed by inductively coupled plasma atomic emission spectroscopy, and coupon samples were analyzed by secondary ion mass spectrometry. The results show a distinct “boron effect” on the release kinetics, expected to be caused by an increase in the solubility of the aluminum corrosion products. New models were developed to describe both sets of data as functions of temperature, time, and pH (where applicable)

  11. Aluminum corrosion product release kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Matt, E-mail: Matthew.Edwards@cnl.ca; Semmler, Jaleh; Guzonas, Dave; Chen, Hui Qun; Toor, Arshad; Hoendermis, Seanna

    2015-07-15

    Highlights: • Release of Al corrosion product was measured in simulated post-LOCA sump solutions. • Increased boron was found to enhance Al release kinetics at similar pH. • Models of Al release as functions of time, temperature, and pH were developed. - Abstract: The kinetics of aluminum corrosion product release was examined in solutions representative of post-LOCA sump water for both pressurized water and pressurized heavy-water reactors. Coupons of AA 6061 T6 were exposed to solutions in the pH 7–11 range at 40, 60, 90 and 130 °C. Solution samples were analyzed by inductively coupled plasma atomic emission spectroscopy, and coupon samples were analyzed by secondary ion mass spectrometry. The results show a distinct “boron effect” on the release kinetics, expected to be caused by an increase in the solubility of the aluminum corrosion products. New models were developed to describe both sets of data as functions of temperature, time, and pH (where applicable)

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

    International Nuclear Information System (INIS)

    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 Mg24Y5 - being the effective cathode - intensifies self-dissolution of the alloy under conditions of anodic galvanostatic polarization

  13. Sign of inverse spin Hall voltages generated by ferromagnetic resonance and temperature gradients in yttrium iron garnet platinum bilayers

    NARCIS (Netherlands)

    Schreier, Michael; Bauer, Gerrit E. W.; Vasyuchka, Vitaliy I.; Flipse, Joost; Uchida, Ken-ichi; Lotze, Johannes; Lauer, Viktor; Chumak, Andrii V.; Serga, Alexander A.; Daimon, Shunsuke; Kikkawa, Takashi; Saitoh, Eiji; van Wees, Bart J.; Hillebrands, Burkard; Gross, Rudolf; Goennenwein, Sebastian T. B.

    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)vertical bar platinum bilayers at room temperature, generating spin currents by microwaves and temper

  14. 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

  15. Yttrium iron garnet thickness and frequency dependence of the spin-charge current conversion in YIG/Pt systems

    NARCIS (Netherlands)

    Castel, V.; Vlietstra, N.; van Wees, B. J.

    2014-01-01

    We report the frequency dependence of the spin current emission (spin pumping) in a hybrid ferrimagnetic insulator/normal metal system as a function of the insulating layer thickness. The system is based on an yttrium iron garnet (YIG) film [0.2, 1, and 3 mu m] grown by liquid-phase epitaxy coupled

  16. Influence of a dipolar field on the nuclear resonance of iron-57 in an iron yttrium garnet (1961)

    International Nuclear Information System (INIS)

    The existence of a dipolar magnetic field at the Fe3+ ion level in an iron-yttrium garnet makes it possible to explain the structure and the width of the nuclear resonance lines of Fe57 nuclei observed on the 16 a sites. (authors)

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

    International Nuclear Information System (INIS)

    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)

  18. Laboratory Powder Metallurgy Makes Tough Aluminum Sheet

    Science.gov (United States)

    Royster, D. M.; Thomas, J. R.; Singleton, O. R.

    1993-01-01

    Aluminum alloy sheet exhibits high tensile and Kahn tear strengths. Rapid solidification of aluminum alloys in powder form and subsequent consolidation and fabrication processes used to tailor parts made of these alloys to satisfy such specific aerospace design requirements as high strength and toughness.

  19. Sanmenxia strives to create aluminum industrial base

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>Contradiction between rich alumina resource and relatively weak electrolytic aluminum production capacity is the "bottleneck" inhibiting development of aluminum industry in San-menxia. During the period of "11th Five-Year Development", Sanmenxia will relay on its

  20. Aluminum induced proteome changes in tomato cotyledons

    Science.gov (United States)

    Cotyledons of tomato seedlings that germinated in a 20 µM AlK(SO4)2 solution remained chlorotic while those germinated in an aluminum free medium were normal (green) in color. Previously, we have reported the effect of aluminum toxicity on root proteome in tomato seedlings (Zhou et al. J Exp Bot, 20...

  1. Gating of Permanent Molds for ALuminum Casting

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang

    2004-03-30

    This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.

  2. Trends in the global aluminum fabrication industry

    Science.gov (United States)

    Das, Subodh; Yin, Weimin

    2007-02-01

    The aluminum fabrication industry has become more vital to the global economy as international aluminum consumption has grown steadily in the past decades. Using innovation, value, and sustainability, the aluminum industry is strengthening its position not only in traditional packaging and construction applications but also in the automotive and aerospace markets to become more competitive and to face challenges from other industries and higher industrial standards. The aluminum fabrication industry has experienced a significant geographical shift caused by rapid growth in emerging markets in countries such as Brazil, Russia, India, and China. Market growth and distribution will vary with different patterns of geography and social development; the aluminum industry must be part of the transformation and keep pace with market developments to benefit.

  3. Aluminum-based metal-air batteries

    Science.gov (United States)

    Friesen, Cody A.; Martinez, Jose Antonio Bautista

    2016-01-12

    Provided in one embodiment is an electrochemical cell, comprising: (i) a plurality of electrodes, comprising a fuel electrode that comprises aluminum and an air electrode that absorbs gaseous oxygen, the electrodes being operable in a discharge mode wherein the aluminum is oxidized at the fuel electrode and oxygen is reduced at the air electrode, and (ii) an ionically conductive medium, comprising an organic solvent; wherein during non-use of the cell, the organic solvent promotes formation of a protective interface between the aluminum of the fuel electrode and the ionically conductive medium, and wherein at an onset of the discharge mode, at least some of the protective interface is removed from the aluminum to thereafter permit oxidation of the aluminum during the discharge mode.

  4. Aluminum recovery as a product with high added value using aluminum hazardous waste

    International Nuclear Information System (INIS)

    Highlights: • Granular and compact aluminum dross were physically and chemically characterized. • A relationship between density, porosity and metal content from dross was established. • Chemical reactions involving aluminum in landfill and negative consequences are shown. • A processing method for aluminum recovering from aluminum dross was developed. • Aluminum was recovered as an value product with high grade purity such as alumina. -- Abstract: The samples of hazardous aluminum solid waste such as dross were physically and chemically characterized. A relationship between density, porosity and metal content of dross was established. The paper also examines the chemical reactions involving aluminum dross in landfill and the negative consequences. To avoid environmental problems and to recovery the aluminum, a processing method was developed and aluminum was recovered as an added value product such as alumina. This method refers to a process at low temperature, in more stages: acid leaching, purification, precipitation and calcination. At the end of this process aluminum was extracted, first as Al3+ soluble ions and final as alumina product. The composition of the aluminum dross and alumina powder obtained were measured by applying the leaching tests, using atomic absorption spectrometry (AAS) and chemical analysis. The mineralogical composition of aluminum dross samples and alumina product were determined by X-ray diffraction (XRD) and the morphological characterization was performed by scanning electron microscopy (SEM). The method presented in this work allows the use of hazardous aluminum solid waste as raw material to recover an important fraction from soluble aluminum content as an added value product, alumina, with high grade purity (99.28%)

  5. Aluminum phosphate shows more adjuvanticity than Aluminum hydroxide in recombinant hepatitis –B vaccine formulation

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available Background: Although a number of investigation have been carried out to find alternative adjuvants to aluminum salts in vaccine formulations, they are still extensively used due to their good track record of safety, low cost and proper adjuvanticity with a variety of antigens. Adsorption of antigens onto aluminum compounds depends heavily on electrostatic forces between adjuvant and antigen. Commercial recombinant protein hepatitis B vaccines containing aluminum hydroxide as adjuvant is facing low induction of immunity in some sections of the vaccinated population. To follow the current global efforts in finding more potent hepatitis B vaccine formulation, adjuvanticity of aluminum phosphate has been compared to aluminum hydroxide. Materials and methods: The adjuvant properties of aluminum hydroxide and aluminum phosphate in a vaccine formulation containing a locally manufactured hepatitis B (HBs surface antigen was evaluated in Balb/C mice. The formulations were administered intra peritoneally (i.p. and the titers of antibody which was induced after 28 days were determined using ELISA technique. The geometric mean of antibody titer (GMT, seroconversion and seroprotection rates, ED50 and relative potency of different formulations were determined. Results: All the adjuvanicity markers obtained in aluminum phosphate formulation were significantly higher than aluminum hydroxide. The geometric mean of antibody titer of aluminum phosphate was approximately three folds more than aluminum hydroxide. Conclusion: Aluminum phosphate showed more adjuvanticity than aluminum hydroxide in hepatitis B vaccine. Therefore the use of aluminum phosphate as adjuvant in this vaccine may lead to higher immunity with longer duration of effects in vaccinated groups.

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

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

    2016-02-01

    In this research, zirconium dioxide, ZrO2, 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 ZrO2 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.

  8. Hepatectomy After Yttrium-90 (Y90) Radioembolization-Induced Liver Fibrosis.

    Science.gov (United States)

    Maker, Ajay V; August, Carey; Maker, Vijay K; Weisenberg, Elliot

    2016-04-01

    An obese 55-year-old woman with nonalcoholic fatty liver disease presented 7 years after resection of a T3N1 ileal carcinoid tumor with an elevated chromogranin A, multifocal metastatic disease to the liver, and carcinoid syndrome. She underwent right hepatic artery yttrium-90 (Y90) radioembolization, followed a month later by selective Y90 treatment to segment IV. She then presented to our clinic 10 months later, remaining symptomatic with flushing, diarrhea, anxiety, myalgia, pain, and persistent night sweats despite Sandostatin administration. At least 11 tumors were identified in the right lobe of the liver and three in segment IV on liver-specific imaging. These lesions were stable over a year with no new lesions. At exploration, there was marked hypertrophy of the left lateral segment due to the yttrium-90 treatment of segments IV-VIII, corresponding with preoperative volumetrics predicting a functional liver remnant (FLR) of 40% after extended right hepatectomy. The right lobe and segment IV were fibrotic, hard, and visibly damaged. The gland had a thick, fibrotic capsule, and the parenchyma was dense, inflexible, and difficult to dissect, consistent with the previously reported morbidity of these operations. Extended right hepatectomy was performed. Final pathology demonstrated 15 foci of metastatic well-differentiated neuroendocrine carcinoma that were negative for necrosis, as was expected given her continued symptoms despite radioembolization. Numerous amorphous spheres, frequently in clusters, were present in segments IV-VIII in vessels and approximating tumors consistent with prior Y90 radioembolization. The patient had an uneventful post-operative recovery and remains symptom free on follow-up. Treatment options for metastatic tumors to the liver have increased in recent years and currently include radioembolization in selected patients. Surgical cytoreduction and complete metastasectomy continue to offer improvement in symptoms, quality of life, and

  9. Corrosion barriers for silver-based telescope mirrors: comparative study of plasma-enhanced atomic layer deposition and reactive evaporation of aluminum oxide

    Science.gov (United States)

    Fryauf, David M.; Phillips, Andrew C.; Kobayashi, Nobuhiko P.

    2015-10-01

    Astronomical telescopes continue to demand high-endurance high-reflectivity silver (Ag) mirrors that can withstand years of exposure in Earth-based observatory environments. We present promising results of improved Ag mirror robustness using plasma-enhanced atomic layer deposition (PEALD) of aluminum oxide (AlOx) as a top barrier layer. Transparent AlOx is suitable for many optical applications; therefore, it has been the initial material of choice for this study. Two coating recipes developed with electron beam ion-assisted deposition (e-beam IAD) of materials including yttrium fluoride, titanium nitride, oxides of yttrium, tantalum, and silicon are used to provide variations in basic Ag mirror structures to compare the endurance of reactive e-beam IAD barriers with PEALD barriers. Samples undergo high temperature/high humidity environmental testing in a controlled environment of 80% humidity at 80°C for 10 days. Environmental testing shows visible results suggesting that the PEALD AlOx barrier offers robust protection against chemical corrosion and moisture permeation. Ag mirror structures were further characterized by reflectivity/absorption before and after deposition of AlOx barriers.

  10. Oxidation dynamics of aluminum nanorods

    International Nuclear Information System (INIS)

    Aluminum nanorods (Al-NRs) are promising fuels for pyrotechnics due to the high contact areas with oxidizers, but their oxidation mechanisms are largely unknown. Here, reactive molecular dynamics simulations are performed to study thermally initiated burning of oxide-coated Al-NRs with different diameters (D = 26, 36, and 46 nm) in oxygen environment. We found that thinner Al-NRs burn faster due to the larger surface-to-volume ratio. The reaction initiates with the dissolution of the alumina shell into the molten Al core to generate heat. This is followed by the incorporation of environmental oxygen atoms into the resulting Al-rich shell, thereby accelerating the heat release. These results reveal an unexpectedly active role of the alumina shell as a “nanoreactor” for oxidation

  11. Process for anodizing aluminum foil

    International Nuclear Information System (INIS)

    In an integrated process for the anodization of aluminum foil for electrolytic capacitors including the formation of a hydrous oxide layer on the foil prior to anodization and stabilization of the foil in alkaline borax baths during anodization, the foil is electrochemically anodized in an aqueous solution of boric acid and 2 to 50 ppm phosphate having a pH of 4.0 to 6.0. The anodization is interrupted for stabilization by passing the foil through a bath containing the borax solution having a pH of 8.5 to 9.5 and a temperature above 800 C. and then reanodizing the foil. The process is useful in anodizing foil to a voltage of up to 760 V

  12. Oxidation kinetics of aluminum diboride

    Science.gov (United States)

    Whittaker, Michael L.; Sohn, H. Y.; Cutler, Raymond A.

    2013-11-01

    The oxidation characteristics of aluminum diboride (AlB2) and a physical mixture of its constituent elements (Al+2B) were studied in dry air and pure oxygen using thermal gravimetric analysis to obtain non-mechanistic kinetic parameters. Heating in air at a constant linear heating rate of 10 °C/min showed a marked difference between Al+2B and AlB2 in the onset of oxidation and final conversion fraction, with AlB2 beginning to oxidize at higher temperatures but reaching nearly complete conversion by 1500 °C. Kinetic parameters were obtained in both air and oxygen using a model-free isothermal method at temperatures between 500 and 1000 °C. Activation energies were found to decrease, in general, with increasing conversion for AlB2 and Al+2B in both air and oxygen. AlB2 exhibited O2-pressure-independent oxidation behavior at low conversions, while the activation energies of Al+2B were higher in O2 than in air. Differences in the composition and morphology between oxidized Al+2B and AlB2 suggested that Al2O3-B2O3 interactions slowed Al+2B oxidation by converting Al2O3 on aluminum particles into a Al4B2O9 shell, while the same Al4B2O9 developed a needle-like morphology in AlB2 that reduced oxygen diffusion distances and increased conversion. The model-free kinetic analysis was critical for interpreting the complex, multistep oxidation behavior for which a single mechanism could not be assigned. At low temperatures, moisture increased the oxidation rate of Al+2B and AlB2, but both appear to be resistant to oxidation in cool, dry environments.

  13. Superhydrophobic coating deposited directly on aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Escobar, Ana M., E-mail: annaescobarromero@ub.edu; Llorca-Isern, Nuria

    2014-06-01

    This study develops an alternative method for enhancing superhydrophobicity on aluminum surfaces with an amphiphilic reagent such as the dodecanoic acid. The goal is to induce superhydrophobicity directly through a simple process on pure (99.9 wt%) commercial aluminum. The initial surface activation leading to the formation of the superhydrophobic coating is studied using confocal microscopy. Superhydrophobic behavior is analyzed by contact angle measurements, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The highest contact angle (approaching 153°) was obtained after forming hierarchical structures with a particular roughness obtained by grinding and polishing microgrooves on the aluminum surface together with the simultaneous action of HCl and dodecanoic acid. The results also showed that after immersion in the ethanol-acidic-fatty acid solutions, they reacted chemically through the action of the fatty acid, on the aluminum surface. The mechanism is analyzed by TOF-SIMS and XPS in order to determine the molecules involved in the reaction. The TOF-SIMS analysis revealed that the metal and its oxides seem to be necessary, and that free-aluminum is anchored to the fatty acid molecules and to the alumina molecules present in the medium. Consequently, both metallic aluminum and aluminum oxides are necessary in order to form the compound responsible for superhydrophobicity.

  14. Modification of galvannealed steel through aluminum addition

    International Nuclear Information System (INIS)

    Aluminum is believed to modify and to some extent control the coating characteristics of commercially produced galvanneal sheet steel. These include mechanical, chemical, and aesthetic properties. Whereas the aluminum added to the molten zinc bath is known to form intermetallics before the steel is annealed, our research is primarily concerned with the effect aluminum has on suppression or enhancement of the particular iron-zinc alloy phases in the coating during galvannealing. The microstructure of four commercially important iron-zinc intermetallic phases containing varying aluminum content between 0-1.5 weight percent has been studied. It is also believed that an iron-aluminum alloy, known as the inhibition layer, forms on the steel surface following hot dipping and prior to annealing. Transmission and scattering Moessbauer spectroscopy as well as X-ray diffraction have been used to identify iron-zinc and iron-aluminum alloys present in the coatings. Discussion will be presented on the effect aluminum has on phase suppression for Fe-Zn alloys prepared in commercially produced galvanneal

  15. Crystal growth and anisotropy of high temperature thermoelectric properties of yttrium borosilicide single crystals

    Science.gov (United States)

    Hossain, M. Anwar; Tanaka, Isao; Tanaka, Takaho; Khan, A. Ullah; Mori, Takao

    2016-01-01

    We studied thermoelectric properties of YB41Si1.3 single crystals grown by the floating zone method. The composition of the grown crystal was confirmed by electron probe micro-analysis. We have determined the growth direction for the first time for these borosilicides, and discovered relatively large anisotropy in electrical properties. We measured the electrical resistivity and Seebeck coefficient along [510] (the growth direction) and [052] directions and we found that this crystal exhibits strong electrical anisotropy with a maximum of more than 8 times. An interesting layered structural feature is revealed along [510] with dense boron cluster layers and yttrium layers, with conductivity enhanced along this direction. We obtained 3.6 times higher power factor along [510] compared to that along [052]. Although the ZT of the present system is low, anisotropy in the thermoelectric properties of a boride was reported for the first time, and can be a clue in developing other boride systems also.

  16. Light emission of double-walled carbon nanotube filaments doped with yttrium and europium

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    As the potential applications of carbon nanotubes in the field of electroluminescence, elements yttrium and europium were introduced to modify the emission properties of double-walled carbon nanotubes (DWNTs) to obtain higher efficacy and other properties. The light emission spectrum of the Y-Eu-doped DWNT filament is suppressed in the near-infrared range, while enhanced in the mid-infrared range. The doped DWNT filament can reach higher efficacy than that of the pure DWNT filament at the same input power and can work stably as long as 5000 h at 12 V. These filaments could be useful for the light sources with special functions, such as infrared light sources operated at low input power.

  17. Chemoembolic Hepatopulmonary Shunt Reduction to Allow Safe Yttrium-90 Radioembolization Lobectomy of Hepatocellular Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Gaba, Ron C., E-mail: rgaba@uic.edu [University of Illinois Medical Center at Chicago, Department of Radiology, Section in Interventional Radiology (United States); VanMiddlesworth, Kyle A. [Midwestern University School of Medicine (United States)

    2012-12-15

    Yttrium-90 ({sup 90}Y) radioembolization represents an emerging transcatheter treatment option for the management of hepatocellular carcinoma (HCC). Elevation of the hepatopulmonary shunt fraction risks nontarget radiation to the lungs and may limit the use of {sup 90}Y therapy in patients with locally advanced disease with vascular invasion, who often demonstrate increased shunting. We present two cases in which patients with HCC and portal vein invasion resulting in elevated hepatopulmonary shunt fractions underwent chemoembolic shunt closure to allow safe {sup 90}Y radioembolization. Both patients demonstrated excellent tumor response and patient survival. On this basis, we propose a role for chemoembolic reduction of the lung shunt fraction before {sup 90}Y radioembolization in patients with extensive tumor-related hepatopulmonary shunting.

  18. Thickness- and temperature-dependent magnetodynamic properties of yttrium iron garnet thin films

    Energy Technology Data Exchange (ETDEWEB)

    Haidar, M., E-mail: mohammad.haidar@Physics.gu.se; Ranjbar, M.; Balinsky, M.; Dumas, R. K. [Department of Physics, University of Gothenburg, 41296 Gothenburg (Sweden); Khartsev, S. [Department of Integrated Devices and Circuits, School of ICT, Royal Institute of Technology (KTH), 16440 Kista (Sweden); Åkerman, J. [Department of Physics, University of Gothenburg, 41296 Gothenburg (Sweden); Materials Physics, School of ICT, Royal Institute of Technology (KTH), 16440 Kista (Sweden)

    2015-05-07

    The magnetodynamical properties of nanometer-thick yttrium iron garnet films are studied using ferromagnetic resonance as a function of temperature. The films were grown on gadolinium gallium garnet substrates by pulsed laser deposition. First, we found that the damping coefficient increases as the temperature increases for different film thicknesses. Second, we found two different dependencies of the damping on film thickness: at room temperature, the damping coefficient increases as the film thickness decreases, while at T = 8 K, we find the damping to depend only weakly on the thickness. We attribute this behavior to an enhancement of the relaxation of the magnetization by impurities or defects at the surfaces.

  19. Effect of yttrium on the microstructure of a semi-solid A356 Al alloy

    Institute of Scientific and Technical Information of China (English)

    LIU Zheng; HU Yongmei

    2008-01-01

    The semi-solid slurry of an A356 Al alloy,which was grain-freed by yttrium,was manufactured by low temperature pouring.The effects of grain-refining on the morphology and the grain size of the primary α phase in the semi-solid A356 Al alloy were researched.The results indicate that the semi-solid A356 Al alloy with particle-like and rosette-like primary α-Al can be prepared by low temperature pouring from a liquid grain-refined A356 alloy.The grain size and particle morphology of primary α-Al in the A356 Al alloy are markedly improved by the addition of 0.5 wt.% Y.The fining mechanism of Y on the morphology and grain size of the primary α-Al in the semi-solid A356 Al alloy was delved.

  20. Energy levels of Tb3+ ions in yttrium-gallium garnet

    International Nuclear Information System (INIS)

    The data on the fluorescence and absorption spectra of the Tb3+ ions in yttrium-gallium garnet in the region 3800-6800 A0 have been obtained at 4.20K and 770K. The groups of fluorescence lines in the regions 3800-4830 A0 and 4860-6800 A0 have been assigned to transitions from 5O3 and 5D4 respectively to the Stark components of 7F states. The analysis of the spectra led to the identification of six Stark components each for 5D3 and 5D4 states and thirty six components of 7F states. The local symmetry around the Tb3+ ions is found to be orthorhombic from the complete removal of the degeneracy of the 7F5 and 7F1 electronic states. (author)

  1. Bismuth Substituted Yttrium Iron Garnet Single Crystal Films Prepared by Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Magneto-optic Faraday rotation effect and the amount of bismuth substituted in yttrium iron garnet single crystal films prepared by gel-coating on modified gadolinium-gallium garnet substrates are investigated, where the gel is synthesized by a sol-gel reaction of nitrates and ethylene glycol. The coated gel is annealed in air at temperatures up to 660℃ for 4h, which is about 300℃ lower than that of liquid-phase epitaxy. The maximum amount of Bi substitution is x=2.7 and the crystallization temperature of garnet phase decreases with the increase of x down to 520℃ for x=2.7. In this film, a huge Faraday rotation of -8.1×104 (°)/cm at λ=0.633μm is obtained.

  2. Spin valve effect of the interfacial spin accumulation in yttrium iron garnet/platinum bilayers

    Science.gov (United States)

    Jin, Lichuan; Zhang, Dainan; Zhang, Huaiwu; Tang, Xiaoli; Bai, Feiming; Zhong, Zhiyong; Fan, Xin; Xiao, John Q.

    2014-09-01

    We report the spin valve effect in yttrium iron garnet/platinum (YIG/Pt) bilayers. The spin Hall effect (SHE) generates spin accumulation at the YIG/Pt interface and can be opened/closed by magnetization switching in the electrical insulator YIG. The interfacial spin accumulation was measured in both YIG/Pt and YIG/Cu/Pt structures using a planar Hall configuration. The spin valve effect remained, even after a 2 nm thick Cu layer was inserted between the YIG and Pt layers, which aimed to exclude the induced magnetization at the YIG/Pt interface. The transverse Hall voltage and switching field were dependent on the applied charge current density. The origin of this behavior can be explained by the SHE induced torque exerted on the domain wall, caused by the transfer of the spin angular momentum from the spin-polarized current to the YIG magnetic moment.

  3. Nonaqueous cold extrusion as a route for yttrium barium copper oxide wires

    International Nuclear Information System (INIS)

    Yttrium barium copper oxide (YBCO) superconducting wires of diameter 0.2 to 1 mm in the form of spirals up to 50 cm long were made by a novel nonaqueous cold extrusion technique. Finely ground YBCO powder having a set particle size distribution was intimately mixed with a polypropylene compound and extruded manually into wires which were heat-treated at controlled rates followed by oxygen annealing at 940 C for 10 h. These wires are superconducting with a Tc of 89.5 K, the XRD pattern exhibiting an orthorhombic single phase. Current density at zero field was measured to be 223 A/cm2. The surface morphology of the extruded wires and microstructure of the polished cross section of the sintered wires are also presented

  4. Formation of pinhole-free epitaxial yttrium silicide on silicon (111)

    International Nuclear Information System (INIS)

    This paper reports the growth of structurally continuous, pinhole-free epitaxial YSi2-x films on Si(111) substrates as thin as 30 Angstrom. This is accomplished by depositing both yttrium and silicon in the appropriate stoichiometric ratio onto substrates held near room temperature, which is apparently below the activation energy for the nucleation of a reaction between a deposited Y film and a Si substrate. Diffusion of Si atoms from an evaporation source into a thin Y layer occurs below this barrier energy, allowing the layer by layer formation of YSi2-x without the removal of silicon from the substrate, maintaining a relatively low interface free energy between the growing silicide film and the Si(111) substrate. Samples have been annealed to 500-900 degrees C to improve epitaxy without the creation of pinholes. Use of the template method allows for the growth of thicker films also free of pinholes

  5. Mathematical model of metal-hydride phase change applied to Yttrium

    International Nuclear Information System (INIS)

    We present a mathematical model for the kinetics of hydriding and dehydriding of metal powders. The single powder particle is considered. Its shape is approximated by one of the symmetric ones: sphere, long thin cylinder (wire), or flat thin plate. A few concurrent processes are considered. The model equations are derived from the mass conservation law. We consider the case of the 'shrinking core' morphology, i.e. formation of the hydride skin on the surface of the particle with subsequent growth of this skin. We consider three successive stages of the phase change: skin development, skin growth, and final saturation or degassing. We apply the model to experimental data for Yttrium and show that the approximation of the experimental curves by the model ones is comparable for different cycles and different shapes for similar sets of the kinetic parameters. This also shows that shape of powder particles do not influence significantly on the kinetics of hydriding and dehydriding

  6. Mathematical model of metal-hydride phase change applied to Yttrium

    Science.gov (United States)

    Chernov, I. A.; Manicheva, S. V.; Gabis, I. E.

    2013-08-01

    We present a mathematical model for the kinetics of hydriding and dehydriding of metal powders. The single powder particle is considered. Its shape is approximated by one of the symmetric ones: sphere, long thin cylinder (wire), or flat thin plate. A few concurrent processes are considered. The model equations are derived from the mass conservation law. We consider the case of the "shrinking core" morphology, i.e. formation of the hydride skin on the surface of the particle with subsequent growth of this skin. We consider three successive stages of the phase change: skin development, skin growth, and final saturation or degassing. We apply the model to experimental data for Yttrium and show that the approximation of the experimental curves by the model ones is comparable for different cycles and different shapes for similar sets of the kinetic parameters. This also shows that shape of powder particles do not influence significantly on the kinetics of hydriding and dehydriding.

  7. Eu3+ doped yttrium oxysulfide quantum structures-structural, optical and electronic properties

    International Nuclear Information System (INIS)

    Small particles of trivalent europium doped yttrium oxysulfide nanocrystals (φ ∼ 7 nm) were synthesized using sol-gel polymer thermolysis. The nanocrystals show significant change in the excitation bands corresponding to fundamental absorption and charge transfer absorption bands. The optical spectra essentially comprise of two parts: fundamental absorption (∼260 nm) and Eu3+-X2- ligand (O2-/S2-) charge transfer (∼290 nm) bands. They show significant blue shifts (0.24-0.30 eV), respectively, with respect to the bulk counterpart. These may be explained by considering possible size dependent changes associated with quantum confinement effect in this large bandgap semiconductor system. FT-IR spectra revealed the difference in chemisorbed species between bulk and nanocrystalline samples. The results of the solid-state photo-induced electrical impedance spectroscopy studies are reported

  8. Improvement of the homo-biepitaxial YBCO film fabrication process on Yttrium Stabilized Zirconia

    International Nuclear Information System (INIS)

    We present the results of the application of the dc magnetron sputtering modulation mode to fabricate YBCO homo-biepitaxial thin film Josephson junctions on Yttrium Stabilized Zirconia substrate. A 450 in-plane rotation of the grown YBCO films with respect to the substrate orientation is realized by using a thin YBCO buffer layer deposited at a temperature (∼600 deg. C) lower than the optimal value (800 deg. C). The control of the in-plane orientation allows to form Josephson junctions between two YBCO superconducting region of the film with and without buffer layer. We obtained that the modulated deposition mode improves the crystalline in-plane orientation of YBCO on buffer layer/YSZ substrate, increases the grain size and decreases the film stress. The improved homo-epitaxial process was applied for fabrication of dc SQUID devices

  9. Laser plume spectroscopy. 2. Graphite yttrium-stabilised and zirconium oxide targets

    International Nuclear Information System (INIS)

    Spectral and kinetic properties of a plume formed in the vicinity of a graphite and a pressed yttrium-stabilised zirconium oxide (YSZ) powder targets irradiated in air by a 10.6-μm pulsed CO2 laser with a peak power of 1.5-9 kW at room temperature are studied. The plume propagated at right angles to the target surface and at an angle of 450 to the laser radiation. The spectral and kinetic characteristics of its luminescence were measured discretely along the entire length of the plume. It is shown that the YSZ plume as well as the graphite plume is a flux of nonequilibrium gaseous plasma at a temperature of about 4.7-3.1 kK, in which a luminescence of YO and ZrO radicals is excited. (interaction of laser radiation with matter. laser plasma)

  10. 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.

  11. Hybrid yttrium iron garnet-ferromagnet structures for spin-wave devices

    International Nuclear Information System (INIS)

    We study coupled ferromagnetic layers, which could facilitate low loss, sub 100 nm wavelength spin-wave propagation and manipulation. One of the layers is a low-loss garnet film (such as yttrium iron garnet (YIG)) that enables long-distance, coherent spin-wave propagation. The other layer is made of metal-based (Permalloy, Co, and CoFe) magnetoelectronic structures that can be used to generate, manipulate, and detect the spin waves. Using micromagnetic simulations, we analyze the interactions between the spin waves in the YIG and the metallic nanomagnet structures and demonstrate the components of a scalable spin-wave based signal processing device. We argue that such hybrid-metallic ferromagnet structures can be the basis of potentially high-performance, ultra low-power computing devices

  12. Preparation and properties of yttrium, lanthanum and lanthanide o-nitrobenzoates

    International Nuclear Information System (INIS)

    The conditions of the formation of yttrium, lanthanum and lanthanide o-nitrobenzoates were studied and their quantitative composition and solubilities in water at 298 K were determined (their solubilities are of the order of 10-2 moldm-3). The IR and X-ray spectra for the obtained complexes and the dehydrated rare earth element o-nitrobenzoates were recorded; all prepared complexes are crystalline compounds. The conditions of thermal decomposition of the complexes were also studied. It was found that on heating above 523 K the complexes decompose explosively and undergo a melting process at the same time. Therefore the thermal decomposition for complexes being studied was carried out in the temperature range 273-523 K. From the results it appears that during the dehydration process or with the increase of temperature no transformation of the nitro group to nitrito occurs. (Author)

  13. Powder synthesis and spectroscopic properties of ytterbium-doped yttrium oxysulfide

    Institute of Scientific and Technical Information of China (English)

    Gang Yao; Liangbi Su; Xiaodong Xu; Lihe Zheng; Jun Xu

    2008-01-01

    Ytterbium-doped yttrium oxysulfide(Yb:Y2O2S)has been synthesized by solid-state reaction with sulfide flux.Diffuse reflection and emission spectra have been measured in order to determine the crystal field splitting of Yb3+ ion in the YOS lattice.According to the crystal-field levels probed in the spectra,the crystal field splitting of 2F7/2 manifold of Yb3+ ion in YOS is 709 cm-1,which is large enough for the quasi-three-level laser operation of Yb3+ ion.Emission peak position,width,full-width at half maximum (FWHM),and normalized intensity of Yb:YOS are fitted from its emission spectrum.For comparison,relevant data of 5.4 at.-% Yb:YAG is also provided.

  14. Complete eradication of hepatic metastasis from colorectal cancer by Yttrium-90 SIRT

    Institute of Scientific and Technical Information of China (English)

    Sean Garrean; Amanda Muhs; James T Bui; Michael J Blend; Charles Owens; William S Helton; N Joseph Espat

    2007-01-01

    Yttrium-90 (Y-90) radioembolization, also known as selective internal radiation therapy (SIRT), is a regional hepatic therapy used in the treatment of unresectable colorectal cancer (CRC) liver metastases. In SIRT,Y-90 impregnated microspheres are injected into the VASCULAR SUPPLY of hepatic tumor, leading to selective irradiation and necrosis of tumor TISSUE. While several studies demonstrate improved local control and survival with SIRT, the specific indications for this therapy have yet to be defined. Typically, SIRT is given in combination with chemotherapy as multimodal treatment for unresectable hepatic CRC. However, it HAS ALSO FOUND INCREASING USE as a salvage therapy in chemorefractory patients. Herein, the authors describe their experience with SIRT as "stand alone" therapy in a surgically-prohibitive, chemotherapy naive patient with hepatic CRC metastasis. The results suggest that Y-90 SIRT may have potential applications beyond its usual role as a palliative or salvage therapy for unresectable hepatic CRC.

  15. Valence Control of Ce Ions in Cerium-substituted Yttrium Iron Garnet

    Institute of Scientific and Technical Information of China (English)

    SONG Fengbing; LI Qiang; ZHONG Zhifeng

    2005-01-01

    Cerium-substituted yttrium iron garnet(CexY3-xFe5O12, Ce∶YIG) was prepared via coprecipitation. The structure, morphology, valence state and constituent of Ce ions were investigated respectively. X-ray powder diffraction(XRD) analysis shows that Ce∶YIG was of single cubic YIG phase. The result of X-ray photoelectron spectroscopy(XPS) indicates the Ce ions in Ce∶YIG were in the state of trivalence. Scanning electron microscope(SEM) demonstrates the conglobation of Ce∶YIG particles about 0.2μm scale.The magnetic properties were studied by a vibrating sample magnetometer(VSM) and the result exhibits that substitution of Ce3+ changes the magnetic parameters of YIG. The effects of doping content of Ce ions and synthesis temperature on valence control were discussed in detail.

  16. Nonlinear dynamics of three-magnon process driven by ferromagnetic resonance in yttrium iron garnet

    Science.gov (United States)

    Cunha, R. O.; Holanda, J.; Vilela-Leão, L. H.; Azevedo, A.; Rodríguez-Suárez, R. L.; Rezende, S. M.

    2015-05-01

    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.

  17. Thermo-transferred thermoluminescence (TTTl) in potassium-yttrium double fluoride doped with terbium

    Energy Technology Data Exchange (ETDEWEB)

    Gallegos, A.; Rivera, T.; Diaz G, J. A. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Azorin, J. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, San Rafael Atlixco No. 186, Col. Vicentina, 09340 Mexico D. F. (Mexico); Azorin, J. C. [Universidad de Guanajuato, Division de Ciencias e Ingenierias-Campus Leon, Lomas del Bosque No. 103, Col. Lomas del Campestre, 37000 Leon, Guanajuato (Mexico); Licona, R.; Rivas, F.; Hernandez C, G. [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias Quimicas, 14 Sur y San Claudio, Ciudad Universitaria, Puebla de Zaragoza, Puebla (Mexico); Khaidukov, N. [Institute of General and Inorganic Chemistry, Lenin SK 11 Prospect 31, Moscow 117907 (Russian Federation)

    2011-02-15

    This paper presents results of studying the thermo-transferred thermoluminescence (TTTl) phenomenon in potassium-yttrium double fluoride doped with terbium (K{sub 2}YF{sub 5:}Tb) at different impurity concentrations (0.8%, 0.95% and 0.99%). Previously to study the TTTl phenomenon, structural characterization and chemical composition of the materials were determined. The structural studies were conducted using a scanning electron microscope; meanwhile, chemical composition was analyzed using energy dispersive X-ray spectroscopy. Thermoluminescence kinetics was studied irradiating the samples with {sup 137}Cs gamma rays as well as with {sup 90}Sr/{sup 90}Y beta rays, analyzing the glow curves by the deconvolution method for obtaining the kinetic parameters. (Author)

  18. Thermo-transferred thermoluminescence (TTTl) in potassium-yttrium double fluoride doped with terbium

    International Nuclear Information System (INIS)

    This paper presents results of studying the thermo-transferred thermoluminescence (TTTl) phenomenon in potassium-yttrium double fluoride doped with terbium (K2YF5:Tb) at different impurity concentrations (0.8%, 0.95% and 0.99%). Previously to study the TTTl phenomenon, structural characterization and chemical composition of the materials were determined. The structural studies were conducted using a scanning electron microscope; meanwhile, chemical composition was analyzed using energy dispersive X-ray spectroscopy. Thermoluminescence kinetics was studied irradiating the samples with 137Cs gamma rays as well as with 90Sr/90Y beta rays, analyzing the glow curves by the deconvolution method for obtaining the kinetic parameters. (Author)

  19. Experimental and simulation studies for optimisation of plasma spraying of yttrium oxide powder

    International Nuclear Information System (INIS)

    Yttrium oxide coating by virtue of its excellent thermal property and chemical stability shows very strong resistance to high temperature and corrosive environment. Present paper presents extensive experimental and simulation work for optimised process parameters of yttria coating in Ar-N2 plasma. Simulation studies on temperature field, velocity field and species transport between Ar-N2 plasma and entrained air have been reported. Temperature and velocity profiles of yttria particle have been calculated assuming dilute loading condition. The velocity and temperature of yttria particles have been experimentally determined by using Spray watch imaging system. Calculated values of velocity and temperature of yttria particles are found to agree fairly well with the experimentally measured values. (author)

  20. Sintering and optical quality of highly transparent yb-doped yttrium lanthanum oxide ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Maxim; Zayats, Sergey [Institute of Electrophysics UrB of RAS, Amundsen st 106, 620016 Ekaterinburg (Russian Federation); Kopylov, Yury; Kravchenko, Valery [Institute of Radioengineering and Electronics named after V.A. Kotelnikov, RAS, Vvedensky Sq. 1, 141120 Fryazino, Moscow region (Russian Federation)

    2013-06-15

    To produce highly transparent Yb-doped yttrium lanthanum oxide (Yb{sup 3+}:(La{sub x}Y{sub 1-x}){sub 2}O{sub 3}) ceramics two original technologies were used: laser synthesis of nanopowder and pulsed magnetic compacting. Sintering of the compacts in vacuum 3 x 10{sup -4} Pa at 1600-1700 C during 13 hours led to transparent ceramics fabrication. The ceramics with relative density higher than 99.99% and grain size about 40 {mu}m were fabricated. Full transmittance of 1.8 mm thick Yb{sub 0,11}La{sub 0,23}Y{sub 1,66}O{sub 3} ceramics reaches 82.5% rate at 800 nm. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Superstrong coupling of a microwave cavity to yttrium iron garnet magnons

    Science.gov (United States)

    Kostylev, Nikita; Goryachev, Maxim; Tobar, Michael E.

    2016-02-01

    Multiple-post reentrant 3D lumped cavity modes have been realized to design the concept of a discrete Whispering Gallery and Fabry-Pérot-like Modes for multimode microwave Quantum Electrodynamics experiments. Using the magnon spin-wave resonance of a submillimeter-sized Yttrium-Iron-Garnet sphere at millikelvin temperatures and a four-post cavity, we demonstrate the ultra-strong coupling regime between discrete Whispering Gallery Modes and a magnon resonance with a strength of 1.84 GHz. By increasing the number of posts to eight and arranging them in a D4 symmetry pattern, we expand the mode structure to that of a discrete Fabry-Pérot cavity and modify the Free Spectral Range (FSR). We reach the superstrong coupling regime, where spin-photon coupling strength is larger than FSR, with coupling strength in the 1.1 to 1.5 GHz range.

  2. Thermal decomposition of lanthanides (III) and yttrium (III) solid complexes from ethyl ene diamine tetraacetic acid

    International Nuclear Information System (INIS)

    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 H2 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.)

  3. A study of an ion-exchange process for separation of strontium and yttrium

    International Nuclear Information System (INIS)

    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)

  4. Spectroscopic Properties of Neodymium-Doped Yttrium Orthovanadate Single Crystals with High-Resolution Measurement

    Science.gov (United States)

    Sato, Yoichi; Taira, Takunori

    2002-10-01

    The absorption and fluorescence spectra of the neodymium-doped yttrium orthovanadate (Nd:YVO4) single crystal were investigated carefully. For the 808.8-nm absorption cross section, the published values varied between 18.4 and 25.6 × 10-20 cm2 for π-polarization. The authors evaluated this spectroscopic parameter with high resolution at 0.5 nm, and discovered 48.4 cm-1 at 808.8 nm even for the absorption of 1 at.% Nd3+-ion-doped YVO4 single crystal. This value is 1.3 times larger than the well-known value, and confirms that Nd:YVO4 is very suitable for microchip lasers, and that certain laser characteristics of Nd:YVO4 of previous works should be re-evaluated.

  5. Phase Analysis of Cemented Carbide WC—Co Boronised with Yttrium

    Institute of Scientific and Technical Information of China (English)

    刘寿荣; 郝建民; 等

    2002-01-01

    Phase analysis for the coated surface with B4Cand Y2O3of cemented carbide WC-20Co in vacuum-heating was carried out by high-temperature X-ray diffraction from ambient temperature to 1300℃,The results show that,the high-concentration active boron atoms are released from the boron-supply agent B4Clocated on the alloy surface and diffused into the γphase,leading to forming the three-element boron-bearing compound W2Co21B6beside forming boron-bearins compounds on the blank surface.By contrast with boronising only,the element yttrium in boronization broadens the boronising temperature range during vacuum-sistering,catalyzes the decarbonisation decomposition of B4C and promotes diffusion of active boron atoms into the bulk of WC-Co.

  6. Manganese-doped yttrium orthoaluminate: A potential material for holographic recording and data storage

    International Nuclear Information System (INIS)

    Optical properties of manganese-doped yttrium orthoaluminate crystals (Mn:YAlO3), grown by the Czochralski technique, are reported. Luminescence and absorption spectra indicate the presence of Mn4+ ions in as-grown crystals, and Mn3+, Mn4+, and Mn5+ ions simultaneously in photoexcited crystals. A permanent diffraction grating, erasable by heating, was obtained in the crystals with diffraction efficiency of more than 50% at 514.5 nm reading wavelength and 1 - 2% in 632 - 930 nm wavelength range. Reading at wavelengths longer than 630 nm did not damage the recorded grating. The electro-optical effect observed in the photoexcited crystals implies that manganese ions disturb the YAlO3 crystal structure so that it becomes noncentrosymmetric. copyright 1998 The American Physical Society

  7. Calculation of neutron cross sections on isotopes of yttrium and zirconium

    International Nuclear Information System (INIS)

    Multistep Hauser-Feshbach calculations with preequilibrium corrections were made for neutron-induced reactions on yttrium and zirconium isotopes between 0.001 and 20 MeV. Recently new neutron cross-section data have been measured for unstable isotopes of these elements. These data, along with results from charged-particle simulation of neutron reactions, provide unique opportunities under which to test nuclear-model techniques and parameters in this mass region. A complete and consistent analysis of varied neutron reaction types using input parameters determined independently from additional neutron and charged-particle data. The overall agreement between calculations and a wide variety of experimental results available for these nuclei leads to increased confidence in calculated cross sections made where data are incomplete or lacking. 75 references

  8. Lead exposure from aluminum cookware in Cameroon

    Energy Technology Data Exchange (ETDEWEB)

    Weidenhamer, Jeffrey D.; Kobunski, Peter A. [Department of Chemistry, Geology and Physics, 401 College Ave., Ashland University, Ashland, OH 44805 (United States); Kuepouo, Gilbert [Research and Education Centre for Development (CREPD), Yaounde (Cameroon); Corbin, Rebecca W. [Department of Chemistry, Geology and Physics, 401 College Ave., Ashland University, Ashland, OH 44805 (United States); Gottesfeld, Perry, E-mail: pgottesfeld@okinternational.org [Occupational Knowledge International, San Francisco, CA (United States)

    2014-10-15

    Blood lead levels have decreased following the removal of lead from gasoline in most of the world. However, numerous recent studies provide evidence that elevated blood lead levels persist in many low and middle-income countries around the world at much higher prevalence than in the more developed countries. One potential source of lead exposure that has not been widely investigated is the leaching of lead from artisanal aluminum cookware, which is commonly used in the developing world. Twenty-nine samples of aluminum cookware and utensils manufactured by local artisans in Cameroon were collected and analyzed for their potential to release lead during cooking. Source materials for this cookware included scrap metal such as engine parts, radiators, cans, and construction materials. The lead content of this cookware is relatively low (< 1000 ppm by X-ray fluorescence), however significant amounts of lead, as well as aluminum and cadmium were released from many of the samples using dilute acetic acid extractions at boiling and ambient temperatures. Potential exposures to lead per serving were estimated to be as high as 260 μg, indicating that such cookware can pose a serious health hazard. We conclude that lead, aluminum and cadmium can migrate from this aluminum cookware during cooking and enter food at levels exceeding recommended public health guidelines. Our results support the need to regulate lead content of materials used to manufacture these pots. Artisanal aluminum cookware may be a major contributor to lead poisoning throughout the developing world. Testing of aluminum cookware in other developing countries is warranted. - Highlights: • Cookware is manufactured in Cameroon from scrap aluminum including car parts. • Twenty-nine cookware samples were evaluated for their potential to leach lead. • Boiling extractions to simulate the effects of cooking released significant lead. • Potential lead exposures per serving are estimated as high as 260 μg.

  9. Lead exposure from aluminum cookware in Cameroon

    International Nuclear Information System (INIS)

    Blood lead levels have decreased following the removal of lead from gasoline in most of the world. However, numerous recent studies provide evidence that elevated blood lead levels persist in many low and middle-income countries around the world at much higher prevalence than in the more developed countries. One potential source of lead exposure that has not been widely investigated is the leaching of lead from artisanal aluminum cookware, which is commonly used in the developing world. Twenty-nine samples of aluminum cookware and utensils manufactured by local artisans in Cameroon were collected and analyzed for their potential to release lead during cooking. Source materials for this cookware included scrap metal such as engine parts, radiators, cans, and construction materials. The lead content of this cookware is relatively low (< 1000 ppm by X-ray fluorescence), however significant amounts of lead, as well as aluminum and cadmium were released from many of the samples using dilute acetic acid extractions at boiling and ambient temperatures. Potential exposures to lead per serving were estimated to be as high as 260 μg, indicating that such cookware can pose a serious health hazard. We conclude that lead, aluminum and cadmium can migrate from this aluminum cookware during cooking and enter food at levels exceeding recommended public health guidelines. Our results support the need to regulate lead content of materials used to manufacture these pots. Artisanal aluminum cookware may be a major contributor to lead poisoning throughout the developing world. Testing of aluminum cookware in other developing countries is warranted. - Highlights: • Cookware is manufactured in Cameroon from scrap aluminum including car parts. • Twenty-nine cookware samples were evaluated for their potential to leach lead. • Boiling extractions to simulate the effects of cooking released significant lead. • Potential lead exposures per serving are estimated as high as 260 μg.

  10. Deposition and electrochemical characterization of Yttrium doped Barium cerate and zirconate heterostructures

    International Nuclear Information System (INIS)

    Epitaxial heterostructures consisting of an yttrium doped barium cerate, BaCe0.8Y0.2O3,(BCY) layer sandwiched between two yttrium doped barium zirconate, BaZr0.8Y0.2O3,(BZY) thin layers have been deposited on insulating (001) MgO substrates by pulsed laser deposition. The first BZY layer was aimed at improving the lattice match with the MgO substrate, the second at protecting the BCY layer. Ionic conductivity has been studied in the 300 °C–600 °C temperature range as a function of the BCY thickness in dry air and wet 5% H2 in Ar atmosphere. In both atmospheres, heterostructures showed a conductivity slightly larger than that of BCY pellets sintered under optimized conditions. Such a result has been attributed to the absence of blocking grain boundaries in the epitaxial heterostructures due to their good crystallographic quality. The BCY sandwich heterostructures showed an improved chemical stability relative to standard BCY pellets. - Highlights: • Heterostructures based on BaCe0.8Y0.2O3 and BaZr0.8Y0.2O3 were realized by PLD • Ionic conductivity has been studied in the 300 °C–600 °C range. • The conductivity was greater than that of optimized BaCe0.8Y0.2O3 pellets • The result was ascribed to the high film quality and to the lack of blocking grains • The chemical stability was improved relative to standard BaCe0.8Y0.2O3 pellets

  11. Availability of yttrium-90 from strontium-90: a nuclear medicine perspective.

    Science.gov (United States)

    Chakravarty, Rubel; Dash, Ashutosh; Pillai, M R A

    2012-12-01

    Yttrium-90 (T(½) 64.1 hours, E(βmax)=2.28 MeV) is a pure β⁻ particle emitting radionuclide with well-established applications in targeted therapy. There are several advantages of ⁹⁰Y as a therapeutic radionuclide. It has a suitable physical half-life (∼64 hours) and decays to a stable daughter product ⁹⁰Zr by emission of high-energy β⁻ particles. Yttrium has a relatively simple chemistry and its suitability for forming complexes with a variety of chelating agents is well established. The ⁹⁰Sr/⁹⁰Y generator is an ideal source for the long-term continuous availability of no-carrier-added ⁹⁰Y suitable for the preparation of radiopharmaceuticals for radionuclide therapy. The parent radionuclide ⁹⁰Sr, which is a long-lived fission product, is available in large quantities from spent fuel. Several useful technologies have been developed for the preparation of ⁹⁰Sr/⁹⁰Y generators. There are several well-established radiopharmaceuticals based on monoclonal antibodies, peptides, and particulates labeled with ⁹⁰Y, that are in regular use for the treatment of some forms of primary cancers and arthritis. At present, there are no generators for the elution of ⁹⁰Y that can be set up in a hospital radiopharmacy. The radionuclide is procured from manufacturers and the radiopharmaceuticals are formulated on site. This article reviews the development of ⁹⁰Sr/⁹⁰Y generator and the development of ⁹⁰Y radiopharmaceuticals. PMID:23009585

  12. Fabrication and properties of Er/Tm/Pr tri-doped yttrium lanthanum oxide transparent ceramics

    International Nuclear Information System (INIS)

    Highlights: • Er/Tm/Pr:(Y0.9La0.1)2O3 transparent ceramics were fabricated by conventional ceramics processing. • The sensitization of 2.7 μm emitted light of Er3+ ion is realized by co-doping Tm3+ and Pr3+ ions into Er3+-doped transparent ceramic. • The mechanism of the 2.7 μm emissions of Pr/Er/Tm:(Y0.9La0.1)2O3 ceramics is explained by the energy sketch. • Er/Tm/Pr:(Y0.9La0.1)2O3 ceramics exhibit the potential as a good candidate for mid-infrared lasers. - Abstract: Er/Tm/Pr tri-doped yttrium lanthanum oxide transparent ceramics were fabricated by conventional ceramics processing. Their microstructures and spectroscopic properties were investigated. The energy transfer mechanism between Tm3+, Pr3+ and Er3+ was also discussed. The Er/Tm/Pr:(Y0.9La0.1)2O3 ceramics display a dense structure with no pores and uniform grains of about 40 μm. The results shows that population inversion between the 4I11/2 and 4I13/2 level of Er:(Y0.9La0.1)2O3 transparent ceramics is enhanced by co-doping Tm3+ and low amount of Pr3+ (0.5 at.%). When concentration of Pr3+ ions is high (2 at.%), 2.7 μm emission is restrained significantly due to the concentration quenching of Pr3+ ions. This Er/Tm/Pr tri-doped yttrium lanthanum oxide transparent ceramics can be considered as a promising material for mid-infrared lasers

  13. radio embolization of yttrium 90 glass microspheres in treatment of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    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

  14. Process for separation of zirconium-88, rubidium-83 and yttrium-88

    International Nuclear Information System (INIS)

    A process for selective separation of strontium-82 and strontium-85 from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, passing the first ion-containing solution through a first cationic resin whereby ions selected from the group consisting of molybdenum, niobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in the first ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the first resin, contacting the first resin with an acid solution capable of stripping adsorbed ions from the first cationic exchange resin whereby the adsorbed ions are removed from the first resin to form a second ion-containing solution, evaporating the second ion-containing solution for time sufficient to remove substantially all of the acid and water from the second ion-containing solution whereby a residue remains, dissolving the residue from the evaporated second-ion containing solution in a dilute acid to form a third ion-containing solution, said third ion-containing solution having an acid molarity adapted to permit said ions to be adsorbed by a cationic exchange resin, passing the third ion-containing solution through a second cationic resin whereby the ions are adsorbed by the second resin, contacting the second resin with a dilute sulfuric acid solution whereby the adsorbed ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, and zirconium are selectively removed from the second resin, and contacting the second resin with a dilute acid solution whereby the adsorbed strontium ions are selectively removed. Zirconium, rubidium, and yttrium radioisotopes can also be recovered with additional steps. 1 fig

  15. Fatigue analysis of aluminum drill pipes

    Directory of Open Access Journals (Sweden)

    João Carlos Ribeiro Plácido

    2005-12-01

    Full Text Available An experimental program was performed to investigate the fundamental fatigue mechanisms of aluminum drill pipes. Initially, the fatigue properties were determined through small-scale tests performed in an optic-mechanical fatigue apparatus. Additionally, full-scale fatigue tests were carried out with three aluminum drill pipe specimens under combined loading of cyclic bending and constant axial tension. Finally, a finite element model was developed to simulate the stress field along the aluminum drill pipe during the fatigue tests and to estimate the stress concentration factors inside the tool joints. By this way, it was possible to estimate the stress values in regions not monitored during the fatigue tests.

  16. Spray Rolling Aluminum Strip for Transportation Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kevin M. McHugh; Y. Lin; Y. Zhou; E. J. Lavernia; J.-P. Delplanque; S. B. Johnson

    2005-02-01

    Spray rolling is a novel strip casting technology in which molten aluminum alloy is atomized and deposited into the roll gap of mill rolls to produce aluminum strip. A combined experimental/modeling approach has been followed in developing this technology with active participation from industry. The feasibility of this technology has been demonstrated at the laboratory scale and it is currently being scaled-up. This paper provides an overview of the process and compares the microstructure and properties of spray-rolled 2124 aluminum alloy with commercial ingot-processed material

  17. Recycling of Aluminum from Fibre Metal Laminates

    OpenAIRE

    Zhu, G.; Xiao, Y; Yang, Y.; Wang, J.; Sun, B; Boom, R.

    2012-01-01

    Recycling of aluminum alloy scrap obtained from delaminated fibre metal laminates (FMLs) was studied through high temperature refining in the presence of a salt flux. The aluminum alloy scrap contains approximately mass fraction w(Cu) = 4.4%, w(Mg) = 1.1% and w(Mn) = 0.6% (2024 aluminum alloy). The main objective of this research is to obtain a high metal yield, while maintaining its original alloy compositions. The work focuses on the metal yield and quality of recycled Al alloy under differ...

  18. Changes in porosity of foamed aluminum during solidification

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to control the porosity of foamed aluminum, the changes in the porosity of foamed aluminum melt in the processes of foaming and solidification, the distribution of the porosity of foamed aluminum, and the relationship between them were studied. The results indicated that the porosity of foamed aluminum coincides well with the foaming time.

  19. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its... the aluminum cargo tank must meet the steel structural standards of the American Bureau of...

  20. 49 CFR 229.51 - Aluminum main reservoirs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Aluminum main reservoirs. 229.51 Section 229.51... Aluminum main reservoirs. (a) Aluminum main reservoirs used on locomotives shall be designed and fabricated as follows: (1) The heads and shell shall be made of Aluminum Association Alloy No. 5083-0,...

  1. Formulation and method for preparing gels comprising hydrous aluminum oxide

    Science.gov (United States)

    Collins, Jack L.

    2014-06-17

    Formulations useful for preparing hydrous aluminum oxide gels contain a metal salt including aluminum, an organic base, and a complexing agent. Methods for preparing gels containing hydrous aluminum oxide include heating a formulation to a temperature sufficient to induce gel formation, where the formulation contains a metal salt including aluminum, an organic base, and a complexing agent.

  2. 49 CFR 178.505 - Standards for aluminum drums.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for aluminum drums. 178.505 Section 178... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.505 Standards for aluminum drums. (a) The following are the identification codes for aluminum drums: (1) 1B1 for a non-removable head aluminum...

  3. Nanshan Aluminum Reached Strategic Cooperation with CSR Corporation Limited

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    As a key supplier of aluminum profiles and aluminum plate,sheet and trip products for CSR Corporation Limited,Nanshan Aluminum will join hands with CSR Corporation Limited to reach strategic cooperation.On January 5,Nanshan Aluminum signed strategic cooperation agreement with CSR Sifang Locomotive&Rolling; Stock Co.,Ltd,both

  4. X-ray photoelectron spectroscopy study of catalyzed aluminum carbide formation at aluminum-carbon interfaces

    Science.gov (United States)

    Rabenberg, L.; Maruyama, Benji

    1990-01-01

    Aluminum carbide may form at aluminum-graphite interfaces during the high-temperature processing of graphite fiber-reinforced aluminum metal matrix composites. The chemical interactions leading to the formation of the aluminum carbide in the solid state involve the breaking of the carbon-carbon bonds within the graphite, the transport of the carbon atoms across the interface, and the reaction with the aluminum to form Al4C3. The aluminum carbide formation process has been followed using X-ray photoelectron spectroscopy of model, thin-film, reaction couples. The overall reaction is shown to be catalyzed by the presence of water vapor. Water at the interface increases reaction kinetics by apparently weakening the bonds between the surface carbon atoms and their substrate. This result is in general agreement with what is known to occur during the oxidation of graphite in air.

  5. A simple aluminum gasket for use with both stainless steel and aluminum flanges

    International Nuclear Information System (INIS)

    A technique has been developed for making aluminum wire seal gaskets of various sizes and shapes for use with both stainless steel and aluminum alloy flanges. The gasket material used is 0.9999 pure aluminum, drawn to a diameter of 3 mm. This material can be easily welded and formed into various shapes. A single gasket has been successfully used up to five times without baking. The largest gasket tested to date is 3.5 m long and was used in the shape of a parallelogram. Previous use of aluminum wire gaskets, including results for bakeout at temperatures from 20 to 660 degree C, is reviewed. A search of the literature indicates that this is the first reported use of aluminum wire gaskets for aluminum alloy flanges. The technique is described in detail, and the results are summarized. 11 refs., 4 figs

  6. Coordination Structure of Aluminum in Magnesium Aluminum Hydroxide Studied by 27Al NMR

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The coordination structure of aluminum in magnesium aluminum hydroxide was studiedby 27Al NMR. The result showed that tetrahedral aluminum (AlⅣ) existed in magnesiumaluminum hydroxide, and the contents of AlⅣ increased with the increase of the ratio of Al/Mg andwith the peptizing temperature. AlⅣ originated from the so-called Al13 polymer with the structureof one Al tetrahedron surrounded by twelve Al octahedrons.

  7. Diffuse Parenchymal Diseases Associated With Aluminum Use and Primary Aluminum Production

    OpenAIRE

    Taiwo, Oyebode A.

    2014-01-01

    Aluminum use and primary aluminum production results in the generation of various particles, fumes, gases, and airborne materials with the potential for inducing a wide range of lung pathology. Nevertheless, the presence of diffuse parenchymal or interstitial lung disease related to these processes remains controversial. The relatively uncommon occurrence of interstitial lung diseases in aluminum-exposed workers—despite the extensive industrial use of aluminum—the potential for concurrent exp...

  8. Differences of growth response to aluminum excess of two Melaleuca trees differing in aluminum resistance

    OpenAIRE

    Houman, Yoshifumi; Tahara, Ko; Shinmachi, Fumie; Noguchi, Akira; Satohiko, Sasaki; Hasegawa, Isao

    2009-01-01

    Factors that inhibit the growth of plants in strongly acidic soils include low pH and aluminum excess. We evaluated two Myrtaceae species (Melaleuca cajuputi and Melaleuca bracteata), which are useful trees in tropical regions due to their resistance to low pH and excessive aluminum, to determine their response characteristics to environmental stresses. The results revealed that M.cajuputi, the growth by the aluminum concentration was not inhibited. However, the root growth of M.bracteata, by...

  9. Aluminum hydroxide nanoparticles show a stronger vaccine adjuvant activity than traditional aluminum hydroxide microparticles

    OpenAIRE

    Li, Xinran; Aldayel, Abdulaziz M.; Cui, Zhengrong

    2013-01-01

    Aluminum hydroxide is used as a vaccine adjuvant in various human vaccines. Unfortunately, despite its favorable safety profile, aluminum hydroxide can only weakly or moderately potentiate antigen-specific antibody responses. When dispersed in an aqueous solution, aluminum hydroxide forms particulates of 1–20 µm. There is increasing evidence that nanoparticles around or less than 200 nm as vaccine or antigen carriers have a more potent adjuvant activity than large microparticles. In the prese...

  10. Infiltration of molten aluminum in aluminum-nickel powder preform

    International Nuclear Information System (INIS)

    It has been shown by the present author that when molten aluminum comes in contact with nickel, an exothermic reaction is initiated and both stiochiometric and non-stiochiometric phases form at the interface. For nickel powders, such reaction is expected to be much faster due to high surface area to volume ratio of the fine particles. Infiltration of molten metals in ceramics powder preforms has long been used to fabricate near or net-shaped Metal Matrix Composite components. For metallic preforms however, it is important to see if the exothermic reaction compromises the infiltration of the molten metal constituent, i.e. defective components. The current project studied the fabrication of near net-shaped Intermetallic Matrix Composites, (IMC) via molten metal infiltration and subsequent reaction with the metal powder preform. X-ray diffraction (XRD), Optical and SEM microscopes were used to characterize the infiltration, reaction and the resulted microstructure. It is expected that the molten metal temperature, holding time within the molten metal, the infiltration pressure, i.e. metallostatic pressure and the preform compaction pressure are all important parameters to be considered carefully to achieve sound components. The current report examined the feasibility of such fabrication technique and the resultant microstructure. (author)

  11. Southwest Aluminum Increase Two Production Lines and May Become the Largest Aluminum Fabricator In the World

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Recently,Wu Bing,Director of Chongqing Economic Committee,announced at the"Industrial Economy Meeting"that the city will"facilitate the technical upgrade and capacity expansion of the existing production lines at Southwest Aluminum with great efforts on the construction of one additional hot continuous rolling line and one cold continuous rolling line so as to have a comprehensive production ca- pacity of 1.2 million tons on aluminum processing profiles for the achievement of building Southwest Aluminum into the world largest aluminum processing enterprise".

  12. Preliminary Study on Aluminum Content of Foods and Aluminum Intake of Residents in Tianjin

    Institute of Scientific and Technical Information of China (English)

    XUGe-Sheng; JINRng-Pei; 等

    1993-01-01

    Aluminum contents of 64 kinds of foods in Tianjin were detrmined.The results showed that the aluminum levels in diffeent kinds of foods varied greatly,and most foodstuffs from natural sources(including contamination from food processing)contained less than 10mg/kg,Aluminum contents were higher in foodstuffs of plant origin,especiallydry beans containing large amounts of aluminum naturally.Lower concentration of aluminum seemed to be present in foodstuffs of animal origin.It was estimated that the potential daily intake of aluminum per person from natural dietary sources in Tianjin was about 3.79 mg.This estimated figure of dietary aluminum intake was very close to the measured data from 24 daily diets of college students.which was 4.86±1.72mg.Considering all the potential sources of natural aluminum in foods.water and the individual habitual food,it would apear that most residents in Tianjin would consume 3-10mg aluminum daily from natural dietary sources.

  13. South West Aluminum: Next year The Capacity of Auto-use Aluminum Sheet will Reach 5000 Tonnes

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Following supplying supporting aluminum products for"Shenzhou"spacecraft,"Long March"rocket,Boeing and Airbus,South West Aluminum again tapped new economic growth points,i.e.automobile-use aluminum products.According to what the reporter has learned from South West Aluminum Group recently,this group has finished early stage

  14. China Aluminum Processing Industry Development Report 2011

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>In 2011,China’s aluminum processing industry maintained a high growth rate,with the aluminum output reaching 23,456,000tons,up 20.6% y-o-y.Overshadowed by complicated situation both at home and abroad,China’seconomy slowed down and declined by2.2% y-o-y.In 2011,China’s aluminum processing industry showed a downward tendency,that is,it grew at a high speed before the3rd quarter,but suffered from a shortage of orders in the remaining time of the year and the growth rate fell increasingly.Between January and August,China’s aluminum output rose by 26% y-o-y;

  15. Aluminum-CNF Lightweight Radiator Components Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal relates to a new materials concept for an aluminum-carbon nanofiber composite, high thermal conductivity ultra lightweight material that will form the...

  16. Macrodeformation Twins in Single-Crystal Aluminum

    Science.gov (United States)

    Zhao, F.; Wang, L.; Fan, D.; Bie, B. X.; Zhou, X. M.; Suo, T.; Li, Y. L.; Chen, M. W.; Liu, C. L.; Qi, M. L.; Zhu, M. H.; Luo, S. N.

    2016-02-01

    Deformation twinning in pure aluminum has been considered to be a unique property of nanostructured aluminum. A lingering mystery is whether deformation twinning occurs in coarse-grained or single-crystal aluminum at scales beyond nanotwins. Here, we present the first experimental demonstration of macrodeformation twins in single-crystal aluminum formed under an ultrahigh strain rate (˜106 s-1 ) and large shear strain (200%) via dynamic equal channel angular pressing. Large-scale molecular dynamics simulations suggest that the frustration of subsonic dislocation motion leads to transonic deformation twinning. Deformation twinning is rooted in the rate dependences of dislocation motion and twinning, which are coupled, complementary processes during severe plastic deformation under ultrahigh strain rates.

  17. Electrometallurgical treatment of aluminum-based fuels

    International Nuclear Information System (INIS)

    We have successfully demonstrated aluminum electrorefining from a U-Al-Si alloy that simulates spent aluminum-based reactor fuel. The aluminum product contains less than 200 ppm uranium. All the results obtained have been in agreement with predictions based on equilibrium thermodynamics. We have also demonstrated the need for adequate stirring to achieve a low-uranium product. Most of the other process steps have been demonstrated in other programs. These include uranium electrorefining, transuranic fission product scrubbing, fission product oxidation, and product consolidation by melting. Future work will focus on the extraction of active metal and rare earth fission products by a molten flux salt and scale-up of the aluminum electrorefining

  18. ALUMINUM NITRIDE AS A HIGH TEMPERATURE TRANSDUCER

    International Nuclear Information System (INIS)

    The high temperature capabilities of bulk single crystal aluminum nitride are investigated experimentally. Temperatures in excess of 1100 deg. Celsius are obtained and held for eight hours. Variation in the performance of single crystal samples is demonstrated.

  19. Masking of aluminum surface against anodizing

    Science.gov (United States)

    Crawford, G. B.; Thompson, R. E.

    1969-01-01

    Masking material and a thickening agent preserve limited unanodized areas when aluminum surfaces are anodized with chromic acid. For protection of large areas it combines well with a certain self-adhesive plastic tape.

  20. The effect of surface implantation of yttrium and cerium upon the oxidation behaviour of stainless steels and aluminized coatings at high temperatures

    International Nuclear Information System (INIS)

    Assessments have been carried out on the extent to which the oxidation resistance of metals at high temperatures can be improved by surface implantation with yttrium or cerium. The elements were implanted to a concentration of 0.2 to 0.8%, to a depth of 0.2 μm. Yttrium implantation reduced the magnitude of oxidation and oxide spallation for a 20% Cr/25% Ni/Nb steel in carbon dioxide, at 800 to 8500C. The benefits approached those from a comparable yttrium alloy addition. The oxidation behaviour of a 15% Cr/4% Al steel, in air and carbon dioxide, at 1100 to 12000C, was improved markedly by a 0.86% yttrium alloy addition but yttrium implantation into the steel was without significant influence. The oxidation behaviour of aluminized coatings on three nickel based alloys in air, at 11000C, was also unaffected by implantations of either yttrium or cerium. The mechanisms associated with the results are discussed in detail. (author)